Interrupting chamber with a field distributor cylinder for high-voltage or medium-voltage circuit breakers

An interrupting chamber for a high-voltage or medium-voltage circuit-breaker, said interrupting chamber containing at least:

• a first contact comprising an arcing contact and a main contact mounted to move along the axis of the interrupting chamber;
• a second contact comprising an arcing contact and a main contact;
• actuation means making it possible to actuate the first contact so that it moves between a closed position in which the two contacts are in mutual contact and an open position in which they are separated;
• a tube made of a high permittivity dielectric material, extending longitudinally along the axis and positioned so that, regardless of the relative position of the contacts, the two arcing contacts are located inside the tube and the two main contacts are located outside the tube;
• and
• a nozzle (16, 116) that is made of a high permittivity dielectric material, that is coupled in fixed manner to the first contact (12, 112), and the nozzle that is located inside the tube (18, 118), wherein the nozzle extends past contacting ends of the first arcing contact and the second arcing contact when the circuit breaker is in either an open or closed position,
• wherein the high permittivity dielectric material of the tube reduces the electric field on the contacts during breaking and in the open position.