Patent US3564520A successfully refreshed from Google Patents.
US3564520A
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US
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Magnetic head assembly
Assignee: Ampex Corp
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Filing: 1963-12-02
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Granted: 1971-02-16
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Expires: 1983-12-02
Abstract
Abstract THIS INVENTION RELATES TO A MAGNETIC HEAD ASSEMBLY AND TO A METHOD FOR MANUFACTURING SUCH AN ASSEMBLY. MORE PARTICULARLY THIS INVENTION RELATES TO A LONGITUDINAL TYPE OF MAGNETIC HEAD ASSEMBLY WHEREIN A METAL BODY INCLUDES AN INTERNAL CAVITY WITH A RADIUSED GROOVE SURFACE WHICH RECEIVES A RADIUSED CORE HAVING SUBSTANTIALLY THE SAME RADIUS OF CURVATURE AS THE GROOVE SURFACE.
Inventors
- 👤 Robert A Michaud
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:53
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/187; G11B5/29
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |