US2313055A - Grinding tool dresser - Google Patents

Description

March 9, 1943. G. A. DE vLlEG y 2,313,055

GRINDING TOOL DRESSER Filed Aug. 2, 1940 Sheets-Sheet l Mardi 9, 1943. GQA, DE \`/1 |Ec ;A 2,313,055

GRINDING TOOL DRESSER Filed Aug. 2, 1940 2 Smets-sheet 2 Zig. 3. b

-lNVENTOR A Gerard .Del/Neg 093m, Wm, @ivan/HJ ATTORNEY Patented Mar. 9, 1941? UNITED vS-'IATES PATENT OFFICE i 2,313,055 A l GRINDING Tool. DREssER v Gerard A. De Vlieg, Rockford, Ill. i Application August z, i940, serial No. 349,815

19 Claims.

The invention relates to the dressing of the grinding Wheels to different contours and the general object is to provide a mechanism which is simple in construction, which is convenient to operate, and which employs asingle dressing point guided in a novel manner to generate a wide v'ariety of selectively variable contours.

Another object is to provide for the dressing of a grinding wheel to contours controllable selectively and each composed of contiguous portions which are of different shapes and merge accurately with each other.

A further object is to provide for adjustment of the dressing tool guide in a novel manner that enables convex or concave contours to be produced selectively.

Still another object is 4to provide a novel adjustable mounting and guide for a tool by which different portions of the grinding wheel periphery are dressed by different characteristic movements of the tool support.

The invention .also resides in various novel combinations andarrangements of the parts by means of which accuracy and precision of operation are combined with ruggedness and low cost ofA l'construction and convenience of adjustment in service use.

Further objects and-advantages of the invention will become apparent as the following description proceeds, taken in connection with the accompanying drawings, in which Figure 1 is a generalperspective view of a dresser attachment embodying the invention.

the dressing point positions in dressing various wheel shapes. l

Fig. is an elevational view of a gage for facilitating adjustment of the dresser point.

By way of exempliflcation, the invention has been illustrated herein as embodied in a wheel dressing attachment of a form developed for use in a ymulti-purpose machine tool for grinding reamers, hobs, cutters, uted shafts, etc. It will be understood by those skilled in the artfhowever, that grinding tool dressers embodying the present invention may be adapted to a large vawheel'axis (see Fig. 6)!while guiding this oscil riety -of other machines. Accordingly', even.

of the invention as expressed in the appended claims. I

In the instant embodiment, the dresser includes a single dressing tool or point i0, such as a dia` mond or other extremely4 hard material, xed on the end of a pin Il and adapted to -dress the periphery of agrinding Wheel W. The'wheel in turn is used to shape a workpiece to a desired contour corresponding to the cross section to which the periphery of the grinding wheel is dressed.

In accordance with the present invention, the improved tool mountingandguide are adapted to dress the wheel periphery in a wide variety of 'selectively-variable shapes, thereby affording ka high degree of versatility in the machine operation. For example, the Wheel W may be dressed asfindicated in Fig. '7 with two angularly disposed anks I2vand I3 merging in asharp'edge I4 encircling the wheel. Alternatively, thel point I0 may be used to dress-an edge I4*ab of convex cross section and merginginto angled flanks L23' and.v

13e as shown in Fig. 8, or with an edge |41" of concave cross section disposed between angled flanks I2h and I 3b, as shown in Fi'g. 9. n Two different otions ofthe dressing point i0 are combined in enerating the variety of wheel 'I'he wheel direction generally toward and away from the lating movement with a suitably adjusted -template, the position of whose' guiding edges correspbnds to the desired angularity ofl`the wheel anks. On the other hand, the curved contour is produced during turning of the'point III about an axis (indicated at I5 in Fig. 2) extending gen-- erally tan'gentially of the wheel. Thus, if it is del sired to -form a convex edge llla as shown in Fig. 8, the point l 0 is displaced laterally outward from the axis of oscillation I5 a distance R1 equal to the desired radius of curvature. With the dressing point so located, oscillation of it about the the amount of displacement being equal to' the desired radius R: for the concavity. Then, by

