US2365302A - Grinding apparatus and method - Google Patents

Description

Dec. 19, 1944.

'r. c. SHUTT El'AL GRINDING APPARATUS AND METHOD 4 Sheets-Sheet 1 Filed May 2a, 1945 5011519 JJlemez' am, 140

Dec. 19, 1944. v SHUTT AL 2,365,302

GRINDING APPARATUS AND METHQD 4 Sheets-Sheet 2 Film; May 28, 1945 120mm ajmz lowly JJ'iem Dec. 19, 1944.

-'r. c. SHUTT ET AL v GRINDING APPARATUS AND METHOD 4 Sheets-sheaf. 3

Filed May 28, 1943 120mm @1211 M Z oazls JJ'ieziver 4 ad/l8 Dec; T c AL I GRINDING APPARATUS AND METHOD 4 Sheets-Sheet 4 Filed May 28, 1943 ails" said 'srna ller' plug.

Patented Dec. 19, 1944 2.365.302"; GRINDING APPARATUSIAND METHOD l mm; cjsh'ua and Louis J. Steiner, A Detroit, Mich;

Application May 28; 1943, Serial-No.-488,900-

:11Claims; (c1.5 1' 10b).

The presentiinv'ention relates to. metal grind? ing apparatus, 'a'ndinor'e particularly to a"nove l method and apparatus for grinding a contour on a," work piec'e corresponding identically with that on a master template. I

' More specifically; ,the

invention comprises grinding apparatus including "a grinding machine having a rotatable'spindle carrying a, grinding wheel and means for dressing said grinding wheel to corresponding with the diameterof a circular guide or element mounted on the table of the grinding machine in axial alignment with the grinding wheel. in onefe'rnbodirnentfof the in vention, the guide meanscOnsists of circular plugs of progressively varying diameter removably mounted in an opening in-thetable axially aligned with theax'is' of the, grinding wheel. These removable plugs serve a dual purpose in thepresent invention. First, they. serve, as a guide means, for positioninga wheel dressing device in Suchmanner thatupon operation of said device it will] dress the grinding wheelto a diameter correspondin iiactly to that of the plug. Secondl'y-, .the cylindicalplug serves as a guide, for. a combinedmaster;template and jig which. holds the work while it is being ground to shape by the grind ing'wheel.

Qne of th important advantages. orsthe in-j vention over prior devices is that inaccuracies in grinding due towearofvthe grindingwheel are wholly. eliminted. Thisj -is achieved' by. the suc-- cessive manual} replacement of one. plug by a slig'htly ,.smaller plug.' smiths dressing lof he grinding wheel to correspond to the diameter of, By virtue of this-arrange! ment,highly accurajte grinding can bedone and in actual practice it is easy to maintain a toler-v ance as low as 0.0005 of an inch.

The principal object oftheinvention sit provide 'aj metal' grinding apparatus which will duplicate orreproduce curved jandlor' straight contours upon metal work-pieces rapidly an with great accuracy.

Another object of thefin ventionv istoprovide,

a grinding apparatusfin whichftheftzustomary inaccuracies due t'of'weariof the grinding wheel are eliminated and high precision v grinding is inadepo'ssible' I Another-object ofjtheinventionis to provide means foraccurately dressing the peripheryof a grinding wheel to make it-conform to a given surface contour on a master tracer block.

Still another object of the invention is 'to'p'rovicle conveniently arranged means on the table ofa grindingmachine for quickly and accurately L dressinga" grinding" wheel; and which means can be readily'swung out of the'way aboutits mount ing means'so'as notjto interfere with the man pu lation offthe work duringthe grinding operation.-

-'Other objects and advantages oi the invention: will be apparent from the-following description taken in conjunction with the accompanying drawings in which? v Fig. 1 is-afront"elevation'of agrinding machine and a grinding wheel dressing device embodying the principlesof the'invention; Fig. -2 is a sectionarplan view taken on-the .2' f Fig.1 "andshowing the inactive posinon of the wheel'd-ressing device in dot-and-dash lines; -v

Fig. 3 is a vertical sectional view through the wheel dressing device taken on the line'3-3:-"of Fig.2; 'l-

-Fig. 4isa fragmentaryview partly in sectlon illustrating the/manner in which' the work is carried by the master template 'andguidedto reproduce thecontour of the template on said work-piece; y H 'f Fig. 5 is a" view similar to Fig. 4, 'but showing a guide plug of 'smallersize and aj'grindingwheel of like size,-whereby-the relationship between the template and grinding'wheel-is unchanged regardless of wear and *l'epe'ated dressing or the grindingwhe'el; '-f- I Fig. 6' is a perspectiveview; 'of the} I combined master'template'and work'holderj Fig. '7 is a vie'wsimilarto-Fig s; but-snow ng a modifiedtracer block forthe'wheel dressingdevic,-wher'eby the grinding wheel may be -given a' desired predeterminedirregularsurface con; figuratiom i l Fig. 8'is' a'vie'w of a-modified' form of wheel dressing device in which' the wheel dressing hit is spring-pressed toward a circulajr guideplug instead of having the body of the wheel dressing device "adjustablewith'respect to said plug *Fig; 9 is a'view partially insection' of the wheel dressing device'sho'wn in Fig.8; and e "Fig. 10 is a sectional view taken on the line lil.l0ofFig 8. H 1 Referring now'to Fig. '1 of "the drawings; the

grinding machine comprises a tablel' carrying" spaced, vertical posts 2 andf3. A transverse member 4fis mounted on the {posts-2 and-*3 in vertically" spacedr'elation: to theta ble "IL; The transverse member- 4 carries a' conventional "or suitable spindle 5 adaptedtobedriven by a'pulley 6; A grinding 'wheel" Iris suitably mounted in the spindle '5. It'will be understood that the 4 spindle '5' may be raised-or lowered by any conventional or suitable means (not shown) to position the grinding wheel I to suit the work or the wheel dressing device described later.

The table is provided with a tapered opening 8 having its axis vertically aligned with the axis of the spindle 5. A circular guide plug 9 having a tapered shank H) is mounted in the taperedopening 8. Figure 1 shows the grinding wheel I dressed to exactly the same diameter as the plug 9. A series of plugs 9 of progressively varying diameter is provided so that as the grinding wheel wears in use a slightly smaller plug is substituted and the grinding wheel is then dressed to correspond to the diameter of the substituted plug.

The grinding wheel dressing device is generally indicated by the numeral I l and comprises a body l2, the base of which rests flush upon the upper surface of the table I. The wheel dressing device H is made so that it can be bodily moved toward and away from the grinding wheel 1 to facilitate wheel dressing and to be swung out of the way about the post 3 when not in use. To this end, the body 12 is provided with an elongated slot l3 (Fig. 3). The post 3 is threaded as indicated at [4 and a nut l5 and cooperating washer l6 serve to clamp the body 12 in any desired position relative to the grinding wheel l, or to clamp the same in its inactive out-of-theway position, as indicated by the dot-and-dash lines in Fig. 2. While a conventional nut, washer and thread have been shown as a locking means for the wheel dressing device i I, it will be understood that any other suitable clamping means may be employed. Y

The body 12 is provided with a generally T- shaped slot N, (Fig. 2), the head portion 18 of which is adapted to receive a master tracer block I9 which is rectangular in cross-section. The block I9 is held in place in the slot portion l8 by a screw 23 threaded into a boss 2! formed on the body i2. The block l9 preferably extends above the upper surface of the body 12 so that it can be easily grasped for removal. The stem portion 22 of the T-shaped slot 11 is enlarged medially of its length to receive a cylindrical slide member 23. The lower end of the slide member 23 has a transverse bore 24 (Fi 3) in which a combined tracer and dressing bit 25 is freely mounted for reciprocation. The tracer-bit 25 ha an enlarged pointed end 26 which is adapted to engage a surface 21 on the block IS. The tracer-bit 25 also 3 position the slide 23 and is pivotally connected to said slide by a screw 31. The opposite end of said operating lever is flattened to provide a handle portion 38.

