GB584888A - Improvements in or relating to pneumatic operating mechanisms for electric switchgear - Google Patents

Abstract

584,888. Pneumatically-actuated switches. REYROLLE & CO., Ltd., A., and CHRISTIE, J. Feb. 2, 1945, No. 2633. [Class 38 (v)] [Also in Group XXVIII] in a reversible pneumatic operating mechanism for a switch, a double-acting piston B controls transfer ports E', E<2>, so that when air under pressure is admitted to eitther end A<5>, A<6> of the cylinder A, the piston B, after an initial operative movement, opens one of the ports E<1>, E<2>, to transfer part of the compressed air under the control of a reducing valve C<4>, C<3> to the opposite end of the cylinder to damp the subsequent movement of the piston. Air from the " damping end of the cylinder escapes to atmosphere at H<4>, H<3> through bleed passages A<2>, A<1>, adjustable at A<4>, A' and also through preliminary discharge ports F<2>, F<1>. Air from a reservoir D is supplied to the cylinder through non-return valves D', D<3> under the control of valves H<2>, H<1> actuated by interlocked solenoids. Flexible pipes E', E<4>, together with a plurality of axially spaced transfer ports and a slide valve coupling device, may be provided for timing adjustment, and a similar arrangement may be made for the timing adjustment of the discharge ports F<2>, F'. The mechanism may open or close a circuit-breaker or isolator, to which the piston is coupled by a transverse member B'.