Patent GB-411139-A (GB)
Title: Improvements in and relating to clocks
IPC: G04B21/02
Filed: 1932-12-01
Abstract: 411,139. Clocks. KEY, E. P., 74, Victoria Road, and GOLD, S., 187, Ewell Road, both in Surbiton, Surrey. Dec. 1, 1932, No. 34044. [Class 139.] Accessory mechanism such as striking or chiming means are operated from the time drive without the provision of additional devices through the medium of a pinion which is automatically moved into and out of mesh with a wheel of the time drive at the proper times. The invention is described in connection with the quarter chimes and striking devices of an electric clock. A synchronous motor drives through a time train 14 in which a fourtoothed pinion 15 co-operates through a lever 16 with an " initiating lever " 17 to start a chiming operation. The chiming spindle 22 is coupled through gears 24, 25 with the spindle 26 of the usual locking disc 27 which is coupled to a cover member 27<a> which has a small angular movement relatively thereto. At the quarter, a pin of wheel 15 bears on the end of the lever 16 and depresses the lever 17 so that the end 37 of a double spring 30 moves clear of a slot in the locking disc 27 pushing aside the cover member 27<a> which immediately returns and prevents re-entry of the end 37 of the spring. The end 38 of the spring is thus stressed, and when the pin slips over the end of lever 16, the lever 17 is kicked back, the cam 46 moving one end of the spindle 33 of pinion 32 against spring 35 so that the pinion moves out of gear with the wheel 43 and into gear with a wheel 36. At the end of the chime, the member 27<a> is displaced and the next slot of the member 27 registers with the end 37 of the spring 30 restoring the parts to normal, the lever 17 returning by gravity and the spring 35 moving the pinion 32 into gear with the wheel 43. Striking mechanism. A pin 47 on the disc 27 co-operates with a lever 48 which carries a cam blade 49 and with which moves a lever 51 on the same axis 50. During the last two quarters of the chime, the pin 47 engages the lever 48 moving with levers 48, 51 clockwise, the cam blade 49 shifting the pinion 56 axially to disengage clutch members 57, 58 and permit free rotation of the pinion. During this movement, the spring cam 53 at the end of lever 51 is drawn beneath and past a projection 54 and is rocked against the influence of a spring 52. When the pin 47 rides clear of a projection 63 in the lever 48, both levers 48, 51 and the cam blade 49 are moved counterclockwise by the spring 64 until a pin 65 engages a stop part 66 which is carried by a stop lever 61 which has pin and slot connection with the striking rack 21 and has been positioned by the hour cam 20. The cam 53 moving back over the projection 54 ricks the lever 41 and moves the pinion 40 out of mesh with the wheel 44 and into mesh with the striking pinion 45. Striking proceeds because the return of blade 49 has re-engaged the pinion 56 with the striking rack 21 and movement is transmitted from the spindle 23 until the stop 66 moves away from the pin 65 and the cam 53 rides clear of the projection 54 when the lever 41 effects reverse from " strike " to " chime." While striking is in progress the disc 27 is stationary with spring 37 bearing on the periphery. Upon re-engagement of wheels 40, 44 slight further movement is transmitted to the spindle 22 and thus to the disc 27 to bring the next slot into register with the spring 37 which terminates the operation. The arm on cover plate 27<a> co-operating with hour slot on the disc 27 is extended radially at 67 and the hour teeth at 68 to prevent upset of relationship between hands and striking mechanism due to the clock stopping.