US2983053A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Education machine of the question and hidden answer variety
Assignee: Individual
•
Filing: 1957-05-20
•
Granted: 1961-05-09
•
Expires: 1977-05-20
Abstract
No abstract record available.
Inventors
- 👤 Thomas L Bartholomew
- 👤 Carl S Kuhn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:24
CPC Classifications
G; G09; G09B; G09B7/00; G09B7/06; G09B7/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2149459A
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US2148259A
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US2545381A
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US2591327A
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US2690621A
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US2656618A
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US2697882A
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US2835052A
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US2877568A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-05-08 | 1964-11-07 | 1965-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-05-08 | 1968-11-07 | 1969-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-05-08 | 1972-11-07 | 1973-05-09 | $7700.00 | Window Closed / Lapsed |