Other

Electronic Measuring Devices, Inc.

Klaus Ulbrich

Russell S Shelton

A stylus is supported by an upper coupling member which is supported by a lower coupling member which is supported by a probe which is movably supported by a rail of a coordinate positioning machine. The coupling members are held together by a permanent magnet, and their relative positioning is established by first and second sets of positioning elements provided on the first and second coupling members respectively. The sets of positioning elements are mutually engagable in a plurality of angular orientations about the axis of the coupling to provide a plurality of angularly indexed positions at which the lower coupling member has stable and repeatable positions relative to the upper coupling member. The coupling is carried to the indexing dock where a carrier engages the lower coupling member, and the lower coupling member is released from the upper coupling member by energizing an electromagnet which repels the coupling members apart. The indexing dock rotates the lower coupling member about its axis to change its angular orientation of the lower coupling member relative to the upper coupling member. The stylus is connected to a stylus mount on the lower coupling member, and the stylus mount has a plurality of stylus-receiving mounting holes which have axes extending in different directions from the axis of the stylus mount and have different inclinations relative to the axis of the stylus mount. A plurality of lower coupling members can interchangeably be mounted on the upper coupling member. When not in use, the lower coupling members are held in storage docks which accept their lower coupling members regardless of their angular orientation about the coupling axes.

Coordinate positioning apparatus with indexable stylus, components thereof, and method of using it

A probe is mounted on a machine head which has mobility and readouts in three linear coordinate directions. The probe carries a stylus with a tip which has mobility relative to the head in three nonlinear coordinate directions which are nonaligned with the axes of head movement. A mathematical model, produced by a calibration technique before measurements are taken, translates readouts of the stylus tip's position in the nonlinear coordinates into values which are aligned with the coordinate axis system of the machine head. The probe has three flex wire motion guiding devices connected together in series, and each of these devices has a second member movably supported on a first member by flexible wires arranged in two nonparallel sets of parallel wires. The second member is thus constrained to movement in a single arcuate path which lies transverse to the longitudinal axes of the wires in both sets. The distance of movement between the first and second members is sensed by a differential optical transducer which has two light source elements which emit light beams and two light sensor elements which receive these beams. The elements on each of the relatively movable members face in opposite directions so that movement between the members lengthens one beam and shortens the other beam. An electronic circuit compares signals from the light sensor elements and provides an output signal which indicates the position of the second member relative to the first member.

Probe, motion guiding device, position sensing apparatus, and position

A coordinate measuring machine obtains accurate readings by analyzing the mechanical vibrations which occur between a contact point where a probe contacts a workpiece and a readout point where a position-sensing device produces signals indicative of the relative positioning between the probe and the workpiece. The position-sensing device produces an oscillating signal due to the mechanical vibrations. A set of sequential readings is taken of this oscillating signal, and an average of these sequential readings is calculated to produce a final output signal which substantially represents an equilibrium position of the vibrations. The routine for producing the final output signal is triggered in response to the deceleration which occurs when the probe contacts the workpiece.

Measuring method and apparatus

A probe is mounted on a machine head which has mobility and readouts in three linear coordinate directions. The probe carries a stylus with a tip which has mobility relative to the head in three nonlinear coordinate directions which are nonaligned with the axes of head movement. A mathematical model, produced by a calibration technique before measurements are taken, translates readouts of the stylus tip's position in the nonlinear coordinates into values which are aligned with the coordinate axis system of the machine head. The probe has three flex wire motion guiding devices connected together in series, and each of these devices has a second member movably supported on a first member by flexible wires arranged in two nonparallel sets of parallel wires. The second member is thus constrained to movement in a single arcuate path which lies transverse to the longitudinal axes of the wires in both sets. The distance of movement between the first and second members is sensed by a differential optical transducer which has two light source elements which emit light beams and two light sensor elements which receive these beams. The elements on each of the relativly movable members face in opposite directions so that movement between the members lengthens one beam and shortens the other beam. An electronic circuit compares signals from the light sensor elements and provides an output signal which indicates the position of the second member relative to the first member.

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Flanders, NJ, United States of America

Klaus Ulbrich