Patent US3820701A successfully refreshed from Google Patents.
US3820701A
Expired / Lapsed
US
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Differential tape drive
Assignee: 3M Co
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Filing: 1973-04-23
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Granted: 1974-06-28
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Expires: 1993-04-23
Abstract
Abstract A differential tape drive comprising a hard surfaced capstan, a hard surfaced idler roller having a diameter greater than that of the capstan and a resilient surfaced transfer roller forced into contact with the capstan and the idler roller. The transfer roller is driven by the capstan and drives the idler roller to tension a length of magnetic tape extending from the nip between the idler roller and the transfer roller to the nip between the capstan and the transfer roller.
Inventors
- 👤 K Clunis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:16
CPC Classifications
G; G11; G11B; G11B15/00; G11B15/18; G11B15/26; G11B15/28; G11B15/295
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
119 words
A differential tape drive comprising: a hard surfaced capstan, a hard surfaced idler roller supported for free rotation about an axis spaced from and parallel to the axis of said capstan, said idler roller having a diameter greater than that of said capstan, a resilient surfaced transfer roller supported for free rotation about an axis spaced from and parallel to the axis of said capstan and said idler, said transfer roller having a diameter greater than the spacing between said capstan and said idler roller, and means for applying a force of a predetermined magnitude at the axis of said transfer roller to urge said transfer roller with equal force into engagement with said capstan and said idler roller.
Claim 2
Dependent Claim
119 words
A differential tape drive comprising: a hard surfaced capstan, a hard surfaced idler roller supported for free rotation about an axis spaced from and parallel to the axis of said capstan, said idler roller having a diameter greater than that of said capstan, a resilient surfaced transfer roller supported for free rotation about an axis spaced from and parallel to the axis of said capstan and said idler, said transfer roller having a diameter greater than the spacing between said capstan and said idler roller, and means for applying a force of a predetermined magnitude at the axis of said transfer roller to urge said transfer roller with equal force into engagement with said capstan and said idler roller.
Claim 3
Dependent Claim
25 words
The differential tape dRive of claim 1 wherein said resilient surface of said transfer roller has a durometer in the range from 55 to 65.
Claim 4
Dependent Claim
52 words
The differential tape drive of claim 2 wherein said capstan and said idler roller engage the same axial height of said transfer roller and wherein said predetermined magnitude force is from 13 to 37 ounces per inch of axial engaging height of said transfer roller with said capstan and said idler roller.
Claim 5
Dependent Claim
20 words
The differential tape drive of claim 1 wherein said transfer roller is self-aligning with said capstan and said idler roller.
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) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |