The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 31, 1977
Filed:
Sep. 24, 1975
Graham John Siddall, Keyworth, EN;
Michael Antony Player, Aberdeen, SC;
The Rank Organisation Limited, London, EN;
Abstract
A method of determining the coordinates of the center of curvature of the curved surface of a workpiece on a surface measurement instrument of the type having a workpiece table rotatably mounted on a main spindle, and a sensor for contacting the surface of a workpiece mounted on the table. The method comprises the steps of traversing the sensor over the workpiece surface and deriving three signals representing the value of the radial distance from the spindle to the workpiece surface at three points spaced along the traverse. From these values, and a knowledge of the angular separation of the three points an approximation for the coordinates of the center of the curved surface of the workpiece with respect to the spindle can be derived using the algorithm ##EQU1## WHERE X AND Y RESPECTIVELY REPRESENT THE COORDINATES OF THE CENTER OF THE WORKPIECE, R.sub.1, R.sub.2, R.sub.3 REPRESENT THE RADIAL DISTANCE FROM THE SPINDLE AXIS TO THE WORKPIECE SURFACE AT THE THREE POINTS ALONG THE TRAVERSE, AND .phi. REPRESENTS THE ANGULAR SEPARATION OF THE THREE POINTS. Using a further algorithm derived from this an estimate of the radius of curvature of the surface can also be provided.