GB1337733A - Electric switch devices - Google Patents

Abstract

1337733 Snap-action switches; switch contacts MK ELECTRIC Ltd 19 April 1971 [26 Feb 1970] 9401/70 Heading H1N A switch comprises a first fixed contact 31 having a knife edge 32 constructed from precious metal inlay material on both sides of the knife edge and forming the fulcrum for and the contact with a rocking contact 34 rockable on knife edge 32 to bring it into and out of engagement with a further fixed contact 22. As shown, the precious metal is silver and rocking contact 34 engages a different further fixed contact in each of its two positions, Fig. 2 (not shown). Knife edge 32 has a groove 33, Fig. 1 (not shown) in its middle through which passes a flat portion 36, Fig. 1, of rocking contact 34. Rocking contact 34 is rocked by a pressure member 40 bearing on flat portion 36, Fig. 1, and is spring urged against contact 34 by two springs 44 in rocker operating member 13 pivoted at 38. Member 40 is pivoted on a pin 41 slidable in slots in rocker 13. Depression of rocker 13 snaps over contact 34. To aid in moving over contact 34 it has projections 46 which are engaged by projections 45, Fig. 2, on rocker 13. Instead of engaging a different fixed contact at each end, rocking contact 34 may engage a different fixed contact on opposite sides of one end. The switches may be multi-gang with a common pivot pin.