GB364620A - Improvements relating to automatic electric circuit breakers - Google Patents

Abstract

364,620. Automatic circuit-breakers. ALLGEMEINE ELEKTRICIT€TS - GES., 2, Friedrich Karl-Ufer, Berlin. Sept. 1, 1930, No. 26108. Convention date, Feb. 8. [Class 38 (v).] An automatic circuit - breaker of the screw plug type is operated by a guided press-button a, Fig. 1, carrying pivotally a lever b the free end of which bears a roller k engaging between projections w<1>, w<2>, Fig. 3, of a pivoted tumbler member d. The rotation of this member strains a coiled spring t surrounding the pivot on which the contactcarrying lever g is mounted so that towards the end of the closing operation the lever g slips past the bent-over projections r of the lever b and is moved rapidly by the strained spring t to cause the rectilinearly guided contact bridge h to engage fixed contacts q. The switch may be tripped on overload either by an electromagnet plunger m or by a bimetallic strip z<1>, the former operating the release lever o directly through a push rod n and the latter when heated moving to the right followed by a blade spring z<2> which releases an intermediate lever i acting on the release member o. The release member o on rotation engages by a projection o<1> the roller k and lifts it out of the recess in the tumbler member which, under the action of a throw-off spring f engages the contact carrying lever g to open the circuit-breaker. This action is independent of the return of the pushbutton a and operating member b which are returned separately by relatively light springs z surrounding the guides for the pushbutton. A releasing pushbutton a<1> is arranged to act as the releasing lever o for providing manuallyoperated tripping action.