A switching device includes an electrode housing having an opening; a first electrode provided inside the electrode housing; and a second electrode that fits in the opening such that the second electrode comes into and out of contact with the first electrode. The electrode housing generates an ablation gas through an arc generated between the first electrode and the second electrode. Until the first electrode and the second electrode become separated by a certain distance, a gas including the ablation gas is retained in an enclosed space defined by the first electrode, the second electrode, and the electrode housing. When a distance by which the first electrode and the second electrode are separated from each other exceeds the certain distance, the gas in the enclosed space is discharged through a gap defined between the opening and the second electrode, such that the gas is blown onto the arc.

A switching device includes an electrode housing having an opening; a first electrode provided inside the electrode housing; and a second electrode that fits in the opening such that the second electrode comes into and out of contact with the first electrode. The electrode housing generates an ablation gas through an arc generated between the first electrode and the second electrode. Until the first electrode and the second electrode become separated by a certain distance, a gas including the ablation gas is retained in an enclosed space defined by the first electrode, the second electrode, and the electrode housing. When a distance by which the first electrode and the second electrode are separated from each other exceeds the certain distance, the gas in the enclosed space is discharged through a gap defined between the opening and the second electrode, such that the gas is blown onto the arc.

The contact apparatus includes a fixed contact, a movable contact, and an arc extinguishing member. The movable contact is movable between a closed position where the movable contact is in contact with the fixed contact and an open position where the movable contact is separate from the fixed contact. The arc extinguishing member is for discharging an arc extinguishing gas offering a capacity for extinguishment of an arc, into a space containing the fixed contact and the movable contact.

The contact apparatus includes a fixed contact, a movable contact, and an arc extinguishing member. The movable contact is movable between a closed position where the movable contact is in contact with the fixed contact and an open position where the movable contact is separate from the fixed contact. The arc extinguishing member is for discharging an arc extinguishing gas offering a capacity for extinguishment of an arc, into a space containing the fixed contact and the movable contact.

Device for making and/or breaking a current including a pair of permanent contacts (3, 4), at least one of the contacts (3, 4) being movable. At least one permanent contact (3, 4) including a main portion (3.1, 4.1) having a free end and an end protection portion (3.2, 4.2) secured to the free end of the main portion (3.1, 4.1), designed to be in mechanical and electrical contact with the other permanent contact (4, 3) only during an operation for opening or closing the pair. The end protection portion (3.2, 4.2) is made of a single transition metal having a melting temperature that is strictly higher than that of the main portion (3.1, 4.1) to which it is secured, or of an oxide or carbide of such a metal, or even of zinc oxide. For application in particular to high- or medium-voltage circuit breakers.

Device for making and/or breaking a current including a pair of permanent contacts (3, 4), at least one of the contacts (3, 4) being movable. At least one permanent contact (3, 4) including a main portion (3.1, 4.1) having a free end and an end protection portion (3.2, 4.2) secured to the free end of the main portion (3.1, 4.1), designed to be in mechanical and electrical contact with the other permanent contact (4, 3) only during an operation for opening or closing the pair. The end protection portion (3.2, 4.2) is made of a single transition metal having a melting temperature that is strictly higher than that of the main portion (3.1, 4.1) to which it is secured, or of an oxide or carbide of such a metal, or even of zinc oxide. For application in particular to high- or medium-voltage circuit breakers.

A gas circuit breaker includes a sealed tank, a movable side main electrode and a fixed side main electrode in the sealed tank facing each other, a movable side arc electrode and a fixed side arc electrode in the sealed tank facing each other, a cylinder at a circumference of the movable side arc electrode, a piston in the cylinder in a slidable manner and forming a puffer chamber together with the cylinder, an insulation nozzle in the sealed tank, an exhaust pipe at a circumference of the fixed side arc electrode and exhausting heat gas, which is sprayed on an arc generated in the insulation nozzle in the opening electrode operation, to an outside, and a closing plate in the exhaust pipe. One or more vent holes leading the heat gas from an inside of the exhaust pipe to the outside is on a surface of the closing plate.

A gas circuit breaker includes a sealed tank, a movable side main electrode and a fixed side main electrode in the sealed tank facing each other, a movable side arc electrode and a fixed side arc electrode in the sealed tank facing each other, a cylinder at a circumference of the movable side arc electrode, a piston in the cylinder in a slidable manner and forming a puffer chamber together with the cylinder, an insulation nozzle in the sealed tank, an exhaust pipe at a circumference of the fixed side arc electrode and exhausting heat gas, which is sprayed on an arc generated in the insulation nozzle in the opening electrode operation, to an outside, and a closing plate in the exhaust pipe. One or more vent holes leading the heat gas from an inside of the exhaust pipe to the outside is on a surface of the closing plate.

The contact apparatus includes a fixed contact, a movable contact, and an arc extinguishing member. The movable contact is movable between a closed position where the movable contact is in contact with the fixed contact and an open position where the movable contact is separate from the fixed contact. The arc extinguishing member is for discharging an arc extinguishing gas offering a capacity for extinguishment of an arc, into a space containing the fixed contact and the movable contact.

The contact apparatus includes a fixed contact, a movable contact, and an arc extinguishing member. The movable contact is movable between a closed position where the movable contact is in contact with the fixed contact and an open position where the movable contact is separate from the fixed contact. The arc extinguishing member is for discharging an arc extinguishing gas offering a capacity for extinguishment of an arc, into a space containing the fixed contact and the movable contact.