GB521217A - Improvements in or relating to synchronous-motor clocks - Google Patents

Abstract

521,217. Electric clocks. FIRCHOW NACHFGR APPARATEU. UHREN-FABRIK AKT.-GES., P. Nov. 12, 1938, No. 32941. Convention date, Dec. 23, 1937. [Class 139] In a mechanical clock movement the regulator 26 (balance or pendulum) is adjusted so that normally it goes slightly slow of correct timing, and a synchronous motor 11 which constantly winds up the main spring 20 also causes a recoil to be given, at regular intervals, 'to the regulator to increase its rate for a short time. By this means the average timing is correct and at the commencing of a period of current failure 'the clock shows correct time. The main spring 20 is wound by a non-self-starting motor 11 through eccentric 15, lever 16, and pawl 17 and is connected by gearing to escapement 25 and to a disc 36 which indicates the time or carries 'the operating members of a time switch. The motor 11 also drives a ratchet and pawl 30, 31 to stress a helical or leaf spring 33 between shaft 32 of the ratchet and a shaft 34 of the going train. The roller pin 27 on the balance 26 coacts with lever 25 and with a buffer spring 28. Spring 33 becomes stressed and the amplitude of pin 27 increases until it reaches and recoils from buffer 28 The spring expends some of its energy and the balance goes at a faster rate for a short time, after which shaft 34 reverts to its normal speed and spring 33 becomes stressed again.