Patent DE433487C successfully refreshed from Google Patents.
Patent US3542971A successfully refreshed from Google Patents.
US3542971A
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US
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Magnetic transducer having positioning surfaces
Assignee: Individual
•
Filing: 1967-08-21
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Granted: 1970-11-24
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Expires: 1987-08-21
Abstract
No abstract record available.
Inventors
- 👤 Dennis Willard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:06
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/1272; G11B5/147; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49055; Y10T29/4906; Y10T29/49066
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2668878A
Cited
US2754569A
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US2868889A
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US2895015A
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US2939920A
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GB769651A
Cited
US2946859A
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GB889793A
Cited
GB889794A
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US3233046A
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US3426338A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-23 | 1974-05-25 | 1974-11-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-23 | 1978-05-25 | 1978-11-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-23 | 1982-05-25 | 1982-11-24 | $7700.00 | Window Closed / Lapsed |