US2931864A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Colinear double channel magnetic recorder and reproducer head
Assignee: Michigan Magnetics Inc
•
Filing: 1957-04-19
•
Granted: 1960-04-05
•
Expires: 1977-04-19
Abstract
No abstract record available.
Inventors
- 👤 William D Moehring
- 👤 Charles F Murphy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:30
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/29
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2563445A
Cited
FR884881A
Cited
US2413108A
Cited
FR1055860A
Cited
US2668878A
Cited
US2769866A
Cited
US2756280A
Cited
FR1113815A
Cited
FR1112823A
Cited
US2800534A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-04-05 | 1963-10-05 | 1964-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-04-05 | 1967-10-05 | 1968-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-04-05 | 1971-10-05 | 1972-04-05 | $7700.00 | Window Closed / Lapsed |