US1729780A - Centerless grinding machine - Google Patents

Description

Witneaa'el Oct. l, 1929., H. w. HOLMES CENTERLESS GRINDING'MACHINE .Original Filed Feb. l0, 1926 l #Zim 3v Sheets-Sheet l in/nemica .HaroLd W7 .Halxmes Oct. 1, i929. H. w. HQLMES CENTERLESS GRINDING MACHINE original Filed Feb. 1Q, 1926 3 Sheecs-Sheet 2 d e M e m W 0a. 1 1929. H. w. HOLMES l,7z9,7su

CENTERLES S GRINDING" MACHINE Original Filed Feb. 1.0, 1926 3 Sheets-Sheet 5 .E ll i A l I l" ,4; 319.7 5 I* Y 72 v gwmznkw J'larold W'JIolmes j Gillot mut Patented Oct. I, 1929 I .UNITED STATES PATENT l carica HAROLD W. HOLMES., OF DETROIT, MICHIGAN, ASSIGNOiR', BY MESNE ASSIGNMENTS,

T CINCINNATI Gl'IRINDIEIRS INCORPORATED, OF CINCINNATI, OHIO, A CORPORA- TION4 OF OHIO cEN'rnRLEss GRINDING MACHINE Application led February 10, 1926, Serial No. l87,406. Renewed. November 194, 1928.,

This invention relates to grinding machines, and more particularly to one adapted 'for grinding special shapes of round work, such as a cylinder havinga shoulder or en- 5 largement thereon, which is ground'and r0- tated between and respectively by a rapidly rotated grinding wheel and aslowlyvrotated work regulating wheel.

It has been proposed heretofore to grind cylindrical bodies in a centerless grinding machine having a rapidly .rotated grlnding Wheel anda slowly rotated` work regulating wheel between which the work is positioned during the grindingv operation. This machine has been'satisfactory for certain types of cylindrical work but has not-been readily and easily adaptable for grinding work of special shapes, such as certain types of shouldered pieces of different diameters, lengths,

and weights, on a satisfactory productionlsuccessive pieces of work will be groundin' exactly the same manner and to substantially the same uniform size.

A further object is the provision of terless grinding machine constructed 1n such a manner as to be easily adapted for grinding a large variety of special t pes of cylindrical work of varying lengt diameter, and

40 weight, and lwhich may be operated periodically or automatically to grind successivework pieces, and thereby render the grinding machine useful and advantageous in various fields where ithas been impossible heretofore to use it. i

In grinding shouldered work it has been necessary for the operator to place the Work between the wheels accurately in a" position for grinding. In so doing there has been great danger of injury tothe operator by wheel, may be moved periodically by a suit- .7" 5

aV cena accidental contact between his hand and one of the wheels. It is a still'f'rther object of the invention to provide mechanisms in a grinding machine of this general type whereby work pieces may be presented in a posi tion for; accurate grinding in such a manner as to mmlmize the danger of injury to the operator and such that'successive 'work pieces may be ground in a systematic manner, and whereby the grinding machine may be utilized to the best advantage in the interest of increased production-and economy of time.

In accordance with certain features of the invention I provide a centerles's grinding ma- 4 chine for grinding special types of cylindrical Work while positioned or held between oppositely disposed work-holding members or blades and in contact with a rapidly rotated grinding wheel and a slowly rotated work regulating wheel arranged as in any one of the now well known types of centerless grinding machines. Preferably, the wheels are so mounted that one wheel, .such as the grinding abley mechanism towards and away from the other and preferably so that the grinding wheel may be directly and positively fed into-v or toward the work. In order that the ma- *chine may be readily and easily adaptable for grinding work pieces of different diameter or length andalso to achieve certain other advantages I provide a mechanism arranged cev Ato 'move one of theiwork-holding members or blades, preferably through positions parallel to the work axis, towards the work into approximate contact therewith while the movable wheel is away from the other and then 'into contact with the work during grinding and thereafter 'withdrawn while )the two wheelsv are separated to permit discharge of ground workL In the machine illustrated in the accompanying drawings, the ground work is discharged laterally preferably by rollin it off in the direction of rotation ofthe wor regulating wheel.

. The work may be placed in a grinding position between the wheels by hand, but in accord'ance with the preferred embodiment of my invention I provide a mechanism adapted to move a work piece an invariable distance in 100 lan axial direction into a position between the .tion to the wheel and work-holding wheels for grinding. This mechanism is preferably arranged to operate in timed relablade movements, so as to move a workpiece between the wheels when they are separated and j when the movable blade is in approximate grinding position. 'If desired, and preferably, the wheel and work-holding blade movements may be operated by power connections which may be manually controlled by a de- 'Avice adapted to connect lthe power with their respective actuating mechanisms and atthe -same time actuatefthe' work moving mechanism to move a work piece between the wheels 'at a desired rate into a grinding position.

