Abstract: The gas-blasted circuit-breaker includes a movable arc contact, a fixed arc contact opposing the movable arc contact, an insulating nozzle, a puffer cylinder, a hollow conductor, an insulating rod connected to the puffer cylinder, and a fixed piston fitted inside the puffer cylinder. An insulating gas is ejected to a space between the puffer cylinder and the fixed piston by driving the insulating rod and is sprayed to an arc generated upon interruption of a current. The hollow conductor is in a cylindrical shape having a cross section parallel to the axis thereof. The cross section is smaller in diameter on the downstream side of a flow of insulating gas. The hollow conductor has a closed end on the downstream side of the flow of insulating gas and has a cylindrical barrel portion provided with a plurality of opening.

Abstract: Disclosed herein is a gas-blasted circuit-breaker comprising a movable arc contact; a fixed arc contact opposed to the movable arc contact; an insulating nozzle disposed at the movable arc contact on the fixed arc contact side thereof; a puffer cylinder disposed on the side opposite to the insulating nozzle; a hollow conductor that holds the fixed arc contact opposed to the insulating nozzle; an insulating rod connected to the puffer cylinder; and a fixed piston fitted inside the puffer cylinder; wherein an insulating gas is ejected to a space between the puffer cylinder and the fixed piston by driving the insulating rod and is sprayed to an arc generated upon interruption of a current; and wherein the hollow conductor is in a cylindrical shape having a cross section parallel to the axis thereof, the cross section being smaller in diameter on the downstream side of a flow of insulating gas, the hollow conductor having a closed end on the downstream side of the flow of insulating gas, and the hollow conductor