US3704554A

US3704554A - Lens processing machine with movable workpiece spindle

Info

Publication number: US3704554A
Application number: US137386A
Authority: US
Inventors: George J Laughman
Original assignee: Bausch and Lomb Inc
Current assignee: Bausch and Lomb Inc
Priority date: 1971-04-26
Filing date: 1971-04-26
Publication date: 1972-12-05
Anticipated expiration: 1989-12-05

Abstract

A machine has a plurality of generally fixed work-tool heads for performing multiple operations upon lens material to form a lens at a common mounting block disposed upon a movable, for example pivotal, workpiece spindle. The plurality of work-tool heads are generally stationary relative to the exemplary pivotal workpiece spindle. The provision of the common mounting block reduces operational time for manufacturing a spherical or plano lens by eliminating the need for mounting, dismounting and remounting the lens at each of different and separate operational stations. Runout of the optical axis of the formed lens surface due to remounting is thereby eliminated and is a significant factor in reducing machine operating time and reducing tool wear. The worktool heads have spindles which carry, for example, tools for generating, lapping, edging and/or polishing a lens. The lens material is carried by the exemplary pivotal workpiece spindle about a fixed pivot point to move in an arcuate path between the work-tools heads to dispose the axis of the workpiece spindle to intersect the axis of each work-tool head, respectively, at a fixed pivot point irrespective of the design parameters of the lens. After alignment of each of the axes to its respective fixed pivot point the lens material is linearly moved, respectively, toward each work-tool which is, in turn, cooperatively linearly moved toward the lens material to engage and perform an operation upon the lens material.

Description

United States Patent Laughman [151 3,704,554 [451 Dec. 5, 1972 1541 LENS PROCESSING MACHINE WITH MOVABLE WORKPIECE SPINDLE [72] Inventor: George J. Laughman, Perinton,

[73] Assignee: Bausch & Lomb Incorporated,

Rochester, NY.

[22'] Filed: April 26, 1971 V [21] Appl.'No.: 137,386

[56] References Cited UNITED STATES PATENTS 1,229,162 6/1917 Starin..'

2,747,337 5/1956 Geula ..51/3

Primary ExaminerLowell A. Larson AttorneyFrank C. Parker and Bernard D. Bogdon [57] ABSTRACT A machine has a plurality of generally fixed work-tool heads for performing multiple operations upon lens material to form a lens at a common mounting block disposed upon a movable, for example pivotal, workpiece spindle. The plurality of work-tool-heads are generally stationary relative to the exemplary pivotal workpiece spindle. The provision of the common mounting block reduces operational time for manufacturing a spherical or piano lens by eliminating the need for mounting, dismounting and remounting the lens at each of different and separate operational stations. Runout of the optical axis of the formed lens surface due to remounting is thereby eliminated and is a significant factor in reducing machine operating time and reducing tool wear. The work-tool heads have spindles which carry, for example, tools for generating, lapping, edging and/or polishing a lens. The lens material is carried by the exemplary pivotal workpiece spindle about a fixed pivot point to move in an arcuate path between the work-tools heads to dispose the axis of the workpiece spindle to intersect the axis of each work-tool head, respectively, at a fixed pivot point irrespective of the design parameters of the lens. After alignment of each of the axes to its respective fixed pivot point the lens material is linearly moved, respectively, toward each work-tool which is, in turn, cooperatively linearly moved toward the lens material to engage and perform an operation upon the lens material.

9 Claims, 2 Drawing Figures PATENTEDnEc 51912 POSITION H GEORGE J. LAUGHMAN I INVENTOR.

I i, BERNARD D. BOGDON POSITION I ATTORNEY LENS PROCESSING MACHINE WITH MOVABLE WORKPIECE SPINDLE BACKGROUND OF THE INVENTION 1. Cross-Reference to Related Application The present invention is an improvement invention over that described in a patent application entitled, Multiple Head Lens Processing Machine, Ser. No. 51,943 for Applicant James AQClark.