The worlrmoving mechanism may be constructed an'd arranged lto withdraw aut'omatically when the manual control device is moved to its original position so as to disconnect the power and stop the wheel and blade moving mechanisms at the end of one cycle, that is, after completion of the grinding operation and when'the-.wheel and work-holding yblade havemoved away from Vthe lwork toA permit discharge thereof and the blade rey turned-to an approximate grinding position.- y V Other objects will be in part obvious or in art pointed out hereinafter.

he invention accordinglyconsists the features 'of construction, combinations of elements,.and arrangements-ofparts as w1ll be exemplified inthe structure' to be hereinafter describedv and the scope of the application of which will be indicated in the' following l claims.

In the accompanying drawings, in which is shown a vention,

Fig. '1 is an elevational view from the right I vhand side, with parts broken away, of a centerless grindingmachine embodying the' invention;

Fig. 2 isa detached perspective view of the work moving mechanism and the manual control device connected therewith;

Fig. 3 isl a detail view of a portion of the;`

work moving mechanism;

Fig. 4 is a detached perspective view of the power connection to lng member;

Fig. 5 is a detail perspective view of the the movable work-hold-l t-ripper mechanism;

" Fig. 6 is a sectional view along the line 6--6 of Fig. 1; p A

y Fig. 7 'is a sectional elevational view through the trunnion i'n which the grinding wheel spindle is mounted;

Figs. 8 to 10 inclusive are diagrammatic views showing the positions of the work and various mechanisms of the machine during its operation; and

Fig. 11 1s a diagrammatic view showing the shape and relative positions of the cams coulpropriately secured to the frame. regulat-in wheel 23 is mounted, beneath and preferredK embodiment of my ilkl lwhich a work regulating wheel is arranged beneath and is peripherally opposed to the grinding wheel. The apparatus includes a frame 10 (Fig. 1) within which ismounted a grinding wheel vspindle 11 carrying a grinding wheel 12. The grinding wheel spindle' 11 is rotated rapidly froma suitab1e source ofpower by a belt'13 passing over a pulley 14 secured uponv the spindle '11.

A1 column 15 may be moved 'vertically .within Va cylindrical portion '16 of the frame 10to which it is splined, by means of a hand" wheel (not shown) keyed to the shaft of a worm 17 i meshing with a worm wheel 18 keyed to a screwshaft 19v engaging threads in 'a boss 20 integral with or otherwise ap- A work periphera ly opposed to the grinding wheel, upon a spindle 24 for rotation in suitable bearings (not shown)- and is substantially enclosed within the, bearing casing 25 supported upon the block 26 mounted upon the upper lportion of the column 15; the regu-v lating wheel may be rotated relatively slow- -ly from anyfsuitable source of power, such as a motor 27 connected directly to a shaft 28having a worm 29 thereon meshing with a worm wheel-30 upon the regulating wheel spindle 24. .i

'A'n auxiliary frame 33 fixed n the column 15 extends upwardly in the rear (tothe right, as viewed in Fig. 1) of the regulatin wheel 23. A work holding member'or -bla e 34 is slidably mounted in acarriage 35 havin a portion 36 adapted to move in the vertical slideways 37 in the frame 33. The carriage I'35 may-be movedrvertically by means of a *pinion 38 meshing with the rack 39 secured upon the" carriage 435. The work-holding lio member 34 may beV suitably adjusted and maintained with its work-contacting or guiding edge parallel to the axis of the grinding wheel y means of a pair of pins 40, each slidably supported and engaging the member 34 at one end and a cam 41 atthe other end, thereby assuring that the guiding or workengaging surface of thevwork-hol'ding member 34 is maintained parallel to itself or to v the axis of the grinding wheel as it is moved in and out for'use with work of different sizes'.` The arrangement of the cams 41 and coacting parts is not per se my invention and is described in detail and claimed in the copending application Serial No. 91,861 of Fred M. Kern and Ernest R. Seward, filed March 3, 1926,v and to that application referpan 42 is mounted upon the top of the column 15 and is secured to the block 26 by means of bolts 43.

