| 摘要 |
PROBLEM TO BE SOLVED: To provide a protective element having a temperature sensing element which can open and protect a circuit when the temperature excessively rises, repeatedly used when an abnormal state is eliminated, or permanently open the circuit when an abnormal state cannot be eliminated. SOLUTION: A lead 2 is fixed to one end of a metal case 1, an opening part on the other end is closed by an insulating bushing 3, and a fixed contact 5 is provided on an inner end of a lead 4 through the insulating bushing 3. A leaf spring 11 formed of a shape memory alloy as a temperature sensing element performing the shape memory function of returning to the stored shape at a predetermined temperature, a strong compression spring 12, a temperature sensing pellet 8 as the temperature sensing element having the permanent deformation function performing the irreversible shape change at the temperature higher than the predetermined value when the abnormal state is not eliminated, a movable contact 13 and a weak compressive spring 14 are stored in the metal case 1.
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