2. Field of the Invention This invention relates to a lens processing machine and more particularly to a lens processing machine having a single workpiece holder movable, for example by pivoting, between tool carrying spindle heads, for performing a plurality of differing operations upon a lens material for manufacturing a single lens or block of lenses. 7

3. Description of the Prior Art ln the optical lens manufacturing industry, considerable time, material and accompanying expense is being expended in creating a fine finished lens. The majority of the machinery and devices available are equipped to carry out only one step in the multi-step operation of lens manufacturing. For example, presently 'a separate machine is utilized for each of the steps of rough grinding, fine grinding, edging and polishing. These machines cannot be modified to carry out more than one of these functions without extensive costly change. To do so is generally not feasible. Some machines have been adapted to simultaneously provide essentially the same process step at different areas of a single lens, for example, grinding a singlet lens having differing focal length surfaces such as a bifocal ophthalmic lens, but these machines likewise must be extensively altered to carry out more than one process.

Other multiple operation methods include modifying conventional machines for operating multipurpose tools adapted, for example, for initially rough grinding and subsequentially fine grinding for lens generation. Tools of this type are relatively expensive and require a rather extensive operational control system which further adds to the cost of the operation.

The industry has for many years successfully and competitively manufactured quality lens following the conventional methods using standard machinery. As labor costs rise in the United States and as particular foreign manufacturers improve their quality and use relatively low cost labor, it is increasingly difficult to maintain a competitive position using standard wellestablished methods. The additional time that is required to set up a lens for any second or following process operation is increasing and becoming noticeably expensive. In addition, in the process of dismounting and remounting a lens for further processing, it is extremely difficult, if not impossible, in reasonable manufacturing time to axially align the lens in an attempt to retain the first established optical axis in order to conduct the subsequent processes with reference to the lenses established axis. Because of the alignment difficulty, each following operation must be adapted to remove sufficient material to establish a new concentric axis in addition to being adapted to carry out its specific designated operation, such as polishing. It is difficult to ascertain the reduction-in quality machined into the lens each time it is remounted and its center of curvature is reestablished. There is little doubt, however, that as a spindle rotates faster and as stock removal becomes less, as for example during polishing, that lens quality decreases in terms of regularity and conformance, since the inertia of a polishing tool causes uneven loads on a fast turning eccentrically disposed lens.

In the hereinbefore mentioned cross-referenced Clark patent application, the operation of the embodiment according to the principles of the invention described therein is specifically critical because of the arcuate path of the pivotable tool spindle heads, since at only one point along their operational path do they produce a spherical lens. This is complicated further by the fact that tool wear necessitates continuing adjust ment to produce a desired curvature in the manufactured lens.

At least two additional difficulties are present in machines of the type described in the Clark application. One difficulty arises because of the complicated method which must be employed to oscillate the spindle head to break up the grinding or polishing process in order to achieve the best results in a finished lens. A second factor of difficulty is that, where a fixed workpiece spindle of the type disclosed in the Clark application is utilized, it is necessary to include a rinse cycle between an operation by a generating spindle head where one type of slurry is needed and an operation by a polishing spindle head where a second type of slurry is needed. In Clark, only one slurry trough is incorporated and it is disposed about the workpiece spindle.

SUMMARY OF THE INVENTION This improvement invention provides a machine for performing multiple operations in the manufacture of a lens, for example, generating by rough milling and polishing, while the lens is affixed to a single lens holder on a workpiece spindle for disposing the lens material for engaging a work head spindle fixed relative to the workpiece spindle. The necessity of dismounting and remounting a lens for progressive processing in the manufacture of lenses has been eliminated. The lens and the lens holder rotate about an axis disposed for moving relative to a base, for example, by pivoting the lens holder about a fixed pivot to a station for engaging rotatable work head spindles fixed relative to the base. The workpiece spindle is disposed before the work head spindle for operation when the axes of the spindles intersect at a predetermined fixed point. The spindles are individually controllable for traversing linearly to bring the workpiece material in operational engagement with the tool of the spindle head. The linear movement of either the workpiece or the tool head provide for ease of adjustment in the initial setup for the manufacture of any lens, and further provides for ease of adjustment to compensate for variations due to, for example, tool wear.

As hereinbefore mentioned, where the workpiece spindle is pivotable between the tool spindle heads there is provided the fixed pivot point for the workpiece spindle and, in addition, all respective tool spindle heads have an axis of rotation extending to intersect the axis of the workpiece spindle at a fixed pivot point for the respective spindle head, when the workpiece spindle is disposed before that respective spindle head.

