| 摘要 |
1,137,325. Automatic circuit-breakers. GENERAL ELECTRIC CO. 17 Feb., 1967 [17 Feb., 1966], No. 7609/67. Heading H1N. A tripping device for a circuit-breaker comprises a magnetic core 60 surrounding a current conductor 38 and having two pairs of pole pieces 66, 68, and an armature 54 which is attracted to the pole-pieces 66 to turn a trip bar 46 when a large overload current occurs in the conductor 38. A bimetallic strip 57 is secured to the conductor 38 and is heated by the conductor so that it may move the armature 54 towards the pole-pieces 66 to cause tripping when an overload current of an intermediate value occurs. A further bimetallic strip 50 is carried by a short-circuited single turn winding 64 on the core 60 and is heated by the winding 64 to turn the trip bar 46 under relatively low overload conditions. |
