US2292874A - Wheel truing mechanism - Google Patents

Description

Aug. 11, 1942. R. E. FLANDERS WHEEL TRUING MECHANISM Filed April 4, 1940 4 Sheets-Sheet 1 Aug. 11, 1942. R. E. FLANDERS 2 3 WHEEL TRUING MECHANISM I Filed April 4, 1940 I 4 Sheets-Sheet 2 Augl'll, 1942. I RVE, FLANDERS 2,292,874

WHEEL TRUING MECHANISM Filed April 4, 1940 4 Sheets-Sheet 5 g 1 1942- R. E. FLANDERS 2,292,874

WHEEL TRUING MECHANISM Filed April 4, 1940 4 Sheets-Sheet 4 Patented Aug. 11, 1942 UNITED STATES PATENT OFFICE 2,292,874 7 WHEEL TRUING MECHANISM Ralph E. Flanders, Springfield, Vt., assignor to Jones & Lamson Machine Company, Springfield, Vt., a corporation of Vermont Application April 4, 1940, Serial No. 327,890

. 14 Claims.

This invention relates to mechanism for truing grinding wheels to formed contours, and particularly where the contour is controlled by a pattern or former cam.

One object of this invention is to provide reduction mechanism by which a, pattern or former cam of relatively large size may reproduce its contour on the grinding wheel to a smaller size, this facilitating accuracy in the production of the wheel contour.

Further objects are to provide actuating and controlling means for the truing device further facilitating accuracy of truing.

A further object is to make possible variations in the pattern from true contour to allow for clearance between the former cam and its follower which variations will not be reproduced in the wheel form.

Another object is to produce a desired angle between faces on the trued wheel from flatter angle faces on the pattern.

For a more complete understanding of this invention, reference may be had to the accompanying drawings in which Figure 1 is a central longitudinal vertical section through mechanism embodying the invention.

Figure 2' is a diagrammatic View illustrating a form of templet or former cam and the contour of the wheel resulting from the use thereof.

Figures 3 and 4 are sectional Views on the correspondingly numbered section lines of Figure 1.

Figure 5 is a rear end elevation of the same.

Figure 6 is a fragmentary front elevation of the same.

Figures 7 and 8 are detail sections on lines 1-! and 8B, respectively, of Figure 3. I

Figure 9 is a developed section on line 99 of Figure 8.

As illustrated in the accompanying drawings, the truing mechanism is arranged for application to a grinding machine of the type shown in my Patent No. 2,184,011 for Grinding machine granted December 19, 1939. It comprises a cylindrical casing I intended to fit within the tubular extension 4 shown in that patent. This casing l is shown as provided at its outer end with a depending portion 2 in which is secured a bar 3, this bar being contacted with the end of the shaft 5| shown in that patent so that the entire truing mechanism may be conrolled as a unit in a manner similar to the truing mechanism of the pat! ent.

The casing is angularly adjustable with reference to the portion 2 as by a rack and pinion la and 2a. a This casing I has a forwardly extending hood 5 extending beyond a forward end wall 6 provided with an enlarged opening 1 therethrough for the passage of a rock shaft 8-carried by a pivotally mounted arm 9. I The arm 9 has a pair of spaced end walls Ill and H and at -it's lower endis provided with conical bearing openings l2 for the pivot members l3 and [4 on which the arm is mounted for oscillation. It will be noted that the rock shaft 8 is carried by the arm 9 a relatively short distance from its pivotal axis. Also carried by this arm and ,journaled in the wall portions I0 and II is a second rock shaft IS. The rock shaft 8 carries at its forward end for-. wardly of the partition 6 a rectangular head 20. This head is provided with a vertical groove to slidably receive a rib 2| on a truing device block 22. This truing device block is secured to the head as by a screw 23 passingthrough a slot-24 in the block and threaded into the head 20. The head 25 of this screw is set within a recess 26 at the forward end of the block. At 21 is shown a truing device, which may comprise one 'or more diamonds, carried by a bar 28 secured in position by a set screw 29 which bears thereon. This set screw passes through a cap 30 secured to the top face of the block 22 as by the screws 3|; The rear end of this cap extends over the head 20 and an adjustingscrew 32 passing through this extension and bearing on the upper face of the head provides means for adjusting the block 22 vertically'when the screw 23 has been loosened to permit it, The opening 1 through which the shaft 8 and its bearing boss 33 projects is closed to the 'outervface of the wall member 6 by a flexible diaphragm 35 which permits the necessary motion of the shaft 8 laterally and longitudinally and'at the same time seals the opening I from the entrance of coolant and particles removed from the grinding wheel which is shown at 36. 1

The rear end of the rock shaft I5 is provided with a vertical slot 40 in which is mounted a cam follower 4|, being shown as secured therein by a set screw 42 (see Figure 3). This follower is arranged to bear on the forward edge of a templetor cam former 45, the contour of which is chosen to suit the particular contour to which it is desired to true the grinding wheel. This formercam may be secured to a gear casing 46 as by the screws 41. The casing [is shown as provided with a removable cover portion 59 which maybe removed to afford access to the interior of the casing and facilitate removal and replacement of former cams 45 of the desired contours. As illustrated the particular former cam is intended to true multiple ridged wheels, Figures 2 and 3 showing the former cam as provided with the fiat topped ridges 5| separated by valleys 52 for shaping the wheel with the spaced ridges 53 with interposed valleys 54.

Means are provided for holding the follower yieldingly against the edge of the former cam. For this purpose, as shown best in Figures 1 and 4, a lever or arm 60 having a pair of spaced side members is fulcrumed at 60a on a block 6| butting a block 62 through both of which the rock shaft passes and to which block 62 it is fixed as by the pin 63. The lower end of the lever 60 carries a shoe 65 which bears against a shoe 86 carried at the lower end of a bracket portion 61 projecting from the arm 9 below its fulcrum. The upper end of the lever or arm 60 has a transverse connecting portion 68 to which is secured a block 69 forked at its upper end to straddle a reduced diameter portion I of the rock shaft I5. This block 69 is secured in a guideway II in the member 68 and is held in position as by a screw I2. At its upper end this block 69 has an ear I extending over a portion of the member 68 and through this extension passes an adjusting screw I6 which bears on the member 68. The back face of the extremity of the block 69 is rounded and bears against the hub portion 'I'I of a gear segment I8 pinned as at I9 to the part I0 and butting against a shoulder formed by the larger diameter portion of the shaft I5. The block 62, engaging the block 6| carrying the pivot 60a for the lever arm 60, is yieldingly held retracted to hold the follower against the former cam as by means of a spring 80 engaging at one end over a pin 8I projecting from the block 62 and at the other about a pin 82 spanning a recess 83 in the arm 9.

As shown the distance of the axis of the shaft I5 from the center of oscillation of the arm 9 is four times the distance of the axis of the shaft 8 from its centerof oscillation, so that there is a reduction of 4 to 1 in the amount of motion laterally between the cam follower and the truing device. The distance from the bearing of the shoe 65 against the shoe 66 to the axis of the fulcrum 60a is approximately one half the distance of this bearing from the axis of the rock shaft I5 so that there is a reduction of only 2 to 1 in the in and out motion of the diamond relative to that of the cam follower. This variation in ratio between the in and out motions and the lateral motions of the truing device and the templet follower causes the production of relatively steep wheel faces from flatter and easier cam faces.

Other desired specific proportions between traverse and in and out motions, and in amplitude reduction might be produced by corresponding choice of lever arm lengths as may be desired.

