GB604459A - Improvements in or relating to switches - Google Patents

Abstract

604,459. Electric selectors. STROMBERG-CARLSON CO. Aug. 22, 1945, No. 21444. Convention date, April 21. [Class 40 (iv)] A selector switch comprises a ball-race unit 37 which is reciprocated under control of the solenoids 14 in response to impulses, cam elements 62 projecting into the ball-race serving to advance a ball 47 (Fig. 7) along the race stepby-step. At each step the ball raises the cooperating cam element to close one of a set of contacts 8, 9 by means of a pusher 10. Construction. - The solenoids 14 comprising the driving magnet are mounted in a block 15 which is screwed to the cam assembly support 20, the armature 25 being pivoted on knife edges 17 and 22 on the block and support respectively and being urged away from the solenoids by springs 35. The opposite face of the block is provided with hardened inserts 36 having V-notches serving as bearings about which the ball-race unit 37 oscillates, knife edges 40 on the inturned end portions thereof engaging the V-notches. The ball-race 44 of flattened elliptical outline has openings 45, 46 in the upper and lower plates 42, 43, the latter also being provided with a knife edge 43a co-operating with the recess 48 in one end of a toggle link 49, the other end of which engages a notch 51 in the armature. The cam assemblies each comprise two plates 57, 59 having holes through which the cams 63 and 62 project respectively. A switch 75 is fitted to the block 15 and is actuated by a push-rod 79 under control of the armature 25. Operation.-With the switch 75 closed, energization of the solenoids 14 by an incoming impulse results in the ball-race moving downwards under the action of return spring 85. At the end of the impulse, springs 35 restore the armature and raise the ball-race. On the downward movement of the ball-race, the ball 47 moves down with it followed by the cam 62a to the full extent of its movement, indicated by the dotted lines (Fig. 7), whereupon the ball depresses cam 62b and is itself moved along the ball-race thereby, passing under cam 62c into contact with the side of 62d. Cam 62c is depressed in a similar manner during the next upward movement of the ball-race and the ball is moved over cam 62d into contact with 62e. The upper cams are each associated with a cylindrical stem 63 engaging a pusher 10 so that the sets of springs 8, 9 are actuated in turn, the set corresponding to the digit received remaining operated at the end of the impulse train. Automatic hunting is obtained by connecting the switch 75 in the solenoid circuit, each attraction of the armature serving to interrupt the energizing circuit. Double-capacity switch.-In a modification (Fig. 8, not shown), both the upper and lower cams are effective in operating spring sets.