Patent US3543389A successfully refreshed from Google Patents.
US3543389A
Expired / Lapsed
US
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Method for cleaning metal surfaces
Assignee: AT&T Inc
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Filing: 1969-07-07
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Granted: 1970-12-01
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Expires: 1989-07-07
Abstract
No abstract record available.
Inventors
- 👤 Gerard A Baldauf
- 👤 Michael J Elkind
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:42
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/14; C23G1/20; C23F; C23F3/00; C23F3/04; C23F3/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2287050A
Cited
US2098744A
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US3031747A
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US3063944A
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US3199189A
Cited
US3242093A
Cited
US3242090A
Cited
US3297580A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-30 | 1974-06-01 | 1974-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-30 | 1978-06-01 | 1978-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-30 | 1982-06-01 | 1982-12-01 | $7700.00 | Window Closed / Lapsed |