Moist heating pad

Abstract

An improved heating device such as a heating pad comprising a fabric base and insulated resistance wire mounted in said pad, preferably in a backward and forward sinuous pattern, at least one thermostat connected in series with the resistance wire element at both ends by means of lead wires of a low resistance metal such as copper, each thermostat being positioned intimately with a span or straight portion forming part of a sinuous loop of resistance wire, a switch connected in series with the resistance wire, and a plurality of bars of a metal such as lead mounted in the pad. In an improved embodiment the insulation on the resistance wire is formed of a plastic material able to withstand the elevated temperatures attained by the resistance wire during operation.

I claim: 
     
       1. A moist heating pad comprising: a. a flexible moisture permeable base sheet,   b. an electrical resistance wire heating element having an insulation sleeve mounted on said flexible base in a pattern comprising a plurality of substantially parallel banks of backward and forward sinuous loops having straight portions substantially perpendicular to the longitudinal direction of said banks,   c. at least one thermostat encased in an insulation jacket connected in series with said heating element and connected at both of its ends by insulated lead wires of a highly conductive metal, said thermostat being positioned parallel and in close proximity to a straight portion of one loop of said heating element,   d. a plurality of strips of a water .[.absorption.]. .Iadd.adsorption .Iaddend.lead alloy mounted on said flexible base sheet each within one of said sinuous loops .Iadd.said strips being heated by said heating elements to drive off adsorbed water, .Iaddend.   e. an electrical line cord having a switch therein being electrically connected to said heating element, and   f. a flexible moisture permeable cover enclosing said flexible base sheet, said heating element, said.[.metal.]. strips and said thermostat.   
     
     
       2. A moist heating pad according to claim 1, wherein both the lead wires connected to said thermostat are of copper. 
     
     
       3. A moist heating pad according to claim 1, wherein said heating element is formed of nichrome wire. 
     
     
       4. A moist heating pad according to claim 1, wherein said insulation sleeve of said heater element is formed of silicone rubber. 
     
     
       5. A moist heating pad according to claim 1, wherein said thermostat is encased in a plastic heat-shrunk jacket. 
     
     
       6. A moist heating pad according to claim 5, wherein one of the lead wires connected to said thermostat is enclosed within said heat-shrunk jacket. 
     
     
       7. A moist heating pad according to claim 1, wherein said flexible base sheet is formed of fabric. 
     
     
       8. A moist heating pad according to claim 1, having a plurality of thermostats each similarly mounted. 
     
     
       9. A moist heating pad according to claim 1, having an inner cover within said outer cover, both of said covers being formed of fabric. 
     
     
       10. A moist heating pad according to claim 1, having a fabric strip covering each bank of sinuous loops, and affixed in place by turned-over ends of said .[.metal.]. strips. .Iadd. 11. A moist heating pad comprising: a flexible moisture permeable base sheet, an electrical resistance wire heating element having an insulation sleeve mounted on said flexible base in a pattern of backward and forward sinuous loops, a thermostat having its opposite ends connected to insulated lead wires of a hightly conductive metal, said wire heating element and said insulated lead wires of said thermostat being connected together to connect said heating element and thermostat in series with an electric line cord, said thermostat being positioned in close proximity to a loop of said heating element, a plurality of flat lead alloy elements mounted on said flexible base sheet and uniformly within said sinuous loops, said flat lead alloy elements adsorbing water and being heated by said heating element to drive off adsorbed water, and a flexible moisture permeable cover enclosing said flexible base sheet, said heating element, said lead alloy elements and said thermostat. .Iaddend.