摘要 |
<p>A non-contact gaging method and apparatus develops the sharply defined silhouette spanning opposite edges of an object (32), measuring the silhouette of bolts (32) and other threaded fasteners, to determine thread pitch, pitch diameter, major and minor diameter, flank angle, length of thread engagement and other fastener dimensions, to high accuracy. A laser (14) provides a beam which is focused by an object lens (28) on a pinhole in a shade (16), providing a point source from which the beam diverges. A collimating lens (18) produces a collimated broad iluminating beam (34) of laser light dimensioned to encompass the object (32). The illuminating beam is incident on a planar two-dimensional detector array (26). An image processor (30) counts pixels between light/dark transitions to provide precise dimensional measurements that are compared to stored values to reach an accept/reject decision as objets (32) pass the gaging system.</p> |