GB478890A - Improvements relating to electric circuit breakers having arc-suppressing means - Google Patents

Abstract

478,890. Arc-rupturing in switches. ELLISON, Ltd., G., and ANDERSON, J. July 29, 1936, No. 20966. [Class 38 (v)] In a circuit-breaker of the kind in which auxiliary contacts are separated after the main contacts and are associated with an electromagnetic arc-suppressing device in which the arc formed on breaking the circuit can be whirled and extinguished, the arcsuppressing device comprises an electromagnet e mounted between a pair of parallel iron plates t, two or more concentric metal rings v, w also mounted between the plates, the inner ring v being adapted to serve as, or to carry, the auxiliary fixed contact 4, and the outer ring or rings w being formed with an aperture 3 through which the auxiliary movable contact l can pass, and insulating plates u arranged between the inner faces of the iron plates t and the ends of the rings, so as to form with the latter a whirling chamber or chambers m in which the arcs set up between the auxiliary contacts are confined and extinguished. The winding of the electromagnet e is connected at one end to the fixed main contact b and at the other end to the fixed auxiliary contact 4. A wiper contact 6 associated with the movable contacts may be arranged to bear against the outer ring w until the arc is extinguished. In a modification, the electromagnet is mounted concentrically with the rings.