Abstract:
An application for an apparatus for sharpening a cutting blade includes a source of high pressure water stream capable of cutting steel and a sharpening jig for positioning and holding the cutting blade perpendicular to the high pressure water stream, the sharpening jig provides a mechanism for moving the cutting blade so that a cutting edge of the cutting blade predictably passes beneath the high pressure water.

Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates to the field of hardened tools and more particularly to a method for sharpening hardened tools such as diamond alloy tool bits. 
       BACKGROUND OF THE INVENTION 
       [0002]    Stone, such as marble and granite, is often cut using a rotating blade made with diamond. In order for such a blade to efficiently cut stone, its cutting edge must be sharp or, approximately at right angles. As such a blade is used, the edges often round resulting in a dull blade that is less effective in cutting stone or, more significant, a blade that places undue stress on the attached saw, causing stalling or a burned-out motor. 
         [0003]    Prior to the present invention, to extend the life of these expensive blades, the blades were sharpened by using a hard grinding wheel. Such a process improves the life of the blade, but does not completely and evenly sharpen the blade. Because the blade is so hard, the grinding wheel develops ruts as it sharpens the blade. The ruts are usually curved, therefore, do not sharpen the blade edge at a right angle. Parts of the blade that are sharpened when the grinding wheel is new are often sharper (flatter, right angled) than parts that are sharpened when the grinding wheel is worn and has these ruts. This often results in an unbalanced blade that vibrates or wobbles when used. 
         [0004]    Water jet or fluid jet cutting systems are known as evidenced by U.S. Pat. No. 5,782,673 to Warehime. This patent describes a fluid jet cutting and shaping system with an X-Y table beneath the fluid jet for positioning and moving the object to be cut. 
         [0005]    What is needed is a method and apparatus for sharpening diamond edge blades and other very hard blades that repeatedly and consistently sharpens the surfaces of the blade. 
       SUMMARY OF THE INVENTION 
       [0006]    In one embodiment, an apparatus for sharpening a cutting blade including a source of a high pressure water stream capable of cutting steel and a sharpening jig for positioning and holding the cutting blade perpendicular to the high pressure water stream, the sharpening jig provides a mechanism for moving the cutting blade so that a cutting edge of the cutting blade predictably passes beneath the high pressure water stream. 
         [0007]    In another embodiment, a method of sharpening a diamond cutting tool is disclosed including providing a diamond cutting tool having a dull cutting edge. A source of high pressure water capable of cutting steel is provided. A sharpening jig positioned beneath the high pressure water holds the cutting blade of the diamond cutting tool perpendicular to the high pressure water while the diamond cutting tool is rotated. As the cutting edge of the diamond cutting tool passes beneath the high pressure water, the dull cutting edge is cut sharp by the high pressure water, thereby sharpening the diamond cutting tool. 
         [0008]    In another embodiment, an apparatus for sharpening a cutting blade is disclosed including a source of a high pressure water stream capable of cutting steel and a device for positioning and holding the cutting blade perpendicular to the high pressure water stream. The device for positioning and holding the cutting blade is capable of moving the cutting blade so that a cutting edge of the cutting blade predictably passes beneath the high pressure water stream. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which: 
           [0010]      FIG. 1  illustrates a plan view of a diamond cutting blade of the prior art. 
           [0011]      FIG. 2  illustrates a side view of a sharpened diamond cutting blade of the prior art. 
           [0012]      FIG. 3  illustrates a side view of a dulled diamond cutting blade of the prior art. 
           [0013]      FIG. 4  illustrates a grinding wheel used to sharpen a diamond cutting blade of the prior art. 
           [0014]      FIG. 5  illustrates a system of the present invention for sharpening a diamond cutting blade. 
           [0015]      FIG. 6  illustrates a plan view of a diamond cutting tool of the prior art. 
           [0016]      FIG. 7  illustrates a system of the present invention for sharpening a diamond cutting tool. 
           [0017]      FIG. 8  illustrates a system of the present invention for sharpening a diamond edging tool. 
           [0018]      FIG. 9  illustrates an adapter of the present invention for holding diamond edging tools within the system of the present invention during sharpening. 
           [0019]      FIG. 10  illustrates a system of the present invention for sharpening a curved diamond edging tool. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    Reference will now be made in detail to the presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Throughout the following detailed description, the same reference numerals refer to the same elements in all figures. 
         [0021]    Referring to  FIG. 1 , a plan view of a diamond cutting blade of the prior art will be described. A typical diamond cutting blade  10  of the art has a cutting surface  14  and a plurality of cutting points  16 . The cutting blade  10  has a center hole  12  for installing the cutting blade  10  on a saw hub (not shown). For proper cutting, the cutting blade  10  must be as close to round as possible to prevent vibration and wobble on the saw and must be as sharp as possible, especially when cutting hard stone such as marble and granite. 
         [0022]    Referring to  FIG. 2 , a side view of a sharpened diamond cutting blade of the prior art will be described. The cutting points  16  of the cutting blade  10  are visible. The edge  14   a  of the cutting blade  10  is sharp being that it is substantially flat and at substantially a right angle with a 90 degree tangent of the rotation of the blade. 
         [0023]    Referring to  FIG. 3 , a side view of a dulled diamond cutting blade of the prior art will be described. The cutting points  16  of the cutting blade  10  are visible. The edge  14   b  of the cutting blade  10  is dull being that it is substantially curved and its edges are not at substantially a right angle with a 90 degree tangent of the rotation of the blade. 
         [0024]    Referring to  FIG. 4 , a grinding wheel used to sharpen a diamond cutting blade of the prior art will be described. In the past, a grinding wheel  22  or other suitable grinding device was used to flatten the rounded edges  14   a  of a cutting blade  10  to restore its ability to cut. In this example, the grinding wheel  22  is affixed to a shaft  24  by a fastener  26  and rotates on the shaft  24 . The shaft  24  is coupled to a source of rotation (not shown). The flat edge of the grinding wheel  22  contacts the rounded edge  14   a  of the dull cutting blade  10  and grinds away the rounded edge  14   a  until it is flat as in  FIG. 2 . Unfortunately, this method is very time consuming and creates an uneven cutting blade  10  because of difficulties in grinding the blade into a balanced, round blade. Such difficulties are a result of uneven wear of the grinding wheel  22 . The grinding wheel  22  begins flat, but as it contacts the edge of the dull blade  10 , it wears proportionately to the surface area that must be removed from the edge  14   a  of the cutting tool  10 , thereby forming ruts in the grinding wheel  22 . 
         [0025]    Referring to  FIG. 5 , a system of the present invention for sharpening a diamond cutting blade will be described. High pressure water  52  is used to cut hard materials such as marble and granite. The water jet  52  is a very high pressure directed stream of water, usually in the range of 20,000 to 55,000 psi. The water is forced through an orifice in a jewel. The orifice is typically 0.010″ to 0.015″ in diameter. Some water jet cutters  50  use abrasives suspended in the water to cut harder materials or cut faster. The present invention works with many known water jet cutters and is not limited to any particular type or style of water jet cutter. 
         [0026]    In the exemplary sharpening system of  FIG. 5 , a diamond cutting blade  10  is rotatably affixed to a sharpening jig  30 . The sharpening jig  30  has a base  32  and a holding arm  36  attached to the base  32  by a threaded fastener  34  such as a bolt, etc. In this way, the sharpening jig  30  is easily affixed to the bed of the water jet cutting system (not shown). The cutting blade  10  to be sharpened is affixed to a hub  42 / 44 / 46 / 48  consisting of an upper hub  44  and a lower hub  46  and optionally, washers or spacers  44 , all held together by a bolt  42  that threads into the base  32 . The cutting blade turns freely on the hub  42 / 44 / 46 / 48 . To reduce bending of the cutting blade  10  under the stress of the high pressure water stream, a standoff  40  is affixed to the base  32  between the top surface of the base  32  and the cutting blade  10 . As shown, the water jet  52  from the water jet source  50  (as known in the industry) is directed substantially perpendicular to the cutting blade  10 . The sharpening jig  30  is positioned on the table of the water jet cutting device (not shown) and the water jet is aligned to cut the rounded edge  14   a  off of the cutting blade  10 , forming a sharp edge  14   a . As the rounded edge  14   a  is cut from one section of the cutting blade  10 , the cutting blade  10  is rotated on the hub  42 / 44 / 46 / 48  until the entire cutting blade  10  has sharp edges  14   b  as shown in  FIG. 2 . 
         [0027]    Referring to  FIG. 6 , a plan view of a diamond cutting tool of the prior art will be described. Other diamond cutting tools are known in the industry for cutting holes in stone, for example the cutting tool  60  for cutting faucet holes in stone counter tops. This cutting tool  60  has a cutting edge  62  and cutting surfaces  64  as known in the industry. 
         [0028]    Referring to  FIG. 7 , a system of the present invention for sharpening a diamond cutting tool will be described. To sharpen a diamond cutting tool  60 , the cutting tool  60  is threaded onto a threaded shaft  82  that is connected to a source of rotation, in this example a crank handle  84 . Other sources of rotation are known in the industry and all such sources are included here within. The threaded shaft  82  passes through and is rotatable held in position by a riser  80  attached to a base  72 . The base  72  has a holding arm  76  attached to the base  72  by a threaded fastener  74  such as a bolt, etc. In this way, the sharpening jig  70  is easily affixed to a bed of the water jet cutting system (not shown). The cutting tool  60  to be sharpened is threaded onto the threaded shaft  82  and positioned under the water jet  52  from the water jet source  50  far enough that the rounded edge of the cutting tool  60  is cut off by the water jet  52 . The cutting tool  60  is rotated by the source of rotation (e.g., the crank  84 ) until the entire cutting surface of the cutting tool  60  is sharp. 
         [0029]    Referring to  FIG. 8 , a system of the present invention for sharpening a diamond edging tool will be described. This system has a base  91  onto which a drive motor  90  is mounted. The shaft  92  of the drive motor  90  is stabilized by a bearing  94  that is affixed to the base  91  by fasteners  95  as known in the industry. A chuck  96  holds the edging tool  98 . In this example, the edging tool  98  is a flat surface edging tool  98  having angled cutting surfaces  99 . To sharpen such a edging tool  98 , the edging tool  98  in the chuck  96  is rotated by the drive motor  90  and the water jet  52  is positioned to cut the rounded edges of the cutting surfaces  99 . The water jet  52  is controlled at the water jet system to pass across the entire cutting edge of the edging tool  98  as the edging tool  98  rotates, thereby sharpening all edges  99  of the edging tool  98 . 
         [0030]    Referring to  FIG. 9 , an adapter of the present invention for holding diamond edging tools within the system of the present invention during sharpening will be described. The adapter  104  has a bit end  102  for insertion into the chuck  96  (see  FIG. 8 ) and a body  100  that has a hollowed, threaded portion for accepting a threaded cutting tool (not shown). 
         [0031]    Referring to  FIG. 10 , a system of the present invention for sharpening a curved diamond edging tool will be described. Curved diamond edging tools  110  are known in the industry and used to create bull-nosed edges or rounded edges for countertops and the like. The sharpening system of  FIG. 8  is used to sharpen curved diamond edging tools  110  by tightening the bit end  112  of the curved diamond edging tool  110  in the chuck  96  and, as the curved diamond edging tool  110  is rotated by the drive motor  90 , the water jet  52  passes along the curved cutting surface of the curved diamond edging tool  110 . The travel of the water jet  52  is programmed into the water jet system to track the curvature of the curved diamond edging tool  110 . 
         [0032]    Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result. 
         [0033]    It is believed that the system and method of the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes.