Patent US3909577A successfully refreshed from Google Patents.
US3909577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulse controlled flushing system
Assignee: Hurco Acquisition Corp
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Filing: 1973-12-11
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Granted: 1975-09-30
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Expires: 1993-12-11
Abstract
Abstract The machining gap between a workpiece and an electrode is flushed by an increased flow of dielectric fluid during timed interruptions in the pulses producing electric discharge through the gap. The flushing period is prolonged until terminated by detection of a drop in voltage across the gap when the electrode reenters the workpiece following retraction that occurs simultaneously with interruption in the discharge producing pulses.
Inventors
- 👤 Leif Houman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:46
CPC Classifications
B; B23; B23H; B23H1/00; B23H1/02
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
124 words
Apparatus for machining a workpiece, comprising an electrode spaced from the workpiece to form a gap therebetween, means for supplying current to the electrode to provide intermittent electric discharges across said gap, means for simultaneously retracting said electrode from the workpiece and initiating flushing flow of fluid to flush debris from the gap, timing means for establishing timed retraction periods during which said electrode is retracted and the current to the electrode is interrupted, gap monitoring means for detecting return of the electrode to the workpiece following termination of said timed retraction periods, and means responsive only to said return of the electrode as detected by the gap monitoring means for terminating said flushing flow of fluid which is prolonged belong said retraction periods.
Claim 2
Dependent Claim
124 words
Apparatus for machining a workpiece, comprising an electrode spaced from the workpiece to form a gap therebetween, means for supplying current to the electrode to provide intermittent electric discharges across said gap, means for simultaneously retracting said electrode from the workpiece and initiating flushing flow of fluid to flush debris from the gap, timing means for establishing timed retraction periods during which said electrode is retracted and the current to the electrode is interrupted, gap monitoring means for detecting return of the electrode to the workpiece following termination of said timed retraction periods, and means responsive only to said return of the electrode as detected by the gap monitoring means for terminating said flushing flow of fluid which is prolonged belong said retraction periods.
Claim 3
Dependent Claim
30 words
The apparatus of claim 1 including means for monitoring gap conditions to generate command signals; and means for increasing said flow of the fluid to obtain additional flushing on demand.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |