US3789157A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shielding device for overlapping the front face of a magnetic head in magnetic tape cartridges of the compact cassette type
Assignee: Emtec Magnetics GmbH
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Filing: 1971-07-19
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Granted: 1974-01-29
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Expires: 1991-07-19
Abstract
Abstract A device for shielding magnetic tape cassettes includes a hollow sheet metal parallelepiped with side recesses and with the shielding walls of the parallelepiped arranged to overlap the front face of a head and also the sound head shielding.
Inventors
- 👤 J Greiner
- 👤 D Engelsmann
- 👤 J Gersch
- 👤 F Landbrecht
- 👤 R Muller
- 👤 W Wenger
- 👤 O Wiedemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:33
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/10; G11B5/11; G11B23/00; G11B23/02; G11B23/04; G11B23/08; G11B23/087; G11B23/08707; G11B23/08792
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
107 words
A device for shielding the front face of a magnetic head used with magnetic tape cassettes comprising in combination, a compact cassette and a hollow parallelepiped, said parallelepiped having a back wall and top and bottom walls and a pair of side walls, the front face of said parallelepiped being open to permit the magnetic head to be inserted therein, and said parallelepiped being made of a sheet metal to provide shielding surfaces from the top and bottom and two side walls thereof which are disposed to completely overlap at least the front face of the magnetic head, and said shielding device being mounted in said cassette.
Claim 2
Independent Claim
107 words
A device for shielding the front face of a magnetic head used with magnetic tape cassettes comprising in combination, a compact cassette and a hollow parallelepiped, said parallelepiped having a back wall and top and bottom walls and a pair of side walls, the front face of said parallelepiped being open to permit the magnetic head to be inserted therein, and said parallelepiped being made of a sheet metal to provide shielding surfaces from the top and bottom and two side walls thereof which are disposed to completely overlap at least the front face of the magnetic head, and said shielding device being mounted in said cassette.
Claim 3
Dependent Claim
53 words
A device as set forth in claim 1, wherein the side walls of said parallelepiped each contain a recess, a slot extending from the edge of each side wall and communicating with said recess, and wedge shaped punch outs being above and below said slot spaced from each other to form said slot.
Claim 4
Dependent Claim
26 words
A device as set forth in claim 1, wherein the upper and lower edges of said side wall which extend from said back wall are slotted.
Claim 5
Dependent Claim
15 words
A device as set forth in claim 1, wherein said sheet metal is soft iron.
Claim 6
Dependent Claim
24 words
A device as set forth in claim 1, wherein said sheet metal has a magnetic axis disposed in the direction of the tape run.
Claim 7
Dependent Claim
31 words
A device as set forth in claim 1, in combination therewith a plurality of similarly shaped devices having proportionately larger dimensions, and said similarly shaped devices being nestled in each other.
Claim 8
Dependent Claim
57 words
A device as set forth in claim 1, said cassette having a pressure spring on one side of the tape with the magnetic head being movable into contact with the other side of the tape, said spring being in said device spanning said end walls, and the front face of said head being inserted into said device.
Claim 9
Dependent Claim
21 words
A device as set forth in claim 7 wherein said side walls are slotted, and said spring extending through the slots.
Claim 10
Dependent Claim
49 words
A device as set forth in claim 1, wherein the side walls of said parallelepiped each have a recess and the outer edges of each side wall having a slot at the height of said recess and communicating with said recess for the insertion of a tape pressure spring.
Claim 11
Dependent Claim
31 words
A device as set forth in claim 9, wherein each side wall includes a finger formed by said slot and said recess and the base of said finger having an indentation.
Claim 12
Dependent Claim
100 words
A device as set forth in claim 9, wherein a right angled slot is disposed at the lower edge of said recess, a finger being formed by said slot which extends from said edge of said side wall and by said recess and said right angled slot, said finger including a shoulder disposed on one side of said right angled slot and said recess including a shoulder on the opposite side of said right angled slot, said shoulders being reciprocally staggered, and said right angled slot terminating in a unilateral arch which extends toward the back wall of said parallelepiped.
References Cited (Backward Citations)
US3126162A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |