Circuit breaker with a double acting circuit-breaking chamber and an inverted structure

A circuit breaker for high or medium voltage, comprising at least the following:

• a first insulating envelope in which there is mounted a drive bar adapted to move in translation along an axis (A-A′);
• and
• a second insulating envelope that is attached to the first insulating envelope, and in which there is mounted a circuit-breaking chamber comprising a first contact comprising a main contact, an arcing contact, and a blast nozzle for extinguishing an arc, all fixed together, and a second contact comprising a main contact and an arcing contact fixed together;
• wherein the circuit-breaking chamber is in communication with the interior of the first insulating envelope, and wherein the arc blast nozzle in the circuit-breaking chamber includes a divergent portion that is oriented towards the first insulating envelope, wherein extinguishing the arc results in hot gases that penetrate into the interior of the first insulating envelope and the interior of the second insulating envelope.

A circuit breaker for high or medium voltages, comprising at least the following:

• a drive bar movable in translation along an axis (A-A′);
• and
• a circuit-breaking chamber comprising:
• a first contact comprising a main contact, an arcing contact, and a blast nozzle for extinguishing an electric arc, all fixed together, the first contact movable in translation along the axis (A-A′);
• a second contact disposed facing the first contact and comprising a main contact and an arcing contact that are fixed to each other, the second contact movable in translation along the axis (A-A′);
• and
• transmission means for separating the first contact and second contact from each other during a circuit-breaking operation,
• wherein the second contact and the drive bar are coupled together such that they move together in translation in the same direction, and wherein the transmission means are disposed on the side of the said chamber that is adjacent to the drive bar and are adapted to transmit the motion of the driven second contact to the first contact, and
• wherein the second main contact comprises a hollow metal tube, the inner diameter of which is substantially equal to the outer diameter of a metal member that is fixed to the blast nozzle, a total stroke (C1) of the first contact and a total stroke (C2) of the second contact being so determined that the metal member projects out from the hollow metal tube at the end of the opening operation, and thereby constitutes a field electrode for reducing the field on the second arcing contact.