Patent US4933303A successfully refreshed from Google Patents.
US1960348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filtration of acid sludge
Assignee: IG Farbenindustrie AG
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Filing: 1932-07-30
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Granted: 1934-05-29
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Expires: 1952-07-30
Abstract
No abstract record available.
Inventors
- 👤 Emmerich V Pongratz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:59
CPC Classifications
C; C01; C01B; C01B17/00; C01B17/69; C01B17/90; C01B17/92
Claims Analysis
Total Claims: 0
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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) | 1937-05-28 | 1937-11-27 | 1938-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-05-28 | 1941-11-27 | 1942-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-05-28 | 1945-11-27 | 1946-05-29 | $7700.00 | Window Closed / Lapsed |