US2659358A - Grinding wheel truing apparatus - Google Patents

Description

Nov. 17, 1953 o. E. HILL GRINDING WHEEL TRUING APPARATUS 4 Sheets-Sheet 1 Filed May 8, 1951 OIVA E. H/LL qq F78 Ill/eater fiacork' y Nov. 17, 1953 O. E. HILL GRINDING WHEEL TRUING APPARATUS Filed May 8 1951 4 Sheets-Sheet 2 O/vA E. HILL Nov. 17, 1953 O, E, H 2,659,358

GRINDING WHEEL TRUING APPARATUS Filed May 8, 1951 4 SheetsSheet 5 22 as H IZG , hill/altar IE7 OIVA E. HILL I53 I32 57% L -ELLM Nov. 17, 1953 o. E. HILL 2,659,358

GRINDING WHEEL TRUING APPARATUS Filed May 8, 1951 4 Sheets-Sheet 4 Patented Nov. 17, 1953 GRINDING WHEEL TRUING APPARATUS Oiva E. Hill, West Boylston, Mass, assignor to Norton Company, Worcester, Mass, at corporation of Massachusetts Application May 8, 1951, Serial No. 225,199

5 Claims.

The invention relatesto a grinding-wheel trulug-apparatus, and more particularly to a truing apparatus for truing a. formed face on the periphery of a grinding-wheel. The present invention relates toa modifiedform of the truin apparatus disclosed-in my copending application, Serial sNo." 183,775, J filed September 8, 1950.

One :object of ---the invention is to provide a simple-and thoroughly. practical truing apparatus for:truin mnrirregular shape. on the periphery of the grindingwheelhaving for example spaced portions .of; difierent .-diametersand an irregular surface therebetween: Another object is to provide anphydraulically-actuatedelectrically-controlled:=truinglapparatus successively to true the periphery-of a" grindingrwheel having spaced portions, of ;difierent diameters; andan-irregular surface therebetween.:, Another object ofthe inventiorris- ;.to provide-a truing apparatus .with an hydraulically-actuated .cam, {mechanism automatically tog position: the; truing; tool 1successivelyv to true. multiple diameters on ;a single grinding wheel-anda formed facetherebetween. Another object is 1; to provide. an hydraulically operated traverse mechanismior atruing tool and an hydraulically operatedcam mechanism actuated in timedrelation therewith successively to position the truing tool for truing portions of the periphery of the wheel to betrued. Another object is to provide an hydraulically operated cam control mechanism in; timed relation with; the traversing movement ofthe truingtool; to position the truing tool to true spaced-portions oi varying diameters combined with a master camanda follower for generating an irregular; formed face therebetween. Other objects will beinpa-rt obvious or in part pointed out hereinafter.

The invention accordinglyrconsists in the features of construction, combinations of elements, and arrangementsyof parts as willbe exemplified in the structure to be hereinafter described, and thescope of the application of-whiqh .Will be indicated in the following claims.

In the accompanying drawings, -in which is shown one of various possible embodiments of the mechanical'features of this invention,

Fig. 1 ,is, a front elevation of Y the improved formed .wheel truing apparatus;

Fig. 2 is'aplanzview'of the truing; apparatus;

Fig. 3 is, a verticalsectional view,-;tak en approximately. on, the, line i 3, 3 of, Fig. 1, through the truing. apparatus;

4 is .a horizontal sectional-view, taken approximately on the line 4--4 oflFig, 1;

-1 i aecombined draulic and electrical diagram of the control andactuating mechanism for the truing apparatus;

Fig. 6 is a fragmentary diagrammatic view showing the positions of the parts as the truing too traverses toward the right; and

Fig. '7 is a, similar fragmentary diagrammatic view showing the positions of the parts as a iurther traversing movement of the truing tool toward the right. The truing apparatus has been illustrated-in the drawings as applied to a grinding machinehaving a rotatable grinding wheel H! which is partially surrounded by a wheel guard H. The grinding wheel I!) may be a single grinding wheel as shown in Fig.- 1, or if desired may be a plurality of adjacent grinding wheels having a peripheral formed face thereonto be trued.; The wheel guard H serves-as a support for an up wardly extending bracket [2. The bracket 12 supports a slide base l3 which is fixedly mounted thereon by-a plurality of screws |4.- Theslide base l3 isprovided with a dovetailed slideway 15 j which mates with a correspondingly V shaped dovetailed slideway on a longitudinally movable slide IS. The slide IBis arranged to traverse longitudinally in a direction parallel to the axis of rotation of the grinding wheel II]. An hydraulically operated mechanism is provided for traversing the slide [6 longitudinally comprising an hydraulic cylinder I l which is formed integral with the slide base l3. The cylinder [1 contains a slidably mounted piston 18 mounted on one end of a piston rod I9. the piston rod I 9 is fastened to a bracket 20 formed integral with the longitudinally movable" slide it. When fluid under pressure is passed through a pipe 2| into a cylinder chamber 22 '(Fig. 5), the piston l8 together with the slide 15 will be moved longitudinally toward theright. During this movement of the piston 18, fluid within a cylinder chamber 23 may exhaust through a pipe 24. A suitable fluid pressure system and a control mechanism therefor for supplying fluid under pressure to the cylinder I! will be hereinafter described.

The longitudinally movable slide l6 serves as a support for a transversely movable vertically arranged sleeve 25. The sleeve 25 is preferably square in cross section as indicated in Fig. 4. The sleeve 25 is provided with a central aperture for supporting a vertically movable spindle -26. The spindle 25 supports a truing tool holder 27 at its lower end. The truing tool holder 21 is provided-with a diamond or truing tool 28 which is arranged to true the periphery of the The other endof 3 grinding wheel H] as will be hereinafter described.

The sleeve 25 is provided with a pair of vertically extending ribs or slides 33 and 3| which serve as guides for controlling the vertical movement of the sleeve 25. A plurality of rollers 32, 33, 34 and 35 (Fig. 4) are mounted on studs 36, 31, 38 and 39 respectively. The rollers 32, 33, 34 and 35 are arranged to engage the opposite faces of the slides 33 and 3| to support the sleeve 25 having free vertical sliding movement. The studs 31 and 39 are preferably provided with eccentric portions for supporting the rollers 33 and 35 to facilitate a transverse adjustment of the rollers so as to take up lost motion between the sliding parts. A similar set of rollers (not shown) are provided for supporting the lower end of the slides 30 and 3|.

Similarly a plurality of rollers 49, 4|, 42 and 43 are provided for engaging the opposed side faces of the slides 30 and 3|. These rollers are rotatably supported on studs 44, 45, 46 and 41 respectively. The studs 45 and G1 are preferably provided with eccentric portions for supporting the rollers 4| and 43 to facilitate a transverse adjustment of the rollers to take up backlash between the sliding parts. It will thus be seen that an. anti-friction sliding support has been provided for the sleeve 25 so that it may be freely moved'in a vertical direction to carry the truing tool 28 in'the desired and predetermined path to true a predeterminedshape on the periphery of the grinding wheel ID.

A suitable adjusting mechanism is provided for adjusting the spindle 26 relative to the sleeve 25 to facilitate either a manual adjustment of the truing tool or diamond 28 or an automatic feeding movement thereof during a truing operation. The upper end of the sleeve 25 is provided with an integral flange B which serves as a support for a bracket 5|. The upper end of the spindle 26 is provided with a screw thread 53 which meshes with a surrounding nut 55. The nut 54 is rotatably supported on the flanged portion 50 of the sleeve 25. A gear '55 is keyed to the nut 54. -The'gear 55 meshes with a pinion 56 mounted on the upper end of a vertically arranged rotatable shaft 51. The shaft 57 is rotatably mounted within the bracket 5| and is provided at its lower end with a manually operable hand wheel 58. 'It will be readily apparent from the foregoing disclosure that rotation of the hand wheel 58 will be transmitted through the shaft 51, the pinion 55, the gear 55, to rotate the nut 54 and thereby to impart an axial adjustment of the truing tool spindle 26.

