US2312347A - Dressing device - Google Patents

Description

March 2, 1943. V s. MADsEN DRESSING DEVICE` Filed Jan. 4; 1941 3 Sheets-Sheet 1 l v l l JlL NVs/vfozz/ :Senn CW/aagsen Mafch 2, 1943. s. MDsl-:N l l 2,312,347

l DRESSING DEVICE March 2, 1943.` s. MADsEN DRESSING DEVICE Filed Jan.. 4. 1941 3 Sheets-Sheet 3 5 NVE/#Top em OW cra/sen v frraeafx vPatented Mar. 2, 1943 DRESSING DEVICE I Sern Madsen, Rockford, lil., assigner to Mattison Machine Works, Rpckford, Ill., a corporation of 'Illinois Application January 4, 1941, Serial No.l 373,083

` (ci. 12s- 11) 24 Claims.

This invention relates to a device for dressing the periphery of a grinding wheel to an irregular contour.

One object is to provide for a novel device for generating a plurality of contiguous arcuate surfaces on a wheel periphery by means ofa single dressing point.

Another object is to generate contiguous reverse arcs by swinging a dressing point successively about spaced parallel axes.

A further object is to provide novel means for insuring the maintenance of a constant angle between the dressing tool and the wheel surface during generation of the different contours.

vStill another object is to provide `adjustment of the radii of the curves generated. It is also an object to provide a dressing devic which is readily adaptable to a socalled surface grinder.

Anotherlobject is to interlock the moving parts of the dressing tool mounting in a novel manner such as to render the device simple and foolproof in operation.

The invention also resides in the novel `con-- struction of the tool mounting which contributes to simplicity in construction, convenience in operation, and precision in the location and mergence of the differently curved surfaces.

Other objects and` advantages ofthe invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which- Figure 1 is a perspective view of a wheel and dressing device embodying the present invention. Fig. 2 is a fragmentary end elevational view.

Fig. 3 is a transverse sectional viewftaken along the line 33.of Fig. 4.

Fig. 4 is a longitudinal section taken along the line 4-4 of Fig. 2. i

Figs. 5, 6 and 7 arediagrammatic viewsillustrating the motions of the tool actuating member in dressing different portions of the grinding wheel surface.

Fig. 8 is a fragmentary view of the dressed grinding wheel showing the dressing tool in different positions.

Figs. 9 and 10 are views similar to Figs. '4 and 2 showing a modied form of the invention, Fig. 9 being a section taken along the line 9-9 of Fig. 10.

Fig. 1l isa fragmentary perspective View of a portion of Fig. 10. 1

While the invention is susceptible of various modifications and alternative constructions and of ,application in various ways, it has .been shown in the drawings and will be described herein for forming a particular contour on the abrasive wheel 2 of a so-called surface grinder to which the device is well suited. It will be understood, however, that I do not intend to limit the invention by such exemplary disclosure but aim to cover -all modifications, alternative constructions and uses falling within the spirit and scope of the invention as expressed in the appended claims.

The operation of dressing a grinding wheel in accordance with the present invention involves moving a single dressing point or diamond I lat.

erally across the periphery of a wheel 2 to be dressed while the latter is power rotated about a fixed axis. In the case of the surface grinder shown, the dressing point is located directly beneath the wheel and is supported from one end of lthe horizontally reciprocable work table I8 in a position such that the tool is lnot brought into engagement with the wheel during the normal grinding stroke. The wheel is mounted for vertical adjustment toward the dressing point to determine the depth of the cut taken by the latter.

The movements of the dressing point are controlled in a manner such as to generate arcuate sections of diierent curvatures with the contiguous sections merging precisely. `In thel present instance, one concave arcuate section 3 at the center of the wheel is flanked by sections 4 and 5 of convex curvature merging with the centralsection at the points 6 and -1 rFig. 8) of tangency of the contiguous-arcs. Generation of this contour is accomplished by swinging the dressing point successively about spaced parallel axes and through accurately defined angular limits.` To this end, the point I .is carried by and projects laterally from a tool holder in the form of a horizontal shaft 8 which is swingable about its own axis 9 but in two different positions 91 and 92 (Figs.

5 and 7) thereof to generate the arcs 4 and 5 andl is also bodily swingable about a parallel axis IIJ; The latter extends horizontally and generally tangentially of the wheel 2 and is spaced, in this instance, on the side of the dressing point opposite the shaft axis 8 so as to generate the reversely curved or concave intermediate arc 3.

Referring first to the form of the invention shown in Figs. 1 to 8, the axis i8 lis that of a shaft II larger than the shaft 8 and having a bore I2 in which the smaller shaft is journaled.

'I'he shaft II is journaled intermediate its ends inl a bearing I3 formed in a block I4 supported by a bracket I5 on the work table I6 which may be moved beyond its normal working range to move the dressing device into and out of operative position relative to the wheel. To provide I relative to the supporting shaft ,II.

for vertical and some angular adjustment of the block, the latter is supported by wedges I1 which may be shifted endwise by screws I8 after which the block is clamped to the bracket by screws I8. The longitudinal position of the block is'maintained by a transverse key 2li.

The shaft 8 is held against endwise movement For this purpose, the offset forward end 2| is backed by a vertical surface 22 on the shaft II. Intermediate its ends, the shaft 8 is formed with an annular groove 23 opening outwardly and registering with asimilar groove 24 in the shaft II. A segmental key 25 is fastened in the groove 24 by pins 28 and is disposed in the groove 23 thereby locking the shaft 8 against forward axial movement.

The dressing tool I is carried in the forward 'end 2| of the shaft 8 which end is offset and the wheel. The pin is clamped in place-by a screw 28 and is backed by a screw 28 threading into the other end of the bore and providing a` simple means by which the position of the point relativev to the axes 9 and I0 may be adjusted conveniently.

The rear end 38 of the shaft 8 projects from the larger shaft II and carries means for oscillating the shafts individually and performing several additional functions. In the present instance, this actuating means comprises an arm 3| having its upper end disposed in a slot in the shaft end 30 and pivoted on a screw 32 threaded therein. The arm is thus coupled to the shaft 8 to oscillate the latter and is also swingable longitudinally of the shaft about the transverse axis defined by the screw 32. A knob 33 projecting rearwardly from the lower end of the arm provides a convenient handle for grasping the arm. To facilitate manipulation .of the device, the shaft slot preferably is formed at an angle such that the arm and the dressing point I are always disposed in the same plane.

Movements'of the actuating arm in opposite directions about its pivot 32 are utilized toselect the axis about which the dressing point is next to swing, that is, to couple the shaft II to the arm or to free this shaft and permit independent oscillation of the shaft 8. For this purpose, a slot 34 slightly wider than the thickness of the arm is formedlin the rear end of the shaft II and extends diametrically across Ythe shaft from the shaft 8. When the arm is in register angularly with this slot, it will move into the slot as shown in Fig. 4 as the arm is pushed forwardly.

The side walls of the slot thus constitute lugs which coact with the arm to couple the latter to the larger shaft Il the latter being oscillated as the arm is moved back and forth. During "'this movement, the tool I is swung about the axis III to dress the arcuate portion 3 of the wheel surface. Now, when the arm is pulled rearwardly out of the slot 34, it is disconnected from the shaft II and only the shaft 8 may be oscillated by swinging the arm.

.Stops are provided for limiting the range of oscillation of the shaft II when coupled to the arm 3|, thereby defining the length and position of theV wheel surface 3. Herein, two stationary stops and 38 project rearwardly into the path of the arm in positions to interrupt the movement of the arm when the dressing point I reaches either of the points 8 and 'I of tangency after traversing the arc 3 or either of the arcs 4 and 8. Theserstops comprise lugs formed on an arcuate plate 31 which is fastened by screws 38 to the block I4 beneath the shaft lI I.

A mechanical interlock is provided for preventing the actuating arm from being coupled to or uncoupled from the shaft I I except when in a limit position against one of the stops. This includes a bar 39 'rigid with and projecting forwardly from the arm in position to register with notches 40 and 4I in the plate 31 when the arm is 'in a limit position against one of the stops;

When the arm is pushed forwardly into the slot 84 (Fig. 4) to couple it to the shaft II, an upwardly opening notch 42 in the bar 39 registers with the lower edge portion of the plate 31. Thus. the arm is free to swing away from the stop and in this movement the shoulder 444 on the bar moves in behind the plate 31 thereby locking the arm against outward Lmovement until the other plate notch is encountered. v

The' coupling and uncoupling movements of the arm 3| are also utilized to effect automatic operation of an interlock for holding the shaft II against turning when it is uncoupled from the armand while the shaft 8 is being turned individually. To form this interlock, the upper edge of the plate 31 is disposed in the groove 24 of the shaft II and formed with semi-circular notches 45 and l48 inthe same angular positions as the notches 48. and 4I. On the side ofthe shaft I I opposite the shaft 8 and at the bottom of the slot 34, the shaft Il is formed with a bore 41 positioned to aline with the notches 45 and 48 in the opposite limit positions of the arm. A pin 48 received in this bore is urged endwise and outwardly by a compression spring 49, such movement being limited by av plate 50 on the end of the shaft I I. A notch 5| is formed in the pin in position to register with the upper edge of the plate l31 when the arm 3| is pressed into the slot 34.

