GB617625A - Improvements in or relating to electric circuit breakers - Google Patents

Abstract

617,625. Automatic circuit-breakers. PIPPONZI, A. May 28, 1946, No. 16260. Convention date, May 24, 1945. [A Specification was laid open to inspection under Sect. 91 of the Acts, Oct. 22, 1946.] [Class 38 (v)] In a multipole circuit-breaker the fixed contacts 1 are bridged by contacts 2 mounted on insulating blocks 3<1> loosely attached to a common carrier bar 3 guided on rods 11, 12, by a part 15 passing through the block 3<1> which is secured by a cotter-pin 16 under the bar 3, Fig. 3. Contact pressure is provided by a single spring 8 compressed between the bar 3 and a plunger 7 attached to the toggle mechanism. With an odd number of poles, the contact bridges may be mounted on a circular or polygonal carrier to provide balanced contact pressure from the central spring. The toggle mechanism comprises a lever 5 pivoted at 19 to the handle 20, and a lever 4 pivoted to the member 7 and latched by its extended. arm 41 engaging between the nose 611 of a trip lever 6 pivoted.at 19 and a stop-lug 22 provided on the lever 6 so that the toggle is maintained underset. When the'tail 6<1> of the trip-lever is struck by the armature 23 of an electromagnet 24, the toggle collapses under endwise pressure. of the spring 8 and a nut 10 on the plunger 7 forcibly strikes the bar 3 which rises under the action of the opening springs 13, 13<1>, which maintain the contacts open. The Specification as open to inspection under Sect. 91 states that a bimetal strip heated by conduction from a metal cylinder surrounded by the electromagnet coil may operate the trip arm on prolonged small overloads, Fig. 6 (Cancelled) (not shown), and an iron wire or similar high temperature-coefficient resistance may shunt the magnet coil to provide a time delay, Fig. 5 (Cancelled) (not shown). Also, arcing contacts and magnetic blow-out plates may be provided. This matter does not appear in the Specification as accepted.