US4184932A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electropolishing process
Assignee: Hoechst AG
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Filing: 1978-09-25
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Granted: 1980-01-22
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Expires: 1998-09-25
Abstract
Abstract Axially unsymmetrical articles are electropolished zonewise, or the inside and outside surfaces of articles are electropolished zonewise and simultaneously. To this end a cathode of which the geometrical configuration and surface area correspond to the surface to be electropolished is arranged opposite an anode; more particularly, the cathode is subdivided into a plurality of segments which are non-conductive with respect to one another, through which segments a current of the necessary density is alternately passed and discontinued, at intervals, for a period compatible with the production of the desired electropolishing effect.
Inventors
- 👤 Michael Ahlgrim
- 👤 Gerhard Mietens
- 👤 Helga Zygmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:08
CPC Classifications
C; C25; C25F; C25F3/00; C25F3/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
134 words
A process for electropolishing an article having an electrically conductive metallic surface, this surface being connected to a source of E.M.F. to form an anode, which comprises zonewise electropolishing an axially unsymmetrical article, by arranging, opposite the anode, a cathode of which the geometrical configuration and surface area correspond to the surface to be electropolished, the cathode being subdivided into a plurality of segments which are non-conductive with respect to one another, through which segments a current of the necessary density is alternately passed and discontinued, at intervals, so as to provide for a given segment a ratio of switch-on to switch-off period of 1:1 to 1:5 and the intervals are selected so as produce interruptions of at least 10 seconds and at most 5 minutes, with the production of the desired electropolishing effect.
Claim 2
Dependent Claim
134 words
A process for electropolishing an article having an electrically conductive metallic surface, this surface being connected to a source of E.M.F. to form an anode, which comprises zonewise electropolishing an axially unsymmetrical article, by arranging, opposite the anode, a cathode of which the geometrical configuration and surface area correspond to the surface to be electropolished, the cathode being subdivided into a plurality of segments which are non-conductive with respect to one another, through which segments a current of the necessary density is alternately passed and discontinued, at intervals, so as to provide for a given segment a ratio of switch-on to switch-off period of 1:1 to 1:5 and the intervals are selected so as produce interruptions of at least 10 seconds and at most 5 minutes, with the production of the desired electropolishing effect.
Claim 3
Dependent Claim
140 words
A process for electropolishing an article having an electrically conductive metallic surface, this surface being connected to a source of E.M.F. to form an anode, which comprises zonewise electropolishing simultaneously the inside and outside surfaces of an article, by arranging, opposite the anode, a cathode of which the geometrical configuration and surface area correspond to the surface to be electropolished, the cathode being subdivided into a plurality of segments which are non-conductive with respect to one another, through which segments a current of the necessary density is alternately passed and discontinued, at intervals, so as to provide for a given segment a ratio of switch-on to switch-off period of 1:1 to 1:5 and the intervals are selected so as to produce interruptions of at least 10 seconds and at most 5 minutes, with the production of the desired electropolishing effect.
Claim 4
Dependent Claim
140 words
A process for electropolishing an article having an electrically conductive metallic surface, this surface being connected to a source of E.M.F. to form an anode, which comprises zonewise electropolishing simultaneously the inside and outside surfaces of an article, by arranging, opposite the anode, a cathode of which the geometrical configuration and surface area correspond to the surface to be electropolished, the cathode being subdivided into a plurality of segments which are non-conductive with respect to one another, through which segments a current of the necessary density is alternately passed and discontinued, at intervals, so as to provide for a given segment a ratio of switch-on to switch-off period of 1:1 to 1:5 and the intervals are selected so as to produce interruptions of at least 10 seconds and at most 5 minutes, with the production of the desired electropolishing effect.
Claim 5
Dependent Claim
26 words
The process as claimed in any one of claims 1 or 2, wherein the cathode is subdivided into segments which are substantially equal in surface area.
Claim 6
Dependent Claim
37 words
The process as claimed in any one of claims 1 or 2, wherein the surface of a stainless steel article is electropolished with a current density of 5 to 50 amperes/dm 2 at the anode and cathode.
Claim 7
Dependent Claim
58 words
The process as claimed in any one of claims 1 or 2, wherein the current is obtained from a rectifier having a predetermined capacity and the cathode is divided in segments having such dimensions that from the given capacity of the rectifier and the surface of a segment the current density necessary for effecting the desired electropolishing results.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-01-21 | 1983-07-23 | 1984-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-01-21 | 1987-07-23 | 1988-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-01-21 | 1991-07-23 | 1992-01-22 | $7700.00 | Window Closed / Lapsed |