Oxford English for Pv m w j Electrical and Mechanical
B
Eric H. Glendinning Norman Glendinning
Oxford University Press
Oxford English for
Electrical and Mechanical
Engineering
Eric H. Glendinning Norman Glendinning,
C Eng, MIMechE
Oxford University Press
Oxford University Press Walton Street. Oxford 0X2 6DP
Oxford New York
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are trade marks of Oxford University Press
ISBN0 19 457392 3 © Oxford University Press 1995 First published 1995
Second impression 1995 No unauthorized photocopying
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording .orotherwise, without the prior written permission of Oxford University Press.
This book is sold subject to the condition that it shall not. by way of trade or otherwise, be lent, re-sold, hired out. or otherwise circulated without the publisher's prior consent in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed on the subsequent purchaser.
The publisher and authors of Oxford English for Computing. Oxford English for Electronics, and Oxford English for Electrical and Mechanical Engineering would like to thank the teachers and students of the following institutions for their advice and assistance in the preparation of these books:
Italy
Istituti Tecnici Industrials Aldini-Valeriani. Bologna Avagado. Turin Belluzi. Bologna Benedetto Castelli. Brescia Conti. Milan de Preto. Schio Euganeo. Este Fermi. Rome Fermi. Naples Fermi. Vicenza Ferrari. Turin Gastaldi. Genoa Giordani. Naples Giorgi. Milan Giorgi. Rome Hensemberger. Monza Leonardo da Vinci. Florence Marconi. Verona Miano. San Giorgio. Naples Paeocapa. Bergamo Panetti. Bari Pasolini. Milan Peano. Turin San Felipo Neri. Rome Zuccante. Mestre Istituti Professionali:
Caselli. Siena Cinnici. Florence Galileo Galilei. Turin Galvani. Milan Istituto Tecnico Commerciale Lorgna, Verona
France
Ecole Nationale du Commerce, Paris Lycee Bouchardon. Chaumont Lycee Monge. Chambery Lycee du Dauphine, Romans Lycee Technologique Industriel. Valence
The publisher and authors would like to thank the following for their kind permission to use articles, extracts, or adaptations from copyright material. Every effort has been made to trace the owners of copyright material in this book, but we should be pleased to hear from any copyright owner whom we have been unable to contact in order to rectify any errors or omissions.
Collins CDT GCSE: Technology by M Horsley and P Fowler. Collins Educational, an imprint of HarperCoIlins Publishers Limited Eraba Limited. Livingston
The following articles were all taken from The Education Guardian © The Guardian:
Electric motor’ by Helen Davies. 20 April 1993 Central heating' by J Harker. 8 December 1992 Fridge' by H Birch. 30 April 1991 Electronic scales' by H Birch. 10 December 1991 'Wave power' by H Davies. 23 November 1993 Road breaker' by H Birch. 24 September 1991 Disk brakes’ by R Leedham. 16 March 1993 Magnetic levitation train' by H Birch. 7 July 1992
Air Film Material Handling Systems'. Aerofilm Systems. The Netherlands 'Design tools for speed and quality' by John Fox. Professional Engineering. June 1993. The adaptation of this article is reproduced by permission of the Council of the Institution of Mechanical Engineers. London. UK.
Beating the lire risk with water-based hydraulics' by PTweedale. Professional Engineering. November 1993. The adaptation of this article is reproduced by permission of the Council of the Institution of Mechanical Engineers. London. UK.
'On the make’ by Judith Massey. Personal Computer Magazine. August 1992 'Types of corrosion, how it occurs and what to look for'. Design Engineering. June 1991 Working at a light engineering plant (people at work) by T May. Wayland (Publishers) Limited 1982
The publishers would like to thank the following for permission to reproduce illustrations:
Computer Shopper; Computervision: The Education Guardian; Engineering News; Technology Basic Facts by C Chapman. M Horsley & E Small. HarperCoIlins Publishers Ltd: Volkswagen UK Ltd
The publishers would like to thank the following for their permission to reproduce photographs:
British Aerospace; Derek Cattani; DataTech Ltd; The Engineering Council: The Engineering Training Authority; Graduates to Industry; Intelligence Systems; Marconi; Peugeot-Talbot; Lucy Porter; Rolls-Royce; Salter Houseware; The Science Photo Library; Scottish Power; Sport for TV; The Telegraph Colour Library: Volkswagen UK Ltd
Typeset in Monotype Photina and Univers
Printed in Italy
PageUnitTopic
101Engineering
152Courses
213Materials
264Mechanisms
315Forces
366Electric motor
427Student
468Central heating
509Safety at work
5510Young engineer
5811Washing machine
6512Racing bicycle
7213Lasers
7714Technician
7915Refrigerator
8416Scales
9117Portable generator
9818Road breaker
10619Disc brakes
11220Staff engineer
11621Lawn-mower
12322Corrosion
12823Maglev train
13724CAD designer
14025Supercar
14626Graphs
15227Waste recycling
15728Robotics
16529Careers
16930Applying for a job
Technical syllabus
General
General
Engineering materials Mechanisms. Cams Statics and Dynamics Electrotechnology Electrical
Automatic systems General
General. Engineering design Automatic systems. Transducers Mechanics. Gear systems Mechanical technology Robotics. General Fluid mechanics
Automatic systems. Strain gauges Electrotechnology. Power generation Pneumatics Hydraulics
General. Process control
Engineering design
Mechanical technology. Corrosion
Electrical machines. Motor selection
CAD
General
General
Technical plant
Robotics. Stepper motors
General
General. Company structure
Contents
Page
10Engineering- what's it all about?
10Tuning-in
11ReadingIntroduction
12Language studydeals/is concerned with
13Word studyWord stress
13Writing
14Listening
1 5Choosing a course
15Tuning-in
16ReadingHaving a purpose
20WritingLetter writing. 1: requesting info
21Engineering materials
22Tuning-in
22ReadingScanning tables
23Language studyMaking definitions
24WritingAdding information to a text
26Mechanisms
26Tuning-in
26ReadingScanning a text
27WritingWays of linking ideas. 1
29Language studyDealing with technical terms
29Speaking practice
31Forces in engineering
31Tuning-in
31Reading 1Predicting
33Reading 2Grammar links in texts
34Language studyThe present passive
34ListeningListening to lectures
Page
36 The electric motor
36Tuning-in
36ReadingSkimming
39Language study Describing function
39WritingDescribing components
41Word study
42An engineering student
42Tuning-in
42Listening
44WritingComparing and contrasting
46 Central heating
46Tuning-in
46ReadingPredicting
48Language studyTime clauses
49Word study
so Safety at work
50Tuning-in
51ReadingUnderstanding the writer's purpose
5 3Language study Making safety rules
5 3WritingWays of linking ideas. 2
55Young engineer
55Tuning-in
56Listening
57WritingDescribing and explaining
57Speaking practice
58Washing machine
58Tuning-in
58ReadingReading diagrams
62Language study If/Unless sentences
63WritingExplaining a diagram
Page
65Racing bicycle
65Tuning-in
67ReadingPrediction
68Language studyDescribing reasons
68WritingDescribing contrast
69Word studyProperties of materials
70Speaking practice
70Technical readingGear systems
72Lasers
72Tuning-in
72Reading
73Language studyused to/for
73Word studyNoun + noun compounds
74WritingDescribing a process, 1: seque
75Technical readingLaser cutting
77Automation technician
77Tuning-in
77Listening
78Speaking practiceTalking about specifications
79Refrigerator
79Tuning-in
79ReadingDealing with unfamiliar word
81Language studyPrinciples and laws
81Word studyVerbs and related nouns
82WritingDescribing a process. 2: locati
84Scales
84Tuning-in
85Reading 1Meaning from context
85Reading 2Comparing sources
87Language studyCause and effect. 1
88Technical readingStrain gauges
Page
91Portable generator
91Tuning-in
91ReadingReading diagrams
93Language studyCause and effect, 2
94Word studyVerbs with -ize/-ise
94WritingDescribing a process, J: segue
95Technical readinglocation Wave power
98Road breaker
98Tuning-in
98Reading
101Language studyAllow and prevent links
103WritingExplaining an operation
103Technical readingAir skates
105Speaking practice
106Disc brakes
106Tuning-in
107ReadingCombining skills
108Language studyVerbs with up and down
108Word studyVerbs + -en
109WritingExplaining an operation
110Technical readingWater-based hydraulics
112Staff engineer
112Tuning-in
114Listening
114Language studyVerbs with on and off
116Lawn-mower
116Tuning-in
118Reading 1Predicting
119Reading 2Grammar links, 2
119Language studyDescribing functions
120Word studyNoun + noun, 2: function
121WritingDescription and explanation
122Speaking practiceExplaining function
Page
Unit 22123Corrosion
123Tuning-in
124ReadingSkimming
125Language studyCause and effect. 1
126Speaking practiceExchanging information
126Technical readingCorrosion of materials
Unit 23128Maglev train
128Tuning-in
129Reading 1Inferring
130Reading 2Dealing with unfamiliar words. 2
131Language studyPrediction
133WritingExplanations
1 34Technical readingMotor selection: operating environment
Unit 24137Computer Aided Design (CAD)
137Tuning-in
137Listening
138Language studyNecessity: have to and need (to)
Unit 25140Supercar
140Tuning-in
142ReadingPredicting: using first sentences
144Language studyCertainty
145WritingSummaries
Unit 26146Graphs
146Tuning-in
147Language studyDescribing grapl is
149Word studyCommon verbs in engineering
149WritingDescribing a graph
151Technical readingProperties and applications of carbon
steels
Unit 27152Waste recycling plant
152Tuning-in
154ReadingTransferring information, making notes
1 55Language studyPossibility: can and could
156WritingDescribing a process. 4: reason and
method
Page
157 Robotics
157 Tuning-in
157 Reading 1Revising skills
159Reading 2Transferring information
162Language studyConcession: even if and although
163Technical reading Stepper motors
165 Careers in engineering
165 Tuning-in
167ReadingInferring
168Speaking practice Role play
168ListeningInferring
169Applying for a job
169 Tuning-in
169ReadingUnderstanding job advertisements
172 Speaking practice Role play
172WritingWriting a CV and letter of application
175Technical readingCompany structure
177 Student A Speaking practice 181Student B Speaking practice
Glossary of engineering terms
Engineering - what's it all about?
Tuning-in
Task 1Listthemainbranchesofengineering.Combineyourlist with others in your
group. Then read this text to find out how many of the branches listed are mentioned.
Engineering is largely a practical activity. It is about putting ideas into action. Civil engineering is concerned with making bridges, roads, airports, etc. Mechanical engineering deals with the design and manufacture of tools and machines. Electrical engineering is about 5 the generation and distribution of electricity and its many
applications. Electronic engineering is concerned with developing components and equipment for communications, computing, and so on.
Mechanical engineering includes marine, automobile, aeronautical, 10 heating and ventilating, and others. Electrical engineering includes electricity generating, electrical installation, lighting, etc. Mining and medical engineering belong partly to mechanical and partly to electrical.
Task 2Completetheblanksinthisdiagramusinginformationfromthetext.
Engineering
Electrical 2
Medical
Reading Introduction
In your study and work, it is important to think about what you are going to read before you read. This helps you to link old and new knowledge and to make guesses about the meaning of the text. It is also important to have a clear purpose so that you choose the best way to read. In this book, you will find tasks to make you think before you read and tasks to help you to have a clear purpose when you read.
Task 3Studytheseillustrations.They show some of the areas in which engineers
work. Can you identify them? What kinds of engineers are concerned with these areas - electrical, mechanical, or both?
Task 4Nowreadthefollowing texts to check your answers to Task 3. Match each
text to one of the illustrations above.
Transport: Cars, trains, ships, and planes are all products of mechanical engineering. Mechanical engineers are also involved in support services such as roads, rail track, harbours, and bridges.
Food processing: Mechanical engineers design, develop, and make 5 the machines and the processing equipment for harvesting, preparing and preserving the foods and drinks that fill the supermarkets.
Medical engineering: Body scanners, X-ray machines, life-support systems, and other high tech equipment result from mechanical and electrical engineers combining with medical experts to convert ideas
10into life-saving and life-preserving products.
Building services: Electrical engineers provide all the services we need in our homes and places of work, including lighting, heating, ventilation, air-conditioning, refrigeration, and lifts.
Energy and power: Electrical engineers are concerned with the 15 production and distribution of electricity to homes, offices, industry, hospitals, colleges and schools, and the installation and maintenance of the equipment involved in these processes.
Source: Adapted from Turning ideas into action, Institution of Mechanical Engineers, and Engineering a Career, Institution of Electronics and Electrical Incorporated Engineers.
Language study deals/is concerned with
What is the link between column A and column B?
AB
mechanicalmachines
electricalelectricity
Column A lists a branch of engineering or a type of engineer. Column B lists things they are concerned with. We can show the link between them in a number of ways:
1Mechanical engineering deals with machines.
2Mechanical engineers deal with machines.
3Mechanical engineering is concerned with machines.
4Mechanical engineers are concerned with machines.
5Machines are the concern of mechanical engineers.
Match each item in column A with an appropriate item from column B and
link the two in a sentence.
AB
1marineaair-conditioning
2aeronauticalbroads and bridges
3heating and ventilatingcbody scanners
4electricity generatingdcables and switchgear
5automobileecommunications and equipment
6civilfships
7electronicgplanes
8electrical installationhcars and trucks
9medicalipower stations
Word study Word stress
Words are divided into syllables. For example:
Each syllable is pronounced separately, but normally only one syllable is stressed. That means it is said more slowly and clearly than the other syllables. We say 'engine but encjin'eer. A good dictionary will show the stressed syllables.
Listen to these words. Try to mark the stressed syllables.
machinery
mechanical
machine
install
installation
electricity
electrical
electronics
aeronautical
ventilation
Writing
Fill in the gaps in the following description of the different branches of engineering using information from this diagram and language you have studied in this unit.
Engineering
Mechanical
Medical
The main branches of engineering are civil,',, and
electronic. Mechanical engineering is!machinery
of all kinds. This branch of engineering includes !, automobile,
, and heating and ventilating. The first three are concerned with
transport:, cars and planes. The lastwith air-
conditioning, refrigeration, etc.
Electrical engineering deals withfrom generation to use.
Electricity generating is concerned with ™stations. Electrical
installation dealscables, switchgear, and connecting up
electrical equipment.
Two branches of engineering include both _fand 1!
engineers. These are mining and '1engineering. The former deals
with mines and mining equipment, the latter with hospital1 ’ofall
kinds.
Listening
Task 8E3 Listen to these short extracts. To which branch of engineering do these
engineers belong?
Task 9E3Listen again. This time note the words which helped you decide on your
answers.
Choosing a course
Tuning-in
Study this list of points to consider when deciding whether to study engineering. Tick [/] the statements which refer to you. Then ask your partner which statements refer to him or her.
1You enjoy practical projects - creating and investigating things.
2You like finding out how things work.
3You are interested in improving the environment.
4You like helping people.
5You enjoy solving problems.
6You enjoy organizing activities.
7You enjoy science programmes on TV or on the radio.
8You sometimes read articles on scientific or engineering topics.
9You have a lot of determination and stamina.
If you have ticked most of these statements, engineering is the right course of study for you.
Source: Adapted from Cyberpunks and Technophobes, BBC Education
Task 2Fillinthe gaps in this text. Each gap represents one word. Compare your
answers with your partner. More than one answer is possible for many of the gaps.
In the United Kingdom you can !engineering at a college of
further education or a university. Most college courses tfrom one
to two years. University undergraduate courses Jengineering last
from three to four years.
A college will takeafter four years of secondary school
education. Most students study full-time,day-release courses are
available for people who!in local engineering companies.
Students will be given a certificate a diploma at the
8of their course.
Most university students will have completed sixof secondary
school. Others will have taken a diploma course at collegegive
degrees. A Bachelor’s degree 11threetofouryears.AMaster’s
llrequires a further year.
Task 3 El Listen to the text and note the words used on the tape for each gap.
Reading Having a purpose
As a student of engineering or as a professional engineer, you have to read a great deal. Make a list of some of the kinds of texts you may read. It is important that you develop the most effective skills for getting the information you want quickly and accurately when you read.
Mechanisms123
Motion and force124
Forces125
Levers126
Linkages128
Inclined plane130
Lifting systems132
Rotary systems134
Gear systems134
Shafts and couplings140
Bearings and lubrication142
Clutches and brakes144
Cams146
Crank-sliders147
Electrical Applications 3
David W. Tyler
CEng, MIEE
Order
CodeTypePrice each
RK65VPCB Latch PI 2w20p
BX96EPCB Latch PI 3w25p
YW11MPCB Latch PI4w29p
FY93BPCB Latch PI 5w35p
YW12NPCB Latch PI6w42p
YW13PPCB Latch PI 8w48 p
RK66WPCB Latch PI 10w54p
YW14QPCB Latch PI 12w58p
BH61RPCB Latch PI 17w60p
efficiency, 127,163 effort, 126 elasticity, 189 electric motor, see motor electrical energy, 60 electrical system producing motion, advantages and disadvantages, 178 electricity, safety with, 87 electrocardiography, 30 electromagnetic radiation, 56 electromechanical counters, 71 electronic(s), 61-122 constructional techniques, 83-5 designing with, 64-5,69, 116-21 digital, 89-122
materials/fittings/components used in, 50,62-3 systems-, 65
SALES ENGINEER
rSinclair is one of the UK's largest
private engineering groups, with an international reputation. The sealing systems operation requires a Technical Sales Y Engineer to sell the world-renowned / Chesterfield range of products throughout the Midlands.
You should have previous sales and mechanical engineering experience with a bias to maintenance products and mechanical engineering.
The successful candidate will ideally be between 30 and 45 years of age living in the Midlands with a mechanical engineering background.
The company offer a good basic salary, commission and company car. Apply in writing, with full CV to: J. FORD
SINCLAIR SEALING SYSTEMS LTD.
16 CANYON ROAD, NETHERTON INDUSTRIAL ESTATE, BIRMINGHAM B2 OER Closing date 17 December 19—
SINCLAIR
f
StepAction
1Open the top cover
2Set the MTR switch to MTR mode, that is, move it to the left.
3Close the top cover
4Switch the system off
5Wait 5 seconds
EEB NATIONAL CERTIFICATE MODULES IN REFRIGERATION (EVENING)
This course provides students with a basic knowledge of the technology of refrigeration, including system elements, procedures and the need for safe working practice.
Bearing
mmShaft limits mm
Heavy loadingLight loading
-12—+0.003
-0.005
12.1-30—+0.005
-0.003
30.1-50—+0.007
-0.003
50.1-75+0.018
-0.003+0.013
-0.000
75.1-100+0.023
-0.005+0.016
-0.003
100.1-120+0.028
-0.010+0.020
-0.005
Task 5When you read, it is important to have a clear purpose. Here are some of the
purposes you may have for reading the above texts. Match one purpose to each text.
1finding a job
2pricing a component
3finding out how to do something
4choosing the best chapter to read
5looking for specific information on a topic
6learning about electrical equipment
7choosing a course
8looking for a specification
Choosing a course requires careful reading of college and university brochures. Your purpose here is to find the most appropriate course for each of the following prospective students. Use the Course Guide which follows and answer using the course code.
1A student who has just left school and wants to become a technician.
2A student who wants to design ships.
3A student who wants to get an engineering degree and also improve his knowledge oflanguages.
4A student who wants a degree eventually but whose qualifications at present are enough to start an HND course.
5A student who wants to work as an engineer with the air force.
6A technician employed by a company which installs electrical wiring in factories.
7A student with a National Certificate in Electrical Engineering who is prepared to spend another two years studying to improve her qualifications.
8A student interested in how micro-organisms can be used in industry.
C o u r s 6 Gu i d o E I\l G 1 IM E E R 1 IM G
EE22Higher National Diploma in Electronic and Electrical Engineering. Two years, full-time. For potential electronic and electrical engineers. The first year is common and the second year allows students to specialize in either electronic or electrical engineering subjects. Successful students may continue to a degree course.
EE17National Certificate in Electrical Engineering. One year, full-time. For potential technicians or for those who wish to gain entry to an HND course.
EE3Higher National Certificate Course in Electrical Engineering. Two years, day-release. This course provides the technical education required for senior technicians employed in the electrical installation industry.
H300Bachelor of Engineering (B Eng) - Mechanical Engineering for Europe. Four years, full-time, including one year study and work attachment in France or Germany.
H400Bachelor of Engineering (B Eng) - Aeronautical Engineering. Three years, full-time, or four years including one year of professional training in the aircraft industry.
HJ36Bachelor of Engineering (B Eng) - Naval Architecture and Ocean Engineering. Three years, full-time.
H340Bachelor of Science (Engineering) - Mechanical
►
H250Bachelorof Engineering (B Eng) - Manufacturing
Management. A two-year HND course in engineering followed by two years of technology and management designed to produce managers qualified in high technology.
Further information may be obtained by contacting one of these information centres and requesting the appropriate course leaflet by code number.
All E courses:
Information Centre Fraser College ParlettStreet Glasgow GL2 2KL
All H courses:
Information Centre Maxwell University Hunter Square Glasgow GL1 5PN
Writing Letter writing, 1: requesting information
Write a letter to either the college or the university mentioned in Task 6 asking for information on a course which interests you. Set out your letter like this:
21 Route de St Fargeau 18900 Russe FRANCE
30 August 199-
Information Centre
Fraser College
Parlett Street
GLASGOW
GL2 2KL
UK
Dear Sir/Madam^
Please send me further information on course EE2 - National Certificate in Electrical Engineering.
Yours faithfully
Danietf Romwo
Daniel Romero
Engineering materials
Ribbed plastic pipes stacked near a road construction site where they will be laid for drainage along the sides of a new section of motorway.
Tuning-in
List the materials you know which are used in engineering. Combine your list with the others in your group and classify the materials as metals, thermoplastics, etc.
Reading Scanning tables
In engineering it is important to practise reading tables, charts, diagrams, and graphs because so much information is presented in these ways. We will start in this unit with a table.
Scanning is the best strategy for finding information in a table. With scanning, you know before you read what sort of information you are searching for. To scan a table, you move your eyes up and down the columns until you find the word or words you want. To scan quickly, you must learn to ignore any information which will not help you with your task.
1soft
2ductile
3malleable
4tough
5scratch-resistant
6conductive and malleable
7durable and hard
8stiff and brittle
9ductile and corrosion-resistant
10 heat-resistant and chemical-resistant
Properties
Metals
Aluminium
Copper
Brass(65%copper. 35% zinc)
Mild steel (iron with 0.1 5% to 0.3% carbon)
High carbon steel (iron with 0.7% to 1.4% carbon)
Light, soft, ductile, highly conductive, corrosion-resistant.
Very malleable, tough and ductile, highly conductive, corrosion-resistant.
Very corrosion-resistant. Casts well, easily machined. Can be work hardened. Good conductor.
High strength, ductile, tough, fairly malleable. Cannot be hardened and tempered. Low cost. Poor corrosion resistance.
Hardest of the carbon steels but less ductile and malleable. Can be hardened and tempered.
Aircraft, engine components, foil, cooking utensils
Electric wiring, PCBs. tubing
Valves, taps castings, ship fittings, electrical contacts
General purpose
Cutting tools such as drills, tiles,
saws
Thermoplastics
ABS
Acrylic
Nylon
Thermosetting plastics
Epoxy resin
Polyester resin
Irea formaldehyde
High impact strength and toughness, scratch-resistant, light and durable.
Stiff, hard, very durable, clear, can be polished easily. Can be formed easily.
Hard, tough, wear-resistant, self- lubricating.
High strength when reinforced, good chemical and wear resistance.
Stiff, hard, brittle. Good chemical and heat resistance.
Stiff, hard, strong, brittle, heat- resistant. and a good electrical insulator.
Safety helmets, car components, telephones, kitchenware
Aircraft canopies, baths, double glazing
Bearings, gears, casings for power tools
Adhesives, encapsulation of electronic components
ImlW
Moulding, boat and car bodies Electrical fittings, adhesives
Scan the table to find:
1A metalused to make aircraft
2Plasticsused for adhesives
3Steel which can be hardened
4An alloy suitable for castings
5A plastic with very low friction
6A material suitable for safety helmets
7A metalsuitable for a salt-water environment
8A metalfor general constructionuse but which should be protected from
corrosion
9A plastic for car bodies
10The metal used for the conductors inprinted circuit boards
Language study Making definitions
Study these facts from the table about aluminium:
1Aluminium is a light metal.
2Aluminium is used to make aircraft.
We can link these facts to make a definition of aluminium:
1+2 Aluminium is a light metal which is used to make aircraft.
Task 4Usethetableonthepreviouspage to make definitions of each of the materials
in column A. Choose the correct information in columns B and C to describe the materials in column A.
ABC
1An alloyallows heat or current to flow easily
2A thermoplasticremains rigid at high temperatures
3Mild steeldoes not allow heat or current to flow easily
4A conductora metalcontains iron and 0.7% to 1.4% carbon
5An insulatora materialbecomes plastic when heated
6High carbon steelan alloycontains iron and 0.15% to 0.3% carbon
7Brassformed by mixingmetals or elements
8A thermosetting plasticconsists of copper and zinc
Writing Adding information to a text Study this text about aluminium.
Aluminium is used to make aircraft, engine components, and many items for the kitchen.
We can add extra information to the text like this:
Aluminium, which is light, soft, and ductile, is used to make aircraft, engine components - for example, cylinder heads - and many items for the kitchen, such as pots.
Note that the extra information is marked with commas or dashes:
, which
-for example,... - , such as...,
Add this extra information to the following text about plastics.
1Plastics can be moulded into plates, car components, andmedical aids.
2Thermoplastics soften when heated again and again.
3Thermosetting plastics set hard and do not alter if heatedagain.
4ABS is used for safety helmets.
5Nylon is self-lubricating.
6Nylon is used for motorized drives in cameras.
7Acrylic is a clear thermoplastic.
8Acrylic isused for aircraft canopies and double glazing.
9Polyesterresin is used for boat and car bodies.
10Polyesterresin is hard and has good chemical and heat resistance.
Plastics are synthetic materials. They can be softened and moulded into useful articles. They have many applications in engineering. There are two types of plastics: thermoplastics and thermosetting plastics.
ABS is a thermoplastic which is tough and durable. Because it has high impact strength, it has applications where sudden loads may occur.
Nylon is a hard, tough thermoplastic. It is used where silent, low-friction operation is required.
Acrylic can be formed in several ways. It is hard, durable, and has many uses.
Polyester resin is a thermosetting plastic used for castings. It has a number of useful properties.
Mechanisms
Tuning-in
Identify these simple mechanisms. Try to explain the principles on which they operate.
Reading Scanning a text
Scanning is the best strategy for searching for specific information in a text. Move your eyes up and down the text until you find the word or words you want. Again, try to ignore any information which will not help you with your task.
Scan the text opposite quickly to find out which of these mechanisms are mentioned.
1cam4 foot pump
2tap5 escalator
3pendulum
Mechanisms
Mechanisms are an important part of everyday life. They allow us to do simple things like switch on lights, turn taps, and open doors. They also make it possible to use escalators and lifts, travel in cars, and fly from continent to continent.
5Mechanisms play a vital role in industry. While many industrial processes have electronic control systems, it is still mechanisms that deliver the power to do the work. They provide the forces to press steel sheets into car body panels, to lift large components from place to place, to force plastic through dies to make pipes.
10All mechanisms involve some kind of motion. The four basic kinds of motion are:
Rotary: Wheels, gears, and rollers involve rotary movement.
Oscillating: The pendulum of a clock oscillates - it swings backwards and forwards.
15 Linear: The linear movement of a paper trimmer is used to cut the edge of the paper.
Reciprocating: The piston in a combustion engine reciprocates.
Many mechanisms involve changing one kind of motion into another type. For example, the reciprocating motion of a piston is changed 20 into a rotary motion by the crankshaft, while a cam converts the rotary motion of the engine into the reciprocating motion required to operate the valves.
Now read the text to find the answers to these questions.
1What does a cam do?
2What does oscillating mean?
3How are plastic pipes formed?
4What simple mechanisms in the home are mentioned directly or indirectly?
5What is the function of a crankshaft?
6Give an example of a device which can produce a linear movement.
7How are car body panels formed?
8What do mechanisms provide in industry?
Writing Ways of linking ideas, 1
When we write, we may have to describe, explain, argue, persuade, complain, etc. In all these forms of writing, we use ideas. To make our writing effective, we have to make sure our readers can follow our ideas. One way of helping our readers is to make the links between the ideas in our writing.
What are the links between these pairs of ideas? What words can we use to mark the links?
1Mechanisms are important to us.
2They allow us to travel.
3Mechanisms deliver the power to do work.
4They play a vital role in industry.
5Friction is sometimes a help.
6It is often a hindrance.
Mechanisms are important to us because/since/as they allow us to travel.
Sentence 4 is the result of sentence 3. We can link 3 and 4 like this:
Mechanisms deliver the power to do work so they play a vital role in industry.
Mechanisms deliver the power to do work; therefore they play a vital role in industry.
Sentence 6 contrasts with sentence 5. We can link 5 and 6 like this:
Friction is sometimes a help but it is often a hindrance.
Show the links between these sets of ideas using appropriate linking words.
1Copper is highly conductive.
It is used for electric wiring.
2Weight is measured in newtons.
Mass is measured in kilograms.
3Nylon is used for bearings.
It is self-lubricating.
4ABS has high impact strength.
It is used for safety helmets.
5The foot pump is a class 2 lever.
The load is between the effort and the fulcrum.
6Friction is essential in brakes.
Friction is a nuisance in an engine.
Load
7The upper surface of a beam is in compression. The lower surface is in tension.
8Concrete beams have steel rods near the lower surface. Concrete is weak in tension.
Language study Dealing with technical terms
One of the difficult things about the English of engineering is that there are many technical terms to learn. Newer terms may be the same, or almost the same, in your own language. But many terms will be quite different and you may not always remember them.
When this happens, you will have to use whatever English you know to make your meaning clear.
The same thing may happen in reverse when you know a technical term but the person you are communicating with does not recognize it. This may happen in the Speaking practice tasks in this book. Again, when this happens, you will have to make your meaning clear using other words.
Task 5Thetechnicalwordsin column A are similar in meaning to the more general
English in column B. Match them.
AB
1oscillatesachanges
2rotatesblarge, thin, flat pieces
3reciprocatescmoving stairs
4has a linear motiondgoes round and round
5convertsemovement
6motionfgoes in a line
7escalatorgswings backwards and forwards
8sheetshgoes up and down
Task 6Tryto explain how this simple mechanism operates using whatever English
you know. Write your explanation down. Compare your explanation with the technical explanation given on page 4 of the Answer Book. Learn any technical terms which are unfamiliar to you.
Treadle linkage
Speaking practice
Task 7Workinpairs, A and B. Each of you has a diagram of a cam. Describe your
diagram to your partner. Your partner shoufcftry to reproduce your diagram from the spoken description you provide.
Student A: Your diagram is on page 177.
Student B: Your diagram is on page 181.
Thes text on the next page will help you with the vocabulary you need.
Cams are shaped pieces of metal or plastic fixed to, or part of, a rotating shaft. A 'follower' is held against the cam, either by its own weight or by a spring. As the cam rotates, the follower moves. The way in which it moves and the distance it moves depends on the
5shape of the cam. Rotary cams are the most common type. They are used to change rotary motion into either reciprocating or oscillating motion.
If you do not understand what your partner says, these questions and phrases may be helpful.
1Could you say that again/repeat that, please?
2What do you mean by X?
3Where exactly is the X?
4What shape is the X?
5How does the X move?
If your partner does not understand you, try to rephrase what you say.
Forces in engineering
Tuning-in
Working in your group, try to explain these problems.
1Why doesn’t the ship sink?
2What makes the spring stretch and what keeps the weightup?
3Why doesn’t the box slide down the slope?
Reading 1 Predicting
As you learnt in Unit 1. it is important to think about what you are going to read before you read. Do not start to read a text immediately. One way to help your reading is to think about the words which might appear in the text. The title might help to focus your thoughts. Which words might appear in a text with the title Forces in engineering?
The text you are going to read is called Forces in engineering. Here are some of the words it contains. Can you explain the link between each word and the title of the text?
weightbuoyancyequilibrium
elasticitymagnituderesultant
newtongravity
Now read the text. Use the information in the text to check the explanations you made in Task 1.
Forces in engineering
To solve the ship problem, we must look at the forces on the ship (Fig.
1). The weight, W, acts downwards. That is the gravity force. The buoyancy force, B, acts upwards. Since the ship is in equilibrium, the resultant force is zero, so the magnitudes of B and W must be the
5same.
BB-W=0
Another very important force in engineering is the one caused by elasticity. A good example of this is a spring. Springs exert more force the more they are stretched. This property provides a way of measuring force. A spring balance can be calibrated in newtons, the
10unit of force. The block in Fig. 2 has a weight of 10 newtons. The
weight on the balance pulls the spring down. To give equilibrium, the spring pulls up to oppose that weight. This upward force, F1, equals the weight of the block, W.
f F,=W v w
Fig. 2
It is important to get the distinction between mass and weight 15 absolutely clear. Mass is the quantity of matter in an object. Weight is the force on that object due to gravity. Mass is measured in kilograms, whereas weight, being a force, is measured in newtons.
We have looked at buoyancy, elasticity, and gravity. There is a fourth force important in engineering, and that is friction. Friction is a help in 20 some circumstances but a hindrance in others. Let us examine the forces on the box (Fig. 3). Firstly, there is its weight, W, the gravity force, then there is the reaction, R, normal to the plane. R and W have a resultant force trying to pull the box down the slope. It is the friction force, F, acting up the slope, that stops it sliding down.
Reading 2 Grammar links in texts
One of the ways in which sentences in a text are held together is by grammar links. In this extract, note how each expression in italics links with an earlier expression.
Another very important force in engineering is the one caused by elasticity. A good example of this is a spring. Springs exert more force the more they are stretched. This property provides a way of measuring force.
Sometimes these links cause problems for readers because they cannot make the right connection between words in different parts of a text.
Study these common grammar links:
1A repeated noun becomes a pronoun.
Springs becomes they.
2A word replaces an earlier expression.
Force in engineering becomes one.
3A word replaces a whole sentence or clause.
Springs exert more force the more they are stretched becomes This property.
With which earlier expressions do the words in italics link? Join them as in the example above.
Friction in machines is destructive and wasteful. It causes the moving parts to wear and it produces heat where it is not wanted. Engineers reduce friction by using very highly polished materials and by lubricating their surfaces with oil and grease. They also use ballbearings and roller bearings because rolling objects cause less friction than sliding ones.
Source: S. Larkin and L. Bembaum (eds.). The Penguin Book of the Physical World
Language study The present passive
Study these instructions for a simple experiment on friction.
Horizontally calibrated spring balance
Fig. 4
1Place a block of wood on a flat surface.
2Attach a spring balance to one end of the block.
3Apply a gradually increasing force to the balance.
4Note the force at which the block just begins to move.
5Pull the block along so that it moves at a steady speed.
6Note the force required to maintain movement.
7Compare the two forces.
When we describe this experiment, we write:
A block of wood is placed on a flat surface. A spring balance is attached to one end of the block.
This description uses the present passive. We form the present passive using is/are + past participle.
Complete this description of the experiment using the present passive.
A block of woodon a flat surface. A spring balance I
to one end of the block. A gradually increasing force Ito the
balance. The force at wrhich the block just begins to move
The blockalong at a steady speed. The force required to maintain
movement. The two forcesIt is found that the first
force is greater than the second.
What does this experiment show?
Listening Listening to lectures
The listening passage you are going to hear is an extract from a typical engineering lecture. Here are some of the features of lectures.
Incomplete sentences: Spoken language is not divided neatly into sentences and paragraphs. For example:
Now what I thought 1 might do today ... What we are going to talk of...
Repetition and rephrasing: Lecturers often say the same thing more than once and in more than one way. For example:
It will turn, revolve.
Signpost expressions: Lecturers often use expressions to help the students know what they are going to do next, what is important, etc. For example:
What we are going to talk of is the extension of a force.
In the same way as when reading, it is helpful to think about the topic of a lecture before you listen. The topic here is The Moment of a Force. Can you explain the links between these words from the lecture and the topic? Use a dictionary to help you if necessary.
turningdistanceproduct
pivotperpendicularleverage
fulcrumhinge
E3 Now listen to the lecture to check your explanations.
During the lecture, the lecturer drew this diagram on the board. Which of the words in Task 6 can be used to talk about the diagram?
Here are some signpost expressions from the lecture. What do you think the lecturer is indicating each time? Select from the labels below, a to e.
We're going to talk about the moment of a force.
If you can think of a spanner...
But what you have to remember is ...
Something simple to illustrate.
I’m thinking of a practical job.
Why do we put a handle there on the door?
Is that understood? All right?
Well that is then a little explanation of how you calculate moments.
Emphasizing an important point Showing that the lecture is over Checking that the students can follow him Introducing the topic of the lecture Giving examples to illustrate the points
Listen to the tape again and answer these questions according to the information given by the lecturer.
What advantage does a longer spanner offer in loosening a tight nut?
What is the formula for calculating the moment of a force?
W7hy is it sometimes difficult to apply a force at right angles in a motor car engine?
Why is the handle of a door at the edge?
Write down the formulae for calculating force and distance.
The electric motor
Tuning-in
Working in your group, list as many items as you can in the home which use electric motors. Which room has the most items?
Reading Skimming
In Unit 3 you studied scanning - locating specific information quickly. Another useful strategy is reading a text quickly to get a general idea of the kind of information it contains. You can then decide which parts of the text are worth reading in more detail later, depending on your reading purpose. This strategy is called skimming.
Skim this text and identify the paragraphs which contain information on each of these topics. The first one has been done for you.
a What electric motors are used for paragraph 1 b The commutator c Why the armature turns d Electromagnets
e Effect of putting magnets together
f The armature
para
In an electric motor an electric current and magnetic field produce^
a turning movement. This can drive all sorts of machines, from wrist-watches to trains. The motor shown in Fig. 1 is for a washing machine. It is a universal motor, which can run on direct current or
5alternating current.
An electric current running through a wire produces a magnetic2
field around the wire. If an electric current flows around a loop of wire with a bar of iron through it, the iron becomes magnetized. It is called an electromagnet; one end becomes a north pole and the
10other a south pole, depending on which way the current is flowing around the loop.
►
Fig. 1
If you put two magnets close together, like poles - for example,3
two north poles - repel each other, and unlike poles attract each other.
15In a simple electric motor, like the one shown in Fig. 2, a piece of4
iron with loops of wire round it, called an armature, is placed between the north and south poles of a stationary magnet, known as the field magnet. When electricity flows around the armature wire, the iron becomes an electromagnet.
Fig. 2
►
20 The attraction and repulsion between the poles of this armature5
magnet and the poles of the field magnet make the armature turn.
As a result, its north pole is close to the south pole of the field magnet. Then the current is reversed so the north pole of the armature magnet becomes the south pole. Once again, the 25 attraction and repulsion between it and the field magnet make it turn. The armature continues turning as long as the direction of the current, and therefore its magnetic poles, keeps being reversed.
To reverse the direction of the current, the ends of the armature6
wire are connected to different halves of a split ring called a 30 commutator. Current flows to and from the commutator through small carbon blocks called brushes. As the armature turns, first one half of the commutator comes into contact with the brush delivering the current, and then the other, so the direction of the current keeps being reversed.
Source: Adapted from 'Inside out: Electric Motor', Education Guardian
Task 3Matcheachofthesediagramswiththecorrectdescription. A. B. C. or D. One
of the descriptions does notmatch any of the diagrams. (The diagrams are in the correct sequence, but the descriptions are not.)
Motor run on direct current
A
The armature turns a quarter of a turn. Then electric contact is broken because of the gap in the commutator, but the armature keeps turning because there is nothing to stop it.
B
When current flows, the armature becomes an electromagnet. Its north pole is attracted by the south pole and repelled by the north pole of the field magnet.
C
When a universal motor is run on direct current, the magnetic poles in the armature change while those of the field magnet remain constant.
D
When the commutator comes back into contact with the brushes, current flows through the armature in the opposite direction. Its poles are reversed and the turn continues.
Language study Describing function
Try to answer this question:
What does an electric motor do?
When we answer a question like this, we describe the function of something. We can describe the function of an electric motor in this way:
An electric motor converts electrical energy to mechanical energy.
We can emphasize the function like this:
The function of an electric motor is to convert electrical energy to mechanical energy.
Match each of these motor components to its function, and then describe its
function in a sentence.
ComponentFunction
1armatureatransfers rotation from the motor
2bearingsbcreate an electromagnetic field
3brushescconverts electromagnetic energy to rotation
4commutatordreverses the current to the armature
5drive shaftesupport the drive shaft
6field windingsfsupply current to the armature
Writing Describing components
Dismantle this simple dc motor into its components by completing the labelling of the chart below.
3Loopofwire
I
4
Now study this description of the motor.
A simple dc motor consists of a field magnet and an armature. The armature is placed between the poles of the magnet. The armature is made up of a loop of wire and a split ring known as a commutator. The loop is connected to the commutator. Current is supplied to the motor through carbon blocks called brushes.
To write a description, you need to use language to:
1dismantle a piece of equipment into its main parts. These expressions will help:
consists ofX
A A is made up ofXandY
is composed ofY
2name components:
Carbon blocksas brushes.
called
3locate components:
The armature is placed between the poles.
4connect components:
The loop is connected to the commutator.
Complete the text with the help of the diagram on the next page. Use the following words:
are made up is placed is composed consists
A transformeroftwo coils, a primary and a secondary. The coils
are wound on a former which is mounted on a core. The coilsof
a number of loops of wire. The coreof thin pieces of soft iron. U-
and T-shaped pieces are used. The formeron the leg of the T.
Now label the diagram opposite using the completed text.
ll_n
Word study
Study these expressions for describing how components are connected to each other.
A is bolted to B. = A is connected to B with bolts.
A is welded to B. = A is connected to B by welding.
A is fixed to B. = no specific method given
Explain each of these methods of connection.
1screwed
2soldered
3attached
4wired
5bonded
6glued
7riveted
8welded
9brazed
10nailed
An engineering student
Tuning-in
List some of the subjects studied by engineering students. Shan.- \ <>ur list with others in your group.
Task 2Find out what these terms mean in education. Use a dictionary if necessary.
1pass
2resit
3assessment
4fail
5drop out
6period
7full-time
8module
Listening
When listening, it is important to have a clear purpose so that you can concentrate on the parts of the message which best meet v< ur needs. It also helps to think about what you will hear before you listen. The next two tasks will help you to prepare for listening and to have a clear purp» >se.
Task 3Youare going to hear an interview with David, a student of electrical
engineering at a Scottish college of further education. He is a mature student writh previous service in the Navy.
Here is David's weekly timetable. Some of the information is missing. Before you listen, try to answer these questions about the timetable.
1What time does David start each day?
2When does he finish?
3How long is a class?
4How many classes does he have each week?
5What do the numbers mean after each class, e.g. 150?
6How often does he have breaks?
8.45-10.15MONDAY
Design and make
150TUESDAYWEDNESDAYTHURSDAY
Technology
138FRIDAY
Technology
051
053
Bre a k
10.30-12.00Design and make
150Tutorial
063
140406051
L U N CHBREAK
13.00-14.30MathsCommunicationsMaths
510510606510510
Bre a k
14.45-16.15TechnologyPrinciplesTechnologyPrinciplesSelf-study
053138039051
Task 5E3Listen to Part 3 of the interview. Try to complete the information missing from the timetable. Compare your answers with a partner.
Task 6OListen to the last part of the interview. Answer these questions. Part 4
11When does he practise sport?
12Where can you go for sport?
13What kind of sports can you practise there?
14What is he going to do after the Certificate?
15What does he want to be?
Task 7EDNow listen to the whole tape. Answer these more difficult questions.
1W hy did David leave the Navy?
2Why did students drop out of the class?
3Why did he dislike school?
4Why do most students find PSD a bit of a nuisance?
5Why does he want to know when it’s raining?
6W7hy does he not have to use the library?
7Why does he enjoy technology most?
Writing Comparing and contrasting
Task 8WriteyourowntimetableinEnglish.
MONDAYTUESDAYWEDNESDAYTHURSDAYFRIDAY
Write a short comparison and contrast of your timetable and David's. These expressions may be useful:
more time/hours/classes/maths than less time/maths/physics than fewer hours/classes than not as much time/maths/physics as not as many hours/classes as start/finish earlier/later than
Note that less and much are used for things which cannot be counted.
Central heating
Tuning-in
How can you heat a house in cold weather? List the possible ways. Reading Predicting
In Unit 5 we learnt how using the title can help us to predict the contents of a text. Diagrams are also very useful in helping the reader to make the right guesses about what a text will contain. Before you read a text, read the title and look at any diagrams it contains.
Using the diagram, try to explain the function of these components:
the pilot light
the heat exchanger fins
the flue
the thermostat
the pump
Scan this text quickly to check the explanations you made in Task 2. You may not find all the information you want.
Gas central heating
Most gas central heating works on the 'wet' system of heat transfer between water flowing through pipes. Atypical system includes a boiler, a network of pipes, a feed, and expansion tank, radiators, and a hot water storage system.
5In conventional boilers, water is heated by gas burners. It is then pumped around the central heating system and the hot water storage cylinder. The flow of gas to the burner is controlled by a valve (or valves) which can be operated by a time switch or by a boiler thermostat, hot water cylinder thermostat, or by a
10thermostat located in one of the rooms.
Air is necessary for complete combustion and is supplied to the burners either from inside the house, when adequate ventilation must be ensured, or directly from outside through a balanced flue.
Water is circulated through a heat exchanger above the burner. The 15 heat exchanger is made of tubes of cast iron or copper, which resist corrosion. Both types use fins to increase the surface area in contact with water, which improves the transfer of heat. A thermostat located in the boiler causes the gas control valve to shut off when the water temperature reaches the pre-set level.
20 After being pumped through a diverter or priority valve, water circulates around either one of two loops of pipework, which act as heat exchangers. One loop passes through the inside of the hot water storage cylinder in a coil arrangement. Heat is transferred to the surrounding water, which can then be drawn off from this 25 cylinder from various hot taps in the house when required. The loop then returns to the boiler for re-heating.
The other loop of the circuit passes to the radiators, which provide room heating. Several radiators are generally connected, where one pipe provides the hot water input and the other carries the cold 30 water back to the boiler. In this way, all radiators receive hot water directly from the boiler.
Source: 'Inside out: Central Heating', Education Guardian
Put these statements in the correct sequence. The first and last have been done for you.
aWater is circulated through a heat exchanger.I
bThe loop returns to the boiler for re-heating.
cOne loop passes through the inside of the hot water storage
cylinder in a coil of pipes.
d Water is heated by gas burners.
eThe hot water is pumped through a diverter valve.
fThe other loop of the circuit passes to the radiators.
g Cold water from the radiators returns to the boiler.7
Use the statements in Task 4 to label the stages shown in this diagram of a heating system.
Language study Time clauses
What is the relationship between these pairs of actions? How can we link each pair to show this relationship?
1Cold water passes through a heat exchanger.
The water is heated.
2The water is heated.
It reaches a pre-set temperature.
3The water is heated.
It is pumped to a diverter valve.
4The water temperature reaches the right level.
The gas control valve shuts off.
We can show how actions are linked in time by using time clauses.
We can use as to link two connected actions happening at the same time. For example:
1/4s cold water passes through a heat exchanger, the water is heated.
We can use until to link an action and the limit of that action. For example:
2The water is heated until it reaches a pre-set temperature.
Note that until normally comes between the stages.
We can use after to show that one action is followed by another action. For example:
3After the water is heated, it is pumped to a diverter valve.
We can use when to show that one action happens immediately after another. For example:
4When the water temperature reaches the right level, the gas control valve shuts off.
Note that when the time word comes first in the sentence, a comma I.) is used after the time clause.
Link these sets of actions with appropriate time words.
1The system is switched on.
Cold water passes through a heat exchanger in the boiler.
2The water passes through the heat exchanger.
The water becomes hotter and hotter.
The water reaches a pre-set level.
3The water temperature reaches the pre-set level.
A thermostat causes the gas control valve to shut off.
4The water is pumped to a diverter valve.
The water goes to the hot water cylinder or the radiators.
5Hot water passes through the inside of the hot water storage cylinder in a coil arrangement.
Heat is transferred to the surrounding water.
6The hot water flows through the radiators.
The hot water loses heat.
7The water passes through the radiators.
The water returns to the boiler.
Word study
The words listed in the first column of this table are common in descriptions of technical plant. They describe how substances are moved from one stage of the process to the next. Some of these words can be used for any substance; others are more specific. Write an X under Solids, Liquids, or Gases if the word on the left can be used to talk about them. The first example has been done for you.
SolidsLiquidsGases
carriedXXX
circulated
conveyed
distributed
fed
piped
pumped
supplied
Safety at work
Tuning-in
What do these warning labels on chemicals mean? Match each label to the correct warning.
a Highly flammable b Harmful c Explosive d Corrosive e Oxidizing f Toxic
MAKE SURE YOU LEARN THE LABELS! THEY ARE FOR YOUR PROTECTION.
List some of the potential dangers in your laboratory, workshop, or place of work. How is the risk of these hazards reduced?
Study the safety instructions from a workshop below, and then answer these questions.
a Who are the instructions for? b Who wrote them? c What was the writer's purpose?
1Wear protective clothing at all times.
2Always wear eye protection when operating lathes, cutters, and grinders and ensure the guard is in place.
3Keep your workplace tidy.
4The areas between benches and around machines must be kept clear.
5Tools should be put away when not in use and any breakages and losses reported.
6Machines should be cleaned after use.
Reading Understanding the writer's purpose
Knowing what the writer's purpose is. who the writer is. and who the intended readers are can help us to understand a text. The safety instructions in Task 3 are clearly intended to encourage employees to be safety conscious and reduce the risk of accidents. The writer is perhaps a supervisor or the company safety officer, and the intended readers are machine operatives. Knowing these things can help us to work out the meaning of any part of the text we may not understand.
Study the company document on safety on the next page, and then answer these questions.
1Who is this document for? a machine operatives
b managers c all employees d injured employees
2Who wrote this document?
a trade union representative b technician c manager d medical staff
3What is the writer's intention? a to prevent accidents
b to ensure speedy help for injured employees c to protect the company d to warn about dangers
Accident investigation
Whenever an accident occurs that results in an injury (medical case), damage of equipment and material, or both, prompt accident investigation by the immediate manager is required. A written preliminary investigation will be completed by the end of the particular shift or business day on which the accident occurred.
In no event should there be a delay of more than 24 hours. Failure to comply with this requirement may subject the immediate manager to disciplinary action up to and including discharge.
Without adequate accident investigation data the Company may be subjected to costs, claims, and legal action for which it has no defence.
As a minimum, the preliminary accident investigation report will include the following:
1Name, occupation, and sex of injured worker.
2Place and date/time of accident.
3Description of how the accident happened.
4Immediate causes of the accident - unsafe acts and unsafe conditions.
5Contributing causes - manager safety performance, level of worker training, inadequate job procedure, poor protective maintenance, etc.
6Witness(es) - name and department.
7Corrective action taken - when.
The employee who was injured and any employee(s) who witnessed the incident should be separately interviewed as soon as possible. A copy of the report must be submitted to the Manager - Human Resources for review. Another copy of the report is to be retained for a period of not less than the injured employee's length of employment plus five (5) years.
Study this brief report of an accident. In which points does it not meet company policy on reporting accidents?
To:Name
ManagerDepartments Location
Human ResourcesDate
17 May
From:Name
D. TaylorDepartment & Location
Mech. Eng. WorkshopTel.
6200
SubjectPreliminary Report, Accident, 12 May
While turning a brass component on Tuesday, last week, Kenneth Oliver, machinist, received an injury to his eye. He was taken to the Eye Hospital where I understand he was operated on. I believe the accident was due to carelessness.
Language study Making safety rules
What are the differences in meaning, if any, between these statements?
1Wear protective clothing.
2Always wear protective clothing.
3Protective clothing must be worn.
We can make safety rules in these ways:
1Using an imperative.
Wear protective clothing.
Do not wear loose-fitting clothing.
2Always/never are used to emphasize that the rule holds in all cases.
Always wear protective clothing.
Never wear loose-fitting clothing.
3We can use a modal verb^for emph^j?
Protective clothing must be worn.•
Protective clothing should be worn.
Study this list of unsafe environmental conditions (hazards). Write safety rules to limit these hazards using the methods given above. For example:
inadequate lighting
Lighting must be adequate, or Lighting should be adequate.
uneven floors
unguarded machinery
untidy workbenches
untidy workplaces
badly maintained machinery
carelessly stored dangerous materials
inadequate ventilation
damaged tools and equipment
machinery in poor condition
equipment used improperly
equipment operated by untrained personnel
apprentices working without supervision
Writing Ways of linking ideas. 2
In Unit 4 we learnt that to make our writing effective, we have to make sure our readers can follow our ideas. We learnt how to mark reasons, results, and contrasts in our writing.
What are the links between these ideas? What words can we use to mark the links?
1The accident happened.
2The operator’s carelessness.
3The supervisor was not present.
The accident happened because of the operator's carelessness. In addition/moreover, the supervisor was not present.
We use because of to introduce a reason which is a noun or noun phrase. We use in addition and moreover to introduce an additional reason.
What are the links between these ideas? What words can we use to mark the links?
4Suitable protection should be worn.
5Safety helmets should be used where there is a danger of falling objects.
Sentence 5 is an example to illustrate sentence 4. We can mark this in this way:
Suitable protection should be worn. For example/For instance, safety helmets should be used where there is a danger of falling objects.
Show the links between these sets of ideas using appropriate linking words from this unit and from Unit 4.
1Many accidents happen.
Workers' carelessness.
2Education can reduce accidents.
It is important that all workers receive training in basic safety.
3Eye injuries can be serious.
Goggles must be worn for grinding and cutting.
4Safety gloves provide protection for the hands.
They prevent burns.
They reduce the danger of cuts.
5Safety shoes protect the feet against falling objects.
They prevent the feet getting caught in machinery.
6Respirators should be worn in dusty conditions.
Dust can damage the lungs.
7Safety gear exists for every danger.
Each year people are injured.
They refuse or forget to wear the right gear.
Young engineer
Tuning-in
Lucy Porter is a recent winner of the Young Engineer for Britain award. Study this diagram of her invention. Discuss these questions in your group:
1What is it?
2Who is it for?
3How does it work?
Listening
Task 2(SINow listen to Lucy talking about her invention and career plans. As you listen, check your answers to Task 1.
Task 3IS1Now listen again. Here are some of the things Lucy talks about. Put them in the correct sequence. The first one has been done for you.
aHer career plans.
bWhat happens next with her invention.
cHow it works.
dWhy she is planning to study engineering.
eChanges in the design.
fWhat her invention is called. I
gWhat materials she used.
hWho it is intended for.
iHow she made the prototype.
iHow she got the idea.
kHer views on engineering as a career for women.
Task 4Now make notes on what Lucy says about the above topics.
Task 5Label the diagram in Task 1 with these terms:
1rope
2handle
3pulley
4A-frames
5cross-piece
6seat
Task 6Put these steps in the creation and development of the swing in the correct sequence. The first and last have been done for you.
aproblem identified I
bprototype built in wood
cmetal version built
ddesign modified
einvention patented
fmodels built to test design
gprototype modified
hprototype tested
idesign drawn
imanufacturer licensed to produce 10
Task 7ElNow listen again and answer these more detailed questions.
1How did the invention get its name?
2What did she use to test designs which seemed viable?
3Why did she make the first swing from wood?
4What are the advantages of a metal frame?
Writing Describing and explaining
You are going to write a brief description and explanation of Lucy’s invention. It will consist of two paragraphs.
Paragraph J
Use the labelled diagram in Task 1 and the information from the tape to write a brief description of Lucy's invention. Your description should answer these questions:
1What is it called?
2What is it for?
3What does it consist of?
4How are the parts connected?
5What is it made of?
Use the language of description studied in Unit 6.
Paragraph 2
The following steps explain how the swing works. Put them in the correct sequence. Then use so and when to link them into a paragraph.
The rope pulls the seat forwards.
Repetition of these actions causes a swinging motion.
The child pulls down on the handle.
The seat swings back under the weight of the child.
The child releases the handle.
Speaking practice
Work in pairs. A and B.
Student A: Play the part of the interviewer. Base your questions on the topics in Task 3, and any other questions you may wish to add. For example:
a Her career plans. —► What are your career plans?
Student B: Play the part of the swing inventor.
Conduct the interview.
Washing machine
Tuning-in
Many items found in the home contain control systems. The washing machine is one of the most complex. List some of the factors the control system of a washing machine must handle. This diagram may help you.
Fig. 7 Cross- section through a washing machine Reading Reading diagrams
In engineering, diagrams carry a great deal of information. They can also help you to understand the accompanying text. For this reason, it is helpful to try to understand any diagram before reading the text.
Study the diagram again. Try to explain the function of each of these items.
1Pump
2Motor
3Shock absorber
4Solenoid valves
5Heater
6Pressure sensor
7Door lock and sensor
8Temperature sensor
9Fan
Read this text to check your answers to Task 1.
Control systems in the home
Most devices in the home have some sort of control. For example, you can control the volume of a TV by using a remote control. The building blocks of a control system are:
Press buttonSignal isVolume
on remote controlsent to TVis adjusted
The input can be any movement or any change in the environment. 5 For example, a drop in temperature may cause a heating system to come on.
The control may change the size of the output (for example, adjusting the sound of a TV). Often this involves changing one kind of input into a different kind of output. For example, opening a 10 window may set off a burglar alarm.
Outputs can be of many kinds. An alarm system may ring a bell, flash lights, and send a telephone message to the police.
Most control systems are closed loops. That means they incorporate a way of checking that the output is correct. In other 15 words, they have feedback. The thermostat in a central heating system (Fig. 2) provides constant feedback to the control unit.
TemperatureControlBoilerBoiler/Pump
sensorunitswitchRadiators
Feedback
Fig. 2
The control system of a modern washing machine has to take into account several different factors. These are door position, water level, water temperature, wash and spin times, and drum speeds.
20 Most of them are decided when you select which washing program to use.
Fig. 3 shows a block diagram of a washing machine control system.
You can see that this is quite a complex closed loop system using feedback to keep a check on water level, water temperature, and 25 drum speeds.
►
Fig. 3
The control unit is the heart of the system. It receives and sends out signals which control all the activities of the machine. It is also capable of diagnosing faults which may occur, stopping the program, and informing the service engineer what is wrong. It is a 30 small, dedicated computer which, like other computers, uses the language of logic.
Source: P. Fowler and M. Horsley, 'Control systems in the home', CDT: Technology
Read the following text to find the answers to these questions:
1What device is used to lock the door?
2What provides feedback to the control unit about the door position?
Text 1
Door position
The machine will not start any program unless the door is fully closed and locked. When the door is closed, it completes an electrical circuit which heats up a heat-sensitive pellet. This expands as it gets hot, pushing a mechanical lock into place and 5 closing a switch. The switch signals the control unit that the door is closed and locked. Only when it has received this signal will the control unit start the wash program.
Now work in pairs. A and B.
Student A: Read Texts 2 and 3.
Student B: Read Texts 4 and 5.
Complete your section of the table opposite. Then exchange information with your partner to complete the whole table.
Control factorOperatingdeviceFeedbackby
1Door positionheat-sensitivepelletswitch
2Water level
3Water temperature
4Wash and spin times—
5Drum speeds
Text 2
Water level
When a wash program first starts it has to open the valves which allow the water in. There are usually two of these valves, one for hot water and one for cold. Each must be controlled separately depending on the water temperature needed for that program. The 5 valves are solenoid operated, i.e. they are opened and closed electrically.
The rising water level is checked by the water level sensor. This is a pressure sensor. The pressure of the air in the plastic tube rises as it is compressed by the rising water. The pressure sensor keeps the 10 control unit informed as to the pressure reached and the control unit uses the information to decide when to close the water inlet valves.
Text 3
Water temperature
The temperature sensor, a type of thermometer which fits inside the washer drum, measures the water temperature and signals it to the control unit. The control unit compares it with the temperature needed for the program being used. If the water temperature is too 5 low, the control unit will switch on the heater. The temperature sensor continues to check the temperature and keep the control unit informed. Once the correct temperature is reached, the control unit switches off the heater and moves on to the next stage of the program.
Text 4
Clock
The control unit includes a memory which tells it how long each stage of a program should last. The times may be different for each program. The electronic clock built into the control unit keeps the memory of the control unit informed so that each stage of each 5 program is timed correctly.
Drum speed
During the washing and spinning cycles of the program, the drum has to spin at various speeds. Most machines use three different speeds: 53 rpm for washing; 83 rpm for distributing the load before spinning; 100 rpm for spinning.
5The control unit signals the motor to produce these speeds. The motor starts up slowly, then gradually increases speed. The speed sensor, a tachogenerator, keeps the control unit informed as to the speed that has been reached. The control unit uses the information to control the power to the motor and so controls the speed of the 10 drum at all times.
Language study If/Unless sentences
Fill in the blanks in this table using the information in Fig. 3 and the texts in Task 4.
SensorConditionControl unit action
Waterlevel lowopen inlet valves
level high enough
Water temperatureswitch on heater
high enough
Drum speed
decrease motor speed
The conditions which the sensors report determine the action of the control unit. We can link each condition and action like this:
If the water level is low, the inlet valves are opened.
Write similar sentences for the other live conditions given.
Now study this example:
SensorConditionControl unit action
DoorDoor openMachine cannot start
Door closedMachine can start
We can link these conditions and actions as follows:
1If the door is open, the machine cannot start.
2If the door is closed, the machine can start.
3Unless the door is closed, the machine cannot start.
We use unless when an action cannot or will not happen if a prior condition is not true. In example 3. Unless means If... not. We can rewrite 3 as:
If the door is not closed, the machine cannot start.
Unless the ignition is switched on. a car cannot.
Unless the pilot light is on. gas central heating will not
Unless the diverter valve is switched to central heating, the radiators will not
Unless there is current flowing in the primary coil of a transformer, there will be no current in thecoil.
Unless there isin the cylinders, a petrol engine will not start.
Unless the doors area lift will not operate.
Unless mild steel is painted, it will.
Unless electrical equipment is earthed, it may be
Writing Explaining a diagram
Study this diagram of a pressure sensor. Explain how it works by linking each pair of actions with appropriate time words.
A wash programme first starts.
It opens the valves to allow the water in. The water level in the drum rises.
The air in the plastic tube is compressed. The pressure rises.
The diaphragm moves upwards.
This continues.
The switch contacts are separated.
This happens.
The till valves are closed.
Join the following groups of statements to make longer sentences. Use the words printed in italics above each group. You may omit words and make whatever changes you think are necessary in the word order and punctuation of the sentences. Join the sentences to make a paragraph.
1which
The temperature sensor measures the water temperature.
The temperature sensor is a type of thermometer.
2and
The temperature sensor fits inside the washer drum.
The temperature sensor signals the water temperature to the control unit.
3which
The control unit compares the water temperature with the temperature. The temperature is needed for the programme being used.
4If
The water temperature is too low.
The control unit will switch on the heater.
5and
The temperature sensor continues to check the temperature.
The temperature sensor keeps the control unit informed.
6When... and
The correct temperature is reached.
The control unit switches off the heater.
The control unit moves on to the next stage of the programme.
Racing bicycle
Chris Boardman in the 1992 Olympics.
Tuning-in
Label this diagram of a bicycle with these terms.
EH Check your answers by listening to this description.
Compare Fig. 2 (below) with the bicycle shown in Fig. 1 and Task 2. What differences can you note? Write your answers in this table.
Conventional (Fig. 1)Improvement(Fig.2)
Spoked wheels Gear lever on the frame Tubular aluminium-alloy frame Pedals with toe-ciips
Steel gears
Ordinary handlebars
Lightweight frame made from aircraft grade aluminium alloy, composite such as carbon fibre, or die-cast aluminium. The frame shown is a low profile machine, which decreases the wind resistance experienced by the rider.
Aerodynamic handlebars. These also reduce the rider's wind resistance without reducing by too much the power that can be applied to the pedals. They are called 'triathlon' bars because they were developed by a professional American triathlete, Dave Scott. They became popular with racing cyclists after Greg LeMond used them when he won the 1989 Tour de France.
Fig. 2
Task 4Check your answers to Task 3 in column 1 opposite. Then study Fig. 2 again
to find reasons for each improvement.
Disc wheels
Combined gear change and brake levers
Carbon fibre frame Clipless pedals
Precision-engineered aluminium- alloy or titanium gears
Aerodynamic handlebars
Reading Prediction
Study this extract from the text you are going to read.
Bicycles, and especially racing bicycles, have much in common with aircraft:
What similarities between racing bicycles and aircraft do you think the text will cover? Note your predictions.
Read this text to check your answers to Task 5.
Racing bicycle
The standard design of the bicycle has been in existence for about 100 years. But in the past 10 years there have been more changes than during any other decade.
Bicycles, and especially racing bicycles, have much in common
5with aircraft: both are designed to minimize wind resistance, maximize energy efficiency, respond instantly to the demands placed on them, yet weigh very little without losing strength. So, much of the technology used in aerospace has found its way into racing bicycles.
10 The heart of the bicycle is its frame. It must be strong, light, flexible enough to absorb bumps, but not so much that it wastes the energy the rider transmits by pedalling.
Bicycle frame designers share many aims with aircraft engineers, who must design wings which are strong, light, aerodynamic, and 15 efficient at converting engine power into lift. Yet the wings must be flexible enough to absorb turbulence without wasting the engine's thrust. Therefore, the modern bicycle frame and aircraft wing share both materials and design features. Many racing bicycle frames which consist of tubes joined together are made from aluminium 20 alloys similar to those used in aviation. The French company, Vitus, >-
glues the tubes together using the same techniques as those used for connecting aircraft components.
In recent years, aircraft manufacturers such as Boeing have been experimenting with composite materials like Cheval and carbon 25 fibres. It is no surprise that some racing bicycle frames are now manufactured from the same materials.
Perhaps the most innovative frame to date is constructed from die- cast magnesium alloy. Its designer, Frank Kirk, formerly worked in aerospace.
30 Components which fit on bicycle frames have also benefited from aerospace engineering. Many components, such as gearsH^rakes, handlebars, and wheels, are both aerodynamic and often made from aluminium alloys or titanium - another light, strong metal used in aircraft.
Language study Describing reasons
We can describe the reasons for an improvement or design change in a number of ways. Study this example:
Improvement/Design changeReason
Disc wheelsReduce wind resistance.
How many ways do you know to link an improvement and the reason for it? Try to complete this sentence by adding the reason given.
New racing bicycles have disc wheels.
Using to + verb is the easiest way to link improvement and reason. For example:
New racing bicycles have disc wheels to reduce wind resistance.
Another simple way is to use a linking word. You studied this in Unit 5. For example:
New racing bicycles have disc wheels because/since/as this reduces wind resistance.
A more difficult way is to use so that which must be followed by a clause. For example:
New racing bicycles have disc wheels so that wind resistance is reduced.
Link each improvement and reason in Task 4 using the methods given above.
Writing Describing contrast
In engineering, it is often necessary to compare and contrast different proposals, solutions to problems, and developments. In this unit we will focus on contrast - describing differences.
We can show differences in a table like this:
Spoked wheels
Gear lever on the frame
Tubular aluminium-alloy frame
Pedals with toe-clips
Steel gears
Ordinary handlebars
Disc wheels
Combined gear change and brake levers Carbon Hbre frame Clipless pedals
Precision-engineered titanium gears Aerodynamic handlebars
We can describe differences using:
1the comparative form of the adjective or adverb. For example:
The new bicycle is lighter than the old.
The new bicycle is more aerodynamic than the old.
Titanium years can be changed more easily.
2the connecting words but/whereas, in contrast. For example:
On new bicycles the gear and brake lever are combined, whereas on old ones, the gear lever is on the frame.
Old bicycles have spoked wheels. In contrast, the new bicycle has disc wheels.
3using expressions such as unlike/different from. For example:
Unlike the conventional bicycle, the new bicycle has a carbon fibre frame.
The new bicycle is different from the conventional one in that the gears are made of titanium.
Note that these expressions assume that the reader is familiar with the materials used in the conventional bicycle, which are not mentioned.
Describe the differences between a conventional and an improved bicycle using the information in the table above and appropriate expressions from the list provided.
Word Study Properties of materials
Study these examples of adjective and noun pairs for describing the properties of materials.
AdjectiveNoun
flexibleflexibility
lightlightness
strongstrength
AdjectiveNoun
wind resistance
elastic
plasticity
tough
soft
rigid
wear-resistant
brittleness
hard
Speaking practice
Work in pairs. A and B.
Student A:Your task is to explain to your partner how to adjust the distance
between the saddle and the handlebars of a racing bicycle. Use the text and diagrams on pages 177/8 to help you.
Student B:Your task is to explain to your partner how to adjust the height
and tilt of the handlebars of a racing bicycle. Use the text and diagrams on pages 181/2 to help you.
Technical reading Gear systems
Bicycles use a chain and sprocket system to transmit rotary motion from the driver shaft to the driven shaft because of its strength and because it will not slip. When it comes to working out speed changes, you use the number of teeth on the sprockets. For
5example, looking at the system in Fig. 3:
Driver sprocket has 60 teeth.
Driven sprocket has 15 teeth.
Number of teeth on driven sprocket Gear speed ratio =*
Number of teeth on driver sprocket
Calculate the gear ratios of a bicycle with the system shown in Fig. 4 below. It has a double chain-wheel and five driven sprockets on the rear wheel but only the combinations shown below are recommended. You may need a calculator.
Fig. 4
Chain-wheelteethSprocketteethRatio
A511151:3.4
217
321
B42321
424
528
Lasers
Tuning-in
Task 1Whatarelasers?Listanyapplicationsyouknowforlasers.
Reading
Task 2Readthis text to check your answers to Task 1.
Lasers (Light Amplification by Stimulated Emission of Radiation) are devices which amplify light and produce beams of light which are very intense, directional, and pure in colour. They can be solid state, gas, semiconductor, or liquid.
5When lasers were invented in 1960, some people thought they could be used as 'death rays'. In the 1980s, the United States experimented with lasers as a defence against nuclear missiles. Nowadays, they are used to identify targets. But apart from military uses, they have many applications in engineering,
10 communications, medicine, and the arts.
In engineering, powerful laser beams can be focused on a small area. These beams can heat, melt, or vaporize material in a very precise way. They can be used for drilling diamonds, cutting complex shapes in materials from plastics to steel, for spot welding 15 and for surfacing techniques, such as hardening aircraft engine turbine blades. Laser beams can also be used to measure and align structures.
Lasers are ideal for communications in space. Laser light can carry many more information channels than microwaves because of its 20 high frequency. In addition, it can travel long distances without
losing signal strength. Lasers can also be used for information recording and reading. Compact discs are read by lasers.
In medicine, laser beams can treat damaged tissue in a fraction of a second without harming healthy tissue. They can be used in very precise eye operations.
In the arts, lasers can provide fantastic displays of light. Pop concerts are often accompanied by laser displays.
Complete this table of laser applications using information from the text opposite. You may also add any applications you know of which are not included in the text.
MilitaryEngineeringCommunications MedicineArts
drilling diamondstreatingdamaged
tissue
cutting complexinformation
shapesrecording and
reading
Language study used to/for
Study these examples of laser applications:
1Laser beams can be used to measureand align structures.
2They can be used for drilling diamonds.
3They can be used for light displays.
We candescribe applications with used to +infinitive or used for + -ing or noun.
Task 4Describethe applications of lasers using the information in your table in
Task 3 and the structures given above.
Word study Noun + noun compounds
We can use adjectives to describe an object in greater detail. For example:
lightelectric light
a motoran electric motor
steelstainless steel
gearshelical gears
We can also use nouns. For example:
lightlaser light
a motoran air motor
steelcarbon steel
gearstitanium gears
Many relationships are possible in noun compounds. For example:
an air motora motor which uses air
carbon steelsteel which contains carbon
titanium gearsgears made of titanium
Put each of these examples in the correct column.
usesismadeofcontains
What new relationships can you find in the examples below? Rewrite each compound to show the relationship. For example:
a foot pumpa pump which is operated by foot
a ribbon cablea cable which is like a ribbon
a gear levera lever for operating gears
1chain wheel6college lecturer
2disc wheel7toe-clip
3foot brake8boiler thermostat
4a hand throttle9safety helmet
5strain gauge10aircraft engineer
Writing Describing a process, I'.sequence
When we write about a process, we have to:
1Sequence the stages
2Locate the stages
3Describe what happens at each stage
4Explain what happens at each stage
In this unit, we will study how to sequence the stages.
Consider these stages in the operation of a washing machine.
The drum is tilled with water.
The water is heated to the right temperature.
Soap is added.
The drum is rotated slowly.
The dirty water is pumped out.
Clean water is added.
The drum is rotated much faster and the water pumped out.
The clean clothes are removed.
Instead of numbers, we can show the correct order using sequence words.
First the drum is filled with water.
Then the water is heated to the right temperature.
Next soap is added.
After that, the drum is rotated slowly.
Next the dirty water is pumped out.
Then clean water is added.
After that, the drum is rotated much faster and the water pumped out. Finally, the clean clothes are removed.
Study this diagram. It shows an extruder for forming plastic pipes. Describe the extruder.
Now put these stages in the process in the correct sequence.
The hot plastic is forced through the die to form a continuous length of pipe. The rotating screw forces the plastic past heaters.
The plastic granules are mixed and placed in the hopper.
The pipe is cooled and cut to suitable lengths.
The plastic melts.
Describe the correct order using sequence words. Add to your description of the process your description of the extruder from Task 7. Form your text into a paragraph.
Technical reading Laser cutting
Task 10Engineers have to read sales literature describing the products and services of
companies. Read the following sales literature to answer these questions:
1Who is this text for?
2What service does the company provide?
3What are the design benefits of laser cutting?
4Can lasers cut non-metals?
5What limitations are there on the service they provide?
6How does the service cut lead time?
DESIGN ENGINEERS -DEVELOPMENT ENGINEERS - BUYERS- STOCK CONTROLLERS
Frustrated?
By having to restrict designs to suit manufacturing processes?
By the difficulty and high cost of producing accurate prototypes?
By the high cost and lengthy lead times associated with press tools?
By the high stock levels necessitated by minimum batch sizes?
If your answer to any of the above is yes ...
WE HAVE THE SOLUTION! OUR NEW 1500 WATT CNC-CONTROLLED LASER CUTTER IS AT YOUR DISPOSAL
■The Process
Laser technology is not new, but it is only recently that the full benefits have become available to manufacturers.
Taking lightand passing it through a series of lenses makes the light source so great that its power density is several million times that of the sun -this laser energy is then used to cut almost any material.
The light is directed down towards a CNC-controlled table making it very easy to produce accurate complicated shapes without distortion, giving burr-free, smooth, and perfectly square edges.
■The Materials
The laser is suitable for cutting:
-All types of steel including stainless and spring steel.
-Most non-ferrous metals.
-Plastics, wood, fibreglass, and almost any other material you care to mention!
■The Capacity
Carbon Steel - up to 13 mm Stainless Steel - up to 10 mm Plastics - up to 40 mm Wood - up to 40 mm Rubber-upto 40 mm
Table movement 1650 mm x 1250 mm
■The Advantages
Short lead time No tooling costs Low set-up costs Extremely accurate Highest quality Minimal heat affected zones Design flexibility
Source: Eraba Limited
Automation technician
Tuning-in
You are going to hear an interview with Alistair, a technician with an American company based in the United Kingdom. His company produces cellular communication equipment. Try to list some of the products his company might make.
Listening
E3 Listen to Part 1 of the interview. Check your answers to Task 1 and answer these questions.
1What is his job title?
2What does his section build?
3What type of machines are they?
4What does a Fuji robot do?
5What do his machines do?
6What three types of sensors does a robot have?
Task 3E)Listen to Part 2 of the interview and answer these questions.
1How long has he been with the company?
2How many technicians are in his section?
3When does he start work?
4What does he do first when he gets to work?
5Name one thing he might do after that.
6W7hy does he visit plants in Europe?
7Where has he been?
8What does he dislike about travelling?
Task 4IS)Listen to Part 3 of the interview and answer these questions.
1What did the company he previously worked for make?
2Name one thing he feels was good about working for his old company.
3What qualification does he have?
4How long did it take to get this qualification?
5During his work placement, what did he do a lot of?
6What kind of companies did he do installations in?
7W7hat was one of the perks of the job?
Task 5ElListen to the interview again and complete the gaps in this record of Alistair's work experience.
PeriodType of companyProductJob title
2yearsAutomation
technician
yearsTelephone exchange
months Instrument makersStudent placement
Speaking practice Talking about specifications
Task 6Workinpairs.A and B. Some of the design specifications for your drawing
are missing. Complete them with help from your partner.
Before you start, make sure you know how to say these abbreviations and expressions in full:
1max.maximum
2min.minimum
3dia.diameter
4cmcentimetre
5kgkilogram
61.42one point four two
70.55zero point five five
8+plus or minus
You may look at each other’s drawings after you have exchanged information.
Student A: Your specifications are on page 178.
Student B: Your specifications are on page 182.
Refrigerator
Tuning-in
Task 1Studythisdiagram. It explains how a refrigerator works. In your group try to
work out the function of each of the numbered components using the information in the diagram.
Reading Dealing with unfamiliar words, 1
You are going to read a text about refrigerators. Your purpose is to find out how they operate. Read the first paragraph of the text below. Underline any words which are unfamiliar to you.
Refrigeration preserves food by lowering its temperature. It slows down the growth and reproduction of micro-organisms such as bacteria and the action of enzymes which cause food to rot.
You may have underlined words like micro-organisms, bacteria,or enzymes. These are words which are uncommon in engineering. Before you look them up in a dictionary or try to find translations in your own language, think! Do you need to know the meaning of these words to understand how refrigerators operate?
You can ignore unfamiliar words which do not help you to achieve your reading purpose.
Now read the text to check your explanation of how a refrigerator works. Ignore any unfamiliar words which will not help you to achieve this purpose.
Fridge
para
Refrigeration preserves food by lowering its temperature. It slows 1 down the growth and reproduction of micro-organisms such as bacteria and the action of enzymes which cause food to rot.
Refrigeration is based on three principles. Firstly, if a liquid is2
5heated, it changes to a gas or vapour. When this gas is cooled, it changes back into a liquid. Secondly, if a gas is allowed to expand, it cools down. If a gas is compressed, it heats up. Thirdly, lowering the pressure around a liquid helps itto boil.
To keep the refrigerator at a constant low temperature, heat must3
10 be transferred from the inside of the cabinet to the outside. A refrigerant is used to do this. It is circulated around the fridge, where it undergoes changes in pressure and temperature and changes from a liquid to a gas and back again.
One common refrigerant is a compound of carbon, chlorine, and4
15 fluorine known as R12. This has a very low boiling point: -29°C. At normal room temperature (about 20°C) the liquid quickly turns into gas. However, newer refrigerants which are less harmful to the environment, such as KLEA 134a, are gradually replacing R12.
The refrigeration process begins in the compressor. This5
20 compresses the gas so that it heats up. It then pumps the gas into a condenser, a long tube in the shape of a zigzag. As the warm gas passes through the condenser, it heats the surroundings and cools down. By the time it leaves the condenser, it has condensed back into a liquid.
25 Liquid leaving the condenser has to flow down a very narrow tube6
(a capillary tube). This prevents liquid from leaving the condenser too quickly, and keeps it at a high pressure.
►
As the liquid passes from the narrow capillary tube to the larger7
tubes of the evaporator, the pressure quickly drops. The liquid 30 turns to vapour, which expands and cools. The cold vapour absorbs heat from the fridge. It is then sucked back into the compressor and the process begins again.
The compressor is switched on and off by a thermostat, a device8
that regulates temperature, so that the food is not over-frozen.
Source: 'Inside out: Fridge', Education Guardian
Language study Principles and laws
Study these extracts from the text above. What kind of statements are they?
1If a liquid is heated, it changes to a gas or vapour.
2If a gas is allowed to expand, it cools down.
3If a gas is compressed, it heats up.
Each consists of an action followed by a result. For example:
ActionResult
a liquid is heatedit changes to a gas or vapour
These statements are principles. They describe things in science and engineering which are always true. The action is always followed by the same result.
Principles have this form:
If/When (action-present tense), (result-present tense).
Link each action in column A with a result from column B to describe an important engineering principle.
A ActionB Result
1a liquid is heatedait heats up
2a gas is cooledbthere is an equal and opposite
3a gas expandsreaction
4a gas is compressedcit changes to a gas
5a force is applied to a bodydit extends in proportion to the force
6a current passes through a wireeit is transmitted equally throughout
7a wire cuts a magnetic fieldthe fluid
8pressure is applied to the surfacefa current is induced in the wire
of an enclosed fluidgit cools down
9a force is applied to a spring fixedhit sets up a magnetic field around the
at one endwire
iit changes to a liquid
Word Study Verbs and related nouns
Each of the verbs in column A has a related noun ending in -er or -or in column B. Complete the blanks. You have studied these words in this and earlier units. Use a dictionary to check any spellings which you are not certain about.
A VerbsB Nouns
For example:
refrigeraterefrigerator
1condense
2evaporator
3compress
4resist
5
5generate
6conduct
8
7radiate 10 control
Writing Describing a process, 2: location Study this diagram. It describes the refrigeration process.
In Unit 13 we learnt that when we write about a process, we have to:
1Sequence the stages
2Locate the stages
3Describe what happens at each stage
4Explain what happens at each stage
For example:
sequence locationdescription
The refrigeration process begins in the compressor. This compresses the gas
explanation so that it heats up.
In this unit we will study ways to locate the stages.
Put these stages in the refrigeration process in the correct sequence with the help of the diagram above. The first one has been done for you.
aThe liquid enters the evaporator.
b The gas condenses back into a liquid.
c The vapour is sucked back into the compressor.
d The gas is compressed.I
e The liquid turns into a vapour.
fThe gas passes through the condenser.
gThe liquid passes through a capillary tube.
h The high pressure is maintained.
There are two ways to locate a stage in a process.
1Using a preposition + noun phrase. For example:
The liquid turns to vapour in the evaporator.
The gas cools down in the condenser.
2Using a where-cVause. a relative clause with where rather than which or
who. to link a stage, its location and whathappens there.For example:
The warm gas passes through the condenser,where it heatsthe
surroundings and cools down.
The refrigerant circulates around the fridge, where it undergoes changes in pressure and temperature.
Complete each of these statements.
The gas passes through the compressor, where It passes through the condenser, where
The liquid passes through a capillary tube, where The liquid enters the evaporator, where
The cold vapour is sucked back into the compressor, where
Add sequence expressions to your statements to show the correct order of events. For example:
First the gas passes through the condenser...
Make your statements into a paragraph adding extra information from the text in Task 2 if you wish. Then compare your paragraph with paragraphs 6. 7. and
8from the text.
Scales
Tuning-in
Complete this table of common quantities and forces to be measured in engineering, the units in which they are measured, and the instruments you use to measure them.
Quantity/ForceUnitInstrument
1 CurrentAmmeter
2NewtonForce gauge
3 Velocitykm/hr
4°CThermometer
5 ThicknessMicrometer
6OhmOhmmeter
7 Voltage
8 PressureManometer
How can you measure weight accurately? What alternatives are there? If you cannot name the instruments, draw them.
Task 3What do you think are the advantages of electronic scales over mechanical
scales?
Reading 1 Meaning from context
Task 4Read the first two paragraphs of this text and try to fill in the missing words.
More than one answer is possible for some of the blanks. Then check your answer to Task 3 using the completed text.
Electronic scales
para
l
The electronic kitchen scaletakes a larger load and is7
1accurate than its mechanical counterpart. Whereasa
1scale may have a capacity of about 3kg. broken 4
25g units, the electronic scale can Ia
load of*to 5kg broken into units of 5g or even 2g.
The scale Zby converting the load increase on its2
platform *weighing area into a weight reading
1the liquid crystal display (LCD). It is controlled ™a
microprocessor and can therefore lJ
from ounces to grams at the touch of a button. The compact internal components also make it small and lito store.
Reading 2 Comparing sources
When we read, we may wish to look at more than one source of information on a topic to:
1get extra information
2find a text we can understand
3check points where texts disagree
In the tasks which follow, we will compare information from a diagram and a text.
Study this diagram of electronic scales and complete the notes below.
1Load cell
between the platform and base
2Strain gauge
bends with the load cell, stretching the wires, voltage falls in proportion to load
3Circuit board
Converter function
Microprocessor
function
The electronic kitchen scale uses microchip technology. It is small, convenient to store, and more accurate than the traditional mechanical scale.
O
The load cell is an aluminium alloy beam. When a load is placed on the platform, it causes the beam to bend very slightly in the middle where the holes are drilled, producing strain.
The strain gauge consists of small wires through which a voltage flows. It is bonded to the load cell. When the load cell bends, the strain gauge bends with it. The heavier the load, the more it bends and the harder it is for the electricity to travel through the wires (for they are stretched), resulting in a lower voltage. The change in voltage is proportional to the load.
Strain gauge
Load cell
Scan this text to find information on the load cell, the strain gauge, and the circuit board. Note any information in the text which is new, i.e. additional or different to the information obtained from the diagram.
para
Electronic scales use a weighing device called a load cell3
underneath the platform. The load cell, an aluminium alloy beam, eliminates the need for springs, cogs, or other moving parts which can wear, break, or cause inaccuracy in mechanical scales.
5A strain gauge is bonded on the load cell. The strain gauge4
consists of a small piece of metal foil which detects any bending of the beam. A controlled input voltage is supplied to the strain gauge from a battery-powered circuit.
When a load is placed on the platform, it causes the load cell to5
10bend very slightly. This, in turn, causes a change in strain, which
triggers a change in the electrical resistance of the strain gauge.
As the resistance changes, so does the output voltage from the6
strain gauge. In short, the change in voltage across the strain gauge is proportional to the load on the platform.
15The voltage from the gauge is small and has to be amplified and7
then converted into a digital signal. This signal is fed to a specially programmed microprocessor, which converts it into a weight reading. This is displayed on the LCD. The display will automatically switch off a few minutes after weighing is finished,
20thereby saving battery power.
Source: 'Inside out: Electronic scales'. Education Guardian
Language study Cause and effect, 1
Study these actions. What is the relationship between them?
1A load is placed on the platform.
2The load cell bends very slightly.
3The strain gauge is stretched.
4The electrical resistance increases.
In each case, the first action is the cause and the second action is the effect. We can link a cause and effect like this:
1+2 A load is placed on the platform, which causes the load cell to betid very slightly.
3+4 The strain gauge is stretched, which causes the electrical resistance to increase.
In these examples, both the cause and the effect are clauses - they contain a subject and a verb. Study this example:
Cause:The strain gauge is stretched.
Effect:An increase in electrical resistance.
The effect is a noun phrase. We can link cause and effect like this:
The strain gauge is stretched, which causes an increase in electrical resistance.
In Unit 22 we will study other ways to link a cause and an effect.
The diagram below is a cause and effect chain which explains how a strain gauge works. Each arrow shows a cause and effect link. Match these actions with the correct boxes in the diagram.
aAn increase in resistance,
bA load is placed on the scale,
cA drop in voltage across the gauge,
dThe load cell bends very slightly,
eThey become longer and thinner,
fThe strain gauge conductors stretch,
gThe strain gauge bends.
765
Now practise linking each pair of actions, i.e. 1+2. 2+3. and so on.
Technical reading Strain gauges
Read the text below to find the answers to these questions.
1What principle do strain gauges operate on?
2Why is it an advantage to have a long length of conductor formed into many rows in a strain gauge?
3If you want to measure strain in a member, how do you position the strain gauge?
4Why is an amplifier necessary?
5Why is a dummy gauge included in the circuit?
6What is the function of VR2?
7Why would you adjust the output to exactly zero?
8In the circuit shown, how is the amplifier output displayed?
Strain gauges
Strain gauges measure the amount of strain in a member. They work on the principle that the electrical resistance of a wire changes as it is stretched, becoming longer and thinner. The more it is stretched, the greater its resistance. Mathematically, this is written
5as:
Resistance a *-en9th or R a
AreaA
By arranging the wire in tightly packed rows, quite long lengths can be fitted on to a small pad (Fig. 1). Modern strain gauges are made not of wire, but by etching a pattern into metal foil which is stuck to a polyester backing (Fig. 2).^
10 In use, a gauge is stuck on to the surface of the member being tested. Its active axis is fixed along the direction in which you want to measure the strain. Movements on the passive axis will have no real effect on it. The gauge must then be connected to an electronic circuit. Fig. 3 shows a block diagram of the complete circuit. The 15 resistance of the gauge is compared with the resistance of fixed value resistors in the circuit. Any differences in resistance are converted into voltage differences. These very small changes in voltage are amplified before being displayed.
Fig. 3 block diagram of the complete circuit
WheatstoneAmplifierDisplay
The final circuit, shown in Fig. 4, includes a dummy gauge. This 20 compensates for any changes in the resistance of the active gauge caused by temperature changes. The active and dummy gauges form part of the Wheatstone bridge. With no forces applied to the active gauge the output from this part of the circuit should be zero. When forces are applied, the resistance of the active gauge 25 changes so the output voltage to the amplifier changes. The
amplifier magnifies that change so that it can be clearly seen on the meter. The three variable resistors in the circuit each allow different adjustments to be made. VR1 allows you to 'balance' the bridge, getting the resistances exactly equal. VR2 allows you to adjust the 30 'gain' of the amplifier, in other words, how much the voltage is amplified. By adjusting VR3 the output can be adjusted to exactly zero before a load is applied to the member being tested.
In practice, strain gauges tend to be used in pairs or groups, often measuring the strain in various parts of a structure at the same 35 time. When used like this they are often linked to a computer rather than a series of display meters. The computer keeps a constant check on the outputs from each of the strain gauges, making sure that no part of the structure is being loaded beyond normal limits.
Portable generator
Tuning-in
Task 1Listthedifferentwaysinwhichelectricitycanbegenerated.
Reading Reading diagrams
Task 2Studythediagram below of a portable generator. Answer these questions
using the diagram and your own knowledge of engineering.
1What are its main parts?
2What does the engine run on?
3What are the four strokes called?
4What is the function of the crankshaft?
5What do both stator and rotor have?
6What is the difference between stator and rotor?
Read this text to check as many of the answers as you can. You will not find complete answers to all of the questions.
Portable generator
Although most electricity comes from power stations, power can also be generated by far smaller means. Nowadays, electricity generators can be small enough to hold in the hand.
Portable generators are made up of two main parts: an engine,
5which powers the equipment, and an alternator, which converts motion into electricity.
The engine shown (Fig. 1) runs on petrol. It is started by pulling a cord. This creates a spark inside which ignites the fuel mixture.
In a typical four-stroke engine, when the piston descends, the air 10 inlet valve opens and a mixture of air and petrol is sucked in through a carburettor.
The valve closes, the piston rises on the compression stroke and a spark within the upper chamber ignites the mixture. This mini¬explosion pushes the piston back down, and as it rises again the 15 fumes formed by the ignition are forced out through the exhaust valve.
This cycle is repeated many times per second. The moving piston makes the crankshaft rotate at great speed.
The crankshaft extends directly to an alternator, which consists of 20 two main sets of windings-coils of insulated copper wire wound closely around an iron core. One set, called stator windings, is in a fixed position and shaped like a broad ring. The other set, the armature windings, is wound on the rotor which is fixed to the rotating crankshaft. The rotor makes about 3,000 revolutions per 25 minute.
The rotor is magnetized and as it spins round, electricity is generated in the stator windings through the process of electromagnetic induction. The electric current is fed to the output terminals or sockets.
30 This type of generator can produce a 700 watt output, enough to operate lights, television, and some domestic appliances. Larger versions provide emergency power to hospitals and factories.
Source: Adapted from 'Inside out: Portable generator'. Education Guardian
Study this text on the four-stroke cycle. Then label each stroke correctly in Fig. 2 opposite.
In the four-stroke cycle, the piston descends on the intake stroke, during which the inlet valve is open. The piston ascends on the compression stroke with both valves closed and ignition takes place at the top of the stroke. The power or expansion stroke
5follows. The gas generated by the burning fuel expands rapidly, driving the piston down, both valves remaining closed. The cycle is completed by the exhaust stroke, as the piston ascends once more, forcing the products of combustion out through the exhaust valve. The cycle then repeats itself.
Fuel inlet valve
Carburettor
Language study Cause and effect, 2
Study these pairs of actions. What is the link between each pair?
1The gas expands.
2This drives the piston down.
3The piston ascends.
4This forces the products of combustion out.
There are two links between the actions:
They happen at the same time. We can show this using As (see Unit 8).
1+2As the gas expands, it drives the piston down.
3+4As the piston ascends, it forces the products of combustion out.
One is a cause and the other an effect.
1Cause: The gas expands.
2Effect:This drives the piston down.
3Cause: The piston ascends.
4Effect:This forces the products of combustion out.
We can show both the time link and the cause and effect link like this:
1+2The gas expands, driving the piston down.
3+4The piston ascends, forcing the products of combustion out.
CauseEffect
1The piston moves down the cylinder.This creates a partial vacuum.
2The piston creates a vacuum.This draws in fuel from the
carburettor.
3The piston moves up the cylinder.This compresses the mixture.
4The gas expands quickly.This pushes the piston down.
5The piston moves up and down.This rotates the crankshaft.
6The crankshaft spins round.This turns the rotor at
3,000 rpm.
7The armature of the alternator rotates.This induces a current in the
stator windings.
8The alternator runs at a steady 3.000 rpm.This generates around 700 watts.
Word Study Verbs with -ize/-ise
Study this statement:
The rotor is magnetized.
What does it mean? Can you say it another way? We can rewrite this statement
as:
The rotor is made magnetic.
Verbs ending in -ize/-ise have a range of meanings with the general sense of make + adjective.
Task 6Rewrite these sentences replacing the phrases in italics with appropriate
-ize/-ise verbs.
1Some cars are fitted with a security device which makes the engine immobile.
2In areas where the power supply fluctuates, for sensitive equipment a device to make the voltage stable is required.
3Manufacturers seek to keep costs to a minimum and profits to a maximum.
4Most companies have installed computers to control their production line.
5Companies may make their operation more rational by reducing the variety of products they make.
Writing Describing a process, 3: sequence and location
Task 7Fig.3 opposite shows the distribution of power from power station to
consumer. The statements which follow describe the distribution. Put the statements in the correct order with the help of the diagram. The first one has been done for you.
aIt is fed to substations.
b It is stepped up by a transformer to high voltages for long-distance distribution.
cIt is distributed via the grid to supply points.
dIt is distributed to the domestic consumer.
eElectricity is generated at the power stationat 2 5 kV. I
fIt passes via the switching compound to thegrid.
g It is distributed via overhead or underground cables to intermediate substations.
Mark the sequence of stages using appropriate sequence words where you think this is helpful. Add the following information to your statements and make them into a text.
1At the main grid supply points, power is stepped down to 3 3 kV for distribution to heavy industry.
2At intermediate substations, power is reduced to 11 kV for light industry.
3At the distribution substations, power is stepped down to 415 V, 3-phase, and 240 V, 1-phase.
Technical reading Wave power
Task 9Thetwo texts which follow describe two plants for generating electricity from
wave power. Note the similarities and differences between the plants.
Wave power
Electricity j
When the wave recedes, air is drawn in through the turbine, but because of their special design the rotors keep turning in the same direction.
Shut-off valve - this isolates the water column and air chamber from the turbine and generator when the plant is switched off.„
Shut-off valve
This prototype wave-power plant on the Scottish island of Islay was constructed by building a concrete water column across a natural gully on the shoreline. Waves flowing in and out of the gully cause water in the column to move up and down. As the water moves up
5it compresses the air above and forces it through a wide tube at the back of the water column. As the water moves down, air is drawn into the water column.
The moving air passes through a turbine coupled to a generator. Both the turbine and generator are unusual. The turbine is a Wells 10 turbine (named after its inventor) which keeps turning in one
direction even though the air flow is constantly changing direction. It has two rotors, each with four blades.
The generator is a wound rotor induction motor, which acts as a generator when it is turning at speeds greater than 1,500 rpm.
15 Below that speed it operates as a motor and takes power from the grid. This motor/generator is used because the turbine takes some time to build up to a speed where it can generate electricity. When the turbine slows down due to a lull in wave activity, the generator becomes an electric motor and keeps the turbine running at a 20 minimum speed so that it is ready to accept the power from the next batch of waves.
The plant is controlled by a computer. It includes a PLC (programmable logic controller), which monitors the operation of the motor/generator and the amount of electricity going to or being
►
25 taken from the grid. There is also testing equipment to monitor how much electricity the plant is producing and the efficiency of the water column, turbine, and generator.
This experimental plant generates 150 kW. Plans have been approved for the construction of a 1 MW scheme.
Source: Adapted from 'Inside out: Wave power', Education Guardian
Concrete
and
sediment
ballast
Air forced up or sucked down depending on wave action
Seabed
Waves
The Art Osprey makes use of a wave's vertical energy: although waves move through the sea, the water particles' main movement is up and down.
Air vented to atmosphere at top of control stack
The Wells Turbine spins in the same direction despite the air flow reversing
level
Wave
Stone
protection
High hopes for wave power project
The world's first power station in the open sea is to be stationed off Dounreay in Scotland. The machine, called Osprey (Ocean Swell- Powered Renewable Energy), will stand in 18 metres of water a kilometre out and not only harvest the larger waves, which produce
5higher outputs, but also gain power with waves from any direction.
The device is known as an oscillating water column. As a wave rises, air is pushed through an air turbine and sucked back again as the wave falls. The turbine has been designed by Professor Alan Wells, of Queen's University, Belfast. It will generate 2 megawatts.
10There is potential for 300 Ospreys in Scottish waters which could provide 10 per cent of the country's peak electricity demand.
Road breaker
Tuning-in
Task 1Inyourgroup,makealistofanydevicesyouknowwhichusecompressedair.
Task 2Listanyadvantagescompressed-airdeviceshavecomparedwithelectrical
devices.
Reading
Task 3Readthe text below and the diagram opposite to check your answers to
Tasks 1 and 2.
Road breaker
Air has considerable power when it is compressed. Compressed air is used to drive all sorts of machines, from construction tools to paint sprayers.
Pneumatic or air-driven machines all make use of the force exerted
5by air molecules striking a surface. Compressed air exerts a greater pressure than the air on the other side of the surface, which is at atmospheric pressure. The difference in pressure drives the machine.
Pneumatic drills, or road breakers, are powered by compressed air
10produced by a compressor. Compressed-air power is cheap and safe. An air device does not risk creating sparks in an explosive atmosphere and can be used under wet conditions without danger of electric shocks. Compressed air is therefore the only type of power used in some mining or construction operations.
15 A pneumatic drill works a little like an automatic hammer. The compressor pumps the compressed air to the drill through a hose. There it drives a piston up and down. The movement of the piston delivers repeated blows to the chisel that hammers into the road surface.
20 Pressing the throttle, or control lever, downwards releases the control valve. This allows compressed air to enter the drill. The air passes through the valve and down a chamber called a return chamber to the underside of the piston. The pressure forces the piston to rise up the cylinder. As the piston rises, it covers the 25 exhaust, preventing the air from escaping. At the same time, the rising piston starts to compress the air trapped above it.
►
The increase in pressure forces the operating valve to open, admitting air to the top of the chamber and closing off air in the return chamber. As the pressure in the chamber increases to 620 30 kPa (90 psi), it forces the piston to strike the chisel. When the piston passes the exhaust, the air is released into the atmosphere and the valve closes. This opens the return chamber again, which allows the air to pass to the underside of the piston and restarts the cycle.
Source: 'Inside out: Road breaker', Education Guardian
Put the following steps in the operation of the pneumatic drill in the correct sequence with the help of the diagrams. The first one has been done for you as an example.
a The air passes through the valve and down the vertical air port, bThis allows compressed air into the drill,
cIt forces the piston up the cylinder.
d Pressing the control lever opens the control valve.1
eThis admits compressed air to the top of the cylinder,
fThe operating valve closes and the cycle starts again,
gThe pressure of air on top of the piston opens the operating valve,
hAs the piston passes the exhaust, the air leaves the cylinder,
iThe air expands, forcing the piston down.
Now label these components of the drill.
A
B
C
D
E
F
G
Language study Allow and prevent links
Task 6
Fig. 4 shows the most basic components of a pneumatic system, a three-port valve ( 3PV) and a single acting cylinder (SAC). The steps below describe the operation of the system when the push button of the valve is pressed. The first step is a. Put the others in the correct sequence.
Air flow
Fig. 4
a The push button is pressed.1
b Port 3 is blocked, c Ports 1 and 2 are connected, d The piston compresses the spring, e The spool is pushed down, f Air cannot escape.
g Compressed air flows through the valve to the SAC. h The compressed air pushes the piston along.
Study these steps from the operation of the valve.
3Ports 1 and 2 are connected.
4Compressed air flows through the valve to the SAC.
5Port 3 is blocked.
6Air cannot escape.
What is the connection between Step 3 and Step 4?
What is the connection between Step 5 and Step 6?
Step 3 allows Step 4 to happen. We can link the steps in three ways like this:
a Ports I and 2 are connected. This allows compressed air to flow through the valve to the SAC. b Ports 1 and 2 are connected. This permits compressed air to flow through the valve to the SAC. c Ports I and 2 are connected. This lets compressed air flow through the valve to the SAC.
Step 5 prevents something. We can link steps 5 and 6 like this:
Port 3 is blocked. This prevents air from escaping.
Complete the blanks in this description of the operation of the valve with the button pressed.
the push button is pressed, the spool is pushed down.
“ports 1 and 2. This
the valve to the SAC. Port 3 is blocked which t The compressed air pushes the piston along."
compressed air to flow throughair from escaping.
the spring.
Fig. 5 shows the system with the push button of the valve released.
Not pressed
Movement
From cylinder
Air flow
Fig. 5
These are the steps in the operation. Fill in the blanks in the steps, aThe push button is released.
bThe valve spring !up the spool.
cPorts 2 and 3 are I.
d Air from the SAC escapes through
4
e Port 1 is.
f Compressed air cannot enter the
g The cylinder spring pushes theback in.
Task 9Nowwriteyourowndescriptionofhowthesystemoperateswhenthepush
button is released.
Writing Explaining an operation
These steps explain the operation of a road breaker. Link each set of steps into a sentence using the words or phrases provided. Omit unnecessary words and make any other changes required.
1Pressing ...alio wing Press the control lever.
This opens the control valve.
This allows compressed air to enter the drill.
2...forcing...
The air passes through the valve and down the return chamber to the underside of the piston.
The pressure forces the piston to rise up the cylinder.
3As... which The piston rises.
The piston covers the exhaust.
This prevents the air from escaping.
4At the same time ... which
The rising piston starts to compress the air.
The air is trapped above it.
5... admitting... and closing ...
The increase in pressure forces the operating valve to open.
This admits air to the top of the chamber.
This closes off air in the return chamber.
6As...
The pressure in the chamber increases to 620 kPa.
The pressure forces the piston to strike the chisel.
7When ... and...
The piston passes the exhaust.
The air is released into the atmosphere.
The valve closes.
8... which ... and...
This opens the return chamber again.
This allows the air to pass to the underside of the piston.
This restarts the cycle.
Technical reading Air skates
Skim the following extract from a company’s sales literature to identify the paragraphs which describe:
a what an air skate consists of bthe advantages of air skates
c the differences between systems d sizes. loads, and lift height eair pressure required
AIR FILM MATERIAL HANDLING SYSTEMS
para
Material handling systems ? using the air film principle are also known as Air Skates.
The handling of light to very 2 heavy objects using air film to float the load is easy and very economical. A weight of 1,000 kg requires a pulling force of only 1 kg.
An air film skate is composed 3 of a supporting backplate with an O-shaped flexible cushion or element which is inflated by means of compressed air. The escaping air forms a thin film (approx. 0.02 mm) between the element and floor.
Three or more air skates4
combine to ensure that the load starts floating and has the ability for omni-directional movement. The load to be moved is lifted only a few centimetres and as a result of the low pressure (1-2 bar) no clouds of dust are formed and the floor cannot be damaged.
The dimensions of the air5
skates are very small. Four
skates of 30 cm x 30 cm can lift 2,000 kg. The lift height is approx. 1.5 cm. Four skates of 50 x 50 cm can lift 10,000 kg. The lift height is 1.5 cm. Combinations of air skates providing a lift capacity up to 100 tonnes are not exceptional.
When an object is moved 6 using an air film system, a regulator unit correctly distributes the compressed air to the air skates and can compensate for out-of-balance loads. In this way the load is lifted vertically and the load can be moved effortlessly and positioned accurately.
The air skates operate on air 7 volume supplied by a compressor or pneumatic supply system working at a pressure of 5-10 bar (500-1000 kPa).
The air skates may be placed 8 separately under the load which is easily accomplished due to the low height. Two basic systems are available, each with its own characteristics. The external differences in operation of the
Air filmSupportingElement
Supporting
backplate
SYSTEM B
j^
Air film !SupportingElement
Supporting
backplate
The specific application for $ each customer determines the choice of the system, the operating pressure, the element material, etc. Flence, it is necessary to obtain accurate details to get optimal effect from the system.
The use of air film handling techniques is not always considered. Customers who have used the method have been amply rewarded with the following advantages:
-Very efficient
-Limited investment
-Reliable
-Minimal maintenance
-Ergonomic
-Can be used with equal success indoors and outdoors
-Long working life
-Quickly fitted
10
1IIow many skates do you need to lift two tonnes?
2What pressure of air must the compressor supply?
3What depth is the air film between skate and floor?
4What force is required to pull a load of one tonne?
5Can the system be used outdoors?
6How high, typically, is the load lifted?
7What does the regulator unit do?
8How is the air film formed?
Speaking practice
Work in pairs. A and B. You each have a diagram to illustrate the symbols of the International Standards Organisation for pneumatic components. Not all of the symbols are labelled in your diagrams. Your task is to complete the labelling of your diagrams with the help of your partner.
Remember, you must not show your diagrams to each other.
Student A: Your diagram is on page 1 79.
Student B: Your diagram is on page 182.
Disc brakes
Disc brakes
The disc is fixed to the wheel hub and bearing assembly so that it can rotate freely. The caliper fits over the disc and is mounted to the suspension system. Fixed within the caliper are the hydraulic cylinder and brake pads, which only come in contact with the disc when the brake pedal is pressed.
Disc (attached to wheel hub)
Mounting bracket (to suspension)
Hydraulic fluid
Hydraulic cylinder
Caliper
Hole for ventilation
Fig. 7
Tuning-in
Task 1Discuss these questions in your group.
1What forms of transport use brakes?
2What different kinds of brakes are there?
3How do car brakes operate?
Reading Combining skills
Although we have examined the skills separately, in practice we use a mix of skills when we read, depending on our purpose and the level of the text. In the tasks which follow, we will practise skimming, predicting, and scanning.
Study the diagram on page 106 to get a general idea of what the text in Task 5 below contains.
Skim the text below to find which paragraphs contain information on these aspects of disc brakes.
InformationParagraph
a The hydraulics of braking b Principles on which disc brakes operate c The operation of the caliper system d Consequences of heat generated in braking e Energy conversion in braking
Using your answers to Task 3. predict which paragraphs will have the answers to these questions.
What is the function of the calipers?
Why do car wheels have vent holes?
Where are the brakes mounted?
What type of material are brake pads made from?
What is the difference between the master and the wheel cylinder?
What kind of energy does a moving vehicle have?
Scan the text to check your predictions in Task 4. and find the answers to the questions.
Disc brakes
para
Disc brakes are used on cars and motorcycles. They work by7
using friction and hydraulic power. The friction is generated when the brakes - stationary pads mounted to the suspension system - rub against metal discs turning with the wheels.
5The pads are covered with a high-friction material. The resistance2
of the pads against the rotating discs converts the energy of the moving vehicle (kinetic energy) into heat energy in the brakes. As kinetic energy is lost, the car slows down.
This method of braking produces a great deal of heat, so brakes3
10 have to be made from a heat-resistant material, like asbestos. The intense heat also explains why car wheels need vent-holes around the centre: when the car is moving the slots ensure a flow of air over the brakes, helping to cool them down.
When the driver presses the brake pedal, it pushes down the4
15piston in the master cylinder, so creating pressure in the fluid. The
fluid is incompressible. The pressure is transmitted to the wheel cylinder which forces the brake pads against the revolving disc. The master cylinder has a smaller diameter than the wheel cylinder. *■
Hence, a relatively small force applied on the pedal produces a 20 large force on the brake pads.
The brake pads are held in a clamping device called a caliper.5
The caliper system ensures that one brake pad is pushed against the inner surface of the disc while, simultaneously, the other pad is pulled against the outer surface. This gives twice the braking 25 power. The action is like squeezing something between forefinger and thumb.
Source: Adapted from 'Inside out: Disc brakes', Education Guardian
Language study Verbs with up and down
In this book, you have studied a number of verbs followed by up or down. For example:
1Transformers step up the voltage from 25 kV to 400 kV for transmission.
2JJse as little force as possible to break down a machine into its components.
Fill in the blanks in these sentences with either up or down. You have studied these verbs in similar contexts.
1As the car slows, kinetic energy is converted to heat.
2An installation technician connectscables and switchgear.
3A plastic pellet in a washing machine door heatsandpushesthe lock
into position.
4Car wheels are ventilated to coolthe brake discs.
5Transformers are used on construction sites to stepthe mains voltage
to avoid accidents with hand tools.
6Students in David’s maths class were splitinto three groups.
7One of Lucy's friends camewith the name Swingex-L.
8Students should keepwith subjects like maths and physics.
Word Study Verbs + -en
Can you rewrite this sentence replacing the verb in italics with another verb or phrase of similar meaning?
The caliper system ensures that the disc is gripped on both sides.
Here is one way it can be done.
The caliper system makes sure that the disc is gripped on both sides.
Verbs beginning or ending with en often have the meaning of become/make + adjective.
Replace the words in italics in the following sentences with a suitable en verb from this list.
ensureenlargehardenlengthenlessenlighten
loosenroughensharpenshortensoftenstrengthen
tightentoughenweakenwiden
1Steel rods are used to make concrete beams stronger.
2A torque wrench is used to make cylinder head bolts tight.
3Thermoplastics can be made soft by heating them.
4After thermosetting plastics become hard, they cannot be softened again.
5A reamer is a tool used to make a hole larger.
6Corrosion makes structures weak.
7Compressive forces will make a beam shorten tensile forces will make it longer.
8Carbon fibre frames make racing bicycles lighter and stronger.
9Oil can be used to make tight bolts loose.
10Carbon steels are made tough by heating and quenching.
Writing Explaining an operation
Link the statements below to explain the operation of a hydraulic jack. Use the diagram to help you.
Fig. 2
1The jack is placed under the car.
The lever is moved up and down.
2The movement is converted into a reciprocating motion.
The motion slides the piston back and forwards.
3Each movement of the piston pumps a small amount of fluid.
The fluid is pumped from the reservoir through the one-way valve into the main cylinder.
4This action gradually raises the jack.
The car is lifted from the ground.
5The car is lowered.
This is done by releasing the one-way valve.
6This allows the weight of the car to force fluid from the cylinder back into the reservoir.
The car slowly descends.
Divide your explanation into two paragraphs. Include a reference to Fig. 2.
Technical reading Water-based hydraulics
Find the answers to these questions in the text which follows.
1Why is oil superior to water as a hydraulic fluid?
2Why were water-containing fluids developed?
3How can the wear of metal parts be reduced inwater-based hydraulic
equipment?
4What materials should be used where possible for component surfaces in sliding contact?
5Why is sealing difficult with water-containingfluids?
6Why is filtration of sea-water advised?
Hydraulic power was first based on water. The development of the
oilindustry meant the ready availability of power transmission fluids with improved characteristics compared to water. Oil has better lubrication ability and increased viscosity which allowed
5much higher contact loads to be achieved in the machinery as well as lower leakage rates.
Water-containing hydraulic fluids have evolved since the late 1940s in response to the fire ignition risks of oil systems. The safety concerns of the steel, mining, and offshore users have played a
10major part here.
Initially, these fluids were 40/60 water/oil mixture but these have been progressively modified into the 95/5 systems available today.
High water-based fluids have to contain additives so that internal components relying on metal upon metal contact can operate 15 without excessive wear.
►
Water-powered machinery with its inherently non-polluting media is a very attractive prospect especially because of environmental concerns about the consequences of oil leakages and the disposal of oil residues. In order to engineer effectively for water power, the 20 following points need to be considered:
Water lacks boundary lubrication. When oil is used as a hydraulic fluid, it provides lubrication and reduces corrosion. Machinery can operate with some rubbing contact without excessive wear. When water is used, component surfaces in 25sliding contact should be made of corrosion-resistant non-
metallic materials such as ceramics or polymers.
•Water has low viscosity. Sealing is more difficult.
Corrosion. Metals are significantly affected by water. The use of corrosion-preventing additives or non-corrosive materials is 30advised.
Contamination. Using 'raw water' such as sea-water which contains significant amounts of particles and salinity can cause wear and corrosion. Filtration may be necessary.
Source: Adapted from P. Tweedale, 'Beating the fire risk with Water Based Hydraulics', Professional Engineering
Staff engineer
Tuning-in
What do these acronyms used in engineering mean?
1CAD
2CAM
3CIM
4IT
5MRP
6JIT
7PC
8PLC
Now read this text to check your answers.
Acronyms and concepts in engineering and process control
The IT industry's talent for reducing everything to alphabet soup is only equalled by manufacturing, which you can almost discuss without using any real words at all. But it is the only way to avoid jaw-breaking terminology like 'supervisory control and data
5acquisition'.
CAD/CAM (Computer Aided Design/Manufacturing): Use of PCs and workstation applications to automate the design and manufacturing process. Designers use CAD/CAM to prototype designs without redrawing them by hand. Popular PC packages ^
10 include AutoCad, VersaCad and RoboCad. Workstation systems from IBM, DEC, HP, Intergraph, and Computervision. CAM helps in preparation of programs to control robotic and manufacturing equipment.
MRP (Materials Requirement Planning): Breaks down product into 15 list of components needed to build it. Helps manufacturers plan what raw materials they need in stock.
MRP II (Manufacturing Resources Planning): Includes the concept of MRP, but also includes aspects of order processing, distribution, and processing time.
20 JIT (Just-in-Time Manufacturing): Carries on where MRP and MRP
IIleave off. Means you only make the products you have to in order to satisfy market needs. Process extends from design and MRP to distribution of finished products. JIT-embracing manufacturers try not to hold any stock, either of raw materials or finished products,
25 but make products just in time to fill customer requirements.
CAPP (Computer Aided Process Planning): Systems work out how best to route the production of items that need to go through several different processes.
Scada (Supervisory Control and Data Acquisition): Systems collect 30 data, monitor manufacturing processes, and produce management reports on the effectiveness of manufacturing processes. Are often PC systems and use graphical displays to alert shop-floor staff to problems in a process.
Concurrent Engineering: Concept of developing different aspects 35 of a product concurrently. Products' design, manufacturing, and documentation are integrated from the start. If design of a new product is changed, this is automatically passed through to the next stages of production planning. Intended to replace traditional linear approach, where each stage has to wait for previous stage to 40 be completed. Aim is to reduce time-lag between design and finished product.
EDM (Engineering Data Management): Part of a move towards Concurrent Engineering and CIM (Computer Integrated Manufacturing). Central database stores all documentation related 45 to particular products. Product manuals and technical data can be generated from original design information, and engineers should be able to reuse design data from previous projects. One company has halved time between introducing a change request at the design stage and producing complete plans.
50 PLC (Programmable Logic Control): Small, rugged controllers are programmed via a programming panel to do a particular job in a process. Once programmed, the controllers will do the same job as a full computer system, but at a lower cost. They can be reprogrammed easily to do different jobs.
Source: Adapted from J. Massey/On the Make', Personal Computer Magazine
Task 31Whodo you think this text was written for?
2Some words are missing from the text—the subject of some sentences, articles (the, a, an). Why?
3What are AutoCad, VersaCad, and RoboCad?
4What is the difference between MRP and MRP II?
5What do you think the advantages of JIT are?
6What is the aim of Concurrent Engineering?
Listening
You are going to hear an interview with Edward, a staff engineer. The interview contains some of the acronyms listed in Task 1.
Task 4E3Listen to the interview to find these basic facts about Edward.
1What section does Edward lead?
2What does his company do?
3How long has Edward worked for the company?
4How many people started the company?
5What is the company’s turnover?
6Why did he become an engineer?
7What qualification does he have?
Task 5E3Fillin as many spaces as you can in this extract where Edward is describing
CIM. Now listen to the interview again to check your answers and to complete any remaining gaps.
Yes. There’s a 'databaseinthemasterinthe
factory. It holds specifications for every product the factory makes. Bar
coderead the boards coming down the production
and pass the information to the .Therobot
says, ‘OK, I’m going to build product A’, so it pulls the CAD6 from the database, and builds that product. When it’s finished, it
the controller and passes on to the next *tobe
assembled.
In this book, you have studied a number of verbs followed by on or off. For example:
1JIT carries on where MRP and MRP 11 leave off.
2When the robot has finished, it informs the controller and passes on to the next product.
Fill in the blanks in these sentences with either on or off. You have studied these verbs in similar contexts.
1Failure means that expensive development costs must be writtenwith
no result.
2The alarm goesif a window is broken.
3When the water is hot. the control unit movestothenext stage of the
washing programme.
4Components which relymetaluponmetal contact require
lubrication.
5A thermostat causes the gas control valve to shutwhenthe room
temperature is correct.
6Feedback is used to checkwaterlevel,temperature,anddrum speeds.
7A car thief would setthe alarm.
8If a system is needed urgently, there is no question of knockingat the
usual time.
9Power may come from a small turbine engine, runningaclean fuel
like natural gas.
10 The accident occurred after the plane took
1How is the grass cut?
2How is the height of the cut adjusted?
3What is the purpose of the fan?
4How do the cuttings enter the grass box?
5How is power provided?
6How is the motor protected from grass intake?
7What is the function of the hood?
Task 2Analyse the functions of a lawn-mower by completing this ‘W'hy and How
diagram using the labels provided below.
WhyHow
► ■<
Fig. 2 Functional Analysis System Technique (FAST) diagram
arotate blade
btransport cuttings
cstore cuttings
duse spacers
ebring grass upright
fachieve air-flow
gprovide motor
hposition blade height
FAST, a versatile design tool
Before you read the text, think about the answers to these questions:
1Why do products have a finite life?
2How can too little quality ruin a producer?
3What does a customer require of any product?
Now read the text to check your answers and to find out the answers to these questions.
4What is a ‘window of opportunity'?
5What is FAST?
6What does it allow the designer to do?
7How can a design team use FAST to put value into a design?
FAST, a versatile design tool
The task of the engineer is to produce the correct product at the correct cost at the correct time. If a product misses its window of opportunity, the manufacturer can lose up to 33% of the life cycle profits. Lost sales are never made up as changes in the market
5place and in competitors' equipment mean that any product has a finite life.
The correct product is one which will satisfy the customer's requirements: functionality, quality, affordability, and availability. It must also satisfy the producer's requirements: low manufacturing 10 costs, simple quality control, and an identified marketing opportunity. Quality is important to both customer and manufacturer. Too much will ruin the producer, too little will alienate the customer and may also ruin the producer if faulty goods have to be recalled.
15 The designer's goal is to get it right first time. To do this a design process must be used which is effective at producing a good design. An important tool in the design process is the Functional Analysis System Technique (FAST) diagram. This enables the designer to understand the functional relationships of the system 20 being designed. The example illustrated (Fig. 2) shows the technique applied to the design of a lawn-mower.
The customer's requirement Trim lawn' appears in the box to the right of the diagram. Reading from the left, one can ask the question 'Why' of any of the statements contained in the other 25 boxes, and the answers will all lead to the customer's requirement. Starting from the right and asking the question 'How' establishes the reason for the function described.
FAST has many uses-for example, to analyse a competitor's equipment. This tool also enables a design team to put value into a 30 design. The process usually involves combining a number of functions into single parts, thus reducing the number of parts and saving cost in both materials and labour.
Source: Adapted from J. Fox, 'Design tools for speed and quality', Professional Engineering
Reading 2 Grammar links, 2
Study this paragraph from the text. Some phrases have been printed in bold. Answer the questions in italics which follow them.
The designer’s goal is to get it right first time. To do this [To do what?] a design process must be used which is effective at producing a good design. An important tool in the design process is the Functional Analysis System Technique (FAST) diagram. This [ What?] enables the designer to understand the functional relationships of the system being designed. The example shows the technique f Which technique?] applied to the design of a lawn mower.
In Units 5 and 9 we studied how texts are held together by grammar links and meaning links. The text above contains some common grammar links. Such links may cause problems for the reader who reads sentence by sentence because words seem to disappear or change. For example:
1To do this a design process must be used means
To get it right first time, a design process must be used
2This enables the designer to understand means
The FAST diagram enables the designer to understand
3The example shows the technique applied to the design of a lawn-mower means
The example shows the Functional Analysis System Technique
applied to the design of a lawn-mower.
This text has more examples of the links studied here and in earlier units. Answer the questions in the text.
On most mowers, a motor with a power of around 1 kW is used to drive the cutter and fan at over 6,000 revolutions per minute (about the same I&wk' what?] as a fast-revving car). The motor is usually electric but some types [Of what?] use petrol engines. The fan sucks air in through two intakes, one in front of the mower and one behind in the grass box. These currents [Of what?] flow past the motor, helping to keep it [What?] cool, before being forced under the machine. This | What?] supports its f What's?] weight.
Language study Describing functions
To analyse the functions of a machine, we need to be able to answer ‘How’ and ‘Why’ questions. We have studied most of these methods in previous units. We will revise them here and introduce some new methods.
1How questions
Answer this question about the lawn-mower shown in Task 1.
How are the clippings stored?
We can answer ‘How’ questions like this:
1With by + -ing. For example:
The clippings are stored by providing a grass box.
2With i/s«f + to verb or used + for -ing when the instrument is given. For example:
A grass box is used to store the clippings.
A grass box is used for storing the clippings.
Why questions
Answer this question about the lawn-mower.
Why is the impeller rotated?
We can answer ‘Why’ questions like this:
1With to + verb
The impeller is rotated to achieve air-flow.
2With so that + clause
The impeller is rotated so that air-flow can be achieved.
Explain these functions of the lawn-mower.
How are the cuttings transported?
How is air-flow achieved?
How is the blade height positioned?
How is horizontal velocity provided to the blade?
How is the grass impacted with a sharp edge?
Why is a grass box provided?
Why is the grass brought upright?
Why are spacers used?
Why is air-tlow achieved?
Why is a motor provided?
Word study Noun + noun, 2: function
Some noun + noun compounds in engineering contain a noun formed from a verb. You studied such nouns in Unit 1 5. For example:
VerbNounCompound noun
exchangeexchangerheat exchanger
Often these compounds explain the function of the object. For example:
A heat exchanger is used to exchange heat.
A heat exchanger is for exchanging heat.
Explain the function of these objects:
shock absorber signal generator speed governor battery charger pressure regulator circuit breaker hardness tester fuse holder engine immobilizer temperature sensor
What are the names of these objects? Check the spelling in your dictionary, a device used to:
1reduce the speed (of a motor)
2indicate the level of oil (in a gear box)
3grind the surface (of a metal plate)
4inject fuel (into petrol or diesel engines)
5filter oil (for an engine)
6cut wires
7sense moisture (in an environment)
8count binary (numbers)
9compress air
10 convert digital (signals) to analogue (signals)
Writing Description and explanation
You are going to write a description of a hovermower and an explanation of how it works.
The description will answer these questions:
1W'hat is the hovermower for?
2What are its main components?
3How are they connected?
The explanation will answer this question:
4How does it work?
Separate these sentences into those which describe and those which explain.
1A hovermower is for cutting grass.
2When the motor is turned on. air is sucked in by the impeller fan.
3There are four main components: an electric motor, a fan. a cutting blade, and a grass box.
4Pressure under the hood rises, which causes the mower to lift on a cushion of air.
5Some air escapes around the hood, which stabilizes the air pressure.
6The fan is attached to the motor.
7The cutting blade is fixed below the fan.
8After the blades cut the grass, the cuttings are sucked into the grass box by the flow of air to the impeller fan.
9The whole assembly is covered by a hood.
10 The grass box is situated behind the motor.
Form the descriptive sentences into one paragraph and the explanatory sentences into a second paragraph. Give your text a title.
Speaking practice Explaining Junction
Work in pairs, A and B.
Student A: Use the diagram in Task 2 to ask ‘How’ questions of your partner like this: How docs the mower trim the lawn? Answer any questions your partner asks with the help of the diagram.
Student B: Use the diagram in Task 2 to ask ‘Why’ questions of your partner like this: Why is a grass box provided? Answer any questions your partner asks with the help of the diagram.
Corrosion
Scanning electron micrograph of a flake of rusty bodywork from a Ford Cortina car, showing a crystalline area of rust.
Tuning-in
Study these titles of recent news items. What do you think the stories are about? Compare your predictions with other people in your group.
1The crumbling monuments of Paris
2Engine bolt failure blamed for air disaster
Now scan the texts to check if your predictions were correct.
The crumbling monuments of Paris
L
E GRAND PALAIS, completed in 1900 and famous for shows that attract hundreds of thousands of visitors, needs £30 million in emergency restoration work. The metal frame of the palace's huge glass roof has rusted. Emergency repairs were made in the summer after iron bolts fell off but an architect's report has warned that a total collapse is possible.
An estimated £40 million is required to stop rust eating into the city's most visited monument, the futuristic Pompidou Centre, erected in 1977.
Source: Adapted from 'French art calls in the builders',
The Guardian
Engine bolt failure blamed for air disaster
EXPERTS have confirmed that the fatal crash of a cargo plane into an apartment block was caused by failure of a bolt securing one of the plane's massive engines to the wings. Weakened by corrosion, the bolt sheared after take-off, causing one engine to break loose ...
Now discuss these questions in your group:
1What problems are caused by corrosion?
2What if there was no corrosion?
Reading Skimming
Skim the following text to identify the paragraphs which contain:
a Conditions in which corrosion occurs b Need to consider corrosion in design c A definition of corrosion d Factors which limit corrosion e Effects of rust
Corrosion
para
A major consideration in engineering design is maintenance. One 7 of the commonest causes of failure in the longterm is corrosion.
This is any deterioration in the component's appearance or physical properties.
5Corrosion covers a number of processes whereby a metal2
changes state as a result of some form of interaction with its environment. It often occurs where water, either as a liquid or vapour in air of high humidity, is present.
In general, corrosion becomes worse when impurities are3
10present in damp conditions. It never starts inside a material, and there will always be surface evidence that indicates corrosion exists, although close examination may be needed.
A common example of corrosion is the rusting of steel where a4
conversion of metallic iron to a mixture of oxides and other 15compounds occurs. This not only changes the appearance of the
metal but also results in a decrease in its cross-section.
It is imperative that a design takes into account whether a5
material will be affected in a particular environment and, if corrosion is likely, at what rate.
20Many factors can intervene in a way to restrain its progress. An6
example is aluminium and its alloys which perform satisfactorily in many engineering and domestic applications when exposed to air and water. This is due to the rapid production of a tough adherent film of oxide which protects the metal from further attack so that 25corrosion halts.
Source: 'Types of corrosion, how it occurs and what to look for', Design Engineering
Answer these questions with the help of the text above.
1In corrosion, why do metals change state?
2Name two factors which encourage corrosion.
3Where can signs of corrosion always be found?
4What is rust?
5Why may rust be dangerous to a structure?
6What must designers consider regarding corrosion?
7Why does aluminium perform well when exposed to air and water?
Language study Cause and effect, 3
What connection can you see between the following?
corrosion
loss of strength
dampness
reduction in cross-section Put them in the correct order to show this connection.
Cause and effect links like these are common in engineering explanations. You studied them first in Unit 15. You can link a cause and effect when both are nouns or noun phrases, like this:
1If you want to put the cause first.
CauseEffect
Dampnessanisescorrosion
results in gives rise to brings about leads to
2If you want to put the effect first.
EffectCause
Corrosionis caused bydampness
results from is the result of is the effect of is brought about by is due to
Study these lists. A and B. Items in list A are causes of those in list B but the items are mixed up. Link the related items. For example:
reduction in cross-sectionloss of strength
AB
1reduction in cross-sectionacorrosion
2insulation breakdownbbearing failure
3overtighteningcexcessive heat
4overloading a circuitdshearing in metal
5carelessnesseloss of strength
6impuritiesfshearing in bolts
7lack of lubricationgblown fuses
8frictionhshort circuits
9repeated bendingiaccidents
10overrunning an electric motorjwear and tear in machinery
Now write sentences to show the link. For example:
Loss of strength results from reduction in cross-section.
Speaking practice Exchanging information
Task 6Workinpairs.AandB.
Student A: Your information is on page 179.
Student B: Your information is on page 183.
Your partner has some information about two of the types of corrosion on the
following list. Find out what they are and obtain information from him or her
to complete as much as you can of the table below.
Types of corrosion
Common forms of corrosion are:
general or surface corrosion
•pitting
•galvanic or bimetallic corrosion intergranular corrosion exfoliate demetallification
•stress corrosion fretting corrosion crevice corrosion microbiological corrosion
Type
Where does it occur?
What happens?
What is the result?
Technical reading Corrosion of materials
Task 7Scan the table opposite to find the answers to these questions.
1What colour is the corrosion product on nickel-base alloys?
2Which alloys are most susceptible to pitting?
3W'hat does CRES refer to?
4When is chromium susceptible to pitting?
5What is Inconel?
6Which alloys have the highest resistance to corrosion?
7What is the difference in appearance between corrosion on aluminium alloys and corrosion on copper-base alloy?
8Which CRES is more corrosion resistant?
9What visible signs are there of corrosion in titanium alloys?
10Name two alloys subject to intergranular corrosion.
Nature and appearance of corrosion products (Aircraft Engineering)
AlloysType of attack to which alloy is susceptibleAppearance of corrosion products
Aluminium alloysSurface pitting, intergranular and exfoliationWhite or grey powder
Titanium alloysHighly corrosion resistant. Extended or repeated contact with chlorinated solvents may result in degradation of the metals' structural propertiesNo visible corrosion products
Magnesium alloysHighly susceptible to pittingWhite powdery snow-like mounds, and white spots on surface
Low alloy steels (4000-8000 series)Surface oxidation and pitting, surface and intergranularReddish-brown oxide (rust)
Corrosion resistant steel (CRES) (300-400 series)Intergranular corrosion (due to improper heat treatment). Some tendency to pitting in marine environment (300 series more corrosion resistant than 400 series). Stress corrosion crackingCorrosion evidenced by rough surface; sometimes by red, brown, or black stain
Nickel-base alloys (Inconel)Generally has good corrosion-resistant qualities. Sometimes susceptible to pittingGreen powdery deposit
Copper-base alloy, brass, bronzeSurface and intergranularcorrosionBlue or blue-green powder deposit
Chromium (used as a wear-resistant plating for steels)Subject to pitting in chloride environmentsChromium, being cathodicto steel, does not corrode itself, but promotes rusting of steel where pits occur in the coating
Source: 'Data briefs: Corrosion of Materials', Design Engineering
Maglev train
Tuning-in
Study this diagram of a Maglev train. What differences can you note between this and a conventional train?
Now scan the following text quickly to check how many of the differences you have noted are mentioned. Add any other differences you find to your list.
Magnetic levitation train
A MAGLEV (magnetic levitation) train does not run along a track in the normal way. Instead, magnetic fields lift it above the track, so that the train 'floats' along.
Because they have no wheels, axles, suspension, dampers, or
5brakes, Maglev vehicles are light and compact. They are also pollution-free, as no fuel is burned within the train, and cheap to maintain.
The Maglev system at Birmingham Airport carries passengers from the terminal to the railway station and the National Exhibition
10Centre. The cars are made of lightweight fibreglass, carried on an
aluminium chassis.^
All the electrical equipment which powers the cars is situated under the floors or the seats. Each car can take 32 passengers and their luggage, up to a weight of 3 tonnes. The trains travel at a maximum 15 speed of 42 km/h.
A concrete guideway above the ground supports a T-shaped track for the two-car Maglev trains. The train is lifted from the track by magnetic attraction. This is the force by which two opposite magnetic poles attract each other (just as two of the same poles 20 repel each other). Powerful electromagnets at each corner of the train exert a pulling force which lifts the train upwards so that it floats 15 mm above the track.
As people get on and off, the weight of the train varies. It may drop closer to the track than the required 15 mm, or rise further from it.
25 To keep it at an even distance from the track, the force is varied by a microprocessor.
Each train is driven by an electric motor called a linear induction motor. Electromagnetic windings, or coils, on the train generate a magnetic field in which the magnetic poles shift along the train.
30 The field induces electric current in the track, which in turn
generates its own magnetic field. The two fields in the track and the train interact so that the shifting field pulls the floating train along the track.
Source: 'Inside out: Magnetic levitation train', Education Guardian
Reading 1 Inferring
Make a list of the advantages of the Maglev train. You may use the text to help you.
Advantages
Now list the disadvantages. You may use the text to help you. Disadvantages
Now think about your lists. You will probably find that most of the advantages are stated in the text. Few of the disadvantages are listed. You had to infer them, to reason them out. from your knowledge of the world and the information in the text.
Not everything we learn from a text comes from the words on the page or screen. Much of it comes from our own head. When we read, we make mental links between what we read and what we already know about the topic. In other words, we link new information and old to understand the text. This kind of reading is called inferring.
Reading 2 Dealing with unfamiliar words, 2
Answer this question using the extract from the text below.
Why are Maglev trains so light?
Because they have no wheels, axles, suspension, dampers, or brakes, Maglev vehicles are light and compact.
In your answer, you may have used the word damper. Do you know what it means? Do you need to know its exact meaning?
W7e learnt in Unit 14 that we can ignore unfamiliar words which do not help with our reading purpose. Some words we cannot ignore, but often an approximate rather than exact meaning of a word is all that is required. Sometimes we can work out the approximate meaning of a word from its context. For example, we can say that dampers are probably:
1heavy (not light)
2large (not compact)
3part of the undercarriage (same set as wheels, axles, suspension, and brakes)
Try to work out the approximate meaning of any of the words printed in bold in this text whose meaning you do not already know. Check your answers with a dictionary.
When first introduced, linear motors were seen as a major technological breakthrough. However, disappointingly few practical applications have been found for this new development. An earlier innovation, the W7ankel engine, was radically different from conventional engines, having a rotary piston and no valves. Wankel engines were adopted by the Mazda car company. However. W7ankel engines are now rarely used because of problems with fuel consumption and maintenance. The Wankel story illustrates the risks involved in developing any new product - success can mean a market lead over competitors but failure means that expensive development costs must be written off with no result. Sadly, technological superiority does not guarantee success. Betamax video tapes, technically better than their rivals, gave way to VHS because of better marketing.
Language study Prediction
Study this diagram. What will be the result of this action?
\
Action
Two magnets are held together with opposite poles facing.
When an action is always followed by the same result, we can link them like this:
If/When two magnets are held together with opposite poles facing, they attract each other.
If/When two magnets are held together with opposite poles facing, they will attract each other.
When an action is always followed by the same result, the statement becomes a general principle or law. (See Unit 15.) Using the law. we can predict what will happen in particular cases.
Predict the result of the action illustrated here.
Action
Two magnets are held together with like poles facing.
Now write the principle illustrated.
If two magnets
Predict the results of each of these actions. Then link each action and result in a sentence.
Action
1A steel bar is subjected to tensile forces. The bar
F
We apply an effort at E.
3The switch is closed.
✓'o
@6V 3 W
4The switch is pressed.
150 mA
—cr—o—
(M) 240 V, 750 W
■&
240 V
5We move the effort by one metre.
X
VR=1
6We move the effort by 50 centimetres.
VR=2
1 L
7The circuit is broken.
8120Vacisappliedacrosstheprimary.
10 : 1
9We apply an impact load to a brittle body.
Writing Explanations
Study this diagram. It shows how a Maglev train is supported without physical contact with the track. Can you explain how this works?
Levitation magnetLevitationforce
5Levitation railr
. _
15 mm air gap jJ Opposite poles attracting
current Levitation magnet
Vehicle weight downwards on magnet
The explanation consists of a series of at least six steps. The first step is:
1Current Hows through the magnet coil.
The last step is:
6The train is lifted.
Can you think of any of the steps in between?
Explanations consist of a series of steps. Some steps in an explanation have cause and effect links: others have time links. Here are some of the steps which explain how the train is lifted. What kinds of links are there between the stages?
1Current flows through the magnet coil.
2The current creates a magnetic field round the poles.
3The field induces a current in the track.
4The track becomes magnetized.
5The two magnets attract each other.
6The train is lifted.
You can show time links using the structures you studied in Unit 8. You can show cause and effect links using the structures studied in Units 16. 17. and 22. and in these ways:
1+2Current flows through the magnet coil creating a magnetic field round
the poles.
3+4The field induces a current in the track; therefore the track becomes
magnetized.
5+6 The two magnets attract each other. (thereby) lifting the train. Therein/ can be omitted from the last example.
Study these diagrams. They explain how the propulsion system operates.
Try to complete the blanks in this set of steps which form an explanation of the propulsion system.
Currentthrough the motor coils.
The current createsfieldsinthemotor.
currents in the track.
The track becomes
The current through the linear motoris changed.
The magneticin the motors shift.
There isandrepulsionbetweenthenewmotorfieldsandthe
track fields.
The motor pulls the train along the Thethroughthecoilschangesandtheprocessisrepeated.
Divide the steps into two sets and form each set into one paragraph. Show the links between the steps using whichever method you think appropriate.
Technical reading Motor selection: operating environment
What special features would you expect to see specified when rotary motors are being purchased to operate in the following situations?
In a workshop housing a wood planer.
In a boiler house which is regularly hosed down.
In a sewage pump house where the presence of methane gas can be expected. To drive a centre lathe used for turning cast-iron components.
Read the text on the following pages to check your predictions.
When choosing a drive motor for a particular application, the following points must be considered:
1Starting torque
2Starting current limitation
53 Drive speed
4Operating environment
5Rating and duty cycle
We will consider here the operating environment. Attention must be given to the problem of providing sufficient cooling medium to
10carry away the heat from the windings but at the same time not allowing that medium to carry into the motor anything which will harm it or block up the cooling ducts. Particularly harmful are oil vapour, carbon, and cast iron dust. Where machines may get wet, for example on a ship's deck, moisture ingress must be prevented 15 or suitable insulation employed.
Screen protected motor protected against large solid particles
Motor with secondary cooling system protection against most solid material and splashing water
Fig. 7
Probably the most commonly found machine is the totally- enclosed, fan-cooled motor (TEFC). The motor winding is totally enclosed in the motor housing which is usually ribbed on the outside. A fan is mounted on the shaft external to the housing and 20 is protected by a shield. This fan blows air over the casing
removing heat from the motor. In larger sizes, there is also a fan inside the casing blowing air over the windings transferring heatto the casing.
Where motors are required to operate in explosive situations, the 25 motor must be of flame-proof construction. This means that it must be enclosed in such a manner that any explosion which may occur within the motor must be contained within the motor. Often it is easier to prevent explosive gases entering the motor. Ventilated motors are used which draw air from an uncontaminated area. This 30 is pumped into the motor which keeps its internal pressure above that of its surroundings.
Fig. 1 illustrates a variety of protected motors.
Source: Adapted from D.W. Tyler, Electrical Applications, 3
Computer Aided Design (CAD)
Tuning-in
DesignUiew-EH-CRflNE.DU
£ile Ejlit Constrain Region Uieiu Zoom Text Set
1568 V 700 Click to select. Drag to block select. Shitt-clUk to add subtract elements.
Layer:1
Fig. 7
Task 1Study the example of Computer Aided Design in Fig.I. Answer these
questions about the diagram.
1What structure does it show?
2Apart from the design, what other information does the drawing provide?
3What do you think the top row of words arc for - File.Edit, Constrain, etc.?
Listening
Task 2Youare going to listen to an interview with a designer of car engines. He
describes some of the advantages of CAD over traditional approaches to design
-for example, drawing and modelling. Before you listen, list any advantages you think CAD has over these traditional approaches.
Task 3SIStudythefollowingextractfromthe tapescript of the interview. It covers the
interviewer’s first question and answer. Fill in the gaps before you listen. One word is missing from each gap. Then listen to this part of the interview to check your answers.
What do you like about designing on computer?
The fact that youget into three dimensions
immediately. You don’t-to imagine how a
component willfrom two-dimensional drawings.
You can put your thoughts into the solid without
to go via paper. You can see. in the mind’s,
exactly how the components fit together or-fit.
and you can modify, replace, and generally tailor parts very quickly as ideasto you.
Task 4E3 Now listen to the tape and list any advantages of CAD. Combine your answers
with others in your group to make as full an answer as possible. When you have finished, compare your answers with the list you made in Task 2.
Task 5E3 Work in pairs, A and B. Listen to the whole tape again.
Student A: Note any disadvantages of drawing in the table below.
Student B: Note any disadvantages of modelling in the table below.
Now compare notes to complete both sections of the table.
Disadvantages:
DrawingModelling
Task 6Thedesignermentions these components of a design cycle. Put them in the
correct sequence.
study results, modify design, stress analyse, design, stress analyse
Language Study Necessity: have to and need (to)
Study these examples from the interview.
1You don't have to imagine how a component will look from two dimensional drawings.
2... at the end of the day models have to he converted back into drawings for manufacture.
3Normally one needs to go round the circle at least four times.
4With CAD. you need not describe such a feature more than once.
Have to and need (to) can both be used to express necessity. In this sense, they are similar to must. Must is a modal auxiliary verb and has no other forms, whereas have to and need (to) have the same range of forms as other verbs.
The table opposite shows ways of expressing necessity and no necessity in the present.
+ necessity
have todo not have to
need toneed not or do notneedto
must—
Fill in the blanks in these sentenceswithappropriate forms of the verbs in the
table above.
1Designers who work with CADproduce drawings on paper.
2The production planner can use the computer model to calculate what
machiningbe done.
3One problem in working with wood or clay models is that theybe
converted into drawings for manufacture.
4With traditional design, youimagine a three-dimensional shape
from a two-dimensional drawing.
5With CAD. designers can put their ideas into solid shapes without
use paper.
6In engineering drawing repeated featuresbe drawn again each
time but with CAD theybe redrawn.
7Making cars lightermean making them flimsier or less safe.
Supercar
(Think carefully.)
Tuning-in
Study the following recent Volkswagen survey on the car of the future. Decide in your group which developments in the survey are important to you. One person should report the group’s views to the rest of the class.
What changes would you like to see?
We've suggested a few possible developments. Please think carefully about which ones would make a real difference to you and tick the boxes to let us know.
Design
The opportunity to use alternative fuel sources like hybrid (petrol and diesel) or hydrogen power.
□A car that is an office away from work, with facilities such as a fax machine and video-conferencing.
Safety
Speed limiters that vary to give you the safest possible drive for the weather and road conditions.
A computer sensor to tell you if you're driving at a safe distance from the vehicle in front.
EH Automatic engine and fuel supply cut-out in the unfortunate event of an accident.
All-round airbags.
Security
Engine immobilizer which makes it virtually impossible for anyone else to drive your car away.
A tracking device which allows the car to be located fast if it is stolen.
Audio systems built into the chassis or engine of the vehicle to prevent theft.
Performance
Sports car performance combined with fuel economy.
□A computerized route finder which tells you the quickest way to get to your destination.
Servicing by mobile units to save lengthy visits to a garage.
Source: V.A.G. (UK) Ltd
What do you think will be different about cars in the next ten years? Think about the following points. Compare your ideas with other groups.
-materials
-design
-power
-fuel
Read this title and introduction to a text. Try to guess the answers to the questions which follow.
Supercar test for industry
Matthew L. Wald on the technical issues the President's environmentally-friendly car faces...
1Who is the President?
2Who is Matthew L. Wald?
3How can a car be environmentally-friendly?
4Why might a car be called a Supercar?
5What test does industry face?
Now read the first paragraph of the text. Does it help you to answer the questions?
The 10-year co-operative project between government and Detroit for an environmentally-correct supercar will require radically new technologies for solving the car industry's problems: air pollution, over-reliance on imported oil, and loss of market share to imports.
Reading Predicting: using first sentences
In earlier units we studied how reading the title and using diagrams can help you predict the contents of a text. As we saw above, reading the first paragraph can also be very helpful.
A final way to get a good idea of the contents of a text is to read the first sentence of each of the other paragraphs.
Task 4Read these first sentences; then note down what you think the main points of
the text are.
1Some say it cannot be done but others say various components could be pulled together to do the job: electric motors with batteries, fuel cells or flywheels to deliver electricity, plus lightweight, aerodynamic car bodies.
2Instead of steel, some other type of material would be necessary for the ‘supercar' body, some kind of composite or carbon fibre.
3Safety is another issue but lighter need not mean flimsier.
4Reducing body weight and wind resistance will make any car more efficient.
5Electronics can. however.
6Four possible power sources are being investigated.
7Another possibility is fuel cells, which combine oxygen from air with hydrogen to make electricity.
8Yet another approach would be a flywheel, an electrical generator consisting of free-spinning wheels with magnets in the rims that can produce a current.
9A fourth possible power source for the national supercar would be a small turbine engine, running on a clean fuel like natural gas.
Task 5Read one of the following texts as your teacher directs: A. B. C. or D. Note in
this table any information you find on solutions to the problems of designing the Supercar.
TextSolutionReason(s)
AMaterials
BShape
CPower
DPower sourceProblem
1
2
3-
4-
Now share your information with others in your group to complete the table. Text A
Some say it cannot be done but others say various components could be pulled together to do the job: electric motors with batteries, fuel cells or flywheels to deliver electricity, plus lightweight, aerodynamic car bodies.^
5Instead of steel, some other type of material would be necessary for the 'supercar' body, some kind of composite or carbon fibre. Such materials are available now, but are not considered cost competitive with steel. But a research centre in Colorado claims that composites can 'emerge from the mould virtually ready to
10use'. The result would be fewer parts and less labour than current car body construction and, therefore, less cost.
Safety is another issue but lighter need not mean flimsier. The centre points to Indy 500 drivers who routinely survive 230-mph crashes in composite vehicles.
Text B
Aerodynamic drag accounts for more and more of the energy required to move the car as speed rises. The car makers already know howto cut drag sharply. General Motors' Impact has about half the drag of a typical car. The Impact has a rounded front and a
5tapered back. It is also small to present less frontal surface to the wind.
Text C
Reducing body weight and wind resistance will make any car more efficient. But roughly equal to the wind in eating up the car's energy is braking, and internal combustion engines cannot do much about that.
5Electronics can, however. Nearly all electric designs use
regenerative braking. When the driver hits the brake the motors become generators, converting the mechanical energy of the slowing wheels into electricity. That capability virtually guarantees that a super-efficient car will have an electric motor.
Text D
Four possible power sources are being investigated. The simple one is batteries. But if a super-efficient car is to have an attractive cruising range, it cannot carry hundreds of pounds in batteries.
Another possibility is fuel cells, which combine oxygen from air
5with hydrogen to make electricity. But current fuel cells operate steadily, and a car cell would have to handle widely varying demand for energy: zero, while stopped at traffic lights, or several times that consumed by an average house, while accelerating.
Yet another approach would be a flywheel, an electrical generator
10consisting of free-spinning wheels with magnets in the rims that can produce a current. An early application of flywheels might be in a race car built for a twisting course, where frequent braking means high fuel consumption in conventional cars.
A fourth possible power source for the national supercar would be 15 a small turbine engine, running on a clean fuel like natural gas. It would run at a constant speed, generating electricity for driving the vehicle or for feeding a bank of batteries, storing energy for later use.
Read the whole text yourself. How much did the tirst paragraph and the first sentences of the other paragraphs help you to predict the main points of the whole text? Which first sentences were not very helpful? Why not?
Language study Certainty
Study these statements. What is the difference between them? Can you put them in order of certainty?
1A supercar will have an electric motor.
2A supercar might have a flywheel.
3It is likely that a supercar will have a rounded front.
The difference between the statements is how certain the writer is about each development. Study this list of certainty expressions.
CertainFairly certainUncertain
Yeswillwill probablymight
be + likely + vbmay
be + probable thatcould
will possibly
Nowill notbe + unlikely to +vbbe possiblethat
Comment on how likely these predictions are for the next decade, using an appropriate expression from the table above. For example:
1A human powered vehicle (hpv) will exceed 100 km/h.
It is possible that an hpv will exceed 100 km/h.
2A perpetual motion machine will be invented.
A perpetual motion machine will not be invented.
3More factories will be fully automated.
It is likely that more factories will be fully automated.
4Driverless trains will link major cities.
Driverless trains might link major cities.
1Electric cars will become common.
2Most bicycles will have carbon libre frames.
3A more efficient petrol engine will be developed.
4More people will travel by public transport.
5Robots will be used in homes.
6Fewer engineers will be required.
7Diesel engines will replace petrol engines for cars.
8Most waste materials will be recycled.
9An ideal electric motor will be invented.
10Physicists will reach absolute zero (-273T).
Study these statements. Why is will used in the first sentence and would in the second?
1A supercar will have an electric motor.
2A possible power source would be a turbine engine.
In sentence 1 the writer feels certain this will happen. In sentence 2 the writer feels this is only a possibility because it depends on circumstances.
We use would to describe future events which can only happen if certain conditions are met. Study these examples from the text.
Another approach would be a flywheel. (If a supercar were built.)
The result would be fewer parts and less labour. (If moulded composites were used.)
What would happen if these conditions were met?
1If all cars were made of plastic
2If all cars had diesel engines
3If powerful, lightweight batteries were developed
4If all cars were fitted with fly wheels
5If speed limits were reduced
What conditions are necessary for these events to happen;
1All car parts would be recyclable.
2Carswouldtravel 40 km/litre of fuel.
3Carswouldcost much less to produce.
4Carswouldnot require painting.
5Carswouldnot require lubricants.
Writing Summaries
The best way to make a summary of a text is to write down the main points in note form and then link them clearly in your own words. If you are summarizing for others, make sure you do not over-summarize. that is. reduce the text to the point that no one but you can understand what it means.
Study these notes which summarize the Supercar text.
gas turbine with generator
Now convert each section of the notes into one or two sentences. Use the certainty expressions you studied in this unit. For example:
The Supercar will have an electric motor because only electric motors allow regenerative braking.
If you think that your reader will not understand particular terms, define them. For example:
The Supercar will have an electric motor because only electric motors allow regenerative braking, that is, converting braking power back into electrical energy.
Finally, link your sentences into paragraphs. You will need at least two.
-materials, shape, and power - possible power sources
You will also need to add a brief introductory paragraph stating the objectives of the Supercar project.
Graphs
Tuning-in
In engineering, graphs and charts are a common way of giving information. They allow a great deal of data to be presented easily in visual form.
Label the following graphic displays with the correct term from this list:
graphpie chart
bar chartbar chart (column chart)
Study the graph opposite which shows typicaldaily loadcurves for a power
station. Answer these questions about the graph for weekdays.
1When is the peak load?
2When is there least demand?
3When is the load 6 5% of capacity?
4What is the load at 1 p.m.?
Fig. 7
Describe changes in load for these periods:
5Between 6 a.m. and 10 a.m.
6Between 7 p.m. and midnight.
7Between 3 p.m. and 5 p.m.
Language study Describing graphs
Look at the period 6 a.m. to 10 a.m. We can describe the change in load in two ways:
1The load rises.
2There is a rise in load.
We can make our description more accurate like this:
3The load rises sharply.
4There is a sharp rise in load.
Study this table of verbs and related nouns of change. The past form of irregular verbs is given in brackets.
DirectionVerbNoun
Upclimb
go up(went up)
increaseincrease
Downdeclinedecline
decreasedecrease
dipdip
dropdrop
fall (fell)fall
go down (went down)
Levelnot changeno change
remain constant
AdjectiveAdverb
slightslightly
gradualgradually
steadysteadily
steepsteeply
sharpsharply
suddensuddenly
fastfast
Study this graph which shows the load at weekends.
Fig. 2
Write sentences to describe the load during these periods.
Saturday, 8 a.m. to noon.
Saturday. 6 p.m. to 10 p.m.
Saturday, noon to 5 p.m.
Saturday, noon to 1 p.m.
Sunday. 2 a.m. to 8 a.m.
Sunday. 8 a.m. to 9 a.m.
Sunday, noon to 3 p.m.
Sunday. 5 p.m. to 10 p.m.
Look at Fig. 1 and Fig. 2. Make comparisons of these periods. For example:
Sunday. 4 a.m. to 8 a.m./weekdays at the same time.
On Sunday the load remains constant between 4 a.m. and S a.m. but on weekdays it rises sharply.
Sunday, noon to 3 p.m./Saturday at the same time.
Weekdays, 10 p.m. to 11 p.m./Saturday at the same time.
Saturday peak load/Sunday peak load.
Sunday, noon to 1 p.m./the rest of the week at the same time.
Study this list of common verbs in engineering which you have studied in this book. They all have the sense of'make something happen'.
lowermake low
raisemake high
heatmake hot
releasemake free
compressmake smaller volume
reducemake smaller
increasemake larger
Fill in the blanks in these sentences with suitable verbs from the list above.
When thermoplastics arethey soften.
If a gas isit heats up.
Refrigeration preserves food byitstemperature.
A heaterthe temperature of the water.
The rising pistonthe fuel mixture.
Designers try tothe weight of a structure.
When the push button isthe valve spring pushes up the spool.
Pumping fluid into the main cylinder graduallythe jack.
Aerodynamic designwind resistance.
The motor starts up slowly, then graduallyspeed.
At intermediate substations, power isto11 kV for light industry.
When the childthe handle, the seat swings back under the
weight.
Writing Describing a graph
An important mechanical test of a metal is the tensile test to destruction. Increasing loads are applied to a specimen of the metal until it breaks. For a mild steel specimen, a graph of load against extension looks like this:
The following sentences describe the most important stages of the test. With the help of the graph:
-put the stages in the correct sequence to form a text describing the graph.
-fill in the missing references (0. P. E. Y. U. F)
Fromtothe specimen extends in direct proportion to the load
applied.
This rapid extension continues until point.themaximumload,is
reached.
Fromthere is a rapid increase in length for each increase in load.
Atthe specimen finally fractures.
Afterthe specimen lengthens further but the load falls.
Soon after P the material reaches its elastic limit, marked on the graph as point
Task 7Add this extra information to your text.
aUp to the elastic limit, the steel will regain its original length when the load is
removed.
bUp to U there is no change in the cross-section of the steel,
cAfter the elastic limit, the steel will not regain its original length,
dAfter U the specimen undergoes ‘waisting'.
eY is the yield point.
Refer to each of these figures at an appropriate place in your text. Use expressions such as these:
As shown in Figure A.
See Figure A.
(Figure A)
y|
B
Technical reading Properties and applications of carbon steels
Study the diagram below which shows how tensile strength, hardness, and ductility vary with the percentage of carbon in carbon steels. Answer these questions:
1What percentage of carbon gives the greatest tensile strength?
2W7hat happens to ductility between 0.08% and 0.87% carbon?
3How does increased carbon affect hardness?
4What is the effect on tensile strength of increasing carbon beyond 0.84%?
5What happens to ductility beyond 0.87% carbon?
% Carbon
Properties of carbon steels
Now study the diagram below for extra information and answer these questions.
1What is high carbon steel?
2How much carbon does tool steel contain?
3Compare the properties of mild steel and hard steel.
4What kind of steel is tin plate made from?
5W7hat kind of steel are car springs made from?
Low
carbon
steelMild
steelMedium
carbon
steelHigh carbon steel
Hard steelSpring gradesTool steel
Tin plate,Ship andRailwayLocomotiveCarMetal cutting
wire,boilerrails,tyres,springs,and forming
rivets,plates,crank pins,woodcuttingtap drills,tools,
pipesstructuralconnectingtools,ball racesdrills,
sections,rods,crusher rolls,wire dies
turbineaxles,hammers,
rotors,gears,hand chisels
marinegun barrels_.<V\
shafts
0.080.150.350.550.851.051.20
% Carbon
Properties and applications of carbon steels
Waste recycling plant
Aluminium can recycling. The bales seen here contain over one million cans.
Tuning-in
You are going to read a text on recycling domestic refuse. The main components of refuse are given in the list below. Using your knowledge of engineering, discuss in your group how one of these components could be recovered from refuse and what use could be made of the materials recovered. Your teacher will decide which component each group will discuss.
Ferrous metalsGlassPlastics
PaperOrganic materialsNon-ferrous metals
Now report your solutions to the rest of the class. Be prepared to answer questions and defend your ideas.
Read the text below to see how the solutions proposed by your class compare with those used in the experimental plant described.
Recycling domestic refuse
The consumer society produces more and more refuse. A number of solutions to this problem have been proposed. In some countries refuse is burnt to generate electric power. In Germany, producers must take back unwanted packaging for recycling. In other 5 countries, householders are asked to separate out refuse so that it can be recycled more easily. This text describes an experimental plant in Holland designed to recycle domestic refuse.
The rubbish collected from households consists of a mixture of organic materials such as kitchen waste, and inorganic materials 10 such as glass and plastic bottles, tin cans, and packaging.
The rubbish is first passed through a hammer mill to shred it. The mill consists of rotating steel arms which break up any large items to reduce them to a more manageable size. Any items which may cause damage later in the process are rejected at this stage.
15 The shredded mixture passes under an electromagnet which
removes ferrous metals. Much of this is tin cans. Almost all ferrous metals are recovered in this way.
After that, the residue is carried by conveyor belt to an air classifier. A stream of air is blown through the classifier, which has a zig-zag 20 shape. Low density materials such as plastic, paper, and some organic substances rise to the top of the classifier. Higher density materials such as glass and non-ferrous metals fall to the bottom and are discarded. These could be further separated out using a range of processes. For example, an eddy current mechanism 25 could screen out aluminium waste. Froth flotation techniques could recover glass.
The low density portion is carried to a rotating drum where it is screened. Fine organic materials pass through the screen leaving a mixture which consists mainly of plastic and paper. The organic 30 residue can be used for compost or to make bricks.
The next stage is to separate the plastic from the paper. This was initially a problem as both are similar in density. The solution is to wet the mixture. The paper absorbs water and as a result becomes denser than the plastic.
35 In the final stage, the wetted mixture is passed through a second air-classifier where the lighter plastic leaves from the top and the denser wet paper from the bottom. The recovered paper could be fed to pulp mills for further recycling.
The remaining plastic is a mixture of thermosets and 40 thermoplastics. It is not easy to separate these out but the mixture can be melted and formed into insulating materials for building.
Reading Transferring information, making notes
Using the information in the text, complete the labelling of the flowchart. Add these labels:
plastic and paper mixtureair classifier
high density materialsrotating drum
shredded mixtureferrous metals
paperwetted mixture
line organic materials
Study these notes on the first stage of the recycling process. They contain information on location (Where?), action (What happens?), reason (Why?), and method (How?). Read the text again to complete the notes for the other stages.
Stage 1
Where?hammer mill
What happens? the waste is shredded
Why?to reduce it to a manageable size
How?using rotating steel arms to break up any large items
Stage 2
Where?
What happens?
How?by magnetism
Stage 3
Where?
What happens? high and low density materials are separated
How?by a current of air which carries low density materials to
the top while high density materials fall to the bottom
Where?
What happens?the low density portion is screened
Why?
Stage 5 What happens?
Why?to give the paper and plastic different densities
Stage 6
Where?
What happens?
How?by a current of air which carries low density plastic to the
top while wet paper falls to the bottom
Language study Possibility: can and could
Answer these questions about the text.
1Does this plant screen out aluminium waste?
2Does it recover glass?
3Is recovered paper fed to pulp mills?
4Is recovered plastic melted and formed into insulating blocks?
5Is organic residue used for compost and bricks?
The answer to questions 1.2. and 3 is No. The answer to questions 4 and 5 is Yes/Maybe. How do we know? Look at the text.
1An eddy current mechanism could screen out aluminium waste.
2Froth flotation techniques could recover glass.
3The recovered paper could be fed to pulp mills for further recycling.
4The mixture can be melted and formed into insulating materials for building.
5The organic residue can be used for compost or to make bricks.
W7e use could in examples 1.2. and 3 to show that something is possible but is not in fact done. The reasons why nothing is done in these examples may be expense or lack of demand. We do not know.
We use can in examples 4 and 5 to show that something is possible and may in fact be done.
Fill in the gaps in this text with either can or could. Be prepared to justify your answers.
1With present technology werecycle almost all domestic refuse.
But in practice market forces determine what is worth recycling.
2Successful plants in a number of countries show that refusebe
used as a fuel in power stations.
3If we recycled most of our refuse, the increasing problem of waste disposal
—be solved.
4Sweatersbe produced from old plastic bottles. A company in the
United States converts the waste plastic into polyester yarn. It takes twenty-five two-litre bottles to make a sweater.
