Patent US4239828A successfully refreshed from Google Patents.
US4239828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-lubricating magnetic recording diskette
Assignee: 3M Co
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Filing: 1976-03-29
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Granted: 1980-12-16
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Expires: 1996-03-29
Abstract
Abstract A flexible magnetic recording disk is contained in an envelope having a wiping fabric which is impregnated with a highly fluorinated alkyl polyether which transfers to the disk as it rotates within the envelope to lubricate the interface between the rotating disk and a magnetic recording head.
Inventors
- 👤 Constance J. Knope
- 👤 Kent A. Kirkevold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:10
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/71; G11B5/72; G11B5/725; G11B5/7253; G11B5/7257; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
87 words
Method of extending the useful life of a flexible magnetic recording disk which is contained in an envelope to which a wiping fabric is attached in facing relationship to the disk comprising the steps of (1) applying to the wiping fabric a dilute solution of a lubricant primarily comprising a highly fluorinated alkyl polyether having a viscosity index as herein defined of about 10-130, and (2) evaporating the solvent to provide about 1-20 parts by weight of the lubricant per 100 parts by weight of the fabric.
Claim 2
Dependent Claim
87 words
Method of extending the useful life of a flexible magnetic recording disk which is contained in an envelope to which a wiping fabric is attached in facing relationship to the disk comprising the steps of (1) applying to the wiping fabric a dilute solution of a lubricant primarily comprising a highly fluorinated alkyl polyether having a viscosity index as herein defined of about 10-130, and (2) evaporating the solvent to provide about 1-20 parts by weight of the lubricant per 100 parts by weight of the fabric.
Claim 3
Dependent Claim
29 words
Method as defined in claim 1 wherein the fabric is immersed in the solution for about 1-20 seconds and then dried by exposure to air at ordinary room temperature.
Claim 4
Dependent Claim
28 words
Method as defined in claim 2 wherein the solution contains about 0.1 to one part by weight of the lubricant per 100 parts by weight of the solvent.
Claim 5
Dependent Claim
73 words
A diskette comprising an envelope containing a flexible magnetic recording disk and a tissue-like wiping fabric attached to the envelope in facing relationship to the disk, characterized by the fact that the fabric is impregnated with a lubricant primarily comprising a highly fluorinated alkyl polyether having a viscosity index as herein defined of about 10-130, there being about 1-20 parts by weight of the polyether per 100 parts by weight of the fabric.
Claim 6
Dependent Claim
73 words
A diskette comprising an envelope containing a flexible magnetic recording disk and a tissue-like wiping fabric attached to the envelope in facing relationship to the disk, characterized by the fact that the fabric is impregnated with a lubricant primarily comprising a highly fluorinated alkyl polyether having a viscosity index as herein defined of about 10-130, there being about 1-20 parts by weight of the polyether per 100 parts by weight of the fabric.
Claim 7
Dependent Claim
36 words
A diskette according to claim 4 further characterized by the fact that said polyether comprises a major proportion of the lubricant and a telomer of F 2 C═CF 2 comprises a minor proportion of the lubricant.
Claim 8
Dependent Claim
43 words
A diskette according to claim 4 further characterized by the fact that said polyether is a highly fluorinated propyl polyether and comprises a major proportion of the lubricant and a telomer of F 2 C═CF 2 comprises a minor proportion of the lubricant.
Claim 9
Dependent Claim
39 words
A diskette as defined in claim 4 further characterized by the fact that said polyether is selected from the group consisting of ##STR4## and the dimer thereof: ##STR5## where n is an integer providing a viscosity index of 10-130.
Claim 10
Dependent Claim
44 words
A diskette as defined in claim 7 further characterized by the fact that said polyether is the dimer having a viscosity index of about 23 and there are about 11 parts by weight of the lubricant per 100 parts by weight of the fabric.
Claim 11
Dependent Claim
27 words
A diskette as defined in claim 8 further characterized by the fact that a telomer of F 2 C═CF 2 comprises a minor proportion of said lubricant.
References Cited (Backward Citations)
US3319012A
Cited
US3398011A
Cited
US3630910A
Cited
US3668658A
Cited
US3778308A
Cited
US3778308B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |