GB747915A - Improvements in or relating to electro-magnetic relays - Google Patents

Abstract

747,915. Electromagnetic relays. STANDARD TELEPHONES & CABLES, Ltd. Sept. 17, 1954 [Sept. 21, 1953], No. 25995/53. Class 38(5) A relay, Figs. 1, 2, -7, comprises upper and lower sets of movable wire contact springs 12, 8 biased towards opposed sides of fixed blade contacts 10 and controlled by horizontal edges of an insulating plate 19 having two apertures 23. Pairs of upper and lower blade springs 13, 6 bias the plate 19 downwardly so that when the relay is not energized contacts 12 are permitted to engage contacts 10 and contacts 8 are held open. The free ends of the springs 6 engage the L-shaped armature 2 whereby when the relay is energized the plate 19 is raised to change-over the contacts 8, 10, 12. The free ends of the blades 10 are moulded in an insulating block 16 held by the downward bias of the blades against upwardly-extending portions of side arms 4 of a member 3 mounted on the yoke 1. The fixed ends of the contacts 8, 10, 12 are moulded in insulating blocks 7, 9, 11 which, together with the springs 6, 13 form a pileup mounted on the member 3 by a U- shaped spring clamp 14, slots in the latter engaging tongues 15 on the member 3. The blades 10 may alternatively comprise pairs of wire contacts. In a modification (Figs. 8-11, not shown) the springs 6 are omitted and the armature engages the plate 19 directly; also, the ends of the block 16 are located in apertures in the upward extensions of the side arms 4. In another construction, Fig. 4, the springs 10 are movable and springs 8, 12 stationary, and to this end the block 16 has a downward extension engaged by the armature 2 and an upward extension engaged by the springs 13, the springs 8, 12 being positioned by comb and card plates 30, 31 fixed between the upward extensions of the side arms 4.