| 摘要 |
<p>1,263,819. Automatic circuit-breakers. WESTINGHOUSE ELECTRIC CORP. 19 Nov., 1969 [5 Dec., 1968], No. 56652/69. Heading H1N. A circuit-breaker 3 cannot be reset after tripping if the contacts have failed to open, e.g. because of welding. In normal resetting, a radius 171 at the knee 61 of the toggle 53, 55 engages a surface on a latch member 71 to pivot it against a spring 93 to move a trip bar 73 to a latching position in which a surface 89 on the trip bar 73 engages a surface 91 on the latch member 71, member 71 including a roller 77 under which engages the hook-shaped end 95 of a releasable trip member 57. If the contacts 19, 21 are welded, the toggle 53, 55 is restrained from moving sufficiently to actuate the latch member 71 to its latching position and, if the handle 49 is released after a resetting attempt, the tension spring 67 automatically moves the handle back to the "on" position, thus indicating that the breaker has not reset and the contacts are closed.</p> |
