US4052583A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of and apparatus for electrical-discharge machining with a traveling-wire electrode
Assignee: Japan Kinoko Research Center Foundation
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Filing: 1976-06-23
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Granted: 1977-10-04
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Expires: 1996-06-23
Abstract
Abstract The relative movement of a workpiece and a traveling-wire electrode in an electrical-discharge machining apparatus is interrupted temporarily while the application of the usual electrical pulses for effecting machining is continued until and after discharge substantially ceases. The leakage current is then measured to provide an indication of workpiece thickness. This indication is used to control a machining parameter, whereupon the relative movement and machining with the new parameter, are resumed.
Inventors
- 👤 Kiyoshi Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:57
CPC Classifications
B; B23; B23H; B23H7/00; B23H7/02; B23H7/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
137 words
In a method of electrically machining a conductive workpiece in which: a traveling-wire electrode and the workpiece are relatively displaced transversely to the length of the traveling-wire electrode and define a machining gap between them, a machining liquid is supplied to said gap, and a series of electrical pulses are applied across the workpiece and the electrode to generate machining discharges in the gap to remove material from the workpiece, the improvement which comprises: a. temporarily interrupting said relative displacement of said electrode and said workpiece; b. continuing the application of said pulses during the interruption until the discharges across the gap substantially cease; and c. when said discharges across the gap substantially cease, measuring the leakage current across said gap for at least one further applied pulse, said leakage current providing an indication of workpiece thickness.
Claim 2
Dependent Claim
137 words
In a method of electrically machining a conductive workpiece in which: a traveling-wire electrode and the workpiece are relatively displaced transversely to the length of the traveling-wire electrode and define a machining gap between them, a machining liquid is supplied to said gap, and a series of electrical pulses are applied across the workpiece and the electrode to generate machining discharges in the gap to remove material from the workpiece, the improvement which comprises: a. temporarily interrupting said relative displacement of said electrode and said workpiece; b. continuing the application of said pulses during the interruption until the discharges across the gap substantially cease; and c. when said discharges across the gap substantially cease, measuring the leakage current across said gap for at least one further applied pulse, said leakage current providing an indication of workpiece thickness.
Claim 3
Dependent Claim
74 words
The improvement defined in claim 1 wherein the machining has parameters of pulse duration, interpulse interval, pulse current, speed of said relative displacement and speed of said traveling-wire electrode, at least one of which is adjustable, said method further comprising: d. controlling an adjustable one of said parameters in dependence upon the indicated workpiece thickness; and e. resuming said relative displacement and the machining of said workpiece with the adjustable parameter as thus controlled.
Claim 4
Dependent Claim
14 words
The improvement defined in claim 2 wherein the adjustable parameter is the pulse duration.
Claim 5
Dependent Claim
14 words
The improvement defined in claim 2 wherein said adjustable parameter is the interpulse interval.
Claim 6
Dependent Claim
14 words
The improvement defined in claim 2 wherein the adjustable parameter is the pulse current.
Claim 7
Dependent Claim
28 words
The improvement defined in claim 2 wherein the adjustable parameter is a combination of the pulse duration, the interpulse interval and the peak current of the electrical pulses.
Claim 8
Dependent Claim
16 words
The improvement defined in claim 2 wherein said parameter is the speed of the traveling-wire electrode.
Claim 9
Dependent Claim
17 words
The improvement defined in claim 2 wherein the adjustable parameter is the speed of said relative displacement.
Claim 10
Dependent Claim
127 words
In an apparatus for the electrical machining of a conductive workpiece including: a traveling-wire electrode, means for relatively displacing said traveling-wire electrode and a workpiece in accordance with a predetermined program while maintaining a machining gap therebetween, means for supplying a machining liquid to said gap, and means for applying electrical pulses across said workpiece and said electrode to effect material-removal machining discharges across said gap, the improvement which comprises: a. means for temporarily halting said relative displacement while permitting continued application of said pulses; and b. means effective to the substantial termination of said discharges for measuring leakage current across said gap upon application of at least one further electrical pulse, the magnitude of said leakage current being an indication of the thickness of said workpiece.
Claim 11
Dependent Claim
127 words
In an apparatus for the electrical machining of a conductive workpiece including: a traveling-wire electrode, means for relatively displacing said traveling-wire electrode and a workpiece in accordance with a predetermined program while maintaining a machining gap therebetween, means for supplying a machining liquid to said gap, and means for applying electrical pulses across said workpiece and said electrode to effect material-removal machining discharges across said gap, the improvement which comprises: a. means for temporarily halting said relative displacement while permitting continued application of said pulses; and b. means effective to the substantial termination of said discharges for measuring leakage current across said gap upon application of at least one further electrical pulse, the magnitude of said leakage current being an indication of the thickness of said workpiece.
Claim 12
Dependent Claim
23 words
The improvement defined in claim 9, further comprising means responsive to the indication of workpiece thickness for controlling a parameter of the machining.
Claim 13
Dependent Claim
40 words
The improvement defined in claim 9 wherein said means effective upon substantial termination of said discharges includes detector means responsive to oscillations in circuit with said gap, and current-sensing means operated by said detecting means for measuring said leakage current.
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) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |