US3340538A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic identification code recording
Assignee: Northrop Grumman Guidance and Electronics Co Inc
•
Filing: 1963-10-31
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Granted: 1967-09-05
•
Expires: 1983-10-31
Abstract
No abstract record available.
Inventors
- 👤 Donald S Oliver
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:35
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B5/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
72 words
A MAGNETIC RECORDING DEVICE FOR PRODUCING A RADIAL MAGNETIC FIELD COMPRISING: A SUBSTANTIALLY CIRCULAR RECORDING HEAD HAVING A PAIR OF WIDELY SPACED POLE PIECES, BOTH OF WHICH HAVE NEEDLE SHAPED PORTIONS WITH THE POINT DEFINING A GAP; MEANS ENERGIZING THE RECORDING HEAD TO PRODUCE OPPOSING POLARITIES IN EACH NEEDLE SHAPED PORTION; AND A RELATIVELY THIN FILM OF MAGNETIZABLE MATERIAL IN THE GAP AND IN CLOSE PROXIMITY TO ONLY ONE NEEDLE SHAPED PORTION.
Claim 2
Dependent Claim
72 words
A MAGNETIC RECORDING DEVICE FOR PRODUCING A RADIAL MAGNETIC FIELD COMPRISING: A SUBSTANTIALLY CIRCULAR RECORDING HEAD HAVING A PAIR OF WIDELY SPACED POLE PIECES, BOTH OF WHICH HAVE NEEDLE SHAPED PORTIONS WITH THE POINT DEFINING A GAP; MEANS ENERGIZING THE RECORDING HEAD TO PRODUCE OPPOSING POLARITIES IN EACH NEEDLE SHAPED PORTION; AND A RELATIVELY THIN FILM OF MAGNETIZABLE MATERIAL IN THE GAP AND IN CLOSE PROXIMITY TO ONLY ONE NEEDLE SHAPED PORTION.
References Cited (Backward Citations)
US2840440A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-09-04 | 1971-03-06 | 1971-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-09-04 | 1975-03-06 | 1975-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-09-04 | 1979-03-06 | 1979-09-05 | $7700.00 | Window Closed / Lapsed |