US2994164A

US2994164A - Method and apparatus for simultaneously grinding lenses

Info

Publication number: US2994164A
Application number: US41548A
Authority: US
Inventors: Ernest T Dalton
Original assignee: American Optical Corp
Current assignee: American Optical Corp
Priority date: 1960-07-08
Filing date: 1960-07-08
Publication date: 1961-08-01
Anticipated expiration: 1978-08-01

Description

E. T- DALTON Aug. 1, 1961 METHOD AND APPARATUS FOR SIMULTANEOUSLY GRINDING LENSES Filed July 8, 1960 6 Sheets-Sheet 1 w T m V w ERNEST T: DIQLT N BY I 1? HT QNEYS Aug. 1, 1961 E. T. DALTON 2,994,164

METHOD AND APPARATUS FOR SIMULTANEOUSLY GRINDING LENSES Filed July 8, 1960 6 Sheets-Sheet 2 o INVENTOR a ERNEST 7. DQLTON B 0am my ATTORNEYS Aug. 1, 1961 E. T. DALTON 2,994,164

METHOD AND APPARATUS FOR SIMULTANEOUSLY GRINDING LENSES Filed July 8, 1960 6 Sheets-Sheet 5 15a y 154 km N w:

INVENTOR ERNEST 77 DA T HTTORNEYS Aug. 1, 1961 E. T. DALTON 2,994,164

METHOD AND APPARATUS FOR SIMULTANEOUSLY GRINDING LENSES Filed July 8, 1960 6 Sheets-Sheet 4 INVEN 70R ERNEST 7. DHLTON FJTTZORNEYS 2,994,164 METHOD AND APPARATUS FOR SIMULTANEOUSLY GRINDING LENSES Filed July 8, 1960 E. T. DALTON Aug. 1, 1961 6 Sheets-Sheet 5 Z Z ZW mz. 8 u 7 MW,

INVENTOIZ ERNEST 7. DALTON 1961 E. T. DALTON 2,994,164

METHOD AND APPARATUS FOR SIMULTANEOUSLY GRINDING LENSES Filed July 8, 1960 6 Sheets-Sheet 6 /az rf F A94 rl /66.) If M97 4 I w I G /84:/ U I M42 47 i I86 l i [88 I /682 '4 5 7 f ma/ 5 i 5 I682 /90 W aas 72 I72 lZZJ Tliij INVENTOR v ERNEST T DALTON ATTORNEYS United States Patent 2,994,164 METHOD AND APPARATUS FOR SIMULTA- NEOUSLY GRINDING LENSE Ernest T. Dalton, Southbridge, Mass, assignor to American Optical Company, Southbridge, Mass, a voluntary association of Massachusetts Filed July 8, 1960, Ser. No. 41,548 29 Claims. (Cl. 51111) The field of this invention is that of lens grinding, and the invention relates, more particularly, to novel and improved methods and apparatus for simultaneously grinding two spherical surfaces of a spherical lens and to methods and apparatus for automatically rough grinding, finish grinding and polishing a series of spherical lenses in continuous sequence.

In the manufacture of lenses or other articles wherein surfaces of prescribed curvature must be generated upon two opposite surfaces of each lens or article, it has been customary to form the desired degree of curvature upon one of said surfaces by abrading that surface with suitable tools as the article or lens is rigidly mounted upon a block or support. Thereafter, the lens or article is removed from its support and is remounted upon a support with its previously formed surface secured thereto as by use of pitch or other suitable adhesive, thereby to permit forming of the other of said curved surfaces.

As will be understood, such a process of mounting and remounting the lenses or other articles to be ground upon blocks or supports is time-consuming and expensive and requires great care to assure that centers of curvature of the opposite curved surfaces are properly aligned and to assure that the first-formed surface of the article is not marred during remounting. In the past, various methods and apparatus have been proposed for simultaneously grinding both surfaces of a lens or other article so that alternate blocking of the article was not required, but such attempts have generally proved unsuccessful in that the apparatus required for this purpose was limited to producing only the specific lens curvatures for which the apparatus was designed and therefore was not economically feasible or in that such apparatus and methods have not produced satisfactorily true or smooth optical surfaces on such articles as lenses and have resulted in frequent breakage and rejection of lenses processed thereby.

It is an object of this invention to provide an improved method for simultaneously grinding or polishing two spherical surfaces of a spherical lens or of a similarly shaped article; to provide a method for rough grinding, finish grinding and polishing a series of spherical lenses in continuous sequence; to provide such a method which does not require blocking of the lens or other article; and to provide such methods for producing lenses or articles with true and smooth surfaces of various selected curvatures.

Another object of this invention is to provide an improved apparatus for simultaneously grinding both spherical surfaces of a spherical lens; to provide such an apparatus which can accomplish formation of lens without requiring blocking of the lenses; and to provide such apparatus which is adapted to form true and smooth lens surfaces of various selected curvatures. An additional object of this invention is to provide such an apparatus which is adapted to accomplish continuously changing interengagement of abrading means with surfaces of a spherical lens, that is, to move abrading means engaged with lens surfaces through continuously changing paths, for smoothly and accurately grinding or polishing the lens surfaces.

It is a' further object of this invention to provide an improved lens grinding apparatus of high capacity which 2,994,164 Patented Aug. 1, 1961 ice is inexpensive to manufacture and operate but which can be operated with safety and accuracy and with minimum supervision for forming spherical lenses of various selected lens curvatures.

Another object of this invention is to provide such lens grinding apparatus which is adapted for conveniently re moving prism or random irregularity of lens thickness from spherical lens being ground by the apparatus, and to provide such apparatus which can accomplish prism removal with minimum lens breakage.

An additional object of this invention is to provide such an apparatus or mechanism which can be automatically operated to receive, to grind or polish, and to reject a lens; to provide such a mechanism which can be conveniently adapted to rough grind, to finish grind or to polish a lens; and to provide a plurality of such mechanisms which can be connected in series by conveyor means with individual mechanisms adapted for automatic operation to rough grind, finish grind and polish a series of lenses in continuous sequence.

Briefly described, the method provided by this invention for simultaneously grinding both spherical surfaces of a spherical lens includes the steps of providing a pair of members each having a spherical abrading surface of curvature respectively complementary to the curvatures of lens surfaces to be ground, and supporting the members so that the member abrading surfaces are disposed in abrading relation to respective lens surfaces to be ground. The method also includes confining the lens for rotation between the members, preferably permitting limited tilting or edgewise movement of the lens between the members. In addition, the method includes rotating the members about respective radii of the member abrading surfaces, and oscillating the members against said lens surfaces through arcs substantially corresponding to respective curvatures of the abrading surfaces, thereby to abrade spherical surfaces of curvature complementary to the abrading surfaces on the lens and to rotate the lens on an axis which intersects the centers of curvature of the lens surfaces.

The preferred method according to this invention comprises establishing a series of lens grinding stations, and, at each station, providing a pair of members each having a spherical abrading surface of a curvature respectively complementary to the curvatures of lens surfaces to-be ground, pairs of members at successive groups of stations in the series having abrading surfaces appropriate for rough grinding, finish grinding and polishing a lens respectively. The method further comprism providing bumper means at each station for defining a lens-receiving space, disposing one of the members at each station beneath the space with its abrading surface between the bumper means, feeding a lens received at the station over the bumper means into the space onto said member so that the member abrading surface is in abrading relation to a lens surface, and lowering the other member from above the space for disposing its abrading surface between the bumper means in abrading relation to the other lens surface. Abrasive material appropriate for rough grinding, finish grinding and polishing a lens respectively is supplied between the lens surfaces and the member abrading surfaces at said successive groups of stations, and the members are rotated about respective radii of the abrading surfaces and are oscillated against the lens surfaces through arcs substantially corresponding to respective curvatures of said abrading surfaces, thereby to abrade surfaces of curvature complementary to said abrading surfaces on said lens and to rotate the lens on an axis which intersects the centers of curvature of the lens surfaces. According to this invention, the memberlo cated beneath said space at each station is thereafter lowered for permitting the lens to slide from within the space. The preferred method also includes the steps of supplying a lens to the first station in said series and con veying the lens between successive stations in the series for progressively rough grinding, finish grinding and polishing the lens in continuous sequence.

It can be seen that the method provided by this invention comprises a novel and advantageous method of simultaneously grinding both spherical surfaces of a spherical lens without requiring blocking of the lenses and that the method is easily adapted for progressively rough grinding, finish grinding and polishing a lens to form a finished lens from a lens molding or pressing.

However, it should be understood that the method and apparatus provided by this invention is useful for grinding spherical surfaces on other types of articles and that the term lens is used herein without intended limitation, it being understood that this term includes lens pressings, lens blanks, finished lenses, biconvex lenses, bioconcave lenses and meniscus lenses as well as other similarly shaped articles wherever appropriate.

According to this invention, the apparatus provided for carrying out the above-described methods includes a pair of members or laps each having a spherical abrading surface which can be either concave or convex, the abrading surfaces having curvatures complementary to respective curvatures of spherical surfaces to be ground or polished on a lens and being mounted in abrading relation to respective lens surfaces. The apparatus further includes means for rotating the members about respective radii of the abrading surfaces of the members, preferably in the same direction, for abrading spherical surfaces on said lens sides and for rotating the lens on an axis which intersects the centers of the curvature of the spherical lens surfaces. In addition, means are provided for oscillating the members to move the abrading surfaces relative to the lens through arcs substantially corresponding in curvature to respective abrading surfaces, thereby to continuously change interengagement of the abrading means and the surfaces of the lens so that said lens surfaces can be smoothly and accurately ground. Means, such as a plurality of bumpers or rolls disposed in spaced relation around the lens periphery, are also provided to confine the lens between the members for said rotation and abrading, the confining means preferably being spaced from the lens periphery for permitting limited tilting or edgewise movement of the lens therebetween.

In a practical embodiment of this invention, a plurality of rolls, which can be interconnected for simultaneous rotation, are mounted on a frame in circumferentially spaced relation within a plane which is preferably inclined to the horizontal for defining a space adapted to receive a lens. A pair of members each having a spherical abrading surface are provided with spindles which extend oppositely of respective abrading surfaces of the members in extension of radii of the abrading surfaces, and means, such as a pair of brackets pivotally mounted in coaxial relation on the frame, support the spindles to hold the abrading surfaces between said bumpers or rolls respectively above and beneath the above-described plane or lens-receiving space in abrading relation to lens surfaces, at least one of the members preferably being attached to its spindle by universal joint means to assure proper engagement of the members with a. lens disposed within said space. The apparatus includes means for supplying abrasive material between the abrading surfaces and the surfaces of a lens disposed within said space, for example pump means supplying abrasive material in a liquid medium through axial bores in said spindles and abrading members, and means are provided for rotating the spindles to grind or polish said lens surfaces and for rotating the lens within said space on an axis which intersects the centers of curvature of the lens surfaces. Means are also provided for oscillating the spindles, for example by reciprocally pivoting the spindle-supporting brackets, so that the abrading surfaces move through arcs substantially corresponding in curvature to the abrading surfaces, whereby interengagement of the abrading surfaces and lens surfaces is continuously changed during grinding.

In a preferred embodiment of this invention, chute means are provided for sliding a lens into the lens-receiving space over the bumpers or rolls and for sliding a lens out of the lens-receiving space beneath the bumper or rolls. Preferably also, pistons are attached to the spindle, and said bracket means have chamber portions fitted over the pistons to support the spindle for rotation and for sliding axial movement therein, means being provided for regulating fluid pressure within the bracket chamber portions for axially moving the pistons to elevate the abrading member which is above the lens-receiving space when desired to permit insertion of a lens within the space through the chute means and to lower the abrading member which is below the lens-receiving space when desired to permit removal of a lens from the space through said chute means.

Preferably a number of automatic mechanisms as abovedescribed are mounted in series and are interconnected by appropriate lens conveyor means whereby a lens can be successively received within an apparatus, can be ground therein, and can be removed therefrom for trans fer to the next apparatus in the series. In this arrangement, the successive mechanisms can be adapted to rough grind, finish grind and to polish a lens so that a lens fed through the apparatus can be rough ground, finish ground and polished in continuous sequence.

Other objects, advantages and details of construction of the methods and apparatus provided by this invention will appear in the following more detailed description of preferred embodiments of the invention, the description referring to the drawings wherein:

FIG. 1 is a perspective view, partially cut away, of the automatic lens grinding or polishing apparatus provided by this invention;

FIG. 2 is a View similar to that of FIG. 1 at different perspective and to enlarged scale;

FIG. 3 is an end elevation view, partially in section of an individual lens grinding or polishing mechanism provided by this invention for incorporation in the apparatus of FIG. 1;

FIG. 4- is a section view to enlarged scale along line 44 of FIG. 2;

FIG. 5 is a partial end elevation view, partially in section and to enlarged scale, similar to FIG. 3;

FIG. 6 is a section view along line 6-6 of FIG. 5;

FIG. 7 is a partial perspective view into the lens-receiving space of the lens grinding mechanism provided by this invention;

FIG. 8 is a partial section view to enlarged scale similar to FIG. 3;

FIG. 9 is a partial section view similar to FIG. 8; and

FIG. 10 is a partial schematic diagram of the electrical circuitry of the apparatus of this invention.

In FIGS. 1 and 2., 10 illustrates the apparatus of this invention in an application adapted for receiving lens moldings or pressings at one end as indicated by the arrow 10a, and for automatically transferring the lens moldings or pressings through a succession of lens grinding or

polishing mechanisms

12a, 12b and in continuous sequence to deliver finished, fully polished lenses at the outlet end of the apparatus as indicated by the arrow 10b, conveyor means 14 being adapted to transfer the lenses between successive grinding or polishing mechanisms. Automatic operation of the apparatus 10 for forming finished lenses from lens moldings or pressings will be more fully explained below following detailed description of the individual lens grinding or polishing mechanisms 12.

As shown in FIGS. 1-4, each lens grinding or polishing mechanism 12 includes a support or table 16 preferably having an inclined top portion 16.1 which is apertured at 16.2 to receive a frame 18, the frame as shown in FIG. 4 having an open bottom adapted to fit over the support aperture 16.2 and having a bottom flange 18.1 which is secured to the support by screws 18.2. The frame, which can be of cast or molded construction, is preferably of substantially cylindrical configuration and is mounted on the support 16 with its axis normal to the top portion 16.1 of the support. A pair of frame bosses 18.3 are diametrically opposed near the top of the frame and

shafts

20 and 22 are fixedly secured in coaxial relation within respective bosses.

As shown in FIGS. 4 and 5, a diaphragm 24 of flexible material such as rubber or plastic film has its margin fitted over the top of the frame 18, and a roller housing 26, including an annular wall 26.1 and an inturned flange 26.2, is mounted on top of the diaphragm margin 24.1 and is attached to the frame by screws 26.3, thereby to form a seal around the top of the frame. At least three roller or bumper supports 28 are secured to the inturned flange within the roller housing each having a bearing retainer 28.1 attached to the support by a screw 28.2 for holding a bearing 3% upon which a roller or bumper 32 is mounted by means of a bearing retainer 32.1 and a screw 32.2, the rollers having rims 32.3 of stifiiy resilient, preferably slippery, cushioning material such as rubber, plastic, Teflon or similar material and being freely rotatable on the bearings. The rollers are disposed in circumferentially spaced relation within the roller housing 26 and are adapted to define a space 34 for receiving -a lens pressing or lens blank such as the meniscus lens 36 shown in FIGS. 3-9, the space preferably lying along a plane which is inclined to the horizontal in a manner corresponding to the top portion of the table 16. As is best illustrated in FIG. 7, the rollers 32 preferably define a space 34 which is adapted to receive the lens 36 therein with substantial clearance so that the lens has considerable freedom of tiltin or edgewise movement within the space, and preferably, the rollers are interconnected by means of a drive belt 37 of rubber or similar material so that free rotation of one roller results in rotation of all rollers. Of course, although three rollers are illustrated, it should be understood that more than three rollers can be utilized within the scope of this invention.

As can be seen by reference to FIGS. 3-9, the rollers 32 are adapted to support or confine a lens blank or lens pressing such as the meniscus lens 36 to be ground or polished by suitable abrading members such as the conventional laps 3S and 4% the laps each having a spherical abrading surface, 38.1 and 46.1, respectively complementary to spherical surfaces, 36.1 and 36.2, of the lens 36. The laps can be of any conventional type such as molded copper or diamond impregnated materials and preferably are smaller in size than the lens 36. The laps are normally disposed between the rollers 32 at respective sides of the plane of the lens-receiving space 34 for holding the lens within the space, but are adapted to be moved from between the rollers to permit insertion or removal of a lens therebetween in the manner described below.

As shown particularly in FIGS. 4 and 5, the lap 38 disposed beneath the lens 36 is secured to a lap support 38.2 by being molded or otherwise interfitted with the grooves 38.3 of the support, whereas the support, in turn, is fitted within a bore 42.1 in the spindle 42. The support has curved slots 33.4 fitted over pins 42.2 fixed to the spindle whereby the support can be held on the spindle during rotation cf the spindle and support in one direction, but can be twisted in the opposite direction when the spindle is stationary for removing the support from the spindle in conventional manner. The spindle is splined adjacent its lower end as at 42.3 so that it can be moved axially through a correspondingly splined bushing 44 but is otherwise adapted for rotation with the bushing. As illustrated, the spindle 42 extends oppositely of the abrading surface 38.1 in axial extension of a radius of 6 the abrading surface. The spindle has a threaded portion 42.8 adjacent the spindle splines and has a shoulder 42.5 facing said threaded portion, ball bearings 46 being mounted on the spindle and spaced by a sleeve 48 to be held against the shoulder 42.5 by a nut 50 engaged with the threaded spindle portion.

A piston member 52, including the sleeve portion 52.1 and the radially-extending flange 52.2, is internally threaded as at 52.3 for engagement with a threaded bushing'54 which [fits within an. aperture in the diaphragm 24 to clamp the edge 24.2 of the diaphragm aperture into engagement with the piston sleeve, thereby to form a seal around the top of the piston member. The piston member is mounted on the spindle bearing 46 for permitting rotation of the spindle within the piston member, but the piston member has an annulus 52.4 fitted between the spindle bearings 46 whereby the spindle and piston members are adapted for corresponsive axial movement.

The piston member is mounted Within a bracket member 56 which is preferably formed in two parts connected by screws 56.1, as shown, to fit over the piston flange, the bracket fitting closely against the piston sleeve at either side of the piston flange as at 56.2 and 56.3 for forming a guide in which the piston member is adapted to slide and forming a chamber or cylinder 58, the wall of which is slidably engaged with the periphery of the piston flange as at 56.4. The bracket is journaled at 56.5 and 56.6 upon

respective shafts

20 and 22 and a bracket arm 60 as shown in FIG. 3 is extended through an aperture 18.4 in the mechanism frame by means of which the bracket, and therefore the spindle 42 and the abrading member 33, are adapted to be pivoted or oscillated about the common axis of the shafts from a point outside the frame. The bracket is also provided with a bearing support 62 shown in FIG. 4, which is secured to the bracket by screws 62.1 for mounting bearings 64 in which the bushing 44 is rotatably disposed. A pulley 66 of conventional type is fixed to the bushing 44 by a nut 66.1 threadedly engaged with the bushing, and a drive belt 68 extended through an aperture 18.5 in the mechanism frame is connected around the pulley in conventional manner, whereby the spindle 42 and therefore the abrading member 38 are adapted to be rotated about a radius of the abrading surface 38.1. The bracket is further provided with air passages 70 and 72 which lead into the bracket chamber 58 at respective sides of the piston flange 52.2, tapered couplings 73 serving to connect each passage to a flexible tube 73.1 through which compressed air can be introduced within the chamber at either side of the piston flange. As shown, O-rings 57 or other gasket means of suitable type are secured between the bracket and piston member for sealing off the chamber 58 and for preventing leakage of air around the piston flange, whereby when air is introduced into the chamber through either of said passages, the piston, and therefore the spindle 42 and the abrading member 38, are adapted to be moved either axially toward or away from the lens 36 and the lens receiving space 34.

Preferably the piston member has an aperture 52.5 leading from the piston chamber 58 inside the piston sleeve 52.1 so that pressurized air can leak from the chamber through the threaded portion 52.3 of the piston for preventing entry of extraneous matter such as ground glass or abrasive particles within the piston sleeve, the gasket 52.6 being held within the sleeve by a retaining ring 52.7 for otherwise sealing the sleeve.

The second lap 40, disposed above the lens 36, is secured to a lap support 40.2 by being molded or otherwise interfitted with the grooves 40.3 of the support, and the support is provided with a pair of curved slots 40.4. The outer gimbal 74.1 of an universal joint means 74 preferably is pivotally connected to an inner gimbal 74.2 by pins 74.3 and ends of these pins are fitted Within the curved slots of the lap support for removably mounting the lap support on the outer gimbal in the manner described above with reference to the member 38. The inner gimbal is, in turn, pivotally connected to a spindle 76 by means of a pin 74.4 whereby the spindle and lap support are adapted to be rotated together but are otherwise adapted for a degree of movement relative to each other in the manner conventional in tmiversal joints. For convenience of manufacture, the spindle 76 is formed in two parts including a tapered sleeve 76.1 which is connected to the gimbal by the pin 74.4 and a main spindle portion 76.2 into which the spindle sleeve is wedged or otherwise secured. The spindle is splined as at 76.3 adjacent the spindle end oppositely of the universal joint so that the spindle can be moved axially through a correspondingly splined bushing 78 but is otherwise adapted for rotation with the bushing. The main sleeve portion of the spindle has a threaded portion 76.5 adjacent the spindle splines and has a shoulder 76.6 facing said threaded portion, bearings 80 being mounted on the spindle and spaced by a sleeve 82 to be held against the shoulder by a nut 84 engaged with the threaded spindle portion.

A piston member 86 including the sleeve portion 86.1 and the radially extending flange 86.2 is mounted on the spindle bearings 80 for permitting rotation of the spindle within the piston member, but the piston member has an annulus 86.3 fitted between the spindle bearings, whereby the spindle and piston member are adapted for corresponsive axial movement.

The piston member is mounted within a bracket member 88 which is preferably formed in two parts connected by screws 88.1 as shown to fit over the piston flange, the bracket fitting closely against the piston sleeve at either side of the piston flange as at 88.2 and 88.3 for forming a guide in which the piston member is adapted to slide and for forming a chamber or cylinder 90 in which the chamber Wall, unlike the wall of the chamber 58, has a small clearance around the periphery of the piston flange 86.2 as at 88.4. A pair of arms 92 are attached to opposite sides of the bracket by means of screws or bolts 92.1 as shown in FIG. 3, and for conveniences of manufacture, can be grooved for mating with a matching ridge on the bracket as at 92.2 shown in FIG. 4, the arms extending downwardly along the outside of the frame 18 and being journaled at 92.3 and 92.4 upon

respective shafts

20 and 22. A U-shaped arm 94, see FIGS. 1 and 2, attached to each of the bracket arms 92 by screws 94.1 connects the arms, whereby the bracket, and therefore the spindle 76 and the abrading member 40, are adapted to be pivoted about the common axis of the shafts from a point outside the frame. The bracket is also provided with a bearing support 96, shown in FIG. 4, which is secured to the bracket by screws 96.1 for mounting bearings 98 in which the bushing 78 is rotatably disposed. A pulley 100 of conventional type is fixed to the bushing 78 by a nut 100.1 threadedly engaged with the bushing, and a drive belt 102 is connected around the pulley in conventional member, whereby the spindle 76 and therefore the abrading member 40 are adapted to be rotated. The bracket 88 is further provided with

air passages

104 and 106, see FIG. 5, which lead into the bracket chamber 90 at respective sides of the piston flange 86.2, tapered couplings 108 serving to connect each passage to a flexible tube 110 through which compressed air can be introduced within the chamber at either side of the piston flange. When air is introduced into the chamber 90 through either of said passages, the piston, and therefore the spindle 76 and the abrading member 40, are adapted to be moved either axially toward or away from the lens 36 and the lens-receiving space 34. However, since small clearance exists as at 88.4 between the wall of the bracket chamber and the piston flange and since no airtight seal is formed between the bracket member and the piston member at 88.2 and 88.3, axial motion of the piston can be easily restrained in the manner described below.

