Pocket surface roughness gage

Abstract

A compact, efficient, self-contained dynamic surface roughness gage includes a staging frame that supports a reciprocatable arm that can be pivoted about an axis perpendicular to a V-shaped working surface at the underside of the frame between releasably fixed positions located 90.degree. apart to facilitate staging the gage on different workpiece configurations. The arm supports a probe comprising a skid and a stylus which is coupled by way of a special flexure to a stereo phonograph cartridge so that only the vibratory motions of the stylus in a direction perpendicular to the nominal plane of the frame working surface are coupled to the transducer. As the probe scans over a workpiece surface with the skid following the same track as the stylus, the two outputs from the transducer are summed to produce a single electrical analog of the vibratory motion of the stylus in that favored direction. That signal is coupled to a control circuit which processes the signal and applies an instruction to a display which thereupon shows a number correspnding to the surface roughness of the workpiece as measured by the gage.