Patent US2933827A successfully refreshed from Google Patents.
US2933827A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Educational device
Assignee: Individual
•
Filing: 1956-07-26
•
Granted: 1960-04-26
•
Expires: 1976-07-26
Abstract
No abstract record available.
Inventors
- 👤 Alberts Cecil Darwin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:49
CPC Classifications
G; G09; G09B; G09B1/00; G09B1/02; G09B1/04; G09B1/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1179813A
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US1571777A
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CH130506A
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US2062157A
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GB450893A
Cited
US2025942A
Cited
US2104515A
Cited
US2088951A
Cited
US2538601A
Cited
US2581839A
Cited
US2556518A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-04-26 | 1963-10-26 | 1964-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-26 | 1967-10-26 | 1968-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-26 | 1971-10-26 | 1972-04-26 | $7700.00 | Window Closed / Lapsed |