US2418086A - Lens surfacing machine - Google Patents

Description

March 25, 1947. D. E. MU-LHOLLAND ETAL 2,418,086

LENS SURFAGING MACHINE 1s Sheets-Sfieei 1 Filed May 15, 1945 Mara! 1947. D. E. MULHOLLAND ETAL 2,413,086

LENS SURFACING MACHINE Filed May 15, 1945 13 Sheets-sheaf 2 March 25, 1947.

. D. E. MULHOLLAND ETAL 2,418,086

LENS SURFACING MACHINE Filed May 15, 1945 13 Sheets-Sheet 3 044 10 5. M04 #042. #N0, Gus 7794 F196 March 25, 19475 MULHOLLAND r AL 2,418,086

LENS SUBFACING MACHINE F iled May 15, 1945 13 SheetsSheet 4 March 1947- D. E. MULHOLLAND ETAL 2,418,036

was SURFACING MACHINE Filed May 15, 1945 13 Sheets-Sheet 5 -lvlzmrch 2 5, 1947- D. E. MULHOLLAND ETAL LENS SURFACING MACHINE Filed May 15, 1945 13 Sheets-Sheet 6 March 25, 1947.

D. E. MULHOLLAND ETAL 2,418,086-

LENS SURFACING MACHINE Filed May 15; 1945 13 Sheets-Sheec 7 Marcb 25, 1947- DE. MULHOLLAND ETAL LENS SURFACING MACHINE Filed May 15, 1945 13 Sheets-Sheet 8 I March 25', 1947. I D. E. MULHOLLAND ETAL 2,418,036

LENS SURFACING MACHINE Filed May 15, 1945 l3 Sheets-Sheet 9 I III March 25, 1947. D. E.-MULHOLLAND ETAL 2,418,086

LENS SURFACING momma:

Filed. May 15, 1945 l3 Shets-Sheet 10 swam MS Mi ch 25, 1947. D. E. MULHOLLAND ETAL 2,418,036

LENS SURFACING MACHINE l3 Sheets-Sheet 11 Filed May 15, 1945 March 25, 1947.

D. E. MULHOLLAND ETAL LENS SURFACING MACHINE Filed May 15, 1945 13 Sheets-Sheet l2 swam W06 Marfih 1947- DE. MULHOLLAND ETAL 2,418,056

LENS S'URFACING MACHINE I 5 Fi led May 15, 1945 l3 Sheets-Sheet l3 Patenied Mar. 25, 1947 LENS SURFACING MACHINE David E. Mulholland, Reading, Pa, Gustave Fast, Salisbury, Md, and Kirk S. Lawrence, West Reading, Pa.

Application May 15, 1945, Serial No. 593,850

28 Claims.

This invention relates to grinding or polishing machines and more particularly to machines for rinding or surfacing lens blanks with a curved surface.

A principal object of the invention is to provide improved means for rotating a lens blank spindle and for simultaneously moving a member in which the spindle is mounted to and fro in a curved path to cause the lens blank to move in such a path.

Aprimary feature of the invention consists in providing hydraulic means, such as an oil gear motor for rotating the lens supporting spindle as it is moved to and fro in a curved path.

Another feature of the invention consists in providing an oil gear motor for rotatin the spindle having means whereby a part of the oil for driving the motor is employed to lubricate bearings for the spindle.

A further feature of the invention consists in providing a rectilinearly movable slide which is flexibly connected to the lens holding means so that reciprocation of the slide will cause the lens holding means to move to and fro in a curved,

path.

A still further feature of the invention consists in providing an apron or flexible shield which is successively wound and unwound on spaced rollers during movement of the lens holding means so as to protect the bearings of the spindle from material incident to the grinding operation.

Other and more specific features of the invention, residing in advantageous forms, combinations and relations of parts, will hereinafter appear and be pointed out in the claims.

In the drawings,

Figure l is a side elevational view of a machine embodying the invention.

Figure 2 is a plan View of the machine illustrated in Figure 1.

Figure 3 is an enlarged vertical sectional view of the right end portion of the machine.

Figure l is an enlarged vertical sectional view taken longitudinally of the pivoted beam adjacent the lens supporting spindle.

Figure 5 is a fragmentary transverse sectional view taken on line 55 of Figure 3.

Figure 6 is a fragmentary vertical sectional view taken on line t% of Figure 2.

Figure 7 is a fragmentary horizontal sectional View taken on line 7-7 of Figure 1.

Figures 8 and 9 are plan and side views respectively of the rectilinearly movable slide.

Figure 10 is an end view of the slide.

Figure 11 is a detail sectional view on line I i-! l of Figure 8.

