US3570193A

US3570193A - Mobile implement sharpening machine

Info

Publication number: US3570193A
Application number: US846871A
Authority: US
Inventors: Francis T Barrett
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-08-01
Filing date: 1969-08-01
Publication date: 1971-03-16
Anticipated expiration: 1988-03-16

Abstract

A WHEEL SUPPORTED GRINDING MACHINE FOR SHARPENING ROUND IMPLEMENT BLADES EITHER UNDER FIELD CONDITIONS WHEN THE BLADES ARE MOUNTED ON THE IMPLEMENT OR UNDER SHOP CONDITIONS WHEN THE BLADES ARE REMOVED FROM THE IMPLEMENT. THE MACHINE INCLUDES A DEPTH GAUGE ROLLER AND A PAIR OF COOPERATING WORKPIECE DRIVING ROLLERS WHICH POSITION THE DISK OR BLADE TO BE SHARPENED IN A PROPER ORIENTATION RELATIVE TO THE GRINDING WHEEL. THE GRINDING WHEEL ITSELF IS ADJUSTABLY MOUNTED FOR SELECTIVE CUSHIONED ENGAGEMENT WITH THE OPPOSITE SIDES OF THE WORKPIECE. THE WHEEL SUPPORT FOR THE MACHINE IS ADAPTED SO AS TO ACTUALLY ALLOW THE FRONT OF THE MACHINE TO MOVE SO AS TO FOLLOW IRREGULARITIES IN THE BLADE DURING THE SHARPENING THEREOF, AND THEREBY PREVENT BINDING. THE MACHINE IN ITS SHOP POSITION IS IN THE NATURE OF A HIGHLY STABLE UNIT PROVIDED WITH A THREE-POINT SUPPORT.

Description

Mam}! 1971 F. T. BARRETT MOBILE IMPLEMENT SHARPENING MACHINE .3 Sheets-Sheet 1 Filed Aug. 1; 1969 n R W J U i v M N9 .mmmwm iiill r V O H F. lL Q WW L L l B /l\ QR mm on vm mm M T m\ W m T w m m J, vn vn March 16, 1971 T, A T 3,570,193

MOBILE IMPLEMENT SHARPENING MACHINE Filed Aug. 1, 1969 3 Sheets-Sheet 2 Francis T. Barrett INVIJN'I'OIL BY @100 MW Anne Mamh 1971 F. T. BARRETT MOBILE IMPLEMENT SHARPENING MACHINE 3 Sheets-Sheet 3 Filed Aug. 1, 1969 w m e r I i w W B T. m m ow a r (T3 F o w IFI "if 6 09 v9 United States Patent 3,570,193 MOBILE IMPLEMENT SHARPENING MACHINE Francis T. Barrett, RR. 1, Box 165, Pocahontas, llowa 50574 Filed Aug. 1, 1969, Ser. No. 846,371 Int. Cl. B24b 23/00 US. Cl. 51-173 16 Claims ABSTRACT OF THE DISCLOSURE A wheel supported grinding machine for sharpening round implement blades either under field conditions when the blades are mounted on the implement or under shop conditions when the blades are removed from the implement. The machine includes a depth gauge roller and a pair of cooperating workpiece driving rollers which position the disk or blade to be sharpened in a proper orientation relative to the grinding wheel. The grinding wheel itself is adjustably mounted for selective cushioned engagernent with the opposite sides of the workpiece. The wheel support for the machine is adapted so as to actually allow the front of the machine to move so as to follow irregularities in the blade during the sharpening thereof, and thereby prevent binding. The machine in its shop position is in the nature of a highly stable unit provided with a three-point support.

The instant invention generally relates to tool sharpeners, and is more particularly concerned with a mobile convertible machine specifically adapted for sharpening implement blades such as the disks of disk harrows and the like.

It is a primary object of the instant invention to provide a disk sharpening machine which is equally adapted for use in sharpening harrow disks and the like while the disks are mounted on the harrow, or when the disks are removed, the sharpening machine being capable of assum ing a mobile field working position, and a stable shop position, depending upon the work involved.

Another significant object of the instant invention resides in the provision of a sharpening machine particularly adapted for the sharpening of all round implement blades on either or both sides thereof in a highly effective manner and in a manner wherein allowance is made for irregularities in the blades.

Another significant object of the instant invention is to provide a compact economical unit capable of effectively performing its intended purpose.

Basically, the objects of the instant invention are provided for by the utilization of a mobile frame having dual rear wheels and a single vertically adjustable front wheel over which is mounted a pair of workpiece driving rollers, a depth gauge roller, and an adjustable grinding wheel. The workpiece engaging rollers are adjustable so as to selectively open for the introduction of a workpiece. The grinding wheel, through the adjustable mount therefor, is cushioned so as to accommodate itself to irregularities in the blade, and the front wheel, in addition to being vertically adjustable, can be so orientated as to allow for a swinging of the complete machine so as to follow irregularities during the grinding operation and avoid a jamming or binding of the wheel against the blade being sharpened. The machine is capable of being swung to an upright position resting on the two rear wheels and the rear edge of the upper cover or shield, thereby providing an upright grinding wheel having a solid three-point support. The machine in this position receives an adapter which is utilized to grip and mount a single disk for the sharpening thereof, the gauge roller and the workpiece driving rollers also being operative in this position.

3,576,193 Patented Mar. 16, 1971 "ice These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of the machine of the instant invention in its operative field position orientated so as to engage one of a series of implement mounted blades;

FIG. 2 is a perspective view of the opposite side of the machine of FIG. 1 wherein the front wheel has been turned to the side so as to allow for a swinging of the front of the machine whereby a binding of the grinding wheel against the blade should any substantial irregularities in the blade occur, is prevented;

FIG. 3 is a perspective view of the sharpening machine vertically orientated in its shop position with the blade stabilizing attachment mounted thereon;

FIG. 4 is a transverse cross-sectional view taken substantially on a plane passing along line 4-4- in FIG. 1;

FIG. 5 is a cross-sectional view taken substantially on a plane passing along line 5-5 in FIG. 1;

FIG. 6 is a cross-sectional view taken substantiallyon a plane passing along line 6-6 in FIG. 5;

FIG. 7 is a cross-sectional view taken substantially on a plane passing along line 7-7 in FIG. 3;

FIG. 8 is a cross-sectional view taken substantially on a plane passing along line 8-8 in FIG. 3;

FIG. 9 is a perspective detail of the upper portion of the disk stabilizing attachment; and

FIG. 10 is a cross-sectional detail taken substantially on a plane passing along line 10-10 in FIG. 1.

Referring now more specifically to the drawings, reference numeral 20 is used to generally designate the mobile implement sharpening machine comprising the instant invention. This machine is particularly adapted for use as a means of sharpening disks of disk harrows and like equipment, both while mounted on the equipment and removed therefrom. This machine 20 includes a supporting frame or framework 22, a transverse vertically orientated front panel 24, a pair of side panels 26 integral with the opposed vertical edges of the front panel 24 and extending rearwardly therefrom in laterally spaced parallel relation to each other, and a rigid forwardly projecting support beam 28 aflixed centrally to the front panel 24 and extending forwardly therefrom. This beam 28 can be rigidified and stabilized by a flat underlying plate 30 affixed, through an upstanding flange 32, to the forward face of the front wall 24.

The machine 20 is mobile and includes a pair of laterally spaced rear wheels 34 mounted on a common transverse axle 36 which is in turn supported by a vertically orientated yoke-like member 38, the lower ends of the legs of which receive the axle 36 therethrough, the converging upper portion of the yoke 38 being received within and afiixed to an elongated rigid cover shield 40. The shield 40 includes a top panel 42 and opposed integral depending side panels 44 which terminate above the frame side panels 26. The continuous generally U-shaped rear edge of the shield 40 is orientated in a substantially common plane with the rear extremities of the two rear wheels 34 whereby a positive supporting base will be provided for the machine 20 when vertically orientated in the shop position thereof as shown in FIG. 3.

