GB1366509A - Time of day indicating apparatus - Google Patents

Abstract

1366509 Time switches; electric selectors SUNCRUX RESEARCH OFFICE KK 13 Aug 1971 [14 Aug 1970 27 May 1971 7 Aug 1971 (2)] 38209/71 Heading H1N [Also in Division G3] In an electric clock in which time is displayed by the illumination of successive areas of a dial (see Division G3), the illumination may be controlled by a switch in the form of rotary drums 72, 77 having conductive areas against which are pressed fixed contacts Sm 0 -Sm 12 and Sh 0 - Sh 12 connected to the illumination sources of twelve minute and twelve hour areas respectively. The conductive areas on the minutes drum 72 are in the form of a stepped sleeve 75 fitted over an insulating sleeve 73a so that the minutes lamps are lighted cumulatively. The corresponding areas on hours drum 77 are twelve square contacts 76 fitted in an insulating sleeve 73b and engaging a conducting sleeve 74 beneath the latter. The minutes drum 72 is on a shaft 70 rotated once per hour and intermittently advances the hours drum 77 by indexing gearing-see Fig. 9. An alternative switch is described in which each section comprises two spaced contact arms (92, 93, Figs. 16, 17, not shown) which are carried on a rotary disc (87) and wipe the periphery of an adjacent, fixed contact disc (88). The surface of the fixed disc is made up of twenty-four conducting portions (E 1 , E 2 &c.) which are separated by insulating portions (I 1 , I 2 &c.) and connected in pairs, each pair being used to light one of twelve display lamps (96). In a further alternative, both display sections are controlled by a mechanism comprising a rotary plastics drum 107, Fig. 18, having moulded steps 107d to operate contact arms A 1 -A 12 which co-operate with fixed contacts G 1 -G 12 . The drum is advanced in steps by a pawl arm 110 actuated by an electromagnet 104 which receives a pulse each five minutes from a switch 122 operated by a cam 121 on a motor shaft. Once during each revolution of the drum, a pawl 107c thereon advances a ratchet wheel (115, Fig. 19, not shown) on a shaft carrying a rotary contact 118. The contact 118 moves over a conductive ring and contact areas K 1 -K 12 to control the hours display. The contacts are connected to terminals on boards 119, 120.