Patent US3470020A successfully refreshed from Google Patents.
US3470020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making a magnetic film
Assignee: International Business Machines Corp
•
Filing: 1965-12-20
•
Granted: 1969-09-30
•
Expires: 1985-12-20
Abstract
No abstract record available.
Inventors
- 👤 Lee J Boudreaux
- 👤 Barry L Flur
- 👤 Kenneth B Scow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:02
CPC Classifications
H; H01; H01F; H01F10/00; H01F10/26; H01F10/28; H01F10/30; H01F41/00; H01F41/14
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1972-09-29 | 1973-03-31 | 1973-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-09-29 | 1977-03-31 | 1977-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-09-29 | 1981-03-31 | 1981-09-30 | $7700.00 | Window Closed / Lapsed |