Handbook of Watch and Clock Repairs (1972)

Contents

Preface

Part One: G E N E R A L

Workbench and tools

Materials

The turns and their uses

Part Two: W A T C H E S

The movement

Overhauling and cleaning

Wheel trains

Hands, dial and motion work

Keyless work

Barrels, mainsprings and fusee chains

Escapements

Balances

Shock proofing

103

Cases

109

Magnetism

113

Part Three: C L O C K S

The movement

116

Pendulum clocks

119

Striking clocks

128

Preface

THERE have been many books written on the repair of watches

and clocks but the majority have been intended for the serious

horologist and the apprentice.

Little has been done to publicize horology as a hobby.

Many will say that to do such a thing is inadvisable without

proper training. But what of the present-day hobbyists who are

self-taught and whose interest in their subject is such that their

knowledge and skill often surpass those whose full-time

occupation it is?

I have known men who, since their youth, have been interested

in radio. Their knowledge and skill today are extensive and

although not qualified in the official sense, nevertheless they have

become authorities on their subject. Similar remarks can be

directed towards other occupations, and so it is with watch and

clock repairing.

In writing this book, I have assumed that the reader has no

knowledge of the subject and I have endeavoured, therefore, to

concentrate on the basic principles rather than advanced work.

An attempt has also been made to show the beginner that quite

a lot of practical work can be done with limited equipment and

a small initial outlay.

In the course of overhauling a movement the beginner will

frequently be confronted with a job beyond his ability and which

requires the use of equipment not in his possession. The appendix

at the back of the book will guide the reader on how to go about

sending work to an outside repairer. Once having established a

contact, no job should be too big or too difficult to tackle.

A little practice at home dismantling and assembling some old

movements will quickly introduce confidence and provide the

reader with the light touch necessary when working on watches.

P R E F A C E

Appreciation and thanks are extended to Messrs Parechoc

S.A., Le Sentier, Switzerland

(manufacturers of the Kif Flector),

The Universal Escapement Ltd., La Chaux-de-Fonds, Switzer

land

(manufacturers of the Incabloc), and to Erismann Schinz

Ltd., Le Neuveville, Switzerland (manufacturers of the Monorex)

for supplying me with detailed information and drawings of their

shock absorbers.

A special word of thanks is given to Messrs Baume & Co. Ltd,

50 Hatton Garden, London (Longine watches) and Smiths Clocks

& Watches Ltd, Sectric House, Cricklewood, London, both of

whom have been most helpful in supplying information and

drawings.

It is worthy of note here that in my approach to the industry,

I found an unexpected enthusiasm to help when it was known that

the book was to be a hobby book rather than a textbook. It was

considered that such a book was badly needed and all concerned

wished it every success.

Last, but by no means least, my special thanks go to Mr S.

Pleasants who has done so much in producing original drawings

and preparing illustrations for publication, frequently, I might

add, having to alter them as a result of a change in the original

manuscript. For him it was a nightmare gallop keeping pace with

the typewriter keys.

Part One

GENERAL

CHAPTER ONE

Workbench and tools

WATCHES and clocks can be overhauled and simple repairs

carried out without the need of an elaborately equipped work

shop. To begin with, a small rigid table with adequate lighting

will provide the workbench, and the tools can be limited initially

to a selected few to cover general work. More specialized tools

can be obtained later if and when the need arises.

However, it is the intention here to describe typical workshop

conditions and then leave you free to modify these arrangements

to suit your requirements.

A workbench is required, or alternatively a shelf firmly secured

to a wall.

The working surface of the bench should be at least 3 ft. from

the ground (Fig.

1). This will enable close work to be carried out

without bending low, resulting in greater comfort and increased

control. The length of the bench top needs to be about 3 ft.

6 in.

to permit working with both elbows spread out. The width

should be between

18 and 20 in. to allow space behind the work

in hand for small tools and accessories in use.

Strips of wood about 2 1/2 in. wide placed on edge on the top of

the bench along the two ends and along the back prevent items

being knocked to the floor.

A few drawers built under the top for storage of work, tools,

materials, etc., completes the bench.

It is essential that all work be conducted away from dirt or dust

WATCH AND CLOCK REPAIRS

because the smallest piece of foreign matter in a watch can cause

the movement to stop, and dust will soak up the oil and cause the

movement to dry out.

Sometimes it is quicker and cheaper to secure a shelf to a wall.

A strong, well made shelf securely fitted is much preferred by

many repairers.

