GB638684A - Improvements relating to trigger release mechanism - Google Patents

Abstract

638,684. Automatic circuit-breakers. REYROLLE & CO., Ltd., A., SMALL, J. F. S., and ALLAN, A. Dec. 1, 1947, No. 31657. [Class 38 (v)] [Also in Group XXIV] In a release catch in which a resilientlyloaded member is restrained by a catch until a desired moment of release, a rolling device is provided between the catch and loaded member to reduce friction and the force required to trip the catch. In Fig. 1 a loaded lever A is held by a catch lever B and a roller C is interposed between surfaces A<SP>2</SP>, B<SP>2</SP> on the two levers, respectively. On upward movement of the lever B the roller C rolls on both surfaces A<SP>2</SP>, B<SP>2</SP> until the lever A is released. The roller C is retained on lever B by means of trunnions C<SP>1</SP> engaging in elongated apertures B<SP>4</SP> in forked extensions B<SP>3</SP> on the lever. In Fig. 4, two rollers D, E are interposed between the surface A<SP>2</SP> of lever A and a fixed abutment surface G<SP>1</SP> and are carried in a cradle F which is movable downwards by a rod F<SP>1</SP> to cause the rollers D, E to roll on the surfaces G<SP>1</SP>, A<SP>2</SP>, respectively, and on each other to effect release of the lever A. Various other arrangements for supporting the two rollers by means of pivoted links are also described. In Fig. 12, a pair of rolling toggle links P, Q are utilized for restraining movement of a loaded member R. The ends of these links roll on a surface R<SP>1</SP> of the member R and a fixed surface G<SP>2</SP>, respectively, and on each other when moved in a downward direc, tion to break the toggle to allow the member R to move. The links P, Q are supported by bell-cranks S, S<SP>1</SP> and U, Ul and links T, T<SP>1</SP>, V and X and operated by a bell-crank W, W<SP>1</SP>.