GB197913A - Self-regulating electric striking apparatus for clocks - Google Patents

Abstract

197,913. B³hler, G. May 20, 1922, [Convention date]. Striking-mechanism: chimes; going trains: clock movements.-The cams and contact discs actuating the striking-mechanism of a main or secondary electric clock are rigidly secured to the indicator ratchet wheels so that moving the hands automatically re-sets the striking-mechanism. The four-step cam 14 on the minute ratchet 5 operates the quarter-hour striking-mechanism by means of a contact arm 13 which closes for one to four seconds a contact in an electromagnetic striking-circuit by an appropriately shaped contact-piece 20 carried by the seconds ratchet 6, the normally open circuit of the strike-work being closed once in each second by the pendulum. A control contact 18 is established four times in the hour by the minute ratchet. The hour striking is effected by a twelve-step cam on the hour-ratchet 7 and an arm 13 which makes contact for the appropriate number of seconds on a disc 16 fixed to the seconds ratchet. An alarm circuit is closed by a spring contact piece 22 in the insulated rotary disc 23 contacting with a stud in the hour ratchet. A slip ring 24 on the disc 23 and a brush complete the circuit with the piece 22. The time-indicating mechanism consists of the three ratchets 5, 6, 7 and their inclicators on the same spindle. The seconds ratchet 6 receives impulses from a pawl 8, and the minute ratchet from a recessed part of the same pawl when one deeper recess 9 in the seconds ratchet permits engagement. The hour ratchet 7 is moved by a further recessed part of the pawl each time one of five equally spaced deeper recesses in the minute ratchet permits engagement therewith. Instead of a recessed pawl, one with a straight edge may be used arranged to co-operate with ratchet-teeth of different heights.