US2981607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-destructive tests for distinguishing between objects formed of dissimilar metals
Assignee: AT&T Inc
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Filing: 1958-07-11
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Granted: 1961-04-25
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Expires: 1978-07-11
Abstract
No abstract record available.
Inventors
- 👤 Jr John Danaczko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:32
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/20; G01N33/202; G01N33/2028
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
82 words
A NON-DESTRUCTIVE METHOD OF DISTINGUISHING BETWEEN ARTICLES OF SILVER OR PALLADIUM WHICH COMPRISES THE STEPS OF RUBBING THE ARTICLES ON A SHEET OF ALUMINA-IMPREGNATED FILTER PAPER UNTIL VISIBLE MARKS APPEAR THEREON, AND THEN TREATING SAID VISIBLE MARKS WITH A SOLUTION CONTAINING BY WEIGHT: 25 TO 50 PERCENT DISTILLED WATER, 20 TO 40 PERCENT (NH4)2S2O8, AND 20 TO 50 PERCENT NH4IH WHEREBY THE VISIBLE MARKS CAUSED BY THE SILVER ARTICLES WILL BE DISSOLVED WHILE THOSE CAUSED BY THE PALLADIUM ARTICLES WILL REMAIN UNCHANGED.
Claim 2
Dependent Claim
82 words
A NON-DESTRUCTIVE METHOD OF DISTINGUISHING BETWEEN ARTICLES OF SILVER OR PALLADIUM WHICH COMPRISES THE STEPS OF RUBBING THE ARTICLES ON A SHEET OF ALUMINA-IMPREGNATED FILTER PAPER UNTIL VISIBLE MARKS APPEAR THEREON, AND THEN TREATING SAID VISIBLE MARKS WITH A SOLUTION CONTAINING BY WEIGHT: 25 TO 50 PERCENT DISTILLED WATER, 20 TO 40 PERCENT (NH4)2S2O8, AND 20 TO 50 PERCENT NH4IH WHEREBY THE VISIBLE MARKS CAUSED BY THE SILVER ARTICLES WILL BE DISSOLVED WHILE THOSE CAUSED BY THE PALLADIUM ARTICLES WILL REMAIN UNCHANGED.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-24 | 1964-10-24 | 1965-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-24 | 1968-10-24 | 1969-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-24 | 1972-10-24 | 1973-04-25 | $7700.00 | Window Closed / Lapsed |