US2377992A - Automatic turret grinding or polishing machine - Google Patents

Description

June 12, 1945. v

G. A. CARLSON 2,377,992

AUTOMATIC TURRET GRINDING OR POLISHING MACHINE Filed Oct. 14, 1943 4 Sheets-Sheet l INVENTOR u 1945- cs. A. CARLSON' AUTOMATIC TURRET GRINDING OR POLISHING MACHINE Filed Oct. 14, 1943 4'Sheets-Sheet 2 INVENTOR H C'arZson June 12, 1945. AKCARLSON 2,377,992

AUTOMATIC TURRET GRINDING OR POLISHING MACHINE Filed Oct. 14, 1943 4 Sheets-Sheet 4 a) Pll lllll llil Patented June 12, 1945 I UNITED STATES PATENT OFFICE AUTOMATIC TURRET GRINDING OR POLISHING MACHINE Gustave A. Carlson, Detroit, Mich.

Application October 14, 1943, Serial No. 506,131

Claims.

This invention relates to automatic turret grinding or polishing machines particularly designed for, what is known in shop parlance, as a special purpose machine, although as will appear more fully hereinafter, the machine of the present invention is capable of other uses.

The present machine is particularly designed for removing the sharp edged burr formed at the line of juncture between the bore and the outer curved face of a special purpose washer which forms a part of a precision job, the bore, after the washer has been hardened, being lapped to accurate dimension after which the outer curved face of the washer is ground to exact ize, to form a smooth highly polished, finished surface. The grinding of the outer curved face of the washer after the lapping of the bore thereof, tends to form a very sharp knife-like edge, or burr, at the line of juncture between the curved outer face of the washer-and the bore which it is necessary to remove. Removal of this burr which has heretofore always been performed by hand, is effected by the use of a flat disk of abrasive cloth, or paper, clamped at the end of a suitable fixture which is rotated and thrust into the bore of the washer so as to cause the flexible disk of abrading material to engage the sharp edged burr and remove the same, all as will be more fully hereinafter described.

The present invention has for its principal ob ject to provide a new and improved machine of comparatively simple, inexpensive construction which consists primarily of a plurality of rotatahle chucks in which the washers are adapted to be engaged, which chucks are mounted on a rotatable turret adapted to be intermittently rotated to bring the chucks and the washers carried thereby into alignment with a rapidly rotated tool shank which carries the flexible disk of abrading material.

Another object of the invention is to provide a new and improved means of simple and inexpensive construction for rotating and indexing the turret head.

A further object is to provide a simple and inexpensive means for simultaneously rotating a plurality of the work chucks at a plurality of work stations.

Another object of the invention is to provide a machine of the character described with a plurality of small compressed air, or electric drills of standard construction, which can be readily mounted upon a tool carrying head; the use of would be required if the abrasive disk carrying shanks of the machine were driven from the main gearing thereof.

A further object of the invention is to incorporate in a machine of the character described, simple gearing connections between the gearing means for actuating the turret and rotatable chucks carried thereby and the tool carrying head to cause the latter to be reciprocating to and from the tool carrying chucks when the latter are brought by the intermittent rotation of the turret to a position in alignment with the tool carrying heads.

The above and other objects of the invention will appear more fully from the following more detailed description and by reference to the accompanying drawings forming a part hereof, wherein Fig. 1 is a front, perspective view of a machine constructed in accordance with the present invention;

Fig. 2 is a greatly enlarged central, vertical section through one of the work carrying chucks, the washer to be operated upon showing in full lines the flexible abrading disk when the latter is in its working position and in dotted lines the disc in its raised inoperative position;

Fig. 3 is a horizontal section, partly broken away, taken on the line 3-3 of Fig. 1; I

Fig. 4 is a vertical detail taken substantially on the line 4-4 of Fig. 3;

Fig. 5 is a vertical section taken substantiall on the line 55 of Fig. 3;

Fig. 6 is a plan view of the tool carrying head with the cover thereof removed to illustrate the gearing contained therein;

Fig. '7 is an enlarged detail taken substantially on the line l'l of Fig. 6; and

Fig. 8 is a detail of a means for rotating the work chucks.

