US 5,231,587 AGranted

Computer controlled lens surfacer

AssigneeLOH Optical Machinery, Inc.

InventorCharles E. Frost

Life of this patent

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Abstract

There is provided a lens generating apparatus and method for generating a surface on a lens blank, or other workpiece, of a wide range of shapes utilizing rotary movement of the components without a linear way system. The lens generating apparatus includes a rotatable tool support spindle which rotates a spheric tool about a first axis. The tool spindle is directly carried by a high torque, low inertia, direct drive servo motor which rotates the first rotational axis of the spherical tool about a second rotational axis. A workpiece spindle holds the workpiece and rotates it about a third axis which generally lies in the same plane as the first axis. The workpiece spindle is rotatably supported by a second high torque, low inertia, direct drive servo motor which rotates the third rotational axis about a fourth axis. The orientation of the first and third rotational axes are controlled by a CNC computer which controls the rotation of the two direct drive servo motors in dependence upon the rotational orientation of the workpiece. The spherical tool is controlled so as to follow a predetermined three dimensional tool path relative to the lens blank.

Claims3

Dependent claims

An apparatus for generating a surface on a lens blank during an automated grinding operation, said apparatus comprising:

(a) a base;
(b) a lens blank support spindle rotatable about a first rotational axis;
(c) a lens blank mounting disposed on a longitudinal end portion of the lens blank support spindle and moveable therewith for securing a lens blank;
(d) means for rotating the lens blank mounting and the lens blank support spindle relative to said base about said first rotational axis;
(e) means for rotating the lens blank support spindle relative to the base about a second rotational axis which is non-coincident to said first axis;
(f) a tool spindle rotatable about a third rotational axis which is non-coincident to said second rotational axis;
(g) a tool support mounting disposed on a longitudinal end portion of the tool spindle and moveable therewith for securing a surface generating tool;
(h) means for rotating the tool and tool spindle about said third rotational axis;
(i) means for rotating the tool spindle relative to the base about a fourth rotational axis which is non-coincident to said first, second and third rotational axes;
and
(j) computer controlled means for controlling the orientation of said first and third rotational axes with respect to said base wherein the computer controlled means operates by having variations in the rotational angular position of a portion of the apparatus that rotates around the first rotational axis control the velocity of rotation of the first axis about the second axis and the velocity of rotation of the third axis about the fourth axis;
wherein the lens blank and tool are juxtaposed and controllable by the computer controlled means so as to be capable of forming a lens surface without linear motion of the lens blank or tool during the grinding operation;
and
wherein at least part of said apparatus is rotatable on each of said four axes during grinding.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/954,405Filed 29 Sep 1992 · continuation
Priority: 12 Jul 1990
Granted: 27 Jul 1993
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

B24B 13/06
Machines or devices designed for grinding or polishing optical surfaces on lenses or surfaces of similar shape on other work; Accessories…
B23Q 1/4804
With sliding pairs and rotating pairs: a single rotating pair followed perpendicularly by a single sliding pair
B23Q 1/50
Using particular mechanisms: with rotating pairs only , the rotating pairs being the first two elements of the mechanism
B23Q 1/522
A single rotating pair: which is perpendicular to the working surface