A third support wheel 46 is adjustably mounted at the forward end of the frame beam 28 to which a hollow vertically elongated rectangular sleeve 48 is secured. The wheel 46 is rotatably mounted by a horizontal yoke 50, the bight end of which is rigid with the lower end of a vertically elongated rectangular standard 52 which is in turn vertically slidable and adjustable within the beam secured sleeve 48. In this manner, the vertical position of the wheel 46 can be adjusted so as to properly orientate the machine 20 relative to the disk or disks to be sharpened. Once adjusted, an appropriate lock screw 54, threaded through one wall of the sleeve 48, is tightened against the internally received standard 52. By the same token, a rotational adjustment of the wheel 46 is possible by a complete removal of the standard 52 from the sleeve 48 and a reinsertion thereof with the wheel orientated in the particular direction desired, for example transversely of the machine as suggested in FIG. 2. This position is particularly desirable in that it enables the front of the machine 20 to easily swing so as to better follow any irregularities in the contour of the disk or blade being sharpened. It will be noted that the wheel mounting sleeve 48 is actually aflixed to one side of the frame beam 28 at the forward end thereof.

A vertically orientated drive motor 56 is mounted between the frame side panels 26 adjacent the front panel 28 and has the drive shaft thereof projecting vertically upward into the protective enclosure defined by the depending side panels 44 of the shield 40. The motor drive shaft includes lower and upper drive pulleys 58 and 60. The lower drive pulley 58 drives, through the associated endless belt 62, a forwardly located pulley 64 aflixed to the vertical shaft 66 of a gear box 68 mounted on the front face of the forward wall 24. This gear box 68 in turn drives a forwardly extending shaft 70 which is rotatably received through a support sleeve 72 mounted, through appropriate upright members, in vertically spaced relation above the support beam 28. The shaft 70 in turn mounts a relatively firm rubber work gripping and driving roller 74 on the extreme forward end thereof, located forward of the frame beam 28.

A second relatively firm rubber gripping and driving roller 76 is mounted adjacent the roller 74 for cooperation therewith on an elongated shaft 78 paralleling the shaft 70 and also rotatably mounted within an elongated hollow sleeve 80. The shaft 78 is located laterally of gear box 68 and is driven directly from the gear box driven shaft 70 by a pair of gears 82, one mounted on each of the

shafts

70 and 78 immediately forward of the gear box '68. The shaft supporting sleeve 80 is supported at the same level of the shaft supporting sleeve 72 by a plurality of upright members 84 engaged between the sleeve 80- and an underlying flat elongated support plate 86. This support plate 86 has the rear end thereof pivotally affixed, as indicated by reference numeral 88, to the underlying frame. In this manner, the plate sup ported roller 76 can pivot laterally away from the fixed position roller 74 so as to facilitate an introducion of the blade to be sharpened therebetween. The actual outward or lateral movement of the roller 76 is effected by a linkage system which includes a vertically elongated control rod 90 bracket mounted on the frame 22 adjacent and to one side of the gear box 68. The upper end of the control rod '90 includes an integral laterally directed handle 92 which overlies the top panel of the shield 80. The lower end of the control rod 90 includes a rigid laterally directed link 94, the outer end of which is pivotally engaged with an elongated spring loaded rod 96 at one end thereof. If so desired, this rod 96 can be adjustable in length through the incorporation therein of an appropriate turnbuckle mechanism. The second end of the rod 96 is pivotally affixed to one end of an L-shaped member 98, the apex point of which is pivotally mounted on a frame supported plate 100, this latter pivotal mounting being indicated by reference numeral 99. The second end of the L-shaped member 98 is in turn pivotally mounted to the first end of a second L-shaped member 102 which underlies the

shaft supporting sleeves

72 and 80 and is secured to the upper face of the plate or plate-like member 86 which supports the sleeve 80. Thus, upon a cranking movement of the control rod handle 92 in a first direction, the associated linkage will effect a laterally outward swinging of the plate 86, and hence the disk gripping roller 76, such being illustrated in phantom lines in FIG. 5. By the same token, a swinging of the handle in the second direction will move the roller 76 against a disk tobe sharpened Which will previously have been positioned between the

rollers

74 and 76. Appropriate means can of course be provided so as to secure the orientation of the roller 76 in the gripping and work piece driving position thereof adjacent the roller 74 through an overcenter positioning of one or more of the links or through an appropriate lock means engageable with the control rod or handle.

