Industrial Design

A Short Course in Industrial Design Eskild Tjalve Senior Lecturer, Department o f Engineering Design, The Technical University o f Denmark

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Butterworths (Publishers) Inc Boston: 10 Tower Office Park, Woburn, Mass. 01801 First published in Denmark in 1976 as 'Systematisk udformning af industriprodukter' First published in English 1979 © E. Tjalve, 1979 All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, including photocopying and recording, w i t h o u t the written permission of the copyright holder, application for which should be addressed to the publisher. Such written permission must also be obtained before any part of this publication is stored in a retrieval system of any nature. This book is sold subject to the Standard Conditions of Sale of Net Books and may not be re-sold in the UK below the net price given by the Publishers in their current price list.

British L i b r a r y Cataloguing in P u b l i c a t i o n Data

Tjalve, Eskild A short course in industrial design. 1. Engineering design I. Title 620'.0042

TA174

78-41280

ISBN 0-408-00388-X

Typeset by Butterworths Litho Preparation Department Printed in Scotland by Thomson Litho L t d . , East Kilbride

Preface T h e c r e a t i o n o f a n e w p r o d u c t takes i n m a n y levels o f a c t i v i t y a n d m a n y s k i l l s , o f w h i c h t h e f i r s t a n d f o r e m o s t are t h o s e o f design engineers a n d i n d u s t r i a l designers. I t is easy t o recognise t h e e x t r e m e s w h e n c o m p a r i n g t h e r e s p o n s i b i l i t i e s o f t h e design e n g i n e e r a n d t h e i n d u s t r i a l designer, b u t n o t so easy t o say w h e r e t h e r e s p o n s i b i l i t y o f one ends a n d t h e o t h e r begins. T h e design engineer is i n v o l v e d in design w h i c h is o f t e n k n o w n b y o t h e r names, e.g. s k e t c h i n g , d e t a i l d e s i g n , d i m e n s i o n i n g , e t c . A c o n s i d e r a b l e p a r t o f t h e w o r k o f design engineers a n d i n d u s t r i a l designers consists o f t h e same a c t i v i t i e s , i.e. f o r m u l a t i o n o f suggestions o f shape, ' m o d e l l i n g ' o f these ( s k e t c h i n g , d r a w i n g o r h a r d w a r e m o d e l l i n g ) , i n v e s t i g a t i n g a n d a p p r a i s i n g t h e v a r i o u s p o s s i b i l i t i e s . These a c t i v i t i e s i n v o l v e t h e creative m i n d at m a n y levels a n d are t h e s u b j e c t o f t h i s b o o k , w h i c h n o t o n l y i n t r o d u c e s t h e s t u d e n t t o t h e p r i n c i p l e s o f e v o l v i n g a d e s i g n , b u t surveys t h e c r i t e r i a b y w h i c h these are assessed. T h r o u g h o u t t h i s b o o k t h e w o r d ' d e s i g n e r ' has been used as a b l a n k e t t e r m f o r p e o p l e w o r k i n g w i t h design (i.e. engineers, designers and others) of products. T h e c o n t e n t s o f t h i s b o o k s h o u l d be seen as p a r t o f t h e design t e c h n i q u e . In t h e o v e r a l l p l a n f o r p r o j e c t e v a l u a t i o n a n d design o n l y t h e m e t h o d s c o n n e c t e d w i t h t h e f i n a l phases o f design p r o j e c t have been d e s c r i b e d . T h e danger o f f o r m u l a t i n g s y s t e m a t i c m e t h o d s in c o n n e c t i o n w i t h c o n s t r u c t i o n w o r k , is t h a t o t h e r s are led i n t o t h i n k i n g t h a t a s y s t e m a t i c a p p r o a c h necessarily gives t h e r i g h t a n s w e r . T h i s is j u s t n o t so. T h e m o s t e f f e c t i v e s o l u t i o n is achieved b y t h e r i g h t balance o f s y s t e m a t i c s a n d i n t u i t i o n . T h e s y s t e m a t i c a p p r o a c h s h o u l d t h e r e f o r e be seen as t h e f o u n d a t i o n f o r t h e a p p r o p r i a t e a t t i t u d e t o i n n o v a t i o n , n a m e l y an u n d e r ­ s t a n d i n g o f t h e f a c t t h a t one c a n , t h r o u g h a c o n s c i o u s e f f o r t l o o k o b j e c t i v e l y a n d s y s t e m a t i c a l l y at all t h e design c r i t e r i a a n d premises o n w h i c h a n y p a r t i c u l a r s o l u t i o n is based. E x i s t i n g p r o d u c t s have t o a great e x t e n t been used as e x a m p l e s . These are i n c l u d e d p a r t i c u l a r l y

