US2599698A - Grinding machine - Google Patents

Description

June 10, 1952 'A. H. DALL 2,599,698

GRINDING MACHINE Filed March a, 1950 s Sheets-Sheet 1 4 TTO/PNE VS June 10, 19 2 A. H. DALL 2,599,698

GRINDING MA Filed' March 3, 1950 8 Sheets-Sheet i6 INVENTOR.

flLEE/FT'H, BALL '1? Y FiQE. 5U

June 10, 1952 A. H DALL 2,599,698

GRINDING MACHINE Filed March 3, 1950 S-Sheets-Sheet 3 INVEN TOR.

flLBERT H, DflLL June 10, 1952 A. H. DALL GRINDING MACHINE Filed March 3, 1950 8 Sheets-Sheet 5 Fig-'7 l w 7* 45/ e4 1 we 88 E June 10, 1952 A. H. DALI. 2,599,698

GRINDING MACHINE Filed' March 5, 1950 8 Sheets-Sheet e INVENTOR.

' flLBE/FT H, DflLL BY June 10, 1952 A. H. DALL 2,599,698

GRINDING MACHINE Filed March 3, 1950 8 Sheets-Sheet 7 INVEN TOR. H0 flLBE/FT H, DflLL BY /jj 22 21% Hz June 10, 1952 A. H. DALL GRINDING MACHINE Filed March 3, 1950 8 Sheets-Sheet 8 i w mvz Patented June 10, 1952 UNITED: STATES PATENT @FFECE.

GRINDING MACHIN E Albert H: Dall, Cincinnat Cincinnati Milling M Ohio, aroma-ration of i, Ohio, assignor to'The achine- 00., Cincinnati, Ohio Application March 3, 1950, Serial No. 147,507

17 Claims;

ing machine disclosed in'application of-Dallet al., Serial No. 741,076, which issuedas Patent'No. 2,567,558 on May 16, 1950;

One of the objects of the. present inventionis the provision ofa grinding machine capable of;

utilization in the production of work;of1maxi+ mum precision due. to elimination of vibrations due to unbalance. in the grinding structure-and the provision of supplemental meansfor control. of relative movement. of parts'of the machine.

during final finish grinding operations.

A further object of the presentginventionis the provision of a grinding, machine constructed; to

avoid damage to the; work dueto springingof the;

parts of the machine duringa finishing operation andwhich will maintain asubstantially constant minimum pressure between grinding wheel and worl: during such finishing operation.

An additional object ofthe invention is-theprovision in a grinding machine of improved means;

for selectively controlling the nature; of the mounting orsupporting of thegrindingwh-eelj spindle during the performanceofdifferent-open ation-s by the machine.

The present invention furthercontemplatesthe provision of controlled *resili-entymeans for deter? mination of thenature and extent Of-gengagement of-the grinding wheel and worlrcluringa surfacing operation and'of novel structuraldetailsgfor accomplishment of this 4 and the above referred" to objects.

Other objects and advantages-of? the'present" invention should bereadi-ly apparentbyreference. to the following specification, considered 'irrconjunction with the accompanying drawings form? ing apart thereof; anditistobe understood-that any modifications may be made in the exactstructural details there shown and described;

within thescope of-the appended-claims,withoutdeparting fromor exceeding the spirit of *the'invention.

Figure -1 is-a sectional view of the spindle por tion and associate partsof a grinding machine;

embodying the present invention.

Figure 2 is a transverse'sectional viewon the line 2--2 of "Figure 1.

Figure 3 is a fragmentary sectional view of one form of' spindle clamping-- means taken on the line 3-3 of Figure 1.

Figure 4-is a vertical-section on theliIieM- -Q ofFigure 3. t

Figure 5 is a. fragmentary vertical sectional the gage mounting.

Figure '7 is a fragmentary front view of the controlvalve bracket as utilizedcin connection with the mechanism illustrated in Figure 1.

Figure 8 is a vertical section on the line 88 of Figure 7;

Figure 9 is a horizontal section on the line 9-9 of Figure 8.

Figures 10, 11, 12, and 13 are diagrammatic views-illustrating different conditionings of the hydraulic controlcircuits of the machine effectable by the valve and control mechanism. shown in Figures Ho 9.

Figure 141s a fragmentary vertical sectional view illustrating a manually operable clamping means for the grinding wheel spindle.

Figure 15. is a view in elevation of a modified form of hydraulic control valve assembly.

Figure 16 is a vertical sectional view as on the line |6-l 6. of Figure 15.

Figuresl'l to 19 are diagrammatic views of the controls selectively eflectable by the valving mechanism of'Figures and 16.

Figure 20 is a diagrammatic view of another modifiedform of the present invention.

In the drawings the reference character 29 designates the base or bed of a cylindrical grinding machine having the ways 2| and 22 mounting the movable wheel head 23 which supports the spindle for a grinding wheel 24. The detail mounting 'of-the spindle 24 is substantially that illustrated and claimed in pending application, Serial No. 741,076, which issued as Patent No. 2,507,558 on May 16, 1950. It includes the spindle housing 26 having mounted at one end the hearing structure 2'! supportingthe right handend of the spindle for rotary and slight axial. oscillatory or gyratory movement. At the left hand portion-of the" machine there is mounted inthe housing 26"a sleeve 28' locked in position as-by screws'29 and-having secured in position therein an orbital series of tubes 3|. The opposite endsofythese tubes and rods are held byresilientbushings of Neoprene? or similarmaterial 32 in bearing sleeve 33 whichcircurnscribes the left handportionof the spindle 24' and is supported for limitedmovementgwithinthe housing 262 It will be noted by;reference-to Figure lth'at the resilient rods and-tubes are mounted at a slight angle to-the horizontal axis of'the spindle, or

spring, rods v and, conduitv apertures formedin the.

alternatively, may be given a permanent flexure or set in an upward direction so that their resilient action normally will tend to urge the sleeve 33 upwardly or away from seating position as respects the housing 23. As a result of this construction, the wheel bearing end of the spindle is yieldable or resiliently supported by the tubes and rods with its outer bearing sleeve in clearance relation to the housing such that the spindle and its bearing unit may freely vibrate or oscillate about the bearing 2? as a center for the purpose of unit balancing or other operations as hereinafter described.

