Abstract: The compressed-gas breaker has a movable contact member (1) and a fixed contact member (2) having in each case at least one arcing contact (6, 7) as well as, fixed on the movable contact member (1), a pressure space (10) of a volume independent of the switching travel and storing arc-compressed quenching gas in breaking, and has an insulating nozzle (8) arranged coaxially to the two contact members (1, 2). With this breaker, the parting speed of the arcing contacts (6, 7) is increased significantly with respect to the drive speed without an appreciable increase in its drive energy and without changing its quenching geometry. The arcing contact (7) of the fixed contact member (2) being guided displaceably in axial direction in a sliding contact (14) and being part of a converter element is operated by the movable contact member (7) and arranged downstream of the nozzle constriction (9) of the insulating nozzle (8).

Abstract: The gas-blast breaker exhibits two contact members (1, 2) which are located in a housing filled with insulating gas and can be brought into and out of engagement with one another along an axis (5), and an insulating material nozzle (4) through the nozzle constriction (6) of which an arc burns during a switching process. The nozzle constriction (6) is formed by several segments (7) which follow one another in the circumferential direction, can be moved in the radial direction and can be loaded with a centripetally acting force.In this gas-blast breaker, the cross-section of the nozzle constriction (6) which is effective during a switching process is intended to be largely independent of the number of switching processes performed and causing nozzle erosion.