where

t h e y i l l u s t r a t e d i f f e r e n t a p p r o a c h e s t o t h e same p r o b l e m a n d d i f f e r e n t results — a n d n o t because t h e y are p a r t i c u l a r l y g o o d o r b a d . T h e r e is t h u s n o i m p l i e d e v a l u a t i o n in t h e i r p r e s e n t a t i o n . I w o u l d l i k e t o t h a n k t h o s e c o m p a n i e s w h i c h have c o n t r i b u t e d t o t h e e x a m p l e s b y s u b m i t t i n g m a t e r i a l o f v a r i o u s k i n d s . T h e p h o t o g r a p h s w h i c h are n o t a c k n o w l e d g e d w e r e t a k e n o n m y b e h a l f b y F r a n k S c h m i d t , t o w h o m I am very grateful. It is m y h o p e t h a t m a n y o f t h o s e w h o are i n v o l v e d in t h e e v o l u t i o n o f p r o d u c t s w i l l f i n d t h i s b o o k useful w h e t h e r t h e y are engineers o r designers. I also h o p e t h a t t h e b o o k w i l l f i l l a gap i n t h e l i t e r a t u r e c o n n e c t e d w i t h t h e t e a c h i n g o f e n g i n e e r i n g design in t h e schools o f e n g i n e e r i n g . In t h e t r a d i t i o n a l a p p r o a c h , a m a t e r i a l o b j e c t requires a r o u g h d r a w i n g b e f o r e o n e c a n get d o w n t o t h e necessary s p e c i f i c c a l c u l a t i o n s a n d d e t a i l i n g . A l o t o f t i m e is r i g h t l y used o n these essential p r o c e d u r e s , y e t so o f t e n n o o n e w i l l q u e s t i o n h o w t h e idea be­ h i n d a n y p a r t i c u l a r s c h e m e has e m e r g e d . It is t o o c o m m o n a m i s t a k e t o regard t h e f i r s t idea f o r a design as t h e o n l y o n e o r even as t h e best. L a s t l y I h o p e t h a t t h e b o o k m a y be an i n s p i r a t i o n t o i n d u s t r i a l designers in t r a i n i n g a n d in p r a c t i c e , as i t m u s t be i m p o r t a n t f o r designers t o get an idea o f t h e phases a c o m p l e x p r o d u c t goes t h r o u g h , as w e l l as a general v i e w o f t h e r e l e v a n t c r i t e r i a f o r e v a l u a t i o n . Eskild Tjalve

1 CREATION OF A PRODUCT 1.1

T h e idea o f f o r m

3

1.2

Life o f the product

1.3

Properties o f t h e p r o d u c t

1.4

T h e step-by-step creation o f t h e p r o d u c t

6 7 7

1. Creation of a Product 1.1 The idea of f o r m A v e r y great p a r t o f o u r w o r l d consists o f o b j e c t s

the handwheel)

w h i c h have o n e f u n d a m e n t a l p r o p e r t y , f o r m : i.e. a

valve seat).

