Tank-type gas-filled circuit breaker with impulsive seal breaking means for initiating piston operation

Claim 1

In a tank-type gas-filled circuit breaker having interrupting contacts disposed in a contact-chamber and an insulating operating rod which is directly connected to open the interrupting contacts by a pulling force on the operating rod, an operating mechanism comprising: a high pressure gas chamber disposed separate from and outside of said contact chamber; a cylinder arranged within said high-pressure gas chamber; a piston disposed to opeate witnin said cylinder and forming therein a first cylinder region in which one side of the piston is constantly exposed to be acted upon by high pressure gas contained in said high pressure gas chamber; a second cylinder region formed on the other side of the piston; a low pressure exhausting chamber disposed within said high pressure gas chamber so as to be capable of being connected with said second cylinder region; sealing means separating said low pressure exhausting chamber and said second cylinder region so as to prevent low pressure from being communicated to said second cylinder region when the sealing means is closed, said piston being directly connected to said insulating operating rod and being acted upon by a resilient biasing means for pushing the operating rod to hold the interrupting contacts in closed position; and means for impulsively breaking said seal and establishing instantaneous communication between said second cylinder region and the low pressure exhausting chamber, whereby the high pressure gas acting on said one side of the piston creates an impulsive pressure differential on the piston so as to pull the rod against said biasing means and operate the interrupting contacts when the means for impulsively breaking the seal opens the seal.