Patent US4198218A successfully refreshed from Google Patents.
Patent US3380680A successfully refreshed from Google Patents.
US3380680A
Expired / Lapsed
US
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Method and apparatus for maintaining proper tape tension on a tape recorder
Assignee: Ampex Corp
•
Filing: 1965-12-10
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Granted: 1968-04-30
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Expires: 1985-12-10
Abstract
No abstract record available.
Inventors
- 👤 Dunsheath Thomas Judson
- 👤 Johnson Delmar Ronald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:26
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/43
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US558426A
Cited
US3137767A
Cited
US3076618A
Cited
US3091410A
Cited
US3219246A
Cited
US3270973A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-04-30 | 1971-10-30 | 1972-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-04-30 | 1975-10-30 | 1976-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-04-30 | 1979-10-30 | 1980-04-30 | $7700.00 | Window Closed / Lapsed |