GB748313A - Improvements in or relating to electro magnetic relays - Google Patents

Abstract

748,313. Electromagnetic relays. ERICSSON TELEPHONES, Ltd., and DISTIN, L. S. Nov. 5, 1953, No. 30586/53. Class 38(5) A miniature relay unaffected by mechanical shock comprises a core surrounded by a coil 14 and secured to an insulating support 10 by a nut 15, the magnetic circuit being completed by long and short L-shaped pole pieces 16, 17 fixed to the core ends and forming between them a gap 18 bridged by a flat strip armature 19. Secured by screws 20 to the pole piece 16 is a contact spring stack 21 comprising contact springs 23, 24, insulated by mica strips 22, and a mounting plate 26 having turned-over lugs 27 supporting a pin 28. The pin 28 pivotally supports an arm 29 carrying a double-ended contact 30 which engages, alternatively, the springs 23, 24, a saddle portion 31 of the arm 29 carrying the armature 19, and an apertured upturned lug 32 of the portion 31 providing a further bearing on the pin 28. The arm assembly is balanced about the pin 28 and biased to hold the armature away from the pole pieces by a torsion. spring 35 acting between a notch in the arm and a lateral projection 36 of the plate 26. Thus when the coil 14 is energized the contacts 24 30 are broken and the contacts 23, 30 are made. The movement of the arm 29 is limited by stops 8, 9 and these may be bent to adjust the movement. A non- magnetic bracket 38 clamped to the core between the support 10 and the coil 14 is fixed to the free end of the pole piece 16 by screws 39 and serves to support the pole piece. The relay is enclosed in a casing which engages a rubber band 41 on the support 10 and the relay has a yieldable connection with the closed end of the casing by means of spring blades 42 clamped to the core. The casing may be sealed to the support 10 and exhausted through a tube 43.