In order to hold the nut 54 in adjusted position, a serrated wheel 59 is fixedly mounted on the upper end of the shaft 57. A spring pressed pawl 60 mounted on the bracket 5| is arranged to engage the serrated wheel 59 and thereby to hold the feed nut 5c in adjusted position.

In order to steady the upwardly extending portion of the feed screw 53, an arm 6| is clamped around a cylindrical surface formed on the upper end of the screw 53 (Figs. 1 and 2). The righthand end of the arm 6| is provided with a spring pressed ball 52 which rides in a vertically arranged groove 63 formed in a vertically extending bracket 64. The bracket 55 is fixedly mounted on the flange 5B of the sleeve 25. It will be readily apparent from theforegoing disclosure that the arm Bl serves to hold the screw '53 and the spindle 26 against rotary motion but allows a free axial movement thereof.

It is desirable to provide an automatically actuated mechanism for imparting a feeding movement to the truing tool at the ends of its longitudinal traversing movement. This is preferably accomplished by a pawl and ratchet mechanism comprising a ratchet wheel 66 which is keyed to the nut 54 (Fig. 3). A pawl carrier 67 (Figs. 1, 2 and 3) is rotatably mounted on the nut 54 and is provided with a pivotally mounted feed pawl 58. ihe feed pawl 58 is supported by a stud G9 fastened to the pawl carrier 51. A compression spring Iii serves normally to maintain the pawl 68 in operative engagement with the ratchet wheel 85. A manuall operable rotatable eccentric 7| (Fig. 2) is provided to facilitate rocking the pawl 88 to an inoperative position if desired so as to facilitate a manual adjustment of the truing tool spindle 25. A compression spring '52 normaliy urges the pawl carrier 81 in a clcckwise direction (Fig, 2) with a stud T3 in operative engagement with a stop surface 14 which is fixedly mounted on the flange 50 of the sleeve 25.

An automatically operated mechanism is provided for actuating the pawl carrier 6'1 at the ends of the traversing movement of the truing tool to facilitate an automatic downward feed of I the pawl carrier 6'? in a counterclockwise 'direction so as to impart a predetermined downward feeding movement to the truing tool 28. The ad-' justable dog '15 is adjustably supported by a T- slot 76 formed in the upper surface of the bracket The height of the dogl5 issufiieient' to allow maximum vertical movementof the spin dle 26 relative to the sleeve'25. I i

The pawl carrier 61 is provided with a'laterally.

extending arm H which supports "a roller ldon a stud 79. The roller 18 is arranged in the path of a cam face 85 formed'on an adjustable 'dog'fii so that when the slide is approaches the lefthand end of its stroke, the pawl carrier-61 is rocked in a counter-clockwise direction'so as to impart a predetermined down feeding movement to the truing tool 28. The height of the cam face 85 is sufficient to allow maximum vertical movement of the spindle 26 relative to the sleeve 25. ihe dog 8| is adjustably supported by the T-slot '15. It will be readily apparent from the foregoing disclosure that 'when the slide i5 traverses toward the right, the pawl carrier 61' will move into engagement with the dog 15 as the slide approaches the right-hand end of its stroke thereby imparting a down feeding movement to the truing tool 28 before the .return stroke of the slide 55. Similarly when the slide |3 travels toward the left, the roller E3 will engage the cam face 85 on the dog 8| as the slide iii approaches the left-hand end of its stroke to impart a down feeding movement of the truing tool 23.

A suitable forming mechanism is provided for generating a predetermined shape on the periphery of the grinding wheel H3. This mechanism may comprise a forming bar 85 which is anchored to a bracket 86 by means of a clamping bolt 87. An adjusting screw 88 serves to precisely adjust the forming bar 35 in a longitudinal direction. The bracket 86 is-fixedly supported on the fixed bracket l2. The forming bar 85 extends through an elongated slot 89 (Fig. 3)

formed in the sleeve 25 and arranged to slide upon a, slide surface 90 formed on the :longitudinally' movable slide I6. A follower 9| isflxed ly mounted on the sleeve 25 and is arranged to follow a portion of the form on the bar- 65 during the longitudinal movement of the slide IS in a manner to be hereinafter described.

A. hydraulically operated, lifting mechanism is provided for causing a vertical motion of the sleeve 25 to true .a. shouldered portion on the grinding wheel. This mechanism may comprise a slide bar 95 which is slidably supported on the longitudinally movable slide I6. A follower 96 is fixedly mounted on the sleeve 25 and is arranged to be actuated by the bar 95 whenit is moved longitudinally relative to the slide I6.

The bar 95 is arranged to be traversed longitudinally relative to the slide I 6 by an hydraulically operated mechanism comprising a cylinder I which is fixedly mounted on the slide I6. The cylinder I90 contains a sl-idably mounted piston IOI which is connected to one end of a piston rod 99. The other end of the piston rod 99 is connected to the slide bar 95. When fluid under pressure is admitted through a pipe I03 into 'a cylinder chamber I02, the piston IOI together with the piston rod 99 and the slide bar 95 are moved toward the right. During this movement of the piston IOI, fluid within a cylinder chamber I 04 exhausts throu h a pipe I05, a throttle valve I06 is provided in the pipe line I to regulate the rate of exhaust of fluid from the chamber I04 thereby determining the rate of longitudinal movement of the slide bar 95. A ball check valve I 01 is provided so that when fluid under pressure is passed through a pipe I08, it may bypass the throttle valve I06, through the ball check valve I01 into the cylinder chamber I04 so that the piston l0I may be moved toward the left at a relatively fast rate of speed.

A fluid operated control valve I09 is provided to control the admission to and exhaust of fluid from the cylinder I00. This control valve I09 comprising a pilot valve I I0 which is normally held in a right-hand end position by a compression sprine I I I. A solenoid S2 is provided which when energized serves to shift the pilot valve I I0 toward the left to reverse the flow of fluid so as to shift the control valve I09 into a reverse position. The pilot valve IIO serves to control the admission to and exhaust or fluid from a pair of opposed end chambers I I2 and H3 to control thelongitudinal shifting movement of a slidably' mounted valve member II4.

An hydraulic system is provided for supplying fluid under pressure for actuatin the various parts of the truing apparatus comprising a motor driven fluid pump I50 which draws fluid through a pipe I 5I from a fluid reservoir I52 and forces fluid under pressure through a pipe I53 to the control valves as will be hereinafter described, An adjustable pressure relief valve I54 is connected in the pipe line I53 to facilitate exhaustins excess fluid under pressure through a pipe. I55 into the reservoir I52.

A fluid operated control valve I25 is provided for controlling the admission of fluid to the control valve I09. This valve is a piston type valve comprising a slidablv mounted valve member I26- which is moved endwise by the admission to an exhaust of fluid from end chambers I21 and I28 formed at the opposite ends thereof. lhe valve !25 includes a pilot valve I29 which is normally held in a right-hand end position by a compression spring I30. A solenoid, S3 is provided,

forshifting the pilot valve I29 toward the left tofacilitate reversing the position of the slidablymounted valve member I26. In the positionof' the valve I25 (Fig. 5). fluid under pressure pass.- ing, through the pipe I53. may pass through a chamber .I3I in the slidably mounted valve member I26 and pass out through a pipe I32 to the control valve I09. When the solenoid S3 is energized. the slidably mounted valve member I26 is moved toward the right into a right-hand end position which serves to cut off the flow of fluid to the control valve I09 and thereby to cut off the passage of fluid under pressure to the cylinder I00.

Air-hydraulically operated control valve I35 is provided, for controlling the admission to and exhaust of fluid from the cylinder I I. This valve comprises a slidably mounted valve member I36. A pilot valve I3! is normally held in a righthand end position by a compression spring I38. A solenoid SI is provided which when energized serves to shift the pilot valve toward the left thereby shifting the valve member I 36 toward the right. The pilot valve I31 serves to control the admission to and exhaust of fluid from a pair of end chambers I39 and. I40 formed in opposite ends of the control valve I35. In the position of the valve I35 (Fig. 5), fluid under pressure in the pipe I53 passes through a valve chamber MI and through the pipe 24 into the cylinder chamber 23 to cause the piston I8 to move toward the left. Durinsi the movement of the piston I3 toward the left, fluid within the cylinder chamber 22 may exhaust through the pipe 2I into a valve chamber I42, through a central passage I43 in the valve member I36, through a valve chamber M4 and exhaust through a pipe I45 and a throttle valve I46 into the reservoir I52. The throttle valve I45 serves to control the rate of exhaust of fluid and thereby determines the rate of traversing movement of the piston I0.

It is desirable to provide means for bypassing fluid around the throttle valve I46 so that the slide I6 may move rapidly during idle portions of its stroke. This mechanism may comprise a bypass valve I56 which is preferably a piston type valve comprising a valve stem I51 having a pair of spaced valve pistons I55 and I 59 formed integrally therewith. A compression spring I60 normally serves to urge the valve stem I51 downwardly into the path of a pair of spaced adjustable dogs I GI and I62 which are carried by the slide I6. A pair of fluid pipes I63 and I64 are connected to opposite sides of the valve I56 and in the position as shown in Fig. 5 allow fluid to bypass throuah a valve chamber I65 formed between the valve pistons I58 and I59 so that unrestricted flow of fluid may bypass the throttle valve I46 thereby facilitating a rapid movement of the slide I6. It will be readily apparent from the foregoing disclosure that when the valve stem I51 rides down the slope of the dog I6I, the compression spring I60 will cause a downward movement of the valve stem l5l so that the valve piston I58 cuts off the passage of fluid between the pipes I53 and IE6 thus rendering the bypass valve I56 inoperative so that the throttle valve I46 thereafter controls the rate of movement of the slide I6.

A suitable electrical control apparatus is provided for controlling the energization of solenoids SI, 32 and S3 so as to control the admission to and exhaust of fluid from the cylinders IT and I00. As illustrated in Figs. 3 and 5, a slide bar I10 is slidably supported on the longitudinally movable slide I6 in sliding contact with the slide bar 95. The slide bar I10 is held in frictional engagement with the slide I6 so that the bar 95 may be moved longitudinally by the piston |I without moving the bar I until the lost motion between the adjustable stop screws Ill and I12 is taken up. The upper surface of the slide bar I10 is provided with a plurality of surfaces IIOa, I10b, I100, I10d, I106 and Iliif which are arranged in the path of an actuating roller I13 of the limit switch LS3.

Another slide bar I15 (Figs. 3 and 5) is slidably supported by the slide I6 and is held in frictional engagement therewith by a friction plate I16 (Fig. 3). The slide bar I15 is arranged so that it moves longitudinally with the slide I6 until the lost motion is taken up between adjustable stop screws I11 and I18, carried by the bar I15 and end surfaces of the slide base I3. of spaced notches I19 and I80 into which an actuating roller ISI of the limit switch LS2 may drop as the slide I8 and bar H5 move longitudinally so as to actuate the limit switch LS2 and thereby to control the energization and deenergization of the solenoid S3. The energize.- tion of the solenoid S3 is in part controlled by a magnetic switch I85 having a pair of normally open contactors I86 and I88 and a normally closed contactor I81.

A main control switch I90 is provided for connecting a source of electrical energy to the circuit. A manually operable starter switch 59! is provided for starting the truing cycle. Closing of the starter switch I9I serves to energize a mag netic switch I92 and thereby close a normally open contactor I93.

The operation of the improved formed wheel truing apparatus will be readily apparent from the foregoing disclosure. The main switch I9? is closed to render the electrical circuits operative. Closing of the main switch I90 serves to energize the solenoid S3 so that the valve member I26 is shifted toward the right thereby cutting off fluid under pressure from the pipe I32. The truing cycle may then be started by closing the push-button starter switch Isl which serves to energize the magnetic switch I92 which sets up a holding circuit. The closing of the starter switch I9I serves to energize the solenoids SI and S2 which remain energized during the traversing movement of the slide I6 to the right. Fluid under pressure from the pump I passes through the control valve I35, through the pipe 2| into the cylinder chamber 22 to start movement of the piston I8 and the slide I 6 toward the right. Due to the fact that the bypass valve I56 is opened, the slide I6 and truing tool 28 travel first at a relatively fast rate until the follower 9| is about to engage the surface 85a of the template 85 and the truing tool 28 is about to contact the side face Illa of the grinding wheel Ill. At this time the valve stem I51 rides down the sloping surface of the dog I6I thereby cutting off the bypassing of fluid between the pipes I63 and I64 so that thereafter the fluid exhausting from the cylinder I1 is controlled by the throttle valve I46. Fluid under pressure remains within the cylinder chamber 22 during the entire traversing movement of the piston I8 toward the right. Engagement of the follower 9| with the side face 85a of the template 85 serves to stop the movement of the slide I8 toward the right with the truing tool 28 in engagement with the side face I0a of the grinding wheel I0.

The slide bar 515 is provided with a pair I When the follower 9| moves into engagement with the surface a of the template 85, the slide bar I15 has shifted longitudinally relative to the slide base I3 so that the stop screw I11 is in engagement therewith. The roller I8I of the limit switch LS2 rides into the groove I13 thereby shifting the limit switch LS2 to open the upper contacts thereof so as to break a circuit through contactor I81 of switch I85 to deenergize the solenoid S3 so that fluid under pressure may pass through the pipe I32, through the control valve I09, through the pipe IE8 into the cylinder chamber I02 to cause the piston IOI to move toward the right at a speed governed by the throttle valve I06. Movement of the piston IOI toward the right causes a corresponding movement to be imparted to the slide bar 95. During the initial movement of the slide bar 95, the slide bar I10 remains stationary until the stop screw I1I moves into engagement with the left-hand end thereof. As the slide bar moves toward the right, the follower 95 moving up the inclined surface 951) of the slide bar 95 imparts a vertical movement to the sleeve 25 so that the follower 9| rides up the side face 85a of the template 85 and the truing tool 28 moves upwardly along the side face Illa of the grinding wheel I9 to true the same. When the slide bar I10 moves toward the right, the roller I13 swings in a counterclockwise direction to actuate the limit switch LS3 thereby energizing the magnetic switch I85. As the follower 5| reaches the radius [01) of the grinding wheel It, the pressure within the cylinder chamber 22 moves the piston I8 toward the right and the shape of the template 85 controls the vertical movement of the follower 9| to generate the radius I01) on the grinding wheel I0 and also the formed surface I0c i generated by the follower Si riding up the surface 850 of the template During the movement of the slide bar 65 toward the right to move the surface 950 into the position illustrated in Fig. 6, the roller I13 rides along the notch I10b maintaining the limit switch LS3 with the upper contacts closed to maintain the magnetic switch I85 energized until the roller I13 engages the inclined surface I which serves to shift the limit switch LS3 into the position illustrated in Fig. 5 thereby opening the circuit to the coil of the magnetic switch I85. The roller IiII is in engagement with the notch I19 of the slide bar I15 so that the lower contacts of the limit switch LS2 are closed thereby setting up a holding circuit to maintain the magnetic switch I85 energized and the solenoid S3 deenergized. The solenoid S3 remains deenergized until the piston I0! again moves and actuates the limit switch LS3 to energize magnetic switch I85. During the latter longitudinal movement of the piston I 8 and the slide I6 toward the right, the roller |8I rides out of the notch I19 to shift the limit switch LS2 into the position illustrated in Fig. 5 so a to energize the solenoid S3 after the generation of the surface We on the wheel I0.

When the follower 9| approaches the shoulder 85d on the template 95 and the truing tool 28 approaches the shouldered face I0d on the grinding wheel I0, the roller I 8| drops into notch I80 on the slide bar I15 thereby shifting the limit switch LS2 to deenergize the solenoid S3 so that the control valve I25 may again pass fluid under pressure through the pipe I32 to the control valve I09. Fluid under pressure passes from the control valve I09 through the pipe I03 to again -move the piston- II toward the right. This movement causes a corresponding movementrto the right of theslidebar 95 so thatthe-follower 96 slides upwardly due-to-thesloping surface 95d on the slide bar 9-5 to raise the sleeve 25"andthe truing tool 28 in a vertical direction to true the shouldered face lildon the grinding'wh eel ID as the follower SI rides up theshoulderedface 85d onthe template 85.- The upward movement of the follower 96 and truing'tool 28 continues until the fol-lower -96 is raised onto the portion "95c andthe follower 9l' h'aspassed partially aroundthe'radi-us 85c on the -template 85 so that the truing tool 28'is partially around the-radius 'IOeof the grinding wheel I0.- At'this point fluid under pressure within the cylinder *chamber- 22 .until the slide I6 engages and opens the normally closed limit switch LS4 which serves to break the holding circuit thereby deenergizing the magnetic switch I92. Breaking the circuit and deenergizing switch I92 also serves :to deenergize the sole- .noids Sl and S24. thereby shifting the-:control valves I35 and I09 respectively into the positions illustrated in Fig. 5 where they remain during the return traversing stroke of the piston I8 and slide I6 toward the left. The operation of the follower relative to the template 85 together with the controls above described operate in a similar manner on the traversing movement toward the left to again pass the truing tool across the face of the grinding wheel. Prior to the return stroke of the truing tool, the dog engages the pawl carrier 61 and rocks it in counterclockwise direction. This movement serves through the pawl 88 and the ratchet wheel 66 to impart a down feeding movement to the truing tool 28before the truing tool starts its return traverse toward the left. Similarly as the piston I8 and slide I6 approach the left-hand end of the traversing stroke, the roller "I8 rides up the cam face 80 of the dog BI to again impart a down feeding movement to the truing tool 28 so that it is positioned for the next truing operation.

It will thus be seen that there has been provided by this invention a grinding wheel truing apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a grinding wheel truing apparatus having a slide base, a longitudinally reciprocable slide thereon, a transversely movable truing tool carrier on said slide, a truing toollthereon, means including a piston and cylinder on said base to traverse said slide longitudinally, means including a follower on said carrier which operatively engages-aiaforming baron saidislide to-impart a controlled transverse movement to the truing tool carrier during longitudinal movementofthe slide, means including a longitudinally movable cludinga cylinder on said slide, a-sli'dable piston therein :whichis operatively-connected to said cam-to'm-ove said cam longitudinally-relative-to said slide; said first follower and forming bar serving to hold said slide stationary during --movement of said cam and control means includinga control valve mechanism operatively connected tea-both of said cylinders alternately and successively-to traverse said slide longitudinally -and to traverse said cam, longitudinally-relative to theslide to generate apredetermined contour grinding wheel. 2;;In a grinding wheel truing apparatus having abase, a longitudinally reciprocable slide, a transv on. the operativenface of. a

versely movable truingtool carrier, on said, slide, a

truing tool 'adjustably mounted on; said carrier,

- means including afolloweron said carrier which operatively engages a, forming bar on saidslide to impart a controlled transverse movement to the twins 1 r i ri rine. lon itud nal. mov m oftheslide, acyliride ton said baSe @piStonsI-idab n d; h reicwhichr s. re i rely-co nally, means including ed. o i s i eto,traver eth -slid lon itud a longitudinally movable cam on said slide which engages a follower on said carrier to impart a transverse movement to the truing tool carrier when the slide is stationary to true a shouldered face on a grinding Wheel being trued, a cylinder on said slide, a piston slidable therein which is operatively connected to said cam to actuate said cam, and control means including a control valve mechanism operatively connected to both of said cylinders alternately and successively to traverse said slide longitudinally and to traverse said cam longitudinally relative to the slide so as to generate a predetermined contour on the operative face of a grinding wheel.

3. In a grinding wheel truing apparatus having a base, a longitudinally reciprocable slide thereon, a transversely movable truing tool carrier on said slide, a truing tool adjustably mounted on said carrier, a forming bar fixedly mounted relative to the base, a follower on said carrier which engages said forming bar to facilitate generating a predetermined shape on a peripheral portion of a grinding wheel being trued, means including a cylinder on said base, a piston slidable therein which is operatively connected to said slide to traverse said slide longitudinally, a longitudinally movable cam on said slide, a second follower on said carrier in operative engagement with said cam, means including a cylinder on said slide, a piston slidable therein which is operatlvely connected to said 0am to move said cam longitudinally relative to said. slide to cause a transverse movement of the carrier relative to the slide to facilitate truing a side face or a shouldered face on a grinding wheel being trued, said first follower and forming bar serving to hold theslide stationary during a transverse movement of the carrier for shoulder or side truing,

and control means'including a control valve mechanism 0-perativel connected to both of said cylinders intermittently to traverse said slide longitudinally and to traverse said cam longitudinally relative to said slide to generate a predetermined contour on the operative face of a grinding wheel.

4. In a grinding wheel truing apparatus having a base, a longitudinally reciprocable slide thereon, a transversely movable truing tool carrier on said slide, a truing tool adjustably mounted on said carrier, a follower on said carrier and a forming bar which is engaged by said follower and is fixedly mounted relative to the base to facilitate generating a predetermined shape on a portion of the operative face of a grinding wheel, a cylinder on said base, a piston slidable therein which is operatively connected to said slide to reciprocate said slide, means including a follower on said carrier and a longitudinally movable cam on said slide to facilitate a transverse movement of the carrier for side or shoulder truing, a cylinder on said slide, a piston slidable therein which is operatively connected to said cam to traverse said cam longitudinally relative to said slide, and electrically-controlled hydraulically-actuated mechanism operatively connected to both of said cylinders intermittently to traverse said slide longitudinally and to traverse said cam relative to said slide to generate a predetermined contour on the operative face of a grinding wheel.

5. In a grinding wheel truing apparatus, as

claimed in claim 4, in combination with the parts and features therein specified of a solenoid-actuated control valve operatively connected to said 'slide cylinder to control the admission to and exhaust of fluid from the slide cylinder, a second solenoid-actuated control valve operatively connected to said cam actuating cylinder to control the admission to and exhaust or fluid from the cam actuating cylinder, a third solenoid-actuated control valve operatively connected to said second valve to control the admission of fluid to said second valve, a magnetic switch operatively connected to said third valve to actuate said third valve, means including a cycle start switch operatively connected to the first and second valves to energize the first and second valves to initiate a truing cycle, means including a switch on said slide which is actuated by and in timed relation with the longitudinal movement of said cam to energize said magnetic switch and the third valve to cause a transverse movement of the carrier for a side face or shoulder grinding operation.

OIVA E. HILL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,171,516 Alvord Sept. 5, 1939 2,248,463 Ott July 8, 1941 2,302,854 Granberg Nov. 24, 1942 2,433,027 Casella Dec. 23, 1947 2,576,570 Castelll Nov. 27, 1951 FOREIGN PATENTS Plumber Country Date 536,300 Great Britain May 9, 1941

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