US2617236A

US2617236A - Lens grinder

Info

Publication number: US2617236A
Application number: US99372A
Authority: US
Inventors: Robert E Allen; William F Utzinger
Original assignee: Univis Lens Co
Current assignee: Univis Lens Co
Priority date: 1949-06-16
Filing date: 1949-06-16
Publication date: 1952-11-11
Anticipated expiration: 1969-11-11

Description

Nov. 111, 1952 R. ALLEN ETAL LENS GRINDER Filed June 16. 1949 4 Sheets-Sheet l FIG.

INVENTORS ROBERT E. ALLEN Nov. M, 1952 R. E. ALLEN ETAL LENS GRINDER 4 Sheets-Sheet v 2 Filed June 16. 1949 I INVENTORS ROBERT E. ALLEN \[VILLIAM F UTZINGER Nov. 11, 1952 R.- E. ALLEN EI'AL LENS GRINDER 4 Sheets-Sheet 3 Filed June 16. 1949 F UTZINGE?I (4775x 9 r'TTfi:

INVENTORS ROBERT E. ALLEN WILLIAM BY Nov. M, 1952 R. E. ALLEN ETAL LENS GRINDER 4 Sheets-Sheet 4 Filed June 16, 1949 4 d 4 8 8 w '0 l2 un 8 L 5 9 [1 HH W d m FIG. IO

FIG.

INVENTORS ROBERT E. ALLEN R F- G Z W! M m L- I- m M Bl J Patented Nov. 11, 1952 UNITED STATES PATENT OFFICE LENS GRINDER Robert E. Allen and William F. Utzinger, Dayton,

Ohio, assignors to Univis Lens Company, Dayton, Ohio, a corporation of Ohio Application June 16, 1949, Serial No. 99,372

8 Claims. 1

This invention relates to optical lens grinding machines, and more particularly to a machine for edging a lens blank.

The invention, in general, is embodied in a machine having a lens blank holding means, an abrading element for grinding the edge of the lens blank, pattern means for determining the peripheral shape of the lens blank, means for controlling the movement of these members in a predetermined manner, and means for driving the machine.

One of the objects of the invention is to provide a support for mounting the lens blank element so that the peripheries of the lens blank and the abrading element can be brought into contact. This support is free floating and provides for moving the lens blank element toward and away from the other element. The support also cooperates with means for causing relative translatable movement of these elements while their peripheral surfaces are in abrading relation with one another.

A feature of this construction is that a small, lightweight and compact machine can be provided which is adapted for either dry edging plastic lenses with an abrasive belt, for example, or for grinding glass lenses with a small and inexpensive diamond wheel. It has been found impractical from a cost standpoint to equip a standard lens edging machine with a diamond wheel of the usual or regular size. The construction here provided is adaptable for using an extremely small size of diamond wheel which is both practical and economical. With the latter construction, the machine is equipped with a small pump and coolant reservoir which replaced the suction pump provided to remove the dust or cuttings resulting from dry edging plastic lenses. Furthermore, in addition to cutting a square edge for rimless mountings, the machine can also be adapted to edge lenses for frame mountings since it can cut a bevelled edge when provided with an abrading element which cuts a V-shaped section around the periphery of the lens blank.

An additional object of the invention is to provide an arm for rotatably supporting the driven lens blank element, the arm being swingable on a pivot means for movement of the lens blank element toward and away from the abrading element, as well as for longitudinal movement relative to the abrading element. A feature of this construction is that the lens blank element and the pattern-means, for determining the peripheral contour of the lens blank, can be swung so that the lens blank crosses the abrading element with its axis of rotation parallel to the axis of rotation of the abrading element, and while so moving the lens blank is free to move in a direction at right angles to said axes of rotation in response to movement of the pattern means.

Another object of the invention is to provide a cam and cam follower, as part of the pattern means, for controlling the movement of the lens blank element whereby the lens blank is gradually lowered into contact with the abrading element. This feature of the construction prevents a deep out being taken too rapidly from the, lens blank, such as would occur if the lens blank element under the full weight of the supporting arm remained continuously in contact with the abrading element. In operation, the lens blank while being edged is raised and lowered, with respect to the abrading element, in response to movement of the cam follower. This movement prevents the lens blank from being heated excessively and its optical properties are not distorted. A further feature resulting from this construction is that the lens blank is moved across substantially the entire surface of the abrading element, thus assuring even wear across the entire peripheral surface of the abrading element.

