GB564681A - Improvements in and relating to snap action devices particularly suitable for electric switches - Google Patents

Abstract

564,681. Snap-action switches; switch contacts. BRITISH THOMSON-HOUSTON CO., Ltd.- (General Electric Co.). Aug. 13, 1943, No. 13135. [Class 38 (v)] A snap - switch, suitable for controlling fractional h.p. capacitor motors, comprises a slotted spring strip 11 of the shape shown in Fig. 4, carrying contacts 18, 19 co-operating with fixed contacts 20, 21 carried by L-shaped members 25, which are frictionally held in the base by bent-out ears 27 and have projecting ends adapted for connection to leads. The space between the arms 16, 17 receives the shank of a press-button operating member, the button 31 of which is frictionally secured to the shank by curved upper parts of a single spring member or, as shown, of a pair of springs 32, the lower parts of which are bent to provide pivots for arms 16, 17. Depression of button 31 causes the arms 16, 17 to move over centre with respect to the plane of strip 11, the latter then engaging contacts 20. The over-centre movement is due to combined deformation of springs 32 and arms 16, 17, which reinforce the contact-pressure in both switch positions. In order to prevent collective movement of the strip and contacts away from contacts 20, 21, movement of the button in both directions is limited by compression of the return spring 35 and by a flange 37 on the button respectively.