GB731937A - Improvements relating to electromagnetic relays - Google Patents

Abstract

731,937. Electromagnetic relays. TELEPHONE MANUFACTURING CO., Ltd., and CARPENTER, R. E. H. May 13, 1953 [May 29, 1962], No. 13720/52. Class 38 (5). A one-side-stable polarized electromagnet;c relay comprises a pivoted armature moving in an air-gap in a magnetic structure, the armature being acted on by both a mechanical and the opposing polarizing magnetic force, which forces would both become zero if the armature moved to a plane set at an angle to the central plane of the air-gap, sufficient movement for this being, however, prevented by the configuration of the relay. Thus the armature can make use of the whole of the air-gap while the resultant restoring force sets always in one direction. In a relay of the kind disclosed in Specifications 315,496, [Class 38 (v)], and 559,047, in which armature a mounted centrally on springs s between the pole of polarizing magnets m, m<SP>1</SP> so that one end moves in an airgap between poles l, l<SP>1</SP> energized by winding w and the other end moves between contacts c, c<SP>1</SP>, the mechanical force is displaced by setting the springs at an angle and the magnetic polarizing force is displaced by the poles of magnets m, m<SP>1</SP> lying at different distances from the central plane AB. When the relay is deenergized, the armature rests against contact c under the influence of overriding magnetic force, and when the relay is energized, the armature turns to engage contact c<SP>1</SP> but does not pass through the plane at which the restoring force is zero. Alternatively, the poles of magnets m, m<SP>1</SP> may be displaced along directions parallel to the central plane, from the central pivot of the armature, and the mechanical force is provided by two helical springs asymmetrically arranged with respect to the plane, Figs. 6, 9 (not shown). The relay may be constructed as described in Specification 619,546, but with the poles at different heights, Figs. 7, 8 (not shown). Fig. 10 shows an arrangement in which centrally pivoted armature a mechanically biased by unequally acting springs S, moves in the two gaps between the mutually off-set ends r, r<SP>1</SP> and r<SP>2</SP>, r<SP>3</SP> of pole pieces t, t<SP>1</SP> fixed to the ends m, m of a horseshoe permanent magnet.