US2769640A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Educational mathematical game apparatus
Assignee: Individual
•
Filing: 1953-05-04
•
Granted: 1956-11-06
•
Expires: 1973-05-04
Abstract
No abstract record available.
Inventors
- 👤 Ruth B Elder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:49
CPC Classifications
G; G09; G09B; G09B19/00; G09B19/02; A; A63; A63F; A63F3/00; A63F3/04; A63F3/0415
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US88421A
Cited
US1246152A
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US1400887A
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US1415019A
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US1402807A
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US1655380A
Cited
US1699132A
Cited
US2380106A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-11-06 | 1960-05-07 | 1960-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-11-06 | 1964-05-07 | 1964-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-11-06 | 1968-05-07 | 1968-11-06 | $7700.00 | Window Closed / Lapsed |