GB536929A - Improvements in and relating to electrical switchgear employing air or gas-blast circuit-breakers - Google Patents

Abstract

536,929. Switchgear structures. DAVIES, D. R., and METROPOILTAN-VICKERS ELECTRICAL CO. Ltd. March 19, 1940, No. 5123. Addition to 526,429. [Class 38 (v)] The switchgear structure as described in the parent Specification is modified so as to provide a vertically, or, as shown, a horizontallywithdrawable circuit-breaker unit with means for duplicate-bus bar selection. The chamber 10 supporting the discharge-vent 35 and arc-chutes 11 of the several phases, is mounted on a casing 9 on a truck 6 in which is a reservoir from which gas is led to each of the chutes by way of a vertical insulating tube 15. The arcuate contact 19 is mounted on an arm 18, wich is pivoted at 1'7 to a conducting element 16 fixed on the tube 15 and formed with contacts 33, 34. The selector contacts 32 are carried on stems 21 within insulating bushings 22, which. each extend through a slot 23 in casing 9 and are supported on a carriage 24 extending across the casing and provided with lugs 25 to freely receive a threaded rod 26 on which is a non-rotatable nut 28. Rotation of rod 26 by the handle 31 and brush gearing 29 raises and lowers the carriage 24, an interlocking device preventing racking-in of the breaker unless the stems 21 are in either extreme position. In a modification, Fig. 2 (not shown), each element 16 is tubular and in continuous sliding engagement with a garterspring socket carried by the associated stem 21.