For accuracy of truing it is desirable that the shafts 8 and I5 do not turn relative to the casing as the arm 9 is rocked. For this reason means are provided for holding these shafts against such rocking motion in relation to the wheel and templet which, however, requires that they do rock relative to the arm 9 as this arm oscillates. One means for holding the shaft 8 is shown best in Figures 3 and 4. The block 62 is provided with an arm 90, the outer end of which is journaled and slidably mounted on a shaft 9| extending between a pair of spaced ears 92 and 93 carried by a rock shaft 94. This rock shaft 94 is fulcrumed at opposite ends on the fixed centers 95. As the arm 9 is swung back and forth this connection results in rocking of the shaft 94, while maintaining the arm in horizontal position, and consequently holding against rocking the central rock shaft 8. Thus the truing tool does not rock about the axis of the shaft 8. In order to control the shaft I5 in the same manner, the arm 90 is provided with an upwardly extending segmental gear portion 91. This portion meshes with gear teeth 98 on a shaft 99 pivoted on the centers I00 and I02 of the arm 9. The shaft 99 also has a gear portion I03 which meshes with the teeth of the segment 18. Thus as the arm 9 oscillates, carrying the shaft 99 laterally, the gear 98 riding on the segment 91 is rotated, this rotation also rotating the gear portion I03 and controlling the segment I8 to prevent rocking of the shaft I5 so that the former cam is held in a definite angular position relative thereto as it traverses the former cam.

The distance to which the cam follower may approach the follower cam may be limited, if desired, as by the stop and lock nuts I05 threaded on the forward end of the shaft I5. This permits the valleys ofthe templet to be cut inwardly for the sake of clearance between the end of the former cam without causing this cut away portion to be effective in producing a corresponding contour of the grinding wheel. This is shown, for example, in Figure 2 where the root of the valley has been cut away as at' I06 below the normal path desired for the cam follower.

The mechanism for actuating the truing device and for causing rocking of the arm 9 comprises a motor I I0 mounted in a compartment I I I to the rear of a transverse partition 2. The rear end of the compartment III is closed off by a cap II3 to the extension II4 of which the shaft 3 is secured. The motor I I0 is secured to the forward face of a transverse web H5 and its armature shaft I I 6 carries a driving gear I I? which meshes with a larger gear I I8 on a worm shaft I I9. This worm shaft I I9 extends through the partition I I2 and into the gear casing 46 where it has a worm II9a meshing with a worm wheel I20 keyed to a shaft I2I as best shown in Figure 9. This shaft I2I has a large diameter portion I22 presenting at opposite ends a shoulder against which bear the bushings I23 and I24. Journaled on these bushings I23 and I24 are the gears I25 and I26. These gears have opposed clutch faces I 21 and I28 and the enlarged diameter portion I22 has slidably keyed thereto a clutch collar I30 which may be moved into driving engagement with either of the gears I25 or I26. Th gear I26 meshes with a gear I3l keyed to a screw shaft I32, and a block I33 threaded on this screw shaft is provided with a vertical slot I34 in which rides a slide I35 having a socket I38 into which extends a pivot member I31. This pivot member I31 issecured to the portion I I of the arm 9 as by being threaded thereinto, and its opposite end receives the center I02. When the clutch collar I30 is in driving relation to the gear I26, therefore, the gear I3I is driven in one direction to produce a traverse of the block I33 in one direction along the screw I32, thus to rock the arm 9 in one direction. When the clutch collar I 30 is moved into engagement with the gear I25 in the position shown in Figure 9, the gear I26 is disconnected and the gear I 25 is rotated. This gear I25 meshes with a gear portion I40 of a the screw shaft gear I3I, but as the sleeve, I4I

acts as a reverse counter shaft, the drive from the gear I25 is in the reverse direction to the drive from the gear I26, thus to cause traverse of the block I33 in opposite directions depending on whether the gear I25 or the gear, I26 is engaged by the clutch collar I30.