Preferably the piston member has an aperture 86.4

leading from the piston chamber inside the piston sleeve 86.1 so that pressurized air can leak from the chamber around the spindle sleeve portion 76.1 for preventing entry of extraneous matter within the piston sleeve, the gasket 86.5 being held within the piston sleeve by a retaining ring 86.6 for otherwise sealing the piston sleeve.

As shown in FIG. 4, a motor 114, preferably an electric motion, is mounted upon a support 116 which is held upon the shaft 22 by means of a split collar 116.1 and bolt means 116.2, and has a shaft 114.1 which extends to either side of the motor for supporting a pulley 118 at either end thereof to be engaged with the

drive belts

68 and 102 respectively, thereby to drive the belts, preferably in the same direction, for rotating the

spindles

42 and 76. A second motor 120 shown in FIGS. 4 and 5 is mounted beneath the table 16.1 by means of screws 120.1, and has a shaft 120.2, see FIGS. 3 and 4, which extends to either side of the motor for supporting a driving disc 122 at either end thereof. Each driving disc is provided with a dove-tailed groove 122.1 which extends transversely through the disc axis and which has a slide 124 movable therein, the slide members each having nut means 124.1 adapted to lock the slide in any selected position within a disc groove in conventional manner. Each of the slide members has a ball portion 124.2 or similar means adapted to be received Within a socket 126.1 on a turnbuckle 126 or other connector of adjustable length to form a universal joint connecting the slide and turnbuckle, and each turnbuckle has an additional socket 126.2 at its other end Which receives a ball 60.1 in the bracket arm 60 or a ball 94.2 on the bracket arm connector 94 respectively. In this construction, the slides 124 can be locked in the driving disc grooves 122.1 at any selected position of eccentricity relative to the disc axes so that operation of the motor 120 for rotating the discs is adapted to reciprocate the turnbuckles 126 for pivoting or oscillating the

bracket members

56 and 88 to any desired degree. The length of the turnbuckles is preferably adjustable in conventional manner whereby the stroke or are of oscillation of the members can be individually and conveniently located relative to a lens being ground. In this construction, oscillation strokes of the abrading members can be alternated if desired so that both abrading

members

38 and 40 will not overhang the same side of the lens 36 at the same time thereby to prevent possible interference of the abrading members such as might occur if the curvature of the abrading member 38 were relatively shallow compared to the curvature of the member 40.

As above described, the abrading members or

laps

38 and 40 are adapted for cooperation with the rollers 32 to confine a lens 36 therebetween, and the abrading members are adapted to be rotated and oscillated by means of their

respective spindles

42 and 76 for grinding or polishing the lens surfaces 36.1 and 36.2. For this purpose, the abrading member spindles as shown in FIG. 5 are each provided with a central bore 42.6 and 76.7 respectively. The lap 38 and the lap support 38.1 attached to the spindle 4-2 are apertured as at 38.4 and 38.5 respectively in alignment with the spindle bore 42.6 and gasket means 128 are fitted between the lap support and spindle so that the spindle bore and said apertures form a continuous passage through which an abrasive material such as corundum or jewelers rouge can be pumped in a liquid medium between the lap abrading surface 381 and the lens surface 36.1, thereby to effect grinding or polishing of the lens surface and to cool the laps and lenses as the lap is rotated and oscillated. In a corresponding manner, the lap 40.1 and the lap support 40.2 are apertured as at 40.4 md 40.5 respectively in alignment with the spindle bore 76.7 which extends through both the spindle sleeve 76.1 and the main spindle portion 76.2. The spindle sleeve has a spherical surface 76.8 fitted against the lap support aperture 40.5 and gasket means such as the O- ring 130 are fitted between said surface 76.8 and the lap support so that the spindle bore 76.6 and apertures 40.4 and 40.5 form a continuous passage through the universal joint means 74 through which an abrasive material can be pumped in a liquid medium between the lap abrading surface 40.1 and the lens surface 36.2, thereby to effect grinding or polishing of the lens surface 36.2 and cooling of the lap and lens as the lap is rotated or oscillated.

As illustrated in FIG. 4, the

spindles

42 and 76 each have a bushing 132 secured in threaded engagement thereto oppositely of the abrading members and each bushing has a bearing 134 mounted thereon. A pair of coupling members 136 are mounted upon respective bearings 134 so that said bushings and coupling members are adapted for relative rotation, each coupling having an aperture 136.1 aligned with a bushing bore 132.1 and with a spindle bore 42.6 or 76.7 and having a nipple 138 connecting the coupling to a conduit 140 through which abrasive material can be pumped in a liquid medium. The coupling members are provided with sealing means 142 between the members and the bushings so that abrasive material can be pumped therethrough as the bushings are rotated relative to the members, and preferably each coupling member has an arm 136.2 which fits within a slot 144.1 in one of a pair of angle supports 144 mounted upon

respective bracket members

56 and 88, thereby to prevent rotation of the coupling members. The diaphragm 24 sealed around the frame 18 and the piston member 52 is adapted to collect the liquid abrasive-carrying medium supplied through the spindle bores.

According to this invention, a cup-shaped cover means 146 is apertured as at 146.1 shown in FIGS. 3, 7 and 8 to fit over the piston member 86 and is attached to the roller housing 26 by screws 146.2, the cover having an aperture 146.3 receiving one end of an inclined chute 148 through which a lens or other article can be slided into the lens-receiving space 34 over the rollers 32. The roller housing 26 is similarly apertured at at 26.4 to receive one end of an inclined chute 150 through which a lens or other article can slide out of the lens-receiving space 34 beneath the rollers or bumpers 32, the chute 150 preferably being apertured at 150.1 to fit over the piston member 52 for a purpose to be described below. As will be readily understood, the inclined disposition of the lens-receiving space 34 and the

chutes

148 and 150 facilitates insertion and removal of a lens within the space 34 and also permits liquid abrasive medium collected upon the diaphragm 24 to flow along the chute 150 to return by gravity flow to the pump means 152 as shown in FIG. 2.

As shown in FIGS. 3, 5, 7 and 8, the chute means 148 of the mechanism 12 is apertured as at 148.1 and 148.2, and a bell-crank member 154 is pivotally mounted thereon as at 154.1, the bell-crank member having pins 154.2 and 154.3 adapted to fit alternately within respective chute apertures as the member is pivoted, thereby to engage lenses within the chute means 148 for preventing their passage through the chute means. When the bell-crank member is in the position shown in full lines in FIG. 8, the pin 154.2 engages a lens 36a in the chute means and prevents sliding of the lens into the lens-receiving space 34. However, when the bell-crank member is pivoted to the position shown in dotted lines in FIG. 8, the pin 154.2 is withdrawn through the chute aperture 148.1 permitting the lens 36a to slide into the lens-receiving space 34 while, at the same time, the pins 154.3 are moved upwardly through the chute apertures 148.2 to engage the second lens 36!) in the chute, thereby to assure that only one lens is permitted to slide into the space 34. Thereafter, when the bell-crank member is returned to its original position, the lens 36b can advance into engagement with the pin 154.2 for subsequent release into the lens-receiving space 34. A ram cylinder unit 156, preferably of the pneumatic type, is mounted upon the cover means 146 and has a piston member 156.1 engaged with a clip 154.4 carried by the bell-crank member for controlling pivoting of the bell-crank member. Preferably, a dog 158 is pivotally mounted on the chute means as at 154.1 to assure that a lens does not advance inadvertently into the space 34 by riding over other lenses within the chute.

According to this invention, a plurality of lens grinding or polishing

mechanisms

12a, 12b, and are preferably mounted in series within a housing 160 to form the automatic apparatus 10 as shown in FIGS. 1 and 2. By proper selection of the

laps

38 and 40 in each mechanism and by provision of the proper abrasive material between the abrading surfaces and the lens surfaces in each mechanism, for example by furnishing copper laps and corundum or other suitably coarse abrasive for the

mechanisms

12a and 12b and by furnishing jewelers rouge or other suitably fine abrasive and laps formed of diamond impregnated material for the mechanism 120, the mechanisms can be adapted to perform rough grinding, finish grinding, and polishing operations respectively upon a lens passed successively through the mechanisms.

In this construction, hopper means (not shown) can be provided for continuously feeding lenses into the chute 148 of the first mechanism 12a in the series as indicated by the arrow 10a in FIGS. 1 and 2, and conveyor means 14 can be provided for transferring each lens successively between the

mechanisms

12a and 12b and between the

mechanisms

12b and 120 to be fed ultimately from the chute 150 of the mechanism 120 as finished, fully polished lens or lens blanks as indicated by the amrow 10b. The conveyor means 14 preferably each chm-prise a chute 162 having a continuous belt 162.1 suspended between shafts 162.2 which are rotatably mounted at respective ends of the chute, the chutes 162 extending between a chute 150 of one mechanism to the chute 148 of the next mechanism in the series and preferably being attached thereto by permanent means such as brazing or welding. A motor 164 is mounted upon a mechanism frame adjacent each chute 162 and is connected, preferably by universally jointed shaft means 164.1, to shafts 162.2 at one end of respective chutes 162, thereby to drive the belts 1 62.1. As thus constructed, the belts can be provided with carrier means, such as. the buttons 162.3, therealo ng for receiving lenses through the chutes 150 and for advancing the lens to the chutes 148 of the next mechanism in the series.

As will be understood by reference to FIG. 10, indicates transformer means the primary of which 170.1 is adapted to be connected to a power source and to various conventional circuits (not shown) through the terminals 178 for energizing the rotating motors 114, the oscillating motors 120-, the conveyor motors 164 and the pump means 152 when the conventional starting switch means as represented at 1 80 are moved to closed circuit position. The secondary winding 170.2 of the transformer means then also provides power for the illustrated circuits of the apparatus in conventional manner.

As shown, auto matic operation of the apparatus 10 in the preferred embodiment of this invention is principally controlled by

timers

166 and 168 which are shown only schematically in FIG. 10. Upon closing of the cycling switch 182, the timer 166 is energized and after some delay energizes the relay 184 through timer contacts 166.1 for closing relay contacts 184.1 to energize the timer 168 and for closing relay contacts 184.2 to energize valves 186. The valves 186 preferably comprise conventional solenoid-type pneumatic valves: and are adapted to supply compressed air from a source not shown for actuating the ram cylinder unit 156 shown in FIG. 8 whereby the cylinder unit rapidly performs its cycle of operation as above described for releasing a lens in each chute 148 to slide into the lens-receiving space 34 associated therewith. The valves 186 are also adapted for establishing relatively high air pres-sure in the

piston chambers

58 and 90, shown in FIG. 5, beneath the piston flange 52.2 and above the piston flange 86.2 respectively in each of the

mechanisms

12a, 12b and 120, whereby each set of abrading

members

38 and 46 are held be tween rollers 32 in engagement with respective surfaces 36.1 and 36.2 of the lens supplied to each mechanism. As the motors 11-4, 120, 116 and the pump means 152 are operating, the abrading members are continuously rotated and oscillated in engagement with the lens surfaces, and abrasive material in a liquid medium is supplied between the abrading members and the lens surfaces through respective spindle bores.

The abrading members rotate upon axes coinciding with radii of the abrading surfaces 38.1 and 40.1 respectively so that the lens surfaces are ground or polished to curvatures complementary to those of respective abrading surfaces. At the same time, the abrading members are oscillated over the lens surfaces between the positions shown in full and dotted lines in FIG. 9 so that all portions of the lens surfaces are engaged by various portions of the abrading surfaces, whereby the lens surfaces can be smoothly ground or polished without creation of grooves, ridges or other surface aberrations such as might occur as a result of slight irregularities in the abrading surfaces if a portion of a lens surface were continuously traversed by the same portion of an abrading member as where the abrading member is merely rotated. The abrading members in each mechanism can be rotated in the same direction as shown or can be rotated in opposite directions, but in either case, will rotate each lens 36 relatively slowly around an axis which intersects the centers of curvatures of the lens surfaces, thereby to further assure that each portion of a lens surface is engaged by various portions of the abrading surfaces. Since the rollers 32 confining the lenses are freely rotatable and since each lens has substantial clearance around its periphery, the lenses will also have some freedom of tilting or edgewise movement between the abrading members so that the lenses can rock within the space 34. Where the rollers are adapted to rotate together, as preferred, each lens 36 can move smoothly between abutting engagements with various rollers during edgewise lens movement without snapping motions such as might occur if a rotating lens were moved against a stationary confining roller.

As grinding or polishing of the lenses 36 progresses in each mechanism, the abrading members 40 are biased downwardly by air-pressure in the piston chambers 90 to maintain a controlled pressure engagement of the abrading surfaces and lens surfaces. However, since there is clearance around each piston flange 86.2 Within the chamber 90 as at 88.4 in FIG. 5, downward axial movement or depression of the abrading members 40 is easily restrained or cushioned so that prism or random irregularity of thickness in the lens 36 can be gradually ground away without risk of cracking or otherwise damaging the lens.

At the end of the preselected period for which the timer 168 is set, the timer 168 actuatcs the timer 166 through the contacts 168.1, thereby to repeat the operative cycle of the apparatus after the delay period established by the timer 166. During said delay period, the relay 184 opens its contacts so that valves 186 release the high air pressures established in the

piston chambers

58 and 90. During said delay period, the timer 168 also actuates the relay 188 through timer contacts 168.2 for closing relay contacts 188.1, 188.2 and 188.3 to energize the valves 196 as indicated in FIG. 10. The valves 190 preferably are similar to the valves 186 and func tion in converse manner so that compressed air is introduced into the

piston chamber

58 and 90 above the piston flange 52.2 and beneath the flange 86.2 by the valves 190 as air is released from beneath the flange 52.2 and from above the flange 86.2 in each mechanism by the valves 186, thereby lowering each abrading member 38 so that the ground or polished lenses 36 resting on said members are permitted to slide from the spaces 34 beneath the rollers 32 along the chutes 150 to be advanced to the next mechanism in the series by the conveyor means 14, and thereby elevating the abrading members 40 so that lenses to be ground and polished can be subsequently permitted to slide from the chutes 148 over the rollers 32 to enter the spaces 34.

Thereafter, preferably after said slight delay, the timer 166 is adapted to again actuate the relay 184 as above described for releasing a lens in each chute 148 to slide into the lens-receiving space 34 associated therewith and for repeating the above-described procedure so that the abrading member 38 is elevated to receive the new lens inserted within the lens-receiving space and so that the abrading member 40 is lowered into pressure engagement with the new lens to repeat the above-described lens grinding or polishing cycle. Preferably, the air introduced into the piston chambers 53 is at substantially higher pressure than that introduced into the chambers so that the abrading members 38 in each mechanism can be moved rapidly into position between the rollers 32 to receive the new lenses fed therein, but the abrading members 40 will be slowly lowered to assure suflicient time for insertion of the new lenses within the spaces 34 before the abrading members 41 move between the rollers 32 into engagement with the lenses.

It sometimes occurs that as the abrading members are moved outwardly of the lens-receiving space 34 to permit replacement of a lens therein, the lens 36 previously ground or polished within the space will adhere to one member or the other as a result of suction formed between the lens and the abrading member by the liquid abrasive medium. Accordingly, as shown in FIGS. 3 and 8 particularly, in each mechanism the aperture 150.1 in the chute is titted over the piston member 52 but is preferably too small to permit passage of the lens 36 therethrough, and the piston member 56 is adapted to move the abrading member 38 beneath the chute. In this construction, a lens adhered to the abrading member 38 will be stripped therefrom as the abrading member passes through the chute aperture as shown in FIG. 8 and will slide along the chute 156 out of the space 34.

Correspondingly, the cover means 146 in each mechanism is apertured at 146.4 and a stripper arm 169 is slidably mounted within the aperture for movement into and from the lens-receiving space 34, the stripper arm preferably carrying a bifurcated member 169. 1 inside the cover and having a bumper 169.2 of rubber, plastic or similar resilient, cushioning material mounted between member bifurcations. A ram cylinder unit 171 preferably of pneumatic type, is mounted on the exterior of the cover means 146 of each mechanism and has a piston member 171.1 joined to the stripper arm by a connector 171.2. In this construction, the ram cylinder unit can be actuated by the valve means in conventional manner for extending the stripper arm toward the lensreceiving space 34 at the same time that the abrading member 40 is retracted therefrom in the manner abovedescribed, the bumper 171.2 being adapted to pass in close proximity to the abrading member 40 to engage the lens 36 if it is adhered to the abrading member 40 for stripping the lens therefrom so that the lens can slide from the space 34 through the chute 150. The ram cylin der unit is preferably adapted to retract automatically after stripping of the lens from the abrading member so that the stripping arm is rapidly withdrawn from the space 34 to permit insertion of a new lens to be ground within the space.

Preferably a pair of

switches

172 and 174 of conventional type are mounted in spaced relation upon the bracket 88 of each mechanism 12 as illustrated in FIGS. 24, and a tripping arm 176 is fixed to the piston 86 of each mechanism by screws 176.3, as shown in FIG. 5, for movement therewith, the arm carrying an adjusting screw 176. 1 and a coil spring 1762. In this construction, the screws 176.1 in each of the rough and finish grinding mechanisms, 112a and 1212 respectively, can be adapted to engage actuating means such as the pushbuttons 172.1 of the switches 172 as the pistons move downwardly in reducing the thickness of lenses 36 during grinding thereof, thereby individually to actuate the valve means 190 for moving abrading

members

38 and 40 outwardly from the space 34 in the manner above described when the lenses have been ground to the desired thickness even though the grinding period established by the timer 168 has not expired. As the abrading member 40 of each mechanism is elevated, the spring 176.2, which is connected to actuating means such as push-pull plunger 174.1 of the switch 174, is adapted to operate valve means of any suitable type (not shown) for interrupting supply of abrasive material by the pump means 152 shortly after the abrading surfaces 38.1 and 40.1 have separated from corresponding lens surfaces.

As shown in FIG. 10, actuation of the switch 172 is adapted to halt the grinding process in an individual mechanism 12 so that grinding process is renewed by normal operation of the

timers

166 and 168 as the timers function in repeating the above-described operative cycle. As will be understood as the pistons 86 move downwardly into engagement with a new lens disposed within the lens-receiving space of each mechanism, the coil spring 176.2 is adapted to return the switch 174 to its original position for assuring supply of abrasive material shortly before the abrading surfaces 38.1 and 40.1 are engaged with the surfaces of the new lenses. Preferably, as shown, the

switches

172 and 174 and the tripping arm 176 are also provided upon the polishing mechanism 12c even though lens thickness is not usually reduced in that mechanism during polishing, the switches and arm in this application serving to prevent injury to the abrading

members

38 and 40 if, for any reason, a lens should not be supplied to the lens-receiving space of that mechanism at the proper time.

-In the illustrated embodiment of this invention, there are three mechanisms 12 each of which is regulated by the

timers

166 and 168 to operate for a similar period of time as modified by interrupting action of the tripping arm 176. Thus, this arrangement is best suited for processing lenses wherein the required rough grinding, finish grinding and polishing periods are approximately the same. In the most usual case, however, the period of time required for polishing lense substantially exceeds the rough and finish grinding times, and according to this invention, additional mechanisms 12 could be incorporated within the apparatus to share in polishing of the lenses moved through the apparatus. For example, a satisfacory arrangement has been made wherein seven mechanisms 12 are mounted in series with five of the mechanisms being devoted to polishing the lenses, the timer being set for transferring lenses between the mechanisms at one-minute intervals so that each lens is rough and finish ground for one minute and is polished for five minutes. This process thus produces finished, fullypolished meniscus lenses from lens pressings or moldings in seven minutes, and furnishes one finished lens each minute in continuous sequence without requiring other than general operator supervision.

It will be noted that, in the illustrated embodiment of this invention, the abrading

members

38 and 40 in each mechanism are adapted to oscillate about a pivot point which lies on the common axis of the shafts and 22 as shown in FIG. 4 and that this pivot point is positioned a fixed distance below the lens-receiving space 34. Thus, the abrading member 38 which is rigidly secured to its spindle 42 can be oscillated only at a radius equal to the distance between the space 34 and said pivot point. However, abrading action of the member 38 is adapted to form a spherical lens surface 36.1 of a curvature complementary to that of the member abrading surface 38.1 even though the radius of said curvature differs from the radius of said member oscillation. This is possible in that, since the lens 36 is loosely supported between the rollers 32,

the lens is adapted to tilt orrock within the space 34 as the member 3% is oscillated, the tilting or rocking of the lens compensating for differences between member curvature and member oscillation to assure proper abrading engagement of the abrading surf-ace 38.1 and the lens surface 36.1. The abrading member 40 which is yieldingly held in engagement with the lens 36 is adapted to ride up and down in its supporting bracket 88 during rocking of the lens, the universal joint means 7 4 through which the member 40 is rotated and oscillated permitting formation o-f a lens surface 36.2 of curvature complementary to that of the abrading surface 40.1 despite rocking of the lens and despite differences in the radius of curvature of the surface 46.1 and the radius of oscillation of the member 40.

Since the rollers 32 can permit only limited tilting of the lens 36 while properly confining the lens between the abrading members 38 and 44), it is preferred that the distance between the space 34- and the pivot point of the abrading members approximately correspond to the radius of curvature of member abrading surfaces. Thus, the illustrated embodiment of the invention is principally adapted to grind or polish meniscus lenses, and preferably the radius of member oscillation is about six diopters which will approximately correspond to the radius of curvature of the most common ophthalmic meniscus lenses. 0f course, it should be understood that this invention is not limited to provision of the above-described six diopter oscillating radius or to the manufacture of meniscus lenses, but that the pivot axis formed by the shafts 2t} and 22 can be located in various positions relative to the lens-receiving space 34 for grinding or polishing biconvex lenses, bioconcave lenses or other articles within the scope of this invention.

It should be understood that although particular embodiments of this invention have been described for the purpose of illustration, this invention includes all modifications and equivalents thereof which fall Within the scope of the appended claims.

Having described my invention, I claim:

1. Apparatus for making an article having spherical surfaces on two opposite sides, said apparatus comprising: a pair of members each having a spherical abrading surface, said abrading surfaces having curvatures complementary to the curvatures of the spherical surfaces to be formed on respective sides of the article and being mounted in abrading relation to said respective article sides; means for rotating said members about respective radii of said abrading surfaces to abrade spherical surfaces on said article sides and to rotate said article on an axis which intersects the centers of curvature of said spherical article surfaces; means for oscillating said members to move the abrading surfaces against the article sides to bring about an abrading action; and means for supporting said article to be abraded and rotated between said members during said oscillation.

2. Apparatus for simultaneously grinding both spherical surfaces of a spherical lens, said apparatus comprising: a pair of members each having a spherical abrading surface, said abrading surfaces having curvatures complementary to the curvatures of respective lens surfaces to be ground and being mounted in abrading relation to said respective lens surfaces; means for supplying abrasive material between said abrading surfaces and said lens surfaces; means for rotating said members about respective radii of said abrading surfaces to abrade said lens surfaces and to rotate said lens on an axis which intersects the centers of curvature of said lens surfaces; means for oscillating said members to move the abrading surfaces against the lens surfaces to bring about an abrading action; and a plurality of bumpers adapted for engaging the lens around the lens periphery to confine the lens for said rotation between said members, said bumpers being spaced for permitting limited tilting movement of the lens there between during said oscillation.

3. Apparatus as set forth in claim 2 wherein said bumpers comprise rolls mounted for free rotation in a plane extending in a direction transversely of the axis of rotation of said lens.

4. Apparatus for simultaneously grinding both spherical surfaces of a spherical lens, said apparatus comprising: a pair of members each having a spherical abrading surface, said abrading surfaces having curvatures complementary to the curvatures of respective lens surfaces to be ground; spindle means fixed to one of said members oppositely of its abrading surface in axial extension of a radius of said surface for holding said abrading surface in abrading relation to one of said lens surfaces; universal joint means secured to the other of said members oppositely of its abrading surface; second spindle means secured to said universal joint means for pivotal movement relative to said other member and for holding the abrading surface of said other member in abrading relation to the other of said lens surfaces; means for supplying abrasive material between said abrading surfaces and said lens surfaces; means for rotating said spindle means to abrade said lens surfaces and to rotate said lens on an axis which intersects the centers of curvature of the lens surfaces; means for oscillating said spindle means to move said abrading surfaces against the lens surfaces to bring about an abrading action; and means adapted for engaging the lens around the lens periphery to confine the lens for said rotation and abrading between said members.

5. Apparatus as set forth in claim 4 wherein said spindle oscillating means are individually adjustable for scillating said spindle means in individually selected paths.

6. Apparatus for simultaneously grinding both spherical surfaces of a spherical lens, said apparatus comprising a pair of members each having a spherical abrading surface of curvature respectively complementary to the curvatures of lens surfaces to be ground and each having a bore extending through its abrading surface, a spindle fixed to one of said members oppositely of the member abrading surface in axial extension of a radius of said abrading surface for holding the abrading surface in abrading relation to a corresponding lens surface, said spindle having an axial bore aligned with the bore in said member forming a passage through which a liquid abrasive-carrying medium can be introduced between said abrading surface and lens surface, universal joint means having one part secured to the other of said members oppositely of the member abrading surface and having a second part pivotally connected to the first part, said joint parts each having a bore therethrough and having means cooperable for connecting the bores during pivoting of said parts, a second spindle fixed to the second part of said joint means for holding the abrading surface of said other member in abrading relation to the other of said lens surfaces, said second spindle having an axial bore aligned with said joint means bores and the bore in said other member for forming a passage through which a liquid abrasive-carrying medium can be introduced between the abrading surface of said other member and said other lens surface, means for rotating said spindles to abrade said lens surfaces and to rotate the lens on an axis which intersects the centers of curvature of the lens surfaces, means for oscillating said spindles to move said abrading surfaces against the lens surfaces to bring about an abrading action, and means adapted for engaging the lens around the lens periphery to confine the lens for said rotation and abrading between said members.

7. Apparatus for simultaneously grinding both spherical surfaces of a spherical lens, said apparatus comprising: a frame; a pair of members each having a spherical abrading surface, said abrading surfaces having curvatures respectively complementary to the curvatures of lens surfaces to be ground; spindle means fixed to respective members oppositely of said abrading surfaces in axial extension of respective radii of the surfaces; a pair of bracket means pivotally mounted on the frame and rotatably supporting respective spindle means for holding said abrading surfaces in abrading relation to respective lens surfaces; means for supplying abrasive material between said abrading surfaces and said lens surfaces; means for rotating said spindle means to abrade said lens surfaces and to rotate said lens on an axis which intersects the centers of curvature of said lens surfaces; means reciprocally pivoting said bracket means for oscillating said spindles to move said abrading surfaces against the lens surfaces to bring about an abrading action; and means for engaging the lens around the lens periphery to confine the lens for rotation and abrading between said members.

8. Apparatus as set forth in claim 7 wherein said second spindle is slidably mounted for axial movement through its supporting bracket means and wherein said apparatus further comprises a piston movable with said second spindle, cylinder means enclosing said piston, and pneumatic means for actuating piston movement within the cylinder means to normally move the abrading member fixed to said spindle toward said other abrading member for holding the lens in pressurable engagement therebetween and to raise said abrading member for permitting replacement of said lens when desired.

9. Apparatus as set forth in claim 8 wherein said piston has sufiicient clearance within said cylinder means so that said abrading member fixed to said second spindle can be yieldingly biased toward said other abrading member.

10. Apparatus for simultaneously grinding both spherical surfaces of a meniscus lens, said apparatus comprising: a frame; a pair of members each having a spherical abrading surface, said abrading surfaces having convex and concave curvatures respectively complementary to the curvatures of the lens surfaces to be ground; a spindle fixed to the member having a convex abrading surface oppositely of its abrading surface in axial extension of a radius of said surface; universal joint means secured to the other of said members oppositely of its concave abrading surface; a second spindle secured to said universal joint means for pivotal movement relative to said other member; a pair of bracket means pivotally mounted on the frame in coaxial relation at approximately the center of curvature of said abrading surfaces for supporting respective spindles to hold said abrading surfaces in abrading relation to respective lens surfaces; means for supplying abrasive material between said abrading surfaces and said lens surfaces; means for rotating said spindles to abrade said lens surfaces and to rotate said lens on an axis which intersects the centers of curvature of said lens surfaces; means reciprocally pivoting said brackets for oscillating said spindles to move said abrading surfaces against the lens surfaces to bring about an abrading action; and bumper means mounted in spaced relation for engaging the lens around the lens periphery to confine the lens for rotation and abrading between said members.

'11. Apparatus for simultaneously grinding both spherical surfaces of a spherical lens, said apparatus comprising: a frame; a plurality of bumpers mounted on the frame in circumferentially spaced relation within a plane for defining a space adapted to receive a lens; a pair of members each having a spherical abrading surface of curvature respectively complementary to the curvatures of lens surfaces to be ground; means normally supporting said members for holding said abrading surfaces between said bumpers respectively above and beneath said space in abrading relation to a lens disposed within said space; means for rotating said members about respective radii of said member abrading surfaces for abrading said lens surfaces and for rotating said lens on an axis which intersects the centers of curvature of said lens surfaces; means for oscillating said members to move said abrading surfaces against said lens surfaces to bring about an abrading action; and means for moving said abrading members outwardly from said space for permitting remetal; f aJ ns; om. ai ace enea h. a dbumrs s nd; nse on of e i h n. d. sp ce v r; d. bumpers.

12. Apparatus for simultaneously grinding bothspherical surfacesv of a sphericallens, said apparatuscomprising: aiframe; a plurality of bumpers mounted on the frame incircumferentially spaced relation within a plane for defininga space adapted to receive a lens; a pair of members. each having a. spherical abrading surface of curvature. respectively complementary to curvatures of lens surfaces to be ground; means normally supporting said. members for holding said abrading surfaces between said bumpers respectively above and beneath said space; means adapted to elevatethat member which is. supported above said space for permitting insertion of a lens to be ground said space; chute means adapted to slide a lens over said bumpersinto said space; means for supplying abrasive. material between said abrading surfaces and said lens surfaces; means for rotating said members about respective radii of said member abrading surfaces in abrading relation to spherical surfaces of a lens within the space for abrading said lens surfaces and for rotatingthe lens on an axis which intersects the centers of curvature of. said lens surfaces; means for oscillating said members to move said abrading surfaces against said lens surfaces to bring about an abrading action; means adapted to lower the other of said members for permitting removal of the lens from said space; and chute. means adapted to slide the lens out of said space beneath said bumpers.

13. Apparatus for simultaneously grinding both spherical surfaces of a spherical lens, said apparatus comprising: a frame; a plurality of bumpers mounted on the frame in circumferentiall-y spaced relation for defining a space adapted to receive a lens; a pair of members each having a spherical abrading surface of curvature respectively complementary to curvatures of lens surfaces to be ground; spindle means secured to respective members oppositely of their abrading. surfaces in axial extension of respective radii of the surfaces; piston means connected to each spindle means; a pair of bracket means pivotally mounted upon the frame, said bracket means each having a chamber portion enclosing respective pis-. ton means and supporting respective spindle means for rotation and sliding axial movement therein; means regulating fluid pressure. within the bracket chamberportions to slide the piston means therein for moving the abrading surfaces of said members between said bumpers at respective sides of the lens-receiving space into pressurable engagement with surfaces ofva lens to be ground therein and for moving said abrading surfaces from be: tween the bumpers to permit replacement of the lens; means for supplying abrasive material between the abrading surfaces and the lens surfaces; means for rotating the spindle means to abrade said lens surfaces; and means for reciprocally pivoting said bracket means to oscillate said spindle means, thereby to move said abrading surfaces against the lens surfaces to bring about an abrading action.

14. Apparatus for making a spherical lenscomprising: a plurality of lens grinding mechanisms mounted in series; each mechanism having a frame, a plurality of bumpers mounted on the frame in circumferentially spaced relation within a plane. for defining a space adapted to receive a lens, a pair of members each having a spherical abrading surface of curvature respectively complementary to the curvatures fxlenssurfaces to be ground, pairs of members in successive groups of mechanisms in said serieshaving abrading surfaces appropriate for rough s ng, fin h .dingand p l s n a e spe t v y, means, pr tin said members for a y in aid member abrading surfaces between said bumpers respectively above and beneath said space, means adapted to elevate the member above said space for permitting insertion of a lens received at the mechanism into said space 18 over: said. bumpers, means supplying abrasive mate, rial betweenssaid. abrading. surfaces and said lens surfaces, the. abrasive material supplied to said. successive.

on an axis which intersects the centers of curvature of i said lens surfaces, means for oscillating saidmembers .to

move said. abrading surfaces against. said. lens surfaces to bring, about an-abrading action, and means adapted to:

lower the member beneath said space to permit sliding. of a lens from within said space beneath said bumpers; means supplying a lens to the first mechanism in the series; and means conveying the lens between said mechanisms for successively rough grinding, finish grinding and polishing the lens.