Preferably the bench should be situated against a window

facing north. The reflected light obtained is softer and more

suited to this type of work.

If an adjustable electric lamp is mounted on the bench top or

secured to the wall in the case of a shelf, the lamp can be pulled

down close to the work and there should be no fear of eye strain.

Having provided the workbench and the lighting, attention

Fig. 1. Workbench.

WORKBENCH AND TOOLS

must now be given to tools. The following list is a guide to the

tools that need to be obtained to start with and to those that can

be purchased when a little more experience has been gained and

the range of work being undertaken has been widened.

INITIAL TOOL KIT

1 pair flat-nose pliers 4 in.

2 cleaning brushes

(medium

1 screwdriver 7 in.

and soft)

1 set watch screwdrivers

1 pin-vice

1 eye-glass 2-in. focus

1 oilstone, fine/medium

1 pair fine tweezers

handles

1 pair heavy tweezers

broaches

2 oilers

rat-tail files

1 oil cup (watch oil)

pillar files

- fine, medium and

1 oil cup

(clock oil)

coarse - 4 and

6 in.

2 pairs hand removing levers

1 vice,

2\ to

3-in. jaws

1 pith holder

1 watchmaker's hammer

SUPPLEMENTARY TOOL KIT

1 pair round-nose pliers 4 in.

1 round-face hammer

1 pair snipe-nose pliers 4 in.

1 brass-faced hammer

1 pair brass-faced flat-nose

1 watchmaker's spirit lamp

pliers

4 in.

1 blueing pan

1 pair top-cutting nippers 4 in.

1 graduated steel stake

1 screwdriver 12 in.

1 flat burnisher

1 double lens eye-glass

1/4-in.

glass dust covers

focus

1 pair turns with accessories

1 eye-glass 3-in. focus

2 clock spring clamps

Too much emphasis cannot be placed on the need to buy good

quality tools. It is better to start with a few good ones and slowly

build up a kit, than to buy poor quality tools that must inevitably

lead to repair work of a low standard. Make your purchases from

firms who specialize in this equipment and who thoroughly

understand your requirements.

WATCH AND CLOCK REPAIRS

The application of special tools will be dealt with in the

appropriate chapters, but a few hints on the use and maintenance

of the more common ones may prove helpful at this stage.

Files. The two most useful types of file for watch and clock

repairing are pillar files and rat-tail files (Fig.

2). Useful sizes are

4 in. and 6 in. in coarse, medium and fine cuts.

Fig. 2. Files, (a) Pillar (b) Rat-tail.

Files are cutting tools and must be treated as such. The teeth

are shaped like those of a saw and consequently cut in one

direction only.

Soft metals such as brass need new files but steels can be cut

better with a part worn file where the tips of the teeth have been

worn down. It follows then that new files commence their life

by being used for brass and are then passed over for use on steels.

It is sometimes more economical to use a double-sided file such

as a pillar file, for both metals, in which case the side used for

brass is marked by passing a piece of white chalk across the teeth.

It is essential that you are able to file accurately and therefore a

little practice may prove worth while.

Place a piece of brass rod horizontally in the vice. Hold the

pillar file by the handle in the right hand. Place the file on the

brass and place the forefinger and thumb of the left hand on the

end of the file.

A forward stroke is now made with just sufficient downward

pressure for the file teeth to cut the metal.

A flat surface can best be obtained by keeping the file hori

zontal. To do this the stroke is made with a light downward

pressure on the file handle and a heavier downward pressure on

the file tip.

As the centre of the file nears the brass, so the two pressures

WORKBENCH AND TOOLS

are adjusted until, when the file is equidistant over the brass the

two pressures are the same.

As the stroke continues, the two downward pressures are pro

gressively reversed until, when the file has reached the end of its

stroke, the heavier downward pressure is being made on the

handle and the lighter downward pressure on the tip.

A little practice and it will be found that the knack of maintain

ing these varying pressures will not be difficult.

Pillar files usually have both edges smooth thus enabling one

face of a step to be filed without removing metal from the

adjacent face.

Quite frequently taper pins will have to be made by filing; this

is known as 'pin-filing'.

A small block of fibre or hard wood is needed having in one

face a number of grooves of varying depths. The block is placed

in the vice with the grooves uppermost. A piece of selected brass

rod or wire is placed in the jaws of the pin-vice

(Fig.

3), the

protruding length dependent on the length of the pin required.