shape, a c e r t a i n a r r a n g e m e n t o f parts a n d an o v e r a l l

T h e valve seat is a n n u l a r because o n e m u s t be

s t r u c t u r e . F o r m m a y arise as f o l l o w s ( F i g u r e 1 ) :

able t o face i t o f f w i t h a m i l l i n g c u t t e r t o m a k e

1. A n

uncontrolled

depends solely

process,

where

the

form

on the conditions o f the en­

laws as w e l l as t h e c o n d i t i o n s o f t h e e n v i r o n ­ m e n t , e.g. ice c r y s t a l s , m i c a . process c o n t r o l l e d

ditions

of

the

environment,

e.g.

animals and the c o n d i t i o n s o f the e n v i r o n m e n t , p r o d u c t s , a beaver's d a m ,

b i r d s ' nests. Now

that our

form

of

the

valve consists o f

two

mould

f r o m w h i c h t h e valve h o u s i n g is cast.

S i m i l a r c o m m e n t s t o t h e above can be m a d e o n t h e c u p a n d saucer s h o w n in F i g u r e 3 : T h e c u p a n d saucer have r o t a t i o n a l either

symmetry,

because t h e y are t h r o w n o n t h e

potter's

w h e e l o r , (if t h e y w e r e m a d e in a m o u l d ) s i m p l y

manufactured everyday

whole environments

outer

intersecting cylinders.

living

4 . A process c o n t r o l l e d b y t h e wishes o f m e n o r

dominate

The

T h e c y l i n d e r f o r m is d e t e r m i n e d b y t h e

b y genes a n d t h e c o n ­

organisms.

e.g. m a n u f a c t u r e d

i t f i t t i g h t l y against t h e gasket. T h e i n n e r c a v i t y o f t h e valve is shaped t o f a c i l i t a t e flow.

v i r o n m e n t , e.g. p e b b l e s , m o u n t a i n ranges. 2. A process c o n t r o l l e d b y p h y s i c a l a n d c h e m i c a l

3. A

i n t o one of translation (of the

products

world

increasingly

— indeed

are m a n - m a d e

where

— w e need t o

because

cups

and

saucers

traditionally

have

rotational symmetry. T h e c u p is c y l i n d r i c a l because a c e r t a i n appearance

analyse m o r e c l o s e l y t h e processes b y w h i c h f o r m

was d e s i r e d .

is d e t e r m i n e d , so t h a t w e m a y design o u r e n v i r o n m e n t

T h e c u p is s m a l l e r in d i a m e t e r at t h e base p a r t l y

as m u c h t o o u r l i k i n g as p o s s i b l e . As a f i r s t a t t e m p t at t h i s analysis let us e x a m i n e

because i t is t h e n s t a c k a b l e a n d p a r t l y f o r reasons o f appearance.

t h e valve in F i g u r e 2 . T h e design o f t h e valve a n d

T h e n o t c h in t h e base o f t h e c u p lets t h e w a t e r

t h e parts f r o m w h i c h it is assembled is as f o l l o w s :

drain

away

if i t

is w a s h e d ( u p s i d e d o w n ) i n a

washing up machine. T h e t w o c o n n e c t i n g pieces are h e x a g o n a l because o n e m u s t be able t o assemble t h e valve w i t h an a d j u s t a b l e spanner. T h e r o t a t i n g n u t u n d e r t h e h a n d w e e l is also h e x ­ agonal so t h a t it can be t i g h t e n e d w i t h a s p a n n e r .

T h e shape o f

t h e h a n d l e ensures t h a t t h e

part

w h i c h is h e l d does n o t get t o o h o t w h e n t h e c u p is b e i n g u s e d . T h e edge o f t h e saucer is t u r n e d u p because it m u s t be able t o h o l d l i q u i d s p i l t f r o m t h e c u p .

T h e h a n d w h e e l is r o u n d because t h e h a n d m u s t be able t o grasp it f i r m l y in all p o s i t i o n s .

Even if these t w o e x a m p l e s are a l i t t l e s i m p l i f i e d

T h e s p i n d l e is t h r e a d e d because o f its f u n c t i o n ,

t h e y s t i l l s h o w c l e a r l y t h a t t h e design o f a p r o d u c t

w h i c h is t o t r a n s f o r m t h e r o t a r y m o v e m e n t ( o f

a n d its e l e m e n t s d e p e n d s o n m a n y d i f f e r e n t f a c t o r s .

Figure

1

Form

can arise in four

ways

Creation

Figure

e.g.

m a n u f a c t u r i n g process, f u n c t i o n , ease o f h a n d ­

ling,

appearance

and

economics.

Another

very

i m p o r t a n t f a c t o r , w h i c h w e m u s t n o t f o r g e t , is t h e person

who

designs

the product.

However

many

2

of a Product

The form of the valve is determined number of factors

5

by a large

A n understanding of the factors w h i c h influence t h e design m u s t

be b u i l t

on a knowledge

of

the

v a r i o u s stages i n t h e l i f e o f t h e p r o d u c t . In t h e f o l ­ l o w i n g pages, t h e r e f o r e , w e w i l l e x a m i n e a m o d e l o f

the

t h e life o f a p r o d u c t f r o m i n c e p t i o n t o d e s t r u c t i o n ,

d e s i g n , t h e r e w i l l a l w a y s be r o o m f o r t h e designer

as w e l l as a m o r e d e t a i l e d m o d e l o f t h e w a y in w h i c h

t o express his ideas a n d personal j u d g e m e n t .

a p r o d u c t comes into being.

r e q u i r e m e n t s t h e r e are in t h e s p e c i f i c a t i o n o f

Figure 3

Many factors determine

the form of a cup

(R0rstrand)

6

Creation

of a Produc t

1.2 Life of the product

p r o d u c t is c o m p l e t e l y s p e c i f i e d . F o r p r o d u c t s w h i c h are t o be p r o d u c e d i n great n u m b e r s , t h e design a n d

All

p r o d u c t s are c r e a t e d , used a n d e v e n t u a l l y dis­

carded.

L e t us, t h e r e f o r e ,

examine a little

more

choice o f p r o d u c t i o n m e t h o d f o l l o w next, b u t f o r t h e sake o f c l a r i t y t h i s phase has been l e f t o u t i n

closely w h a t happens t o a p r o d u c t before, d u r i n g

Figure 4 . N e x t comes t h e p r o d u c t

a n d a f t e r use.

process, a f t e r w h i c h t h e p r o d u c t is sold t o t h e dealer, is used i t p e r f o r m s a process

f r o m w h o m i t is resold t o t h e c o n s u m e r . O n l y n o w

brings a b o u t a n e x t e r n a l change f r o m o n e

can t h e p r o d u c t f u n c t i o n a c c o r d i n g t o its i n t e n d e d

When a product which

manufacturing

I t is t h e need f o r t h i s t r a n s f o r ­

p u r p o s e . T h e l i f e o f t h e p r o d u c t ends w i t h d e s t r u c ­

m a t i o n t h a t has caused t h e p r o d u c t t o be c r e a t e d ,

t i o n . T h i s process can be a c t i v e , w h e r e t h e p r o d u c t

state t o a n o t h e r .

may

for example:

be c r u s h e d , t a k e n a p a r t o f m e l t e d d o w n , o r

passive, w h e r e i t rusts, c r u m b l e s o r d e c o m p o s e s , e t c . Scissors:

A w h o l e sheet o f paper -

Fiie:

i n t o t h e design process f r o m ail o t h e r p r o d u c t - r e l a t e d

A blank w i t h burrs — a blank w i t h chamfered

Television:

A person w i t h a need f o r e n t e r t a i n m e n t

E f f e c t i v e design is o n l y

possible i f t h e

information

Extruder:

Plastic granules — c o n t i n u o u s l e n g t h o f

plastic p r o f i l e w i t h t h e r e q u i r e d cross s e c t i o n . B e f o r e t h e p r o d u c t is used t h e user has b r o u g h t it f r o m a dealer, w h o i n t u r n has b r o u g h t i t f r o m t h e m a n u f a c t u r e r . W h e n i t has e i t h e r served its p u r ­ pose, w o r n o u t o r b r o k e n , i t is d e s t r o y e d . If these events are a r r a n g e d in sequence, w e c a n i l l u s t r a t e t h e life o f t h e p r o d u c t as s h o w n i n F i g u r e 4 . T h e s t a r t i n g p o i n t is t h e use f o r w h i c h t h e p r o d u c t is i n t e n d e d . T h e f i r s t phase is t h e design process i n w h i c h possible m e t h o d s o f s a t i s f y i n g t h e user needs examined,

ing

board

and in other

departments. Thus, the

— a person e n t e r t a i n e d a n d i n ­ p r o d u c t is s p e c i f i e d d u r i n g t h e design process, b u t w i t h r e q u i r e m e n t s a n d wishes f r o m all t h e o t h e r

formed.

are

activities.

designer is a w a r e o f w h a t h a p p e n s b e y o n d t h e d r a w ­

edges. and

F i g u r e 4 s h o w s t h a t , i d e a l l y , i n f o r m a t i o n is f e d

paper d i v i d e d

i n t o t w o pieces.

a n d in w h i c h

the finally

chosen

stages i n m i n d . It is i m p o r t a n t t o realise t h a t F i g u r e 4 s h o w s t h e general

course

of

an i n d u s t r i a l l y

manufactured

p r o d u c t . I n p r o d u c t s t h a t are designed a n d m a d e b y t h e same p e r s o n t h e f i r s t t w o processes can be c o m ­ b i n e d . N o t e also t h a t t h e r e m a y be o t h e r i n p u t t o t h e design process o t h e r t h a n i n f o r m a t i o n o n need o r f u n c t i o n , such as an idea f o r a p r o d u c t o r n e w competing

products. The input

shown

in F i g u r e

4 , h o w e v e r , is c o n s i d e r e d t h e general o n e , because in t h e o t h e r s i t u a t i o n s o n e s t i l l has t o g o b a c k a n d start w i t h t h e n e e d .

Feed-back information

r

1

Γ

Information Of need

_

DBSIGK/ Specificaéion of Ihe product

/f^iv mater Lais

UAKJUrACTUI^E

^

SALE

h

DESmUCT/ON

)Ñaste mo^terials

Product Object in

Object in, first

Figure

second

state

4

USIKJQ Showing

PKOCESS

the processes in the life of a

product

state

Creation

1.3 Properties o f the product

of a Product

7

T h e a i m in d e s i g n i n g is t h a t t h e q u a l i t i e s p r e s e n t in t h e finished p r o d u c t s h o u l d c o r r e s p o n d t o t h e

A n y o b j e c t ( p r o d u c t , m a c h i n e , o r s y s t e m ) possesses

p r o p e r t i e s r e q u i r e d . A s t h i s a i m , h o w e v e r , is n o t al-

characteristic

ways

may

p r o p e r t i e s . S o m e o f these p r o p e r t i e s

be d e s i r e d , b u t o t h e r s m a y be m o r e o r less

unwanted. The most

important

Thus

p r o p e r t y o f all is

t h e p r i m a r y f u n c t i o n o f t h e p r o d u c t , because it is

achieved, w e must distinguish

between the

desired p r o p e r t i e s a n d t h e realised ones. w e c a n arrive at a m o d e l

o f t h e design

process as s h o w n i n F i g u r e 5. T h i s s h o w s t h e step-

t h i s t h a t helps t h e user in his n e e d . T h e o t h e r desir-

b y - s t e p process f r o m t h e analysis o f t h e p r o b l e m t o

able p r o p e r t i e s m a y b e : pleasing a p p e a r a n c e , ease o f

the finished product.

handling, safety, durability and reliability. Before

the

product

is

designed

the

I n t h e i n i t i a l analysis stage, t h e p r o b l e m is exrequired

a m i n e d f r o m all sides. T h i s results o n t h e o n e h a n d

p r o p e r t i e s s h o u l d be listed b y t h e designer, p e r h a p s

in a c o n c r e t e f o r m u l a t i o n o f t h e desired f u n c t i o n ,

in c o l l a b o r a t i o n w i t h

a n d o n t h e o t h e r h a n d , i n a list o f t h e desired p r o p e r -

period

when

t h e user. D u r i n g t h e design

the product

is c r e a t e d ,

it

is these

p r o p e r t i e s t h a t d e t e r m i n e t h e decisions a n d c h o i c e s

ties w h i c h c o n s t i t u t e t h e c r i t e r i a t h a t m u s t m a k e u p the b a c k g r o u n d f o r the selection o f solutions.

t h a t are m a d e .

N e x t f o l l o w s t h e stage o f s y n t h e s i s , i.e. t h e stage

Unfortunately

o n e c a n n o t design a p r o d u c t in

in w h i c h t h e p r o d u c t

is c r e a t e d . T h i s is d o n e b y

such a w a y t h a t t h e desired p r o p e r t i e s are d e t e r m i n e d

r o u g h l y d e t e r m i n i n g step b y step o n t h e basic p r o p e r -

o n e a f t e r t h e o t h e r , f o r t h e y are n o t i n d e p e n d e n t

ties

variables. We f i n d , h o w e v e r , t h a t f i v e p r o p e r t i e s c a n

surface.

be d i s t i n g u i s h e d f r o m all o t h e r s , in t h a t t o g e t h e r t h e y completely define the p r o d u c t . T h e y are:

of

structure,

f o r m , material, dimension, and

W h e n t h e basic p r o p e r t i e s are d e c i d e d o n , t h e design o f t h e p r o d u c t is f i n i s h e d , a n d i t c a n be m a n u f a c t u r e d . A f t e r m a n u f a c t u r e the p r o d u c t exists, and

For the product

as a

whole:

S t r u c t u r e (i.e. t h e

possesses s o m e 'realisedproperties.,

elements o f the

are close t o t h e ' d e s i r e d p r o p e r t i e s ' t h a t w e r e f o r m u -

which hopefully

product and their

l a t e d d u r i n g t h e i n i t i a l analysis.

relationship) For each

Form

element:

1.4 The step-by-step creation o f t h e p r o d u c t

Material Dimension

T h e design m o d e l

Surface

s i m p l i f i e d o n e , t h a t serves o n l y t o give a general v i e w

s h o w n in F i g u r e 5 is a g r e a t l y

o f t h e design process. I t c a n n o t be used as a recipe These f i v e p r o p e r t i e s are t h e basic properties.

It

for

d e s i g n i n g a p r o d u c t . I t c a n , h o w e v e r , be elab-

is i m p o r t a n t t o emphasise t h a t these are t h e variables

o r a t e d t o t r y t o achieve t h i s . A s w e are p r i m a r i l y

which

concerned w i t h the quality of ' f o r m ' , we will only

t h e designer c a n m a n i p u l a t e , a n d i t is b y

successively

deciding

on

these

that

a product

is

c r e a t e d . T h u s all t h e o t h e r p r o p e r t i e s , desirable as well

as u n d e s i r a b l e ,

are d e r i v e d

from

the

m a k e t h e m o d e l m o r e d e t a i l e d in t h e stages w h e r e t h e basic p r o p e r t i e s are l a i d d o w n .

basic

properties.

We c a n call t h e d e t a i l e d m o d e l the product

syn-

thesis, as i t s h o w s t h e i n d i v i d u a l steps t h r o u g h w h i c h

BASIC

PJ^0P£R:T/£3

Structure Form

DESlfZED

REALISED P/^OPE/ZTIEö

Uc^tercaL

PIZOPEfZr/äS

DimenscoK Sur/Uce Figure

5

Tfie basic properties

are the variables

which the designer can manipulate. depend on these

The other

properties

of the

product

8

Creation

of a

Product

PROBLEM ANALYSIS

MAI/

Abhe'^s presto (onentatíonj

FUm

Tiltit^'ß mirror (cívtsst/icatioti)

Figure

182

The best basic

structure

182

Case history:

chromosome

apparatus

5.3 Quantified structure O n t h e basis o f t h e c h o s e n basic s t r u c t u r e i n F i g u r e

n u m b e r o f sketches are m a d e , as s h o w n i n

182 a n u m b e r of crucial specifications and the main

183.

Figure

T h e s e , h o w e v e r , c a n o n l y give a c e r t a i n general

d a t a m u s t be l a i d d o w n , so t h a t a k a r y o t y p e o f t h e

impression of the possibilities, while a m o r e detailed

d e s i r e d q u a l i t y c a n be p r o d u c e d . T h e m o s t i m p o r t a n t

assessment

d a t a o f t h e c o n s t i t u e n t s u b - s y s t e m s are e x a m i n e d

t h r e e - d i m e n s i o n a l s t r u c t u r e m o d e l . T h i s is m a d e o f

a n d d e c i d e d o n ( t y p e o f m i c r o s c o p e , f i l m cassette,

p l a s t i c f o a m i n s u c h a w a y t h a t all t h e e l e m e n t s c a n

of

the quantified structure

requires a

l e n g t h o f l i g h t rays, e t c ) a n d a f t e r t h a t , m o d e l l i n g

be easily m o v e d a b o u t . F i g u r e 1 8 4 s h o w s a n u m b e r

of

o f t h e best q u a n t i f i e d s t r u c t u r e s .

v a r i o u s q u a n t i f i e d s t r u c t u r e s c a n t a k e p l a c e , as

described

in

Chapter

2.

In

the

first

instance

a

SYMBOLS ffl Μ

Μ

o

o

Kiicroscope

1« F

Film cassette

i

F5

EM Ο

K^ovinj system

5

Ο

or

Ys

Figure

183

Quar)tified

η

Μ

structures

L

on ttie basis of the best basic structure

shown

in Figure

182

Case history The three-dimensional structure models make it

: chromosome

apparatus

183

d i f f e r e n t p r o j e c t i n g lenses) a n d t o t h e A b b e ' s p r i s m .

possible t o evaluate s u c h aspects as w o r k i n g space

In this w a y t h e picture o f the desired c h r o m o s o m e

f o r t h e operator, mechanical c o m p l e x i t y , heat ( f i l m

is f o c u s s e d a n d o r i e n t a t e d . T h e t i l t i n g m i r r o r , w h i c h

n o t t o o close t o t h e l a m p ) , h e i g h t , w i d t h a n d d e p t h

performs

of

p i c t u r e , is p o s i t i o n e d t h r o u g h a m o v i n g s y s t e m t h a t

the

instrument

etc.

On

t h e basis o f s u c h

an

the

classification

of

the

chromosome

e v a l u a t i o n t h e q u a n t i f i e d s t r u c t u r e m a r k e d B—9 i n

is a c t i v a t e d b y a k e y b o a r d w i t h a c o n t r o l k n o b f o r

Figures 1 8 3 a n d 1 8 5 is c h o s e n .

each c h r o m o s o m e .

