Patent ID: 6226884
Filing Date: 2001-05-08
Classification: B23Q,G01B,G05B,Y10T

Abstract:
A method of performing measurements on a machine, the machine having relatively movable parts, one of which is capable of carrying a tool or probe for performing an operation on a workpiece, and first and second structures rigidly connected to respective ones of the relatively movable parts each structure having three single spherical supports thereon spaced in a triangular array, the method comprising the steps of:calibrating a measuring bar;using the calibrated measuring bar to make a determination separately for each structure of the relative positions on the respective structures of the centers of the spherical supports which comprise calibration points;providing six pre-calibrated measuring bars each measuring bar having surfaces at its ends for contacting surfaces of the spherical supports;connecting the measuring bars between the spherical supports with contact areas of each end of each measuring bar in contact with the surface of one of the spherical supports, each of the three supports on each structure having two measuring bars connected to it;driving the machine to cause relative movements of the relatively movable parts of the machine to perform the operation on a workpiece and taking readings from the extendible measuring bars; andusing the readings from the measuring bars to provide information relating to the instantaneous positions of the calibration points of all of the supports relative to each other.