The wire is laid in one of the grooves and held at a slight

downward angle. The groove selected is that which allows the

wire to just stand proud of the surface of the block.

A fine pillar file is selected and a light forward stroke is made.

The right hand can control the file better if the forefinger is

Fig. 3. Pin-vice.

straight and its tip resting on the side of the file. At the same time

the pin-vice is rotated between the forefinger and thumb of the

left hand causing the wire to revolve against the direction of the

file.

When the stroke is completed, the file is drawn back, lightly

resting on the wire to keep the wire in the groove, and the

1 4

WATCH AND CLOCK REPAIRS

pin-vice is rotated in the opposite direction in readiness for

the next stroke.

A little practice and synchronization of movement will be

achieved.

Fig.

4. Correct methods of holding watchmaker's screwdrivers; and

(centre) screwdriver blade.

Watch screwdrivers. These are best purchased as a set of three

or four in a box. The correct method of holding them is shown

in figure

With constant use screwdriver blades need re-shaping. This is

done by using a smooth file. The blade of the screwdriver should

be well blunted and the taper kept long

(Fig.

4). If the taper is

short and the blade end is sharp, the screwdriver will tend to rise

out of the screwdriver slot and damage the screw head.

Oilers. These can be purchased quite cheaply in attractive

plastic cases, but on the other hand they are simple to make

which sometimes proves more satisfying.

Two sizes are required. A small one for jewel holes and a larger

one for general work.

The small one can be made from a sewing needle. Heat the

point to a blue, file two flats opposite each other, place the needle

WORKBENCH AND TOOLS

on the vice and tap out the end using the round-face hammer.

Finish off with a small oilstone. Figure 5 shows an enlarged view

of the shaped end.

The larger one can be made from a short length of steel wire.

Long slender handles are now needed. These can be made from

lengths of wooden rod rounded off at each end.

The method of transferring oil from the oil bottle to the move

ment is accomplished in two stages. First, a large watch screw

driver is dipped into the bottle of oil and one drop of oil is placed

in an oil cup. The tip of the oiler is then placed in the oil resulting

in a small quantity of oil being deposited on the oiler.

The tip of the oiler is then allowed to touch the part to be oiled

and if the oiler is correctly shaped the oil will be transferred by

capillary action.

Eye-glasses. The list of tools includes three sizes of eye-glasses,

a 1/4-in. focus double lens, a 2-in. focus single lens (Fig. 6) and a

3-in. focus single lens. The 1/4-in. is for examining very fine work

such as jewel holes in watches. The 2-in. is for general use when

working on watches, and the 3-in. is for clock work.

The lens holder is fitted into the socket of the eye where it

should remain without discomfort leaving both hands free to

work.

The lens holders vary slightly in diameter and thickness and it

Fig. 5. Oilers.

Fig. 6. Eye-glass.

1 6

WATCH AND CLOCK REPAIRS

is sometimes more satisfactory to try a few glasses for fit before

making a purchase.

If after continual use it is found that the inner face of the lens

tends to steam up, two or three holes about 1/8 in. diameter drilled

through the side of the holder will cure the trouble.

Some repairers prefer to fit head-wires to their eye-glasses. At

least this does prevent the eye-glass from falling at a moment

when a delicate operation is in progress.

A piece of spring steel wire is looped at one end to hold the

eye-glass and the remainder is curved to fit the shape of the head.

The end should reach the back of the head and then be bent into

a small loop to prevent the end from digging in.

For those who wear spectacles, eye-glass holders can be

purchased that will fit the spectacle frames. Your optician will

be the best person to give advice in this respect.

Tweezers. Apart from eye-glasses, tweezers are possibly the

most used tools, particularly in watch repairing. Tool manufac

turers produce wide ranges of tweezers of many shapes, sizes,

qualities and uses and it is therefore sometimes difficult to know

how to make a selection.

It is advisable to start with two pairs of good quality tweezers

for general use. One for light work and the other a little more

robust.

Earlier in this chapter advice was given against buying cheap

tools. This applies particularly to tweezers.

The slightest tendency to twist or reluctance to grip properly

may result in the part snapping out and being lost or damaged.

A good pair of tweezers will pick up a hair between the points

from a piece of glass. It should be possible to place a piece of thin

metal between the points and apply plenty of pressure without the

points curling outward. If they do curl outward (Fig. 7), then the

points need trimming. This is best done by using a small oilstone.

If the outward curve is considerable, then the points must be

carefully bent inward using the small flat-nose pliers.