The grinding wheel spindle 11 and the work regulating wheel spindle 24 may bear a fixed relation to each other but I prefer to construct themachine so that one of the wheels may be moved towards or away from the other Wheel to facilitate feeding workbetween the wheels and subsequently discharging the ground work. This may be accomplished by mounting the grinding wheel so it may be moved periodically toward and away from the other wheel. Thus, the grinding wheel spindle 11 carriedin a tapered split bearing 45 (Fig. 6) is adjustab-ly mounted within the trunnion 46 (Fig. 7) and has its laxis located eccentric to that of the trunnion. The latter has a vcylindrical bearing surface 47 mounted for rotative osc-illation'abou't its axis in the frame 10 (see Figs. 6 and 7) and is provided with a rearwardly extendingarm 48 having an'adjustable roller 49 positioned therein adapted to ride upon an arm 50. The roller 49 is held by a member 53 which is adapted to be moved within a slot 54 in the arm 48 yby means of an adjusting screw 55. The arm 50 is pivoted at one end to turn about a shaft 56 and has a cam roller 57 ai the other end adapted to ride upon the peripheral sur# face of a cam 58 fixed upon the cam shaft 59.

` The inter-relation and eoaetion of the arm 48 4 cam 58.

' with the arm 5 0 and immediately associated parts, whereby a wide variability of the action of thefixed cam 58 may be achieved by varying the position ofthe roller 49 lengthwise of the arm 50, are notper'se my invention but permit the achievement, in coaetion with the other parts of the apparatus herein described, of many important ad-l vantages, and they are described in detail and claimed in the-co-pending application Serial No. 85.790 of Fred M. Kern, filed February y3, 1926, and to that application reference ma be had for further' details of the'constructlon and action thereof. A relatively heavy weight` 60 (Fig. 1 is suspended by a rod 61 fromthe end of the, arm 48- and serves to hold the j cam follower 57 upon the The lateral thrust on thegrinding` wheel spindle 11 due t the pull of belt`13 upon pulley 14 is taken y a roller race 62 (Fig. A6) suitably positioned in the trunnion 46 as ililustrated. The pulley 14 is .secured lupon Imeans of-a nut 64.

one tapered end ofthe grinding wheel spindle 11 by means of a nut 63, and the grinding wheel 12 is secured upon the other end by In order that`.the grinding wheel may be shifted axially through a suitable distance to eliminate grain markings', the spindle l11 is -mounted for l V'eciprocation lengthwise As illustrated, the spindle has a yoke collar' 65 (Fig. 6) fixed thereon and provided with a movable bushing 66 having a groove for the insertion of a'yoke 67, which is keyed to a 'L shaft 68 and supported for rocking movement in a bearing in the trunnion46, as shown in Fig. 7. A crank arm 70 is ykeyed to the outer end of the shaft 68 and is provided with a cam roller 71 which is adapted to engage the radial face of a cam 72mounted upon the camshaft 59. The radial face is provided with a raised. portion 78, suitably placed thereon to move the grinding wheel spindle axiallyy during grinding of a work piece.

Preferably, I provide but one raised portion, 1

73, and the remainder of the cam face is plane so that toward the end of the grinding operation the wheel will be given a single y quick, short, axial movement to smooth over the work surface. The arm 70. is Iheld by suitable means, such as spring (not shown), so that the cam roller presses against the cam face, and the wheel 12, as in the preferred embodiment just noted' is lheld in` one 'position except as moved by the raised portion on the cam. p

Turning now to Figs. 1 and 4 of the drawings, a U-shaped member 75 is mounted to swing about a horizontal pivot 76 secured in a bracket 77 integral with a plate 78 lsecured to a.' flat portion of the block 26 by means ofbolts 79. `The distance that the U-shaped member 75 may swing in one direction may be adj ust-ably limited by means of an adjustable stop screw 80 (see Fig. 4). A front workholding member or blade 83 is held, by bolts 84, in a groove 85 on a fixture 86 which is adjustably mounted-u on the front arm of the U-shaped member 75 by means of. bolts 87 passing through a slot 88'in the fixture, The fixture 86 is provided with -an opening 89 which extends to a connection 90 for a pipe 91 so that a suitable liquid or coolant may be supplied over the top of the member 83 directly upcn the work being ground.

Inaccordanc'with the preferred embodiment of the invent-ion, the member 75 is actuated by a cam 95 mounted upon the camshaft 59 (Figs. 1 and 4). An arm 96 is keyed at one end to a shaft 97 and is provided at its other end with a cam roller 98 adapted to engage the peripheral surface ofthe cam 95. A second arm 99 is keyed at one end to the sha-ft 97 and isl provided at its other end with a. block 100 pivoted in the arm 99 to slid-ably engage a rod101.4 The rod 101 is pivotally secured at one end to the movable member 75 and is threaded at the other end for adjustable nuts 102 (Fig. 1) which holds a spring 103 upon the rod'and inv contact with the block 100. A spring 104 (Fig. 1) is fastened be- -tween thelfront of the water pan 42 andv the fixture 86 upon the front -arm of member 75 and, in tending to swing member 75 in counter-clockwise direction, acts to maintain the cam roller 98 in contact with the peripheral surface of the cam 95. A

The camshaft 59 may be rotated by means of a worm 108 (Fig. 1) on a shaft 109 meshing with a worm wheel 110 fixed upon the camshaft. The vshaft 109 may be rotated from any appropriate source of power by means of a belt 111 passing over a clutchv i pulley 112 on the shaft 109.