The second drive pulley 60 on the drive shaft of the motor 56 drives, through an endless belt 104, a pulley 106 mounted on a vertical shaft 108 which is in turn rotatably mounted on the frame 22 adjacent the gear box 68. A second pulley 110 is also mounted on the rotatable shaft 108 for rotation therewith, the pulley 110 being located in spaced relation above the pulley 106 and, through an appropriate endless belt, drives a forwardly located pulley 112 affixed to a depending shaft 114. The shaft 114 mounts, on the lower end thereof, the grinding wheel 116.

The grinding wheel shaft 114 is rotatably received through and supported by a vertical sleeve 118 afiixed to the outer end of an elongated beam 120, the inner end of which is rotatably received about the vertical shaft 108 between the pulleys 106 and 110. The beam 120 in turn supports an overlying shield or covering panel 122 which extends to and through the open forward end of the main shield 40 so as to provide an effective covering for the operating equipment.

The beam 120 pivots about the vertical shaft 108 so as to provide for a swinging adjustment of the grinding wheel 116 whereby an adjustment of the grinding wheel 116 to the disk being sharpened is achieved, the grinding wheel 116 actually being capable of suflicient movement so as to effect a selective grinding of both edges of the disk involved and rotatably driven by the

drive rollers

74 and 76. A small arcuate shield 124 is mounted on the sleeve 118 and swings about the grinding wheel 116 in outwardly spaced relation therefrom. The pivotal mounting of the beam 120 is controlled by an elongated adjusting screw 126 which is threadedly received through an internally threaded thrust nut 128 pivotally mounted within a pillow block 130 affixed to the lower edge of the beam 120. The adjusting rod 126 projects laterally from the thrust nut 128 and is rotatably received through the upper end of a support standard 132 affixed to the frame and projecting upwardly therefrom. The outer end of the threaded rod 126 is provided with an appropriate crank handle 134. A pair of relatively firm rubber or elastomeric cushion forming collars 136 are mounted on the threaded rod or shaft 126 to the opposite sides of the upper end of the shaft positioning standard 132, such cushions 136 being held in yielding engagement against the opposite sides of the top of the standard 132 by appropriate set collars whereby should the grinding wheel 116 engage against a raised portion on the blade or disk being sharpened, a slight outward movement of the grinding wheel can be effected. In this manner, a jamming or improper wearing of the wheel is prevented, and at the same time, possible damage to the disk or blade is also prevented. The collars 136 further function as a means for providing a constant resilient pressure of the grinding wheel 116 against the disk.

In order to properly locate a disk between the disk holding and

rotating rollers

74 and 76, an adjustable depth gauge or guide roller 138 is mounted on the forward end of the frame beam 28 and selectively projectable forward therefrom. This roller 138 is rotatably received within the bifurcated end of a fiat plate 140 slidably engaged with the undersurface of the beam 28 and adjustably positioned therealong by appropriate bolt means 142 extending through an elongated slot 144 in the guide roller mounting plate 140 and into threaded locking engagement with the beam 28. Utilizing this depth gauge roller 138, a whole series of disks can be sequentially sharpened to a common depth.

Referring specifically to FIG. 2, it will be appreciated that the machine is positioned horizontally, mounted on the three support wheels, this position being heretofore referred to as the field position in that when so orientated, the machine 20 can sharpen disks without necessitating a removal of the disks from the equipment. In this position, it will be noted that the front wheel 46 is preferably orientated so as to allow for a lateral swinging of the forward portion of the machine 20 thereby avoiding any tendency for a jamming due to irregularities which might appear on the disk being sharpened. By the same token, inasmuch as only a single support is provided at the forward end of the machine 20 this allows for a rapid and automatic following of any blade deformities, such as could not occur were a dual or two-wheel support provided at the forward end of the machine 20. In addition, the height of the grinding wheel can also rapidly and simply adjusted merely through an adjustment of the single forward support wheel. These advantages are readily achieved without adversely affecting the stability of the machine itself.

Incidentally, the spring-loaded nature of the roller adjusting rod 96 also contributes to accommodating any irregularities in the blade being sharpened.

With continued reference to FIG. 2, the top main shield 46 can, if deemed desirable, have the forward portion thereof stabilized by appropriate bracing plates or members 146. Mounted on the top panel 42 of the shield is a bracket 148 having a pair of upstanding longitudinally spaced legs 150 through which an elongated rod 152 extends. The rod 152 projects forwardly of the shield 40 and terminates in a comfortable handle or handgrip 154. Grasping this handle 154, while stabilizing the rear wheels 34, one can conveniently upend the machine '20 to the vertical position of FIG. 3, such being the shop position utilized to grind or sharpen disks removed from the associated equipment. Once swung into this vertical position, it will be appreciated that a highly stable three point support is provided for the machine, consisting of the U-shaped rear edge of the main shield 40 and the two rear wheels 34. In this position, no movement of the machine 20 during the grinding operation will be possible, the stability provided insuring a proper sharpening operation.

Once in the shop position, the front wheel 46 is removed and the blade or disk stabilizing and guiding apparatus 156 mounted. This apparatus or attachment 156 consists of an elongated rectangular rod 158 which is received through the sleeve 48 and locked into the desired adjusted position thereof. The upper end of the rod 158, or that end of the rod corresponding with the top of the machine 20 includes a vertically extending rigid member 160 upon which a transverse T-head 162 is provided. The member 160 adjustably mounts, through a bracket 164, a grooved roller 166 which engages the disk and is in generally opposed cooperating relation to a second rotatably mounted grooved roller 168. The grooved roller 168 is rotata'bly mounted on the upper end of an elongated rigid link 170, the lower end of which is rotatably mounted on a bracket 172. The bracket 172 is in turn slidably positionable along the projecting end of the rod 158 outward of the sleeve 48 to the opposite side thereof from the upright member 160, this bracket 172 being locked in any adjusted position by an appropriate adjusting screw 174. The roller mounting link is biased toward the disk by an elongated tension member 176 including a tension spring portion 178 and a link chain portion 180. The tension spring portion 17 8 has the free end thereof selectively engageable in any of a series of holes 182 on the upper portion of the link 170 for a variation in the biasing force thereof. By the same token, a notched bracket 184 is provided on the upright rigid member 160 and selectively receives any of several links of the chain portion of the tension member 176 whereby a variation in the biasing force urging the roller 168 against the disk is possible. The adjustability of the grinding wheel as well as the workpiece gripping and rotating rollers will of course function in the same manner in the vertical or shop position of the machine 20. The T or crosshead 162 on the rigid upright member 160 functions as a wide support for use by the operator of the machine during the grinding operation.

From the foregoing, it will be appreciated that a highly unique disk sharpening machine has been described. This machine is equally adaptable for use in the grinding or sharpening of implement mounted disks and individual free disks, the machine itself being movable between a mobile three wheel supported position in which it is adjustable so as to properly engage the grinding wheel against an implement mounted disk and capable of easily following any irregularities in the blade being sharpened, and a vertical highly stable three-point supported vertical position for the sharpening of disks removed from the associated disk bearing equipment. In the vertical position, as previously described, the machine is supported on the two rear wheels 34 and the rear edge of the shield 40. It is contemplated that a rubber cushion be provided about the rear edge of the shield so as to, in conjunction with the rubber wheels, provide a cushioned base for the machine which enhances the smooth operation thereof and contributes in the formation of what might be considered the finest all-purpose indoor and outdoor stand tool grinder or sharpener. In this regard, it will also be appreciated that the slim design of the construction enables an operator to hold all metals flat against the face of the grinding wheel in that the housing and motor do not interfere with a proper leveling of the particular item being sharpened.

Another highly significant advantage residing in the construction as heretofore set forth in detail is the fact that the blades or disks to be sharpened, whether large or small, are engaged adjacent the outer edge thereof by the work-gripping and driving

rollers

74 and 76. Thus, the disks, regardless of the size thereof, are driven at a predetermined speed, timed to the speed of the grinding wheel so as to avoid an overheating thereof such as could be harmful to the metal of the blade being sharpened.

A further highly significant feature of the aforedescribed construction, and in particular the pivotally mounted grinding wheel and the shaft mounted cushion forming yieldable collars 136, is the ability thereof to rapidly and automatically true a grinding wheel so as to eliminate vibration and damage to the wheel. More particularly, when a new grinding wheel, that may be slightly out of round, is placed on the machine and adjusted into operative engagement with a blade, the stone, through the resilient collars 136, will tend to press harder on the high wheel spots and less on the low wheel spots whereby a relatively rapid truing of the wheel occurs during the actual sharpening operation. Further, the constant pressure maintained by the collars 136 ensure that the wheel, once trued, is thus maintained.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modi fications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

What I claim as new is as follows:

1. A disk sharpening machine comprising a horizontal frame having forward and rear ends, laterally spaced dual rear support wheels mounted on and supporting the rear end of the frame, a single vertically adjustable front support wheel mounted on and supporting the forward end of the frame, motor means mounted on said frame, a pair of workpiece engaging and driving rollers mounted on said frame at the forward end thereof in spaced relation above the front wheel, first drive means engaged between the motor means and the pair of rollers for a driving thereof, a grinding wheel positioned in spaced relation above the pair of rollers, second drive means engaged between the motor means and the grinding wheel, and means for adjusting the grinding wheel transversely of the rollers, said front support wheel being positionable transversely relative to the rollers whereby a lateral shifting of the front of the machine can be automatically effected in response to irregularities of a roller mounted workpiece.

2. The machine of claim 1 including a shield-like member overlying the frame, said shield-like member having a rear edge located in substantially a common plane with the rearmost portions of the dual rear support wheels and in spaced relation laterally of and between said wheels whereby upon a vertical tipping of said machine a positive three-point support therefor is provided.

3. The machine of claim 2 wherein the adjustable front support wheel is rotatably mounted on a rigid vertically elongated standard, a vertically elongated standard receiving sleeve afiixed to the frame at the forward end thereof, said front wheel standard being slidably received within said sleeve and selectively locked in any of a plurality of adjusted positions.

4. The machine of claim 3 including a disk stabilizing attachment selectively mounted within the sleeve in place of the front wheel standard, said attachment including a pair of opposed disk engaging rollers, one of said rollers being mounted for a swinging movement thereof toward and away from the second of the attachment rollers, and means resiliently biasing the attachment rollers relatively toward each other for a grasping of a disk therebetween, said attachment being utilized upon a vertical positioning of the machine.

5. The machine of claim 4 including a depth gauge roller mounted on said frame vertically below the pair of workpiece engaging and driving rollers, and means mounting the depth gauge roller for selective longitudinal extension and retraction relative to the forward end of the frame so as to define a positioning means for a disk to be received between the pair of engaging and driving rollers.

6. The machine of claim 5 wherein said second drive means includes a vertical shaft rotatably mounted on said frame, pulley means mounted on said motor means and said shaft, drive belt means engaged between said pulley means, an elongated beam rotatably mounted on said shaft, said beam projecting forwardly from said shaft, the grinding wheel being rotatably mounted on said beam through a grinding wheel mounting vertical shaft, and drive bell: and pulley means engaged between the grinding wheel shaft and the vertical shaft for a transmittal of the dfiiving force of the motor means to the grinding wheel s aft.

7. The machine of claim 6 wherein the means for adjusting the grinding wheel transversely of the workpiece engaging and driving rollers comprises an internally threaded nut pivotally affixed to the grinding wheel mounting beam, an elongated externally threaded adjusting rod threaded within the nut, a rigid frame supported member rotatably mounting the adjusting rod, elastomeric cushioning collars mounted on said adjusting rod and engaged with the opposite sides of the rod supporting memher so as to resiliently fix the position of the rod for an adjustment of the beam relative thereto, and rod turning means on said rod for effecting a rotation thereof and a corresponding adjustment of the beam and grinding wheel thereon about the beam supporting vertical shaft.

8. The machine of claim 7 including means for adjusting one of said workpiece engaging and driving rollers relative to the other of said workpiece engaging and driving rollers for the facilitation of the introduction of a workpiece therebetween, said last-mentioned means including an elongated control rod rotatably mounted on the frame, a handle on one end of said control rod for a manipulation thereof, and a series of linkage-like members interconnecting the control rod and the adjustable one roller, one of said linkage-like members including a resilient movement accommodating section therein.

9. The machine of claim 2 including a depth gauge roller mounted on said frame vertically below the pair of workpiece engaging and driving rollers, and means mounting the depth gauge roller for selective longitudinal extension and retraction relative to the forward end of the frame so as to define a positioning means for a disk to be received between the pair of engaging and driving rollers.

10. The machine of claim 2 wherein said second drive means includes a vertical shaft rotatably mounted on said frame, pulley means mounted on said motor means and said shaft, drive belt means engaged between said pulley means, an elongated beam rotatably mounted on said shaft, said beam projecting forwardly from said shaft, the grinding wheel being rotatably mounted on said beam through a grinding Wheel mounting vertical shaft, and drive belt and pulley means engaged between the grinding wheel shaft and the vertical shaft for a transmittal of the driving force of the motor means to the grinding wheel shaft.

11. The machine of claim 10 wherein the means for adjusting the grinding wheel transversely of the workpiece engaging and driving rollers comprises an internally threaded nut pivotally affixed to the grinding wheel mounting beam, an elongated externally threaded adjusting rod threaded within the nut, a rigid frame supported member rotatably mounting the adjusting rod, elastomeric cushioning collars mounted on said adjusting rod and engaged with the opposite sides of the rod supporting member so as to resiliently fix the position of the rod for an adjustment of the beam relative thereto, and rod turning means on said rod for effecting a rotation thereof and a corresponding adjustment of the beam and grinding wheel thereon about the beam supporting vertical shaft.

12. The machine of claim 2 including means for adjusting one of said workpiece engaging and driving rollers relative to the other of said workpiece engaging and driving rollers for the facilitation of the introduction of a workpiece therebetween, said last-mentioned means including an elongated control rod rotatably mounted on the frame, a handle on one end of said control rod for manipulation thereof, and a series of linkage-like members interconnecting the control rod and the adjustable one roller, one of said linkage-like members including a resilient movement accommodating section therein.

13. A disk sharpening machine comprising a horizontal frame having forward and rear ends, laterally spaced dual rear support wheels mounted on and supporting the rear end of the frame, means mounted on and supporting the forward end of the frame, motor means mounted on said frame, a grinding wheel mounted on said frame, drive means engaged between the motor means and the grinding wheel, means for adjusting the grinding wheel transversely of the frame, and a shield-like member mounted on and overlying the frame, said shield-like member having a rear edge located in substantially a common plane with the rearmost portions of the dual rear support wheels and in spaced relation laterally of and between said wheels whereby upon a vertical tipping of said machine a positive three-point support therefor is provided.

14. The machine of claim 13 wherein the rear edge of the shield-like member is cushioned, said rear support wheels also being of a cushioning type material.

15. The machine of claim 13 wherein said drive means includes a vertical shaft rotatably mounted on said frame, pulley means mounted on said motor means and said shaft, drive belt means engaged between said pulley means, an elongated beam rotatably mounted on said shaft, said beam projecting forwardly from said shaft, the

grinding wheel being rotatably mounted on said beam through a grinding wheel mounting vertical shaft, and drive belt and pulley means engaged between the grinding wheel shaft and the vertical shaft for a trans mittal of the driving force of the motor means to the grinding wheel shaft, the means for adjusting the grinding wheel comprising an internally threaded nut pivotally affixed to the grinding wheel mounting beam, an elongated externally threaded adjusting rod threaded within the nut, a rigid frame supported member rotatably mounting the adjusting rod, elastomeric cushioning collars mounted on said adjusting rod and engaged with the opposite sides 'of the rod supporting member so as to resiliently fix the position of the rod for an adjustment of the beam relative thereto, and rod turning means on said rod for effecting a rotation thereof and a corresponding adjustment of the beam and grinding wheel thereon about the beam supporting shaft.

16. The machine of claim 13 including a pair of workpiece engaging and driving rollers mounted on said frame 10 at the forward end thereof in spaced relation below the grinding wheel, drive means engaged between the motor means and the pair of rollers for a driving thereof, a depth gauge roller mounted on said frame below the pair of work-engaging and driving rollers, and means mounting the depth gauge roller for selective longitudinal extension and retraction relative to the forward end of the frame so as to define a positioning means for a disk to be received between the pair of engaging and driving rollers.

References Cited UNITED STATES PATENTS 2,487,709 11/1949 Hodges 51-173 2,742,742 4/1956 Barrett 51173 WILLIAM R. ARMSTRONG, Primary Examiner US. Cl. X.R. 51-247