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US4363949A Expired / Lapsed US ⏱️ 0.0 years remaining

Travelling wire EDM apparatus

Assignee: Agie Charmilles New Technologies SA
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Filing: 1980-11-21
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Granted: 1982-12-14
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Expires: 2000-11-21
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Abstract

Abstract A correction system for a travelling wire EDM machine cutting a workpiece by means of a travelling electrode wire stretched between two guide members and comprising a pair of servo motors for effecting displacement of the guide members relative to their respective support arms, such as to incline the electrode wire relative to the workpiece for providing the cut in the workpiece with an appropriate predetermined conicity or draft. One of the servo motors providing such displacement is, in addition, controlled such as to compensate for thermally-induced expansions or contractions of one of the support arm guide members relative to the other.

Inventors

  • 👤 Jean Pfau
  • 👤 Benno I. Bonga

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 16:21
CPC Classifications
B; B23; B23H; B23H7/00; B23H7/02; B23H7/06

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 279 words
In an apparatus for cutting by electrical discharges an electrode workpiece by means of a travelling electrode wire, said electrical discharges occurring in a machining zone between said electrode wire and said workpiece, said apparatus comprising a pair of electrode wire guide members mounted one on the end of a support arm and the other on the end of another support arm, said support arms being disposed parallel to each other on each side of the machining zone in the workpiece, and a pair of servo motors for displacing both said support arms in unison and said workpiece relative to each other along respective X- and Y-axes according to a predetermined path program, the improvement comprising a second pair of servo motors arranged one to displace one of said guide members in a first direction along the axis of its corresponding support arm and the other along a second direction perpendicular to the axis of its corresponding support arm such as to guide said wire with a predetermined inclination relative to said workpiece in the course of a cutting pass according to inclination information included in said path program, means for obtaining a pair of control signals from said program inclination information, means for controlling said one of said second pair of servo motors for displacing said one of said guide members relative to its corresponding support arm in said first direction as a function of one of said signals, and means for controlling the other of said second pair of servo motors for displacing the other of said guide members relative to its support arm in said second direction as a function of the other of said signals.
Claim 2
Dependent Claim 279 words
In an apparatus for cutting by electrical discharges an electrode workpiece by means of a travelling electrode wire, said electrical discharges occurring in a machining zone between said electrode wire and said workpiece, said apparatus comprising a pair of electrode wire guide members mounted one on the end of a support arm and the other on the end of another support arm, said support arms being disposed parallel to each other on each side of the machining zone in the workpiece, and a pair of servo motors for displacing both said support arms in unison and said workpiece relative to each other along respective X- and Y-axes according to a predetermined path program, the improvement comprising a second pair of servo motors arranged one to displace one of said guide members in a first direction along the axis of its corresponding support arm and the other along a second direction perpendicular to the axis of its corresponding support arm such as to guide said wire with a predetermined inclination relative to said workpiece in the course of a cutting pass according to inclination information included in said path program, means for obtaining a pair of control signals from said program inclination information, means for controlling said one of said second pair of servo motors for displacing said one of said guide members relative to its corresponding support arm in said first direction as a function of one of said signals, and means for controlling the other of said second pair of servo motors for displacing the other of said guide members relative to its support arm in said second direction as a function of the other of said signals.
Claim 3
Dependent Claim 63 words
The improvement of claim 1 further comprising means for measuring the temperature of each of said support arms, means for determining the difference in temperature, and means for controlling said one of said second pair of servo motors for displacing said one of said guide members such as to compensate for difference in length of said support arms due to difference in temperature.
Claim 4
Dependent Claim 134 words
In an apparatus for cutting by electrical discharges an electrode workpiece by means of a travelling electrode wire, said apparatus comprising electrode wire guide members mounted each on the end of one of a pair of parallel support arms, one of said support arms being disposed above the workpiece and the other below the workpiece, a first pair of servo motors for displacing both said support arms in unison and said workpiece relative to each other along respective X- and Y-axes according to a predetermined path program, the improvement comprising means for measuring the temperature difference between said support arms and means for displacing one of said guide members along the axis of its support arm such as to compensate for difference in length of said support arms due to the difference in temperature.
Claim 5
Dependent Claim 134 words
In an apparatus for cutting by electrical discharges an electrode workpiece by means of a travelling electrode wire, said apparatus comprising electrode wire guide members mounted each on the end of one of a pair of parallel support arms, one of said support arms being disposed above the workpiece and the other below the workpiece, a first pair of servo motors for displacing both said support arms in unison and said workpiece relative to each other along respective X- and Y-axes according to a predetermined path program, the improvement comprising means for measuring the temperature difference between said support arms and means for displacing one of said guide members along the axis of its support arm such as to compensate for difference in length of said support arms due to the difference in temperature.

References Cited (Backward Citations)

US3731044A Cited
US3731045A Cited
US3849624A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1985-12-13 1986-06-14 1986-12-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1989-12-13 1990-06-14 1990-12-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1993-12-13 1994-06-14 1994-12-14 $7700.00 Window Closed / Lapsed

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