US 4,394,099 AGranted

Plastic lens contour cutting machine

AssigneeLemay Corporation

InventorEmil Santinelli

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Abstract

In a plastic lens grinding machine of the type having a head mounted on a base and adapted to carry a lens pattern and a plastic lens having a base curvature, the head is capable of movement parallel to the axis of rotation of the plastic lens. A carriage is mounted on the base and is movable perpendicular to said axis of rotation, with the carriage having an improved rotatable cutter with a cutting edge made of a metal of high hardness and adapted to be rotated at high speed in order to be self-coolant. A hydraulic damper is mounted on the carriage and connected to the base for regulating the gravitational movement of the carriage towards the axis of rotation of the plastic lens, thus regulating the engagement of the metallic cutter blade with the periphery of the plastic lens. An improved bevel aligning device is provided having a base curve cam connected to the head and a cam tracer connected to the carriage, with the cam having a surface forming the same base curvature as the plastic lens. The tracer is in bearing contact with the surface of the cam and effects a movement of the head with the lens in a first direction to a position that aligns the center of the lens with the beveling device. The bevel aligning device further includes a biasing spring connected to the head and to the base for effecting movement of the head in a circular direction resulting in bearing contact of the surface of the cam against the tracer. By this arrangement, when the lens and the lens pattern are rotated, with the cutter being rotated at high speed, the carriage moves toward the axis of rotation thereby effecting an engagement of the cutter with the plastic lens periphery. The cutter cuts and edges the plastic lens while the beveling device simultaneously forms a bevel at the center of the periphery of the plastic lens.

An improved machine for cutting, edging, contouring, and beveling the periphery of a plastic lens, said machine being of the type having a head mounted on a base and carrying a lens pattern and a plastic lens which is to be cut and has a base curvature, means for rotating said pattern and said lens about a common axis, wherein the machine includes a carriage mounted on said base and having a pattern follower in bearing contact with said pattern and having a rotatable cutter with a cutting edge capable of engaging said periphery of said lens, said cutting edge forming a beveling means, means for moving said carriage substantially perpendicular toward and away from said axis, said movement effecting an engagement of said cutter with said periphery of said lens, the improvement comprising:

said cutter having a cutter edge of a metal of a high hardness and rotatable at high speed, said cutter having a cutting face and a radial plane of rotation, said cutting face forming a clearance angle with said radial plane, said face operative to direct particles along said face away from said radial plane of rotation;
and
bevel aligning means including base curve cam means connected to said head and cam tracing means connected to said carriage, said cam means having a surface forming the same base curvature as said lens, said tracing means being in bearing contact with said surface for effecting a movement of said head with said lens in a first direction to a position that aligns the center of said lens with said beveling means, said aligning means including biasing means connected to said head and said base and effecting a movement of said head in a second direction resulting in bearing contact of said surface of said cam means against said tracing means, said surface of said base curve cam means including a plurality of discrete sectors, each of said sectors having a different base curvature surface, said cam means rotatable to effect bearing alignment between the surface of any selected sector and said tracing means, whereby when said selected sector has a surface forming the same base curvature as the base curvature of said lens, said tracing means effects a movement of said head with said lens in said first direction to a position that aligns the center of said lens with said beveling means,
whereby when said lens and said lens pattern are rotated and said cutter is rotated at high speed, said carriage moves toward said axis effecting an engagement of said cutter with said lens periphery to cut and edge said plastic lens and simultaneously form a bevel at the center of said periphery.

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Abstract

Claims12