Fluid-blast circuit interrupters with two selectively-operated fluid-blast sources

Claim 1

THE COMBINATIONIN A PUFFER-TYPE CIRCUIT INTERRUPTER OF A SUBSTANTIALLY CLOSED METALLIC GROUNDED TANK, A PAIR OF TERMINAL BUSHINGS EXTENDING INTO SAID GROUNDED METALLIC TANK, AN INTERRUPTING ASSEMBLY SUPPORTED AT LEAST IN PART BY SAID PAIR OF TERMINAL BUSHINGS, THE INTERRUPTING ASSEMBLY INCLUDING A MOVABLE CONTACT, A RELATIVELY STATIONARY CONTACT AND A PAIR OF SPACED INSULATING OPERATING RODS FOR EFFECTING SEPARATION OF THE SAME, A DRIVING OPERATING ROD FOR EFFECTING RECIPROCAL MOVEMENT OF SAID PAIR OF SPACED INSULATING OPERATING RODS, A PUFFER CYLINDER SUPPORTED BY ONE OF SAID TERMINAL BUSHINGS AND HAVING A PUFFER PISTON MOVABLE THEREIN, MEANS BIASING SAID PUFFER PISTON IN A DIRECTION TO FORCE A BLAST OF GAS INTO THE ARC ESBABLISHED BETWEEN SAID RELATIVELY STATIONARY AND MOVABLE CONTACTS, THE ENDS OF THE SPACED INSULATING OPERATING RODS ABUTTING SAID PUFER PISTON TO CHARGE THE SAME DURING THE CLOSING OPERATION OF THE INTERRUPTER, AN ACCUMULATOR CONTAINING A LIQUEFIED GAS, VALVE STRUCTURE ASSOCIATED WITH SAID ACCUMULATOR TO RELEASE A BLAST OF LIQUEFIED GAS THEREFROM, CHECK VALVE MEANS ASSOCIATED WITH SAID PUFFER CYLINDER, AND MAGNETIC STRUCTURE INCLUDING A ROTATABLE CAM SLEEVE HAVING A CAM LUG FOR EFFECTING OPERATION OF SAID VALVE STRUCTURE FOR SELECTIVELY OPERATING SAID VALVE STRUCTURE ONLY AT CURRENTS ABOVE A PREDETERMINED VALUE.