Magnetic chuck

摘要

A magnetic chuck for use in grinding optical lenses consisting of a means for increasing or decreasing the magnetic force exerted by a magnetic attachment surface contained in a housing sized for use in a lens grinding machine, wherein the means for increasing or decreasing the magnetic force exerted by the magnetic attachment surface is operated by means of manually operating a control to rotate a permanent magnet 90 degrees from a first position to a second position, where in the first position the magnetic force exerted by the magnetic attachment surface is minimal and in the second position, a substantial increase of magnetic force is exerted by the magnetic attachment surface for secured attachment of the lens piece during grinding of a raw glass lens blank into an optical lens.