US1859737A - Grinding machine - Google Patents

Description

May 24,1932. .W.J.GUH D 1,859,737

GRINDING MACHINE Filed May 25, 3.928

2 Sheets-Sheet l wad@ I. umm

May 24, 1932 w. J. GUILD 1,859,737

GRVTNDING MACHINE Filed May 25, 1928 2 Sheets- Sheet 2 5 wam@ J. Gum

Patented May 24, 1932v UNITED STA TES PATENT OFFICE WALDO J. GUILD, OFWORCESTEB, MASSACHUSETTS, ASSIGNOR T THE HEALD MA- CHINE COMPANY, OF WORCESTER, MASSACHUSETTS, A CORPORATION 0F MASSA- cnusnm's enINmNe MACHINE l Application led May 25,

The invention, which isan improvement on an invention lof Carle J. Highberg, as.

shown in a copending application Serial No. 266,287, filed March 31, 1928, relates to in.- A 6 ternal grinding machines and particularly to the Work holding and Work rotating mechanism thereof. The present invention is shown applied to a grinding machine that is manually controlled, but it shouldv be understood that it can equally well be applied to an automatic machine in which the grinding operation is automatically terminated when each workpiecehas been ground to the desired internal diameter. The present invention utilizes the centerless work holdim?.r means of the Highberg invent-ion.

More specificallyv the present invention contemplates a simplification of the aforesaid ccnterless work holding means by giv- 20 ing directly to one or more of the idler rolls that constitute said means the cross-feed movement that causes the grinding wheel to cut deeper into the workpiece, instead of feeding the work head as a whole or the wheel head in relation to the work head.

The invention further contemplates an arrangement of the work holding and work rotating rolls whereby workpieces can be very easily placed in grinding position and ejected or removed therefrom.

The above and other advantageous features of the invention will hereinafter more fully appear from the following description which, taken in connection with the accompanying drawings, constitutes an illustrative embodiment of the invention. In the said drawings Fig. 1 is a front elevation of a grinding o machine .embodying the invention.

Fig; 2 is a plan view of the machine.

Fig. 3 is an end eleva-tion of the machine taken from the left-hand side of Figs. 1 and 2.

Fig. 4 is a fragmentary view of the work rotating roller detached from the machine, showing it in the position in relation to its supporting bracket inwhich it ejects a worknece.

l Fig. 5 is al fragmentary view of the trans- 1928. Serial No. 280,609.

verse feeding roller and bracket. v

Like reference characters refer to like parts throughout the drawings.

Referring first to Figs. 1 and 2, an internal grinding machine is shown, having a reciprocatory table or carriage 1 by'ithe reciprocation of which the grinding traverse is produced. The table l in this instance carries a Wheel head2, which ismounted on an interposed cross-slide 3, the latter being provided in order to allow of a periodic transverse movement of the grinding wheel 4 in relation to the Work head of the machine to compensate for wear on--said grinding wheel. It should be understood, however, that such compensating means forms no part of the. present invention.

rlhe grinding wheel 4 is mounted on a spindle 5 which is journalled in the usual its supporting `manner in the Wheel head 2;-the spindle driving means which causes rapid rotation of the grinding wheel need not be herein described, as such is well known in this art, and any suitable form thereof may be provided. Similarly, the aforesaid reciprocating motion of the table 1, to cause the rotating grinding Wheel 4 to make the required interior traverse of a. workpiece, may be imparted in any well known manner, but as illustrative of a specific embodiment of such, reference should be had to United States Letters Patent No. 1,582,468, granted April 27, 1926, to Heald and Guild, which shows fluid pressure actuating and reversing mechanism to produce the aforesaid traverse.

The table 1 carries a pair of spaced ad-A justable dogs 6 and 7 which are adapted to alternately engage and move a reversing member 8, these parts constituting the controlling means of the aforesaid actuating and reversing mechanism. By means. of a hand lever 9 the direction of travel of the table can be-controlled independently of the automatic actuation above set forth, while an inclined arm lisupported by a vertical rod 11 on the front of the machine, and adapted to be raised when the operator steps upon a treadle 12, will cause the reversing dog 6, which is pivotally mounted on its adjustable carrying block 13, .to be lifted clear of the reversing member 8, whenever the operator desires to interrupt the grinding. In Athis manner the work and wheel can be separated at any time for the purpose of dressing the grinding wheel 4 bymeans of a dressing device 14, or in order to allow the operator to remove the ground workpiece and place an unground workpiecey 1n the machine.

Referring to Figs. 1, 2 and 3, a bridge 15 is attached to the machine frame and spans the ways 16, 16 which support the table 1, thus allowing said table to move thereunder. This bridge V provides an upwardly extending frame portion 17 which supports the work' holding and work rotating means, and

the` cross-feed mechanism therefor. Said work holding and work rotating means comprises three tangential work supporting rollers 18, 19 and 20. The roller 18 constitutes the bottom support for a workpiece a and is stationarily mounted on a stud 21 projecting from the frame portion 17 The roller 19 constitutes one of the side supportssiliently supported by spring means in order to hold the workpiece in position, yet to allow of the advance of the roller 19.

Still referring to the same figures, the frame portion 17 provides an upwardly projecting portion 17a. Said portion has a horizontal hole therethrough, which constitutes a bearing support for a screw,shaft 24. A ratchet wheel 25 is mounted on, but not fastened to, the. forwardly extending portion of this shaft, while in front of the ratchet wheel is a hand wheel 26 that is fastened to the shaft. Between the hand wheel and the ratchet wheel is a compressible washer or friction pad 27. By means of a collar' 28 onone side of thebearing portion Y 17 a, and a nut 29 screwed on to the threaded front end of the screw shaft 24, these parts can be drawn together on the screw shaft,

thus eliminatinor end motion of the shaft in relation to its bearing support and, at the same time, providing a friction drive for the screw shaft through the ratchet 25, the pad 27, and the hand wheel 26. The nonpositive form of drive is desirable for a reason that will hereinafter appear.

The screw shaft 24, as best shown in Fig. 5, extends through an internally threaded member 30 which` ,as shown in dotted lines in said figure', provides a grooved projecting portion 31 that-is held from longitudinal displacement in a hub 32 of the arm 23, by means of a pin 33 fitting in the said groove. This connection, while keeping the parts together,

allows the member 30 complete freedom of angular movement relative to the hub 32 and the arm 23. The arm 23 is pivotally attached at 34 to the frame portion 17, and rotation of the screw Vshaft 24, therefore, moves the roller 19 in relation to the machine frame. It should be observed that such movement, which causes the grinding wheel 4 to grind a workpiece ato size, is actually a very small one, so that there is practically no rise and fall of the member 30 which will interfere with its actuation bythe screw shaft 24 that is in al substantially fixed horizontal position. If it is' desired to grind -a substantially different size of workpiece a, a roller 18 of different diameter may be supplied, and for the adjustment of the center of this roller, and also of the pivotal center of the movable Varm 23, slots 21a and 34a respectively are provi-ded in the frame 17.

The slot under roller 18 is at an angle of 45 so that the movement will be out and down at the same time, while the slot under the armcarrying the roller 19 is in a horizontal plane for adjustment outward. By this arrangement, the drivin'g roller 2O can remain in its original position on the same lhorizontal plane as the center of the grinding wheel.

