Circuit breaker comprising an improved gas flow management

A high-voltage circuit breaker filled with an insulating gas and having a main axis, comprising:

• a female arcing contact and a male arcing contact that are designed to selectively be in electrical contact one with the other, that are radially surrounded by an insulating nozzle;
• two main contacts facing axially each other and arranged radially outside of the insulating nozzle, each of the main contacts being assigned and electrically connected to one of the arcing contacts,
• a support carrying one of the two main contacts and the associated arcing contact, in which a thermal volume, a compression volume and an exhaust gas chamber are formed, so as to be aligned axially within the support,
• a first radial wall axially separating the thermal volume and the compression volume, which is axially movable within the support,
• a second radial wall axially separating the compression volume and the exhaust gas chamber,
• characterized in that it further comprises a buffer volume that is separated from the compression volume and the exhaust gas chamber by associated walls that is designed to be connected to the compression volume by means only to allow gas under pressure, that is stored in the buffer volume, to be discharged towards the compression volume, and
• wherein the buffer volume is also able to be selectively connected to the exhaust gas chamber and to an annular main chamber surrounding the support depending on the operating conditions of the high-voltage circuit breaker.