US3700499A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording element
Assignee: Wyeth Holdings LLC
•
Filing: 1969-06-17
•
Granted: 1972-10-24
•
Expires: 1989-06-17
Abstract
Abstract A MAGNETIC RECORDING ELEMENT COMPRISING A SUPPORT HAVING THEREON A RECORDING FILM OF PARTICULATE MATERIAL CONSISTING ESSENTIALLY OF MAGNETIC PARTICLES HAVING AN IRON CORE WITH AN LAYER OF IRON NITRIDE, FE4N, COATING.
Inventors
- 👤 Gottfried C Haack
- 👤 Lindley Clair Beegle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/712; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/256
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |