GB596094A - Improvements relating to light current relays - Google Patents

Abstract

596,094. Electromagnetic relays. SIEMENS BROS. & CO., Ltd., and FOOT, G. H. July 18, 1945, No. 18421. [Class 38(v)] In a sensitive light-current relay, one or more contact balls 3 serve as bridging members between contacts on two relatively moving members 1, 2. In the form shown in Fig. 1 rotation of an inner member 1 causes four balls 3 to roll so that each moves out of engagement with a contact 5 and into engagement with a contact 6 on the outer member 2 while remaining in contact with a contact 4 on the member 1. The contacts 4 project slightly and may be resilient or mounted on springs. One or both of the ball races 1, 2 may be slightly concave. Fig. 3 shows a relay having two arrangements of the kind shown in Fig. 1 placed respectively above and below a horse-shoe magnet 12 with a moving coil 14 arranged between its poles. Current flowing through the coil 14 causes it to turn and operate a spindle 31 to which are fixed the two inner members 28 and 32 of the ball races. The relay may be provided with a return spring 33 or it may be returned by reverse current or an additional coil. In modifications, the contact mechanism is operated by a pivoted or plunger armature.