| 摘要 |
PROBLEM TO BE SOLVED: To simplify the mechanism so as to secure reliable operation by providing an energizing means wrapped round a circumscribing current-carrying part to expand the space between a current-carrying element formed by connecting a pole contact current-carrying part and the circumscribing current-carrying part by a temperature- sensitive melting body and a holder, while keeping electric insulation, and an energizing means disposed in the pole contact current-carrying part to be expanded. SOLUTION: A current-carrying element 2 is divided into two parts, a pole contact current-carrying part 21 and a circumscribing current-carrying part 22. The pole contact current-carrying part 21 has an upper end opening 21a where the lower end 22a of a straight bar-like circumscribing current-carrying part 22 is inserted with play, and a low melting point alloy 5 as a temperature sensitive melting body having conductivity is filled and solidified in a gap of an inner fit part. When an electric part generates heat, heat is transmitted to a conductive contact pin 1 to melt the low melting point alloy 5 and release the restraint of an inner coil spring 24, so that the circumscribing current-carrying part 22 is vigorously moved upward in the axial direction to be separated from the pole contact current-carrying part 21, thereby intercepting a current- carrying path. As a means for sensing the temperature rise to intercept current-carrying is built in the conductive contact pin, the mechanism can be simplified. |
