GB1142464A - Magnetic switch - Google Patents

Abstract

1,142,464. Retractive switches. INDUSTRIONICS CONTROLS Inc. 28 April, 1966, No. 18663/66. Heading H1N. A switch includes a contact bar 42 free for limited transverse and longitudinal sliding movement to obtain wiping action when moved in a housing 20 between abutments, and has portions of the bar as contacts and some of the abutments as contacts, and some of the contacts are permanent magnets to provide a snap-action switch with no pre-travel. A plunger 44 actuates bar 42 between permanent magnet contacts 32 and fixed contacts 28, the bar being attracted back to contacts 32 upon release of the plunger. The switch may be normally open, normally closed or changeover, and the plunger may have a restoring spring 96, Fig. 5 (not shown). The contact bar 42 may be a permanent magnet and the contacts 32 merely of magnetic material. Bar 42 may have silvered contact portions. Contacts 32 may be short cylindrical bar magnets 54, Fig. 2 (not shown). The contact bar 204 may pivot about a magnet 201 to move between a magnet 202 and an abutment 208, or pivots on a magnet 211, Fig. 7 (not shown), between magnet 212 and an abutment 208, or magnet 218, Fig. 8 (not shown). Other embodiments describe operation with alternate depression of two plungers, Figs. 10, 11 (not shown). An extra fulcrum 224, Figs. 9, 10 (not shown), may be provided to give pivoting movement of the contact bar about two parallel axes upon depression of an actuating plunger, the two axes being a permanent magnet contact and the fulcrum.