US2940541A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of purifying gases
Assignee: Columbia Southern Chemical Corp
•
Filing: 1956-10-15
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Granted: 1960-06-14
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Expires: 1976-10-15
Abstract
No abstract record available.
Inventors
- 👤 Edwin K Plant
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:32
CPC Classifications
B; B01; B01D; B01D45/00; B01D45/02; C; C22; C22B; C22B1/00; C22B1/02; C22B1/08
Claims Analysis
Total Claims: 0
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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) | 1963-06-14 | 1963-12-14 | 1964-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-06-14 | 1967-12-14 | 1968-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-06-14 | 1971-12-14 | 1972-06-14 | $7700.00 | Window Closed / Lapsed |