GB516530A - Improvements in or relating to electric circuit-breaking devices of the gas-blast type - Google Patents

Abstract

516,530. Gas-blast switches. REYROLLE & CO., Ltd., A., COATES, F., LEESON, B. H., and ALLAN, A. June 21, 1938, No. 18387. [Class 38 (v)] An air or gas - blast circuit - breaker has the arc formed within an enclosure having on one side only in the wall thereof one or more lateral discharge vents past which the arc is drawn, and the blast is derived from a source external to the enclosure and forced through the arc path and out of the enclosure through the vents, the blast-supply to the enclosure being controlled by a valve member which is constituted by one of the relatively-movable contacts or by a part associated therewith. The gas may be air, nitrogen, carbon dioxide, argon, or a gaseous fluorinated alkyl chloride such as dichloro - difluoro - methane.. The invention is described and illustrated in Figs. 1-8 (not shown), in its application to certain Figs. of Specifications 516,529 and 516531, the arrangement of Fig. 1 (not shown) including also a plug associated with the arcing structure and filling the tip of the hollow movable contact in the closed position so as to free the blast near the beginning of the opening movement. Specification 516,532 is also referred to. The arcing enclosure of Fig. 9 has vents K' and aligned inlet ports K<2> supplied by pipe G<3>, the ports being successively uncovered by a spring-controlled valve K<3> which is normally held closed by a projection K' on the movable contact C. Fig. 10 shows an arrangement for withdrawing the movable contact C into clean gas in the open position, by placing a plate M across the container D so as to leave a clean-gas space M<1> below it. The gas reservoir F<3> contains contactactuating mechanism, the operation of which. before the contact actually moves, opens a valve M<2> by means of the system M'... M<6>. Thus the container D may all be filled with compressed gas while the switch is closed, the valve allowing the discharge side to exhaust and the blast to be set up before the contact moves, so obviating the need for perfect gastight closure of the vents B<4>. At the end of the opening stroke, pressure is again restored by closure of the valve. Where a solid contact C and separate gaspipe are used, the valve is placed in the latter, and the compartment M<1> mav contain insulating liquid. Alternatively or additionally, a series-break M', M<9> may occur in timed relation to the main break and in a gas or liquid-filled casing M'. The Specification also refers to an arrangement which is similar to that of Figs. 7, 8 of Specification 516,529. The rod-contact may be kept fixed and circuit opened by movement of the arcing enclosure.