| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit breaker having an isolation function, which is improved so that movement of a handle to an OFF position can be inhibited surely in welding state of the main circuit contact, and which has an easy and simple assembling structure without losing assembling property of parts. SOLUTION: A switching mechanism 6 of the circuit breaker is composed of an assembly of a handle lever 8 joined to the handle 7; a latch 11 of a trip mechanism; a toggle link mechanism pin-linking the upper link 12 and the lower link 13 to stretch them between the latch and a contactor holder 4; and a switching spring 17. A projection 12b is formed at the side edge of the upper link 12, and an arm shaped stopper piece 8b is installed on an ON side of the handle lever 8 so as to face the projection. A wall part 8c preventing the movement of the handle by bumping against the tip of the projection 12b and a notched step part 8d in which the wall part crawls into lower side of the projection in a trip operating state to lock and restrict the handle lever at a trip position are formed at the stopper piece. Then, as for a pivot bearing of the handle lever and the upper link, U-groove-shaped open style bearings 8e, 12c are adopted which have easy and simple assembling property. COPYRIGHT: (C)2006,JPO&NCIPI
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