Patent US4097710A successfully refreshed from Google Patents.
US4097710A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for electrical machining
Assignee: Individual
•
Filing: 1977-02-16
•
Granted: 1978-06-27
•
Expires: 1997-02-16
Abstract
Abstract A source of intermittent unipolar voltage pulses is connected across an electrode and a workpiece to be machined, defining between them an erosion gap which is swept by a continuously moving, slightly electrolytic liquid. With suitable spacing of the pulses, the flow of the liquid removes excess ions and detritus from the erosion gap while its conductivity limits the voltage peak at the beginning of each discharge. To insure an even distribution of the flow, the liquid is admitted to the gap from above through one or more passages formed in the electrode, spreading symmetrically in opposite directions.
Inventors
- 👤 Alfred Marie Aime Maillet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:59
CPC Classifications
B; B23; B23H; B23H3/00; B23H3/10; B23H3/02; B23H2300/00; B23H2300/10
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
93 words
A method of machining a metallic workpiece by electro-erosion, comprising the steps of: positioning an electrode adjacent said workpiece with an intervening gap; continuously passing a weakly conductive ionizable liquid through said gap; and periodically energizing said electrode and said workpiece with a unidirectional voltage sufficient to generate ionic discharge pulses with a cadence in a range of substantially 20 to 200 Hz within said liquid in said gap with a spacing sufficient to allow detritus to be swept off, thereby letting the current in said gap substantially decay before each new pulse.
Claim 2
Independent Claim
93 words
A method of machining a metallic workpiece by electro-erosion, comprising the steps of: positioning an electrode adjacent said workpiece with an intervening gap; continuously passing a weakly conductive ionizable liquid through said gap; and periodically energizing said electrode and said workpiece with a unidirectional voltage sufficient to generate ionic discharge pulses with a cadence in a range of substantially 20 to 200 Hz within said liquid in said gap with a spacing sufficient to allow detritus to be swept off, thereby letting the current in said gap substantially decay before each new pulse.
Claim 3
Dependent Claim
21 words
A method as defined in claim 1 wherein the inherent conductivity of said liquid ranges between substantially 0.001 and 0.15 mho/cm.
Claim 4
Dependent Claim
22 words
A method as defined in claim 1 wherein said discharge pulses are separated by intervals at least equal to the pulse width.
Claim 5
Dependent Claim
22 words
A method as defined in claim 1 wherein said liquid is circulated into said gap through a central aperture in said electrode.
Claim 6
Dependent Claim
40 words
A method as defined in claim 4 wherein said aperture is a slot with a width on the order of 1 mm and said liquid is driven through said slot under a pressure difference between substantially 1 and 5 bars.
Claim 7
Dependent Claim
16 words
A method as defined in claim 1 wherein said electrode is driven negative by said voltage.
Claim 8
Dependent Claim
36 words
A method as defined in claim 6 wherein said gap has a width of about 0.1 to 0.2 mm and the mean potentiel difference across said gap ranges betwen substantially 4 and 20 volts during discharge.
Claim 9
Dependent Claim
30 words
A method as defined in claim 1 wherein said electrode and said workpiece are set in relative vibration with at least one substantially complete vibratory cycle accompanying each discharge pulse.
Claim 10
Dependent Claim
14 words
A method as defined in claim 1 wherein said liquid is an alkalinic medium.
Claim 11
Independent Claim
110 words
An apparatus for machining a metallic workpiece by electro-erosion, comprising: an electrode spaced by a gap from a surface of a workpiece to be machined; a reservoir containing a weakly conductive ionizable liquid; pump means for continuously driving said liquid through said gap; and a source of intermittent unipolar voltage pulses with a cadence in a range of substantially 20 to 200 Hz connected across said electrode and said workpiece for periodically energizing said electrode and said workpiece to generate ionic discharge pulses within said liquid with a spacing sufficient to allow detritus to be swept off, thereby letting the current in said gap substantially decay before each new pulse.
Claim 12
Independent Claim
110 words
An apparatus for machining a metallic workpiece by electro-erosion, comprising: an electrode spaced by a gap from a surface of a workpiece to be machined; a reservoir containing a weakly conductive ionizable liquid; pump means for continuously driving said liquid through said gap; and a source of intermittent unipolar voltage pulses with a cadence in a range of substantially 20 to 200 Hz connected across said electrode and said workpiece for periodically energizing said electrode and said workpiece to generate ionic discharge pulses within said liquid with a spacing sufficient to allow detritus to be swept off, thereby letting the current in said gap substantially decay before each new pulse.
Claim 13
Dependent Claim
36 words
An apparatus as defined in claim 10 wherein said electrode overlies said workpiece and is provided with a central aperture which opens into said gap, further comprising conduit means extending from said reservoir to said aperture.
Claim 14
Dependent Claim
27 words
An apparatus as defined in claim 11 wherein said aperture is a narrow slot extending over the greater part of said electrode in a major dimension thereof.
Claim 15
Dependent Claim
28 words
An apparatus as defined in claim 12 wherein said slot has a width on the order of 1 mm, said major dimension being on the order of centimeters.
Claim 16
Dependent Claim
16 words
An apparatus as defined in claim 11, further comprising vibrator means mechanically coupled with said electrode.
Claim 17
Dependent Claim
26 words
An apparatus as defined in claim 10 wherein said source includes a supply of alternating voltage and rectifier means for suppressing alternate half-cycles of said voltage.
Claim 18
Dependent Claim
21 words
An apparatus as defined in claim 15 wherein said rectifier means is connected to pass only negative pulses to said electrode.
Claim 19
Dependent Claim
34 words
An apparatus as defined in claim 16 wherein said source further comprises an electronic switch controlled by timing means for passing only a part of the unsuppressed half-cycles of said voltage to said electrode.
Claim 20
Dependent Claim
21 words
An apparatus as defined in claim 17 wherein said electronic switch is provided with a control electrode connected to said supply.
Claim 21
Dependent Claim
24 words
An apparatus as defined in claim 18 wherein said timing means further includes an integrating network inserted between said supply and said control electrode.
Claim 22
Dependent Claim
24 words
An apparatus as defined in claim 18 wherein said timing means further includes a binary counter inserted between said supply and said control electrode.
Claim 23
Dependent Claim
23 words
An apparatus as defined in claim 10 wherein said source has an open-circuit voltage in a range of substantially 50 to 100 V.
References Cited (Backward Citations)
US2766364A
Cited
US2996602A
Cited
US3334210A
Cited
US3616343A
Cited
US3594299A
Cited
JPS4319659Y1
Cited
US3530270A
Cited
US3607689A
Cited
US3864541A
Cited
US3699303A
Cited
US3851135A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-26 | 1981-12-26 | 1982-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-26 | 1985-12-26 | 1986-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-26 | 1989-12-26 | 1990-06-27 | $7700.00 | Window Closed / Lapsed |