Contained within the bearing sleeve for effecting an automatic centering of the spindle with respect to the sleeve under varying load conditions are the conventional rocker shoe bearings 34 supported in position as by pivoted studs 35 and cage unit 39, suitable portings as at 31 being provided from the bores of the resilient tubular members 3| for supply of lubricating medium under pressure as through the piping 33.

Formed at the end of the spindle is a counterbore 39 receiving the balancing balls or weights 49 normally locked in position by the disc 4| urged into said locking position by spring 42. A piston plunger 43 slidable in cylinder 44 is actuable by pressure medium introduced through porting 45 from the tube 3| which may be utilized to move the piston 43 outward to effect temporary unclamping of the weights or balls 49 for effecting dynamic balancing of the parts.

In conditioning the machine for grinding operations, the spindle 24 is rotated by power applied to the multiple sheave 55, and the piston 43 is initially hydraulically outwardly urged to release the members 43 and permit them automatically to take up the necessary positions for effecting proper vibration eliminating dynamic balancing of the wheel and spindle structure. The hydraulic pressure is then released or reduced so that the member 4! will move to position to clamp the balancing devices in this automatically selected position.

For performance of normal grinding operations, truing of the grinding wheel and the like, it is desirable that the spindle be maintained in a fixed or non-shifting position with respect to the wheelhead. This may be accomplished automatically by utilization of a mechanism such as particularly illustrated in Figures 3 and 4, for example. As there shown, the sleeve 33 is provided with a hardened insert or anvil 41 engageable by the ball or other hardened tip 49 on the plunger or looking member 49. This plunger has a piston portion 59 slidably in the casing and outwardly urged by spring 52. Mounted in a slot of the piston portion is a wedge block or link 53 constituting a clamp actuator oscillatable about pin 54 on the interposed bearings 55, whereby provision is made for free adjusting movement of the link under pressure conditions.

The casing 5| is provided with a transverse bore providing opposed cylinders as at 53 and 51. Slidable in these cylinders are the flanged piston bushings 58 and 59 which, in turn, support for sliding movement the clamp piston 69 having the terminal cylindrical piston portions 3| and 62 and the intermediate slotted body portion providing the furcations 63 and 64, the clamp link or lever 53 fitting into the slot 65 between these furcations. The position of the link in the slot and its movement with the piston 69 on reciprocation thereof is controlled by the antifriction rollers 66 and 61 carried by the pivots 68 and 69 extending transversely of the slot and connecting the members 63 and 64, the members 66 and 51 being disposed in close interfitting but rolling engagement with the opposite sides of the member 53.

Extending transversely of the casing 5| and disposed above the transverse bore therein is an abutment stud comprising the co-axial portions 68 and 69 journaled in the casing 5| with an intermediate eccentrically disposed portion 10. The stud is provided with a head or nut-like member as at H to facilitate rotary adjustment and thus positioning of the eccentric i0 and can be locked in desired rotative adjusted position by screw 12. Mounted on the eccentric are the antifriction bearings 13 rotatably supporting an adjustable abutment in the form of a roller 14 in position to engage the upper arcuately formed cam or eccentric wedge terminal portion 15 of the clamp link or lever 53.

By reference to Figure 3, it will be noted that introduction of pressure into the cylinder or piston chamber 51, as through conduit 16, serves to force piston 62 and. piston bushing 59 to the left, roller 61 correspondingly moving link 53 which by reaction between roller 14 and surface 15 tightly forces the clamp plunger 49 downward against the bearing sleeve 33 to clamp the sleeve in position within the wheelhead housing so that the spindle is rigidly locked in place with respect to the housing as indicated in Figure 1.

At this time it will be noted that the shoulder 11 on the web or furcation B4 of the piston member has moved to the left a distance sufiicient to clear the end of the piston bushing 59. At this point the piston is in its extreme left hand position and the flange 18 on the piston bushing 58 has a clearance as respects the stop shoulder 19 of the member 5|.

In the event that it is desired to efiect a slight release of the clamping action while maintaining a controlled and predetermined steadying of the bearing sleeve 33, pressure may be introduced into the left hand end of the cylinder 53 by way of conduit 89 while pressure is still maintained in the conduit 16. This pressure will react on the piston bushing 58 moving the same to the right until the flange of the bushing is seated against the casing 5| while at the same time the shoulder 1'! of the piston member will be seated against the bushing 59. With the parts in this position the piston is, therefore, rigidly held against movement in either direction and the clamp link 53 and. plunger 49 correspondingly rigidly maintained in position to limit any upward or vertical movement effected by the reaction of the spring rods 30 and tubes 3| as respects the bearing sleeve 33. Dispositioning of the sleeve, however, permits of a limited back and forth oscillatory movement of the sleeve and thus of the grinding wheel spindle 24 and wheel 25 as guided by the inter-engagement of the tip 48 with anvil 41. The arrangement of the spring rods or supports for the sleeve is such that their automatic influence normally effects the upward releasing movement only. To create a controlled inward or forward yielding deflection reaction as respects the bearing, a spindle, tending to yieldingly maintain the wheel in engagement with the Work, use is made of the plunger 8| slidably mounted in the bushing 82 secured in the rear portion of the wheel head 23 and normally held in retracted position as indicated in Figure 5 by the spring 84. A compression spring 85 contained within sleeve 86 carried by the bushing 82 51 bears: atyone. endagainst. the member. 8 I and at; its 1 outer end; against: the hydraulically ac.- tuable piston- 81, actuating medium for.=.the. piston 81 being supplied through conduit 88 connectedtoqthe outer'end of sleeve'86.; Itwill be evident that movement toward the left of piston 81. will. tend to, compress spring-.85, overcoming. the.-force:of;spring, to. an extent dependent upon the, pressure, created. againstpressure 81 and.-.thus1;-shiftxmember; BI toward the left and into; engagement with the. bearing sleeve 33;

the.; s1eeve: 33 .to register the. extent ofits con-.

