Patent US2921840A successfully refreshed from Google Patents.
US2921840A
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US
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Process for preparation of carbon monoxide
Assignee: Shawinigan Chemicals Ltd
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Filing: 1956-11-09
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Granted: 1960-01-19
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Expires: 1976-11-09
Abstract
No abstract record available.
Inventors
- 👤 Herbert S Johnson
- 👤 Arthur H Andersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:20
CPC Classifications
B; B01; B01J; B01J8/00; B01J8/18; B01J8/24; B01J8/42; C; C01; C01B; C01B32/00; C01B32/40; Y; Y10; Y10S; Y10S118/00; Y10S118/05
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) | 1963-01-18 | 1963-07-20 | 1964-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-18 | 1967-07-20 | 1968-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-18 | 1971-07-20 | 1972-01-19 | $7700.00 | Window Closed / Lapsed |