This specific structure provides for ease of oscillation by the respective spindle head, if required, to break up the work pattern of the work tool upon the lens material. Oscillation is particularly desirable at a polishing spindle head.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of an embodiment having a single workpiece spindle pivotable between two work-tool spindle heads according to the principles of the present invention; and

FIG. 2 is a partial illustration of the embodiment illustrated in FIG. I viewed from line 22 of FIG. 1 in the pivoting plane of the workpiece spindle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment according to the principles of the present invention is schematically illustrated in FIG. 1 and partially shown in FIG. 2 as viewed in the direction of the plane of operation illustrated in FIG. 1. Disposed for pivoting about an axis A-A fixed relative to a base is a workpiece spindle assembly for operational movement between a plurality of pivoting positions, for example, Position I and Position II. The workpiece .spindle assembly is illustrated in broken lines at Position II. The workpiece spindle assembly 10 is pivotal about a base axle 12, as best seen in FIG. 2, concentrically disposed about the axis AA symmetrically journaled within a base support 14. Parallelly extending from the base axle 12 and affixed thereto are spaced apart

guide rods

16 and 18 for journaling within

support runners

20 and 22 affixed to a workpiece spindle holder 24. A hydraulic cylinder 26 is affixed to the base axle .12 and has a movable piston rod 28 for controllably raising and lowering the workpiece spindle holder 24 along its

corresponding guide rods

16 and 18. The workpiece spindle holder 24 includes a hydraulic motor for controllably rotating a spindle 30 about a work holder operational axis BB' to correspondingly cooperatively rotate a workpiece 32 carried at the uppermost end of the workpiece spindle 30 in a workpiece chuck for securely retaining the workpiece 32, for example, .by a suitable vacuum means. It will be appreciated that this embodiment is particularly desirable for manufacturing lenses and in such cases the workpiece material includes materials for manufacturing lenses, such as, glass.

Adjustable stops

34 and 34 are each affixed to the base and are initially adjusted to dispose each resting pad 35 and 35', respectively, for engaging the workpiece spindle holder 24 at its outermost surface, to thereby dispose the workpiece spindle holder 24 for operation at either, for example, Position I or Position II.

It will be appreciated that each of the plurality of positions for performing work operations upon the workpiece material 32, may have disposed thereat a different tool, each for engaging the workpiece material 32 to perform an operation. For example, at Position I, a work-tool head 36 may be disposed for carrying out, for example, a generating operation to manufacture a lens from the workpiece material 32.

Similarly, a work-tool head 40 is disposed for engaging the work-tool spindle 10 at the Position II for carrying a tool 42 for performing, for example, a polishing operation upon the lens material 32. In the preferred embodiment the work-tool heads 36 and 40 are hydraulically operated to rotate their

respective worktool spindles

44 and 46 respectively carrying

tools

38 and 42 about a work-tool spindle axis C-C' and D- D, respectively. Work-tool head 36 and workpiece holder 24 are properly oriented to each other for operation at Position I when the work-tool head axis C-C intersects the operational axis 8-8 at an imaginary fixed point X. Similarly, work-tool head 40 is in correct operational disposition at Position II forhaving its tool 42 engaged with the workpiece 32 when the work-tool axis D-D' intersects the work holder axis 8-8 at an imaginary fixed point Y.

Embodiments according to the principles of this invention are ideally suited for incorporation of oscillation of either, for example, the generating tool 38 or the polishing tool 42 to break up the engagement pattern between each respective tool and the workpiece material 32. It is readily known that the break-up is desirable in order to, for example, evenly polish the surface. To this end eccentrically disposed

linkages

48 and 50 are in any suitable mariner driven by a rotatable disc 52 powered, for example, by a hydaulic motor, not shown. The

linkages

48 and 50 are affixed to the worktool heads 36 and 40, respectively, in any suitable manner for pivotal rotation about pivot pins 54 and 56, respectively, fixed relative to work-tool heads 36 and 40.

When the disc 52 is caused to rotate about its center at point Z, the cranking motion of the

linkages

48 and 50 pivoting at the disc 52 and the respective pivot pins 54 and 56, cooperatively causes the work-tool heads 36 and 40 to oscillate back and forth in the directions of

arrows

58 and 60, respectively.

It should be appreciated that during the oscillation of either of the illustrated work-tool heads 36 or 40, that the oscillation is pivotal about the imaginary intersection points X and Y, respectively. It will be appreciated that either work-tool head may be held stationary simply by removing its respective cranking linkage.

