US3694627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heating element & method of making
Assignee: Whirlpool Corp
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Filing: 1970-12-23
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Granted: 1972-09-26
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Expires: 1990-12-23
Abstract
Abstract A method of making a heating element such as a heating panel for an oven or other heating device comprising applying to a heat resistant base such as a metal panel a fired vitreous ceramic first coating, then applying over this first coating a fired vitreous ceramic second coating containing dispersed metal particles and then applying over this second coating a plating of metal chemically bonded to metal particles contained in the second coating and then applying over the metal plating a fired vitreous ceramic protective coating with the result that there is provided an electrically conducting resistant heating layer that is protected by the ceramic protective coating. The disclosure also includes the heating element so produced.
Inventors
- 👤 John K Blatchford
- 👤 Edward C Peterson
- 👤 Jan C Burda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:03
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/20; H05B3/22; H05B3/26; H05B3/262; H05B2203/00; H05B2203/002; H05B2203/003
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
46 words
The heating element of claim 1 wherein said heat resistant base comprises a metal panel having a pair of opposite surfaces, a first coating is fixed to both said surfaces, and said coating containing said metal particles is fixed to one only of said first coatings.
Claim 2
Independent Claim
56 words
The method of making an electrical resistance heating element, comprising: applying to a heat resistant base a fired vitreous ceramic coating containing dispersed metal particles; treating the coating so that it will accept a layer of metal deposited by electroless metal deposition; and applying over said ceramic coating by electroless metal deposition a layer of metal.
Claim 3
Dependent Claim
29 words
The method of claim 3 wherein the treatment applied to said coating comprises partial removal of surface portions to increase surface exposure of said metal particles in said coating.
Claim 4
Dependent Claim
37 words
The method of claim 3 wherein said coating is partially fired to provide a porous surface to receive said metal layer and the treatment applied to said coating comprises sensitizing and activating the surface of said coating.
Claim 5
Independent Claim
79 words
The method of making a heating eleMent, comprising: applying to a heat resistant base a fired vitreous ceramic first coating; applying over said first coating a fired vitreous ceramic second coating containing dispersed metal particles; plating over said second coating a metal layer in contact with metal particles in said second coating, said metal particles being present in sufficient quantity to nucleate said plating metal layer; and applying over said plating metal layer a fired vitreous ceramic protective coating.
Claim 6
Dependent Claim
43 words
The method of claim 1 wherein said dispersed metal particles are protected from oxidation by incorporating in said vitreous ceramic second coating prior to firing a reducing agent activated during the firing of said second coating to minimize oxidation of the metal particles.
Claim 7
Dependent Claim
41 words
The method of claim 1 wherein said heat resistant base comprises a metal panel having a pair of opposite surfaces, said first coating is applied to both said surfaces, and said second coating is applied to one of said first coatings.
Claim 8
Dependent Claim
26 words
The method of claim 1 wherein said second coating is partially removed to increase the surface exposure of said particles prior to applying said metal layer.
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) | 1975-09-26 | 1976-03-27 | 1976-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-26 | 1980-03-27 | 1980-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-26 | 1984-03-27 | 1984-09-26 | $7700.00 | Window Closed / Lapsed |