초록 ▼

In order to measure the surface profile of a workpiece, a yoke having two fixed feet is held in contact with the surface as the workpiece is rotated. A dynamic probe is mounted on the yoke by means of a transducer which outputs a signal dependent upon the position of the dynamic probe relative to a

In order to measure the surface profile of a workpiece, a yoke having two fixed feet is held in contact with the surface as the workpiece is rotated. A dynamic probe is mounted on the yoke by means of a transducer which outputs a signal dependent upon the position of the dynamic probe relative to a transducer datum. The fixed feet and the foot of the dynamic probe have a similar shape and size so that they detect irregularities in the workpiece surface with equal sensitivity. Fourier analysis of the signal caused by movement of the dynamic probe directly by the workpiece and also by movement of the yoke enables the profile of the workpiece to be determined. In order to improve the frequency response of the transducer output over the range of harmonics considered, the angles between the dynamic probe and the fixed probes are unequal. The apparatus does not require a precision spindle type machine to rotate the workpiece and is therefore particularly suitable for in situ measurement of workpiece profiles.

대표청구항 ▼

An apparatus for measuring a surface profile of a workpiece having a generally circular section, comprising a probe assembly, means for rotating the workpiece relative to the probe assembly, the probe assembly comprising a yoke, a pair of feet mounted on the yoke for engagement with the workpiece su

An apparatus for measuring a surface profile of a workpiece having a generally circular section, comprising a probe assembly, means for rotating the workpiece relative to the probe assembly, the probe assembly comprising a yoke, a pair of feet mounted on the yoke for engagement with the workpiece surface at the section to be measured at first and second locations spaced in the direction of relative movement so that the feet and yoke follow variations in the surface profile upon such movement, and detector means which is mounted on the yoke operable to provide a signal dependent upon the distance relative to the probe assembly of a third location on the work piece surface spaced from the feet locations in the direction of relative movement, the signal varying in accordance with the relative rotational position of the workpiece and the probe assembly, the feet being adapted to follow variations in the surface profile substantially as closely as the detector means, the apparatus further comprising signal processing means responsive to the signal from the detector means for determining the surface profile of the workpiece, said signal processing means being operable to take into account variations in the detected distance due to movement of the yoke caused by the feet engaging irregularities in the surface profile in addition to variations in the detected distance due to surface irregularities directly detected by the detector means.