US2496139A - Wet grinding knife sharpener - Google Patents

Description

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qflmmc. 3% 111133 E. W. \mms WET GRINDING KNIFE SHARPENER 2 Sheets-Sheet 1 Filed July 16, 1947 mwmmw WW we mm M WEN E. W. was

WET GRINDING KNIFE SHARPENER Filed July 16, 19417 H il l l IHWQ l IHIIIIIH 2 Sheets-Shet 2 INVENTOR,

EMMA! W mm BY Hi5 ATTUEMEYE Patented Jan. 31, 1956 TITED STATES rarenr OFFICE WET GRINDING KNIFE SHARPENER Pennsylvania.

Application .luly 16, 1947-, Serial No. 751,225

11 Claims. 1

This invention relates to a wet grinding knife sharpener, and more particularl pertains to such a sharpener wherein the operator draws the edge of the knife back and forth across a side face of. a grinding wheel mounted for rotation on a horizontal axis, the knife being held at. a constant sharpening angle .to either face by an. associated conical guide mounted coaxially with the grinding wheel, and wherein the drawing movement of the. knife rotates the grinding Wheel.

The conical knife guides, one for each face of the wheel, are resiliently held. against the respective sides of the grinding wheel by springs, and their small ends enter recesses in the sides of the grinding wheel, said recesses being coaxial with the axis of rotation of the wheel. The spring action makes the device self-adjusting.

The lower portions of the grinding wheel and knife guides are submerged. in a fluid which, as they rotate, washes away the. cutting debris.

The knife guides also act to dress the faces of the grinding wheel adjacent the recesses, in a. manner to be described, so that the ground edge of the knife will never be dulled by use on a mutilated grinding wheel. Each conical knife guide, moreover, has a circle of holes, concentric with. the axis of rotation of the assembly of grind wheel and conical knife guides, and, as the said assembly is rotated in the fluid, during the sharpening process, the cuttings from the knife blade and the debris from the grinding wheel are Washed away, to the end that a superior wet grinding condition is obtained.

In order that both sides of the cutting edge of a knife blade may be ground without turning the knife sharpener end for end, I provide the conical guide member on each face of the grinding wheel, so that first one guide may be used for grinding one side of. the cutting. edge, and then the other guide may be used for grinding the other sideof th cutting edge.

Therefore, it is the principal object of my invention. to provide a knife-actuated grinding wheel which has a container for holding fluid for washing the grinding Wheel while it is being used.

Another object of the invention is to provide a knife-actuated grindin wheel provided with knife guides which also function to dress the wheel while it is being used, said guides being spring urged against the grinding wheel and, thus, self-adjusting.

Another object of the invention is to provide a knife-actuated grinding wheel, with guides 2 whichv keep the blade to be sharpened at the correct. angle. and which protect the cutting edge from edge contact with. any portion of the grinding wheel.

With these and further objects in. view, which will become apparent. from the description to follow, the invention will be described with reference. to the. drawings in. which;

Fig. 1 is a perspective view of. my novel. knife sharpener.

Fig. 2 is an. end elevation of the knife sharpener.

Fig. 3 isa top plan. view of the knife sharpener.

Fig. 4 is a. side elevation of my knife sharp.- ener,. with parts being. broken away to show one of. the knife'guides and the. spring cooperating therewith.

Fig. 5 is an end elevation of the knife sharp} ener, partly in section approximatel on the line 55 of Fig. 1, to. show the. mounting of the grinding, wheel. and the relationship. of the knife guides. with. respect thereto..

Fig. 6 is an. elevation of one of the. knife guides as it appears from. that side. which makes. con.- tact. with the grind. stone.

Fig- 7 is a sectional View of the knife guide of Fig. 6. in a plane including the axis of rotation.

Fig. 8 is an enlarged detail section of part of the grinding wheel. and one of the knife guides, showing the position of the. parts with a knife in position for sharpening. V

Fig. 9 is an. elevation of one of the springs.

In the drawings, the same reference numerals are. applied to the same parts throughout the several views, and the sectional views are taken on the: section lines looking. in the direction of the arrows...

