Abstract: A replaceable lens surfacing pad with integral wear indicating pattern. Pad material is conformable to the face of a lens surfacing tool and is impervious to the abrasive slurry used in fining and polishing operations in the manufacture of optical quality lenses. A wear indicating pattern is milled, embossed, or etched into the pad face which contacts the lens in association with the abrasive slurry. The pattern consists of one or more intermediate faces at one or more levels between the pad face contacting the lens and the opposite pad face bonded with pressure sensitive adhesive to the lens surfacing tool. As the lens surfacing operation progressively erodes the pad face contacting the lens, the remaining distance to one or more intermediate faces reveals the regularity or irregularity and amount of pad wear before surfacing tool damage occurs.

Abstract: A gradient dyeing machine employing a motor driven threaded camshaft to simultaneously rotate a symmetrical cam of appropriate configuration at the end of the shaft and move a ramp-shaped arm pivotally attached to a threaded carriage riding on the camshaft forward from the motor toward the cam at a continuously increasing angle relative to the camshaft over the surface of the rotating cam, to continuously and repeatedly immerse a lens holder to progressively decreasing depths in a lens coloring liquid.