Practical Clock Repairing E-Book

Donald De Carle

• Herausgeber: NAG
• Kategorie: Lebensstil
• Sprache: Englisch

Seitenzahl: 458

Veröffentlichungsjahr: 2020

Beschreibung

The repair of clocks calls for a variety of skills and crafts, few of which can be 'picked up' by bench work alone. In the horological trade, it is technical practice that the 'prentice hand' is first tried out on clocks, before attempting repair work on watches. Clocks have the advantage of possessing sizeable and robust parts and of being easier to handle. But there the advantage for the repairer ends. The sizes, shapes, complications and even the nationalities of clocks appear to be without end. Every movement has detail difference and, naturally, the defects when due for repair, are as varied. In this book, the author has dealt with the usual faults likely to develop in each type of movement in general use; from the lordly grandfather to the humble alarm. All the tools and equipment are described and illustrated, together with the ways of using them. The craftsman's most important and valuable tools of all - his skilful fingers - are shown in use in the clearest manner. As is usual in N.A.G. Press textbooks, the drawings have been specially made from parts under working conditions. A glance through the book will show their usefulness and clarity. Over 400 line drawings are used throughout and the reader is left in no doubt of what he is asked to do in following the author's clearly written technical and practical instructions.

Leseprobe

PRACTICAL CLOCK REPAIRING

By the same author

Clock and Watch Repairing

Complicated Watches and Their Repair

Practical Watch Adjusting

Practical Watch Repairing

Watch and Clock Encyclopedia

Watchmaker’s and Model Engineer’s Lathe, The

PRACTICAL CLOCK REPAIRING

by

DONALD DE CARLE F.B.H.I.

Illustrations by

E. A. AYRES F.B.H.I.

N.A.G. Press

First published in 1946

New editions 1953 and 1969

This edition published by NAG Press, an imprint of

The Crowood Press Ltd, Ramsbury, Marlborough Wiltshire SN8 2HR

www.crowood.com

This e-book first published in 2019

This impression 2017

© NAG Press and Donald de Carle 1946, 1953 and 1969

All rights reserved. This e-book is copyright material and must not be copied, reproduced, transferred, distributed, leased, licensed or publicly performed or used in any way except as specifically permitted in writing by the publishers, as allowed under the terms and conditions under which it was purchased or as strictly permitted by applicable copyright law. Any unauthorised distribution or use of this text may be a direct infringement of the author’s and publisher’s rights, and those responsible may be liable in law accordingly.

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

ISBN 978 0 7198 3107 2

PREFACE

The clock repairer has been badly served by books, particularly really practical ones, in the past. Why this is I cannot understand because clock repairing is one of the highest of the skills and at times calls for considerable specialised knowledge. Yet no authoritative book on clock repairing has appeared for approximately 50 years.

After I had finished writing Practical Watch Repairing, my publisher Arthur Tremayne, said, “The next job is to write a book that deals with clocks in exactly the same way—one that can be understood almost without reading it; that shows in every possible illustration the clockmaker’s most important tools—his fingers”.

Practical Clock Repairing is the result. The subject is treated in exactly the same way as in its companion volume, and I sincerely hope that it will be found as valuable to my fellow craftsmen as I am told Practical Watch Repairing has been.

I have described processes and operations in minute detail because I am sure that although some readers may be impatient of such lavish description and illustration, the big majority, particularly among the apprentices, will prefer to see it all in black and white with no knowledge assumed and nothing left to chance.

Practical Clock Repairing first appeared in serial form in the pages of the Horological Journal and, like its companion work, drew many valuable suggestions which I have incorporated in the book.

For his care and skill in preparing the abundant illustrations my thanks are due to Mr. E. A. Ayres. They are due also to Mr. Maurice Aimer and Mr. E. Bruton, who have read through the proofs.

Pinner, Middlesex.D. de CARLE

1951.

CONTENTS

PREFACE

INTRODUCTION

CHAPTER 1. WORKSHOP AND BENCH. Stands and brackets for clocks. Workshop layout. Tools and equipment

CHAPTER 2. EXAMINING THE MOVEMENT. Names of parts. Part dismantling. Letting down the mainspring. Examination for wear. Checking the escapement. Adjusting and repairing escapements. Checking depths of wheels. Using the depth tool

CHAPTER 3. DISMANTLING AND REPAIRING THE MOVEMENT. Complete dismantling. Removing the mainspring. Testing pivots. Polishing pivots. Using the burnisher. Using the broach. Rebushing—three methods

CHAPTER 4. CLEANING AND REASSEMBLING. The cleaning machine. Cleaning holes. Immersion cleaning. Cleaning with benzine. Mainspring winders. Winding mainsprings by hand. Assembling the movement. Testing during assembly. How much oil ? Fitting the movement into the case. Types of crutch

CHAPTER 5. GEARING—PART I. The ideal gear. Simple calculations of gear ratios. Distances of centres. Types of gear teeth. Uniform lead. Pitch. Correct and incorrect meshing. Using the sector. Lantern pinions

CHAPTER 6. GEARING—PART II : CALCULATIONS. Train calculations. Finding the sizes of missing wheels. Motion work calculations. Table of clock trains with lengths of pendulum. Table of 12-hour motion work trains

CHAPTER 7. STRIKING CLOCKS. Checking the action of the striking mechanism. Dismantling. Test, correction and repair. Assembly. Pinning up plates. Oiling charts

CHAPTER 8. CHIMING CLOCKS. Examining the chiming mechanism. Automatic correction of chime sequence. Dismantling. Examination and rectification. Assembly. Adjustment. Testing. Oiling charts. Adjusting the ‘drop off’

CHAPTER 9. THE PENDULUM. Simple and compound pendulums. Equivalent simple pendulum. Seconds pendulum. Altering rates. Suspension springs. Arcs. Table of circular error. Barometric error. Calculations. Table of pendulum lengths for particular number of vibrations. Compensated pendulums. Security of fixing. Steadying long case clocks. Testing for swaying. Crutches. Sympathetic vibration

CHAPTER 10. MAKING A FUSEE TIMEPIECE PENDULUM MOVEMENT. The train. Making the plates. Using scraper and file. Marking off. Drilling and broaching. Turning pillars. Planishing tools. Using diamantine and polisher. Making the barrel. Barrel arbor

CHAPTER 11. MAKING A FUSEE TIMEPIECE—continued. Turning between centres. Filing squares. Using the polisher. Barrel arbor holes. Fusee and arbor. Finishing the fusee. The ratchet. Maintaining power wheel. Fusee click spring. Filing springs and clicks. Pin rounding tool

CHAPTER 12. MAKING A FUSEE TIMEPIECE—continued. The great wheel. Maintaining power spring. Fusee iron and block. The train. Crossing out wheels. Using pinion wire. Turning long arbors. Filing up pinion wire. Hardening and tempering. Peening to straighten. Polishing pinions. Turning to receive the wheel. Fitting the wheel. Riveting. The facing tool. Pivot polishing. Using the polisher. Crossing out. Soldering collets

CHAPTER 13. MAKING A FUSEE TIMEPIECE—continued. The escapement. Back cock. Pallet arbor. Crutch. Hardening pallet pads. Finishing pallet surfaces. Polishing pallet pads. Using depthing tools. Planting the escapement. Fitting the back cock. Cutting oil sinks

CHAPTER 14. MAKING A FUSEE TIMEPIECE—continued. Maintaining power detent. Finishing the plates. Riveting pillars. Barrel ratchet and click. Tension spring. Cannon pinion. Hour wheel bridge. Hour wheel. Minute wheel and cock. Motion work. Pendulum and its suspension. Pendulum bob. Dial feet. General finish. Finishing the ends of pivots. Making pins. Blueing hands. Lacquering. Screws. Assembly. Fusee chain. Setting up. Adjusting rod

CHAPTER 15. FRENCH CLOCKS. Cleaning methods. Cleaning oil sinks. Use of chalk. Pendulum clocks. Removing pins. Names of parts. Testing shakes of striking work. Examining the train. Escapement end-shake correction. Extending a pivot. Systematic dismantling. Pivot polishing. Preparing a burnisher. Repairing worn squares. Blueing screws. Fitting a new spring. Pivot repairs. Assembly. Examination of operation. The hammer. Brocot escapement. Ting tang movements. Carriage clocks. Repeating clocks. Alarm mechanisms. Grande sonnerie. Stop work

CHAPTER 16. CARRIAGE CLOCK ESCAPEMENTS. Contrate wheels. Checking the action. Adjusting index pins of platform escapements. The cylinder escapement, its action, adjustment and repair. Banking. Cleaning platform escapements

CHAPTER 17. ENGLISH FUSEE BRACKET CLOCKS. Checking the escapement. Releasing the mainspring set up. Examining the wheels and pinions. Four methods of cleaning. Fitting a new fusee line. Cleaning a rusty fusee chain. List of checks to make before winding up the mainspring. Fusee striking movement action. Strike silent operation. Dismantling and assembly. Making a new rack tail. Speed of striking. Half-hour striking. Rise and fall mechanism. Chiming clocks. Pin barrel operation

CHAPTER 18. WEIGHT-DRIVEN AND ANTIQUE CLOCKS. The grandfather clock. Methods of cleaning. Setting in beat. Testing striking. The regulator. Mercurial pendulums. Dead beat escapements. Pallet repair. Antique clocks. Restoration. Verge escapements. Pallet angles

CHAPTER 19. ALARM CLOCKS. Charges for repair. Cleaning. Removing winders and hand-set piece. Removing bezel and hands. Escapement adjustments. Closing pivot holes. Removing balance spring. Polishing balance wheel pivots. Fitting new pallet pins. Click spring repairs. Assembly and oiling : quick cleaning method

CHAPTER 20. 400-DAY GERMAN CLOCKS. To clean, repair and adjust. Examining. The escapement. Assembling. To correct the escapement

APPENDIX I. DEPTHING TOOL DIMENSIONS

APPENDIX II. TURNING AND SPIRAL CUTTING A CLOCK FUSEE

INTRODUCTION

CLOCK REPAIRING is an important job and demands specialist knowledge. Often the main work of the shop where watches and clocks are repaired is the repair of watches, clocks being relegated to the apprentice with some supervision by a watch repairer. Repairing clocks forms most excellent practice for the would-be watch man, but clock work is an absorbing subject and worthy of very close study; in fact, clocks can be a lifetime’s study, as are watches. Of the two, it is debatable which requires the greater skill.

Watches may require more delicate skill and a finer touch, acquired only by long practice, but clocks, with their vastly greater variety, no doubt require more knowledge. One has only to consider the type of clocks that pass through the average clockmakers’ hands : timepieces, strikes, chime, grandesonnerie, musical, calendar, while the majority of the work of his counterpart, the watchmaker, consists of timepieces, a chronograph occasionally, and repeaters at wide intervals.

Another important aspect of clock repairing is that the clock repairer often enters the house of the customer and it is felt that a special training should be provided to fit him for this important office. The man takes with him the reputation of the company he serves. If he is the master man, the remarks that follow may not apply, because he is the personality of his business.

