Patent US3601980A successfully refreshed from Google Patents.
Patent US1905883A successfully refreshed from Google Patents.
US1905883A
Expired / Lapsed
US
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Apparatus for contacting solid and gaseous materials
Assignee: Dow Chemical Co
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Filing: 1930-02-13
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Granted: 1933-04-25
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Expires: 1950-02-13
Abstract
No abstract record available.
Inventors
- 👤 Edwin O Barstow
- 👤 Sheldon B Heath
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:52
CPC Classifications
F; F26; F26B; F26B17/00; F26B17/12; F26B17/14; F26B17/1408; F26B17/1416; F26B17/16
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) | 1936-04-24 | 1936-10-24 | 1937-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1940-04-24 | 1940-10-24 | 1941-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1944-04-24 | 1944-10-24 | 1945-04-25 | $7700.00 | Window Closed / Lapsed |