US3156784A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic eraser
Assignee: International Business Machines Corp
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Filing: 1961-01-30
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Granted: 1964-11-10
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Expires: 1981-01-30
Abstract
No abstract record available.
Inventors
- 👤 Herbert J Kump
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:07
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/02; G11B5/024
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
A MAGNETIC RECORD ERASER COMPRISING IN COMBINATION, A MOVABLE MAGNETIC RECORD OF EXTENDED SURFACE AND MEANS FOR SUBJECTING SAID RECORD OF SURFACE TO AN ALTERNATING MAGNETIC ERASE FIELD, SAID MEANS COMPRISING ROTOR MEMBER HAVING A PLURALITY OF RADIALLY DISPOSED UNIDIRECTIONAL FLUX PRODUCING POLE ELEMENTS ARRANGED IN UNIFORMLY SPACED CONDITION IN A CIRCUMFERENTIAL MANNER ABOUT THE PERIPHERY OF SAID ROTOR MEMBER, SAID ROTOR MEMBER BEING MOUNTED WITH ITS PERIPHERAL SURFACE PROXIMATE SAID MAGNETIC RECORD SURFACE, AND MEANS FOR ROTATING SAID ROTOR MEMBER IN TIMED RELATION WITH THE MOVEMENT OF SAID RECORD SURFACE WHEREBY SAID POLE ELEMENTS SUBJECTS SUCCESSIVE INCREMENTS OF SAID MAGNETIC SURFACE WHILE IN MOTION TO AN ALTERNATING DAMPED MAGNETIC FIELD VARIATION.
Claim 2
Dependent Claim
112 words
A MAGNETIC RECORD ERASER COMPRISING IN COMBINATION, A MOVABLE MAGNETIC RECORD OF EXTENDED SURFACE AND MEANS FOR SUBJECTING SAID RECORD OF SURFACE TO AN ALTERNATING MAGNETIC ERASE FIELD, SAID MEANS COMPRISING ROTOR MEMBER HAVING A PLURALITY OF RADIALLY DISPOSED UNIDIRECTIONAL FLUX PRODUCING POLE ELEMENTS ARRANGED IN UNIFORMLY SPACED CONDITION IN A CIRCUMFERENTIAL MANNER ABOUT THE PERIPHERY OF SAID ROTOR MEMBER, SAID ROTOR MEMBER BEING MOUNTED WITH ITS PERIPHERAL SURFACE PROXIMATE SAID MAGNETIC RECORD SURFACE, AND MEANS FOR ROTATING SAID ROTOR MEMBER IN TIMED RELATION WITH THE MOVEMENT OF SAID RECORD SURFACE WHEREBY SAID POLE ELEMENTS SUBJECTS SUCCESSIVE INCREMENTS OF SAID MAGNETIC SURFACE WHILE IN MOTION TO AN ALTERNATING DAMPED MAGNETIC FIELD VARIATION.
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) | 1967-11-10 | 1968-05-11 | 1968-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-11-10 | 1972-05-11 | 1972-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-11-10 | 1976-05-11 | 1976-11-10 | $7700.00 | Window Closed / Lapsed |