Patent EP0092325A1 successfully refreshed from Google Patents.
EP0092325A1
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EP
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Recording disc
Assignee: 3M Co
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Filing: 1983-03-28
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Granted: —
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Expires: 2003-03-28
Abstract
Abstract A recording disc (10, 18) is provided by a disc-shaped, formed-sheet-metal support (18) across which a flexible recording sheet (10) is stretched. The formed-sheet-metal support (18) has a central spindle opening (30) which can be precisely centered by simultaneously punching the spindle opening (30) and the circular periphery, thus permitting hight-speed rotation of the recording disc (10. 18) in use.
Inventors
- 👤 Sten R. Minnesota Mining And Gerfast
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 11:32
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/24; G11B23/00; G11B23/0014; G11B23/0021; G11B23/0028; G11B23/0035; G11B23/02; G11B23/03; G11B23/033; G11B5/00; G11B5/74; G11B5/82; G11B5/825
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
101 words
A recording disc (10,18) comprising a) a rigid, symmetrical disc-shaped support (18) having axial projections at its hub (20) and near its rim (22), the peaks of which define an unobstructed radial plane along one face of the support; b) said support including a flange (24) connecting the projections; and c) a taut, flexible recording sheet (10) secured to the support (18), which sheet (10) contacts the peaks of the projections (20,22) and is spaced from the flange (24); characterized in that: 1) the disc-shaped support (18) is formed-sheet-metal and 2) the disc-shaped support (18) has a central spindle opening (30).
Claim 2
Dependent Claim
101 words
A recording disc (10,18) comprising a) a rigid, symmetrical disc-shaped support (18) having axial projections at its hub (20) and near its rim (22), the peaks of which define an unobstructed radial plane along one face of the support; b) said support including a flange (24) connecting the projections; and c) a taut, flexible recording sheet (10) secured to the support (18), which sheet (10) contacts the peaks of the projections (20,22) and is spaced from the flange (24); characterized in that: 1) the disc-shaped support (18) is formed-sheet-metal and 2) the disc-shaped support (18) has a central spindle opening (30).
Claim 3
Dependent Claim
64 words
A recording disc (10,18) as defined in claim 1 further characterized in that 1) extending beyond the peak of the rim projection (22) is a ramp (26) which is inclined about 3-30° from the radial direction and 2) the recording sheet (10) extends over the ramp (26) and is secured to the disc-shaped support (18) radially beyond the peak of the rim projection (22).
Claim 4
Dependent Claim
23 words
A recording disc (10,18) as defined in claim 1 further characterized in that said recording sheet (10) has a randomly oriented magnetizable layer.
Claim 5
Dependent Claim
21 words
A recording disc (10,18) as defined in claim 1 further characterized in that said support (18) is a soft aluminum alloy.
Claim 6
Dependent Claim
18 words
A recording disc (10,18) as defined in claim 1 further characterized in that said support (18) is ferromagnetic.
Claim 7
Dependent Claim
60 words
A recording disc (40-48) as defined in claim 1 further characterized by pairs of hub (50,52) and rim (54,56) projections and ramps (58,60) which define an unobstructed radial plane along each face of the support (48), and a taut, flexible recording sheet (40,42) extending across the projections (50-56) and ramps (58,60) of each face and spaced from the flange (62).
Claim 8
Dependent Claim
104 words
The process of making the recording disc (10,18) of claim 1 characterized by the steps of 1) forming sheet metal into a disc-shaped support (18) having axial projections at its hub (20) and near its rim (22), the peaks of which define an unobstructed radial plane along one face of the support (18) and a flange (24) connecting said projections (20,22), 2) punching a central spindle opening (30) into the disc-shaped support (18), 3) stretching a recording sheet (10) across the projections (20,22), and 4) securing the recording sheet (10) to the disc-shaped support (18) radially beyond the peak of the rim projection (22).
Claim 9
Dependent Claim
28 words
The process as defined in claim 7 wherein step 2) is further characterized by simultaneously punching the central spindle opening (30) and the periphery of the support (18).
Claim 10
Dependent Claim
42 words
The process as defined in claims 7 or 8 wherein step 1) is further characterized by forming the support (18) to provide beyond the peak of the rim projection (22) a ramp (26) which is inclined about 3-30° from the radial direction.
Claim 11
Dependent Claim
52 words
The process as defined in claim 7 wherein step 1) is further characterized by forming the sheet metal to provide axial hub (50,52) and rim (54,56) projections on each face of the support (48), and step 3) is further characterized by stretching a recording sheet (40,42) across the projections on each face.
Claim 12
Dependent Claim
28 words
The process as defined in claim 10 wherein step 4) is further characterized by sealing the two recording sheets (40,42) to each other beyond the rim projections (54,56).
References Cited (Backward Citations)
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