Pliers (Fig. 8). If the serrations on the inner face of the pliers are

too coarse, the tops of the serrations can be removed by filing.

WATCH AND CLOCK REPAIRS

Hand-removing levers. These are essential for removing hands

and are easily made. Two pairs are needed, one fine pair for

watches and a larger pair for clocks.

Make the levers from brass as shown in figure

10.

Pith holder. A round metal container about l 1/2 in. diameter

Fig.

10. Hand lifting lever.

Fig. 11. Blueing pan.

and l 1/2 in. deep is required. Place some pieces of lead in the

bottom and melt them down. A layer about 1/4 in. is all that is

needed, enough to make it firm when standing on the bench. Pack

the container tight with pith sticks about

1 1/4 in. long. The ends

of tweezers and watch screwdrivers are kept clean by prodding

them into the pith.

Tools such as files, gravers, etc., must have handles fitted to

them.

Heat the handle end of the tool to a cherry red making sure

that the cutting end is not affected by the heat.

Burn the tool into the handle almost to the desired position.

Hold the tool vertically with the handle downward and strike

WORKBENCH AND TOOLS

the vice a few hard blows with the tool handle. This should result

in the handle being firmly in position.

Broaches. When broaching a hole do not use force. Small

broaches can be held in a pin-vice and rotated between the fore

finger and thumb. Larger broaches need thin wooden handles.

When cutting with a broach plenty of lubrication and frequent

clearing of broach cuttings is necessary.

Blueing pan. This is used for blueing polished steel parts The

pan is a piece of brass sheet measuring approximately 1 1/2 in. x 1 in.

and drilled with a row of graduated holes at one end.

To the other end is riveted a short length of steel rod over which

a wooden handle is driven (Fig. 11).

The parts to be blued are placed on the pan which is then passed

through a spirit flame.

As the temperature of the steel parts increases, the surface

colour of the steel changes to blue.

The pan is removed from the flame and the parts are either

dropped into oil or they are allowed to cool off and given a coat

of colourless lacquer.

Graduated Stake. (Fig.

12). This is a flat steel block, hardened

Fig.

12. Graduated stake.

and polished, and drilled with holes of different sizes to suit the

work in hand. The under-side is stepped so that it can be held

between the jaws of a vice.

Watchmaker's Hammer

(Fig.

13). These hammers can be

purchased with heads of steel or brass. The steel head is a

WATCH AND CLOCK REPAIRS

general purpose hammer, but when the work is more delicate

and the risk of damage greater, a brass head is used.

Finally, a useful set of tools

(Fig.

14) is supplied by Smiths

Clock and Watch Division, London, England.

Fig. 13. Watchmaker's hammer.

Fig.

14. Smith's set of tools,

(a) Case nut spanner, (b) Alarm stop spanner,

(d) Balance screw key. (e) Hairspring collet adjuster, (f) Bezel remover,

(g) De Luxe 12 ligne case opener, (h) Suction case opener, (i) De luxe

8 3/4 ligne case opener, (j) Yachting timer opener, (k) Empire watch case

opener.

(1) De luxe dustproof case opener,

(m) Empire crown key.

(n) Special screwdriver,

(o) Hexagon nut spanner (8 χ

10 ΒΑ), (ρ)

Circular hand extractor, (q and r) Pair of hand lifting levers.

CHAPTER TWO

Materials

Oil. The lubrication of watches and clocks is done by oil refined

specially for the purpose. Clock oil has a slightly greater viscosity

than watch oil. Both are supplied in small bottles of convenient

size.

In Chapter 5 we shall be discussing the oiling of a watch move

ment and when you realize how very little oil a complete watch

needs, you will then appreciate that even a small bottle will last

a very long time.

When ordering your oil, be it for watches or clocks, buy the

very best. Poor quality oil soon thickens and you will find yourself

dismantling and cleaning the movement all over again.

Make sure it is watch or clock oil. Don't be misled into thinking

that light machine oil will do, no matter how superior the quality

may be.

If the viscosity of the oil is too great for the working parts, the

resistance is going to effect the time-keeping.

Pegwood. Sticks of pegwood are sold in bundles about

6 in.

long. They are used mainly for cleaning out pivot holes. This is

done by shaving one end of a stick to a fine point, inserting the

point through the jewel hole and lightly twisting between the

finger and thumb. Any dirt in the hole will become embedded in

the pegwood. Great care must be taken to ensure that the point

does not break off in the pivot hole. Until experience is gained it is

advisable to examine the pivot hole after this operation to make

sure it is clear. If a piece does break off it can be removed by

inserting the pegwood from the other side.