5At present wenot easily separate thermosetting plastics from
thermoplastics.
Writing Describing a process, 4: reason and method
In Units 1 3 and 1 5 we learnt how to sequence and locate the stages in a process. In this unit we will study ways to describe and explain what happens in each stage.
Look again at the notes on Stage 1.
Stage 1
Where?hammer mill
What happens?the waste is shredded
Why?to reduce it to a manageable size
How?using rotating steel arms to break up any large items
Note how we can combine information on sequence, location, process, reason, and method. For example:
Sequence + location
The waste first passes to a hammer mill
+ action
The waste first passes to a hammer mill, where it is shredded + reason
The waste first passes to a hammer mill, where it is shredded to reduce it to a manageable size
+ method
The waste first passes to a hammer mill, where it is shredded to reduce it to a manageable size using rotating steel arms to break up any large items.
Combine information on the other stages in the same way to make a full description of the recycling process. Note that you can help your reader understand the sequence by carrying information from one stage to the next. For example:
Stage 1The waste is shredded.
Stage 2The shredded waste ...
Stage 5The mixture is wetted.
Stage 6The wetted mixture...
Robotics
Tuning-in
Together, try to write a definition of a robot. Compare your answer with the definition of an industrial robot given on page 36 of the Answer Book.
Reading 1 Revising skills
In the tasks which follow, we will revise some of the reading skills you have studied.
Study this diagram which shows the components of an industrial robot. What do you think the functions of the three components shown are?
The manipulator
This is the bit which actually does the mechanical work, and in this case it is anthropomorphic (i.e. of human-like form), resembling an arm.
The power supply
For heavy-duty hydraulic or pneumatic machines this will be a 5 compressor. In smaller, lightweight versions which use electrical stepper motors rather than hydraulics or pneumatics, this would be omitted.
The computer
The controlling computer is fitted with appropriate interfaces. These may include digital inputs, digital outputs, ADCs (analogue- 10 to-digital converters), DACs (digital-to-analogue converters), or stepper motor control ports. These control the various compressors, stepper motors, and solenoids, and receive signals from the manipulator's sensors.
Read the following text to find the answers to these questions.
What is the work volume of a manipulator?
W7hat is the work volume of a human?
Why is the work volume of a human greater than that of an industrial robot? What are degrees of freedom?
Work volume
Robots are multifunctional so an important design issue for the manipulator is its 'work volume': the volume of space into which it can be positioned. The greater the work volume, the more extensive the range of tasks it can be programmed to carry out.
5 As a human being, your work volume consists of all the places your hands can reach. Most industrial robots have a much more limited work volume because they are bolted to the floor. Even with the same limitation applied, however, the human body is a very flexible machine with a work volume described - very 10 approximately- by a cylinder about 2.2 m high with a radius of about 1.8 m and a domed top.
Degrees of freedom
In order to achieve flexibility of motion within a three-dimensional space, a robot manipulator needs to be able to move in at least three dimensions. The technical jargon is that it requires at least 15 three 'degrees of freedom'. Figs. 2 a-d show a number of the more common types of robot manipulator mechanisms. Each has the requisite three degrees of freedom, allowing either linear or rotational movement.
Study the text and accompanying diagram (Fig. 2a) below and note how the information has been transferred to Table 1.
Fig.TypeDegrees of freedom
linear rotationalWork volume
2aCartesian or rectilinear30cube
?,b
2c
2d
Table 1
Common types of manipulator
Fig. 2a is the simplest. Its three degrees of freedom are all linear and at right angles to each other, so they correspond to the three Cartesian co-ordinates. Driving it presents no mathematical difficulties, since each degree of freedom controls a single
5Cartesian co-ordinate without affecting the others. Fairly obviously, the work volume of the Cartesian manipulator is a cube.
Fig. 2a Cartesian or rectilinear manipulator
Work in groups of three. Your teacher will select a text for you. Read the text and diagram to complete your section of Table 1.
Text 1
The second type of manipulator, shown in Fig. 2b, is called a cylindrical manipulator because of the shape of its work volume. It has one rotational and two linear degrees of freedom. Because of the rotational aspect, however, the maths needed to position it
5becomes more involved, which means that for a given response speed a faster processor is necessary.
Text 2
Fig. 2c shows the spherical manipulator which has two rotational and one linear degrees of freedom. The work volume is indeed a sphere, and once again the complexity of positioning the device increases.
Fig. 2c Spherical or polar manipulator
Text 3
The final type of manipulator has three rotational degrees of freedom. This is the most complex type to control, but it has increased flexibility. Fig. 2d shows this type of manipulator-the anthropomorphic arm. The work volume of a practical manipulator
5of this form is shown in Fig. 3. You will notice that it is basically spherical but has missing portions due to the presence of the arm itself and because the rotations cannot achieve a full 360 degrees. The scallops on the inner surface are caused by constraints imposed by the joints.
Side view
Fig. 3 The work volume of an anthropomorphic manipulator
Task 7Now exchange information with the others in your group to complete the
table.
Task 8Complete the blanks in this text.
Mechanical wrist
It is worth pointingthat a human arm has far more freedom
the minimum three degrees of freedom, giving very great
flexibility in terms _positioning, path taken, and angle of
approach. Even without a wrist, the redundant degrees of freedom of the
body would allow you to carry out most normal operations. Any
of the basic manipulators shownFigs. 2 a-d. on the other
. would be virtually useless as they stand. Although they could
get to any position, theyonly approach objects from a single
angle.
89
To take an. removing a screw would be impossible
the manipulator could not align a screwdriver to tit the screw properly. Even if it was able to, it still would 10bepossibletocarryout the necessary
rotating action.
A wrist is therefore added to most basic manipulators to '1the
required mechanical flexibility to 12realjobs.Ingeneral, for total
flexibility the wrist itself requires three degrees of freedom, thereby bringing the grand total up to six. The 'commontype of wrist has two bending
and one rotational degrees of freedom. Fig. 4 shows this type of mechanical wrist.
Language Study Concession: even if and although
We can use if (see Unit 11) to link two statements like this:
1The switch is on.
2The lamp lights.
If the switch is on. the lamp lights.
When statement 1 is true, statement 2 is also true.
When statement 1 surprisingly has no effect on statement 2. we can use even if or although. For example:
A car is fitted with a seat belt warning light. The light operates under these conditions:
Seat occupiedIgnitionBeltLight
YesOnClosedOff
YesOnOpenOn
YesOffClosedOff
NoOffClosedOff
Study these examples of normal and faulty operation:
Normal
If the seat is occupied, the ignition on and the belt closed, the light is off.
Faulty
Even if the belt is closed, the light stays on.
Although the belt is closed, the light stays on.
Give other examples of normal and faulty operation of this circuit.
Technical reading Stepper motors
Read the text which follows to find the answers to these questions, then complete the table.
1Why would you use a stepper motor to position the head of a disk drive unit?
2Name two components that are present in other electric motor types but absent from stepper motors.
3For accuracy in positioning, would you select a stepper motor with a large or a small step angle?
TypeAdvantagesApplications
Variable reluctanceNodetenttorque
High dynamic torque at low speed
Hybrid typeGoodspeed/torque
characteristics
Can be made very small, very efficient
A stepper motor does not run in the same way as a normal DC motor, i.e. continuously rotating. Instead, it runs in a series of 10 measured steps. These steps are triggered by pulses from a
computer, each pulse making the motor turn either in a forward or a reverse direction by an exact interval, typically 1.8, 2.5, 3.75, 7.5, 15, or 30 degrees. Accuracy is within 3% to 5% of the last step.
The rotor in a stepper motor is constructed from several permanent 15 magnets with north and south poles. The stator is wound into a series of electromagnets, usually four, which can be switched on and off. Figs. 5a and b illustrate the operation of a permanent magnet-type stepper motor. When current is applied to the stator coils, it creates the pole arrangement shown in Fig. 5a. Poles 1 and 20 2 are north. Hence, the rotor south pole is attracted to both of them and settles in the mid position as shown. When the stator currents are changed to produce the pole arrangement shown in Fig. 5b, pole 1 has south polarity. This repels the rotor which moves to the new position as shown. Each polarity change on the stator causes 25 the rotor to move (in this case) 45 degrees.
Stepper motors can be divided into two groups. The first one works without a permanent magnet. The second one has a permanent magnet, usually located on the rotor.
Variable reluctance motors form the first group. As there is no 30 permanent magnet, the variable reluctance motor has practically no detent torque. The rotor spins freely and gives good acceleration and high speed if lightly loaded. Applications include micropositioning tables.
The second group comprise the permanent magnet motor, the 35 hybrid motor, and the disc magnet motor. The permanent magnet type offers high dynamic torque at low speed and large step angles. This is a low cost motor used extensively in low inertia applications such as computer peripherals and printers.
The hybrid type combines features of both types mentioned above. 40 It has good speed/torque characteristics and micro-stepping capability. Steps of 1.8 degrees are possible.
Disc magnet motors can be made very small and are very efficient. One of their first applications was in quartz-controlled watches.
Tuning-in
Task 1List some of the jobs in engineering. Combine your list with others in your
group.
Task 2Work in groups of three. A. B. and C. Scan your section of this text. A. B. or
C. How many of the jobs in the combined list you made in Task 1 are mentioned in your section?
Jobs in engineering A
Professional engineers may work as:
Design engineers:They work as part of a team to create new products and extend the life of old products by updating them and finding new applications for them. Their aim is to build quality and
5reliability into the design and to introduce new components and materials to make the product cheaper, lighter, or stronger.
Installation engineers: They work on the customer's premises to install equipment produced by their company.
Production engineers:They ensure that the production process is 10 efficient, that materials are handled safely and correctly, and that faults which occur in production are corrected. The design and development departments consult with them to ensure that any innovations proposed are practicable and cost-effective.^
B
Just below the professional engineers are the technician 15engineers.They require a detailed knowledge of a particular
technology - electrical, mechanical, electronic, etc. They may lead teams of engineering technicians. Technician engineers and engineering technicians may work as:
Test/Laboratory technicians:They test samples of the materials 20 and of the productto ensure quality is maintained.
Installation and service technicians:They ensure that equipment sold by the company is installed correctly and carry out preventative maintenance and essential repairs.
Production planning and control technicians: They produce the 25 manufacturing instructions and organize the work of production so that it can be done as quickly, cheaply, and efficiently as possible.
Inspection technicians:They check and ensure that incoming and outgoing components and products meet specifications.
Debug technicians:They fault find, repair, and test equipment and 30 products down to component level.
Draughtsmen/women and designers:They produce the drawings and design documents from which the product is manufactured.
C
The next grade are craftsmen/women.Their work is highly skilled and practical. Craftsmen and women may work as:
25 Toolmakers:They make dies and moulding tools which are used to punch and form metal components and produce plastic components such as car bumpers.
Fitters:They assemble components into larger products.
Maintenance fitters:They repair machinery.
40 Welders:They do specialized joining, fabricating, and repair work.
Electricians:They wire and install electrical equipment.
Operators require fewer skills. Many operator jobs consist mainly of minding a machine, especially now that more and more processes are automated. However, some operators may have to 45 check components produced by their machines to ensure they are accurate. They may require training in the use of instruments such as micrometers, verniers, or simple 'go/no go' gauges.
Source: Adapted from S. Moss & A.S. Watts, Careers in Engineering, 3rd edition
Task 3Combine answers with the others in your group. Howmany of the jobs listed
in Task 1 are mentioned in the whole text?
Task 4Who would be employed to:
1test completed motors from a production line?
2find out why a new electronics assembly does not work?
3produce a mould for a car body part?
4see that the correct test equipment is available on a production line?
5find a cheaper way of manufacturing a crankshaft?
Reading Inferring from samples
In Task 5 below and in the Listening (Task 7), you are asked to infer from a small sample of text information which is not clearly stated. Use the clues in the samples and the knowledge you have gained from the text Jobs in engineering.
As agroup, try to identify the jobs of these workers from their statements.
1We perform standard chemical and physical tests on samples, usually as a result of a complaint from inspectors on the production line. We are an important part of production. We have the authority to stop the line if we find something seriously wrong. It's interesting work, and we're able to
5move around from test to test and chat. Sometimes, admittedly, the work
gets a bit repetitive.
2All machinistscan be difficult. The older blokes especially don't like me telling them their work isn't good enough and instructing them to do it again. One or two of them seem to thinkthe inspector is always outto get
10them. I'm constantly havingtocalmthingsdown.
3We measure up the components to see that they are the right size and shape, and we make any minor adjustments ourselves with hand tools or power tools. All along, parts will need adjusting slightly and you have to check things at each stage with measuring instruments and gauges. You
15 have to get a feel for it-clearances have to be just right. Otherwise things won't fit together.
4Ifind myjob a very satisfying one. It's never easy to say exactly why one likes a job. I think the basic thing I get out of my profession at the moment is the creativity that is involved in design work. You start from square one
20 with a plain sheet of paper. You draw a component. You design
something and perhaps a few months later you can see the end product. And you get told whether or not your design works! I think it's that aspect that I find most satisfying.
5I enjoy myjob. I really like doing the same thing every day-exactly the
25 same job. You knowwhatto lookforand howthingsshould be. You know howthe machine-orthe machines-run, when a machine is working properlyand when there is something wrong with it. I really like the routine. I don't have dreams of becoming a supervisor or anything like that. I'm just content running my machines.
630 Mycompany makes desalination equipment. Ittakesthesaltoutofsea
waterso it can be usedfordrinking and irrigation. A lot of ourcustomers are in the Middle East. I have to go there whenever new equipment is being set up to make sure it's properly installed and everything is running OK.
Source (quotations 1-5): T. May, People at Work: Working at a light engineering plant
Speaking practice Role play
Work in pairs. A and B. Each of you has profiles of three workers in a light engineering plant which supplies car electrical components such as starter motors, fuel pumps, and alternators.
Play the part of one of these workers and be prepared to answer questions from your partner about your work. Your partner must try to identify your job from your replies.
In turn, find out about your partner.
Do not give your partner your job title until he or she has found out as much information as possible and has made a guess at your occupation. Try to find out:
1Age
2Education
3Qualifications
4Nature of work
5Who he/she is responsible to
6What he/she feels about his/her work
Before you start, work out with your partner useful questions to obtain this information.
Student A: Your profile is on pages 179/80.
Student B: Your profile is on page 183.
Listening Inferring from samples
(SI Listen to these workers talking about their jobs. Try to match each extract to one of these jobs.
a Methods engineer b Systems analyst c Toolmaker
d Machine tool development fitter e Foreman/woman f Applications engineer
Applying for a job
Tuning-in
What sort of engineering job do you do at present or would you like to do in the future? What are the attractions of the job? Compare answers with others in your group.
Reading Understanding job advertisements Answer the questions below about this job advertisement.
AAA Castleton Airport
As a highly successful part of AAA pic, we handled approximately 5 million passengers last year. Further expansion of the airport facilities has created a career opportunity for the following:
Engineering Technicians
c.£13,000
In this multi-skilled role you will carry out corrective and preventative maintenance on a variety of electrical, electronic, and mechanical plant. You will use computer-based monitoring systems for effective control, fault diagnosis, and operation of plant and equipment.
Applicants should have a recognized HNC or National Certificate in Electrical / Electronic Engineering and have served a recognized apprenticeship. Experience in the operation and maintenance of electro¬mechanical plant utilizing electronic system control including experience of HVAC plant and systems, electronic PLC systems, boiler control systems, positional and electronic speed control systems including hydraulics, pumps, and heat exchangers would be desirable.
This demanding position requires effective communication skills together with a flexible attitude.
A clean current driving licence is essential.
In return you can expect an attractive salary and benefits package.
Please forward a comprehensive CV to Denise Dickens, Personnel Department, Administrative Block A, Castleton Airport, Castleton CS213SL. Closing date for receipt of completed applications is 31 December.
1Which company is advertising?
2Where are the jobs based?
3At what professional level are the jobs available?
4Applicants from which branch of engineering are eligible?
5What qualifications are required?
6In addition to qualifications, what must the applicants have completed?
7List some of the areas in which experience is sought.
8Might you be considered for the jobwithout this experience?
9In addition to qualifications and experience, whatcharacteristics should
applicants have?
10Which non-professional qualification is essential?
11What might a benefits package include?
12What are PLC systems?
13What does HVAC mean?
14What is a CV?
Task 3FionaWeaverdecidestoapply for one of the posts. Study her CV below.
Answer these questions.
1What is her highest educational qualification?
2Why do you think the education and experience sections of her CV start with the most recent events?
3Why does she give two references?
4Why has she chosen these people to be her referees?
5Why does she include interests and activities?
CURRICULUM VITAE
Personal details
Name:Fiona Weaver
Date of birth:7 April 1974
Address:6 Haymarket,Newcastle,NCI4YU
Marital status:Single
Education and qualifications
1991-1995Faraday CollegeofFurtherEducation, Newcastle
-National Certificate in Electrical and Electronic Engineering (day release from S & T (UK) Ltd)
1985-1990George Stephenson Secondary School,Newcastle
I hold a clean driving licence. I have been driving for three years.
Work experience
1995 to present Inspection Technician
Sturner & Thomson (UK) Ltd
-Responsible for checking incoming components and completed products using a wide range of test equipment including computer-based record systems.
1991-1995Apprentice electrical technician
Sturner & Thomson (UK) Ltd
1990-1991Office junior
Brent & Wicker, Solicitors
-Basic secretarial duties—filing, word-processing, telephone receptionist, in a busy lawyers' office
Interests and activities
Travel, modern dance, swimming
ReferencesCollege:
Mr Andrew Wood Head of Department Electrical Engineering Faraday College Cornwallis Road NEWCASTLE NC2 3PL
Study this letter of application which accompanied the CV. What information does it add to the CV?
6 Hayxnarket Newcastle NCI 4YU
15December 19-
Ms Denise Dickens Personnel Department Administrative Block A Castleton Airport Castleton CS21 3SL
Dear Ms Dickens,
Re: Engineering Technicians
I would like to apply for the post of Engineering Technician as advertised in today's issue of the Tribune. I enclose my CV with the names of two referees.
You will note from my CV that I have a National Certificate in Electrical and Electronic Engineering and considerable experience. My work at S & T (UK) means that I am familiar with HVAC plant and systems including electronic system control. As an inspection technician, I have experience of a wide range of systems for product testing and component evaluation.
I enjoy my work at S & T but would like now to broaden my experience, especially in the area of maintenance. I feel that I can bring considerable skill to the post together with the ability to work well in a team. I am also interested in further improving my qualifications by studying for an HNC, part-time.
I look forward to hearing from you.
Yours sincerely
'?aut<z ‘Weave*
Fiona Weaver
Speaking practice Role play
Imagine you are Ms Dickens of Castleton Airport. List Fiona’s strong points and weak points. Plan questions to ask her at her interview.
Now divide into pairs so that you are working with another student. Act out the interview with one being the applicant and the other the personnel officer. You can change Ms Dickens to Mr Dickens and Fiona Weaver to Michael Weaver if you wish.
Task 7Study the advertisements on the following pages. Select suitable jobs for
which these applicants could apply.
1Technician engineer. 2 7. HNC in Electrical Engineering, with two years' sales experience.
2Professional engineer. 35. with live years’ experience in the automotive industry.
3Design engineer. 42. BSc in Mechanical Engineering, with experience in managing projects both in-house and subcontracted.
4Technician. 24. National Certificate in Mechanical Engineering, two years’ shop floor experience.
5Electrical engineer. 50. HNC, long experience in maintenance of high voltage plant.
6Mechanical engineer. 46. HND. experience in maintenance.
7Yourself
SALES ENGINEER
Sinclair is one of the UK's largest private engineering groups, with an international reputation. The sealing systems operation requires a Technical Sales Engineer to sell the world-renowned Chesterfield range of products throughout the Midlands.
You should have previous sales and mechanical engineering experience with a bias to maintenance products and mechanical engineering.
The successful candidate will ideally be between 30 and 45 years of age living in the Midlands with a mechanical engineering background.
The company offera good basic salary, commission and company car. Apply in writing, with full cv to: J. FORD
SINCLAIR SEALING SYSTEMS LTD.
16CANYON ROAD, NETHERTON INDUSTRIAL ESTATE, BIRMINGHAM B2 OER Closing date 17 December 19—
SINCLAIR
PROJECT/DESIGN ENGINEER
We are a long established medium/ heavy engineering company (Liverpool area) specializing in mechanical handling equipment and require to appoint a project/design engineer for our busy drawing office.
The applicant should be aged between 28 and 40 and must have a sound and practical engineering background. Ideally he/she should be a time served draughtsperson, capable of running projects from initial concept, through design and detail including to final installation. He/She should have experience in fork truck attachments, lifting beams, and conveyor systems; must be able to work on his/her own initiative and liaise with customers. This is an extremely responsible position with good prospects for further advancement.
Please reply in writing with full cv in the first instance to Box 1383, The Herald, Liverpool LI 1QP.
SUBCONTRACT MANAGEMENT
INTERNATIONAL MECHANICAL/ELECTRICAL PROJECTS £NEG AND GENEROUS BENEFITS
John Blair Engineering, part of the Nelson House Group, is a UK and International leader in power and process engineering. Continuing success in gaining new contracts world-wide has resulted in the ongoing growth of our Operations Division. This has created oppor¬tunities for additional Senior Subcontract Personnel.
Your prime responsibilities will involve:
•the award and management of subcontractors working on major turnkey projects;
•the administration of change control procedures;
•identification of liabilities and risk assessment;
•cost forecasting;
•variation management.
To be successful in this challenging position you will be qualified to degree level in a Mechanical, Electrical, or Quantity Surveying discipline and have 10 years experience at a Senior level preferably with a large, successful organization. Good communication and inter¬personal skills are an essential requirement.
Salary is negotiable at a level attractive to high calibre individuals and in addition to the career prospects you would expect from a Company of our stature, we offer an attractive range of benefits, substantial pension provision, free life assurance, permanent health insurance, and generous relocation expenses where appropriate.
To apply please send a full cv stating current salary to: Planning and Development Manager, John Blair Engineering Limited, Dumbarton Road, Clydeside, Dumbartonshire G52 1YA, quoting reference number: 86/46/12.
JOHN BLAIR
J
ENTERPRISE THROUGH ENGINEERING
Senior Electrical Engineer
A MAJOR ROLE FOR A DEDICATED PROFESSIONAL
The Semiconductor UK plant at Knutsford covers over 300,000 square feet, over 100,000 square feet of which is devoted to clean rooms. We are currently investing some $90 million in new equipment and buildings and the upgrading of plant and facilities.
In this high tech environment devoted to the design and manufacture of semiconductors, efficient and effective electrical supply and distribution systems are essential. We now have an opening for a Senior Electrical Engineerto take full responsibility forthe management, use and engineering of the electrical supply and distribution on the site. Your expertise will be called upon during electrical enhancement, upgrades, and maintenance work. You will also have a responsibility for electrical safety and energy management conservation.
Qualified to degree level and preferably holding professional status you will have excellent knowledge of and expertise in the design of HV and LV distribution and control systems, gained ideally during yourtime in a manufacturing and operational/maintenance environment.
This important role carries an excellent salary and generous benefits including free private health care, life assurance, contributory pension scheme, and a progressive relocation package if necessary.
To apply, please write with full C.V. to:
Brian Williamson, Human Resources Department, Semiconductor UK pic. Larkspur Industrial Estate, Knutsford WA16 8QT.
[) Semiconductor UK
Part of the N & S Group, one of the world's major suppliers of automotive components, PREMIER VANDERBILT LTD is a market leader in the , Py K manufacture of plain bearings for automotive and ^general engineering applications.
QUALITY ENGINEER - c.£l6k
Our manufacturing facility at Wycliffe Valley, Bathgate, commenced production in early 1992 and the workforce has expanded rapidly. We now require a Quality Engineer to join us.
Reporting to the Quality Assurance Manager, you will be responsible for ensuring quality related activities are implemented in line with company policies and objectives.
Educated to at least HNC level in mechanical engineering, experience in quality improvement in the automotive industry would be a distinct advantage. A working knowledge of SPC, FMEA, DOE, and problem solving techniques is essential.
Together with an attractive salary the benefits are those which can be expected from a progressive organization. There will be excellent opportunities for career development as the company continues to grow.
To apply, please send a cv stating current salary, to, Stuart P. Alexander, Human Resources Manager, Premier Vanderbilt Ltd, 10 Stonehouse Road, Wycliffe Valley Industrial Estate, Bathgate, Berks RG202EW.
Closing date for applications is Wednesday 5 January 19— and interviews will be held during January 19—.
MECHANICAL FITTER and PROJECT ENGINEER
FOR MECHANICAL HANDLING
We require young, enthusiastic people in the maintenance department to work in conveyoring and specialist machinery for the Glass Container Industry. Applicants should have previous experience working on a shop floor with minimum supervision and be willing to work shifts with overtime. Annual salary will be not less than £13,500.
Please apply in own handwriting enclosing CV to:
Mrs M Ramsay GLACIER GLASS PACKAGING LTD
1Grayshill Road,
Westfield Industrial Estate Bristol BS68 9HQ.
(Only applicants selected for interview will receive an acknowledgement within the next 3 weeks.)
f
ENGINEERS FOR SALES
c£1 6,500K + Car
Whether customers are looking for induction motors or datacomms technology, the engineers who make up our sales team can be confident that the solution is in our catalogue. As the country's leading distributor of electronic, electrical, and mechanical engineering products, we can supply customers with some 40,000 different items—all within 24 hours of an order being placed.
If anything we have even more to offer engineers who would like to build on their expertise in sales. If you hit your targets—and we'll give you all the training you need to ensure that you do—you can look forward to high earnings and opportunities to develop your career further.
You'll visit customers in your area, selling them SB products and services, then feeding the information back via written reports, so you'll need to be able to impress decision makers with yourtechnical ability, deciding priorities and motivating yourself to succeed.
This is a role that calls for proven sales experience and a background in electronic/electrical engineering (HNC essential). Bring us that and we can offer you the environment and scope to achieve your ambitions
All in all, there have never been better reasons to breakout (with or without the box). For more information and and application form, please send your full CV quoting ref E530H to Julia Beckett, Personnel Officer, SB Components Ltd, PO Box 26, Retford, Northants NN32 9RS.
SB Components Limited
Write your CV and a letter of application for one of the posts advertised in Task 7. You may invent suitable qualifications and experience if you are still a student.
Technical reading Company structure
Board
Managing
Director
DevelopmentManufacturingQualityMarketingField Service
ManagerManagerManagerManagerManager
ManagerEngineer
Manager
Fig. 7
Complete the blanks in this text using information from Fig. 1.
The head of an engineering company in the UK is the ortheChief
Executive Officer (CEO). If it is an American subsidiary, the head may be known as the Vice President. Unless the person at the top is the Chairman of the company, or the owner, he or she will be responsible to a “,or,in
the case of a US subsidiary, the President. In turn, the Chairman or President is responsible to the company shareholders.
