US3006331A - Apparatus for dressing grinding wheels and holding work pieces thereto - Google Patents

Description

Oct. 31, 1961 RQ n AND HOLDING A. AKERT 3,006,331 APPARATUS Fo REssING GRINDING WHEELS woRx PIECES THERETO Filedarch 24. 1958 4 Sheets-Sheet 1 Oct. 31, 1961 Y c. A. AKERT 3,006,331

APPARATUS FOR DRESSING GRINDING WHEELS AND HOLDING WORK PIECES THERETO Filed March 24, 1958 4 Sheets-Sheet 2 i@ @Maa/52W oct. 31, 1961 C. A. AKERT 3,006,331

APPARATUS FOR DRESSING GRINDING WHEELS v AND HOLDING WORK PIECES THERETO Filed March 24. 1958 4 Sheets-Sheet 3 3f/aide@ Oct. 31, 1961 3,006,331

C. A. AKERT APPARATUS FOR DRESSING GRINDING WHEELS AND HOLDING WORK PIECE-S THERETO Filed March 24. 1958 4 Sheets-Sheet 4 Wal Hmm

United States Patent Cce 3,006,331 Patented Oct. 31, 19761 3,006,331 APPARATUS FOR DRESSING GRINDING WHEELS AND HOLDING WORK PIECES THERETO Carl A. Akert, 948 Cuyler Ave., Chicago, Ill. Filed Mar. 24, 1958, Ser. No. 723,538 18 Claims. (Cl. 12S-11) This invention relates to grinding wheels; to a tool adapted to dress or prole grinding wheels with both arcuate and flat surfaces; and to a novel grinding wheel auxiliary tool which readily may be employed to accurately dress a grinding wheel without the use of indicator gauges or other measuring devices, and which during `actual grinding operations further may be arranged for accurately and assuredly positioning the work piece for which the wheel is dressed.

Devices of the general character of the type disclosed herein, of course, have been known and extensively used for some time. Further, the technique of grinding surfaces of work pieces with profiled abrasive wheels is quite advanced and rapid. However, when using these known devices initially to dress a grinding wheel to the desired shape, the preparation of the wheel is both time consuming and tedious, and more often than not consumes far more time than the actual grinding operation. Besides, almost without exception, such known devices are of complicated construction and operation -and further require the use either of extraneous separate steel yguide tapes, special templates, gauge blocks, height and indicator gauges, or other measuring means to achieve the desired wheel profile. Diiiiculty of adjustment and lack of precision in practice are common; cut and try techniques or operations prevalently are practiced to properly dress a Wheel. These practices obviously are objectionable; since, they not only require considerable time to achieve the desired results, but further require the employment of highly skilled and expensive operators. Moreover, once a grinding Wheel is dressed to the desired shape, none of these known devices provides means whereby the Work piece for which the wheel is shaped may be readily held for the actual grinding operation. Such provision, besides being of great convenience, could appreciably increase the utility of the auxiliary device and cut down total expenditure of time and preparation when grinding specially shaped surfaces.

The present invention, in contrast, contemplates the provision of a novel device with which grinding wheels may be dressed accurately and conveniently to various profiles; which provides its own means for measuring various dressing operations; and which further is adaptable to hold the Work piece, for which a wheel is specially dressed, when the same is being ground.

Accordingly, a primary object of this invention is to provide an improved auxiliary device for use with grinding Wheels, which device overcomes the foregoing and other shortcomings found in other prior art devices used for similar purposes.

Another primary object of this invention is to provide a combination tool arranged for dressing arcuate and other surfaces on grinding wheels, and for holding a Work piece for which a wheel is ground to shape.

Stated somewhat diiferently, it is an object of this invention to provide a tool for use with grinding wheels, and including an arbor for detachably receiving a Work engaging member which may be, for instance, either a grinding wheel cutting point or structure arranged to hold the Work piece for which a wheel is dressed to grind the same.

Another object is to provide means whereby the arbor and the work engaging member carried thereby may be readily and precisely positioned relative to the grinding wheel, there being provision incorporated within the herein tool for accurately measuring the positioning movement of the work engaging member.

As an aspect or corollary of the foregoing object it is within the contemplation of the present invention to provide a tool having, -within limits defined only by its own size and the size of the Wheel to be dressed, infinite adjustment and measuring means for positioning the Work engaging member. p

Another objectof this invention is to provide a tool whereby the abrasive surface of a grinding wheel may be accurately profiled without requiring highly skilled and expensive labor for such operation.

A further and more specic object is to provide a tool adapted to profile both flat and arcuate shaped surfaces on a grinding wheel, and further to incorporate in said tool novel measuring means whereby the cutting element thereof may be readily and precisely positioned to produce the desired shaped surface on said wheel.

A still further specific object of this invention is to provide a grinding wheel dressing tool which, when employed to profile arcuate surfaces, has easily adjustable stop means providing limits for conning the cutting tool within a prescribed path to achieve the desired wheel profile.

Other speciiic objects of this invention are to provide the herein tool with means whereby its arbor and work engaging member may be linearly or rotatably positioned, including means -for measuring the aforesaid movements; to incorporate the arbor as a slidable head having actuating and measuring means in the form of a calibrated micrometer adjustment to achieve linear movement; and to provide a rotary spindle to carry the slidable head, the spindle having a novel indexing plate with an annular array of stops for measuring and limiting rotary movement.

Another specific object is to provide an auxiliary tool for use with, and dressing of, a grinding wheel, the tool having a work engaging arbor or carrier including a novel plate having positionable stops for limiting rotary movement of a carrier mounted cutting tool when dressing an arcuate surface in said wheel; the plate further including an annular array of stops for measuring angular positioning movement of a carrier mounted Work piece when grinding the surface of the latter With said wheel.

Ancillary objects are to provide a grinding wheel auxiliary tool which is strong of construction, yet has simplicity of design and a relatively few number of parts, and which thus is economical to manufacture; and to provide a tool which otherwise is Well adapted to perform the services required of it.

The vforegoing and other objects, advantages and features of construction will become more apparent upon a consideration of the following description together with the accompanying drawings.

In the drawings:

FIGURE 1 is a side elevation view, partly in crosssection, showing the auxiliary device embodying the present invention prepared to dress a wheel;

FIGURE 2 is a cross-sectional plan view taken on line Z--Z in FIGURE 1;

FIGURE 3 is a plan view of the auxiliary device;

FIGURE 4 is a front elevation view of the same;

FIGURE 5 is a diagrammatic view illustrating the manner in which the tool cutting element is variously positioned to prole a convex arcuate surface of a grinding Wheel;

FIGURE 6 similarly illustrates posioning of the tool to achieve or profile a concave grinding wheel surface;

FIGURE 7 is a View taken on line 7 7 in'FIGURE 1;

FIGURE 8 is an enlarged fragmentary view showing the positionable stops;

FIGURE 9 is a front elevation view of the work engaging member employed to hold the work piece for which a Wheel is dressed;

FIGURE 10 is a fragmentary cross-sectional view taken on line 10-19 in FIGURE 9;

FIGURE 11 is a front elevation view of the housing structure in which the slidable head is mounted;

FIGURE 12 is a view partly in cross-section illustrating means whereby positioning of the rotatable plate may be interpolated between positions defined by its annular array of stops;

FIGURE 13 is a view taken on line 13-13 in FIG- URE 1; and

FIGURE 14 is a cross-sectional view taken on line 14-,14 in FIGURE 1.

The structure selected for illustration is not intended to serve as a limitation upon the scope or teachings of the invention, but is merely illustrative thereof. There may be considerable variations and adaptations of all or part of the teachings depending upon the dictates of cornmercial practice.

Referring to the drawings, the present invention for the purpose of illustration is embodied in atool 21 intended for use with amagnetic chuck 22 of the grinding device. Support for the tool 211 is provided by a pedestal orbase 23 having ailat undersurface 24 and made of suitable magnetic material. An upstanding standard or verticalsupport bracket structure 25 is provided medially of the base 2,3 and integrally therewith. Thesupport bracket structure 25 is provided with anopening 26 extending horizontally therethrough, and in which there is mounted abearing collar 27 in bearing contact with arotatable shaft 28. Thebearing collar 27 protrudes outwardly .from thesupport bracket structure 25 for engagement with an annular shoulder 2.9 integrally provided inshaft 28, thereby preventing axial movement ofshaft 28 to the left, as seen in FIGURE l. At its outer or rearward .end 30,shaft 28 has mounted thereto an axially extendinghandle 31 which is suitably knurled to facilitate handling vand turning of theshaft 28. A set screw 3-2 provides means for facile attachment and removal of the handle V31 to and from theshaft 28.

