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:
Jun. 13, 1989
Filed:
Mar. 02, 1988
Jeffrey M Kingsbury, Santa Rosa, CA (US);
Sola USA, Inc., Petaluma, CA (US);
Abstract
A method and apparatus for molding and casting ophthalmic lenses includes a front surface die and a back surface die slidably and removably received in the bore of a molding or casting apparatus. Molding or casting compound is introduced by conventional means between the two dies, and the dies are urged together to impress the die surfaces on the compound as the compound is cured by thermal or chemical means. At least one of the dies includes at least one gate channel formed in the edge thereof parallel to the axis of the bore and extending from the optical forming surface to a point adjacent to the opposite, external die surface. In compression molding, the gate channel comprises a vent through which excess molding compound is discharged from the molding cavity as the dies are urged together. As the gated die is fully inserted in the bore, the gate channel opening to the exterior is sealed, thus limiting the discharge effect and controlling the thickness of the molded part. In casting, the dies are partially inserted in the bore, and the gate channel serves as an injection channel to introduce the casting compound into the casting cavity. The dies are urged together in the bore, the gate channel first serves to vent excess casting compound from the casting cavity. Full die insertion in the bore causes the gate channel opening to the exterior to be sealed, thus limiting the discharge effect and controlling the thickness of the cast part.