US 3719461 A
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Description (OCR text may contain errors)
March 6, 1973 R. 1.. TOPPING 3,719,461
SHARPENER FOR CUTTING BLADES Filed Aug. 24. 1970 I ENTOR R0552?- L.. OPP/N6 ML ATTORNEY United States Patent US. Cl. 51-204 9 Claims ABSTRACT OF THE DISCLOSURE A knife sharpener having an elongated body member comprising at least one sharpening stone mounted in a base member having in sliding engagement therewith a non-coextensive cover. Thus, a handle for the sharpening stone is provided by sliding the cover from one end of the base member to the other.
BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to sharpeners for cutting blades and in particular to a sharpening stone mounted in a base member having in combination a slidable non-coextensive cover. Even more particularly, it relates to a combination sharpening stone mounted in such a base member.
(2) Description of the prior art Sharpening stones of various materials and constructions are well known and have long been used for provicling sharp edges on various cutting blades, e.g. knives, scissors, and the like. oftentimes, one needs and desires sharpening stones having varying characteristics. However, in some instances a plurality of stones is undesirable and for this reason so-called combination sharpening stones have been provided. In such stones, one portion thereof may be of a coarse abrasive grain and another portion of a relatively finer abrasive grain. Thus, one can purchase and store one sharpening stone rather than two.
One problem associated with the use of sharpening stones and in particular smaller stones such as often found around the home is that such are easily broken. Breakage may occur from ones dropping accidentally the sharpening stone on, eg the kitchen floor or the like or in merely tossing such stone after use into a cabinet drawer for later use. A further problem associated with use of sharpening stones is that housewives are often heard to complain that using a sharpening stone results in abraded fingertips, fingernails, and the like. Therefore, houswives often avoid the use of a sharpening stone unless such is provided with a handle. The provision of some sharpening stones, and in particular small ones, with handles is not satisfactory, however, because of the fact that such increases undesirably their cost.
SUMMARY OF THE INVENTION A sharpener is provided in which an elongated body member comprising at least one sharpening stone is mounted in a base member having a slidable non-coextensive cover. In sliding the cover from one end of the base member to the other, a portion of the sharpening stone is exposed for use and a handle is provided by means of which the sharpening stone can be held during its use.
Quite advantageously, the base member in which the stone is mounted cushions, to some extent, the impact of the stone by and with other materials in which it comes into contact and which heretofore often resulted in breakage. The sliding cover in combination with the base member provides an effective and economical handle by means of which the sharpening stone can be held in ones hand during use without abrading ones fingertips.
3,719,461 Patented Mar. 6, 1973 BRIEF DESCRIPTION OF THE DRAWING The invention is described hereinafter in greater detail by reference to the drawing in which:
FIG. 1 is a side elevation of a sharpener in accordance with the invention;
FIG. 2 is an end view of the sharpener shown in FIG. 1; and
FIG. 3 is a plan view of the sharpener showing sharpening stones of different grain size.
DETAILED DESCRIPTION. OF THE INVENTION Turning now to the drawing, there is disclosed in FIG. 1 thereof a sharpener 10 for knife blades and the like in accordance with my invention. Such sharpener comprises an elongated body member 11 mounted in an elongated base member 12 provided with flanges 13, 14 on which is mounted for movement back and forth, as indicated by the arrow in the drawings, a slidable cover 15 by means of flanges 16, 17. The latter flanges, as shown in FIG. 2, and U-shaped and flanges 13, 14 fit therein. Although not shown in the drawing, flanges 13, 14 are provided with stop means at each end thereof to preclude cover 15 from sliding oif the base member.
In the preferred aspect of the invention, elongated body member 11 is made up of at least two sharpening stones having different abrasive characteristics. Such combination stone may have, for example, one portion thereof of a relatively coarse abrasive grain and another portion of a finer abrasive grain. However, if desired, the elongated body member may be entirely of one size or type abrasive gram.
Sharpening stones and their manner of manufacture are well known and require no detailed explanation herein. However, in general, sharpening stones comprise particulate abrasive grain held together by means of some suitable binder material. Such are readily available commercially in various sizes and shapes, e.g. round and rectangular, and of various abrasive grains, i.e., natural or synthetic, of various grain sizes. A preferred abrasive stone for use in the practice of my invention is one being of circular shape cross section and of either silicon carbide or aluminum oxide abrasive grain.
The sharpening stones, merely by way of example, may vary from about 3 to 6 inches in length and be from about A inch to 1 inch in diameter.
Base member 12., as well as cover 15, is desirably of some suitable plastic material as such can readily be formed into any desired shape and length by means of extrusion, molding, milling from a solid plastic bar, and the like. A suitable means of manufacture is extruding a plastic material through a die of the desired size and shape, e.g. to produce the U-shaped cross section and flanges shown herein in FIG. 2. The size base member and cover formed will, of course, depend on the size abrasive stones desired in the finished sharpener. However, in general the sharpening stone should fit snugly into the base member to about mid-point its diameter. Thus, as shown in the drawing, the sharpening stone will extend outwardly from the elongated base member whereby to expose the body member, at least in part, for use. Although the stone fits snugly within the base member, it is desirable that such be also secured within the base member by means of some suitable adhesive. This will then prevent the stone, should it become loosened, from separating from the base member and becoming more susceptible to breakage. Spot bonding the sharpening stone to the base member is found entirely satisfactory; however, if desired, adhesive may be applied the entire length of the sharpening stone.
The sharpening stone should not fit snugly into the slidable cover so that such can be readily moved back and forth along the length of the stone and base member. However, the cover need be only slightly wider than the diameter of the sharpening stone to permit satisfactory sliding movement.
Any thermoplastic material which can be readily and economically molded or milled is suitable for use in the practice of the invention. Many such materials are readily available on the market and in various colors pleasing to the housewife. Merely by way of example one may use nylon, polyethylene, polyacetal resins, polystyrene and the acrylonitrile-butadiene-styrene resins commonly referred to as the ABS resins.
In the practice of my invention, ABS resin was extruded through a die to provide a base member having outside dimensions of /2" across the bottom, Vs" sides depending upwardly 90 therefrom and flanges A5") depending 90 in opposite directions from the sides as shown in FIG. 2. The base member produced was 6" in length.
A similar member was extruded for formation of the slidable cover except that its length was only 3 inches. To this member was adhesively secured L-shaped means 6%.," thick) having legs of equal length Thus U- shaped flanges were formed (FIG. 2) for sliding contact with the flanges on the base member.
Two sharpening stones 0/2" x 3"), one coarse and the other containing finer abrasive grain (see FIG. 3), were then positioned in the base member to which suitable adhesive had been applied previously. On drying of the adhesive, the slidable cover was positioned on the base member for sliding back and forth. The ends of the flanges on the base member were then slightly deformed upwardly thereby to form stop means to prevent the cover from sliding off the base member.
As many different embodiments of my invention will occur to those skilled in the art, it is to be understood that the specific embodiment of the invention as presented herein is intended by way of illustration only and not limiting upon the invention, but that the limitations thereon are to be determined only from the appended claims.
What I claim is:
'1. Sharpener for cutting blades in which an elongated body member comprising at least one sharpening stone is mounted in an elongated base member, said body member extending at least in part outwardly from said base member thereby in part exposing said body member for use, said elongated base member having in combination a cover adapted for sliding engagement lengthwise thereon, said cover being noncoextensive with the length 5 of the base member whereby said body member may be in part always exposed along its length.
2. Sharpener according to claim 1 wherein said elongated body member comprises at least two distinct sharpening stone portions, one of said at least two portions comprising coarse abrasive grain and the other of said portions comprising a relatively finer grain, and said cover adapted for sliding engagement being non-coextensive with the length of the base member whereby one of said portions may be exposed while the other is covered.
3. Sharpener according to claim 2 wherein said body member is circular in cross section.
4. Sharpener according to claim 3 wherein said body member comprises only two distinct sharpening stone portrons.
5. Sharpener according to claim 4 wherein said sharpening stone portions comprise silicon carbide.
6. Sharpener according to claim 4 wherein said sharpening stone portions comprise aluminum oxide.
7. Sharpener according to claim 4 wherein said slidable cover is of such length as to be separately coextensive with each of said sharpening stone portions.
8. Sharpener according to claim 7 wherein said elongated base member and cover are of a thermoplastic material.
9. Sharpener according to claim 3 wherein about onehalf of said circular body member is exposed.
References Cited UNITED STATES PATENTS OTHELL M. SIMPSON, Primary Examiner US. Cl. X.R. 51-211