FIELD OF THE INVENTION
This invention relates to sharpening knives and the like, and more particularly, to an improved adjustable abrasive sharpener.
SUMMARY OF THE PRIOR ART
In the prior art numerous abrasive sharpeners for knives and the like exist having fixed abrasive elements forming a V-shaped sharpening slot. Such known fixed abrasive elements are oriented at a fixed angle to sharpen a blade at an angle as desired for a range of different knife types. Most sharpeners are set at either a standard angle and/or an Asian angle that is preset and static. All manufacturers use blades that produce set knife angles that may vary from knife style to another. These varying set angles may not match the standard or santoku angle of prior fixed angle sharpeners. Accordingly, it is desirable in the prior art to provide an adjustable V-shaped sharpener by which the sharpening angle may be varied to range of sharpening angles to more closely match the prescribed sharpening angle of the knife edge from the original blade manufacture.
SUMMARY OF THE INVENTION
It is therefore an objective of the invention to provide an improved abrasive knife sharpener having adjustable abrasive elements to selectively vary the sharpening angle of a blade. The sharpener includes a pair of pivotally mounted abrasive elements forming a sharpening slot whereby the abrasive elements can selectively be moved toward and away from each other to vary their orientation and sharpening angle. Such adjustability is achieved by a rotary adjustment mechanism for ease of use and significant control of the angle between a respective pair of abrasive elements. By varying the angle between the abrasive elements the user may select a sharpening angle that more closely matches the prescribed manufacture specifications.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of the adjustable abrasive sharpener of the invention;
FIG. 2 is a top plan view of the adjustable abrasive sharpener of FIG. 1;
FIG. 3 is a front elevational view of the adjustable abrasive sharpener of FIG. 1;
FIG. 4 is a front elevational view, with the cover removed, of the adjustable abrasive sharpener of FIG. 1;
FIG. 5 is a front elevational view, with parts in section, taken along lines 5-5 of FIG. 2;
FIG. 6 is a top plan view, with parts in section, taken along lines 6-6 of FIG. 4;
FIG. 7 is a top partial plan view of the adjustable arms of the adjustable abrasive sharpener of FIG. 1;
FIG. 8 is a front partial elevational view of the adjustable arms of the adjustable abrasive sharpener of FIG. 1;
FIG. 9 is a bottom partial plan view of the rack and pinion of the adjustable abrasive sharpener of FIG. 1;
FIG. 10 is a partial front elevational view, with parts removed, of the adjustable mounting of the abrasive elements of the invention of FIG. 1.;
FIG. 11 is a partial top plan view, with parts removed, of the adjustable mounting of the abrasive elements of the invention of FIG. 1;
FIG. 12 is a bottom partial plan view, taken along lines 12-12 of FIG. 10, of the adjustable arms of the adjustable abrasive sharpener of FIG. 1; and
FIG. 13 is bottom perspective view of the angle locking bracket of the adjustable abrasive sharpener of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1-13, there is illustrated the adjustable abrasive sharpener of the invention for sharpening knife blades and the like, generally designated by reference numeral 2. Although the sharpener 2 discloses a manual adjustment of the sharpening angle, it is within the scope of the invention to employ other techniques employing the invention, such as an electro-mechanical mechanism (not shown) and the like. As best seen in FIGS. 1-3, the abrasive sharpener 2 includes an elongated frame 4 forming a handle portion 6 at one end. The end 8 of handle 6 curves downward and includes a flat bottom surface 10 which serves as a support area during sharpening. The frame 4 further includes upwardly opening U-shaped section 12 forming a bottom support surface 12a and a curve upward extending portion 12b (FIGS. 3). A housing 14 is positioned within the U-sharped section 12. A sharpening slot 16 having abrasive elements 16a which are oriented to each other at a generally fixed V-angle is provided on the top of housing 14. A pair of additional slots 18 are formed on the top of housing 14 and each include a pair of pivotally mounted abrasive elements 18a, 18b forming an adjustable generally V-angle to be capable of varying the sharpening angle of the blade of a knife dependent on desired results. As will be apparent from the following description, the abrasive elements 18a, 18b can simultaneously be adjusted toward and away from each other through rotation of exterior adjustment actuator, such as knob 20, which is shown being situated between the two respective slots 18. It is within the scope of the invention, however, to situate the knob 20 on either side of one of the adjustable slots 18 or other desired position where convenient.
As previously described, the abrasive elements 18a and 18b in each slot 18 are arranged with respect to each other to form a cutting slot having a generally V-configuration to sharpen an inserted blade edge (not shown) through its movement through the slots 18. The abrasive elements 18a are affixed to a removable support 22a mounted on pivotal arm 23a by a threaded member 24a as seen in FIGS. 4, 5, 8, and 10. The opposing abrasive elements 18b are affixed to a removable support 22b mounted on a removable arm 23b by a threaded member 24b. The pivot arms 22a, 22b of both adjustable slots are pivotally mounted on pivot pin 26. As seen in FIGS. 7, 8, and 11, the arms 23a and 23b are offset from other in a lateral direction relative to the frame 4 and extend downward.
The hub 20a of the adjustment knob 20 is suitably secured to a downwardly extending rod 28 having a lower open ended reduced end portion 28a and acting as part of the adjustment actuator of the invention. A lower elongated pinion 30 is secured end portion 28a (FIGS. 5, 6 and 8-10). A spring 32 is disposed between the lower end 30a of pinion 30 and a portion of frame 4 (FIGS. 5, 8, 9 and 10) A circular plate 34 having a plurality of open engagement slots 36 arranged on its periphery for an extent of 360° is rigidly mounted on rod 28 (FIGS. 4, 8, 9, and 12). The rod 28, pinion 30, and plate 34 are mounted on frame 4 to be rotated for a predetermined range and be vertical moved a limited degree through use of knob 20 as will be apparent.
As best seen in FIGS. 8, 9, 10, 11 and 13, an angle locking bracket 40 is mounted in fixed relationship on frame 4. As seen in FIG. 13, the angle locking bracket 40 has an upper plate 42 supported on opposed pairs of spaced legs 44 which are interconnected by an opposed based members 46. A modified circular opening 48 is formed in plate 42. A cut-out area 48a exceeding the radius of opening 48 extends from a stop surface 50 to a second stop surface 52 (FIG. 11) limits the amount of rotation of shaft 28 by knob 20. To accomplish the foregoing result, vertical keys 54 exteriorly projecting on rod 28 rotates in cut-out area 48a for maximum angle of rotation as established between stop surfaces 50, 52 (FIGS. 11 and 13). Four engagement pins 60 extend downward from plate 42 of the angle locking bracket 40. In the uppermost position of knob 20 and rod 28 the pins 60 extend into four respective engagement slots 36 of circular plate 34 and lock rod 28 and pinion 30 against rotation. By pressing knob 20 downward to compress spring 32, the locked engagement slots 36 move away from the engagement pins 60 and the rod 28 and pinion 30 can be rotated to the extent determined by stops 50, 52 as they contact keys 54. The extent of rotation determines the adjustment of the sharpening angle between abrasive elements 18a and 18b of both adjustable sharpening slots.
A pair of connecting members 60,62 in the form of adjustment gear racks are mounted by suitable means on frame 4 for relative reciprocal movement in a direction perpendicular to the axis of rotation of rod 28 as seen in FIGS. 6, 8, 9, and 10. The rack 60 includes linear rack gear section 64 which engages pinion 30 at all position vertical positions of rod 28. The rack 62 includes linear rack gear section 66 and engages pinion 30 at all suitable vertical positions of rod 28. The pinion 30 moves the adjustment racks in opposite directions in either direction of rotation of rod 28 when the engagement pins are released. The end portions 60a of adjustment racks 60 include a plurality of upwardly opening slots 62a. The end portions 62a of adjustment racks 62 include a plurality of upwardly opening slots 62b (FIG. 5).
As seen in FIGS. 8 and 10, the bottom of pivot arm 23b is formed in a curvature from which four projections 70 project into corresponding slots 62a for an extent dependent on the rotational position of the pivot arm 23a as established by the relative position of the adjustment rack 60. As seen in FIG. 5, the bottom of pivot arm 23b is formed with a curvature from which four projections 72 extend into a corresponding slots 62a for an extent on the rotational position of the pivot arm 23b as established by the relative position of the adjustment rack 62. From the foregoing it should apparent that rotation of knob 20 in a clockwise direction moves rack 60 left to the right viewing FIGS. 8 and 9 to pivot arm 23a toward pivot arm 23b. Similarly, clockwise rotation of knob 20 will move adjustment rack 62 from right to left through pinion 30 to pivot arm 23b toward pivot arm 23a. Thus, the angle between abrasive elements 18a and 18b in both slots are varied. To move the pivot arms 23a, 23b away from each other the knob 20 may rotate in a counter clockwise direction viewing FIG. 7. As stated previously, the knob 20 must be depressed to release the engagement in order to permit adjustment rotation of the knob 20. Indicia elements (not shown) may be provided exteriorly adjacent the knob 20 to indicate a range of sharpening angles dependent on the extent of rotation of knob 20 and pinion gear 30. After an angle of sharpening is selected dependent on desired results, the knob is released and spring 32 urges automatic upward movement of the rod 28 and circular plate 34 so as the four engagement pins 60 are inserted into four engaging slots 36 which are in alignment with the engagement pins 60 as established by the angular relationship of pivot arms 23a, 23b in a particular adjusted position. The abrasive elements 18a, 18b in the two sharpening slots may have different abrasive properties, such as a coarser and finer abrasive quality.
Patent Application
20140120812