In some quarters this trade of ours is regarded as a profession; there need be no delusions on that score; there is little doubt that it is a trade, one of the oldest and, in fact, the very first of the engineering trades. Clocks were the first of all mechanical instruments, and a man who qualifies as a first class clock repairer has achieved something and is a worthy citizen. It is with this background that a man should approach a customer; he should be polite, but not obsequious, act in a businesslike manner and, when he visits the customer’s house, know what he has come for and be capable of doing the job.

An inexperienced man should not be sent to a customer’s house to do the work expected of a craftsman. What happens in the workshop is one thing, but outside, with no supervision and perhaps an interested spectator, is quite another matter; so it is important that the outside representative should be experienced, not only in his craft, but also in selling the service he is rendering, and by that is meant in conveying unobtrusively to the customer the impression that he is a capable man. It may be asking a lot; but this book will aim at producing a man who is a good craftsman, not perhaps in the same way as the man who works only at the bench, but one who can understand and do his job well and at the same time is a good salesman, a salesman of the service he renders.

The class or quality of work to be done varies in different parts of the country and even in different parts of the same town. Therefore it is difficult, even impossible, to advise on the predominance of a particular type of clock. Some districts produce an abundance of carriage clocks and French clocks generally, others English clocks, i.e. grandfather and bracket clocks. All districts seem to have a fair share of the calotte, or folding type of clock, but these are really large watches. In this book the intention is to give equal importance to all types of clocks, from simple adjustments to extensive repairs.

Obviously an inexpensive clock will not stand the same expenditure of time and consequent expense of repair as a valuable antique or a fine quality clock. Discretion must be used; it may be found that the craftsman has a flair or an aptitude for one particular type of clock in one or other of the following categories : English clocks—grandfather or bracket, antique clocks; carriage clocks and French clocks; large watch type of clocks. Then there is the general type of work, i.e., the modern English strike and chime movement, electric clocks, American clocks, alarm clocks, including the style of clock that requires washing out only, without polishing, as the plates are treated with some form of protective lacquer by the manufacturer.

If the workshop is large enough and specialists can be employed, this should certainly be encouraged.

PRACTICAL CLOCK REPAIRING

CHAPTER ONE

WORKSHOP AND BENCH

WHERE POSSIBLE it is preferable to allot a workshop especially for the repair of clocks. Too often watches and clocks are handled in the same workshop and even at the same bench. If a separate workshop is not practicable, clocks should be repaired at a separate bench, as far away from the watch bench as possible. Clocks will not suffer because of the close proximity of the watches, but the watches will be affected. Repairing clocks is a noisy business; riveting new bushes, heavy filing, testing striking and chiming mechanisms, and so on.

A great deal of unavoidable dust is made when cleaning. The repair of some clocks such as calottes, French clocks and carriage work generally, is not so disturbing, although the cleaning of the French and carriage clocks is dust provoking. Therefore, a separate workshop for the repair of clocks is imperative if good work is to be done.

In addition to the bench, a good strong steady table is required; a useful size is 3 ft. by 4 ft. Make sure it is firm and cannot rock. It is advisable to spend some little time to even up the table in all directions with a spirit level. A standard level surface is required so that pendulum clocks can be put into beat before sending home. On to this table lay a piece of plate glass about 18 inches by 12 inches and inch to inch thick; this is for testing the level of clock cases. Nothing is more detrimental to the accurate timekeeping of a pendulum clock than a clock case that rocks as the pendulum swings. This is not always apparent until tested on a glass plate. Attention will be given to this subject later.

The next thing is a strongly fitted shelf, which should be as long as possible and about 9 inches wide. Use good substantial wood, at least 1 inch thick; fix and even up with the spirit level, both lengthways and from back to front, and not more than 5 ft. high from the floor. It will be easy to lift a reasonably heavy clock on to the shelf and it will be at sight level, which is convenient, should adjustments be necessary to the clocks. Both the table and the shelf are for clock testing, the shelf for the lighter types and the table for the large heavy bracket type.

Fig. 1. Wall stand to hold four grandfather clock movements.

Some form of stand is also required to hold grandfather clock movements while they are being tested, as it is neither necessary nor desirable to remove the case to the workshop when only the movement needs repair. The stand shown in Fig. 1 is very useful if wall space is available; it has the advantage of being out of the way, but has the disadvantage of making the movement difficult to get at.

Fig. 2. Simple stand for long case movements.

Fig. 3. Paper hood to keep off dust.

Another and more simple stand is to plug iron brackets to the wall, a pair for each long case movement (Fig. 2). If this system is adopted it is advisable to make a paper hood for each movement to protect it from dust. Take a sheet of stiff brown paper about 35 inches long and 6 or 7 inches wide; fold it in half and let it rest on the bell (Fig. 3).

Fig. 4. Grandfather clock movement horse.

The stand illustrated in Fig. 4 is the type used for many years past by the old English clockmakers; it permits the repairer to walk round the clock, but it takes up floor space. A cupboard fitted with shelves and a glass door is an asset to the clock workshop; it is very useful for storing carriage, calotte, boudoir and the smaller type of clocks while testing, as dust should be excluded and the clocks should always be under observation.

Fig. 5. French clock movement horse.

The lower shelf can accommodate the French clock “horse” (Fig. 5) used when testing the movement alone.

Fig. 6. Clock repairer’s bench.

A good size for the bench is 3 ft. 6 in. to 4 ft. wide, 2 ft. deep and about 38–39 in. high. A rack is fitted at the back for large tools, such as files, burnishers, etc. It should be very substantially made of good stout wood, and should be screwed down to the floor (Fig. 6). The clock repairer’s bench must be firm. A stool with no back is preferable to one fitted with a back; much of the work is done standing and the stool can be pushed under the bench out of the way, which would not be possible if a back were fitted, and yet drawn out easily for use.

Fig. 7. Suggestion for a model clock repairer’s workshop.

A good light is essential; daylight for preference. The workshop facing north is ideal, as a steady light is then assured. The floor should be covered with a good quality plain linoleum, brown in colour for preference, and the walls and all woodwork painted cream so that light is reflected and not absorbed. Environment has a lot to do with encouraging good work; remember a third of our working days are spent in the workshop, so it is worth some attention. Frequently workshops are dull, miserable, dustridden back rooms. It is true that some of the finest clocks the world has seen were made despite such deplorable conditions, but that does not mean they should be perpetuated. Fig. 7 shows an excellent model for a clock workshop.

Fig. 8. Flat nosed pliers, and (bottom) Round nosed pliers.

Fig. 9. Nippers.

Fig. 10. Small and large screwdrivers, 7-inch and 12-inch.

Fig. 11. Watchmaker’s screwdriver.

Fig. 12. 3-inch focus eye-glass.

Fig. 13. Tweezers; a small fine pair and a larger, stronger pair.

Fig. 14. Round faced hammer for riveting, and (right) flat faced hammer.

Fig. 15. Vice, 3 in. jaws.

Fig. 16. Turning arbor.

Fig. 17. Set of chamfers. The wheels should be rounded as shown in the small drawing.

Fig. 18. A clockmaker’s throw.

Here are some tools which are essential. This is not the complete list; others will be introduced as and when required. There should be two pairs of pliers, 1 pair flat nose and 1 pair round nose (Fig. 8); a pair of nippers (Fig. 9); a large screwdriver about 12 inches long and a small one about 7 inches long (Fig. 10); also two screwdrivers of the watchmaker’s type (Fig. 11) with blades of about 2 mm. and 4 mm. wide. A three-inch focus eyeglass (Fig. 12); two pairs of tweezers, one fairly fine and the other more robust (Fig. 13); two hammers, one flat faced and the other round faced for riveting (Fig. 14); a firm vice (Fig. 15); two or three pillar files 6 inches long, one coarse, one medium and one fine cut, and about six rat-tail files. A set of turning arbors (Fig. 16); six cutting broaches and six round broaches for opening and burnishing holes. A set of chamfers (Fig. 17); a set of burnishing chamfers, similar to Fig. 17, but with the wheels rounded as shown, not square; a clockmaker’s throw (Fig. 18); if you possess or are able to acquire a lathe so much the better, but for the beginner the throw is to be preferred; it is slower and the student is better able to “feel” the work and gain the sense of touch essential to good craftsmanship. The lathe is quicker and may be preferred from a commercial point of view, but at this stage the aim is to teach how to do the job and not how to make money quickly; that comes with experience.

Fig. 19. Lozenge shaped graver.

Fig. 20. Square nosed graver.

Fig. 21. Burnishers, flat and oval.

Fig. 22. Large broach.

Fig. 23. Setting the handle of a file or similar tool; strike the handle smartly on the vice two or three times in the manner shown.

Two gravers will be required, both inch square, one whetted to a lozenge shape as Fig. 19 and the other to a square-nosed shape as Fig. 20; two burnishers, one flat and the other oval (Fig. 21). Buy handles of suitable size for all the files and burnishers and special handles for the larger broaches, both cutting and burnishing (Fig. 22). Spend a little time in fitting the tools into the handles correctly, i.e., straight and firm; nothing is more annoying than a file fitted into one side of its handle and then not firm. For good work you must have good tools in good condition. To fit files, etc., into handles, heat the tang to a cherry red; make sure the active part of the tool is not discoloured and then burn the tool into the handle to within about inch of its final position; then hold the tool, say a file, upright, and strike the end of the handle smartly on the vice two or three times and this will drive the file firmly ino the handle giving a comfortable tool for as long as the file will cut (Fig. 23); this applies equally to all tools to which handles are, or should be, fitted. A firm fitting handle is of great help in controlling a tool.

Provide yourself with two oilstones, one fine and one medium. The double type of oilstone with one side fine and the other medium is not satisfactory as both sides have to be oiled and it is therefore difficult to keep the bench clean when using such a stone.

CHAPTER TWO

EXAMINING THE MOVEMENT

THE FIRST type of clock to be dealt with is the “lacquered plate” variety, embracing the modern mass-produced alarm, strike and chime clocks. At one time Germany had almost a monopoly of this market, but in recent years Canada and America have come into the field with the alarm clock and in addition vast quantities of alarm, strike and chime clocks are being produced in the United Kingdom.

Fig. 24. Chime movement viewed from the back.

Fig. 25. Nomenclature of the parts of a chime clock, which includes the chime, strike, and going trains.

Fig. 26. Chime movement viewed with the dial removed.

The plates and all brass work are lacquered and have something of a gilt appearance; the levers, racks, clicks, cocks and springs are pressings. They are not expensive clocks as a rule, but if certain details are attended to they give quite good results. Study Figs. 24, 25, 26, so that you become familiar with the parts and their names. A chime movement with pendulum has been selected for the purpose of nomenclature because it incorporates chime, strike and timepiece parts.

First of all, dismantling and assembly of a straightforward pendulum timepiece will be described, together with the best methods of cleaning and repairing the parts.

It would be futile to attempt to describe the various methods of removing these movements from the case, but in many instances the movement is secured to the dial on pillars and the dial is screwed on to the case. First of all remove the pendulum, then lay the clock flat on the bench, dial uppermost; open the front bezel and remove the three or four wood screws to be found on the outer edge of the dial. The movement can now be lifted out of the case.

Another popular system is where the movement is secured by lugs to the inside of the case, and the dial is screwed on to the case from the outside. In this instance remove the hands and then unscrew the movement from inside the case. The dial need not be removed.

