Apparatus and method for forming a workpiece surface into a non-rotationally symmetric shape

An apparatus for shaping a workpiece surface to a predetermined non-rotationally symmetric shape, said apparatus comprising:

• spindle means for rotating the workpiece about an axis;
• spindle sensing means for sensing an angular position of the rotating workpiece;
• shaping means cooperating with said spindle means for removing portions of the rotating workpiece to shape the workpiece surface into the predetermined non-rotationally symmetric shape, said shaping means comprising a cutting blade, radial positioning means for relatively positioning said cutting blade and said rotating workpiece along a radial direction relative to the axis of the rotating workpiece, and transverse positioning means for relatively positioning said cutting blade and said rotating workpiece along a transverse direction to the radial direction;
• radial and transverse position sensing means for sensing respective relative radial and transverse positions of said cutting blade and the workpiece;
• and
• control means cooperating with said spindle means and said shaping means for positioning said cutting blade in predetermined varying transverse positions during a revolution of the workpiece responsive to the radial and transverse position sensing means and the spindle sensing means to form the workpiece surface into the predetermined non-rotationally symmetric shape, said control means further comprising radial position closed loop control means cooperating with said radial positioning means and said radial position sensing means for controlling the radial position of said cutting blade in a closed loop.

A retrofit apparatus for retrofitting a turning machine for aspherically shaping a workpiece surface to permit a retrofitted turning machine to shape a workpiece surface to a predetermined non-rotationally symmetric shape, the turning machine of the type including spindle means for rotating the workpiece about an axis, spindle sensing means for sensing an angular position of the rotating workpiece, shaping means cooperating with the spindle means for removing portions of the rotating workpiece, the shaping means comprising a cutting blade, radial positioning means for relatively positioning the cutting blade and the rotating workpiece along a radial direction relative to the axis of the rotating workpiece, and transverse positioning means for relatively positioning the cutting blade and the rotating workpiece along a transverse direction to the radial direction, radial and transverse position sensing means for sensing respective relative radial and transverse positions of the cutting blade and the workpiece, and a first controller comprising means for controlling the spindle means and the shaping means for forming an aspherical surface;

• said retrofit apparatus comprising:
• shape component generating means for generating both aspherical and non-rotationally symmetric shape components together defining the predetermined non-rotationally symmetric shape;
• and
• a second controller adapted to be operatively connected to the spindle means, spindle sensing means, first controller, shaping means, radial position sensing means, transverse position sensing means, and shape component generating means, said second controller comprising means for controlling the spindle means and the shaping means for positioning said cutting blade in predetermined varying transverse positions during a revolution of the workpiece responsive to the radial and transverse position sensing means and the spindle sensing means to form the workpiece surface into the predetermined non-rotationally symmetric shape from the shape components.

A method for retrofitting a turning machine for aspherically shaping a workpiece surface to permit a retrofitted turning machine to shape a workpiece surface to a predetermined non-rotationally symmetric shape, the turning machine of the type including spindle means for rotating the workpiece about an axis, spindle sensing means for sensing an angular position of the rotating workpiece, shaping means cooperating with the spindle means for removing portions of the rotating workpiece, the shaping means comprising a cutting blade, radial positioning means for relatively positioning the cutting blade and the rotating workpiece along a radial direction relative to the axis of the rotating workpiece, and transverse positioning means for relatively positioning the cutting blade and the rotating workpiece along a transverse direction to the radial direction, radial and transverse position sensing means for sensing respective relative radial and transverse positions of the cutting blade and the workpiece, and a first controller including means for controlling the spindle means and the shaping means for forming an aspherical surface, said retrofit method comprising the steps of:

• generating both aspherical and non-rotationally symmetric shape components together defining the predetermined non-rotationally symmetric shape;
• and
• operatively connecting a second controller to the spindle means, spindle sensing means, first controller, shaping means, radial position sensing means, transverse position sensing means, and shape component generating means;
• and
• operating the second controller to control the spindle means and the shaping means for positioning the cutting blade in predetermined varying transverse positions during a revolution of the workpiece responsive to the radial and transverse position sensing means and the spindle sensing means to form the workpiece surface into the predetermined non-rotationally symmetric shape from corresponding non-rotationally symmetric shape components.