Split-electrode series-laminated heater

Claim 1

A laminate heater comprising, in combination, a flat, circular, disc-like, conductive layer having affixed to one side two separate, half-moon shaped electrically conductive means which constitute split electrodes for the heater, a circular shaped conductive coating layer affixed to the opposite side of the conductive layer, said conductive layer and conductive coating layer each being a continuous structure and having the same surface configuration at their mating surface, said split electrodes being in the same plane and being located in a flat plane so that the electrodes may rest upon a flat surface in a non-rocky condition, said electrodes being positioned with a gap therebetween of a width such that excess current will not flow through the gap between the two electrodes, but being sufficiently close enough together so that heat is generated in the gap region at substantially the same rate per unit-area as heat is generated in the region above the split electrodes, said conductive layer is an isotropic material formed of a fiber material with an elastomeric binder and conductive material incorporated therein, and the gap between the electrodes is approximately equal to twice the conductive layer thickness.