Knife-edge sharpening apparatus

#This invention claims the benefits of provisional application Serial No. 60/173,848, filed on Dec. 30, 1999 and non-provisional application Ser. No. 09/746,331, filed on Dec. 22, 2000.

#This invention relates in general to the field of apparatuses for sharpening knives and other cutting blades, and more particularly to counter-rotating wheels having intermeshing teeth for sharpening blades.

#Blade sharpening is, of course, quite old and there have been many improvements in the methods and devices used for forming a knife-edge on a blade. Heretofore, a problem with sharpening a blade has been the time that it takes to grind and hone the blade to achieve a satisfactory sharpness. Also, with conventional sharpening equipment and methods, a burr is left on the edge when the blade is ground. This burr can be honed or polished off, but this requires an additional operation, time and effort. Sharpening equipment has evolved from files and polishing stones, to grinding and polishing wheels, to combinations of such wheels, to intermeshing worm gears.

#FIG. 1 is a front elevational view of one of a plurality of toothed disks concentrically stacked and progressively angularly offset to form the wheel illustrated in FIG. 2.

#FIG. 2 is a pictorial view of a first embodiment of a sharpening wheel according to this invention.

#FIG. 3A is an edge elevational view of the sharpening wheel of FIG. 2, lateral lines other than those defining the tips of the teeth of the disks having been removed for clarity.

#Referring to FIGS. 1 and 2, a sharpening wheel of the invention, generally designated 2, is illustrated to be an assemblage of a plurality of circumferentially toothed disks 4, the disks being concentrically aligned in stacked relation. Each disk is circular, has a plurality of radial teeth 6 uniformly spaced around the disk's circumference, and defines a mounting hole 8 concentric with an axis 10 of the disk. The disks, except as noted below for other embodiments, are preferably uniform having the same dimensions and number of teeth.

#Referring to FIGS. 2 and 3A, the disks are stacked adjacent each is other and aligned along their axes forming a plurality of layers. Preferably eleven layers, L1 through L11, are used to assemble a sharpening wheel.

#Following the first layer L1, each succeeding layer, i.e. disk, is angularly offset in a certain amount in a common direction from an immediately preceding disk. As illustrated, starting from an edge 12 of a tooth on a disk in the first layer L1, a corresponding edge 12 of a matching tooth in the second layer L2 is offset a certain angular amount 14 in the direction of arrow 16. In the preferred embodiment, each successive layer (L3 through L11) is offset the same amount 14 and in the same common direction 16 from its immediately preceding layer. This arrangement creates a sharpening wheel having a plurality of “composite” teeth 18 each consisting of a queue of adjacent but offset teeth 6, one tooth from each layer. In the preferred embodiment, the long axes of the composite teeth are uniformly angular with respect to the wheel's axis. Each composite tooth, 18 or 30, has a leading, jagged edge 20 across its length defined by the leading edges of the apexes of the teeth 6 in its queue. These leading edges are in relation to the direction of rotation 34 shown in FIGS. 4A and 4B. the direction of rotation in this case being opposite to the offset direction 16, but both the offset direction and the direction of rotation could be the same. The composite teeth would be sloped in the opposite direction. The direction of rotation determines which edge of the composite tooth is the leading edge. In operation, these jagged edges machine the blade being operated-on to efficiently and precisely sharpen it.