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CONTENTS OF BOOK X. Page Vibrating Tool .......................................... 129 Hairspring Vibrating ...................................... 129 Vibrating a Flat Spring .................................... 129 Timing a Watch ......................................... 130 Adjustments ............................................. 131 Breguet Hairsprings ....................................... 131 ·Over Coil Tweezers ...................................... 131 Making Gradual Over Coil ................................. 132 Construction of Lever Escapement ............................ 132 Action of Lever Escapement ................................ 133 Lock .................................................... 133 Slide and Run ............................................ 133 Lift .................................................... 134 Drop ................................................... 134 Adjusting the Escapement ................................. 134 Adjusting the Guard Pin .................................. 135 Adjusting the Banking Pins ............................... 135 Adjusting the Roller Jewel ................................ 136 Shifting Pallet Jewels ..................................... 136 Adjusting the Lock ....................................... 137 Adjusting the Draw ...................................... 137 Copyright, 1914 and 1915, by JOHN DREXLER. VIBRATING TOOL. A convenient tool for vibrating is shown in Fig. 299. It is made of an American watch dial, and a steel shoul­ dered wire with a screw in one end to hold it to the dial and two nuts at the other end to allow a bridge from any movement to be adjusted so that the lower pivot just touches the dial. The post is fastened in the hole of the second bit and the dial feet are adjusted to make the tool stand level. HAIRSPRING VIBRATING. Vibrating is a method of finding a hairspring of cor­ rect length and strength to allow a balance of a certain weight or size to make the proper number of turns or vibrations in a certain time. Balances being of different weights and sizes, a spring is fit, only, for the balance on which it is vibrated. The simplest way to vibrate a hair­ spring is to hold it with a tweezer near the end and com­ pare its vibrations ( when set in motion) with a balance of a timed movement having the same kind of a train, as the one for which the spring is being vibrated. The train of a watch may be slow, or fast, but the number of vibra­ tions which a balance of a properly timed watch makes, in one minute, can be found by dividing the number of teeth in the fourth wheel by the number of leaves in the escape wheel pinion and multiplying the result by twice the number of teeth in the escape wheel. VIBRATING A FLAT SPRING. To vibrate a hairspring, select a balance from a timed movement with the same kind of train as the one for which the spring is to be vibrated, and adjust it on the post of the vibrating tool so that the lower pivot just touches the dial and the balance vibrates without tipping sidewise. Press the collet of the spring to be vibrated on its staff and hold the hair. spring near the end with a tweezer. With the dial between the fingers, twist back and forth to start the trial balance. When it steadies down, bring the two balance arms together, move them apart a little as shown by the dotted circle in Fig. 299, and observe the arms of both balances. If the balance 129 that is being tested vibrates faster than the trial balance, take hold nearer the end of the spring and try the vibra­ tions as before. If it vibrates too slowly, take hold far­ ther from the end. Where the tweezers hold the spring, when the balance arms vibrate together for a while, is the place for the regulator pins. Without releasing the spring after it is vibrated, place the regulator in the center of its index. Lay the hairspring and balance on the bridge with the points of the tweezers beside the regulator pins. With another tweezer, grasp the spring a little beyond the stud, release the first tweezer and break off the spring where it is held. Remove the hairspring from the balance, insert the end between the regulator pins and into the stud, and pin it as you did in the collet. Turn the pin until the hair­ spring is parallel with the bridge. Press it in tight, and take off both ends of the pin close to the stud. True the hairspring on the bridge, in the round and in the flat and make the path of the regulator so that it does not move the col/et from the center of the hole jewel. Re­ move the hairspring from the bridge, true it, press it on the staff, so the watch will be in beat, fasten the balance in the movement and set the regulator in the center of the