US2279092A - Grinding wheel truing apparatus - Google Patents

Description

April 7, 1942- 2 J. oLsoN 2,279,092

' GRINDING WHEEL TRUING APPARATUS Filed Feb. "7, 1941I 2 sheets-sheet 1 F575 l F572 www April 7, 1942. J, OLSYQN 2,279,092

GRINDING WHEEL Taurus APPARATUS Filed Feb. 7', 1941 2 sheets-sheet 2 Patented Apr. 7, 1942 GRINDING WHEEL TRUING ABPARATS Jolm Olson, Leicester, Mass., assignor to Norton Company, Worcester, Mass., a corporation of Massachusetts Application February 7, 19111, Serial No. 377,883

4 Claims.

rlhe invention relates to grinding machines. and more particularly to a grinding wheel truing apparatus for producing a radius on the periphery of a grinding wheel.

One object of the invention is to provide a simple and thoroughly practical radial truing device for a grinding machine. Another object of the invention is to provide a radial truing device which ls arranged for truing a radius on either corner of the peripheral face of a grinding wheel or a radius which extends from one side of the wheel to the other.

Another object of the invention is to provide a suitable adjustable stop mechanism whereby the movement of the diamond or truing tool may be accurately stopped after completing its circular movement to generate a radius on the desired portion of the grinding wheel face. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the fea tures of construction, combinations of elements, and arrangements of parts, as will be exemplifled in the construction to be hereinafter described, and the scope of the application of which Will be indicated in the following claims.

In the accompanying drawings in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. l ,is a side elevation, partly broken away and shown in section, of the improved grinding wheel truing apparatus;

Fig.' 2 is a plan View of the improved truing apparatus;

Fig. 3 is a fragmentary cross sectional View, taken approximately on the line 3-3 of Fig. l, showing the rotatable stop member in its various positions in full and dotted lines;

Fig. 4 is a fragmentary detail view, on an enlarged scale, of the rotatably adjustable stop;

Fig. 5 is a similar fragmentary view, on an enlarged scale, showing the stop lugs in the opposite position;

Fig. 6 is a similar fragmentary view, on an enlarged scale, showing the stop lugs in an intermediate position to facilitate movement of the truing tool in a semi-circular path;

Fig. 7 is a fragmentary sectional view, on an enlarged scale, showing the truing apparatus arranged for truing a radius on the lower corner of the grinding wheel;

Fig. 8 is a similar fragmentary View, on an enlarged scale, showing the truing apparatus arranged for truing a radius on the other corner of the abrasive wheel: and

Fig. 9 is a similar view, showing the truing tool arranged for moving in a semi-circularpath to true a radius extending across the entire peripheral face of the grinding wheel.

A grinding wheel truing apparatus has been illustrated in the drawings, comprising a base l0 .which is providedwith a dovetailed surface l-l which in turn mates with a correspondingly shaped surface formed on the upper faceof a grinding machine table l2. The base Hl is arranged to be removably attached to the table l l by means of a clamping block I3 and a manually operable clamping screw I4.

The base l0 serves as a support for a pivotally mounted C-shaped frame IE. The frame E5 is provided with trunnion studs E6 and Il which are journalled in anti-friction bearings i8 and i3. The anti-friction bearings I8 and I9 are supported in the base Ill. The pivotal axis of `the trunnion I6 is aligned with the axis of the trunnion stud Il and their axes are arranged in a substantially vertical position. The C-shaped` frame l5 serves as a support for a truing tool holder 20 which is adjustably clamped in position on the frame l5. Thetruing tool holder'Zi) adjustably supports a truing tool, such as a diamond 2l, which is arranged to engage and true the peripheral face of a grinding wheel 22. The grinding wheel 22 is supported on a rotatable spindle 23 which is journalled in suitable bearings (not shown) in the grinding machine. The truing tool holder 20 fits within a horizontally positioned cylindrical aperture formed in the C shaped frame l5 and is arranged so that it may be adjusted in a plane normal vto the pivotal axis of the C-shaped frame l5 and held in adjusted position by means of a clamping screw 24. By adjusting the truing tool holder 20, the diamond or truing tool 2l may be accurately positioned relative to the pivotal axis of the C-shaped frame l5 so that it will generate a curved face on the periphery of the grinding wheel of a desired and predetermined radius.

A sleeve 26 is keyed to the upper end of the trunnion stud Il. The sleeve 26 is provided with an integrally formed enlarged heady 21 which serves as an end cap to enclose the aperture at the top of the frame it. A manually operable handle 28 is iiXedly mounted to `the cap 2l and` extending lugs 29 and 30 (Fig. 2) which serve as supports for adjustable stop screws 3| and 32. The stop screws 3| and 32 are arranged in the path of the handle 28 so that as it is swung in a circular path in either direction, either the stop screw 3| or the stop screw 32 will serve to limit the movement of the truing tool and prevent it from cutting a groove in the side face of the grinding wheel. By adjusting the stops 3| and 32, the swinging movement of the truing tool may be limited as desired. As shown in Fig. 2, the stops are set so that the manually operable handle 28 may be swung from a full line position in a counterclockwise direction into position 28a to swing the C-shaped frame I5 from a full line position (Fig. 7) into a broken line position |5a which in turn transmits a corresponding movement to the truing tool 2| to swing it into position 2Ia, thus generating a curved faceor radius on the lower peripheral corner of a grinding wheel 22 (Fig. 7). n

In'truing a radius on either corner of the grinding wheel, it is desirable to denitely limit the arcuate swinging movement of the diamond to prevent it from undercutting the surface so that an element of the radius or curved face is tangent to an element of the peripheral surface of the grinding wheel. To accomplish this result, a stopmechanism is provided comprising a rotatable member 35 which is rotatably supported on a stud 36 which is in turn xedly mounted relative to the base I0. The member 35 is provided with a pair of oppositely extending, staggered stop lugs 31 and 38. The rotatable stop member 35 is arranged to be located in one ofk three operating positions by means of a springpressed ball 40 (Fig. 2) which is carried bythe member 35 and arranged to engage apertures formed in the adjacent end face 4I formed integral with the frame I0. ber 35 is positioned as shown in Figs. l, 2, 3 and 4, the truing apparatus is set up for generating a radius on the lower corner of the grinding wheel 22 (Fig. 7). The stop lug 38 projects upwardly and serves to limit themovement of the actuating lever 28 as it swings in a. clockwise direction. At this time the stop lug 3'| projects downwardly and is arranged in the path of an adjustable stop screw 42 which serves definitely to locate the rotatable stop member 35 and thus limit the arcuate swinging movement of the diamond 2| when it reaches the full line position as shown in Fig. 7. In this position of the rotatable stop 35, the operating lever 28 together with the C-shaped frame I5 and the diamond or truing tool 2| may be swung through 90 degrees in a counterclockwise direction into the broken line positions I5a and 2Ia, respectively, as shown in Fig. 7. The stop screw 42 is screw threaded through a portion I0 of the base. l

If it is desired to true a radius on the other or upper corner of the wheel 22 (Fig. 8), the rotatable stop member 35 is rotated 180 degrees into the position illustrated in Fig. 5, so that the stop lug 31 serves to limit the counterclockwise movement of the manually operable lever 28, and in which position an adjustable stop screw 43 which is screw threaded through a portion of the frame I (Fig. 3) serves definitely to locate the rotatable member 35. In this position of the rotatable stop member 35. it will be readily apparent that the truing tool 2| may be swung to 90 degrees from the full line position (Fig. 8) into the broken line position 2lb, in which position the clockwise swinging movement of the manu- When the stop memally operable lever 28 is limited by means of the stop screw 3| (Fig. 2).

If it is desired to true a semi-circular radius extending from one side of the wheel to the other on the periphery of the wheel, asv shown in Fig. 9, the rotatable stop member 35 is shifted into the position shown in Fig. 6, in which position the manually operable control lever 28 is free to swing through 180 degrees and is limited in its path of swing by the adjustable stop screws 3| and 32, respectively (Fig. 2).

By the provision of the stop members above described, it will be readily apparent that a radius may be generated on either corner of the wheel or a radius which extends across the entire face thereof, depending upon the setting of the rotatable stop member 35. While the disclosure in the drawings illustrates the apparatus as being applicable to the forming of a convex radius on the periphery of the grinding wheel, it will be readily apparent that the apparatus is equally applicable for generating a concave radius at either corner of the wheel or to produce a grooved face on the periphery of the grinding wheel, it being merely necessary adjustably to advance the truingvtool holder 20 toward the right (Fig. 1) so that the truing tool 2| projects toward the right of the axes of the C-shaped frame I5 by a distance equal to the concave radius which it is desired to produce.

