Patent ID: 8051576
Filing Date: 2011-11-08
Classification: G01B

Abstract:
1. A metrological instrument comprising: a turntable for supporting a workpiece, wherein the turntable is rotatable about a spindle axis; a support supporting a stylus gauge for carrying an elongate stylus, the support comprising i) a support body and ii) an attitude arm which is mounted to the support body so as to be rotatable about a pivot axis, the attitude arm holding the stylus gauge, wherein the stylus gauge is arranged to generate a signal representative of the deflection of the elongate stylus along a measurement direction as the stylus follows a surface of the workpiece on rotation of the turntable about the spindle axis; an attitude switching mechanism for rotating the attitude arm about said pivot axis to switch the attitude of the stylus between a first attitude in which the longitudinal axis of the stylus is generally aligned with the spindle axis and a second attitude in which the longitudinal axis of the stylus is generally perpendicular to the spindle axis; wherein the attitude arm comprises i) a first adjuster for moving the stylus tip in a direction perpendicular to both the spindle axis and the measurement direction when the stylus is aligned with the spindle axis to allow alignment of the measurement direction with the spindle axis, and ii) a second adjuster for moving the stylus tip in a direction perpendicular to both the spindle axis and the measurement direction when the stylus is aligned perpendicular with the spindle axis to allow alignment of the measurement direction with the spindle axis.