Clock Repair Archive – – :
Waterbury made a triple plate self correcting lantern pinion mechanism with time and strike style shutoff wires. On the left side back plate looking at the unit from the front , the lever on top of the trip lever is the self correct lever. Stamped on the back of the movement: Patented 5/24/1910 ; 1/23/1917 ; 1/29//1918 ; 5/21/1918 ; 5/27/1919 6/5/1924 ; 4/14/1925. The best way to approach this mechanism, if an overhaul is planned , is to treat it as two separate mechanisms with a common middle plate. As far as bushings are concerned , this is the least confusing, in my opinion, unless you are fortunate enough to work in an environment where it is possible to work uninterrupted. I prefer to do the chime mechanism first, because it is often necessary to rebush the gear system that winds the mainspring. Those gears are hard steel so be careful. they are usually somewhat loose on the shaft, and that is not usually a problem, Just be sure the bushings are as tight as possible. Check the #2 wheel chime bushing on the long end of the shaft; it is very close to the movement post, and if it is worn too severely, it may be a problem to get a bushing to fit. Be sure to assemble the chime silent lever before the mechanism is completely assembled. The trip lever is the one with the flat blued steel arm that extends into the front mechanism (the front mechanism being the section that carries the centerpost and the hour tube hand end) . The self correct lever is directly above the trip lever. The lock pin for the self correct stop on the 4th wheel must go past the self correct stop on all but the hour; so that when it releases on the hour it will be clear of the lock pin when it starts the travel for the hour sequence. The short tab on the bottom of the self correct lever fits in the small hole in the middle plate. This mechanism has a rack and snail on the front plate. The gathering pallet has 2 pins. The chime is tripped by the chime trip cam in the front plate mechanism on the back of the centerpost. There is a high lift on this cam that is meant to trip the chiming mechanism at the hour on the self correct. Looking at the back plate from the back of the clock the self correcting lever is on the upper right hand corner. It has a 3 pronged tension washer to hold it in place when it is moved by the pin on the 3rd wheel. The triple plate design allows for the time gear train and the strike ear train to be positioned at the front and the chime at the back. The warning wheel (5th wheel)) in the chime gear train has almost one turn before the lock position; this allows for the self-correct to function properly. the pin on the 4th wheel is the self correct pin. It works with the self correct lever; the high lift moves the lever to clear this pin on the hour. the sequence cam is on the 3rd wheel. the 3rd wheel o has a pin on the front of the wheel to trip the strike and a pin on the back to set the self correct lever to grab the pin on the 4th wheel.All of the slots on the 3rd wheel are the same depth because the self correct is done with the levers, This mechanism has a through the dial regulator at the 12 o’clock position and a chime silent lever below that . the rack index arm will move: it is riveted on in the mechanisms i have seen. The setting of the index arm is critical because the shutoff arm that rides in the grooves must be adjusted so it will work in conjunction with the gathering pallet. It must shutoff with the last pin on the gathering pallet having just cleared the last tooth on the rack. The mainspring measurements are as follows:
Time mainspring:.018in. X .750in. X 96in.
Strike mainspring: .014in. X .874in. X 78in.
Chime mainspring: .0225in. X .874in. X 78in.
The pendulum length is 7 ¼ inches from the top of the suspension to the bottom of the pendulum. The center arbor winds to the right , the right arbor winds to the left . and the left arbor winds to the right. The suspension spring is .0035in. thick , and 1.6 inches long . The key size is somewhere between a 7 and an 8 , an 8 fits loosely and a 7 fits very tightly. The regulator end is between a 3 and a 5 ; the 5 will work but it is quite snug.