Methylated spirit. This is used as fuel in the watchmaker's spirit

lamp. When burning, it gives off a clean smokeless flame and does

not blacken or tarnish articles heated in it. This is essential when

tempering steel because of the necessity of watching the colour

change.

WATCH AND CLOCK REPAIRS

Benzine and Gasoline. As a cleaning agent for watch and clock

movements, benzine is undoubtedly the best. It can be purchased

from a chemist or drug store. A good alternative to benzine is

gasoline, particularly that sold as fuel for cigarette lighters. Both

fluids have a high rate of evaporation and should therefore be

kept in air-tight containers.

W A R N I N G

: Both benzine and gasoline are highly inflammable and

must therefore be kept well away from naked flames. Under no

circumstances have them standing near when the watchmaker's

spirit lamp is in use.

Cleaning fluids. As an alternative to using benzine or gasoline

there are many proprietary cleaning fluids available on the

market. Providing they are supplied by a reputable supplier

these cleaning fluids have much to commend them.

Polishing powders. These are commonly known as crocus

powder, red-stuff and rouge, the only difference being their

fineness of grain. Rouge is the coarsest and crocus powder the

finest. The powder is mixed with oil to produce a cutting paste.

The medium grade is that most commonly used on watches.

Chalk. This is used on the cleaning brushes for cleaning the

movements and to maintain the cleanliness of the brushes them

selves. A convenient form is billiard chalk. It is applied by

stroking the brush over the chalk a few times.

Pith. The cleaning of watch pivots and similar parts is done by

using pith. It is the pith from an elder tree that has been dried,

peeled and prepared in sticks.

Emery sticks. Two pieces of hard wood approximately

5 in. χ

2 in. x 1/2 in. pl a ne d flat b o t h sides are required. F o u r grades of

emery paper ranging from very fine to medium are cut into 2 in.

strips. One strip from each grade is glued to the wood. These

emery sticks, as they are now called, are very useful for reducing

or s mo o t h i n g steel or brass surfaces.

Dial enamel. This is used for repairing white enamel dials. It

has a low melting point and sets hard with a glossy surface.

CHAPTER THREE

The turns and their uses

THERE are two methods of turning. One is to use a lathe and the

other is by means of turns.

Turns are a simple device. Motive power is produced by a

hand-operated bow looped once around a ferrule, and the graver

(cutting tool) is held in the other hand. A little practice is neces

sary to acquire the knack of synchronizing these two movements

and after that, simple turning can be done with a high degree of

accuracy.

The lathe has many advantages over the turns. It is not hand

operated which means both hands are free for the work, and it is

far more comprehensive in the number of operations and func

tions it can perform. Being a precision machine it is easier to

achieve the same degree of accuracy.

The turns consist of two centres and a handrest with a steel or

brass beam passing through them (Fig.

15). One of the centres is

secured to the beam at one end, and it is here that the turns are

held in a vice. The handrest and remaining centre are free to slide

and can be locked to the beam in any position.

Turning. The work to be turned is placed on a turning arbor

(Fig.

16), or in an adjustable ferrule

(Fig.

17). In both cases the

assembly is supported between the centres.

Fig.

15. The turns.

WATCH AND CLOCK REPAIRS

The handrest is brought close to the work and locked in

position.

The string of the bow is passed once around the ferrule and the

Fig. 16. Arbor.

Fig.

17. Adjustable ferrule.

bow held in the left hand. A turning graver is held in the right

hand and is placed on the handrest close to the work.

At each downward stroke of the bow the graver is brought up

to the work and a cut is made. The bow is then moved upward

and the graver is moved away from the work just enough to give a

clearance. The process is then repeated.

Turning arbors and adjustable ferrules are supplied in a wide

range of sizes. The bows are supplied in a few sizes and there is a

choice of materials from which the bow-string is made.

When using a turning arbor, a hole is drilled in the metal from

THE TURNS AND THEIR USES

end to end which is then broached out smooth. The tapered hole

will now push tightly on to the arbor.

Holding the work by an adjustable ferrule involves the selection

of a ferrule of suitable size and then clamping it to the work.

The gravers are made from square or diamond section hardened

steel. The cutting ends are ground as shown in figure

18. The

graver at

(a) is used for roughing down the metal,

(b) is for

finishing off a square shoulder, cuts being made by the side of

the tool as well as the point, and

shoulders.

After grinding, the face is levelled and smoothed on an oilstone,

and finally polished on an Arkansas stone. The side faces are then

held flat on the stone and drawn carefully across to remove any

burrs.

Each graver should be fitted with a wooden handle as described

in Chapter 1.

Having secured the work on an arbor or in a ferrule, it is now

placed between the centres and the centres are brought up into

Fig. 18. Gravers.

position and locked. There should be no end float of the work.

Apply a little oil at each centre.

Adjust the handrest to bring it close to the work. The exact

distance will come with experience. If the distance is too great the

WATCH AND CLOCK REPAIRS

graver point will tend to drop and cause chattering. If the hand-

rest is too close, there will be insufficient space to rest the graver

and operate freely.

The height of the handrest must now be adjusted. Cutting is

done by the point of the tool which has to be in line with the

Fig. 19. Turning.

centre of the work. If the graver is too high it will not cut, and if

it is too low it will tend to lift the work and be drawn under. It is

during the downward stroke of the bow that the cuts are made.

Let us assume we have a piece of 1/4 in. diameter brass rod 1/4 in.

long that has been drilled through its length and broached to fit

a suitable size arbor.

The work is mounted between the centres and the turns made

ready for use.

First let us reduce the diameter. The graver is positioned as

shown in figure 19 (a) and must be held quite firmly. A downward

movement of the bow is made and the graver is allowed to just

touch the work at the same time moving slightly to the left. If

the work is not true an indication will be given by the graver not

THE TURNS AND THEIR USES

making a complete cut but only removing metal from the high

spots.

The bow is given an upward stroke and the graver is moved

away from the work by means of very slight finger pressure.

Carrying on from where the previous stroke finished, the

operation is repeated until sufficient length of the material has

been cut.

The graver is then returned to the beginning and the metal is

further reduced in diameter.

This process is repeated until the work is revolving completely

true and the diameter has been reduced to the predetermined size.

Now to turn the face. The graver is held as shown in figure

19 (b) and the process of cutting repeated, this time moving the

graver fore and aft.

Brass requires a higher cutting speed than steel and therefore

a longer bow is needed.

Bows are supplied in different lengths and are usually made of

whalebone.

The 'string' is either horsehair that can be purchased in hanks,

or cotton thread coated with beeswax.

Fig. 20. Drill.

There is a tendency for cotton thread to fray and because of

this horsehair is to be preferred.

The tension on the 'string' must allow slip to take place when

looped around the ferrule in case the graver should dig into the

WATCH AND CLOCK REPAIRS

work. This acts as a safety device and saves the work from

damage.

Drilling. As with the turning, there are two methods of drilling

in use by watchmakers. Again, one method is to use a lathe and

the other is by bow and ferrule.

To use a lathe is to ensure precision. This cannot be said of

the bow and ferrule method.

The type of drill used by watchmakers is shown in figure 20,

and it will be seen that cutting takes place in one direction only.

The size of the bow will depend on the size of the drill used.

For the smallest drills a

9 in. bow with horsehair is sufficient.

The selected drill is mounted in a stock and the lock screw

tightened

(Fig.

21). A ferrule is secured to the other end of the

stock to take the bow. The horsehair is so looped around the

ferrule as to rotate the drill in a clockwise direction during a

downward stroke.

The stock centre at the ferrule end is positioned in a shallow

hole drilled in a steel plate held in the vice.

The work is held against the drill and cutting takes place at

each downward stroke of the bow.

Fig. 21. Drilling.

Part Two

WATCHES

CHAPTER FOUR

The movement

A W A T C H movement of high quality is necessarily complicated.

Many hundreds of parts are used, each one cut and fashioned by

craftsmen of unquestionable skill.

Some of these parts are so small they have to be seen under a

powerful magnifying glass before their perfection of design and

manufacture can be fully appreciated.

The term 'movement' applies to the complete watch less the

case and it is measured in lignes.

The ligne was originally a French measure, being

1/12th of a

pouce or French inch. It travelled to England with the French

watchmakers. The ligne was further divided into

12 douzièmes.

The ligne used today by the watch industries in Europe is the

French measure—1 ligne is equal to 2.55883 millimetres. This is

approximately 3/32nds of an inch.

