GB187974A - Improvements in or relating to circuit breakers - Google Patents

Abstract

187,974. Wijk, P. G. van. Oct. 26, 1921, [Convention date]. Automatic circuit-breakers, &c.- In overload cut-outs in which the circuit may be broken automatically or manually, a knob is provided which when turned continuously by hand in one direction alternately opens and closes the circuit. and when turned in the other direction, breaks the circuit but cannot remake it. On the occurrence of an overload, the electromagnet 2 attracts its core 5, pins 7 upon which strike against a lever 9 pivoted at 10 and release its right hand end from engagement with a tooth on the lower end of the contact-carrying member 12 which is pivoted on an axis 14, with the result that the member 12 is urged by a spring 28 to move counter-clockwise, Fig. 2, and break contact at 17. The member 12 has pivoted to it at 25, Fig. 4, an arm 23 which is normally pulled by a spring against a projection 26; and the hand knob 15 which also moves about the axis 14 carries a cam 22, a disc 19 and a finger 31, Fig. 10. When the knob 15 is rotated in a clockwise direction, Fig, 4, the cam 22 eventually presses against the lever 23 and so drives the member 12 to the limiting position shown in Fig. 2. Further rotation of the knob 15 causes the cam 22 to lift and pass beneath the arm 23 and it is not till the knob 15 is thus freed from the member 12 that the resetting of the cut-out is completed by the cam 20 on the disc 19 allowing contact to be remade at 17. When the knob 15 is rotated in a counter clockwise direction, the cam 22 lifts and passes beneath the arm 23. The finger 31 carried by the knob 15 is adapted to press down the lever 10 and so release the contact-carrying member 12 once every revolution, whichever way the knob 15 is turned.