GB479097A - Improvements relating to electric circuit breakers having arc-suppressing means - Google Patents

Abstract

479,097. Arc - rupturing in switches. ELLISON, Ltd., G., and ANDERSON, J. July 29, 1936, No. 47/38. Divided out of 478,890. [Class 38 (v)] A circuit-breaker of the type having auxiliary fixed and pivotal contacts in parallel with main fixed and pivotal contacts b, o and arranged to separate after the main contacts, and having associated with the auxiliary contacts an electromagnetic arc-suppressor having parallel plates between which the arc can be whirled and extinguished, has two (or more) non-magnetic metal plates h, i on one end of the core d of the electromagnet e; the plate h serving as fixed auxiliary contact and the plate (or plates) i being formed at one side of the centre with an aperture k through which the auxiliary contact l can pass. The space between the plates h, i is closed by fireproof insulating rings to form a narrow annular chamber. Winding e is connected to contacts b, h by leads f, g, respectively. Contact l is mounted on lever q on a part r on the lever p carrying main contact o, and is urged by spring s so as to remain in contact with h after o separates from b, and if desired a wiper contact may be provided to bear against plate i long enough to allow extinction of the arc in the chamber, the latter being effected by the radial magnetic field set up by the electromagnet. Where no wiper contact is provided, any arc that persists after contact l has left the chambers will be rotated by the field in the same way as the arcs in the chambers. U.S.A. Specification 2,027,219 is referred to.