| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit breaker with an isolation function that improves reliability of a cutoff operation by strengthening a contact separation force of a movable contact during a trip operation in a contact fusion state due to improvement of a pivotal coupling part between an upper link of a toggle link and a latch. SOLUTION: An opening/closing mechanism 6 of the circuit breaker is composed of a handle lever 8 connected to an operation handle 7, the latch 11 locked to a latch receiver 10 while its one end is pivotally supported to a spindle 9, the upper link 12 and a lower link 13 that are connected to each other via a toggle pin 14, the toggle link pivotally coupling the other end of each link to the latch 11 and a contact holder 4, and an opening/closing spring 17 stretched between the toggle pin and the upper end of the handle lever. A connecting shaft 11a provided to the latch is fitted to a U-shaped open-type bearing part 12b formed at the upper end of the upper link so as to be slidably and pivotally coupled. A return spring force of the opening/closing spring 17 is directly applied to the toggle pin 14 without receiving constraint of the upper link during the trip operation in a state in which contact fusion occurs. COPYRIGHT: (C)2008,JPO&INPIT
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