초록 ▼

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,

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.

대표청구항 ▼

A method of molding a lens comprising: placing a male mold and a female mold in facing relation so as to define therebetween a molding space; mounting one of said molds for movement toward and away from the other mold; mounting gate means adjacent said other mold for providing a passage for thermopl

A method of molding a lens comprising: placing a male mold and a female mold in facing relation so as to define therebetween a molding space; mounting one of said molds for movement toward and away from the other mold; mounting gate means adjacent said other mold for providing a passage for thermoplastic resin; said other mold defining a window width for admitting thermoplastic resin to said molding space; said outer mold floating away from said one mold in response to the admission of thermoplastic resin; operatively engaging said other mold with compression means movable from a home position to an end position to move said other mold toward said one mold and to compress thermoplastic resin within said molding space; adjusting the home position of said compression means so as to define a maximum distance said other mold may be displaced from said one mold to thereby adjust the initial window width so as to balance thermoplastic resin fill speed and compression pressure applied to thermoplastic resin within said molding space; delivering molten plastic resin under pressure to said molding space until sufficient resin is injected to increase the distance of said other mold from said one mold to said maximum distance; reducing said injection pressure while moving said compression means so as to operatively engage and apply pressure to said other mold; continuing to apply pressure so as to compress said resin within said molding space to form a lens blank; moving said one mold away from said other mold to provide access to said lens blank; and removing said lens blank from said molding space. An apparatus for molding a lens comprising: a male mold and a female mold defining therebetween a molding space; means mounting one of said molds for movement toward and away from the other mold; gate means mounted adjacent to said other mold for passage of thermal plastic resin; and other mold defining a window width for admitting thermoplastic resin to said molding space; said other mold floating away from said one mold in response to the admission of thermoplastic resin; compression means for operatively engaging said other mold and movable from a home position to an end position to move said other mold toward said one mold and to compress thermoplastic resin within said molding space; and means for adjusting the home position of said compression means to adjust the initial window width so as to balance thermoplastic resin fill speed and control the compression pressure applied to thermoplastic resin within said molding space.