Importance

Loading Importance Indicators...

Abstract

An apparatus, for making a lens from thermoplastic material in the form of a monolithic preform mass, having a press; and a pair of lens molds positioned in said press. The monolithic preform mass has at least one or more radii and is disposed between the lens molds such that said one or more radii make point or line contact with said lens molds. Means are provided for closing the pair of lens molds, and pressing the molds toward each other and against said preform mass to a predetermined pressure; and for heating up the molds until the preform mass begins to soften with the predetermined pressure varying slightly therefrom. The means for heating continuing to heat up the pair of lens molds, while holding and maintaining the predetermined pressure on the preform mass; wherein the heating up is repeated until the preform mass is reconfigured and/or transformed by compression molding into a lens defined by the pair of lens molds; and whereby the heating up of said pair of lens molds is terminated while maintaining said predetermined pressure until a finished, formed lens is removed from the molds with the apparatus of the invention, air bubbles are prevented from being entrapped in the lens by virtue of the preform mass having one or more radii making point or line contact with each of the lens molds.

Loading the Abstract Image...

First Claim