Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
158 words
In an electrical heating device comprising a generally flat substrate having an upper insulating surface, a semi-conductor pattern carried by said upper surface of said substrate, and a pair of generally flat metallic conductors mounted in a face-to-face engagement with said semi-conductor pattern, that improvement wherein: said semi-conductor pattern includes a pair of spaced connector portions and at least one heating portion extending between and electrically connected to each of said connector portions; said connector portions have an electrical conductivity greater than that of said said heating portion; and, each of said metallic conductors is in face-to-face engagement with a respective one of said connector portions, and the surface thereof in such engagement has an area that is less than the area of the upper surface of said respective one of said connector portions, the area:perimeter ratio of said surface of said conductor being about D/4 wherein D is the major dimension of said area of said conductor.
Claim 2
Dependent Claim
158 words
In an electrical heating device comprising a generally flat substrate having an upper insulating surface, a semi-conductor pattern carried by said upper surface of said substrate, and a pair of generally flat metallic conductors mounted in a face-to-face engagement with said semi-conductor pattern, that improvement wherein: said semi-conductor pattern includes a pair of spaced connector portions and at least one heating portion extending between and electrically connected to each of said connector portions; said connector portions have an electrical conductivity greater than that of said said heating portion; and, each of said metallic conductors is in face-to-face engagement with a respective one of said connector portions, and the surface thereof in such engagement has an area that is less than the area of the upper surface of said respective one of said connector portions, the area:perimeter ratio of said surface of said conductor being about D/4 wherein D is the major dimension of said area of said conductor.
Claim 3
Dependent Claim
31 words
The heating device of claim 1 wherein an insulating layer overlyies said semi-conductor pattern and said conductors and sealing engages portions of said substrate that are free from said semi-conductor pattern.
Claim 4
Dependent Claim
34 words
The heating device of claim 1 including a wire electrically connected to each of said conductors, each such electrical connection being made by a connector engaging said wire and extending through a respective conductor.
Claim 5
Dependent Claim
18 words
The heating device of claim 1 wherein said heating portion includes areas having different conductivities (ohms per square).
Claim 6
Dependent Claim
32 words
The heating device of claim 1 wherein the minimum distance from said heating portion to a side edge of said heater is less than the width of either of said connection portions.
Claim 7
Dependent Claim
31 words
The heating device of claim 1 wherein said heating portion extends from one of said connection portions through a loop of at least 180° to the other of said connection portions.
Claim 8
Dependent Claim
21 words
The heating device of claim 6 including two of said heating portions connected to generally opposite sides of said connection portions.
Claim 9
Dependent Claim
23 words
The heating device of claim 1 including two of said heating portions, each of said heating portions having substantially the same watt density.
Claim 10
Dependent Claim
23 words
The heating device of claim 1 wherein said heating portions are substantially identical and extend in generally opposite directions from said connection portions.
Claim 11
Dependent Claim
57 words
The heating device of claim 1 wherein each of said connecting portions are adjacent each other, and said heating portion extends from each of said connecting portions in a direction forming an angle of not less than about 90° with a line extending directly from one of said connecting portions to the other of said connecting portions.
Claim 12
Dependent Claim
14 words
The heating device of claim 10 including at least two of said heating portions.
Claim 13
Dependent Claim
82 words
In an electrical heating device comprising a generally flat substrate having an upper insulating surface, a semi-conductor pattern carried by said upper surface of said substrate, and a pair of metallic conductors mounted in face-to-face engagement with said semi-conductor pattern, that improvement wherein: said semi-conductor pattern includes generally U-shaped heating portions extending in opposite directions from and electrically connected to each of said conductors; and each of said heating portions includes areas of different conductivities (ohms per square) connected electrically in series.
Claim 14
Dependent Claim
82 words
In an electrical heating device comprising a generally flat substrate having an upper insulating surface, a semi-conductor pattern carried by said upper surface of said substrate, and a pair of metallic conductors mounted in face-to-face engagement with said semi-conductor pattern, that improvement wherein: said semi-conductor pattern includes generally U-shaped heating portions extending in opposite directions from and electrically connected to each of said conductors; and each of said heating portions includes areas of different conductivities (ohms per square) connected electrically in series.
Claim 15
Dependent Claim
37 words
The heating device of claim 12 wherein each of heating portions includes a pair of parallel, spaced apart leg portions of a first conductivity and an intermediate portion of a second conductivity different from said first conductivity.
Claim 16
Dependent Claim
46 words
The heating device of claim 13 wherein said semi-conductor pattern includes a pair of spaced connector portions, each of said leg portions has one end thereof connected to a respective one of said connector portions, and the other end thereof connected to a said intermediate portion.
Claim 17
Dependent Claim
13 words
The heating device of claim 12 wherein said heating portions are substantially identical.
Claim 18
Dependent Claim
56 words
The heating device of claim 14 wherein said connecting portions are adjacent each other, and a said heating portion extends from each of said connecting portions in a direction forming an angle of not less than about 90° with a line extending directly from one of said connecting portions to the other of said connecting portions.