| 摘要 |
1278058 Automatic circuit-breakers FEDERAL PACIFIC ELECTRIC CO 1 Aug 1969 [1 Aug 1968] 38769/69 Heading H1N In a single or multipole circuit breaker having a thermally releasable trip bar 72, Fig. 1, as in Specification 1,053,654, in which over-centre toggle links 58, 60 are released through latch 70 and cradle 52 to permit contact 18 to open about pivot 38, additional quick-acting electromagnetic release means is provided independently of the latch 70. Each contact arm 20 has its pivot 38 located in slots 44 by a pivoted latch 84 carrying an armature 80 adjacent to a magnetic yoke 78 mounted on the bimetal 24 of the thermal release trip. In the event of a sudden overcurrent the latch 84 releases pivot 38 whereby the contact arm 20 is free to pivot about pin 66 (at the switch closed position 66a) on the end of toggle link 60 whereby the arm 20 opens to the position shown hatched in Fig. 1. The circuit breaker may additionally be released by electrodynamic forces between the contact arm 20 and the current loop 92 for the fixed contact 16. In this example the latch 84 is slightly chamfered at (84a<SP>11</SP>), Fig 5 (not shown) whereby the pin 38 forces the latch 84 back against the action of its torsion spring 40. |
