GB1003486A - Electromagnetic relays - Google Patents

Abstract

1,003,486. Electromagnetic relays. AMERICAN MACHINE & FOUNDRY CO. March 6, 1963 [March 8, 1962], No. 8959/63. Heading H2B. A relay whose armature is retained in the position to which it was last attracted by permanent magnetism comprises a winding mounted on a core 45, a first pole piece 15 coupled to one end of said core and a second polepiece 16 coupled to the other end, a magnetic yoke 32 between the polepieces with its legs 35, 36 on opposite sides of the core, a permanent magnet 3 extending between leg 35 and polepiece 16, a permanent magnet 4 extending between leg 36 and polepiece 20 and an armature 5 pivoted about an axis transverse to the core to rock between pole faces 17 and 25. The winding is encapsulated in epoxy resin and enclosed in a non-magnetic metal box 1. Cooperating with the armature are a plurality of V-shaped biasing springs 60 each of which is fixed to a terminal pin 61 mounted in a block 55 and co-operates with resilient contacts 57, 59 having terminal pins 56, 58 extending through the block 55. The winding may comprise a single coil or two coils connected in series and parallel. The coils may be differentially energized. The armature pivot comprises a cylindrical magnetic member 53 secured to it which is seated in a groove in the yoke. The fixed contacts are bifurcated by an offset slot to limit any tendency for the furcations to vibrate. Specification 838,988 and U.S.A. Specifications 2,955,174 and 2,960,583 are referred to.