GB461368A - Improvements relating to electric switchgear - Google Patents

Abstract

461,368. Switchgear structures. ELLISON, Ltd., G., and STRATTON, H. T. Nov. 6, 1935, No. 30665. [Class 38 (v)] Electric switchgear comprises the combination of fixed main and earthing contacts contained in a case, a slidable carriage carrying complementary contacts and movable between the fixed main and earthing contacts, means actuated by the carriage for preventing opening of the lid of the case except when the complementary contacts are earthed, and a hand lever for actuating the carriage. The fixed main contacts c are housed in an oil-containing casing a having a hinged or removable lid b, and connected to bus bars. The main movable contacts are carried on a carriage g, which is horizontally slidable on guides h to separate contacts j from contacts c, and in the other extreme position to bring contacts k into engagement with earthing contacts l. The contacts j are connected by the flexible leads n and pivotally-connected links m to the terminal posts o having sockets p to receive testing plugs. A handle t on a shaft r is adapted to operate the carriage through the lever system s, z, q, and a cam w on the shaft r normally co-operates with a bell-crank y to limit the movement of the carriage to separation of c, j and their arcing-contacts 9, 10. In this position of the parts a further cam 6 has moved clear of the lever y, so permitting the latter to be moved to an inoperative position by a normally-padlocked push piece x, so allowing the handle t to be further rotated for moving the carriage to the earthing position. A flange 7 is apertured at 8 to allow the handle t to be padlocked in any of its three positions. To lock the lid b against removal in any but the earthing position of the carriage, a member 2 on the latter engages in a depending part 3' of the lid. Accidental return of the carriage when the lid is off is prevented by a spring plunger 4, 5 in a removable safety cover f for the contacts c, which plunger only allows movement of the carriage when the lid is replaced.