摘要 |
<p>A resettable thermal cut-off fuse, under normal temperature condition, keeps the circuit in a closed state by allowing a switch member which is energized by a spring in the circuit-breaking direction to be joined through the medium of a thermal pellet capable of retaining a solid state under the normal temperature condition to a check means which is prevented from rotating in the spring's energizing direction. When the ambient temperature rises to a prescribed level and, consequently, the thermal pellet melts, the fuse allows the switch member to rotate in the spring's energizing direction to open the circuit. When the ambient temperature falls and returns to its normal level, the fuse can be manually reset by rotating in the circuit-making direction until it resumes firm engagement with the check means to close the circuit.</p> |