GB716967A - Improvements in rotary electric switches - Google Patents

Abstract

716,967. Multi-position switches. SIMPLEX ELECTRIC CO., Ltd. July 25, 1952 [July 28, 1951], No. 17922/51. Class 38(5) In a rotary switch having spring-loaded mechanism to locate it in any one of a plurality of switching positions, the spring means of the said mechanism is centrally accommodated within the hollow interior of a contact-operating cam or a bush forming a bearing for the switch operating spindle, whereby the dimensions of the switch casing are kept to a minimum. The switch comprises an insulating casing 10 housing contactcarrying springs 18, 19 spaced one above the other, and a contact-carrying spring 23 on a level with the spring 18. The springs 18. 19, 23 co-operate respectively with fixed contacts 26, 27, 28, upper springs 18, 23 being operated by an eccentric 36 of a hollow insulating cam 34 and lower spring 19 by an eccentric 35 of the cam. The cam 34 is driven by a spindle 38 through a plate 44 cooperating with a flat 46 on the spindle and with internal cam ribs 45, the peaks of the eccentrics 35, 36 having grooves 37 spaced at 90 degrees receiving convex surfaces 33 of the springs 18, 19, 23 in each of the four switch positions. To locate the switch in each of these positions a plate 48 carrying balls 49 and rotated by. but axially slidable within, the cam 34, is urged by a spring 47 accommodated within the cam. so that the balls cooperate with four 90 degrees displaced radially disposed recesses of a plate 50 fixed to the switch cover 11. The switch is secured to a panel 15 by a threaded bush 12 and nut 14, a circlip 43 on the spindle 38 forming a bearing therefor by engaging a shoulder 42 of the bush 12. In an alternative construction the spring 47 is housed in the bush 12, other components of the locating mechanism being suitably modified.