GB995570A - Improvements in or relating to electromagnetic relays - Google Patents

Abstract

995,570. Electromagnetic relays. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Dec. 10, 1963 [Dec. 18, 1962], No. 47783/62. Division H2B. A relay comprises a core 1 having four longitudinally spaced transverse polepieces 2, 3, 4, 5, at least one magnetic reed contact unit 10 bridging polepieces 2 and 4 and arranged so that the overlapping ends of its reeds 11 and 12 are opposite polepiece 3, at least one magnetic reed contact with 14 bridging polepieces 3 and 5 and arranged so that the overlapping ends of its reeds 15 and 16 are opposite polepiece 4, and at least one energizing winding. The core may be remanent. Three energizing windings 7, 8, 9 are wound on the core as shown. Contact units 10 are closed by energizing windings 7 and 8 in the same sense and contact units 14 by energizing windings 8 and 9 in the same sense. If the core is remanent the units are opened by energizing their respective windings 7, 8 and 8, 9 in opposite senses. Each of the windings 7 and 9 may be replaced by two windings. If the core is non-remanent the centre winding 8 may be replaced by a permanent magnet which will retain the units in their operated positions if it is strong enough. The outer windings 7 and 9 may be replaced by permanent magnets. The contact units 10+14 may be electrically connected to form a changeover contact set. Copper slugs, or shortcircuited turns of the windings may be used to provide a make-before-break or a breakbefore-make contact set. Flux concentrating members 23, 23<SP>1</SP> are provided and the relay may have a magnetic screen. The contact units are clamped to the polepieces by U- shaped spring clips (Fig. 2, not shown). Specification 971,084 is referred to.