US2443468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-taught educational clock
Assignee: Individual
•
Filing: 1945-03-03
•
Granted: 1948-06-15
•
Expires: 1965-03-03
Abstract
No abstract record available.
Inventors
- 👤 Ira C Madden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:21
CPC Classifications
G; G09; G09B; G09B19/00; G09B19/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US110213A
Cited
US510178A
Cited
US723288A
Cited
US802807A
Cited
US1276344A
Cited
US1356929A
Cited
US1972206A
Cited
US2037966A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-06-15 | 1951-12-15 | 1952-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-06-15 | 1955-12-15 | 1956-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-06-15 | 1959-12-15 | 1960-06-15 | $7700.00 | Window Closed / Lapsed |