An additional object is to provide a driving means, such as a pulley and endless belt, for applying power from a prime mover to rotate the lens blank and associated mechanism, in which the belt pull or torque is applied at a point which, when projected, lies in a plane extending at right angles to the axis of rotation of the pulley, and which plane also extends through the projected axis of rotation about which the pivotally mounted support for the lens blank element moves. The support is thus free floating in that the support at all times pivots about a point in line with the belt pull.

It is also another object to provide pattern means for controlling the peripheral configuration of the lens blank, which comprises a cam member and a pattern member, and which are translatably movable with respect to one another. Means in the form of a feed screw and an engaging element are provided for causing movement between these members. A feature of this construction resides in having the feed screw driven from the same shaft means provided for driving the pattern member. The feed screw is also utilized to control the rate at which the lens blank is moved into abrading relation with the abrading element- The regulation thus effected prevents the lens blank from being cut to pattern size at a rate which causes excessive heating thereof.

Other features of this invention reside in providing an abrading element in the form of a drum adapted to receive an abrasive belt having a surface of silicon carbide grit or similar material. The drum is driven at a high rate of speed, of the order of 5000 R. P. M., and the lens holder at a low rate of speed, of the order of 2 R. P. M. Also, if desired, the suction pump for removing the dust or cuttings from the grinding operation can be driven from the same power source provided for driving the lens blank, or a pump can be operated therefrom to circulate a coolant where a diamond wheel is used.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred forms of embodiments of the invention are clearly shown.

In the drawings:

Fig. 1 is a top plan view of a machine embodying one form of the present invention;

Fig. 2 is a side elevational view of the machine shown in Fig. 1;

Fig. 3 is a front elevational view of the machine as seen from the right side of Fig. 2;

Fig. 4 is a side elevational view, partly in section, of the switch and mounting mechanism therefor;

Fig. 5 is a broken, back elevational view, partly in section, showing the pivotal connections between the arm and base, and a part of the shaft driving means, as seen from the left end in Fig. 1;

Fig. 6 is a broken, verticalrsectional view, partly in elevation, showing the lens holder, pattern means and feed screw as carried by the arm;

Fig. 7 is a diagrammatic view illustrating the positioning of the link, shaft and pulley relative to the pivotal connection between the link and the base;

Fig. 8 is an elevational view of the cam and supporting bracket as seen from the right side in Fig. 3; and

Figs. 9 to 11 are diagrammatic views illustrating modified constructions of the cam shoe and abrading element for bevel edging the edge of the lens blank.

Referring further to the drawings, the machine shown includes a supporting base It. A support, indicated generally at H, includes a link I2, an arm member 13, and a second arm member 14 integral with member l3 and at right angles thereto. One end of member l3, as seen in Fig. 5, is pivotallymounted within the U -shaped yoke IS.

A shaft i6 extends through member [3 and yoke [5. This shaft is journalled at each end in the bearings [1. These bearings are mounted so as to be carried by both the yoke and member l3, as shown. There is a press fit of the bearing H in member 13 and a running fit of the bearing [1 in the yoke l5. Suflicient clearance is provided between the yoke and member l3 to allow free swinging movement of member [3 about the shaft IS in a, plane at right angles to the base [0.

The yoke I5 is slidably mounted at the bottom on the seat 20 formed on the base. A pair of oval shaped openings 2| extends through the top of the base and seat 20. The screws 22, Fig. 5, engage the bottom of the yoke l5 through these openings. These screws also connect the yoke to the link [2 which, in turn, is pivotally connected with a screw at its outer end to the base, as indicated at 24. Movement of the yoke l5 4 on the seat 20 is controlled by the movement of the link [2 about the pivot 24.

Transmission means is provided which comprises, in general, the shaft It, a shaft 21 extending longitudinally through arm member l3, and a spindle shaft 28 carried by the arm member l3. These shafts are rotatably mounted and driven by a pulley 30 connected to the shaft 16. Shaft H5 drives shaft 21 through a worm 3| and gear 32, Fig. 5. Shaft 21, in turn, drives shaft 28 through a worm 33 and gear 34, Fig. 6. Thrust bearings 35, Fig. 2, are provided at each end of shaft 21. The shaft 28 is journalled for rotation within the

bearings

36 and 31 which extend through the inner end of arm member l3. Power is transmitted from the motor 38, Fig. 2, which is provided with a driving wheel, through the belt 39 from the driving wheel to the pulley 30.

The axis of pivot 24, when projected upwardly, substantially intersects the peripheral edge of the pulley 30 substantially most remote from the free end of arm I3 and from the driving pulley of motor 38. Referring to the diagram of Fig. I, the arrangement of the arm members, i. e., link 12, shaft 16 and pulley wheel 30 with respect to the pivot 24 are shown. This construction provides for a free floating arm which is unaffected by the pulling action of the belt 39 on the pulley 30 and shaft IS. The force or pull of the belt 39 is thus applied in the direction of the arrow 41'], Fig. 7, and at a point in the plane extending through the pulley 30 at right angles to its axis of rotation and through the projected axis of rotation of the pivot 24. The application of this force in that plane does not cause a turning or moving force to be exerted on the members l3 and I5. The arm i4 is thus free to swing in a plane parallel to the top of base [0. Furthermore, with this construction the length of arm I3, 1. e. the radius of the arc through which the arm l4 swings parallel to the top of base it], can be made a maximum within the prescribed size limits of the machine. The axes of rotation of the lens blank holder, pattern means and the abrading element, as hereafter described, can thus be maintained in substantially parallel alignment during the cutting or edging operations. This construction also provides for leading the belt 39 from the motor driving pulley onto the pulley 30 at a point which does not swing out of the plane extending through the pulley 30 at right angles to the axis of rotation of the pulley 3i] and through the projected axis of rotation of the pivot 24. The belt 39 thus remains on the pulley 3!) when the supporting members l3, Hand 15 swing about the pivot 24.

In the preferred construction an electric motor of about horsepower capacity and capable of rotation at 5000 R. P. M. is provided. This speed of rotation is reduced through the gearing mechanism provided so that the shaft 28 rotates at a rate of about 2 R. P. M.

A lens holder is provided for mounting the lens blank 42, Fig. 3, in working position. The holder includes a positioning member 43 which is received on the pins 44, Fig. 6, which project from the head 45 formed on the end of shaft 28. Member 43 thus rotates with the shaft 28. A retractable pad 41 also forms part of the holder. This pad is positioned to engage the lens blank on the opposite side from member 43. The pad is faced with a rubber washer 48 on the front and engages at the back with a ball bearing 49. Bearing 49 is rotatably mounted on the compression shaft 5| and the pad 41 rotates with the lens blank. Shaft 5| is received within the bearing 52 carried in the outer end of arm member M. A pin 53, Fig. 6, on the head of shaft 5| projects through a slot in the edge of bearing 52. This pin prevents rotation of the shaft 5|. A coil spring 54 encircles the shaft and seats against the head at one end and against the inner end of bearing 52 at the other. This spring forces the pad 41 against the lens blank. The outer end of shaft 5| is threaded to receive a knurled knob 55. This knob is adjustable and provides for moving the shaft 5| and pad 41 toward and away from the lens blank for either positioning or removing the lens blank in the holder. A stop nut 56 on the end of shaft 5| prevents the knob 55 from backing off the shaft. A set screw 51 retains the bearing 52 in the. arm.

A shaft extension member 6| is coupled to the end of shaft 28. This member is formed with pins 62 fitting in openings in the cam follower for positioning the cam follower, indicated at 63 in Figs. 3 and 6, which forms part of the pattern means for determining the peripheral shape or contour imparted to the lens blank 42. In operation, a follower 63 is used which has a peripheral shape or contour of either regular or irregular form, and to which form the lens blank 42 is patterned when edged. The follower 63 is rotatably driven by member 6|. A threaded shank 64, projecting from the outer end of member 6|, extends through a central opening in the follower. A tapered and externally threaded section in the form of a feed screw 61 is threadedly connected to the shank 64 and driven thereby from shaft 28. The body of the screw is threaded as shown at 61a, Fig. 1, and the head knurled, as indicated at 61b, Fig. 6, to facilitate mounting on shank 64. Screw 61 retains the follower 63 on the pins 62. The outer end of the screw forms a bearing area 68 having a flanged head 69.

Referring further to Figs. 1 and 4, the base In is formed with a boss 1|. This boss is drilled to receive a spring pressed cap 12. At right angles to this-bore, the boss is drilled to receive a short rod 13 which fastens a hinge member 14 to the boss. The hinge carries the knife arm or lever 15 to which the knife blade 16 is adjustably attached. The edge of the blade 16 is bent inwardly, as shown, and forms an element adapted to engage the threads on the feed screw 61 when arm member I4 is in operating position. The spring pressed cap 12 bears against the lower end of the pivotally mounted lever 15 and holds the knife blade 16 in engagement with the threads on the body of the feed screw. An arm 18 is connected to the lower end of the lever 15. This arm extends through an opening 19 in the top of the base H). A switch 86 having a push button 80a is provided to control the startingand stopping of motor 38. Switch 80 is open when the button 80a is depressed. Thus, when the arm 4 is set so that the threads on the feed screw 61 engage with the blade 16, the lever 15 is pivoted inwardly at the bottom, i. e., moves clockwise and against the cap 12. This movement causes the arm 18 to move away from button 86a whereby the switch closes to start the motor. When the arm I4 is driven to a point where the blade 16 disengages from the threads on the feed screw and engages the bearing area 68 and the spring cap 12 moves lever 75 counterclockwise and arm 18 depresses button a. motor.

The follower 63 engages with and rotates upon a cam means 8|. This cam controls the movement of the follower in a direction perpendicular to its axis of rotation. The cam means 8| includes a bracket 82 screwed to the top of the base l0, Figs. 1, 3 and 8. An adjusting screw 82b cooperates with a knurled nut 83 and extends up through the top of base l0 and through the bracket. The cam shoe 84 is fastened to the top of the adjusting screw 82b and is raised or lowered relative to the bracket when the nut 83 is adjusted. This shoe is formed with a declining surface 8411 (Fig. 3) extending longitudinally in the direction of the axis of rotation of the follower 63. This surface forms an arc of a curve extending transversely to the axis of rotation of the follower 63, as indicated at 84b in Fig. 8.. In operation, the periphery of the follower 63 is placed first in contact with the high portion of the cam shoe 84., As the feed screw 61 drives the arm l4, the follower moves down over the surface 84a of the shoe from the high to the low point and gradually lowers the arm and lens blank.

Theabrading element for the lens blank comprises, in general, a quill housing 9| having a centrally positioned spindle shaft 92, Fig. 3. This shaft is secured at one end within the upper part of the base 0. The quill housing 9| is supported at each end on bearings 93 mounted on the shaft 92. This quill housing 9| thus rotates freely. The quill housing 9| is enlarged to provide a drum portion 94 which is encircled by a removable abrasive belt 95. This belt is substantially the full width of the drum as shown in Fig. 3. In one form, this belt is constructed of a heavy fabric-like material having a coating of silicon grit on its outer surface. The belt is held on the drum by the end flange member 91 which is fastened to the end of the drum with screws. The drum 94 is constructed with a peripheral curve having substantially the same radius of curvature as the arc of surface 842) (Fig. 8) on the cam shoe so that the lens blank will be edged to conform to the pattern of the follower 63. If desired, a diamond wheel of the same size can be substituted for the drum 94 and belt 95.

A groove is formed in the opposite end of the quill housing 9| to receive a belt |0|.' This belt is directly driven from the motor 38 and rotates the drum at a rate of speed of the order of 5000 R. P. M. The shaft means for driving the holder provides for rotating the lens blank in a direction opposite to the direction of rotation of the drum 94 and at a rate of speed of the order of 2 R. P. M. Then when the edge of the lens blank 42 comes into contact with the abrasive surface of the belt 95, a cutting engagement is obtained.

A suction pump 05, Fig. 3, is also driven from the motor 38. A recessed area I66 is provided in the top of the base beneath the drum 94 to receive the cuttings and dust from the grinding operations. These cuttings are removed through an opening in the surface I66 which connects with an adapter 101. A hose, not shown, connects between the adapter and the suction inlet |08 of the pump.

