US3963530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stainless steels coated with black oxides
Assignee: Coral Chemical Co
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Filing: 1974-10-24
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Granted: 1976-06-15
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Expires: 1994-10-24
Abstract
Abstract A firmly adherent black oxide coating for chromium-containing martensitic and ferritic stainless steel substrates, particularly windshield wiper blade assemblies, consisting essentially of (Fe,Cr) 2 O 3 and Fe 3 O 4 .
Inventors
- 👤 Thomas J. Smollett
- 👤 Bozidar Stipanovic
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:42
CPC Classifications
C; C23; C23C; C23C22/00; C23C22/70; C23C22/72; B; B60; B60S; B60S1/00; B60S1/02; B60S1/04; B60S1/32; B60S1/38; B60S1/3801; F; F24; F24S; F24S70/00; F24S70/20; F24S70/25; Y; Y02; Y02E; Y02E10/00; Y02E10/40; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
47 words
A chromium-containing martensitic or ferritic stainless steel substrate coated with a firmly adherent compact and smooth black oxide coating consisting essentially of a substantial amount of sodium and (Fe,Cr) 2 O 3 and Fe 3 O 4 of a thickness from about 1.5 to about 4.5 microns.
Claim 2
Dependent Claim
47 words
A chromium-containing martensitic or ferritic stainless steel substrate coated with a firmly adherent compact and smooth black oxide coating consisting essentially of a substantial amount of sodium and (Fe,Cr) 2 O 3 and Fe 3 O 4 of a thickness from about 1.5 to about 4.5 microns.
Claim 3
Dependent Claim
25 words
The substrate of claim 1 containing a coating wherein up to 25% of sodium is found in the uppermost layer of the black oxide coating.
Claim 4
Dependent Claim
16 words
The substrate of claim 1 wherein said substrate is a component of a windshield wiper assembly.
Claim 5
Dependent Claim
12 words
The substrate of claim 3 wherein said substrate is an architectural panel.
Claim 6
Dependent Claim
17 words
The substrate of claim 1 wherein said substrate is a component of a solar energy absorptive device.
Claim 7
Dependent Claim
19 words
The substrate of claim 1 wherein the thickness of the coating is from about 2 to about 4 microns.
References Cited (Backward Citations)
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US2537830A
Cited
US2537035A
Cited
US2542994A
Cited
US2618578A
Cited
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Cited
US3645802A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-15 | 1979-12-15 | 1980-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-15 | 1983-12-15 | 1984-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-15 | 1987-12-15 | 1988-06-15 | $7700.00 | Window Closed / Lapsed |