US2241412A - Knife sharpener - Google Patents

Description

Patented May 13, 1941 KNIFE SHARPENER.v

Alexis E. Meade and Margaret L. Meade,

. Lakewood, Ohio` Application August 9, 1939, serial No. 289,216

11 Claims.

This invention relates to knife sharpeners, and one object of the invention is to provide a simple and compact portable device for this purpose. Another object is to provide means for removably supporting the abrasive members employed in the f Sharpener and means for readily releasing such abrasive members for replacement. Another object is to provide a structure composed of a minimum number of parts which shall be economical to manufacture and simple to assemble. The invention consists` in certain features and elements of construction in combination, as herein shown and described and. as indicated by the claims.

In the drawing:

Fig. 1 is a side elevation of a knife Sharpener embodying this invention.

Fig. 2 is an end elevation of the same.

Fig. 3'is a bottom plan view.

Fig. 4 is a vertical section taken substantially as indicated at line 4-4 on Fig. 2.

Fig. 5 is a transverse vertical section taken as indicated at line 5-5 on Fig. 4, looking toward the working faces of the abrasive members on one carrier and with the other carrier removed from the base.

Fig. 6 is a transverse vertical section taken at the same plane as Fig. 5, but looking in the direction of arrow 5 6 on Fig. 4, and assuming the other abrasive carrier to be removed from the frame.

Fig. I is a perspective view of the frame alone.

Fig. 8 is a perspective view of one of the abrasive members showing its working face.

Fig. 9 is a perspective view of the abrasive member showing its back face.

This inventionis illustrated as embodied in a small portable knife Sharpener suitable for domestic use in sharpening household carving knives and other knives employed for culinary purposes. The same principles of design, however, may be applied to a larger device for use in restaurants, butcher shops and other commercial establishments.

As shown in the drawing, the structure includes a base frame, I, which is generally oblong in shape, and at the middle of its length includes upstanding portions, 2, at both sides, which are arranged in pairs to form vertical guidek slots, 3, disposed in a common plane extending across the frame and perpendicular to the plane of its base. The frame also includes horizontal guideways, 4, l, extending longitudinally at both sides. The pair of hood-like housings, 5 and 6, are mounted on the frame for sliding engagement withthe guideways,-l, 4. The housings, 5 and 6, are preferably in the form of castings, but are provided with sheet metal bottom plates, 1 and 8, respectively, whose edges extend laterally into the grooves which constitute the guideways, 4, 4.

The hood or housing, 5, supports two abrasive members, 9, 9, which are spaced apart laterally, and the housing, 6, carries a single abrasive member, I0, centrally located and dimensioned to pass between themembers, 9, 9. These abrasive elements, 9 and In, are disposed with their working faces oppositely oblique to a vertical plane, and are formed with lugs, II, projecting from their ends for engagement with the hoods or housings, 5' and 6; the lugs, II, at the upper ends are received in notches formed in the castings which constitute the hoods, 5 and 6, and at the lower ends the lugs, II, are engaged by hooks, 1a and 8, depending from the ends of the bottom plates, 'I and 8, respectively. Both castings, 5 and 6, include suitable seating surfaces against which the abrasive stones, 9 and I0, are lodged, and said castings also include side fianges, 5a and 6a, which embrace the abrasive stones laterally and iit into recesses in the side walls thereof. One such recess is seen at 9* in Fig. 4, and Figs. 8 and 9 show the recesses, I0, of the stone, I0. Thus the abrasive stones are firmly and solidly secured to the hoods, 5 and 6. l

The outer ends ofthe plates, 1 and 8, include depending lugs, I2, I2, for connection with coil springs, I3, I3, whose inner ends are coupled by means of a link, Il, slidably mounted in a groove, I5, in the transverse bridge portion, I 6, of the frame, I. Thus the hoods or housings, 5 and 6, are yieldingly tied together by the springs, I 3, and the link, Il, and are normally urged thereby into their initial positions, as shown in Fig. 1.

With the parts at these positions the oppositely oblique planes of the working faces of the stones, 9 and I0, respectively, intersect near the upper end of the guide slot, 3; but if a knife blade be inserted between the stones and pressed downwardly, it will tend to force them in opposite directions toward the positions illustrated in Fig. 4, with the housings, 5 and 6, separated more widely than in their initial positions, and with the springs, I3, somewhat extended under the resulting tension. If the knife blade be reciprocated between the stones, their abrasive action will operate to sharpen its edge, and this action may be distributed over substantially the entire length of the abrasive members, 9 and I0, by-varying the pressure upon the knife blade so as to allow is usualLV highly Polished.

