US2471207A

US2471207A - Blade sharpener

Info

Publication number: US2471207A
Application number: US786436A
Authority: US
Inventors: Grover C Freeman
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-11-17
Filing date: 1947-11-17
Publication date: 1949-05-24
Anticipated expiration: 1966-05-24

Description

G. C. FREEMAN BLADE SHARPENER May 24, 1949.

2 Sheets-Sheet 1 Filed Nov. 17, 1947 Grover Cfieeman,

May 24, 1949. G. c. FREEMAN BLADE SHARPENER 2 Sheets-Sheet 2 Filed Nov. 17, 1947 Grover Cfireemcm,

Patented May 24, 1949 UNITED STATES i OFFICE Claims.

This invention relates to knife sharpeners and more particularly to such sharpeners which are especially adapted for home use.

There are many types of knife sharpeners which are particularly adapted for home use such as in the kitchen or the like. Most of these sharpeners, however, are soon relegated to nonuse because they are difiicult in operation or become ineffective in their function. Furthermore, many of these sharpeners are too expensive for wide acceptance and use. In addition, many of these Sharpeners are complicated in use for the average individual due to the fact that they are not adapted to guide the blade to obtain the proper bevel on the blade edge so that the operator must properly position the blade during the sharpening operation.

Having in mind the difliculties of the prior art devices it is an object of this invention to provide a knife sharpener that comprises simplicity of design, economy of construction and efficiency of operation. There is another object of the invention to provide a sharpener that will properly position the blade during the sharpening operation in order to obtain a proper bevel on the edge, and to bias the blade against the sharpening member.

The foregoing objectives and others ancillary thereto are preferably accomplished according to a preferred embodiment of the present invention, by a holder which is formed from one piece of spring sheet metal and is adapted to freely support a stone while simultaneously providing resilient guides for retaining a blade against the side of the stone as it is moved thereagainst. The holder is preferably formed from a thin sheet of spring steel that is formed in a general U-shape with the bottom of the U flattened to provide a base and the arms of the U angling slightly toward each other to resiliently grip the sides of a stone seated therebetween.

The ends of the arms are flared outwardly below the top edge of the stone to provide guides for directing a blade between one of the arms and the side of the stone, and the edges of the arms are turned laterally to overlie the edges of the stone and are angled toward each other from their tops to their bottoms to provide guides for holding the blade at an angle relative to the sides of the stone, to obtain the proper bevel on the edge of the blade.

In the event of a round stone, these guide flanges serve to support the stone because they grip a substantial portion of the circular periphery of the stone. If the stone is square, however,

small lugs may be formed inwardly from the arms to underlie the stone but these lugs should not exceed the guide flanges in length but are preferably shorter than the depth of the bottoms of the guide flanges so that a blade will pass by the lugs in the event that it is moved to the bottom of the guides. If it is desired, the angular guide flanges may be turned outwardly on their edges to form flat guide flanges in lieu of edge guide flanges. The holder may be fixed to a suitable support or it may be provided with a removable handle to be hand-held during the sharpening operation.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein like reference characters indicate like parts throughout and in which- Fig. 1 is a view in perspective of a preferred form of a sharpener in accordance with the present invention and incorporating a round stone,

Fig. 2 is an edge View in elevation of the sharpener shown in Fig. 1,

Fig. 3 is a cross-sectional view taken on line 3--3 of Fig. 2, and showing modified blade guides,

Fig. 4 is a view in perspective of the handle removed from the sharpener,

Fig. 5 is an edge view in elevation of the sharpener shown in Fig. 1 and with a blade in sharpening position against a side of the stone and angularly supported by the guides,

Fig. 6. is a view in perspective of a modified construction incorporating a, square stone, and having the modified guides,

Fig. 7 is an edge view in elevation of the sharpener as shown in Fig. 6,

Fig. 8 is a cross-sectional view taken on line 88 of Fig. 7, and having plain blade guides,

Fig. 9 is a view in perspective of the handle for the sharpener shown in Fig. 6, and

Fig. 10 is an edge view in elevation of the sharpener shown in Fig. 6 and 7, and with a blade in operative position therein.

Referring now to the drawings, specifically to Fig. 1, a sharpener in accordance with the present invention, comprises three members, namely; a flat stone l, a holder 2 and a handle 3. The holder 2 comprises a single sheet of material,

preferably spring steel, although any suitable material having a degree of resiliency may be employed. The holder 2 is formed into a general U--shape with a flattened base 4 with inwardly inclined sides which terminate in upwardly extending arms 5 which resiliently engage the sides of the stone 1 and are substantially parallel but are preferably angled slightly toward each other in order to firmly grip the stone I.

The arms or sides 6 terminate slightly below the top of the stone I in outwardly extending flanges I. The side edges of the arms or sides 6 are bent inwardly to form flanges 3 which are angled from their tops, at the junction of the flanges l, inwardly to their bottoms, at the junction with the side arms 5, as best shown in Fig. 2. The handle 3, as best shown in Figs. 1 ands,- comprises a single strip of material, preferably a spring material, which is centrally bent upon itself to form a handle portion 9 which termihates in laterally extending arms In which are adapted to overlie anderigage one of the holder sides 5 and which terminate in U-shaped clips ll" which are adapted to nest around the edges of the side 5'. By this construction thehandle may readily be installed as shown in Fig. 1 or sprung apart and removed in the event that the holder 2 secured to a support the base 4 being provided with screw holes l2 for this latter purpose.

Inth epreferred embodiment of the invention, the sharpener preferably embodies around stone I; as best shown in Figs. 1 and 3, and in this case the sides 6 have a circular configuration to conform: to, the shape of'the stone and the guide flanges 8 are curved in accordance with the edges of'the sides 6. As the sides 6 extend vertically through a substantial portion of the diameter of the stone, the guides 8- are sufficiently long to embrace a substantial portion or" the periphery of the stone; Consequently, the flanges 8 preferably serve to embrace and support the stone I as-yvell asto function as blade guides.

According to a modification, as illustrated in Figs. 3 and 5, the angularly disposed-edges of the flanges-t may be turned outwardly to form guide flanges 821, for flatly engaging the sides of a blade during a sharpening operation, which blend into the top flanges 1. Depending upon the type'and' quality of the material used in forming the holder 2 the inner guide edges of the flanges 8 may become roughened through extended use and in. this event it is preferred to provide the fiat engaging guide flanges 8a.

In the operation of'th'e invention, as shown in Fig. 5, ablade B may be sharpened by inserting itbetween a side of the stone l and the corresponding side or arm 6 of the holder 2, and the blade then drawn longitudinally from the sharpn'el or moved in a Sawing motioh back and forth through the sharpener. In this operation, the blade Bis inserted between the side of the stone and the angular flanges i to b e guided down between the stone and the adjacent side 6; In this position, the blade B is 'angularly guided by the guide flanges 8, or do, against the side-of the stone l to produce the proper bevel on its edge E. During this action, the side porti'oh 5 is resiliently flexed outwardly and biases the arm or side 6 and its guide flanges 3 toward the stone I, so that the edge E of the blad B is resiliently retained against the side of the stone 1'.

After some use. the side of the stone l will become worn and grooved, whereupon the stone may be 'pivotally turned within the holder 2 to 4 position the worn grooves at an angle to the movement of the blade B and thereby present a new or fresh sharpening surface. Obviously, in use, the blade B is inserted on one side of the stone 1 and between the adjacent side 6 to sharpen one side of the edge E and is then inserted on the opposite side of the stone l and the opposite side 6 to sharpen the other side of the edge E. It will be noted that the stone l is supported by the flanges 8 in a position spaced above the base 4. By this construction, the edge E will not abut the base when the blade B is moved past the bottom of the stone l, and the particles abraded from the blade and stone are permitted to fall from the stone and collect on the base l so that they do not interfere with the sharpening operation.

According to a modification of the invention the sharpener may comprise a square or rectangular stone as shown in Figs. 6 and 8. This modification is substantially the same as that previously described, except that it comprises a square stone I which is supported by a holder 2 which carries a handle 3. The holder 2' has a flat base 4 provided with screw apertures 12" and that extends into the angular sides 5 which bend into the upright sides 8 that terminate ihto angular flanges l and have guide flanges 8' ex tending inwardly from the side edges thereof.

The sole difference between this modification and the preferred embodiment resides in the difference in shape which is necessary to accommodate the square stone and the provision of lugs- Hl, extending inwardly from the sides of the holder 2, to form supports for the stone i. In.

view of the fact that the guide flanges 8' are flat, to abut the end edges of the square stone I, they do not perform the supporting function of the curved flanges 8, and, consequently, the stone I" must be supported by separate means, such as the lugs I4, so that it may be spaced above the base 4' to accommodate a blade in the event that it is inserted completely past the stone l.

Obviously, the lugs Hi may be struck from the sides 6 asshown in Fig. 6, or from the sides 5 as shown in- Fig. 8. These lugs M are preferably of a length that is less than the width of the guide flanges at their bottoms, as clearly shown in Fig.

'7, so that a blade will not abut the lugs butwillpass thereby in the event that it is moved downwardly completely past the stone I.

Whereas the sides 5 of the preferred embodiment have their edges inclined outwardly to the ends of the base 4, which is at least as long as the diameter of the stone I and sides 6, and may be longer to provide accessibility to the holes I 2 in the modification the edges of the sides 5' may be perfectly straight and parallel as the base 4 will thereby be at least equal to the length of-the stone l to provide a suitable support for the Consequently, as

sharpener during operation. shown in Fig. 9, the handle 3' may comprise the handle portion 9' and arms it which terminate squarely in U-shape clips H to flt around the parallel edges of the sides 5.

In addition, for convenience of disclosure, the

guide flanges 8' are shown as terminating inoutwardly extending flat engaging side flanges 3b which are similar to the flanges 8a shown in F 3 in the preferred modification. I

In operation, as shown in Fig. 10, the blade B is inserted between the side of the stone I and the corresponding side 6' in engagement with the guide flanges 8" in the same manner as shown in Fig. 5 and described in connection with the preferred embodiment. It will be noted in Fig. 10, that the supporting lugs 14 are of such a length that they cannot interfere with the movement of the blade B down past the side of the stone 8'.

As previously described, when the stone becomes worn it may be turned angularly. In the case of the square stone however, it is necessary to completely withdraw the stone from between the arms 6 to turn it and then re-insert it between the side arms. Consequently, the square or rectangular stone 1 is limited to two effective angular positions, whereas, the round stone I may be pivoted to several angular positions. This is the primary reason for its preference of the round stone structure over the square modification.

Although a certain specific embodiment of the invention has been shown and described, it is obvious that many modifications thereof are possible. The invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the appended claims.

What I claim as new is:

l. A sharpener comprising a flat cylindrical stone, and a holder including side portions for freely supporting said stone therebetween, said side portions being resiliently biased to engage the sides of said stone and bias a blade against said stone when it is inserted between one of said side portions and the adjacent side of said stone, and flanges extending inwardly toward each other from the lateral edges of said side portions and overlapping and conforming to the peripheral surface of said stone, said flanges being tapered to provide inwardly inclined edges for guiding a blade at an angular position when it is inserted between a side portion and said stone.

2. A sharpener as defined in claim 1 wherein the inclined guiding edges are turned outwardly to provide smooth, flat flanges for engaging and guiding the blade.

3. A sharpener as defined in claim 1 wherein the upper horizontal edges of said side portions are flared outwardly away from the sides of the stone to guide a blade between said portions and the respective sides of the stone.

4. A sharpener including a flat cylindrical stone and a holder for supporting said stone, said holder comprising a base, side portions supported by said base and resiliently biased to engage the sides of the stone and support the stone in spaced relation above said base, and flanges extending toward each other from the lateral edges of said side portions to engage a blade inserted between the stone and one of said side portions, said flanges conforming to and engaging the peripheral surfaces of said stone and being tapered to provide inwardly inclined edges for guiding a blade at an angle against the side of the stone.

5. A sharpener as defined in claim 4 wherein the stone is round, the side portions are circular to correspond thereto, and the flanges are curved to partially surround and thereby support said stone.

6. A sharpener including a flat stone and a holder supporting said stone, said holder comprising a single sheet folded to provide a centrally positioned base portion with arms extending upwardly therefrom and forming side portions spaced above said base and corresponding in shape to the conformation of the stone, said side portions being spaced substantially the thickness of said stone and biased to flatly engage the opposite sides of said stone, flanges formed inwardly along the lateral edges of said side portions to overlie the edges of said stone, and engage to bias a blade against said stone when it is inserted between said stone and one of said side portions, said flanges being tapered to define inclined guides for angularly positioning a blade against said stone, and flare top edges on said side portions to guide a blade downwardly between said stone and one of said side portions.

7. A sharpener including a flat stone and a holder supporting said stone, said holder comprising a single sheet folded to provide a centrally positioned base portion with arms extending up-- wardly therefrom and forming side portions spaced above said base and corresponding in shape to the conformation of the stone, said side portions being spaced substantially the thickness of said stone, and biased to flatly engage the opposite side of said stone, curved flanges formed inwardly along the lateral edges of said side portions to surround the edges of and thereby support said stone, and engage to bias a blade against said stone when it is inserted between said stone and one of said side portions, said flanges being tapered to define inclined guides for angularly positioning a blade against said stone, and flared top edges on said side portions to guide a blade downwardly between said stone and one of said side portions.

8. A sharpener including a flat stone and a holder supporting said stone, said holder comprising a single sheet folded to provide a centrally positioned base portion with arms extending upwardly therefrom and forming side portions spaced above said base and corresponding in shape to the conformation of the stone, said side portions being spaced substantially the thickness of said stone and biased to flatly engage the opposite sides of said stone, flanges formed inwardly along the lateral edges of said side portions to overlie the edges of said stone, and engage to bias a blade against said stone when it is inserted between said stone and one of said side portions,

, said flanges being tapered to define inclined guides for angularly positioning a blade against said stone, lugs struck inwardly from said side arms to support said stone between said side portions, said lugs having a length less than the width of said flanges to be by-passed by a blade guided by said flanges, and flare top edges on said side portions to guide a blade downwardly between said stone and one of said side portions.

9. A sharpener including a flat stone, a holder for supporting said stone, and a handle for said holder, said holder comprising a single sheet folded to provide a centrally positioned base portion with arms extending upwardly therefrom and forming side portions spaced above said base and corresponding in shape to the conformation of the stone, said side portions being spaced substantially the thickness of said stone and biased to flatly engage the opposite sides of said stone, flanges formed inwardly along the lateral edges of said side portions to overlie the edges of said stone, and engage to bias a blade against said stone when it is inserted between said stone and one of said side portions, said flanges being tapered to define inclined guides for angularly positioning a blade against said stone, and flare top edges on said side portions to guide a blade downwardly between said stone and one of said side portions, said handle comprising a strip centrally folded upon itself to form a handle portion, the arms of said folded strip being bent outwardly ammo:

at anoint spaced. from the central fold; and

wardly. from their lateral edges in opposed relat- 10 tionship, said flanges being tapered from. the up per end inwardly to the bottom and snugly engagingthe edges of the fiatstone, whereby a knife passedfbetweenone of the side members and the stone is biased by the side member and guided by theinclinededges against the adjacent flat suriasce of the stone,

GROVER C.

REFERENCES" eITEn The foilewing. references are of record in the file of this patent:

UNITED STATES PATENTS- Number Name Date 300,656' St. Pierre: June 17, 1884. 560,052 Strong.v May 12, 1896 1,439,711 Reder Dec. 26, 1922- 1,4'77,820 Graser Dec. 18, 1923- 1,619,-5s1. Long Mar. 1, 1927' 2,009,420 Till July 30,1935 2,370,324 Probst Feb, 27.1945