Abstract: A method and an apparatus for a precision optical distance measuring device which can be used to determine both external and internal target geometries. The beam from a frequency modulated laser diode is split into reference and target beams. A closed loop control system modulates the amplitude of the reference beam to maintain a balance between the power in the target return beam and the reference beam. This enables the sensor to operate with targets of widely varying reflectivity and across a broad range of angles of incidence of the target beam to the target. The reference and target return beams interfere at a detector producing a beat wave. The beat frequency is linearly related to the distance of the target from the sensor. The frequency of the beat wave is determined to high precision, thus giving the position to high precision.

Abstract: A non-contact laser-based sensor guided by a precision mechanical system scans a thread form producing a set of digitized images of the thread form. The digitized images are analyzed to derive quantitative information about thread characteristics such as pitch, lead, root radius, flank angle, surface roughness, helix variation, and pitch diameter. Thread form data may be stored and later retrieved in order to provide traceability and verification of thread form measurements to a predetermined thread form specification. The apparatus and method of the invention can measure characteristics for shapes similar to threads, such as gears and dies used for cold forming processes. The thread measurement system can be mounted on thread making machines and used for on-line monitoring and control of the thread forming process.

Abstract: A monitoring system having a stylus mounted to a support that controllably moves the stylus along a travel path as it contacts an object of interest. The object is supported by a rotating turntable and held in place by a manually actuatable retainer that exerts a repeatable downward force on the object. A frame that supports the stylus is supported by a flexure plate that makes the task of orienting the frame easier. The frame supports a saddle that can be raised and lowered by a belt system driven by a D.C. pancake motor. The entire monitoring system achieves a required degree of accuracy in monitoring object shape at a reduced manufacturing cost.

Abstract: A monitoring system having a stylus mounted to a support that controllably moves the stylus along a travel path as it contacts an object of interest. The object is supported by a rotating turntable and held in place by a retainer that exerts a repeatable downward force on the object. A frame that supports the stylus is moved by a number of motors to provide three mutually orthogonal directions of motion to the stylus. Coordinated translations of the stylus and rotations of the object allow the monitoring system to check the shape of the object and compare the measured shape with specifications for the object.