GB895658A - Improvements in or relating to pull-cord electric switches - Google Patents

Abstract

895,658. Snap-action switches. MILLER GWYNNE & CO. Ltd., and MILLER, B. R. Nov. 3, 1960 [Nov. 6, 1959], No. 37784/59. Class 38 (5). A two-pole pull-cord switch comprises an insulating base 10 having terminals 12, 15 carrying fixed contacts 18, 20 which co-operate with spring strips 19, 21 secured to terminals 13, 14. Strips 19, 21 are actuated by the ends of an insulating member 23 pivoted at 22 and having a V-shaped projection whose apex 28 engages a similarly-shaped leaf-spring 29 carried by a bracket 30. Member 23 also has a slot 45 in which slides the hooked end 46 of a link 43 whose other end passes through a bore 44 in a brass rod 37 and engages a piston 42 urged upwardly by a spring 41, the boss 36 of rod 37 being attached to the cord through a screwed cap, Fig. 8 (not shown). In the position shown in Fig. 4, both contact sets are closed through depression of the strips 19, 21 by the member 23 whose surface 24 abuts the base 10. To open, members 37, 43 are pulled down to rotate member 23 to a horizontal position after which, the spring 29 completes the switching movement, and the release of the cord allows members 37, 43 to be restored by the spring 41, the link end 46 moving to the upper end of the slot 45, Fig. 8 (not shown). Member 23 has a lug 53 which projects through the switch housing to indicate the closed position, such indication being improved by making the member 23 a different colour from that of the switch base and cover. The strips 19, 21 may be arranged so that they are deflected away from the fixed contacts by the ends of the member 23, or so that they move in the same plane of movement as member 23.