US4229636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spark erosion machining process
Assignee: Cegedur Societe de Transformation de lAluminium Pechiney SA
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Filing: 1979-05-22
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Granted: 1980-10-21
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Expires: 1999-05-22
Abstract
Abstract A process for the spark erosion machining of a workpiece having a cylindrical orifice, formed of any desired cross-section, the invention utilizes an electrode which is moved relative to the workpiece. According to the invention, a first rapid rough shaping pass is performed by descent of the electrode parallel to the generatrices of the orifice. On raising, the electrode is then translated perpendicularly to the generatrices by a distance r and then is lowered at a slower speed and is raised again before performing a circular translation of radius r. The electrode is again lowered and raised, and the operation is repeated n times so as to perform a complete revolution. The present process allows efficient machining of dies for metal extrusion.
Inventors
- 👤 Gerard Izari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:08
CPC Classifications
B; B23; B23H; B23H7/00; B23H7/26; B23H7/28
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
162 words
A process for the spark erosion machining of a workpiece having a cylindrical orifice of any given cross-section, the process being effected by means of a single electrode which is displaced relative to the workpiece, the process sequentially comprising the steps of: making a first rapid rough pass relative to the workpiece by causing the electrode to descent through the orifice parallel to the generatrices of the orifice to spark erode surfaces of the orifice; raising the electrode; translating the electrode perpendicularly to the generatrices by a distance r so that a point is located at P 1 on the surfaces of the orifice; lowering the electrode into the rough orifice parallel to the generatrices; rasing the electrode; translating the electrode to a point located at P 2 on the surfaces of the orifice; lowering the electrode parallel to the generatrices; raising the electrode; and repeating the translation, lowering, and raising steps n times until the translation has made a complete revolution.
Claim 2
Dependent Claim
162 words
A process for the spark erosion machining of a workpiece having a cylindrical orifice of any given cross-section, the process being effected by means of a single electrode which is displaced relative to the workpiece, the process sequentially comprising the steps of: making a first rapid rough pass relative to the workpiece by causing the electrode to descent through the orifice parallel to the generatrices of the orifice to spark erode surfaces of the orifice; raising the electrode; translating the electrode perpendicularly to the generatrices by a distance r so that a point is located at P 1 on the surfaces of the orifice; lowering the electrode into the rough orifice parallel to the generatrices; rasing the electrode; translating the electrode to a point located at P 2 on the surfaces of the orifice; lowering the electrode parallel to the generatrices; raising the electrode; and repeating the translation, lowering, and raising steps n times until the translation has made a complete revolution.
Claim 3
Dependent Claim
33 words
A process according to claim 1 wherein the descent of the electrode after translation takes place at an identical speed or slower speed than the descent of the electrode during the rough pass.
Claim 4
Dependent Claim
60 words
A process according to claim 1 wherein the process is comprised of at least one semi-finishing stage with n spark erosion passes and circular translation of radius r and at least one finishing stage at a lower speed with n' spark erosion passes and a circular translation of radius r', n' and r' being greater than n and r respectively.
Claim 5
Dependent Claim
22 words
A process according to claim 3 wherein the electrode descends deeper into the orifice during successive stages of rough-shaping, semi-finishing and finishing.
Claim 6
Dependent Claim
18 words
A process according to claim 4 wherein the electrode extends completely beneath the spark eroded orifice thus produced.
Claim 7
Dependent Claim
32 words
A process according to claim 5 wherein structure mounting the electrode is of a smaller cross-section than that of the electrode so that the mounting structure penetrates into the spark eroded orifice.
Claim 8
Dependent Claim
38 words
A process according to claim 1 wherein the translation between P 1 and successive points established during successive passes, the points being P 2 . . . P n-1 and P n , is along a circular path.
Claim 9
Dependent Claim
26 words
A process according to claim 1 wherein the workpiece to be machined is subjected to a movement of lateral translation while the electrode only moves longitudinally.
Claim 10
Dependent Claim
18 words
A process according to claim 1 wherein a dielectric liquid is circulated by suction during the finishing operation.
Claim 11
Dependent Claim
24 words
A process according to claim 9 and further comprising, during finishing operation, degassing with adjustable periodicity by withdrawal toward the top of the electrode.
Claim 12
Dependent Claim
23 words
A process according to claim 1 wherein the process is carried out on workpieces which have been subjected to a preliminary thermal treatment.
Claim 13
Dependent Claim
20 words
A process according to claim 1 and further comprising after machining by spark erosion, subjection of the workpiece to polishing.
References Cited (Backward Citations)
US3727023A
Cited
US4135070A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-21 | 1984-04-21 | 1984-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-21 | 1988-04-21 | 1988-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-21 | 1992-04-21 | 1992-10-21 | $7700.00 | Window Closed / Lapsed |