US2971296A - Grinder with oscillating head - Google Patents

Description

Feb. 14, 1961 M. M. BASS ETAL GRINDER WITH OSCILLATING HEAD Original Filed March 29, 1956 5 Sheets-Sheet 1 INVENTOR. MILES M 81458 RAMsAr M an: y a: c. HAMMOND PHIl/F J: ROBIJCHUNG ATTORNEYS Feb. 14, 1961 M. M. BASS ETAL 2,971,296

GRINDER WITH OSCILLATING HEAD Original Filed March 29, 1956 5 Sheets-Sheet 2 Z Y INVENTOR. MILEJM. ans:

5 RAMS/1V M azu ATTORNEYS M. M. BASS ETAL GRINDER WITH OSCILLATING HEAD Original Filed March 29, 1956 Feb. 14, 1961 5 Sheets-Sheet 3 a N m w Y 5 NC V. NSr MO- B ME W5 N a M o R I.,MAR Q bw M m A s r MM W 5 2 2 MHMP f v 3 M U 2 2 Feb. 14, 1961 5 Sheets-Sheet 4 INVENYOR. MILES BASS mmsnr M. 8541. y 1:! c. HAMMOND PHIL/P J: ROB/SCHUNQ ATTORNEYS Feb. 14, 1961 M. M. BASS ETAL 2,971,296

GRINDER WITH OSCILLATING HEAD Original Filed March 29, 1956 5 Sheets-Sheet 5 m 50 L\\ \\\Y] L\ i/ Z ll lllu us \\\\\jT \\\\1\\ I23 34 36 T Q 6 I35 133 '25 I22 {I28 25 I ii X IIQ 2 l 1 I34 m m '24 T 29 I3] I26 INVENTORL M1155 M. ans:

7 RAMJAY M. 8:11 vBY LEE 6. HAMMOND g PHILIP J. nos/Hume TTORNEYS United States Patent GRINDER WITH OSCILLATING HEAD now Patent No. 2,922,258, dated Jan. 26, 1960. Di-

vided and this application May 11, 1959, Ser. No. 812,449

9 Claims. (CI. 51-55) This invention relates to a grinder andparticularly to one in which the grinding wheel may be caused to oscillate at a controllable frequency and amplitude. This is a division of our application Serial No. 574,728, filed March 29, 1956, now Patent No. 2,922,258, granted lanuary 26, 1960.

In conventional tool grinding equipment, it is customary to provide a rotatable grinding wheel adjacent a work supporting table. The table is normally movable for adjustment relative to the axis of the grinding wheel, so that the plane defined by the working surface of the wheel and the plane defined by the table top will intersect at whatever angle is desired to facilitate grinding the work in a desired manner. However, in all of these grinders, insofar as we are aware, it is necessary for the workman who is utilizing the machine, such as for grinding a tool point, to manually move the tool point across the working face of the grinding wheel. The reasons for such movement of the tool point across the face of the grinding wheel are well known to the industry and may be summarized here by pointing out that such movement of the tool tends both to speed the grinding operation and to work out any irregularities whichmay exist in the face of the grinding wheel, i.e., dress the wheel. This latter tends to secure a more nearly flat and a more smoothly ground surface than would be possible if no such movement of the tool point were employed. Further, this movement of the tool point effects a desirable amount of socalled cross-grain grinding and prevents the wheel grit from channeling the work.

This movement, while universally practiced where tool points and grinders are used, is nevertheless tedious, time consuming and tiring to the workman. Also, it is difficult to grind a tool accurately while manually moving it along a table and with respect to a grinding surface. Further, where the tool is moved relative to the table, the table becomes worn, and such wear is often sufi'lcient to alter the positional relationship between a tool being held on the table and the wheel.

These disadvantages of the technique previously employed have long been recognized, but no acceptable provision for solving them has, insofar as we are aware, been offered to the industry. It is recognized that some machines have been provided which hold the tool mechanically and provide a relative oscillation between the wheel and the tool, but these machines are relatively expensive, are often difiicult to utilize, and their use is limited to conditions involving high production operation.

It is therefore desirable to provide a tool grinding machine adaptable to general use, by which a workman can maintain all of the precision and individual attention to the exact shaping to the tool point, which is customarily obtained where the tool point is guided by hand, while avoiding the fatigue, inconvenience and occasional inaccuracy which sometimes occur where the relative motion of the tool with respect to the axis of the grinding 2,971,296 Patented Feb. 14, 1961 wheel is provided by manually moving the tool across the face of the grinding wheel.

Accordingly, a principal object of the invention has been the provision of a grinding machine effective for obtaining the individual shaping of the work, such as a tool point, which is customarily obtainable by hand guiding of said work with respect to the grinding surface, while eliminating the fatigue, inaccuracy and inconvenience of manually moving the work back and forth across the face of the grinding wheel.

A further object of the invention has been to provide a machine, as aforesaid, in which the workman can hold the work, especially a tool point, stationary with respect to a supporting table, either with or without assistance of a mechanical holder or guide, and the relative motion of the work with respect to the axis of the grinding wheel is provided by the machine.

A further object of the invention has been to provide a machine, as aforesaid, having a device by which the axis of the grinding wheel is caused to oscillate with respect to the work supporting table.

A further object of the invention has been to provide a device, as aforesaid, in which either or both the frequency and amplitude of said oscillations are individually controllable.

A further object of the invention has been to provide a machine, as aforesaid, in which the preceding named objectives may be accomplished while retaining the previously convent onal practice of adjusting the table to change the angle between the plane of the grinding face of the wheel and the plane of the work supporting surface of the table.

A further object of the invention has been to provide a device, as aforesaid, by which the foregoing named objectives may be accomplished in a machine capable of relatively general use.

A further object of the invention has been to provide a machine, as aforesaid, in which the several adjustments above mentioned may be made simply, accurately, and while the machine is in motion, and wherein the machine will remain in an adjusted condition reliably through any ordinary term of use.

A further object of the invention has been to provide a device, as aforesaid, which will be adaptable to use with many types of grinding wheels, but which will be specifically adapted to use with diamond filled grinding wheels.

A further object of the invention has been to provide a device, as aforesaid, which will also be adapted to use with grinding wheels employing a technique commonly identified as electrolytic grinding.

A further object of the invention has been to provide a device, as aforesaid, which will eliminate the inaccuracies resulting from wear of the table surface, which now sometimes occurs where the tool is moved along, and with respect to, the surface of the table.

A further object of the invention has been to provide a machine, as aforesaid, which can be employed by any ordinarily skilled personnel without requiring the use of techniques different from those which are already familiar.

A further object of the invention has been to provide a device, as aforesaid having a wheel supporting spindle which is adaptable for conversion Without major change therein to double-end operation, whereby a second Wheel and table arrangement may be provided adjacent to the opposite end of the spindle supporting the first named wheel.

A further object of the invention has been to provide a machine, as aforesaid, which will be adaptable for grinding tools of a variety of shapes.

Other objects and purposes of the invention will be apparent to persons acquainted with equipment of this general type upon reading the following disclosure and inspecting the accompanying drawings,

In the drawings:

Figure 1 is a side elevational View of the machine to which this invention relates, with the adjacent side sheets thereof broken away.

Figure 2 is a sectional view taken on the line IIII of Figure 1.

Figure 3 is a sectional view taken on the line Ill-J11 of Figure l. V

' Figure 4'is a sectional view taken on the line IV--IV of Figure 3.

, Figure 5 is a sectional view taken on the line VV of Figure 1.

Figure 6 is a sectional view taken on the line VIVI of Figure 3.

Figure 7 is a sectional view taken on the line VIIVII of Figure 6.

For the purpose of convenience in description, the terms upper, lower, left, right, and derivatives thereof, will have reference to the machine and parts thereof as appearing in Figure 2. The terms front and rear will have reference to the left and right sides, respectively, of the machine as appearing in Figure 1. The terms inner, outer, and derivatives thereof, will have reference to the geometric center of said machine and parts thereof.

GENERAL DESCRIPTION In meeting the objects and purposes above set forth, we have provided a machine having an adjustable, but relatively stationary, table with which a manually operable tool holder may be used, if desired, said machine having a structure for supporting a rotatable grinding wheel adjacent to said table. The grinding wheel is mounted for oscillatory movement transversely of its rotational axis. During such movement, the center of said Wheel traces an arcuate path which is generally parallel to the surface of the grinding table, that is, the tangent at the midpoint of said path is parallel both to the surface, and to an adjacent edge 5d, of said table. This result is obtained by securing the grinding wheel 11 (Figures 1 and 4) to a shaft 12, which is rotatably mounted adjacent to the table 14 upon a shaft support bracket 13. The support bracket 13 is in turn pivotally supported by the bearing assembly upon the platform 15 of the machine frame 11). The shaft 12 is continuously rotated by a belt 16 driven by the motor 17.

Oscillation of the bracket 13 about its pivotal support 29 is, in the preferred embodiment here shown, effected by a lever 18 (Figures 2 and 5) pivotally supported by the pillow block 19 on the upper wall 34 of frame 10 and connected to the bracket 13 by the pitman 21. The lower end of the lever 13 is caused to oscillate, or is alternatively held against oscillation, by a roller 22, which is mounted upon the shaft 26, rotatable at a con trollable speed with the pulley 25. The shaft 26 may be moved radially of the axis of the pulley by a hand wheel 23 working through a mechanism 24 for adjusting the amount of eccentricity of the shaft 26 with respect to said pulley. The amplitude of oscillation of said wheel 11 is, therefore, controlled by the eccentricity, if any, of the roller 22 with respect to said pulley 25. Rotation of said pulley 25 is secured through the belt 27 driven through a suitable speed reducer 28 from, and by, the motor 29. The speed of such oscillation is adjusted through the speed reducer 23 in response to adjustment of the hand wheel 31.

DETAILED CONSTRUCTION A. Frame and table 7 As shown particularly in Figures 1 and 2, the base frame 10 of the grinding machine to which this invention relates is upright, substantially rectangular, in this particular embodiment, and fabricated from any sturdy, conventional material, such as steel plates. A platform or bed plate 15 is mounted upon the upper. wall 34 of the frame 19 and extends forwardly of the front wall 123 of the machine frame 10. The forward end of the platform 15 is provided with ways 35 on its upper surface, which engage and slidably support the base 36 of the table 14 for slidable, adjustable movement rearwardly and forwardly of the machine frame. 10. Such movement is obtained by means of the threaded engagement between the screw 37 (Figures 3 and 4) and the double or split nut 38, which has front and rear portions 40 and 41, respectively, through both of which the screw 37 is threadedly received. One portion, here the rear portion 41, is rigidly secured to the platform 15 between the ways 35. The screw 37 is rotatably supported upon the front end of the table base 36 and held against axial movement with respect thereto in a substantially conventional manner. A hand Wheel 45 is secured to the front end of the screw 37 for effecting rotation threreof, hence movement of the base 36 along the ways 35.

The table base 36 (Figures 3 and 4) extends laterally of, and above, the ways 35 and supports the bottom of a hood 46, which substantially surrounds the table 14 and the grinding wheel 11. Left and right table support members 47 and 48 (Figures 6 and 1) are mounted upon, and extend upwardly from, the table base 36 adjacent to its lateral edges (Figure 3) within the hood 46. The members 47 and 48 are preferably hollow and have concave, arcuate upper surfaces 4? having a substantially horizontal common axis 50 (Figures 4 and 6) lying within the plane defined by the upper surface 51 of the table 14. A pair of table brackets 52 and 53 (Figure 5) are secured to, and depend from, the lower surface of the table 14 near its lateral edges. Said brackets 52 and 53 have arcuate, convex lower surfaces 54 (Figure '6), which are snugly, slidably and respectively receivable into the upper, concave surfaces 49. Side plates 55 are secured to, and extend downwardlybeyond, the lateral sides of the brackets 52 and 53. Said side plates 55 embrace the lateral sides of the support members 47 and 48 when they are engaged by the brackets 52 and 53, respectively, in order to prevent dirt from entering between the brackets and their corresponding support members. The brackets 52 and 53 are slidable with respect to the support members 47 and 48 for effect The bearing assembly 26, which pivotally supports the support bracket 13 (Figuresl and 4) includes a pivot shaft 82, which is substantially parallel with the extended axis of the screw 37 and is secured at its opposite ends in the blocks 83 and 84 (Figure 1) mounted upon the rearward end of the platform 15. The shaft 82 is preferably located substantially directly behind the center line of the. table base 36. The support bracket 13 (Figure 4) includes a cylindrical housing 35 at its lower end, which encircles the pivot shaft 82 and is rotatably mounted upon said shaft by means of the bearings 86. Said bracket 13 also includes a support plate 87, which is secured to, and spaced from, the housing 35 by a pair of webs 88'. The shaft housing 89, in which the grinder shaft 12 is rotatably supported by means of the bearings 91, is mounted upon the plate 87. The grinder shaft 12 is axially parallel with the pivot shaft 821. and extends both forwardly and rearwardly from within the shaft housing 89.

A grinding wheel mount 92 (Figure 4) is rigidly secured to the front extension 93 of the shaft 12 by means of a bolt 94 in a substantially conventional manner..

The rearward face of the wheel mount 92 and the forward annular end wall 95 of the shaft housing 89 are provided with a suitable sealing device for preventing the Waste materials of the grinding operation from getting'into the bearings 91. The grinding wheel 11 is secured to the front surface of the wheel mount 92, as by means of bolts 96 (Figure 4), so that the planar grinding face of said wheel 11 lies in a substantially vertical plane and said Wheel can be disposed adjacent to, and parallel with, the edge 78a (Figure 5) of the table 14 within the recess 78.

The support bracket 13 and that portion of the shaft 12 and the shaft housing 89 disposed outside of the hood 46 are substantially enclosed by an enclosure 97 (Figure 4), which is mounted upon the frame and has an opening 93 in its front wall, through which said shaft housing 89 extends. The opening 98'is laterally elongated to permit oscillation of said housing 89 with respect to the enclosure 97. The space between the housing 89 and the enclosure 97 is closed by an annular sheet 99 having a flanged, internal edge 99a, which snugly embraces the housing 89. Said flanged edge 99a, hence the sheet 99, is secured to the housing 89 by a resilient ring 81 and said sheet 99 slida-bly and snugly engages the front wall of the enclosure 97 to provide a dust seal.

C. Wheel drive mechanism The rear extension 106 of the shaft 12 supports a pulley 1117 (Figures 1 and 4), which is connected to a pulley 108 by the belt 16, said pulley 108 being mounted upon the shaft of the motor 17. The motor 17 is supported below the platform 15, in this particular embodiment, upon a motor mount 169 so that the axis of said motor is parallel with the shaft 12 (Figure 2). The motor mount 1119 is pivotally supported along one edge thereof, parallel with said motor axis, upon a pivot shaft 111, which is supported upon the frame 10. An arm 112 extends from the opposite edge of said motor mount 1G9 and supports a substantially horizontal pin 113 near its free end, which pin slidably extends through a lengthwise slot 114 in the support bar 115 near the lower end thereof. The upper end of said bar 115 (Figures 1 and 2 is pivotally mounted upon the upper wall 34 of the machine frame 10.

D. Oscillatory drive mechanism The pitman 21 is pivotally supported at one end upon the front web 88 between the support plate 87 and the cylindrical housing 85. The other end of said pitman 21 is pivotally secured to the upper end of the lever 18, which lever is pivotally supported between its upper and lower ends by a pivot shaft 116 and a pillow block 19 mounted upon the top wall 34 adjacent to the bearing assembly 211. The lower end of the lever 18 is provided with a slot 118 which is elongated lengthwise of said lever 18. The roller 22 (Figures 5, 6 and 7) is rotatably disposed within the slot 118 and is engageable with the side walls of said slot. The shaft 26 is rigidly secured to an adjustment block 119 (Figure 7), which is part of the adjustment mechanism 24 for effecting movement of the roller 22 into and out of a position of concentricity with the pulley 25.

The adjustment mechanism 24 (Figures 6 and 7) is comprised of an outer cylindrical housing 122, which is supported upon the front wall 123 of the machine frame 11) and rotatably supports an inner, cylindrical housing 124 by means of the bearings 125. Said inner and outer housings are concentric and their common axis is preferably parallel with the pivot shaft 82 (Figure 4). The inner housing 124 (Figure 7) extends slightly rearwardly of the outer housing 122 to mount the pulley 25. A pair of spaced, transverse, substantially parallel slide rods 12-6 and 127 extend diametrically through, and are secured to, the inner housing 124. Said rods 126 and 127 slidably support the adjustment block 119 within the yoke 133 and with respect to the inner housing 124 for movement in a direction parallel with said slide rods. Said adjustment block 119 is provided with an elongated opening 128, which is axially transverse of the slide rods 126 and 127 and radially elongated in a direction which, if projected, would intersect said rods 126 and 127 at an acute angle, such as approximately 60 (Figure 6). An adjustment rod 129 extends through the opening 128 and is engaged at its opposite ends by the arms 131 and 132 of the yoke 133, which embraces the opposite sides of the adjustment block 119. The yoke 13 3 is movable within, and lengthwise of, the inner housing 124, whereas the adjustment block 119 is movable transversely of said inner housing 124, but not lengthwise thereof. Thus, when the yoke 133 is moved lengthwise of said inner housing 124-, such movement will be translated into transverse movement of the adjustment block 119 as a result of the cam action of the walls of the elongated opening 128 upon the adjustment rod 129, depending upon the direction of movement of said yoke 133.

The front end of the yoke 133 (Figures 6 and 7) rotatably supports the rearward end of an adjustment screw 134, which is co-axial with, and extends into, the inner housing 124. Said screw 134 extends forwardly through, is threadedly engaged by, and is supported upon, a hub 135 (Figure 1), which hub is supported. upon the front wall 123 of the frame 14 The hand wheel 23, for effecting rotation of the screw 134, is mounted on the front end of said screw 134. Thus, by appropriate rotation of the wheel 23, the roller 22 is caused by the adjustment mechanism 24 to move into and/ or out of a position of concentn'city with the pulley 25.

The pulley 25 is connected by the belt 27, in a substantially conventional manner, to the output of the speed reducer 23, which is controlled by the hand wheel 31 mounted thereon, and which is connected to the motor 29, also in a substantially conventional manner.

OPERATION Prior to operating the grinding machine to which this invention relates, certain adjustments may be required in order to properly prepare said machine for said operation. Having selected a grinding wheel 11 having the proper type of grinding face 194, said wheel is mounted upon the wheel mount 92 (Figure 4) by the bolts 96. During the securing of said wheel 11 on the mount 92, it may be advantageous to move the table 14 forwardly, away from the wheel mount 92. This is accomplished by turning the hand wheel 45 in the proper direction, whereby the table base 36 will be moved along the ways 35 by the operation of the screw 37 and the split nut 38 in a manner which will be apparent.

When the proper adjustment of the table has been obtained, the motor 17 (Figure 1) can then be energized, thereby causing the shaft 12 and grinding wheel 11 to rotate. The motor 29 is also energized, which drives the speed reducer 28, which in turn rotates the pulley 25 of the adjustment mechanism 24. The pulley 25, acting through the inner housing 124 (Figure 6) and the adjustment block 119, causes the shaft 26, hence the roller 22, to rotate about the axis of the inner housing 124.

If the axis of the roller 22 (Figures 6 and 7) is eccentric with respect to the axis of the pulley 25, rotation of the pulley 25 will effect a reciprocable pivoting of the lever 18 about the pivotal axis provided by the lever bearing 19. Such reciprocation will be transmitted by the pitman 21 (Figure 2) to the support bracket 13 for effecting a corresponding pivotal reciprocation of said support bracket about the pivotal axis thereof provided by the bearing assembly 20. This will cause the shaft 12 to oscillate through a relatively small arc crosswise of the machine, the tangent of said are at its midpoint being substantially parallel to the pivot axis 511 of the table 14, and thereby effect a similar laternal oscillation of the grinding wheel 11. Where the grinding wheel, as shown here, has a relatively narrow grinding face 104, the oscillation of the grinding wheel will be relatively small and,

as a general rule, will be somewhat less than'the'radial width of the grinding face on said wheel 11. Thus, the path traversed by the axis of the shaft 12 during said oscillations, although arcuate, will be relatively fiat and substantially parallel to pivot axis 50 or" the table 14. However, since the path of oscillation of said shaft 12 is arcuate, and since the radius of this are is substantially less than, here approximately one-half of, the axial distance between the shaft 1'2 and the shaft of the driving motor 17, some provision must be made for keeping the belt 16 under uniform tension during the operation. This is accomplished by pivotally supporting the motor mount 109 upon the pivot shaft 11.1 so that said motor partially hangs upon the belt 16. Thus, as the shaft 12 moves upwardly and downwardly a relatively small distance during the arcuate movement thereof, the motor 17 is free to move upwardly and downwardly this same slight distance.

The [flexible and resilient annular sealing sheet 9% (Figure 4) permits movement of the shaft housing 89 with respect to the enclosure 97 during the oscillation of said shaft housing 39 without impairing the seal provided thereby. The opening 98 in the enclosure Q7, through which the shaft housing 89 extends, is sufficiently large to permit the desired oscillation of the shaft housing 89.

Adjustment of the oscillation distance or amplitude of the shaft 12 is effected by turning the hand wheel 23 associated with the adjustment mechanism 24. As shown in Figures 6 and 7, turning of the hand wheel 23 effects either a forward or rearward movement of the yoke 133, whereby the adjustment block 119, which supports the shaft 26, is moved in a direction transversely of the axis of the inner housing 124. This movement of the block 119 produces a corresponding radial movement of the roller 22, thereby causing or changing the eccentricity in the axis of the roller 22 with respect to the inner housing 124. By appropriate adjustment of the hand wheel 23, the roller 22 can be caused to be completely concentric with the pulley 25, whereby the grinding wheel ill can be caused to rotate without any reciprocation or oscillation whatsoever.

It will be recognized that the adjustment of the table E4, the adjustment mechanism 24 and the speed reducer 2 8 can be effected while the machine is in operation.

The necessary adjustments having thus been completed, the tool, as shown at 137 in Figure 4 is placed upon the table 14 and held there, either manually or by mechanical means, while the grinding wheel 11 reciprocates with respect to the table 14.

Although particular, preferred embodiments of the invention have been disclosed hereinabove for illustrative purposes, it will be understood that variations of modifications thereof, which do not depart from the scope of such disclosure, are fully contemplated unless specifically stated to the contrary in the appended claims.

What is claimed is:

1. In a grinding machine having a bracket supporting a grinding wheel for rotation around a first axis and a frame supporting said bracket for pivotal movement around a second axis spaced from and parallel with said first axis; an elongated pivot member pivotally supported upon said frame for pivotal movement around a pivot axis near to and parallel With said second axis; means connecting one end of said pivot member to said bracket whereby pivotal movement of said pivot member effects pivotal movement of said bracket; bearing means supported upon said frame near said other end of said pivot member; a driven member supported within said bearing means for rotation around a third axis parallel with said second axis; a shaft having an axis parallel with said third axis, and positioning means drivingly connected to said driven member and to said shaft and supporting said shaft upon said driven member for. radial movement into andv out of a position. coaxial means connected between said driven member and said positioning means for effecting said radial movement of said shaft. with respect to said third axis.

2. In a grinding machine having a bracket supporting a grinding wheel for rotation around a first axis and a frame supporting said bracket for pivotal movement around a second axis spaced from and parallel with said first axis; an elongated, substantially upright pivot member supported at a point spaced from the ends thereof upon said frame for pivotal movement around a pivot axis near to and parallel with said second axis; means connecting the upper end of the pivot member to said bracket whereby pivotal movement of said pivot member elfects pivotal movement of said bracket; means defining a lengthwise slot in said pivot member near the lower end thereof and opening in a direction parallel with said second axis; a bearing structure supported upon said frame near said lower. end of said pivot member; a driven member supported within said bearing structure for rotation around a third axis parallel with said second axis; positioning means supported within said driven member for movement in a direction substantially perpendicular to said third axis, said positioning means being drivingly connected to said driven member for rotation therewith; a shaft supported upon said positioning means for radial movement therewith toward and away from a position coaxial with said third axis and also being drivingly connected thereto for rotation therewith; means on said shaft engageable with the walls of said slot and movable lengthwise of said slot, whereby movement of the shaft axis around said third axis pivots said pivot member around said pivot axis; and manually operable adjusting means mounted upon said frame and engageable with said positioning means for efiecting said radial movement of said shaft.

3. The structure of claim 2 wherein said driven member includes a cylindrical sleeve coaxially and rotatably supported within said bearing structure, and a pair of spaced parallel rods mounted upon and'within said sleeve and intersecting perpendicularly the rotational axis thereof; wherein said positioning means includes a slide member slidably supported upon said rods within said sleeve for movement perpendicularly of said third axis, said slide member having an elongated cam slot therethrough, the sidewalls of said cam slot defining substantially parallel planes intersecting said rods and the third axis at acute angles; and wherein said adjustment means includes a bifurcated member having a pair of arms extending along opposite sides of said slide member within said sleeve and supporting between said arms a rod extending through and slidably engaging said side walls of said cam slot, and means engaged with said bifurcated member for effecting movement thereof with respect to said sleeve in a direction parallel with said third axis, whereby said slide member is moved lengthwise of said parallel rods and radially within said sleeve.

4. In a grindingmachine having a bracket supporting a grinding wheel for rotation about a first axis and a frame supporting said bracket for pivotal movement around a second axis spaced from and parallel with said first axis, an adjustable eccentric and means deriving oscillatory motion from said eccentric and applying same to effect oscillatory motion of said bracket, the improve ment in means adjusting the radius of eccentricity of said eccentric which comprises bearing structurernounted on said frame; a cylindrical sleeve coaxially and rotatably supported within said bearing structure for rotation about a third axis parallel with said second axis; a pair of spaced parallel rods mounted upon and extending diametrically within said sleeve and rotatable therewith; a slide member slidably supported upon said rods Within said sleeve for movement perpendicularly of said third axis, said slide member having an elongated cam slot therethrough, the side walls of said cam slot defining substantially parallel planes intersecting said rods and said third axis at acute angles; a bifurcated member having a pair of arms extending along opposite sides of said slide member within said sleeve and a rod supported between said arms and extending through and slidably engaging the side walls of said cam slot, rotatable threaded adjusting means rotatably attached to said bifurcated member for moving said bifurcated member axially with respect to said bearing structure and said sleeve upon rotation of said adjusting means with respect to said hearing structure to thereby move said eccentric radially with respect to said sleeve.

5. In a grinding machine having a support bracket supporting a grinding wheel for rotation around a first axis and a frame supporting said bracket for pivotal movement around a second axis spaced from and parallel with said first axis, an eccentric and means deriving oscillatory motion from said eccentric and applying oscillatory motion to said bracket; adjustable supporting and driving means for said eccentric arranged for permitting adjustment of the throw of said eccentric while same is in operation and for holding same in a precisely determinable adjusted position including bearing structure fixedly mounted on said frame; a cylindrical sleeve coaxially and rotatably supported within said bearing structure for rotation about a third axis parallel with said second axis; a pair of spaced parallel rods mounted upon and extending diametrically within said sleeve; driving means on said sleeve for rotating same; a slide member slidably supported upon said rods and located within said sleeve and movable perpendicularly with respect to said third axis, said slide member having an angularly positioned cam surface thereon, said cam surface defining a plane intersecting said third axis at an actue angle, said eccentric being mounted on said slide member and said slide member being drivingly connected to said sleeve so that said eccentric is rotated by said driving means about said third axis; a bifurcated member having a pair of arms extending along opposite sides of said slide member and located within said sleeve; a rod supported on and extending between said arms and slidably engaging said cam surface, adjusting means attached to said slide member and manually operable means for moving said adjustable means axially with respect to said bearing structure and said sleeve and thereby effecting movement of said bifurcated member axially of said sleeve and thereby moving said eccentric radial y with respect to. said sleeve.

6. Mechanism for adjustably supporting the throw of an eccentric with respect to an axis and arranged for adjustment of said throw while said eccentric is rotating around said axis and for holding same in adjusted position after said adjustment is effected, comprising in combination: bearing structure and means for supporting same; a cylindrical sleeve concentric with said axis and supported within said bearing structure for rotation around said axis, a pair of spaced parallel rods mounted upon and extending diametrically within said sleeve; driving means for rotating said sleeve; a slide member slidably supported upon said rods and located within said sleeve for movement radially with respect thereto, said slide member having an elongated cam slot therethrough, the side walls of said cam slot defining substantially parallel planes intersecting said rods and said axis at acute angles, said eccentric being mounted on said slide member and said slide member being drivingly connected to said sleeve so that said eccentric is rotated by said driving means around said axis; a bifurcated member having a pair of arms extending along opposite sides of said slide member within said sleeve; a rod supported between said arms extending through and slidably engaging the side walls of said cam slot; adjusting means attached to said slide member and manually operable means for moving said adjusting means axially with respect to said bearing structure, thereby effecting movement of said bifurcated member axially of said sleeve and therebymoving said eccentric radially with respect to said sleeve.

7. Mechanism for adjustably supporting the throw of an eccentric with respect to an axis and arranged for adjustment of said throw while said eccentric is rotating around said axis and for holding same in adjusted position after said adjustment is effected, comprising in combination: bearing structure and means for supporting same; a cylindrical sleeve concentric with said axis and supported within said bearing structure for rotation around said axis, a pair of spaced parallel rods mounted upon and extending diametrically within said sleeve; driving means for rotating said sleeve; a slide member slidably supported upon said rods and located within said sleeve for movement radially with respect thereto, said slide member having a radially angular cam surface thereon, said eccentric being mounted upon said slide member and said slide member being drivingly connected to said sleeve so that said eccentric is rotated by said driving means around said axis; a reaction member extending along said slide member within said sleeve and supporting means slidably engaging the cam surface; adjusting means attached to said reaction member and manually operable means for moving said adjusting means axially with respect to said bearing structure, thereby effecting movement of said reatcion member axially of said sleeve and thereby moving said eccentric radially with respect to said sleeve.

8. A grinding machine, particularly for grinding tools, comprising in combination: a support frame; a bracket pivotally supported near its lower end upon said frame for oscillation with respect thereto about a first axis; a grinding wheel; a shaft for supporting said grinding wheel and means rotatably supporting said shaft on said bracket near the upper end thereof, the axis of said shaft being parallel to said first axis; drive means mounted upon said frame below said first axis in substantial vertical alignment with said first axis and said shaft; means connecting said drive means to said shaft for constantly rotating said shaft, said drive means being partially supported on said shaft by said connecting means; eccentric means including a driven member rotatably supported upon said frame, a driving member eccentrically mounted upon said driven member and means for adjusting the eccentricity of said driven member with respect to said driving member; a lever pivotally mounted between its ends upon said frame, one end of said lever having a slot into which said driven member is operably received; an adjustable pitman connected to the other end of said lever and to said bracket at a point spaced from the said first axis; whereby rotary movement of said eccentric means results in oscillatory movement of said bracket so that an axial face of said grinding wheel is oscillated in a plane perpendicular to the axis of said rotatable shaft; and a work support adjustably mounted onsaid frame.

9. The structure of claim 7 wherein said cam surface is provided by the wall means defining a slot extending through said slide member, said wall means being substantially perpendicular to a plane defined by the lengthwise axes of said parallel rods, and wherein said means slidably engaging the cam surface is an element extending into said slot and rigidly secured to said reaction member.

References Cited in the file of this patent UNITED STATES PATENTS 2,471,443 Munro May 31, 1949 2,544,604 Mader Mar. 6, 1951

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