Patent US3329178A successfully refreshed from Google Patents.
US3472971A
Expired / Lapsed
US
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Magnetic tape duplicating device with fluid pressure applied through head gap
Assignee: International Business Machines Corp
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Filing: 1967-06-28
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Granted: 1969-10-14
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Expires: 1987-06-28
Abstract
No abstract record available.
Inventors
- 👤 Racime J Van Den Berg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:44
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/86; G11B5/865
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2747027A
Cited
US2795651A
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US2747026A
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US2905767A
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GB1001452A
Cited
US3161120A
Cited
US3310792A
Cited
US3320599A
Cited
US3324570A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-13 | 1973-04-14 | 1973-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-13 | 1977-04-14 | 1977-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-13 | 1981-04-14 | 1981-10-14 | $7700.00 | Window Closed / Lapsed |