trolled; resilient movement; By observations of the extenttofthis; movement? suitable adjustmentsxmaybe-made of theactuating pressure in troduced through; the conduit 88. and thus the permissible-movement of. the resilient supported grinding wheel during. this finishing operation. Therstructure andgmanner of control .of the parts just-described, will be particularly apparentby.

reference to; Figures 7. to 13 inclusive. Mounted on'thezbase or bed 2010f the. machine: is a control bracket 92: having: a bore inv which is pressed bushingzi93 .:receiving the.;rotatable valve member.

94actuableoby handle 95. These parts are of conventional hydraulic valve design in which the bushing 93, is provided with a series of external circumferential groovesiorming in connection with;the bracket 92. aseries of axially spaced closed-passages, having inwardly extending portings asindicatedlin Figure-8 for cooperation with thegpvalvenmember 94-. This valve member is, in turn; provided with acentralbore, and interconnectedtamrular and axially extending grooves by which-varioushydraulic porting connections may begefiected as particularly illustrated in Figures 10i1to. 13.;inclusive.

Suitable, hydraulic pressure creating devices are;;employed, such as. the pump 96 having an intake. at .91extending into the tank or reservoir 98;;anda pressure conduit99, the amount of pressure being controlledas by relief valve. I00. A branchconduit IOI extending from the conduit 99 through pressureqreducing valve I02 supplies byawayof conduit I03wlowpressure hydraulic mediumi as for; power lubrication as distinguished from;actuation. purposes while a return conduit IMrprovides a reservoir; connection for exhaust of fluid: from the several potential actuating mechanisms; As shown inFigure 8,. this conduit llyiS COIltiDllOllSlYj coupled bya port I05 with thei roove I06 ofvalvestand thence to the surfacmgroove .I 01 in-said valve which extendsin an axial direction to the extent of grooves I08, I09 and IIIlofthe'. bushing 93. By selective rotary positionings of the valve, this groove may therefore be;alignedjwithjproper portings ofthe bushin such 1 as. .theporting III of groove IIO to couple :theseveral grooves to reservoir in one or morepositions.of;the:valve member. Thevalve is Provided.with..a.,second groove] I2 extendingccir- 6 cumferentiallyaof azmajorportionthereof isoithat conduit I .I 3; will be coupled with: reservoir during. most I of the positionings thereon.

The valve" body. 9411s provided; with: acpthird peripheral groove as at, I I4 in; constant, com-t munication: with the; 1 main 1 pressurerlconduit 99 by way ofjport H5; This groove communicates through the cross. drilling; or, passage I16 with theaxial pressure bore: II1 in-the valvetbody whichextends through most .of then-length of the valve body and is selectively; couplable: with: various .of the-control grooves; such asv I08, I09; and; I I ;0',by means of.:the..selected radial portings such as;v I .612 in the-valve body. 9.5..

The primary "connections for; varioustselected operations of the machine. have been; diagram.-. matically illustrated in Figures 10 to": l3..:inclue; S1Ve.

InFigure: 10, asinsEigure 7, thecontrolhandle 95 -for determination of the position of thezyalve, body 94: is indicated in its. extreme leftrrhand. or. counterclockwiserposition. In: this: position the low pressure conduit I03iistscoupled jby way ofbushing groove II8-, port-.IIQ; valve? groove I29; surface grove; I2I-, port. I60,groovem-Ifirlrto piping; 38:- extending to. the clamp .release-cylin-. der 44 and to: the bearingcylinder; 33 forluhrie cation at low pressure .of: the; bearing zslioesrflr- At ,the; same timethe: high pressure-conduit 99' igcoupled: by way: of; groove.::I I0. and-.l.conduit-.

15*, to I the; right hand piston chamber: 5:'I:.for: clamping. the parts. in the position.indicatediin Figure-13; In this position the left .h-andpiston: chambere andiconduit 88' to the .resilientspindle.

backing up structure particularly illustratedtin Figure 51 are connected to FIQSBIVOH.

The mainqspindle. by-virtue of the: secure. clampingofiits bearing sleeve 33;is .thus.l rigidly.

held-in position-within the wheelheadandrthe machine continued for what is; known as roughgrinding or.- apprecia-ble stock. removal 1 from a work piece for truing or; other standardaoperations. Inthis mannerthe essentialstock removal andproper generation of the desired cyl-indri-.-. caljor-like surface ofirevolution on a worlcpiece may. be rapidly and satisfactorily effected;

However, whenitisdesiredto produce an 18X: tremely accurate surface or. surfaces. of high finish, as.v for exampleuini the, grinding. ofyrollsfor. use in productionof: metal foil or thelike ithas been found thateven with most. accurate setting of the partscapable with ordinary grinds ing machine constructions, during theifinal finish grinding operationthere is a certain tension;re-

, lease in thepartsof the grinding machine.

may cause. a, grinding wheel to slightly. diginto: or mars the, highly. polished surface. which it is desired to produce within an, accuracy of tenthsof thousandths. ofan inch. Likewise even. the slightest-.run-out; of the wheel. spindle :or surface of the wheel:duringsuchfinishing op-. eration may produce like deleterious results,

These are, eliminated or.-minimized to a.maximum extent by utilization ofthe parts-hereinabovedescribed in the-manner indicatedrin connection with the diagrammatic view; Figure 11; Here the control handle 95 has been shifted in a clockwisezdirectionto the position indicated" in the dotted lines in Figures '7 and 11 As there indicated, the low pressure lubrication conduit I03Lis still coupled with the spindle bearing and clamp 1 structures, maintaining a low pressure but of 'insufficient amount to causeanyloosening of the balance mechanism clamping device.- The high pressure. throughconduit: 99," however, is

coupled by way of the central bore III of the valve body to groove III) and conduit 16 as before, but additionally to groove I09 and thence to conduit 80, causing balancing pressures against the piston bushings 58 and 59 so that the clamp 49 is slightly released, freeing the bearing sleeve 33 for slight resilient movement of the spindle 24 as previously described. At the same time the pressure bore I II is coupled by way of groove I08 to conduit II3, discharging into chamber I2I whence it passes by way of the spiral resistance groove I22 to permanent reservoir connection I23. This resistance is variably adjustable with respect to the intermediate pressure conduit 88 by means of the adjusting screw I24 so that the value of pressure in conduit 88 reacting against piston 81 can be delicately adjusted and controlled.

It will be evident that in this particular relationship of the parts the clamp 49 is sufficient- 1y released so that the member 3 and spindle are slightly upwardly deflected to an extent limited by the locked position of the members 53-49 and at the same time any pressure between the grinding wheel and work will tend to exert a yielding rearwardly of the grinding wheel by fiexure of the rods and tubes 30 and 3I which normally hold the spindle axis in a fixed vertical plane. The amount of resistance to such pressure effected fiexure of these resilient supporting members or the maintenance of the various parts under a predetermined light pressure against appreciable fiexure or displacement is determined by the setting of the variable resistance I22 determining the reaction of the spring 85 against the plunger. In this manner the grinding wheel is maintained against the work with a very light pressure but in a manner entirely independent within the fine limits under consideration of any possible slight relative springing action of the work support and grinding wheel support and the wheel itself through the flexible mounting of its spindle being permitted automatically to adjust or compensate for any slight outof-round or other irregularities of either the wheel surface or work surface, permitting production of an extremely accurate surface of high finish and preventing damage to work surface during this final finishing operation. It will be appreciated that this resilient action may involve a very slight substantially constant horizontal angular displacement of the grinding wheel spindle, slightly varying the previous parallelism existing. between the wheel surface and .work surface or alternatively that if the wheel has been worn slightly from a true cylinder during previous grinding operations, such tilting may restore the parallelism. In the event that these improvements are applied to a standard universal grinding machine or grinding machine in which the work support or table has a vertical pivotal mounting or swivel adjustment, the angle of relative traverse of the work and grinding wheel surface may be set exactly parallel to avoid any feed line or other deleterious markings on the work'surface, thus attaining utmost satisfactory action in connection with the final resilient or yielding engagement finishing operation.

When the control handle 95 is shifted to the second dotted line position as shown in Figure '7, or the position-indicated in Figure 12, it will be noted that pressure is coupled .to the conduit 80, completely releasing the clamped mechanism while the conduits I5 and H3 are coupled to reservoir. In this condition, the spindle bearing unit 33 is completely released for checking up as to the balanced condition of the spindle and grinding wheel.

Further movement in a clockwise directionto the third dotted line position in Figure 7 or the Figure 13 position maintains this released or unlocked condition of the spindle but at the same time couples the high pressure conduit 99 with the piping 38, building up the general pressure in the bearings and at the same time a suflicient pressure in the chamber or cylinder 44 to release the balancing member clamp 4I so that the balancing elements 48 may be moved automatically by vibratory centrifugal force resultant fromany out of balance condition to take up the necessary position to counteract and compensate for said out of balance condition in the spindle and-as The spindle having been persociated parts. mitted to run in this condition sufficient time for the weights properly to establish their position and dynamically balance the structure, the handle is shifted back to the Figure 12 position for tryout as to correctness of the automatic balancing and then moved into either the Figure 11 or Figure 10 position, depending on whether a stock removal type grinding or a strictly finishing type grinding operation is to be performed.

In this connection, attention is invited to the fact that by the employment of the yielding bushing mountings 32 for the members 38 and 3I, while the parts are firmly and securely anchored in position, a slight relative angling movement is permitted, eliminating the possibility of any canting or tendency to misalignment of the bearing unit 33 and contained parts when moving from clamped to unclamped position or when freed for spring pressure grinding operations.

In Figures 14 to 19 there has been illustrated a slightly modified form of control mechanism in which the control of clamping of the floating bearing sleeve 33 is manual in place of hydraulic. In this instance the housing 26 supports the sleeve nut I24 receiving the clamp screw I25 having at its upper end the operating or pilot wheel I25, and at its lower end the stud position I2! is movable into clamping engagement with the hardened insert I28. It can be understood that as in the hydraulically controlled form the downward movement of the stud I21 may securely lock the spindle in position within the housing. Alternatively, a slight loosening will allow of the necessary free floating for the final grindin operation. To facilitate determination of the exact backing off from clamping position, the sleeve I24 is preferably provided with suitable graduations at I29 for cooperation with the pointer I30 on pilot wheel I26.

The functions of release of the balancing members and of control of the spring backing up pressure for the spindle movement during finish grinding are determined as before by suitable couplings of hydraulic pressure which is elfectable through the positionings of valve I 3I rotatable by handle I32. This valve is mounted within the casing I33 which corresponds in substance to the valve block or casing 93 and contains a hydraulic resistance varying element I34 corresponding in all respects to the member I24 of Figure 9.

As particularly illustrated in Figure 16, the pressure conduit 99 'of the hydraulic system is coupled to the outer groove I35 of the valve bushing I36 and thence by way of porting I31 to the valve groove I38 and through port I39 to the -central pressure chamber or bore I40 axially dis-' posed within the valve. Likewise, the exhaust or return conduit I 04 is connected to'thepassage I 4| in the valve block I 33 1 and by way of porting I142 to the outer groove of the bushing and thence through porting 143 to the distributor groove I44 circumscribin the valve body I3I. An additional porting I45 connects by way of groove I46, porting I41 with the drain groove I48, in turn'coupled 'bypassage I49 to the space I50 back of thepistonportion II of the variable resistance control valve I34 to take care of any leakage into thisspaceand prevent building up of back pressure condition.

"The peripheral "groove I44 communicates with a groove or passage I52 preferably extending'in an axial direction on the surface of "the valve I3I and selectively couplableas bythe portings I53 and I54 with the grooves I55 and I55 of the bushing. Groove I55 of the bushing is coupled by way of conduit l59 with "the piston chamber 44 for effecting release of the balancing ball clamp head I4I while groove I56 is correspondingly coupled with the passage or conduit I51 extending to the variable resistance control groove I22a.

The several hydraulic couplings efiectable by movement of handle I32 and thus of valve I3I to its different positions, as illustrated in'Figure 15, will be best understood by reference to the diagrammatic views, Figures 17, 18, and 19. InFigure 17, thehandle has been indicated in its-left'hand position'sothat the parts are conditioned for a finish grinding operation. In this instance, the conduit I59 is connected by way of the peripheral groovings of the valve to the exhaust conduit I04 while .the pressure conduit 99 is connected through the central bore or passage I40 and the porting topassage I51 leading to the resistance determinator I22a introducing the .selected pressure through the intermediate take-off conduit 88 to react on the piston 81 and thus determine the force exerted by spring 85 by way of member. 8| against the sleeve 3, limiting its rearward movement under the effect of grinding pressure.

This operation and the structural parts are the same as those previously described in detail in connection with Figure 5 of the drawings.

When thehandle I32 is moved to its central position, as shown in the full lines in Figure 15, the circuit is conditioned as indicated in Figure 18. In this form the conduits I59 and I57 are both coupled to the return' or low pressure conduit'I'Il I while the pressure conduit 99 is blanked off as respects reaction on any of the pressure shiftable. elements. Inthis position, ifthe screw 125 is in its lowered or clamping position the machine isjconditione'd for regular grinding or truing operations Whileif it is released, the balanced condition of the machine may be determined.

When in this released position, if it is desired to effect automatic readjustment of the balancing mechanism the handle is thenmoved .in a clockwise'direction to a third position indicated in "the dotted lines in Figure and diagrammatically in Figure 19. In this position it will be noted thatthe pressure conduit 99 is coupled by way of I40 to the balancing ball release conduit I59 while the conduit I51, as well as conduit I'2 3,'are connected to reservoir sothat'there is noreactionon thepiston 81.

From the foregoing it will be evident that in connection with a releasableor potential resilient or free mounting of the grinding wheel spindle, permitting of a limited back and forth play'of the same so that the amount of resistance to horizontal movement may be controlledto effect a very light resilient pressure of the wheel and spindle as an entirety toward the-work, which movement, being relative to the wheelhead, will be independent of release of any slight mechanical stress existing between the supporting bed or base and the wheelhead which might otherwise interfere with the accuracy of finish oflthe work piece. It will be further noted that for utmost efficiency the amount of this spring action may be controlled by avariable hydraulic pressure, reacting against the grinding wheel spindle in a direction toward the work, the strength and compressibility of-the intervening spring 85 shown determining whether the'reaction of the hydraulic pressure on;piston 81 effects a direct or resiliently dampened action as respects the pressure .or potential fluctuation of this spindle. It will also .be.noted that in both of the .forms shown operation of a single'lever determines the conditioning of the machine for balancing, grinding, and ,finish grinding operations, although the actual lockingo'f'the spindle against vibratory oroscillatory movements .may be effected either directly manually or indirectly through hydraulic .mechanism also under the control of said lever and valving.

It will be understood that "the present invention may be employed with various forms, of-conventional grinding machines, as for, example, the machine shown injPatent "2,101,644. As .diagrammatically illustrated in connection with Figure ,10, the machine includes Ways 161,, [68 formed on the bed 20 which SHPPOitjthereQiprocating carriage I59. Swiveled on thiscarriage as at 163 is the table I64 provided with work supporting means I65 for maintainingthe ,work piece I66 in proper opposing relation to "the grinding wheel 25. In thisform-of machine, the in and out or feeding movement is appliedto the grinding wheel while the relative translatory movement is. effected by axial shifting 'of .the work piece and its supportingtable-and carriage along the .bed120. Due to the pivotal connection between the carriage and work table it isipossible, if desired, during thefinishing operation ;to effect a slight angular positioning of the axis and thus the surfaceof the work with respect to the axis of the spindle housing 26. This adjustment may also be effected by slight angling of the'wheel spindle support as provided in various commercial grinding machines. This permits ofjoompensation for any minute angular displacement of the surface of the wheel 25 due to the potentially.free horizontal movement of its Spindle during the finishing operation so that the surfaces of the wheel and work maybe maintained .egwexactly parallel, thus reducing the possibilityof formation of feed lines on the work due to greater pressure of one edge or the other of the wheel against the work.

Figure 20 illustrates diagrammatically anadditive feature of the invention capable of utilization with the forms previously described and particularly adapted for employment when 'extremely light finishing cuts are being taken or in instances where the relationship of work and grinding member may be such as to tend to cause slight undesirable vibratory movement of the grinding wheel'spindle. This form is-most a'dvantageously utilizable, for example, inthe'final finishingof large rolls which frequently are-several feet in diameter by ten feet or more in length. Such rolls are used for production of metal foil or the like and must be of extreme accuracy and unblemished surface throughout.

As has been previously pointed out, the mounting of the grinding wheel spindle 24 and its releasable journal or hearing sleeve 33 are such, that as an entirety they may pivot about the bearing 21 when the clamping element 48 is released. In Figure there has been illustrated in detail the yielding pressure member BI and associate elements for reaction on the member 33 to effect an urge of the spindle 24 in a direction to effect engagement of its supported grinding wheel 25 with the work piece I66.

It will be understood that this is entirely sufficient and effective for many grinding operations. On the other hand, there may arise conditions in which an irregularity in form or mounting of the work piece or other grinding conditions may tend to create a variance in position of the grinding wheel during traversing which might set up a vibratory reaction in the spindle 24, or in which it is desired that a greater potential backing up pressure be given to the spindle to resist rearward deflection by work engagement, which pressure will be of a nature to more than overcome the force of the resilient axial centralizing members such as 3I.

For greatest operating efiiciency under these varying conditions, there may be provided at a suitable point on the housing or support 23 a supplemental housing I providing a cylinder I1I to receive a pusher piston I12 as has been indicated in Figure 20. By reference to this figure, it will be noted that the diameter of the cylinder and chamber is preferably less than the diameter of the cylinder for the piston. 81 with the result that if equal pressures be introduced into the respective chambers for reaction on these pistons a. greater force will be exerted by the piston 81 than by the piston I12, creating a predominating urge of the spindle and its supported grinding wheel in the direction of the work to counteract the reaction force between work and grinding wheel during the grinding operation. In Figure 20 there has been indicated, as in preceding views, the conventional pressure source 96 which may be coupled by valving mechanism as heretofore described to the conduit II3 extending to the variable resistance groove I22 so that the pressure reaction may be varied as respects the conduit 88. Branching from conduit 88 is the auxiliary pressure conduit I13 coupled with chamber I1I for actuation of thepiston I12; varying the effective pressure in conduit 88 will proportionately vary the pressure reactions against the respective pistons. The conduit I13 has been shown as including a resistance or choke coil I14 to retard or damp out the flow reactions between the cylinders for pistons 81 and I12. pressure is built up in conduit 88, since there is no separate drain or outlet for the chamber I1I, equal unit pressures will be created as respects the respective pistons although a different actual force will be exerted therein due to the differential between the piston area on which said unit pressure reacts. The choke I14, however, will damp out instantaneous pressure reactions between the cylinders produced by pressure variants on the wheel 25 or otherwise, thus steadying and stabilizing the pivotal or floating action of the spindle 24. The piston I1I thus acts as an opposed yielding resistor which reacts on the It will be understood that as 12 spindle in opposition to the pressure members The viscous damping coil I14 serves to damp out anyhigh frequency motions due to close pitched undulations in the work piece caused by prior grinding operations. On the other hand, the coil will not damp out motions caused by runout of the work piece which have relatively low frequency motion. Nor will it damp out motions caused by slight changes of parallelism of the work periphery and its direction of motion.

These changes in work run-out and parallelism are the result of thermal changes in the work piece or machine during long finishing operations on such things as large rolls for rolling mills.

On finishing operations on rolls, the condition of the face of the grinding wheel is very critical. Constant pressure between this face and work is highly desirable over long periods. Changes in work dimension due to temperature will create large variations in pressures between wheel and work where the wheel is held very rigidly. Thus, it is desirable to have in a machine the possibility of holding the wheel rigidly for rough grinding and elastically for finish grinding, such as is attained by the hereinabove described structures.

What is claimed is:

1. A grinding machine including a bed, a work support and a wheel support mounted on the bed for relative reciprocating and feeding movements, said wheel support including a housing member, a wheel spindle supported within the housing member for yielding movement relative thereto, said spindle having a wheel supporting portion, means for yieldingly urging the wheel supporting portion in a direction toward the work support, said means for yieldingly supporting the spindle including deflectable resilient members having a portion fixed with respect to the housing and a second portion fixed with respect to the wheel supporting portion of the spindle, said means for yieldingly urging the wheel supporting portion of the spindle in the direction of the work support including a pressure actuable piston, a source of pressure medium for supplying pressure to the piston, and a pressure regulator for determining the reaction force exerted by said means on the piston.

2. A grinding machine including a bed, a work support and a wheel support mounted on the bed for relative reciprocating and feeding movements, said wheel support including a housing member, a wheel spindle supported within the housing member for yielding movement relative thereto, said spindle having a wheel supporting portion, means for yieldingly urging the wheel supporting portion in a direction toward the work support, said means for yieldingly supporting the spindle including deflectable resilient members having a portion fixed with respect to the housing and a second portion fixed with respect to the wheel supporting portion of the spindle, said yielding means for urging the wheel supporting portion of the spindle in the direction of the work support including a separate expansion spring element, a piston backing member for said spring element, and a source of pressure medium for supplying pressure to urge the piston against the element.

