Sunbeam Corporation Limited

Clifford R Stine

Charles W Murin

William M Sullivan

William W Irwin, Jr

Richard J Prins

James R McNair

Sherry B Hirsch

A flexible, electric heating pad having a self-limiting heating element is provided. The heating element includes a pair of relatively spaced conductors surrounded by a positive temperature coefficient (PTC) material. A layer of electrically insulating material surrounds the PTC material. The PTC material includes a polyolefin resin having a relatively low flexural modulus. The heating element is disposed in a generally serpentine configuration within passages formed in the covering material of the heating pad. The passages are formed by joining together layers of covering material using ultrasonic welding or other suitable ways. The temperature of the heating element is controlled using controller circuit which utilizes a solid state timed interval control circuit. A safety circuit is provided for non-resettably disconnecting electrical power from the heating element if short or open circuit conditions occur therein. A temperature indicator and a variable automatic shutoff circuit are also provided with the controller circuit. A method of making the heating pad is also provided.

Flexible self-regulating heating pad combination and associated method

Heating pad

Controller for use with electric heating pads

A heater for a water bed including an elongated PTC cable having conductors by a carbon loaded polymer material with the cable being tortuously disposed with closely spaced parallel lengths supported in a coplanar sandwiched relationship by adhesively coated sheets of polyester and aluminum, the sheets and cable being sealed in a polyvinyl chloride envelope.

Water bed heater

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Laurel, MS, United States of America

Clifford R Stine