Referring to Fig. 1, I provide a support casing 20 having feet- 2| and- 22, a. fluid cup 23:, and having. upwardly projecting side members 214 and 25. The side members. 24 and 25 preferably, but not necessarily, have a circular upper edge of a radius equal to. the radius of the grinding wheel to be used, as will be described. Concentric with the center of curvature of side members 24 and 25 are apertured hearing bosses 2B and 21 (see Fig. 2) having a shaft 28' aflixed therein, across the cup 23,. at brim leveL. which acts as a. mount.- in for sleeve 25 (Fig. 5) on which the. grinding wheel and knife. guides, to be described, are mounted. for rotation. The shaft 28 is fitted tightlyin. the bearing apertures. as itis; desirable to have the cup leakproof' at those points to prevent the escape of. fluid. It will b appreciated 3 that the shaft 28 can be mounted rotatably if desired. Sleeve 29 extends substantially the length of that portion of shaft 28 which is within the inside of the cup and is rotatable upon shaft 28. Sleeve supports the grinding wheel, knife guides, and knife guide springs.

I provide an abrasive grinding wheel 30, preferably of stone or mineral substance, having side faces 3! and 32 which are substantially parallel and lie in planes normal to the axis of rotation of sleeve 29. Grinding wheel 35 has a central circular aperture 33, with an inside circumferential groove 34 (Fig. 8) located on a plane parallel to and halfway between faces 3| and 32. On sleeve 29 is mounted a narrow support wheel 35 having a rim portion 3'6 which has therein a circumferential groove 31. The grinding wheel is held on said wheel by means of a circular wire member 38 which, by springing outwardly, keys together said grinding wheel and said support wheel. From what has been said, it will be apparent that the grinding wheel 35 is rotatable with reference to the shaft 28. It will be understood from what follows that the mounting of the grinding wheel is not of controlling importance so long as there is a central recess in each of the grinding wheel faces which will allow entry therein of the small end of the associated conical knife guide, to be next described. 7

Referring to Figs. 2 and 5, rotatably mounted on sleeve 25 is a left knife guide 40 and right knife guide 4i, each of which is roughly conical in shape, with the small end truncated so as to fit over the sleeve 29 and to fit into the aperture 33 (Fig. 8) for a slight distance. The right-hand knife guide 4! will be particularly described as typical of both knife guides, guide 46 being a left-hand counterpart of guide 4!. The circumferential rim 42 is bent parallel to the axis of rotation, and is at a distance from the axis of rotation equal to that of the periphery of the grind stone 30, so the two are at the same level, as best seen in Fig. 2, in which position they prevent the accidental entry of a knife blade into the wrong place. The cross section of said knife guide 4!, as shown in Fig. 8, further shows, inwardly of rim 42, a vertical band 43 which is bent to angular portion 44 which has an inward offset 45 a further angular portion 46, and then a vertical section 4?, which has therein an aperture 48 which is slightly larger in diameter thanthe diameter of sleeve 29 so that the knife guide in addition to being rotatable upon sleeve 29 may wobble, slightly, thereon. At 49 Where the knife guide makes contact with the edge 50 of the grinding wheel aperture 33 there is provided a circle of holes 5! (see Fig. 6) which aid in the carrying away of cutting debris.

It will be understood that the knife guides, as represented by guide 4!, are not true truncated cones, but are modified to provide the bearing portion 47 and to provide the band 52 so that a knife blade 53 laid against the guide touches only at shoulders 54 and 55. The face 56 of the knife blade not being in contact with the knife guide receives no frictional rubbing action thereby as the knife blade is drawn back and forth by the operator. Therefore, the depressed band 52 eliminates the marring of the sides of the knife sharpened thereon, points 54 and providing adequate support and guidance for the knife. Moreover, a two point contact with the knife face provides a more stable knife resting position, at the proper angle for sharpening, than would occur in using a perfectly fiat support surface.

The conical slope of the knife guide determines the included angle of the cutting edge to be ground on the knife and may be sloped as desired.

As seen in Fig. 8, sleeve 29 has on the end thereof a groove 66 for supporting a helical-spiral spring 5i (see also Fig. 9), the small end of which engages groove 5%] and the large end of which abuts against the guide 4! to resiliently hold it against the edge 5i: of the grinding wheel.

As a knife blade 53 is drawn back and forth, after it has been rested against the guide, the grinding wheel and guide will rotate about shaft 28. As the knife blade 53 is forced downwardly into the V-shaped angle between the knife guide and the stone, the knife guide on the upper side is forced outwardly which wobbles the whole knife guide on its mounting sleeve 29 so that the lower part thereon receives the full pressure of the spring forcing it against the part of the edge of the grinding wheel aperture 33 which is in the lowermost position, and breaks off any rim left on face 32 of the grinding wheel, at the edge of aperture 33, which may be made by wearing away of the portion of the stone just outwardly from it due to the abrasion of the knife. As the grinding wheel turns this dressing action progresses entirely around edge 50. In this way, the face 32, of the stone is kept in a dressed condition so that the cutting edge of the knife blade sharpened thereon will not be dulled by the existence of a rim caused by wear of the grindstone. it will be understood that there may be some slight rotational movement of knife guide 4| with respect to the grinding wheel, as they are not coupled together, and this in conjunction with the holes 5!, in the knife guide, further helps in the dressing action.

Due to the fact that the knife guide is resiliently held against the grinding wheel the knife blade can never jam in the sharpener.

As seen in Fig. l, fluid Ill, preferably water, is placed in the cup to a water line H which may be marked on the outside of the casing, and the movement of the grinding wheel and the knife guides, rotationally, swish the water in and out through the holes, carrying away the cuttings from the knife and the debris from the stone, thus keeping such harmful matter away from the grinding area, and accomplishing a wet grinding action. The cup in the casing collects and keeps off the surface on which the grinding device is used, all the cutting debris, which may be later dumped therefrom.

As seen in Fig. 2, the knife guide 40 is a lefthand duplicate of knife guide 4! and is mounted and acts in the same manner.

In operation, the operator grinds one edge face of the knife using the right knife guide and grinds the other edge face of the knife by using the left knife guide, both sides of the stone being used in such a complete operation. Although use of both sides of the grinding wheel is preferable from a convenience standpoint, the action of grinding both faces of the cutting edge can be obtained by the use of one side of the grinding wheel if the same is turned end for end after grinding one edge face so that the knife is en.- tered from the other side.

A few back and forth movements of the knife are suiiicient to sharpen the knife to a very keen cutting edge, and the parts are so positioned that the point of a knife can be sharpened as easily as, the middle portion of the edge, due: to. the fact that. the; knife. guides; are resiliently in con tact. with the stone. and are. notstationar-y with respect thereto;

The various portions ofthe device such as the casing, the sleeve, and the knife guides may be made of any type of metal, preferably non-corrosive and not hardened to a point where they would damage the knife accidentally drawn thereon, and the grinding wheel may be made of any suitable abrasive material, natural or of compacted and cemented particles, or the grinding wheel may be of hard material which has an abrading surface in the form of file or other type of roughened surface.

The fluids to be used with the knife sharpener are a matter of convenience, and water has been specified as the most convenient fluid, although non-evaporating fluids and lubricant fluid such asoil may be used if such is desired.

I am aware that certain details of construction specified are not necessary to the successful operation of my invention and I' do not deem myself limited to the particular construction used, therefore, F claim my invention broadly.

What I claim is:

1. In a knife sharpener. in combination, a casing having spaced side members; a shaft held'by and extendingbetweensaid side members; an abrasive wheel mounted on said shaft for rotation between the side members, said wheel having a circular recess. coaxial with said shaft; a knife guide having" a small endportion and a rim portion, rotatably -rnounted on said shaft; the small end having a hole therein of a diameter large enough through which said shaft protrudes, so that said guide may be wobbled on said shaft the small endentering said recess so the side of the guide rests against the peripheral edge of the recess-, said guide havin a circumferential circle of holes extending therearound at its points of contact with the wheel foraiding in removing cutting debris, and means resilientlyv holding such guide against the associated recess in t e wheel.

2. In a knife sharpener, in combination, a fluid holding cup; a wheel abrasive member mounted on a shaft held bythe cup, forrota tional movement, said shaft-being horizontal and the. lower portion of; the wheel belowthe shaft being within the confines of the cup and the upper portion of' the Wheel above the shaft being above the upperedges of' the cup; truncated conical knife guide means held against the. side of the wheel, the. truncated end pointed toward the wheel and slipped over the shaft until the frwsto-conical surface comes in contact with said wheel, the frusto-conical face acting as a knife positioning means, so that a knife having the side of its blade laid thereagainst has the opposite cutting edge face positioned at the proper angular position on the wheel, and so that drawing the knife back and forth grinds said edge in contact with the wheel; audafi uid heldin the, cup in which fluid, the wheel and the ide: m ans. s. a h s. of. cu n d bri upon rotation of said stone andguide: means by the sharpening operation.

3. In a knife sharpener as set forth in claim 2, in which a circumferential row of holes are formed in the truncated end of the knife guide means adjacent to the line of contact with the abrasive wheel for aiding in removing cutting debris.

4.... In. a knife sharpener as set forth. in claim. 2,. in; which the frustoeconical surfaces of the knife guidemeans. is provided with an annular recess to form spaced-apart, knife supporting points.

5. In av k-nife sharpener as set forth in claim 2, including means; for resiliently holding the knife guide means; against the abrasive wheel.

Ina. knife sharpener, in combination, an abrasive wheel having a circular aperture extending from side to side and, being coaxial. with the. Wheel axis; a narrow disc mounted within the aperture on a plane halfway between the planes. of." the side faces of the wheelfsaid disc having a central aperture, and said disc having its periphery in contact with the wheel and fastened thereto; a sleeve on which the disc. is secured, said sleeve running through the disc aperture and extending beyond the limits of the. side faces of the wheel, said sleeve being circumferentially grooved on each end; a shaft on which the sleeve is rotatably mounted, said shaft extending beyond the ends of the sleeve: a cup having spaced side members extending upwardlyfrom' the brim of the cup, said shaft being 5 mounted within the confines of the cup and between the side members on a level with the brim, whereby the wheel may be rotated so that its lower half at any given time is within the confines of the cup: a knife guide having a small end portion and a rim portion for each side of the Wheel, each guide having a central aperture by" which it" may be slipped on the sleeve so the small end portion enters slightly into the aperture in the wheel, said mounting on the sleeve being loose so the guide can wobble slightly thereon inaddition to rotating thereon, each guide having a circle of holes concentric with theaxis of rotation of the wheel at a radial distancefrom the axis of rotation of the Wheel so that they are opposite the associated peripheral edge of the aperture in the wheel for aiding in removing cutting debris, and each of said guides having on the outer surface a circular recessed band between said circle of holes and the outer rim, said band being recessed toward the interior of the cone-to provide spaced-apart knifesupporting points: ahelical-spiral spring for each guide member, the small end of a spring being mounted inthe groove in the sleeve on the end thereof associated with the associated guidemember and the large, end of the spring abutting the. interior of the associated guide member to hold it against the wheel; and a fluid held in the, cup to a level approximating the bottom of the shaft.

7.. Ina knife sharpener, in combination, a fluid holding cup having upwardly projecting spaced idememb rs; a shaft mounted between the, side m mbers acrossv the cup atbrimlevel; asleeve r0.- tatablymountedonthe shaft, said sleeve. having a, circumferential. groov on. eachend; a disc. mounted on the. sleeve at. its. midpoint, said disc. having a peripheral groove; an abrasivewheel mountedonthe disc,.said disc being; within.a.cen.- tral aperture,- in the; wheel, saidwheelbeing widerv than the disc, and: said central aperture of the wheel; having, on the. mid-line of its. periphery a V.-- shaped-groove;, a wire key member locking'the, disc and the wheel together in cooperation with the disc groove and V-shaped wheel groove, whereby the wheel isrotatable within the cup, the lower half thereof,.at any position of the wheel, being below brim level; a modified truncated hollow conical guide for each side of the wheel, the hole in the truncated end of a guide allowing it to be mounted on the sleeve, truncated end first, so the truncated end fits slightly into the wheel aperture on the associated side of the wheel, the outer surface of the guide from the truncated end extending outwardly and beyond the inner peripheral edge of the Wheel aperture; a helical-spiral spring for each guide, the small end engaging the groove in the associated sleeve end and the large end engaging the interior of the associated cone-guide to hold it against the wheel at the periphery of the wheel aper ture; 'and a fluid held within the cup to a level above the lowest level of holes in the guides.

8. In a knife sharpener, in combination, a fluid holding cup having upwardly projecting spaced side members; a shaft mounted between the side members across the cup at brim level; a sleeve rotatably mounted on the shaft, said sleeve having a circumferential groove on each end; a disc mounted on the sleeve at its mid-point; an abrasive wheel mounted on the disc, said disc being within a central aperture in the wheel which is wider than the disc, whereby the wheel is rotatable within the cup, the lower half thereof, at any position of the wheel, being below brim level; a modified truncated hollow conical guide for each side of the wheel, the hole in the truncated end of a guide allowing it to be mounted on the sleeve, truncated end first, so the truncated end fits slightly into the wheel aperture on the associated side of the wheel, the outer surface of the guide from the truncated end extending outwardly and beyond the inner peripheral edge of the'wheel aperture, a helical-spiral spring for each guide, the small end engaging the groove in the associated sleeve end and the large end engaging the interior of the associated cone guide to hold it against the wheel at the periphery of the wheel aperture; and a fluid held within the cup to a level above the lower holes in theguides.

9. In a knife sharpener, in combination, a fluidholding cup having two upwardly projecting spaced side members; a shaft mounted between the side members across the cup at brim level; a sleeve rotatably mounted on the shaft, said sleeve having a circumferential groove on each end; a disc mounted on the sleeve at its midpoint; an abrasive wheel mounted on the disc, said disc being within the central aperture in the wheel which is wider than the disc, whereby the wheel is rotatable within the cup, the lower half thereof, at anyposition of the wheel, being below brim level; .a modified truncated hollow conical guide for each side of the wheel, the hole in the truncated. end of each guide allowing it be mounted on the sleeve, truncated end first, so the truncated end fits slightly into the wheel aperture on the associated side of the wheel, the outer surface of each of the guides from the truncated end extending for a distance outwardly and beyond the inner peripheral edge of the wheel aperture, a helical-spiral spring for each guide, the small end engaging the groove in the associated sleeve end and the large end engaging the interior of the associated guide to hold it against the wheel at the periphery of the wheel aperture.

10. In a knife sharpener, in combination, a fluid holding cup having upwardly projecting spaced side members; a shaft mounted between the side members across the cup at approximately brim level; a sleeve rotatably mounted on the shaft, said sleeve having a circumferential groove on each end; a disc mounted on the midpoint of the sleeve; an abrasive wheel'mounted on the disc, said disc being within a central aperture in the wheel which is wider than the disc, whereby the wheel is rotatable within the cup, the lower half thereof, at any position of the wheel, being below brim level; a modified truncated hollow conical' knife guide for each side of the wheel, the hole in the truncated end of each guide allowing it to be mounted on the sleeve, truncated end first, so the truncated end fits slightly into the wheel aperture on the associated sid of the wheel, the outer surface of the guidefrom the truncated end extending outwardly and beyond the inner peripheral edge of the wheel aperture, and each of said guides having a circle of holes concentric with the axis of rotation of the sleeve and wheel and at a radial distance therefrom to bring the center of said holes even with the peripheral edge of the aperture in the wheel; a helical-spiral spring for each guide, the small end engaging the groove in the associated sleeve end and the large end engaging the interior of the associated cone guide to hold it against the wheel at the periphery of the wheel aperture; and a fluid held within the cup to a level above the lowermost holes in the guides.

11. In a knife sharpener, in combination, a fluid holding cup having upwardly projecting spaced side members; a shaft mounted between the side members across the cup at brim level; an abrasive wheel mounted for rotation on the shaft, within the confines of the cup, the lower half of the wheel, at any position of the wheel being below brim level, and said wheel having a central recess, on each face, of circular contour; a modified truncated hollow'conical guide for each side of the wheel, the hole in the truncated end of each guide allowing it to be mounted, truncated end first,

into the recess on the associated side of the REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 719,880 Rose Feb. 3, 1903 730,706 Rose June 9, 1 903 1,398,741 Rose Nov. 29, 1921 1,946,968 Gallagher Feb. 13, 1934 2,232,402

Norton Feb. 18, 1941

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