Patent US3001891A successfully refreshed from Google Patents.
US3001891A
Expired / Lapsed
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Method and apparatus for preparing magnetic recording elements
Assignee: RCA Corp
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Filing: 1959-06-30
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Granted: 1961-09-26
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Expires: 1979-06-30
Abstract
No abstract record available.
Inventors
- 👤 Arthur I Stoller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:47
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/842; G11B5/845; H; H02; H02P; H02P9/00; H02P9/14; H02P9/26
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
114 words
IN THE MANUFACTURE OF MAGNETIC RECORDING ELEMENTS OF THE TYPE HAVING A SOLID LAYER OF MAGNETIC PARTICLES IN A NON-MAGNETIC BINDER, AND HAVING A PREDETERMINED DIRECTION OF RECORDING AND PLAYBACK ALONG SAID LAYER, THE METHOD COMPRISING COATING A SURFACE OF A SUPPORT WITH A LIQUID LAYER INCLUDING SAID MAGNETIC PARTICLES AND SAID BINDER, SIMULTANEOUSLY APPLYING SUPERIMPOSED MAGNETIC FIELDS INCLUDING AN A.C. MAGNETIC FIELD AND A D.C. MAGNETIC FIELD TO SAID LAYER WHILE STILL IN A LIQUID CONDITION, SAID A.C. MAGNETIC FIELD HAVING A STRENGTH SUFFICIENT TO MOVE SAID PARTICLES IN SAID LIQUID LAYER, SAID D.C. MAGNETIC FIELD HAVING A MAJOR COMPONENT PARALLEL TO SAID DIRECTION FOR RECORDING AND PLAYBACK, AND THEN SOLIDIFYING SAID LAYER.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-09-25 | 1965-03-27 | 1965-09-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-09-25 | 1969-03-27 | 1969-09-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-09-25 | 1973-03-27 | 1973-09-26 | $7700.00 | Window Closed / Lapsed |