GB696816A - Improvements in or relating to snap-action electric switches - Google Patents

Abstract

696,816. Press-button retractive switches; tumbler switches. ASHLEY ACCESSORIES, Ltd. June 11, 1951 [June 9, 1950; June 9, 1950], Nos. 14407/50 and 14409/50. Class 38 (v) A snap-action switch comprises a trifurcated blade spring 13, the outer links of which are corrugated at 14 and are clamped to pillars 12 on the base by screws or by pins on the cover 18, the centre bowed limb being acted upon on one face by a dolly 20 and on the opposite face by a spring plunger 25. Counterclockwise movement of the dolly snaps the spring 13 over-centre to open contacts 16, 27 and depresses the plunger 25, which restores the spring 13 to the position shown when the dolly is moved back again. The open position of the spring is determined by stops 26 which may form further contacts, and one contact 27 may be insulated from the spring, the contacts 27 then acting to bridge two pairs of fixed contacts, Figs. 3-5 (not shown). The spring may be actuated by a pushbutton, Fig. 6 (not shown), the plunger 25 restoring the spring when pressure on the button is released, and in a further arrangement, Fig. 7 (not shown), the spring 13 is mounted at one end. The centre limb of the spring may be secured with the operating member and restoring means acting on one or both outer limbs.