Methods and apparatus for producing contact lenses
AssigneeCooperVision International Limited
InventorsRobert Oag, Edward James Harley Evans, Robin Frith
Life of this patent
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Abstract
The present invention concerns methods and an apparatus for producing contact lenses, such as silicone hydrogel contact lenses, and further relates to methods and an apparatus for producing silicone hydrogel contact lens mold assemblies, methods and apparatus for producing silicone hydrogel contact lenses using such mold assemblies, and silicone hydrogel contact lenses and lens member bodies produced using such methods and apparatus.
Claims18
A method of producing a silicone hydrogel contact lens mold assembly, the method comprising;
- placing one of a male mold member and a female mold member on the other of a male mold member and a female mold member to form a contact lens mold assembly comprising a contact lens shaped cavity defined between the male mold member and the female mold member, said cavity containing a polymerizable silicone hydrogel contact lens precursor composition;
- and
- coupling the male mold member and the female mold member together by inserting one or more heated elongate elements into the male and female mold members thereby causing a portion of the male and/or female mold members to become melted or softened, and then withdrawing said one or more heated elongate elements from the male and female mold members, wherein said melted or softened material then cools to form a weld between the male and female mold members;
- and wherein
- throughout a first time period beginning when the first of said one or more heated elongate elements is inserted into the male and female mold members and continuing until at least 3 seconds after the last of said one or more heated elongate elements is withdrawn from the male and female mold members, the male and female mold members are pressed together by applying a force in the range of from 20 N to 100 N to the male and female mold members.
A system for the production of a silicone hydrogel contact lens mold assembly, the mold assembly comprising a contact lens shaped cavity defined between a male mold member and a female mold member, the system comprising:
- a clamp arranged to compress the mold assembly;
- one or more elongate elements, said one or more elongate elements being mounted for movement relative to the clamp to pass a tip of each elongate element through the male and female mold members while they are being compressed by the clamp, and
- a control system configured to control operation of the clamp and the one or more elongate elements such that throughout a first time period beginning when the first of said one or more elongate elements is inserted into the male and female mold members and continuing until at least 3 seconds after the last of said one or more elongate elements are withdrawn from the male and female mold members, the clamp exerts a force in the range of from 20 N to 100 N on the male and female mold members.
Dependencies are inferred from the claim text.