As hereinbefore explained, the machine of the present invention is particularly designed to remove the burr, formed on a hardened steel wash er of special construction, between the bore of the washer at the line of juncture thereof with a curved ground outer face of said washer. The type of operation to be performed can best be understood by reference to the showing of Fig. 2 of the drawings, wherein the numeral l0 indicates the washer, or work piece, which as shown is provided with a bore II and a curved outer face l2. These washers which are required to be machined to very accurate and precise finished dimensions, are first rough machined by machine tool cutting operations to within a few thousandths of the required finished size, after which the washers are hardened. The bore l is lapped to accurate finished size after which the curved outer face I2 -is then ground to finished dimension and contour. As above stated, the grinding of the curved face l2 causes a slight burr to be formed at the line of juncture between said face and the finished bore, which burr may frequently be of smallerdiameter than the required finished diameter of the bore II. It is, therefore, necessary to remove this burr on all of the finished work pieces so that the washer may be placed over the part of the machine on which it is adapted to fit. It is always desirable to remove the burr even though it may not be of less diam eter than the required finished size of the bore so as to eliminate the sharp razor-like edge which the burr presents with the consequent danger of cutting the fingers on the hands of the workers required to handle the washers after tl have been finished.

As shown in Fig, 2, the washer H is placed within a chuck l3 carried in a post 14 and adapted, when the turret hereinafter to be described is intermittently rotated, to bring the washer 2 in alignment with the rotatable shank 15 which carries adjacent to its lower end, a flexible disk of abrading material'l6. When the shank I5 is brought downwardly by means presently to be described, the end of the shank enters the bore H and causes the flexible disk It to be distorted from its substantially flat position. to the bowllike shape shown in full lines to cause the abrasive face of the disk IE to engage the edge, or

burr, formed at the line of juncture between the bore II and the ground face |2 oi the washer l0, and effectively remove the same.

The machine proper comprises a hollow, cy lindrical housing, or base 20, upon the upper end of which is rotatably mounted a turret head 2|,

which carries a plurality of chuck carrying posts I4 in which the chucks |3 may be either fixedly secured or said chucks may be rotated by means presently to be described. The machine is driven by an electric motor (not shown) mounted within the base of the machine; an electric switch 22 being provided on the outside of the base 2! for control of the motor. The electric motor drives by means of a belt 23, a pulley 24 secured to the end of the main driving shaft 25, to which is keyed a worm 26. The worm 26 meshes with a worm gear 21, suitably keyed to the lower end of a vertical drive shaft 28. At its upper end the shaft 28 carries a sprocket pinion 29 that meshes with a drive chain 30. The drive chain 30 is also trained about a plurality of small sprockets 3|, 32, 33 and 34, which are located in position to correspond with the working positions of the chucks around the rear half of the machine when the turret in its intermittent rotation brings the chucks successively under the flexible disks.

As shown in Fig. 3, the turret is provided with eight heads, or chucks, five of which are adapted to be driven, while they are in the working zone in the rear half of the machine, and three of which are not driven as the turret moves into the front loading and unloading zone. The chain 34 also engages with the teeth of a Sprocket gear 35 rotatively mounted on a sleeve 36 which passes through the center of a bearing block 31 cen-- trally secured to the turret head 2| (see Fig. 5) suitable anti-friction bearings 38 being interposed between the sleeve 36 and bearing block 3?. Suitably secured to the sprocket 35 to rotate therewith is a pinion 39 that meshes with, and drives, a gear 40. -Mounted on the hub 4U--a of the gear 40 is a pair of cams 4|, 42 which are secured to the gear 40 to rotate therewith by means of one or more bolts or screws 43; the gear 40 and cams 4|, 42 forming in efiect an unitary rotatable assembly mounted on the upper end of a vertical shaft 44. Carried by this rotatable assembly is a driving pin 45 which projects upwardly beyond the assembly and forms a part of what in effect is a Geneva type of intermittent drive. A small roller 45a carried by the pin 45 is adapted to engage within one of a plurality of radially extending slots 46 formed in the lower face of a drive plate 4l affixed to and carried by the center block 3'! and the turret head 2|; there being eight of such slots one for each of the chucks carried by the turret head. As the ro tatable assembly consisting of gear 40 and cams 4| and 42 rotates, the small roller 45a carried by the projecting end of the pin 45 engages within one of the slots 46 and produces a rotation of the turret through one-eighth of a revolution, the pin 45 being so located in the rotatable assembly consisting of the gear 40 and cams 4|, 42 as to cause rotation of the turret during approximately 90 degrees of the rotation of the said assembly.

