Abstract: In the electrical discharge machining of the surface of a recess in a workpiece electrode to a shape corresponding to that of a tool electrode, the electrodes are relatively displaced, during a finishing phase of machining, along an axis of penetration and simultaneously in a plane perpendicular to the axis of penetration with a cyclic translational movement whose amplitude increases with the penetration of the tool in the workpiece. This provides a virtual 3-dimensional dilatation of the tool as it advances, and enables control of the sparking in both the frontal and lateral parts of the machining zone, such that the shape of the machined portion is an image of the tool shape. The cyclic translational movements can be obtained with an eccentric member whose eccentricity relative to a shaft is controlled by limiting axial movement of the shaft at a position corresponding to a predetermined penetration.

Abstract: In the electrical discharge machining of the surface of a recess in a workpiece electrode to a shape corresponding to that of a tool electrode, the electrodes are relatively displaced, during a finishing phase of machining, along an axis of penetration and simultaneously in a plane perpendicular to the axis of penetration with a cyclic translational movement whose amplitude increases with the penetration of the tool in the workpiece. This provides a virtual 3-dimensional dilatation of the tool as it advances, and enables control of the sparking in both the frontal and lateral parts of the machining zone, such that the shape of the machined position is an image of the tool shape. The cyclic translational movements can be obtained with an eccentric member whose eccentricity relative to a shaft is controlled by limiting axial movement of the shaft at a position corresponding to a predetermined penetration.

Abstract: In the electrical discharge machining of the surface of a recess in a workpiece electrode to a shape corresponding to that of a tool electrode, a method whereby the electrodes are relatively displaced, during a finishing phase of machining, along an axis of penetration and simultaneously in a plane perpendicular to the axis of penetration with a cyclic translational movement whose amplitude increases with the penetration of the tool in the workpiece. This provides a virtual 3-dimensional dilatation of the tool as it advances, and enables control of the sparking in both the frontal and lateral parts of the machining zone such that the shape of the machined portion is an image of the tool shape. The cyclic translational movements can be obtained with an eccentric member whose eccentricity relative to a shaft is controlled by limiting axial movement of the shaft at a position corresponding to a predetermined penetration.

Abstract: In the electrical discharge machining of the surface of a recess in a workpiece electrode to a shape corresponding to that of a tool electrode, the electrodes are relatively displaced, during a finishing phase of machining, along an axis of penetration and simultaneously in a plane perpendicular to the axis of penetration with a cyclic translational movement whose amplitude increases with the penetration of the tool in the workpiece. This provides a virtual three-dimensional dilatation of the tool as it advances, and enables control of the sparking in both the frontal and lateral parts of the machining zone. The cyclic translational movements are obtained from a rotatable shaft having an axis parallel to the axis of penetration and an eccentric member cooperating with the rotatable shaft to slide relative to the shaft in a direction forming a predetermined angle with the direction of penetration, the eccentric member being rotated in unison with the shaft about its axis.

Abstract: In the electrical discharge machining of the surface of a recess in a workpiece electrode to a shape corresponding to that of a tool electrode, the electrodes are relatively displaced, during a finishing phase of machining, along an axis of penetration and simultaneously in a plane perpendicular to the axis of penetration with a cyclic translational movement whose amplitude increases with the penetration of the tool in the workpiece. This provides a virtual three-dimensional dilatation of the tool as it advances, and enables control of the sparking in both the frontal and lateral parts of the machining zone. The cyclic translational movements are obtained from a rotatable shaft having an axis parallel to the axis of penetration and an eccentric member cooperating with the rotatable shaft to slide relative to the shaft in a direction forming a predetermined angle with the direction of penetration, the eccentric member being rotated in unison with the shaft about its axis.

Abstract: In the electrical discharge machining of the surface of a recess in a workpiece electrode to a shape corresponding to that of a tool electrode, a method whereby the electrodes are relatively displaced, during a finishing phase of machining, along an axis of penetration and simultaneously in a plane perpendicular to the axis of penetration with a cyclic translational movement whose amplitude increases with the penetration of the tool in the workpiece. This provides a virtual 3-dimensional dilatation of the tool as it advances, and enables control of the sparking in both the frontal and lateral parts of the machining zone such that the shape of the machined portion is an image of the tool shape. The cyclic translational movements can be obtained with an eccentric member whose eccentricity relative to a shaft is controlled by limiting axial movement of the shaft at a position corresponding to a predetermined penetration.

Abstract: In the electrical discharge machining of the surface of a recess in a workpiece electrode to a shape corresponding to that of a tool electrode, the electrodes are relatively displaced, during a finishing phase of machining, along an axis of penetration and simultaneously in a plane perpendicular to the axis of penetration with a cyclic translational movement whose amplitude increases with the penetration of the tool in the workpiece. This provides a virtual 3-dimensional dilatation of the tool as it advances, and enables control of the sparking in both the frontal and lateral parts of the machining zone, such that the shape of the machined .[.position.]. .Iadd.portion .Iaddend.is an image of the tool shape. The cyclic translational movements can be obtained with an eccentric member whose eccentricity relative to a shaft is controlled by limiting axial movement of the shaft at a position corresponding to a predetermined penetration.