US4587402A
Expired / Lapsed
US
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Planar heating unit
Assignee: Panasonic Holdings Corp
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Filing: 1983-06-23
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Granted: 1986-05-06
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Expires: 2003-06-23
Abstract
Abstract PCT No. PCT/JP83/00203 Sec. 371 Date Feb. 22, 1984 Sec. 102(e) Date Feb. 22, 1984 PCT Filed Jun. 23, 1983 PCT Pub. No. WO84/00275 PCT Pub. Date Jan. 19, 1984.A planar heating unit comprises a base plate (1) having a surface electrically insulated by an insulation enamel layer (2a) or the like, a heating conductor (3) placed on the insulation surface of the base plate for generating Joule heat, and an enamel layer (4) fixing the heating conductor to the base plate (1) and covering the upper surface of the heating conductor.
Inventors
- 👤 Atsushi Nishino
- 👤 Masaki Ikeda
- 👤 Yoshihiro Watanabe
- 👤 Tadashi Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:19
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/18; H05B3/20; H05B3/22; H05B3/28; H05B3/283
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
69 words
A planar heating unit comprising a heat resistant metal base coated with an insulating enamel layer on at least one surface of said base, an exposed covering enamel layer fixed on said insulating enamel layer, and, as a heating conductor, a metal strip having a thickness of not more than 120 μm covered by said covering enamel layer, said metal strip being spaced apart from said insulating enamel layer.
Claim 2
Dependent Claim
69 words
A planar heating unit comprising a heat resistant metal base coated with an insulating enamel layer on at least one surface of said base, an exposed covering enamel layer fixed on said insulating enamel layer, and, as a heating conductor, a metal strip having a thickness of not more than 120 μm covered by said covering enamel layer, said metal strip being spaced apart from said insulating enamel layer.
Claim 3
Dependent Claim
26 words
A planar heating unit as set forth in claim 1, wherein said insulating enamel layer comprises a glass frit having a softening point of 470°-650° C.
Claim 4
Dependent Claim
20 words
A planar heating unit as set forth in claim 1, wherein said covering enamel layer contains an infrared radiating material.
Claim 5
Dependent Claim
26 words
A planar heating unit as set forth in claim 1, wherein said covering enamel layer comprises a glass frit having a softening point of 470°-650° C.
Claim 6
Dependent Claim
26 words
A planar heating unit as set forth in claim 1, wherein an electrical insulation material is interposed between the insulating enamel layer and said heating conductor.
Claim 7
Dependent Claim
24 words
A planar heating unit as set forth in claim 5, wherein the whole of said heating conductor is covered with the electrical insulation material.
Claim 8
Dependent Claim
22 words
A planar heating unit as set forth in claim 5, wherein said electrical insulation material is made of fine particles fused together.
Claim 9
Dependent Claim
22 words
A planar heating unit as set forth in claim 5, wherein said electrical insulation material is formed into a layer by spraying.
Claim 10
Dependent Claim
52 words
A planar heating unit as set forth in claim 1, wherein said metal base comprises a steel plate containing 0.001-0.1% by weight of carbon, 0.005-0.04% by weight of copper, 0.01-0.02% by weight of phosphorus, and a nickel layer of not more than 20 mg/dm 2 covering the surface of the steel plate.
Claim 11
Dependent Claim
31 words
A planar heating unit as set forth in claim 1, wherein the surface of said metal base is formed with a projection for surrounding an installation area for said heating conductor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-05 | 1989-11-04 | 1990-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-05 | 1993-11-04 | 1994-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-05 | 1997-11-04 | 1998-05-06 | $7700.00 | Window Closed / Lapsed |