US2194422A - Grinding wheel truing apparatus - Google Patents

Description

March 19, 1940. c. e. FLYGARE El AL GRINDING WHEEL TRUING APPARATUS 2 Sheets-Sheet 1 Filed Sept. 20, 1938 x a I gvwmfom CFIHL GFLYGHRE CHHRLEs EHLvnRD v March 19, 1940.

C. G. FLYGARE El AL GRINDING WHEEL TRUING APPARATUS Filed Sept. 20, 1938 2 Sheets-Sheet 2 F us. E

CFIRL EFL C YGFIRE HFIRLES E.HLVUHD Patented Mar. l9,

2.194.422 Gamma wnnm. mums APPARATUS Carl G. Flygare and Charles C. Alvord, Worcester, Mass., assignors to Norton Company, Worcester, Mass a corporation of Massachusetts Application September 20, 1938, Serial No. 230,832 4 Claims. (01. 125-11 The invention relates to grinding machines,

and more particularly to a grinding wheel truing apparatus for truing the operative face of a grinding wheel.

One object of the invention is to provide an improved truing apparatus for producing a predetermined operative face on the grinding wheel. A further object of the invention is to provide a truing apparatus for truing the operative face a grinding wheel for grinding two adjoining surfaces on a work piece, such as a cylindrical surface adjacent to a tapered surface or two adjoining tapered surfaces.

A further object of the invention is to provide a thoroughly practical truing apparatus in which an adjustable forming bar is utilized to true off a corner of the wheel so that the wheel may be accurately formed to grind a cylindrical" or tapered face on a workpiece and a portion of a tapered surface adjoining the same. A further object of the invention is to provide such an apparatus with a pivotally mounted forming bar having a nut and screw mechanism for adjusting the same. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure 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. 1 is an end elevation of the improved grinding wheel truing apparatus;

Fig. 2 is a fragmentary plan view of the improved truing apparatus shown in Fig. 1;

Fig. 3 is a rear elevation of the truing apparatus shown in Figs. 1 and 2;

Fig. 4 is a fragmentary plan view showing the forming bar set at an angle for truing a taper adjacent to one edge of the grinding wheel; and

Fig. 5 is a diagrammatic plan view showing the arrangement of the wheel and the work when utilized for grinding a cylindrical surface on a work piece adjacent to a tapered surface.

As illustrated in the drawings, a fragment of a grinding machine has been illustrated comprising a transversely movable grinding wheel III which is supported on a transversely movable slide (not shown), as is common practice in the grinding machine art. The grinding wheel I 0 is partially surrounded by a wheel guard II. The grinding wheel l0 and its transversely movable supporting slide (not shown) are inturn mounted on a longitudinally reciprocable carriage (not shown) which traverses longitudinally relative to the base of the machine. This machine may be of the type shown in the prior patent to Norton No. 1,096,188 dated May 12, 1914,

to which reference may be had for details of disclosure not'contained herein.

Thework piece I5 to be ground is rotatably supported on a headstock center l6 and a footstock center H, such as diagrammatically shown in Fig. 5 of the drawings. The footstock center i! is carried by a footstock it which is in turn supported on a pivotally mounted swivel table IQ of the type universally employed on the standard or plain cylindrical grinding machines, such as for example that shown in'the expired patent to Norton No. 762.838 dated June 14, 1904, to which reference may be had for details of disclosure not contained herein. The swivel table 19 also serves as a support for a headstock (not shown). A swivel adjustment is provided for adjusting the'swivel table so that the axisof the work piece l5 when supported on-the centers I6 and I l is either parallel to or at an angle to the path of travel of the grinding wheel so that either a true cylindrical surface or a tapered surface may be ground.

In grinding a work piece, such as that shown in Fig. 5, which has a cylindrical portion 20 adjoining a tapered surface 2|, difliculty has been experienced in grinding the true cylindrical surface up to its junction with the tapered surface and in producing an accurate surface adjacent to the joint therebetween. It has been found that greater accuracy may be obtained if the grinding wheel is formed with a true cylindrical surface 20 for grinding the work piece l5 and is provided with an angled-01f portion which is tapered to the same degree as the tapered surface M of the work piece I 5, so that when the grinding wheel and work piece aretraversed longitudinally, as the wheel approaches the end of its stroke toward the right (Fig. 1), the wheel will not only grind the cylindrical surface but the angled-01f portion of the wheel will grind a. small portion of the taper, thus producing an accurate surface right up to the junction line between the cylindrical and frusto-conical surfaces.

The improved truing apparatus as shown relates particularly to an apparatus for truing a grinding wheel for such an operation. A truing apparatus has been illustrated in the drawings which is attached to the footstock i 8. A truing apparatus frame 25 (Fig.

