초록 ▼

The heating element includes a flexible graphite fiber-loaded impregnated paper saturated with a binder to ensure and maintain intimate electrical contact between the graphite fibers. In one form, two segments of the graphite fiber-loaded paper are coupled in series through a common bus bar and are

The heating element includes a flexible graphite fiber-loaded impregnated paper saturated with a binder to ensure and maintain intimate electrical contact between the graphite fibers. In one form, two segments of the graphite fiber-loaded paper are coupled in series through a common bus bar and are electrically coupled to an SCR control circuit using a thermistor as a temperature responsive device. The graphite fiber-loaded paper with thermistor and electrical leads are encapsulated between cover sheets to provide an extremely thin highly flexible drapable therapeutic heating pad. Another form of heating pad includes providing the graphite fiber-loaded paper in the form of strips bonded to a plastic substrate. Electrical leads are attached and the substrate is enclosed by a cover sheet to provide a highly flexible heating pad. Two discrete methods of forming the latter heating pad are disclosed including silk screening and die pressing operations.

대표청구항 ▼

A heating pad comprising a pair of sheet-like segments each formed of a paper sheet containing a predetermined percentage of graphite fibers and saturated with a thermoplastic material; a pair of flexible plastic cover sheets disposed on opposite sides of and thermally and chemically bonded to said

A heating pad comprising a pair of sheet-like segments each formed of a paper sheet containing a predetermined percentage of graphite fibers and saturated with a thermoplastic material; a pair of flexible plastic cover sheets disposed on opposite sides of and thermally and chemically bonded to said segments by said thermoplastic, said segments being integral with said cover sheets, and electrical circuit means for applying current to said graphite fiber-containing segments and resistively heating said pad, including means for electrically coupling said segments in series one with the other and means for controlling current in said segments in response to variations in temperature in the heating pad for maintaining the resistive heat output at a predetermined temperature.