초록 ▼

The four components of the deviations of a rotary table from an ideal axis of rotation can be obtained by a single measuring method wherein a test body (4) having a plurality of well-defined measurement points is placed on the rotary table (1) and the positions of said measuring points are then dete

The four components of the deviations of a rotary table from an ideal axis of rotation can be obtained by a single measuring method wherein a test body (4) having a plurality of well-defined measurement points is placed on the rotary table (1) and the positions of said measuring points are then determined by means of a coordinate-measuring instrument (3), for each of various angular positions of the rotary table, there being thus a set of ascertained measurement-point coordinates for each of the angular positions of the rotary table. From the sets of measurement-point coordinates, the travel deviations fa, fr and ft of the axis of rotation, and the angle-position deviation pw are then determined by calculation.

대표청구항 ▼

The method of using a multiple-coordinate measuring machine to calibrate a rotary table adapted to support a workpiece for measurement by said machine, wherein the machine includes a prove for measurement of the coordinates of a succession of different contacts with a workpiece, which method compris

The method of using a multiple-coordinate measuring machine to calibrate a rotary table adapted to support a workpiece for measurement by said machine, wherein the machine includes a prove for measurement of the coordinates of a succession of different contacts with a workpiece, which method comprises the steps of (a) selecting a ball plate having at least three mutually spaced balls fixedly mounted to said plate, (b) mounting said plate to the rotary table so as to expose said balls for probe-contact measurement, (c) performing a first set of different multiple-contact measurements on each ball for a first angular position of the rotary table and calculating therefrom the positional coordinates of each ball center when in said first angular position, (d) repeating step (c) for each of a succeeding plurality of angularly indexed positions of the work table, for at least one complete rotation of the table, (e) statistically determining from the plural angularly-indexed positional coordinates of the centers of said balls, a selected one or more of a plurality of different deviations as a function of indexed angular position and for said at least one rotation, said different deviations comprising: axial-travel deviation, fa (ar (at (aw, (f) storing the predetermined deviation values as a function of indexed angular position; and (g) using the stored deviation values as corrections to coordinate measurements on a workpiece mounted to and indexed via the rotary table.