Patent US3436491A successfully refreshed from Google Patents.
US3436491A
Expired / Lapsed
US
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Helical scan recorder with tapered drum to prevent oxide build-up
Assignee: Ampex Corp
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Filing: 1966-12-27
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Granted: 1969-04-01
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Expires: 1986-12-27
Abstract
No abstract record available.
Inventors
- 👤 James E Quinn
- 👤 Delmar R Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:28
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/60; G11B15/61
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
82 words
A HELICAL SCANNING ASSEMBLY FOR USE IN MAGNETIC TAPE RECORDING AND REPRODUCING APPARATUS COMPRISING A PAIR OF SUBSTANTIALLY CYLINDRICAL, COAXIAL AND CLOSELY SPACED DRUMS, AND MEANS FOR MOUNTING ONE OF SAID DRUMS FOR ROTATION WITH RESPECT TO THE OTHER OF SAID DRUMS, SAID ROTATABLE DRUM HAVING AN OUTER DIAMETER WITH AN INWARD TAPER IN THE DIRECTION OF THE OTHER OF SAID DRUMS WITH SAID TAPER CONTINUOUSLY EXTENDING TO THE EDGE OF SAID ROTATING DRUM ADJACENT THE OTHER DRUM, WHEREBY THE OUTER DIAM-
Claim 2
Dependent Claim
82 words
A HELICAL SCANNING ASSEMBLY FOR USE IN MAGNETIC TAPE RECORDING AND REPRODUCING APPARATUS COMPRISING A PAIR OF SUBSTANTIALLY CYLINDRICAL, COAXIAL AND CLOSELY SPACED DRUMS, AND MEANS FOR MOUNTING ONE OF SAID DRUMS FOR ROTATION WITH RESPECT TO THE OTHER OF SAID DRUMS, SAID ROTATABLE DRUM HAVING AN OUTER DIAMETER WITH AN INWARD TAPER IN THE DIRECTION OF THE OTHER OF SAID DRUMS WITH SAID TAPER CONTINUOUSLY EXTENDING TO THE EDGE OF SAID ROTATING DRUM ADJACENT THE OTHER DRUM, WHEREBY THE OUTER DIAM-
References Cited (Backward Citations)
US3333753A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-03-31 | 1972-09-30 | 1973-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-03-31 | 1976-09-30 | 1977-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-03-31 | 1980-09-30 | 1981-04-01 | $7700.00 | Window Closed / Lapsed |