GB523420A - Improvements in and relating to high tension electric switches - Google Patents

Abstract

523,420. High-tension switches; actuation of switches. COATES, W. A., DAVIES, D. R., HOBBS, D., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. Jan. 5, 1939, No. 421. [CLass 38 (v)] An H.T. isolating or disconnecting switch comprises a pair of contact tubes 19 which are oppositely movable to engage fixed contacts 22, 24 in a metal chamber 3 preferably containing liquid (as oil) or gas. The tubes 19 telescope on the ends of a metal) rod 28 within a metal sleeve 17 in a condenser or other bushing 16 which is carried on a wormwheel 9 rotatable by a worm 13. The sleeve 17 carries a pair of caps 18 having threaded engagement with the tubes 19, and the latter are splined to engage projections on plates 20 secured in insulating sleeves 21, so that rotation of bushing 16 causes axial movement of the tubes 19. In a modification which avoids the need to divide the casing 3 and make a fluid tight joint at the division, the bushing 16 is secured within the " closed " lower end of a metal sleeve, which extends upwards between the casing 3 and insulator 21 and is provided at the top with a geared flange. In this form also, the upper movable contact is dispensed with and the end conductor 28 is in continuous engagement with the upper contact, Fig. 2 (not shown). In a further form, the bushing-liner is threaded to engage corresponding threads on the movable contact, the upper end of which is bared to telescope with a conductor rod. Means (not shown) are provided for preventing rotation of the movable contact, Fig. 3 (not shown).