US4514937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the surface treatment of magnetic recording media
Assignee: BASF SE
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Filing: 1982-01-15
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Granted: 1985-05-07
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Expires: 2002-01-15
Abstract
Abstract A method and apparatus for burnishing the surface of magnetic recording media, wherein there is relative movement between the surface to be burnished and the abrasive member, and the abrasive member is urged against the said surface, the pressure applied being increased over a period of time or at a plurality of locations, and then being reduced again.
Inventors
- 👤 Manfred Gehrung
- 👤 Klaus Schoettle
- 👤 Helmut Kreissler
- 👤 Peter Rudolf
- 👤 Joachim Hack
- 👤 Friedrich Anslinger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:06
CPC Classifications
B; B24; B24B; B24B7/00; B24B7/10; B24B7/12; B24B7/13; B24B21/00; B24B21/04; B24B7/16
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
142 words
A method of treating the surface of magnetic recording media by burnishing, comprising: applying relative movement between the surface to be burnished and an abrasive member, pressing the abrasive member against the said surface, commencing with an unused portion of said abrasive member against a portion of said surface and controlling the pressure with which the said abrasive member portion is applied to said portion of said surface during the burnishing operation by burnishing at a lower burnishing pressure and then increasing from said one pressure up to a maximum burnishing pressure as the abrasive member portion in contact with the surface said portion of surface becomes loaded with abraded material from said surface and then reducing to less than the maximum pressure, and wherein the increase in the applied pressure occurs with a decrease in the abrasiveness of the abrasive member.
Claim 2
Independent Claim
142 words
A method of treating the surface of magnetic recording media by burnishing, comprising: applying relative movement between the surface to be burnished and an abrasive member, pressing the abrasive member against the said surface, commencing with an unused portion of said abrasive member against a portion of said surface and controlling the pressure with which the said abrasive member portion is applied to said portion of said surface during the burnishing operation by burnishing at a lower burnishing pressure and then increasing from said one pressure up to a maximum burnishing pressure as the abrasive member portion in contact with the surface said portion of surface becomes loaded with abraded material from said surface and then reducing to less than the maximum pressure, and wherein the increase in the applied pressure occurs with a decrease in the abrasiveness of the abrasive member.
Claim 3
Dependent Claim
40 words
A method as claimed in claim 1, wherein a pressure member at the location at which the abrasive member is pressed against the surface to be burnished is oscillated transversely to the direction of relative movement during the burnishing operation.
Claim 4
Dependent Claim
77 words
The method as claimed in claim 2, wherein the magnetic recording media is a disk which is rotated at a speed of 100 to 500 rpm, and the abrasive member is a belt incrementally moved from a feed roll to a take-up roll and pressed in a trapezoidal area against the surface of said disk commencing at a pressure of about 0.2 bar and increased gradually to about 2.0 bar over a period of about eight seconds.
Claim 5
Dependent Claim
100 words
The method as claimed in claim 1, wherein the magnetic recording media is a web moved continuously in one direction and the abrasive member is a belt continuously moved in said direction from a feed roll to a take-up roll at a speed different from the web speed so as to maintain relative movement between said web and said belt and whereby any given portion of said web surface is first contacted by an unused portion of the abrasive belt at a relatively lower pressure and later contacted by a used portion of said abrasive belt at a higher pressure.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-06 | 1988-11-05 | 1989-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-06 | 1992-11-05 | 1993-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-06 | 1996-11-05 | 1997-05-07 | $7700.00 | Window Closed / Lapsed |