US2404025A - Knife sharpener - Google Patents

Description

July 16, 1946. J BARNES 2,404,025.

KNIFE SHARPENER Filed 061;. 6, 1944- A llilll l HM INVENTOR. Jase v71 L. Barnes Patented July 16, 1946 UNITED STAT ES PATENT OFFICE KNIFE SHARPENER Joseph L. Barnes, Indianapolis, Ind.

Application October 6, 1944, Serial No. 557,427

Claims.

My present invention relates to a knife sharpener of the kind having a pair of rotary files between which the knife blade may be drawn for sharpening it.

One object of the invention is to provide a knife sharpener of simple, durable and inexpensive construction comprising a base and a pair of rotary files or other suitable abrasives, mounted thereon.

Another object is to provide a means to permit rotation of the files in one direction and prevent their rotation in the other direction as a knife blade is reciprocated between them.

Still another object is to provide a knife sharpener which can be easily used by any unskilled person and operated merely by a reciprocating motion of the knife blade while held between a pair of rotary files.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my device whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in my claims and illustrated in the accompanying drawing, wherein:

Figure 1 is a plan view of a knife sharpener embodying my invention and showing in dotted lines the relation of a knife thereto while being sharpened.

Figure 2 is a front elevation of the knife sharpener showing a knife blade in section, and

Figure 3 is an enlarged sectional view on the line 33 of Figure 2.

On the accompanying drawing I have used the reference numeral ill to indicate a base which is preferably rigidly mounted on a table or cabinet top as by countersunk screws I2.

Thebase it has a pair of shoulder rivets l4 extending upwardly therefrom which are peened as at [B to retain them in position. On each rivet a rotary file I6 is journalled. The shouldered character of the rivets prevents any binding of the files and permits them to rotate freely.

The files I6 are provided with teeth It as illustrated in Figure 3 and the teeth of one file point clockwise while those on the other point counterclockwise. The files l6 are in the shape of cone frustums to bevel the sides of a knife blade as indicated at t8, the blade itself being designated 20. The teeth i8 as will be noted in Figure 3 mesh with each other so that there is an overlapping of the peripheries of the files at their lower ends as shown in Figure 2, thus presenting file faces entirely down to the lower sharp edge of the knife blade. This eliminates the wire edge caused by ball types of sharpeners wherein the balls contact each other. With respect to those types of sharpeners having rotary files provided with three files instead of two, my arrangement eliminates the necessity of the third file.

The teeth I8 may be considered as cutting in one direction, that is when the knife is drawn downwardly in Figure 3. I provide a wedge-like stop or holding pawl 24 coacting with the files which is spring-pressed downwardly in Figure 3 by a spring 26. The stop 24 floats on a pin 28 extending upwardly from the base l0 and, accordingly, as the knife is drawn toward the user, the stop wedges in between the rotary files and they are held so that their cutting teeth l8 act upon the knife to sharpen it. When the knife is pushed away from the user, the friction between the knife and the files will rotate the files (clockwise for the right hand one and counter-clockwise for the left hand one), this being permitted by the holding pawl 24 backing up due to such rotation. Thus the teeth 13 act only when the direction of travel of the knife blade relative to them is such that they can cut metal therefrom, and the device is automatically operable with only the requirement that the knife blade 22 be held down between the files and reciprocated.

Abrasives other than files such as carborundum or the like may be employed and other changes may be made in the construction and arrangement of the parts of my device without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope without sacrificing any of the advantages thereof,

I claim as my invention:

1. In a knife sharpener of the character disclosed, a base, a pair of rotary abrasive elements thereon, said abrasive elements being shaped as frustums of cones and having intermeshing teeth at their lower edges, and wedge means for permitting rotation of said abrasive elements in one direction and preventing their rotation in the opposite direction, said wedge means being constrained to wedging position between said abrasive elements.

2. A knife sharpener comprising a base, a pair of frustum shaped rotary abrasive elements thereon. having teeth meshing with each other at the bases of the frustums, and a holding pawl spring urged to wedgebetween said elements and stop their rotation as a knife blade is drawn between them and to release and permit their rotation as the knife blade is pushed in the opposite direction.

3. A knife sharpener comprising a pair of frustum shaped rotary abrasive elements having teeth meshing with each other at the bases of the frustums, and a. holding pawl to wedge between said elements and stop their rotation as a knife blade is drawn between them.

4. In a knife sharpener of the character disclosed, a pair of rotary abrasive elements, said elements being frustum cone shaped, and a wedge biased to frictionally engage between said elements for permitting of their rotation in one direction and preventing their rotation in the opposite direction.

5. A knife sharpener comprising a base, a pair of frustum cone shaped rotary abrasive elements thereon, and a holding pawl spring urged to wedge between said elements and stop their rotation as a knife blade is reciprocated between them in one direction and to release and permit their rotation as the knife blade is reciprocated between them in the opposite direction.

JOSEPH L. BARNES.

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