US2520279A - Knife sharpener - Google Patents

Description

Aug. 29, 195o J. GALLO 2,520,279

KNIFE SHARPENER Filed May 16, 1946 Patented Aug. 29, 1950 UNITEDY STATES PATENT OFFICE KNIFE SHARIENER J ohn Gallo, Medford, Mass. Application May 16, 1946, Serial N0. 670,099

1 Claim. 1

This invention relates to knife Sharpeners of the type which employ partly overlapping steel disks between which the knife is drawn.

One object of the present invention is to provide a Sharpener of this type wherein knives having their edges beveled on one side only may be sharpened, the metal being removed from the knife only on the beveled side.

A further object of the invention is to provide a Sharpener in the use of which the metal of the knife is removed at one time from one face only, the other face being supported and rolled adjacent to the edge.

Still another object is to reduce the cost of manufacture of Sharpeners of this type by requiring grinding of only one of the steel disks, this grinding being a costly operation.

Another object, where the disks are positioned on the same side of the support, is to provide means for limiting the lateral motion of the intermediate disk which will not require additional accuracy in the disk mountings.

For a complete understanding of this invention, reference may be had to the accompanying drawings in which Figures l, 2 and 3 are rear, end, and front elevations, respectively, of a Sharpener embodying the invention.

Figure 4 is a sectional view to a larger scale n line 4 4 of Figure 1.

Figures 5 and 6 are diagrammatic views illustrating the sharpening actions of the Several disks.

Figure '7 is a view somewhat similar to Figure 4, but showing a modification.

Referring iirst to Figures 1, 2 and 3 the sharpener comprises an angular plate support l having flanges 2 and 3 arranged at an obtuse angle to each other. The flange 2 is shown as provided with a pair of spaced perforations l for receiving fasteners (not shown) by which the sharpener may be mounted on any suitable support such as a handle member or a table tcp, or the like. The flange 3 carries three disks 6, 1 and 8. Each of these disks is shown as journaled on a rivet 9 and outwardly of each of the disks and between it and the adjacent end of the rivet is positioned a retaining washer I0. The central disk 1 is hardened and ground around its periphery at Il to form with its side faces the sharp edges I2, and this center disk 'l is shown as positioned on the outside face of the iiange 3. The side disks 6 and 8 are shown as arranged on the inner face of the ange 3. These side disks are not ground to pre- Sent cutting edges, but instead may be circular punchings, which, as they come from the stock, are formed with a rounded edge, as at I 5. These rounded edges are presented to face the center disk 1. While these disks are not ground, they are preferably hardened so that the hard rounded edges I5 act to roll against the edge portion of a knife blade Which is being drawn between the disks 6 and 1 or l' and 8 where they overlap and remove or turn rough edge portions or burrs to- Ward the opposite face of the knife for removal by the central disk, Such a punching is somewhat rough on its periphery, but this is not detrimental, it being important, however, for best results that these disks be hardened.

The eiect of this arrangement is illustrated in Figures 5 and 6. Referring to Figure 5, the rounded disk 6 rolls against the knife edge on one side while the center disk 1 cuts the metal away on the other side. As shown, the sharpening is all done on the right hand edge of the knife blade as viewed in the direction of Figure 5, the knife being drawn forwardly between the disks 1 and 6. When the knife is drawn between the disks l and 8, however, the cutting is done by the ground disk 'l on the left hand face of the knife blade, While the disk 8 serves to roll the edge portion on the opposite face of the blade. From this it will be seen that if a knife having a bevel on one face only, as, for example, on the right hand face as viewed in Figure 5, the knife will be drawn between the disks 6 and 1, while if the bevel of the edge is on the left, the knife will be drawn between the disks 1 and 8, as shown in Figure 6.

Where it is desired to sharpen the knife by removing stock from both sides, the knife is drawn rst between the center disk 1 and one of the side disks and then between the center disk and the other side disk.

This arrangement makes possible the proper sharpening of knife blades beveled on one face only, although it permits sharpening of knife blades beveled on both faces Where this is desired. Also, since it is necessary to grind only one of the three disks, this being the center disk l, and this operation is relatively expensive, the cost of the Sharpener is reduced from that of constructions where all of the disks are ground as well as hardened.

While as shown the center and side disks are positioned on opposite faces of the flange 3, it being found desirable to separate the disks axially, nevertheless the same principle of operation may be performed where all the disks are carried on the same side of the support as shown in Figure 7. Where the disks are so arranged, the

center disk 1a may be positioned between the washers l0 which are of less diameter than and are journaled substantially coaxially with the side disks on the side disk rivets, as shown. All the disks are loosely journaled on the rivets and the rivets are loosely7 set in the support, this looseness requiring no great accuracy in making or assembling the parts so that quantity production is easy and cheap, and it permits self-adjustment and rotation of the` disks to present various portions froin Ytime to time into operative relation to the knife blade thus to distribute the wear. Since the central disk is spaced from the sup.` port with this construction, it might have undue play were it not for the washers I0 against one or the other of which it may be pressed by pressure exerted by the knife blade 5inserted between the center disk and the opposite side disk. These Washers I0 then serve as stops with one 2or the other of which the central disk may engage and Since .this @Dieci iS with the @des 0f the @enter disk; it" hes il? .detrimental @Heet .9.11 .its slitting ds@ These washers .I9 .may be .fermes .es Pphiess .Or @ents .Similar t9' the A.Sigle disks ses? .83 'lbisf-rrar1semsni Qf ,disks .and .Washers may be used, if desiree., .Where @.11 @i the .disks ai@ tiene@ wie .thus beve uliinsesigesif? Qivfraiiee ille. knife preferably .drawn frein .the had; feel@ @.f the @ange ..3 toward .the forward face, and a direction substantially parallel to the base ange 2. Thisprovides a shearing out onthe knife blade by the center disk'l. i

From the foregoing description of an embodiment of this invention, it should be evident to those skilled in the art that various changes and modifications might be made Without departing from its spirit or scope.

I claim:

A device of the class described, comprising a support, a, center disk and two side disks loosely journaled to said support in partly overlapping relation on either side of said center disk, said. center disk being hardened and having a ground periphery presenting cutting edges with its side faces, and vWashers journaled Acoaxial with said side disks in the plane of said central disk and `forming stops with one or the other of which said central disk may engage to limit the lateral motion of said central disk by pressure of a kniie blade inserted between said central disk and the Qpposite side disk.

JOHN GALLO.

REFERENCES CITED The following 4references Yare of record in `the @le @f this Patenti UNITED STATES PATENTS Number Name Date 591,028 Bauroth r..- Oct. 5, 1397 l,`58g,3i1,2 Wright p May 1l, 1925 1,594,198 Holtzman July 27, 1926 21,4%63909 .Davis -n.- Aug. l0, 1948 FOREIGN PATENTS Number Country Date 97,110 ySwitzerland ec. l, 1922 113,591 Switzerland June 1G, 1925

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