Correction apparatus for NC lathe

A correction apparatus for an NC lathe equipped with a spindle, at least two tool rests provided so as to be movable in the direction along the axis of said spindle and in the direction perpendicular to the axis of said spindle, feed mechanisms for moving each of said tool rests in said directions, and a feed controller for generating movement target position data regarding each of said tool rests, for numerically controlling said feed mechanisms on the basis of the generated movement target position data and for moving each of said tool rests to its movement target position,

• said correction apparatus for correcting the movement target positions of said tool rests, the movement positions of which are numerically controlled on the basis of said movement target position data, comprising:
• a correction amount setting section for receiving said movement target position data from said feed controller, for recognizing the position of each of said tool rests in the direction along the axis of said spindle and/or in the direction perpendicular to the axis of said spindle on the basis of the received movement target position data, and for setting correction amounts for canceling the displacements of the other tool rest in the direction along the axis of said spindle and/or in the direction perpendicular to the axis of said spindle caused depending on the position of the one of said tool rests in the direction along the axis of the spindle and/or in the direction perpendicular to the axis of said spindle, and
• a correction execution section for correcting said movement target position data for said other tool rest on the basis of the correction amounts having been set by said correction amount setting section.