Abstract: A probe assembly for use with a three axis inspection machine that is intended to measure deviation of work piece surfaces in three axes includes apparatus for statically balancing the probe in the X and Y axes and also for restricting motion of the probe to a single axis or to any combination of the axes. The probe assembly includes a universal joint arrangement on the distal end of the measuring arm of the machine permitting deflection in the X and Y axes and also includes means for permitting travel in the Z axis. The various components are interconnected so as to make it possible to selectively preclude movement in either the X, Y or Z axis or to permit movement in one, two or all three axes, as desired. Furthermore, easy release friction means are employed to permit the probe stylus holder to slide along its longitudinal axis to prevent inadvertent damage to the actual probe assembly itself. The assembly is also designed to measure deviation of the probe, either by a printout or on an analog meter.

Abstract: This invention relates to method and apparatus for improving the accuracy of optical or electrical position measuring apparatus wherein movement of one object relative to another is measured. One known system employs primary and secondary windings each comprising a multiplicity of series-connected conductors arranged on adjacent faces of relatively movable members of insulating material. In another system an optical Moire fringe pattern is moved in correspondence as regards extent and sense with the movement with the object and the number of fringes displaced from a fiducial line are counted.