Abstract: A gas-blast circuit-breaker includes a jacket filled with a dielectric gas. A mobile arc contact cooperates with a fixed arc contact within the jacket. The mobile arc contact is part of a mobile contact assembly which is displaceable axially in the jacket between a closed position and an open position. The mobile contact assembly includes a first tube carrying the mobile arc contact and a second tube, which is coaxial with the first tube, carrying a mobile permanent contact with a gas blast nozzle coupled thereto. A ring joins the first tube and the second tube to define a gas-blast chamber and a compression chamber on opposite sides of the ring. The compression chamber communicates with the gas-blast chamber. An annular piston having an annular recess closes the compression chamber. A compression spring influences the annular piston against a fixed front stop.

Abstract: An arc-rotating magnetic blast coil for the contact element of an electric switch, the coil comprising, in particular, a conducting cup (1) which is cylindrical in shape and which is connected to a current inlet (33), a winding (23) disposed inside the cup to produce a magnetic field along the axis of the cup and having one end (14) connected to the cup, a conducting core (7) connected to the other end (12) of the winding and situated in the center of the winding, and a fixed circuit-breaking contact disposed ahead of the coil relative to said cup within the magnetic field produced thereby and electrically connected to said core, characterized in that the winding is constituted by means of a flat conductor (8) comprising a plurality of turns wound on the core together with an insulating sheet, and in that means (16, 9) are provided for putting the winding under compression.