Patent US2491741A successfully refreshed from Google Patents.
US2491741A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ent office
Assignee: —
•
Filing: —
•
Granted: 1949-12-20
•
Expires: 1966-12-20
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:41
CPC Classifications
C; C07; C07D; C07D489/00; C07D489/02; C07D489/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1672000A
Cited
GB190208640A
Cited
US1064227A
Cited
US1458992A
Cited
US1717585A
Cited
US2081547A
Cited
US2058081A
Cited
US2211630A
Cited
US2223937A
Cited
US2328000A
Cited
US2376313A
Cited
US2406892A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-12-19 | 1953-06-20 | 1953-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-12-19 | 1957-06-20 | 1957-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-12-19 | 1961-06-20 | 1961-12-20 | $7700.00 | Window Closed / Lapsed |