The American watch industry uses a measure originated by

Aaron L. Dennison in

1850 employing a series of numbers with

zero size as a basis. This is equal to 35/30ths of an inch. Move

ments larger than 0 are identified by full integers such as

1,2,

etc. Movements smaller than 0 are identified as

1/0, 2/0,

3/0, 4/0,

etc. Each step is equal to 1/30th of an inch.

There is a further complication that jewellers also use lines,

but the jewellers' line is 1/40th of an inch.

The use of the ligne or line as a measure is not consistent with

modern manufacturing methods and a number of watch manu

facturers have changed over completely to millimetres.

WATCH AND CLOCK REPAIRS

It is of interest to note that most wheel or gear trains in common

use are designed to reduce speed and increase power. In mechanic

ally powered timepieces the reverse is the case.

Motive power. Power is provided by a mainspring coiled in a

barrel. The inner end of the spring has a rectangular hole known

as the eye. This is hooked to an arbor in the centre of the barrel.

The outer end of the spring is hooked to the inner face of the

barrel side. The mainspring occupies about one-third of the

space inside the barrel. The action of winding a watch spring

causes the arbor to rotate and the inner end of the mainspring to

wind itself round the arbor.

There are three methods of using the mainspring to drive the

wheel train and they are known as the going barrel, the stationary

barrel and the fusee.

The going barrel. Gear teeth are cut on the outer edge of the

barrel and this is known as the main wheel. The arbor is squared

at one end to receive a key or a ratchet wheel. During the process

of winding the spring, the spring tension is held by a ratchet known

as the clickwork.

When the movement is functioning, the arbor remains station

ary and the barrel rotates around it.

The stationary barrel. This method will be found mostly in

American watches. The barrel remains stationary and the arbor

revolves in the centre. At one end of the arbor is fitted a toothed

wheel.

The fusee. The time-keeping of old watches was affected by the

drop in power when the mainspring ran down, and so a means of

compensation was necessary. This compensation was accom

plished by the introduction of the fusee.

A cone-shaped pulley was positioned next to the barrel. The

pulley had a spiral groove machined in its face in which a chain

was placed. One end of the chain was hooked to the base of the

cone and the other end of the chain was hooked to the outer face

of the barrel side.

Gear teeth were cut on the bottom edge of the cone and formed

the main wheel. When the mainspring was wound, the chain was

THE MOVEMENT

pulling on the smallest diameter of the cone with minimum

leverage.

As the spring unwound itself and the power became pro

gressively less the chain was being transferred from the fusee and

was winding itself on to the barrel. This caused the chain to pull

on an ever increasing diameter of the cone with a proportionate

increase of leverage. By this method suitable compensation was

achieved.

The wheel train. The teeth of the main wheel mesh with the

leaves of the centre wheel pinion. In the same way the centre

wheel meshes with the third wheel pinion, the third wheel meshes

with the fourth wheel pinion, and the fourth wheel meshes with

the escape wheel pinion.

The centre wheel rotates once every hour and therefore carries

the minute hand. The fourth wheel rotates once every minute and

so carries the seconds hand.

The escapement. Some means of controlling the speed of the

wheel train is now required. This is done by the escapement which

consists of an escape wheel, a lever and a balance.

The balance is to a watch as a pendulum is to a clock. The

balance wheel is mounted on a staff that has a very fine pivot at

each end both of which operate in jewel pivot holes.

The fitting of a spring to the wheel provides self-contained

motive power enough to cause the wheel to vibrate many times

before coming to rest. The more accurate the balance and the

lower the frictional resistance at the pivots, the greater will be

the number of vibrations performed by the balance.

The escape wheel is controlled by the balance through the

lever. One end of the lever is fitted with two pallets which allow

the escape wheel to revolve one tooth at a time.

When a tooth of the escape wheel comes into contact with one

of the pallets, that end of the lever is pushed sideways which

causes the other end to transmit a small impulse to the balance.

It is this small impulse caused each time the escape wheel

moves that prevents the balance from slowing down and

stopping.

WATCH AND CLOCK REPAIRS

It will be seen therefore that the wheel train moves in a series

of jumps.

To ensure sustained accuracy of time-keeping, each part of the

movement must be machined with precision, all pivots finely

polished, all friction surfaces adequately lubricated, and the

movement must be enclosed in a dust and moisture-proof case.

Everything possible must be done to reduce friction to a

minimum. So-called jewels are fitted as pivot bearings. These

jewels derive their name from the time when watchmakers used

rubies. This practice no longer applies, instead a synthetic material

of equal hardness is used.