Put the case away in a safe place and proceed to dismantle the movement. If the movement is secured to the dial remove the pin which holds the hands in position, this will release a small collet or washer and the minute and hour hands can then be pulled off with the fingers. Sometimes the hands are held in position by a screw collet only, no pin being fitted; usually the collet has a knurled edge and the procedure is to hold the minute hand steady and unscrew the collet, the hands then being pulled off as mentioned before.

The dial is removed by withdrawing the pins which run through the dial feet. Place the dial, hands, collet and case screws in a box for safety. It is not advisable to leave the dial exposed on the bench. Dials are usually silvered; the surface is delicate, and a tool dropped on it or drawn across its surface would mar the finish.

The next operation is to let down the mainspring. Place a key of the correct size on the winding square and wind forward for a fraction of a turn which will enable the click to be released. Hold the click out and away from the ratchet and at the same time reverse the direction of the key. It will only be possible to unwind about a half to three-quarters of a turn at a time. When the key has been reversed as far as possible, let the click in again to engage the teeth of the ratchet. Reposition the hand and proceed until the mainspring is fully unwound.

It is very unsafe just to release the click with no brake on the mainspring, or even to attempt to let the key slip through the hand. If such methods are adopted there is the risk of breaking the end of the mainspring and, should the mainspring be a strong one, of causing injury to the hand. Next, remove the minute wheel collet, which will allow the hour wheel to be lifted off, and then remove the minute wheel itself. Now examine both holes of the pallet arbor and the pallet face or pads for wear.

Fig. 27. Showing method of examining side-shake of pivots.

Hold the pallet arbor between the first finger and thumb (Fig. 27), as near the pivot as possible, and move it from side to side to ascertain if the hole has worn large. It is difficult, if not impossbile, to convey here when a hole is so large as to require rebushing. When the hole has worn to say 25 per cent. larger than its original size, or has worn oval, then it should be rebushed. There are instances, however, when it is debatable, and in such circumstances it is advisable for the novice to seek the advice of a good clock repairer and he will soon gain the necessary experience to be able to determine when a hole should be rebushed.

Proceed to examine all the pivot holes for wear. It may be necessary to hold some of the pinion arbors with the stout tweezers when testing, as it will not be possible to get the fingers into the movement.

Fig. 28. Right shows the amount of end-shake, and left the amount of side-shake.

Make a note, mental or otherwise, of the holes needing to be rebushed. How to do this rebushing will be explained later. Next examine the end shake of the pallet arbor and all the pinions. Here again the amount of end shake necessary is debatable; so, as for the side-shake, seek advice. For those who find it impossible to obtain such help the illustrations (Fig. 28) will form a guide.

Fig. 29. Method of holding the movement while examining the escapement.

Next examine the escapement. Hold the movement as shown in Fig. 29 with the first finger of the left hand on the fourth wheel impelling it in the going direction. Hold the crutch with the right hand and move it to one side to allow a tooth of the escape wheel to unlock, and with an eye-glass examine the position of the escape wheel tooth as it drops on to the pad of the pallet. For the depth to be correct it should be approximately 4 degrees measured from the pallet arbor centre. It is not practicable to measure 4 degrees on the pad, but by studying Fig. 30 it will be possible to make an estimate of the correct amount of locking.

Fig. 30. Showing the 4 degrees depth of the anchor escapement.

Escapements of this description allow for a fair amount of latitude; the clock will go if the pallet depth is a little deeper or much shallower and it is always safer to err on the shallow rather than on the deep side. If the locking is deep the arc of the pendulum must be large and to maintain a large arc power is needed. As the oil thickens the power to the escape wheel lessens, and if the pendulum fails only once to cause the escape wheel to unlock, the clock stops.

Fig. 31. Illustrating the cycle of action of the solid type of anchor escapement. The black teeth make clear the progress of the teeth actually in action during the locking, recoil, impulse, drop on to exit pad, and recoil.

Fig. 32. Cycle of action of the metal strip type of anchor escapement.

The illustrations (Figs. 31 and 32) show the solid type and the strip type of pallet; they are the “anchor” or “recoil” escapement, and it will become apparent that the shape of the pallet pads and of the escape wheel teeth can vary considerably, indicating the amount of latitude for this type of escapement to function satisfactorily. An important point to watch is the “drop,” i.e., the amount of movement of the escape wheel tooth between its release by one pallet and its arrest by another tooth locking on the other pallet. The amount of drop should be as little as possible, for two reasons : (1) it is lost power, (2) excessive drop disturbs the vibration of the pendulum, and the less the pendulum is disturbed the better the time-keeping; but locking will be dealt with first.

Fig. 33. Device for adjusting the Garrard escapement. The screw at the top adjusts the pallet cock hole.

Fig. 34. Wrong method of attempting to close solid pallets.

With the solid type of pallet, if the locking is found to be too deep it can usually be adjusted by altering the position of the pallet holes. In the case of the Garrard movement the screw shown in Fig. 33 adjusts the pallet cock hole, and as the pallets are nearer the pallet cock than the front plate hole, it is, as a rule, only necessary to adjust one end. To make the depth shallower, slightly loosen the two pallet cock screws and turn the screw a little in a clockwise direction and this will draw the pallets up and away from the escape wheel. If on the other hand the escapement is too shallow, the screw is turned anti-clockwise, which will cause the pallet to move downwards. When the depth is satisfactory examine the drop; if it is excessive you must exercise discrimination. These pallets are too heavy to close in. I have seen illustrations such as the one here (Fig. 34) where heat is applied to the belly of the pallets and then squeezed in the jaws of a vice while hot. I feel the results are doubtful and the risk great. At the worst, if the drop is a little more than it should be it will not stop the clock; excessive drop may affect the timekeeping but this type of clock is not a scientific instrument; it was not made for “fine time” and the error in its performance due solely to excessive drop is negligible, compared with the risk already mentioned, and the time taken for correction. With the astronomical regulators and fine clocks, where fractions of a second are of some account, it is another matter.

