High-voltage circuit-interrupter having a closing resistance and improved shunting-resistance contacts therefor

Claim 1

A high-voltage circuit-interrupter of the type for eliminating high-voltage surges on the controlled line comprising, in combination: a. means defining a separable pair of main contacts including a movable main contact; b. an operator for effecting the opening and closing motions of said separable pair of main contacts; c. means defining a separable pair of resistance contacts including a movable resistance contact disposed in electrical series relationship with said separable pair of main contacts so that in the closed-circuit position of the circuitinterrupter the line current passes serially through the two pairs of separable contacts; d. means defining a closing resistance connected electrically in shunt with said separable pair of resistance contacts so that when said separable pair of resistance contacts are closed the closing resistance is shorted out of the controlled circuit; e. said operator including a first movable member responsive to the movement of said movable main contact; f. a second movable member responsive to the movement of said movable resistance contact; g. means biasing said second member and said movable resistance cOntact to the open-circuit position; h. said first and second movable members being in an abutment condition in the fully open-circuit position of the circuitinterrupter; i. said first movable member forcing said second movable member and consequently the movable resistance contact into the closed-circuit position during the closing operation of the circuit-interrupter against the tension exerted by said biasing means; j. said operator providing sufficient velocity of said first movable member during the opening operation of the circuitinterrupter and the inertia of said second movable member being so great that said second movable member lags behind the first movable member during the opening operation of the circuitinterrupter; k. and means effecting the closing of the separable pair of main contacts during the closing operation of the circuitinterrupter prior in point of time to the closing of the separable pair of resistance contacts so that the closing resistance is connected serially into the controlled circuit during the closing operation and subsequently shorted out by the delayed closing of the separable resistance contacts, whereby high-voltage surges on the controlled line tend to be eliminated.