US3017875A - Form dressing device - Google Patents

Description

Jan. 23, 1962 A. J. JoNEs 3,017,875

FORM DRESSING DEVICE Filed April 17, 1957 4 Sheets-Sheet l ATTORNEY INVENTOR ALV/N J.JONES Jan. 23, 1962 A. J. JONES FORM DRESSING DEVICE 4 SheetsSheet 2 Filed April 17, 1957 INI/ENTOR.

ALV/N .fon/Es TTRNEY Jan. 23, 1962 A. J. . JONES 3,01%?5 FORM DRESSING DEVICE Filed April 17, 1957 4 SheetsSheet 5 TORNEY Jan. .23, 1962 A. J. JONES FORM DRESSING DEVICE Filed April 17, 1957 E mm EJ. VJ mw l- A TORNEY 3,017,875 FRM DRESSING DEVICE Alvin J. Jones, Waynesboro, Pa., assigner to Landis Tool Company, Franklin, Pa. Filed Apr. 17, 1957, Ser. No. 653,418 7 Claims. (Cl. 12S-11) This invention relates to forming and dressing apparatus for abrasive wheels.

For the grinding of work having spaced shoulder portions such as the crank pins and line bearings of an automotive crankshaft, the corners of the grinding wheel must be formed to a small radius. None of the devices used at present for this purpose is satisfactory. Perhaps the most commonly used means is a small piece of abrasive which the operator holds against the corner of a rotating Wheel, testing the contour from time to time until an acceptable radius is formed.

It is an object of the present invention to provide means whereby corners of predetermined radii may be formed rapidly and accurately without interrupting the operating cycle of a grinding machine.

A further object is to provide axially spaced dressing members formed to dress wheel corners to a predetermined radius.

A yfurther object is to provide means for limiting the penetration of the dressing members.

FIGURE 1 is a partial end elevation of a grinding `machine showing the means for `advancing and retracting a dressing device relative to the grinding wheel.

FIGURE 2 is a partial sectional plan view of a single dressing unit.

FIGURE 3 is a partial plan view of a plurality of dressing units arranged for simultaneously dressing a plurality of wheels of different diameters.

FIGURE 4 is `a partial sectional plan View of a dressing tool for dressing the corners of a grinding wheel.

'FIGURE 5 is an enlarged plan view of a corner of a grinding wheel showing the relation between the corner dresser and the locating roller when the corner dressing operation is performed before the face of the grinding wheel is dressed.

FIGURE 5A shows the relation between the wheel face, corner dresser yand the face dresser when the corner dressing operation is performed before the face dressing operation.

FIGURE 6 is an enlarged plan view showing the relation between the corner dresser and the locating rolle-r when the corner dressing operation is performed after the face of the grinding wheel is dressed.

FIGURE 6A shows the relation between the wheel face, corner dresser and the face dresser when the corner dressing operation is performed after the face dressing operation.

Numeral 10 indicates the bed of a grinding machine, 11 is a wheel base slidably mounted on said bed 10. 12 to 17 inclusive are grinding wheels rotatably mounted on said wheel base 11. These wheels are rotated through conventional means by a moto-r 20 mounted on wheel base 11.

As shown in FIGURE 2, each dressing unit consists of one or two diamond impregnated rollers 30 and 31 with an intermediate or adjacent locating roller 32 all rotatably mounted on bearings 33 on a shaft 34. Between said rollers and said bearings 33 is a sleeve 40 having threaded end portions on which nuts 41 and 42 are mounted to hold the rollers in proper axial position. A series of peripherally spaced teeth are formed on each of said nuts 41 and 42 so that the nuts may serve as impellers when acted upon by a stream of air or liquid to provide initial rotation of the dressing rollers before they engage the grinding wheel.

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Shaft 34 is mounted on a yoke 50 on the end of shaft 51. Shaft 51 is slidably mounted in a housing 52 and has a key way 53 in which a key 54 in the upper portion of housing 52 slides and prevents rotation of the shaft 51. The other end of shaft 51 is reduced in diameter and has a threaded portion 55 which extends through the cap 56 on housing 52. One end of spring 57 engages said cap 56 and the other end engages a shoulder 58 on shaft 51. A nut 59 on said threaded portion 55 determines the ex-tent to which shaft 51 may be moved in said housing 52 by spring 57, A limit switch 61 is mounted on a bracket 60 attached to housing 52. When said housing 52 is moved axially to position the dressing rollers against a grinding wheel, housing 52 may continue to move a slight distance after the dressing rollers engage the grinding wheel until locating roller 32 engages tlie wheel `at which time the movement of the shaft is stopped while housing 52 may continue to advance against spring 57. The result of the relative movement between the dresser shaft 51 and housing 52 causes switch 61 to engage nut 59 to close a circuit to put into operation the means for retracting the entire dressing assembly whether it consists of one or more than one dresser.

One or more dressing units may be mounted on wheel base 11 on a slide member 70 slidably mounted on suitable guide surfaces in whee-l base 11. Slide member 70 has a longitudinally extend-ing dove-tail guide portion 71 on which each of the dressing units is mounted for `axial adjustment relative to the grinding wheel. Means for moving slide member 70 4tow-ard and from operative position consists of a piston having a piston rod S1 connected to a depending portion 82 of slide member 70. Piston 80 is slidably mounted in a cylinder 83 in wheel base 11. Forward movement of -piston 80 and slide member 70 is limited by an adjustable stop member having a threaded connection with sleeve 91. Said stop member 90 is hollow and slidably mounted on a spline shaft 92 connected through suitable mechanisms including a worm wheel 95 and a worm gear 96 with means (not shown) for adjusting the wheel base 11 to compensate for wheel wear and dressing.

Wheel guard has Aan opening 101 to commit the entrance of the dressing device into engagement Iwith the wheel or wheels. Said opening 101 is provided with Ia pivoted cover member 105 connected to a piston 106 by means of piston rod 107. Said piston 106 is mounted in cylinder 108 linto which fluid under pressure may be introduced in timed relation with the movement of the dressing device in order to lift cover 105 when the dressing device is approaching the grinding wheel and to replace after the dressing device has been withdrawn.

In FIGURE 3, as shown, a plurality of dresser units mounted on slide member 70 and operable when Aadvanced to the dot and dash line to engage and dress Wheels of different diameters by virtue of the yielding mounting of each of the dresser units in the respective housing 52. In the retracted position, the dresser units are in substantial axial alignment. The slide member 70 advances them to the operative position and continues to move forward until the wheel of the smallest diameter is engaged by its dresser.

FIGURE 5 shows the relation between the dressing roller 31 and the locating roller 32 when the corners are dressed first. When the dressing tool approaches the grinding wheel, the locating roller 32 engages the undressed wheel surface and limits the extent of the dressing operation of roller 31 on the corners of the wheel. The surface of locating roller 32 is advanced to a lesser extent relative to the dressing roller 31 shown in FIG- URE 6in which iocating roller 32 engages the previously dressed wheel face. The face dressing may be effected in the conventional manner by a diamond dressing tool 3S as shown in FIGURES 5A and 6A.

In FIGURE 6, the surface of the roller is substantially tangent to the radius formed on the wheel corner.

FIGURES 5 and 6 lboth show the dressing roller 31 to consist of an intermediate portion 110 extending through an arc slightly less than 90. This portion of the roller is not necessarily a true arc. lt may be any suitable curve on either of said portion 110 or end portions 111 and 112 respectively. The straight line surfaces of roller 31 are tangent to the intermediate portion at points less than 90 apart. The angle between the faces of the end portions adjacent to the grinding wheel are more than 90 apart. Rollers 30 and 31 may be of any material or composition suitable for renewing the cutting surface of a grinding wheel either by dressing7 or crushing.

Operation The face of the grinding wheel may be dressed by single point diamond dressers as shown in Patent 2,248,463, granted July 8, 1941, and Patent 2,340,683, granted February 1, 1944. The dressing operations disclosed in these patents may be performed before or after the dressing of the corners.

When it is desired to perform a dressing operation, piston 80 is actuated to move slide member 70 toward the grinding wheel. Movement of slide member 70 is transmitted to the dressing roller 30 through housing 52, spring 57 and dresser shaft 51. When the rollers 30 and 31 engage the grinding wheel, their forward movement is retarded, but slide member 70 and housing 52 continue to move and the dierence in movement of the two members is taken up by spring 57. When roller 32 engages the Peripheral surface of the grinding wheei, it serves as a stop to prevent further penetration of the grinding wheel by the rollers 30 and 31. The continued forward movement of slide member 70 and housing 52 causes switch 61 to engage nut S9 and complete a circuit (not shown) to reverse the supply of fluid under pressure to cylinder 83 so that piston 80 will move to a rearward position and withdraw the dressing tool from the grinding wheel.

The above description of the operation is the same regardless of whether a single wheel is being dressed or whether a plurality of wheels are being dressed as shown in FIGURE 3. No previous adjustment or setting of the `dresser mounting is required to adjust a dresser to the position 0f the grinding wheel surface. If a pluraltiy of wheels is being dressed, the respective dressers are advanced and the advance of the main slide continues until the smallest wheel has been engaged and dressed by its dresser. In retracted position, the dressers are all in axial or longitudinal alignment. When advanced, each dresser adapts itself to the diameter of a particular wheel regardless of the position of the other dressers on the same slide.

I claim:

1. A wheel dressing device for dressing a predetermined -orm on a grinding wheel comprising a holder, a dressing roller mounted for free rotation on said holder, said roller being formed to correspond to the shape to be produced on the grinding wheel, and means for effecting a preliminary rotation of said roller before it engages the grinding wheel.

2. A wheel dressing device for dressing a predetermined form on a grinding wheel comprising a holder, a dressing roller mounted for free rotation on said holder, said roller being formed to correspond to the shape to be produced on the grinding Wheel, means for eecting a preliminary rotation of said roller before it engages the grinding wheel, and means on said roller mounting for engaging the grinding wheel and limiting the approach of said dressing roller relative to said grinding wheel.

3. A wheel dressing device for dressing a grinding wheel comprising a. housing movable toward and from an operative relation with the grinding wheel, a shank slidably mounted in said housing and urged in one direction by a spring, a dresser holder on said shank, a dressing roller rotatably mounted for free rotation in said holder, and means adjacent said dressing roller for engaging the grinding Wheel and limiting the approach of said dressing roller relative to said grinding wheel.

4. A wheel dressing device for dressing a predetermined form on a grinding wheel comprising a holder, a dressing roller mounted for free rotation on said holder, said roller being formed to have an arc of contact with said wheel of less than means for effecting a preliminary rotation of said roller before it engages the grinding wheel, and means on said roller mounting for engaging the grinding wheel and limiting the approach of said dressing roller relative to said grinding wheel.

5. A wheel dressing device for dressing predetermined forms on a plurality of axially spaced grinding wheels comprising a base member slidably mounted for movement toward and from the grinding wheels, a plurality of dressing tools each slidably mounted on said base member in spaced relation corresponding to the spacing of said grinding Wheels, each of said dressing tools comprising a dressing roller mounted for free rotation and having a predetermined form corresponding to the form to be produced on the respective grinding wheels, each of said dressers being yieldingly held in a predetermined forward position, whereby when all of said dressers are advanced to engagement with the grinding wheels, each Will accommodate itself to the diameter of the wheel which it is to dress.

6. A wheel dressing device for dressing predetermined forms on a plurality of axially spaced grinding wheels comprising a base member slidably mounted for movement toward and from the grinding wheels, a plurality of dressing tools each slidably mounted on said base member in spaced relation corresponding to the spacing of said grinding wheels, each of said dressing tools comprising a dressing roller mounted for free rotation and having a predetermined form corresponding to the form to be produced on the respective grinding wheels, each of said dressers being yieldingly held in a predetermined forward position, whereby when said base member is advanced toward the grinding wheels, it will continue to advance after the largest wheel is engaged by its dressing roller until the smallest wheel has been engaged by its dressing roller.

7. A wheel dressing device for dressing a predetermined form on a grinding wheel comprising a base member slidably mounted for movement toward and from said grinding wheel, a dressing tool slidably mounted on said base member for adjustment on said base member toward and from said grinding wheel, said dressing tool comprising a dressing roller mounted for free rotation and having a predetermined form corresponding to the form to be produced on the grinding wheel, said dresser being yieldingly held in a predetermined forward position, whereby to yieldingly engage a grinding wheel when advanced on said base member into engagement with said grinding Wheel.

References Cited in the le of this patent UNITED STATES PATENTS 1,687,252 Laessker Oct. 9, 1928 1,877,505 Haas et al Sept. 13, 1932 2,170,389 Payne Aug. 22, 1939 2,213,665 Brendel et al Sept. 3, 1940 2,360,127 Harley et al Oct. 10, 1944 2,393,463 Gottlieb Jan. 22, 1946 2,586,673 Linxweiler et al Feb. 19, 1952 2,701,986 Petty Feb. 15, 1955 FOREIGN PATENTS 183,614 Great Britain Aug. 3, 1922 428,004 Great Britain May 3, 1935 UNITED STATES PATENT FFCE CERTFICATE F CRRCTN Patent No., @012875 V January 23 1962 Alvin J1, Jones It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read as Icorrected below.

yIn the grantq4 line 2 and in the heading to the printed specificationv line 4 for v'Frankli1f1" each occurrencev read Signed and sealed this 8th day of May 1962.,

SEAL) Attest:

ERNEST W., SWIDER Attesting Officer DAVID L. LADD Commissioner of Patents

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