The managers of the various departments which are vital to a company report directly to the Managing Director. These managers may be referred to as the Management Team. They are required to advise the Director on the consequences of any decision made by the Board in terms of costs, personnel, materials, time, plant, etc. They also have to brief the Director on any matters
which should be taken to the Board for decision.
The, with the support of the Mechanical. Electronic, and
Sections, is responsible for the introduction of new products. The decides how the new products will be produced. The and Industrial Engineer Manager report to this member of the Management Team.
Theensures that the products are fault-free and that the
components and materials used in their manufacture meet company
standards. Thehandles market research, promotion, and sales.
The Field Service Manager is responsible for the installation and maintenance of the company’s products wherever required.
The structure shown in Fig. 1 is common to most engineering companies but there can be differences in reporting channels. For example, in some companies the Field Service Department may report through Marketing, through Quality, or even through a separate Product Assurance and Support Group.
Although the company structure shows managers for each separate department, departments are interdependent. For example, the Development Manager would not start the design of a new product without lirst discussing the project with other managers. The design would not be completed without regular meetings with other departments to ensure that it fitted the customers’ requirements, that cost targets would be met without adversely affecting quality, manufacturability, and serviceability. These meetings would ensure that trained manpower, tooling, documentation, etc., were in place at the correct time for each stage of the product’s launch.
Unit 12
Use this text and diagrams to help you. Your partner has the same diagrams but without the text. Make sure your instructions are simple and clear.
Adjusting the distance between the saddle and the handlebars
It is important that the distance between the saddle and the handlebars should suitthe rider.
Place the elbow at the point of the saddle and stretch out your arm and hand. The distance between the handlebars and the fingertips
5should be approximately 5 cm. If necessary, slide the saddle forwards or backwards after loosening nuts A.
When re-tightening, make sure the saddle remains in an almost horizontal position and see that it is properly centred.
After re-tightening, ensure that the saddle is secured firmly and 10 cannot be moved.
Unit 14
Complete the missing design specifications.
Design specifications for a compression spring: ^working length 1
*max. outside dia.
mean dia.
cm
Specification
Material Wire size
*Load to be supported at working length 1 free length 4.80 cm
Type of endsclosed and ground
Wound L.H. or R.H.
Treatmentstress relieve
Finishzinc plate
cm/min.
Note. The spring diameter may be varied within the limits stated. The number of coils may be altered if necessary providing the conditions starred thus are maintained.
Unit 22
Pitting describes the form of corrosion where localized grains of metal are consumed. leaving small, irregular, but possibly deep, holes.
Although the amount of material removed may be small, the metal may be perforated.
Galvanic corrosion results where two dissimilar metals are connected in the presence of moisture producing an electrolytic cell. The more active metal becomes the anode and corrodes away, while the less active will be protected.
Unit 29
1Choose from one of these three profiles, aAge22
Job titleMachine tool development fitter
EducationCollege of Technology, full Technician’s Certificate by day
release over 4 years
DutiesWorks on automatic machines in the machine tool
development department, one of 17 millers, turners, and grinders. Responsible for maintenance of machines, making jigs, and fixtures for specialist jobs and for building and commissioning new machines
Responsible to Foreman
Likes/dislikes Likes the job because of the variety of work bAge42
Job titleGeneral foreman/woman
Education Technical college, City & Guilds Certificate by day release
DutiesIs in charge of 26 people - machine tool operators, tool setters,
etc. Based on the shop floor. Controls everyday production jobs
Responsible to Superintendent
Likes/dislikes Doesn't like having to sack people
22
Applications engineer
Technical college. City & Guilds Certificate by day release over 4 vears
Works in applications department - around 30 people. Responsible for liaison between the company and the customer. Tries to ensure that the customer’s requirements can be met by the company’s products. Carries out tests on the products and sends results to the customer on how the product performs.
Responsible to Department manager
Likes/dislikes Gets a lot of job satisfaction because he/she gets to see an end result. Finds the systems in the factory a bit cumbersome. They can hold up the work of the section.
2Your partner is one of these workers:
Methods engineer Systems analyst Tool maker
Student B
Speaking practice
Unit 4
Task 7
Unit 12
Use this text and diagrams to help you. Your partner has the same diagrams but has no text. Make sure your instructions are simple and clear.
Adjusting the handlebar height and tilt
A comfortable position is the best test. Different heights and angles of the handlebars should be tried until you find the position which most suits you.
To adjust the height, unscrew the expander bolt A by three or four
5turns. Give a sharp blow to the bolt head to loosen the handlebars. Re-tighten once the proper height is obtained.
Make sure the handlebars stem is not pulled too far out of the frame tube. The stem must remain at least 65 mm engaged in the front fork. The grooved part of the expansion slits should not show.
10Totiltthe handlebars, loosen bolt B.
After all adjustments have been made, make sure both bolts are firmly secured with the correct tools. The handlebars should not twist when the front wheel is held firmly between the knees.
Unit 14
Complete the missing design specifications.
Design specifications for a compression spring: ^working length 1
mean dia. 1.67 cm
Specification
Material Wire size
*Load to be supported at working length 1
free lengthcm
Type of ends
Wound L.H. or R.H. L.H.
Treatment
Finish
0.0005 cm/min.
Note. The spring diameter may be varied within the limits stated. The number of coils may be altered if necessary providing the conditions starred thus are maintained.
=0
Symbol
for
Spring to push piston back
Unit 22
Demetallification is the effective removal of one metal from an alloy, such as zinc from a copper-zinc alloy.
Although the metal remaining after attack retains similar dimensions to the original, it lacks mechanical strength and is porous.
Microbiological corrosion is more often found in hot countries, but it also occurs in tanks, such as fuel tanks. Fungus enters through the ventilation system or with the fuel and grows inside the tank. This leads to leakage and can result in structural failure.
Unit 29
1 Choose from one of these three profiles, a Age28
Job titleMethods engineer
EducationFE College, Higher National Diploma, (a sandwich course - 6
months work, 6 months study). University, BSc (Eng)
DutiesPart of a team whichplans new components andhow they are
to be manufactured. Also responsible for specifying or recommending new equipment and new machines. If there is a problem with production or materials used for a project, the team has to sort it out.
Responsible to Production engineering manager
Likes/dislikes Enjoys working as part of a team and solving problems
bAge 24
Job titleSystems analyst
EducationPolytechnic, BA in Business Studies
DutiesAssistant analystin management services department. Part of a
team composed of analysts and programmers. When a department has a problem, he/she has to analyse it and come up with a solution. If it is a solution which can be solved by a computer, the team design, write, and test a computer program for the problem. If it goes well, the program is put into use. This may involve training a ‘user’ in the new system.
Responsible to Section leader
Likes/dislikes Enjoys working with so many departments. Doesn't like it when a user changes his/her mind about something after hours have been spent designing a system.
cAge 2 3
Job titleToolmaker
EducationCollege of Technology. City& Guilds sandwich course
DutiesOne of 50 who work in thetool room - titters, turners, millers.
grinder, jig borers. Spends time on each kind of machine - surface grinders, lathe, mill.
Responsible to Foreman/woman
Likes/dislikes Likes working with his/her hands.Enjoys getting experience with different kinds of machines.
Your partner is one of these workers:
Machine tool development titter
Foreman/woman
Applications engineer
Glossary of engineering terms and abbreviations
The definitions in this glossary refer to words only as they are used in this book. The meanings of certain words will vary according to context. As the texts in this book are authentic and come from a variety of sources, some inconsistency in hyphenation and spelling is inevitable.
The unit and task numbers indicate where the word tirst appears.
Abbreviations used in the text
R = Reading section SP = Speaking practice T = Task TS = Tapescript LI = Unit
W = Writing section
11= noun ad] = adjective v = verb
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A-frame /'ei freim/n |U10. T5] a structural frame in the shape of the letter A
ac /ei 'si:/11 [U23, T6] alternating current aerodynamic /.earaodai'naemik/rtt//
[U12, T31 designed to reduce wind resistance
air classifier /'ea ,kkesifai3(r)/ n [U27,
T3| a machine which uses air to segregate materials by size and weight alarm /a'lcum/ n [ U11,T3| a means of attracting attention utilizing either sound or vision
alloy /'aebi/11 | U12, T3] a metal formed by mixing together other metals and elements
alternator/'o:lt3neit3(r)/111U17, T3] a type of generator producing alternating current
amplifier/'<emplifai?(r)/71 1U16, T81 an electronic device which converts small signal changes to large anthropomorphic /.aenBrapa'moTik/11 [U28, T3] of human-like form armature/'u:ni3tf3(r)/11 [U6, T2] the moving part of an electric motor which comprises a piece of iron with loops of wire running round it: the current through the wire is reversed to provide the changes in magnetic lields required to make the motor run
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bearing /'beamy 11 [U2, T4| a device to reduce friction and wear between a rotating shaft and a stationary part: may contain balls or rollers bimetallic corrosion /.baimataelik ka'raojn/11 | U22, T6j see galvanic corrosion block diagram /'blok .daiagnem/11 [ U11, T3 ] schematic drawing showing different functions in a system or stages in a process
body scanner/’bndi,sk«n3(r)/11 fU1, T4] a medical electronic device for building up an image of the internal organs of a patient
brittle /'britl/ adj | U3, T21 describes a material which tends to break easily, e.g. glass
brushes /'brAjiz/11 [U6, T2] spring-loaded carbon blocks which carry the electric current to the commutator of an electric motor buoyancy /'boiansi/ n [U5,T3| the upthrust exerted by a fluid buzzer/'bAza(r)/ n [U7,T5 TS| a device which uses an electric signal to produce a buzzing sound
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CAD /k<ed/ nIU20, T1 ] computer-aided design
CAM /kcem/ n[U20, T2] computer-aided manufacture cam /kaem/n[U4, T7 ] a specially profiled part which is fitted to a rotating shaft to produce linear motion capillary tube /ks'pilari ,tju:b/ n [ U15, T2] a tube with a very small diameter bore CAPP /k<ep/ n[U20, T2] computer-aided process planning carbon fibre/'ka:bn ,faibo(r)/ n|U25,
T5] high-strength fibre made from carbon atoms
carburettor/,ka:b3'ret3(r)/ n | U17, T3] a device where air and petrol are mixed in an internal combustion engine Cartesian co-ordinates /ka: ti:3n kao'oidinsts/ n [U28, T5J information about the position of a body in space using distances measured from three intersecting planes chain wheel /'tjein wi:l/ rt fU 12, T1 ] a toothed pulley or sprocket used for transmitting torque by a chain charger/'tja:d33(r)/ n f U15, T4| a device which contains a unit for converting mains power to direct current at a suitable voltage for charging batteries chisel /'tjizl/ n | U18, T3] a steel tool with one end formed into a cutting edge CIM /sim/ n | U20, T1 ] computer-integrated manufacturing: describes a series of processes or activities co-ordinated by using a computer circuit breaker /'s3:kit ,breik3(r)/ n f U21, T61 an electrical switch fitted with an overload protection cut out closed loop /.klaozd'luip/ n [ U11, T3] a system where part of the output of a system is fed back into the input to modify the output
commutator/'kDmju:,teit3(r)/ n[U6, T2f the part of the armature of an electric motor which is in contact with the brushes; it reverses the flow of current through the armature
compact disc /.kompskt 'disk/ n IU13, T2] plastic disc used to store high quality sound recordings or computer data on its surface
component evaluation /kam.paonant ivaeljo'eijn/ n [U30, T4| the testing of a component to ensure it conforms to specifications composite /'kompazit/ n fU25, T41 a fibre-reinforced plastic material compressed air /kam.prest'esfr)/ n IU18, T1 ] air at higher than atmospheric pressure: used to power pneumatic devices such as drills compression /kam'prejn/ n |U4,T4] the effect of forces which act to squash a structure
computer model /kam’pjuUa ,mDdl/ n | U24, T7] a representation of a design created in 3I) on a computer using a CAI) programme computer-based /ksm'pjuita .beist/adj | U30, T31 describes a system which relies on the use of a computer condenser/kan'denssCr)/ n III 15, T2] a unit where vapour is converted back into a liquid
conductor /k3n'dAkt3(r)/ n fU3, T3| a material which will transmit electricity or heat
constraint /kan'streint/ n [U28, T61 limit imposed by the nature of a mechanism cooling duct /'kuiliq dAkt/ n [U23, T91 a passageway to allow air to pass to a hot surface, for example, in a motor corrosion-resistant /ka'rsosn ri.zistant/ adj [U3, T3| describes a material which can be used in environments where long¬term strength or appearance is important, e.g. stainless steel corrosive /ka'raosiv/ adj [ U9, T1 ] describes a substance which corrodes (eats or wears away), usually by chemical action
crankshaft /'kneijkJ'a:ft/ n [U4, T2| the main shaft of an engine which carries the cranks for the pistons crevice corrosion / krevis k3,roo3n/ n | U22, T6] corrosion in cracks or crevices in pipes carrying liquids cylinder head /'silinda ,hed/ n [ U3, W] a plate which seals the ends of cylinders on internal combustion engines: it contains the valves
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damper/'dsmp3(r)//i |U23,T2] a device fitted between the chassis and axle of a vehicle to remove spring effects and smooth travel database /'deitabeis/ n [U20, T2J a bank of information stored in a computer for easy access dc/di:' si:/11 [U6, T5] direct current debug /,di:'bAg/ vt [U29,T2] detect, locate and correct faults degrees of freedom /di,gri:z av 'friidam/11[U28, T4] the movements achievable by a robot in three-dimensional space
desalination /.dksteli'neijn/n [U29, T5] production of fresh water from sea water die/dai/n [U13, T7] a specially shaped block of metal used as a mould for other materials die-cast /'daika:st/ adj [ U12, T6 ] produced from moulds disc brakes/'disk breiks/ n [U19, T2] brakes in which a caliper clamps brake pads onto a disc connected to the wheel of the vehicle
diverter valve /dai'v3:to ,v;elv/n [U8, T6| a valve used in central heating to redirect the flow of hot water from radiators to water heating and vice versa documentation /.dokjomen'teijn/11 [ U30, T9] the complete description of a product in words and drawings at every stage in its manufacture ductile /'dAktail/ adj |U3, T3] describes a material which can be stretched and yet retain its strength, e.g. copper ductility /dAk'tiliti/11[U26, T9| quality of being ductile
engine /'end3in/n[ U3, W] a device which coverts fuel into work equilibrium/ ekwi'libriam/ n [U5,T3] balance (a structure is in equilibrium when all the forces on it are stable and there is no movement) escalator/'esk3leita(r)/ n [U4, T2| moving stairs evaporator/i'vsep3reit3(r)/ n [U15,T2| a unit in which a liquid is converted into a vapour
exfoliate corrosion /eks'faoliat k3,r303n/ n | U22, T6] when flakes of metal are displaced due to corrosion extrusion /ik'stru:3n/ n [U13, T7] a manufacturing process whereby a material in its plastic state is forced through a die. e.g. to make plastic pipes
El
feedback /'fi:dbaek/ n [U11, T3] a signal responding to the output of a system which is returned to the input to modify the output
field magnet /'fi:ld .maegnat/ n[U6, T2] a magnet for producing and maintaining the magnetic field in a generator or electric motor friction /'frikjn/ n [ U5, T2] the resistance experienced when two bodies rub against each other fuel cell /'fjosl sel/ n|U25,T4] a cell which converts the chemical energy of a fuel to electrical energy fulcrum /'folkram/ n[U5, T6] the pivot point of a system of levers, e.g. the screw in a pair of scissors
G
EDM /,i: di: 'em/ n |U20, T2] engineering data management elastic limit /i'laestik .limit/n [U26,T6] the point at which a material will no longer return to its original shape after tensile forces are released elasticity /ilass'tisiti/ n | U5, T3] the property of a material to stretch and then return to its original state encapsulation /ig.kcepsjo'leijn/ n [U3, T3] the process of completely embedding a component in a resin as protection from the environment galvanic corrosion /gael'vaemk ks.raojn/11[U22, T6] the corrosion which results when two dissimilar metals are connected in the presence of moisture gears /gisz/11 [U12, T1 ] an arrangement of toothed wheels which mesh together to change the speed or direction of movement goggles /'gogolz/ n [U9, T71 protective eye wear completely surrounding the eyes granules /'grienjoalz/ n fU13, T7] material, e.g. plastic, in the form of small grains
grinder /'grainda(r)/ n 1 [U9,T3]a machine with a rotating disc of abrasive material used for sharpening tools and removing rough edges [ U29 SP (A)] a grinding machine operator guard /ga:d/ n [U9, T3] a device to safeguard the operators of moving machinery hammer mill /’haema mil/ n IU27, T3| a crushing machine using impacts from rotating arms hazard /'haezad/ n [U9, T21 danger heat exchanger /'hi:t iks.tjemd.ptr)/ n | U8, T31 the part of a boiler where the water is heated heat-resistant/'hi:t ri.zistant/«d/ [U3, T3] describes a material which will withstand exposure to high temperature hinge 'hindj/ n [U5, T6] a flexible mounting for doors and lids hydraulic /hai'dro:lik/adj [U19, T2] describes a system using cylinders and
pistons and driven by a fluid ignition /ig'nijn/ n |U28, T9| the circuit which allows high-tension current to pass to the sparking plugs in an internal combustion engine insulator /'insjo,leit3(r)/ n | U3, T3| a substance which will not transmit electricity or heat interface /‘intafeis/ II [U28, T21 hardware and software to enable a computer to communicate with the device to be controlled
intergranular corrosion /.mtsgnenjob ka'r303n/ II [U22,T6| corrosion at the boundaries of the crystal grains of a material
IT/ai 'ti:/ n | U20, T1 ] information technology jig /d3ig/ n [U29 SP (A)] a work-holding device made for a specific component, e.g. to hold it for drilling JIT/,d3ei ai 'ti:/ n [U20, T2| just-in-time manufacturing laser/'leiz3(r)/ II [U13,T2] Light Amplification by Stimulated Kmission of Radiation
LCD /,el si: 'di:/ n [U16, T6] liquid crystal display
load cell /'bod sel/ n IU16, T5] a load- measuring element using an electrical strain gauge as the measuring device malleable /'nueliobl/ adj [U3, T3j describes a material which can be stretched without breaking apart, e.g. copper
manipulator/ma'nipjo.leitatr)/ n |U28, T2J the part of a robot which carries out the work methods engineer /'meOadz end3i,ma(r)/ n IU29,T7] someone concerned with establishing the best production method and equipment for making an article micrometer /mai'kromit3(r)/ n | U29, T2l a U-shaped gauge used for precise measurement of thicknesses: the gap between the measuring faces is adjusted by rotating a screw thread encased in a graduated sleeve microprocessor/.maikrao'prsosesatr)/
;i [ U16, T5] integrated circuit chip at the centre of a computer for controlling the system and processing the data mill /mil/ n IU29, SP (B)] a milling machine: uses multi-toothed cutters to shape metals and plastics miller/'nub(r)/ n [U29, SP (A)| a milling machine operator MRP /,em a: 'pi:/ n |U20,T2] materials
□
requirement planning pedal/'ped(a)l/ /i[U12,T1] foot-operated lever, e.g. the accelerator pedal of a car pendulum/'pendjobm//i |U4, T2] the swinging weight used for time control in some clocks pilot light /'paibt lait/ n | U8, T2] a small flame used to ignite the main burners in a gas-fired heating boiler pitch /pitJ"/ n [U28, T8| angular displacement along the lateral axis pitting /'pitnj/ n | U22, T61 corrosion due to localized chemical reaction plant /plci:nt/ n [U8, T7) the machines in a factory and all the buildings PLC /,pi: el 'si:/ n (U20, T21 programmable logic control/controller: the system/device by which a microprocessor controls a stage in a process automatically pneumatic drill /nju:,maetik dril/ n | U18, T31 a drilling machine using compressed air for power pressure regulator/'preja ,regjoleito(r)/ n (U21, T6] a device for adjusting or maintaining pressure levels prototype/’pr3ot3,taip/n |U10,T2TSJ the first working model pulley /'poll/ ;i [ U10, T5] a grooved wheel over which a rope passes
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reaction /rii'iekjn/ /i |U5,T3] the force which opposes an applied force reamer /ri:ma(r)/ n [U19, T6| a tool for enlarging a drilled hole to a precise diameter recycling/,ri:'saiklii]/ n |U27,T1] extracting from waste all materials that can be reprocessed to be used again refrigerant/ri'frK^arant/111U15, T2] a substance which changes easily from a liquid to a gas and which can be used in refrigeration to remove heat energy and transfer it to the surroundings regenerative braking /ri'djenorativ breikny n [U25, T5] a method of braking electric motors where the motor becomes a generator converting the energy of the slowing wheels into electricity remote control /ri.maot kan'traol/ n [ U11, T3] a device for controlling something from a distance respirator/'respa,reita(r)/n [U9,T7] a mask worn over the nose and mouth to filter air
resultant /ri'zAltant/ n |U5, T2| the single outcome of a number of different vectors revolve /n'volv/ vi[U5,T7 TS] turn, rotate
robotics rao'bDtiks/ n [U28] the study or production of machines which perform tasks in a manner similar to humans roll /raol/ n [U28, T8| angular rotation about a longitudinal axis rotor /'raota(r)/ n [U17, T2 | rotating part of a generator
scallop /'skolap/ njU28, T6] fan-shaped curve
scratch-resistant /'skraetj ri.zistant/ adj | U3, T3| describes a material which retains its appearance when exposed to abrasion
sensing device 'sensnj di.vais/ n[U7, T5 TS | a device which monitors the operating environment and is sensitive to change
shock absorber /'Jok ab,zo:ba(r)/ n | U11, T2 ] a device for absorbing shocks and vibrations signal generator signal djenareitafr) n[U21, T61 electronic device which produces various signals used in tests and measurements solenoid 'saolanoid/ n [U11,T2] a coil with an iron core which is pulled into the coil by a current passing through the coil solenoid valve /'saolanoid ,vaelv [U11, T2] a valve operated by a solenoid spanner /'spiena(r)/ n [U5, T7 TS] a tool, or level, for applying force to nuts and bolts
speed governor /'spi:d,gAvana(r)/ n (U21, T61 a device fitted to an engine to limit its speed to a pre-set level spring balance spriq 'baelans/n | U5, T3| a measuring device in which the force applied is calculated by the extension of a spring sprocket /'sprnkit/ /i [U12, T10| a toothed wheel over which a chain passes stator/'steita(r)/ n | U17, T2] stationary part of a generator strain gauge 'strein geid^ n |U16, T5J a device for measuring strain in a structure switchgear/'switj’gia(r)/ n [U1, T5] switches and associated equipment for controlling large electrical currents systems analyst 'sistamz .amalist/ n | U29, T7 ] someone responsible for examining a problem to see whether it is suitable for a computer application
□
tachogenerator /'tiekao.djenareitafr)/ n [ U11, T4 ] a sensor for measuring the speed of rotation TEFC /,ti: i: ef 'si:/adj[U23, T9] totally- enclosed fan-cooled (motor) tension /'tenjn/;/ fU4, T4] the effect of a pulling force which tends to stretch a body thermoplastic /'03:mao,plaestik/ n | U3, T11 a plastic which softens when heated and hardens when cooled thermosetting plastic /,03:m3osetii] pUestik/ n [U3, T3 | a plastic which retains its shape and rigidity at high temperatures thermostat /'03:mastaet/ n [U8, T3| a control device which operates at a pre-set temperature throttle /'Orntl/ n | U18, T3] a valve for controlling the supply of a gas or liquid (e.g. fuel) to an engine thrust /0rASt/ n [U12, T6] force of propulsion tooling/'tuilirj/ n[U13,T10] all
manufacturing equipment required for the manufacture of a product toxic /'tDksik/ adj[ U9, T1 ] poisonous transformer/,tnEns'fD:m3(r)/ n[U6, T6| a device for stepping up or down the voltage of an alternating current treadle /tredl/ n[U4, T6] a linkage used to convert oscillating into rotary movement and vice versa turbine /'t3:bain/ ;i fU17, T9] a machine which produces power when steam, gas or water is passed over the blades attached to the rotating drive output shaft turbulence /'t3:bjobns/ n[U12, T6] violent or uneven movement of air turner /’t3:n3(r)/ n \U29, SP (A)] a lathe operator
□
yaw /jo:/ n [U28, T8] angular rotation about a vertical axis yield point /'ji:ld point/ n [U26, T7] the point where the elastic limit is reached
u
undercarriage /'Ands.kajridy n[U23, R2] the supporting framework of a vehicle comprising wheels, axles, suspension, etc.
□
vapour /'veipa(r)/ n [U15, T2] a gas that can be liquefied by increasing its pressure vernier /'v3:ni3(r)/ n IU29, T2] a measuring gauge fitted with an auxiliary scale which allows the operator to read the main scale with an accuracy of one tenth of a division
w
waisting /'weistiq/ n [U26, T7]
deformation which brings about narrowing of the section of a rod or material under tension wave power /'weiv ,pao3(r)/ n[U17, T9] a method of generating electricity by using the movement of waves in water work volume /'W3:k ,vDlju:m/ n[ U28,
T4] the space volume into which the manipulator of a robot can be positioned: hence the volume where useful work can be done
Oxford English for Electrical and Mechanical
This course is intended for students of Electrical Engineering and Mechanical Engineering in universities, colleges, and technical schools, and for technicians and engineers. It can be used for self- study in conjunction with the Answer Book.
Student's Book
The thirty units contain authentic reading and listening passages from a wide variety of sources. The topics have been chosen to cover areas that are common to both Electrical Engineering and Mechanical Engineering. The course aims to develop all four skills through a series of tasks that encourage students to combine their knowledge of English with their technical knowledge. The Student's Book contains a comprehensive glossary of important technical terms.
Cassette
The cassette contains interviews with people studying Engineering or working in the engineering industry.
Answer Book
The Answer Book contains a key to the tasks and exercises, the tapescripts, and useful unit-by-unit teaching notes.
Cover photograph
Robot welding of a body shell on the Rover production line at Cowley near Oxford by James Holmes
Task 4Thereareexamples on the following pages of some of the kinds of texts you
may read in your studies or working life. Match them to this list:
1table
2index
3contents
5manual
6price list of components
8job advertisement
Task 4 E3 Listen to Parts 1 and 2 of the interview in turn. Answer these questions. Compare your answers with a partner.
Part 1
1What is the name of David’s course?
2How long is the course?
3How old is David?
4 How long was he in the Navy?
5 How many types of submarines are there?
Part 2
6How many weeks of teaching does he have left?
8What happens if you fail the tests once?
9How many are in his class?
10What kind of problems has he had?
Task 6Answer these questions on the technicalinformation in the interview.
1What sort of tasks can the robots perform?
1The switch is on.
2The lamp does not light.
Even if the switch is on. the lamp does not light.
Although the switch is on. the lamp does not light.
Stepper motors are useful wherever accurate control of movement is required. They are used extensively in robotics and in printers, plotters and computer disk drives, all of which require precise positioning or speed. In a plotter, for example, by using two motors
Task 10Read the text again to find the answers to these questions.
2Who is the Chairman of a company responsible to?
3Who comprise the Management Team?
4In what way might companies differ in structure from the example given?
5Which department would advise on whether a new product would meet customers’ requirements?
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