Cylindrical coordinate measuring machine.

摘要

A machine for measuring objects of generally circular cross-section includes a platen movable vertically along a measuring axis and three measuring heads having probe tips which are located along radii arranged symmetrically about the measuring axis. Linear and rotary measuring devices respectively determine the position of the platen along the measuring axis and the angular position of the platen. Each measuring head had measuring devices for determining the position of its probe tip with respect to the measuring axis. The circular object is placed on the platen with its axis generally coinciding with the measuring axis and the probe tips are urged into contact with a circumferentially extending surface on the object. Then the platen and the object on it are moved axially. During the axial displacement, the radial position of the probe tips is measured at intervals and the axial position of the object for each interval is measured by the linear measuring device. From the measurements derived from the measuring heads it is possible to construct an axial profile of the object and to locate the axis of the object. Also by rotating the platen with one of the probe tips in contact with the circumferentially extending surface on the objects it is possible to construct a circumferential profile and to detect any deviation from true circularity.