GB1398053A - Counting device - Google Patents

Abstract

1398053 Electric clocks TRI-TECH Inc 23 Jan 1973 [26 June 1972] 3455/73 Heading G3T [Also in Division G4] Transfer between adjacent numeral wheels 16 of a digital clock Figs. 1 and 2 (not shown), is provided by an epicyclic gear 42 mounted in a cage 30 which is freely supported between the wheels 16 and coupled to a lever 50 driven by a cam 20 on the lower order wheel 16 so as to counteract the gear drive and prevent movement of the higher order wheel while the lower order wheel moves from 1 to 9 and so cause rapid movement of the higher order wheel while the lower moves from 9 to 0. The cage 30 is rotably supported on bushes 21, 23 formed on the adjacent number wheels. The gear 42 is rotably mounted within a slot 34 in the cage 30 and is permanently meshed with gears 22, 24 also formed integrally with the moulded plastics number wheels 16. The lever 50 is hooked over a fixed pivot bar 53 and has a stud 55 pivoted in the cage 30; a follower portion 57 engages cam 20. As the lower number wheel rotates, the gears 22, 43, 44, 24 tend to rotate the upper wheel but the rising surface of cam 20 pivots lever 50 against spring 60 to rotate the cage 30 in the opposite direction so there is no resultant movement until the follower 57 drops off the nose 27 of cam 20 and the upper number wheel is rotated quickly through 36 degrees (or such other angle as is required for the clock digits). The clock is driven by a synchronous motor (63). The hours wheel is formed separately from its gear 24 and bush 23 and coupled to them by a pawl and ratchet (87, 89) so as to permit setting of the wheel by a thumb wheel (76). A second thumb wheel (75) directly drives the seconds wheel.