Figures 12 and 13 are horizontal sectional views taken on lines i2-i2 and l3-13, respectively, of Figure 4.

Figure. 14 is a sectional view on line l4l4 of Figure 13, the upper part of the structure being omitted.

Figure 15 i an enlarged fragmentary sectional view of portions of the coacting gear wheels, the view being taken in the plane of radial openings in one of the wheels.

Figure 16 is an enlarged vertical sectionalview of the lower spindle bearing.

Figure 17 is a bottom view of the bearing in Figure 16.

Figure 18 is a plan view of the lower gear sleeve bearing. Figure 1 9 is a, sectional view taken on line til-49 of Figure 18.

Figure 20 is a side view of a cast ironblock which, after being cut in two, forms opposed way blocks for side 'wall portions of the beam.

Figure 21 is a fragmentary sectional viewtaken onlineEI-EiofFigureZO. Figure 22 is a plan view of the upper spindle bearing. r Figure 23 is a sectional view taken on line 23-43 of Figure 22.

Figure 24 is a fragmentary sectional view taken on line 24-24 of Figure 22.

Figure 25 is a fragmentary sectional view taken on line 25-25 of Figure 22.

Figure 26 is a plan view of the pin or fulcrum on which the idler'gear wheel of the'gear motor is rotatably mounted.

Figure 27 is a side elevational View of the pin or post of Figure 26. Figure 28 is an enlarged fragmentary View of the spindle and adjacent parts.

" Figure 29 is a front side view of the construction illustrated in Figure 28.

Figure 30 is a plan view of a portion of the spindleair seal ring,

Figure 31 is a transverse vertical sectional view of the ring.

Figure 32 is a plan view of a dle pump ring.

Figure 33 is a side elevational view of a portion of the pump ring.

portion of the spin- Figure 34 is an enlarged detailed sectional View Q showing the profile of the lower edge of the pump ring.

The present invention is particularly'designed for use in a pivoted beam I of the character fully described and claimed in the copending patent application of Mulholland and Lawrence, Serial Nb. 488,256, filed May 24, 1943, with which a relatively stationary rotatable surfacing meniber of the character there shown or of any other similar character may be associated.

The beam may/in the main, be formed'as a single unitary casting having side walls 2 and a top wall 3. At the end nearest the surfacing means, the beam is preferably provided with suitable hydraulic mechanism whereby it can be selectively caused to move toward and away from the surfacing means. The hydraulic mechanism may be ofthe same character as that illustrated in said copending application where the beam is formed with a downwardly extending yoke 4 having oppositely projecting posts 5 which are respectively adapted to cooperate with diaphragms 6 mounted within opposed cylinders land 8. The beam is preferably maintained in a condition of balance and it will, therefore, immediately respond to changes in forces to which it is subjected by the hydraulic means or any other means.

Downward pivotal movement of the beam is preferably limited by an adjustable stop consisting of a rod 9 which is screw threaded in the hub 'of a rotatable hand wheel Ii] suitably journaled in brackets .Il secured to the end wall of thebeam, the lower end of the stop rod being engageable with a part l2 rigid with the base ofthe machine.

' ..As in th copending application referred to,

upward pivotal movement of the beam by the hydraulic mechanismmay consist of an inverted yoke or U-shaped member 13 rigid with the base which straddles a yoke or U-member it rigid with the beam, the yoke I3 being provided with a vertically adjustable screw threaded memher [5. This member may be conveniently rotated through any suitable means by a shaft lfiIwhich extends through an elongated slot in one of the legs or arms of the yoke I l and the lower. end of the screw threaded member is adapted to be engageable with the bottom or web portlon of .the yoke it. Thus an adjustable stop is provided which acts in opposition to the hydraulicv means for pivoting the beam upwardly whereby the amount of material removed from the faceof-the work being surfaced by the surfacing means may be accurately controlled.

The bearings I! which afford the pivotal sup port for the beam are vertically adjustable in upright standards l8 so that at the conclusion of the'surfa'cing'operation the beam will be in a predetermined angular position with reference to the vertical. The vertical adjustment of the bearings may be conveniently obtained, as in said pending application, by providing upwardly extending rotatable rods [9 which are screw threadedwithin depending portions 20 of the bearings, adapted to be rotated by a motor 2|, for example. i

Extending upwardly from adjacent that part of the beam above the adjustable stop member l5 are side wall portions 22 having curved grooves 23in their inner faces affording guideways in which the lens holding means is movable back and forth so as to cause a lens blank mounted thereon to move in a curved path. The side wall 'portions each consist of a plate-like way block 24 whose. upper inner edge has a recess 25 and a-cur'ved retaining member 26 which is removably secured to the upper edge of the way block 'bybolts or the like 21 so as to form the grooves member to thus provide wall portions having concentric. recesses. .The curved retaining members 26 maybe similarly formed by first machining a ring to the desired dimensions and then cutting itin half so as to provide two members.

