| 摘要 |
768,937. Automatic circuit-breakers. GENERAL ELECTRIC CO. May 23, 1955 [May 25, 1954], No. 14833/55. Class 38(5) An electromagnetic tripping device responsive to the current flowing through a conductive stud 15 has a U-shaped core 16 with its legs straddling a transverse intermediate portion 23 of the stud, this portion interconnecting other stud portions 21, 22 extending longitudinally parallel to the axis of the stud. When moderate overloads occur, an armature 31 is attracted to the core 16 against the bias of a spring 56 and turns a lever 12 to produce tripping of a circuit breaker indicated at 10, an inverse time delay being provided by a dash pot 40. Within an intermediate range of overloads, tripping is produced by a second armature 32 which is attracted by the core against the bias of a spring 43. In this case an inverse time delay is provided by an escapement mechanism 37. Under heavy overload conditions, the force acting on the armature is sufficient to overcome the bias of a spring 39 which normally maintains a lever 54 against a stop 55 on a lever 51. Thus with currents above the intermediate range, substantially instantaneous tripping occurs. As the armature 31 and levers 53, 54 can move against the bias of the spring 39 without turning the lever 51 coupled to the dashpot 40. |
