Adjustable contact lens mold
OwnerGeoffrey H. Galleyinventor
Life of this patent
Estimating the term…
Abstract
A plastics material mold for casting a contact lens from curable material. Disposable male and female mold members (20,22;50,51) define a mold cavity and each having a curved surface (21,23;52,54) for molding respective optical surface of the contact lens, the male mold member having a shoulder (26,53) which is a slidable fit with a generally cylindrical, e.g. frusto-conical, surface (25,55) on a female mold member to permit relative mold member movement during curing without substantially affecting the optical quality of the molded optical surfaces. The sliding fit shoulder and female surface are relatively simple to mold with accuracy and thus permit the edge (29) of the eventual cast lens to be formed relatively reliably and accurately.
Claims10
A plastics material mold for casting a contact lens from curable material which shrinks during curing, said mold comprising:
- a male mold member;
- a female mold member;
- said male and female mold members being adapted to fit together to define a mold cavity;
- said male and female mold members each presenting a curved surface for molding a respective desired optical surface of a contact lens;
- said male mold member having a shoulder adjacent and circumferentially surrounding said curved surface of the male mold member, said shoulder presenting a substantially right-angled external corner in any cross-section around its circumference;
- said female mold member presenting a generally cylindrical surface adjacent and circumferentially surrounding said curved surface of the female mold member;
- said male and female mold members being provided with a means of initially limiting the motion of each towards the other during assembly of said mold members and subsequently permitting such movement during the curing of said curable material;
- and
- said external corner of said shoulder having a circumferentially continuous slidable fit with said generally cylindrical surface when the mold members are assembled to permit the mold members to move slidably directly towards one another during curing and consequent shrinkage of said curable material introduced into the mold cavity to cast a lens, said cast lens thereby having a circumferential edge formed between said external corner of said shoulder and said generally cylindrical surface.
A plastics material mold for casting a contact lens from curable material, said mold comprising disposable male and female mold members adapted to fit together to define a mold cavity and each providing a curved surface for molding a respective desired optical surface of the contact lens, the male mold member having a shoulder which is a circumferentially continuous slidable fit with a generally cylindrical surface on the female mold member outwardly of the optical curved surfaces to permit relative mold member slidable movement directly towards one another during curing without substantially affecting the optical quality of the molded optical surfaces;
- said male and female mold members being provided with a means of initially limiting the motion of each towards the other during assembly of said mold members and subsequently permitting such movement during the curing of said curable material.
Dependencies are inferred from the claim text.