Fig. 35. Showing the amount of drop with the solid pallet anchor escapement.

An important point where notice must be taken and a remedy applied, is when the drop is not sufficient. When a tooth has dropped off the pad an appreciable space must be visible between the back of the tooth and the back of the pad from which it has just dropped (Fig. 35). If there is not sufficient drop there is a risk, when the pallet or the escape holes wear, or the escape wheel is slightly out of truth, of the pallet pad butting on the top of the escape wheel tooth; this can cause the clock to stop and also damage the teeth. Fortunately, the correction is quite simple if the lack of sufficient drop is, for instance, on the entry pad; that pad is stoned away, taking care to retain the original curve.

Fig. 36. Correct method of holding pallets between copper or brass chops in the vice.

Fig. 37. Stroking pad with Arkansas stone. Inset shows the direction of the grain.

Usually the solid type of pallets are hard and will not respond to the file, so proceed as follows. Remove the pallets and make secure in the vice, between copper or brass chops, as shown in Fig. 36. Use a Turkey or India stone and hold it much as you would a file, and proceed to reduce the pad, using a circular movement. Hold the stone firmly and, one might say, stiffly, inspecting the pad frequently to see that the surface is kept flat and at the same time retains the original curve. A little practice will make it quite simple. Test in the clock frame occasionally, and when sufficient metal has been removed finish the surface as follows. Hold the pallets on the end of an emery buff held in the vice, as shown in Fig. 37, and with the Arkansas slip in the right hand stroke the acting surface lengthways, using the same strokes you would employ if draw filing. Continue thus until all the rough marks made with India or Turkey stone are removed.

Next finish with the No. 000 emery buff, still keeping the strokes lengthways. This is important because if the surface were finished with a cross grain, the escape wheel teeth would cut across the grain and the pad would then act as a fine file and so wear the teeth. On the other hand, if the grain is lengthwise the teeth operate with the grain and consequently the wear is nothing like so great. Finally finish the surface with an oval burnisher, rubbing the surface, still lengthways, until it is polished. The inset (Fig. 37) shows the correct direction of the grain. The above remarks apply to all acting surfaces, whether pallet pads, pins which have work to do, springs impinging on another surface, or the surface upon which a spring operates; this principle makes for mechanical efficiency.

Fig. 38. Metal strip type of anchor escapement.

Fig. 39. Correct method of closing the pallets of a strip of metal anchor escapement.

If the pallets are of the strip of metal type (Fig. 38) the method of correction is much simpler than that employed when dealing with the solid kind. For instance, if the drop on both pallets is excessive they can be closed in as illustration (Fig. 39) with safety.

While the pallets of this type of escapement are usually soft, it is advisable to apply heat to ensure that they do not fracture.

Fig. 40. Correct method of bending the exit pallet.

Fig. 41. Adjusting one pallet only by peening.

On the other hand, if the drop needs adjusting on one pallet only it can be treated as shown in Fig. 40. If it is not desired to apply heat at all the adjustment can be made by peening the pallet needing attention as illustrated in Fig. 41.

Wear on the pads is removed by filing with a fine, worn file, finishing with a fine emery buff and burnishing as already explained.

Fig. 42. The escape wheel is firmly held with the first finger of the left hand, while the third wheel is moved backwards and forwards to check depth.

To proceed with the examination of the movement. Remove the pallets and examine the depths of the wheels into their pinions. As gearing is such an important subject two chapters are devoted to it and the reader is referred to these chapters to study what is a correct depth. To examine the depth of the third wheel into the escape wheel pinion, hold the escape wheel firmly with the first finger of the left hand and try the shake of the teeth in the leaves of the pinion, by moving the third wheel backward and forward (Fig. 42). The shake should be perceptible and appreciable, and there must be no suspicion of tightness.

Next place the first finger of the left hand on the arbor of the escape pinion and press downwards slightly, so to make the teeth engage as deeply as possible, then move the third wheel at least one complete revolution; the movement will be a little stiff because of the pressure on the escape wheel arbor, but it should be smooth and even, there must be no semblance of sticking, or of a jerky movement. Try all the wheels and pinions, including the depth of the barrel teeth into the pinion of the intermediate wheel.

Fig. 43. Depth tool.

Should one of the depths be “sticky,” it may be due to butting or wear of the pinion leaves. The procedure is then to fit the offending wheel and pinion up in the depth tool so that the action can be seen easily. If, for instance, it is the escape pinion and third wheel, remove these from the frame. Adjust the runners of the depth tool* (Fig. 43) so that the distance between each set of runners is exactly equal to the distance between the escape wheel and the third wheel holes. To do this place a male runner in each limb of the depth tool; make one runner secure by the knurled screw and leave the other runner loose. Place the fixed male centre into the third wheel hole, adjust the screw controlling the distance apart of the two sets of runners, until the loose male runner enters the escape wheel hole. Make sure the tool is upright before making the final adjustment of the screw last mentioned. The runners are now at the exact distance between the two holes, or, the “distance of centres.” From this point on no account touch the screw controlling the distance apart of the runners.

Fig. 44. Third wheel adjusted in depth tool to engage escape wheel pinion so that the depth can be examined easily.

Fit the escape and third wheels in the female ends of the runners and adjust so that the third wheel comes at the top of the head of the escape wheel pinion (Fig. 44). Make the runners secure by the screws, to bind the wheels, so that not only is there no end-shake but the wheels are stiff to move. Now the depth is clearly observable by rotating the third wheel slowly; observe the complete circle of the gear. The chapters on gearing will now be of assistance enabling determination of the fault and suggesting the remedy.

