Trip-free overload circuit breaker

910,786. Electrically-tripped switches. WOOD ELECTRIC CORPORATION. Aug. 17, 1959 [Jan. 13, 1959], No. 28055/59. Class 38 (5). A double-break, trip-free circuit-breaker comprises fixed contacts 18, 20 co-operating with movable contacts 68, 70 carried by a V-shaped resilient wire bar 66 secured by an enlarged head 78 to to a leaf spring 72 having one end hinged at 74 and the other slidable against a rivet 76. Contact 20 is connected through a Z-shaped strap 24 to a thermostatic latch 26 connected to a terminal 32 and adjustable by a screw 60 engaging an arm 62 on the strap 24. An abutment roller 48 is carried by a member 28 pivoted at 52 and urged towards the head 78 by a torsion spring 86, members 48, 78 being engaged by a wedging roller 82 mounted at one end of a link 80, whose other end is pivoted to a manually-operable button 12 passing through a hole in the strap 24. Depression of the button 12 forces the roller 82 between members 48, 78, the former being locked by the engagement of member 28 with a block 56 on the latch 26, and the latter moving to the right to close the contacts with a wiping action produced by the bar 66 and the spring 72, Fig. 2. The contacts may be opened by withdrawal of the button 12 or automatically on overload by clockwise movement of the latch 26, which releases the member 28 and allows the spring 72, assisted initially by the bar 66 and subsequently by the spring 86, to restore members 48, 78, 82 to the positions shown in Fig. 1. All the functional parts, apart from the button 12, are mounted between two parallel insulating plates which are telescoped into an insulating casing 10, Fig. 3 (not shown). Specification 907,595 is referred to.