In a gas circuit breaker, arc-extinguishing gas is filled in a container. A movable portion housed in the container includes a movable arc contact. The movable portion includes a pressure accumulator that increases pressure of an arc-extinguishing gas. An opposing portion housed in the container includes an opposing arc contact, an exhaust pipe, and a shielding portion. The shielding portion includes a first shielding wall intersecting with an axial direction of the pipe and a second shielding wall having a cylindrical shape extending from the first shielding wall toward the movable portion along the axial direction of the pipe. The second shielding wall includes through-holes. Lengths of the respective through-holes along the axial direction are from 18 millimeter's to 55 millimeters inclusive. An arc-extinguishing gas whose pressure has been increased in the pressure accumulator flows into a space to extinguish arc discharge, and flows into the second shielding wall.

A switchgear includes an interrupter unit. The interrupter unit is provided with first and second switching contact pieces that are movable relative to one another. A switching-gas duct that runs through the interrupter unit originates at an arc gap in which an electric arc can burn. The duct connects the arc gap to the surroundings of the interrupter unit. At least some sections of the switching-gas duct are delimited by mutually encompassing elements similar to an annular duct. One of the elements is a first member which is braced at the end similar to a pipe joint and which has a free end that projects in the direction of the arc gap.

To provide a gas circuit breaker having a space-saving reliable double motion mechanism having a high degree of freedom in design. A double motion mechanism section of the gas circuit breaker is formed of a drive-side connecting rod, a driven-side connecting rod, levers connecting them and a guide regulating operations of the drive-side connecting rod and the driven-side connecting rod. A movable pin is connected to a first grooved cam formed in the drive-side connecting rod, a second grooved cam formed in the guide and third grooved cams formed in the levers respectively, and posture holding members are provided in the movable pin. The movable pin moves in the respective grooved cams by an operation of the drive-side connecting rod, thereby rotating the levers, driving the driven-side connecting rod in an opposite direction of the drive-side connecting rod, and driving the driven-side arcing contact in an opposite direction of the driven-side arcing contact.

A vacuum interrupter assembly is provided. The vacuum interrupter assembly includes an operating mechanism, a vacuum chamber including a number of bellows assemblies, a conductor assembly including a first contact assembly and a second contact assembly, the first contact assembly including a stem and a contact member, the first contact assembly stem including an elongated body with a proximal first end, a medial portion, and a distal second end. The first contact assembly stem body has a reduced length. The first contact assembly stem body having a reduced length generates less heat and electrical resistance.

A vacuum interrupter assembly is provided. The vacuum interrupter assembly includes an operating mechanism, a vacuum chamber including a number of bellows assemblies, a conductor assembly including a first contact assembly and a second contact assembly, the first contact assembly including a stem and a contact member, the first contact assembly stem including an elongated body with a proximal first end, a medial portion, and a distal second end. The first contact assembly stem body has a reduced length. The first contact assembly stem body having a reduced length generates less heat and electrical resistance.

Disclosed is an abrasion resistant material having low cost and excellent abrasion resistance, a puffer cylinder, and a puffer type gas circuit breaker. The abrasion resistant material includes: a base material which is formed of pure aluminum or aluminum alloy and has an unevenness structure formed on its surface; and an aluminum hydrated oxide film which is formed on the surface of the base material, wherein a surface of the aluminum hydrated oxide film is provided with an unevenness structure which is finer than the unevenness structure of the base material.

Disclosed is an abrasion resistant material having low cost and excellent abrasion resistance, a puffer cylinder, and a puffer type gas circuit breaker. The abrasion resistant material includes: a base material which is formed of pure aluminum or aluminum alloy and has an unevenness structure formed on its surface; and an aluminum hydrated oxide film which is formed on the surface of the base material, wherein a surface of the aluminum hydrated oxide film is provided with an unevenness structure which is finer than the unevenness structure of the base material.

A medium-, high-, or very high-voltage circuit breaker (10), comprising at least one arc-control chamber (12) and an outer casing (14) in which the arc-control chamber (12) is arranged. In the invention, the circuit breaker includes sealing ring (52) for sealing an opening (50) in a discharge cap (40) of the arc-control chamber (12), the ring (52) being movable between a sealing position and a retracted position in which they allow the gas to pass, the circuit breaker being configured in such a manner that in the closed position, the sealing ring (52) are in their retracted position, and in such a manner that passage from the retracted position to the sealing position takes place during an operation of opening the circuit breaker.

There is provided a gas circuit breaker that includes: a puffer shaft connected to one of a pair of arcing contacts, a puffer cylinder that is coaxially provided on an outer circumference of the puffer shaft, an insulating nozzle that is fixed to the puffer cylinder on a breaker side, an insulating rod that connects the puffer shaft and an operating device to each other, a shaft guide that is provided on an outer circumference of the puffer shaft and the insulating rod, and an exhaust guide that is provided on an outer circumference of the shaft guide, in which hot gas is discharged into a gas tank through a shaft exhaust hole of the puffer shaft, between the puffer shaft and the shaft guide, and a conductor exhaust hole of a movable side exhaust conductor in the middle of interrupting operation, the shaft exhaust hole of the puffer shaft communicates with a shaft guide exhaust hole of the shaft guide in a region near a current zero point before the termination of the interrupting operation, and thus an exhaust flow path changes.

There is provided a gas circuit breaker that includes: a puffer shaft connected to one of a pair of arcing contacts, a puffer cylinder that is coaxially provided on an outer circumference of the puffer shaft, an insulating nozzle that is fixed to the puffer cylinder on a breaker side, an insulating rod that connects the puffer shaft and an operating device to each other, a shaft guide that is provided on an outer circumference of the puffer shaft and the insulating rod, and an exhaust guide that is provided on an outer circumference of the shaft guide, in which hot gas is discharged into a gas tank through a shaft exhaust hole of the puffer shaft, between the puffer shaft and the shaft guide, and a conductor exhaust hole of a movable side exhaust conductor in the middle of interrupting operation, the shaft exhaust hole of the puffer shaft communicates with a shaft guide exhaust hole of the shaft guide in a region near a current zero point before the termination of the interrupting operation, and thus an exhaust flow path changes.