Patent US3304627A successfully refreshed from Google Patents.
US3304627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Educational device
Assignee: Individual
•
Filing: 1966-02-04
•
Granted: 1967-02-21
•
Expires: 1986-02-04
Abstract
No abstract record available.
Inventors
- 👤 Richard T Cella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:07
CPC Classifications
G; G09; G09B; G09B3/00; G09B3/06; G09B3/08
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1351362A
Cited
US1587685A
Cited
US1636991A
Cited
US2595980A
Cited
US3114212A
Cited
US3166860A
Cited
US3180310A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-02-20 | 1970-08-22 | 1971-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-02-20 | 1974-08-22 | 1975-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-02-20 | 1978-08-22 | 1979-02-21 | $7700.00 | Window Closed / Lapsed |