Temperature responsive switch with shape memory actuator
AssigneeTherm-O-Disc, Incorporated
InventorsPhilip B. Eder, William F. Quinn, Mark A. Roberts, Richard E. Welch, David W. Clow
Life of this patent
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Abstract
A temperature actuated switch having a resilient switch blade that is movable between open and closed positions and extends perpendicular to an elongated actuator of shape memory alloy. The actuator has an elongated deformed shape at normal temperatures and a contracted recovered shape at an elevated temperature. An end portion of the actuator is attached to the switch blade to provide movement of same between open and closed positions as the actuator changes between its deformed and recovered shapes.
Claims26
A temperature actuated switch comprising a polymeric housing having a cavity therein, a pair of terminals having terminal contacts in said cavity and terminal leads extending externally of said housing from said terminal contacts, a resilient switch blade having a movable blade contact normally engaging one of said terminal contacts, said switch blade being connected in electrically conductive relationship with the other of said terminal contacts, an actuator of shape memory alloy positioned in said cavity said actuator being in the shape of a coil spring and having one actuator end portion attached to said switch blade and an opposite actuator end portion attached to said housing, said actuator having an extended deformed shape at normal temperatures wherein said blade contact engages said one of said terminal contacts, and said actuator having a contracted recovered shape at an elevated temperature wherein said actuator bends said switch blade in a direction away from said one of said terminal contacts to separate said blade contact from said one of said terminal contacts.
A switch assembly comprising a polymeric housing having opposite ends, opposite side and opposite front and rear surfaces, a cavity in said front surface, notches in said front surface extending between said cavity and said opposite ends, a pair of terminals having terminal leads received in said notches and terminal contacts positioned in said cavity, a switch blade positioned in said cavity and having a blade contact normally engaging one of said terminal contacts, said switch blade being connected in electrically conductive relationship with the other of said terminal contacts, an elongated actuator of shape memory alloy having an end portion attached to said switch blade, said actuator having an extended deformed shape at normal temperatures wherein said blade contact engages said one of said terminal contacts, and said actuator having a contracted recovered shape at an elevated temperature wherein said switch blade is moved to an open position with said blade contact separated from said one of said terminal contacts.
A switch assembly including an actuator of shape memory alloy being in the shape of a coil spring, a resilient switch blade, said switch assembly having a fixed contact and said switch blade having a movable contact, said switch blade being movable between contact closed and contact open positions, said actuator having an end portion attached to said switch blade, said actuator having an extended deformed shape at normal temperatures and a contracted recovered shape at an elevated temperature, and said contacts being in said closed position when said actuator is in one of said shapes and being in said open position when said actuator is in the other of said shapes.
Dependencies are inferred from the claim text.