Patent US4026781A successfully refreshed from Google Patents.
US4026781A
Expired / Lapsed
US
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Anodizing means and techniques
Assignee: SCIONICS OF CALIFORNIA Inc
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Filing: 1972-03-28
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Granted: 1977-05-31
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Expires: 1992-03-28
Abstract
Abstract An anodizing system uses both positive and negative current pulses. Such pulses are adjustable to achieve different adjusted values of positive and negative currents. These values are sensed and used to maintain automatically such values. The ratio of negative current to positive current is preferably greater than 3% for the production of relatively thick, dyeable, hard anodized coatings and conventional (normal) anodic coatings of light shades of integral colors using a simple sulfuric acid bath which may be maintained at relatively high temperatures. Current may be applied at nearly full current density initially without burning. In some cases, additional means may be provided to increase the throwing power by eliminating the negative current and using means such as capacitors or inductors to prolong the decay of the positive pulses, preferably such that the then composite positive pulses are maintained above a zero value. These composite positive pulses are maintained in a ratio and wave shape which yields both good throwing power and high quality, even coatings, and produces the anodic coatings at relatively high current densities.
Inventors
- 👤 Frederick S. Newman
- 👤 John R. Thorne
- 👤 John T. Hartman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:11
CPC Classifications
C; C25; C25D; C25D11/00; C25D11/02; C25D11/04; C25D11/005; C25D11/024; C25D21/00; C25D21/12; Y; Y10; Y10S; Y10S204/00; Y10S204/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
126 words
In an anodizing system wherein an anodizing tank contains an anodizing bath and there are electrode means in said bath for conducting an electrical current through said bath and wherein one of said electrodes is a part to be anodized by having its outer surface converted into an oxide with the oxygen for production of said oxide being supplied from said bath, the combination including a power supply connectable to said electrode means to produce a current flow through said bath for production of said oxide in said anodizing process, said power supply incorporating means alternately producing positive and negative current through said bath with the ratio of average negative current to average positive current being greater than approximately three percent but less than twenty percent.
Claim 2
Dependent Claim
126 words
In an anodizing system wherein an anodizing tank contains an anodizing bath and there are electrode means in said bath for conducting an electrical current through said bath and wherein one of said electrodes is a part to be anodized by having its outer surface converted into an oxide with the oxygen for production of said oxide being supplied from said bath, the combination including a power supply connectable to said electrode means to produce a current flow through said bath for production of said oxide in said anodizing process, said power supply incorporating means alternately producing positive and negative current through said bath with the ratio of average negative current to average positive current being greater than approximately three percent but less than twenty percent.
Claim 3
Dependent Claim
133 words
In an anodizing system wherein an anodizing tank contains an anodizing bath and there are electrode means in said bath for conducting an electrical current through said bath and wherein one of said electrodes is a part to be anodized by having its outer surface converted into an oxide with the oxygen for production of said oxide being supplied from said bath, the combination including a power supply connected to said electrode means to produce a current flow through said bath for production of said oxide in said anodizing process, said power supply including means for producing a sequence of positive pulses with a time interval between pulses which is longer than the pulse width, and means for prolonging the duration of each pulse such that the current never reaches a zero value.
Claim 4
Dependent Claim
133 words
In an anodizing system wherein an anodizing tank contains an anodizing bath and there are electrode means in said bath for conducting an electrical current through said bath and wherein one of said electrodes is a part to be anodized by having its outer surface converted into an oxide with the oxygen for production of said oxide being supplied from said bath, the combination including a power supply connected to said electrode means to produce a current flow through said bath for production of said oxide in said anodizing process, said power supply including means for producing a sequence of positive pulses with a time interval between pulses which is longer than the pulse width, and means for prolonging the duration of each pulse such that the current never reaches a zero value.
Claim 5
Dependent Claim
21 words
A system as set forth in claim 1 including means for passing a gas through said bath to agitate the same.
Claim 6
Dependent Claim
26 words
A system as set forth in claim 1 in which said power supply includes means whereby the magnitude of said average negative current may be adjusted.
Claim 7
Dependent Claim
26 words
A system as set forth in claim 1 in which said power supply includes means whereby the magnitude of said average positive current may be adjusted.
Claim 8
Dependent Claim
54 words
In a system as set forth in claim 1 in which said power supply includes means for monitoring said average negative current and deriving a signal when said average negative current tends to deviate from a desired magnitude and, means responsive to said signal for maintaining said average negative current at said desired magnitude.
Claim 9
Dependent Claim
53 words
A system as set forth in claim 1 in which said power supply includes means for monitoring said average positive current and deriving a signal when said average positive current tends to deviate from a desired magnitude, and means responsive to said signal for maintaining said average positive current at said desired magnitude.
Claim 10
Dependent Claim
48 words
A system as set forth in claim 1 in which said power supply includes means for preventing the flow of negative current, and means for prolonging the flow of positive current such that the current through said bath diminishes but remains at a positive value above zero value.
Claim 11
Dependent Claim
21 words
A system as set forth in claim 2 in which said means includes capacitor means connected in parallel with said tank.
Claim 12
Dependent Claim
21 words
A system as set forth in claim 2 in which said means includes inductive means connected in series with said bath.
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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) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |