US2878092A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Educational system and apparatus
Assignee: Individual
•
Filing: 1955-04-29
•
Granted: 1959-03-17
•
Expires: 1975-04-29
Abstract
No abstract record available.
Inventors
- 👤 Mitchell Leuelle O'neal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:48
CPC Classifications
G; G09; G09B; G09B29/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US393934A
Cited
US468929A
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US151182A
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US676127A
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US637456A
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US880023A
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US1100983A
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US1142651A
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US1140589A
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US1337937A
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US1392726A
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US1497379A
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US1735078A
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US2072511A
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US2295954A
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US2362877A
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US2569254A
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US2700587A
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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) | 1962-03-16 | 1962-09-15 | 1963-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-03-16 | 1966-09-15 | 1967-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-03-16 | 1970-09-15 | 1971-03-17 | $7700.00 | Window Closed / Lapsed |