US2600548A - Grinding wheel truing apparatus - Google Patents

Description

June 17, 1952 L. J. LALIME GRINDING WHEEL TRUING APPARATUS 3 Sheets-Sheet 1 Filed Sept. 5, 1946 June 17, 1952 L. J. LALIME 2,600,548

GRINDING WHEEL TRUING' APPARATUS Filed Sept; 5, 1946 3 Sheets-Sheet 2 INVENTOR June 17, 1952 J. LALIME 2,699,543

GRINDING WHEEL TRUING APPARATUS Filed Sept. 5, 1946 3 Sheets-Sheet 5 a \D N Patented June 17, 1952 eeelieeieee pi mee 5, 94 seie i fle-ee if The pre ent inxeption xele te togpngmvemente in e j'i qin' Wh t His 2 pi nc pa o v w. de endvel'and Limnmxed ndi g wheel tryin ap a atus naming .2 pl a li y 9 twine device a apte v r ,h 'uin vb el 'q ye y incl ned peripheral grinfi ir f .a ehpl sie .inding wheel to cause feces" 1:9 Jge trged w t accurac mid a n, m p edete mined an le with ,l elajiion fio ne anggher} his a ur he obj ct of Ja iny mi n .1 p id a nove n mm yied t i e -en er tt e o is e fieral descri fi lll ada ted vtrui j x the faces of e equa vt u- H V .Q m valq s cran wheel for .the filmin me re eeeiive ieme er and s eu de .2 Mine cs we a whis h pxoyisicnn mafia me we em ,potions ofth whee um pleyices 1n; m'we manner to QQntIpI theihi gh degree of accuracy required, the size Of the included angle betwe n .tlge en ndm i qe T m chine 2 ed in t e d wings a mbbdyijn in i q mk lgei e e a 'i u s o flie .inv i qpl pri e Ia sh ld nd n .me iii e o t p hav n a w rk .tahl a In d him ,fi enelat ymovements .meansi r 1:9 ampl 'SHpPQ j ng 1 Wor th .o .a c oss slide. em gta g ind ng wheel Spindle vin i @13 e li l et en a n an t the axis of rp atibnfif th w d .Tl croes' slide 911 .which'gge spiridle'is rrgour jge d fcr hou de etinqi e The W n e exews Pre iew i e e rda c With th inv ntien; m innise' a fi min evic which i mounted il iiml .si e j he g dme wh e or .mwememlw t 1 'w eu e t fortruin the metereexiphera rind ng eu e cf t .8)" en L 9. twine s e e which is1mou edet't. rea id .Q xtbe gr ndin w e for l i e fihe' 1 el ferin in i v ei 0f ithe wi eel. The 12 eel a e mount d i9. cause the mnekmp w 9 'amete and hoqlde sired eagl wit re including {the tru ihg es is s1 i h t at the lan .0: moyem efe hp mig .tppl w t ea on to .th .e tieclie li e i 'l z esi @1 3 t parts vam ie y :21 m."fed- Dr v nteny pe i't e er e m me el rei e e 1 Mine. e-

'yices.

Further in accordance with the invention,

means a e pr qed cfqfefl q ing e emn ular adjustment of me rin e he? E e ide .Q me me hin f siz c the "iiihi'de' i a r angle between gmeter enq' s hou-l er r1 ding surfces' of @eva tae" thit -it W th t 'a'b iew as may he'i 0 feapuree of ighe inventipn; Fig. 2 is a ifragmentary gene ehdwv a Shoulder gmqing' machine1similair 13o Athafi;

40 Egg. 1:, egibepi: ftl-iat fllthe grindizig wheel ing devices; Fig. 6 illustrating a grinding wheel having its axis set at a 45 degree angle for the grinding of a shoulder when. the included angle is exactly 90 degrees, this being the arrangement shown in greater detail in Fig. 1; Fig. 7 being similar to Fig. 6, but with the grinding wheel axis tilted slightly to produce a slightly less than 90 degree included angle between the inclined grinding surfaces; Fig. 8 being similar to Fig. 6, but with the grinding wheel axis tilted slightly in the opposite direction to produce a slightly greater than 90 degree included angle between the inclined grinding surfaces; Fig. 9 illustrating a grinding wheel having its rotational axis set at a 30 degree angle from the axis of rotation of the work, and with the truing devices arranged to produce an included angle of 120 degrees between the inclined grinding surfaces; and Fig. 10 illustrating a grinding wheel with its axis of rotation set at degrees from the axis of rotation of the work, and with the truing devices arranged to produce a 90 degree included angle between the inclined grinding surfaces.

