Abstract: A blocking mechanism comprises a similified rotary dial mechanism and a l clamp which automatically depressurizes a molten alloy tank in response to a release of the lens clamp pressure. A lens seat is provided with a raised resilient pad to accommodate the recessed portion of a bifocal lens. The application of final lens clamping pressure cannot occur until the lens clamp contacts the lens in order to assure that an operator's finger cannot become accidentally pinched.

Abstract: Disclosed is a blocked lens thickness gauge for measuring the thickness of a semi-finished lens that is blocked for surfacing of the concave side thereof. A lens contacting sensor shaft is supported between two sets of orthogonally mounted ball bearings and a needle shaft, the latter being supported on spring-loaded bearings such that the needle shaft is urged toward the lens contacting sensor shaft by the spring loading. A slipping clutch is also provided to allow the needle shaft to absorb inertia forces resulting from abnormal shocks.

Abstract: Disclosed is apparatus for polishing the edges of lenses, such as eyeglass lenses. The apparatus includes a lens holder, a motor for rotating the lens holder, a hand screw mechanism for opening and closing the lens holder, a polishing pad, a motor for rotating the polishing pad, a hand pivot mechanism for pivoting the polishing pad towards and away from the lens holder, a container for polishing abrasive, and a hand screw mechanism for translating the the polishing pad axially to bring different portions of the polishing pad into engagement with lenses gripped by the lens holder.

Abstract: A method and apparatus for aligning a lens blank upon a lens blocking device. The apparatus comprises a transparent aligning member, attached by arm means to a stanchion on the lens blocking machine. Vertically aligned perpendicular intersecting linear indicia are imprinted upon the upper and lower surfaces of the transparent member for vertically aligning an underlying lens without introducing a parallax error. A lens retaining member is also carried by the stanchion and is selectively pivoted into position to retain the aligned lens blank for blocking. The method consists of rotating a lens blank upon a lens blocking machine until perpendicularly intersecting linear indicia on the surface of the lens are vertically aligned with perpendicularly intersecting indicia on the upper and lower surfaces of a transparent aligning member.