In use, the sharpener will be placed with its base, I, resting-upon a horizontal surface, such as a table top, and will be steadied by one hand engaging one oi' the housings, 3 or 3. With the handle of the knife held in the other hand, its

blade will be inserted in the slots, 3, and recipro-` cated with some downward pressure, which tends to separate the housings, 3 and 3, moving them slidably in the'guideways, l, 3.

As a warning and reminder that the fingers grasping the housing should not be placed too close to the guide slots, 3, the upstanding frame portions, 2, include laterally extending guard flanges, 23, disposed adjacent the guide slots, 3, 3, at both sides of the latter, but spaced apart sufi'iciently -to admit the hilt of an average size knife between them. Thus, in placing the hand over the housing, 3 or 3, to steady the device, the operator will be careful to keep his thumb and fingers back of the adjacent guard anges, 20, and will thus be in no danger of injury from the knife as it is reciprocated between the abrasive members, 3 and III.

To insure that the initial position of the abrasives will be such as to bring the intersections of the oblique planes of their working faces in alignment with the slots, 3, 3, the inward movement of the housings, 3 and 3, is checked by fixed stops formed on the frame, I. The bridge portion, I3, of the frame carries an upstanding stop lug, II, with which the working face of the abrasive stone, I3, will' engage at the innermost limit of movement of its supporting housing, 3. The side members of the frame, I, are provided with inwardly projecting lugs, I3, which engage the two abrasive stones, 3, at their working faces when their supporting housing, 3, has reached its inner limit of movement. As the working faces oi' the stones wear away with use, the housings, 3 and 3, will be permitted to approach a little more closely, but the working faces will occupy substantially the same initial positions, independently of -the amount of wear they have experienced.

Of course, when the abrasive elements, 3 and III, become unduly worn, they will be replaced by new stones, and their renewal is rendered quite simple. The'springs, I3, are first unhooked from the link, I 3, and then from the lugs, I2, so that the slidable housings areuncoupled from each other and may be removed endwise from the frame, I. The screws, I3, which secure the bottom plates, I and 3, in place on the cast housings, 3 and 3, may then be removed to release the lower ends of the abrasives from the hook-shaped lugs, 'In and 3*, which hold them in place. The abrasive elements will then be withdrawn from between the positioning flanges, 3* and 3l, and fresh stones substituted for them, so that upon re-assembly of the parts the device will be ready for further use.

The springs, I3, I3, being connected together by the link, Il, but not anchored to the frame, act as a single spring yieldingly urging the housings, 3 and 3. toward each other, and to insure independence of the spring. v From the frame it-` self the link, I4 is made freely slidable in the groove, I3, which accommodates it in the bridge member of the frame. 'I'he use of two springs instead of a single continuous spring is only a matter of convenience arising from the fact that the middle portion of the frame isoccupied by the lower ends of the abrasive members, 3 and I3, leaving no space through which a continuous coil spring could conveniently extend, but it will be evident that in place of the link. the spring could be formed with a straight section of wire connecting the two coil sections and integral therewith. The separate link, I4, however, renders it a little more convenient to disengage th,r springs when it becomes necessary to remove the housings or carriers, 3 and 3, from the support to replace the abrasive members. But when the springs are in coupled relation and acting as a unitary spring connection between the parts, 3 and 3, they insure that the pressure exerted by the abrasive members, 3 and I3, on opposite sides of the knife blade, will be equalized, since any pressure exerted against one of the housings will be transmitted to the other through the spring connection.

It will be seen that the structure herein described reduces the number of parts to a minimum, in that no external housing is required, since the movable -units which support the abrasive members, 3 and I0, are themselves formed as hoods or housings. of external contour which renders them manually engageable for steadying the device on a bench or table. 0n each unit a single disengageable portion, the bottom plate, 'I or 3, ypermits the ready removal of the abrasive member or members for replacement, and this same bottom plate provides the lug for connection with the spring which controls movement of the unit on the horizontal guideway of the frame.

In use the device requires no special skill. and it is practically impossible -to make an error in using it so as to injure the knife blade. As seen in Fig. '2, the top wall portions of the housings, 3 and 3, are spaced apart by a substantial distance even when the housings stand at their limits of nearest approach to each other. This opening between the top walls affords a clear vision of the upper ends of the abrasive members, 3 and I3, sov that the edge of the knife blade may be readily inserted in the V-shaped opening which is formed by the intersecting planes of the working faces of the abrasives. And as also seen in Fig. 1, the upstanding portions, 2, 2, of the base frame which contain the guide slots, 3, do not extend quite as high as the abrasives themselves; hence, there is no danger` of striking the edge of the blade against the walls of the guide slots, 3, 3, in entering it between the abrasives; its first contact will be with the abrasive surfaces themselves.

As indicated in Fig. 7, the base frame is of skeleton design with wide openings between its guideways. 'Ihis permits the device to be readily cleansed by holding it under a water faucet so that a flushing stream of water may flow down between the spaced top walls of the housings, 3 and 3, and over the surfaces of the abrasive members, thus clearing away any accumulated dust or metallic fragments and escaping readily throughthe large openings in the base frame. This will prevent the working faces of the abrasive members from becoming glazed by filling up with dust and' metallic particles, and the occasional wetting of the abrasive surfaces will improve their efficiency. l

It may also be noted that the side walls of the housings, and 6, extend into closely overlapping relation to the upstanding lateral flanges of the base frame in which the guide grooves, l, 4, are formed. This tends to prevent the guideways from becoming sprung, and holds them in engagement with the bottom plates, 1 and 8, of the housings throughout the range of sliding movement. It also enhances the appearance of the device, as will be readily appreciated upon inspection of Fig. 1.

While there is shown and described herein certain specific structure embodying 'the invention, it will be manifest to those skilled in the art that various modifications and re-arrangements of the parts may be made without departing from the spirit and scope of the invention, and that the same is not limited to the particular form herein shown and described, except in so far as indicated by the appended claims.

We claim:

1. In a knife Sharpener, a frame including a vertical guide slot and horizontal guideways extending transversely thereof, carriers mounted for sliding movement toward and from each other on said guidewaya abrasive members on said carriers disposed with their working faces in oppositely oblique relation tothe guide slot for engaging opposite sides of a knife blade introduced therein, and means yieldingly urging said carriers toward each other, each carrier including a pair of spaced side ilanges forming a channel to receive the back of an abrasive member, the sides of the abrasive member being recessed to accommodate the side flanges of the channel which are thus disposed within the width of the working face of said abrasive member whereby similarly mounted abrasive members on the two carriers may extend past each other with only slight lateral clearance between them.

2. In a knife sharpener, a frame providing a vertical guide slot and horizontal guideways extending transversely thereof, a pair of carriers supporting abrasive means arranged with their working faces in oppositely oblique relation -to the guide slot of the frame and in planes which intersect at the plane of the slot, each carrier including a body portion which holds the abrasive member in fixed angular relation to the guideway and a bottom plate having laterally extending portions slidably engaging the guideways of the frame, said bottom plates having downwardly extending lugs, and tension spring means connecting said lugsto each other to yieldingly urge the carriers and their abrasive means toward each other for maintaining contact of Ithe working surfaces with equal pressure against opposite sides of the knife blade disposed in the guide slot.

3. In a knife sharpener, a frame providing a vertical guide slot and a horizontal guideway extending transversely thereof in opposite directions therefrom, a pairof carriers mounted for sliding movement on said guideway and abrasive means on said carriers disposed with their working surfaces in oppositely oblique relation to the guide slot and in planes which intersect at the plane of the slot, said slot extending below the l faces of the 'abrasive vmembers on said carriers respectively for altering the limits of movement of the carriers toward each other in accordance with 4the wear of said working faces.

4. In a knife sharpener, a frame comprising a base with upstanding portions at the middle of its length and at two opposite sides, said portions having transversely aligned vertical guide slots, the base having a horizontal guideway; a pair of housing members mounted for sliding movement toward and from each other on the guideway, abrasive members supported on adjacent portions of the housings with their working faces in oppositely oblique relation respectively to the plane of the guide slots and disposed between said upstanding portions of the frame, means yieldingly urging the housings toward each other and stop means limiting their approach at a position in which the upper portions of said working faces lie in planes which form a V- shaped opening for initial entry of a knife blade to be sharpened, `the top walls of said housings being spaced apart by a substantial distance greater than the width of said V-shaped opening to aord a clear view of the upper end portions of the abrasives when the blade is being entered between them. t

5. In a knife Sharpener, a frame comprising a base with upstanding portions at the middle of its length and at two opposite sides, said portions having transversely aligned vertical guide slots, the base having a horizontal guideway; a pair of housing members mounted for sliding movement toward and from each other on the guideway, abrasive members supported on adjacent portions of the housings with their working faces in oppositely oblique relation respectively to the plane of the guide slots and disposed between said upstanding portions of the frame, means yieldingly urging the housings toward each other and stop means limiting their approach at a position in which the upper portions of said working faces lie in planes which form a V-shaped opening for initial entry of a knife blade to be sharpened. the top Walls of the housings being spaced apart by a substantial distance exposing the upper ends of the abrasive members, and the base frame being open between its guideways to permit a flushing flow of liquid to pass between the housings over the abrasives and to escape readily through the open frame.

6. In a knife Sharpener, a frame comprising a base with upstanding portions at the middle of its length and at two opposite sides, said portions having transversely aligned vertical guide slots, the base having a horizontal guideway; a pair of carriers mounted for sliding movement toward and from each other on the guideway, abrasive members supported on adjacent portions of the carriers with their working faces in oppositely oblique relation respectively to the plane of the guide slots and disposed between said upstanding portions of the frame, means yieldingly urging the carriers toward each other and stop means limiting their approach at a position in which the upper portions of said working faces lie in planes which form a V-shaped opening for initial entry of a knife blade to be sharpened, the upstanding portions of the frame terminating below the upper ends of the abrasives to insure entry of the knife edge in said V-shaped opening without contact with the edges of the guide slots.

7. In a knife sharpener, a base frame providing a vertical guide slot and horizontal guideways, a pair of carriers mounted for sliding movesaid carriers disposed with their working faces in oppositely4 oblique vrelation to the guide slot and in planes which intersect at the plane of the slot, a pair of tension springs each connected to one of said carriers and a rigid link connectlng said springs together, said frame having a bridge with a, guideway along which-said link is movable in response to the tension of the springs, whereby the carriers are urged toward each other by said tension for applying equal pressure to opposite sides oi' a knife blade inserted in the guide slot and between the'abrasive members. 8. In a knife sharpener, a frame comprising a base having a horizontal guideway and upstanding portions at the middle rof its length and at two opposite sides formed with transversely aligned vertical guide slots, a pair of movable units each comprising a hood-like, manually engageable body slidably engaging the horizontal guideway and supporting an abrasive member, the abrasive members of the two units being disposed with their working faces in oppositely oblique relation to the plane of the guide slots and contained between said upstanding portions of the frame, the planes of said working faces intersecting at the plane of the slots, and means yieldingly urging said units toward each other along the guideway, said upstanding portions of the frame having outwardly and vertically extending guard flanges disposed in pairs at opposite sides of both guide slots, the flanges of each pair being spaced apart by a substantial distance greater than the width of the slot.

9. In a knife Sharpener which includes a frame,

a pair of carriers both movably mounted on the frame, abrasive members on vsaid carriers respectively disposed with their working faces in planes which intersect at an acute angle, guiding means on the frame controlling the movement of both carriers and maintaining the angular relation between the working faces of the abrasive members yas the latter are moved apart by the introduction of a knife blade between them, means fixed on the frame providing a guide slot for the blade tobe sharpened, said slot extending in a plane substantially bisecting the angie between ment on said guideways, abrasive members on the working faces of said abrasive members, and spring tension means connecting said carriers to each other adapted tobe stressed by the introduction of a knife bladev between the abrasive members whereby said members are urged with equal pressure against the opposite sides of the knife blade respectively.

10. In a knife sharpener, a frame comprising a base having a -horizontal guideway and upstanding portions at the middle of its length 4tions of the frame having outwardly and vertically extending guard flanges disposed in pairs at opposite sidesof both guide slots, the ilanges of each pair being spaced apart by a substantial distance greater than the width of the slot.

11. In a knife Sharpener, a frame comprising a base having a horizontal guideway and upstanding portions at the middle of its length and at two opposite sides formed with transversely aligned vertical guide slots, a pair of movable units each supporting an abrasive member and slidably engaging the horizontal guideway, the abrasive members of the two units being disposed with their Working faces in oppositely oblique relation to the plane of the guide slots and contained between said upstanding portions of the frame, the planes of said working faces intersecting at the plane of the slots. and means yieldingly urging said units toward each other along the guideway, said upstanding portions of the frame having outwardly and vertically extending guard iianges disposed in pairs at opposite sides of both guide slots.

' v ALEXIS E. MEADE.

MARGARET L. MEADE.

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