Voscillating the point about its axis I5, it will generate the groove of concave cross section. Q Finally, if simply a sharp edge is desired .for the grinding wheel, the tip of the grindingpoint III is located precisely on its axis of oscillation as shownin Fig. 7, so that the position of the tip on a longitudinal axis, the axis I5 above referred to, and also to fulcrum universally'about transverse axes preferably disposed intermediate the bars ends.L The bar I6 has an offset lower end portion IB with a generally transverse bore I9 (Fig. 2) in which'the pin II is slidably mounted for endwise movement, the bore I9 being angled downward slightly as shown. A set screw 20 threaded in the lower end of the bar releasably .holds the pin II inposition.A The point I may thus be shifted toward andaway-from the longif tudinal bar axis I (for varying the radius of the point's oscillatory movement as described above) by loosening the set screw and shifting the CII pin II the necessary amount.- If desired, this may be accomplished conveniently with the aid `of a micrometer gauge`20 (Fig. 10) adapted 'to nt on the lower` end or the.y bar I8 and having an abutment 20b against which the point -lll is brought to'position the point a distance from the axis I5 corresponding to the reading on4 scales 20c.

28a and 29a. Herein, these are straight so as to produce straight flanks. By properly curving the guides, any other desiredshape of flank may be obtained. A handle I1 on the upper end of the bar may be grasped conveniently and utilized either to turn the bar while holding it seated in the guide notchor to swing the bar along either of the edges 28a or 29B while pressing the bar against such edge.

To enable the angles of the wheel i-lanks I2 and I3 to be varied individually relative 'to the plane of rotation of the wheel, the templates 28 and 29 are mounted forindependent bodily adjustment around the axis I5. For this purpose, the plate 28.`is screwed to the peripherally ilanged upper end of the sleeve 22 (Figs. 1 and 3). The plate 29 is fixed to a ring or collar 30 (Figs. '2 and 4) seated in an annular recess 3| in the upper end of the sleeve 22 and coaxial with the latter. Ilhis ring `30 is normally held in angularly adjusted position by a pair of, cylindrical clamp blocks 32 having nose portions 32a projecting into an annular peripheral recess 33 in the ring, the

blocks 32 being pressed down into lockingl posi- Upon desired angular position. vThe sleeve 22 can be swiveled about its longitudinal axis to adjust the position of its guide plate 128, the sleeve 'iltting into a split sleeve y depending lfrom a .housing designated generally as 36. 'Lugs 38 on th'e op- A bau and socket mounting, designated gen- I,

erally as 2|,` is provided for supporting the dresser bar I6 within a generally tubular housing or sleeve 22 (Fig.v2). This includes a spherical enlargement or ball 23 rigid with the b ar intermediate. the ends of the latter and having its v center 23* lying on the longitudinal axis I5 of thebar. Thesleeve 22 has a longitudinally ta pered bore 24 in its upper portionterminating in an undercut recess 25 at its lower end in which the ball 23 is socketed. A collar`26, threaded in longitudinal axis I5 and can also be tilted in any desired direction about the center 23B of the ball 23, this center lying onV the axis I5.V

Herein, the bar I9 is guided during its swinging movements andflocated while turning 4 by Y edges 28B and 299 on templates 28- and 29'which coact with-*the upper end portionfof the bar.

`of curvature coincident with the axis I5., The plates-are of generally sector shape and their edges coact to define a V-notch embracing the bar and locating the'axis o! the latter coincident withthe axis I5 when the-bar isseated at the root of the notch as show n in Fig. 3. In this position, the dresser-barY may-be oscillatedabout its longitudinal axisv I5,;or, alternatively, the bar may be swung s0 that it'rides `along one or" the other `oi"the edges 23"#0129'9. VvThisswmging movement is, as explained abovepusedin dressflanks of the grinding wheel W,.and,the angularity of thenanks so dressed is controlled by the angle included between The' contour produced'on theanks I2 and I3 The latter is of arcuate contour with its center' the guideA edges. 4

correspondsto the shape of the guide surfaces'ls lrigidly in its adjusted position.

posite sides of the split 31 are 4drawn together by a socket head screw- 39, to clamp the sleeve 22 'I'he angular adjustment of the plates,4 28, 29

lis indicated by aV pair of scales 40, 4I engraved cooperates Vwith an index mark 40B on the split sleeve 35 to indicate'the angular position of the guide plate 28 while an index mark 4'I (see Fig.

4) on the periphery 'of the guide plate 29 cooperates withthe scale 4 I to show the angular position of this latter guide plate.

VTo enable theA entire contour to be dressed by the same portion of the point I0, it is necessary at all times to maintain the pin II at the same` angle, perpendicular `in-'the present instance, to the part of the contour it is engaging. This involves turning the pinl II about'the axis I5 between the dressing of the intersecting wheel -anks I2 and I3 as in Fig. 7 as well as -when an intermediate curve I4 is generated as inFlgJ.

Moreover, the extentof the turning movement I must be gauged accurately in order that the contiguous surfaces of the different angles or shapes will merge accurately. Positively acting means is therefore providedfor limiting the turning of the bar IIS tofa range corresponding to the angleineludedv between the guide edges V28`and 29B. In the vpresent instance, this meansY comprises a cross bar 42 extending through and xed to the bar l6 above the plates 28 and 29 and arranged to cooperate with stop lugs 43 and 44 rigidwith and upstanding-from' the plates beyond the' outer Yends of the guide surfaces 28 and 29%. y'I'he active stop. surfaces 43* and 44 extend parallel to and are spaced laterally from eachguide surface toward the other guide surface a distance deter'- mined by the'diameters of thebar I6 and the' cross pin 42. This spacing is such that when the baris pressed into the notch defined by the guide surfaces and rotated luntil one end of the pin 'en'-l gages -one stop, the pin II carrying the dressing vpoint will'be disposed exactly perpendicular to one of the guide surfaces and, thereiore, t the `wheel surface that will be dressed by movethe plates 28 and' 28 andspaced from the stops 43'and 44 a distance equal to the diameter of the cross pin 42. These are lower than' the main stops so'that asthe bar I6 is turned whileseated in the root of the V-notch, the ends of the cross pinwill pass overthe auxiliary stops. Then, as

the bar. is swung outwardlyalong one guide surface, the pin end will be lowered suiicient1y..as

shown in phantom in-Fig. 6, to render the aux- `iliary stop eiective in preventing reverse turning In this way, the dressing point is is of'the bar. held positively in the correct position asit oscillatd along the guide surface.

Provision is made for bodily adjustment of the dressing attachment in the plane of rotation of the wheel to be dressed and also perpendicular to this plane or parallel to the wheel axis. For this' purpose, the housing 36 in which the sleeve 22 ts`is mounted to slide on af frame 45 ,(Fig; 1) in a. direction transverse to the axis of an arbor 46 which carries the grinding wheel W. The frame 4.5 is, in turn, mounted on a main frame 41 for adjustment in a direction paralleling the arbor.

More particularly, the housing 36 includes a cylindrical central body portion 48 and an integral depending semicircular wheel guard 49 (FigL 1).- A combined guide and clamp shoe 58of rec-v tangular shape (Figs. 2 and 5) is disposed b eneath the Abodyportion A48 of the vdresserhousing and is xed en the lower end of a pin I extending upwardly through the body portion 48.

A head 52 is threaded on the upper end of this pin 5I and has an operating handle 53 fixed toit.

dresser housing 36 rigidly in position. On" the other hand, when the handle 53 is turned to release Athe shoe 58 the ,latter guides 4the dresser housing for free ,sliding movement along the v guideway 54.

` To move the dresser housing 36 with respect to the frame45, a non-rotatable lead screw 56 ilxed in the body portion '48 of the dresser housing is used. This screw 56 extends through 'alined bores in-.a pair of spaced guide lugs 45? on the frame 45. Between these lugs, and threaded on the screw 56, is a knurled thumb wheel 51. Rotation of this thumb wheel 51 thus serves to 'shift the lead screw 56- axially and to move the dresser housing 36 correspondingly along its guideway. A micrometer gaugeis provided for indicating the adjusted position of the housing, including a scale 58 engraved on the hub of the wheel 51 and 'an index mark 58a 'on the adjacent portion of the l front lug-45B. (See Fig. 1.)