1.17 may be transmitted to a shaft 118` and consequentlyto the belt 111 through the in` strumentality of a belt 119 connecting cone pulleys 120 and 121.` A suitable toothed clutch 122, which i's'splined to the shaft-,109,

is provided for connecting the clutch pulley 112 with the worm 108. j

The clutch 122 may be moved to engage or disengage thepulley 112 by a manually controlled device. Such a device (Figs. 1 and 5) may include a clutch yoke having hubs 125 and-126 pivotally mounted upon' the shaft 97. An arm 127 extends rearwardly from the hub 125 and is provided with a V-shaped projection 128 on its end (Fig. 1).l The projection 128 is adapted to contact with the V- shaped end projection 129 on a pin 130 vslidably mounted in a boss 131 in the frame of the machine. A spring 132 maintains a Contact between the V-surfaces of the end projections 128 and 129. A fork 133 extends downwardly and forwardly from the hubs 125 and 126 and carries a pair of pins 134 (Fig. 5) adapted to ride in a groove 135 in the clutch collar. A double link 136 projects forwardly and is secured at one end to the fork 133 and supported at the other end by a downwardly extending arm A137 of a bell crank 138 pivotally mounted upon the shaft 56. A vertically positioned rod 140 having a slot 141'is mounted to )slide upon a pin 142 in the forward end of the double link 136. The rod is secured at its lower end to a link 143 (Fig. y1)

' which is keyed to a shaft 144 suspended in the frame of the machine for rotary movement. A clutch operating lever 145 Ais secured upon the shaft 144'so that movement to Jche left, as viewed in Fig. 1, will move 'the rod 140 upward relative to the Vdouble link 136 (Fig. 5') to strike against the forwardly extending arm 146 of the bell crank 138, and thereby turn the bell crank to move the double link 136 andthe fork 133 forwardv (that bring the rod 140 vto ahigher iosition, whereby the projection 153 (Fig. 5) will be positioned in an appropriate part of the path circumscribed by a projection 154 on a tripper cam 155, which is secured to the camshaft 59.

'VVitli'the-rod 140 in such a position, the projection 154 of cam 155 engages the projection 153 on the rod 140 to move the double link 136 horizontally (to the right as viewed in Fig. 5) an amount suflicient to disengage the clutch 122 'from the pulley 112.

In order to expedite the grinding of successive work pieces and to eliminate the danger of injuring the workmen, .I provide a device for moving work axially preferably an invariable distance between the wheels to an appropriate grinding position. A preferred forn'wf device for this purpose comprises a horizontally disposed casing 158 (Figs. 1, 2, and 3) mounted on thei'aight hand sideof the machine (the side seen in Fig. 1)

'to the water pan 42, parallel to the axis of the grinding wheel, by means of bolts 159 passing through slots 160 in=`abr`a`cket 161. A plunger 163 (Fig. 3) is adapted to move within the casing 158 between rollers 164, and is moved towards thev wheels Aby means 'of a rope 165, secured at one end toan ear 166 on the plunger, passingover a pulley 167 to a bolt or hook 168 to which it is secured and which is adjustably mounted upon ,an arm 169 on the lever 145 by means of a set screw 170. The plunger 163 is operated against .the tension of a spring` 171 (Fig. 3) secured at one end to a pin 172 in the plunger and at the other end to a pin 173 (Fig. 2) in the casing. The position of rest of the plunger 163 may be Varied by means of an adjustable stop screw 174, threaded in a projection 175 in the casing, engaging the ear 166 on the plunger 163. A work conveyor 176 is pivoted to turn about a pin 177 in the casing 158 and is normally hel iagainst an adjustable stop screw 178 by leans of a leaf sp1ing'179. The work conveyor 17 6 may be of any construct-ion suitable for thev work,

'and that shown in the drawings (Figs. 2 and 3) is particularly adapted for receiving headed work pieces,lsuch as shackle bolts.

Thus, the shank of the bolt may rest upon cient distance to allow the plunger 163 to` push the work on to the work regulating wheel 23 and between the work-holding members 34 and 83.

