GB467764A - Improvements in circuit-controlling devices - Google Patents

Abstract

467,764. Retractive switches and mechanical switches without quick action. EVANS, C. J., and EVANS, S. C. July 8, 1936, No. 19421/35. [Class 38 (v)] In a switch having an actuating plunger slidably mounted in a tubular element and carrying contact connecting means, a relatively fixed contact carrying element carries a plurality of contacts either directly or in portions of insulating or conducting material carried thereby, such contacts being furnished with means for adjusting their relative positions so as to vary at will the order in which they come into operation and the positions of the actuating plunger at which they come into operation. As shown in the Figure, the operating rod 6 slides within a tubular element 7 projecting from the side of a cylindrical casing 10 of insulating material. Projecting inwardly from the end and/or side of this casing are a series of relatively fixed spring plunger contacts each mounted within an externally-threaded casing 17 and provided with a lock-nut 20 so that the position of each contact is adjustable in relation to the casing. Mounted on the operating rod is an insulated bridging member adapted to co-operate with the relatively-fixed spring plunger contacts, the bridging member being formed with a flat end surface 22 and a side or peripheral surface 23 which is inclined or tapered. The operating rod may be acted upon by a spring 21 to retract it to the outer position with an oppositely-acting spring or, alternatively, no spring may be furnished, the switch being capable of being moved in one or other of two directions from a central position. At the outer ends of the plunger casings are transverse holes through which leads may be passed and held in position by clips 18 acted upon by the springs 19. The adjustment provided by the screwing in and out of the spring plunger casings determines in the case of the plungers 11, 12 the order in which they engage the end surface 22 of the movable contact and also the point in the path of the moving contact at which each individual plunger engages such surface. Similarly, adjustment of the lateral contacts 15, 17 determines the order and position in which they engage the inclined lateral surface 23. One or more of the plunger contacts may be adjusted to remain in engagement with the movable contact during the whole of its range of movement. The plungers may be arranged at an angle to the switch axis.