In Fig. 9 a modified construction is illustrated. This construction is adapted to provide for bevel edging the lens blank 42. The feed screw 61 is provided with a second bearing surface 5 terminating in a head 6. The cam shoe surface 84a is. extended to provide a recessed horizontal Switch 80' then opens and stops the surfaceI II. Infadditionto the abrading element 95 another abrading element 9511 having 'a V notch lcu'ttingsurface Il8 isfprovided. The overall depthof' the notch II 8is equal to or slightly greater than the distance which the surface II"! is below thesurface Il9ofthe cam shoe so that the over-all diameters 'of the lens blank will'not be changed by further .cutting. In operation, when thefollower' 63 reaches the'lowest part of the cam surface 84a, i.e., surface'IlS, the lens blank has moved across the surface 95 of the abradin'g' element .and is' cut-down toithe desired shape and dimensions. I Further movement ofthe arm -'I4 is prevented by engagement of blade I with the head 69. The arm l t is raised bythe operator to free blade I6 from engagement with head 59 and the arm sw-ung horizontally-so that blade 'I5 engages 'between the'heads69 and IIB. This movement -is sufficient to bring the follower 63- into 'engagement'with thesurfa'ce -I I1 and to center thelens blank 42 in the V-notch I E8 of 'the abrading element 95a. Rotationof the abrading element cuts abevel edge on each side-of the lens blank.

A further modification is Shown' inF-ig'lO. In this form, the bevel edge can be completed as a continuous part of the cutting operations. The cam sole surface 84a -is extended to provide a downwardly sloping surface I20 terminating in a horizontal surface I2I having a stop member I22. 'Where, for example, the bevel on the lens blank is-to be 45 degrees, the slope of surface I20 is" 22 degrees from vertical. The abrading element95a is provided with a'V-notch I I8a having oppositely disposed sides I23 and 12311 sloping at 45 degrees. 'The over-all depth of the notch I Illa is equal to the depth of the cam surface I2I below surface [I9 so that the cutting to produce the bevel edges does not reduce the-over-all finished diameters of the lens blank. 'Inoperation, the follower 03 moves from thesurfa'ce I-I9 down theslope of surface I20. This movement'causes the lens blank to-movedown the slope-of surface I230, and the rotation of the abra'dingelement produces a bevel edge on one side of the'lens blank. -As the follower 53 moves acrosssurface I2I,the other side of the lens blank is brought into contact with-the-surface I23 which' produces a bevel edge on that side-of the lens blank. Engagement of the-follower 63 with the stop member I22 prevents the lens blank from being too deeply'cut or bevelled by'engagement with-surface I23.

Another formof construction for bevel edging is shown in Fig. 11. The cam shoe 84 is provided with a surface I24 which slopes upwardly at '30 degrees from horizontal where the beveledge is to be at 45 degrees. A horizontal surface I20 and an oppositely'disposed surface I28 sloping'at'22 /2 degrees from vertical are also provided. The abrading element 95a is provided with a surface I30 slopin upwardly at-45 degrees, a horizontal surface I3I and'a surface I32 at 45 degrees oppositely disposed from surface I30. In operation, as the follower 63 moves up the surface I24 the lens blank is brought into contact with surface I30 and gradually-cut down to the desired overall dimensions and shape. As shown, the lens blank edge in contact with surface I30 will be out at an angle of 45 degrees. 'Movement-of the follower across surface- I26 provides for removing any tail that may be formed from the cutting on surface I30. Movement of the follower across surface I26 carries the lens blank across surface I3I. Further movement of the 8 follower down the surface 128, i. e., at'22 /2 degrees, brings the'other edge of lens blank into contact with'the 45 degree surface I32 and produces a finished bevel of 45;degrees onthat edge.

In operation, the arm I4 is :raised manually and swung backat right angles to the top of base If). Such movement disengages the feed screw 61 from the knife blade I6. The lever I5'is then moved by the spring caps I2 to a position opening the switch and stopping motor 38. In the raised'position the underside of arm member I4 'is'exposed. This facilitates either mounting or removing a lens blank.

When a lens blank is mounted in the holder, the arm'l4 is lowered from the raised position. The arm I4 is swung parallel to the top of base I0 until the'follower 63 rides on the high part of the cam shoe-84. The knife blade I6 is adjusted so that in this position it then engages 'between the threads at the end of the feed screw 61 farthest'from the head 69. This engagement moves the lever "I5 in a direction which causes the motor switch to close. The motor, in turn, drives the shafts I6, 21 and 28, the quill 9|, and the blower I05. Shaft 28 rotatesboth the lens holder and the follower, and drives the feed screw 61. The rotation of the feed screw, while in engagement with the knife blade I6, causes the support II to move about the pivot '24. This movement causes the rotating follower 53 to move gradually down the surface 84a, of the cam shoe. The lens blank rotates in synchronism with the follower and is also responsive to the movement of the follower at right angles to its axis of rotation, since the supporting arm I3 is free to pivot about shaft l6. This construction provides for gradually cutting the lens blank down to the desired shape as the lens blank moves down into contact with the rotating belt 05 and across the belt from one edge thereof to the other. A's the edging of the lens blank progresses, the arm I4 swings in an are about the pivot 24. The radius of this are is such that when the edging of the lens blank is completed the axis of rotation of shaft 28, carrying the lens blank and follower, is parallel to the axis of 'rotationof the abrading element. This construction provides for accurately edging the lens blank'according to the pattern of the follower.

