US2288691A - Sharpening mounting for disks - Google Patents

Description

July,7, 1942. J. N. FENDER SHARPENING MOUNTING FOR D ISKS Filed June 5, 1941 iT/YDEZ? 1 N VENTOR.

,4 rra P/Yzy Patented July 7, 1942 UNITED STATES PATENT oFFIcE' SHARPENING MOUNTING F OR DISKS Joseph N. Fender, Dallas, Tex.

Application June 5, 1941, Serial No. 396,670

9 Claims.

This invention relates to grinding machines and it has particular reference to a machine for sharpening plow disks by grinding.

The foremost objects of the invention are: First, to effect the required rotation of the disk solely by its frictional contact with the emery wheel; second, to provide a disk mounting which, by virtue of the frictional rotation imparted to the disk by the grinding wheel, is oscillated to similarly move the disk at its point of engagement with the grinding wheel, thereby to produce a curved bevel on the disk; third, to provide a disk mounting capable of adjustment in height to effect proper correlation between the disk and grinding wheel and to further provide a base constructed for ready portability and to allow for tilting of the entire machine to impose sufficient weight on the disk in grinding to insure maximum abrading effect of the grinding wheel; and fourth, to provide means for neutralizing the oscillating effect of the mounting and at the same time predetermining the degree of inclination of the mounting toward the grinding wheel in order to relieve the weight imposed on the wheel through the disk and to thereby produce a true circular edge by grinding off the high places to remove irregularities and nicks in the cutting edge.

Broadly, the invention seeks to provide an inexpensive machine by which the cutting edges of plow disks may be renewed efficiently without requiring power of operation other than that required to drive a conventional emery or carborundum wheel, a common fixture of any reasonably well-equipped shop. Moreover, the invention includes among its features anattachment to deaden or muffle the penetrating ring produced by subjecting the disc to the effects of a grinding wheel.

With the foregoing objects as paramount, the invention has other objects and certain features of accomplishment to become apparent in the course of the following description, taken with the accompanying drawing wherein:

Figure 1 is a rear perspective view of a disk sharpening mounting constructed according to the present invention.

Figure 2 is an elevational View of the upper portion of the mounting in vertical section.

Figure 3 is a detail View of the underside of the oscillating unit taken on line 3-3 of Figure 2.

Figure 4 is a detail perspective view of the slotted collar, a part of the oscillating unit.

Figure 5 is a detail perspective view of the attachment serving the dual functicn'of holding screw rod mounting by which vertical adjustment of the machine is efiected.

Cutting edges of plow disks have heretofore been renewed in many ways, as by filing, grinding, rolling and beating. In sharpening by filing, unless accomplished by accurate, automatic machines, an irregular edge is produced resulting in an out-of-round disk and non-uniformity with others of a gang. Disks sharpened by rolling or beating are invariably flattened or flared and are therefore thrown out of balance when placed in the soil, thus displacing the strain upward, resulting in possible breakage of the cast spool or spindle. Moreover, disks sharpened by these methods are heated'and the temperature thereof changed rendering it easy for the edges to readily split and curl. The present invention makes possible the reconditioning of a disc in a minimum of time, without added cost and insures a true, rounded bevel on the cutting edge thereof without changing the temperature of the steel and further, operation of the machine requires but a minimum of attention.

Continuing with a more detailed description of the drawing, reference is primarily made to Figure 1, wherein is shown the base [0 constructed porting the disk mounting.

of strap iron shaped into a rectangle or square with radially extending projections for stability. Pivoted upon a transverse bolt l2 in the base Ill is the lowermost section l3 of the upright sup- In being thus joined to the base, the upright may be tilted forwardly and rearwardly with respect to a grinding wheel 14 which is not a part of this invention and is shown only to illustrate the operative relationship with the disk l5, disposed on the mounting.

The upper and mounting carrying section of the upright is identified by reference numeral l6 and telescopically receives the lower section [3 and is secured against displacement from adjusted positions on the section l3 by means of a sleeve. 18 against displacement.

the disk on the mounting and for silencing the noise attending the grinding.

