US3546793A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Educational apparatus
Assignee: Adtech Inc
•
Filing: 1968-06-05
•
Granted: 1970-12-15
•
Expires: 1988-06-05
Abstract
No abstract record available.
Inventors
- 👤 Thomas H Roelofs
- 👤 Edward J Weldon Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:25
CPC Classifications
G; G09; G09B; G09B23/00; G09B23/06; G09B23/18; G09B23/183; G09B23/186
Claims Analysis
Total Claims: 0
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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) | 1973-12-14 | 1974-06-15 | 1974-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-12-14 | 1978-06-15 | 1978-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-12-14 | 1982-06-15 | 1982-12-15 | $7700.00 | Window Closed / Lapsed |