Patent ID: 6884955

Claim:
In a pushbutton switch having a pushbutton pivotally mounted on a hollow casing, a linkage movably received inside the casing and having a first distal end securely in contact with the pushbutton and a second distal end securely connected to a heat sensitive plate which is able to curve in reaction to heat and has a first distal end securely connected to a first distal end of a first terminal, wherein a second distal end of the first terminal extends out of the casing, a second terminal having a first distal end provided with a first contact mounted thereon and a second distal end extending out of the casing, wherein the heat sensitive plate has a second distal end provided with a second contact selectively in contact with the first contact, wherein the improvements comprises: the pushbutton having a slot adapted to receive therein a free end of the linkage and a receiving space in communication with the slot so as to allow the free end of the linkage to move toward the receiving space when an electrical overload occurs in the pushbutton switch, and the linkage having a cutout defined in the second distal end to have a portion of the heat sensitive plate to be received in the cutout and an extension formed with the linkage and extending out into the slot, such that when the heat sensitive plate reacts to heat and curves to cause the first contact to separate from the second contact, a free end of the linkage received inside the slot is able to move toward the receiving space to allow a free movement of the heat sensitive plate without any limitation to hinder the curvature movement of the heat sensitive plate.