| 摘要 |
The dual element fuse of the present invention has at least one fusible element and at least one mass of heat softenable material; and that fusible element will respond to a short circuit to fuse and thereby assure opening of the circuit, whereas that mass of heat softenable material will respond to a long-continued relatively-low potentially-hurtful overcurrent to soften and thereby initiate opening of the circuit. That dual element fuse has a shunt element which shunts the mass of heat softenable material and which will fuse after that mass of heat softenable material has initiated opening of the circuit; and hence that shunt element will minimize arcing as that mass of heat softenable material initiates opening of the circuit. That shunt element has a current rating which is larger than the current rating of the mass of heat softenable material, so it will not fuse until after that mass of heat softenable material has initiated opening of the circuit; and that shunt element has a current-interrupting characteristic which has the same shape as that of the current-interrupting characteristic of the fusible element, so its clearing time will be similar to the clearing time of that fusible element. Where the dual element fuse of the present invention has a plurality of fusible elements and a plurality of masses of heat softenable material, a connecting ring electrically interconnects one end of each of those fusible elements. In doing so, that connecting ring keeps any higher-than-normal-electrical-resistance connection between one of those fusible elements and an adjacent heat absorber from generating so much heat that it initiates premature softening of the mass of heat softenable material which is a part thereof.
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