During the 270 degree non-driving rotation of the rotatable assembly, a lock pin 50 carried by a pivoted lever arm 5| is caused to be engaged within one of a plurality of holes 52 provided in a lock plate 13 secured to the bearing block 3! thereby to hold the turret against rotation and with the chucks l3 in proper alignment with the tool heads which carry the flexible abrading disks. The lever arm 5| is pivoted at one end upon a bolt, or stud 53, which in turn is mounted in a boss 54 that projects upwardly from a horizontal web 55 that extends across the hollow, tubular housing 28 adjacent the upper end thereof. The other end of the lever 5| carries a pin 56 which projects downwardly between the jaws 51 formed in a yoked end of a projecting ear 58 of a lever 59,. The lever 59 is pivoted intermediate its ends upon a stud, or pin 60 secured in a boss 10 that projects upwardly from the web 55, the lever 59 resting upon a washer l|l-a loosely carried by the pin 60 and interposed between the lower face of the lever 59 and boss H1. The lever 59 carries a pair of cam rollers 1|, [2 for engagement with the periphery of the cams 4|, 42 respectively. With the parts of the position as shown in 3, the roller 12 is shown as engaged with the throw of the cam 42 while the roller H is shown as engaged with the dwell of the cam 4|. As the rotatable assembly heretofore described rotates in a counterclockwise direction, as indicated by the arrow A in Fig. 3 of the drawings, the roller 12 will ride off the throw portion of the cam 42 just as the roller 45a carried by the pin 45 begins to engage within a slot 46, the roller H simultaneously being engaged by the throw por tion 4|-a of the cam 4|. This causes the lever 59 to be rotated upon its pivot 54, thus causing the pin 55 by its engagement with the jaws 51 of the yoked ear 58 of the lever 59 to move the lever 5| upon its pivot 53 to withdraw the stop pin 50 from the hole 52 with which it had been engaged. As the rotatable assembly continues its rotation in the direction of the arrow A (Fig. 3) the turret 2| will be rotated through one-eighth of a revolution as the pin 45 travels through its circumferential path of movement. Just as the pin 45 and roller 45-a become disengaged from pointed out, are carried by a tool shank I which is preferably provided at its lower end with a the flexible disks I6. These disks, as heretofore knurled nut I5-a for holding the abrading disks in positionupon the tool shank and for readily removing the same when they becom worn. As hereinbefore stated the tool shanks are preferably driven by a small standard compressed air shown as being driven by small compressed air motors clamped within a split clamping brackt et 16 carried by a tool head 'l'I. As shown the machine is provided ,Withthree motors 15, each of which is connected by a piece of flexible tubing, or hose I8 with a suitable fitting 19 secured to the top of the head I1 and provided with:- an inlet pipe 80 adapted to be connected to a source of compressed air. Each of the split brackets 75 is secured, as by a bolt 8|, to a vertically adjustable tool carrying head 82, a spring pressed lock pin 83 being provided for engagement within one 1' of a plurality of holes 84 to hold the split bracket IS in various adjusted angular positions relative to the tool carrying head 82. Each of the tool carrying heads 82 is secured for vertical adjustment by means of a split sleeve type of construction shown most clearly in Fig. 5 and indicated by the reference character can whereby the head 82 and motor 15 may be mounted for vertical adjustment upon a post 85 carried by the head TI. The post 85 project at its upper end into a suitable bearing support provided in. the head, l1 and each post 85 is formed with rack gear teeth 86 for engagement by the teeth of a gear 81 encased within the head H. A plate 58 secured to the outer side wall of the head T! has formed on it a key 88a that projects into an elongated keyway'89 formed in the post'85 to hold the same against rotation while permitting vertical sliding movement thereof. The gear 81 is rotatably carried upon a bolt secured in one of the radially extending arms seer a spider 9!. there being three of such arms 98 one for each of the motor I5. Each gear 8? meshes with a gear 92 carried for rotation upon a bolt, or stud 93, also secured in the spider arm 90. Each gear 92 has suitably secured to it a rack pinion 94, the teeth of which engage with the teeth of a rack 95 formed in a rack head 96 mounted within the tool head IT.

The tool head TI is supported on, and carried by, the upper end of the tubular shaft 36, which projects through a central hole in the turret 25.

the head I1 being supported upon a plate-like extension 98 of a bracket 99, the latter being secured as by set-screws 99-41 to the upper end of the tubular shaft 36. The rack head 955 is car ried by the upper end of a lift rod I69. the lower end of which projects below the bottom of the sleeve 36 and is provided with cam rollers IilI for engagement with a lift cam i I32 secured to the lower end of the shaft 44. The lift cam I52 is provided with a high throw portion NEH-o. which extends around the cam for approximately an arc of 90 degrees, the throw portion Hi2 being so located below and relatively to the pin 45 as or electric motor.. In the particular embodiment of theinvention illustrated the tool shanks are to engage the cam roller II'II just before the pin 45 enters one of the slots 46 to rotate the turret and so that the flexible abrading disks I6 and clamping nut I5--a on the end of the tool shank I5 will be lifted clear of the washers Ifl just before rotation of the turret starts.

In addition to the high throw portion I02--a, the cam I 03 is provided with a plurality of throws I02-b which are of lesser height than the throw I02-a, the purpose of the throws I02b being to cause the flexible disk I6 to be reciprocated up and down as it is rotated thereby to present new abrading surfaces to the washer and avoid the wearing of a groove in the flexible disk which would otherwise occur if the disk were held in a vertical, stationary position during its rotation.

As hereinbefore pointed out, the chucks l3 which carry the washers I0 may either be held stationary during the engagement of the disks I6 with the washers III, or the chucks I3 and washers Iii may be rotated during the abrading or polishing operation, in which event the construction shown in Fig. 8 is employed, the chucks I 3' bein mounted upon the upper end of a stub shaft I I0 mounted for rotation in the chuck carrying posts I l, suitable anti-friction bearings I II preferably being interposed between the shaft Ill] and chuck carrying post. Secured to the-lower end of the shaft III! is a gear II2 which is adapted. when the turret is brought to one of its locked, stop positions, to engage with a gear H3 carried by the upper end of a second stub shaft H4 and which at its lower end has secured to it one of the sprockets 29, 3|, 32, 33 or 34, as the case may be. As each of these sprockets 29 to 34 inclusive are driven by the chain 30, Obviously rotation of the chucks and the part carried thereby will result. I

The manner in which the machine operates should be fully apparent from the foregoing description but for clarity the following brief description of the complete operation of the machine is given. Assuming that the switch 22 is actuated to cause the driving motor of the machine to rotate the pulley 24, rotation of such pulley is of course communicated through worm 26, worm wheel 2'! and shaft 28 to the sprocket pinion 29. As the sprocket 29 rotates it will drive the chain 39 which in turn produces rotation of the central sprocket and the gear 2-H which is attached to it. Rotation of the gear 39 is communicated to the gear 40, shaft 44 and the rotatable assembly consisting in addition to the gear 40 of the two cams 45, 42; Let it be as sumed that the compressed air motors '15 have been set in rotation by the opening. of a valve (not shown) in the-compressed 'air line leading to the inlet pipe 80 or by the actuation of suitable valves on each individual motor; the rotation of the motor 15 having been commenced before the switch 22 is cut in. Let it also be assumed that the parts are substantially in the position shown in Fig. 3 of the drawings, with the lock pin 50 in engagement with one of the holes 52 of the lock plate 13. As the pin 45 moves towards the slot 46 in the driving plate 41 which lies in the path of movement of said pin, the cam roller 12 will ride off the throw of the cam 42 shortly before the pin reaches said slot 45. Immediately thereafter, and just as the pin 45 is adapted to engage within the said slot 46, the cam roller 'II is engaged by the throw portion 4Ia of the cam 4|, thus withdrawing the lock pin fill from the hole 52 with which it had been engaged. Substantially simultaneously with this action the high throw I.02--a of cam I02 engages-With the roller on the bottom of the lift rod I00 causing the latter to be moved vertically upward. The upward movement of lift rod I00 is communicated by rack 95, rack pinion 94 and gears 92 and 81 to the rack gear teeth 86 formed on the upper end of post 85, thus causing the post 85 to be raised and carry along with it the tool carrying head 82, the clamping bracket 18 and the compressed air motor 15, This raises the lower end of the tool shank to an extent sufficient to clear the washer ID as indicated in the dotted line showing in Fig. 2.

