Patent US2840440A successfully refreshed from Google Patents.
US2840440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording and pickup system
Assignee: Individual
•
Filing: 1953-10-07
•
Granted: 1958-06-24
•
Expires: 1973-10-07
Abstract
No abstract record available.
Inventors
- 👤 Donald J Mclaughlin
- 👤 Frederick R Fluhr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:11
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/488; G11B5/4886; G11B5/127; G11B5/1278; G11B5/265; G11B5/29; G11B5/295
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
GB512766A
Cited
US2643130A
Cited
US2614169A
Cited
US2750579A
Cited
US2685492A
Cited
US2714133A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-23 | 1961-12-23 | 1962-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-23 | 1965-12-23 | 1966-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-23 | 1969-12-23 | 1970-06-24 | $7700.00 | Window Closed / Lapsed |