It will be particularly noted from Fig. 2 that the tracer-bit 25 rides in the stem portion 22 of the slot H as the slide 23 is raised or lowered by manipulation of the operating lever 36.

In using the wheel dressing device H, the clamping nut 15 is released and the body I2 is adjusted relative to the plug 9 so that the diamond point 29 engages the plug and lies along a line drawn through the center of the post 3 and the center of said plug, the elongated slot l3 permitting any shifting of the body 12 that may be necessary. The clamping nut I5 is then tightened to lock the body 12, against movement relative to the table I. It will be apparent from the arrangement of the links 33 and th operating lever 36 that when the handle portion 38 is pulled down, the slide 23 will be raised, carrying the tracer-bit 25 withit. The pointed end 26 of the tracer-bit 25 is engaged with the plain surface 21 of the block l9 under the influence of the spring 3|. The spindle 5 is rotated at this time so that as the diamond point 29 engages the grinding wheel I, it will true up said wheel and form a peripheral surface thereon in parallel with the surface 21 of the master tracer block l9. After the wheel 1' has been dressed, the wheel dressing device I i may be moved out of the way by loosening the nut l5 and turning the body l2 about the post 3. Tightening of the nut l5 will then look the device l I in its inactiv position.

It will be understood that as the grinding wheel I Wears, and progressively smaller plugs 9 are mounted in the opening 8 in the table I, the elongated slot l3 in the body l2 will permit the dressing device H to be successively locked in closer to the axis of the spindle. In this way, the wheel dressing device H can be readily adjusted to dress the grinding wheel from the time that it is initially used until it has been worn to such degree as to require discarding.

The circular guide plug 9, in addition to serving as a means for positioning the wheel dressing dehas a reduced and pointed end 28 upon which is preferably mounted a diamond 29 for dressin the grinding wheel I. A threaded closure plug 30 slidably receives .the reduced portion of the tracer-bit 25 and is mounted in the slide 23 at one end of the bor 24. A spring 3| surrounds the reduced portion of the tracer-bit 25 and engages the inner side of the closure plug at one end thereof and the enlarged portion of said tracerbit at the opposite end and constantly urges the pointed end 26 into engagement with the master surface 2'3. The lower end of the block [9 is tapered as indicated at i9 (Fig. 3) so that it can readily displace the tracer-bit 25 during insertion of said block.

The body l2 carries an integral lug 32 which serves as a support for one end of a pair of links 33, a pin 34 extending through the lug 32 and pivotally supporting the lower ends of said links. The upper ends of the links 33 are pivotally connected by a pin 35 to an intermediate portion of an operating lever 35. One end of the operatinglever engages a fiat surface on the upper end of vice H to dress the grinding wheel I, also serves as a guide for a combined master template and work holder 4!! shown in Fig. 6. This template includes a base portion 4i which is adapted to rest fiush upon the upper surface of the table 1. The longitudinal edge 42 of thebase portion M is provided with a contour or configuration which it is desired to reproduce upon a suitable workpiece X indicated in dot-and-dash lines. As shown, the work piece X is adapted to rest against the base 4| and a wall 43 extending upwardly from said base. One end of the workpiece X is also adapted to be engaged with a transverse abutment 44 formed on the end of the template 40. The work-piece X is clamped to the master template 40 by any suitable clamping means (not shown).

In use, th master template 40, with the workpiece X attached, is manually moved upon the table i with the contoured edge 42 disposed to ward the guide plug 9. The work-piece X, of course, is engaged with the grinding wheel 1. As the work-piece X is ground away, the edge 42 of the template 40 engages the periphery of the guide plug 9 and upon movement of the edge 42 along said plug, the material of the work-piece X will be ground away to a configuration conforming to the contour of said edge. Any wear on the grinding wheel can be compensated for, as

wheel previously explained, by substituting a smaller plug 9 in the opening 8 and then dressing'the grinding wheel 7 so that its diameter will correspond exactly to that of the substituted plug. By maintaining this identity of diameters, it is possible to duplicate various contours with unusually high accuracy. If desired, the work-piece X may be rough ground to the. approximate shape of the template 49 and then accurately ground to final form on the template 40. v I A.