In order to obtain a desired curvature on, for example, the workpiece material 32 for a lens, the following initial procedure is practiced. An appropriate tool, for example, a ring tool is installed on the work-tool head 36 for generating the desired curvature. The work-tool head 36 is linearly adjusted as necessary in either of the directions of double ended arrow 62 relative to the imaginary fixed pivot point X to a distance directly proportional to the desired curvature of the lens. In addition, angle adjustment to the ring tool is made in order for the high point of the ring tool to pass through the optical axis of the lens concentric with rotational axis BB. Further, adjustable stop 34 is set up to insure intersection of the work-tool head axis'C-C with workpiece holder axis D-D' at point X. Afterwards, linear adjustment is made to fix the extent of the upward movement of the workpiece material 32 in order to obtain the proper thickness in the lens to be generated. This adjustment can be made by mathematical computation and more readily by trial and error process which is most practical. The extent of the upward movement is controlled by adjusting a dead stop, not shown.

Once this initial set-up is made, generation of a lens from a lens material 32 can be carried out. Adjustments for the work-tool head 40 for polishing are similar as with respect to intersection alignment of the respective axes. Thus, the work head tool 40 is also linearly adjusted as necessary in either of the directions of double ended arrow 64 relative to the imaginary fixed pivot point Y. in polishing, however, a different technique is used with regard to the extent of the upward movement of the lens material 32 while engaging the polishing tool 42. In this case in order to provide a constant pressure of the material against the polishing tool 42 there is no dead stop and the hydraulic pressure of the piston consistently urges the lens material into the polishing tool 42.

What is claimed is:

1. A machine for processing a lens from lens material, comprising: v I

first processing means affixed to the base for carrying a first tool in a linear path for engaging and performing a first operation upon the lens material;

second processing means affixed to the base for carrying a second tool in a linear path for engaging and performing a second operation different than that of the first operation upon the lens material; and

a lens material holder rotatably carried by the base for disposing the lens material firstly before the first processing means and secondly before the second processing means for engaging the lens material for respectively performing the different first and second operations thereon.

2. A machine for processing a lens from lens material, comprising:

a base;

a lens material holder rotatably carried by the base for substantially concentrically positioning the lens material on the axis of rotation of the lens material holder;

first processing means for carrying a first tool in a linear path for engaging the lens material for performing a first operation thereon; and

second processing means for carrying a second tool in a linear path for engaging the lens material for performing a second operation different than that of the first operation upon the lens material.

3. A machine for processing a lens from lens material, comprising:

a base;

first processing means for carrying a tool for performing a first operation on the lens material;

second processing means for carrying a tool for performing a second operation different than that of the first operation on the lens material; and

a lens material holder rotatably carried by the base for substantially concentrically disposing the lens material at the axis of rotation of the lens material holder, the lens material holder being pivotable to carry the lens material between the first and second processing means and to dispose the lens material at each processing means for the processing means to perform its respective operation on the lens material.

4. The machine for processing a lens from lens material, as defined in claim 3, wherein the pivotable lens material holder for carrying the lens material includes:

means for linearly traversing the lens material in the direction of the axis of rotation of the lens material holder for engaging each tool of each respective processing means for performing the respective operation on the lens material.

5. A machine for processing a lens for lens material, as defined in claim 3, wherein:

first processing means defines a holder for carrying a lens generating tool, the tool for performing the first operation on the lens material; and second processing means defines a holder for carrying a lens polishing tool, the tool for performing V the second operation different than that of the first operation on the lens material.

6. The machine for processing a lens from lens material, as defined in claim 3, wherein at least one of the processing means for carrying a tool for performing an operation on the lens material includes:

means for linearly traversing its respective tool for engaging the lens material for performing the respective operation on the lens material. Y 7. The machine for processing a lens from lens material, as defined in claim 6, wherein the pivotal lens material holder for carrying the lens material includes:

means for linearly traversing the lens material in the direction of the axis'of rotation of the lens material holder for engaging each. tool of each respective processing means for performing the respective operation on the lens material. 8. A machine for processing a lens from lens material, comprising:

a base; first processing means affixed to the base having an axis for carrying a tool in a linear path to engage the lens material to perform a first operation thereon; second processing means affixed to the base having an axis for carrying a tool in a linear path to engage the lens material to perform a second operation different than that of the firstoperation upon the lens material; and a lens material rotatably carried by said base about an axis, substantially concentrically positioning the lens material at the axis of rotation of the lens material holder and pivotable between the first and second processing means about a base fixed pivot point to dispose the axis of rotation of the lens material holder to intersect each axis of each respective processing means, respectively, at a fixed pivot point. 9. A method of processing a lens from lens material, comprising:

mounting lens material upon a rotatable workpiece spindle; disposing the lens material on the workpiece spindle before a work-tool head for performing a first operation upon the lens material; engaging the lens material with a tool carried by the work-tool head for performing the first operation upon the lens material;

pivoting the lens material from the disposition before operation different than that of the first operation upon the lens material; and

engaging the lens material iwith a tool carried by the second work-tool head for performing the second operation different than that of the first operation upon the lens material.

Claims

1. A machine for processing a lens from lens material, comprising: a base; first processing means affixed to the base for carrying a first tool in a linear path for engaging and performing a first operation upon the lens material; second processing means affixed to the base for carrying a second tool in a linear path for engaging and performing a second operation different than that of the first operation upon the lens material; and a lens material holder rotatably carried by the base for disposing the lens material firstly before the first processing means and secondly before the second processing means for engaging the lens material for respectively performing the different first and second operations thereon.

2. A machine for processing a lens from lens material, comprising: a base; a lens material holder rotatably carried by the base for substantially concentrically positioning the lens material on the axis of rotation of the lens material holder; first processing means for carrying a first tool in a linear path for engaging the lens material for performing a first operation thereon; and second processing means for carrying a second tool in a linear path for engaging the lens material for performing a second operation different than that of the first operation upon the lens material.

3. A machine for processing a lens from lens material, comprising: a base; first processing means for carrying a tool for performing a first operation on the lens material; second processing means for carrying a tool for performing a second operation different than that of the first operation on the lens material; and a lens material holder rotatably carried by the base for substantially concentrically disposing the lens material at the axis of rotation of the lens material holder, the lens material holder being pivotable to carry the lens material between the first and second processing means and to dispose the lens material at each processing means for the processing means to perform its respective operation on the lens material.

4. The machine for processing a lens from lens material, as defined in claim 3, wherein the pivotable lens material holder for carrying the lens material includes: means for linearly traversing the lens material in the direction of the axis of rotation of the lens material holder for engaging each tool of each respective processing means for performing the respective operation on the lens material.

5. A machine for processing a lens for lens material, as defined in claim 3, wherein: first processing means defines a holder for carrying a lens generating tool, the tool for performing the first operation on the lens material; and second processing means defines a holder for carrying a lens polishing tool, the tool for performing the second operation different than that of the first operation on the lens material.

6. The machine for processing a lens from lens material, as defined in claim 3, wherein at least one of the processing means for carrying a tool for performing an operation on the lens material includes: means for linearly traversing its respective tool for engaging the lens material for performing the respective operation on the lens material.

7. The machine for processing a lens from lens material, as defined in claim 6, wherein the pivotal lens material holder for carrying the lens material includes: means for linearly traversing the lens material in the direction of the axis of rotation of the lens material holder for engaging each tool of each respective processing means for performing the respective operation on the lens material.

8. A machine for processing a lens from lens material, comprising: a base; first processing means affixed to the base having an axis for carrying a tool in a lineaR path to engage the lens material to perform a first operation thereon; second processing means affixed to the base having an axis for carrying a tool in a linear path to engage the lens material to perform a second operation different than that of the first operation upon the lens material; and a lens material rotatably carried by said base about an axis, substantially concentrically positioning the lens material at the axis of rotation of the lens material holder and pivotable between the first and second processing means about a base fixed pivot point to dispose the axis of rotation of the lens material holder to intersect each axis of each respective processing means, respectively, at a fixed pivot point.

9. A method of processing a lens from lens material, comprising: mounting lens material upon a rotatable workpiece spindle; disposing the lens material on the workpiece spindle before a work-tool head for performing a first operation upon the lens material; engaging the lens material with a tool carried by the work-tool head for performing the first operation upon the lens material; pivoting the lens material from the disposition before the work-tool head for performing the first operation upon the lens material to a disposition before a second work-tool head for performing a second operation different than that of the first operation upon the lens material; and engaging the lens material with a tool carried by the second work-tool head for performing the second operation different than that of the first operation upon the lens material.