US2258568A - Grinding wheel truing apparatus - Google Patents

Description

1941- c. G. FLYGARE 2,258,568-

GRINDING WHEEL 'I 'RUING APPARATUS Filed Jan. 22, 1940 2 Sheets-Sheet 1 CHFL EFL YEHHE Oct 7, 1941. c. G. FLYGARE GRINDING WHEEL TRUING APPARATUS 2 Sheets-Sheet 2 Filed Jan. 22, 1940 CHRL EFLYEHEE II: hr"

Patented Oct. 7, 1941 Carl G. Flygare, Worcester, Mass., assignor to Norton Company, Worcester, Mass., at corporation of Massachusetts I Application. January 22, 1940, Serial No. 314,968

3 Claims.

The invention relates to grinding machines, and more particularly to a grinding wheel truing apparatus for truing an irregular form or I shape on a grinding wheel.

. One object of the invention is -to provide a formed wheel truing apparatus for truing an irregular form or shap upon the operative face of a grinding wheel. Another object of the invention is to provide a footstock truing device for producing an irregular shape or form on the periphery of a grinding wheel. A further object of the invention is to provide aform truing apparatus for a grinding machine in which a follower is moved through an irregular path to produce a transvers movement of the truing tool to reproduce a desired and predetermined shape on the periphery of the grinding wheel. 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 ample, that shown in the prior U. S. patent to Wallace H. Wood, No. 2,071,677, dated February 23, 1937. The wheel I8 is arranged to be fed transverselyby means of a-grinding wheel feeding mechanism (not shown) such as, for example, that shown in the prior U. S. Patent No. 2,071,677, above referred to, to which reference may be had for details of disclosure not contained herein. This feeding mechanism may be manually actuated or it may be automatically and intermittently actuated either continuously or in timed relation with the longitudinal reciprocatory movement of the table II.

The table II may be traversed manually by means of a manually operable table traversing tatable shaft 22 which is in turn journalled in 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 a plan view of a portion of a grinding machine, showing the grinding wheel form truing apparatus in operative position;

Fig. 2 is-a fragmentary end elevation of a grinding machine having the improved form wheel truing apparatus shown in an operative position. I

Fig. 3 is a combined fragmentary front elevation, taken approximately on the line 3-3 of Fig. 1, and an electrical diagram of an electrical safety interlock.

A grinding machine has been illustrated in the drawings having a base l0 which supports a longitudinally movable work supporting table II on the usual V-way l2 and flat way I3. The table It supports a swivel table M, the upper surface of whichis formed as a dovetailed shaped surface which mates with a correspondingly shaped surranged for a transverse feeding movement, such as is common practice in the old and well known cylindrical grinding machines such as, for exsuitable bearings within the'base Ill. The shaft 22 carries a gear 23 on its outer end which meshes with a gear 24 supported on a rotatable shaft 25. A manually operable traverse ,wheel 26 is 'also mounted on the shaft 25 and is fixedly mounted to rotate with the gear 24. apparent from the foregoing disclosure that when the hand traverse wheel 26 is rotated in either direction, a longitudinal traversing movement will be imparted to the table II through the gear and rack mechanism above described.

If desired, the table it maybe reciprocated by a power operated mechanism such as, for example, afluid pressure cylinder 30 whichis supported on the under side of the table I I (Fig. 2). A fluid pressure pump 3| (Fig. 3) is driven by means of an electric motor 32 to convey fluid under pressure to the cylinder 30 so as to reciprocate the tabl II as desired. The hydraulically operated table reciprocating mechanism has not been illustrated indetail, since this mechanism is identical with that shown in the above-mentioned U. S. patent to Wood, No. 2,071,677, to

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

The'improved form wheel truing mechanism is preferably supported on the footstock I6 and comprises .a transversely movable slide member 35 which is arranged to slide transversely within an aperture formed integral with the footstock IS. The right-hand end of the slide 35 (Fig. 2) is provided with 'a-downwardlyextending arm 36 which is rigidly fastened to the end of the slide 35. The arm 36 supports a diamond or truing tool .31 which is arranged to engage the pcriphery of the grinding wheel I8 at a point sub- It will be readily stantially in a horizontal plane passing through the wheel and work axis. An inverted U-shaped bracket 38 is fixedly mounted on the left-hand end of the slide 35 (Fig. 2). The bracket 38 supports a V-shaped follower member 39 which is arranged to engage the peripheral surface of a forming bar 48. The forming bar 48 is of a circular cross section so that when one surface becomes worn, the forming bar 48 may be rotated a slight amount to present a fresh, correctly shaped forming surface. The U-shaped bracket 38 straddles the forming bar 48 so'that the follower bears the same relation to the forming bar 48 as the diamond truing tool 31 does to the grinding wheel I8. The follower 39 is preferably accurately shaped to correspond with the shape of the truing tool 31 so that when the follower .is traversed relative to the forming bar 48, it

