Therm-O-Disc, Incorporated

Therm-O-Disc, Incoporated

James B Kalapodis

William F Quinn

Jerry L Polles

Wayne M Motley

Ralph L Bishop

Matt M Grist

David Lanham

Carl R Reid

A switch having closed and open positions moves from one position to the other in response to either an elevated temperature or an excessive pressure. A switch member of bimetal material or shape memory alloy operates in response to an elevated temperature, and a foil diaphragm that cooperates with a bumper operates the switch member in response to elevated pressure. The diaphragm may rupture to vent excessive pressure in the event pressure continues to rise despite operation of the switch member or due to failure of the switch member to operate.

Pressure and temperature responsive switch assembly

A thermal switch assembly includes a dielectric spacer and a switch blade member of shape memory metal sandwiched between a pair of flat metal plates. The spacer provides a cavity between the plates and the switch blade member has a switch blade portion projecting into the cavity. The switch blade member has a mounting portion engaging one of the metal plates, and the switch blade portion normally is under bending stress in engagement with the other metal plate to provide a current path between the plates. At elevated temperatures, the switch blade portion of shape memory metal moves out of engagement with the other metal plate to interrupt the current path. Fasteners integral with the dielectric spacer cooperate with the metal plates and the switch blade member to hold the switch assembly together with the spacer and the mounting portion of the switch blade member compressively sandwiched between the metal plates.

Thermal switch

A thermal switch assembly has a contact member of shape memory alloy sandwiched between a pair of electrically conductive outer members. A contact arm on the contact member has a deformed shape at normal temperatures and a recovered shape at elevated temperatures. The contact arm occupies two different positions in its deformed and recovered shapes, and provides a current path between the outer members in one position while interrupting the current path in the other position.

Thermal switch assembly

A thermal switch having a current carrying switch blade actuator of shape memory metal has a resistance less than 20 milliohms and a contact force greater than 150 grams. The actuator is deformed to less than about 8% strain, and a very hard high strength dielectric material is used for a spacer.

A thermal switch assembly includes a dielectric spacer and a switch blade member of shape memory metal sandwiched between a pair of flat metal plates. The spacer provides a cavity between the plates, and the switch blade member has a switch blade portion projecting into the cavity. The switch blade member has a mounting portion engaging one of the metal plates, and the switch blade portion normally is under bending stress in engagement with the other metal plate to provide a current path between the plates. At elevated temperatures, the switch blade portion of shape memory metal moves out of engagement with the other metal plate to interrupt the current path. Fasteners integral with the dielectric spacer cooperate with the metal plates and the switch blade member to hold the switch assembly together with the spacer and the mounting portion of the switch blade member compressively sandwiched between the metal plates.

A thermal switch assembly has a stiffener disc positioned against a support flange that extends inwardly from a peripheral wall of a plastic assembly grommet. An actuator member of shape memory metal is received in a recess in the stiffener disc, and an insulator ring lies against the disc and actuator member on the opposite side of the disc from the support flange. A cap member is positioned against the insulator on the opposite side thereof from the stiffener disc, and a resilient actuator blade on the actuator member extends through a central opening in the insulator into engagement with the cap member. The actuator blade normally completes a circuit between the stiffener disc and the cap member, and automatically disengages from the cap member at an elevated transition temperature to open the circuit.

A thermal switch having a current carrying switch blade actuator of shape memory metal has a resistance less than 20 milliohms. The actuator is deformed to less than about 8% strain, and a very hard high strength dielectric material is used for a spacer.

A thermal pellet holds contact-carrying resilient switch blades in bending stress with the contacts closed. Melting of the thermal pellet relieves the bending stress and allows movement of the switch blades to open the contacts.

Thermal pellet cutoff switch

A thermal cutoff having a single switch blade that is held in a contacts-closed position under bending stress by a thermal pellet and that moves to a contacts-open position solely by relief of the bending stress upon melting of the thermal pellet.

Growing community of inventors

Fayetteville, NC, United States of America

James B Kalapodis