| 摘要 |
Disclosed is a mechanism for preventing the operation of a circuit interrupting device during the occurrence of excessive overcurrent. The circuit interrupting device includes an insulative housing having circuit-connectable opposed terminals thereon. Included within the housing is an arcing rod which is electrically connected to one terminal and which, in response to an overcurrent, moves away from a stationary contact electrically connected to the other terminal. Arcing rod movement elongates an arc formed between the arcing rod and the contact in an arc extinguishing environment to extinguish the arc and interrupt the circuit. The mechanism of the invention includes a shoulder on the arcing rod and one or more magnetic yokes positioned adjacent, but normally out of contact with, the shoulder. When an overcurrent through the device occurs which exceeds the device's rating, flux generated by current flow through the arcing rod moves the yoke to engage the shoulder thus preventing arcing rod movement. The yoke may be normally biased away from the shoulder by one or more springs.
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