Abstract: A molding apparatus and method for producing a thermoplastic lens having a minimum of stress including a male mold and a female mold defining therebetween a molding space, one of the molds being mounted for movement towards and away from the other mold, and a gate mounted adjacent to the other mold for the passage of thermoplastic resin. The other mold defines a window width for admitting thermoplastic resin to the molding space. A compression pressure applying member such as a wedge-shaped slide member is further provided for moving the other mold toward and away from the one mold so as to compress thermoplastic resin within the molding space as well as to automatically withdraw the other mold from the one mold prior to the injection of thermoplastic resin.

Abstract: Method and apparatus for molding a plurality of lenses of thermoplastic resin of different optical power and/or mass that comprises a plurality of molding stations, each including a rigidly supported male mold and a female mold allowed to float freely within defined limits. At each molding station, a wedge-shaped slide member whose position is controlled by a hydraulic piston is movable an independent distance over the female mold between a home position allowing maximum free floating and an operative position independent for each slide member to transfer a compression force onto an injected body of molten resin at said station. The hydraulic pistons are actuated from a common manifold to allow equal compression pressure at each molding station after the slide members move their independent distances.