US4312898A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for making magnetic tape
Assignee: EMAG LLC
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Filing: 1980-09-12
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Granted: 1982-01-26
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Expires: 2000-09-12
Abstract
Abstract A high-precision, metal-faced, calender roll which can be readily reconditioned by thermal means. The calender roll has a surface which is advantageously formed of that class of nickel-titanium alloys having thermally-responsive shape memory properties. The calender roll is particularly useful in avoiding time consuming repair and undesirably prolonged runs in making high quality magnetic tape.
Inventors
- 👤 Gordon L. McDaniel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:51
CPC Classifications
C; C22; C22F; C22F1/00; C22F1/006; G; G11; G11B; G11B5/00; G11B5/84
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
64 words
In a process for continuously making, on a web-processing line, a web of magnetic recording media of the type wherein a magnetic powder is dispersed in a coating of resin binder to form said magnetic recording media and carried on a sheet of organic resin film through a calender apparatus comprising a compliant roll and a second roll, the improvement comprising the steps of
Claim 2
Dependent Claim
64 words
In a process for continuously making, on a web-processing line, a web of magnetic recording media of the type wherein a magnetic powder is dispersed in a coating of resin binder to form said magnetic recording media and carried on a sheet of organic resin film through a calender apparatus comprising a compliant roll and a second roll, the improvement comprising the steps of
Claim 3
Dependent Claim
71 words
calendering said web of magnetic recording media against a compliant calender roll surface formed of a sleeve of a shape-memory alloy, to achieve a smoothing and compression thereof, until said roll becomes damaged. 2. thereupon heating said sleeve to a transformation temperature to remove said damage while maintaining said roll in place on said processing line; and then 3. cooling said roll; and 4. resuming calendering of said magnetic recording member.
Claim 4
Dependent Claim
71 words
calendering said web of magnetic recording media against a compliant calender roll surface formed of a sleeve of a shape-memory alloy, to achieve a smoothing and compression thereof, until said roll becomes damaged. 2. thereupon heating said sleeve to a transformation temperature to remove said damage while maintaining said roll in place on said processing line; and then 3. cooling said roll; and 4. resuming calendering of said magnetic recording member.
Claim 5
Dependent Claim
28 words
A process as defined in claim 1 wherein said metal sleeve is a NITINOL alloy and said damage is removable at a temperature of 125° C. or less.
Claim 6
Dependent Claim
26 words
A process as defined in claim 2 wherein said sleeve is heated to remove damage by application of radiant heat to the exterior of said sleeve.
References Cited (Backward Citations)
US3398011A
Cited
US4100326A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-01-25 | 1985-07-27 | 1986-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-01-25 | 1989-07-27 | 1990-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-01-25 | 1993-07-27 | 1994-01-26 | $7700.00 | Window Closed / Lapsed |