The means for holding a lens blank consists, in the main. of a body element 29, a rotatable spindle 30 which is journaled in the body, and an oil gearmotor 3| for rotating the spindle. The body element includes an upper member 32-, which may be termed a spindle way block, having curved ribs or rings removably connected thereto at opposite sides extending into the guideways 23 to afford a slidable support for the entire lens holding means. One of the ribs may be. in the form of a ring 33a and may be con-. veniently marked on its outer side in degreesso that movement of the lens holding meansin degrees may be easily noted. The other rib 33b on the opposite side of the way block is pref--v erably not in the form of a ring but instead may be only a segment of a ring so that the lens surfacing means shown in Figure 2 and designated A may be mounted adjacent that side of the beam and extend over the top thereof to operatively cooperate with a lens blank mounted on the spin-. dle and not interfere with free pivotal movement of the beam.

Secured to the under side of the spindle way block by bolts 34 or the like and forming apart ofthe body element of the lens holding means are. plate members 35 and 35 respectively forming the top and bottom plates of an oil gear motor which involves two gear wheels 38. The sides of the oil gear motor are formed by a plate 39 which is clamped between the top and bottom gear plates and rigidly connected to the under side of the bottom plate 36 is a member 46 for housing the lower end of the spindle 353. For con venience, this member may be formed in two complementary parts which may be easily connected by bolts M or the like.

oil, or other fluid if desired, is supplied under pressure to the oil gear motor through a flexible conduit or pipe 42 which communicates at one end with a suitable supply pipe 43 and which at its other end communicates with a swivel connection 44 mounted on the lower end of the body element 29 and having communication with a passageway 45 leading upwardly to the gear motor. This passageway communicates with diverging passages MB which direct the oil against the teeth of the gear wheels 38 to cause the wheels to rotate in opposite directions. The passages t5 are formed by mounting a substantially diamond-shaped plate 41 in one of the -V-shaped recesses in the intermediate gear plate 39.

One of the gear wheels is keyed to a sleeve 43 which is splined, as indicated at 49, to the spindle 30 so that, as the gear wheels are forced to rotate in opposite directions by the fluid supplied thereto, the spindle is caused to rotate.

As the flexible oil supply pipe 42 is secured to the swivel connection 44, the lower end of the body is free to move back and forthin a curved, path between the two dot and dash line positions indicated in Figure 6. To take up the slack which occursin the flexible conduit as the body moves to and fro and yet to permit that movement to be unhampered, the conduit may advantageously be supported on a roller carried on a shaft 5| supported at its opposite ends in lugs 52 extending downwardly from a horizontal plate 53 rigidly connected to the top wall of the beam.

Betweenthe roller 50 and the point at which the conduit is connected to the main supply pipe, the conduit is provided with a weight 54 to take up the slack. Adjacent the swivel connection 44, the flexible conduit may also preferably pass beneath a roller carried on a shaft 5% mounted at its opposite ends in the side walls 2.

t is thus to be seen that oil under pressure may be supplied to the gear motor without interfering with swinging movement of the body element in the guideways in the side wall portions of the beam and that the motor will operate continuously during sliding movement of the body in a curved path to eifectrotation of the spindle. To. insure perfect sphericity of the lens surface to begenerated, the axis about which the body element swings :to and fro is intersected by the of rotation of the spindle.

To supply lubricant to the guideways, a pair of brackets 51 is mounted on opposite ends of each way block 2d on which gravity feed oilers 53 are mounted, communicatingthrough passages 59 in the brackets with the inner end portions of the grooves 23. From there, the lubricant may pass into transversely extending grooves 56 in the top and bottom walls of the guideways, the transverse grooves in the bottom wall of the guideways being clearly seen in Figure 21.

