GB377212A - Improvements in and relating to electric switch operating mechanism - Google Patents

Abstract

377,212. Automatic circuit-breakers. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London.-(Assignees of Thumim, C.; P.O. Box 5312, Philadelphia, U.S.A.) April 20, 1931, No. 11696. Convention date, April 18, 1930. [Class 38 (v).] The operating rod 1 and opening spring 7 of a circuit-breaker are connected to separate levers 11, 12 so that during the closing movement, the rod 1 descends further than the top of the spring and in the closed position the end of the rod abuts the end of the compressed spring. To close the circuit-breaker, a pair of motors 2, 3 drive centrifugal devices and so turn the lever 4 clockwise, this motion is imparted through links 13, 14, 15, the intermediate pivots of which are constrained to move in defined paths by links 19, 21, to the lever 12, and by means of a roller 16, on the common pivot of link 15 and lever 12, to the lever 4. In the closed position the right-hand end of a catch 28 drops on the left side of a pin 29 on the lever 4 and so retains the circuit-breaker closed. In any position of the apparatus, tripping is effected by turning a catch 25 clockwise so as to clear a roller 24 on the end of a lever 23, which thereupon turns counterclockwise and moves a lever 20 similarly. This causes upward movement of the link 21 with consequent buckling of the toggle formed by links 13, 14. Both the spring 7 and rod 1 are released and the spring acts upon the lower end of the rod 1 driving the initial part of its motion and is then arrested by a buffer spring 40. As the toggle 13, 14 buckles, its common pivot pin engages an arm of the catch 28 so as to turn it counterclockwise and free it from the pin 29, whereupon a resetting spring 32 returns the apparatus to the initial position ready for a reclosure.