Patent GB-406049-A (GB)
Title: Improvements in automatic reclosing mechanism for oil circuit-breakers
IPC: H01H75/04
Filed: 1932-08-22
Abstract: 406,049. Automatic circuit-breakers. JOHNSON & PHILLIPS, Ltd., Victoria Works, Charlton, and WOOD, P. M., 38, Green Lane, Eltham, both in London. Aug. 22, 1932, No. 23464. [Class 38 (v).] Spring-motor actuation ; retarding devices ; indicators.-A circuit-breaker of the free-handle type has an automatic reclosing device which is adapted to be preset to operate in response to the opening of the breaker to effect reclosure thereof, by moving the handle or actuating element first to the " Qff and then back to the " on " position, the device being adapted to operate a given number of times only for each presetting. As applied to a breaker mounted at the top of a pole, Figs. 1, 2 (not shown), the actuating element of the breaker is "down" when the breaker is in closed position, and remains " down " when the breaker is tripped open. To reclose, the element is first moved " up " and then "down," by means of a rod 7 and a crank 6 on an operating shaft 5 that makes one revolution for each reclosure under the action of a coil spring 8. The latter is connected at one end to a rod 9 and at the other to shaft 5, and 9 is normally retained by gravity-latches 27 pivoted at 28, whereas 5 is retained by a lug 14 thereon engaging a roller 15 on an arm 16, which is pivoted at 17 and deflectable by an arm 22 under the action of a cable 19. The latter is raised by the opening movement of the breaker to release 5 and allow it to reclose the breaker, the cable allowing 15 to move back in the way of 14 as the revolution is nearing completion. This operation is repeated as many times as are necessary up to the prescribed limit, and in each operation, means such as dashpots in the breaker tank itself or in the reclosing mechanism, or an oil pump in the latter, cause the up-stroke of 7 to be effected slowly and the down-stroke quickly. The rod 9 passes through plates 10... 12 which are rotatable about shaft 5 and provided with a shaft 13 adapted to receive a presetting handle. By means of the latter, the unit 9 ... 13 is rotated clockwise (to tension 8) a number of times (preferably three) corresponding to the number of reclosures before locking- out takes place. At each complete rotation, 9 deflects 27 which then spring back into retaining position and finally latch the unit. The latter rigidly carries a dial 32 and loosely carries a gear wheel 31 having a pointer 33 for the dial 32, the wheel 31 being of, say, 42 teeth and co-operating with a wheel 30 on shaft 5 having, say, 12 teeth. The pointer 33 also co-operates with a stop 34 on dial 32, and in presetting moves clockwise two-sevenths of a turn from the position shown in Fig. 3 for every turn made by the unit 9...13, so that when preset for three reclosures, the pointer engages the left-hand side of the stop and prevents further presetting. Thus three reclosures can be made before 33 engages the other side of 34 to lock the mechanism against further attempts until another presetting has been effected. The dial 32 is numbered to indicate the state of the mechanism. For manual opening a handle 35 is moved to the right to cause an arm 38 to raise arm 16, the shaft 5 making a half-turn until 14 engages a part 37. The latter is moved to the left by handle 35 to reclose. The weight of the lever 7 is counterbalanced by a weighted arm, Fig. 2 (not shown). The Provisional Specification refers also to a weight-actuated device.