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US 5,796,327 AGranted
Thermally responsive electrical switches
AssigneeOtter Controls Limited
InventorDavid Andrew Smith
Life of this patent
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AssigneeOtter Controls Limited
InventorDavid Andrew Smith
Estimating the term…
A thermally-responsive current-sensitive switch having a molded plastic body containing first and second terminals in the form of metal stampings and having an internal chamber wherein a leaf spring and a snap-acting bimetallic blade of the same shape are together spot-welded to one of the terminals with the leaf spring underlying the bimetal in registry therewith and at its other end carrying a sliver contact which cooperates in switching operations with the other switch terminal. In one embodiment, the spring bias of the leaf spring tends to open the switch and the force generated by the bimetal in its contacts-closing movement is sufficient to overcome the spring bias of the leaf spring, whereas in another embodiment the leaf spring develops either a neutral force or a contacts-opening force. The leaf spring electrically shunts the bimetal, whereby the current-carrying capability of the switch is increased and different switch specifications can use the same bimetal with different leaf springs.
A thermally-responsive switch comprising a molded plastic body portion capturing therein first and second spaced-apart terminal conductors, a leaf spring cantilevered from one of said conductors and extending toward the other of said conductors, said leaf spring having a free end carrying a contact which constitutes a moving contact of the switch and is adapted to cooperate in switching operations with said other of the two conductors, and a snap-acting bimetallic actuator cantilevered from said one of said conductors and extending towards said other of said conductors, said bimetallic actuator cooperating with said leaf spring such that thermally induced movements of said bimetallic actuator transfer to the leaf spring to determine a condition of the switch, the bimetallic actuator being electrically shunted by the leaf spring which makes electrical contact with both a fixed end and said free end of the cantilevered bimetallic actuator.
Dependencies are inferred from the claim text.