GB419290A - Improvements in polarised electric relays - Google Patents

Abstract

419,290. Light current relays. SIEMENS & GENERAL ELECTRIC RAIL-. WAY SIGNAL CO., Ltd., and COOK, J. S., Caxton House, Westminster. May 1, 1933, No. 12650. [Class 38 (v).] A polarized relay has two movable polarized armatures arranged substantially to close two magnetic circuits, one of which circuits is that of an electromagnet over a gap between the poles of which the armatures extend and the other magnetic circuit being that of a polarizing magnet. As shown in Figs. 1 and 2, the operating coils 2 are mounted on parallel soft-iron cores secured to a yoke-piece 3 at one end and bearing pole-pieces 5, 6 at their other ends. Straddling these pole-pieces is secured a U-shaped permanent magnet 1 having polepieces 14 mounted in front of the pole-piece 5, but separated from the front surface thereof by a non-magnetic spacer 9. Between the projecting upper edge of the spacer 9 and an insulating cross-bar 15 the knife-edge lower ends of two armatures 16 are pivotally held, the upper ends of the armatures carrying insulating strips 17 with bridging contacts 18 secured by rivets 19. The armatures are normally held in the non-contacting position shown against adjustable back stops 13 by coil springs 11 or, alternatively, by suitably arranged blade springs. When the coils 2 are energized in one direction one armature is attracted to engage fixed contacts 21, the other being held against its stop by the spring tension assisted by magnetic repulsion, the reverse action taking place when the coils are energized in the opposite direction. The action of the relay may be adjusted by means of a slidingly adjustable magnetic shunt 22 bridging the poles of the permanent magnet, one end of this shunt being tapered as shown in Fig. 3.