The block I33 is arranged to cause reversing action of the clutch collar I30. To this end it is provided with a forked extension I50 which straddles the bar II mounted for axial sliding motion Within supporting bushings I52. It carries thereon between these bushings a pair of dogs I54 and I55, which may be secured thereto as by the set screws I56, so that as the block I33 approaches one limit of its motion in one direction, it contacts one or the other of these dogs I54 and I55, causing an axial motion of the bar I5I. This bar I5I has secured thereto a block I60 having a socket I6I in which is positioned the rear end of a rod I62 which extends through a second slide bar I63 and has a V head I64 at its forward end. This bar I63 is slidably mounted in bushings I65 and has secured thereto a pair of spaced collars I66 and I 61. Between these collars is mounted a hub portion I58 of a clutch shifter I10, which as shown best in Figure 7, has a pair of spaced fingers I1I which ride within a peripheral groove I12 of the clutch collar I30. Thus as the block I33 approaches one limit of its motion and contacts one or the other of the dogs I54 and I55 and moves the bar I5I axially, it also moves the bar I63 axially so that one of the collars I66 or I61 may engage the shifter member and finally shift the clutch collar I30 out of clutching engagement with one of the gears I or I26 and into clutching engagement with the other of these gears, thus to reverse the direction of rotation of the threaded shaft I32 and thereby the direction of traverse of the block I33.

In order that this shift may take place quickly, a load and fire mechanism is employed of which the head I64 forms a part. Cooperating with this head is a roll I15 journaled at the forward end of a plunger I16 (see Figure 3). This plunger is pressed, as by the spring I11, into engagement with the head I64 and acts to move the bar I63 axially as soon as the apex of the head I64 rides beyond the axis of rotation of the roll I15 in either direction. The spacing between the hub I68 and the collars I66 and I61 permits the shifter to move over quickly to its other limit of motion when impelled by this load and fire mechanism, allowing the clutch to remain in one clutching position until it is quickly snapped over into the other clutching position. The rear end of the plunger I16 is shown as carrying a dog I 80 which may actuate certain electric switches within casings I8I for a purpose which is not material to this invention.

In order to hold the follower against the follower cam surface, a friction device for preventing the arm 9 from running ahead is provided. This comprises a rod I85 (see Figures 1 and 4), having one end pivoted to the casing I at I86 and extending between the shoes I81 and I88 supported by a yoke I89 pinned to the head I90 of a bolt I9I carried by the arm portion II. A spring I92 bearing between the inner face of the yoke I89 and the shoe I81 causes the shoe to press against the rod I85 and apply a frictional drag to the swinging motion of the arm 9.

The sleeve I4I between the gears I40 and I46 has an eccentric portion I which serves to actuate the plunger I86 of a pump I81 which may be employed to supply lubricant to various parts of the mechanism. The operation of the mechanism is as follows. When the wheel is to be trued the mechanism is moved bodily toward the grinding wheel by any suitable means, for example, as shown in my Patent No. 2,184,111, to which reference has been made, and the motor H0 is started. The rotation of this motor turns the screw shaft I32 first in one direction and then in the other, the traverse of the block I33 causing the reversal of the direction of rotation of the screw I32 at each traverse limit of the block. This motion of the block I33 swings the arm 9 back and forth, causing the follower 41 to traverse the cam 45 and the truing device to traverse the grinding wheel face, but in a shorter path than that of the follower, while the spring 80 causes the follower to move in and out following the cam contour and to correspondingly move the truing device to a less extent by rocking of the lever 60, except as the rocking of this lever may be prevented by the presence of the stop nuts I05. During this traverse of the follower along the former cam 45 and the truing device across the wheel face, both the follower M and the truing device are held against rocking motion about the axis of the arm 9 by the mounting of the arm and its connections to the shafts 8 and 10. When truing has been completed the mechanism as a whole, including the casing I, is retracted from the wheel. 7

i From the foregoing description of an embodiment of this invention, it should be evident to those skilled in the art that various changes and modifications might be made without departing from the spirit or scope of this invention as defined by the appended claims.

I claim:

l. A truing mechanism comprising a pivoted arm, a truing device carried by said arm for motion substantially parallel to the pivotal axis of said arm, a stationary templet, a follower for said templet mounted on said arm for movement along said templet and substantially parallel to said axis, operative connections from said follower to said device for causing motion of said follower parallel to said pivotal axis to move said device parallel to said axis, means yieldingly holding said follower against said templet, and means for swinging said arm.

2. A truing mechanism comprising a pivoted arm, a pair of rock shafts mounted for axial motion in said arm substantially parallel to and at different distances from the pivot axis of said arm, a wheel truing device carried by one of said shafts, a cam follower carried by the other of said shafts, a former cam for traversing engagement by said cam follower, operative connections between said shafts insuring simultaneous axial motions thereof, means yieldingly pressing said follower against said former cam, and means for oscillating said arm.

3. A truing mechanism comprising a pivoted arm, a pair of rock shafts mounted for axial motion in said arm substantially parallel to and at different distances from the pivot axis of said arm, a wheel truing device carried by' one of said shafts, a cam follower carried by the other of said shafts, a former cam for traversing engagement by said cam follower, operative connections between said shafts insuring simultaneous axial motions thereof, means yieldingly pressing said follower against said former cam, means for oscillating said arm, and means for holding both shafts against rocking motion.

4. A truing mechanism comprising a pivoted arm, a pair of rock shafts mounted for axial motion in said arm substantially parallel to and at different distances from the pivot axis of said arm, a wheel truing device carried by one of said shafts, a cam follower carried by the other of said shafts, a former cam for traversing engagement by said cam follower, operative connections between said shafts insuring simultaneous axial motions thereof, means yielding pressing said follower against said former cam, means for oscillating said arm, means holding one of said shafts against rocking motion as said arm is oscillated, and connections from said one shaft to the other shaft for holding said other rock shaft against such rocking motion as said arm is oscillated.

5. A truing mechanism comprising a pivoted arm, a pair of rock shafts mounted for axial motion in said arm substantially parallel to and at different distances from the pivot axis of said arm, a wheel truing device carried by one of said shafts, a cam follower carried by the other of said shafts, a former cam for traversing engagement by said cam follower, operative connections between said shafts insuring simultaneous axial motions thereof, means yieldingly pressing said follower against said former cam, means for oscillating said arm, a member fixed to each shaft and provided with a gear segment, a shaft journaled in said arm and having a gear portion engaging each segment, a second rock arm, and a connection from said second rock arm to one of said segments.

6. In combination, a casing, an arm fulcrumed in said casing about an axis substantially parallel to a casing axis, a pair of rock shafts axially slidable in said arm at different distances from said fulcrum axis and substantially parallel thereto, the closer of said shafts projecting from said casing and carrying a wheel truing device, the opposite end of the other of said shafts carrying a cam follower, connections between said shafts causing axial motion of one to produce axial motion of the other, a former cam for contact by said follower, a block secured to said device-carrying shaft, a second arm pivoted to said block transverse to said axes, said second arm bearing at one end on a portion of said first-mentioned arm and at its opposite end operatively secured to said follower-carrying rock shaft, means yieldingly holding said second arm in angular position to hold said follower against said former cam, means for oscillating said first-mentioned arm to cause said follower to traverse said former cam, and means for holding said shafts against angular motion during the rocking of said firstmentioned arm.

7. In combination, a casing, an arm fulcrumed in said casing about an axis substantially parallel to a casing axis, a pair of rock shafts axially slidable in said arm at different distances from said fulcrum axis and substantially parallel thereto, the closer of said shafts projecting from said casing and carrying a wheel truing device, the opposite end of the other of said shafts carrying a cam follower, connections between said shafts causing axial motion of one to produce axial motion of the other, a former cam for contact by said follower, a block secured to said device-carrying shaft, a second arm pivoted to said block transverse to said axes, said second arm bearing at one end on a portion of said first-mentioned arm and at its opposite end operatively secured to said follower-carrying rock shaft, means yieldingly holding said second arm in angular position to hold said follower againstsaid former cam, means for oscillating said first-mentioned arm to cause said follower to traverse said former cam, means for holding said shafts against angular motion during the rocking of said first-mentioned arm, a rod pivoted at one end to said casing, and a friction shoe carried by said first-mentioned arm and engaging said rod.

8. A truing mechanism comprising a truing tool carrier movable in and out and transversely, a templet, a follower mounted for traversing said templet and for in and out motion following the contour of said templet, connections between said follower and tool causing in and out motion of said follower to produce in and out motions of said tool and traversing motions of said follower to produce transverse motion of said tool and a stop limiting the inward motion of said follower whereby said templet and follower may have clearance not reproduced in the contour produced by said tool.

9. A truing mechanism comprising a support, a lever fulcrumed on said support, an arm fulcrumed on an axis transverse to the fulcrum axis of said lever, and movable with said lever, a wheel truing device and a cam follower supported by said lever and operatively connected to said arm, a relatively stationary cam, means for yieldingly urging said cam follower against said cam, and means for rocking said lever to cause said follower to traverse said cam.

10. A truing mechanism comprising a support, a lever fulcrumed on said support, an arm fulcrumed on an axis transverse to the fulcrum axis of said lever, and movable with said lever, a wheel truing device and a cam follower supported by said lever and operatively connected to said arm, a relatively stationary cam, means for yieldingly urging said cam follower against said cam, and means for rocking said lever to cause said follower to traverse said cam, said wheel truing device being positioned nearer to the fulcrum of said lever and to the fulcrum of said arm than is said follower to cause motions of said truing device through a smaller amplitude than motions of said follower.

11. A truing mechanism comprising a support, a lever fulcrumed on said support, an arm fulcrumed on an axis transverse to the fulcrum axis of said lever, and movable with said lever, a wheel truing device and a cam follower supported by said lever and operatively connected to said arm, a relatively stationary cam, means for yieldingly urging said cam follower against said cam, and means for rocking said lever to cause said follower to traverse said cam, said wheel truing device being positioned nearer to the fulcrum of said lever and to the fulcrum of said arm than is said follower to cause motions of said truing device through a. smaller amplitude than motions of said follower, the ratio of said distances from said fulcra of said follower and device being greater for said lever than for said arm whereby a flatter former cam produces a steeper contour on a grinding wheel trued by said mechanism.

arm, a lever fulcrumed on said arm for motion with and transverse to the motion of said arm, a pair of slides carried by said arm for motion transverse to the motion of said arm, and operatively connected to said lever, cooperating elements comprising a former cam and a follower for said cam, one of said elements being fixed and the other of said elements being carried by one of said slides, means yieldingly holding said elements in contact' with each other, a truing device carried by the other of said slides, and means for rocking said arm.

13. A truing mechanism comprising a rock arm, a lever fulcrumed on said arm for motion with and transverse to the motion of said arm, a pair of slides carried by said arm for motion transverse to the motion of said arm, and operatively connected to said lever, cooperating elements comprising a former cam and a follower for said cam, one of said elements being fixed and the other of said elements being carried by one of said slides, means yieldingly holding said elements in contact with each other, a truing device carried by the other of said slides, means for rocking said arm, and means holding said slides against rocking about their own axes as they are moved by the rocking of said arm;

14. A truing mechanism comprising a rock arm, a lever fulcrumed on said arm for motion with and transverse to the motion of said arm, a pair of slides carried by said arm for moing said elements in contact with each other, a

truing device carried by the other of said slides, a rotary screw arranged transverse to said arm,

- a block threaded on said screw and operatively RALPH E. FLANDERS.

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