When the pin 45 enters into slot 46, it will cause the drive plate 41 to be rotated, thus producing rotation of the bearing block 31 and the turret 2| causing the latter to be rotated through one-eighth of a revolution and to bring three of the chucks in correct alignment with the three compressed air motors and the flexible disks driven thereby. Just as the roller 45 passes out of the slot 46 which it has moved'from the right side to the left side of the vertical center line passing through the axis of rotation of the turret, as shown in Fig. 3, the cam roller 12 rides off the dwell portion of the cam 42 into the throw portion thereof while the cam roller 4| rides off the throw portion 4|--a of the cam 4| into the .dwell portion thereof. This causes the lever 49 to be rotated in a counter-clockwise direction (Fig. 3) and causes the jaws 51 formed in the yoked ear 58 of the lever 59 to move the pin 56 secured to'the lever 5| to move the said lever 5| upon its pivot 53 in a clockwise direction (Fig. 3)

to push the stop pin 59 into engagement with the next hole 52 of the stop plate 13. The turret 2| now being held in a stationary locked position with three of the chucks IS in vertical alignment with the three compressed air motors 15, the disks I6 are caused to be lowered into engagement with the washer II] as indicated in full lines in Fig. 2 of the drawings because of the fact that the roller Ifll of the lift rod rides off the high throw portion |02a of the cam I02. The successive plurality of the lesser throws, or nodes |02-b of the cam then engage the roller llll and cause the lift rod 00 to be moved comparatively slowly up and down and communicate its vertical movements to the compressed air motors, the tool shanks I5 and the disks carried thereby, until the roller |0| again rides up on the high throw |02a of the oam I02 to raise the disks clear of the washer after which the turret is again rotated through one-eighth of a revolution as above described.

It will of course be understood that the number of motors I5 with which the machine is provided may obviously be varied, and likewise the position of such motors may readily be changed. For example, the motor 15 and disk I6 carried thereby shown at the rear end of the machine might be dispensed with and both front and rear portions of the machine used for loading and unloading, or it is perfectly obvious that the tool carrying head might be provided with two motors 15 on each of the posts 85 with but very slight modification of the motor carrying brackets and so that the washers carried by two adjacent chucks would be subjected to the abrading operation.

It will likewise be understood that although the drawings show, and the foregoing specification describes, anembodiment of the invention that has proven highly successful in actual commercial operation, many changes, variations and Ill modifications in the constructional details of such embodiment may be resorted to without departing from the spirit of the invention as set forth in the claims hereunto appended.

Iclaim:

1. In a machine of the character described, a rotatable turret, a plurality of work carrying chucks carried thereby, a tool carrying head mounted in juxtaposition to said turret, a plurality of rotatable abrading tools carried by said head each consisting of a flexible disk of abrading material, means for intermittently rotating said turret to bring said chucks into alignment with said abrading tools, means for reciprocating said abrading tools during the rotation thereof to bring said flexible disks into engagement with the bore of a work piece carried by said chucks to thrust said flexible disks into said bore and including means for reciprocating said tools to continuously change the line of contacting en gagement of said disk with the work piece during an abrading operation.

2. In a machine of the character described, a rotatable turret, a plurality of work carrying chucks carried thereby, a tool carrying head fixedly mounted in juxtaposition to said turret, an

individual self-contained rotary motor carried by said head, a flexible disk of abrading material carried by said motor, intermittent driving means for rotating said turret to bring said chucks successively into alignment with said disk of abrading material, cam means connected/with said intermittent driving means and mean for causing reciprocation of said motor and disk relative to said tool carrying head and said turret to bring said flexible disks into engagement with the bore of a work piece carried by said chucks.