The number of jewels used in a watch varies with the quality

of the movement. The usual number is 7,

15,

17 or 21.

The seven-jewelled movement indicates that only the escape

ment is fitted with jewels. The majority of jewelled watches have

fifteen jewels which takes them up to the third wheel.

In addition to jewels being used as bearings for wheel pivots,

they are also used as caps for the balance wheel pivot bearings,

these are known as end-stones.

After a movement has been oiled, jewels and end-stones retain

the oil by capillary action.

The train of wheels and the escapement are supported by two

plates known as the bottom plate which is beneath the dial, and

the top plate. Sometimes the top plate is dispensed with and a

number of bridge pieces or cocks are used instead.

Between the bottom plate and the dial is the motion work. This

consists of a cannon pinion, an hour wheel and a minute wheel.

Winding mechanisms. There are three types of winding mechan

isms. Early watches were supplied with separate keys, and were

wound through a hole in the back.

Modern watches are keyless, the winding mechanism being part

of the movement.

Lastly there is the automatic type. The action of moving one's

wrist causes a weight to swing which in turn winds the main

spring. Overwinding is prevented by a slipping clutch mechanism.

CHAPTER FIVE

Overhauling and cleaning

IF a watch develops a fault then it must be traced and put right.

If the movement is clean and oiled there is usually no need to

carry out any additional work other than check the watch for

time-keeping.

In this chapter we are going to discuss generally the complete

overhaul and cleaning of wristwatch movements. The remain

ing chapters in this section deal with specific assemblies of parts

in greater detail and must therefore be read in conjunction with

this chapter.

Plates I to VI are those of a

5 1/4 x 8 3/4 ligne 15-jewel lever

movement. They serve to show the sequence of assembly of the

parts in a modern wristwatch and the identification of parts

by name.

Too much emphasis cannot be placed on the need for careful

inspection as the work of dismantling continues. A great deal of

conscientious work can be put into the inspection and cleaning

of individual parts after dismantling but when the movement is

once again assembled the original fault may still be there. If the

history of the watch is unknown to you then it must be borne in

mind that some of the parts may not be the originals and that

incorrect replacements may have been fitted or that bad fitting

may have taken place. Before opening the case examine the watch

closely. Frequently much useful information can be obtained

that might otherwise have remained obscure.

Methods of opening watch cases are dealt with in Chapter

and you are advised to read this before proceeding any further.

If when the case has been opened a considerable amount of

dust is found inside, then the case needs some kind of

attention.

Operate the hand-set and turn the hands in the normal direc

tion and listen for fouling against the glass or dial. With a keyless

WATCH AND CLOCK REPAIRS

watch it should be possible to pull the winding stem out and push

it in without undue force or looseness. The feel of the action

should be smart and positive. Test the side-shake of the winding

stem. There should be just sufficient to prevent binding when being

operated. This is very important because a loose fitting winder is

an open invitation to dirt and dust to enter the movement.

Examine the case for signs of it having been dropped or knocked.

A blow on the case frequently results in broken balance pivots if

shock absorbers are not fitted. Remove the glass and inspect it

for signs of fouling by the hands. Carry out the same inspection

on the dial. The most likely fault will be fouling by the tip of the

minute hand. Lightly touch the hands and apply side pressure to

see if they are loose.

Operate the hand-set and hold the watch so that it can be

viewed from the side, turn the hands and observe their movement.

This will disclose any tendency to foul the dial and to foul them

selves. When carrying out this check make sure that the dial is

flat with the bottom plate and is firmly secured.

With the aid of an eye-glass inspect the seconds hand to see if it

is free of the dial face and that there is clearance between the

seconds hand pipe and the hole in the dial.

If when turning the hands it is noticed that the tip of the

minute hand rises and falls, this is an indication that the centre

wheel is not upright. But if the minute hand rotates at a constant

height above the dial and the hour hand rises and falls, then the

centre arbor can be suspected of being bent.

The centre arbor can easily be checked by spinning it between

a pair of callipers. If the arbor is bent, lay it on a flat steel stake

and lightly tap it with the peaning end of the watchmaker's

hammer.

To correct the uprightness of a centre wheel necessitates one of

the centre holes being bushed. This calls for the use of equipment

that is unlikely to be in the possession of a beginner, e.g. a lathe

and a punch and stake. In this event the work of bushing will have

to be sent away.

We now check the hour wheel to make sure that it has some

Handbook of Watch and Clock Repairs (1972) - page 1