GB484011A - Improvements in and relating to electric circuit breakers with arc extinguishing means - Google Patents

Abstract

484,011. Fluid - blast switches. STRAUSS, (nÚe RUPPEL), F. Nov. 17, 1936, No. 31429. Convention date, Nov. 25, 1935. [Class 38 (v)] In a circuit-breaker with arc - extinguishing fluidblast produced by the pressure due to the heat of the arc in a blow-out chamber which is closed with the exception of the opening through which the movable switch - member is drawn out, devices under the influence of the pressure in the blow-out chamber are provided, which act, along at least a portion of the switching-off movement in opposition to the accelerating forces exerted by the pressure in the blowout chamber on the movable switch-member. In one construction, Fig. 2, the arc formed on separating the movable contact 2 from the fixed contact 1 is drawn through a tube 3 of gas-yielding material. An insulating extension 4 of the contact 2 carries a piston 5 movable in a cylinder 6. During the first part of the switching-off movement, the space 9 below the piston is connected with the space 8 subject to the pressure of the arc gases by means of grooves 7 in the wall of the cylinder 6, but during the latter part of the movement the spaces are shut off from one another by the piston, and the pressure of the arc gases in the space 8 exerts a retarding effect. In a modification, Fig. 3 (not shown), the contacts are separated in a chamber filled with water, oil or other liquid, and a piston carried by an extension of the movable contact rod moves in a cylindrical extension of the chamber. In another construction, Fig. 4 (not shown), the movable contact rod is tubular, and carries the piston at its lower end. The Specification as open to inspection under Sect. 91 describes a further modification, Fig. 5 (Cancelled), in which the piston 5 is fixed and the cylinder 6 forms an extension of the hollow movable contact rod 2. This subject-matter does not appear in the Specification as accepted.