Extreme precision is required in surfacing lens blanks and the rotating spindle is, therefore, journaled so that it will not vibrate or wabble within the body 25. For this reason the'spindle is provided with spaced shoulders iii and 62,

respectively, and an intermediate downwardly tapering peripheral surface $3. The opening in the body in which the spindle is disposed has correspondingly shouldered portions and an intermediate bearing E i having a downwardly tapering inner surface 65 of the same inclination as the tapered peripheral surface of the spindle. This bearing which is preferably provided at its upper end with a laterally projecting circular flange fit-underlying the upper shoulder 6| of the spindle is advantageously formed with an outer steel shell portion 6'! and a lining of suitable bearing material 68. The upper surface of the top flange of the bearing is undercut, as indicated at E9 in Figure 24 and id in Figure 25, and the inner surface of the tapering portion thereof is undercut, as indicated at H in Figure 23, so that the bearing material which is applied to the shell in. a molten state may flow intothese parts and be firmly interlocked therewith. The outer surface of the bearing shell is cylindrical in part, as indicated at 12, so as to be held firmly within a corresponding cylindrical opening in the body and, in addition, portions of its outer surface incline inwardly and downwardly, as indicated at it, to form spaces M between the bearing and the body for receiving lubricant under pressure.

In the present embodiment of the invention, the bearing is shown as providing three lubricant receiving spaces and each one of them communicates by a duct 15 with an annular groove 19 formed in the inner face of the bearing. The bearing is so positioned within the opening in the body that one of the spaces is in direct communication with a lubricant supplying groove 11, to be hereinafter described, formed in the under side of the wayblock 32. The inner face of the bearing is provided with a plurality of longitudinally extending grooves l8 which communicate attheir lower ends with the annular groove 16 and the upper surface of the flange 66 of the bearing is formed with aplurality of radially disposed grooves 79 which form continuations of the longitudinal grooves .78. It; is thus to be seen that, since the annular groove i5 is in open communication with each of the lubricant spaces .14, the grooves 78 and 19 are likewise, at all times, in communication with all of the spaces. An ample supply of lubricant is, therefore, always available for the hearing.

The upper portion of the spindle is so formed that the lower shouldered portion 62 is spaced from the body whereas the upper shouldered portion 6! andthe downwardly inclined peripheral surface thereof are in engagement with the hearing es. When lubricant is supplied under pressure to the grooves on the inner face of the bearing, as hereinafter pointed out, athin film of oil is always maintained between the coasting surfaces of the spindle and bearing so that the spindle, in effect, floats on oil.

Oil under pressure is supplied to the bearing 34 by providing the second gear wheel 38, the idler gear wheel, with a plurality of radially extending passages :89 whose outer ends terminate in the inner walls 8! of the spaces between the teeth of the gear. The gear is rotatably mounted on a fulcrurnpin. or post 82 which is keyed, as indicated at '83, to the top mOtOr plate 35. The bushing 84 which is freely rotatable about the pin is keyed to the idler gear and has radial passages 85 in alignment with the passages thereof.

The fulcrum pin has a longitudinally extending passage 86 which communicates at its upper end with'the passage Tl, heretofore described, leading to one of the lubricant spaces 74. Adjacent its lower end, it is'formed with a radial passage 8? in the same plane asthe radial passages 80 in the idler gear so that, as the idler gear rotates, the radial passages thereof successively communicate with the radial opening 8? in the fulcrum pin and thus cause lubricant to enter the longitudinal passageway of the pin.

In the operation of the oil gear motor, most of the oil supplied to the gear wheels is discharged fromthe motor on the side opposite of the oil inlet side, passing through an outlet passage 88 having communication with a separate passageway 89 in the swivel joint 44 to which another flexible pipe 99 identical with the sup ply pipe 42 is connected. The outlet pipe and the supply pipe are preferably connected by clips 9 landmove together in unison.

Although the oil is discharged through passage 88, a thin coating or film-0f oil nevertheless remains on the teeth of the gear wheels and the teeth interlock so accurately that, as each tooth of the driving gear wheel extends into the space between the adjoining teeth of the idler gear wheel, a large part of the oil remaining on the teeth is forced under pressure through the radial passageways into the other communicating passages heretofore described to lubricate the bearmg.

Surrounding the sleeve 58 which, as previously described, is keyed to both the driving gear wheel and to the stem portion of the spindle are upper and lower sleeve bearings 92 and 93, respectively. The lower end of the upper bearing is provided with a flange 94 overlyin the upper surface of the driving gear wheel and the upper end of the lower sleeve bearing is formed with a similar flange 95 underlying the bottom surface of that wheel. The flanges of both of these sleeves have grooves 96 formed in their outer faces which communicate with longitudinally extending grooves=91 in-the-inner faces of the bearings.

Thus oil which seeps from'the gear motor be tween the top andbottom faces of the driving gear wheel will pass. into the grooves ofthese bearings and thus lubricate the stem portion of the spindle, that is, the outer surface of sleeve 48.

The spindle is secured within the body element against upward longitudinal displacement by a thrust collar 98 encircling the lower end of the stem portion, a locking ring 99, washer I and lock nuts IIlI being employed to secure the thrust collar in the desired position. A bearing I02 which'encircles the lower end of the spindle has a laterally projecting lower flange I03 interposed between the bottom gear plate 36 of the body and the thrust collar whereby the bearing is rigidly clamped to the body.

The inner surface of the bearing Hi2 and the bottom surface of the flange I03 thereof are coated or lined, as indicated at I04, with suitable bearing material. gear motor into the grooves in the upper and lower sleeve bearings 92 and 93 will seep downwardly into grooves IIMa in the inner surface of the bearing and the bottom flange thereof to lubricate engaging portions of the bearing and spindle, as well as engaging portions of the bearing flange and the thrust collar 98. Thus an abundance of oil is always supplied between all relatively moving parts of the body and spindle. Excess oil passing downwardly may collect in a sump formed by the member 40 housing the lower end of the spindle.

The lens holding means, as a whole, is movable back and forth in the curved guideways 23 by a rectilinearly movable reciprocating slide I35 which advantageously consists of two side members Hit and two end members I01. The outer faces of the side members have converging portions Hi8 to fit within and be slidably supported by V-shaped grooves in the inner faces of suitable members rigid with the side walls of the beam as shown in dot and dash lines in Figure 5. Reciprocating movement is imparted to the slide by a rod Hi9 pivotally connected at one end by a pin Iii! to the forward portion of the slide and E f pivotally connected at its other end by a pin I I I to a rotating disk II2, as seen in Figure 7. The disk may be rotated in any convenient manner, such as by a motor I I3.

The lens supporting means extends downwardly into the space between the side and end members of the slide and each end of the bodyelement thereofis connected to the opposite end of the slide by a pair of flexible metal bands, the pair of bands secured to the end of the slide adjacent the connecting rod II9 being designated by II4 and the pair of bands connected to the other end of the slide being designated by H5.

The bands thus extend toward each other and, to prevent them from fouling in moving the lens holding means, bands II lare connected to lugs I it which, as may be seen in Figure 8, are spaced a greater distance apart than a pair of lugs II? at the opposite end of the slide to which the bands Iiii are connected. The other ends of the bands underlie the curved under surface of the spindle way block it and their end portions I I8 are pref-' erably clamped to the underside of the way block by removable plates I I9 and studs I20, which permit the bands to be self-aligning. It will be observed that the bands extend downwardly from the way block to their point of attachment to the horizontal slide and thus they always exert a downward pull on the block.

.Theends of the .bandssecured to. the slide I Oil which has passed from the oil adjacent faces of the lugs.

are each connected between spaced portions of a rod or clamp I2 I which is adapted to be positioned within a U-shaped recess in the lug of the slide to which, the band is to be secured. The outer ends of the rods I2I are screw threaded to receive lock nuts I22 for securing them to the lugs. Resilient or spring means is preferably employed in the connection of the rods to the lugs so as to absorb some of the shock which is naturally transmitted to the bands, and consequently to the lens holding means,'each time the slide reverses its direction of movement, and for this purpose a coil spring I23 is interposed between the lock nuts on the ends of the rods and the Suitable spring caps I24 are'preferably employed at opposite ends of each coil spring.

When the slide IE5 is moved by the rod I09in one direction, one pair of the flexible bands causes the lens holding means to move generally in the same direction, and when the slide is caused to move in the opposite direction, as described, the other pair of bands causes the lens holding means to also move in the opposite direction. However, since the lens holding means is supported by curved ribs which extend into the similarly curved guideways 23. it will travel in a curved path while the slide travels in a rectilinear path. This difference in character of movement of the two bodies is made possible by the flexible bands connecting them. Rotation of the spindle as the lens holding means moves to and fro in a curved path is, of course, not dependent upon this connection since the oil supplied to the oil gear motor within the lens holding means is fed thereto by a flexible pipe pivotally connected directly to the holding means.

To prevent water and other material incident to the surfacing operation, such, for example, as loose particles of the surfacing means and par.- ticles of glass from the lens itself, from working down into the spindle bearings and also for preventing oil supplied to the bearings from working its way out around the top of the spindle, the spindle is provided with an annular flange 25 at its upper end, and a seal I25 is mounted in the spindle way block 32 immediately below the flange I215 encircling thecylindrical portion I21 of the spindle. An apron I28 having an opening intermediate its ends of substantially the same diameter as the outer diameter of the seal I26 is rigidly clamped to the upper surface of the spindle way block by a clamp member I29 which, like the apron, extends transversely of the spindle way block from one side thereof to the other. The clamp encircles the seal and, as seen in Figure 5, has portions which extend beneath it at diameterically opposed points in alignment with the axis of curvature of the upper surface of the way block. While the under surface of the apron clamp is curved and conforms to the upper surface of the-spindle way block, its upper surface is flat and is disposed in a plane slightly below the under side of the peripheral flange I25. Bolts I133 may be conveniently employed for connecting the clamp to the spindle way block.

The ends of the apron I28 are respectively secured to rollers RSI which may be conveniently mounted on the brackets 5! on the upper end portions of the circular way blocks or wall portions 2 8. Rigid with one end of each roller is a sheave I32 around which one end of a wire cable or the like I33 may be wound. The wire cable of each sheave extends downwardly on the outside of the adjacent wall; of the beam and may be secured by a tension spring indicatedv in dot and dash lines. As seen in Figure 3, the wire cables I33 are connected to the sheaves in such manner that the tension of the springs to which they are respectively secured will cause the rollers I3I to rotate in opposite directions. The two ends of the apron I28 are oppositely wound upon the rollers I SI so that the pull of the spring connected to one of the wire cables I33 acts in opposition to the pull of the spring connected to the other wire cable. Thus the rollers maintain the apron in tension and as the lens surfacing means moves to and fro the apron is successively wound on one roller and unwound from the other.

Overlapping the upper face of the apron is a plate I35 having an openingfor receiving the top flange I25 of the spindle which extends transversely of the spindle way block from one side thereof to the other. The side edges of this plate are curved upwardly as indicated at I36 so as not to present sharp edges which would otherwise cut into the apron as the lens holding means moves back and forth.

In assembling the apron clamp I29 with the lens holding means, tapered dowels I3! are preferably employed and, should it be desired to render the oil gear motor inoperative and secure the spindle against rotation to the spindle way block, a bolt such as indicated in dot and dash lines at I38 may be employed.

The seal I 25 for preventing water and such material as abrasive grains and particles of glass from the lens itself from working down into the spindle bearings as well as for preventing oil supplied to the bearings from working its way out around the top of the spindle consists of a pump ring I40 which is shrunk on to the upper portion of the outersurface of the cylindrical part i2! of the spindle and an encircling air seal ring I 4| The pump ring is formed on its outer face with inclined vanes or ribs I42 forming intervening grooves I43. The lower edge of the ring is serrated or kerfed to provide surfaces I44 which incline upwardly in the direction of rotation of the ring, the upper end of each inclined surface being connected to the lowest or trailing end of the next preceding inclined surface by a substantially vertical wall portion or face I45. The ribs I42 extend upwardly at a greater angle to the horizontal than the inclined surfaces I44 and they are preferably positioned with respect to them so that the upwardly facing side wall of each rib intersects the lowest point of a serration and the downwardly facing side wall intersects the uppermost point of the next preceding serration, the downwardly facing side of the portion of the rib between these points being preferably in the same plane as the adjacent inclined surface.

It will thus be seen that any oil which is forced upwardly by the action of the oil gear motor heretofore described between the upper cylindrical portion of the spindle. and the way block 32 will, when the spindle is rotated, be engaged by the inclined surfaces I44 and thus be subjected to downward pressure, overcoming the upward pressure imparted to it.

Such oil as might seep upwardly between the outer face of the pump ring and the air seal ring I45 will be subjected to a downward force by the ribs I42.

The air seal ring I 4| may advantageously be made of bronze and is of channel-shape in cross section having a web I46 and inner and outer annular walls I41 and I48 respectively. The web 10 or bottom portion I 46 of the channel rests in part on the circular way block 32 as seen in Figure 4, and in part on the apron clamp I29 as viewed in Figure 5.

This ring affords a chamber into which air under pressure is introduced and from which it is designed to escape into the space between the apron clamp I29 and the overlying portion of the top flange 25 of the spindle. In addition, the pressure of the air effectively prevents the escape of any oil which may rise to the top of the pump ring 568. The top of the inner wall I41 is formed with a groove I49 which serves as a surface break to impede the flow of capillary oil.

The outer wall Hi8 of the ring is formed with two openings communicating with passageways 1959 in the apron clamp I29 through which air is, admitted to the ring. In the present embodiment of the invention, the passageways I50 are drilled in the apron clamp. The outer ends of these passageways are closed by removable plugs l5 l, while the under side of the clamp is formed with ports Hi2 communicating with the passagewaysv and formed so as to receive pipe connections. Ports I52 are connected with branch pipes I53 to a coupling I54 which receives air under pressure from a flexible pipe I55.

This combination seal of a vane pump on the spindle for driving or pumping the oil downwardly and of a circular air chamber effectively prevents water, grit, etc., passing downwardly around the spindle where it would contaminate and ruin the bearings and also effectively prevents oil from seeping out from under the spindle flange where it might interfere with the surfac ing of the work.

As is known, a spherical surface will be im-.

parted to a lens blank when-the spindle supporting the blank rotated simultaneously with bodily movement of the spindle to and fro in a curved path, whereas a cylindrical surface will be im-.

parted to a lens blank when it is moved to and fro in a curved path without being rotated.

From the foregoing, it will be perceived that simple and reliable means have been provided whereby lens blanks may be surfaced with extreme precision by workers not necessarily having the knowledge and skill which has heretofore been required in doing work of this character.

What we claim is:

1. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting member having curved guideways, lens blank holding means movable to and fro in said guideways for moving the lens blank in a curved path. said means including a body member, a spindle journaled in said body on which the lens blank is adapted to be mounted, hydraulically operated means mounted in said member and movable therewith for rotating th spindle as said means is moved to and fro, and passages in said body through which the fluid is conducted to and away from said hydraulic means.

2. Li a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, and lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means comprising a body element supported in said guideways, a spindle journaled in said body on which a lens blank is adapted to be nounted, and an oil gear motor having a plurality of gear wheels mounted in said body for rotating said spindle as the body moved back andjforth, one of said gear wheels being rigid with said spindle.

3. In a machine for surfacing lens blanks with a'relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, and lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means including a body element supported in said guideways, a spindle journaled in said body on which a lens blank is adapted to be mounted, an oil gear housed within said body for rotating thespindle as the body is moved back and forth, said oil gear motor having a gear wheel rigid withthe spindle and a cooperating gear wheel having ducts for the passage of oil to lubricate said spindle.

4. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, thecombination of a supporting element having curved guideways, and lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means including a body element supported in said guideways, a spindle journaled in said body on which a lens blank is adapted to be mounted, an oil gear motor mounted in said body for rotating the spindle as the body is moved back and forth, said oil gear comprising a pair of rotatable gear wheels, one of said gear wheels being rigid with the spindle and the other of said gear wheels having radial passageways communicating with the inner portion of the space between the teeth thereof through which oil is forced by the teeth of the other gear wheel to lubricate the'spindl when said wheels are rotated.

1 5'. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, and lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means including a body element supported in said guideways, a spindle journaled in said body on which a lens blank is adapted to be mounted, an oil gear mounted in said body for rotating the spindle as the body is moved back and forth, said oil gear comprising a pair of rotatable gear wheels one of which is rigid with the spindle, a pin mounted in the body affording a rotatable mounting for the last named gear wheel and said pin having passageways through which oil may pass from said motor to lubricate the spindle.

I 6. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, and lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means including a body element supported in'said guideways, a spindle journaled in said body on which a lens blank is adapted to be mounted, and an oil gear motor mounted in said body for rotating the spindle as the body is moved back and forth, said oil gear comprising a pair of gear wheels,'a pin within the body affording a pivotal mounting for one of said gears and the other of said gears being rigid with the spindle, said first named gear wheel having a plurality of radial passageways and said pin having a 1ongitudinally extending passageway communicating with said radial passageway, the outer ends of said radial passageways respectively terminating in the bottom wall of the spaces between the.

teeth of the said wheel wherebythe teeth of the cause the lens blank to move in a curved path, 1

said means including a way block supported in said guideways, a spindle journaled in said block on which a lens blank is adapted to be mounted,

and mechanism mounted on the under side of said way block housing the lower end of the spindle, said mechanism having an oil gear motor for rotating said spindle provided with a plurality of gear wheels one of which is rigid with the spin-.-

dle, and a pin affording a mounting on which the second gear wheel is rotatable, said pin havinga longitudinal passageway for receiving oil from said second named wheel, and a groove on the under side of said way block for conducting oil from said longitudinal passageway to the spindle.

8. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of. a supporting element having curved guideways, and lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means comprising a body element slidably supported in said guideways, a spindle rotatably mounted in said body element on which a lens blank is adapted to be'mounted, an oil gear motor mounted within said body element for rotating the spindle as the body moves back and forth, pipe connections pivotally mounted at the lower end of said body to which flexible conduits may be attached, and'means for supplyin oil from said motor to the spindle, the lower portion of said body housing the lower end of said spindle and forming a sump for oil draining from the spindle.

9. In a, machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, and lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means comprising a body element slidably supported in said guideways, a spindle for holding a lens blank ro-tatably supported in said body, a bearing in the body for said spindle, hydraulic means for rotating the spindle as the body moves to and fro, said hydraulic means being movable with said body, said bearing having portions 'spaced from contiguous parts of the body forming spaces for receiving lubricant under pressure and having passageways permitting lubricant to pass.

from said spaces to the inner face of said bearing.

10. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved" guideways, and lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means comprising a body element provided with an opening slidably supported on'said guide ways, a bearing within said opening having portions spaced from adjacent walls of the opening, and an oil gear motor mounted within said body for rotating said spindle and for supplying lubricant under pressure to said spaces between the bearing and the body, said bearing having passageways for conducting oil from said spaces to the inner faceof the bearing.

1.1. In a machine for surfacing lens blanks with arelatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, a lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means comprising a body element slidably supported on said guideways, a lens blank supporting spindle rotatably mounted in said body, the axis of rotation of said spindle being disposed at substantially 90 to the axis of rotation of said surfacing means and having an exterior downwardly tapering surface, and a bearing in said body for the spindle, said bearing having a downw'ardly tapering inner face conforming to said tapering surface of the spindle and being provided with a circumferential oil receiving groove adjacent its lower end, portions of the outer face of said bearing being spaced from said body to provide lubricant receiving spaces communicating with said groove, and means operable upon rotation of said spindle for supplying lubricant under pressure to said groove.

12. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, a lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means comprising a body element slidably supported on said guideways, a lens blank supporting spindle rotatably mounted in said body having a downwardly tapering exterior surface, and a bearing for said spindle within the body, said bearing having a flange portion underlying a portion of the spindle and a tubular portion having a downwardly tapering inner surface engaging said tapering surface of the spindle, the inner surface of said tapering portion and the upper surface of said flange having grooves adapted to receive lubricant, said grooves in said flange terminating short of the periphery thereof, and means for supplying lubricant under presure to said grooves during rotation of the spindle.

13. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, a lens blank holding means movable back and forth in said guideways to cause the lens blank to move in a curved path, said means comprising a body element slidably supported on said guideways, a lens blank supporting spindle rotatably mounted in said body, a plurality of bearings mounted in said body for said spindle, each of said bearings having longitudinally extending lubricant receiving grooves and the upper one of said bearings having a laterally projecting flange underlying a part of the spindle, said flange having radially extending grooves terminating short of the periphery thereof communicating with the longitudinal grooves of said upper bearing, and means operable upon rotation of said spindle for supplying lubricant under pressure to said grooves.

14. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supportin element having curved guideways, a body member movable to and fro in said guideways, a spindle rotatably mounted in the body member, said spindle affording a mounting for a lens blank and having a downwardly tapered peripheral surface, a hearing in the body for said tapered surface of the spindle, said body having an enlarged portion forming a housing for the lower end of the spindle, and removable means within said housing for locking said spindle against upward movement.

15. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, a body member movable to and fro in said guide'ways, a rotatable spindle journaled in said body affording a mounting for a lens blank, said spindle having a shouldered portion and a downwardly tapering peripheral surface, a bearing in said body surrounding said peripheral surface and underlying a portion of said shouldered portion of the spindle, and means removably mounted on the lower end of the spindle for locking the spindle against upward movement with respect to the body.

16. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a beam member having upstanding wall portions respectively provided with curved recesses on their inner faces, members removably connected to said wall portions and overlying the recesses thereof so as to form curved grooves in the inner faces of said walls, and a lens blank holding means movable back and forth in said guideways to cause a lens blank to move in a curved path.

17. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a beam having upstanding wall portions respectively provided adjacent their upper edges with curved recesses, members removably connected to said wall portions overlying said recesses to form curved grooves in the inner faces of said walls, and lens holding means between said walls movable to and fro longitudinally thereof, and ribs removably secured to opposite sides of said lens holding means slidably mounted Within said grooves whereby said means is caused to travel in a curved path when moved to and fro.

18. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, a body movable back and forth in said guideways having a rotatable spindle on which a lens blank is adapted to be mounted, apron means secured to said body member adjacent the upper end of the spindle and extending in opposite directions therefrom for preventing loose material incident to the surfacing from dropping on to the top of the body.

19. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having surved guideways, a body movable back and forth in said guideways having a rotatable spindle on which a lens blank is adapted to be mounted, a flexible apron above said body having an opening intermediate its ends through which said spindle extends, said apron being secured to and movable with said body, spaced means respectively connected to opposite ends of the apron for maintaining the apron in ten sion as the body moves to and fro.

20. In a machine for surfacing lens blanks with a relatively stationary rotatable surfacing means, the combination of a supporting element having curved guideways, a body movable back and forth in said guide-ways having a rotatable spindle on which a lens blank adapted to be mounted, and an apron above said body connected thereto and having an opening interme-

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