1) is fixedly mounted a on the 'footstock l5 and is provided with a boss 25 having an aperture 21 which serves as a support for a footstock truing tool 25 having a truing tool diamond 25 mounted in the outer end there- 5 of. A binder or clamping screw 35 serves to lock the truing tool 28 in adjusted position. 1 This .well

known type of truing tool may'be utilized to true a cylindrical portion on the grinding wheel |5 when the grinding wheel and swivel table l9 are traversed or reciprocated longitudinally relative to each other.

The'truing apparatus frame has an enlarged head portion 32 which is provided with a central aperture 33. A rod 34 passes through the aper- 15 ture 33 and is arranged to be clamped rigidly in position therein by clamping screws and 35. The rod 34 serves as a support for a transversely movable truing tool support 31. The support 31 is provided with a vertical downwardly extending m arm 35 which is provided with an enlarged boss 35 having an aperture which slidably fits the rod 34. A pair of clamping screws 45 and 4| serve to adjust the boss 39 so that a nice sliding fit may be obtained. The support 31 is provided with a as spaced bearing member 42 which is spaced from the boss 35 and which slidably fits on the rod 35. The downwardly extending arm 35 serves as a support for a diamond or truing tool 43 which is preferably located so that the diamond or truing 3o tool 43 contacts with the periphery of the grinding wheel in a horizontal plane passing through the grinding wheel axis and the work axis. A guide bar 45 is rigidly fixed to the downwardly extending arm 38 of the support 31 and is guided 35 by the L-shaped guide block 45 which is fixedly mounted on the frame 25. The guide bar 45 and the guide block 45 serve to guide the frame 31 and prevent any lateral swinging movement thereof during the truing operation.

The truing apparatus frame is arranged so that it is normally urged toward the left (Fi 1) by means of a compression spring 55 which surrounds the rod 34 and is interposed between the bearing boss 42 and an adjustable collar 5| which is secured on the rod 34 by means of a clamping screw 52. A stop collar 53 is provided on the rod 34. The stop collar 53 is provided'with a clamping screw 54 and serves to limit the movement of the frame 31 toward the left (Fig. 1).

A forming bar is. provided for controlling the transverse movement of the frame 31 and the truing tool 43 so as to produce the desired contour on the wheel being trued. As illustrated in the drawings, a straight forming bar is con- 55 nected by bolts 5| and 52 to a pivotally mounted bracket 53 which is fixedly supported on a vertically arranged shaft 54. The shaft 54 is jour-' nailed in spaced bearings 55 and 55 (Fig. 1) in a bracket 51 which is fixedly mounted on the wheel 90 guard II. An adjusting arm 55 is fixedly mounted on the upper end of the shaft 54 and supports a nut 59 adjacent to its left-hand end I (Fig. 2). A rotatable adjusting screw 15 meshes with said nut and is journalled in a bearing 1| 85 fixedly mounted on the bracket 51. The screw 15 is provided with an actuating knob 12 and a graduated dial 13, both of which serve to facilitate adjustment of the position of the forming bar 55. An indicator pointer arm 15 is fixedly mounted on-the left-hand end of the arm 58 (Fig. 2) which extends in the path of a graduated scale 15 fixedly mounted on the wheel guard II. By rotation of the knob 12 the nut and screw mech- 7 anlsm serves to rock the arm 55 and the shaft 54 so asto position the forming bar 45 as desired, thatis, either parallel to the relative path of travel between the wheel and work axis or at an angle relative there A bracket 55 which is fixedly mounted to the 5 wheel guard II is provided with an elongated slot 5|. A clamping screw 52 passes through the elongated slot 8| and is screw threaded into the forming bar 55 and serves to clamp the bar 55 rigidly in adjusted position. t

A suitable follower 55 is provided for engaging the operative surfaceof the forming bar 55 to transmit a transverse movement to the diamond or truing tool 43 so as to produce a predetermined shape on the grinding wheel l5. As illustrated in 15 the drawings, the follower 55 is mounted in the outer end of a sleeve 55 which is journalled in a boss 51 formed integral with the truing tool support 31. A rotatable adjusting screw 55 is held against endwise movement by means of an end cap'59 fastened to the end of the boss 51. The screw is screw threaded into the sleeve 55 and serves to facilitate a transverse adjustment of the truing tool support 31 so as to position the truing tool 43 relative to the periphery of the grinding wheel, as desired. The collar 5| is preferably adjusted to compress the spring 55 so that the follower 55 is maintained in engagement with the master or forming bar 55 with sumcient pressure to maintain the diamond or truing tool 43 in position during a truing operation. 4

--When the grinding wheel and work piece are reciprocated longitudinally relative to each other in a wheel truing position, the follower 55 following the forming bar 55 will true a predetermined shape on the periphery of the grinding wheel, depending upon the shape of the forming bar 55 and its angular position relative to the path of travel between the wheel and work sup- 0 port. As illustrated in the drawings, a straight forming bar 55 has been provided. This bar, however, may be of any desired shape to produce the desired contour on the periphery of the grinding wheel. As illustrated in Fig. 2, the forming bar 55 has been illustrated as positioned substantially parallel to the path oftravel between the wheel and work support, and in which position a true cylindrical surface will be produced on the grinding wheel. 1 u

The operation of this improved truing apparatus will be readily apparent from the foregoing disclosure. Assuming all ofthe adjustments have been previously made, in the preferred operation for producing a wheel to grind a work a piece such as that illustrated in Fig. 5, in which a grinding wheel having a true cylindrical surface is angled off at one end so as to grind a small portion of the taper 2| adjacent to the cylindrical portion 25 of the work piece l5, it is desirable to utilize-the diamond 25 which is held in a fixed position relative to the footstock |5 to true the main portion of the grinding wheel |5 to a cylindrical shape. After this operation has been completed, the forming bar may be adjusted into a position such as that shown in Fig. 4 so that after the cylindrical face has been trued to the desired extent, the corner or edge portion of the grinding wheel may be tapered 01! so that during the grinding operation, at the end of the relative reciprocatory stroke between the grinding wheel and work, it will engage and grind a small portion of the taper 2|, thus enabling the production of an accurate line of division between the true cylindrical surface 25 and the I has been ground, the swivel table may then be swivelled so that the main portion of the grinding wheel 2| will be in a position to grind the taper II. In grinding the taper II, the relative recipments 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.

We claim: I

1. In a grinding machine having a rotatable grinding wheelya wheel guard therefor, and a work support including a footstock, said grinding wheel and work support being reciprocable longitudinally relative to each other, agrinding wheel truing apparatus therefor including a supporting frame fixedly mounted on the footstock, a truing tool adjustably mounted on said frame and arranged to true a cylindrical face on the grinding wheel, a transversely movable truing tool carrier on said frame, a second truing tool mounted on said carrier, an adjustable follower on said carrier, and a pivotally mounted forming bar on said guard which cooperates with said follower to produce a transverse movement of the carrier and second truing tool to true a tapered face on the grinding wheel, said truing tools being arranged so that when the grinding wheel and work support are reciprocated longitudinally, the first truing tool trues a cylindrical face and the second truing tool trues a frustoconical face adjacent to said cylindrical face on the grinding wheel.

2. In a grinding machine having a rotatable grinding wheel, a wheel guard therefor, and a work support including a footstock, said grinding wheel and work support being reeiprocable longitudinally relative to each other, a grinding wheel truing apparatus therefor including-a supporting frame fixedly mounted on the footstock, a truing tool adjustably mounted on said frame and arranged to true,a cylindrical face on the grinding wheel when the grinding wheel and footstock are traversed longitudinally relative to each other, a transversely movable truing tool carrier on said frame, a second truing tool mounted on said carrier, an adjustable follower on said carrier, a forming bar pivotally mounted on said wheel guard which cooperata with said follower to produceatransversemovementofthecarrierand a v 0,104,492 J taper 2|. After the cylindrical surface 20 truing tool during the relative longitudinal reciprocation between the grinding wheel and footstock to true a frusto-conical face on the grinding wheel, yieldable means acting upon said carrier to 'maintain said follower in engagement with the forming bar, andmeans including a nut and screw mechanism angularly to adjust the position of the forming bar to vary the taper produced upon said wheel.

3. In a grinding machine having a rotatable grinding wheel, a wheel guard therefor, and a work support including a footstock, said grinding wheel and work support being movable longitudinaily relative to each other, a grinding wheel truing apparatus including a frame fixedly mounted on said footstock, a horizontally arranged guide bar adjustably supportedon frame, a horizontally movable truing tool carrieif supported on said guide bar, a truing tool adjustably mounted thereon, a horizontally adjustable follower on said carrier, 2. pivotally mounted forming bar cooperating therewith to cause a transverse movement of the carrier and truing tool during therelative longitudinal reciprocation between the grinding wheel and footstock, a vertically arranged shaft onsaid wheel guard pivotally to support said bar means including a nut and screw adjustment for said follower whereby the position of the follower may be adjusted relative to said carrier precisely to adjust the position of the truing" tool relative to the grinding wheel, and means including a nut and screw mechanism rotatably to adjust the vertical wheel and work support being movable longitudinaily relative to each other, a grinding wheel truing apparatus including a frame fixedly mounted on said footstock, a guide bar adjustably supported on said frame and positioned normal to the axis of the grinding wheel, a movable truing tool carrier supported on'said guide bar, a truing tool adjustably mounted thereon, an adjustable follower on said carrier, a pivotally mounted forming bar which is arranged to pivot about an. axis normal to the axis of the grinding wheel, said bar having an operative face which may be positioned at an angle relative to the axis of the wheel, said bar cooperating with said follower'tocause a transverse movement of the carrier and tool during the longitudinal reciprocation between the grinding shaft so as to precisely position the forming bar wheel and footstock, and means including a nut

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