Considering now the operation of the machine, the grinding wheel 12 is rotated rapidly to give it a suitable grinding speed and in the direction indicated by the arrow (Figs. 1, 8, 9 and 10) from any appropriate source of power by means of a belt 13 passing over the pulley `14 on the grinding wheel spindle 11. The work regulating wheel 23 is rotated relatively slowly, in the direction indicated by the arrow, through shaft 28, worm 29 and worm wheel 30 by means of a motor 27. With the pulley 112 rotating at a desired speed, the camshaft 59 may beset in rotation by pulling the lever 145 to the left, as viewed in Fig. 1, which raises the rod 140 to strike against the arm 146 of the bell crank 138. This throws the double link 136 forward (to the left in Figs. 1 and 5) and brings the clutch 122 into engagement with the pulley 112.

With the lever 145 in this position, it will be noted that the projection 153 on therod 140 is above and out of the path circumscribed by the projection 154 on the tripper cam 155 so lthat the machine may operate completely and continuously automatically. Thus, the camshaft 59 together with the cams 58, 72 and '95 thereon may rotate uniformly and continuously with the cam rollers 57, 71 and 98 in contact therewith respectively to actuat-e their respective mecha'- nisms, namely, for moving the grinding wheel 12 towards and away from the work regulating wheel 23, for moving the U-shaped member 75`to carry the front work-holding member or blade 83 cyclically towards'and away from the Work, and for reciprocating the grinding wheel axially during grinding of the work.

It will be noted that rotation of the cam 58 (Figs. 7, 11 and 1) raises and lowers the cam roller 57 to raise and lower the freeend of the pivoted arm 50 which in turn raises and lowers the cam roller 49. The latitude of movement of the arm 48 may be reduced or increased by adjusting the position of the cam roller 49 on the arm 48 by turning the change the position of the axis of the grinding wheel spindle 11 which, as already noted, is eccentrically mounted inthe trunnion 46, thereby causing the grinding wheel 12 to move cyclically towards and away from the other wheel. v

' The cam roller 71 (Fig. 7) is maintained in contact with the projection 73 and the vradial face of the cam 72 by means of a spring (not shown). This causes a reciprocation of the arm and the yoke 57 and consequently l an axial reciprocation of theA grinding wheel spindle 11, depending uponthe shape of the cam face. In the machine illustrated in the drawings, the grinding wheel 12 is moved any spring of the machine to be taken out and also allows a sparking out operation that tends to produce a better finish. It is preferably during the time that the grinding wheel is held against the work or during this period of dwell of the cam, that the grinding wheel spindle is oscillated.' However, there is preferably only one oscillation; that is, while 'the grinding wheel is dwelling against the Work it is moved about 1/ 8 of an inch away from the shoulder or head on the work,r if grinding shouldered work, and again brought back to position. This tends to take outfany scratches or wheel marks on the work.

At the same time the cam 95 (Figs. 4 and 11) vis rotateduniformly with the cam roller 98 in contact therewith, thereby causing oscillation of the arm 96, turning ofthe shaft 97, and oscillation of the arm 99 tol move the rod 101 and cause oscillating movement of the member 75 to move the front workholding member or blade 83 towards and away from the -work holding member 34 between the wheels. It should be noted that,

since the member 75 is pivoted to swing about 4 a pivot shaft 76 which is horizontally disposed and parallel to the axis of the grindtions parallel to itself and to the work axis,-

inasmuch as the axis of the latter is parallel to the'axis of the'grinding wheel. I prefer that its movements be parallel to itself f'or I am thereby enabled to achieve many thoroughly practical advantages.

The relative movement of the grinding wheel -12 and the front work-holding member or blade 83 towards and away from the work W is illustrated in Figs. 8, 9 and 10. The normal position of the grinding wheel 12 and the front blade 83 is shown in Fig.-8 with the grinding wheel away from the work and the frontblade away frombutin approximate contact with the work. Nowwhen the lever 145 (Fig. 1) is moved to the left to connect power with the camshaft 59,the cams 58 and 95 are rotated so as to move the front blade 8 3into contact withthe work W, and so that the front blade 83 holds the work W against the workholding member 34, and then bring the grinding wheel 12 into operative grinding contact with the work, as viewed in Fig. 9. After completion of the grinding operation the grinding wheel 12 moves away from the work and then the front blade 83 withdraws allowing ,the work to roll in the direction of rotation of the work regulating wheel 23 and be v discharged, as indicated in Fig. 10.

The speed of the automatic movements above described may be increased or decreased by adjusting the belt 119 (Fig. I) in appropriate position upon the cone pulleys 120 and 121. Thus, the work pieces may be ground at a mostsuitable rate depending upon the character of the work and such other variable factors as will now be readily understood by those skilled inthe art. V

, The normal position of rest ofthe grinding wheel 12 and the front blade 83 when the automatic movements are stopped vis that illustrated in Fig. 8. If it is desired to operate the machine automatically for one complete cycle and then stop with the front blade 83 and the grinding wheel 1.2 away from the regulating wheel, this may be accomplished by moving the lever 145 (Fig. 1) to bring the projection 153 (Fig. 5) on the rod 140 to a l predetermined location within the path circumscribed by the projection 154 on the tripper cam 155.

It will be observed that with Ithe tripper cam 155 in the proper position upon the camshaft 59 relative to the cams 58 and 95, that the front work-holding member or blade 83 and the movement of the grinding wheel 12 may be brought to a position of rest, such as is illustrated in Fig. 8, as the projection 154 Vcomes in contact with the projection 153 to move the double link 136 and the clutch yoke to disengage the clutch 122 from the pulley 112.

It will be observed that the center Vof the eccentric trunnion 46 (indicated at the intersection of the lines A and C in Fig. 7) is between the center ofthe grinding wheel spindle 11 (indicated by the intersection of lines B and C) and `the cam 58, and that the parts are so arranged that rocking movement of the trunnion moves the grinding wheel in the substantially vertical portion of an arc. The cam 58, as shown diagrammatically in Fig. 11, is so shaped as to cause the grinding wheel to move abruptly into an a proximate grinding position and then gra ually to grind the' work, the wheel then being withdrawn quickly to its initial position. This `.cam may be Vshaped to give the type of operation desired,

butas illustrated it has a spiral face which, when rotated in the direction of the arrow (Fig. 11),. movesthe cam roller 57 from a point a to a higher point I; to feed the wheel into the work. The grinding wheel then dwells upon the work while the cam-roller 57 contacts with the portion between the points Z2 and c which are substantially equidistant from the camshaft 59. From the points c to d on the cam 58, the cam roller 57 drops away rapidly and then climbs the incline 1l-a, thus moving the grinding wheel rapidly away from and then towards the work.

The cam 95 is so shaped and so located upon the shaft 59 relative to the cam 58 that the arm will move the positioning blade 83 into approximate contact with work between the wheels when the grinding .wheel is away from the other wheel, and into` contact with the work during grinding, and then away from thework as the grinding wheel is moved away from the other wheel to permit discharge of ground work by rolling laterally in the direction of rotation of the wrk regulating wheel 23. As shown in Fig. 11, the cam roller 98 is shown in its position of rest e upon the cam 95. When the camshaft 59 is rotated, the roller 98 moves along the peripheral surface of the cam 9 5 from e to .f and thereby causes the front guide blade 83 to move into contact with the work 'w (as shown in Fig. 9), and remains in that position until the wheels by hand when the grinding wheel 12 and the front bladev83 are away from their operative grinding positions. But in accordance with my preferred practice, a manually controlled work conveying device of the type previously described' is employed for feeding successive work pieces between the wheels in a position for grinding. rlhus, when the lever 145 is moved to the left to -engagethe clutch 122, the rope 155 is moved simultaneously a definite distance at any desired rate to move the plunger 163 an invariable amount and thereby push a workpiece, which has been placed by hand uponthe work carrier 176, on the work regulating wheel 23 and between the rear blade 34 andthe front blade 83 after the grinding wheel 12 and the blade to move the rod 140 downwardly so as to bring the projection 153 lto an appropriate .point within-thepath Circumscribed by the described, the work may be placed between projection 154 so the movement of .the grinding wheel towards and away from the other wheel, and the movement of the arm 75 towards andvaway from the work, will be brought to astop in the position shown in Fig. 8 after completing the cycle. At the same time the spring 171 returns the plunger 163 to a position of rest against the screw 174 and into a position for receiving another piece of work which is to be fed between the wheels.

It will thus be seen that, in accordance withv certain features of the invention a grinding machine is provided which is easily adaptable for grinding a large variety of cylindrical work, such as shouldered Work, in a more i economical and satisfactory manner than has heretofore been possible. of the length, size or weight of thework piece to be ground, successive work pieces of the same type are brought tothe same position between the wheels for grinding and held in that position by a movable work-holding member or blade which isin contact vwith the work throughout its entire length vand maintains contact between the work and the rear Work-holdingmember. or blade, and assures that no irregularities will be formed upon the i work due to a-sligh't movement out ofthe vvmost suitable grinding position. Furthermore, the successive Work pieces are fed to the same grinding position between the Wheels and the ground work discharged from the machine in a safe andmost economical manner.

