GB1296489A - - Google Patents

Abstract

1296489 Clocks KIENINGER & OBERGFELL 29 Dec 1970 [27 Dec 1969 25 April 1970] 61751/70 Heading G3T [Also in Division H1] In a digital alarm clock or time switch having minutes drums 4, 5 and an hours drum 6 which are driven by a synchronous motor 22 and indicate the current time, the alarm or other device is switched on when the indicated time is identical to that shown on digital alarm-time setting drums 36,37. The motor 22 drives the minutes drum 4 via gearing 23-29 and a stepping mechanism 30. The lens of minutes drum 5 is driven by the drum 4 through a decade coupling, and itself drives the hours drum 6. Hour indications 9 are carried on eight trihedral bars 8,9,10 which are carried on the drum 6 and are indexed around their own axes as the drum 6 is driven about a central axis 7. The alarm setting drums 36,37 are provided with radial webs 54, 53 and with external toothings 61,60 respectively which are engageable by a manually operable member to rotate the drums about a spindle 40. Each web 53,54 carries a contact rivet 52, one end of which co-operates with a corresponding one of springy contacts 81, 79 which are carried on alarm actuating discs 38,39 respectively. The two discs 38, 39 are connected in series via a further springy contact 80 on the former and a continuous conducting track 83 on the latter. The other end of each rivet 52 slides on a corresponding track 51 which is carried on one face of a resilient insulating disc 49 or 50. The discs 49,50 are attached to fixed bushings 41,42 and carry pins 55 for connection to the external (alarm) circuit. Indentations 56 in the setting drum webs 53, 54 co-operate with domed tips 57 of the pins 55 to provide detented positioning of the setting drums 36,37. An alternative embodiment is described in which the contact rivets 52 are replaced by apertures in the webs 53, 54 and the wipers 79,81 may pass through the apertures into spring contact with the tracks 51. The alarm actuating disc 38 is driven by the minutes drum 4 via a gear (71) Fig.2 (not shown), which is coupled to a transmission tube (70), and intermediate gears (74,74). The actuating disc 39 is driven by the hours drum 6 via a gear (67), a spindle (66) which passes through the transmission tube (70), and further gearing (69,77).