Figure 6 is a fragmentary detail View of the pivotal mounting of the machine for tilting, and Figure 7 is a fragmentary detail view of the Passing through the sleeve I8 is a screw rod 2|, the latter being threadedly passed through a nut 22 (Figure 2) non-rotatably disposed at the top of the lowermost upright section [3. A crank 23 is aflixed to the upper end of the screw rod 2| and by operating this crank it is obvious that the engagement of the screw rod with the threaded nut 22 will cause the upper section Hi to be raised and lowered with respect to the lower section of the upright and that the Weight of the upper assembly will prevent any undue displacement of the respective parts.

The foregoing describes two adjustments, that of tilting the entire mounting on its pivot [2 so that the disk l5 may assume the proper angular relation to the grinding Wheel M to produce a bevel a and the means by which the mounting may be raised and lowered to accommodate the disk to a grinding Wheel at any height.

In order to produce the prerequisite rounded bevel on the disk, it is necessary that the latter be oscillated in an arcuate plane so that the point of contact between the disk and grinding wheel will be constantly moved between the inner edge of the bevel to the outer and cutting edge during rotation of the disk. This is accomplished by means of a pinion 24, mounted on a shaft 25, which meshes with a gear 25 carried by a stub shaft 21. The pinion and gear are disposed in a circular housing 28, filled with a suitable lubricant.

The housing 28 is suspended by a tubular member 29 serving as a sheath for the shaft. On the upper end of the member 29 there is mounted a housing 30 containing a bearing 3| embracing shaft 25. An annular shoulder 28a, in the housing 30 rests on the inner race of the bearing 3| (Figure 2) while the outer race of the bearing rests in a machined cavity in a reducer 23a threaded upon the upper end of the tubular member 29. The inner race rests on a shoulder provided on shaft 25. A dust cap 33a. covers the open lower end of the skirt of the housing 33 surrounding the reducer 29a.

Some disks have larger hub openings than others and to accommodate these, a substantially cone-shaped adapter 3|a is placed over the upper end of shaft 25 and rests on a light coiled spring 3| 2), the lower end of the latter surrounding a Y nut 32a, bearing on the shoulder 28a to lock the housing for common rotation with shaft 25. Disposed on top of the housing 39 and embracing the adapter 3|a is a concaved disk 32 of leather or similar material on which is mounted the disk Iii to be sharpened.

The housing 30, the shaft housing 29 and the associated elements just described are suspended by means of diametrically opposed pivot pins 33, each being journaled in bearing apertures provided in upwardly extending arms 34 and 34a, the lower ends of the latter being bolted or otherwise secured to either side of a nut or collar 34b mounted stationarily on the shaft housing 23. The lower ends of arms 34 are connected to a frame 35, the latter being pivoted axially at b to the housing |1 disposed at the top of the upper section N5 of the upright or stand. Braces 36 aid in maintaining rigidity of the frame. The lower ends of these braces are connected at (Figures 1 and 2) to a depending rod 31 whose upper end, being likewise connected to the pivotal point I) of the frame 35, is also movable when the frame is moved.

It has been particularly pointed out previously that the power of rotation of the disk I is obtained from the grinding wheel I4. This is done by so disposing the disk relative to the grinding wheel that its rotative axis is slightly offset relative to the plane of rotation of the grinding wheel. Of course, the direction of rotation of the disk is determined by the position of the disk relative to the wheel, that is whether the axis of the disk is on one side of the rotative plane of the Wheel or the other.

Referring again to the specific means for oscillating the shaft and disk, it will be observed in Figures 1, 2 and 3 that the stub shaft 21 on which the gear 26 is mounted, extends through the housing 28 at the bottom. An arm 38, carrying numerical graduations, is afiixed near one end to the stub shaft 21, functioning therefore in the nature of a crank. A collar 39 conforms to and is slidable on the arm 38 and has a pin 40 connected thereto, to which is pivotally connected one end of an articulated arm 4|. The opposite end of this arm is pivotally connected to the lower end of the depending rod 31. A wheel clamp 42 secures the outer end of the arm 4| to the pin 40.

It is apparent therefore in operation that as the disk I5 is rotated by the grinding Wheel M the shaft 25 will rotate to operate the pinion 24 and consequently the enmeshing gear 26. The stub shaft 21 to which the arm 33 is aflixed will cause the latter to revolve, moving the collar in a circular manner. The eccentric motion thus effected is brought about by the fact that one end of the arm 4| is constrained against other than pivotal movement on a horizontal plane and articulated motion, permitted by the pivoted joints of which the arm is composed. These movements are provided in order that the arm 4| may follow the circular movements of the arm 28, the radius of which is determined by the position of the collar 39 on the said crank arm 38. Rotation of the crank arm imparts to the housing 28 an oscillating motion on a slight arcuate plane which is transmitted to the disk H) by virtue of the fulcrum at 33. Thus, the rounded bevel a is produced.

It is to be noted that the collar 39 is slotted at 39a. When it is desired to neutralize the oscillative effect produced by the eccentric relation between the pivotal points 40 and 21, the collar 33 is slid along the arm 33 so that the slot will i receive the extended end of stub shaft 21 and when points 40 and 21 are axially aligned, no oscillating effect is provided.

Mounted on one side of the frame 35, parallel to and movable thereon is a rail 42 on which is movably disposed a weight 43, slidably secured in position on the rail by a plate 44. The degree of pressure imposed by the disk on the grinding wheel is increased and decreased by respectively moving the weight 43 forwardly or rearwardly on the rail 62. This also varies the cutting depth and consequently the speed of the sharpening operation.

It frequently happens that disks are encountered with rather deep nicks or indentations in the cutting edges. If the entire Weight of the mounting is imposed on the grinding wheel through the disk, the bevel would of course follow the indentation. To insure against this in the sharpening of out-of-round, irregular or indented disks, the oscillating unit is rendered inoperative by so moving the collar 39 on arm 38 as to bring pivot points 40 and 21 into axial alinement. When this is done, the shaft 25 is held in stationary relation to the other parts of the assembly. A chain 53 or its equivalent (Figure 1) has one end connected to the lower end of the upper stand section 6 and its opposite end to the base N). This chain limits the angle of incline of the stand when the latter is tilted and in order that even this may be varied or adjusted, a turnbuckle 5| is incorporated in the length of chain. It is apparent therefore that only the high points of the disk will be engaged by the wheel I4 until such time as these have been ground off to the depth of the deepest indentation.

The disks I5, usually made of high grade steel are disposed to ring penetratingly during the grinding operation. In order to mufile or deaden this noise, a device such as illustrated in Figure 4 is employed and consists of a circular flange a l having on its underside a strip of leather or other material 45 which bears against the concaved face of the disk [5. Radial spokes @6 connect the flange M with the hub 41, through which the shaft 25 passes. A nut 43 is threaded on the shaft 25, as shown in Figure 4 to hold the retaining device on the disk and consequently secures the latter firmly in place on the sharpener mounting.

Manifestly, the construction as shown and described is capable of some modification and such modification as may be construed to fall within the scope and meaning of the appended claims is also considered to be within the spirit and intent of the invention.

What is claimed is:

1. Apparatus for sharpening disks in combination with a grinding wheel, a tiltable, vertically adjustable stand, a frame pivotally attached to the top of said stand for limited rotation through its major axis, a shaft and shaft housing pivotally suspended by said frame for limited oscillation in a vertical plane and adapted to hold a disk in operative relation to said grinding wheel whereby its rotative motion will be imparted to said disk and shaft and means operative through the rotation of said shaft to cause the latter to oscillate on its pivot.

2. A mounting for disks in sharpening comprising in combination with a grinding wheel, a portable base, a sectional stand tiltably supported on said base for movement toward and away from said grinding wheel, means for axially moving one section of said stand relative to the companion section to vary the height of said stand, a frame pivoted for rotation in a plane parallel to the axis of said stand, a shaft housing pivotally suspended by said frame for limited swinging movement in a vertical plane, a shaft in said housing arranged to carry a disk for operative engagement with said grinding wheel and whereby the motion of the latter will be transmitted to said disk to rotate said shaft and means utilizing the rotative motion of said shaft to effect oscillation thereof.

3. A mounting for disks in the process of sharpening in combination with a grinding wheel, a portable base, a stand mounted on said base for tilting movement relative to said grinding wheel, means to effect height adjustment of said stand, a shaft indirectly supported by said stand and capable of swinging movement in planes parallel with and transverse to the axis of said stand, said shaft being arranged to support a disk for operative engagement with said grinding wheel and whereby the motion of the latter will be effective to rotate said disk and shaft and means effective through the rotation of said shaft for swinging the latter in a plane parallel to the axis of said stand.

4. A mounting for plow disks in the process of sharpening in combination with a grinding wheel, a base, an upright and vertically adjustable stand pivotally disposed on said base for tilting movement toward and away from said grinding wheel, a shaft having a housing suspended at its upper end for swinging movement in a plane parallel with the longitudinal axis of said shaft, means connecting said shaft housing to said stand for swinging movement in a plane at right angles to the axis of said stand, said shaft carrying a disk for grinding engagement with said grinding Wheel whereby rotation of the latter will be effective to rotate said disk and shaft and means in eccentric relation with the loWer end of said shaft to swing the same on its pivot when rotated.

5. Apparatus for supporting a plow disk in operative relation to a grinding wheel in the process of sharpening, a mounting tiltable toward said grinding wheel whereby its weight will be imposed through a disk carried thereby on said grinding wheel, said mounting including a shaft arranged to carry said disk and hold the same in operative relation to said grinding wheel and to effect rotation of said disk through rotation of said grinding wheel, a housing for said shaft, means supporting the upper end of said housing for swinging movement, means having eccentric connection with the lower end of said shaft to impart swinging movement thereto during rotation to arcuately move the point of contact of said disk with said grinding wheel.

6. A structure as set forth in claim 5 in which the shaft is likewise mounted for limited adjustment in a plane at right angles to the plane in which it is constrained to move in operation.

'7. A structure as described in claim 5 in which the eccentrically connected means is comprised of a housing supported at the lower end of the disk carrying shaft, a pinion in said housing carried by said shaft, a gear enmeshing said pinion, a crank arm affixed to the shaft of said gear, a sleeve slidably disposed and securable at adjusted positions on said crank arm and an articulated arm connected at one end to said sleeve and constrained at its other end against other than pivotal movement in a horizontal plane whereby rotation of said crank arm by said shaft will cause said housing and shaft to oscillate.

8. A disk grinding mounting comprising in combination with a grinding wheel, a supporting stand pivoted for tilting movement in a plane at right angles to its longitudinal axis toward and away from said grinding wheel, a disk carrying shaft mounted in a frame suspended from the upper end of said stand for swinging movement toward and away from said stand and arranged for adjustment in planes at right angles to the axis of said stand whereby said shaft and a disk carried thereby will receive its rotation from the rotation of said grinding wheel by contact of said disk therewith, means effecting eccentric connection between the lower end of said shaft and said stand whereby to employ the rotation of said shaft for effecting swinging movement thereof and means for limiting the angle of inclination of said stand toward said grinding wheel to predetermine the cutting depth of the latter.

9. A disk sharpening mounting comprising in combination with a grinding wheel, a vertically adjustable stand pivoted at its base for inclination toward said grinding wheel and capable of horizontal displacement on its pivot, means carried by said stand for supporting a disk in sharpening relation to said grinding wheel whereby rotation of the latter will cause rotation of said disk, automatic means for oscillating said disk during its rotation to arcuately move its point of contact with said grinding wheel, means to render said oscillating means ineffective and means for limiting the angle of inclination of said stand to predetermine the effective cutting range of said wheel on said disk.

JOSEPH N. FENDER.

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