INFRA-RED HEAT SOURCE FOR DEMOLDING CONTACT LENSES

• Main Authors: ANDERSEN, FINN, WALKER, CRAIG, DAGOBERT, HENRI, ROSS, DENWOOD, MARTIN, WALLACE A, MOSIER, KENT DWAYNE, DAVIS, WELTON IVAN, III, PEGRAM, STEVE, BEATON, STEVE, KINDT-LARSEN, TURE
• Format: Patent
• Language: English; French
• Published: 13.11.2007
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; BLASTING; COMBUSTION ENGINES; DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS ORMACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS,CLIPS, WEDGES, JOINTS OR JOINTING; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; HOT GAS OR COMBUSTION-PRODUCT POSITIVE-DISPLACEMENT ENGINEPLANTS; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; LIGHTING; MECHANICAL ENGINEERING; NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCESIN A PLASTIC STATE; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THERMAL INSULATION IN GENERAL; TRANSPORTING; USE OF WASTE HEAT OF COMBUSTION ENGINES; WEAPONS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

Disclosed are methods and corresponding apparatuses utilized in the production of ophthalmic lenses, and more specifically for the separation of the corresponding mold halves between which contact lenses are produced. The method to which the several variations of this invention are directed includes: (1) loosening one of the mold halves relative to the contact lens by applying a thermal gradient across the mold and lens, thereby weakening the adhesion therebetween; and (2) subsequent to the loosening step, separating the corresponding mold halves by prying or lifting them apart. There are herein disclosed several embodiments of the invention which achieve these steps in various ways. With respect to the step of loosening the molds relative to the contact lenses by applying a thermal gradient thereacross, there are described devices for directing infra-red energy, steam, or coherent light energy onto the mold half. With respect to the step of separating the mold halves, subsequent to the application of the thermal gradient, there are described devices for prying, rotating and lifting, or purely lifting the loosened mold half away from the other mold half and the contact lens therein. Each of the separating devices include component elements which hold stationary one of the two mold halves as the other is removed.