Right and left-hand screw thread optical discriminator
AssigneeMectron Engineering Company, Inc.
InventorJames L. Hanna
Life of this patent
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Abstract
An optical device for discriminating threaded workpiece by the handedness by their screw thread profiles. The device presents a pair of light beams which pass generally tangent to the workpiece at angularly displaced positions. The light beams are inclined to follow the helix direction of a given handedness of a workpiece. Upon axial advancement of a workpiece through the device, a chopped output from the photodetectors indicates that the handedness of the threads matches the inclination of the light beams. The oppositely threaded workpiece, however, provides a generally constant DC output. With appropriate signal processing electronics, an automatic system for discriminating workpieces by thread handedness is provided.
Claims7
A system for discriminating between right and left-hand threaded workpieces, comprising;
- a workpiece support for positioning said workpiece,
- first and second light emitting means for presenting first and second light beams which are oriented to pass adjacent and generally tangent to a threaded portion of said workpiece at angularly displaced points, said light beams further inclined at the helix angle of a designated one of either said right or said left-hand threads of said workpiece,
- first and second light detecting means for receiving said first and second light beams respectively after passing adjacent said workpiece, and outputting signals proportional to the light incident thereon, and
- displacement means for causing relative longitudinal displacement between said workpiece and said light beams whereby a varying output from said light detecting means indicates the presence of a workpiece having said designated threads, and a generally constant output from said detecting means indicates a workpiece having the opposite of said designated threads.
Dependencies are inferred from the claim text.