Referring to the drawings, the illustrated machine comprises a base generally indicated at I0, a transversely movable slide support l2 which carries on a swivel mounting (not shown) a work table l3 having thereon a headstock l4 and a footstock [6, a grinding wheel support in the form of a cross slide 18 adapted for movement at right angles to the Work table 18, and a grinding wheel 28 having its axis of rotation set at an angle to the plane of movement of the work. The work table is movably supported on a slideway comprising a Vshaped way 22 and a fiat way 24,

translatory movement being imparted to the table by means of feed connections which may be of ordinary description including a cylinder and a piston on a piston rod generally indicated at 26. The cross slide I8 is supported for sliding movement on a way generally indicated at 38, and is adapted to be moved toward and away from the work through connections which include a cross feed screw 32, a nut formed in 2. depending lug 34 on the cross slide 18 and a hand wheel 38 at the front of the machine. The grinding wheel 28 is mounted on a spindle 48 which carries at its other end a pulley 42 connected through belts M and a pulley 48 to be driven from an electric motor 48.

In accordance with a feature of the invention, the grinding wheel assembly above described, is supported on the cross slide I8 in a manner to permit of a slight angular adjustment of the grinding wheel with relation to the truing devices of the machine hereinafter to be described. To this end, a swivelling wheel spindle supporting plate 52 is mounted to turn about a swivel 54 on the cross slide l8, and is formed with an upwardly extending standard 56 which provides a bearing for the grinding wheel spindle 48 and with a supporting bracket 58 to which is secured the spindle motor 48. In the embodiment of the invention shown in Fig. l of the drawings, in which the grinding wheel spindle is set at approximately a degree angle to the work, a mechanism for adjusting the angular position of the support 52 and the grinding Wheel 20 is provided, which comprises an adjusting worm 88 and Worm supporting shaft 62 which is mounted at the rear of the cross slide 48 in lugs 64, 68. The worm 68 engages the teeth of a worm gear segment 68 formed in the rear end of the swivel support 52. The swivel support 52 is rigidly secured in adjusted position with relation to the cross 4 slide 18 by means of a series of clamping machine screws 10, I2, 14, I6 and 18, which extend through slots in the swivel support 52, and are screwthreaded into the face of the cross slide 18. The slots referred to, are disposed circumferentially of the swivel 54 and permit the swivel support 52 and grinding wheel 20 to be adjusted angularly in each direction by a small amount approximating three degrees with relation to the cross slide 18.

In the embodiment shown in Figs. 1, 2 and 3 of the drawings, the grinding wheel spindle 40 and grinding wheel 28 are set with the rotational axis at a 45 degree angle with the work, and the grinding wheel is formed with two inclined surfaces including a diameter grinding surface for grinding the peripheral surface of the work along the axis thereof, and a shoulder grinding surface 82 disposed at a degree angle with relation to the diameter grinding surface 80. A truing device which may be of ordinary description, is provided for truing the diameter grinding surface 88, said device comprising generally a support 84 which is adapted to be mounted on the work table 13, and a truing tool 88. In accordance with the invention, a separate truing device is provided for truing the shoulder grinding surface 82, comprising a bracket 88 which is adapted to be mounted on the work table l3, and carries thereon a truing tool support 98 and a truing tool 92 adapted for engagement with the shoulder grinding surface 82 of the grinding wheel at the rear side of the wheel. As best shown in Figs. 1 and 2, the tool support 98 is mounted for adjustment on a guideway 94 formed on the support 88 at a 45 degree angle to the axis of rotation of the work, so that the truing tool may be adjusted along a line extending radially of the grinding wheel. An adjusting screw 95 having a knurled head 98 screw-threaded to the tool support 98 and supported against axial movement in a bearing I80 at the end of guideway 94 provides a convenient means of adjustment of truing tool 92.

The operation of the truing apparatus above described, and particularly illustrated in Figs. 1 to 3 of the drawings, may be briefly described as follows: The truing device comprising truing tool 86 for truing the diameter grinding surface of the wheel, and the shoulder truing device comprising truing tool 92 for truing the shoulder grinding surface, are located in their adjusted position preparatory for the truing operation which is performed while the grinding wheel is running by effecting a translatory movement of the sliding support l2 and work table 13 thereon to the right, so that the truing tools 86 and 92 respectively, are caused to engage with and true the respective diameter and shoulder grinding surfaces. In order that these surfaces, and more particularly the shoulder grinding surface 82 may be trued to precisely the desired angle, an adjustment or correction may be made in the angular position of the swivel support 52 and grinding wheel 20 mounted thereon by loosening clam-ping screws 16 to 18 inclusive, and thereafter by rotating the worm shaft 62 and worm 68. Diagrammatic Figures 6 to 8 inclusive of the drawings, indicate the manner in which this correction is made. Fig. 6 illustrates a truing operation under conditions in which the grinding wheel spindle 48 is set at exactly a 45 degree angle to the plane of movement of the work support, and in which the included angle between the diameter and shoulder grinding surfaces is exactly 90 degrees. In the event that inspection of work previously completed on the machine, indicates that the grinding surface should be trued to a slightly smaller included angle, the swivel support 52 and grinding wheel assembly thereon may be swung slightly in a counterclockwise direction through a small angle. In the drawings, an adjustment of three degrees is indicated, and in which the grinding wheel spindle 46 is set from a 45 to a 48 degree angle with relation to the plane of movement of the work. Under these conditions the diameter grinding surface 85 will be trued in the normal manner to a plane parallel to the direction of movement of the work support, while the surface '82 will be trued to a less than 90 degree angle with the diameter grinding surface 80. Similarly, if the desirability of a greater than 90 degree included angle is indicated, adjustment of the grinding wheel assembly including the swivel support 52 and grinding wheel 26 may be effected in a clockwise direction, so that the grinding wheel spindle axis is set from 45 to 42 degrees with relation to the :plane of movement of the work support. The diameter grinding surface 85 is again trued to a plane which is parallel to the direction of movement of the work support, while the shoulder grinding surface 92 is trued to a greater than 90 degree angle with the shoulder grinding surface 82. While in the drawings, a range of adjustment of three degrees in each direction is indicated, it will be understood that any range of adjustment larger or smaller than that indicated may be employed if so desired.

Figs. 4 and 5 of the drawings, illustrate a modified form of truing apparatus embodying the several features of the invention, which is adapted for the truing of a shoulder grinding wheel having the axis of rotation of the wheel set at a 30 degree angle from the plane of transverse movement of the work. In this form of the invention, the grinding wheel assembly including a grinding wheel III], a grinding wheel spindle H2, pulleys H4 and H6, belts II 8 and motor I26, are carried in a swivel support I22 with the spindle and grinding wheel set at a 60 degree angle from the plane of movement of the cross slide I8, and at a 30 degree angle from the plane of movement of the slide support I2 and work table I3. Angular adjustment of the position of the swivel support I 22 and of the grinding wheel assembly thereon is obtained by means of a worm shaft I24 mounted at the forward end of the cross slide I8 in lugs I26, I28, and a worm I36 which engages with a worm gear segment I32 cut in the forward end of the swivel support I22. In the embodiment of the invention illustrated in Figs. 4 and 5, the swivel support I22 is rigidly clamped in adjusted position by means of a number of clamping screws designated at I34, I36, I33, I49 and I42 which extend through slots formed in the swivel support I22, and are screwthreaded into the cross slide I8.

The truing devices provided for this form of the invention, comprise the truing tool 86 carried on its bracket 84 on the work table I3 for the truing of the diameter grinding surface indicated at 244 of the grinding wheel I I0. The mechanism provided for this form of the invention for truing the shoulder grinding surface of the wheel designated at I45, comprises a truing tool I46 which is supported and arranged for engagement with a portion of the grinding wheel diametrically opposite that engaged by the diameter surface truing tool 86. The truing tool I46 is mounted in a holder I 48 adjustably supported in a housing I50 which is in turn mounted for sliding movement on ways I52 on a bracket I 54 fixed to a transverse abutment I56 on the cross slide I8. The holder I48 is shifted radially toward the grinding wheel by means of a positioning screw I58 connected at its rear end by bevel gears I60 with a vertical shaft I62 which is in turn connected through bevel gears I64 with a horizontal actuating shaft I66. At its forward end the shaft I66 is formed with a hand wheel I68. For moving the tool holder I46 across the face of the grinding wheel, driving connections are provided in the form of a driving screw I16 which is screw-threaded into the base of the housing I50 and supported against axial movement to turn in a bearing provided in an upwardly extending flange I12 of bracket I54. The screw I16 is driven by means of an electric motor I14 through connections which comprise a belt I16 which passes around a pulley I18 driven from the motor I14 and around a pulley I carried on the screw shaft I16. Control of the motor I14 to cause the diamond tool holder I46 to dress the shouldered surface of the grinding wheel may be effected by any suitable electric circuit to the motor I14 as, for example, one which is responsive to switches on panel I84 (Fig. 4) with separate control buttons marked respectively Stop, Start and Reverse. The operation of truing the shoulder grinding surface of grinding wheel I I it is readily performed either during the operation of truing the diameter grinding surface or independently thereof.

The relationship of the grinding wheel I I 0 and the two truing tools 86 and I46 for the truing of the diameter grinding surface I44 and shoulder grinding surface I45 of the grinding wheel IIG set at a 30 degree angle from the work in accordance with the disclosure of Figs. 4 and 5, is particularly illustrated in diagrammatic form in Fig. 10. From an inspection of Fig. 10, it will be appreciated that in order to obtain a 90 degree in cluded angle of the grinding surfaces I44 and I45, the truing tool I46 must move in a plane which is inclined 60 degrees to the axis of rotation of the wheel III] and 30 degrees from the plane of movement of the slide support I2 and work table IS. A maximum rigidity of the supporting slide for the shoulder truing tool I46 is obtained by mounting the shoulder truing device directly upon the cross feed slide I8 which also carries the grinding wheel assembly. A truing device of the general type illustrated in Figs. 4 and 5, for the truing of the shoulder grinding surface of the wheel I I0 is of general application and is capable of use in the manner herein described for any angular setting of the grinding wheel and grinding wheel spindle with relation to the cross feed slide and work support, and for the truing of relatively inclined diameter and shoulder grinding surfaces of whatever included angle. In the event that a truing device of this general type is employed for the truing of a shoulder grinding surface of a wheel set at a 45 degree angle as shown in Figs. 1 and 3, the tool support slide will then be supported on ways to move in a plane parallel to that of the work support. Any inaccuracy which might be found to exist in the angular relation of the machined supporting ways for the work table and the shouldered truing tool support is quickly and easily compensated for by a compensatory adjustment in the angular position of the swivel support I22 and the grinding wheel assembly mounted thereon.

Diagrammatic Fig. 9 of the drawings illustrates still another form .of the shoulder grinding wheel in which the wheel is set at a 30 degree angle from the plane of movement of the work support, and in which the shoulder surface truing tool and the diameter surface truing tool are maintained in parallel relation, to produce an included angle of 120 degrees between these surfaces. As in the instances previously discussed, an adjustment of the included angle to the most exacting standard is readily obtained by an appropriate angular adjustment of the grinding wheel assembly with its swivel support upon the cross slide [8.