3. In a machine of the character-described, a rotatable turret, a plurality of work carrying chucks carried thereby, a tool carrying head fixedly mounted in juxtaposition to said turret, an individual self-contained rotary motor carried by said head, a flexible disk of abrading material carried by said motor, intermittent driving means for rotating said turret to bring said chucks successively into alignment with said disk of abrading material, cam means connected with said intermittent driving means, means for causing reciprocation of said motor and disk relative to said tool carrying head and said turret to bring said flexible disk into engagement with the bore of a work piece carried by said chucks, including a rack bar actuated by said cam means and a second rack bar upon which said motor is adjustably mounted and gearing carried by said tool carrying head and interposed between said rack bars.

4. A machine as set forth in claim 3 in which said cam means includes a cam throw portion for moving said disk of abrading material into and out of engagement with the work piece carried Jy said chuck and a plurality of cam throws of lesser amplitude than said first named cam throw to cause the flexible disk to be reciprocated slowly relative to said work piece during the rotating engagement of said disk with said Work piece.

5. In a machine of the character described, a rotatable turret, a plurality of work carrying chucks carried thereby, a tool carrying head mounted in juxtaposition to said turret, a plurality of rotatable abrading tools carried by said head each consisting of a flexible disk of abrading material, means for intermittently rotating said turret to bring said chucks into alignment with said abrading tools, means for rotating said chucks comprising a plurality of chain sprockets located at spaced intervals substantially in alignment with said abrading tools, a single driving chain trained upon said sprockets, a driving spur pinion connected with, and driven by, each of said sprockets, and each of said work chucks being provided With a spur gear adapted to be brought into driving engagement, with one of said driving spur pinions to be rotated thereby when said chucks during the intermittent rotation of said turret are brought into alignment with said abrading tools.

6. In a machine of thecharacter described a fixed supporting base, a driving gearing carried thereby, a turret mounted for rotation upon said base, a plurality of work carrying chucks carried by said turret, a tool carrying head fixedly mounted in juxtaposition to said turret, a plurality of rotatable abrading tools carried by said tool head each consisting of a flexible disk of abrading material arranged in spaced relationship about said tool head, an intermittent driving mechanism interposed between said gearing and said turret for rotating said turret to bring said chucks into alignment with said abrading tools, stop means for holding said turret against rotation when said chucks are brought into alignment with said abrading tools, cam means secured to, and rotating in unison with said intermittent driving mean to cause said abrading tools to be moved into and out of engagement with a work piece carried by said chucks during the rotation of said turret and to hold said abrading disks in reciprocating contacting operative engagement with said Work piece when said turret is held against movement.

7. In a machine of the character described a fixed supporting base, a driving gearing carried thereby, a turret mounted for rotation upon said base, a plurality of work carrying chucks carried by said turret, a tool carrying head fixedly mounted in juxtaposition to said turret, a plurality of rotatable abrading tools carried by said tool head each consisting of a flexible disk of abrading material arranged in spaced relationship about said tool head, an intermittent driving mechanism interposed between said gearing and said turret for rotating said turret to bring said chucks into alignment with said abrading tools, stop means for holding said turret against rotation when said chucks are brought into alignment with said abrading tools, cam means secured to, and rotating in unison with said intermittent driving means to cause said abrading tools to be moved into and out of engagement with a work piece carried by said chucks during the rotation of said turret and to hold said abrading disks in contacting operative engagement with said work piece when said turret is held against movement, said stop means comprising a stop plate secured to said turret provided with a plurality of spaced holes, a pair of pivoted levers mounted adjacent said stop plate, a stop pin carried by one of said levers, and cam means associated with said intermittent driving means to cause said stop pin to be engaged within one of said holes to prevent movement of said turret when said turret is not being rotated by said intermittent driving means and for disengaging said stop pin during the periods of rotation of said turret.

