Patent US3478441A successfully refreshed from Google Patents.
US3478441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Teaching aid for self instruction and testing
Assignee: ZADIG PATENTS
•
Filing: 1967-12-05
•
Granted: 1969-11-18
•
Expires: 1987-12-05
Abstract
No abstract record available.
Inventors
- 👤 Ernest A Zadig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:44
CPC Classifications
G; G09; G09B; G09B7/00; G09B7/06; G09B7/063
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-11-17 | 1973-05-19 | 1973-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-11-17 | 1977-05-19 | 1977-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-11-17 | 1981-05-19 | 1981-11-18 | $7700.00 | Window Closed / Lapsed |