In the case of a depth that is too deep (i.e., the wheel teeth engage the pinion leaves so deeply that unnecessary friction is caused) there are three remedies :—

(1) Change the wheel or the pinion for a smaller one,

(2) increase the distances between the holes in the plates,

(3) reduce the diameter of the wheel by topping.

To deal with (1) first, it is often not economical or possible to change the parts, and it is seldom necessary. But if through some circumstance it is possible, then sector the wheel and the pinion and find which of the two it is most advantageous to change; the chapter on gearing explains how to use the sector.

(2) Unless the plates have been maltreated, i.e., new bushes badly fitted or the holes have been hammered up, it is not advisable to drill new holes, but again, if it is thought necessary to resort to this method proceed as follows. First open the holes of the wheel much larger than would be the case if a new bush only were being fitted. In this instance it is better to move the offending wheel rather than the pinion of the escape wheel because this will not upset the escapement. Next plug the new holes with brass wire. Fit the wire tightly into the hole, rivet well, and file off superfluous metal from both sides, finishing with water-of-Ayr stone. The procedure is explained fully when fitting new bushes. Both holes of the wheel should be plugged. With the pointed ends of the runners in the depth tool, and the depth tool used as dividers (making sure not to touch the distance of centres screw) scribe an arc from the escape wheel hole across the plug in the third wheel hole. Then fit the third wheel and the centre wheel in the runners to ascertain their correct distance of centres, and scribe another arc with the pointed ends of the runners using the hole of the centre wheel as a centre. The new hole is drilled at the intersection of the arcs. This is explained more fully in Chapter 13, page 133et seq.

(3) To reduce the diameter of the wheel, by topping, is in most circumstances the more practical method of overcoming the trouble. See page 78 of Practical Watch Repairing where the use of the topping tool is explained. The information given equally applies to clock work.

* Readers wishing to make depth tool are referred to page 228, where a dimensioned drawing is given.

CHAPTER THREE

DISMANTLING AND REPAIRING THE MOVEMENT

THE MOVEMENT should now be completely dismantled for a close examination of every part for wear or breakage. It will be assumed for convenience that, other than the removal of the motion work, the movement has not been dismantled. Unscrew the pallet cock screws and remove the pallet cock. Make it a habit to associate the screws with the parts to which they belong; a deal of time and trouble may thus be saved. Next, remove the pallets. Place the movement on the edge of an upturned cardboard box (Fig. 45). In this manner parts projecting from the movement, as in this instance, the winding square, centre arbor, etc., are free, so that when the back plate is removed the train does not jump out of position with the attendant risk of damage to the pivots.

Fig. 45. Upturned cardboard box used as movement stand.

Next, unscrew the four pillar nuts and gently lift the back plate up and away from the movement. Now remove the escape wheel, third, and intermediate wheels, and also the barrel. The centre wheel is held firmly in position by the cannon pinion which is driven friction tight on to the centre arbor. The necessity for removing the centre wheel at all is debatable. The manufacturers say it is advisable not to remove the cannon pinion because it may not be possible to replace it as tightly as it was originally; owing to the fact that the cannon pinion has been driven home once, the hole will be larger than before it was driven into position and the second fitting cannot be as tight. But it is generally better practice to remove it so as to ensure cleaning the hole and pivot properly.

Fig. 46. Method of holding plate to remove cannon pinion.

To remove the cannon pinion hold the plate in the palm of the left hand as Fig. 46, and strike the end of the centre arbor with a fairly heavy brass, or brass-faced, hammer. Strike with a good decisive blow, not a riveting tap.

Fig. 47. Stake for removing cannon pinion.

Bergeon of Switzerland have designed a useful stake for the purpose of removing the cannon pinion (Fig. 47). Place the plate on the stake as illustrated and give the centre arbor a smart blow with the brass hammer. This tool is also useful for replacing the cannon pinion.

Fig. 48. Adjusting end-shake of barrel arbor.

All the component parts are now lying on the bench and the barrel should be next to receive attention. Hold the barrel firmly in the left hand, grip the barrel arbor square with the brass lined pliers and test the end-shake of the arbor in the barrel. If it is tight, place the barrel on a hollow stake, such as a piece of brass tube, or an old and smaller barrel, and strike the end of the arbor with the brass hammer (Fig. 48). Consider which end it is best to strike; by giving endshake to the arbor the position of the barrel can be altered. In this instance strike the end opposite the square which will tend to bring the barrel teeth away from the second wheel.

Fig. 49. Removing barrel cover.

When satisfied that the barrel arbor endshake in the barrel is correct, proceed to prise off the cover with a clock screwdriver (see Fig. 49). Next remove the barrel arbor and to do this reverse the arbor a little to unhook it from the eye of the mainspring. It is not always necessary or advisable to remove the mainspring from the barrel; if the oil appears clean it is quite safe: to leave it. Should, however, the spring appear to be very dirty with thick oil, proceed as follows to remove it. Hold the barrel in the left hand, and with the brass lined pliers in the other hand pull out the centre of the spring very gently, far enough for the inner coil to be held by the hand, and then carefully manipulate the spring so as to uncoil it from the barrel. This is most important; to pull the spring straight out will distort it. When only the last or outer coil remains barrel carefully unhook the eye of the spring from the barrel hook. Cleaning and replacing the spring will be dealt with later.

Fig. 50. Testing pivot with finger nail.

Fig. 51. Fit up in throw to polish pivots.

The movement is now in pieces and the rest of the repairs can be proceeded with, rebushing worn holes, for instance, and polishing pivots. Before rebushing a hole, the pivot must be in perfect condition; usually wear, in the form of ridges, can be seen quite easily, but to make sure pass the finger nail of the third finger along each pivot (see Fig. 50) and it will be possible to feel any roughness. To polish the pivot, fit up in the throw, as shown in Fig. 51. and if the pivot is badly cut use a fine worn file first.

The steel work of the type of clock under repair is usually made from mild steel and is soft, not hardened and tempered; it will be quite easy to file. Hold the file down on to the pivot firmly to hold it in position. Cause the wheel to rotate slowly; it will revolve toward you and then move the file forward with a steady even pressure, using enough pressure to feel the file cutting; use plenty of oil on the file. When a full forward stroke is accomplished, ease the pressure off the file slightly, still causing the wheel to rotate, and then give another forward stroke, continuing thus until the ridges in the pivot are removed.

When satisfied with the surface of the pivot, proceed to burnish it. First clean the pivot by dipping into benzine or petrol and brushing well, then clean the bed in the runner with a brush dipped in benzine or petrol. Do not remove the runner from the throw to clean, as by so doing the “seating” will be altered.

Fig. 52. Sharpening or “making” surface of burnisher.

When both pivot and runner are clean and dry replace the wheel in the throw and in place of the file use a flat burnisher about 6 inches long. Sharpen or “make” the burnisher, by cleaning it on a No. 2 emery buff. The surface of the burnisher must be cross grained (Fig. 52), the fine ridges made by the emery buff acting as a very fine file, so fine that the surface produced is a polished one or, to be more correct, a burnished surface. The burnisher cuts slightly and also closes up the pores in the metal, hardening it by forming a thin tough skin.

Before using, wipe the burnisher on a clean linen rag and smear a little oil on the surface. Hold the burnisher on the pivot, causing the wheel to rotate fairly quickly and using an even pressure, both in the forward and backward strokes, gradually increasing the speed of the burnisher so that it travels faster than the speed of the pivot. A few strokes in this manner and the pivot is polished, or burnished. With a little practice you will find polishing pivots quite simple.

Having polished all the pivots that required it proceed to bush the holes. After a worn pivot has been polished its hole is almost sure to need rebushing. There are two methods of rebushing and both will be described here. The objectionable practice of closing the holes by punching up, is not good clock repairing; it can disfigure the plates and the metal so spread is thin and the life of the repair is short.

Fig. 53. Method of testing uprightness of hole during broaching.

Fig. 54. Chamfering hole to receive rivet of bush.

To deal with the riveted bush first. Open the hole from the inside, i.e., the opposite side to the oil sink, with a cutting broach. Open it to an extent sufficient to ensure that the walls of the new bush are reasonably substantial. It is important, while broaching, to keep the hole upright, and to ensure this hold the plate up at about sight level, with the broach as far as possible in the hole. By turning the plate half a turn it is possible to see if the broach is upright and at right angles to the plate, both ways. If it is not, sway the broach over to the required position while broaching. Figure 53 shows the broach upright and also out of upright. Chamfer the hole from the oil sink side sufficiently to receive the rivet of the bush (Fig. 54). Next select a piece of bush wire with a hole a little smaller than the pivot it is to fit.

Fig. 55. Turning arbor, with bush.

Brass bush wire is sold by the material dealers in lengths of about 2 inches, of assorted outer and inner diameters. Cut off a length of the wire equal to a little more than the thickness of the plate. Place the bush on a turning arbor as shown in Fig. 55 and turn to a slight taper, about the same taper as the cutting broach, reducing the diameter of the bush until it enters the hole in the plate from the inside to about half the depth of the hole. Turn both ends square and reduce the length of the bush so that it is a little longer than the full depth of the hole in the plate. Remove the bush from the turning arbor.

Fig. 56. Driving home and riveting bush.

Place the plate, oil sink side down, on to a flat stake, insert the bush and, with a flat end punch, drive home the bush flush with the plate. Now reverse the plate and chamfer the end of the bush until the sink is about as deep as the original oil sink before the chamfer was cut for the rivet. Then rivet the bush, using a round end punch. The metal so spread should fill the chamfer made for that purpose. Open the hole from the inside with a cutting broach—always apply a little oil to the cutting broach—until the pivot fits tightly and no more. Hold up the plate occasionally while broaching, with the broach as far as possible in the hole to ensure that the hole is upright, as explained when opening the hole to receive the bush. The illustrations (Fig. 56) show the procedure of riveting the bush.

The hole is then burnished with the round broach. These broaches are cleaned by drawing an emery buff—say No. 1 or 2—up and down their full length; this makes the grain lengthwise; its action is similar to the flat burnisher already mentioned. Smear a little oil on the broach and insert it in the hole from the inside and lightly open the hole until the pivot fits freely. The broach is twirled in the fingers in a similar manner to that employed when using the cutting broach. Not only does the round broach polish the inside of the hole, it also hardens the surface. As the bush has been riveted do not use much pressure for fear of dislodging it, but if the hole were solid with the plate, considerable pressure would be desirable, as will be explained when describing how to make a clock movement in Chapter 11, page 103.

Fig. 57. (Left) Burnichser; and (right) cutting wheel chamfering tool.

Fig. 58. Chamfering tool made from rat-tail file.

Fig. 59. Filing bush on protrusion.

When the side-play of the pivot is satisfactory, finish the oil sink side with the wheel chamfering tool using the cutting tool first and then the burnishing one (Fig. 57). If the bush has been cut to the exact length it should be flush with the inside of the plate and it will only be necessary to remove the burr thrown up by the broaching, using the rat tail chamfer (Fig. 58) for the end-shake to be correct, and the job is done. On the