A similar thumb-wheel-operated .screw anrangement is provided for shifting the frame` 45 to and fro with respect to the wheel spindle hous ing 41. .In this connection, observe that the frame 45` includes an arcuate wheel guard portion 45b on its inner side overlying a complementally shaped guard projection 68 (Fig. 5) on the hous-l with it which guides -the movement or the frame L (Fig. 3). A non-rotatable lead screw 6I is fixed to the frame 45 and passes through a split sleeve 41a onthe wheel spindle housing 41 Figs. 1 and 5 5).

wheel51 described above, is threaded on this lead screw 6I and is revolved to shift the screw in and yout for shifting th frame. 45 and parts carried by it. To clamp the screw 6I against movement, ar in socket head .sicrew 63 is turnedto tighten the split sleeve 418. The dresser housing 36 and frame 45 cooperate to form a guard for the grinding wheel W. As heretofore noted, the dresserfhousing includes I5 a guard portion 49 (Fig. 1) which overlies the upper front side of the wheel and which, it may be noted, incidentally slides along thefront face of the frame 45 during positional adjustment of the dresser housing. As indicated in Fig. 2, the lower sidesof the dresser housingand frame are shaped to receive the wheel and a resilient sheet metal plate 64 spans the gap between them pre- Let it-first be assumed that the periphery of the wheelW is to be formed with straight flanks I2 and I3 intersecting 'ata sharp edge I4 as 3 mg, the guide edges 28a, 29 are adjusted to positions corresponding to the desired angles of the wheel flanks I2 and I3. For this adjustment, the screw 39 (Fig. 1) is loosened torelease the split clamping sleeve 3 5 and. the inner sleeve 22 is turnedv until the scale and marker 48, 48 show the guide edge 28a to be located in precisely the desired angular position for the flank I2, whereupon the clamp is tightened. Then the screws 40 34 are :loosened to release the clamps 32 and the ring 38 is turned around until its 'guide edge is positioned at the precise' angle required for the other ilank I3,I the angular relation of this guide edge to the sleeve 22 being shown by the scale 4 course, againgclamped tightly in position.

Next, the dressing point I8 is adjusted so that its active tip lies precisely on the longitudinal axis I5 of the dresser bar. For this purpose, the

set screw 28 is loosened and the pin II is shifted axially against the abutment 2 8". on the.microme ter gauge with the latter positioned on the'bar I6 asl shown in Fig. 10 and set with its scale reading zero. With the guides set up as described, the dresser` 'housing 3 8- and. frame' 45jv must also be preliminarily positioned.. For'this purpose the operator *grasps the handle of the dresser 'bar I6 and pulls l it into the root'of the notchV defined by the guide Gn edges 28a, 29a, so as to locate'the point I8 ina iixed plane in which the point I4 of inter- 'sectiozrwill be formed. The clamp sleeve 41a (Fig. 1) is loosened and thele'a'd s crew 63 run out, or drawn in, by. rotation Aof the thumb-wheel 62 65 until the `dresser point. I8 is located at a point relative to'the width of the wheel at which the edge I4 is ton be formed. Thereupon the sleeve 41B iskagain tightenedand 'the handle 5 3'Swung` to loosen the shoe 58 from its gibs 55 so that-fthe dresser housing 36 can be 'fedtoward the wheel periphery sufficiently to take the iirst cut across the latter. n

y After such adjustment of the dressing point, "f the motor (not shown) for rotating the wheel W ing 41 and having a, pin and S101-, nneetion 58 15 is started. Actual dressing of the wheel maybe A knurled thumb wheel 62', like the thumb f shown in Fig. '7.` vAs va preliminary tosuch dressf 45 and marker 4I.` Thereafter, the ring 3 8 is, of

to be generated asl dictated bythe contour of the wheel at the start. For example, if the wheel has been-previously dressed to the approximate contour desired, the operation may be started at the point `of intersection I4. In such a case, the bar I6 would rst be pressed into the'root of the notch between the guides 28.and 29B as shown in Fig. 3 the pin II and the point I0 being disposed in the full line position c (Fig. 7) so as to engage theWheel at-the desired point of intersection of the flanks I2 and I3. If the ank I3 is the first to be dressed, the handle. II is, as a preliminary, turned counter-clockwise as viewed in Fig. 3 until the cross pin comes against the stop 44 (Fig. 6) thereby bringing the dressing pin II to the position d (Fig. 7), the point I0 remaining on the axis I of the bar I6. Next, the bar IB is swung outwardly along the Aguide surface 29a while being maintained in contact therewith. A'

cut is thus taken across the flank by swinging cf mergence between opposite e f started at any desired pointalongthe contour stop 44 and the bar I6 swung outwardly alongV the guid 29, the pin Il and point IU being disposed.

beyond the wheel flank' I 3F inthe position f (Fig. 8). To dress this flank, the bar is rocked backwardly across the guide 29 to position the pin IIas indicated at g whereupon. the bar I6 will be disposed in the root ofthe guide notch. Then, the handle I1 is turned clockwise to generate the curve I4 by the point I0 as the pin passes through the full line position and reaches position lh. at which time the cross pin will engage the stop 43. Theilank i281 is-then dressed as the bar is moved out along the guide 28a. It will be observed thatwhen the`point I0 s at the points of the arc I4 .and the flanks I2 and I3, that is in positions of the bar to the position shown in phantom in Fig. 6. The poi'nt IIIYmay pass beyond the flank.

