US3015628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferroso-ferric oxide for magnetic impulse record members
Assignee: C K Williams & Co
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Filing: 1960-12-07
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Granted: 1962-01-02
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Expires: 1980-12-07
Abstract
No abstract record available.
Inventors
- 👤 Joseph W Ayers
- 👤 Robert A Stephens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:34
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70678; G11B5/70684
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
115 words
A MAGNETIC IMPULSE RECORD MEMBER HAVING A UTILIZABLE SIGNAL OUTPUT OVER THE WHOLE FREQUENCY RANGE UP TO 20,000 CYCLES PER SECOND COMPRISING, A NON-MAGNETIC STRIP HAVING THEREON AN ATTACHED TRACK CONTAINING A BINDING MEDIUM HAVING THEREIN A SYNTHETIC FERROSO-FERRIC OXIDE FORMED FROM A SYNTHETIC, FERRO-MAGNETIC GAMMA FERRIC OXIDE MONOHYDRATE, SAID FERROS-FERRIC OXIDE CONSISTING ESSENTIALLY OF VERY FINE-GRAINED, PLATE-LIKE CRYSTALLINE PARTICLES HAVING A LENGTH OF NOT MORE THAN FIVE MICRONS, ALSO HAVING A LENGTH TO WIDTH RATIO OF MORE THAN 5 TO 1 AND A WIDTH TO THICKNESS RATIO OF AT LEAST 3 TO 1 AND HAVING A COERCIVITY OF FROM ABOUT 250 TO 600 OERSTEDS AND A RETENTIVY OF FROM ABOUT 1500 TO 2500 GAUSS.
References Cited (Backward Citations)
US2694656A
Cited
GB675195A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1965-01-01 | 1965-07-03 | 1966-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1969-01-01 | 1969-07-03 | 1970-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1973-01-01 | 1973-07-03 | 1974-01-02 | $7700.00 | Window Closed / Lapsed |