While an illustrative form of the invention has been described in considerable detail, it will be understood that numerous changes in the construction and arrangement of the several parts and in the general application of the invention may be made, without departing from its principles and scope. The terms and expressions used herein have been employed as terms of description and not limitation.

What is claimed is:

1. In a grinding machine having a work support and a grinding wheel carriage supported on the machine for relative cross and translatory movement on the machine, rotary work supporting means on the work support, a spindle support mounted swivelly on the grinding wheel carriage at right angles to the directions of said cross and translatory movement, a grinding wheel spindle mounted on said swivel support, and a grinding wheel mounted on the spindle having relatively inclined abrading surfaces for work periphery and shoulder grinding, the combination of a truing attachment for truing said relatively inclined abrading surfaces to a predetermined included angle at a single setting of the grinding wheel and truing attachment, which comprises a work periphery truing tool mounted on the machine for movement in said translatory path and positioned for movement across said work periphery abrading surface in truing engagement therewith, a shoulder truing tool mounted in the machine to move in a linear path angularly related to said translatory path and positioned for movement across the work shoulder abrading surface in truing engagement therewith at the opposite side of the spindle from the work periphery truing tool, said shoulder truing tool being further supported from the machine for shifting movement transversely of said path against the shoulder abrading surface of the wheel, and means securing the swivel spindle support to the carriage in a position of fine angular adjustment to determine the included angle between the periphery and shoulder abrading surfaces.

2. In a grinding machine having a work suppor and a grinding wheel carriage supported on the machine for relative cross and translatory movement on the machine, rotary work supporting means on the work support, a spindle support mounted swivelly on the grinding wheel carriage at right angles to the directions of said cross and translatory movement, a grinding wheel spindle mounted on said swivel support, and a grinding wheel mounted on the spindle having relatively inclined abrading surfaces for work periphery and shoulder grinding, the combination of a truing attachment for truing said relatively inclined abrading surfaces to a predetermined included angle at a single setting of the grinding wheel and truing attachment, which comprises a work periphery truing tool mounted on the work support for movement in said translatory path for truing said work periphery abrading surface, a

shoulder truing tool support mounted in the machine to move in a linear path angularly related to said translatory path across the work shoulder abrading surface at the opposite side of the spindle from the work periphery truing tool, said shoulder truing tool support being further supported from the machine for shifting movement transversely of said path against the shoulder abrading surface of the wheel, a shoulder truing tool mounted on said shoulder truing tool support, and means securing the swivel spindle support to the carriage in a position of fine angular adjustment to determine the included angle between the periphery and shoulder abrading surfaces.

3. In a grinding machine having a work support and a grinding wheel carriage supported on the machine for relative cross and translatory movement, rotary work supporting means on the work support turning on an axis extending in the direction of said translatory movement, a spindle support mounted swivelly on the grinding wheel carriage at a right angle to the directions of said cross and translatory movements, a grinding wheel spindle mounted on said swivel support, a grinding wheel mounted on the spindle having relatively inclined abrading surfaces for work periphery and shoulder grinding, the combination of a truing attachment for truing said relatively inclined abrading surfaces to a predetermined included angle at a single setting of the grinding wheel and truing attachment, which comprises a work periphery truing tool mounted on the work support for movement in said translatory path for truing said work periphery abrading surface, a shoulder truing tool mounted on the work support at the opposite side of the spindle from the work periphery truing tool to move in said translatory path across the shoulder abrading surface, said shoulder truing tool being further supported on the work support to move transversely of said translatory path for adjustment of the shoulder truing tool against the shoulder abrading surface of the Wheel, and means securing the swivel spindle support to the carriage in a position of fine angular adjustment to determine the included angle between the periphery and shoulder abrading surfaces.

4. In a grinding machine having a work support mounted for translatory movements in the machine, a rotary work supporting means on the work support turning on an axis extending in the direction of said translatory movement, a grinding wheel carriage mounted on the machine for cross feeding movement toward the work support, a spindle support mounted swivelly on the grinding wheel carriage on an axis at right angles to the carriage, a grinding wheel spindle on the swivel support, a grinding Wheel on the spindle having relatively inclined work periphery and shoulder abrading surfaces, the combination of a work periphery truing tool mounted on the work support for movement in said translatory path for truing said work periphery abrading surface, a shoulder truing tool support mounted on the work support at the opposite side of the spindle from the periphery truing tool, a shoulder truing tool mounted on said shoulder truing tool support to move with the work support in said translatory path across the shoulder abrading surface, a guideway on the work support on which the shoulder truing tool support is adjustable along a path directed radially toward the axis of the grinding wheel spindle, actuating 9, means connected between the work support and shoulder truing tool support for moving the shoulder truing tool against the shoulder abrading surface of the wheel, and means securing the swivel support to the carriage in a position of fine angular adjustment to determine the included angle between the periphery and shoulder abrading surfaces. 7

- 5. In a grinding machine having a work support, rotary work supporting means on the work support, and a grinding wheel assembly including a grinding wheel carriage on the machine. a spindle support mounted swivelly on the grinding wheel carriage at right angles to the carriage, a grinding wheel spindle mounted on said swivel support, and a grinding wheel on the spindle having two relatively inclined work periphery and shoulder abrading surfaces, said work support and grinding Wheel carriage being mounted on the machine for relative cross and translatory movements, the combination of a dressing attachment for dressing said relatively inclined abrading surfaces on'the grinding wheel to the desired angles at a single setting which comprises a truing device mounted on the work support at the work engaging side of the grinding wheel spindle including a work periphery truing tool carried on the work support and movable relatively to the grinding wheel in a fixed path following the direction of said translatory movement for truing said work diameter abrading surface, a second truing device comprising a shoulder truing tool, a shoulder support on which said shoulder tool is mounted on the carriage movable in a fixed path for truing engagement with the other of said abrading surfaces at the opposite side of the grinding wheel from the work periphery truing tool, actuating means connected with said shoulder tool support to move said shoulder tool support and shoulder truing tool in said path, and fine gauge adjusting means controlling the angular position of the swiveling spindle support and grinding wheel spindle on the carriage.

6. In a grinding machine having a work support and a grinding wheel carriage supported on the machine for relative cross and translatory movement, rotary work supporting means on the work support turning on an axis extending in the direction of said translatory movement, a grinding wheel having relatively inclined work periphery and shoulder abrading surfaces, a grinding wheel spindle on which the grinding wheel is mounted, and a spindle support on the carriage on which the wheel spindle is supported for swiveling adjustment with relation to the directions of said cross and translatory movement, the combination of a dressing attachment for dressing the relatively inclined Work periphery and shoulder abrading surfaces of said grinding wheel which comprises a work periphery abrading surface truing device on the work support at the work engaging side of the grinding wheel spindle including a truing tool responsive to the relative translatory movement of the work support and carriage for truing said work periphery abrading surface, a shoulder abrading surface truing device disposed at the opposite side of the grinding wheel spindle from the periphery abrading surface truing device comprising a shoulder truing tool support mounted in the machine for movement in a path of predetermined fixed direction, and a shoulder abrading surface truing tool mounted on the tool support for movement in said fixed path across said shoulder abrading surface, and adjusting means controlling the swivel position of the swivel support and grinding wheel to vary the included angle between said relatively inclined work periphery and shoulder abrading surfaces.

7. In a grinding machine having a work support mounted in the machine for translatory movement, rotary work supporting means on the work support turning on a horizontal axis, and a grinding wheel assembly including a grinding wheel carriage mounted in the machine for cross feeding movement, a spindle support mounted swivelly on the grinding wheel carriage on a vertical axis, a grinding wheel spindle mounted on said swivel support to turn on a horizontal axis set at approximately a angle to the direction of said translatory movement, and a grinding wheel on the spindle having relatively inclined work periphery and shoulder abrading surfaces, the combination of a work periphery surface truing device comprising a work periphery abrading surface truing tool, and means supporting said tool on the work support at the work engaging side of the grinding wheel spindle, a shoulder surface truing device comprising a shoulder truing tool support mounted on the work support, and a shoulder abrading surface truing tool mounted on the said shoulder truing tool support engaging a portion of the shoulder abrading surface of the grinding wheel at the opposite side of the grinding wheel spindle from the work periphery abrading surface truing tool, and adjusting means controlling the angular position of the swiveling support and grinding wheel spindle on the grinding wheel carriage to vary the included angle of said relatively inclined abrading surfaces.

8. In a grinding machine having a work support mounted in the machine for translatory movement, rotary work supporting means on the work support, and a grinding wheel assembly including a grinding wheel carriage mounted in the machine for cross feeding movement, a spindle support mounted swivelly on the grinding wheel carriage on an axis at right angles to the carriage, a grinding wheel spindle mounted on said support, and a grinding wheel mounted on the spindle having relatively inclined work periphery and shoulder abrading surfaces, the combination of a truing device comprising a work periphery abrading surface truing tool mounted on the work support and engaging a portion of the work periphery abrading surface of the wheel at the work engaging side of the grinding wheel spindle and acting to true said work periphery abrading surface, a shoulder abrading surface truing device disposed at the opposite side of the wheel spindle from the first mentioned truing device comprising a shoulder abrading surface truing tool, a shoulder truing tool support slidably supported on the grinding wheel carriage for movement along a fixed path a-ngularly related to the direction of said translatory movement of the work support, an electric motor, and driving connections from the motor to move said slidable support and truing tool across the shoulder abrading surface, and adjusting means controlling the angular position of the spindle support on the carriage to vary the included angle of said work periphery and shoulder abrading surfaces.

9. In a grinding machine a combination in accordance with claim 8 in which the shoulder truing device comprises a guideway on the spindle carriage, a shoulder truing tool supported on the guideway for movement along the line of movement followed by the truing tool across the shoulder abrading surface, and a-tool holder movably supported on the shoulder truing tool support for adjustment in a direction perpendicularly toward and away from the grinding wheel axis, and actuating means on the machine connected with the work truing shoulder support operable to move the shoulder truing tool support in the guideway for truing said shoulder abrading surface.

10. In a grinding machine having a work support supported for translatory movement, rotary work supporting means on the work support turning on an axis extending in the direction of said translatory movement, and a grinding wheel assembly including a grinding wheel carriage supported on the machine for cross feeding movement toward the work support, a spindle support mounted swivelly on the grinding wheel carriage on an axis at right angles to the carriage, a grinding wheel spindle mounted on said support, said spindle being disposed on the carriage with its axis at approximately a 30 angle from the direction of said translatory movement, and a grinding wheel having relatively inclined work periphery and shoulder abrading surfaces, the combination of a work periphery abrading surface truing device comprising a work periphery abrading surface truing tool mounted on the work support, a shoulder abrading surface truing device disposed at the opposite side of the grinding wheel spindle from said work periphery abrading surface truing device comprising a shoulder abrading surface truing tool, a

12 support on which said shoulder surface truing tool is mounted, and a guideway on the grinding wheel carriage on which the shoulder truing tool support is movable to true said shoulder abrading surface at a 90 included angle with relation to the work periphery abrading surface of the wheel, actuating means on the machine connected with the tool support operable to move said tool support on its guideway, and adjusting means controlling the angular position of the wheel spindle support on the carriage to vary the included angle of said trued work periphery and shoulder grinding surfaces LESTER J. LALIME.

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

UNITED STATES PATENTS Number Name Date 1,769,143 Koskinen July 1, 1930 1,871,504 Einstein Aug. 16, 1932 2,004,426 Booth July 11, 1935 2,178,842 Paine Nov. 7, 1939 2,272,088 Hultgren Feb. 3, 1942 2,287,701 Nelson June 23, 1942 2,323,401 Johnson July 6, 1943 FOREIGN PATENTS Number Country Date 451,465 Germany Oct. 31, 1927

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