US2524433A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording
Assignee: Columbian Carbon Co
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Filing: 1947-12-11
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Granted: 1950-10-03
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Expires: 1967-12-11
Abstract
No abstract record available.
Inventors
- 👤 Charles D Downs
- 👤 Martin John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:32
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70626; G11B5/70642; G11B5/70678; Y; Y10; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31971; Y10T428/31993; Y10T428/31996
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
43 words
A LIQUID COATING COMPOSITION COMPRISING A LIQUID FILM-FORMING VEHICLE AND COPPER FERRITE CONTAINING COPPER EQUIVALENT TO ABOUT 27% OF COPPER OXIDE SUSPENDED IN THE VEHICLE, THE COPPER FERRITE BEING PRESENT IN AMOUNT SUFFICIENT TO PRODUCE A RETENTIVITY CAPABLE OF RETAINING A MAGNETIC RECORD.
Claim 2
Dependent Claim
43 words
A LIQUID COATING COMPOSITION COMPRISING A LIQUID FILM-FORMING VEHICLE AND COPPER FERRITE CONTAINING COPPER EQUIVALENT TO ABOUT 27% OF COPPER OXIDE SUSPENDED IN THE VEHICLE, THE COPPER FERRITE BEING PRESENT IN AMOUNT SUFFICIENT TO PRODUCE A RETENTIVITY CAPABLE OF RETAINING A MAGNETIC RECORD.
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) | 1953-10-02 | 1954-04-03 | 1954-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-10-02 | 1958-04-03 | 1958-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-10-02 | 1962-04-03 | 1962-10-03 | $7700.00 | Window Closed / Lapsed |