8. In a machine of the character described a fixed supporting base, a driving gearing carried thereby, a turret mounted for rotation upon said base, a plurality of work carrying chucks carried by said turret, a tool carrying head fixedly mounted in juxtaposition to said turret, a plurality of rotatable abrading tools carried by said tool head each consisting of a flexible disk of abrading material arranged in spaced relationship about said tool head, an intermittent driving mechanism interposed between said gearing and said turret for rotating said turret to bring said chucks into alignment with said abrading tools, stop means for holding said turret against rotation when said chucks are brought into alignment with said abrading tools, cam means secured to, and rotating in unison with said intermittent driving means to cause said abrading tools to be moved into and out of engagement with a work piece carried by said chucks during the rotation of said turret and to hold said abrading disks in contacting operative engagement with said work piece when, said turret is held against movement, said stop means comprising a stop plate secured to said turret provided with a plurality of spaced holes, a pair of pivoted levers mounted adjacent said stop plate, a stop pin carried by one of said levers, cam means associated with said intermittent driving -means to cause said stop pin to be engaged within one of said holes to prevent movement of said turret when said turret is not being rotated by said intermittent driving means and for disengaging said stop pin during the periods of rotation of said turret and additional cam means associated with said intermittent driving mechanism for causing said flexible abrading disks to be moved into engagement with the work piece carried by said chucks when said stop pin is engaged with one of the holes of said stop plate.

9. In a machine of the character described a fixed supporting base, a driving gearing carried thereby, a turret mounted for rotation upon said base, a plurality of work carrying chucks carried by said turret, a tool carrying head fixedly mounted in juxtaposition to said turret, a pluralsaid chucks into alignment with said abrading tools, stop means for holding said turret against rotation when said chucks are brought into alignment with said abrading tools, cam means secured to, and rotating in unison with, said intermittent driving means to cause said abrading tools to be moved into and out of engagement with a work piece carried by said chucks during the rotation of said turret and to hold said abrading disks in contacting operative engagement with said work piece when said turret is held against movement, said stop means comprising a stop plate secured :to said turret provided with a plurality of spaced holes, a pair of pivoted levers mounted adjacent said stop plate, a stop pin carried by one of said levers and cam means arranged with said intermittent driving means to cause said stop pin to be engaged within one of said holes to prevent movement of said turret when said turret is not being rotated by said intermittent driving means and for disengaging said stop pin during the periods of rotation of said turret and additional cam means associated with said intermittent driving mechanism for causingsaid fiexible abrading disks to be moved into engagement with the work piece carried by said chucks when said stop pin is engaged with one of the holes of said stop plate, including means for causing said flexible disks to be recipro'cated slowly relative to said work piece during said period.

10. In a machine of the character described, a

fixed supporting base, a driving gearing carried thereby, a turret mounted for rotation upon said base, a plurality of work carrying chucks carried by said turret, a tool carrying head fixedly mounted in juxtaposition to said turret, a plurality of rotatable abrading tools carried by said tool head each consisting of a flexible disk of abrading material arranged in spaced relationship about said tool head, an intermittent driving mechanism interposed between said gearing and said turret for rotating said turret to bring said chucks into alignment with said abrading tools, stop means for holding said turret against rotation when said chucks are brought into alignment with said abrading tools, cam means secured to, and rotating in unison with said intermittent driving'means to cause said abrading tools to be moved into and out of engagement with a work piece carried by said chucks during the rotation of said turret and to hold said abrading disks in contacting operative engagement with said work piece when said turret is held against movement, said stop means comprising a stop plate secured to said turret provided with a plurality of spaced holes, a pair of pivoted levers mounted adjacent said stop plate, a stop pin carried by one or said levers and cam means arranged with said intermittent driving means to cause said stop pin to be engaged within one of said holes to prevent movement of said turret when said turret is not being rotated by said intermittent driving means and for disengaging said stop pin during the periods of rotation of said turret, additional cam means associated with said intermittent driving mechanism for causing said flexible abrading disks to be moved into engagement with the work piece carried by said chucks when said stop pin is engaged with one of the holes of said stop plate, including means for causing saidv flexible disks to be reciprocated slowly relative to said work piece during said period, and gearing means interposed between said last mentioned icam means and said flexible abrading disks comprising a pair of spaced rack bars carried by said tool head and gearing inter osed between said rack bars, one of said rack bars being provided with an anti-rriction roller for engagement by said last mentioned cam means and an individual selt-contained motor to which said flexible abrading disk is attached carried by the other of said rack: bars.

. GUSTAVE A. CARLSON.

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