At its end 33- extending forwardly from thesupport structure 25, the shaft 2S carries anassembly 34 which includes ahousing 35, anannular member 36encircling housing 35 and press fitted to and secured thereon, and stops 37, 38, positionably adjustable onmember 36. To facilitate mounting of thestops 37, 38,member 36 is provided with an annular array of uniformly angularly spaced threadedopenings 39, and each stop is provided with a body portion 4() having an arcuate slottedopening 41 therein for coincidental arrangement with the array ,of threadedopenings 39. The effective orprotruding portion 42 of each stop extends generally radially with respect to the array ofopenings 39. To secure eachstop 37 or 38 at a desired position,head screws 43 may -b e provided for extension through therespective slot 41 and threadable engagement into matchingopenings 39.

The housing, 35, as seen in elevation in FIGURES 1, 2 and 11, is provided in its front surface with a longitudinal passage 44 communicating between what normally are its upper andlower surfaces 45, 46, respectively. At itsforward side 47, the passage 44 is enlarged and covered by spacedplates 48, 49, secured to thehousing 35 by suitable fasteners, such'as screws 50, to in effect provide an undercut passage in thehousing 35. Ahead 51 is slidably lmounted in the passage 44, thehead 51 being provided withguides 52 at opposed sides thereof for matching engagement with the undercut construction within thehousing 35.

To slidably position head 51 a Vscrew adjustment is provided and includes a shaft 53 Iwhich is rotatably jour- Vnalled in thehousing 35 and mounted therein against Vaxial movement.

through an opening in a boss 55 provided reanwardly of thehead 51 and integral therewith. Turning of shaft 53, thus, correspondingly causesrhead 51 to move slidably in either of opposed directions in passage 44.

At its outer end the shaft 53 is provided With an appropriately calibrated andknurled handle 56, an indicator 57 further being provided onhousing 35 to facilitate reading of the calibrations 58. On the face of plate 46 a further Vernier scale 59 may be provided lwhile thehead 51 may be provided -with a form of pointer or indicator 60 by which head movement further may be measured, the combined readings of the scales 58, 59, being such as to give measurements in a manner similar to the usual micrometer. Aset screw 61, extending throughhousing 35 and engageable with theslidable head 51, is provided to lock the head 5-1 at any desired setting.

Theassembly 34 is mounted securely to the forward end 33 of theshaft 28 by means of another set screw 62 which is arranged to bear against the shaft end 33, as -best seen in FIGURE 2. The enti-re assembly 34 thus may be readily mounted to and removed from theshaft 28.

Theslidable head 51 further carries a :forwardly extending carrying nlock or mountingboss 63 having a horizontal central `bore 64 and rigid vertical lip 65 at one side thereof. A set screw 66 projects radially into thebore 64, in preparation for receiving and retaining the shank of a work engaging member therein.

Referring to FIGURES l, 3 and 4, the Work engaging member is exemplified therein as acutting tool 67, including a shank 68 matingly engagea'b-le Within thebore 64,an outwardly extendingarm portion 69 integral therewith, and provided with a bore 7i) wherein there is seated the shank 71 of a mountingmember 72 carrying a cuttingelement 73 which preferably is a diamond. Aset screw 74 is threadable into thearm 69 for engagement with the shank 71 t-o retain Ithe latter inbore 79. As seen in FIGURE 3, the lip 65 is engageable against the at side surface 75 ofarm 69 to prevent the latter and its shank 68 from turning inbore 64.

It will -be apparent that asshaft 28 is rotated by Vmanipulation ofhandle 31 theentire assembly 34 rotates.

Correspondingly, thestops 37, 38, and in particular their protrudingportions 42, follow a predetermined circular path.

Referring back to FIGURES 3 and 4, a spring biased `stoppin 76 is mounted in asleeve 77 for axial movement therein. Thesleeve 77 is fixed to the side of thesupport structure 25, while the pin 75 further is so arranged and positioned as to be capable of being selectively projected or interposed into the circular path of the protruding portions A42 ofstops 37, 33 to limit the movement thereof, and, consequently, to limit theV rotation of the ent-ire assembly 34. To facilitate axial positioning ofpin 76, at one end thereof there is provided aknurled handle 78.

Refer-ring to FIGURES l, 5 and 6, the cutting element 73Vis illustrated in readiness to dress or prole a grinding wheel '79 which generally is mounted for rotation about what may be considered a fixed axis (not shown). Further, when dressing awheel 79 the center line of the tool or axis of rotation l of theshaft 28 is aligned generally parallel with the medial plane of thevwheel 79, or perpendicular to the grinding wheel axis of rotation. As a result asshaft 28 rotates it sweeps the cuttingelement 73 in an arcuate path generally perpendicular to the plane of thewheel 79. This, of course, is true when the cutting element is offset from the axis of rotation 80. When the cuttingelement 73 is positioned directly in alignment with the axis of rotation S0, rotation ofshaft 28 merely turns the element about a pivot point coincident with the axis Si). For `the purpose of calibration land measurement, that point at which theelement 73 is directly upon the axis of shaft 2S rotation is designated the zero or centered position of the Itool and the calibrated scales 58, 59, accordingly are set at a zero or starting reading.

To achieve this zero setting of cuttingelement 73, thearm portion 69 is provided with an offset 81 of sufficient dimension to compensate for the mounting height of theelement 73 above thearm 69.

`FIGURE 5 illustrates the cuttingelement 73 at alternate positions, shown in phantom lines, when dressing a convex surface 82 on the grindingwheel 79. To achieve the desired radius of curvature on the wheel surface, the cutting element is first positioned below the axis of rotation 80 of shaft 2S at a distance corresponding to the desired radius of the surface 82. This is achieved by turning micrometer screw handle 56 and measuring olf the distance on calibrated scales 58, 59. To measure oi the desired amount or length of arc through which the element is to travel the limit stops 37, 38, are appropriately mounted to thecorrect openings 39 andpin 76 is projected int-o the path of rotation of ythe stop portions 42 -to thereby provide limits dening the ends of the arcuate path which theportions 42, and consequently the cuttingelement 73, travel.

Similarly, the concave surface 83 cut in the grinding wheel is Vachieved by measuring o the desired radius of curvature on the scales 58, 59. In this case, however, the cutting element is disposed or positioned above the axis 80. The sweep of the cuttingelement 73, or the length of its arc of travel, again is defined by appropriately setting thestops 37, 38.

Referring to FIGURES 9 and 10, the tool is illustrated with another form of work engaging member mounted thereto. As shown this member includes a shank 63a matingly engageable in the4bore 64 and capable of being secured therein by set -screw 66. A generally flat plate structure S4 is carried by the shank 63a and further has an undercutslot 85 provided in its forwardflat surface 86. Theplate 84 may be of any general shape, although it is illustrated as circular, and lfurther it is provided with threadedopenings 84a extending therethrough and arranged in the herein exempliiication in a series of concentric annular arrays of openings. The work engaging member, orplate 84, is employed to hold work pieces (not shown) to be ground by the grinding wheel. The work pieces generally are strapped or bolted to theplate 84. Often, once a 'wheel 79 is dressed, using the work engagingmember cutting tool 67, thetool 67 may be removed, theplate 84, with the work piece to be ground mounted thereon, set in place, and the actual grinding operation allowed to proceed. Other times the work Vpiece may require truing on theplate 84. But in either case, accurate movement of theslidable head 51 correctly positions the work piece relative to thewheel 79, and precision positioning is readily achieved by measuring the movement on the scales 58, 59.

As further seen in FIGURES 9 and l0, theplate 84 Vmay carry a V-block 87 mounted thereto. To mount the V-block 87, apassage 88 communicates between opposed surfaces of the same, and ascrew 89 extends in thepassage 88 to a position Whereat it is threadably engageable in a square headed nut 90 sildably mounted in the undercutslot 85. Once the V-block is positioned as desired, tightening `of thescrew 89 with the nut 90 locks it in place. Theslot 85 is so arranged that with thehousing 51 set at the zero position and the axis ofshank 68a is coincident with the axis ofshaft 28, theslot 85 extends radially of the axis ofshank 68a andshaft 28. Theslot 85 is further arranged to extend diametrically across theplate 84.

The V-block 87 further is provided withparallel Slots 91, 92, respectively provided in itsopposed sides 93, 94. Aclamp 95 is mounted to the V-block `87, the clamp comprising an inverted U-shaped member 96 having inwardly facinglegs 97, 97, arranged for slidable mounting in theslots 91, 92. Ascrew 98 is threadable through thebase portion 99 of the U-shaped member 96 for engagement against a work piece 109 held on the upwardlydverging surfaces 101, 102 of the V-block 87. As thescrew 98 is threaded down into engagement with thework piece 100, the U-shaped member 96 is drawn upwardly and thework piece 100 is held firmly in place. Referring back to FIGURES 1 and 7, themember 36 is provided with means for angularly positioning theassembly 34, and in particular theplate 84 when the same is carried thereby. This means is exemplified herein by arranged as a second annular array ofopenings 103 inmember 36 concentric with theopenings 39 therein. Astop 104 is arranged on support structure 2S for selective engagement in anyopening 103, thestop 104 being mounted in -asleeve 105 for axial movement ltherein. A compression spring 106 is provided aboutstop 104 and is anchored between a collar 107 onstop 104 and a shoulder 108 within thesleeve 105. Medially of its ends stop 104 is provided with a diametrally extending pin 109 providing opposed projections intended -for selective registry with diametrallyopposed slots 110 insleeve 105 when thestop 104 is located in its foremost position whereat it is seated inlan opening 103. At its outermost end thestop 104 is provided with a knurled knob 111 by which it may be axially and radially moved. It will be understood that to render thestop 104 ineffective, it is withdrawn, against the action of spring 106, tol a position whereat upon radially turning the knob 111 the pin 109 is positioned to engage against the outer end of thesleeve 105. For the purpose of brevity, only the actuating structure ofpin 104 has been described in detail; although, the structure forpin 76 is similarly arranged As thehandle 31 is turned, it rotates theassembly 34, theplate 84 carried thereby, and the work piece mounted to theplate 84. To position the work piece with reference to the grindingWheel 79 so as to grind surfaces thereon at any desired angle, theassembly 34 is Ilocked at the desired angular position by engaging thestop 104 in theopening 103 positioned before it. As illustrated in FIGURE 7, there are twelveopenings 103 uniformly angularly spaced apart by thirty degrees. Further, appropriate marks may be provided onmember 36 to yfacilitate grinding. That is, if a hexagonal shaped work piece is to be ground, the operation may be performed by .successively positioning thoseopenings 103 having a 6 designation thereat before thestop 104. Similarly, the surfaces of three and four sided work pieces may be ground in the same manner. When it is desired to lock theassembly 34 yand Work piece at -an angular position other than those :for which theopenings 103 are provided, thelock structure 112 shown in FIGURE 12 is employed. Thisstructure 112 includes ascrew 113 threadable in an opening 114 in standard 25 and engageable againstshaft 28 to lock lthe same in interpolated positions intermediate those Afor which 'theopenings 103 are provided.

Thus, with yan url-profiledwheel 79, that is one having only a flat grinding surface thereon, angular surfaces may be ground on a work piece by engaging the same with thewheel 79. And, this is `accomplished Without necessarily profiling angular grinding surfaces into the grinding wheel.

It further should be observed thatythe member 36, its array ofopenings 103, and thestop 104 selectively engageable therein, ideally provide means whereby theslidable head 51 may follow -a linear path disposed at any angle. Thus, with the cuttingtool 67 mounted to head 51, and themember 36 rotated to -a desired angular position, by properly manipulating the screw adjustment handle 56, the cuttingelement 73 may be moved relative to and across the face of thegrinding wheel 79 to proiile or dress a predetermined angular surface thereon.

In much the same manner, as explained hereinbefore, with a mountingplate 84 tixed to thehead 51, yangularly positioningmember 36 correspondingly angularly positions the work piece secured to plate 84. Thereafter, relative movement between thewheel 79 and work piece, to bring the latter into contact with thewheel 79, grinds the desired surface on the work piece.

To prevent backlash and inaccurate movement of the micrometer screw 54, the split friction construction shown -in FIGURES 1, 13 and 14 may be provided. As illustrated, the boss 55 is of .-a slotted construction and has -machine screws 115, 115, provided therein to draw the `lboss portions 117, 117, together to vary the frictional engagement with screw 54 as wear occurs. If the adjustment is too tight, it maybe changed slightly by turningscrew 116, which bears against one of theportions 117,

'to ease the `frictional engagement with screw 54.

Briefly, operation and use of the herein tool is as follows. To provide an arcuate surface in a grinding wheel lthe tool is set as seen in FIGURE l.

