US1651501A

US1651501A - Bevel-edging machine

Info

Publication number: US1651501A
Application number: US715030A
Authority: US
Inventors: Nelson M Baker
Original assignee: American Optical Corp
Current assignee: American Optical Corp
Priority date: 1924-05-22
Filing date: 1924-05-22
Publication date: 1927-12-06
Anticipated expiration: 1944-12-06

Description

Dec. 6, 1927. 1,651,501 1 N. M. BAKER BEVEL EDGING MACHINE Filed M21322, 1924 4 Sheets-Sheet l INVENTOR nelson 111. Baker ATTO NEY Dec. 6,' 1927.

N. M. BAKER BEVELEDGING MACHINE Filed May 22, 1924 4 Sheets-Sheet 2 LNV ENTQR nelson mfBaker.

Dec. 6, 1927. 1,651,501

N. M. BAKER BEVEL EDGING MACHINE Filed New 22, 1924 4 SheetsShe et 5 INVENTOR Jig-' 9 ngssonm akefr Dec. .6, 1927.-

N. M. BAKER BEVEL EDGING MACHINE Filed May 1924 4 sheets-sheet 4 INVENTOR nelson m. Baker.

Patented Dec. 6, 1927.

UNITED ISTFATESI.

OFF CE- NELSON M. BAKER; F SOUTHBBIDGE, MAssAcHUsE rsQA ssIGNoR TO AMERICAN 0P- TIGAL coMr NY, or son rnnmnen, MASSACHUSETTS, A VOLUNTARY ssoo A- TION OF MASSACHUSETTS.

. Application filed May 22,

The present invention relates to animproved lens edging machine a-ndhas particular, reference to a lens bevel edging machine. V I

An important object of the invention isto provide a bevel edging machine including a to -feed one toward the other at a definite speed, means to stop the feed at a predetermined point and to hold this relationship of the stone and lens carriage at this point for a number of revolutions for the finalfin ishing and sizing of the lens being ground, I and means for automatically moving the lens carriage away from the stone and stopping rotation'ol thelens after the lens has been finished. A still further object of the invention is to. provide a bevel edging machine employing a grooved stone which 'is' free. to move longitudinally of the machine, and having a lens carriage so-arranged that the'lens to be ground will be received'within the groove in the stone. and including means to'deter mine the shape and means to determine the automatic clutch to stoptherotation ofthe lens. I A, still further object-bf the invention is to provide a bevel edging machine for grinding both sides of a lenssimultaneously, in? eluding means whereby the speed with which the lens may be ground can be 'regu lated, but soarranged that the resultant fin ished lens will always be ground to a pre determined size. 1

Other objects and advantages of the in vention -will become apparent during the course of the following description. V In the drawings, wherein like numerals are employed to designate like parts'throughout the same size of the lens to be grountLat'ter which thele'ns and lens carriage w ll be automatn cally swung'away from the stone; and an BEVETJ-EDGVINGI MACHINE. 1

. mechanism Figure 5 is a detail perspective of the step by step feed mechanism employed;

igure 6 is an elevation of the size regulating cam;

Figure 7 is a longitudinal section taken through the automatic clutch; 1

Figure 8 is'a view of the machine levelling device; 7 i

Figure. 9 is a machine;

Figure 10 is a similar diagrammatic view illustrating the lens in contact with the stone during the grinding operation;

Figure 11 is another view of the same showing the lens swung-out of engagement with the grinding stone at the endof the grinding operation; j

Figure 12 is a view of the finished lens; Figure 13 is a top planv-iew of a machine employing aslightly different form of'stone mounting; v I

Figure 14 is a sectionfaken on line 1414 diagrammatic View of the otthe arrows. 7 a r In thedrawings, wherein for the purposes of illustration isshown the preferred embodimentof the; invention, the numeral 15" designates-the frame ot' the machine. The

' frame 15 carries the journals 16; in whichare mounted bearings 1 7 The type of stone used ispreter'ably a two part stone and is designated by the numeral 18,'the two sections when clamped together by the plates 19 forming a stone having a substantially .V-shaped groove. Obviously a single stone can' be employed by cutting the V-shaped groove therein and mounting it between the plates 19 as shown in Figures land 9. A

shaft 20 is passed centrally through the 1 stone 18 'a'nd plates 19 and is of sufiicient of Figure 18, and-looking in the direction length to be received within the plain bean ings 17 in thejournals 16; The shaft 20 is so mounted that it may be slid through the hearings in either direction, and to facilitale this movement means 21 are provided to lubricate the bearings 17. One end of the shaft extends a substantial distance beyond the journal 16, as is clearly shown in the diagrammatic view, Figure 9, and is adapted to support a plate 22, the said plate carrying a pair of inwardly extending pins 2; The pins 523 have engagement with a roller carried by a pulley 25. The pulley 25 is mounted on the sleeve .26, in which are cut-the worm threads 27. The worm threads 27 may, ii. desired, be formed in a separate piece and keyed or otherwise placed upon and movable with the sleeve 26. The sleeve 26 is in turn mounted upon the bearing 28, which is arranged around the shaft 20. The pulle f 243 is driven as by the belt 29, and it will be seen that the shaft 520 and plate 22 may he moved longitudinally of the pulley 25 and still be driven thereby in view of the roller :24 mounted between the pins 523. In other words, thepulley E25, sleeveQGand worm threads 2? are adapted to be rotated, but are not designed to move longitudinally, while the shaft 20, stone and parts associated therewith are adapted to be rotated as well as moved longitudinally or laterally oithe machine at the same time.

'be mounted thereon so that the stone 18 may be honed at intervals to keep the groove accurate and smooth. The hone 31 may be of any desired construction, although I have illustrated a double slide hone comprising the

slides

32 and 33 so that the honing member 3i may be raised and lowered into and out of engagement with the stone as desired. A receptacle 235 is also provided and includes the control valve Elli, and spout 37 so as to supply water or the "like to the stone 18 dur ing the grinding operations. l

The lens carriage 1s mounted 111 trout oi the movable stone andis so arranged that it is at an angle to the stone so that the lens 38 will he at an angle to the stone 18 rather than in exact alignment therewith. The lens carriage 559 is pivotally mounted on the shaft 4-0 and is adapted to be swung toward the stone by means of a spring 41 which is connected to the carriage and to a stationary part of the machine so that the lens carriage will at all times be resiliently urged toward the stone. However, means are provided to hold the lens carriage away from the stone when itis desired to remove or replace a lens. To accomplish this a pivoted latch 42 is carried by the carriage and is adapted to engage the member 4-3. As can readily be seen in Figure 1, the latch d2 may be pivoted into and out of engagement with the memher43 so as to hold the carriage away from the stone or allow the spring to move the carriage to ard thi stone. A supporting arm 44 is also carried by the carriage and adapted to abut a portion of the frame 15 to support the lens carriage when it has. been moved away from the stone, as above pointed out.

The lens carriage comprises a pair of opposed aligned shatts a?) and 16, respectively,

as at 51, while the opposite end of the rocker arm {19 is pivotally connected as at 52 to the slidable plunger 53. The slidable plunger 53 is received within a recess 54 in the end of which is mounted a coil sprin or the like 55, so that the coil spring will normally urge the plunger outwardly, thus rocking the rocker arm 49 in such a manner that the shaft 45 will be moved in- *ardly of the carriage. A lever 56 is pivotally mounted on the carriage 39 by means of. a pin or the like 57. The inner end of the lever 56 is forked as at 58 to adapt its engagement with a pin or the like 59 carried by the movable plunger 53, so that upon movement of the lever 56 and by reason of the forked engagement thereof with the'pin on the slidable plunger, the plunger may he slid, in the recess 5% so as to permit oi.

engagement with or disengagement of the shaft 45 with the lens 38 which is to be ground.

The shaft 46 is adapted to be rotated, but is guarded against lateral movement of the machine so that its position or location never changed with respect to the stone. In other words, when it is desired togrind a lens the shaft-s15 is moved outwardly so that the lens may be placed between the pad members 47 on the adjacent ends of the shafts eh") and d6, after which the shaft 45 is adapted to be released so that it will firmlychun) the lens 38 in position for grinding. he opposite end of the shaft 46 is provided with a plurality of patterns or formers 60 which are so mounted thereon that they may be easily removed and interchanged when desired. A locking member 61 is provided to hold the patterns or formers in position when in use upon the shaft 46.

As can readily be seen in Figure 2 and in the diagrammatic view in Figure 9, the worm gear 27 has engagement with the spiral gear 62. The gear (32 carried on the sleeve 63 which is provided with the elongated slot 64, in which received a pin or the like 65. carried by the shaft (36. The pin 65 and slotted sleeve 63 form a telescopic connection so that the shaft 661nay be moved toward and away from the gear 62.

The shaft'66 is provided with a pair of universal joints 67 to permit the shaft 66 to be slightly out ofalignment with the gear 62 if necessary.

The opposite end of the shaft 66 carries the worm gear 68 which meshes with the gear 69 on the shaft 40" so that through ro' t'ation'of the shaft 66 the shafteO is also rotated. The shaft e0 passes through the journal 69, the lower end of the lens carriage 39, and the bearing 70 at the opposite end of the frame. As is clearly shown in Figure 5, sleeve 71 is mounted on the shaft d0, while a pinion 72 and a cam 73 are keyed to the sleeve 71; The pinion 72- meshes with an intermediate gear 741, which in turn meshes with a gear 75 keyed to the shaft li, whereby the shaft lfi is rotated,

thereby rotating the lens'38 in the-groove of thestone 18. Y 1 V.

In order to regulate the shape of the lens 38'which is to be ground, it is necessary to provide the pattern or former 60, which is of the desired shape of the required finished lens. As has been pointed out, to save time I provide a plurality or a gang of formers on theend of the shaft 46. f A'movable contact shoe 76is slidablymounted in the box '77 and is moved to and from the stone by means of the operating lever 78, so that the shoe may be brought; into engagement with any of the desired formers on the shaft 46.

A movable ain 79 en a es an one of the l r; 2: y

openings 80 so as to hold the contact shoe against-accidental displacement during the operation of the machine. The shoe carrying box 77 is mountedupon the slide 81, which is movable in the slide way 82 as is clearly shown in Figure 4 of the drawings.

The slide 81 is provided at the oppoiste end withthe screw threaded bore 83 in which isreceiVed the endof the screw threaded shaft 84' carried by an adjacent dial 85. A

coilspring 86 is arranged between the end of the slideformed inthe slide way'82and abutsagainst the end of the slide, 81 so as to normally urge the slide rearwardly and the slide way forwardly. Upon rotationof the dial the slide 81 may be adjusted within the slide way as desired.

In Figure 6 is shown a stepped annular cam 87, which has a plurality" of faces 88 separated by the curved shoulders 89." The rear face of the stepped cam 87 is provided with the. pins 90 which are received within small recesses 91 formed in the forward end of the slide way 82. A second dial oroperating meinber92 is provided with a recess 93, in which is. received the stepped cam 87,

V as is clearly shown in Figure l, and is provid-edv with the pin 94 adapted to ride upon the faces 88 of the stepped cam. A sleeve 95' is arranged around'the screw threaded shaft 84c and terminates in the flange 96,

which forms a 85 and 92. V a

' As caniheseemnpon rotation of theoperbearing between the two dials ating member 92 the pin 94 may be. moved upon any one of the several faces 88 formed in different planes upon the stepped cam 87, as the cam 87 is held against rotationwithin the recess 93 by means of the pins 90. In this manner different diameters of lenses may be ground with thesame former, said former controlling the shape'of the finishedlens, and not the size. Itwill readily be seen that the spring 1-1 will, during the operation of the machine, hold the former or pattern 60 into engagement with. the contact shoeTS at alltimes so thatthe shape of the former will move the lens carriage to and from the stone, thus reproducmglthc. same shape of lens'as the former, while the give the standard sizes to which: ophthalmic lenses are ordmarily'edged. The dial 85 1sv also provided with graduations to indicate what change has been made in the setting by I The function of' the dial 85 isto move the slide within the slideway so as to set the contact in posi the rotation of the same.

tion for sizes that cannot be obtained from the stepped cam, and to also compensate for wear of the various parts of the shape and size controlling mechanism. In other words we will'assume that We desire to grind a lens the size of which cannot be obtained the stepped cam i from the stepped cam and pin. In this'event" I move the dial 92 and the pin 94 onto the face 88, which will desi nate on the scale either the nearest size above or the nearest size below the actual size'reqnired, I then adjust the dial 85 until the necessary addi tion or subtraction has been made to give 1 the desired size. In this way I can obtain any s ze deslred by working the two adjust ments either singly or together. The slide 82 is also provided with the depending lip 97 which will be more fully described here-' inafter,

In order to simplify the operation-of my improved bevel edging machine I provide automatic means for moving thelensrout of engagement with the stone when it has been ground to] the predetermined desired shape and size, and in addition also provide an automatic clutch which will stoprotation of the/lens after it hasfbeen thrown out of en gageinent. with the stone. This structure comprisesa clutchmember designated "in its the like 100, (see Figure 7).

entirety by the numeral 98, which is associated with the outer end of the shaft '10. One section 99 of the clutch is keyed to the end of the shaft 10 by means of the pin or The movable section 101 of the clutch is slidably mounted upon the sleeve T1 and is provided with a shoulder 103 while the sleeve 71 is provided with a siinilar shoulder 101. A coil spring 105 is disposed between the shoulders 1013 and 101, respectively, so as to normally urge the slidahle section of the clutch into enagement with the stationary portion 99.

1' course, the stationary part is rotatable with the shaft 10 but Qllllitltitl against relative longitudinal movement thereot.

Both sectionsof the clutch are provided with the teeth 100, Fig. 9, as will readily be understood. The movable clutch member is provided with a groove 107, in which pins 108 me adapted to ride. The pins 108 are carried by the yoke 109 which is pivotally mounted. on the pin 110. It will thus be seen that the pins 108 in the groore 10? will allow the clutch member to rotate with the section 99, while at the same time the yoke 109 maybe so rocked that the movable section of the clutch may be moved out of engagement with the other section when desired. A portion 01 the frame 15 is formed that the shaft 110 may be j ournalcd tlierethrough. It is to he understood that the yoke 109 loosely mounted upon the shaft 11.0, Figure 5.

Mounted adj accnt the yoke 109 is a block 111 keyed to the said shaft so that upon movement of the shaft 110 said block 111 will be moved therewith. The block 111. is provided with a spring pressed pin 112 which, as can be seen in Figure 11, comprises the knob 11.3, disc 11 1, and stub pin 115, extending a substantial distance beyond the disc 1141. A coil. spring; 110 normally urges the stub pin 115 toward the yoke 109. The yoke 109 is provided with an aperture in which the stub pin 115 may be received. It will be seen that when the pin 11.5 is received within the aperture in the yoke 109, the yoke 109 will be moved with the shaft 110. On the other hand, when the pin 11:) is removed from the aperture the yoke 109 will again be loosely held on the said shaft.

Keyed to the opposite end of the shaft 110 is an arm 117 which has the extension. 118, as is clearly shown in Figure 5 of the drawings.

Journaled through the frame 15 a shaft. 119, on one end of which is mounted a ratchet wheel 120, while at the opposite end thereof is a double cam 121. The ratchet wheel 120 is preferably arranged inside o'f the frame 15, while thedouble cam 121 is arranged on the outside. The double cam 121 has a cammed surface on its periphery, as at 122, which is clearly shown in Figures 10 and 11 or the drawings. The bunch or hump 123 is clearly shown in Figure 11, and will be more fully described later on.

The flange 01' the double cam is also varying, and as is clearly shown in Figure 5, an alnupt shoulder 12-1 is: provided thereon. The extension 118 on the arm 117 is adapted. to contact with the flange 125 on the double cam 121, and to insure constant contact with this cam a spring 120 connected to the arm and. to a portion of the trame 15.

it hell crank member 12'? is pivotally calricd by the machine, as on the shaft 128,. and has a portion adapted for engagement with the double cam 121, while the opposite arm thereof has engagement with the slide way 82, above referred to, Figure it. The double cam 121 has the face 122, which is. so formed that at the beginning of the operation the hell crank lever 127 will ride there against until a low spot on the cam face 122 rotates in position so as to disengage the lever 12?, and allow the lip 97 to abut a por E iou oi. the frame. This is done so that the slide way will no longer be free to move towards the stone near the end of the grind.- ing of the lens, which enables the lens to take a smooth and true bevel. From then on the cam face docs not contact with the end i l of the bell crank 12? in view of the iact that this surface has been reduced to a point where a slight space is left between the two parts. lltfli'tir'ci', the double cam 121 is; kept rotating;- until the high Spot 123 again contacts with the end 130 01 the bell crank lever to throw the lens carriage away from the stone.

From the tlorcgoing it will be seen that the double cam I. has a thick portion which gradually d crrcasciii to its thinnest end, where it no longer contat i with the bell crank 127, this liOYbCUIlltM'iiillg portion of the double cam 121. being; arranged at that portion of the cam where the last or finishing and sizing touches are being given to theclens. litter the lev- 127 has passed over this thin portion oi the cam it again rises up on the high spot tor the throwing out operation, in order to be in position for the next grinth ing operatioi'i. i

In the grinding o't' ophthalmic lenses oftentimes some lenses can he edged more rapidly than others, depending upon the thickness, etc, of the lens blank. As has been pointed out, a ratchet wheel 120 is keyed to the name shailt as the double cam 121 so that the speed with which the cam 121. i s rotated. will depend upon the rapidity with which the ratchet whorl 120 is rotated.

in l igrure 5 is clearly shown the method or manner in whim the ratchet wheel 120 is rotated, The structure used comprises a pivoted bar 129. which is pivoted on the pin 100 in such a manner that the pawl 131 will be under spring tension so as to hold it in engagement with the ratchet wheel at all times. The opposite end of the bar-1291s provided "with the angularly extending pin 132, against; which abuts the finger 133 car-' lied on the shaft 134, which is rocked by the lever 135. The lever 135 is arranged on the exterior of the frame 15 and is provided with the spring pressed pin 136whichhas engagement with any one of the apertures 137 formed in the said frame. By swinging the lever 135 up and down the bar 129 w1ll likewise be rocked so that one, two, three, or

. any number of teeth on the ratchet wheel 120 axis of the drive shaft 40. When the cam contacting end of the rocker arm 129 .18

closer to the axis of the shaft40 it will be seen that the'cam 73 will have farther to push the said rocker arm down so that the opposite end, that is, the pawl end, will be moved through a greater are, thus rotating the ratchet wheel 121) more than in the'case where the cam '73 does not have to push the contacting end of thevrocker a rm 129 so far. Thus the holes 137 are so arranged that the sprin pressed finger 136 of the lever b L I 135 can gauge any one of the same so that the rocker arm will be posit oned relatively close or far away from theax1s of the drive shaft 40, thus increasing ordecreasing the number of'teeth tripped on the ratchet wheel 120 during each rotationfof the cam '7 3 In other words. the ratchet wheel 120 may be rotated slowly or uickly, dependingu on the uatureof the l'ense being edged, t us slowly or quickly rotating the cam 121' in such a manner that the lens will he fed quickly or slowly to the stone, as the case may be. f. r

In order to level up the machine to prevent the stone from having a; tendency to slide one way or the 'other,'a levelling device is shown 11] Figure 8, and comprises the bent plate 138 Wl11Cl1 ls'ra-ised or loweredjby .ll'ICftlIlS of the threaded shaft 139 and the spring 140. e

The operation of my improved lens bevel edging machine is as follows: the lens 38 is firts placed in a centering device to get the placing the. lens -38between the pads 47 Itj 1s tobe remembered that th'e'shaft 45 is slidable in its'bea'ringby means of the pivoted lever 56, which rocks the rocker arm 49, and upon release of the lever '56 the spring 55 will rock the 'arm'49' in such a mannerthat theshaft 45 will firmly'clamp the lens between the adjacent ends of thetwo shafts. The machine is then set into operation byapplying power by means of the belt 29 to the pulley '25, which rotates upon the bearing sleeve 28. The sleeve 26 is keyed to the pul-' ley 25,'the said sleeve 26 having the worm threads 27cut therein. The worm 27 has engagement with the gear 62 which drives the shaft'66 and through the

gears

68 and 69 drives the shaft'40. At the same time the plate 22 which is keyed to the shaft 20, is

rotated as through the inwardlyextending.

pins 23, having engagement with the roller tatedtherewith. It will thus be seen that V the} shaft 20 may be slid through its bearings 17 so that the grooved stone will in reality be whatmay be termed a floating or sliding grind stone.

The'shaft' 40 is provided near its opposite end with asleeve 71, on which are mounted the pinion72 and the cam'73. The shaft 40 also extends beyond the journal 70 and carries the clutch member 98.1The pinion 72 meshes with the pinion 74, which in turn meshes with the gear 75 on the shaft 46, so as to rotate the said shaft and the lens 38, In addition theform'er or formers 60 which are carried bythe outer ends of the shaft 46 are also rotated so as to regulate the shape'of the lens 'to be ground. The formers 60 are adapted to contact with theshoe' 76, the said shoebeing adjustable to any one of the gang formers 60, as is clearly shown in Figure 1. The pin 7 9- is received in one of the apertures to lock the contact shoe against accidental displacement during the grinding operation. -Now that the shape of the lens to be out hasv been. decided upon, it is necessary. to make the necessary .adjustment for therequired .size. This is done by moving the graduated'dial 92 which carries the, pin 94,which rides upon. the. stepped cam 87, Figure 6. The stepped cam 87 may have any number of faces 88 which are separated by the curved shoulders 89 so that the pin 94 maybe moved up to or lowered down' upon any one ofthe various faces. These faces are so formed with respect to each other that they will give the various standard size lenses. After one of the faces has I been regulated to give the standardsi'ze des ignated for that particular. face, the .re-'

mainder of the faces will automatically give their respective standard size. B rotating lenses that are not standard size, the supplemental graduated dial 85 carried by the screw threaded shaft 84 may be turned. 01-

dinarily, however, it will not be necessary to adjust the dial 85, as the simple adjustment of the dial 9?. will be sufiicent for the various size lenses which are ordinarily ground for spectacles and eyeglasses.

It is to be understocid that the coil spring 41 which is connected to the lens carriage 39 and a stationary part of the bevel edging machine frame Wlll at all times hold the lens in contact with the stone during the grinding operation. except when it is manually pulled away from the stone and locked in that position by means of the pivoted latch 42, or at the end of the grinding operation when the automatic throw out means have separated the lens and the stone. This sprin also holds the former (l0 and the contact s 0e in engagement, as will be readily understood by inspection of the drawings.

At the beginning of the grinding opera tion the bell crank lever 127 is so arranged that one end is on the high point or bunch 12 3 of the double cam 121, and as the cam is gradually rotated the bell crank lever rides down on the cam. At the same time the opposite end of the bell crank lever is in engagement with l the slide way 82, which moves on the frame 15 as is clearly shown in Figure 4 of the drawings. When the bell crank lever portion 130 reaches a certain point on the double cam 121, the lip 97 will abut the frame so that it will no longer slide therealong, thus holding the lens at one spot with respect to the stone so that the finishing revolutions or finish or line grinding will take place. By having the inward motion of the lens stopped at this point and allowing the lens to rotate several times. the lens is ground to an accurately finished size. In order to rotate the cam 121 it isnecessary to rotate the ratchet wheel 1:20 and to this end the cam 73 which is mounted on the sleeve 71 is rotated around, and each time strikes the pivoted bar 129 which rocks the opposite end, thereby moving the ratchet one, two, three, or as many notches as the lever 135 has been set for. Toregulate the number of teeth tripped each time the lever 135 is moved up or down, depending upon the character of lens to be ground so that one or .as many of the teeth may be moved as desired at one time. In some lenses it is necessaryto grind more slowly than in other lenses, so that in the case of a lens which it is necessary to grind slowly a relatively slow movement is given to the cam by tripping one or two teeth at a time on the ratchet wheel, while in the case where lenses may be ground more rapidly more teeth of the ratchet may be tripped or moved each revolution oil the shaft.

At the same time that the bell crank lever 127 is operated by the cam, the pivoted lever 117 rides against the outer face of the said cam in such a manner that when the angular extension 118 rides over the shoulder 1241 the movable section of the clutch will he disenspring 105 will move the said movable section oi the clutch into engagement with the portion 99 of the clutch which is keyed to the shaft 40. As the cam is rotated the arm 117 is gradually pulled toward the frame 15 of the machine until a point is reached where the pin 115 will snap into position in the aperture formed in the yoke 109. \Vhcn the cam reaches a point 121tl1c arm 11.7, through the action of the spring 126, will be snapped inwardly, thus disengaging the clutch members to automatically stop rotation of the lens.

Just prior to the automatic disengagement end 130, ride on to the high point or bunch 123 of the said cam so that the said bell crank lever will be rocked in such a manner that the slide way 82 will be moved onto the frame so that the contact shoe will bear against the pattern or former 60, thus throwing the lens away from the grinding stone, When the machine has reached this point the lens 38 will have been sullicicntly ground and sized to the predetermined desired shape and size. and thclens will be ready for mounting in a spectacle or eye glass frame.

In Figure 10 of the drawings is diagranr matically shown the location oi the lens and other parts of the machine during the grind ing operation, while in Figure 11 shown the bell crank lever when the high point 12 1 is in engagement with the portion 180 of the said bell crank lever, illustrating the lens removed from the stone 18. V

In Figures 13 andl l, I have shown a slightly modificd form of mach ne in which the stone is pivotally mounted instead of slidably mounted. The same form of lens carriage and lens feed controlling mecha nism as well as automatic clutch our ployed, in this form, the change being mor2- ly made in the method of floating or moi-in lilll ico of the lenses the bell crank lever will. at its 1 the'stone. It is to be remembered that in both forms of stone mountings the stone is so arranged that it isresponsive to the different curvatures of lenses ground so that it will accommodate itself by movlng to the right or left so that the lens at all timeswill] 5 in the location of the two major meridians Of course, this displacement will vary with the types of lenses used and the powers.

' This modified form of construction coniprises the 'ba se141 and the bracket-142. The bracket 142 has disposed at one end, preferably a screw threaded plug: H3, which carries a ball or the like 1 14. The opposite end of the bracket contains an adjustable pin 145 so that the stone swing or carriagel lti may be pivotally mounted bet-ween the ball memher 144 and the adjustable member1 r-5. The swing or carriageleti has the hardenedplug 147 which contains a suitable pocket for the reception of the balled memberl t, while the opposite end is provided-with a hardened plug 148 having arecess therein'adapted to receive the pointed end of the adjustable pin 145. The swing-or carriage 146 is provided with the :arms 149, which terminate. in the journal section 150, so as to support the transverse shaft 151 which carriesthe stone 152.

able stone, in that it has a substantially V- shaped groove 153. The stone is'rotated by means ofthe belt and pulley connection 154,

the said pulley being 'lieyed 'to the shaft 155,

the said shaft carrying a gearmember 156. The gear 156meshes with a second gear 157,

' which is carried on the stub shaft 158, which carries at one end the pulley 159. The stone shaft 151 also carries a pulley 160 which ordinarily is in'alignment with the pulley 159, and. to rotate the pulley -160 a suitablebelt connection 161 is trained over the two pulley wheels The

gears

156 and 157 are loosely connectedso that'th'e gear 157, which is: car; ried by the shaft 15S,may be rockedor The type of the stone 152 is identical with the type of stone employed in the slid-v essary free movement of the stone andcarriage will not in any way be affected by the movement of one lens with respect to the other in this manner. 7 v

The shaft 162 corresponds to the shaft 66 in Figure 9, and operates the gears, etc, constituting the-lens carriage 163 in Figure 13. The lens carriage 163 is the same as the lens carriage 39in Figure 9. 1 i

It wilt-be scent-hat when the lens 38 is placed within the lens clamp carried by the lens carriage, it may be received within the substantially Vshap'ed groove 153 of the stone 152, and upon rotation 'of the stone and lens through their respective mechanisms the lens willcause the stone to be swungback and forth so that the stone will readily accommodate itself to the various curved lenses which areused in ophthalmic eyeglass and spectacle mountings.

From the foreg ing it is obvious thatthe operation of thefeed of my improved ma chine is as follows: The lens and lens carriage are fedto the/stone step by step to a predetermined point." After the lens and carriage have reached this predetermined point the lens is allowed to revolve a selected number of times to produce a finish and to grind to an accurate predetermined size, after which the lens carriage and lens are automatically thrown away from the stone and an automatic clutch stops the rotation'of the lens. This is an important feature of my machine. asby having the lens stopped at a certain point and then allowed to rotate number of times it is'possible to edge the lens to (inaccurate and smooth reproduction of-the shape of the former or pattern used and to give the exact predetermined size for tiat shape, which size is determined by the relation'of the dials and 92.

