| 摘要 |
An electrical interruption device is disclosed in which a space efficient spiral spring activates current interruption. The spring is characterized by coils which wind continuously about and approach a central axis, with successive coils of the spring having reduced radius to pass axially through the center of an outwardly adjacent coil. The spring may further be made to assume a flat condition with the spring coils lying flat, nesting interposed between adjacent coils. Advantageously, the spiral spring is conical in shape and is tensioned in a reverse loaded configuration wherein the coils of one end of the spring are pulled axially inward, through and past the coils of other end. Preferably the reverse loaded conical spring forms part of a thermally sensitive device which includes a housing having disposed therein a plunger which is in a biased relationship with the spring. The plunger extends beyond the housing to provide electrical communication with the remainder of the electric circuit, and is held in place against the force of the spring by a meltable solder. On a predetermined condition causing the solder to melt, the plunger is released, whereby it is moved by the force of the spring into the housing and out of electric communication with the remainder of the electric circuit.
|
