US3985916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing and densifying chrome plated metal parts
Assignee: Kaman Sciences Corp
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Filing: 1975-10-23
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Granted: 1976-10-12
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Expires: 1995-10-23
Abstract
Abstract Porous chrome plated surfaces are densified by treating the surface with a chromic acid solution and heating the treated surface to convert the chromic acid to chromic oxide. Repeated treating and conversion steps may be used to completely fill the pores and cracks.
Inventors
- 👤 Peter K. Church
- 👤 Oliver J. Knutson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:47
CPC Classifications
C; C25; C25D; C25D5/00; C25D5/48
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
78 words
A method of treating metal parts having chrome plating thereon wherein said chrome plating contains pores and cracks comprising the steps of: applying a chromic acid solution having a specific gravity of from 1.64-1.66 to said chrome plated metal parts to penetrate the pores and cracks of the chrome plating; and heating the chrome plated metal parts to at least 600° F but below the vitrification temperature of chrome oxide to convert the chromic acid to chrome oxide.
Claim 2
Independent Claim
78 words
A method of treating metal parts having chrome plating thereon wherein said chrome plating contains pores and cracks comprising the steps of: applying a chromic acid solution having a specific gravity of from 1.64-1.66 to said chrome plated metal parts to penetrate the pores and cracks of the chrome plating; and heating the chrome plated metal parts to at least 600° F but below the vitrification temperature of chrome oxide to convert the chromic acid to chrome oxide.
Claim 3
Dependent Claim
19 words
A method according to claim 1 wherein the parts are given a final heat treatment at about 1,250° F.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein said step of heating comprises the step of heating by induction heating.
Claim 5
Dependent Claim
36 words
A method according to claim 1 wherein said chromic acid solution contains an amount of carbon black in an amount equivalent to 0.05-0.5 percent by weight of the chromic acid present in the chromic acid solution.
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) | 1979-10-12 | 1980-04-12 | 1980-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-12 | 1984-04-12 | 1984-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-12 | 1988-04-12 | 1988-10-12 | $7700.00 | Window Closed / Lapsed |