Thereafter, the radius of curvature of Ythe desired surface is measured off by turning screw S4 and measuring off the correct distance on the calibrations 58, 59. To limit the arc or sweep of the cuttingelement 73, thestop structures 37, 38, are set onmember 36 and thecooperable pin 76 is moved to an e'lfective position whereat it is engageable with the stops. To provide a convex surface Vin the grinding Wheel, the cuttingelement 73 is moved below the axis of rotation 80; while to provide a concave surface on thewheel 79, the cuttingelement 73 is moved to a measured position above the axis 80. When proiiling such arcuate Surfaces lon a wheel, the sweep of the cuttingelement 73 is in a plane generally perpendicular to the plane of theWheel 79.

To grind an angular surface on thewheel 79, the entire assembly is rotated -to the predetermined angle and is locked in position by engagingstop 104 in theproper opening 103 positioned before it. If the angular surface is `other than those -which theopenings 103 predetermine, theassembly 34 may lbe rotated to the desired angle and locked in position byscrew 113. Thereafter, by turningscrew lhandle 56, `thehead 51 carries the cuttingelement 73 angularly across thewheel 79 to provide the desired angular surface thereon. I-t will be apparent, of course, that by employing the herein structure it is possible to provide a combination of angle and radius curvatures on the :wheel 79.

When grinding a work piece, the cuttingtool 67 is replaced by the appropriate work piece retention structure shown in FIGURES 9 and 10. Gener-ally, to grind small articles of round configuration the V-block structure 87 is employed. Larger work pieces, and those of varied shape, generally are strapped to plate 84 and trued Ithereon. Thereafter, the work piece is introduced to the surface of thegrinding wheel 79. Specifically, angle grinding is achieved by settingmember 36 at the desired langles and introducing the -work piece to the atproiled wheel 79. As another example, after a wheel is dressed, for instance with a concave profile, theplate 84 is tted to thehead 51 and arranged to introduce the work piece, for which thewheel 79 had been proiiled, to thewheel 79. For this operation the work piece is moved in a direction generally parallel with the plane of thewheel 79 or perpendicular to the axis of rotation thereof.

Generally, when dressing arcuate surfaces into awheel 79, and when employing the V-block structure S7 to grind a work piece of Vround configuration, theassembly 34 is locked in a vertical position, `as seen in FIGURES 1, 4 and 9. From such position, positioning movements of the ywork engaging lmember may be readily measured. However, it should be understood that positioning movement of the work engaging members along paths other than those achieved with the set up in FIGURES 1, 4 and 9 may be readily measured without any appreciable calculation.

The herein invention thus provides a convenient and easy to use tool both for dressing grinding wheels and holding work pieces to be ground and for which the wheels are dressed. It should be understood that when redressing awheel 79, the amount of wheel diameter reduction can be compensated for by a corresponding Vmovement of the wheel Vtowards the cutting element.

Alternatively, the amount of reduction in diameter may be `compensated yfor by correspondingly increasing the micrometer positioning movement of theelement 73, as read on the calibration 58, 59.

The herein construction further provides a tool which may be readily broken down and reassembled as the need arises. The rotatable shaft 2S, itshandle 31,housing 35 andannular member 35 are arranged for quick attachment and detachment. For that matter, however, they may be of integral construction depending upon production and use considerations and the dictates of commercial practice. Theassembly 34 includes thehousing 35, `head 51 slidably mounted therein, andannular member 36 which as a unit combine to provide a novel Work engaging arbor or rotatable carrier further provided with its own integral measuring means for accurately positioning the work engaging member carried thereby. Themember 36 further provides structural indices both for limiting the sweep of the cuttingelement 73 when dressing arcuate surfaces and means for angularly positioning the arbor either for dressing angular surfaces on aWheel 79 or grinding a Work piece.

With the arrangement of the parts above described, it will be apparent that a highly simple, relatively inexpensive and very accurate grinding wheel auxiliary tool is provided. The replaceable and interchangable Work engaging members provide a substantially increased utility for a single tool of this character. These features, coupled with the fact that accurate positioning movement of the work engaging member is measured without the employment of extraneous indicator gauges and the like provide a tool of enhanced use and value heretofore unknown.

It will be understood, as indicated above, that changes in 'construction and arrangement of parts may be resorted to Without departing from the field and the spirit of the invention; that in this application only one 4form of the invention has been disclosed; and that the scope of the invention is deiined in the appended claims.

