The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 07, 1981
Filed:
Aug. 15, 1979
Paolo Baiocchi, Parma, IT;
Gian G Giani, Parma, IT;
Intercast Europe S.p.A., Parma, IT;
Abstract
An improved method for manufacturing spectacle lenses and the like from diglycol allyl carbonate or equivalent plastic by first heating the plastic monomer in the liquid state and containing a polymerization initiator therefor in a planar mold until a degree of polymerization in the range of about 65-85% of completion has been achieved, then removing the partially polymerized material from the mold, subjecting the same to deflection to a curvature corresponding to the desired lens and heating the thus-deflected material until polymerization is complete. Preferably, the initial planar molding step is carried out with a layer or sheet of the material of sufficient size as to contain a plurality of individual lens elements, and after removal thereof from the mold, a plurality of individual lens elements is derived therefrom and such elements are separately subjected to deflection and further polymerization. Preferably, the amount of polymerization initiator exceeds the normally used amount. A post thermal treatment is advantageous to stabilize the lens elements from loss of the curvature imparted thereto.