GB932322A - Improvements in or relating to electric switches - Google Patents

Abstract

932,322. Snap-action switches; retractive switches. SOC. D'ETUDES ELECTRO-MECANIQUES. March 22, 1960 [March 25, 1959], No. 10114/60. Class 38 (5). A snap-action switch operated by a tiltable control lever has mounted within the control lever a resilient strip which rests upon an operating bar, the remote end of which rests upon the free end of a resilient contact-carry blade, tilting of the control lever causing the upper end of the contact blade to move through its dead-centre position. A tiltable operating lever 3 has extension pieces 20, the lower ends of which are pivoted to the switch casing. Trunnions 21 of an operating member 16 slide in slots 19 in the extensions 20 and a notch 17 in the lower end of the operating member 16 rests upon shoulders on a spring contact blade 4. The moving contacts 5 are biased to each end position by a blade spring 22 fitted inside the operating lever 3, and upon tilting the lever 3 to its other position, the contacts 5 snap over to the other fixed contact 9 or 10. The contact blade 4 is reinforced by a folded metal washer 29 (Fig. 4). In an alternative embodiment (Fig. 6) the lower portion of the blade 4 is corrugated, the resilience of the corrugations replacing the blade spring 22. The switch casing 1 and cover 2 are moulded from plastic material, the cover 2 snapping into the casing and being retained by the engagement of projections on the two parts (Fig. 5, not shown). Lugs 15 on the casing 1 allow the casing to be snapped into engagement with a flush-mounting plate. The switch may be converted to a retractive type by the addition of the leaf spring 28 shown dotted in Fig. 1.