US4425496A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of metal coating from dielectric material
Assignee: Electricite de France SA
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Filing: 1980-05-16
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Granted: 1984-01-10
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Expires: 2000-05-16
Abstract
Abstract The metal coating on a dielectric sheet or strip, for instance for use in capacitors, is locally removed by a Corona discharge between the sheet and a point electrode. A current return electrode contacts the sheet and is located in the return path to a HV generator connected to the point electrode.
Inventors
- 👤 Daniel Le Fur
- 👤 Robert Haug
- 👤 Max Goldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:54
CPC Classifications
H; H01; H01G; H01G13/00; H01G13/06
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
133 words
A process for locally demetallizing a metal coating on a strip of dielectric material, comprising the steps of moving said strip along a predetermined path while maintaining said coating in contact with a current return electrode held at a reference potential and while supporting the side of said strip opposite from said coating with a support means held at said reference potential, and applying, to discharge electrode means closely confronting said coating and having a high curvature portion of much greater curvature than that of the portion of said strip which confronts said coating, a DC electrical voltage adapted to maintain a Corona discharge between said discharge electrode means and said coating, whereby demetallization occurs along a predetermined defined zone of said strip as the latter is moved, without damaging said dielectric material.
Claim 2
Dependent Claim
133 words
A process for locally demetallizing a metal coating on a strip of dielectric material, comprising the steps of moving said strip along a predetermined path while maintaining said coating in contact with a current return electrode held at a reference potential and while supporting the side of said strip opposite from said coating with a support means held at said reference potential, and applying, to discharge electrode means closely confronting said coating and having a high curvature portion of much greater curvature than that of the portion of said strip which confronts said coating, a DC electrical voltage adapted to maintain a Corona discharge between said discharge electrode means and said coating, whereby demetallization occurs along a predetermined defined zone of said strip as the latter is moved, without damaging said dielectric material.
Claim 3
Dependent Claim
23 words
A process according to claim 1, wherein the strip is moved past the discharge electrode means to remove the coating along a line.
Claim 4
Dependent Claim
28 words
A process according to claim 1, wherein the electrode means are brought to a positive voltage with respect to the coating so as to strip the coating locally.
Claim 5
Dependent Claim
23 words
A process according to claim 1, wherein the strip is supported and driven by low curvature means made from dielectric thermally conducting material.
Claim 6
Dependent Claim
27 words
A process according to claim 1, wherein said electrical voltage is negative with respect to said coating so as to demetallize said coating by oxidizing it locally.
References Cited (Backward Citations)
US3119919A
Cited
US3198934A
Cited
US3502845A
Cited
US3424895A
Cited
US3754117A
Cited
US3895207A
Cited
US3957608A
Cited
DE2415409A1
Cited
US4132613A
Cited
US3994300A
Cited
US4056007A
Cited
US4219727A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-01-09 | 1987-07-11 | 1988-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-01-09 | 1991-07-11 | 1992-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-01-09 | 1995-07-11 | 1996-01-10 | $7700.00 | Window Closed / Lapsed |