US2157879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification and separation of gaseous mixtures
Assignee: Shell Development Co
•
Filing: 1937-08-14
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Granted: 1939-05-09
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Expires: 1957-08-14
Abstract
No abstract record available.
Inventors
- 👤 Ernest W Zublin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:06
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/14; B01D53/1425; B01D53/34; B01D53/46; B01D53/48; B01D53/52; B01D53/526; B01D2257/00; B01D2257/30; B01D2257/304; B01D2257/40; B01D2257/408; B01D2257/50; B01D2257/504
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) | 1942-05-08 | 1942-11-07 | 1943-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-05-08 | 1946-11-07 | 1947-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-05-08 | 1950-11-07 | 1951-05-09 | $7700.00 | Window Closed / Lapsed |