US4248438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mechanical record cutting method
Assignee: TELDEC Telefunken Decca Schallplatten GmbH
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Filing: 1979-03-19
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Granted: 1981-02-03
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Expires: 1999-03-19
Abstract
Abstract In an apparatus for forming a groove which is modulated to present an information track in a signal record carrier having a copper surface portion by cutting such groove into the copper surface portion by means of a cutting stylus, the stylus is formed to present, during cutting, a rake angle of between 10° and 20°, and the copper constituting the surface portion into which the groove is cut has a Vickers hardness of between 110 and 300, and preferably between 120-220.
Inventors
- 👤 Herbert Knothe
- 👤 Horst Redlich
- 👤 Klaus Roschmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:35
CPC Classifications
G; G11; G11B; G11B3/00; G11B3/44
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
94 words
In a method for forming a signal record carrier having a groove which is modulated to present an information track by providing a copper-containing bath, electrolytically depositing a thin layer of copper from the bath onto a substrate, and cutting such groove into the surface of the copper layer by means of a cutting stylus, the improvement wherein said stylus presents, during cutting, a rake angle of between 10° and 20°, and said bath contains at least one glazing additive which imparts a Vickers hardness of between 110 and 300 to said copper layer.
Claim 2
Dependent Claim
94 words
In a method for forming a signal record carrier having a groove which is modulated to present an information track by providing a copper-containing bath, electrolytically depositing a thin layer of copper from the bath onto a substrate, and cutting such groove into the surface of the copper layer by means of a cutting stylus, the improvement wherein said stylus presents, during cutting, a rake angle of between 10° and 20°, and said bath contains at least one glazing additive which imparts a Vickers hardness of between 110 and 300 to said copper layer.
Claim 3
Dependent Claim
27 words
A method as defined in claim 1 wherein the at least one additive in said bath gives the copper a Vickers hardness of between 120 and 220.
Claim 4
Dependent Claim
18 words
A method as defined in claim 1 or 2 wherein the cutting stylus is constituted by a diamond.
Claim 5
Dependent Claim
79 words
A method as defined in claim 1 or 2 wherein the cutting stylus has a triangular cross section and said step of cutting is carried out by rotating the copper layer and its associated substrate relative to the stylus while applying to the stylus a sufficiently great cutting force to cause it to cut a groove whose average depth is such that none of the original surface of the copper layer will remain between adjacent turns of the groove.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |