| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit breaker locking and holding a movable contactor of which a contact is opened by electromagnetic repulsion of excess current at the contact opening position, and resetting after break by a simple mechanism. SOLUTION: The circuit breaker has a movable contactor 4 and a double torsion spring (contact pressure spring) 7 held by a contactor holder 5, and made to open the contact by the electromagnetic repulsion of excess current, and the offset arm 7b of the contact pressure spring is energized in the contact closing direction by making it touching the rear face of the movable contactor. An engaging recessed groove 4b in which the tip of the offset arm is inserted in the rear face of the movable contactor and locks the movable contactor at the contact opening position is provided. Further, the contact pressure spring is fixed by hooking the leg 7a at both ends of its coil on the hole 5b opened at the contactor holder, or both ends of the contact pressure spring are fixed by a spring locking member 9 inserted into the side wall of the contactor holder, and by utilizing the bending nature of the contact pressure spring itself at the resetting operation, the offset arm is pulled out of the recessed groove, and locking of the movable contactor is released. COPYRIGHT: (C)2004,JPO
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