3. A grinding machine including a bed, a work said wheel support including a housing member,

a-Wheelyspindle.supported within the housing :member foryielding movement relative thereto,

:said spindle having a wheel supporting portion, meanscfor yieldingly urging the wheel supporting portion in a direction toward the work support, saidmeans for'yieldingly supporting the spindle including deflectable resilient members having a vportionfixed with respect to the housing and a second portion fixed with respect to the wheel supporting portion of thespindle, said yielding 1 means for urging the wheel supporting portion of the spindle in the direction of the Work support including a separate expansion spring element, a piston backing member for said spring element, asource of pressure medium for supplying pressure to urge the piston against the element, and a pressureregulator to adjust the pressure reacting on said piston.

4. A grinding machine including a bed, a work support and a wheel support mounted onthe bed for relative reciprocating and feeding movements,

said wheel support including a housing member, a wheel.spindlesupported --within the housing member for yielding movement relative thereto,

said spindle having a wheel supporting portion,

member, a wheel spindle supported within the housing member for yielding movement relative theretmsaidspindle having a wheel supporting portion,.means for yieldingly urging the Wheel supporting portion in a direction toward the Work support, and a locking device carried by .the housing and reacting on the spindle rigidly to secure the spindle in position withrespect to the housing, said lockingdevice havng afirst hydraulically determinable position for rigidly securing the spindle and asecond hydraulically determinable position for effecting a limited release-of the locking device with respect to the spindle, a source of hydraulic actuating. medium and a two-position valve intervening the source and the locking device and selectively positionable todetermine thepositions of thelocking device effectable by said hydraulic medium.

6. A grinding machine including a bed, a work support and awheel support mounted on the bed for relative reciprocating. and feeding movements, said wheel support including a housing member, a wheel spindle supported within the housing member for yielding movement relative thereto, said spindle having a wheel supporting .portion, means for yieldingly urging the wheel supporting portionin a direction toward the work.support, andalocking device carried bythehousingand reacting on .thespindle rigidly to secure .the spindleiin position'with respectto the housing, said locking device having a .first hydraulically determinable positionfor rigidly securing the spindle and a secondhydraulically determinable position for .eifecting ,a limited release of the .lockingdevice with. respect to. the spindle, a source dtlhydraulic actuating medium and a twopusher member in the position valve intervening; the source :and :the locking device and .selectively ipositionablegto determine the positions-of the locking device effectable by said hydralic medium, "a pressure device engageable with the spindleto effect a directional urge against the spindle, said pres sure device including a hydraulically shiftable piston, the .valve having conduit portions for determining the eifective coupling of'the source ofxpressure medium with said, piston to eiTect said directional urge.

7. A grinding machine including a bed,.a work support and a wheel support mounted on the .bed for relative reciprocating and feeding movements, said wheel support including a housing member, a wheel spindle supported-within the housing member for yielding movement relative thereto, said spindle having a wheel supporting portion, means for yieldinglyurging thewheel supporting portion ina direction toward the work support, and a locking device carried by the-housing andreacting on the spindle rigidly to secure the .spindle in position with respect to t-he.housing, said locking device having a first hydraulically determinable position for rigidly securing the spindle and a second hydraulically determinable position for effecting a limited release *ofthe locking device with respect to the spindle, a source of hydraulic actuating medium and-atwoposition valve intervening the source and the locking device and selectively positionable to determine the positions of the locking device eifectable by said hydraulic medium, a pressure device engageable with the spindle toeffect a directional urge against the spindle, said pressure device including a hydraulically shiftable piston, the valve having conduit portions for determining the effective coupling of the source of pressure medium with said piston to eifect said directional urge,'and a pressure variator'for. determiningthe force hydraulically exerted against said piston.

'8. A grinding machine spindle structure including, ahousing or support, a first spindle bearing mounted on the support for oscillation relative thereto, a second spindle bearing, means resiliently supporting the second spindle bearing for bodily movement relative to the support, a grinding wheel spindle journaled in said bearings, releasable clamp means for rigidly securing the. resiliently supported bearing in position on the support, a pusher member carried by the, housing in position to engage and effect a unidirectionalurge against the resiliently supported bearing, and means for actuating the pusher member in thedirection of the bearing, whereby on release ofthe clamping means said pusher member will be effective for oscillating the spindle and said-first bearing for determining the position of the resiliently mounted bearing and the spindlesupported therein with respect-to the support.

'9. A grinding machine spindle structure including a housing or support, a first. spindle bearing mounted on the support for oscillation relative thereto, a second spindle bearing, means resiliently supporting the second spindlebearing on the support. a grinding wheel spindle journaled in said bearings, releasable clamp means for rigidly securing the resiliently mountedbearing in position on the support, a pusher member :carried by the housing in position toengage andveffeet a unidirecticnalurge against the resiliently supported bearing, means .for actuating the direction of the bearing, whereby on release of the clamping means said pushermember will" be efiective-Lfor determining the position of the resiliently mounted bearing and the spindle supported therein, and means for varying the force exerted by the actuating means against the pusher member.

10.'A grinding machine spindle structure including a housing or support, a first spindle bearing mounted on the support for oscillation rela-- tive thereto, a second spindle bearing, means resiliently supporting the second spindle bearing on the support, a grinding wheel spindle journaled in said bearings, releasable clamp means for rigidly securing the resiliently mounted bearing in position on the support, a pusher member carried by the housing in position to engage and effect a unidirectional urge against the resiliently supported bearing, means for actuating the pusher member in the direction of the bearing, whereby on release of the clamping means said pusher member will be effective for determining the position of the resiliently mounted bearing and the spindle supported therein, and means for establishing a substantially constant force reaction of the pusher member against the resiliently mounted bearing.