index. Hold the movement, dial up, above a pocket mirror and observe the action of the hairspring. If it touches the stud, the balance, the bridge or the third wheel, adjust it. Then set the watch to time and regulate it. TIMING A WATCH. If the spring has been properly fitted and vibrated, the watch will be close to time, with the regulator in the center of the index. Should it lose, so that the regulator will not bring it to time, take the spring up a little, at the stud, while if it gains and there is no spring to let out, turn out the timing screws an equal amount on each end of the balance arm. You may distinguish them from the balance screws by their threaded bodies, which are a little longer, and their heads which are not tight against the balance. Some balances have four timing screws, 130 (See 1, 2, 3, 4, Fig. 259), one at each end of the arm and one half way between. If there are no timing screws, place timing washers on the other screws at the balance arms, an equal amount on each side to prevent throwing out of poise. Timing washers are sold in assorted sizes and weights to cause a variation of thirty seconds to five minutes per day. Gold is the heaviest phosphorus, bronze lighter and brass the lightest. ADJUSTMENTS. The word "adjusted," stamped on a movement gen­ erally signifies that the watch will keep the same time in heat as in cold. Adjusted to position means that the watch will keep the same time in different positions. Watches are ad­ justed to three, five, or six positions. Three position adjustment is dial up, dial down and pendant up. Five position adjustment adds pendant to right and pendant to left; while six position adjustment adds pendant down. Isochronism adjustment, stamped on a movement, signifies that the watch will keep the same time with the mainspring fully wound as when it is partly run down. BREGUET HAIRSPRINGS. A portion of the last coil of a breguet hairspring ex­ tends over the other coils and is called the breguet, or over coil. Some over coils are made with a gradual bend, as in Fig. 300; others have two bends, or a knee, as in Fig. 303. Those with a gradual bend are mostly used. Be­ ginning at the bend, or knee, the over coil is shaped in­ ward. Some are straight across the spring, others have a gradual curve, but all are circular in the path of the regulator. When making an over coil, the shape of the old one must be followed. OVER COIL TWEEZERS. Fig. 302 shows a tweezer for making the rise of the over coil. The screw A is to adjust for the thickness of the coil. The spring is held in the groove, as at X, in Fig. 301, the broad way of the coil, and the amount of bend to be given is regulated with the screw S. To make 131 a knee, make the first bend as A in Fig. 303, reverse the tweezer and make the second bend as B. Fig. 304 shows a concave tweezer, lined with brass, as shown by the black, for shaping the circular part of the over coil. If you use a pegwood and an ordinary tweezer for making the bend of the over coil at the rise, finish off the inside corner of the tweezer to avoid making a sharp bend. MAKING GRADUAL OVER COIL. If you are to make a gradual over coil, vibrate the spring a little fast ( about five minutes per day). Hold it on a paper with a tweezer, as in Fig. 300, about three­ quarters of a coil from the end, and with another tweezer gradually lift the coil above the level of the remainder of the spring, not making any sharp bends. Now hold the spring a little beyond the rise with a tweezer and with a pegwood bend the coil inward over the spring, and with a tweezer, like Fig. 304, shape the path for the regulator, bending as in Fig. 305. Pin the spring into the stud, fastened into the bridge, and true it so that the regulator does not move the spring when moved from slow to fast. Have the path of the regulator (A) parallel with the bridge, and with the remainder of the spring ( B), as at X X, in Fig. 307. Center the spring by bending near the rise and where the path of the regulator begins. Then true it in the round and in the flat. (When pinning a spring try to have the pinning in the collet come on a line ( as X in Fig. 308) half way between the stud ( S) and the regulator pins (R) when the regulator is in the middle of the index, as the best results are obtained with a spring pinned in this way.) CONSTRUCTION OF LEVER ESCAPEMENT. The detached lever escapement, so-called because the balance swings free, except when it received impulse, and returns impulse to the fork, is used more than any other escapement; most watch makers considering it the best because of its simple construction, and the consequent ease with which it can be adjusted for accurate time measure- 132 ment.

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