I3 tothe position e (Fig. 7) where the movement of the bar is limited by engagement with the sinterior/ oi the collar.

To dress the flank I2, the `bar is swung reversely along the guide 29'l to the apex ofthe notch and then .turned clockwise until the pin `42 engages the stop 43, the dressing pin -being thereby moved to position b (Fig. '7) with the point I0 coincident with the axis I5 and the wheel point I 4. The flank I2 is dressed by swinging the bar I6 outwardly along the template surface 28 to the position a (Fig. 7).- k

If additional cuts are to lbe taken, the dressing assembly is again advanced-through the medium of the screw 56 after which the bar is moved reversely from position a to position c then turned counter-clockwise to position d and moved along the surface '29 to position e thereby taking a "cut across the flank I3. This procedure may be. A 'repeated as' many times as may be necessary in order -to reduce the wheel tothe desired peripheral contour. When the bar is in either of the positions a or-e, it will be observed that the dressing point is out of the way and the dressed Wheel thus conditioned for-use as desired. To this end the thumb wheel 51 is rotated to move th dresser housing along its guideway 54 onthe frame 45. Customarily the dresser housing is moved until the dresser point I0, positioned with the bar I6 at the root of the guide notch, barely touches the periphery of the grinding Wheel.

Next to be' considered is the case in which the grinding Wheel W is to be formed with an edge of the curve I4i.4 The direcftion of the shiftxis away from the grindingwheel axis and toward the offset lower end I8 of the barA IB. After tightening the screw to lock the pin I I, the attachment is advanced-by `adjustment of the nut -51 to bring thefpoint I0 into cutting position.-

' .After the preliminary set up just described,

i the cross pin 42 may bein engagement with the g and h (Fig. 8), the dressing pin extends perpendicular to these surfaces and remains perpendicular to the flank or the curve in moving across the latter. As a result, the contiguous surfaces,

although of different contour. are perfectly blended together.

Substantially the same procedure is followed.' l

I in dressing the grinding wheel W with the concave cross section" |41 as indicated in Fig. 9 except that as in the preliminary set-up of the parts the tip of the dressing point I0 is displaced beyond or to the right (as viewed in Figs. 2 and 9) of the axis I5 rather than to the left of it as was 'the case in forming a convex cross section edge..

As before the setting of the pin II and therefore the radius of curvature Re for the groove or concave section is determined with the aid of the Y gauge 20 the parts being disposed as show nin Fig. 9. g

In this case, a somewhat different procedure is followed in actual dressing of the wheel because it will be observed from Fig. ,9, the flanks I2b and I3b and the curve -Ilb cannot be dressed in the same relative setting of the dressing point and wheel. Instead, this flanks are rst dressed following the procedure described above in connection with the flanks I2 and I3 (Fig. 7) and then the curve I4 is generated separately by indexing the point I0 toward the wheel axis-and after each such adjustment turning the bar I Il between the positions shown in phantom in Fig. 9. During this, the bar is of course held seated I in the guide notch and not oscillated along the guide surfaces.

It will be apparent from the foregoing that the invention provides a'gauge for guiding a single dressing tool with great accuracy to producev innumerable wheel contours which may be varied selectively as desired. In spite of its flexibility, the attachment is easy to adjust and to operate, no special skill being required. The contours generated are precise and the differently shaped sections always merge accurately to form a smooth continuous wheel surface.

I claim as my invention:

1. In a machine for dressing a grinding wheel,r

the combination of a' frame, means supporting said frame and a rotary grinding wheel for adjustment longitudinally and transversely of wheel axis, a bore in said frame -extending generally tangentially of said-wheel, a sleeve adiustably journaled in said bore;' aring journaled in said sleeve for adjustment about the sleeve axis. templates respectively carried by said sleeve and ring and having guide surfaces coacting to define a V-notch, a bar extending through said -n'otch and sleeve and rotatably supported with its longitudinal axis coincident with said sleeve Naxiswhen the bar is seated inthe root of said notch, said bar` also being fulcrumed intermediate its ends for universal swiveling about a point lying on said axis, one end of said bar being engageable with and guided by said surfaces and the other end being offset laterally from said axis, a dressing point supported by said offsetend for adjustment transversely of said axis and l engageable-with the periphery of said wheel.

2. In a machine for dressing a grinding wheel, the combination of a frame, a bore in said frame extending generally tangentially of said wheel, a sleeve tting in said bore and adjustable angularly, a ring rotatably supported in said sleeve for` adjustment about the sleeve axis, templates respectively carried by said sleeve and ring and having converging guide surfaces, a bar extend ing through said sleeve and rotatably supported with lits longitudinal axis coincident with said sleeve axis when the bar is'pressed against both of said surfaces, 'said bar also being fulcrumed for universal swivelingv about a point lying on said axis and guided by said surfaces during such swiveling, a dressing point supported by said bar for adjustment transversely of said axis and engageable with the periphery of` said wheel.

3. In a machine for dressing a grinding wheel,

guides coacting to form a notch for locating said bar on one of said axes, saidguides being engageable with said bar to guide its swiveling movements, andmeans supporting said guides for individual adjustment around said first mentioned axis.

'7. Mechanism for dressing the periphery of a rotary grinding wheel having, in combination,

an elongated bar mounted to turn on an axis extending generally longitudinally of the. bar and y to swivel universally about transverse intersecting axes, a dressing point engageable with said wheel and mounted on said bar, a pair of'straight guides mounted for individual 'adju ment around vsaid ylongitudinal axis and coact g to form a V-notch, said bar being disposed on said first axis when pressed into the root of said notch.

8. Mechanism for dressing the periphery of a Vrotary grinding wheel having, in combination, an

Y elongated bar mountedto turn about a predeterthe combination of a frame, a bore in said frame extending generally tangentially of said wheel, a sleeve fitting in said bore and adjustable angularly, a ring rotatably supported insaid sleeve for adjustment about the sleeve axis, templates respectively carried by said sleeve and ring and having guide surfaces coacting to define. a V-notch, a'bar extending through said notch and sleeve and supported toturnon an axis coincident with said sleeve axis when the 'bar is seated in said notch, said bar being swingable about transverse axes in moving along said guide surfaces, a dressing point supported by said bar for adjustment transversely of said first axis and engageable with the periphery o f said wheel, and

mounted on said bar, an arcuate surface on saidV stops limiting the turning of said bar in opposite Adirections about said first axis to dene positions of the tool-bearing a fixedl relation to the respec-f tive guide surfaces.

4. In a machine for dressing a grinding wheel,

the combinationof a frame, means supporting said frame and a rotary grinding wheel for adjustment longitudinally and transversely dfwheel axis, guide surfaces on said framecoacting to define a V-notch, a bar embraced by said surfaces 'and supported to turn on a longitudinal axis and and to swivel about transverse axes intersecting said longitudinal axis, one end' of said bar` being engageable with and guided by said'surfaces and the yother e'nd being offset laterally from said rst axis, a dressing Ypoint supported by -said off-'- set end for adjustment transversely of said axis and engageable with the periphery of said wheel. 5. Mechanism for dressing thetperiphery'of a /rotary'grinding wheel having, in combination,

an elongated bar, a bar and socket supporting said bar intermediate its ends to lturn on its longitudinal axis and to swivel universally about transverse intersectingaxes, a', dressing pointmined axis extending generally tangentially of `said wheel and to swivel universally about transverse axes intersecting on said axis, a dressing point engageable with said wheel and mounted on said bar for adjustment transversely of and across said first axis, and means coacting with said bar to locate it on said first axis during rotation of the bar and to guide its movement during oscillation about a transverse axis.

9. Mechanism for dressing the periphery of a rotary grinding wheel having, in combination, an.

elongated bar mounted to turn on an axis extending generally tangentially of said wheel and to swivel .universally about a transverse axis, a dressing point ,engageable with said wheel and bar concentric with saidv axis, and means providing converging guide surfaces locating the bar to turnon said axis when the bar is pressed against Aboth said surfaces and guiding the bar when the f latter is swiveled about, said transverseaxis.

10. Mechanism fordressing the periphery of a vgrinding wheel having, in combination, an elongated bar mounted to turn onits longitudinal axis and also swing in different directions about transverse axes, surfaces embracing said bar and guiding the same during said swinging movements, a member projecting laterally from and transversely-.of said bar and carrying a dressing point engageable with said wheel, and stops limiting the relative movement of said bar about said longitudinal axisv to positions in which said pin vextends transversely of the respective guide surfaces in directions substantially at right angles thereto.

11. Mechanism for dressing the periphery of a grinding wheel having, in combination, an elonmounted on one end of said bar, and means coacting with the other end of .said bar to locatev it during rotation and guide -it during oscillation about one of said transverse axes.

6. Mechanism fof dressing lthe periphery of a rotary grinding wheel having, Ain combination,

an elongated bar mounted to turn on an axis extending generally longitudinally ofthe bar and to swivel universally about transverse inadressing point engageable with 75 tersecting axes,

gated bar mountedv to turn on its longitudinal and also swing in diierent directions about transverse axes, surfaces embracing said bar and guiding the same during saidswinging -move-f said wheel land mounted on said bar, a pair of 6A said convex surface ai/id to oscillate about other axes to dress said flanks, and means guiding said tool throughout its successive movements and operable when maintained effective during such movements to hold the tool at a constant angle to the wheel surface at all pointsjacrossthe latter.

13. Mechanism for dressing a rotary grinding wheel to form singularly disposed flanks on opposite sides 'of the Wheel periphery and an intervening surface, means supporting said tool and guiding the same for dressing movement successively across one of said flanks, said surface and the other ank, means for adjusting said guiding means selectively to vary the position and angle ofthe individual flanks relative to each other, and .independent means for adjusting said tool to vary the curvatureiof said surface while providing for accurate mergence of the contiguous wheel surfaces dressed by the tool.

14. Mechanism for dressing a rotary grinding wheel to form substantially straight anks on opposite sides of the wheel periphery, said mechanism comprising a dressing tool, means supporting and guiding said tool along different paths to dress the respective Shanks while permitting of angular adjustment of the tool when the' latter is disposed between said-paths, and means limiting said angular adjustment to positions in to dress different contiguous peripheral portions 'Y thereof during the rotational and swiveling movej ments of said member, and means positively limiting the rotative movement of said member in one direction to establish a fixed angular relation between the tool and wheel surface during swiveling movement of the member. i 16. Mechanism for dressing the periphery of a rotary grinding wheel having, in'combination, a member mounted to turn about one'axis and to tilt about a transverse axis, a dressing tool carried by said member and engageable with said wheel to dress Adifferent contiguous peripheral portions thereof-'during the rotational and swivel- 'v .while engaging said first stop to prevent reverse rotation of the member;

. f 17. Mechanism for dressing the periphery o f a rotary grinding wheelhaving, in combination, a

member mounted to turn about one axis and to tilt about a transverse axis, a dressing tool carriedVA by said member and engageable with said wheel to dress differently contoured contiguous peripheral v portions thereof during the rotational and swiveling movements of said member, and stopmeans operable to maintain a constant angular relation of said tool 'to the wheel surface during a con- -tinuous movement of said member to dress said V contiguous portions successively.

18; Mechanism for dressing the periphery of a rotary grinding wheel having.' in combination, a member mounted to turn about one axis and to tilt about a transverse axis, a dressing tool carried by said member and engageable with saidI wheel thereof during the rotational and swiveling movements of said member, and means rendered effective in the initial swiveling movement of said member to prevent rotation of the member in one direction during the continued swiveling;V

19. Mechanism for dressing the periphery of a rotary grinding wheel having, in combination, a member mounted toturn about one axis and to tilt about a transverse axis, a dressing tool carried by said member and engageable lwith saidl wheel to`dress differently contoured contiguous peripheral portions thereof during the rotational and swiveling movements ofsaid member, said member having an external surface of arcuate contour, a template engageable with said arcuate surface and guiding said tool to generate said contours during said rotational and swiveling movements, and meansl supplementing the action of said template during certain positions of said swiveling movement to hold said member against saidrotational movement. l f

GERARD A. DE vmne1 to dress different contiguous peripheral portionsv

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