GB213012A - Improvements in or connected with the sensitive elements of relays and the like - Google Patents

Abstract

213,012. Barr & Stroud, Ltd., and French, J. W. Dec. 27, 1922. Differential switches. -Retates to relays in winch the movements of one element are automatically followed by the movements of another element. The handle 9, which may be the one element, and the motor 12, which may drive the other element, are connected by a differential 10, 11 to a disc 1. If the handle 9 is rotated, the disc 1 is rotated and a slot 3 in it actuates the switch members 5, 7 causing the motor 12 to be driven one way or the other. This in turn brings back the disc 1 and switch arm 7 to their original position. To prevent the circuit tn the motor being opened too early when the disc 1 is rotated through more than one revolution by the handle 9, a retaining device such as the electromagnet 16 is adapted to hold the switch member displaced, being energized from the end of the first revolution onwards, through contacts 21, 22 which bear on a disc 19, provided with an insulating piece 20, and driven by the disc 1. In an alternative arrangement, Fig. 6, the insulating piece 20 is mounted on a disc 32 having fixed to it an elliptical wheel 31 gearing with another elliptical wheel 30 on the disc 19. In a modification, Fig. 3, a mechanical retaining device is used in place of the electromagnet 16. The lower end 16' of the switch member 5, 7 is here adapted to pass through a slot in one of two discs 28, 28<1> driven by the disc 1. Before the disc 1 has made one revolution, the slot in the disc 28 or 28<1> has passed the end 16<1> and the switch member is prevented from returning. Specification 213,320 is referred to.