Rimless spectacle lens bore polishing method and apparatus
AssigneeGentex Optics, Inc.
InventorsParesh Kitchloo, Russell F. Weymouth, Jr.
Life of this patent
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Abstract
A method and apparatus for improving the performance of rimless spectacle lenses. An abrasive wire is provided for polishing bore holes which are drilled in lenses. The abrasive wire includes a wire substrate with abrasive particles embedded along its length. The wire and particles are dimensioned for threading through the bore hole and allowing space to perform a soft-filing operation. By polishing the micro cracks formed during drilling, propagation leading to lens failure which arises from spectacle use can be reduced.
Claims27
A method for producing a rimless spectacle lens with a resistance to stress-induced cracking comprising:
- providing an optical grade thermoplastic lens;
- drilling a borehole in the lens;
- and
- soft-filing a borehole surface with an abrasive wire including:
- a wire substrate, and
- abrasive particles embedded on the wire substrate.
A device for use in filing an inner-surface of a drilled borehole within an optical grade thermoplastic lens including an edged, elliptical periphery, that is employed in rimless spectacle construction, wherein the borehole and a nearest periphery of the lens define a land having a length that is at most 20% of a maximum lens length, comprising:
- a soft file device comprising a wire substrate and abrasive particles having a hardness greater than the lens coating embedded on the wire substrate and adapted to soft-file a borehole surface within a thermoplastic lens to partially remove a drill induced stress layer.
An abrasive tool in combination with a workpiece employed to produce a rimless spectacle lens with a resistance to stress-induced cracking comprising:
- an optical grade plastic thermoplastic lens including a borehole;
- an abrasive wire with a linear configuration that is dimensioned to allow the abrasive wire to be drawn through the borehole in an axial direction and to enable soft-filing of a linear section of the borehole including:
- a wire substrate, and
- abrasive particles embedded on the wire substrate.
Dependencies are inferred from the claim text.