GB1044076A - Circuit interrupter - Google Patents

Abstract

1,044,076. High voltage switches. S. & C. ELECTRIC CO. May 15, 1964 [July 10, 1963], No. 20290/64. Heading H2B. To reduce the operating stresses on the bellows 91, Fig. 9, providing a gas tight seal between the auxiliary contact operating rod 97 and an end terminal member of the circuit interrupter of Specification 966,110, a dash-pot arrangement cushions the final opening movement of the auxiliary moving contact or contacts. This dash-pot arrangement comprises a cylinder 153 concentric with a fixed pump cylinder 149 and an annular piston 151 fixed to a movable piston cylinder 147. When the auxiliary contacts are opened, the piston cylinder 147 moves to compress the gas in the cylinders 147, 149 to provide a gas blast for the contacts 130, 133 and the piston 151 moves freely in the space between the cylinders 149, 153 until it covers slots 157 in the cylinder 153, the movement of the moving contact assembly then being braked. In a modified arrangement, Fig. 10 (not shown), the slots are provided in the cylinder 149 so that the initial movement of the piston 151 augments the blast. Shock is further reduced by the provision of a resilient lost-motion connection between the main and auxiliary contact operating arms, Fig. 6. This connection is provided by a stainless steel spring 198 having one end wrapped around a pin 200 on the main contact operating arm 176. The spring is shaped to form a loop the ends of which co-operate with a pin 204 projecting from the auxiliary contact operating arm (not shown). A rigid link 208 with a slot 210 longer than the loop in the spring prevents the spring being stretched beyond its elastic limit.