Abstract:
A sharpener for a serrated knife having a plurality of ribbed cutting edges interspersed with concave cutting edges, the sharpener consisting of an elongated abrasive sharpening member having a longitudinal axis and a peripheral surface, a ribbed configuration on the peripheral surface extending longitudinally of the longitudinal axis for slidably engaging the ribbed cutting edges, and a convex surface on the peripheral surface extending longitudinally of the longitudinal axis for slidably engaging the concave cutting edges.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     The present invention relates to an improved sharpener for a serrated knife. 
     There are serrated knives in existence which have ribbed portions alternating with concave portions on their cutting edges. Insofar as known, in the past there were no sharpeners in existence which could sharpen both the ribbed portions and the concave portions by engaging them individually in complementary mating relationship with a sharpener. 
     BRIEF SUMMARY OF THE INVENTION 
     It is one object of the present invention to provide a sharpener for a serrated blade which has a ribbed configuration for positively engaging ribbed configurations of a knife edge in complementary mating relationship. 
     It is another object of the present invention to provide a knife sharpener having both a ribbed configuration and a convex configuration for engaging ribbed cutting edges and concave cutting edges, respectively, in sharpening engagement. Other objects and attendant advantages of the present invention will readily be perceived hereafter. 
     The present invention relates to a sharpener for a serrated knife comprising an elongated sharpening member having a longitudinal axis and a peripheral surface, and a ribbed configuration on said peripheral surface extending longitudinally of said longitudinal axis. The sharpener preferably includes a convex surface on its peripheral surface extending longitudinally of said longitudinal axis for engaging concave edge portions of a knife in sharpening relationship. 
     The various aspects of the present invention will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings wherein: 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 is a perspective view of one embodiment of the serrated knife sharpener of the present invention; 
     FIG. 2 is a side elevational view taken substantially in the direction of arrows  2 — 2  of FIG.  1  and showing the ribbed configuration; 
     FIG. 3 is a side elevational view taken substantially in the direction of arrows  3 — 3  of FIG.  1  and showing the convex surface on the elongated sharpening member; 
     FIG. 4 is a cross sectional view taken substantially along line  4 — 4  of FIG. 2; 
     FIG. 5 is a perspective view of a knife having a serrated blade with ribbed portions interspersed with concave portions on the cutting edge; 
     FIG. 5A is a fragmentary enlarged plan view of the cutting edge of the serrated blade of FIG. 5; 
     FIG. 6 is a fragmentary cross sectional view taken substantially along line  6 — 6  of FIG.  5  and showing how the elongated sharpening member engages the ribbed edge of the knife and showing also how it is preferably held between a person&#39;s thumb and finger; 
     FIG. 7 is a fragmentary cross sectional view similar to FIG. 6 but showing how the convex surface of the elongated sharpening member engages a concave edge portion of the serrated knife of FIG. 5; 
     FIG. 8 is a perspective view of the elongated sharpening member of the preceding figures mounted on a handle; and 
     FIG. 9 is a cross sectional view taken substantially along line  9 — 9  of FIG.  8 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The serrated knife sharpener  10  includes an elongated sharpening member  11  fabricated of a suitable abrasive ceramic material which can sharpen a blade when it is drawn across it. The elongated sharpening member  11  has a longitudinal axis  12  (FIG. 1) and a peripheral surface  13 . A ribbed configuration  14  is located on one portion of the peripheral surface  13  and extends longitudinally of the longitudinal axis  12  of the sharpening member  11 . Ribbed configuration  14  consists of alternating ribs  15  and valleys  17  (FIG.  4 ). The elongated sharpening member  11  also includes a convex surface  19  on its peripheral surface  13 , and convex surface  19  extends longitudinally of the elongated sharpening member  11 . Between the ribbed configuration  14  and the convex surface  19  there are two substantially planar sides  18  which extend throughout the length of the elongated sharpening member  11 . Also, as can be seen from FIGS. 4 and 7, the peripheral surface  13  also includes elongated substantially planar sides  16  which are located between substantially parallel edges  18  and ribbed configuration  14 . 