'I'hen the shaft is free to turn; However, when the arm is withdrawn to uncouple it from the shaft in either of its limit positions, the pin 48 Y will be alined with one of the .notches 45 and 48 and will move into the latter (see Fig. 3) locking the shaft to the stationary plate.

Figs. 9 to 11 show a somewhat simplified construction -in which the dressing point as before is carried on the offset end 2| of the shaft 8 which at its rear end is pivotally connected to the actu,

ating arm 3| and handle`33. The shaft bearing is supported by a yoke 53 having depending arms 84 and 55 which snugly straddle an upstanding portion 58 of a supporting block 51 and are pinned to a shaft 88 journaled inthis portion to turn on the axis I0 previously referred to. A key 58 projecting into a groove 88in the shaft holds the latter against endwise movement.

' The stops 35 and 38'which limit the movements of the actuating arm in this instance comprise pinsprojecting from the rear end of block 81. Projecting forwardly from the arm 3| is a hook 8| of semicircular cross-section which hook, in either v'I'he coupling is effected by l in a semi-circular notch 65 at the edge of the yoke but cannot be again retracted until it reaches the v other stop.

' As vin the form of the invention first described,

K forward movement ,of the arm 3l couples it to the yoke`53 and also frees the latter for oscillation. entry of the hook 6I arm 54 which thus becomes connected to the actuating arm through the medium of the hook (Figs.

from-the shaft 56 so that the shaft 8 alone will oscillate with the arm.

In the vforward movement of the arm 3I to of a pin 6 6`which is disposed in a bore 61 in the block 51 and urged rearwardly byv a spring 63. The forward end of the pin is adapted to project into the notch 65 in the yoke arm 56 as the actu- To condition the device for dressing of the surface 5, the arm 3I'is retracted from the slot 34 as an incident to which the 'bar' 39 is withdrawn l through the notch 40 and the pin 48 moved by the spring 49 into the notch 46 thereby locking the shaft I I. Then, the arm is swung to the left t'o vertical position carrying the dressing point about the axis 92 and in a convex path to the left side of the wheel. -One pass across the wheel is thus completed. if additional passes are to be made, the wheel is usually set down a small o couple it. to the yoke, the hook 6I engages the end ating arm is retracted. This locks the yoke against turning about the axis I0. Then, when the arm is moved to couple to the yoke arm 56, the pin is pushed out of the notch 65 by the hook and the yoke and dressingv tool are freed for oscillation about the axis 9. There is a pin 66 at each end of the'locking plate 62 coacting with the hook 6I in each limit position of the actuating arm. l

Operation of the improved dressing device in either of the forms above described involves the/ samemanipulationof the .handle 33. For convenience, the operation will be described with reference to the form shown in Figs. 1 to 8, assuming that the wheel has been dressed previously to thedesired contour and is now to be redressed. As a preliminary, the dressing device is moved into operative position with-the tool disposed be.- low the center of the wheel as shown in Fig. 4. Next the wheel is lowered to produce the desired depth of cut, the point I being disposed to one side of the wheel, for example the right hand side. Assuming that the parts are disposed as shown inFigs. l, 3 and 7, the point I will be at the outer end of the arc 4, the actuating arm 3| will be retracted from the slot 34 and hanging downwardly, and the pin 48 will project into the notch 45 locking the shaft II against turning. At this time, the axis of the sh'aft 8 will occupy its right hand position indicated at 91 in Fig. '1.v With the wheel rotating, the actuating arm is first swung'to the left slowly to the dotted position increment and the .operations described above repeated but in reverse order.

Although the wheel surface 3 is ofa different radius and of a different shape than the adjacent surfaces 4 and 5, the dressing tool is always maintainedr at the same angle, ninety degrees herein, relative to the surface it is truin'g. This angle is maintained by virtue of the fact that in each of its three movements the dressing pointy moves about a fixed axis, either III, 31 or 9. The relation does not change during the transfer of the dressing point from one curve to the other because the transfer is made with the point disposed at the point of tangency of the two curves. As a result, the curves ioin'to form a continuous smoothfsurface across the wheelperiphery.

The transfer points are defined accurately by the limit stops for the actuating arm. 'I'hese stops coacting with the various interlocks make it impossible to move the dressing point accidentally beyond the proper position or to shift from one axis to the other in the course of dressing any one of the three arcuate surfaces. Thus, the device isfoolproof in operation and the interlocks as well as all of the movements of the dressing point are controllable by a single hand lever.

It will be observed that the radii of the arcs 3, 4 and 5 may be changed as desired so long as the two are varied by equal amounts. accomplished simply by adjusting the screw 29 which moves the dressing point closer to one of the axes 9l and 92 and away from the other by a shown in Fig. 7 where it will encounter the stop 36. In this movement to the position shown in full lines in Fig. 6, the pointl moves laterally and about the axis 91 across the arcuate surface 4 to the point 6 of tangency. i A convex surface is l thus formed on the wheel.

Next, the actuating arm is pushed forwardly into the slot 34 (Fig. 4) and is thereby coupled to V the shaft II.l Inl this movement, the active portion of the pin 48 is pushed out of the notch 46 and the notch 5I in the pin is brought into reg- ,ister with the plate 31 thereby freeing the shaft II to swing with the arm. Also, the bar 39 is projected through the notch 4I and the notch 42 A therein is brought into alinement with'the plate 31. The device is now conditioned for movement o of the dressing point about thev axis I3 to true the concave surface 3; This is effected simply l by moving the actuating arm reversely from Vthe full. line position to the dotted line position shown corresponding amount.

I claim as my invention:

l. In a whee1 dressing device, the combination of a support pivoted to swing about one axis, a tool holder mounted on said support to swing independently about a parallel axis, a dressing tool carried by said holder, an actuating member pivoted on said holder to swing about a transverse axis and couple the member to or uncouple it from said support for movement of the support by the member, an arcuate stationary plate including the arc of movement of said member about one of said axes, and a transverse shoulder on said member coacting with .said plate to hold said member in coupled lposition during a predetermind arc of movement and then to pass the plate when the member is uncoupled.

2. In a wheel dressing device, the combination of a support pivoted to swing' about one axis, a tool holder mounted on said support to swing independently about a'parallel axis, a dressing tool carried by said holder and movable along tangent arcuate paths during swinging of said holder and support respectively, an actuating member pivoted lori said holder to swing about a transvers:`

axis and couple themember to or uncouple it from said support, a pin for locking' said support against turning. and means actuated by the couplingand uncoupling movementsl of said member to move said pin to inactive andactive positions respectively. f

f 3. In a wheelfdressing` device, the combina- This may bev tion of a support pivoted to swing about one axis, a tool holder mounted on said support to swing independently about a parallel axis, a dressing tool carried by said holder and movable along tangent arcuate paths during swinging of said holder and support respectively, anI

shaft journaled in said member to turn about an axis parallel to said iirst axis and having p-I 'positeends projecting from the member, a dressactive andinactivekpositions to lock said support against turning or to release the support, andv means actuated by the coupling and'uncoupling movements of said member to move said pin to inactive and active positions respectively.

4. In a wheel dressing device, adressing point,

Y means supporting said point to swing about ing tool carried by one of said ends and movable across the wheel periphery by oscillation of said member or said shaft, an actuating arm pivoted on the othner end of said shaft to swing about a third transverse axis, interengaging lugs between said arm and said member operable by swinging of the arm about said third axis to couple` the arm to said member or to release the arm therefrom for independent oscillation of the shaft, and means automatically responsive to release of said arm from said member to lock the latter against turning. e.

9. In a wheel dressing device, a dressing point,

a support therefor swingable about spaced parmember when said point reaches the point of tany gency of said paths.

point is disposed at the point o! tangency of said paths.

5,-In a wheel dressing device, a dressing point,

` means supporting said point to swing about axis, and means locking said member against movement about said transverse axis except when said point is in a predetermined angular position. 6, In a wheel dressing device,.a dressing point, means supporting` said point to swing about spaced parallel axes, an actuating member mounted to swing said supporting means about either of said axes and to swing independently of the supporting means about a transverse axis between two positions. and means coacting with said member in one of said Apositions to lock the same against movement about one of said nrst mentioned axes and in the other position to'prevent swinging of the member about the other axis.

7. Mechanism i'or truing the periphery of a rotary grinding wheel having, in combination, a member mounted to rotate about an axis disposed generally tangentially relative to said wheel, av

shaft journaled in said member to turn about an axis parallel to said first axis and having opposite ends projecting from the member, a dressing tool carried by one of said ends and movable across the wheel periphery by oscillation of said member or said shalt. an actuating arm pivoted on the other end of said shaft to swing about a transverse axis, and interengaslns lugs between said arm and said member operable by swinging oi the arm about said third axis to couple the arm to said member or to release the arm therefrom for independent oscillation of the shaft.

' 8. Mechanism for truing the periphery or a 10. Mechanism for truing a rotary grinding wheel having, in combination, a dressing point, means supporting said point for engagement with the periphery of said wheel and for oscillation about spaced axes and in arcuate paths tangent each other, and means limiting `the movement o said point in one direction along one of said paths to the point oi-tangency between the paths while permitting continued movement of the point in the same direction past said tangent point and along the other o f the paths.

11. Mechanism for truing a rotary grinding wheel having, in combination, a dressing point, means supporting said point for engagement with the periphery oi' said wheel and for oscillation about spaced axes and in arcuate paths tangent to each other, means limiting the movement of lsaid point in one direction along one of said paths to the point of tangency of the paths while permitting continued movement about the other axis, and means limiting reverse movement of said point about said last mentioned axis to said point oi tangency while permitting continued movement about the rst axis.

12. Mechanism for truing a rotary grinding wheel having, in combination, a dressing point, means supporting *s aid,.point for engagement with the periphery ofsaid wheel and for oscillation about spaced axes and in arcuate paths tangent to each other, a single actuating member, and mechanism actuated by selective movementsof said member to cause said point to move successively along said arcuate paths about the different axes. .Y

13. Mechanism for truing a rotary grindin A wheel having, in combination, a member mountrotary grinding wheel having, in combination, a

member mounted to rotate about an axis disposed generally tangentially relative to said wheel, a

. a tool holder on said support to swing independwheel having, in combination, a membermounted to turn on an axis extending generally tanvgentially of said wheel, a holder mounted on -said member to turn about an axis offset laterally from said first axis, and a dressing point on 'said holder positioned for engagement with the wheel periphery along paths disposed between said axes.

16. A wheel dressing device having, in combination, a dressing tool, means supporting said tool for movement successively along tangent arcuate paths of different curvature while maintaining a constant angle between the tool and the path being traversed, actuating means for said supporting means operable selectively when said tool is at the point of tangency of said paths to transfer the tmovement from one path to the' other, and interlocking means operable automatically to prevent deviation of the dressing tool at anytime from the path being traversed.

17. A wheel dressing device having, in combination, a dressing tool, means supporting said tool for movement successively along tangent arcuate paths of different curvature, -actuatingr lmeans for saidA supporting means operable selectively when said tool is at the point of tangency' of said paths to transfer the movement of said point from one of Vsaid paths to the other, and locking means acting selectively to conne movement of said tool to the path being traversed at any one time. l

18. A wheel dressing device having, in combination, a dressing tool, means supporting said tool for movementsuccessively along tangent arcuate paths of reverse curvatures while maintaining the 'tool at a fixed angle to thepath being traversed, actuating means operable selectively to transfer the tool lmotion from one of said paths to the next, and means rendered opently about a parallel axis, a dressing tool carriedby said holder, an actuating member for oscillating said holder mounted for independent movement longitudinally of said axes'to lock said holder and support together for oscillation in unison about said second axis, av locking element on said member providing a transverse notch, and a stationary plate coactng with said notch to hold the member coupled to said support during a predetermined oscillation thereof andthen to free the member for uncoupling from the support.

21. Mechanism for truing the periphery of a rotary grinding wheel having, in combination, a shaft mounted to rotate about an axis disposed generally tangentially relative to said wheel, a second shaft journaled in said first shaft to turn about an axis parallel to said first axis and having opposite ends projecting from the flrst shaft, a dressing tool carried by one of said ends' and movable across the wheel periphery by oscillation of either of said shafts, and actuating means connected t`o the other end of said second shaft and operable selectively to turn either one of said shafts.

22. A wheel dressing device having, in combination, a support, a yoke straddling said superative as'an incident totransfer of said tool port and pivoted thereon, a tool holder pivoted on said yoke to turn about an axis `parallel to the yoke pivot, said holder having an end offset substantially into alinement with said yoke pivot, a dressing point mounted on said offset end, and actuating means connected to the opposite end of said holder and operable selectively to swing said yoke or said holder about their respective axes. j

23. A wheel dressing device having, in combination, a dressing tool, means supporting said tool for movement successively along tangent arcuate paths of diierent curvatures, actuating means for said tool supporting means, and means controlling the motion of said actuating means to -maintain a continuous directional motion of bination, a dressing tool, means supporting said ried. by said holder, and anactuating member for oscillating said holder mounted for independent movement longitudinally of said axes to lock s'aid holder and support together for oscillation in unison about said second axis.

tool for movement successively along tangent arcuate paths each described by rotation about predetermined centers, actuatingmeans for said tool supporting means operable selectively to shift the tool movement successively from one center to the other, and means operable automatically to restrict the motion of the tool by said yactuating means to the selected one of said centers.

SERN MADSEN.

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