GB1232867A - - Google Patents

Abstract

1,232,867. Retractive switches; switch contacts. POLYCONTACT A.G. 19 June, 1968 [14 Feb., 1968], No. 22281/70. Divided out of 1,232,866. Heading H1N. Contact chatter is reduced in a snap-action switch by the provision of a lateral tongue, e.g. 8 or 9 on the moving contact blade 4 whose edge co-operates with a contact face e.g. 10 or 11 which is arranged obliquely to the direction of movement of the moving blade 4 and is resiliently supported so that it yields on being engaged by the moving contact blade 4 and a sliding damping movement occurs between the fixed and movable contacts. A push button 6,moves the moving contact by means of a cantilever spring 5 and C-shaped snap-action spring 7. The oblique face 10 or 11 is provided by the bent over end of a blade spring 12 or 13 clamped between a supporting spring 2 or 3 and a member 16 or 17. Movement of face 10 or 11 is limited by cooperation of a re-entrant portion with spring 2 or 3. The fixed contacts may be bifurcated by means of a longitudinal tapered slot, a longitudinal slot or an inclined offset slot so that each fork oscillates at a different frequency. The contact forks may occupy different rests positions so that they are engaged sequentially by the moving contact. Alternatively the contact edges of the moving contact may have different size forks to engage the forks of the fixed contacts sequentially. The forks may be given different frequencies by making them of different density materials or, by subjecting them to different cold working or heating operations, by making them of different thicknesses or by making them of different lengths. The cooperating contact forks may encounter different frictional resistances.