Patent GB-477005-A (GB)
Title: Improvements in electric circuit breakers
IPC: H01H33/92
Filed: 1936-06-18
Abstract: 477,005. Liquid-blast switches. FLURSCHEIM, C. H., ALLIBONE, T. E., VANCE, W. G. C., DISBURY, E. R., and METROPOLITAN - VICKERS ELECTRICAL CO., Ltd. June 18, 1936, No. 17005. [Class 38 (v)] An E.H.T. circuit-breaker of the horizontal-break type with the contacts operating in a horizontal insulator housing, has the final moving element of the contact - actuating mechanism proper connected through a link to the moving contact rod or plunger or plug and is remote from the contact end thereof, whilst the guiding means for said rod is wholly or in part remote from said contact end. The arrangement is applicable to the switches of Specifications 386,326, 435,143, 435,419, and 441,734. In Fig. 1, the final metal operating member 34 is insulatingly linked at 33 with a plate 29 which is slidable on guide-rods 28 carried on a plate 27 in electrical connection with the metal liner 24 of a condenser or oil-filled type bushing 15. The plate 29 is also secured to a rod 26 of aluminium or aluminium alloy which is secured at 25 to the movable contact proper 8, slidable in a resilient segmental contact 23 connected with the liner 24. The contact 8 is withdrawn into a stress shield 36 in the fully-open position. The fixed contact 1 is housed in an insulating member 4 having cross-jet passages 5 leading into an explosion chamber 6, which, with member 4 is mounted on the inner insulating tube 9. The tube 9 is secured to an oil-pressure chamber 13 carrying a blast cylinder and piston 18, 19. An outer porcelain tube 16 extends between an annular member 17, carrying the chamber 6, and the earthed central chamber 14 which contains all or some of the operating gear, corrugated metal rings being interposed between 16 and 14, 17, if desired. In Fig. 2, the final operating member 34 is forked and has pin and guide connection 41, 40 with a collar 39 on an insulating tube 37, which slides on insulating bushing 15 and sleeve 23 and is connected to 8 by means of the spider 38. Where sleeve 23 is provided with a stress shield, the shield is conical and slotted to receive the spider 38 which is formed as a pair of thin vertical spokes to enter the slots, Fig. 3 (not shown). Fig. 4 shows a dashpot arrangement, applicable to the construction Fig. 1, for retarding the movable contact after a short rapid initial opening. The rod 26 is attached to a cylinder 45 slidable in liner 24, which is extended and provided with a plug 50 in which is adjustably carried a rod 51 and piston 52. Link 33 is pivoted to a lug 46 on the cylinder 45, which lug slides in a slot in lines 24. In opening circuit, the rod 26 and cylinder 45 move freely until the piston 52 engages the smalldiameter part 49 of the cylinder, whereupon the contact is decelerated and allowed to travel at constant speed until part 49 has passed beyond the piston. Other forms of this arrangement are also referred to. In Fig. 5 (not shown) is illustrated a slightly-modified form of cross-jet member. In Fig. 6 (not shown) is illustrated a form of blast-piston with valves arranged to permit rapid automatic reclosure of the switch, whereas Fig. 7 (not shown) illustrates an air-piston connected to, so as to operate, an oil-blast piston, with suitable ports for the air. In a switch operated by cornpressed air, the reservoirs are constituted by hollow parts of the supporting framework, and in a three-phase switch, the three chambers 14 may be welded to interconnecting tubes to which supply-piping is secured, or they may be supported on a single horizontal tube constituting the reservoir. Specifications 477,006 and 477,007 also are referred to.