What is claimed is:

l1. A grinding wheel auxiliary tool comprising: a base, a vertical support bracket rigidly xed to said base, a carrier assembly revolubly mounted about an axial shaft carried by said base bracket, a housing and a head mounted for adjustable movement diametrically of the axis of rotation of the carrier assembly, a work engaging member detachably carried by the head, a micrometer screw drivably associated with the head to move the work engaging member relative to said shaft for measured distances in either of opposed directions from said shaft axis, and means in association with the micrometer screw calibrated to the work engaging member to indicate and directly measure linear positioning movement of the head and the work engaging member carried thereby for predetermining the arc or" movement of said work engaging member relative to a grinding wheel rotatively mounted in fixed relation thereto.

2. The grinding wheel auxiliary tool described in claim 1 and additionally including an indexing member in rigid association with the carrier assembly and provided with an annular arrayV of angularly spaced structural indices, and means arranged for selective cooperable action with any of ,the structural indices thereby to effect limitation of the angular swing of the carrier assembly and the Work engaging member carried thereby.

3. The grinding Wheel auxiliary tool described in claim 2 wherein the Work engaging member comprises an arm mountable to the head and a grinding Wheel cutting element detachably carried by the arm in axial alignment with said carrier assembly shaft.

4. The grinding Wheel auxiliary tool described in claim 3 wherein the indexing member and its structural indices -comprise a plate member provided with an annular array of uniformly angularly spaced openings concentric With the axis of rotation of the assembly and a pair of stop andassi members selectively positionable in any of the openings to predetermine the arc of rotation of the assembly, the means cooperable with the structural indices being selectively interposable into the path of the stop members and engageable thereby to limit the swing rotation of said carrier assembly.

. 5. The grinding wheel auxiliary tool described in claim 3 wherein the work engaging member comprises a support plate provided with means whereby a work piece is mountable thereto.

6. The grinding wheel auxiliary tool described in claim 5 wherein the indexing member and its structural indices comprise a plate member provided with an annular array of openings therein concentric with the axis of rotation of the assembly, and the means cooperable with the structural indices comprises a pin selectively seatable in the openings to lock the assembly and the plate carried thereby at selected predetermined angular positions.

7. The grinding wheel auxiliary tool described in claim 6 and additionally including means associated with the base and arranged to lock the assembly in angular positions other than those dened by the annular array of openings.

8. The grinding wheel auxiliary tool described in claim 6 and additionally including indexing marks on the plate member to designate those openings of the array of openings positionable before the pin so that specifically shaped work pieces may be ground.

9. The grinding wheel auxiliary tool described in claim 5 wherein the means provided with the support plate includes a work piece mounting block adjustably positionable on the support plate and having downwardly converging surfaces for seating a work piece thereon, and clamp means cooperably arranged with the block for maintaining the work piece thereon.

10. A grinding wheel auxiliary tool comprising: a frame including a ilat base adapted for seating at the work area of a grinding machine and an upstanding support extending from said base; a horizontal shaft rotatably mounted in the upstanding support; a handle provided adjacent one end of the shaft to effect manual rotation thereof; a housing xably carried at the other end of said shaft for rotation therewith; a member rigidly associated with said shaft and having an annular array of uniformly angularly spaced structural indices arranged concentric with the axis of rotation of said shaft; means arranged for cooperable action with said indices and limitation of the angular positioning of said shaft; a carrier head mounted in said housing and movable therein diametrically across said axis of rotation; a micrometer screw rotatably mounted in said housing, restrained therein against axial movement, and threadably engageable with said carrier head to move the latter relative to said shaft on said upstanding support for measured distances in either of opposed directions from said shaft axis; calibrations associated with said screw and arranged for registry with indicating means on said housing to directly measure linear positioning movement of said carrier head relative to said shaft; and a work engaging member including a shaping tool in axail alignment with said shaft detachably carried by said carrier head whereby said micrometer screw and calibrations directly predetermine the path of movement of said work engaging member relative to a grinding wheel rotatively mounted in fixed relation thereto.

1l. A grinding wheel auxiliary tool comprising: a support bracket frame, a rotatable shaft fixedly supported on said bracket frame, a handle provided for said shaft to effect manual oscillation thereof, a work engaging member, structure arranged with said shaft for rotation therewith and provided with positioning means whereby said work engaging member is movable and indexed for direct measurement relative to and diametrically across the axis of rotation of said shaft, said work engaging member including dressing instrumentalities in axial kalignment with said shaft,

means for Calibrating angular rotation and linear movement of said work engaging member including an indexing member provided rigid with said shaft and having an annular array of uniformly spaced structural indices arranged concentric with said axis, means cooperable with said indices to limit angular positioning of the shaft, and calibrations associated with said positioning means for directly measuring linear positioning movement of said work engaging member on said support bracket frame relative to said shaft to predetermine the path of movement thereof relative to a grinding wheel rotatively mounted in fixed relation thereto.

12. A grinding wheel auxiliary tool comprising: a support frame seatable at the work area of a grinding machine, a shaft rotatably mounted on said frame, means on said shaft to effect manual rotation thereof, a Work engaging member, a housing carried on said shaft for rotation therewith, a carrier lhead mounted to the housing for movement therein diametrically across the axis of rotation of said shaft and provided with means for detachably receiving the work engaging member, a micrometer screw drivably associated with said 4carrier head to move the same in either of opposed directions, calibrations associated with said screw for directly measuring linear positioning movement of said carrier head and said work engaging member relative to said shaft on said supporting frame to predetermine the radius of the arc of movement for said work engaging member, an indexing plate in rigid association with said shaft and provided with an annular array of openings therein concentric with said axis of rotation, stops adiustably positionable in said openings to predetermine the arc of rotation of said shaft, and means mounted with said frame and selectively interposable into the path of said stops for engagement therewith as said shaft is rotated to limit the degree of shaft rotation and predetermine the arc of displacement of said work engaging member, whereby said micrometer screw and indexing plate directly predetermine the path of movement of said work engaging member relative to a grinding wheel rotatively mounted in fixed relation thereto.

13. The grinding wheel auxiliary tool described in claim 12 wherein the work engaging member comprises an arm mountable to said carrier head and an element for profiling and dressing a wheel.

14. 'I'he grinding wheel auxiliary tool described in claim 13 wherein the indexing plate further is provided with a second annular array of openings which are uniformly angularly spaced and also arranged concentric with said shaft, and means mounted to said frame and selectively seatable in the openings of the second array thereof to lock said shaft, said indexing plate, and said work engaging member in predetermined angular positions.

15. The grinding wheel auxiliary tool described in claim 12 wherein the work engaging member comprises a work piece support structure provided with means whereby a work piece is mountable thereto, and additionally including a second annular array of openings in said indexing plate uniformly angularly spaced from openings adjacent thereto and also arranged concentric with said axis of rotation, and means mounted to said frame and selectively seatable in the openings of the second array thereof to lock said shaft, said support structure, and the Work piece mounted thereto in predetermined angular positions.

16. A grinding auxiliary tool comprising: a support frame, a shaft rotatably mounted on said frame, means on said shaft to effect manual rotation thereof, a work engaging member, a housing carried on said shaft for rotation therewith, a carrier head mounted to the housing for movement therein and provided with means for detachably receiving the work engaging member, a micrometer screw drivably associated with said carrier head to index and move the same in either of opposed directions relative to said shaft axis for direct measured distances therefrom, calibrations associated with said screw 1 1 for directly measuring linear movement of said carrier head and said work engaging member relative to said shaft on said support frame to predetermine the radius of the arc of movement for said work engaging member, an indexing plate in rigid association with said shaftk and provided with an annular array of openings therein concentric with the axis of rotation of said shaft, and means mounted to said frame and selectively seatable in any of said openings to lock said shaft and said work engaging member in predetermined angular limiting positions,

`whereby said micrometer screw and indexing plate directly predetermine the path of movement of said work engaging member relative to a grinding wheel rotatively mounted in fixed relation thereto.

17. The grinding wheel auxiliary tool described in claim 16 wherein the work engaging member comprises a grinding wheel dressing element provided With means for mounting the same to the head.

18. The grinding wheel auxiliary tool described in claim 16 wherein the work engaging member comprises a support plate provided with means for mounting a Work piece thereto.

References Cited in the le of this patent UNITED STATES PATENTS 893,954Huel Iuly 21, 1908 Y1,997,862 Halborg et al. Apr. 16, 1935 2,343,637 Bochenek Mar. 7, 1944 2,404,148 Thompson July 16, 1946 2,442,453 Bley June 1, 1948 2,642,856 Calloway June 23, 1953 2,744,515 Bruderick May 8, 1956 FOREIGN PATENTS 334,558 Great Britain Sept. 5, 1930 517,883 Italy Mar. 3, 1955 720,317 Great Britain Dec. '15, 1954 OTHER REFERENCES Wheel Dressing, etc., by Yarema; Machinery, pages 20 469 to 471, March 13, 1952, vol. `80. (Copy in Division

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