Precision sharpener tool

Abstract

A precision sharpening tool is disclosed, having opposing sharpening elements arranged to form a generally “V” shaped sharpening slot and first and second guide members arranged on opposite sides of the sharpening slot which comprise tensioned spring means arranged to urge a guiding surface against a side of a blade being drawn through the sharpening slot.

Description

[0001] This invention relates to a novel system and tool for sharpening the cutting edge of knives and the like, being particularly suitable for maintaining precision sharpening angles to enable consistent, quality edge sharpening. This is a continuation-in-part of U.S. Ser. No. 10 / 923,618 filed Aug. 20, 2004.BACKGROUND OF THE INVENTION [0002] Sharpening tools are well known in the prior art, for use in sharpening cutting edges such as the blades of knives and the like cutting instruments. [0003] Knife sharpening tools, particularly hand tools and simple automated tools that are easy to use and provide precision sharpened edges of consistent quality continue to be desired by the consuming public. Sharpening tools generally used by the consuming retail public are generally referred to as pocket and hand knife sharpeners. Pocket knife sharpeners generally comprise a sharpening element such as an abrading composite stone or the like material, that is generally packaged in a pouch or th...

AI Technical Summary

Benefits of technology

[0022] Disks or blades in a “V” slot sharpening arrangement are typically overlapped in opposing staggered orientation to provide a sharpening slot of about 35-45°, preferably about 40°, with sharpening means engaging opposite sides of a blade bisecting the slot, at an angle of about 20° to each side of the blade to be sharpened. Once set to the thickness of a blade, the guide members of the present invention retains the blade in a precision manner along about the center bisect of the “V” slot as the blade is being drawn through the slot, overcoming inadequate manipulation skills of the user and thus sharpens the blade to its most efficient edge for cutting a variety of materials.

[0027] Particularly in an embodiment wherein a plurality of opposing sharpening disks are used, they are generally mounted in two interleaved parallel stacks, forming a generally “V” shaped slot comprises a plurality of opposing disks, through which a blade of a knife can be slidably drawn for abrading the sides of the knife blade. Disks can be axle mounted for free rotation and / or can be enabled for driven rotation by crank, motorized means or the like. In driven rotating disk arrangements it is generally preferred that the disk have a cylindrical outer surface for abrading to enable the formation of a concave sharpened blade. In another embodiment, cylindrical composite sharpening sticks are arranged in an angled crossing arrangement, forming the “V” shaped sharpening slot. The sharpening sticks are enabled for axial and rotational movement along their elongate axis, so that the spacial positioning of the apex of the “V” shaped slot is retained constant, but the surface of the sticks which engage the blade can be changed by simply rotating the sticks on their elongate axis or axial movement of the elongate sticks. Such arrangement enables convenient refreshing of the abrading surface by the user.

[0030] In a one preferred embodiment, the quadrilateral rectilinear sharpening elements have generally parallel, elongate sharpening edges and angled ends. Element retaining slots are arranged at about a 40° angle to each other to define the “V” shaped slot and the elements are slidable mounted in the slots. The ends of the sharpening elements are angled so that when mounted, the ends lay at about a 90° angle to the centerline bisecting the “V” shaped slot, enabling convenient variable adjustment of the positioning of the elements in their respective retaining slots by various support means engaging the ends, without change to the geometry or relative position of the “V” shaped slot.

Problems solved by technology

The size of the stone is generally small for convenient pocket carrying, which makes the hands on manipulation of the small stone during the sharpening process generally unsafe for the user and generally requires significant hand manipulation skills to conveniently and accurately sharpen a cutting edge.

Such tools are useful, but are limited in the quality of sharpened edge that can be attained and thus the durability and usefulness of the knife so sharpened.

Unfortunately, holding a knife blade perpendicularly bisecting a “V” slot during the sharpening process requires skilled manipulation of the tool, and frequently the person manipulating the tool ends up producing a sharpened knife having different beveled angles on opposite sides of the knife and / or variations in beveled angle along the length of the blade on the same and / or different sides of the blade.

The result is an improperly sharpened knife which though it may have a sharp edge, is easily dulled.

If the sharpened edge is not centered along the thickness of the blade, the sharpened blade tends to tear or bind during cutting through the thickness of materials.

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