US2449295A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of autoregenerative catalysts
Assignee: Shell Development Co
•
Filing: 1943-03-19
•
Granted: 1948-09-14
•
Expires: 1963-03-19
Abstract
No abstract record available.
Inventors
- 👤 Carlos L Gutzeit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:45
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/70; B01J23/76; B01J23/84; B01J23/74
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-09-14 | 1952-03-15 | 1952-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-09-14 | 1956-03-15 | 1956-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-09-14 | 1960-03-15 | 1960-09-14 | $7700.00 | Window Closed / Lapsed |