US1975663A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for making ketene
Assignee: Carbide and Carbon Chemicals Corp
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Filing: 1932-02-05
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Granted: 1934-10-02
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Expires: 1952-02-05
Abstract
No abstract record available.
Inventors
- 👤 George H Reid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:16
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/87; C07C45/88
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) | 1937-10-01 | 1938-04-02 | 1938-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1941-10-01 | 1942-04-02 | 1942-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1945-10-01 | 1946-04-02 | 1946-10-02 | $7700.00 | Window Closed / Lapsed |