Knife sharpener

Abstract

A knife sharpener comprising a housing plate supporting a pair of sharpening rods that are curved to a specified dimension for maximizing the knife sharpener's ability to utilize and engage adjustable flexible bumper arms mounted on a positive stop that provides the sharpener's rods best angles and pressure for obtaining an even, consistent edge realignment, no matter what sharpening technique is used. Adjustable spring and cam mechanisms enable easy positioning of the initial, crossing-point of the sharpening rods over the center of a sharpening slot.

What is claimed is:  
     
         1 . A blade sharpening apparatus, comprising: 
 a housing plate having a front face and a rear face;    a vertically extending slot commencing adjacent a top end of the housing plate and extending toward a bottom end of the housing plate;    first and second, pivotably mounted sharpening rods defining therebetween a movable cross-over point that constitutes a sharpening region for a knife blade;    a pivoting mechanism for the rods, biasing the cross-over point toward the top end of the housing plate; and    a resilient device located adjacent the bottom end of the knife slot and positioned to be engaged by free ends of the rods when the cross-over point of the rods reaches toward a bottom end of the knife slot, the resilient device exerting a force on the rods which resists the force applied to the rods by a knife blade being sharpened.    
     
     
         2 . The apparatus of  claim 1 , including an adjustment mechanism for the pivoting mechanism that enables setting the cross-over point to coincide with the slot.  
     
     
         3 . The apparatus of  claim 1 , including a stop member in the path of the movable cross-over point.  
     
     
         4 . The apparatus of  claim 3 , wherein the stop member and the resilient device are formed as a single integral stop unit.  
     
     
         5 . The apparatus of  claim 4 , in which the single integrated stop unit comprises a center block which forms the stop member and upwardly protruding left and right bumper arms which constitute the resilient device.  
     
     
         6 . The apparatus of  claim 1 , in which the position of the integral stop unit is vertically movable on the housing plate.  
     
     
         7 . The apparatus of  claim 1 , in which the housing plate is made of a material selected from the group consisting of: a solid UHMW material and a high-density polyethylene material.  
     
     
         8 . The apparatus of  claim 1 , in which the integrated stop unit is made of a material selected from the group consisting of: a solid UHMW material and a high-density polyethylene material.  
     
     
         9 . The apparatus of  claim 1 , in which the first and second sharpening rods, the pivoting mechanism, and the integral stop unit are mounted on the rear face of the housing plate.  
     
     
         10 . The apparatus of  claim 1 , including a cover for the pivoting mechanism.  
     
     
         11 . The apparatus of  claim 1 , in which the pivoting mechanism includes a first pivoting mechanism for the first sharpening rod and a second pivoting mechanism for the second sharpening rod and each pivoting mechanism comprises a pivotable block in which a first end of each sharpening rod is anchored and a respective spring that serves to pivot the block around a pivot point.  
     
     
         12 . The apparatus of  claim 11 , in which the spring is a coil spring.  
     
     
         13 . The apparatus of  claim 11 , in which the pivoting mechanism includes caming devices that enable adjusting an initial position of the cross-over point of the rods.  
     
     
         14 . The apparatus of  claim 13 , in which the caming devices include for each sharpening rod first and second cams which hold tightly therebetween a free end of the spring.  
     
     
         15 . The apparatus of  claim 11 , in which the spring is a plate spring.  
     
     
         16 . The apparatus of  claim 11 , in which the spring is a torsion spring.  
     
     
         17 . The apparatus of  claim 1 , including a first marking that indicate a correct initial location of the cross-over point.  
     
     
         18 . The apparatus of  claim 17 , in which the first marking comprises first and second windows which straddle the knife slot and are located toward the top end of the housing plate.  
     
     
         19 . The apparatus of  claim 1 , including a second marking that indicates the position of a sweet spot of the sharpener.  
     
     
         20 . The apparatus of  claim 19 , in which the second marking comprises first and second windows that straddle the slot and are located adjacent a bottom end of the slot.  
     
     
         21 . The apparatus of  claim 1 , further including universal mounting holes by which the sharpener can be mounted to a support structure.  
     
     
         22 . The apparatus of  claim 1 , further including a tip enhancer.  
     
     
         23 . The apparatus of  claim 22 , in which the tip enhancer comprises a cover plate and two steel rods that are attached to the cover plate, with the steel rods crossing each other to form an approximate “X” shape.  
     
     
         24 . The apparatus of  claim 22 , wherein the tip enhancer is located on a face of the housing plate opposite to the face on which the integral stop unit is located.  
     
     
         25 . The apparatus of  claim 1 , further including a high, blind guide wall which is part of the housing plate and which extends at least about 2 inches above the knife slot.  
     
     
         26 . The apparatus of  claim 1 , further including a channel defined on a front face of the housing plate and straddling the knife slot.  
     
     
         27 . The apparatus of  claim 1 , in which the apparatus utilizes exclusively flathead screws and locknuts for attaching components to the housing plate mounted so that pathogens are unable to form within cavities in the housing plate.