Patent US3791608A successfully refreshed from Google Patents.
US3791608A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Friction sheet for a magnetic tape recording cassette
Assignee: Individual
•
Filing: 1970-09-10
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Granted: 1974-02-12
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Expires: 1990-09-10
Abstract
Abstract A tape guide sheet for a magnetic tape recording cassette, said sheet comprising a support sheet of a plastic material or paper, one surface of said sheet having a layer containing a powder or graphite, molybdenum bisulphide or tungsten bisulphide, the opposite surface of said sheet having a layer of aluminum.
Inventors
- 👤 G Akashi
- 👤 T Hirakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:42
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/02; G11B23/04; G11B23/08; G11B23/087; G11B23/08707; G11B23/08757; G11B23/08764; Y; Y10; Y10S; Y10S242/00; Y10S242/90; Y10S242/914; Y10T; Y10T428/00; Y10T428/29; Y10T428/30; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
26 words
A tape guide sheet as in claim 1, wherein said support sheet comprises polyethylene, polypropylene, polystyrene, polyvinyl chloride, polycarbonate, polyethylene terephthalate, cellulose biacetate, or cellulose triacetate.
Claim 2
Dependent Claim
20 words
A tape guide sheet as in claim 1 wherein said powder has a particle size of less than 10 microns.
Claim 3
Dependent Claim
26 words
A tape guide sheet as in claim 1 wherein the first layer containing said powder comprises a dispersion of said powder in a resinous binding medium.
Claim 4
Dependent Claim
17 words
A tape guide sheet as in claim 1 wherein said second layer of aluminum comprises electrolytically-deposited aluminum.
Claim 5
Dependent Claim
26 words
A tape guide sheet as in claim 1 wherein said second layer has a thickness such that its surface electrical resistance is less than 108 ohm-cm./cm.
Claim 6
Dependent Claim
47 words
A tape guide sheet as in claim 4 wherein said resinous binding medium is selected from the group consisting of a vinyl chloride-vinyl acetate copolymer, an epoxy resin, a vinyl acetate resin, a polyurethane, a styrene-butadiene copolymer, nitro-cellulose, a nylon resin, an acrylic resin and mixtures thereof.
Claim 7
Dependent Claim
32 words
A tape guide sheet as in claim 4 wherein said binder is present in an amount of from 10 to 50 parts by weight, per 100 parts by weight of said powder.
Claim 8
Dependent Claim
21 words
A tape guide sheet as in claim 6 wherein said second layer of aluminum has a thickness greater than 0.005 micron.
Claim 9
Dependent Claim
58 words
A tape guide sheet for use in a magnetic tape recording cassette comprising a support; a first layer on one side of said support consisting essentially of a powder of a graphite, molybdenum bisulphide or tungsten bisulphide dispersed in a synthetic resin binder; and a second layer on the other side of said support consisting essentially of aluminum.
Claim 10
Dependent Claim
25 words
A tape guide sheet as in claim 10 wherein said powder in said first layer has a particle size of less than about 10 microns.
Claim 11
Dependent Claim
26 words
A tape guide sheet as in claim 10 wherein said second layer has a thickness such that its surface electrical resistance is less than 108 ohm-cm/cm.
Claim 12
Dependent Claim
32 words
A tape guide sheet as in claim 10 wherein said first layer comprises the layer which faces the tape when said tape guide sheet is placed in said magnetic tape recording cassette.
References Cited (Backward Citations)
US2778636A
Cited
US2778637A
Cited
US2778635A
Cited
US3502284A
Cited
US3529788A
Cited
US3556433A
Cited
US3556434A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |