| 摘要 |
PROBLEM TO BE SOLVED: To improve a stopper mechanism of a movable contactor provided in an arc-extinguishing chamber so as to enhance strength and safety of component parts by avoiding concentration of an impact load added from the movable contactor on the chamber. SOLUTION: In the circuit breaker equipped with a rotating movable contactor 3 linked with a fixed contactor 2 and a switching mechanism 5 inside a chassis 1 consisting of a case 1a and a cover 1b, and an arc-extinguishing chamber 8 consisting of a box-shaped insulating frame 9 and a plurality of upper and lower steps of grid plates 10 retained in alignment inside the insulating frame along a switching movement path of the movable contactor, with tip parts of the insulating frame faced with each other in adjacency with an inner face of the cover 1b, a knocking part 11a of the movable contactor is formed in protrusion at a rear end of the grid ceiling plate 11 arranged at an uppermost step of the chamber as a stopper means for regulating an open terminal position of the movable contactor and moreover, the grid ceiling plate is locked and retained in free up-and-down movement at a tip part of the insulating frame. Then, a rear face of the movable contactor moving to open at the breaking operation is made in contact with a plate face of the knocking part. COPYRIGHT: (C)2007,JPO&INPIT
|
