John D Macgregor

US Patent:

7019247, Mar 28, 2006

Filed:

Feb 22, 2005

Appl. No.:

11/062381

Inventors:

John MacGregor - Ann Arbor MI, US

Assignee:

Ann Arbor Machine Company - Chelsea MI

International Classification:

B23H 7/30
B23H 7/10

US Classification:

219 692

Abstract:

An electrical discharge machining head incorporating piezo-electric motors for controlling motion of a slide assembly. The slide assembly is translatable within a machine base and its motion is controlled by the piezo-electric motors. The slide assembly precisely controls the movement of an EDM electrode through the wire guide.

US Patent:

7964817, Jun 21, 2011

Filed:

May 17, 2007

Appl. No.:

11/750011

Inventors:

John MacGregor - Ann Arbor MI, US

Assignee:

AA EDM Corporation - Ann Arbor MI

International Classification:

B23H 9/14
B23H 7/26

US Classification:

219 6917, 219 692

Abstract:

An electrical discharge machining apparatus having a wire electrode and a guide system for machining reverse-taper bores in a workpiece, particularly cone-shaped bores. A guide body near the workpiece stabilizes a first portion of an electrode and a second portion of the electrode extends from the guide body terminating in a working tip. As the guide body is wobbled about the longitudinal axis of a desired workpiece bore, the electrode is advanced and the working tip of the electrode erodes progressively larger closed curves in the workpiece, resulting in a reverse taper bore in the workpiece.

US Patent:

45103658, Apr 9, 1985

Filed:

May 6, 1982

Appl. No.:

6/375501

Inventors:

John R. MacGregor - Ann Arbor MI
Gary F. Rupert - Ann Arbor MI
Thomas M. Kennedy - Chelsea MI

Assignee:

Raycon Corporation - Ann Arbor MI

International Classification:

B23P 108
B23P 114

US Classification:

219 69G

Abstract:

EDM apparatus has a servo drive under the control of a main control system for advancing a machining electrode toward a conductive workpiece. When the electrode arrives at a surface of the workpiece to commence EDM machining, the main control system causes a sudden deceleration of the servo. The depth controller detects this sudden deceleration by means of a sensor and sets a zero reference plane from which machining depth is measured. The depth controller can also detect electrode breakthrough by detecting servo acceleration occurring when the electrode breaks through a surface of the workpiece.

US Patent:

43617450, Nov 30, 1982

Filed:

Sep 21, 1979

Appl. No.:

6/077581

Inventors:

Gary F. Rupert - Ann Arbor MI
Thomas M. Kennedy - Chelsea MI
John R. MacGregor - Ann Arbor MI

Assignee:

Raycon Corporation - Ann Arbor MI

International Classification:

B23P 114

US Classification:

219 69G

Abstract:

A process control system for electrical discharge machining apparatus to control automatically the machining of a workpiece. The process control system is operable to receive and retain a plurality of operation instructions regarding electrical discharge machining parameters and transmit operation commands to the electrical discharge machining apparatus to execute the operation instructions in controlling the complete machining of a workpiece. The process control means includes a storage unit operable to store a plurality of operation instructions enabling absolute repeatability of the machining process defined by the operation instructions in the storage unit for a plurality of workpieces. The process control system also includes a digitally controlled servo system to regulate the movement of the electrode toward and away from the workpiece.