GB933602A - Improvements in auto-reclosing electric circuit-breakers - Google Patents

Abstract

933,602. Automatic - reclosing circuitbreakers. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Aug. 27, 1959 [June 24, 1958], No. 20144/58. Class 38 (5). An automatic-reclosing circuit-breaker has a rotatable crank 31 connected to an operating spring mechanism 28 which recloses the breaker after an opening operation and drive means 37 energizable in response to opening movement of the breaker to rotate the crank to charge the spring mechanism. When the opening operation is complete, the crank goes overcentre and rotates in the same direction to reclose the breaker. In the arrangement shown, a latch 8 is released on the energization of a trip coil 21 to permit linkage 3 . . . 7 to collapse under the bias of an opening spring (not shown) causing a bell-crank lever 1 to open the main circuitbreaker contacts (not shown). The lever 1 displaces a prop 23 so permitting a spring 27 to move a plunger 22a upwardly until a flange 22b on the plunger abuts a flange 26b on a cup 26. The plunger 22a is connected by a link 22 to the linkage at 15 and the links 5, 6 and 7 return to the position shown before reclosing commences. The opening movement of the bellcrank lever 1 causes contacts A to close to energize a drive motor 37 which through gears 36 and ratchet and pawl mechanism (not shown) turns the crank 30 in the anti-clockwise direction until it goes over-centre. This permits the spring 28 to force down the plunger 22a and so turn the bell-crank lever 1 to reclose the main contacts, the continued rotation of the crank 31 in the anti-clockwise direction being permitted by the ratchet and pawl mechanism. Auxiliary contacts B are closed, a prop 33 is moved by a cam 32 to close contacts Y so that the motor 37 is energized to drive the crank 31 and cam 32 to the position shown, in which the spring 28 is charged and the crank is held against clockwise rotation by the prop 33. Should the circuitbreaker be closed on to a fault, it will trip open and remain open, preferably in the manner described in Specification 933,603. Contacts L may lock-out the circuit-breaker after a number of operations as described in Specification 933,601.