Patent ID: 7015428

Claim:
A contact heater comprising a plurality of layers: a first layer of a heat conducting adhesive; a first electrical ground sheet extending along the heat conducting adhesive; a first envelope layer; a carrier layer extending along the heat conduction adhesive; a heating element located on said carrier layer; an electrically insulating layer extending along said heating element; a second electrical ground sheet carried by said electrical insulating layer, said second electrical ground sheet having a plurality of openings therein to permit gas passage therethrough; an electrically insulated layer comprising a second envelope layer extending over said second electrical ground sheet; an electrical cord having a first power lead and a second power lead connected to said heating element and a ground wire electrically secured to said ground sheet and said second ground sheet to prevent accidental shock in the event of a heater failure; and said first envelope layer and said second envelope layer an envelope encapsulating said electrical insulating layers, said heating element and at least one of said electrical ground sheets.