Fig.5 illustrates the manner in which the relationship between the grinding wheel 1, the work X and the master template 49 is maintainedby the use of the plug means 9 even after the wheel 7. has worn considerably. n 1 v Fig, 7. illustrates th manner in which a tracer block l9 may have a configured surface i2! provided thereon when it is desired to alter the crosssectional configuration of the work-piece. -This figure illustratesthe tracer-bit .25 and diamond point 29 elevated to a position where the diamond is in engagement with a grinding wheel .7 to dress the same to a contour conforming to the shapeof the surface 21 It will be understood that as the slide 23 is raised and lowered by operation of the lever 36, the spring 3| will urge the tracer point 26 into intimate contact with the surface 2? sothat an accurate duplicationthere of will be effected on the periphery of the wheel 'h' v It will be apparent from the foregoing thatby using the circular guide plugs 9 as a means for positioningthe wheel dressing device ll to dress the grinding wheel 1 to thesame diam'eter as said plug, and by using the same plug as a guide for the master template ii), extremely accurate 9 ,at any portion of its periphery and the work .4

manipulated upon the table in any convenient manner without resulting in inferior grinding Referring to the modified embodiment of :the invention shown in Figures 8 to 10, the wheel dressing device H comprises a body I2 provided with a circular opening l3 (Fig. 9), instead of an elongated opening as in Figure 3. Thus, the body [2 is mounted for simple rotation about the post 3 and is not adjustable in a directiontranse versely-of said post. However, the wheel dressing device l i may be held in any desired radial p sition of adjustment about the post 3 by any suit-1 ablevclamping means, for example the nut l5 and the washer lfi 4 v A slightly modified form of slide 23 is mounted in the body hand is adapted to be raised or lowered by links 33 and an operating lever 36 similar to that previously described. 9

block,23 by a locking screw52 (Fig. 10)} which I 54 is fastened to the outer end of the locking screw 52 by a small set screw 55, which enables the arm 54 to be, so adjusted onthe locking screw- 52 that it can turn through the necessaryangle to lock: and unlock "the wheel dressing bit without hindrance bythe table I, 7 The locking screw 52 extends through an elon; gated vertical slot 56 in the-body l2 so that as the slideil3 is elevated to bring the cutting point 29 intoengagement with the grinding wheel'l, said locking screw will rise vertically in said slot.

In using the wheel dressing device'shown. in Figures '8 to 10,'the bit- 25 may be manually pressedinwardly against the action of the spring 3i so that it will clear the'plug 9 while the body I2 "is being positioned so" that the point 29 0f saidbit falls upona line' 'passing through the center of the post 3 andthe center. of the plug'9; The'dressing bit 25 may then be released and the spring 3| will automatically urge it into snug en gagement with theperipheral surface of the plug 9. Tightening of the nut 15 will securely clamp the body l2 'against the table I. The arm 'dd is then rotated andvthe screw 52-connected therewithlocks the shank 59: of the bit 25 against axial'movement relative to the slide 23 With the dressing bit Zl'wlocked in position, the'lslide Zit -can then be: elevated by "the'operating' lever M i-praise the point 29 'of said bit into engagement withthe grinding wheel l to dress it to the same diameter as thecircular guide plug 9. After the wheel has been dressed,- the nut 15 is loosened and the wheel dressingdevice H 'swung about the. post 3.so that it will be out of the way and The wheel dressing device I i shown inFigures 8 t lO'isparticuIarIy adapted for dressing, grinding wheels having plain peripheral surfaces and is simplified in the respect that it is so constructed that the. necessity for a tracerblock, such asthe block H3 ,or, 59 is eliminated. vThis is accomplished by' having the dressing bit 25 slidably mounted ina bore 2 1 in the lower portion of the slide 23*! so that the working point 29 thereof is urgedtoward the circular guide plug 9 by a spring i3l 'as best shown in Figure 9. The dressing. bit

- ZS has a, reduced shank 59 carrying a pin '5! whichlimits the outward movement of the dressing bit 25 and also maintains the same in assembled relation with the slide 23 The wheel dressing bit 25 can be locked in any desired position of adjustment relative to the slide during the grinding operation.