The cross-feed screw shaft 24, which advances the roller 19 as described, is automatically turned by an intermittently actuated pawl engaging the ratchet wheel 25, and may be manually turned, to either advance or retract the roller 19, by means of the hand wheel 26. As shown in Figs. 1 and 2, the table 1 carries a forwardly projecting bracket 35 which, at the end of the inward travel of veach working stroke of said table, strikes and moves a rod 36. The latter is pivotally attached at 37 to a depending arm 38a carried by a yoke or collar 38 that surrounds a hub provided by the ratchet wheel 25. The rod 36 is also slidably received by a projecting'boss 39 formed on t-he bridge 15. Movement of the rod 36 by actuation from the table 1, consequently, oscillates the yoke 38 and the depending arm 38a, there being a spring 40 to return the partsrto the osition shown in Fig. 1 at the end of eac clockwise oscillation of these parts. Carried by the depending arm 38a on the aforesaid pivot stud 37 is a pawl 41 which, by means of a spring pressed plunger carried inside thereof and a detent in the cylindrical surface of the stud 37,

is resiliently held in the position relative to vthe arm 38a that is shown in Fig. 1, it being understood that the pawl 41 may be deflected upwardly againstv the pressure of the said spring. These parts are not shown in detail because they are very small and are well known in the art for the spring actuation of pawls. When the pawl 41 is moved to the left in Fig. 1, by the oscillation of the arm ICG were? f 38u,` as already. described, an inclined surface v42 on, said pawl strikes a cam member 43 provided by an arm` 44, that is pivotally mounted at 45 to the frame 17 This action forces the pawl 41 inl a clockwise` direction on its pivot stud 38 causing engagement, of

a pawl tooth 46 with lthe ratchet, wheel 25.

The position of the cam member A43 relative to the pawl 41 is adjustable by means of a screw 47 carried on a projecting portion of the frame 17, Said screw engaging Aan arm 48 that is integrally attached to thearm 44.

`A spring 49-is provided to draw the-arm4`8 to the adjustable screw 47. Adjustment. of the positior'of the `cam member 43of course, regulatesthe angular distance through which the ratchet wheel will be moved oneachactuation 'by the pawl 41.

- Means being thus provided to delicately feed one of the tangential supporting rollers as just described, it is obvious that the feed.' At the same. time a certain amount` 'so that it ma oppositely disposedtangential roller, in .this case the roller A20', must be resiliently held I give waybefre the advancing roller, or there could not be any cross- `of pressure must be exerted against the workpiece or it will not be heldin grinding posi- 36 tion or rotated by the roller 20. To that end' the roller 20 is rotatably mounted on a shaft 50 that is held by avforked bracket 51, the latter being supported by an arm 52 that `is -pivotally mounted on the frame 17 at 53, counterclockwise movement of these parts being resisted by a spring 54. It will be observe from Fig.- 3 that the pivot stud 53 is locat d substantially below the shaft 50, and thus in the limited cross-feed movement of the workpiece a as given it by the mechanism already described, the resultant` movement of the roller 20'wil14 be almost, if not quite, in a horizontal., plane. In order to limit the movement of the v1'iollefrl'20 in a' clockwise direction when no vworkpiece 'a is in the' machine, a screw 55 screwed'into the arm 52 is provided, this screwY passing through a lug 56y provided on the rear of the frame-'portion 17,'a nut 57 also being pref;

erably provided to adjust the initial position of the lroller 20.

In order to rotate the workpiece, rotation is imparted to one or more of the three rollers 18, 19 and 20. In; this embodiment of the invention the roller 20 is the' driving roller, vand therefore it is provided' with an integrally formed pulley portion 20a, around which a drivingbelt, nt shown, passes. In order that each 'imn-kpiecev may be held 6ofromlongitudinal movement; the axisof r6- to the axis of workpiece rotation,during'the tation of the roller 20 is inclined with 4respect j grinding operation.f "1`hat is to say, assumingthe axis of rotationofthe workpiece lto be horizontah'theaxis of the shaft 50, and consequently also-.that of the roller 20, when vice provided to hold them successive said workpiece is being ground, is inclined to'thehorizontal. Assuming the roller to be: rotating inthe-direction of the small arrows, Figs. 2 and '3, which is the case, this inclinationV gives the workpieces an end thrust tothe right Figs. 1 and 2,-which causes them to be pressed against a positioning degrinding position.

This positioning device comprises a rotatvin able annular ring 58, which is mounted in ball bearings 59 provided by an annular stationary. member 60 that projects upwardly -fromthe/bridge 15. and which serves at once for the supportgof'said ring and its ball bearings and as a guard to prevent the o rator of the machine from being injuredyliy the grinding wheel. The rotatable rin 58 interferes in no wise with the passage o the 'grinding wheell therethrough to reach a workpiece, but serves t'o hold successive workpieces in accurate longitudinal position a ainst the combined force of the tractive e ect of the grinding, wheel when moving outwardly in its reciprocatory traverse, and

the thrust imparted by the inclination of the axis ofthe roller 20 to the axis of' rotation 'of the workpiece. The means just described forked member 51 isnot integrally attached- Ato the l arm 52,-. but is pivotally mounted thereon by means lof a' shaft 62 rojecting rearwardly-from said forked mem r. Said.

shaft -isthreaded for a nut asv shown, andv extends through a hub portion 63 formed on the arm 52. `The forked membercp'rovides a pair of depressions 64 and 65 on its at rear surface, and a projection 63a on the side of the hub 63contains a spring 66 which presses a .ball 67 forwardly to engage one of these 'depressions inthe forked member V'51. Thus said forked member is resiliently held with the axis of the roll 20 inclined to the axis of rotation of' a workpiece in either onef'of two ositions, which are illustrated respectively y Figs. 1, 2, and 3 on the one hand,v and Fig. 4 on the other hand, the former being Athe grinding position, and the 4latter awork ejecting position.

A'liandle 68 is provided by the forked member 51. When a given workpiece has been 'ground and the grinding wheel 4 has been withdrawn therefrom by movement of the table 1 to the right, Fig. 1, brought about,

by example, by depression of the treadle 12, the operator m'ay cause the finished workpiece to be ejected from the machine by depressing this handle. The relative compressive forces of the springs 54 and 66, as modified by the effective leverage and inclined is now to the left, and the workpiece will be ejected from the machine. being received by any suitable receptacle or chute, not shown.

The finished workpiecehaving been ejected, the operator should raise the handle 68 and return the parts to the position shown in Figs. 1 and 2. I-Ie may then place a new workpiece in grinding position by merely presenting it from above to the rollers 19 and 20. If it does not immediately snap into position, the operator may move the roller 20 bodily away from the roller 519 by depressing the arm 52, and this may be done without again disturbing the inclination of the axis of the roller 20 by pushing down on the hub 63. But if desired, the axis of the roller may be temporarily made horizontal, while loading, therer being under such condiions less tendency for the workpiece to tip over or twist out of position.

Although, as previously stated, the apparatus of the present invention can be readily applied to any of the several forms of automatic grinding machines now known toY the art, being particularly adapted for use in connection with that class of machine in which the control of the size of the workpieces is maintained by devices operated by the position of the cross-feeding mechanism,

a dressing device and compensating means being employed to insure uniform size, all as disclosed in my own'prior and copending application Serial No. 48,734, filed August 7, 1925, now Patent No. 1,682,672, granted August 28, 1928,y I have shown in the present drawings a stop to cause cessation of the cross-fed when the workpiece reaches desired size, leaving it to the operator to cause withdrawal of the wheel from the workpiece. As shown in Figs. 2, 3, and 5, the arm 23 provides a boss 69 which is internally threaded and which holds an adjustable screw 70 that can be locked in an means of a chuck nut 1. The left-hand end, Fig. 3, of the screw', when the grinding operation is completed as determined by the proper setting given to said screw 70, is adapted to engage a projecting portion 72 provided by the frame 17 and thus positively stop the feeding mechanism. Subsequent actuation bythe reciprocating table 1 of the cross-feed'pawl 41, with consequent turning of the ratchet wheel 25 will not turn-the screw desired position by therefor.

It should be noted that the loading and unloading of workpieces which has been described somewhat at length, can be manually performed in much less time than it takes to tell about it. In fact the operator may, after the grinding wheel 5 has been withdrawn from grinding position, grasp the lever 68 with one hand and a fresh workpiece with the other, depress the handle, thus ejecting Va workpiece, raise the handle 68, depress the arm 52 and place an unground workpiece in position, inl a very short space oftime. It will be noticed that the operator has complete freedom of access to the Workholding mechanism from the left hand side thereof, which is the side away from the grinding By this advantageous feature of construction, there is no danger to the operators hand from the rapidly rotating grinding wheel 5.

It is within the contemplation of my invention that automatic means may be provided to change the inclination of the axis ofthe roller 20, as set forth, and also to move it in relation to the rollers 18 and 19 as described. The several sets of movements being regular and occurring at predetermined times in relation to the position of the table 1 on the machine base, cam means may be provided by said table. to perform these functions, and then by the provision of a work holding magazine and escapement devices of any suitable type, of the general nature shown in the aforesaid copending application of Highberg, for example, the machine would be completely automatic so far as the work loading is concerned.

While it is not the intention to claim any instrumentalities not shown, in construing the claims hereto appended those elements of the machine which are now manually controlled and operated may be considered to be either such or automatically and mechanically operated. The above and like changes, falling within the spirit of the invention are to be construed as included in the claims.l

I claim,

1. In a machine of the class described, the combination with a plurality of work holding and work-rotating rolls, of a driving roll, a pivotal mounting for said driving roll whereby it may 'be caused to approach towards or recede from the other rolls for the insertion or discharge of a workpiece, and a further pivotal mounting for said roll whereby said driving roll may be inclined to the axis of rotation of a workpiece to produce an end thrust on the latter, or placed in parallelism therewith to facilitate loading of workpieces.

2. In a machine of the class described, the combination with a plurality of work holding and work-rotating rolls, of automatic feeding means.l associatedlwith one of said rolls to feed it and therefore the workpiece in cutting relation to a grinding wheel.

3. In a machine of the class described, the combination with a roll and means to feed it, of another roll and spring means to back the latter roll up, whereby the workpiece may be held in grinding position and'fed to produce a cutting advance between workpiece and grinding wheel without the use' of a chuck.

4. In a machine of the class described, the combination with a work positioning roll, means to feed it, and a grinding wheel, of a table or carriage by the reciprocatio'n of which a grinding traverse is produced, and means derived from motion of said carriage to actuate said feeding means.

5. In apparatus of the class described, a pivotally mounted arm, a roll constituting one of centerless work holding means on the end of' said arm, an internally threaded member connected by a swivel to said arm, a screw shaft passing through said member and automatic means to feed said screw shaft, whereby to feed said roll to produce the cutting advance of a workpiece.

6. In a grinding machine, the combination with a plurality of work holding and work rotating rollers, of a rotatable annular member, a driving roller that is normally skewed with respect to the axis of the other rollers, whereby to give the workpiece an end thrust to hold it against said annular member, and means for altering the inclination of the axis of said driving roller to eject a workpiece from the machine.

7. In an apparatus of theclass described, a frame for the holdin of a. plurality of rollers for the centerless grinding of workpieces, a bracket pivotally mounted on said frame, a forked member holding one of sa1d rollers pivotally connected to sald bracket, and means for holding said forked member in two end positions to give said roller an inclination to the axis of a workpiece to hold it in centerless grinding position or eject it therefrom.

8. In an apparatus of the class descrlbed, in combination, a roll, means to feed said roll to produce a relative cross feed between a workpiece and a grinding wheel, a spring pressed roll mounted opposite the first named roll, rotating means for one of said rolls, one of said rolls being inclined with respect to the workpiece, and a third supporting means for the workpiece.

9. In an apparatus of the class described, the combination with a roll, means to feed said roll to produce a relative cross feed between a workpiece and a grinding wheel, a

spring pressed roll mounted opposite the first named roll,prota ting means for one of said rolls, one 'of sind" rolls being inclined workpieces.

WALDO J. GUILD.

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