The operation of the improved truing apparatus will be readily apparent from the foregoing disclosure. The truing apparatus base I0 is placed in position on a grinding machine table or support I2 and is clamped in position thereon by means of the clamping member I3 and the manually operable screw I4. The diamond or truing tool 2| and its supporting holder 20 are then adjusted to the desired position relative to the axis of the C-shaped frame I5 to generate the desired convex or concave radius on the operative face of a grinding wheel 22, after which the truing tool is 'clamped in adjusted position. The stop screws 3| and 32 together with the stop screws 43 and 42 are adjusted to limit the arcuate swinging movement of the truing tool as desired, so that it will swing through an arc of exactly degrees on either corner of the grinding wheel, as shown in Figs. 7 and 9, or through degrees as shown in Fig. 9. The stop screws 42 and 43 are then adjusted to limit the swinging movement of the truing tool 2|. The rotatable stop member 35 is then rotated or indexed to the desired position and the apparatus is then ready for operation. The grinding wheel 22 may then be advanced toward the truing tool 2| by the common, well-known feeding mechanism of the grinding machine and the truing tool 2| oscillated to true off the face of the wheel and thus generate the desired and predetermined radius on the periphery thereof. i

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a truing apparatus for grinding machines having a truing apparatus base, means to clamp said base on a grinding machine, a pivotally mounted frame on said base which is arranged to swing in a circular path, pivotal bearing supports for the ends of said frame to support it on a substantially vertical axis, a truing tool adjustably supported on said frame, a manually operable lever to oscillate said frame and truing tool, a pair of adjustable stop screws on said frame to limit the arcuate movement of said lever in either direction to determinethe extreme end positions of said truing tool, a rotatable stop member on said frame having a pair oi oppositely extending staggered stop lugs, said stop lugs being arranged in an intermediate position to facilitate an arcuate movement of the truing tool through 180 degrees, and in its end positions to limit the arcuate movement of the truing tool toward a position with the truing tool axis normal to the axis of the grinding wheel to facilitate truing a quarter-circular face on either corner of the grinding wheel.

2. In a truing apparatus for grinding machines having a truing apparatus base, means to clamp said base on a grinding machine, a pivotally mounted frame on said base which is arranged to swing in a circular path, pivotal bearing supports for the ends of said frame to support it on a substantially vertical axis, a truing tool adjustably supported on said frame, a manually operable lever to oscillate said frame and truing tool, a pair of adjustable stop screws on said frame to limit the arcuate movement of said lever in yeither direction to determine the extreme end positions of said truing tool, a rotatable stop member on said frame having a pair of oppositely extending staggered stop lugs, a pair of opposed staggered stop screws each arranged in the path of one of said stop lugs to determine the extent of rotation of said stop member, said stop lugs being arranged in an intermediate position to facilitate an arcuate movement of the truing tool through 180 degrees, and in its end positions to limit the arcuate movement of the truing tool toward a position with the truing tool axis normal to the axis of the grinding wheel to facilitate truing a quarter-circular face on either corner of the grinding wheel.

3. In a truing apparatus for grinding machines having a truing apparatus base, means to clamp said base on a grinding machine, a pivotally mounted frame thereon which is arranged to swing in a circular path, pivotal bearing supports for the opposite ends of said frame, a truing tool adjustably supported on said frame, a manually operable lever to oscillate said frame and tool to true a curved face on the periphery of a grinding wheel, a pair of spaced adjustable stop screws on said frame to limit the arcuate movement of said lever in either direction whereby said truing tool may swing in a semi-circular path. a rotatable stop member on said frame having a pair of oppositely extending staggered stop lugs, a pair of adjustably staggered stop screws each arranged in the path of one of said v stop lugs accurately to position said rotatable stop member so that the oppositely extending stop lug lies in the path of the manually operable lever to limit the arcuate swinging movement of the truing tool in one direction so that its axis lies in a path substantially normal to the axis of the grinding wheel.

4. In a truing apparatus for grinding machines having a truing apparatus base, means to clamp said base on a grinding machine, a

pivotally mounted frame thereon which is arranged to swing in a circular path, pivotal bearing supports for the opposite ends of said frame, a truing tool adjustably supported on said frame, a manually operable lever to oscillate said frame and tool to true a curved face on the periphery of a grinding wheel, a pair of spaced adjustable stop screws on said frame to limit the arcuate movement of said lever in either direction whereby said truing tool may swing in a semi-circular path, a rotatable stop member on the frame having a pair of oppositely extending staggered stop lugs, a pair of adjustable staggered stop screws each arranged in the path of one of said stop lugs accurately to position said rotatable stop member in its extreme position so that either one or the other of said oppositely extending stop lugs will limit the arcuate swinging movement of the tool in a quarter-circular path at either corner of the grinding wheel.

JOHN OLSON.

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