Patent Publication Number: US-9902047-B1

Title: Sharpening apparatus for scissors

Description:
FIELD OF INVENTION 
     This invention relates to an apparatus for sharpening the cutting edge of a scissors blade, and more specifically to such an apparatus that is hand-held and portable for simultaneously sharpening and polishing the interior and exterior surfaces of the cutting blades of the scissors without the need for a sharpening or honing wheel or a skilled scissors sharpener. 
     BACKGROUND OF THE INVENTION 
     Scissors represent a hand-operated shearing tool used for cutting various thin materials like paper, metal, foil, plastic, or rope. They also are employed by barbers, beauticians, and pet groomers to cut hair. 
     Scissors consist of a pair of metal blades pivoted so that their sharpening edges slide against each other when the respective handles opposite to the pivot point are closed by the user&#39;s hand. The two blades having sharpened edges that cooperate when the scissor blades are closed to produce a precise cut along a material that needs to be cut. 
     But, over time, these sharpened edges of the scissors blades will become dull. Moreover, tougher or abrasive materials will cause the blades to become dull more quickly. Dull blades do not cut as easily or precisely, and can create a danger to the end user by requiring greater hand force to make a cut. Moreover, dulled blades can include rolled edges, burrs, or ragged edges with regions along the cutting surface that are out of alignment with each other. Such misaligned blades can damage the material being cut. 
     Therefore, such dulled scissors blades must be periodically sharpened. Typically, grinding wheels or whetstones have been used to restore the cutting edges along the blades of scissors. But, this constitutes a precise operation in which the angle of the cutting edge of the blade must match the angle of the whetstone or grinding wheel surface. It is easy to damage the cutting edge of the scissors blade further if the sharpening exercise is performed poorly. Thus, most scissors users need to send out their dulled scissors to a professional sharpening service, or to replace the scissors with a new pair of scissors. This can be time-consuming and expensive. 
     Other scissors users have been known to employ more humble methods for sharpening dulled scissors blades. For example, taking a pair of scissors and cutting three strips of sand paper allegedly will restore some degree of sharpness to the cutting edges due to the movement of the cutting edges against the abrasive particles on the sand paper. Other “home-grown” methods for sharpening scissors blades include cutting a pin while sliding it forward along the scissors blades, cutting a couple of strips of aluminum foil that are folded multiple times to produce a thick stack, or pushing the scissors blades against the exterior surface of a glass cylinder like a drinking glass or soda bottle while closing the scissors. However, while these methods do not require expensive equipment or technical skill, they are believed to do a better job of polishing an already-sharpened scissors blade than sharpening the blade itself. 
     U.S. Pat. No. 3,942,394 issued to Juranitch is directed to a finishing sharpener device specially designed for sharpening a knife blade. It includes a handle having a pair of wings extending therefrom. Each of the wings constitutes a flat bar defining a sharpening edge that is arcuate in cross section and smooth. By drawing a dulled knife blade cutting edge across the sharpening edge of one of the wings at the proper angle, the knife blade cutting edge may be restored to its sharpened configuration. The handle of the finishing sharpener serves as a guide for properly drawing the knife blade along the wing&#39;s sharpening edge. But, this process still requires some skill by the person sharpening the knife blade to ensure a proper match of the knife blade cutting edge angle with the angled surface of the sharpening edge of the wing. Moreover, the arcuate cross-section surface of relatively small radial extent having a highly smooth configuration is insufficient for removing material from the cutting edge of the knife blade. This finishing sharpener may only be used after the knife blade is sharpened first on a hone or grinding wheel. 
     Razor Edge Systems of Ely, Minnesota has commercialized a SCISSORSAVER device useful for sharpening, steeling, or maintaining the cutting edges of scissors blades, particularly for use in the meat processing industry. It constitutes a sharpening steel that is engaged by the dulled blades of a scissors closed against the sharpening steel. It also has a vertical post for aligning the scissors blades and providing some sharpening functionality to the interior edge of the blades. The sharpening steel is positioned above the vertical post, so that when the sharpened scissors is removed from the SCISSORSAVER device, the upper sharpening steel falls by means of gravity to return to its standby position against the vertical post. But, this SCISSORSAVER device represents a relatively large, stationary-mounted apparatus that can be positioned in front of or next to a meat processing or factory assembly line worker. It is not particularly useful for barbers, beauticians, pet groomers, crafters, florists, or home users of scissors who would benefit from a small, portable sharpening device. Furthermore, this device must be carefully installed in such a position as to ensure that the upper sharpening steel will, in fact, fall back upon the lower vertical post when the scissors is removed from the device. Otherwise, the upper sharpening steel will not be available to sharpen again a pair of scissors. 
     Therefore, it would be very advantageous to provide a sharpening apparatus that may be used by a relatively unskilled person to simultaneously sharpen the interior and exterior surfaces of the cutting edge of both blades of a scissors by hand and with minimal effort and training. Such an apparatus should be small and portable so that the person may take it out to sharpen the cutting edge of the scissors blades when needed, as opposed to mounting the sharpening apparatus in a stationary location. Moreover, the device should enable the sharpening of the blades of the scissors due to a simple closing of the scissors blades around the sharpening steels of the apparatus. Furthermore, the sharpening apparatus should automatically return itself from its sharpening position to its standby position without regard to the orientation of the device in three-dimensional space. Such a sharpening apparatus can be used to maintain an extremely sharp scissor edge for precise cutting of a material like hair without crushing or other damage with significantly reduced physical force and strain upon the user. 
     SUMMARY OF THE INVENTION 
     An apparatus for the sharpening the blades of a pair of scissors is provided according to the invention. The scissors sharpener comprises a main body having a top surface; a stationary sharpening steel having opposed surfaces that is securely attached to the main body; a bracket secured to the main body having a pivotably mounting assembly; a pivotable sharpening steel having a mounting plate connected to the pivotable mounting assembly; and a U-shaped return spring positioned between the bracket and the mounting plate of the pivotable sharpening steel. The stationary sharpening steel extends vertically above the top surface of the main body. The pivotable sharpening steel rotates with respect to the main body. When a user inserts a pair of scissors so that the inside surfaces of the two blades abut the opposed surfaces of the stationary sharpening steel, and the blades extend beyond the vertical sharpening steel positioned above and below the pivotable sharpening steel, the blades are closed against the pivotable sharpening steel to rotate the pivotable sharpening steel in a horizontal plane with respect to the main body to travel from its standby position along the blade cutting edges, while the vertical sharpening steel provides stable alignment of the scissors with respect to the scissors sharpening apparatus and sharpens the interior of the cutting edges. When the scissors blades are disengaged from the scissors sharpening apparatus, the return spring will bias the pivotable sharpening steel back to its standby position to be ready for sharpening the next pair of scissors. 
     The pivotable sharpening steel extends at an upwardly inclined angle in a vertical plane from the pivotable mounting assembly attached to the main body in order to reduce choking of the scissors blades as the pivotable sharpening steel travels along their cutting edges during the sharpening operation. The bracket mounted to the main body can also pivot with respect to the main body so that the pivotable sharpening steel rotates in a vertical plane while it is also pivoting in the horizontal plane during the scissors sharpening operation. This will further reduce potential chocking of the pivotable sharpening steel along the scissors blades during the sharpening operation. 
     The pivotable sharpening steel preferably comprises a straight segment and two curved segments where the straight segment approaches a longitudinal axis at an angle, the first curved segment is bowed away from the longitudinal axis, and the second curved segment is bowed back towards the longitudinal axis. It has been found that this curved configuration of the pivotable sharpening steel produces a sharper cutting edge along the scissors blade. In another embodiment of the invention, the first curved segment can be bowed towards the longitudinal axis, while the second curved segment bows away from the longitudinal axis. It has been found that this cured curved configuration of the pivotable sharpening steel produces a stronger finish to the sharpened cutting edge of the blade. Two sharpening apparati having these different curved configurations for the pivotable sharpening steel may be used sequentially to sharpen the cutting edges of the scissors blades, and then strengthen their finish. 
     In still another embodiment of the scissors sharpening apparatus, a horizontal niche may be formed within the top surface of the main body with the stationary sharpening steel being omitted. The horizontal niche is used to provide stable alignment of the scissors blades within the main body and with respect to the pivotable sharpening steel during the sharpening operation. The scissors blade cutting edges are sharpened by the pivotable sharpening steel as described above without the need to manipulate the scissors blades along a vertical stationary sharpening steel. This enables quicker engagement by the scissors blades with the sharpening apparatus to shorten the time required to sharpen their cutting edges. 
     The scissors sharpening apparatus of the present invention is smaller and more portable than known prior art devices. Therefore, it may be conveniently accessed and used not only by a person using a scissors on a meat packing or factory assembly line, but also by users of scissors in less industrial settings like a barber, beautician, pet groomer, florist, or crafter. Moreover, the scissors sharpener apparatus may be used quickly and conveniently without reference to its position in three-dimensional space, because unlike prior art devices, gravity is not required to return the sharpening steel to its standby position after the pair of scissors is disengaged from the device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  is a perspective view of a pair of scissors cutting a flat material like a piece of paper; 
         FIG. 2  is a perspective view of a pair of scissors in an opened position; 
         FIG. 3  is a cross-sectional view of the two blades of a pair of scissors in a partially closed position cutting the piece of paper; 
         FIG. 4  is a perspective view of a pair of scissors in an opened position with deformed edges and burrs along the blade; 
         FIG. 5  is a perspective view of the scissors sharpening device of the present invention with the user&#39;s hand and scissors blades shown in phantom lines; 
         FIG. 6  is an exploded view of the scissors sharpener of  FIG. 5 ; 
         FIG. 7  is a perspective view of the scissors sharpener of  FIG. 5  from the opposite point of view; 
         FIG. 8  is a left side elevational view of the scissors sharpener of  FIG. 5 ; 
         FIG. 9  is a front elevational view of the scissors sharpener of  FIG. 5 ; 
         FIG. 10  is a back elevational view of the scissors sharpener of  FIG. 5 ; 
         FIG. 11  is a top plan view of the scissors sharpener of  FIG. 5 ; 
         FIG. 12  is a perspective view of the pivot sleeve for the scissors sharpener; 
         FIG. 13  is a perspective view of the top surface of the spring anchor plate for the scissors sharpener; 
         FIG. 14  is a perspective view of the bottom surface of the spring anchor plate of  FIG. 13 ; 
         FIG. 15  is a perspective view of the return spring of the scissors sharpener; 
         FIG. 16  is a perspective view of the curved sharpening steel assembly, stationary sharpening steel, and anchor bracket portions of the scissors sharpener of  FIG. 5 ; 
         FIG. 17  is a perspective view of the curved sharpening steel assembly of  FIG. 16  with the spring anchor plate shown in phantom lines; 
         FIG. 18  is a perspective view of the curved sharpening steel assembly of  FIG. 16  with the anchor bracket shown in phantom lines; 
         FIG. 19  is a perspective view of the anchor bracket assembly with the spring anchor plate attached to it; 
         FIG. 20A  is a partial perspective view of the scissors sharpener of  FIG. 5  with the scissor blades starting the sharpening process; 
         FIG. 20B  is a partial perspective view of the scissors sharpener of  FIG. 20A  with the scissors blades further progressed through the sharpening process; 
         FIG. 21  is a perspective view of a second embodiment of the scissors sharpener device of the present invention; 
         FIG. 22  is a top plan view of the scissors sharpener of  FIG. 21 ; 
         FIG. 23  is a perspective view of a third embodiment of the scissors sharpener of the present invention with a longitudinal niche in lieu of the vertical stationery sharpening steel; 
         FIG. 24  is a front elevational view of the scissors sharpener of  FIG. 23 ; 
         FIG. 25A  is a partial perspective view of the scissors sharpener of  FIG. 23  with the scissors blades starting the sharpening process; and 
         FIG. 25B  is a partial perspective view of the scissors sharpener of  FIG. 25A  with the scissors blades further progressed through the sharpening process. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A small and portable apparatus for the sharpening the blades of a pair of scissors is provided according to the invention. The scissors sharpener comprises a main body having a top surface; a stationary sharpening steel having opposed surfaces that is securely attached to the main body; a bracket secured to the main body having a pivotably mounting assembly; a pivotable sharpening steel having a mounting plate connected to the pivotable mounting assembly; and a U-shaped return spring positioned between the bracket and the mounting plate of the pivotable sharpening steel. While the stationary sharpening steel extends vertically above the top surface of the main body, the pivotable sharpening steel rotates with respect to the main body. When a user inserts a pair of scissors so that the inside surfaces of the two blades abut the opposed surfaces of the stationary sharpening steel, and the blades extend beyond the vertical sharpening steel positioned above and below the pivotable sharpening steel, the blades are closed against the pivotable sharpening steel to rotate the pivotable sharpening steel in a horizontal plane with respect to the main body to travel from its standby position along the blade cutting edges. The vertical sharpening steel provides stable alignment of the scissors with respect to the scissors sharpening apparatus and sharpens the interior of the cutting edges. When the scissors blades are disengaged from the scissors sharpening apparatus, the return spring will bias the pivotable sharpening steel back to its standby position to be ready for sharpening the next pair of scissors. 
     The pivotable sharpening steel extends at an upwardly inclined angle in a vertical plane from the pivotable mounting assembly attached to the main body in order to reduce choking of the scissors blades as the pivotable sharpening steel travels along their cutting edges during the sharpening operation. The bracket mounted to the main body can also pivot with respect to the main body so that the pivotable sharpening steel rotates in a vertical plane while it is also pivoting in the horizontal plane during the scissors sharpening operation tofurther reduce potential chocking of the pivotable sharpening steel along the scissors blades during the sharpening operation. 
     The pivotable sharpening steel preferably comprises a straight segment and two curved segments. If the first curved segment is bowed away from a longitudinal axis, while the second curved segment is bowed back towards the longitudinal axis, the pivotable sharpening steel produces a sharper cutting edge along the scissors blade. If the first curved segment is bowed towards the longitudinal axis, while the second curved segment bows away from the longitudinal axis, the pivotable sharpening steel produces a stronger finish to the sharpened cutting edge of the blade. Two sharpening apparati having these different curved configurations for the pivotable sharpening steel may be used sequentially to sharpen the cutting edges of the scissors blades, and then strengthen their finish. 
     In still another embodiment of the scissors sharpening apparatus, a horizontal niche may be formed within the top surface of the main body with the stationary sharpening steel being omitted. The horizontal niche is used to provide stable alignment of the scissors blades within the main body and with respect to the pivotable sharpening steel during the sharpening operation. The scissors blade cutting edges are sharpened by the pivotable sharpening steel as described above without the need to manipulate the scissors blades along a vertical stationary sharpening steel. This enables quicker engagement by the scissors blades with the sharpening apparatus to shorten the time required to sharpen their cutting edges. 
     The scissors sharpening apparatus may be conveniently accessed and used by a person using a scissors on a meat packing or factory assembly line, as well as less industrial settings like a barber, beautician, pet groomer, florist, or crafter. Moreover, the scissors sharpener apparatus may be used quickly and conveniently without reference to its position in three-dimensional space, because unlike prior art devices, gravity is not required to return the sharpening steel to its standby position after the pair of scissors is disengaged from the device. 
     For purposes of the present invention, “cut substrate” means a material such as hair, paper, cardboard, metal foil, thin plastic, textiles, cloth, silk, rope, twine, wire, wood veneers, wood, flowers, tree or plant part, or foods like meats that is capable of being cut or trimmed by a pair of scissors. 
     As used within this Application, “scissors” means a hand-operated shearing tool having a pair of metal blades pivoted between an opened and closed position with the blades sliding against each other by means of handles opposite to the pivot point. It includes, without limitation, conventional scissors, hair-cutting scissors for trimming hair, thinning scissors for thinning hair, blade shears for cutting animal&#39;s fleece to make wool, pet groomer&#39;s shears, hobby scissors for cutting or trimming cloth, paper, plastic, wood or other materials used in sewing or hobbies, hedge trimmers, gross shears, averruncators for trimming high branches from trees, pruning shears or secateurs for trimming small branches, loppers for cutting through large branches, metal or tin snips, scissors for separating meat from an animal carcass, kitchen scissors or shears for food preparation, poultry shears for cutting cooked poultry meat, cigar cutters for cutting the tip off a cigar, nail scissors, trauma shears for emergency medical responders to cut clothing off a victim, surgical scissors for cutting human or animal flesh during surgery, and bandage scissors for cutting bandages. 
       FIG. 1  shows a pair of scissors  10  cutting a cut substrate in the form of a sheet of paper  12  along an intended cut line  14 . The produced cut line  16  is shown behind the travel path of the scissors. 
     The pair of scissors  10  is a hand-operated shearing tool that is shown more clearly in  FIG. 2 . It consists of two metal blades  20  and  22  that are pivoted with respect to each other around a pivot point. A fastener  24  like a nut and bolt or rivet is used to secure the two blades together at this pivot point. Between this pivot point and the pointed tip  26  of blade  20  lies cutting edge  28  along its bottom blade surface. Likewise, cutting edge  30  lies along the top surface of blade  22  between the pivot point and its pointed tip  32 . Attached to the opposite end of blades  20  and  22  are a pair of handles  34  and  36 . For a right-handed person, the thumb is inserted through opening  38  in handle  36 , while several fingers are inserted through opening  40  in handle  34 . When the person moves his thumb apart from the fingers to move handles  34  and  36  away from each other, blades  20  and  22  will likewise move apart from each other to move the scissors to its opened position. When the person moves his thumb and fingers together to close handles  34  and  36  against each other, then blades  20  and  22  will likewise come together and slide against each other so that sharpened edges  28  and  30  cut paper substrate  12 . 
       FIG. 3  represents a cross-sectional view of scissors  10  with blade  20  and blade  22 . Blade  20  has a flat inside surface  44 , outside surface  46 , beveled edge  48  in between and along the bottom surface of the blade, and cutting edge  28  defined by the point where beveled edge  48  meets inside surface  44 . Similarly, blade  22  has flat inside surface  50 , outside surface  52 , beveled edge  54  in between and along its top surface, and cutting edge  30  defined by the point where beveled edge  54  meets inside surface  50 . When the scissors  10  is moved by the user to its closed position, blades  20  and  22  pivot so that inside surfaces  44  and  50 , respectively, slide against each other with cutting edges  28  and  30  piercing paper  12  along the length of the portions of the blades that engage the paper. Beveled edges  48  and  54  of blades  20  and  22  act to push the cut edges  56  and  58  of the paper along cut line  16  away from each other to assist the cutting action of the scissors blades as they progress through paper substrate  12 . 
     Thus, it is cutting edge  28  and  30  on the blades  20  and  22  that need to be maintained in a sharpened state. As shown more clearly in  FIG. 4 , cutting edge  30  along scissors blade  22  should be maintained in a state with a continuous, straight edge along the length of the blade. But through usage, especially if the scissors  10  are employed to shear a tough or abrasive cutting material  12 , portions of the cutting edge may become deformed. Such deformation in the blade cutting edge  30  may create an inwardly deflected region  60  deviating towards vertical line A-A shown in  FIG. 3 . Alternatively, such deformations in the blade cutting edge may create an outwardly deflected region  62  deviating away from vertical line A-A. Such deformations cause a “dulled edge” along the scissors blade that yields a poor cut by the scissors. Even more critically, a deformed region along the scissors blade may become worse in its deflection over time to the point that its metal separates from the scissors blade to form a burr  64  along the blade. Such inwardly deflected deformations  60  and burrs  64  can impede the scissors blades  20  and  22  from smoothly gliding past each other along their interior faces  44  and  50  to prevent the scissors from being opened and closed. Moreover, the inwardly deflected deformations  60 , outwardly deflected deformations  62 , and burrs  64  along the scissors blade will crush the cut material  12  adjacent to cut line  16  as the scissors cut, instead of slicing or shearing the material with a neat and uniform cut line. Furthermore, if the scissors  10  is used to cut hair, the deformations and burrs may pull or crush the hair to produce pain and split ends in the person whose hair is being cut. Likewise, if the scissors are used to cut the stem of, e.g., a rose, these deformations and burrs can crush the cut edge of the stem to make the rose susceptible to disease and shorten the life of the flower. 
     While a piece of paper  12  has been shown as the piece of cut material sheared by the scissors for the sake of illustration, a number of other types of cut material like hair, flowers, cardboard, metal fork, plastic, textiles, cloth, silk, rope, twine, wire, wood veneers, tree or plant parts, or meat or other foods are commonly sheared by scissors, and should be understood as being fully covered by the scope of this invention. 
     The scissors sharpener  70  of the present invention is shown in  FIG. 5 . It comprises a main body  72  having a first end  71  and a second end  73 , and end body portion  74  that combine to provide a body assembly  76  that is held by the user&#39;s hand  78 . The blades  20  and  22  of scissors  10  are moved by the user&#39;s other hand (not shown) along vertical sharpening steel  80  and pivoting sharpening steel  82  to sharpen them. 
     As shown more clearly in  FIG. 6 , end body portion  74  may be connected to the distal end  73  of main body portion  72  by means of a plurality of connectors such as dowel pins  86  that are inserted into apertures  88  and  90  formed within the end body portion  74  and corresponding apertures (not shown) formed within main body portion  72 . Other means such as screws or bolts and corresponding threaded holes, or adhesives or welding may be used instead to connect the two body portions together. A single, unitary body may also be employed. By using two separate body portions, however, the end body portion  74 , e.g., may be manufactured from a different material than the material used for the main body portion  72 , or a different color than the color imparted to the main body portion to enhance the decorative appearance of the scissor sharpener  70 . 
     Formed within the bottom surface  91  of main body  72  is indented, contoured surface  92  that may be grasped by the user&#39;s thumb  77 . Meanwhile, semi-circular surfaces  94  and  96  formed within main body  72  and end body  74  portions, respectively, cooperate to form aperture  98  through which the user may insert her middle finger  70 . Finally, the opposite end surface  100  of end body portion  74  is contoured for being grasped by other fingers  81  of the user. A curved trigger  102  may also extend downwardly from end body portion  74  for being grasped by the user&#39;s ring finger  83 . In this marmer, the user can firmly and securely grasp the body assembly  76  of scissors sharpener  70  by her hand  78  to hold it in a stationary position while sliding the scissors blades  20  and  22  along the sharpening steels  80  and  82 . 
     The first end  71  of main body  72  provides attachment surfaces for the stationery sharpening steel  80  and pivotable, curved sharpening steel  82 . As shown more clearly in  FIGS. 7-8 , main body  72  contains a recessed niche  100  defined by side walls  102  and  104 , back wall  106  (not shown), and bottom wall  108 . 
     Stationary sharpening steel  80  represents a honing steel, sometimes referred to as a “sharpening steel”, “sharpening rod”, “sharpening stick”, or (in the food or cooking industry) a “butcher&#39;s steel” or “chef&#39;s steel.” It comprises a rod made from hardened steel, stainless steel or stainless steel alloy, diamond-coated steel, or ceramic. In the case of stationery sharpening steel  80 , it bears a flat cross-section characterized by two opposed faces  110  and two opposed edge surfaces  112 . When made from a carbon-containing stainless steel material like  440 C alloys (sourced, e.g., from Discount Steel of Minneapolis, Minn.) or ceramic, it bears a smoothly, highly polished surface. Optionally, it may include a plurality of longitudinal ridges. When made from diamond-coated steels, the steel material is embedded with abrasive diamond particles. Suitable diamond-coated steel or ceramic materials may be sourced from Saint-Gobain Corporation of Courbevoie, France. But, the material from which the stationary sharpening steel  80  is fabricated must have a higher tensile strength than the metal from which the blades  20  and  22  of scissors  10  are made, or else be treated to a surface hardening process. In this marmer, the functional performance of the stationary sharpening steel  80  is to realign a deformed edge  62  or  64  of the scissors blade when its length is moved along the sharpening steel  80 , rather than to remove metal from the scissors blade edge. When pressure is applied on the scissors blade against the hard sharpening steel, it will cause the blade&#39;s metal to yield to the harder sharpening steel metal or ceramic material to become realigned and sharpened. Yet, the steel surface must be super smooth in order to avoid further damage and deformation caused by the sharpening steel for the scissors blade that could create unwanted burrs along the blade edge. Thus, the stationary sharpening steel does not function like a grinding wheel, whetstone, or hone that is commonly used to remove metal burrs from a blade before it can be sharpened. 
     Stationary sharpening steel  80  is fitted inside niche  100  formed within main body  72 . A bolt or other fastener  116  is inserted through a hole (not shown) formed through the main body  72  secured at its other end by a nut (not shown). The width of opposed faces  110  of stationary sharpening steel  80  should substantially match the width of back wall  106  of niche  100  formed within main body  72  of the scissors sharpener  70 . At the same time, the width of edge surfaces  112  should be substantially less than the width of side walls  102  and  104  of the niche. In this matter, stationary sharpening rod  80  fits in vertical orientation inside niche  100 , so that its movement is arrested by side walls  102  and  104  as scissors blades are moved along the opposite faces  110  of the sharpening steel. Thus, sharpening steel  80  remains substantially stationary during use of the scissors sharpener  70 . 
     Returning to  FIG. 6 , attached to the left side  136  of the main body  72  of the scissors sharpener  70  is the pivotable, curved sharpening steel assembly  119 . It includes an L-shaped anchor bracket  120  that is connected to the lower right-side region  138  of main body  72 . This anchor bracket has vertically disposed panels  122  and  124  which are joined to each other at a roughly perpendicular angle. Panel  122  has a hole  126  (not shown) formed therein for accommodating a bolt or other fastener  128  (see  FIG. 7 ) which is inserted through hole  126  in panel  122 , a corresponding round charmel  130  (not shown) formed within main body  72 , and secured by a nut  131  (not shown) along the left-hand side  136  of the main body. In this marmer, panel  122  of anchor bracket  120  is secured to the right-hand side of main body  72  with panel  124  extending in roughly parallel relationship across the front side surface  132  of the main body. Hole  134  (see  FIG. 6 ) is formed within panel  124  in a position that extends beyond the left-hand side  136  of the main body. 
     Pivot base plate  140  constitutes an L-shaped bracket having panels  142  and  144  that are joined together in roughly perpendicular relation to each other. Panel  142  is vertically disposed and contains aperture  146 . Panel  144  contains aperture  148  near its center and aperture  150  at a peripheral location on the panel (see  FIG. 6 ). Bolt or other fastener  152  passes through aperture  134  in anchor bracket  120  and aperture  146  in pivot base plate  140  in conjunction with washer  154  and washer  156  and is secured at its other end by nut  158  (not shown) to connect the pivot base plate to the anchor bracket and in turn main body  72  of the scissors sharpener. Decorative cap  160  may be used to conceal bolt head  152 . When attached, panel  144  of pivot base plate is positioned at an upwardly inclined angle with respect to the vertical side panel  136  of the main body  72 . Moreover, this panel  44  may pivot up and down as the pivot base plate  140  rotates around the pivot axis provided by bolt fastener  152 . 
     Pivotable sharpening steel  82  comprises a curved sharpening steel arm  170  that is connected to pivot arm plate  172 . This curved sharpening steel arm  170  and pivot arm plate  172  may be separate parts, or they may be one unitary part. Pivot arm plate  172  represents a flat, semi-circular piece having aperture  174  formed therein, and a cylindrical boss  176  extending downwardly from the plate. 
     Sharpening steel arm  170  comprises a rod of steel or stainless steel, ceramic, or diamond-coated steel that is round or oval in cross-section. The length of the scissors blade determines the necessary length of the curved sharpening steel arm  170 . For example, scissors with six-inch long blades will require a curved sharpening steel arm that is approximately 3¼ inches long. A longer curved sharpening steel arm is required for scissor blades longer than six inches. At the same time, the curved regions on the sharpening steel arm  170  enable the sharpening steel arm to project a shorter lateral distance from pivot arm plate  170 , while still providing necessary exterior surface area along which the scissors blades can travel during the sharpening process, than would be the case if the sharpening steel  170  was entirely straight. 
     Like stationary sharpening steel  80 , curved sharpening steel over  170  can be made from a hardened steel, stainless steel or stainless steel allow, diamond-coated steel, or ceramic material. It is preferably made from a carbon-containing stainless steel material like  440 C alloy (sourced, e.g. from Discount Steel of Minneapolis, Minn.) with a super smooth finish. It optionally may include a series of longitudinal ridges around its exterior surface. 
     As shown more clearly in  FIGS. 9-10 , the curved sharpening steel arm  170  of pivotable sharpening steel  82  is roughly co-planar with the pivot arm plate  172 . When pivotable sharpening steel  82  is attached to pivot base plate  140 , the upwardly inclined angle of pivot base plate  140  will cause sharpening steel arm  170  to extend at an upward incline in a vertical plane from the left side of the scissors sharpener  70  past the right side, forming an angle α of approximately 20-50 degrees, preferably 30-45 degrees, formed between the lower surface of the sharpening steel arm  170  and a line parallel to the bottom surface  91  of main body  72 . 
       FIG. 11  presents a top plan view of scissors sharpener  70  showing the curved sharpening steel arm  170  in a horizontal plane. Longitudinal axis B-B roughly parallel to the front surface  132  of main body  72  of scissors sharpener  70  is also depicted. The sharpening steel arm  170  comprises three segments. First, a relatively straight segment  180  extends from pivot arm plate  172  at an angle β with respect to longitudinal B-B. Straight segment  180  passes over the top of the main body  72  of the scissors sharpener when the pivotable sharpening steel  82  is in its standby position shown in  FIG. 11 . This relatively straight segment  180  turns into an outwardly bowed segment  182  with respect to the longitudinal axis B-B. Finally, this outwardly bowed segment  182  of the sharpening steel arm  170  turns into a bowed-back region  184  that turns in an arc back towards the front end  132  of the main body  172  and away from longitudinal axis B-B. An end cap  186  is attached to the end of this bowed-back region  184  of the sharpening steel arm  170  to provide an end-point for travel of the scissors blades  20  and  22  along the sharpening steel arm  170  during the sharpening operation. 
     Turning to  FIGS. 6 and 12 , pivot sleeve  190  has an armular upper housing  192  and armular lower housing  194  with a collar  196  between the two housings. The collar has a larger diameter than that of the two housings. The interior surface  198  of armular upper housing is threaded. The interior surface  200  of armular lower housing is also threaded (not shown). 
     Spring anchor plate  210  is shown in  FIGS. 6 and 13-14 . It comprises a semi-circular, flat panel  21  having a straight edge  212  and a circular edge  214 . Aperture  216  is formed in panel  211  near straight edge  212 . Extending downwardly from the bottom surface of panel  211  is cylindrical boss  218 . 
     Return spring  220  is shown in  FIGS. 6 and 15 . It comprises a U-shaped, curved strip  222  of metal material having the required combination of rigidity and elasticity to act like a spring. Central segment  224  is partially circular. First ear segment  226  comprising a nearly closed circle is connected to one end of the U-shaped central section  224 . Second ear segment  228  also comprising a nearly closed circle is attached to the other end of the central section of the spring  220 . Such a return spring is made from “spring steel” material which may be sourced from W. W. Grainger, Inc. of Lake Forest, Ill., or McMaster-Carr Supply Company of Elmhurst, Ill. 
     In the assembled state of the pivotable sharpening steel assembly  119  (see  FIG. 6 ), curved pivot arm plate  172  of pivotable sharpening steel  82  is positioned above pivot sleeve  190 , which in turn is positioned above spring anchor plate  210 . Return spring  220  is positioned between spring anchor plate  210  and upwardly inclined panel  144  of pivot base plate  140  which is connected to the main body  72  of scissors sharpener  70  by means of anchor bracket  120 . Upper armular housing  192  of pivot sleeve  190  is inserted through aperture  174  in pivot arm plate  172  with bolt  230  screwed through aperture  174  from the top face of the pivot arm plate into engagement with internal threaded surface  198  of the pivot sleeve (see  FIG. 12 ). 
     Meanwhile, lower armular housing  194  of pivot sleeve  190  is inserted through aperture  216  in spring anchor plate  210  (see  FIGS. 13-14 ), through the circular region  238  of return spring  220  defined by central segment  224 , and through aperture  148  in upwardly inclined panel  144  of pivot base plate  140  (see  FIG. 6 ). Bolt  232  is screwed through aperture  148  from the bottom face of panel  144  into engagement with interior threaded surface  200  (not shown) of the lower armular housing  194  of the pivot sleeve  190 . 
     Boss  218  which extends downwardly from the bottom face  211  of spring anchor plate  210  (see  FIG. 14 ) passes through the open region  234  formed by first ear segment  226  of return spring  220 , and then through aperture  150  (see  FIG. 6 ) in upwardly inclined panel  144  of pivot base plate  140 . In this marmer, boss  218  provides an anchor point for the first ear segment end of the return spring  220 . 
     Meanwhile, boss  176  which extends downwardly from the bottom face of pivot arm plate  172  bypasses spring anchor plate  210 , extending past straight edge  212  of the spring anchor plate  210 , and then passes through region  236  formed by second ear segment  228  of the return spring  220 . The distal end  240  of boss  176  abuts the top surface of panel  144  of pivot base plate  140  without being secured to it. 
     Turning to  FIG. 20A , the pivotable sharpening steel  82  is shown in its standby position with its curved sharpening steel arm  170  abutting or closely adjacent to stationary sharpening steel  80 . As seen in  FIG. 9 , the upwardly inclined angle α of the curved sharpening steel  170  is approximately 20-50 degrees in the vertical plane, preferably 30-45 degrees. A pair of scissors  10  is inserted with the interior faces  44  and  50  of blades  20  and  22  abutting exterior flat surfaces  110  of vertical stationary sharpening steel  80  with blade  20  above curved sharpening steel arm  170  and blade  22  below the curved sharpening steel arm (see  FIG. 20A ). 
     When the user closes the scissors blades against this curved sharpening steel arm  170 , the applied force will cause the curved sharpening steel arm  170  to pivot in a backwards direction A away from stationary sharpening steel  80  and along the blades  20  and  22  of the scissors (see  FIG. 20B ). At the same time, the pivotable connection of pivot base plate  140  to anchor bracket  120  allows the curved sharpening steel arm  170  to move in an upwards direction B. This combination of backward and upwards pivoting by curved sharpening steel arm  170  provides improved sharpening of scissors blades  20  and  22  by the curved sharpening steel  170  and stationary sharpening steel  80  of scissors blades  20  and  22 . 
     Turning to  FIG. 11 , the curved sharpening steel arm  170  of pivotable sharpening steel  82  has the three segments: straight segment  180 , outwardly bowed segment  182 , and bowed-back segment  184 . The straight segment  180  commences the travel of the sharpening steel arm  170  along the scissors blades  20  and  22  as the blades are closed against it by the user. For a six-inch scissors blades, this straight segment  180  should be about 1-3½ inches long, preferably about 2 inches long. The back quarter of the scissors blades closest to the scissors pivot point will travel along this straight segment. 
     The sharpening steel arm  170  will travel along the length of the scissors blades until end cap  186  reaches the scissors blades to terminate the travel of the arm  170 . When the outwardly bowed segment  182  of the sharpening steel arm  170  reaches the scissors blades, the round profile of the sharpening steel starts to realign the outwardly displaced deformations  62  in scissors blades  20  and  22  (see  FIG. 4 ) to sharpen the blades, and the bowed-back segment  184  completes the task. Bowed-out segment  182  and bowed-back segment  184  provide the necessary gradual sweep of their exterior surfaces needed to accommodate the remaining three-quarters of the scissors blade length until the tip of the scissors blades contact the end cap  186  in order to sharpen the blades. If bowed-back segment  184  was straight instead of being bowed-back toward longitudinal axis B-B, the scissors blades would be choked off during the sharpening operation, which would destroy the blade edge. 
     The bowed-out segment  182  of the curved sharpening steel  170  should be about ½-1 inches in length, preferably % inch. The bowed-back segment  184  should be about ¼-¾% inches in length preferable ½ inch. 
     At the same time, the flat outside surfaces  110  of vertical stationary sharpening steel  80  act to ensure that the inside edges of the scissors blades are properly aligned to avoid any further damage to the scissors blades, and to realign the inwardly displaced deformations  60  along the scissors blades. The outwardly bowed profile of this segment  182  of the pivotable sharpening steel arm  170  enhances this sharpening action, and causes the sharpening arm to move further along the scissors blades  20  and  22 . The more sharply sloped angle of the bowed-back segment  184  of the sharpening steel arm  170  reduces choking of the scissors blades around the pivotable sharpening steel arm  170 . The upwardly sloped angle α of the pivotable sharpening steel arm  170  in the vertical plane also reduces this choking phenomenon. 
     As the sharpening steel arm  170  pivots in backwards A and upwards B directions to travel along the blades of the scissors to sharpen them, return spring  220  is stretched with its first ear segment  226  anchored in place to panel  144  of pivot base plate  140  by boss  176 , while its second ear segment  228  travels along the rotational path of pivot arm plate  172  which is attached to the pivotable sharpening steel arm  170 . When the user removes the scissors blades  20  and  22  from the pivotable sharpening steel  82  and stationary sharpening steel  80 , the memory incorporated into return spring  220  draws back second ear segment  228  to rotate pivot arm plate  172  via boss  176  back around the pivot axis defined by pivot sleeve  190  and to thereby draw the curved sharpening steel arm  170  of pivotable sharpening steel  82  back to its standby position adjacent to stationary sharpening steel  80  shown in  FIG. 20A . The scissors sharpener is now ready to receive a scissor blade to further sharpen the same pair of scissors or to sharpen another pair of scissors. 
     The structure of the scissors sharpener of the present invention therefore provides improved sharpening of both the interior and exterior surfaces of the scissors blades as the vertical sharpening steel  80  works in combination with the curved sharpening steel arm  170  which can pivot in three dimensional space both in a backwards and upwards direction. At the same time, the return spring  220  enables the pivotable sharpening steel arm  170  to be automatically returned to its standby position upon disengagement of the scissors blades from the scissors sharpener without having to rely upon gravitational force, as many prior art bench top scissors sharpener devices do the scissors sharpener  70  can actually be used upside down. This allows the scissors sharpener of the present invention to constitute a portable, hand-held model that can conveniently be used by a person in a work place without having to maintain the necessary spatial orientation of the curved sharpening steel to enable it to return to its standby position by gravitational force. There is also no need for the user to take the time to travel within the work place to an available bench top scissors sharpener. 
     Another embodiment of the scissors sharpener  240  of the present invention is shown in  FIGS. 21-22 . Its structure is similar to the scissors sharpener  70  embodiment described above, and like numbers are used for the similar elements of the scissors sharpener  240 . The primary difference is the configuration of pivotable curved sharpening steel arm  242 . Longitudinal axis C-C is depicted in  FIG. 22 . When viewed in the horizontal plane shown in  FIG. 22 , straight segment  244  is similar to straight segment  180  of the pivotable sharpening arm  170  of scissors sharpener  70 , shown in  FIG. 11 , and approaches longitudinal axis C-C at angle  7 . However, segment  246  shown in  FIG. 22  is bowed inwardly towards the front edge  132  of the scissors sharpener main body  72  and away from longitudinal axis C-C, instead of being outwardly bowed like segment  182  shown in  FIG. 11 . Segment  248  is also bowed away from longitudinal axis C-C, instead of being bowed back towards the front as in segment  184  shown in  FIG. 11 . 
     For a six-inch scissors blades, the length of straight segment  244  should be about 1-2⅜ inches, preferably about 1½-1¾ inches. Similarly, the length of bowed-in segment  246  should be about ½-1¼ inches, preferably about ½ inch. Finally, bowed-away segment  248  should be about ¼-1 inch, preferably about ½ inch. 
     This alternative curved profile for the pivotable curved sharpening steel arm  242  has been found to provide a stronger edge along the scissors blades  20  and  22 . 
     Thus, the first scissors sharpener embodiment  70  can be used to produce a sharp edge to the scissors blades. The same scissors can then be treated by the second scissors sharpener embodiment  240  to strengthen these sharpened blade edges so they last longer in use before becoming dull again. 
     Still another embodiment  260  of the present invention is shown in  FIGS. 23-25B . Its structure is similar to the scissors sharpener  70  embodiment described above, and like numbers are used for the similar elements of the scissors sharpener  260 . However, there is no stationary vertical sharpening steel  80  in the scissors sharpener  260  or vertical niche  100  for receiving such a vertical sharpening steel see  FIG. 7 ). Instead, as shown in  FIG. 23 , there is a horizontal niche  262  formed within the top surface  264  of the main body  72  of the scissors sharpener  260 . This horizontal niche  262  has a first bottom surface  266 , second bottom surface  268 , and side wall  270 . The first bottom surface is flat. Second bottom surface is also flat, but it is upwardly inclined with respect to the first bottom surface at an angle Δ with respect to the top surface  264 . Angle Δ is about 10-20 degrees, preferably about 15 degrees. 
     As shown in  FIG. 24 , side wall  270  is inclined with respect to top surface  264  of main body  72  at angle ε. Angle ε is about 65-85 degrees, preferable 75 degrees. Meanwhile, first bottom surface  266  is also upwardly inclined with respect to top surface  264 . First bottom surface  266  meets side wall  270  at approximately a 90-degree angle. 
     Turning to  FIG. 25A , the pivotable sharpening steel  82  is shown in its standby position with its curved sharpening steel area  170  forward towards the front of the scissors sharpener  260 . A pair of scissors  10  is inserted with the blade  22  set into horizontal niche  262 . The bottom of blade  22  rests on top of first bottom surface  266  and upwardly inclined second bottom surface  268 , while exterior face  52  of blade  22  rests against inclined side wall  270 . The portion of blade  22  closer to the tip is positioned below curved sharpening steel arm  170 , while the portion of blade  20  is positioned above the curved sharpening steel arm  170 . 
     When the user closes the scissors blades against this curved sharpening steel arm  170 , the applied force will cause the curved sharpening steel arm  170  to pivot in a backwards direction A away from stationary sharpening steel  80  and along the blades  20  and  22  of the scissors (see  FIG. 25B ). At the same time, the pivotable connection of pivot base plate  140  to anchor bracket  120  allows the curved sharpening steel arm  170  to move in an upwards direction B. This combination of backward and upwards pivoting by curved sharpening steel arm  170  provides improved sharpening of scissors blades  20  and  22  by the curved sharpening steel  170 . 
     Turning to  FIG. 11 , the curved sharpening steel arm  170  of pivotable sharpening steel  82  has the three segments: straight segment  180 , outwardly bowed segment  182 , and bowed-back segment  184 . The straight segment  180  commences the travel of the sharpening steel arm  170  along the scissors blades  20  and  22  as the blades are closed against it by the user. For a six-inch scissors blades, this straight segment  180  should be about 1-3½ inches long, preferably about 2 inches long. The back quarter of the scissors blades closest to the scissors pivot point will travel along this straight segment. 
     The sharpening steel arm  170  will travel along the length of the scissors blades until end cap  186  reaches the scissors blades to terminate the travel of the arm  170 . When the outwardly bowed segment  182  of the sharpening steel arm  170  reaches the scissors blades, the round profile of the sharpening steel starts to realign the outwardly displaced deformations  62  in scissors blades  20  and  22  (see  FIG. 4 ) to sharpen the blades, and the bowed-back segment  184  completes the task. Bowed-out segment  182  and bowed-back segment  184  provide the necessary gradual sweep of their exterior surfaces needed to accommodate the remaining three-quarters of the scissors blade length until the tip of the scissors blades contact the end cap  186  in order to sharpen the blades. If bowed-back segment  184  was straight instead of being bowed-back toward longitudinal axis B-B, the scissors blades would be choked off during the sharpening operation, which would destroy the blade edge. 
     The bowed-out segment  182  of the curved sharpening steel  170  should be about ½-1 inches in length, preferably ¾ inch. The bowed-back segment  184  should be about ¼-¾ inches in length preferable ¼ inch. 
     At the same time, the vertically-inclined side wall  270  and inclined first bottom surface  266  and second bottom surface  268  of horizontal niche  262  in main body  72  of scissors sharpener  260  provides stable orientation of scissors  10  to avoid any further damage to the scissors blades  20  and  22  while the blades engage the curved sharpening steel  170  to realign the inwardly displaced deformations  60  along the scissors blades. As the scissors cutting edges get sharpened and polished, they in turn will act themselves to sharpen the inside edges of the blades. In this manner the stationary sharpening steel  80  of the first and second embodiments is unnecessary. This lack of the stationary sharpening steel  80  enables faster sharpening of a pair of scissors by the user, because the user does not need to engage the scissors blades with the stationary sharpening steel before engaging them with the curved sharpening steel  270 . The outwardly bowed profile of this segment  182  of the pivotable sharpening steel arm  170  enhances this sharpening action, and causes the sharpening arm to move further along the scissors blades  20  and  22 . The more sharply sloped angle of the bowed-back segment  184  of the sharpening steel arm  170  reduces choking of the scissors blades around the pivotable sharpening steel arm  170 . The upwardly sloped angle α of the pivotable sharpening steel arm  170  in the vertical plane also reduces this choking phenomenon. 
     As the sharpening steel arm  170  pivots in backwards A and upwards B directions to travel along the blades of the scissors to sharpen them, return spring  220  is stretched with its first ear segment  226  anchored in place to panel  144  of pivot base plate  140  by boss  176 , while its second ear segment  228  travels along the rotational path of pivot arm plate  172  which is attached to the pivotable sharpening steel arm  170 . When the user removes the scissors blades  20  and  22  from the pivotable sharpening steel  82  and stationary sharpening steel  80 , the memory incorporated into return spring  220  draws back second ear segment  228  to rotate pivot arm plate  172  via boss  176  back around the pivot axis defined by pivot sleeve  190  and to thereby draw the curved sharpening steel arm  170  of pivotable sharpening steel  82  back to its standby position adjacent to stationary sharpening steel  80  shown in  FIG. 20A . The scissors sharpener is now ready to receive a scissor blade to further sharpen the same pair of scissors or to sharpen another pair of scissors. 
     The structure of the scissors sharpener of this third embodiment therefore provides improved sharpening of both the interior and exterior surfaces of the scissors blades as the horizontal niche  260  works in combination with the curved sharpening steel arm  170  which can pivot in three dimensional space both in a backwards and upwards direction. At the same time, the return spring  220  enables the pivotable sharpening steel arm  170  to be automatically returned to its standby position upon disengagement of the scissors blades from the scissors sharpener without having to rely upon gravitational force, as many prior art bench top scissors sharpener devices do the scissors sharpener  70  can actually be used upside down. This allows the scissors sharpener of the present invention to constitute a portable, hand-held model that can conveniently be used by a person in a work place without having to maintain the necessary spatial orientation of the curved sharpening steel to enable it to return to its standby position by gravitational force. There is also no need for the user to take the time to travel within the work place to an available bench top scissors sharpener. 
     The curved sharpening steel  242  of the second embodiment can be substituted for the curved sharpening steel  170  in this third embodiment in order to strengthen the cutting edges of the scissors blades  20  and  22  after they have been sharpened. 
     The above specification and associated drawings provide a complete description of the structure and operation of the scissors sharpener of the present invention. Many alternative embodiments of the invention can be made without departing from the spirit and scope of the invention. Therefore, the invention resides in the claims herein appended.