US4039399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a bearing surface
Assignee: Dana Inc
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Filing: 1973-05-29
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Granted: 1977-08-02
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Expires: 1993-05-29
Abstract
Abstract Disclosed herein is a method of making an improved bearing surface wherein a first layer of hard chromium is electrodeposited on a metallic substrate, a second layer of microcracked chromium is deposited on the first layer and the second layer of microcracked chromium is etched to provide a finely porous, friable bearing surface.
Inventors
- 👤 William Patrick Wallace
- 👤 Anthony George Angilella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:02
CPC Classifications
F; F16; F16J; F16J9/00; F16J9/26; C; C25; C25D; C25D5/00; C25D5/10; C25D5/12; C25D5/14; C25D5/48; C25D5/60; C25D5/615; C25D5/617; C25D5/625
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
69 words
A method of forming a bearing surface which comprises the steps of: (a) electrodepositing on a metallic substrate a first layer of chromium having a Vicker's hardness in excess of 775; (b) electrodepositing a second layer of microcracked chromium having a Vicker's hardness in excess of 775 on said first layer; and (c) etching the outer surface of said second layer to provide said surface finely porous and friable.
Claim 2
Independent Claim
69 words
A method of forming a bearing surface which comprises the steps of: (a) electrodepositing on a metallic substrate a first layer of chromium having a Vicker's hardness in excess of 775; (b) electrodepositing a second layer of microcracked chromium having a Vicker's hardness in excess of 775 on said first layer; and (c) etching the outer surface of said second layer to provide said surface finely porous and friable.
Claim 3
Independent Claim
109 words
The method of forming a bearing surface which comprises the steps of: (a) electrodepositing a first layer of chromium on a metallic substrate, said first layer having a crack density of less than 3000 cracks per inch and a Vicker's hardness in excess of 775, (b) electrodepositing a second layer of chromium on said first layer, said second layer being thinner than said first layer and having a crack density of more than 5000 cracks per inch and a Vicker's hardness in excess of 775, and (c) etching the surface of said second layer to remove material along said cracks without substantially reducing the thickness of said second layer.
Claim 4
Independent Claim
109 words
The method of forming a bearing surface which comprises the steps of: (a) electrodepositing a first layer of chromium on a metallic substrate, said first layer having a crack density of less than 3000 cracks per inch and a Vicker's hardness in excess of 775, (b) electrodepositing a second layer of chromium on said first layer, said second layer being thinner than said first layer and having a crack density of more than 5000 cracks per inch and a Vicker's hardness in excess of 775, and (c) etching the surface of said second layer to remove material along said cracks without substantially reducing the thickness of said second layer.
Claim 5
Dependent Claim
20 words
The method of claim 2 wherein said first and second layers are electrodeposited from a single plating bath containing selenium.
Claim 6
Dependent Claim
12 words
The method of claim 2, wherein said etching step comprises electrochemical etching.
Claim 7
Independent Claim
71 words
A method of making a piston ring which comprises the steps of: (a) electrodepositing a first layer of chromium having a Vicker's hardness in excess of 775 on the periphery of a metallic ring; (b) electrodepositing a second layer of microcracked chromium having a Vicker's hardness in excess of 775 on said first layer; and (c) electrochemically etching said second layer to provide a finely porous and slightly friable outer surface.
Claim 8
Independent Claim
71 words
A method of making a piston ring which comprises the steps of: (a) electrodepositing a first layer of chromium having a Vicker's hardness in excess of 775 on the periphery of a metallic ring; (b) electrodepositing a second layer of microcracked chromium having a Vicker's hardness in excess of 775 on said first layer; and (c) electrochemically etching said second layer to provide a finely porous and slightly friable outer surface.
Claim 9
Dependent Claim
26 words
The method of claim 5, wherein the step of electrodepositing said second layer includes depositing the chromium of said second layer from a bath containing selenium.
Claim 10
Independent Claim
100 words
A method of making a piston ring which comprises the steps of: (a) electrodepositing a first layer of chromium plate having a Vicker's hardness in excess of 775 to a thickness in excess of 0.0025 inch on the circumference of a metallic ring; (b) electrodepositing on said first layer a second layer of chromium at a slow deposit rate to provide a finely grained and microcracked structure and a Vicker's hardness in excess of 775; (c) rinsing said second layer; and (d) electrochemically etching said second layer to provide a finely porous and friable outer surface on said second layer.
Claim 11
Independent Claim
100 words
A method of making a piston ring which comprises the steps of: (a) electrodepositing a first layer of chromium plate having a Vicker's hardness in excess of 775 to a thickness in excess of 0.0025 inch on the circumference of a metallic ring; (b) electrodepositing on said first layer a second layer of chromium at a slow deposit rate to provide a finely grained and microcracked structure and a Vicker's hardness in excess of 775; (c) rinsing said second layer; and (d) electrochemically etching said second layer to provide a finely porous and friable outer surface on said second layer.
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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) | 1980-08-01 | 1981-01-31 | 1981-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-01 | 1985-01-31 | 1985-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-01 | 1989-01-31 | 1989-08-02 | $7700.00 | Window Closed / Lapsed |