US4420382A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for controlling end effect on anodes used for cathodic protection and other applications
Assignee: Rio Tinto Alcan International Ltd
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Filing: 1981-01-13
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Granted: 1983-12-13
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Expires: 2001-01-13
Abstract
Abstract `Necking` of elongated cathodic protection anodes is obviated or reduced by means of a nonconductive shield placed around the periphery of the anode, but spaced away from the surface of the anode at the end at which it is connected to a conductor cable. The gap between the shield and the electrode surface is generally in the range of 15-30% of the radius of curvature of the electrode surface. The shield may extend over, but be spaced away from, the end surface of the electrode also.
Inventors
- 👤 George Riedl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:35
CPC Classifications
C; C23; C23F; C23F13/00; Y; Y10; Y10S; Y10S204/00; Y10S204/07
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
98 words
A method of improving the performance of a generally cylindrical anode having an insulated conductor electrically connected at one end thereof and being located within a surrounding body of corrosive medium which comprises placing a shield formed of electrically non-conducting material in said medium and around a minor portion of the length of the cylindrical surface of the anode and around said insulated conductor at said one end of said anode, said shield being spaced away from said cylindrical surface by a substantial distance which is small in relation to the radius of curvature of said cylindrical surface.
Claim 2
Independent Claim
98 words
A method of improving the performance of a generally cylindrical anode having an insulated conductor electrically connected at one end thereof and being located within a surrounding body of corrosive medium which comprises placing a shield formed of electrically non-conducting material in said medium and around a minor portion of the length of the cylindrical surface of the anode and around said insulated conductor at said one end of said anode, said shield being spaced away from said cylindrical surface by a substantial distance which is small in relation to the radius of curvature of said cylindrical surface.
Claim 3
Dependent Claim
35 words
A method according to claim 1 in which the initial gap between the surface of the shield and the adjacent cylindrical surface of the anode is 15-30% of the radius of curvature of the anode.
Claim 4
Dependent Claim
45 words
A method according to claim 1 wherein said shield of electrically nonconducting material has an end portion facing the end surface of said electrode adjacent said cylindrical surface, said shield being spaced away from said end surface to permit access of said corrosive medium thereto.
Claim 5
Dependent Claim
34 words
A method according to claim 3 further comprising providing at least one gas escape passage for release of gas generated within the gap between said shield and the adjacent cylindrical surface of the anode.
Claim 6
Dependent Claim
119 words
An anode assembly comprising an elongated body of electrically conductive material, an insulated conductor electrically connected to said body internally thereof and extending substantially axially out of one end of said body, a cup-shaped nonconducting shield member having an end portion surrounding said insulated conductor and spaced away from the adjacent surface of said body and a generally cylindrical wall portion extending around but spaced away from the adjacent peripheral surface of said elongated body at said one end thereof, said end portion and said cylindrical wall portion being arranged to permit unrestrained access of liquid to the surfaces of said body facing said end portion and said cylindrical wall portion, said body projecting beyond said cylindrical wall portion.
Claim 7
Dependent Claim
119 words
An anode assembly comprising an elongated body of electrically conductive material, an insulated conductor electrically connected to said body internally thereof and extending substantially axially out of one end of said body, a cup-shaped nonconducting shield member having an end portion surrounding said insulated conductor and spaced away from the adjacent surface of said body and a generally cylindrical wall portion extending around but spaced away from the adjacent peripheral surface of said elongated body at said one end thereof, said end portion and said cylindrical wall portion being arranged to permit unrestrained access of liquid to the surfaces of said body facing said end portion and said cylindrical wall portion, said body projecting beyond said cylindrical wall portion.
Claim 8
Dependent Claim
24 words
An anode assembly according to claim 5 wherein said end portion of said shield member is flat, facing the end surface of said body.
Claim 9
Dependent Claim
29 words
An anode assembly according to claim 6 in which one or more gas escape passages are provided in said cylindrical portion adjacent its junction with said flat end portion.
Claim 10
Dependent Claim
46 words
An anode assembly according to claim 5 in which the cylindrical portion of said shield member is spaced away from the adjacent surface of said body, for entrance of liquid therebetween, by a distance equal to 15-30 percent of the radius of curvature of said surface.
Claim 11
Dependent Claim
29 words
An anode assembly according to claim 5 in which the cylindrical portion of said shield overlaps the peripheral wall of said body by a distance of about 2.5-5 cm.
Claim 12
Dependent Claim
44 words
An anode assembly according to claim 5 in which the conductor is connected to the elongated body by means of a connector located axially within said body, the axial length of said cylindrical portion of said shield being sufficient to completely surround said connector.
References Cited (Backward Citations)
US644029A
Cited
US1506306A
Cited
US2329961A
Cited
US2721172A
Cited
US2934485A
Cited
US3182007A
Cited
US3513082A
Cited
US3471395A
Cited
US4175021A
Cited
US4224126A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-12 | 1987-06-13 | 1987-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-12 | 1991-06-13 | 1991-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-12 | 1995-06-13 | 1995-12-13 | $7700.00 | Window Closed / Lapsed |