US3171130A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording
Assignee: Ex-Cell-O Corp
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Filing: 1961-11-20
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Granted: 1965-02-23
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Expires: 1981-11-20
Abstract
No abstract record available.
Inventors
- 👤 Donald M Humphreys
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:07
CPC Classifications
G; G11; G11B; G11B5/00
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
83 words
IN COMBINATION: A PIEZOELECTRIC CRYSTAL CAPABLE OF VIBRATING DURING THE PERIOD OF TIME THAT AN ELECTROMOTIVE FORCE IS APPLIED TO SAID CRYSTAL, WHEREBY A WAVE BEAM IS PRODUCED BY SAID CRYSTAL, SAID WAVE BEAM BEING TRANSMITTED THROUGH THE AMBIENT; SAID CRYSTAL HAVING A WAVE BEAM EMITTING FACE CONCAVELY CURVED IN THE SHAPE OF A SEGMENT OF A SPHERE CAUSING SAID WAVE BEAM TO CONVERGE TO A FOCAL POINT COINCIDENT WITHT THE CENTER OF THE SPHERE; AND RECORD MEDIUM HAVING A MAGNETIC SURFACE THEREON
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) | 1968-02-23 | 1968-08-24 | 1969-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-02-23 | 1972-08-24 | 1973-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-02-23 | 1976-08-24 | 1977-02-23 | $7700.00 | Window Closed / Lapsed |