Heating element
First Claim
1. A heating element comprising a resistance layer forming an electrical resistance disposed between two planar electrodes extending generally parallel to each other and to the resistance layer in which flow of current between the electrodes occurs at right angles to a plane extending generally parallel to the resistance layer, the resistance layer comprising a matrix of an electrically conductive synthetic resin material having a positive temperature coefficient of electrical resistance and a particulate thermally and electrically insulating filler material dispersed throughout the synthetic resin material matrix, the electrodes being disposed at opposite surfaces of the resistance layer and being electrically interconnected through the conductive synthetic resin material matrix.
1 Assignment
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Accused Products
Abstract
In a heating element comprising an electrical resistance layer disposed between two areal electrodes extending generally parallel to one another, the resistance layer is formed to be thermally insulating and is permeated with electrically conductive plastics material having a positive temperature coefficient of electrical resistance. The conductive plastics may comprise thermoplastics material incorporating a particulate filler of granular, spheroidal or bubble form, and the electrodes may be coated black to serve as black bodies. The element may be disposed within a thermally insulating member acting as a heat shield.
34 Citations
11 Claims
- 1. A heating element comprising a resistance layer forming an electrical resistance disposed between two planar electrodes extending generally parallel to each other and to the resistance layer in which flow of current between the electrodes occurs at right angles to a plane extending generally parallel to the resistance layer, the resistance layer comprising a matrix of an electrically conductive synthetic resin material having a positive temperature coefficient of electrical resistance and a particulate thermally and electrically insulating filler material dispersed throughout the synthetic resin material matrix, the electrodes being disposed at opposite surfaces of the resistance layer and being electrically interconnected through the conductive synthetic resin material matrix.
Specification