Knife sharpener

Abstract

A sharpener for sharpening a cutting edge of a cutting tool includes: a housing having an elongated vertically extending slot therein, and an anchor region; and a spring biased sharpening element having a pair of arms, the sharpening element being arranged within the housing and secured to the housing at the anchor region below the vertically extending slot to provide a pivot point for the arms. The sharpening element has: a coil spring portion, arranged at the pivot point, and the pair of arms integrally formed with the coil spring portion, each arm having first and second elongated sharpening portions, respectively, extending from respective ends of the coil spring portion, the coil spring portion and the first and second elongated sharpening portions being spring biased in relation to one another to maintain a crossed relation within housing during a passing through of a cutting edge for sharpening.

What is claimed is: 
     
         1 . A sharpener for sharpening a cutting edge of a cutting tool, comprising:
 a housing extending in an upright plane having an elongated vertically extending slot therein, and an anchor region;   a spring biased sharpening element having a pair of arms, the sharpening element being arranged within the housing and secured to the housing at the anchor region below the vertically extending slot to provide a pivot point for the arms, the sharpening element having:
 a coil spring portion, arranged at the pivot point, and 
 the pair of arms being integrally formed with the coil spring portion, each arm comprising first and second elongated sharpening portions, respectively, extending from respective ends of the coil spring portion, the coil spring portion and the first and second elongated sharpening portions being spring biased in relation to one another to maintain a crossed relation within housing, each elongated sharpening portion being swingable downwardly in crossed relation about the pivot point in a plane adjacent and parallel the plane of the housing, such that a crossing point of the first and second elongated sharpening portions remains within the slot of the housing 
   wherein:   each of the first and second elongated sharpening portions has an upper and lower part and a curved intermediate part extending downwardly from its upper part and relative to the pivot point, and   the spring biasing of the sharpening element applies a force sufficient to urge each of the sharpening portions to, as the elongated cutting tool is drawn downwardly through and outwardly away from the slot, maintain its crossed relationship with the other by pivoting toward the other to thereby provide contact sharpening surfaces of each sharpening portion to respective sides of the cutting edge of the elongated cutting tool.   
     
     
         2 . The sharpener of  claim 1 , wherein the sharpening elements are curved sufficiently so as to provide a substantially uniform angle of contact between cutting edge surfaces of the cutting tool and sharpening contacts of the sharpening elements as the cutting tool is moved downwardly and outwardly through the slot of the housing. 
     
     
         3 . The sharpener of  claim 2 , further comprising a mounting base affixed to a bottom of the housing. 
     
     
         4 . The sharpener of  claim 2 , wherein the mounting base is affixed to the housing using a press fit connection. 
     
     
         5 . The sharpener of  claim 4 , wherein the housing has one or more ports, and wherein the mounting base has one or more spring arms each having a tab at an end portion thereof, the press fit connection being provided by engagement of respective ones of the one or more tabs with a respective ones of the ports of the housing. 
     
     
         6 . The sharpener of  claim 2 , wherein each of the first and second elongated sharpening portions are made of metal and have an abrasive surface formed thereon. 
     
     
         7 . The sharpener of  claim 6 , wherein the abrasive surface comprises a diamond electroplating. 
     
     
         8 . The sharpener of  claim 2 , wherein each of the first and second elongated sharpening portions are made of steel and configured as a blade honing surface. 
     
     
         9 . The sharpener of  claim 2 , wherein the sharpening portions terminate, at a top of the sharpener, in respective arcuate vertical end portions. 
     
     
         10 . The sharpener of  claim 2 , further comprising first and second spring pivots configured to engage with one another and with the coil spring portion. 
     
     
         11 . The sharpener of  claim 10 , further comprising a spring pivot bolt and spring pivot nut configured to be threadingly engagable with one another to securely mount the engaged combination of the coil spring portion and the first and second spring pivots to the housing at the anchor region. 
     
     
         12 . The sharpener of  claim 10 , the housing further comprising a pivot hole located at the pivot point, the spring pivot bolt passing through the pivot hole when threadingly engaging the spring pivot nut. 
     
     
         13 . The sharpener of  claim 10 , further comprising a keying engagement between the housing and the first and second spring pivots.