Sharpening tool

Abstract

A sharpening tool comprising a handle, a housing portion extending from the handle, and a rotatable disk mounted within the housing. The disk can include multiple sharpening stations arranged along its perimeter. A user-actuated knob, rotatably coupled to the housing, enables selective rotation of the disk in order to position a desired sharpening station in an exposed orientation. In some embodiments, the knob rotates the disk in an opposite direction, with their axes of rotation laterally offset. A positioning mechanism, such as a magnet or detent, may bias the disk toward discrete positions, and a locking mechanism may prevent unintended rotation. Each sharpening station can include a first abrasive contact element to sharpen an edge of a blade and a second smoother contact element to support or guide the blade.

I claim: 
     
         1 . A sharpening tool comprising:
 a handle;   a housing portion extending from a front end of the handle;   a disk rotatably mounted within the housing portion;   at least two sharpening stations positioned along a perimeter of the disk;   a knob rotatably coupled to the housing portion and extending from a side thereof;   
       wherein
 rotation of the knob causes the disk to rotate within the housing portion; 
 at any given time, one of the sharpening stations is positioned in an exposed orientation such that it is accessible for sharpening an edge of a blade; and 
 a different sharpening station can be made accessible by rotating the knob to reposition the disk. 
 
     
     
         2 . The sharpening tool of  claim 1 , wherein
 an axis of rotation of the disk is horizontal.   
     
     
         3 . The sharpening tool of  claim 1 , wherein
 at least one of the sharpening stations includes a first contact element comprising   a first material and a second contact element comprising a second material different from the first material; and   an angle in between the first contact element and the second contact element is greater than 10 degrees and less than 90 degrees.   
     
     
         4 . The sharpening tool of  claim 3 , wherein
 the first material is more abrasive than the second material.   
     
     
         5 . The sharpening tool of  claim 3 , wherein
 the first material is a relatively hard abrasive material configured to sharpen a blade edge; and   the second material is a relatively soft material configured to guide or support the blade during sharpening.   
     
     
         6 . The sharpening tool of  claim 3 , wherein
 the first material is a tungsten-carbide; and   the second material is a ceramic.   
     
     
         7 . The sharpening tool of  claim 1 , wherein
 there are at least four sharpening stations positioned equidistant from each other along the perimeter of the disk.   
     
     
         8 . The sharpening tool of  claim 1 , further comprising
 a locking mechanism, wherein
 the locking mechanism prevents rotation of the disk when the locking mechanism is engaged. 
   
     
     
         9 . The sharpening tool of  claim 8 , wherein
 the locking mechanism is disengaged by pressing a button on top of the housing portion.   
     
     
         10 . The sharpening tool of  claim 1 , wherein
 rotation of the knob in a clockwise direction causes the disk to rotate in a counterclockwise direction, rotation of the knob in a counterclockwise direction causes the disk to rotate in a clockwise direction, or both.   
     
     
         11 . The sharpening tool of  claim 1 , wherein
 an axis of rotation of the disk is laterally offset from an axis of rotation of the knob.   
     
     
         12 . The sharpening tool of  claim 1 , further comprising:
 a positioning mechanism configured to bias the disk toward discrete rotational positions;   
       wherein
 each discrete rotational position corresponds to an exposed orientation of one of the sharpening stations. 
 
     
     
         13 . The sharpening tool of  claim 12 , wherein
 the positioning mechanism comprises at least one of a magnet or a detent structure configured to resist movement away from each rotational position.   
     
     
         14 . The sharpening tool of  claim 1 , wherein
 each of the sharpening stations includes a first contact element configured to sharpen an edge of a blade and a second contact element configured to guide and/or support the blade during sharpening.   
     
     
         15 . The sharpening tool of  claim 14 , wherein
 an angle in between the first and second contact elements of a first sharpening station is greater than an angle between the first and second contact elements of a second sharpening station.   
     
     
         16 . The sharpening tool of  claim 14 , wherein
 a second contact element of a first sharpening station has a greater resistance to sliding contact with the edge of the blade than a second contact element of a second sharpening station.   
     
     
         17 . The sharpening tool of  claim 14 , wherein
 a first contact element of a first sharpening station has greater abrasiveness with respect to the edge of the blade than a first contact element of a second sharpening station.   
     
     
         18 . A method to sharpen an edge of a blade, the method comprising:
 providing a sharpening tool comprising:
 a handle; 
 a housing portion extending from a front end of the handle; 
 a disk rotatably mounted within the housing portion; 
 at least two sharpening stations positioned along a perimeter of the disk; 
 a knob rotatably coupled to the housing portion and extending from a side thereof, wherein rotating the knob causes the disk to rotate within the housing portion; 
   rotating the knob until a suitable sharpening station is exposed such that the suitable sharpening station is accessible for sharpening the edge of the blade;   drawing the blade through a first and second contact elements of the suitable sharpening station to sharpen the edge of the blade, wherein the first contact element configured to sharpen the edge of the blade and the second contact element configured to guide and/or support the blade during sharpening.   
     
     
         19 . The method of  claim 18 , wherein
 a second contact element of a first sharpening station has a greater resistance to sliding contact with the edge of the blade than a second contact element of a second sharpening station.   
     
     
         20 . The method of  claim 18 , wherein
 a first contact element of a first sharpening station has greater abrasiveness with respect to the edge of the blade than a first contact element of a second sharpening station.