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. 17, 1983
Filed:
Oct. 17, 1980
David R McMurtry, Wotton-under-Edge, GB;
Renishaw Electrical Limited, Wotton-under-Edge, GB;
Abstract
A method and apparatus for measuring a dimension of a workpiece mounted on a numerically controlled machine tool having a probe for sensing the surface of the workpiece, an automatic means for moving the probe relative to a datum, the automatic means including a first measuring means for producing a signal defining units of distance corresponding to the relative movement of the probe with respect to the datum, and a second measuring means coupled to the first measuring means for accumulating a count corresponding to the relative movement of the probe in respect to the datum. The actual position of the workpiece surface is determined relative to a nominal position thereof, the nominal position being at a known distance from the datum. According to the method the probe is moved to a first position which is one of the actual and nominal positions of the workpiece surface. Operation of the second measuring means is initiated to begin a count of the units of distance defined by the signal from the first measuring means when the probe attains the first position. The probe is then moved to a second position which is the other of the actual and nominal positions of the workpiece surface. The count in the second measuring means is terminated when the probe attains the second position. The count accumulated by the second measuring means on termination thereof defines the actual distance of the workpiece surface from the nominal position.