Multiple optical curve molds formed in a solid piece of polymer
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
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Aug 17, 1999
Grant Date -
N/A
app pub date -
Aug 19, 1996
filing date -
Aug 19, 1996
priority date (Note) -
Expired
status (Latency Note)
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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.
First Claim
Other Claims data not available