GB243125A - Electric switch-gear - Google Patents

Abstract

243,125. British Thomson-Houston Co., Ltd., Trencham, H., Heath, H. C., and Newton, C. W. Sept. 30, 1924. Sliding switch-carriage arrangements.-Relates to electrical switchgear including a circuitbreaker which may be moved in relation to a fixed switchgear structure for isolating purposes, the circuit-breaker being adapted to be moved horizontally to a position from which by vertical movement it can be connected in a selected circuit. As shown in Fig. 1, the circuit-breaker 17 is adapted alternatively to connect a feeder 13 to 'duplicate bus-bars 12, 14 and is arranged for horizontal movement on rails 16 which, after the circuit-breaker has been moved to either of its alternative positions, may be raised in order that the plug connections on the circuit-breaker may engage the sockets corresponding to the feeder and the selected bus-bars. The circuitbreaker is fitted with wheels 19 to roll along the rails 18 which carry nuts 21 working on vertical screwed rods 22 which are rotated through bevel gearing 24 by operating shafts 48 carrying handles 25. A shaft 48 is provided at each side of the circuit-breaker and the two shafts are being interconnected by a chain 23 so that rotation of either handle rotates simultaneously the four rods 22 so raising or lowering the circuit-breaker. To prevent vertical movement of the circuit-breaker in positions other than the two alternative positions at which the isolating connections may be established, guide plates 31 are provided thereon which may only move upwards when between pairs of rollers 33. The bus-bar and feeder sockets are provided with pivoted gravity-controlled shutters 27, 28, 29 covering bus-bar and feeder sockets. These shutters are joined together by links 41, the centre shutter having operating rods 34 attached to pivoted levers 36 normally projecting between the rollers 33 so that they are moved aside on upward movement of the circuit-breaker to open the shutters corresponding to the feeder and selected bus-bar the remaining shutter remaining closed as the movement of the feeder shutter merely moves a pin 38 along a slot 39 in its connecting link 41. Another interlock is provided to prevent downward movement of the circuit-breaker when closed which may be as shown in Fig. 3 where a pivoted cam 47 is attached to a sliding spring-pressed lever 44 cooperating with the tripping bridge 46 of the circuit-breaker trip gear and engages the shaft 48 during the downward movement of the circuitbreaker which is tripped at the commencement of such movement. A second cam projection 49 similarly ensures the tripping during the initial upward movement if the circuit-breaker has been closed for trial purposes when lowered. For earthing the feeder, conducting and insulating extensions are placed on the appropriate insulating terminals of the circuit-breaker, the terminals carrying the insulating extensions being directly connected together in any suitable way with the tank 17.