     An end cap  20  is mounted on one end of the elongated sharpening member  11 , and an end cap  21  is mounted on the opposite end of the elongated sharpening member. End cap  21  differs from end cap  20  in that it includes a tab  22  having an aperture (not numbered) through which a chain  23  extends. The end caps are made of a plastic material and serve the purpose of protecting the ends of the elongated abrasive ceramic member against chipping and also prevent any sharp edges at the ends of the elongated member  11  from piercing a pocket in which the sharpener  10  may be carried. The sharpener is approximately 4½ inches long so that it can be carried in a pocket. Alternatively, chain  23  may be used to fasten the sharpener  10  to a key ring or to any other suitable body. It will be appreciated that the elongated sharpening member  11  may also be fabricated of metal. 
     The sharpener  10  is for sharpening a knife  24  (FIG. 5) having a blade  25  with a serrated edge  27 . The serrated edge  27  includes ribbed configurations  29  which alternate with concave configurations  30 . The ribbed configurations terminate at sharp edges  28 . The concave configurations  30  include concave depressions  26  which terminate at concave sharp edges  36  (FIG.  5 A). 
     The sharpener  10  is used in the manner shown in FIGS. 5-7. The ribbed configuration is of complementary mating shape to the ribbed surface portions  29  of blade  25 . To sharpen the edges  28  of ribbed surfaces  29 , the elongated sharpening member  11  is positioned with its ribbed configuration in complementary mating relationship with each ribbed edge  29  and drawn across each ribbed surface in the direction of arrow  31  (FIG. 5) to sharpen edge  28  while the substantially planar edges  18  are held between the thumb  32  and a finger  33 . In view of the fact that surfaces  18  are substantially planar and parallel to each other, the grasping of these surfaces in the manner noted above, aids in orienting the elongated sharpening member  11  in alignment with each ribbed surface  29  and perpendicular to the edge  28  of each ribbed surface  29  of blade  25 . After each edge  28  of the ribbed surfaces  29  is sharpened by drawing the elongated sharpening member  11  across it, the concave edges  36  can be sharpened by placing the convex surface  19  into complementary mating engagement with each concave surface depression  26  and drawing the elongated sharpening member  11  across each concave edge  36  in the direction of arrow  31 . Here again, the substantially planar parallel surfaces  18  of the elongated sharpening member  11  are grasped between the thumb and forefinger and the sharpening member  11  is oriented substantially perpendicularly to the edge  27  of the knife. 
     Another embodiment of the present invention is shown in FIGS. 8 and 9. In this embodiment the elongated sharpening member  11  is identical to that described above relative to FIGS. 1-7. However, instead of having end caps, such as  20  and  21 , the sharpener  35  has a handle  37  which has substantially parallel planar sides  39  which are substantially parallel to substantially planar parallel sides  18  of sharpening member  11 . Sharpening member  11  may be of any desired length, considering that it is not intended to be carried in a pocket as is the embodiment of FIGS. 1-7. 
     The sharpener  35  of FIGS. 8 and 9 is used in substantially the same manner as described above relative to FIGS. 5-7. In this respect the ribbed surface  14  is placed in complementary mating engagement with each ribbed surface  29  and drawn across the edge  28  thereof. Additionally, the convex surface  19  is placed in engagement with each concave surface depression  26  of blade  25  and drawn across edge  36 . The parallel sides  39  of handle  37  are oriented substantially perpendicularly to the edge of knife blade  25  and thus tend to enhance complete contact with both the ribbed edge portions  29  and the concave edge portions  30 . 
     While the above description has been directed specifically to a sharpener for a knife having a cutting edge with alternating ribbed and concave portions, it will be appreciated that the sharpener of the present invention may be fabricated with either only one or more ribbed configurations on its periphery or only one or more convex configurations on its periphery so as to sharpen knives having only a ribbed configuration or a concave configuration, respectively, on its cutting edge. 
     A model of sharpener  10  has been made which is about 4½ inches long, and the sharpening member  11  has a maximum diameter of about ¼ inch and is made from alumina ceramic. However, it will be appreciated that the sharpening member  11  may have a matrix which includes any suitable type of abrasive including but not limited to silicon carbide, alumina oxide or diamonds. Also, the sharpening member may have a metal, plastic or any other suitable substrate coated with any of the above abrasive materials or any other suitable abrasive material. 
     While preferred embodiments of the present invention have been disclosed, it will be appreciated that it is not limited thereto but may be otherwise embodied within the scope of the following claims.