US2461926A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Educational device
Assignee: Individual
•
Filing: 1946-02-18
•
Granted: 1949-02-15
•
Expires: 1966-02-18
Abstract
No abstract record available.
Inventors
- 👤 Winfield P Russell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:39
CPC Classifications
G; G09; G09B; G09B1/00; G09B1/02; G09B1/16; G09B1/18; G09B1/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US52758A
Cited
US69482A
Cited
US1158774A
Cited
US1256224A
Cited
GB136423A
Cited
US1391986A
Cited
US1519554A
Cited
US1470845A
Cited
FR789526A
Cited
US2204931A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-02-15 | 1952-08-16 | 1953-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-02-15 | 1956-08-16 | 1957-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-02-15 | 1960-08-16 | 1961-02-15 | $7700.00 | Window Closed / Lapsed |