It will be seenfrom the foregoing that I that will readily grind any desired shape and size of lens on both faces of the lens simultaneously. The stones are so mounted that they will readily accommodate themselves to the various change in curvatures and shapes of lenses. Itis understood that the lens carriage is in no way transversely movable while the stone in the first instance is adapted to he slid in either direction by reason of the contact of the lens within the groove, while in the second instance the stone is adapted to-be-"swung in either direction, accomplishing the same result in both in-' tances' It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claims.

Iltl

I claim 1.. ln a grinding machine, a grinding element, a lens holding element, means to rotate the elements, 'means to urge one element toward the other. a pattern on one of the elements, a contact shoe engaging the pattern, means to feed one element intermit tently toward the other, comprising a pivoted rock lever, a rocker cam having a con tact adapted to contact with one end of the rock lever at each revolution of the cam and to rock said lever intermittently, means to change the relationship between the rock cam and the end of the rock lever to regulate the amount of throw given therock lever by each contact with the cam, a pawl engaging the other end of the rock lever. a ratchet wheel operated by he pawl, a second canrrotated by the ratchetand a bell crank lever having one end engaging the second cam and the other end engaging the contact shoe support, the face of said second cambeing so arranged that it will allow the bell crank lever to allow the contact shoe to ret'ract a certain amount for the intermittent travel of the said second cam given it by the ratchet.

l na grinding machine, a grinding element. a lens holding element. means to ro tate the elements, means to urge one element: towards the other, a pattern on one of the elements, a contact shoe engaging the pat tern, means to feed one element intermittently towards the other comprising a pivoted lever, a cam having a contact adapted to contact with one end of the lever at each revolution of the cam and. to rock the said lever intermittently, a second rotatable cam, inter-engaging means between the other end of the lever and the second cam adapted to intermittcntl rotate the second cam as the lever is rocked about the first cam, and a bell crank lever having one end engaging the second cam and the other engaging the contact shoe support, the face of said second cam being so arranged that it. will allow the hell crank lever to allow the contact shoe to retract a certain amount for the intermittent travel of the said second cam given it by the rock lever.

3. In a grinding machine. a grinding element, :1 lens holding element, means to rotate the elements, a clutch in the lens rotating means. means to urge one element to wards the other, a pattern on one of the elements, at contact shoe engaging the pattern, means to feed one element intermittently to wards the other connn'isinp a pivoted lever,

a cam having a contact adapted to contact with one end of the lever at each revolution of the cam and to rock said lever intermittcntly, a second rotatable cam, interengag ing means between the other end of the lever and the second cam adapted to intermitently rotate the second cam as the lever is rocked by the first cam, a bell crank lever having one end engaging the second cam and the other engaging the contact shoe support, the face of said. second cam being so arranged that it will allow the bell crank lever to allow the contactshoe to retract a certain amount for the interi'uittent travel of the said second cam given it by the rock lever, clutch lever means having one end engaging the clutch and the other the second cam, and contact means on the second cam to engage the clutch lever means to release the clutch and stop the rotation of the lens holding means after the surfacing operation has been completed.

4. In a grindin machine, a grinding element, a lens holding element, means to to Late the elements, a clutch on the lens rotating means, means to urge one element towards the other, a pattern on one of the elements, a contact shoe engaging the pattern, means to feed one elementintermittently towards the other comprising a pivoted rock lover, a rocker cam having a contact adapted to contact with one end of the rock lever at each revolution of the cam to rock said lever intermittently, means to change the relationship between the rock cam and the end of the rock lever to regulate the amount of throw given the rock lever by each contact with the cam, a pawl. engaging the other end of the rock member, a ratchet wheel 0perated by the pawl, a second earn rotated by the ratchet, a bell crank lever having one end engaging the second cam and the other end engaging the contact shoe support, the face of said second cam being so arranged that it will allow the bell crank lever to allow the contact shoe to retract a certain amount for the intermittent travel of the said second cam given it by the ratchet, clutch lever means having one edge engaging the clutch and the other the second cam, and

contact means on the second cam to engage the clutch lever means to release the clutch and stop the rotation of the lens holding nieans after the surfacing operation has been completed.

NELSON M. BAKER.