11. A grinding machine spindle structure including a housing or support, a first spindle bearing mounted on the support for oscillation relative thereto, a second spindle bearing, means resiliently supportin the second spindle bearing on the support, a grinding wheel spindle journaled in said bearings, releasable clamp means for rigidly securing the resiliently mounted bearing in position on the support, a pusher member carried by the housing in position to engage and effect a unidirectional urge against the resiliently supported bearing, means for actuating the pusher member in the direction of the bearing, whereby on release of the clamping means said pusher member will be efiective for determining the position of the resiliently mounted bearing and the spindle supported therein, and means for establishing a substantially constant force reaction of the pusher member against the resiliently mounted bearing, said means including a hydraulically actuable piston element, a source of actuating medium reactable on the piston for urging the same in the direction of the pusher member, means for controlling the coupling of the source with said piston element, and means for varying the pressure exerted by the hydraulic medium against the piston.

12. A grinding machine spindle structure including a housing or support, a first spindle bearing mounted on the support for oscillation relative thereto, a second spindle bearing, means resiliently supporting the second spindle bearing on the support, a grinding wheel spindle journaled in said bearings, releasable clamp means for rigidly securing the resiliently mounted bearing in position on the support, a pusher member carried by the housing in position to engage and effeet a unidirectional urge against the resiliently supported bearing, means for actuating the pusher member in the direction of the bearing, whereby on release of the clamping means said pusher member will be effective for determining the position of the resiliently mounted bearing and the spindle supported therein, means for establishing a substantially constant force reaction of the pusher member against the resiliently mounted bearing, said means including a hydraulically actuable piston element, a source of actuating medium reactable on the piston for urging the same in the direction of the pusher member, means for controlling the coupling of the source with said piston element, means for varying the pressure exerted by the hydraulic medium against the piston, and a compression spring member intervening the pusher element and the piston for resiliently transmitting the forces exerted by the piston to the pusher member.

13. In a grinding machine, the combination with a housing, of a spindle mounted therein for movement relative thereto, and means for controlling the movement of the spindle with respect to the housing including a locking member for said spindle, an abutment for cooperation with said locking member, a wedge block intervening the locking member and said abutment, a hydraulically actuable piston for shifting said wedge block as respects the abutment and locking memher to tighten or release the engagement of the locking member with respect to said spindle, a source of hydraulic actuating medium and a valve intervening said source and the piston to determine the reaction of the pressure medium on the piston, independent hydraulically actuable piston means to effect a limited releasing movement of the wedge block, a source of hydraulic actuating pressure for said piston and said piston means, and means for determining the reaction of the pressure medium as respects the piston and the piston means, said means including a valve having a first series of portings to determine the coupling of the pressure medium to the piston, and additional portings to determine the coupling of the pressure medium to said piston means.

14. In a grinding machine, the combination with a housing, of a spindle mounted therein for movement relative thereto, and means for controlling the movement of the spindle with respect to the housing including a locking member for said spindle, an abutment for cooperation with said locking member, a Wedge block intervening the locking member and said abutment, a hydraulically actuable piston for shifting said wedge block as respects the abutment and looking member to tighten or release the engagement of the locking member with respect to said spindle, a source of hydraulic actuating medium and a valve intervening said source and the piston to determine the reaction of the pressure medium on the piston, independent hydraulically actuable piston means to effect a limited releasing movement of the wedge block, a source of hydraulic actuating pressure for said piston and said piston means, and means for determing the rection of the pressure medium as respects the piston and the piston means, additional hydraulically actuable means to exert a radial urge against the spindle to resist work displacement thereof, and a control valve intervening the several hydraulically actuable means and the source of hydraulic pressure, said valve having a first set of portings for coupling the pressure medium to the wedge block piston and a second series of portings positionable simultaneously to couple the actuating pressure to the piston means and the hydraulically actuable means.

15. In a grinding machine having a work piece support and a resiliently supported grinding wheel spindle, a yielding pressure member reacting on the spindle to urge same in a direction to effect engagement of its supported grinding wheel with a work piece held by the work piece support, and an opposed yielding resistor reacting on the spindle in opposition to said pressure member variably to resist movement of the spin-- dle toward the work piece support, a source of hydraulic pressure and conduit means coupling said source'with the pressure member and with the resistor to determine their respective reactions on the spindle.

6. The combination with a precision grinding machine including a support and a grinding wheel spindle mounted thereon for limited oscillatory movement with respect to the support, of means reactable on the spindle for controlling its oscillatory movement with respect to the support, said means including a first hydraulic cylinder, a piston movable therein and hydraulical- 1y actuable in a direction toward the spindle for effecting movement of the spindle in one direction, a second hydraulic cylinder carried by the spindle support and of less diameter than the first cylinder, said cylinder being disposed in opposed relation to the first cylinder, a resistor piston carried by said second cylinder having a less efiective area than the effective area of the first piston, a source of hydraulic pressure medium, means to connect said source to the first cylinder for actuation of the piston carried thereby, conduit means interconnecting the cylinders, and a resistance element in said interconnecting conduit means for damping the reaction effects of the pressure conditions in the respective coupled cylinders.

17. A grinder structure of the character described including an oscillatable grinding wheel spindle, a first yielding means for supporting the spindle in a centralized position, a pressure actuable member for efiecting an oscillation of the spindle in one direction, a resistor reacting on the spindle in opposition to said pressure member, means providing a hydraulic circuit for supplying actuating pressure to said member and to said resistor, and means for proportionately varying the pressure reactions on the pressure member and the resistor.

ALBERT H. DALL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,897,049 Hawes Feb. 14, 1933 1,967,163 Thearle July 17, 1934 2,142,021 Ernst et al. Dec. 2'7, 1938 2,308,843 Wilson Jan. 19, 1943 2,336,202 Walker Dec. 7, 1943

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