GB768141A - Improvements in or relating to electromagnetic relays - Google Patents

Abstract

768,141. Electromagnetic relays. ALLIED CONTROL CO., Inc. April 23, 1954 [Jan. 4, 1954], No. 11786/54. Class 38(5) A relay comprises a U-shaped magnetic frame 12 having a core 19 upstanding from one edge of the frame base 22 and surrounded by a coil 11. A non-magnetic armature-carrying plate 13 is secured to the frame 12 by projections 31, 32 which are received in notches 24, 25, the core 19 extending through an opening 30 in the plate 13 to attract a plate armature 14. The armature is pivoted by a spindle 35 which passes through holes 34 in lugs 33 of the plate 13 and through loops 38 formed on the armature. That half of the armature which is situated on the same side of the spindle 35 as the core 19, overlies the ends of the frame arms 20, 21 whereby when the coil 11 is energized the armature tilts to close the flux paths between the arms and the core. The armature is balanced about the spindle so as to be insensitive to shock. The other, narrower half of the armature carries non-conducting pins 40. 41 which operate reversely-bent spring contact arms 59, 60 fixed to the inner ends of hook terminals 57, 58. The arms 59, 60 are biased downwardly so that when the relay is not energized they engage leaf contacts 63, 64 fixed to hook terminals 65, 66, energization of the relay causing the pins 40. 41 to lift the arms 59, 60 to leave contacts 63, 64 and engage the inner ends of a further pair of hook terminals 61, 62. The armature is additionally biased to its de-energized position by an adjustable coil spring (Fig. 7, not shown). The hook terminals are insulatedly carried by a metal top plate 46 fixed to the ends of prongs 48 on the plate 13. The pull-in and drop-out voltages of the armature are controlled by adjustable stops which limit the armature movement, outward movement being limited by a bushing 69 threaded in the plate 46 to engage the upper side of the armature; inward movement being limited by a stop 72 which engages the armature underside and is supported by a narrower stem 73 which extends through an armature slot 39, the upper end of the stem having a head 71 threaded into the interior of the bushing 69. A container 16 is soldered to the plate 46 and may be exhausted.