US3793170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochemical machining method and apparatus
Assignee: Electrodrill Inc
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Filing: 1971-06-09
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Granted: 1974-02-19
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Expires: 1991-06-09
Abstract
Abstract An electrochemical machining method and apparatus wherein electrolyte is impinged against a workpiece from non-conductive inert nozzles which do not penetrate the workpiece. The electrolyte is cathodically charged from an electrode remote from the nozzles so that very fine jets of electrolyte may be discharged. The nozzles are preferably made of glass and extend in a group or bunch from a header containing the electrode. The current potential is controlled to effect localized accurate cutting of the anodically charged workpiece by the cathodically charged electrolyte jets from each nozzle preventing overlapping of the cuts as by splashing or random uncontrolled jet flow. The outside dimensions of the nozzles have no effect on the size of the cut. In hole drilling operations, any undesired taper of the hole is removed by increasing the current potential after a through hole is formed to flow the electrolyte in a straight path for removing any stock creating the taper. Since the nozzles need not penetrate the workpiece, they may be stationarily mounted and hole patterns and spacings not obtainable with movable tools are now easily provided.
Inventors
- 👤 J Andrews
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:37
CPC Classifications
B; B23; B23H; B23H9/00; B23H9/14; B23H9/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
154 words
The method of electrochemically drilling holes through a metallic workpiece which comprises impinging a jet of electrolyte from a dielectric material nozzle against the surface of a workpiece to be drilled, maintaining a fixed gap between the tip end of said nozzle and said surface, cathodically charging the electrolyte upstream from the nozzle in a relatively enlarged zone, anodically charging the workpiece, establishing a low electrical potential between the cathodically charged electrolyte and the anodically charged workpiece for a time period sufficient to form a dimple in the workpiece which will direct the electrolyte jet away from the workpiece, then increasing the potential sufficiently to continue drilling at the point of impingement of the jet against the bottom of the hole being drilled until a hole is formed through the workpiece, and then again increasing the potential for a period of time sufficient to straighten the hole through the workpiece to a desired diameter.
Claim 2
Independent Claim
190 words
A method of electrochemical drilling which comprises mounting a dielectric material nozzle in fixed spaced relation to the surface of a workpiece, pumping electrolyte through the nozzle to impinge against the workpiece at an area conforming with the inner cross-sectional area of the nozzle, creating a direct current electrical potential between the electrolyte and workpiece to cathodically charge the electrolyte in an unconfined area upstream from the nozzle to prevent release of hydrogen at the nozzle area and to simultaneously anodically charge the workpiece, establishing a low electrical potential between the cathodically charged electrolyte and the anodically charged workpiece for a time period sufficient to form a dimple in the workpiece with side walls directing the electrolyte impinging against the workpiece away from said area conforming with the inner cross sectional area of the nozzle, progressively increasing said potential as cavitation progresses into the workpiece while simultaneously directing electrolyte away from the workpiece after it has impinged against the surface being drilled until a hole is formed through the workpiece, and then further increasing the potential for a period of time sufficient to straighten the hole to a constant diameter.
Claim 3
Independent Claim
144 words
The method of electrochemically drilling holes through a workpiece which comprises impinging a jet of electrolyte from a fixed nozzle against a starting surface of a workpiece to be drilled, maintaining a fixed gap between said nozzle and said starting surface, cathodically charging the electrolyte, anodically charging the workpiece, establishing a low electrical potential between the cathodically charged electrolyte and the anodically charged workpiece for a time period sufficient to form a dimple in the workpiece which will direct the electrolyte away from the workpiece, then increasing the potential as cavitation of the workpiece increases to maintain a potential sufficient to continue drilling at the point of impingement of the jet against the bottom of the cavity until a hole is formed through the workpiece, and then again increasing the potential for a period of time to develop the hole to a desired diameter.
Claim 4
Dependent Claim
16 words
The method of claim 4 wherein the potential increased as cavitation progresses is effected in increments.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein the workpiece is at a level above the nozzle to facilitate drainage of the electrolyte away from the workpiece.
Claim 6
Dependent Claim
36 words
The method of claim 2 wherein a plurality of nozzles are provided for simultaneously forming a plurality of cavities in the workpiece and a single electrode charges the electrolyte en route to the plurality of nozzles.
Claim 7
Dependent Claim
25 words
The method of claim 7 wherein the nozzles are formed on the ends of glass tubes and the electrode is immediately upstream from said tubes.
Claim 8
Dependent Claim
27 words
The method of claim 3 wherein a plurality of nozzle tubeS are provided and the electrolyte is cathodically charged immediately adjacent the inlet ends of the tubes.
References Cited (Backward Citations)
US2937124A
Cited
US2958636A
Cited
US3440161A
Cited
US3403084A
Cited
US3403085A
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US3409534A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |