Abstract:
My invention is a configuration or layout for the pull-through type of knife sharpener that rotationally-stabilizes them during use as well as the sharpeners that incorporate this improvement. The improvement applies to the portable counter-top sharpeners that were primarily designed for sharpening knives. These sharpeners consist of a base with a set of blade-cutters. The blade-cutters are comprised of opposing sharpening members that form a V-notch that a knife blade is placed into and drawn through. The configuration is used to stabilize these sharpeners from the tendency to rotate both longitudinally and laterally while in use. The configuration includes three main features. The base is lengthened when compared to sharpeners of their type and the cutters are mounted on the front end on one side of the base. There is a stabilization-zone which holds a position relative to the base. Part of the handle-area is located in this stabilization zone.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of The Invention  
         [0002]     My invention directly relates to the pull-through family of knife sharpeners. These are manual knife sharpeners that are held stable to a counter-top by hand as a knife blade is pulled across generally opposing cutting elements that removes metal from both sides of the knifes edge.  
         [0003]     2. Description of the Prior Art  
         [0004]     Late in the 19th century, the rock, located near the kitchen outdoor exit, was the dominant sharpening device. In the early 20th century, the pull-through knife sharpener became the predominant kitchen sharpener. It&#39;s reign lasted until the late twentieth century. Many of the pull-through designs were designed to simply hold the sharpener up in the air with one hand while pulling the knife&#39;s edge through with the other.  
         [0005]     In the last two decades, metallurgical science has evolved and prosperity has increased. As time has gone by, knife blades started getting harder and tougher. High carbon steels were alloyed with nickel, chromium and molybdenum to make harder, tougher and primarily stainless steels. The pull-through sharpeners began failing to do the job. Knife sharpeners first began evolving by simply replacing the blade-cutters with harder materials. Higher grades of tool steel as well as tungsten carbide (a harder metal) were employed.  
         [0006]     The new materials only solved half of the new challenges. The alloys that gave the knives stain resistance also increased the toughness of the blades ten-fold. The cutting elements in the sharpeners were cutting stainless steel instead of plain high carbon steel. The difference of cutting high carbon steel to stainless steel can be compared to whittling a pine stick and whittling hardened bubble gum. The stainless alloys made steel tougher. You have to press down several times as hard on the knife blade as well pull the knife several times as hard get the job done.  
         [0007]     Suddenly, it required considerable strength to stabilize the sharpener by hand. The sharpener wants to twist in your hand both longitudinally and laterally. ( FIGS. 9 through 12  show the coordinate definitions of these directions.)  
         [0008]     Old designs became inadequate to do the job.  
         [0009]     U.S. Pat. No.  51 , 285  from 1865 in  FIG. 1  (front view) and  FIG. 2  (side view)  
         [0010]     This is the oldest on-line patent for a dual disk pull-through sharpener. The patent is dated 1865. This was almost a novelty item, a combination serving-fork and sharpener. That indicates that the “pull-through” design approach was already old at the time this patent was applied for.  
         [0011]     Observation of the design shows the long distance of the fork handle to the blade-cutter located between the fork&#39;s prongs. This design couldn&#39;t work today. You wouldn&#39;t be able to hold the fork rigid enough, while held in mid-air, to prevent movement of the fork while pulling a knife&#39;s edge through.  
         [0012]     U.S. Pat. No. 431,887 from 1890 in  FIG. 3  (Perspective view) and  4  (top view)  
         [0013]     The sharpener in this patent is one of few that were made with a long base. 95% were made with a base under on 1 inch. The reason this one had a long base was not one of stabilizing rotation. To sharpen, you pulled the knife past the cutters. This sharpener was not designed to slide over a counter-top&#39;s edge. Once the blade&#39;s tip moved past the blade-cutter, the blade slapped the base, opposed to hitting the counter-top. The location of the blade-cutter across from the handle-area failed to provide much lateral rotation stabilization; however, there was plenty of stability to accommodate knife metallurgy during that period.  
         [0014]     U.S. Pat. No. 1,762,698 from 1928 in  FIG. 5  (Top view),  FIG. 6  (front view) and  FIG. 7  (bottom view)  
         [0015]     This sharpener family had the longest and largest successful production run of any sharpener. It literally dominated the market from around the 1920&#39;s and 1930&#39;s through the 60&#39;s. I saw one for sale in the 1990, which was well beyond the useful life of the design. The reason it was still a marketable device was because of its long successful history. People were still willing to take a chance on it. It has two columns of cutter discs that run the full length of the compact, short base with a handle-area attached directly to the side of the blade-cutter.  
       BRIEF SUMMARY OF THE INVENTION  
       [0016]     There is a need for a low-cost, inexpensive, counter-top, pull-through sharpener that has been rotationally-stabilized. Rotationally-stabilizing the old designs will enable the pull-through technology to be useful with today&#39;s high alloy knives. My invention is a configuration or layout for the pull-through type of knife sharpeners that rotationally-stabilizes them. My invention also includes sharpeners that conform to this improvement.  
         [0017]     The sharpeners are the pull-through type. They are designed to rest on a counter-top and held secure by one hand while the blade of a knife is pulled past the V-notch blade-cutter with the other.  
         [0018]     The improved configuration deals with the general component layout of the sharpener as well as the base design and handle-area location. The blade-cutter is located on the front end of the sharpener&#39;s base.  
         [0019]     There is a stabilization-zone located relative to the base. By locating the handle-area within this zone, the tendency of the sharpener to rotate—can be neutralized.  
         [0020]     This invention significantly improves the pull-through type of sharpener and renews it as a viable option.  
     
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE INVENTION  
       [0021]      FIG. 1  is a front view of a prior art serving fork sharpener.  
         [0022]      FIG. 2  is a side view of a prior art serving fork sharpener.  
         [0023]      FIG. 3  is a perspective view of a prior art long-based sharpener.  
         [0024]      FIG. 4  is a top view of a prior art long-based sharpener.  
         [0025]      FIG. 5  is a top view of the most popular sharpener of prior art.  
         [0026]      FIG. 6  is a side view of the most popular sharpener of prior art.  
         [0027]      FIG. 7  is a bottom view of the most popular sharpener of prior art.  
         [0028]     FIG.,  8 A through  FIG. 21  are of the present invention  
         [0029]      FIG. 8 -A through  8 -F are perspective views of several versions of this invention&#39;s rotationally-stable sharpeners.  
         [0030]      FIG. 9  is a perspective view of an “L” based sharpener and the orientation of different views.  
         [0031]      FIG. 10  is a top view showing lateral rotation direction.  
         [0032]      FIG. 11  is a front view showing clockwise and counter-clockwise rotation direction.  
         [0033]      FIG. 12  is a side view showing longitudinal rotation.  
         [0034]      FIG. 13  is a top view of a sharpener.  
         [0035]      FIG. 14  is a side view of a sharpener.  
         [0036]      FIG. 15  is a perspective view of a sharpener over the edge of a counter-top.  
         [0037]      FIG. 16  is a perspective view of a sharpener with a knife in the beginning position  
         [0038]      FIG. 17  is a perspective view of a sharpener with a knife in ending position.  
         [0039]      FIG. 18  is a side view of a sharpener in use.  
         [0040]      FIG. 19  is a side view showing longitudinal rotational forces being applied to a sharpener.  
         [0041]      FIG. 20  is a long sharpener showing a zone where longitudinal rotation can be neutralized.  
         [0042]      FIG. 21  is a top view of a sharpener that is being stabilized longitudinally by hand.  
         [0043]      FIG. 22  shows the most popular sharpener&#39;s shape of prior art rotating laterally while in use.  
         [0044]      FIG. 23  through  FIG. 39  are of the present invention.  
         [0045]      FIG. 23  shows the location where lateral and longitudinal rotation can be cancelled.  
         [0046]      FIG. 24  shows the blade-path area of the base.  
         [0047]      FIG. 25  shows the stabilization zone&#39;s location relative to the blade-cutter.  
         [0048]      FIG. 26  is a perspective view of an “L” shaped sharpener.  
         [0049]      FIG. 27  is a perspective view of a folding “L” shaped sharpener unfolded for a right-handed person.  
         [0050]      FIG. 28  is a perspective view of a folding “L” shaped sharpener folded.  
         [0051]      FIG. 29  is a perspective view of a folding “L” shaped sharpener unfolded for a left-handed person.  
         [0052]      FIG. 30  is a perspective view of a “T” shaped sharpener.  
         [0053]      FIG. 31  is a perspective view of a rectilinear shaped sharpener.  
         [0054]      FIG. 32  is a perspective view of a rectilinear shaped sharpener with a safety wall.  
         [0055]      FIG. 33  is a perspective view of a rectilinear shaped sharpener with a front alignment tab.  
         [0056]      FIG. 34  is a perspective view of a rectilinear shaped sharpener that has a sculpted handle-area that fits the operator&#39;s hand.  
         [0057]      FIG. 35  is a perspective view of a sharpener that has a vertical handle-area.  
         [0058]      FIG. 36  shows a V-bar blade-cutter.  
         [0059]      FIG. 37  shows a one-piece V-notch blade-cutter.  
         [0060]      FIG. 38  is an exploded perspective view of multiple disc blade-cutter.  
         [0061]      FIG. 39  is a front view of a multiple disk blade-cutter.  
     
    
     DETAILED DESCRIPTION  
       [0062]     Orientation  
         [0063]     My invention is a configuration for knife sharpeners that rotationally-stabilizes them as well as many optional knife sharpeners that conform to the configuration. They will sharpen other things as well. FIGS.  8 -A through  8 -F give an overview of some of the different shapes the sharpener may take. There are several more listed in the document and many other shapes are possible within the configuration.  FIGS. 9 through 12  show the orientation terminology used in this document. All descriptions are of the sharpener or components sitting in front of you and ready for use. In  FIG. 9  there are arrows labeled front view. The view is from the perspective of a person looking in the direction of the arrow at the sharpener.  FIG. 11  is the front view, etc. All of the descriptions of the sharpeners are with a sharpener positioned on a table in front of you and oriented for use. Width is the direction between your left and right. Thickness is from top to bottom. Length is from front to back.  
       Definition of Terms  
       [0064]     Counter-top—Refers to the tops of counters, tables or any suitable working surface.  
         [0065]     Rotationally-stabilized—Old designs were stable on the clockwise/counterclockwise axes. “Rotationally-stabilized” or “rotationally-stable” refers to stability of the additional longitudinal and lateral axis of rotation.  
         [0066]     Hand-stabilized refers to a method of securing the sharpener to the counter-top. It means that there is a handle-area allocated for that use. There can also be additional means for a more permanent mount such as screw holes.  
         [0067]     A long base—Refers to the extra long base length of these sharpeners when compared to other sharpeners of this type. The sharpener base can be from  2 ” to  31 ” long.  
         [0068]     Blade-cutter—The thing that actually removes metal from the knife blade. It is made from generally opposing cutting elements that intersect and form a V-notch. The V-notch types include cutter-bar, multiple disk or file types.  
         [0069]     V-notch—The individual cutting elements are positioned in relation to each other and oriented on the base in such a way that the element&#39;s intersection looks like a generally upright “V” as seen by the operator.  
         [0070]     Cutter-vertex—This is a location on a blade-cutter. It is the intersection of the opposing cutting elements  
         [0071]     Blade-path area—It is the area of the base that the knife passes over. That&#39;s the “comfortable” area allowing for misalignment. It includes space behind the actual area the blade passes over. It runs from the front of the base to the rear of the base.  
         [0072]     Handle-area—area of the base that is/was allocated by the designer for holding the sharpener steady on a counter top by hand during use. Stabilization-zone—Zone related to the base where 2 axes of rotation can be neutralized if a handle-area is located within.  
         [0073]     “L” shaped sharpener—One can be seen in  FIG. 26 .  
         [0074]     “T” shaped sharpener—One can be seen in  FIG. 30 .  
         [0075]     A rectilinear sharpener—One can be seen in  FIG. 31 .  
         [0076]     Vertical safety wall—It is a wall between the handle-area and the blade-path area. One can be seen in  FIG. 32 .  
         [0077]     Front alignment tab—One can be seen in  FIG. 33 .  
         [0078]     Sculpted handle-area—One can be seen in  FIG. 34 .  
         [0079]     A vertical handle-area—One can be seen in  FIG. 35 .  
         [0080]     High-traction surface—This helps secure the sharpener to a counter-top. In the preferred embodiment, silicone rubber would be used; however, there are many coatings that would work.  
         [0081]     There Are Three Key Elements in the Configuration:  
         [0082]     1. The blade-cutter is located on the front of a long base.  
         [0083]     2. There is a stabilization-zone located behind the blade-cutter.  
         [0084]     3. The sharpener sits on a counter-top and is held steady by hand during use.  
         [0085]     The area of the base that&#39;s used as a handle is called the handle-area. To prevent the sharpener from rotating, some of this handle-area needs to be located in the stabilization-zone.  
         [0086]     The clearest way to define the configuration is to describe sharpeners that conform to it. The following describes a rotationally-stabilized sharpener and its design limits.  
         [0087]     The Base Details  
         [0088]     As can be seen in  FIGS. 13 and 14 , there are two main components of a sharpener (S). There is the blade-cutter ( 2 ) that removes metal from the knife blade and there is the base ( 1 ).  
         [0089]      FIG. 15  shows the normal position of the sharpener (S) positioned for use on a counter-top ( 4 ). The sharpener is placed a little past the edge of the counter to prevent cutting it.  FIGS. 16 and 17  illustrate the beginning and ending positions of a knife ( 3 ) being pulled-through the sharpener.  
         [0090]      FIG. 18  is a side view of the sharpener in use. The knife ( 3 ) is tilted down a little, pressed down and pulled back. This would cause a free-standing sharpener to rotate longitudinally and fall off of the counter-top as can be seen in  FIG. 19 .  
         [0091]     In  FIG. 20  you see the sharpener with a rectangle (Z) identified on the base. If you held the sharpener with your hand ( 5 ) in the zoned area (Z) as seen in  FIG. 21 . Longitudinal rotation would be neutralized.  
         [0092]      FIG. 22  is a top view of a wide sharpener on a counter ( 4 ) with a small zone (T) identified on the far left side of a sharpener. If one were to hold the sharpener (S) with a finger-tip located within the hatched area “T”, it would try to rotate laterally along the arc labeled “R”. If you held a sharpener in the stabilization-zone (Z) as show in  FIG. 23 , there would be no lateral rotation. By the way, notice the sharpener&#39;s footprint in this  FIG. 22 . This is the footprint of the most widely manufactured model of prior art listed in the “Description of the Prior Art” section.  
         [0093]     The base has two general areas. There is the blade-path (BP) area and the handle-area (HA).  FIG. 24  shows the knife ( 3 ) positioned over the blade-path (BP) portion of the sharpener&#39;s base. The blade-path area is the area on the base that the knife passes over. That&#39;s the “comfortable” area allowing for misalignment. It can include space behind the actual area the blade passes over. It runs from the front of the base to the rear of the base.  
         [0094]     Stabilization-Zone (Z)  
         [0095]     In  FIG. 25  you will see a V-notch blade-cutter and a box behind it. The box drawn with a dashed line represents the stabilization-zone. The stabilization zone begins a couple of inches behind the blade-cutter. It (Z) extends to the rear of the base. The blade cutter has a line labeled “CV” running through it. This line represents the intersection of the two cutting elements. It is called the cutter-vertex. The width of the stabilization zone is about two and one-half inches to either side of the cutter-vertex. The zone begins at the bottom of the base and extends upward three inches.  
         [0096]     The handle-area (HA) will be attached to the blade-path area (BP) within the stabilization zone (Z) on all sharpeners that conform to the rotationally stabilized configuration of the present invention.  
         [0097]      FIGS. 26 through 35  show some, but not all, of the basic shapes these sharpeners can take. Each sharpener has the handle area (HA) and blade-path (BP) areas of the base ( 1 ) identified.  
         [0098]      FIG. 26  is an “L” shaped sharpener. This is the preferred embodiment.  
         [0099]     In  FIGS. 27 through 29  show a convertible feature. The handle-area is positionable in relation to the blade-path. It can swap between the left and right side, or just switch between the left side and straight. This might be convenient for storage. One way to do this would be a pivot assembly or hinge.  FIGS. 27 through 29  are of an “L” shape with a pivot ( 5 ) that allows folding for storage or converting for left and right handed people.  
         [0100]      FIG. 27  is unfolded for a right-handed person.  FIG. 28  is folded and  FIG. 29  shows it unfolded for a left-handed person. A pivot would also allow for a neutral position, this would make the sharpeners base straight for storage.  
         [0101]     A pivot or hinge are two means for accomplishing this. Others would include a puzzle-piece approach or even a handle-area that slides through the blade-path portion of the base.  
         [0102]      FIG. 30  is a “T” shaped sharpener.  
         [0103]      FIG. 31  has a rectangular shape.  
         [0104]      FIG. 32  is a rectangular shape with a safety wall ( 7 ) to prevent accidents.  
         [0105]      FIG. 33  is a rectangular shape with a tab ( 6 ) in the front that butts up to a counter-top&#39;s edge.  
         [0106]      FIG. 34  shows a general rectangle shape with a sculpted handle-area ( 9 ).  
         [0107]     In  FIG. 35 , the vertical handle-area (HA) is located in the stabilization-zone (Z).  
         [0108]     Blade-Cutter ( 2 )  
         [0109]     The blade-cutter ( 2 ) is the tool that actually removes material from the knife blade. Each blade-cutter type that is supported has a V-notch that the knife is drawn through. The cutters are positioned such that the V-notch is square to the base and makes a “V” as seen by the operator. The sharpener will accommodate different V-notch blade-cutter types. The blade-cutter elements are made out of tungsten carbide in the preferred embodiment. These blade-cutter types include (but are not limited to), the V-bar type as shown in  FIG. 36 , the multiple disk, as seen in  FIG. 38 , and file types.  
         [0110]     Detailed Description of Cutter Types Supported:  
         [0111]     V-Bar Type:  
         [0112]     The blade-cutter in  FIG. 36  is composed of a left cutter bar ( 10 ) and a right cutter bar ( 11 ), which are positioned together to form a “V”. In  FIG. 36 , the cutter-bars are square. In the preferred embodiment, they are rectangular and wider than long.  
         [0113]     A one-piece V-notch blade-cutter is shown in  FIG. 37 .  
         [0114]     Multiple Disk  
         [0115]     The blade-cutter shown in  FIGS. 38 and 39  is called the multiple disk. There are two rows of disks ( 8 ) mounted to a base ( 9 ). Sometimes there are multiple disks per row.  
         [0116]     V-File  
         [0117]     The V-bar design shown in  FIG. 36  is the layout for the V-file type of blade-cutter. Flat files or round files would be substituted for the cutter bars ( 10  and  11 ).  
         [0118]     Other Possible Components  
         [0119]     Another aid is a high-traction surface on the bottom of the base. This helps secure the sharpener to a counter-top. In the preferred embodiment, silicone rubber would be used; however, there are many coatings that would work.  
         [0120]     Method of Operation  
         [0121]     In  FIG. 15  you can see the sharpener (S) positioned upon a counter-top ( 4 ) with the blade-cutter ( 2 ) upward and the edge of the sharpener hanging a little past the edge of the counter-top ( 4 ). The left hand is used to secure the sharpener to the counter-top ( 4 ) as can be seen in  FIG. 21 . A knife&#39;s ( 3 ) blade is laid in the blade-cutter&#39;s ( 2 ) V-notch, next to the handle or hilt of the knife ( 3 ) as seen in  FIG. 16 . As the sharpener is secured with the left hand, the right hand presses the blade downwards as the knife ( 3 ) is drawn back to the ending position as shown in  FIG. 17 . This is repeated until the knife is sharp. It normally takes one to two repetitions.