GB498855A - Improvements relating to electrical relays - Google Patents

Abstract

498,855. Electromagnetic relays. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd. July 16, 1937, No. 19771. Convention date, April 28. [Class 38 (v)] In a polarized relay in which an armature winding builds up a flux to oppose that due to the polarizing magnet to cause the operation of the relay, the armature is made of small substantially uniform cross-sectional area so that it becomes saturated at the normal operating current, thus preventing the tendency for the permanent polarizing magnet to become reversed in polarity. As shown in Fig. 2, the magnetic circuit comprises two U-shaped magnetic yokes 6, 8 with polepieces 6a, 8a and 6b, 8b between which move the shaped ends of a pivoted armature 24. The magnetic yokes are magnetized by a pair of permanent magnets 10 having their polepieces bearing on the rear faces of the magnetic yokes 6, 8 so that like poles are produced at the ends of each yoke. The energizing windings 26 are mounted in the space between the yokes so as to surround the armature and produce a longitudinal flux therein which for one direction of current moves the armature across towards its opposite position and for a reverse direction of current maintains the armature in the same position. The armature shaft carries a series of movable spring contacts 35 ... 38 secured in a block 23a of moulded insulating-material, Fig. 5, the block 23a having a cylindrical extension 23 in which the armature is supported. The movable spring contacts operate between sets of relatively fixed contacts which are moulded into the sides of an insulating frame 1 within which the yoke member 6, 8 and other fixed parts are supported. The frame is fitted with front and rear covers, the former of which is fitted with an inspection window and the latter with spring clips adapted to hold the permanent magnets 10 in position.