Patent US4574186A successfully refreshed from Google Patents.
US4574186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heating sheet
Assignee: Totoku Electric Co Ltd
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Filing: 1983-03-24
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Granted: 1986-03-04
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Expires: 2003-03-24
Abstract
Abstract A heating sheet is provided in which protective covers are laminated to both surfaces of a heating element in which plastic sheets are respectively formed on the two surfaces of a metal foil heating circuit. The protective covers are adhered to the heater element such that indentations or recesses may be formed in those portions of the protective covers which do not correspond to the heating circuit.
Inventors
- 👤 Yoshio Sakai
- 👤 Takeshi Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:07
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/20; H05B3/34; H05B3/36; H05B2203/00; H05B2203/002; H05B2203/003; H05B2203/014; H05B2203/017
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
138 words
A heating sheet comprising a heater element which is obtained by forming a metal foil heating circuit on one surface of a first plastic sheet and superposing a second plastic sheet of the same shape as said first plastic sheet thereover, and adhering said first and second plastic sheets together; through holes formed in a regular pattern in portions of said heater element other than portions having said metal foil heating circuit formed therein; and a pair of protective thermoplastic covers which clamp said heater element therebetween and which are bonded together at a periphery of said heating sheet and through said through holes; wherein those portions of said protective covers which correspond to said through holes are recessed and indented due to said through holes in said heater element, thereby distinguishing the locations of said through holes.
Claim 2
Dependent Claim
138 words
A heating sheet comprising a heater element which is obtained by forming a metal foil heating circuit on one surface of a first plastic sheet and superposing a second plastic sheet of the same shape as said first plastic sheet thereover, and adhering said first and second plastic sheets together; through holes formed in a regular pattern in portions of said heater element other than portions having said metal foil heating circuit formed therein; and a pair of protective thermoplastic covers which clamp said heater element therebetween and which are bonded together at a periphery of said heating sheet and through said through holes; wherein those portions of said protective covers which correspond to said through holes are recessed and indented due to said through holes in said heater element, thereby distinguishing the locations of said through holes.
Claim 3
Dependent Claim
17 words
A heating sheet according to claim 1, wherein said protective covers have a thickness of 0.4 mm.
References Cited (Backward Citations)
US3213521A
Cited
US3539767A
Cited
US3215574A
Cited
US3423574A
Cited
US3584198A
Cited
US3749886A
Cited
US4220848A
Cited
US4293763A
Cited
WO1982000935A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-03 | 1989-09-02 | 1990-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-03 | 1993-09-02 | 1994-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-03 | 1997-09-02 | 1998-03-04 | $7700.00 | Window Closed / Lapsed |