Gas circuit breaker

A gas circuit breaker comprising:

• a container filled with an arc extinguishing gas;
• a stationary contact section arranged in said container to be fixed thereto, said stationary contact section having a stationary arc contact;
• and
• a movable contact section arranged to face the stationary arc contact,
• said movable contact section further comprising:
• a hollow operating rod having a front end portion facing said stationary arc contact and a rear end portion situated away from said stationary arc contact, said operating rod having an exhaust hole in the rear end portion thereof, and being capable of moving forwards linearly towards said stationary arc contact and backwards linearly in an opposite direction;
• a hollow movable cylinder arranged to be coaxial with said operating rod and separated therefrom, so as to surround a part of an outer surface of said operation rod, which is close to the front end portion, and having a flange fixed to an outer circumferential portion of the front end portion of said operating rod, so as to seal a gap between the outer circumferential portion and an outer surface of said movable cylinder;
• a hollow movable arc contact mounted on the front end portion of said operating rod so as to face said stationary arc contact and be able to be engaged therewith;
• an insulating nozzle mounted on said flange of said movable cylinder so as to surround said movable arc contact with a distance, said insulating nozzle and said movable arc contact forming a first flow path for having an interior of said movable cylinder and an atmosphere in said container filled with the arc extinguishing gas communicate to each other through a first opening made in the flange of said movable cylinder;
• a hollow stationary supporting tube arranged to be coaxial with said operating rod, so as to surround a part of the outer surface of said operating rod, other than the front end portion, said stationary supporting tube having a rear end portion fixed to said container, a front end portion substantially facing the flange of said movable cylinder, and including a piston plate having a portion which defines an inner diameter thereof, being made slidable on the outer surface of said operating rod, and a portion which defines an outer diameter thereof, being flush with an outer surface of said stationary supporting tube, and said stationary supporting tube having a second opening in a portion close to the rear end portion, communicating to the atmosphere of the container filled with the gas, a space defined by an inner surface of said supporting tube, an outer surface of said operating rod and said piston plate to form a second flow path for the gas, and said stationary supporting tube being formed insertable and removable with respect to said movable cylinder;
• a parting plate provided on a rear end portion of said movable cylinder, and forming a first space surrounded by the outer surface of said operating rod and an inner surface of said movable cylinder, a portion which defines an inner diameter of said parting plate being formed slidable on the outer surface of said stationary supporting tube, and a portion which defines an outer diameter of said parting plate being larger than an outer diameter of said movable cylinder;
• a current collecting cylinder disposed to be coaxial with said operating rod, a part of said current collecting cylinder being formed slidable on a portion which defines an outer diameter of said parting plate of said movable cylinder, having a current collecting plate at a front end portion thereof, which slides on the outer surface of said movable cylinder and being electrically contact therewith, and having a supporting plate at a rear end portion thereof fixed to said stationary supporting tube, said current collecting cylinder forming a second space together with said parting plate, said stationary supporting tube and said supporting plate, having a plurality of grooves in an inner surface of a central portion thereof in an axial direction of said operating rod, engraved to be parallel to the axial direction, and a plurality of communication holes piercing from an inner surface to an outer surface at a portion of said current collecting cylinder situated between the plurality of grooves and the current collecting plate;
• and
• a check valve provided on said parting plate, for making the first space and the second space communicate to each other.