Patent US4389690A successfully refreshed from Google Patents.
US4389690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic tape cassette including a locking mechanism
Assignee: Fujifilm Holdings Corp
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Filing: 1981-02-06
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Granted: 1983-06-21
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Expires: 2001-02-06
Abstract
Abstract A miniturized video magnetic tape cassette of the type in which a magnetic tape wound on a pair of hubs in the hollow interior of a cassette casing is guided to run across a front opening formed in the casing along a rotatable front cover and in which the tape can be pulled out of the front opening in the cassette. The tape cassette includes locking mechanism having a supporting shaft fixed to a bottom wall of the casing and a hub rotatably mounted on the supporting shaft. An L-shaped locking lever extends from the hub and a first stop extends from the hub in a direction opposite that of the locking lever. A coil spring has a coil portion disposed around an upper portion of a hub in which a slit is formed. A first end of the coil spring is inserted into the slit while the second end abuts against an inner surface of a side wall of the casing.
Inventors
- 👤 Kengo Oishi
- 👤 Osamu Suzuki
- 👤 Choji Komiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:50
CPC Classifications
G; G11; G11B; G11B23/00; G11B23/02; G11B23/04; G11B23/08; G11B23/087; G11B23/08707; G11B23/08735; G11B23/08742
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
185 words
A magnetic tape cassette in which a magnetic tape wound on a pair of hubs in a hollow interior of a cassette casing is guided to run across a front opening formed in said casing and can be pulled out of said front opening, and including a locking mechanism comprising: a supporting shaft fixed to a bottom wall of said cassette casing; a rotary hub rotatably mounted on said supporting shaft; a locking lever extending from said rotary hub for rotating with said rotary hub; a first stop extending from said hub in a direction substantially opposite to a direction of extension of said locking lever, said first stop rotating with said locking lever; means for limiting a range of rotation of said first stop to limit a range of rotation of said locking lever as said locking lever rotates with said rotary hub; and a coil spring having a first end portion thereof locked to said hub, a coil portion thereof disposed around said hub and a second end portion thereof abutted against an inner surface of a side wall of said cassette casing.
Claim 2
Dependent Claim
185 words
A magnetic tape cassette in which a magnetic tape wound on a pair of hubs in a hollow interior of a cassette casing is guided to run across a front opening formed in said casing and can be pulled out of said front opening, and including a locking mechanism comprising: a supporting shaft fixed to a bottom wall of said cassette casing; a rotary hub rotatably mounted on said supporting shaft; a locking lever extending from said rotary hub for rotating with said rotary hub; a first stop extending from said hub in a direction substantially opposite to a direction of extension of said locking lever, said first stop rotating with said locking lever; means for limiting a range of rotation of said first stop to limit a range of rotation of said locking lever as said locking lever rotates with said rotary hub; and a coil spring having a first end portion thereof locked to said hub, a coil portion thereof disposed around said hub and a second end portion thereof abutted against an inner surface of a side wall of said cassette casing.
Claim 3
Dependent Claim
49 words
The magnetic tape cassette of claim 1 wherein said hub has an upper portion around which said coil portion of said coil spring is disposed, said upper portion of said hub having a slit formed therein with said first end portion of said coil spring inserted in said slit.
Claim 4
Dependent Claim
13 words
The magnetic tape cassette of claim 1 wherein said locking lever is L-shaped.
Claim 5
Dependent Claim
21 words
The magnetic tape cassette of claim 3 further comprising a second stop mounted on said locking lever at a bend thereof.
Claim 6
Dependent Claim
29 words
The magnetic tape cassette of claim 1 wherein a hole is formed in said cassette casing adapted for insertion therethrough of a depressing member for depressing said locking lever.
Claim 7
Dependent Claim
39 words
The magnetic tape cassette of claim 1 wherein said rotation limiting means and said first stop prevent said locking lever from contacting said tape located in said cassette as said locking lever is rotated to release a turnable cover.
Claim 8
Dependent Claim
24 words
The magnetic tape cassette of claim 6 wherein said rotation limiting means comprises said inner face of said side wall of said cassette casing.
References Cited (Backward Citations)
US4021856A
Cited
US4087844A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-06-20 | 1986-12-20 | 1987-06-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-20 | 1990-12-20 | 1991-06-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-20 | 1994-12-20 | 1995-06-21 | $7700.00 | Window Closed / Lapsed |