Abstract:
A sharpening guide for use with a chisel and a grinding wheel comprising a rod having a first end and a second end, a pivot assembly carried by the first end, a tool clamp attached to the pivot assembly and movable relative to the rod and adapted to retain the chisel, a base, and a base pivot for movably mounting the rod relative to the base whereby the base pivot is adapted to be mounted adjacent the grinding wheel. A method of sharpening a tool comprising the steps of locating a tool within a tool clamp, rotating the tool clamp toward a grinding wheel about a first axis until the tool is in contact with a grinding wheel, and rotating the tool clamp about a second axis to move the tool across the grinding wheel rotationally.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Technical Field 
         [0002]    The invention relates generally to holders for sharpening tools. More particularly, the invention relates to holders for sharpening gouges with a grinding wheel. Specifically, the invention relates to a gouge sharpening holder with multiple pivot axes, a guide cam, and an axially slidable mount to produce a precision grind. 
         [0003]    2. Background Information 
         [0004]    A chisel is a tool used for removal of material from work pieces such as stone, metal, and wood. The chisel generally includes two distinct ends. The first end is the material removal end, while the second end is the handle. The material removal end is made with various materials and designs depending on the task at hand. The handle end is shaped to allow the user to securely grasp the chisel and may include a hardened tip so that the chisel can be hit with a mallet or hammer to force the material removal end into and through the work piece. When the material end of the chisel is forced through the work piece, material removal and shaping is achieved. 
         [0005]    Woodworking chisels are also immensely popular since wood can be manipulated easier than harder materials. Accordingly, a variety of chisels have been developed to accommodate the various needs of woodworkers. Among the specialized chisels are butt chisels, slick chisels, paring chisels, skew chisels, and carving chisels. The carving style chisel also includes a gouge chisel which is used to create a generally concave surface in the work piece. The gouge chisel creates a generally concave surface due to the chisel&#39;s U-shaped cross-section. A gouge chisel may be either incannel, where the cutting edge is within the U-shaped cross-section, or outcannel, where the cutting edge is on the outside surface the chisel. 
         [0006]    With use, the leading edge of the gouge becomes dull and does not cut or remove material as efficiently. The woodworker must then proceed to sharpen the leading edge. This may be done free hand on a grinding wheel or on a sharpening stone. The use of a grinding wheel makes the sharpening procedure much easier and less time consuming. However, free hand sharpening of a gouge is difficult due to the precision needed in forming the leading edge along the U-shaped cross-section. Further, the grinding wheel in inherently dangerous because the user must apply pressure in the direction of the grinding wheel. If the tool slips off or catches an edge, the user could fall into the grinding wheel and cause severe injury to himself/herself. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention broadly comprises a sharpening guide for use with a chisel and a grinding wheel comprising a rod having a first end and a second end, a pivot assembly carried by the first end, a tool clamp attached to the pivot assembly and movable relative to the rod and adapted to retain the chisel, a base, and a base pivot for movably mounting the rod relative to the base whereby the base pivot is adapted to be mounted adjacent the grinding wheel. 
         [0008]    The present invention also broadly comprises a method of sharpening a tool comprising the steps of locating a tool within a tool clamp, rotating the tool clamp toward a grinding wheel about a first axis until the tool is in contact with a grinding wheel, and rotating the tool clamp about a second axis to move the tool across the grinding wheel rotationally. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The preferred embodiments of the invention, illustrative of the best modes in which Applicants have contemplated applying the principles of the invention, are set forth in the following description and are shown in the drawings. 
           [0010]      FIG. 1  is a side view of a preferred embodiment tool sharpening holder proximate a grinding wheel; 
           [0011]      FIG. 2  is a top view of a lock and release mechanism of a preferred embodiment base taken generally about line  2 - 2  in  FIG. 1 ; 
           [0012]      FIG. 3  is a rear view of a preferred embodiment tool sharpening holder; 
           [0013]      FIG. 4  is a cross-sectional view of a preferred embodiment tool sharpening holder taken generally about line  44  in  FIG. 3 ; 
           [0014]      FIG. 5  is a cross-sectional view of a preferred embodiment tool sharpening holder taken generally about line  5 - 5  in  FIG. 1 ; 
           [0015]      FIG. 6  is an enlarged side view of a preferred embodiment tool sharpening holder with a tool being aligned; 
           [0016]      FIG. 7  is a cross-sectional view of a preferred embodiment tool sharpening holder taken generally about line  7 - 7  in  FIG. 6 ; 
           [0017]      FIG. 8  is an enlarged side view of a preferred embodiment tool sharpening holder with the holding portion being pivoted and axially directed towards the grinding wheel; 
           [0018]      FIG. 9  is a top enlarged view of a preferred embodiment tool sharpening holder with a tool being sharpened on a grinding wheel when the holder is centrally located; 
           [0019]      FIG. 9A  is a top view of a preferred embodiment tool sharpening holder looking down the length of the holder when the holder is centrally located; 
           [0020]      FIG. 10  is a top view of a preferred embodiment tool sharpening holder with a tool being sharpened on a grinding wheel when the holder is rotated fully counterclockwise; 
           [0021]      FIG. 10A  is a top view of a preferred embodiment tool sharpening holder looking down the length of the holder when the holder is rotated fully counterclockwise; 
           [0022]      FIG. 11  is a top view of a preferred embodiment tool sharpening holder with a tool being sharpened on a grinding wheel when the holder is rotated fully clockwise; 
           [0023]      FIG. 11A  is a top view of a preferred embodiment tool sharpening holder looking down the length of the holder when the holder is rotated fully clockwise; and, 
           [0024]      FIG. 12  is a side view of another preferred embodiment tool sharpening holder proximate a grinding wheel. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0025]    At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred embodiments, it is to be understood that the invention as claimed is not limited to the disclosed aspects. 
         [0026]    Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described. 
         [0027]    The gouge sharpening tool holder of the present invention is indicated generally at  14 , as is particularly shown in  FIGS. 1 through 12 . As particularly shown in  FIG. 1 , a preferred embodiment gouge sharpening tool holder  14  includes a base  16  and a rod  18 . The gouge sharpening tool is secured to a table  20  or other suitable sturdy surface with bolts  22 . A grinding wheel  24 , includes an outer surface  26  which rotates about axis  25 , is secured to the table and located proximate the tool holder. 
         [0028]    In accordance with one of the main features of the present invention, base  16  includes a base beam  28  slidable within a mount  30 . Averting to  FIGS. 1 ,  2 , and  3 , the mount further includes a clamp  32  with a handle  34  and a lock  36 . Lock  36  is preferably an enlarged cam with a larger diameter when handle  34  is rotated to a locked position and a smaller diameter when handle  34  is rotated to an unlocked position. In particular, lock  36  is tapered from a smaller diameter to a larger diameter to allow the clamp to lock base beam  28  in one position and unlock base beam  28  is a second position. Thus, base  16  is axially slidable through clamp  32  when the clamp is in the unlocked position and base  16  is fixed when clamp  32  is in the locked position. 
         [0029]    Base beam  28  preferably includes a square cross-section and is oriented such that an edge of base beam  28  rests in the back inner portion of mount  30 . Although the cross-section is preferably square, any shape that can be locked in position may be utilized. 
         [0030]    Base  16  also includes a first end  38  a pair of spaced apart and parallel plates  39  having a pivot connection  40 . Interposing first end  38  and base beam  28  is an enlarged member  42 . A cam base  44  is complimentary shaped to fit over enlarged member  42  and still allow cam base  44  to slide along the outer surface of the enlarged member. Cam base  44  also includes a guide  46  pivotally mounted to cam base  44  at a thumb screw  48 . In particular, when thumb screw  48  is loosened, guide  46  is capable of pivoting about the connection at thumb screw  48 , and when the thumb screw is tightened, guide  46  is then fixed. 
         [0031]    Viewing  FIGS. 1 and 4 , guide  46  includes a first plate  45  and a second plate  47 . The first plate is rotationally secured to the enlarged member at thumb screw  48 . The first plate spaces the second plate away from upwardly extending plate  43  and both enlarged member  42  and cam base  44 . The second plate is generally perpendicular to first plate  45  and arranged to communicate with cam  62  (described infra). In particular, an outer surface  49  of second plate  47  is in frictional engagement with surface  63  of cam  62 . 
         [0032]    In accordance with another main feature of the present invention, base pivot  40  is attached to a housing  50 . The housing is preferably rectangular or square in shape with a hole ( FIG. 3 ) traversing the length of housing  50  and terminating at a boss  54  on a top surface and a boss  56  on a bottom surface. Preferably, housing  50  includes an upper bushing  53  with boss  54  and a lower bushing  55  with boss  56 . Rod  18  is arranged to slide within hole  52  in bushings  53  and  55 . A height adjuster  58  is secured to rod  18  and includes a bottom side located adjacent boss  54 . The height adjuster is preferably a disc with a machined bottom surface to smoothly and evenly abut boss  54 . Further, height adjuster  58  is removably secured around rod  18  and can be tightened or loosened at a bolt  60 . Accordingly, height adjuster  58  can be located along the length of rod  18  as desired to control the height between housing  50  and the tool (described infra). 
         [0033]    A cam  62  is located above height adjuster  58 . Similar to the height adjuster, cam  62  surrounds rod  18  and is removable by loosening a bolt  64 . Cam  62  is generally a right cylinder with a hole  66  traversing the length. In a preferred embodiment, hole  66  is offset from the center of cam  62  and allows non-uniform, or a parabola-like shape at an outer surface of the cam upon rotation of rod  18 . Since the hole is offset, one side of cam  62  is further away from rod  18  than the opposing side of cam  62 , thus meaning that rod  18  is spaced further away from plate in  47  some cam positions while being closer to plate  47  in other cam positions. Further, cam  62  rides against second plate  47  of guide  46  when the tool holder is pivoted towards grinding wheel  24  at pivot connection  40 . Although the cam is shown and described as having a generally circular cross-section, it is within the spirit and scope of the invention to provide a cam with a variety of cross-sectional shapes. 
         [0034]    As particularly seen in  FIG. 3  and upward of cam  62 , rod  18  may have a square cross-section portion at  68  of the rod. A second pivot connection  70  is located at the end of rod  18  that is distal base  16 . Pivot connection  70  preferably includes a bolt  72  proximate a wall  73 , a groove  74  in the end of rod  18 , and a nut  76  welded to a wall  78 . Pivot connection  70  includes walls  73  and  78  which extend upwardly and are spaced apart to receive a tool holding portion  80 . Rotation at pivot connection  70  is prevented when bolt  72  is tightened at nut  76 . Thus, pivot connection  70  allows tool holding portion  80  to rotate when bolt  72  is loosened and prevents rotation of the tool holding portion by compressing walls  73  and  78 .  5  In a preferred embodiment, tool holding portion  80  includes a first side wall  82  and a second side wall  84  spaced apart at the top by an upper wall  86 . First side wall  82  and second side wall  84  are angled inwards toward each other at the bottom of the tool holding portion and meet at and inside of pivot connection  70 . Inner walls of first side wall  82 , second side wall  84 , and upper wall  86  form a cavity  88 . At the lower portion of cavity  88 , first wall  82  and second wall  84  are arranged in a V-shape to easily center the tool. 
         [0035]    The tool is held in place by a bearing  90  which is in turn connected to a threaded rod  92  and a knob  94 . Bearing  90  is preferably used because it will rotate slightly upon axial displacement and help insure that the tool is centered within the holding portion. The threaded rod passes through a threaded hole  96  in upper wall  86  of the tool holding portion. Accordingly, rotation of knob  94  rotates threaded rod  92  through hole  96  and axially displaces bearing  90  to selectively secure or release a tool. 
         [0036]    Tool holding portion  80  further includes a tool alignment  98  connected to second side wall  84  in a preferred embodiment; however it is within the spirit and scope of the present invention to locate the tool alignment on any suitable portion of the tool holding portion, including first wall  82  or upper wall  86 . Tool alignment  98  includes an alignment rod  100  with a first end  102  and a second end  104 . A band  106  surrounds first end  102  and is slidable along the length of the alignment rod. First end  102  of rod  100  slides through a hole  107 , complimentarily sized and shaped, in side wall  84 . Since hole  107  is sized to allow only rod  100  to slide, band  106  prevents the alignment tool from extending beyond the length set by band  106 . Thus, band  106  is set along the length of first end  102  such that rod  100  and second end  104  extend past a front side  108  of the tool holder and second end  104  provides the length that a tool to be sharpened must be inserted beyond the tool holding portion front side for proper alignment. 
         [0037]    Averting to  FIG. 4 , rod  18  is shown traversing hole  52  in housing  50 , height adjuster  58 , and cam  62 . Hole  66  of cam  62  is preferably offset from the center of cam  62  to match the desired contour of the tool (discussed infra). Further, guide  46  is arranged adjacent an outer surface  63  of cam  62  and rotation of rod  18  imparts eccentric rotation of cam  62  along second plate  47  of guide  46 . 
         [0038]      FIG. 5  is a cross-sectional view of cam base  44  disposed on enlarged member  42 . Further base beam  28  is welded to enlarged member  42  in a preferred embodiment. Since cam base  44  is complimentarily shaped to enlarged member  42 , cam base  44  is slidable along the length of the enlarged member. The cam base is fixed in place by rotation of screw  110  in a clockwise direction and released for movement in a counterclockwise direction. As described supra, thumb screw  48  allows adjustability of guide  46 . A washer  112  separates upwardly extending plate  43  of cam base  44  and first plate  45  of guide  46 , while another washer  112  separates thumb screw  48  and first plate  45  of guide  46 . 
         [0039]    Having described the structure of the preferred embodiment, a preferred method of operation will be described in detail and should be read in light of  FIGS. 1  though  11 , and particularly  FIGS. 6 through 11 . 
         [0040]    As seen in  FIG. 6 , a tool  114  is shown being inserted through cavity  88  in the direction associated with arrows  116 . Tool  114  also includes a first end  118  terminating in a tip  120 . Band  106  is located on rod  100  in a position that allows rod  100  to extend beyond front side  108  and band  106  to rest against hole  107 . Accordingly, tool  114  is inserted through cavity  88  until tip  120  is aligned with rod second end  104  to prepare the tool for sharpening. While the present invention is shown sharpening a gouge tool, any tool which requires sharpening with a contour may be utilized. 
         [0041]    Next,  FIG. 7  is a cross-sectional view of tool holding portion  80  with first end  118  of tool  114  secured by axial force in the direction associated with arrow  121  of bearing  90 . Specifically, knob  94  is rotated and bearing  90  forces tool  114  downward by pushing on edges  122  and sets the tool in V-shaped cavity  88  formed by first wall  82  and second wall  84 . When tool  114  is secured within tool holding portion  80 , the tool is supported by bearing  90  on the top and by first wall  82  and second wall  84  on the bottom. After the tool is properly located and secured, tool alignment  98  is returned in the direction associated with arrow  124  to prevent damage to the tool alignment. 
         [0042]      FIG. 8  exemplifies the next two steps, whereby base  16  and base beam  28  is axially moved in the direction associated with arrow  126 . To this end, handle  34  is rotated (as seen in  FIG. 2 ) to release clamp  32  and allow base beam  28  to slide within base mount  30 . After the clamp is released, base beam  28  is moved in the direction of arrow  126  to locate tip  120  proximate grinding wheel outer surface  26 . Next, tool sharpening holder  14  is pivoted about pivot connection  40  in the direction associated with arrow  128 . Further, the user imparts a constant force in the direction associated with arrow  130  such that cam  62  and surface  63  are in constant communication with second plate  47  and surface  49  of guide  46 . Thus the constant force in the direction of arrow  130  means that any rotation of rod  18  follows the contour of outer surface  63  of cam  62  and translates to a similar contour at tip  120  and tool first end  118 . 
         [0043]      FIG. 9  is a top enlarged view of the tool holder with tool  114  extending through cavity  88  and the tool holding portion located proximate grinding wheel  26 .  1 s Tip  120  is also located proximate grinding wheel outer surface  26 . Having taken the above steps, the tool is now ready to be sharpened or ground after grinding wheel  24  is turned on and begins to rotate.  FIG. 9A  is a partial cross-sectional view looking down the tool holder and showing cam  62  off center from rod  18  and height adjuster  58 . 
         [0044]    As seen in  FIG. 10 , tool sharpening holder  14  is then rotated about rod  18  within housing  50  in the direction associated with arrow  132 . In particular, the constant force in the direction of arrow  130  as described above is still applied, but a rotational force in the direction of arrow  132  is also applied. Cam  62  is arranged with outer surface  63  with a contour to the desired grind of tool end  118 . In a gouge tool, the shape is generally parabolic and is achieved by maintaining tip  120  at constant axial distance from the grinding wheel outer surface  26 . Thus, when the tool is rotated, the tip remains the same distance from the grinding wheel, but grinding occurs on a side of the tool end. Further, since outer surface  63  of the cam rotates eccentric from rod  18 , the axial displacement of tip  120  and tool end  118  is controlled by outer surface  63  of cam  62  and allows a perfect parabola shape to be ground into the tool. Although the preferred embodiment is described with a parabolic, or U-shape, it is within the spirit and scope of the present invention as claimed to provide a cam with any shape that matches the desired tool tip contour.  FIG. 10A  is a partial cross-sectional view looking down the tool holder and showing cam  62  off center from rod  18  and being both rotated in the direction associated with arrow  132  and forced in the direction associated with arrow  130  into guide  46 . 
         [0045]      FIG. 11  is a top view of tool sharpening holder  14  being rotated in the direction associated with arrow  134 , opposite arrow  132 , to provide grinding to the opposite side of tool  114 .  FIG. 11A  is a partial cross-sectional view looking down the tool holder and showing cam  62  off center from rod  18  and being both rotated in the direction associated with arrow  134  and forced in the direction associated with arrow  130  into guide  46 . 
         [0046]    In summary, the tool sharpening holder allows a precision grind of a tool with a non-uniform taper by securing the tool with only a single axis of rotation and rotating the tool sharpening holder cam against a guide to provide the desired tool contour. 
         [0047]    Having now described the structure and operation of the first embodiment, only those portions of the remaining embodiment which are different from the first embodiment are described in detail. Likewise, similar numerals refer to similar parts throughout the various embodiments. 
         [0048]    In accordance with a second embodiment of the invention shown specifically in  FIG. 12  without a cam or guide, tool  114  is located within the tool holding portion  80 . Pivotal connection  70  allows the user to adjust the angle of approach θ and to adjust where on the tool tip  120  the grinding wheel will remove material. Height adjuster  58  and rod  18  both operate in the same manner as the first embodiment. 
         [0049]    In operation, the second embodiment locates tool  114  in the same manner as the first embodiment by using alignment tool  98 . Next, pivotal connection  70  is adjusted to provide the correct angle of approach θ and base  16  is axially moved in the direction associated with arrow  136  after clamp  32  is released (which again functions identical to the first embodiment). Once the tool is located proximate and in slight contact with the grinding wheel, handle  34  is rotated to clamp beam  28  and base  16  in that position. Finally, tool  114  is rotated about rod  18  in the directions associated with arrows  132  and  134  as disclosed in the first embodiment to sharpen the tool. 
         [0050]    Accordingly, the gouge sharpening tool is an effective, safe, inexpensive, and efficient device that achieves all the enumerated objectives of the invention, provides for eliminating difficulties encountered with prior art devices, systems, and methods, and solves problems and obtains new results in the art. 
         [0051]    In the foregoing description, certain terms have been used for brevity, clearness, and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirement of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. 
         [0052]    Moreover, the description and illustration of the invention is by way of example, and the scope of the invention is not limited to the exact details shown or described. 
         [0053]    Having now described the features, discoveries, and principles of the invention, the manner in which the gouge sharpening tool is constructed and used, the characteristics of the construction, and the advantageous new and useful results obtained; the new and useful structures, devices, elements, arrangement, parts, and combinations are set forth in the appended claims.