When'the follower moves across the low part of 'the'cam shoe surface 84a, the edging of the lens blank is completed. The arm 14 has then moved a sufficient distance for the threads on theifeed screw to disengage from the knife blade 16. .Blade'16 thenengages adjacent the bearing'area68 and head 69 prevents further longitudinalmovement'of the screw with respect to the blade I6. The lever I5 then is no longer held in-a position to maintain the motor switch closed and the motor stops. The operator then raises the arm 13 to'remove the finished lens blank, inserts a new lens blank, and again lowers the arm to repeat the operation.

While the forms of embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

We claim:

1. In a lens edging machine, in combination, a base; an abrading element; a rotating shaft carried by the base and carrying the abrading element; -a second rotating shaft having a threaded portion; a lens blank holding element carried by the second shaft; means for rotatably supporting the second shaft with the axisthereof substantially parallel with the axis of the first shaft, said means including a pivot on the base having an axis disposed substantially at right angles to the axis of the first shaft, and an arm pivotally mounted on the pivot and extending toward the first mentioned shaft and carrying the second mentioned shaft; a member on the base received by the groove of the threaded portion of the second shaft, for causing swinging movementto be imparted to the arm when the second shaft is rotated; and means for rotating the shafts.

2. In a lens edging machine, in combination, a base; an abradingelement; a rotating shaft carried by the base and carrying the abrading element; a second rotating shaft having a threaded portion; a lens blank holding element carried by the second shaft; means for rotatably supporting the second shaft with the axis thereof substantially parallel with the axis of the first shaft, said means including a pivot on the base having an axis disposed substantially at right angles to the axis of the first shaft, and an arm pivotally mounted on the pivot, said arm including a pivot disposed on an axis transverse to the axis of the first mentioned pivot and including a lever pivotally carried by the second mentioned pivot and extending toward the first mentioned shaft and carrying the second mentioned shaft; a member on the base received by the groove of the threaded portion of the second shaft, for causing swinging movement to be imparted to the arm when the second shaft is rotated; and means for rotating the shafts.

3. In a lens edging machine, in combination, a base; an abrading element; a rotating shaft carried by the base and carrying the abrading element; a second rotating shaft having a threaded portion; a lens blank holding element carried by the second shaft; means for rotatably supporting the second shaft with the axis thereof substantially parallel with the axis of the first shaft, said means including a pivot on the base having an axis disposed substantially at right angles to the axis of the first shaft and an arm pivotally mounted on the pivot, said arm including a rotating driving shaft disposed on an axis transverse to the axis of the pivot, said arm including a lever pivotally carried by the last mentioned shaft and extending toward the first mentioned shaft and carrying the second shaft; gearing between the shafts carried by the arm; a member on the base received by the groove of the threaded portion of the second shaft for causing swinging movement to be imparted to the arm when the second shaft is rotated; and means for rotating the shafts.

4. In a lens edging machine, in combination, a base; an abrading element; a rotating shaft carried by the base and carrying the abrading element; a second rotating shaft having a threaded portion; a lens blank holding element carried by the second shaft; means for rotatably supporting the second shaft with the axis thereof substantially parallel with the axis of the first shaft, said means including a pivot on the base having an axis disposed substantially at right angles to the axis of the first shaft, and an arm pivotally mounted on the pivot, said arm including a bearing support slidably carried on the base, said arm including a shaft carried by the bearing support, the last mentioned shaft being V disposed on an axis transverse to the axis of the 1 first mentioned pivot, said arm including a lever pivoted on an axis transverse to the axis of said pivot and extending toward the first mentioned shaft and carrying the second shaft; gearing between the shafts carried by the arm; a member on the base received bythe groove of the threaded portion of the second shaft for causing swinging movement to be imparted to the arm when the second shaft is rotated; and means for rotating the shafts.

