US4347425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wire-cut, electric-discharge machining power source
Assignee: Fanuc Corp
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Filing: 1980-09-29
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Granted: 1982-08-31
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Expires: 2000-09-29
Abstract
Abstract A wire-cut, electric-discharge machining power source which is provided with a first low-current discharge circuit and a second high-current discharge circuit. The first low-current discharge circuit makes a wire electrode positive and a workpiece negative, and the second high-current discharge circuit makes the wire electrode negative and the work positive. After triggering a discharge by the first low-current discharge circuit, a main discharge for machining is produced by the second high-current discharge circuit.
Inventors
- 👤 Haruki Obara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:18
CPC Classifications
B; B23; B23H; B23H1/00; B23H1/02; B23H1/022; B23H7/00; B23H7/02; B23H7/04; B23H2300/00; B23H2300/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
88 words
An electric-discharge machining power source for using an electrode to machine a workpiece comprising: a first low-current discharge circuit means for making the electrode positive and the workpiece negative to produce a reverse discharge; means for detecting the potential between the electrode and the workpiece to determine when the reverse discharge occurs; and a second high-current discharge circuit means, responsive to the means for detecting the potential, for making the electrode negative and the workpiece positive to produce a main machining discharge upon detection of the reverse discharge.
Claim 2
Dependent Claim
88 words
An electric-discharge machining power source for using an electrode to machine a workpiece comprising: a first low-current discharge circuit means for making the electrode positive and the workpiece negative to produce a reverse discharge; means for detecting the potential between the electrode and the workpiece to determine when the reverse discharge occurs; and a second high-current discharge circuit means, responsive to the means for detecting the potential, for making the electrode negative and the workpiece positive to produce a main machining discharge upon detection of the reverse discharge.
Claim 3
Dependent Claim
74 words
An electric-discharge machining power source according to claim 1, wherein the second high-current discharge circuit means comprises a large-capacitance capacitor connected in series with the electrode and the workpiece, a second high-current source for charging the large-capacitance capacitor, a second transistor inserted in the discharge path of the large-capacitance capacitor, and a second control circuit connected to the means for detecting the potential for switching the second transistor to produce the main machining discharge.
Claim 4
Dependent Claim
75 words
An electric-discharge machining power source according to claim 1 or 2, wherein the first low-current discharge circuit means comprises a small capacitance capacitor connected in series with the electrode and the workpiece, a first low-current source for charging the small-capacitance capacitor, a first transistor inserted in the discharge path of the small-capacitance capacitor, and a first control circuit connected to the means for detecting the potential for switching the transistor to control the reverse discharge.
Claim 5
Dependent Claim
58 words
An electric-discharge machining power source according to claim 1 or 2, wherein the first low-current discharge circuit means comprises a first low-current source, a first transistor for applying the output from the first low-current source to the electrode and the workpiece, and a first control circuit connected to the means for detecting the potential for switching the transistor.
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) | 1985-08-30 | 1986-03-01 | 1986-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-30 | 1990-03-01 | 1990-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-30 | 1994-03-01 | 1994-08-31 | $7700.00 | Window Closed / Lapsed |