GB778909A - Improvements relating to high-voltage electric circuit-breakers - Google Patents

Abstract

778,909. Liquid-blast switches. REYROLLE & CO., Ltd., A. Sept. 15, 1955 [June 18, 1954], No. 17906/54. Class 38(5) An injector forces oil into the turbulator 11 enclosing the arcing zone of a liquidblast switch during the closing movement of the contacts to reduce any tendency to prearcing. If the moving contact 14 is tubular and longitudinally withdrawable for contact separation, an injector may inject liquid into the moving contact and thence into the turbulator during contact separation to prevent cavitation. In Fig. 1 the injectors 20, 21 are separate and each comprises a piston 23 biased by a spring 24 in a cylinder 22 having a non-return inlet and outlet valves 25, 26, the outlet valves 26 being connected to a fixed pipe 19 over which the contact 14 is movable. When the switch is opened by the anticlockwise movement of the lever 15. the spring 24 of the injector 20 moves the piston to force liquid into the contact 14 providing the arc-generated pressure in the turbulator is not too high. During this opening movement, the lever 15 moves the 'piston of the injector 21 to compress the associated spring 24 which on the subsequent closure of the contacts, forces liquid from the injector 21 into the contact 14 and turbulator. In a modified arrangement, Fig. 2 (not shown), a single double-acting piston-and-cylinder injector is used. In this case a spring injects liquid during contact separation, but injection during closing is effected positively by the movement of the piston by the switch operating mechanism. Specification 778,908 is referred to.