US3748712A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tarnish resistant plating for silver articles
Assignee: NEW FRANKLIN MINT
•
Filing: 1971-03-30
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Granted: 1973-07-31
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Expires: 1991-03-30
Abstract
Abstract Articles made of silver or silver alloys containing a high percentage of silver, and particularly silver medals and medallions may be rendered tarnish resistant while still possessing a color closely matched to the original article by plating with a rhodium-platinum alloy. The alloy plating has a thickness of 1 to 50 microinches, and preferably 1 to 10 microinches, and comprises about 1 to 9 weight percent platinum, and preferably 3 to 5 weight percent platinum, with the remainder being rhodium. It is also necessary to provide the silver article with a flash plating of yellow gold prior to plating with the rhodium-platinum alloy in order to obtain the optimum color match.
Inventors
- 👤 K Karawin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:22
CPC Classifications
A; A44; A44C; A44C3/00; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/923; Y10S428/924; Y10S428/926; Y10S428/9265; Y10S428/927; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12889
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
17 words
A tarnish resistant silver article in accordance with claim 1 wherein said base is a silver medal.
Claim 2
Dependent Claim
24 words
A tarnish resistant silver article in accordance with claim 2, wherein said flash layer has a thickness of from about 1 to 30 microinches.
Claim 3
Dependent Claim
36 words
A tarnish resistant silver article in accordance with claim 3 wherein said alloy layer has a thickness of about 1 to 10 microinches and said flash layer has a thickness of about 1 to 7 microinches.
Claim 4
Dependent Claim
30 words
A tarnish resistant silver article in accordance with claim 4 wherein said alloy layer comprises about 95 to 97 weight percent rhodium and about 3 to 5 weight percent platinum.
Claim 5
Dependent Claim
29 words
A tarnish resistant article in accordance with claim 5 wherein said silver base is sterling silver and said plating has an outward visual appearance substantially identical to sterling silver.
Claim 6
Dependent Claim
28 words
A tarnish resistant silver article in accordance with claim 6 wherein said alloy layer and said flash layer each have a thickness of about 2 to 3 microinches.
References Cited (Backward Citations)
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Cited
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US1991995A
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Cited
US2364674A
Cited
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US3515651A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |