Probe for measuring workpieces

Claim 1

A probe for measuring workpieces comprising: a body having an axis; a fixed structure contained within and distinct from the body; means connecting said fixed structure to the body; a movable structure at least partially contained within the body and including a stylus holder to which one or more workpiece-contacting styli are connectable; support means for supporting the movable structure in a rest position on said fixed structure, said support means comprising a plate portion of said fixed structure which is centered about said axis, said plate portion overlying at least a portion of said means connecting said fixed structure to the body in a direction transverse to said axis; bias means for urging the movable structure into the rest position from which it is displaceable in opposition to the bias means when a stylus contacts a workpiece and a displacing force is thereby produced on the stylus, the bias means acting to restore the movable structure to the rest position when the displacing force ceases; sensing means for sensing said stylus contact with the workpiece and for providing an electrical signal indicative thereof; and wherein the bias means acts between the movable structure and the fixed structure, the bias means being biased against a surface of said fixed structure extending transverse to said axis and spaced from said movable member along said axis in a direction away from the stylus holder, and the means connecting the fixed structure to the body includes the sensing means, whereby the forces produced by the bias means are not reacted through the sensing means.