GAS-PRESSURE SWITCH

The gas-blast circuit-breaker has a moving (1) and a fixed switchpiece (2), each having at least one erosion contact (6, 7), and, mounted on the moving switchpiece (1), a pressure chamber (10) which stores extinguishing gas which is compressed by the arc during the switching-off process, and whose volume is independent of the switch movement, and an insulating nozzle (8) which is arranged coaxially with respect to the two switchpieces (1, 2). In this circuit breaker, it is intended significantly to increase the separating speed of the erosion contacts (6, 7) with respect to the drive speed without noticeably increasing its drive energy and without modifying its extinguishing geometry. This is achieved by the erosion contact (7) of the fixed switchpiece (2) being guided in the axial direction in a moving manner in a sliding contact (14) and being part of a converter element arranged downstream of the nozzle constriction (9) of the insulating nozzle (8) and operated by the moving switchpiece (7). During the switching-off process, this converter element transmits the movement of the moving switchpiece (1) in the opposite sense onto the erosion contact (7) of the fixed switchpiece (2).