the slide 35 in a forward direction, that is, to-

Ward the grindingv wheel IS. The spring 4| is contained within an aperture 42 formed within the slide 35. One end of the spring 4| is supported by means of a stud 43 carried by the slid 35. The other end of the spring 4| is supported by a stud 44 which is carried by a block 45 fastened to the footstock frame by means of screws 48. The spring 4|, as above explained, serves normally to maintain the follower 39 in operative engagement with the surface of the forming bar 48 during a truing operation.

The forming bar 48 is supported by a slide 41 which is formed with integral projecting arm-s 48 and 49 (Fig. l). The arms 48 and 49 are provided with apertures, which are arranged to receive cylindrical portions 58 and formed on opposite ends of the forming bar 40. Binding or clamping screws 52 and 53 are provided in the arms 48 and 49 by means of which the forming bar 48 may be rigidly secured in an operative position. When a surface of the forming bar 48 becomes worn, a new forming surfac may be presented by loosening the screws 52 and 53 and then rotating the bar 48 to present a fresh forming surface.

The slide 41 is supported by a bracket 55 which is formed with a vertically extending portion 58 having a dovetailed surface 51 formed therein. The dovetailed surface 51 mates with a dovetailed slide surface formed on the slide 41. The bracket 55 is alsoprovided with a horizontally extending base portion 58 which is'supported on a plane surface 59 formed on the upper portion of the footstock l8.

In order to facilitate adjustment of the position of th forming bar 48 so as to align its axis relative to the path of travel of the table II, the bracket 55 is preferably adjustably supported on the footstock H by means of a pivot stud 88. A pair of adjusting screws 8| and 82 are supported in bosses 83 and 84, respectively, which are formed integral with the footstock l8. The screws 8| and 82 bear against the upper surface of the base portion 58 of the bracket 55 (Fig. 1). By manipulating the screws 8| and 82, respectively, the bracket 55 may be swivelled about the stud 88 to position the forming bar 48 as desired. Lock nuts 85 and 88 are provided to lock the screws 8| and 82 in adjusted position. Clamping screws 81 and 88 are provided rigidly to clamp the base portion 58 of the bracket 55 rigidly in adjusted position on the footstock |8.

The'

clamping screws 81 and 88 pass through elongated slots 89 and 18, respectively, formed in the base portion 58 and are screw threaded into the footstock 8. After the bracket 55 has been adjusted to align the forming bar 48, the clamping screws 81 and 88 may then be actuated rigidly to clamp the bracket 55 and the forming bar 48 in the desired adjusted position.

A bracket 15 is fixedly mounted on the slide' 41 by means of screws 18 and 11 (Fig. 1). The bracket 15 projects through an elongated clearance slot 18 formed in the vertical portion 58 of the bracket 55. The bracket 15 supports a rod 19 which is held in a fixed position with respect to the bracket 15 by means of a nut 88 screw threaded onto the end of the rod 19. The slide 35 supporting the diamond or truing tool 31 is traversed longitudinally with the footstock l8 and the table to pass the truing tool 31 across the peripheral surface of the grinding wheel |8 to true the same. sired transverse movement to the slide 35, the slide 41 supporting the forming bar 48 is held stationary during the truing operation as the bracket 55 moves longitudinally with the table II and footstock I8.

In order to hold the slide 41 stationary, a bracket 8| (Fig. 2) is fixedlysupported on the front of the machine base l8. The bracket 8| serves as a support for a pivot stud 82' which in turn supports a pivotally mounted arm 83. The

arm 83-is provided with an open slot 84 at its upper end which is arranged to engage a reduced end portion 85 on the rod 19. When it is desired to true the grinding wheel, the table is moved toward the left until the arm 83 may be swung into an operative position with the slot 84 in engagement with the reduced end portion 85 on the rod 19. A nut 88 which is screw threaded onto the reduced end portion 85 serves to clamp the arm 83 fixedly to the rod 19. When the arm 83 is clamped in an operative position (Figs. 1 and 2), the table II may be traversed longitudinally to traverse the diamond 31 across the periphery of the grinding wheel l8. The rod 19 serves to hold the slide 41 stationary which in turn holds the forming bar 48 stationary while the table II, the footstock l8 and the transverse slide 35 and truing tool 31 together with the bracket 55 are traversed longitudinally either by rotation of the hand wheeel 28 or by means of the hydraulic table traverse mechanism above referred to. The travel of the follower 39 along the surface of the stationary forming bar 48 serves to transmit a transverse movement to the slide 35 and to the diamond or truing tool 31 to reproduce the shape of the form bar 48 on the periphery of the grinding wheel |8.

It is desirable to provide a safety interlock in case the power traversing movement of the table is utilized. A normally closed limit switch 98 (Figs. 1 and 3) is fixedly mounted on a guard plate 9| which is fixedlymounted to the bracket 15 so that it remains stationary during the traversing movement of the bracket 55. An actuating plunger 92 of the limit switch 98 rides in end of its stroke before the U-shaped bracket 38 A supporting the follower 39 engages either the arm 48 or the arm 49 to open the circuit and stop the motor 32 which in turn stops the pressure In order to transmit the de-.

'pump' 3|, thereby stopping the table traversing movement before any of the parts become damaged. In the normal use of the power traverse of the table, the table -II is reversed before-the safety switch 90 is actuated. The safety switch 90 is provided only as a safety interlocking mechanism to prevent overrunning of the mechanism duringthe truing operation.

During the truing operation, the grinding wheel. I8 may be manually or automatically advanced by actuating the normal wheel feeding mechanism to advance the wheel by the required amount to complete the truing operation. After the truing operation has been completed, the nut 86 is loosened and the arm 83 swung in a counterclockwise direction (Fig. 2) to disconnect it from the rod 19 so that the table II may be traversed longitudinally from a truing into a grinding position without transmitting any relative igioveigient between the follower 39 and the form ar A The operationof this improved truing apparatus will be readily apparent from the foregoing disclosure. The forming bar ll is inserted in an operative position supported by the brackets 48 and 49 and is clamped in adjusted position by the screws 52 and 53. The bracket 55 is then adjusted to align'the axis of the form bar 40 into a predetermined relation with the longitudinal movement of the table I I, after which the bracket 55 isclamped in adjusted position by means of the clamping screws 61 and 68. When it is desired to true the grinding wheel it, the table II is traversed toward'the left to position the reduced end portion 85 of the rod I9 in substantial alignment with the swinging arm 83 which is swung in a clockwise direction into the position illustrated in Fig. 3 with the slot 8| engaging the reduced end portion 85 of the .rod 19. The clamping nut 86 is then tightened to lock the rod 18 relative to the base Ill. The table may then be traversed longitudinally to pass the diamond 31 across the periphery of the grinding wheel. During this movement the form bar 40 is held stationary by the rod 19 so that a transverse movement is imparted to the slide 35 togenerate a predetermined form or shapeon" the periphery of thegrinding wheel l8. After the diamond 31 has been traversed once across the wheel, the wheel It may then be advanced by the wheel feeding mechanism above mentioned to true oil! an additional amount on the return traverse of the table I l. After a predetermined truing operation has been completed, the arm 83 is again disconnected'and the table II traversed toward the right into a grinding position.

It will be readily apparent from the foregoing disclosure that any forming bar of the'desired shape and contour having cylindrical end portions Ill and il to fit the brackets 48 and I! may be utilized to reproduce its shape upon the periphery of the grinding wheel. It will also be readily apparent that when a surface of the form bar becomes slightly worn, the bar, as above described, may be readily rotated to present a fresh forming surface.

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 bemade 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. A truing apparatus for a grinding machine having a transversely movable slide, a follower on said slide, a truing tool on said slide, means to traverse said slide and truing tool longitudinally, a forming bar having a surface of revolution. a slide to support said bar, a frame having a slideway for supporting said slide, a swivel ad- Justment for said frame whereby the axis of the forming bar maybe adjusted relative to the lon- 'gitudinal traversing movement of the truing tool.

2. A truing apparatus for a grinding machine having a transversely movable slide, a follower on run of the truing tool relative to the forming bar.

3. A truing apparatus forfa grinding machine having a transverselyvmovable slide, a follower mounted on said slide, a truing tool mounted on said slide, a forming bar which is engaged by said follower, means including a fluid pressure mechanism having an electric motor driven pump to traverse said slide relative to the forming bar, an

electrical interlock including a limit switch, and a cam actuated by the traversing movement of said truing tool to stop said electric motor driven pump so as to stop the traversing movement of the truing tool to prevent an overrun of the truing tool relative to the forming bar.

CARL G. FLYGARE.

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