15. Apparatus for continuously makingsphericallenses comprising: a plurality of lens grinding mechanisms mounted in series; each mechanism having afrarne, a plurality of bumpers mounted upon theframein circumferentially spaced relation within a plane for defining a 7 space adapted to receive a lens, a pairof members each having a spherical abrading surface of curvature, respectively complementary to the curvatures of the lens sur; faces to be ground, pairs of members in successive groups of mechanisms in said series having abrading surfaces appropriate for rough grinding, finish grinding and polishing a lens respectively, supporting means adapted to move the members for normally holding the member abrading surfaces between the bumpers respectively above and beneath said space in abrading relation to corre sponding surfaces of a lens disposed within the space, said supporting means being adapted to elevate the member located above. the space for permitting insertion of a lens within said space over said bumpers and to lower the member located beneath said space for permitting sliding of a lens from within said space heneath said bumpers, means for supplying abrasive material between said abrading surfaces and said lens stufaces, thea brasive material supplied'to said successive groups of'mechanisms being appropriate for rough grinding, finish grind ing and polishing a lens respectively, means for simul-, taneously rotating the members about respective radii of said abrading surfaces, andmeans for oscillating said members to move said abrading surfaces against said lens surfaces to bring about an abrading action, thereby to abrade surfaces of curvature complementary to said abrading surfaces onsaid lensand to rotate the lens on an axis which intersects the centers ofcurvature of said lens surfaces; means associated with each mechanism adapted to feed a lens within the lens-receiving space thereof; means associated with each rough andfinish' grinding mechanism adaptedto actuate said supporting means for elevating and lowering said-members when a lens disposed within the lens receiving space thereof has been ground to selected'thickness; means associated with each mechanism adapted to periodically actuate said sup: porting means for elevating and lowering saidmembers; means adapted to periodically actuate said feeding and supporting means for feeding a lens into the lens-receiving space of each mechanism and for moving respective mem-f bers into abrading relation thereto; means for supplying lenses to the first mechanism in said series; and conveyof means for transferring lenses between said'mechanisms in continuous sequence for successively rough grinding, finish grinding and polishing each lens.

16. A method of simultaneously grinding spherical surfaces on two opposite sides of an article, saidmethod comprisingas steps: providing a pair of memberseach having a spherical abrading surface of curvature respectively complementary to curvatures to be ground upon the article sides, supporting said members at respective sides of an article to be ground with said abrading sur- I faces in abrading relation thereto, confining said article so that it is free to rotate between said members, rotating the members about respective radii of said abrading surfaces, and oscillating said members for moving said abrading surfaces against said article sides to bring about an abrading action, thereby to abrade spherical surfaces of curvature complementary to said abrading surfaces on said article sides and to rotate said article on an axis which intersects the centers of curvature of said article sides.

17. A method of simultaneously grinding both spherical surfaces of a spherical lens, said method comprising as steps: providing a pair of members each having a spherical abrading surface of a curvature respectively complementary to the curvature of the lens surfaces to be ground; supporting said members at respective sides of a lens with said abrading surfaces in abrading relation thereto; enclosing said lens for limited edgewise movement between said members and' so that it is free to rotate between said members; supplying abrasive material between said abrading surfaces and said lens surfaces; rotating said members about respective radii of said abrading surfaces; and oscillating said members for moving said abrading surfaces against said lens surfaces to bring about an abrading action; thereby to abrade spherical surfaces respectively complementary to said abrading surfaces on said lens and to rotate said lens on an axis which intersects the centers of curvature of said lens surfaces.

18. A method of simultaneously grinding both spherical surfaces of a spherical lens, said method comprising as steps: providing a pair of members each having a spherical abrading surface of curvature respectively complementary to the curvatures of lens surfaces to be ground; providing bumper means for defining a lens-receiving space; disposing one of said members beneath said space with its abrading surface between said bumper means; feeding a lens over said bumper means onto said one member so that the abrading surface of said one member is in abrading relation to a corresponding lens surface; lowering the other of said members from above the space for disposing its abrading surface between said bumper means in abrading relation to the other lens surface; supplying abrasive material between the abrading surfaces and lens surfaces; rotating the members about respective radii of the member abrading surfaces; oscillating said members for moving said abrading surfaces against said lens surfaces to bring about an abrading action, thereby to abrade spherical surfaces of curvature complementary to said abrading surfaces on said lens and to rotate the lens on an axis which intersects the centers of curvature of said lens surfaces; and thereafter lowering said one member so that its abrading surface is moved from between said bumper means for permitting said lens to slide from within said space.

19. A method of making a spherical lens which comprises as steps: establishing a series of lens grinding stations; at each station, providing a pair of members each having a spherical abrading surface of a curvature respectively complementary to the curvatures of lens surfaces to be ground, pairs of members at successive groups of stations in said series having abrading surfaces appropriate for rough grinding, finish grinding and polishing a lens respectively, providing bumperrmeans for defining a lens-receiving space, disposing one of said members beneath said space with its abrading surface between said bumper means, feeding a lens received at said station over said bumper means onto said one member so that the abrading surface of said one member is' in abrading relation to a corresponding lens surface, lowering the other of said members from above the space for disposing its abrading surface between said bumper means in abrading relation to the other lens surface, supplying abrasive material between the abrading surfaces and lens surfaces, the abrasive material supplied at said successive groups of stations being appropriate for rough grinding,

- finish grinding and polishing a lens respectively, simulltaneously rotating the members about respective radii of the member abrading surfaces, oscillating said members for moving said abrading surface against said lens surfaces to bring about an abrading action, thereby to abrade surfaces of curvature complementary to said abrading surfaces on said lens and to rotate the lens on an axis which intersects the centers of curvature of said lens surfaces, and thereafter lowering said one member so that its abrading surface is moved from between said bumper means for permitting said lens to slide from within said space; supplying a lens to the first station in said series; and conveying the lens between said stations for progressively rough grinding, finish grinding and polishing the lens.

20. A continuous method of making spherical lenses which comprises as steps: establishing a series of lens grinding stations; at each station providing a pair of members each having .a spherical abrading surface of a curvature respectively complementary to the curvatures of lens surfaces to be ground, pairs of members at successive groups of stations in said series having abrading surfaces appropriate for rough grinding, finish grinding and polishing a lens respectively, and providing bumper means for defining a lens-receiving space; at each station performing the sequence of steps of raising one of said members from beneath said space for disposing its abrading surface between said bumper means, feeding a lens received at said station over said bumper means onto said one member so that the abrading surface of said one member is in abrading relation to a corresponding lens surface, lowering the other of said members from above the space for disposing its abrading surface between said bumper means in abrading relation to the other lens surface, supplying abrasive material between the abrading surfaces and the lens surfaces, the abrasive material supplied at said successive groups of stations being appropriate for rough grinding, finish grinding and polishing a lens respectively, simultaneously rotating the members about respective radii of the member abrading surfaces and oscillating the members for moving said abrading surfaces against said lens surfaces to bring about an abrading action, thereby to abrade surfaces of curvatu-re complementary to said abrading surfaces on said lens and to rotate the lens on an axis which intersects the centers of curvatures of said lens surfaces; at each rough and finish grinding station, lowering said one member when said lens has been ground to proper thickness so that the member abrading surface is moved from between said bumper means for permitting said lens to slide from within said space; at each polishing station, lowering said one member periodically so that its abrading surface is moved from between said bumper means for permitting said lens to slide from within said space; at each station periodically initiating performance of said sequence of steps; supplying a sequence of lenses to the first station in said series; and conveying'lenses between said stations for successively rough grinding, finish grinding and polishing said lenses in continuous sequence.

References Cited in the file of this patent UNITED STATES PATENTS 1,588,435 Adams June 15, 1 926 1,706,723 Adams Mar. 26, 1929 2,479,898 Beaudette Aug. 23, 1949 2,787,093 Sundberg Apr. 2, 1957 2,919,523 Phillips Jan. 5, 1960