VThe terms regulating wheeland slowly rotated regulating wheelare tobe construed` -regulating Wheel is to be given such a speed.

that the work will rotate during the grinding operation at that rate which is found desirable for the particular operation to be performed. Without reference to the theory of operation, the regulating wheel serves to control the speed of the work and is'drivenjt such a* slow speed that it determines the rate of rotation of the work, and the work may be given a fasteror slower speed byincreasing or decreasing the speed of the regulating wheel respectively; by speed, I mean rate of rotation.

. It will thus be seen that there has been provided in this invention an apparatus in which the several objects hereinabove noted, as well as many thoroughly. practical advantages, are successfully. achieved.

Certain features ofthe apparatus disclosed Thus, regardless in this application are broadly disclosed in,

and claimed in the claims of, my co-pending application Serial No. 71,484, iled November 25,1925;

As'many possible embodiments may be made of the above invention and as many changes might be made in the'embodiment above set forth, itis to be understood that all vmatter hereinbefore'set forth or'shown in the accompanying drawings, is to be interpreted as illustrative and not in a limiting sense.y

Having thus described my invention, what I claim as new and desire to secure by Letl i ters Patent is: f

1. 'A grinding machine comprising a rapidly rotated grinding wheel anda slowly rotated work regulating wheel, means for holding work of round section between said wheels,

saidmeans including a relatively fixed member anda relatively 4movable member, the latter being movable ltoward and away from said `inist-mentioned member, and a mechanism constructed and arranged to move said y second-'mentioned members to positions parallel to the work axis into contact'with the workto hold the .work between itself and said other member during grinding and away from the thereof. n v

2. A grinding machine comprising a rapidly'rotated grinding wheel anda slowlyroground work to permit discharge l tatedvworkl regulating wheel, means for movy ingV one of the wheels towards and awayV from the other, means including a movable f blade for positioning the work in grinding contact with the wheels, and a 'mechanism constructed and arranged to move said blade to positions parallel tothe work axis into approximate contact with the work while` said movable wheelis away from the other and mtojcontact withthe work during grinding and then out of contact with ,the work Ito permit discharge thereof.

3.- A centerless grinding machine comprising a rapidly rotated grindingwheel anda slowly rotated work regulating wheel, a member 'between said wheels for holding work of round section in operative relation thereto, a movable Work engaging member to hold the -work in operative relation with said work holding member during grinding, means' to move the work axially intoA the grinding zone,

and means for `moving said work engaging member so as to permit the work to escape laterally from the grinding zone.

4. A centerless grinding machine comprising a rapidly rotated grinding wheel anda slowly rotated work regulating wheel, means for moving one of the wheels towards and away from the other, means including a blade adaptedto move so as to position the work between the wheels for grinding and to los' move away from the ground work to permit v discharge thereof, and a mechanism constructed and arranged to move a work plece in an axial direction into a grinding position while the wheels are separated.

5. A centerless grinding machine comprising a rapidly rotated grinding wheel and a slowly rotated work regulating wheel, means for moving one of the wheels towards and away from the fother, means therebetween for positioinng work for grinding including a movable blade, a mechanism arranged to move said blade to' positions parallel to the work axis into approximate 4contact with the work while said 4movable wheel isaway from the other and into contact with the workduring grinding and then withdraw to permit discharge of ground worlgand means operating in timed relation with said blade and wheel movementsl to. move awork piece in an axialdirection into a grinding position while 'the wheels are separated.

6. A centerless grinding machine comprising a rapidly rotated grinding wheel and' aI slowly rotated work regulating wheel, means therebetween for positioning worlrfor grinding, means for movingl one of the wheels towards andaway from the other, a mechanism for moving work between the wheels in an ax1al directlon, anda manual devlce to actuate said mechanism to move work into, a grinding positlon while the wheels are separated. n

7. A centerless grinding machine comprising a rapidly rotated grinding vwheel land a slowly rotatin work regulating wheel, means therebetweenl or positioning work for grinding, means for moving one of the `wheels towards and away from the other, a mechanism for moving work between the wheels in an axial direction, and a manual control device for starting and stopping said wheel movements and adapted to actuate said mechanlsm to move work into a grinding position while the wheels are separated,

8. A centerless grinding machine comprising a rapidly rotated grinding wheel and a j slowly rotated work regulating wheel movable relatively towards and from each other,

- means to maintain a work piece of round section in operative relation with said wheels, a manually controlled mechanism to feed a piece of work into the grinding zone at a desired rate, means operating in timed relation with said mechanism to cause the wheels to move through a single cycle relatively4 to- `wards each other afterthe work is in position and to grind, the same to a with said mechanism to cause tne wheels to move through a single cycle relatively towards each other after the work is inposition and to grind the same to a'given size and thereafter separate, and means for automatically discharging the work from the grinding zone while-.the wheels are separated.

yl0. yA centerless grinding machine comprising a rapidly rotated grinding wheel and a slowly rotated v Work regulating wheel, means for moving one of the wheels towards and away from the other, means including a blade adapted to move through parallel positions to position work between the wheels for grinding and permit discharge of ground work laterally, a' mechanism for "moving work between the wheels in an axial direction, and a manual control device forstarting and stopping said wheel and blade movements'and adapted to actuate said mechanism to move work into a grindingposition while the wheels are separated. y

l1. In grinding apparatus, in combination,

of round section is received for simultaneous grinding and rotation, said grinding throat including a grinding wheel rotatable at relatively high speed, a A regulating Wheel rotatable at relatively low speed, said wheels being adapted to present adjacent operative surfaces traveling in opposite directions, `a member for holding workin operative relationto said two wheels and adapted to take up the thrust of the grinding wheel von the work, and a member spaced-from said firstmentioned member for taking up the oppositely directed thrust of the regulating wheel on the work; means for moving a work piece axially into said grinding throat; and means for moving one of said work holding members parallelto itselfiand away from the other, to permitdischarge of a ground work piece-from the rinding throat.

12. In grinding apparatus, in combination, a four-sided grinding throat in which work of round section is'receivedl for simultaneous grinding and rotation, said grinding throat including agrinding wheel rotatable at ,relatively high speed, a regulating wheel rotatable at relatively low speed, said wheels being adapted to present adjacent operative surfacestraveling in opposite directions, a memberl for holding. work inoperative relation to said two wheels and adapted to take up the thrust of the grinding wheel on the workyand a lnember spaced from said rstmentioned` member for taking up the oppositely directed thrust of the regulating wheel on the work; means for' relatively separating said two work holding members to permit the discharge of a ground workpiece from said grinding throat and for relatlvely approaching said two members to hold a work piece in operative relation to said two wheels; and means operative prior to the completion of a four-sided grinding throat in which work y lll) tively high speed, a regulating wheel rotaty able at relatively low speed, said wheels being adapted to present adjacent operative surfacestraveling in opposite directions, a member for holding work in operative rela- 1 tion to said two wheels and adapted to take up the thrust of the grinding wheel on the work, anda member spaced from said lirst mentioned member for taking up the oppositely directed thrust of the regulating wheel on the Work; power lactuated means for changing the relation of said grinding throat to the work, and means operating in timed relatlon thereto for moving a work-piece 1n I an axial direction into the grinding throat.

14. In grinding apparatus, in combination,

a four-sided grinding throat-in which work of round sectlon 1s received for simultaneous grinding and rotation, said grinding throat including a 'grinding wheel rotatable at rela-l able at relatively low speed, said wheels being adapted to present adjacent .operative'sur-l faces traveling in opposite directions, a member for holding workin operative relation to said two wheels and adapted to take up the thrust of the grinding wheel on the work, and a member spaced vfrom said first-mentioned member for'taking up theoppositely directed thrust of the regulating Wheel on the work; mechanism adapted in recurring sequence to relatively. separate said two work" holdingpmembers and to relatively approach them; and means operating in' timed relation to sa1dmechan1sm forjmovmg a. work piece 1n an axial direction into said grinding throat 'prior to the' completion of the relative -approaching movement of said t'wo members, the relative separating movement of said two membersbeing suiliclent to permit- -the dis# charge of a ground work piece in a direction transverse to the grinding throat. 15.. In rinding apparatus, in combination, a four-si ed rinding throat in which work of round section is received for simultaneous. grinding and rotation, said grinding throat including a grinding Wheel rotatable at relatively high spe'ed,\a regulating wheel rotatable at relatively low speed, said wheels being adapted to present adjacent operative surfaces' traveling in opposite directions, a member for holdin work in operative relation to said two whee s and adapted to take up the thrust ofthe grinding wheel on the work, and a member spaced Afrom said first-mentioned member for taking up the oppositely directed thrust of the regulating wheel on the work;

means for relatively separating and' approaching said two wheels and for relatively separating and approaching said two work holding members; and means for moving a l work piece in au axial direction into said grinding throat prior to the completion of the relative approaching movement of the parts comprising said grinding throat.

`Signed at Worcester, Massachusetts, this 16th day of Jan., 1926.

' HAROLD W. HOLMES.

.tively high speed, a regulating wheel rotat-

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