| 摘要 |
A temperature-sensitive switching device is provided in a casing having a pair of leads that extend therefrom, by a spiral spring which forms a first electrical contact and a curved conducting member which forms a second electrical contact. The spiral spring is connected to one of the leads and is expanded and fitted over a thermally-fusible pellet which melts at a predetermined temperature. The outer diameter of the pellet is larger than the inner diameter of the spiral spring contact before it is expanded. The end of the spiral spring contact contains a curved connecting projection, which preferably forms a circular arc, that serves as a sliding contact. The other contact element is provided by a matching fixed curved conducting projection which is connected to the other lead. When the thermally-fusible pellet melts, the tension in the spring is released and it relaxes to its unexpanded size causing the conducting projection on the end of the spring to spiral either into, or out of, contact with the conducting projection on the fixed position lead thereby making, or breaking, the circuit.
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