It will be understood that various changes may be-made in the details of construction of the wheel dressing devices andv in the clamping means therefor shown hereiniwithout departing from the spirit'of' the invention or the scope of the an nexedclairnsr r ;Whatweclaimis:' I r 1. Grinding apparatus comprising: a tablep-a rotatable spindle; means supporting said spindle forro-tation relative to said table: a grinding wheel carried by saidspindle; a circular guide I mounted upon said table below said grinding wheel inaxial alignment with said grinding wheel;; a wheeldresser mounted upon, said table including a dressing tool engageablewith the periphery of saidcircular guide; and means for elevating said dressing tool into engagement with said grindingiwheel to dress the' same toxa diameter corresponding to thatof said circular guide. a

2. Grindingapparatus co-mprisingqa table; a

rotatable spindle; means supporting said spindle wheel to dress the same to a diameter corresponding to that of said circular guide plug.

3. Grinding apparatus comprising: a table; a rotatable grinding Wheel; means supporting said grinding wheel for rotation relative to said table; a circular guide mounted upon said table below said grinding wheel in axial alignment with said grinding wheel; and a grinding wheel dresser including a body, a slide mounted in said body, a wheel dressing bit carried by said slide and adapted to have the working point thereof brought into engagement with said circular guide, and means for elevating said slide to raise said Wheel dressing bit to a position in engagement with said grinding wheel, whereby to dress said grinding wheel to the same diameter as said circular guide.

4. Grinding apparatus comprising: a table; a pair of spaced posts mounted upon said table; a transverse member supported by said posts in vertically spaced relation to said table; a rotatable spindle carried by said transverse member; a grinding Wheel carried by said spindle; a circular guide mounted upon said table below said grinding wheel in axial alignment with said grinding wheel; a wheel dresser mounted upon said table for swinging movement about one of said posts; and a wheel dressing bit carried by said wheel dresser for dressing said grinding wheel to the same diameter as said circular guide.

5. Grinding apparatus comprising: a table; a pair of spaced posts mounted upon said table; a transverse member supported by said posts in vertically spaced relation to said table; a rotatable spindle carried by said transverse member; a grinding wheel carried by said spindle; a circular guide mounted upon said table below said grinding wheel in axial alignment with said grinding wheel; a wheel dressing device mounted upon said table for swinging movement about-one of said posts and including a wheel dressing bit for dressing said grinding wheel to the same diameter as said circular guide; and means for clamping said wheel dressing device against said table.

6. Grinding apparatus comprising: a table; a pair of spaced posts mounted upon said table; a transverse member supported by said posts in vertically spaced relation to said table; a rotatable spindle carried by said transverse member; a grinding wheel carried by said spindle; a circular guide mounted upon said table: below said grinding wheel in axial alignment with said grinding wheel; and a wheel dresser mounted upon said table for swinging movement about one of said posts including a slide, a wheel dressing bit carried by said slide, a spring for yieldably urging the working point of said wheel dressing bit into engagement with the periphery of said circular guide, means for locking said spring-urged wheel dressing bit against movement relative to said slide, and means for elevating said slide to raise said locked wheel dressing bit out of engagement with said circular guide and into engagement with said grinding wheel to dress said grinding wheel to the same diameter as said removable plug.

'7. Grinding apparatus comprising: a table; a rotatable grinding wheel; means supporting said grinding wheel for rotation relative to said table; a circular guide mounted upon said table below said grinding wheel in axial alignment with said grinding wheel; and a wheel dressing device mounted on said table including a body, a slide mounted in said body, a wheel dressing bit mounted in said slide, means carried by said slide yieldably urging the working point of said dress ing bit into engagement with said circular guide,

means for locking said dressing bit against movement relative to said slide, and means for elevating said slide to raise said dressing bit to a position in engagement with said grinding wheel, whereby to dress said grinding wheel to the same diameter as said circular guide.

