Daniel Ewing Boone

US Patent:

59389885, Aug 17, 1999

Filed:

Aug 19, 1996

Appl. No.:

8/699629

Inventors:

Victor Lust - Jacksonville FL
Daniel G. Boone - Jacksonville FL
Robert E. LaBelle - Jacksonville FL
Dennis M. Jones - Shrewsbury MA
Robert G. Petit - Phillipston MA

Assignee:

Johnson & Johnson Vision Products, Inc. - Jacksonville FL

International Classification:

B29D 1100

US Classification:

264 25

Abstract:

An injection molding process for molding an assembly of a frontcurve molds in a plurality of unitary solid piece of polymer in which plurality of frontcurve molds are arranged symmetrically around a single center polymer injection gate. In this arrangement the molten polymer flows radially outwardly therefrom uniformly in all directions to the four frontcurves to form one common molded piece of polymer. In a compression injection molding process, the pressure on the molten polymer is maintained relatively constant, and the mold is mechanically collapsed during the molding operation. The present invention molds an assembly of frontcurve molds in a manner in which there is a significant reduction of residual stress locked into the resultant assembly of frontcurve molds. This results in a significant reduction in warpage and shrinkage of each frontcurve mold, which is not optically stressed, and results in a subsequent casting of an ophthalmic lens which is not optically stressed. Moreover, the assembly of frontcurve molds can function as its own support pallet for product placement and alignment purposes during subsequent production operations.