GB673867A - Improvements relating to electro-magnetic relays - Google Patents

Abstract

673,867. Electromagnetic switches. CARPENTER, R. E. H. Aug. 29, 1950. [Sept. 2, 1949] No. 22847/49. Class 38 (v). Chatter between contacts is eliminated or reduced by mounting a mass on the support of one or both of the contacts so that it can move under friction relatively to the support and does so move owing to its inertia when the contacts engage. The invention is shown (Fig. 2) applied to a relay of the kind described in Specification 619,546, wherein the armature 2 carries contacts 3 adapted to engage one or other of two fixed contacts 4 according to whether the armature moves up or down. The invention is here applied to both the moving and fixed contacts. The moving contact support, i.e. the armature 2 carries a mass 6 pressed against a washer 11 of "Catalin" (Registered Trade Mark) by a centering spring 13. When the contacts 3, 4 collide the mass 6 continues its motion owing to its inertia sliding frictionally on the washer 11. Each fixed contact 4 is carried on a stiff spring 15 which carries at its end a bent strip of metal 23 constituting the mass and embracing a strip of neoprene 22 which embraces the end 21. Any tendency of the strip 15 to vibrate is checked by the inertia of the mass 23 which causes frictional distortion of the neoprene 22. In modifications a ring of neoprene is mounted on the end of the spring 15, Figs. 12, 13 (not shown), and a mass bears frictionally on the spring 15, Figs. 16, 17 (not shown). In other modifications for the moving contact member, the mass 6 instead of moving rectilinearly moves pivotally, Figs. 5, 6 (not shown), the mass consists of a piston moving in oil, Fig. 7 (not shown), or of a disc mounted between two felt washers, Figs. 8, 9 (not shown).