5. In a lens edging machine, in combination, a base; an abrading element; a rotating shaft carried by the base and carrying the abrading element; a second rotating shaft; a lens blank holding element carried by the second shaft; means for rotatably supporting the second shaft with the axis thereof substantially parallel with the axis of the first shaft, said means including a pivoton the base having an axis disposed substantially at right angles to the axis of the first shaft, and an arm pivotally mounted on the pivot, said arm including a bearing support slidably carried on the base, said arm including'a rotating driving shaft carried by the bearing support and disposed on an axis transverse to the axis of the pivot and intermediate thepivot and the first mentioned shaft, said arm including a lever pivoted on the arm on an axis transverse to the axis of said pivot and extending toward the first mentioned shaft and carrying the second mentioned shaft; gearing between the shafts carried by the arm; a driving wheel on the third mentioned shaft; a belt on the wheel; and means for driving the belt, the axis of the pivot of the arm when projected substantially intersecting the peripheral portion of the wheel at a point substantially most remote from the means for driving the belt.

6. In a lens edging machine, in combination, a base; an abrading element; a rotating shaft carried by the base and carrying the abrading element; a second rotating shaft; a lens blank holding element carried by the second shaft; means for rotatably supporting the second shaft with the axis thereof substantially parallel with the axis of the first shaft, said means including a pivot on the base having an axis disposed substantially at right angles to the axis of the first shaft, and an arm pivotally mounted on the pivot and extending toward the first mentioned shafts, said arm including a bearing support slidably carried on the base, a rotating driving shaft carried by the bearing support and disposed on an axis transverse to the axis of the pivot and intermediate the pivot and the first mentioned shaft; gearing between the shafts carried by the arm; a driving wheel on the third mentioned shaft; a belt on the wheel; and means for driving the belt, the axis of the pivot of the arm when projected substantially intersecting the peripheral portion of the Wheel at a point substantially most remote from the means for driving the belt.

'7. In a lens edging machine, in combination, a base; an abrading element; a rotating shaft carried by the base and carrying the abrading element; a second rotating shaft having a threaded portion; a lens blank holding element carried by the second shaft; means for rotatably supporting the second shaft with the axis thereof substantially parallel with the axis of the first shaft, said means including a pivot on the base having an axis disposed substantially at right angles to the axis of the first shaft, and an arm pivotally mounted on the pivot andi extending toward the' first mentioned shaft: and carrying the second mentioned shaft; means for: rotatin the second mentioned shaft; and mechanism: for controlling the lastnamed means' including' a controller having a member received by the groove: of the: threaded portionof: the second mentioned shaft and: movable to eifect': starting and stopping of the shaft"; rotating means by engagement and disengagement, respectively, of the threaded portion of the second'mentioned shaft with said member.

8. In a lens edging machine; incombination, a'base; an abrading element;- a rotating'shaft carried by the base and 'carryingthe abrading element; a secondrotatingshaft having a threaded portion; a lens blank-holding element. carried by thesecond shaft; means for" rotatably supportingthe second shaft with the axis there.- of substantially parallel with the axis of the'first shaft, said means including a pivot on the. base having an axis disposed" substantially atright angles tothe axis-of the first-shaft, and v an arm pivotally mounted on: the pivot, said arm including a pivot disposed on an axistransverseto the axis of the first mentioned pivot= and: including a leverpivotally-oarried byv the= second-I mentioned pivotandi extending. toward the first mentioned shaft and'i carrying: the-second: mentioned. shaft; means for rotating: the: second; mentioned. shaft; and mechanisma for; controlling thelast named means: including a; controller having a member received by thegroovexoff theethreadedportion of the second mentionedshaftand movableto effect starting and stopping of ,theshaf t. rotating means by engagementand disengagement, respectively, of the threadedportion ofithe: second mentioned shaft with said member.

ROBERT. E. ALLEN.

WILLIAM. F. UTZINGER.

REFERENCES CIT-ED The following references are of record in the file of"this patent:

UNITED STATES PATENTS Number Name; Date- 375,332; Bessomet a-l. ,Dec..27-, 1887 1,455,863; Bugbee: .May 22, 192-3 1,457,855 Richardsorr June 5, 1923 1,558,167 Herricko Oot.,24, 1925 1,713,622 Rakel May 21, 1929 2,164,155 Lemay .June 27-, 1939 2,321,382 Harper June 8, 1943