T h e c h o s e n s t r u c t u r e is s h o w n in greater d e t a i l in

Apart

from

the

karyotype,

the

chromosome

a

a p p a r a t u s m u s t also be able t o p h o t o g r a p h t h e w h o l e

screen o n w h i c h is p r o j e c t e d a p i c t u r e o f t h e cell

c e l l . T h i s t o t a l p i c t u r e c a n be t a k e n w h e n t h e d i a ­

Figure

184. The operator

has in f r o n t

of

him

w i t h the chromosomes. Information on the position

p h r a g m is r e m o v e d a n d t h e t i l t i n g m i r r o r is p u t in

a n d o r i e n t a t i o n o f t h e c h o s e n c h r o m o s o m e is t r a n s ­

the mid position.

ferred

mechanically

to

the

movable

Tilting

lens

(three

mirror Abbe's

prism

Moveable lens

Keyboard

Film cassette

Moving system

Figure

184

The ciiosen

quantified

structure

184

Figure

185

Quan ti fied three-dimensional fixed

on spikes,

structures

modelled

in plastic

so that they can be easily moved

foam. Some of the elemen ts are around

185

Figure

185

(continued)

186

Case history:

ctiromosome

apparatus

5.4 Form o f the total system D u r i n g the w o r k o f f o r m designing the c h r o m o s o m e

The

ideas are m o d e l l e d

i n v a r i o u s w a y s as t h e

a p p a r a t u s t h e r e is i n t e r a c t i o n b e t w e e n t h e w o r k o n

w o r k progresses. D e p e n d i n g o n t h e s i t u a t i o n r o u g h

t h e o u t e r f o r m a n d t h e f o r m o f t h e e l e m e n t s , as is

sketches,

g e n e r a l l y expressed in t h e p r o d u c t s y n t h e s i s . T h e

models

description

used. These m o d e l s have been v e r y

on the following

pages o f t h e w a y

in

scale

drawings,

w h i c h t h e f o r m o f t h e t o t a l s y s t e m is d e c i d e d o n ,

connection with

m u s t t h e r e f o r e be seen as parallel t o t h e n e x t s e c t i o n

Figures 1 9 0 a n d 1 9 4 .

on the f o r m of the elements.

and

in plastic f o a m , w o o d the choice

three-dimensional and cardboard

are

important

in

o f f o r m c o n c e p t , see

The criteria that c o u n t w h e n choosing between

T h e q u a n t i f i e d s t r u c t u r e in F i g u r e 1 8 5 is t a k e n as

a l t e r n a t i v e designs, s t e m f i r s t o f all f r o m t h e user a n d

t h e s t a r t i n g p o i n t . As t h e f i l m cassette m u s t n o t be

f r o m t h e p r o d u c t i o n . A s f a r as t h e user is c o n c e r n e d ,

e x p o s e d t o false l i g h t , a n u m b e r o f t h e c o n s t i t u e n t

i t is a q u e s t i o n

e l e m e n t s m u s t be e n c l o s e d i n a l i g h t p r o o f s c r e e n i n g .

cleaning, adjustment and maintenance, psychological

T h e v e r y f i r s t r o u g h design p r o p o s a l s are a r r i v e d a t

factors

by varying the f o r m geometry and the f o r m division,

a p p e a r a n c e ( u n i t y , o r d e r , visual b a l a n c e ) . F r o m t h e

(how

as s h o w n in Figures 1 8 6 a n d 1 8 7 . T h e pages f o l l o w i n g

production

Figure

manufacturing

chosen.

194

describe

how

t h e design is

gradually

of working

is t h e

come

posture, accessibility,

apparatus experienced?)

criteria

process,

in c o n n e c t i o n

choice

d u c t i o n quantities and assembly.

of

with

material,

and the pro­

187

SCALE

1:10

Operativy area

^

Figure

186

/

^

The starting point for form designs is obtained by drawing contour lines closely around screened. Varying the form geometry gives the first rough form design suggestions

the elements

to be

188

FOm

DIVISIOKJ •Starting point

i

Figure

187

Variation

of form

division.

These sl