Patent US4974791A successfully refreshed from Google Patents.
US4974791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic tape cassettes
Assignee: KOLLER INDUSTRIES Inc
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Filing: 1988-07-22
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Granted: 1990-12-04
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Expires: 2008-07-22
Abstract
Abstract A magnetic tape cassette has an improved reel spring, slack limiter and tape guide. The reel spring has a generally rectangular shape with first and second parallel edges extending substantially along its entire length. A flat, central base portion of the spring is bounded by a pair of transition portions which extend at an angle out of the plane of the base. A pair of outer end portions set at a sharper angle to the base complete the spring configuration. A polypropylene slack limiter applies a preloaded tension on the magnetic tape. The polypropylene eliminates the need for laminating a separate bearing material to the slack limiter. The tape guide has a semi-cylindrical, stainless steel insert attached to a plastic mounting core. The core is fastened to the cassette housing.
Inventors
- 👤 William M. Carroll
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:17
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/02; G11B23/04; G11B23/08; G11B23/087
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
148 words
In a magnetic tape cassette, a reel spring comprising an elongated strip of resilient material having first and second edges extending substantially throughout its length parallel to a longitudinal centerline, and the strip further including a flat, central base portion, a first pair of transverse crimps at the ends of the base portion defining transition sections of the strip extending at a first angle to the plane of the base portion, and a second pair of transverse crimps at the outer ends of the transition sections defining end portions of the strip extending at a second angle to the plane of the base portion, and means for mounting said reel spring to the cassette and for fixing the reel spring's orientation relative to the cassette, said means being formed in said base portion intermediate said first and second edges and disposed upon the longitudinal centerline of said spring.
Claim 2
Dependent Claim
148 words
In a magnetic tape cassette, a reel spring comprising an elongated strip of resilient material having first and second edges extending substantially throughout its length parallel to a longitudinal centerline, and the strip further including a flat, central base portion, a first pair of transverse crimps at the ends of the base portion defining transition sections of the strip extending at a first angle to the plane of the base portion, and a second pair of transverse crimps at the outer ends of the transition sections defining end portions of the strip extending at a second angle to the plane of the base portion, and means for mounting said reel spring to the cassette and for fixing the reel spring's orientation relative to the cassette, said means being formed in said base portion intermediate said first and second edges and disposed upon the longitudinal centerline of said spring.
Claim 3
Dependent Claim
15 words
The reel spring of claim 1 wherein the tips of the end portions are rounded.
Claim 4
Dependent Claim
13 words
The reel spring of claim 1 wherein the resilient material is stainless steel.
Claim 5
Dependent Claim
95 words
In a magnetic tape cassette, a reel spring comprising an elongated strip of resilient material having first and second parallel edges extending substantially throughout its length with an uninterrupted surface therebetween, the strip having a central base portion and adjoining end portions extending out of the plane of the base portion, and means for mounting said reel spring to the cassette and for fixing the reel spring's orientation relative to the cassette, said means being formed in said base portion intermediate said first and second edges and disposed upon the longitudinal centerline of said spring.
Claim 6
Dependent Claim
95 words
In a magnetic tape cassette, a reel spring comprising an elongated strip of resilient material having first and second parallel edges extending substantially throughout its length with an uninterrupted surface therebetween, the strip having a central base portion and adjoining end portions extending out of the plane of the base portion, and means for mounting said reel spring to the cassette and for fixing the reel spring's orientation relative to the cassette, said means being formed in said base portion intermediate said first and second edges and disposed upon the longitudinal centerline of said spring.
Claim 7
Dependent Claim
15 words
The reel spring of claim 4 wherein the spring has an overall generally curved configuration.
Claim 8
Dependent Claim
15 words
The reel spring of claim 4 wherein the tips of the end portions are rounded.
Claim 9
Dependent Claim
13 words
The reel spring of claim 4 wherein the resilient material is stainless steel.
Claim 10
Dependent Claim
112 words
A magnetic tape cassette reel spring comprising an elongated strip of resilient material having first and second parallel, exterior edges extending substantially throughout its length parallel to a longitudinal centerline, first and second tips at the ends of the strip connecting the first and second exterior edges, the strip defining a central base portion and adjoining end portions which extend out of the plane of the base portion and means for mounting said reel spring to a cassette and for fixing the reel spring's orientation relative to the cassette, said means being formed in said base portion intermediate said first and second edges and disposed upon the longitudinal centerline of said strip.
Claim 11
Dependent Claim
112 words
A magnetic tape cassette reel spring comprising an elongated strip of resilient material having first and second parallel, exterior edges extending substantially throughout its length parallel to a longitudinal centerline, first and second tips at the ends of the strip connecting the first and second exterior edges, the strip defining a central base portion and adjoining end portions which extend out of the plane of the base portion and means for mounting said reel spring to a cassette and for fixing the reel spring's orientation relative to the cassette, said means being formed in said base portion intermediate said first and second edges and disposed upon the longitudinal centerline of said strip.
Claim 12
Dependent Claim
24 words
The reel spring of claim 8 wherein the end portions are separated from the central base portion by a first pair of transverse crimps.
Claim 13
Dependent Claim
50 words
The reel spring of claim 8 wherein the end portion further comprises a second pair of transverse crimps defining a transition section extending at a first angle to the plane of the base portion and an end portion extending at a second angle to the plane of the base portion.
Claim 14
Dependent Claim
15 words
The reel spring of claim 8 wherein the tips of the end portions are rounded.
Claim 15
Dependent Claim
13 words
The reel spring of claim 8 wherein the resilient material is stainless steel.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |