GB784116A - Improvements in or relating to electromagnetic relays - Google Patents

Abstract

784,116. Electromagnetic relays. WESTERN ELECTRIC CO., Inc. Feb. 22, 1956 [Feb. 25, 1955], No. 5495/56. Class 38 (5). A relay, Figs. 2, 5, comprises an annular core 1 receiving a coil 2, and a flexible armature 4 pivotally mounted on an angle-section spring 5 by the welding of armature legs 35 to tongues formed by slots 42 cut in the spring, the latter being supported on an insulating spacer 9. A non-magnetic spacer 3 is interposed between the armature and the pole faces 40, 41 of the core. When the coil is not energized the spring 5 and a pair of coil springs (Fig. 3, not shown) which bear against the underside of the armature at its free end, hold the armature away from the pole faces 40, 41, the armature movement being limited by the engagement of a catch 31 with a stop 32. In this condition, a comb bar 6 on the armature holds multiple wire contact springs 15 away from fixed wire contact springs 18. Energization of the coil 2 draws the armature towards the core, the flexible character of the armature causing it to bow, the pivoted end of the armature first moving towards the core and the armature performing a rolling motion on the pole faces until it eventually resumes its straight form. This permits the contacts 15, 18 to engage. The action of the flexible armature ensures a smoother relay operation by enabling the armature pull characteristic to be related to the load characteristic of the contacts (see graphs, Figs. 9, 10, not shown). An insulating cover 38 held by clips 21 may protect the contacts. In a modification, Fig. 8, the core 1 is rectangular. Specification 731,486 is referred to.