US3501851A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for teaching
Assignee: PHI TECHNOLOGIES Inc
•
Filing: 1967-07-11
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Granted: 1970-03-24
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Expires: 1987-07-11
Abstract
No abstract record available.
Inventors
- 👤 David D Price Jr
- 👤 William B Huckabay
- 👤 Ford C Price
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:55
CPC Classifications
G; G09; G09B; G09B7/00; G09B7/02; G09B7/04
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) | 1973-03-23 | 1973-09-22 | 1974-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-23 | 1977-09-22 | 1978-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-23 | 1981-09-22 | 1982-03-24 | $7700.00 | Window Closed / Lapsed |