8. Grinding apparatus comprising: a table; a rotatable spindle; means supporting said spindle for rotation relative to said table; a grinding wheel carried by said spindle; a removable, circular guide plug carried by said table below said grinding wheel in axial alignment with said grinding wheel; and grinding wheel dressing means mounted upon said table including a body having a tracer block fixedly mounted therein; a slide movable vertically relative to said block; a combined tracer and wheel dressing bit ounted in said slide, said tracer-bit having one end thereof engageable with said tracer block and its other end provided with a diamond point engageable with said circular plug, means constantly urging said tracer-bit into engagement with said tracer block, and means for elevating said slide to a position to engage said diamond point with said grinding wheel to dress at least a portion of the periphery of said grinding wheel to the same diameter as said circular guide plug and to shape the remainder of said periphery to a contour corresponding to that of the surface of the tracer block engaged by said one end of said tracer-bit.

9. Grinding apparatus comprising: a table; a rotatable spindle; means supporting said spindle for rotation relative to said table; a grinding wheel carried by said spindle; a removable, circular guide plug mounted upon said table below said grinding wheel in axial alignment with said grinding wheel; and wheel dressing means adjustably mounted upon said table and including a body having a tracer block fixedly mounted therein, a slide mounted in said body, a wheel dressing bit carried by said slide, means urging one end of said wheel dressing bit toward said tracer block, said end of said bit being pointed to enable the same to accurately follow the configuration of said tracer block, the opposite end of said wheel dressing bit carrying a cutting element adapted to be engaged with the outer periphery of said circular guide plug to determine the position of said body upon said table for performing a wheel dressing operation, means for clamping said body to said table, and means for actuating said slide to raise said wheel dressing bit out of engagement with said circular guide plug and into engagement with said grinding wheel, whereby to impart a peripheral shape to said grinding wheel corresponding to that of the surface of the tracer block engaged by said pointed end of said wheel dressing bit.

10. Grinding apparatus comprising: a table; a rotatable spindle; means supporting said spindle for rotation relative to said table; a grinding wheel carried by said spindle; a removable circular guide plug mounted upon said table below said grinding wheel in axial alignment with said grinding wheel; and wheel dressing means adjustably mounted upon said table and including a body having a tracer block fixedly mounted therein, a slide mounted in said body, a wheel dressing bit carried by said slide; means'urging one end of said wheel dressing bit toward said tracer block, said end of said bit being pointed to enable the same to accurately follow the configuration of said tracer block, the opposite end of said wheel dressing bit carrying a cutting element adapted to be engaged with the outer periphery of said said body upon said table for performing a wheel dressing operation, means for clamping said body to said table, an operating lever pivotally connected with said slide, and a pair of links pivotally mounted at one end upon said body and pivotally connected at their opposite end to the medial portion of said operating lever, so that upon actuation of said operating lever said slide will be elevated to raise said wheel dressing bit out of engagement with said circular guide plug and into engagement with said grinding wheel, whereby to impart a peripheral shape to said grinding wheel corresponding to that of the surface of the tracer block engaged by said pointed end of said wheel dressing bit.

11. Grinding apparatus comprising: a table; a

rotatable spindle; means supporting said spindle for rotation relative to said table; a'grinding wheel carried by said spindle; a circular guide mounted upon said table below said grinding wheel in axial alignment with said grinding wheel; a wheel dresser mounted upon said table including a dressing tool engageable with the pe-,

riphery of said circular guide; a spring for yieldably urging the working point of said dressing tool into engagement with the periphery of said circular guide; means for locking said spring-urged dressing tool in adjusted position; and means for elevating said dressing tool into engagement with said grinding wheel to dress the same to a diameter corresponding to that of said circular guide.

THOMAS C. SHUTT. LOUIS J. STEINER.

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