US3112585A

US3112585A - Grinding tool for lenses

Info

Publication number: US3112585A
Application number: US65317A
Authority: US
Inventors: Robert E Middeleton; Clifford C Christopherson
Original assignee: SUPERIOR VISUAL PRODUCTS CO
Current assignee: SUPERIOR VISUAL PRODUCTS CO
Priority date: 1960-10-27
Filing date: 1960-10-27
Publication date: 1963-12-03
Anticipated expiration: 1980-12-03

Description

Dec. 3, 1963 R. E. MIDDLETON ETAL GRINDING TOOL FOR LENSES Filed Oct. 27, 1960 IN V EN TOR. ROBERT E MIDDLETON CLIFFORD yRlsTopr-lmsolv BY A TTORNEY United States Patent 3,112,585 GRINDING TOOL FOR LENSES Robert E. Middleton and Clifford C. Christopherson, Denver, (1010., assignors to Superior Visual Products (30., Denver, Colo., a partnership Filed Get. 27, 1960, Ser. No. 65,317 6 Claims. (Cl. 51-204) The present invention relates to an attachment to be used in grinding lenses and the like. More particularly, this invention relates to an attachment constructed in such a fashion as to retain a number of different grinding inserts, and which is especially adapted to grind a wide range of curvatures for contact lenses.

Contact lenses in use today are generally small and relatively thin, so that a relatively small change in curvature of the lens necessitates a considerable prescription change. It is therefore highly desirable to incorporate into a single member a number of grinding surfaces which are each of a different radius of curvature and are easily interchangeable for grinding varying contact lens prescriptions. Moreover, a single tool or member is advantageous in special grinding situations such as where the lens must be ground progressively, requiring several grinding surfaces each of a different radius of curvature to complete the grinding operation. In this and other applications the present invention overcomes the need for numerous tools by providing a universal type attachment which may be formed in a unique way to make possible a safe, rapid and efiicient means for grinding curvatures into lenses and the like over a wide range of radius sizes and configurations.

Accordingly, it is a principal object of the invention to provide for use in association with a lens grinding machine, a universal type tool for grinding varying configurations and curvatures in lenses and the like.

It is another object of the invention to provide, in a lens grinding machine, a tool so constructed that its position atop a motor drive spindle can be selectively varied, to successively present grinding members of different configurations in grinding position.

t is a further object of the invention to provide a grinding or polishing tool presenting a number of surfaces of selected curvatures for grinding or polishing lenses of different sizes and curvatures.

It is a further object of the invention to provide, for use in association with a lens grinding machine, an attachment having a plurality of grinding members arranged to permit successive positioning for rotation about the axis of rotation of the machine to present grinding surfaces of different curvatures for contact lenses and the like.

It is a still further object of the invention to provide a universal type holder for grinding members which is simple in construction, has a long service life, and is easily used in a lens grinding machine.

The above and other objects and advantages of the present invention will become more apparent from the following detailed description taken together with the accompanying drawings, in which:

FIGURE 1 is a front view of a preferred form of the invention, as used in association with a lens grinding machine; and

FIGURE 2 is a sectional view of the preferred embodiment, showing a grinding insert in attached relation.

3,112,585 Patented Dec. 3, 1963 "ice Referring more particularly to the drawings, there is shown by way of illustrative example a preferred form of grinding tool defined by a generally spherical body 12. Essentially, the body 12 is formed to accommodate in a unique way a maximum number of grinding membeds defined by inserts 13 for mounting in association with a lens grinding machine 14. For purposes of description the lens grinding machine is representative of various drive means which may be employed and is made up essentially of a motor drive spindle 16 rotated by a motor drive unit 17, the spindle projecting upwardly through a generally cylindrical storage hopper 18 which is open at the top for reception of the body member 12.

Specifically, the body portion 12 is designed for use such that each grinding member 13 may be selectively and successively positioned in alignment with the drive spindie for rotation about its axis so as to present a surface of the desired radius of curvature for grinding of a particular lens prescription. Accordingly, for each grinding member there must be provided a diametrically-opposed, aligned attaching means for disposition of the grinding tool on the drive spindle with the grinding member in diametrically-opposed relation thereto. To this end, the grinding tool is made preferably of a spherical shape having a series of bores 20 with a diametricallyopposed, coaxially aligned recess or receptacle 22 corresponding to each bore to receive a grinding member 13. Furthermore, although not an essential part of this invention, the bores 20 are so staggered in relation to one another as to permit alternate disposition of the recesses 22 between the bores under substantially uniform spacing so as not to Weaken the body portion as a whole while providing the maximum nurnber of aligned bores and recesses for each grinding member. In this connection, no set geometric configuration need be employed and the spacing between bores and receptacles may be dictated in accordance with the number of grinding inserts desirably secured within the spherical body portion, and of course the size of the body may be varied also in accordance with the desired number of grinding members to be positioned therein.

In design and construction, each bore and recess is positioned on a radial line extending from the center of the body, each bore being essentially of the same size, diameter and length so as to provide for snug-fitting disposition atop the motor drive spindle 16 in order that no slippage between the spindle and the body portion will occur during rotation. The receptacles 22 may be in the form of relatively shallow, wide, circular openings 24 to provide a broad base of the desired size for disposition of each grinding member 13, and in this connection each receptacle may be of a varying cross diameter in order to accommodate grinding inserts of different sizes. Adjacent the exterior of the body each opening 24 di verges outwardly to form a relatively broad beveled surface 25 for ease of insertion of the grinding members 13 and to insure that no contact will be made with the edges of the lens during grinding.

In accordance with the preferred'form of invention, each grinding member 13 is in the form of a generally cylindrical insert having a convex, outer, curved surface 28 which is formed on a radius of curvature in accordance with a particular, selected lens prescription. Thus each curved surface 28 will vary in radius, size and configuration in accordance with the particular size and radius of curvature for a lens to be ground. Although each insert may be merely mounted in snug-fit relation within each of the respective openings 24, it is most preferably permanently positioned in each respective opening through the use of a suitable adhesive and thereby forms essentially a unitary part of the spherical body portion. In accord with conventional practice, a felt pad 31 may be secured over the outer curved surface 28 of each insert so as to provide the actual grinding surface for the contact lens. Actually, the felt pad 39 forms a relatively broad curved surface within the beveled portion of the receptacle and together with the insert itself provides a relatively large curved surface area within the beveled portion to allow ample clearance between the edges of the opening and the contact lens during grinding and thus prevent any danger of damage to the edges of the lens.

In forming the body portion and grinding member, the body portion 12 is preferably composed of glass or a tough, horny plastic substance, which is desirably made transparent or of a clear color. In turn, each of the grinding inserts may be of either a plastic or metallic material which presents a hardened curved surface in forming the outer curved end 28 thereof, although of course little or no wear will be associated with the surface of the insert proper in that the felt pad will remain in contact with the contact lens throughout the grinding operation.

In operation, each grinding insert is placed in position for use by fitting its aligned bore over the motor drive spindle 16. A suitable abrasive or polishing agent may be applied to the grinding surface formed by the felt pad so that upon rotation of the grinding tool, a lens may be brought into contact with the abrasive surface to form the desired radius of curvature in the lens. Normally, only one insert is necessary for each particular lens correction although as stated a particular radius of curvature may be accomplished through a series of progressive grinding operations using inserts of progressively decreasing radius. In this instance, or generally when desired to change grinding surfaces, the tool may be rapidly and easily removed from the spindle and then replaced so that a dilferent bore and aligned insert is positioned in grinding position for the next operation, and this may be done without stopping the motor. In this way, the lens may undergo as many grinding operations as is found necessary to be brought to the desired end configuration, and in this relation the grinding inserts may be used in both grinding and polishing operations, and may be used in the formation of peripheral curves, or beveled surfaces, along with the major curvatures.

Any excess abrasive material will simply fall into the storage hopper 18 in the course of the grinding operation. Moreover, the abrasive material collected in the storage hopper may be separated from the particles ground off the lens and reused as desired.

Essentially, therefore, the present invention comprises a series of aligned grinding members 13 and securing means 20 for attachment of each respective grinding member in grinding position in association with a lens grinding machine. An especially compact relation is provided where the diametrically-opposed and aligned grinding members and securing means are disposed to radiate from a common center, and it is considered to be particularly novel and effective to construct the respective grinding members and securing means in the form of diametricallyopposed recesses for reception of grinding inserts and bores, respectively, in a common body portion. In this connection, it will be evident that although the body portion 12 is preferably of a generally spherical configuration, other geometric forms may be adopted such as a rectangular or oval form. However, the generally spheri: cal form provides for the most compact arrangement in a common unit for all the grinding inserts and additionally provides the safest means of forming such an attachment where the member is under constant rotation and requires periodic removal and replacement.

As a further possible modification it will be recognized that although the grinding members are in the form of inserts, they may form projections from the surface of the body or may be formed out of the spherical body portion itself merely by countersinking into the body portion at spaced intervals to provide a generally convex area for disposition of the felt pad. Additionally, the inserts may be formed for grinding or polishing concave as well as convex surfaces. Again, the use of inserts provides for separate, accurate formation thereof followed by either press fitting disposition or adhesive attachment into the receptacles. Either way, by the use of inserts, it is possible to replace them as desired without destruction of the entire body.

From the foregoing, it will be evident that various modifications and changes may be resorted to in the grinding tool of the present invention without departing from the scope thereof as defined by the appended claims.

What is claimed is:

l. A grinding and polishing tool for use in association with a grindingand polishing machine and the like comprising a body having a plurality of pairs of opposed bores and recesses, said bores being shaped for connection to the machine, and grinding inserts each having a spherical surface and positioned within said recesses with the spherical surface outward, each surface having a different radius of curvature for grinding a selected lens, the axis or" the bore of each of said pairs being aligned with the axis of the spherical surface of the insert positioned within the bores corresponding recess.

2. An attachment for a grinding and polishing machine and the like consisting of a generally spherical body, and a series of coaxially ali ned, radially extending bores and spaced apart circular recesses in said body, a grinding insert retained Within each recess, said grinding and polishing insert having a body portion and a grinding surface, each surface portion being generally convex and of a selected configuration for grinding a selected curvature in a lens.

3. A grinding and polishing tool for use in association with a'grinding and polishing machine having a rotary drive spindle thereon, said tool consisting of a body, a series of relatively shallow radial recesses disposed in spaced relation about said body, a series of radial bores corresponding in number to the radial recesses and being d1sposed in spaced relation about said body between the radial recesses with each bore being diametrically opposed to and coaxially aligned with a radial recess for reception of the drive spindle therein, and a grinding insert positioned in each radial recess having a generally convex outwardly disposed grinding surface whereupon positioning of the drive spindle in a bore, a grinding surface 1s positioned for rotation about the axis of rotation of the drive spindle for the grinding of a selected curvature into a contact lens.

4. A grinding and polishing tool according to claim 3 wherein each radial recess is formed of an inwardly disposed circular opening for reception of each grinding insert and an outwardly flared beveled surface at the surface of said body, each grinding insert being dimensioned for disposition in a corresponding opening with its generally convex grinding surface coextensive with the beveled surface of each radial recess.

5. A grinding tool for use in association with a rotary drive lens grinding machine in the grinding of contact lenses and the like, comprising a series of spaced grinding members presenting spherically shaped grinding surfaces each of a different radius of curvature, said grinding members being arranged in peripheral spaced relation on a spherical surface about a common center, and a corresponding series of diametrically-opposed securing means axially aligned with the spherical axis of each respective grinding member to provide for connection to the lens is adapted for connection to be rotated by the machine grinding machine. for successively positioning each grinding surface at the 6. A grinding tool for use in association with a grinding axis of rotation for a grinding operation.

machine for rotation thereby in the grinding of a selected curvature into contact lenses and the like comprising, 5 Rfel'mces Cited 111 the file of this P a series of axially aligned diametrically-opposed securing UN D S AT PATENTS 5: g gg e 231 ififiji 22 w i t d my 26 1910 having an outer curved ge iie rally co nve x end gort on de 1973527 Di Sam) Sept 1934 2,395,700 Walker Feb. 26, 1946 fining a grinding surface whereupon each securing means 10 3 034 267 Feeney May 15 1962

Claims

1. A GRINDING AND POLISHING TOOL FOR USE IN ASSOCIATION WITH A GRINDING AND POLISHING MACHINE AND THE LIKE COMPRISING A BODY HAVING A PLURALITY OF PAIRS OF OPPOSED BORES AND RECESSES, SAID BORES BEING SHAPED FOR CONNECTION TO THE MACHINE, AND GRINDING INSERTS EACH HAVING A SPHERICAL SURFACE AND POSITIONED WITHIN SAID RECESSES WITH THE SPHERICAL SURFACE OUTWARD, EACH SURFACE HAVING A DIFFERENT RADIUS OF CURVATURE FOR GRINDING A SELECTED LENS, THE AXIS OF THE BORE OF EACH OF SAID PAIRS BEING ALIGNED WITH THE AXIS OF THE SPHERICAL SURFACE OF THE INSERT POSITIONED WITHIN THE BORE''S CORRESPONDING RECESS.