US4468304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro chemical machining methods
Assignee: Rolls Royce PLC
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Filing: 1984-01-24
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Granted: 1984-08-28
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Expires: 2004-01-24
Abstract
Abstract Workpieces which are electrochemically machined, are exposed to corrosion and stray attack by the electrolyte, over surfaces which are not required to be machined. The invention provides a cowl 22 around the workpiece 10 and its fixture 12, a space 24 being provided at the plane of the interface between parts to be machined and parts not to be machined. De-ionized water is pumped into the interior of cowl 22, at a pressure just sufficient to prevent electrolyte entering gap 24, thus protecting the necessary workpiece portions and the apparatus.
Inventors
- 👤 Christopher P. R. Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:48
CPC Classifications
B; B23; B23H; B23H3/00; B23H3/10; B23H9/00; B23H9/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
79 words
A method of electrochemically machining a workpiece including the steps of locating the workpiece in a fixture, enclosing the fixture and/or that part of the workpiece which is not required to be machined in a cowl such that a peripheral space is provided therebetween, and delivering a flow of water the maximum conductivity of which is about 300 micro mhos, to the peripheral space via the interior of the cowl, at a pressure sufficient to prevent ingress of electrolyte.
Claim 2
Independent Claim
79 words
A method of electrochemically machining a workpiece including the steps of locating the workpiece in a fixture, enclosing the fixture and/or that part of the workpiece which is not required to be machined in a cowl such that a peripheral space is provided therebetween, and delivering a flow of water the maximum conductivity of which is about 300 micro mhos, to the peripheral space via the interior of the cowl, at a pressure sufficient to prevent ingress of electrolyte.
Claim 3
Dependent Claim
39 words
A method of electrochemical machining as claimed in claim 1 including the step of delivering the water at a low flow rate so as to avoid interference with electrolyte flow over those workpiece surfaces which are to be machined.
Claim 4
Dependent Claim
22 words
A method of electrochemical machining as claimed in claim 1 including the step of delivering the water from a constant volume pump.
Claim 5
Dependent Claim
24 words
A method of electrochemical machining as claimed in claim 1 including the step of delivering the water from a small capacity, high pressure pump.
Claim 6
Dependent Claim
17 words
A method of electro chemical machining as claimed in claim 3 wherein the water is tap water.
Claim 7
Dependent Claim
16 words
A method of electrochemical machining as claimed in claim 4 wherein the water is tap water.
Claim 8
Dependent Claim
16 words
A method of electrochemical machining as claimed in claim 5 wherein the water has been de-ionized.
Claim 9
Dependent Claim
17 words
A method of electro chemical machining as claimed in claim 6 wherein the water has been de-ionized.
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) | 1987-08-28 | 1988-02-27 | 1988-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-28 | 1992-02-27 | 1992-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-28 | 1996-02-27 | 1996-08-28 | $7700.00 | Window Closed / Lapsed |