Patent Document

REFERENCE TO RELATED APPLICATION  
       [0001]    This application is related to and claims priority to U.S. Provisional ion Serial No. 60/303,542, filed Jul. 6, 2001, entitled KNIFE SHEATH, the of which is incorporated herein by reference. 
     
    
     
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
         [0002]    n/a  
         FIELD OF THE INVENTION  
         [0003]    The present invention relates to a knife sheath, and more particularly to a sheath for a curved or angled knife.  
         BACKGROUND OF THE INVENTION  
         [0004]    Knives require sheaths for varying purposes. A proper sheath requires several attrubutes. Generally, an ideal sheath conforms to the contours of the knife, and incorporates the aesthetic design and quality of the knife. Furthermore, a sheath needs to properly enclose the blade to keep it safe from outside contact or for carrying and storage. Finally, a sheath must allow for easy and reliable insertion and retraction of the knife.  
           [0005]    A problem arises in these criterion with regard to knives having various angles or curvature. Knives having blade portions disposed at an angle with respect to each other, or knives having curved blades are known as shown in FIGS. A-C. Figure A shows a knife  100  having blade  105  with a longitudinal axis  107 , and a handle  110  having a transverse axis  112  and longitudinal axis  115 . This conventional “straight” knife  100  has corresponding longitudinal axes of the blade  107  and handle  115  in parallel alignment. The angle A formed by the blade longitudinal axis  107  and handle transverse axis is a right angle. Sheaths for such knives are fairly straightforward, having a generally orthogonal configuration that follows the contours of the knife blade along the axes shown.  
           [0006]    This is in contrast with the angled or curved knives shown in FIGS. B and C. FIG. B shows a knife  120  having a blade  125 , with longitudinal axis  127 , and a handle  130  with transverse axis  132  and longitudinal axis  135 . In this case, the angle B formed between the blade longitudinal axis  127  and handle&#39;s transverse axis  132  is not a right angle. FIG. C similarly shows a curved knife  140  having a blade  145 , with a centroid  146  having a longitudinal axis  147  running therethrough, and a handle  150  with transverse axis  152  and longitudinal axis  155 . In this case, the angle C formed between the blade&#39;s longitudinal axis  147  and the handle&#39;s transverse axis  152  is also not a right angle.  
           [0007]    Placing knives such as knife  120  or knife  140  into known sheaths, such as rectangularly shaped sheaths more suited for knife  100 , presents several problems. First, the blades do not fit properly. Second, the insertion and retraction of a blade into known sheaths is difficult, with the blade being easily stuck or grated against a surface. This is especially the case with plastic blade safety covers installed in such sheaths. Furthermore, as such knives are primarily intended for kitchen use, little attention has been paid to the needs of sportsmen who may wish to carry such a knife in an easily accessed manner. Many sporting knives are carried on a belt, such that the sheath must hang freely from a belt or other fastening point. The insertion or retraction of curved or angled blades into known straight sheaths creates added problems of friction, misalignment, and awkward movement.  
           [0008]    Accordingly, it would be advantageous to provide a belt-mountable, rugged, easily-accessed sheath for a knife having an angled or curved blade and handle, allowing a user to easily insert and remove the blade into and out of the sheath.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention provides a knife sheath, comprising a hollow body for receiving a knife blade, said body having proximal and distal end portions, a mouth disposed in said proximal end portion, and a first longitudinal axis spanning the proximal and distal end portions. The sheath further includes a suspension strap having first and second end portions secured to each other and to the proximal end portion of the body, to form a loop, and a second longitudinal axis, the second longitudinal axis intersecting with the first longitudinal axis to form a first smallest angle, the first smallest angle being less than ninety degrees.  
           [0010]    Still another embodiment provides for a knife sheath comprising a sheath body having an angled mouth and a strap fixedly attached to the sheath body and forming a loop secured to the sheath body and having a longitudinal axis disposed at an angle with respect to a longitudinal axis of the sheath body, the hanging strap defining a loop extending beyond the angled mouth.  
           [0011]    Yet another embodiment provides a blade carrying tool, comprising a casing having proximal and distal end portions, the proximal end portion defining a mouth for receiving the blade, the casing having a first axis of longitude, and a carrying member having proximal and distal end portions, the distal end portion being fixedly secured to the proximal end portion of the casing, the member having a second axis of longitude, wherein the first and second axis of longitude are not aligned. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:  
         [0013]    [0013]FIG. 1A is a view of a knife having a straight blade;  
         [0014]    [0014]FIG. 1B is a view of a knife having an angled blade;  
         [0015]    [0015]FIG. 1C is a view of a knife having a curved blade;  
         [0016]    [0016]FIG. 1D is a perspective view of a knife sheath in accordance with the invention;  
         [0017]    [0017]FIG. 2 is a view of a first end thereof;  
         [0018]    [0018]FIG. 3 is a view of a second end thereof;  
         [0019]    [0019]FIG. 4 is a top view thereof;  
         [0020]    [0020]FIG. 5 is a bottom view thereof  
         [0021]    [0021]FIG. 6 is a view of a first side thereof;  
         [0022]    [0022]FIG. 7 is a view of a second side thereof; and  
         [0023]    [0023]FIG. 8 is an enlarged sectional view of the sheath taken along section  8 - 8  in FIG. 4. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]    [0024]FIG. 1D illustrates a knife sheath or covering in accordance with the present invention. The sheath includes a sheath body or scabbard  200 , having a front edge  202 , back edge  203 , tip  204 , and top edge  205 . The sheath also includes a suspension or carrying strap  210  and securing member  215 . In the illustrated embodiment, the sheath body  200  is a scabbard or casing made of a robust material such as Cordura nylon which is shaped to provide a particular profile when folded and stitched as shown. The suspension strap  210 , also made of Cordura nylon, includes a strip of material formed into a loop, stitched together at one end, and secured to the sheath body  200  at an attachment point  220 . Cordura nylon is but one of many possible materials suitable for use with the present invention. It is appreciated that several other materials may also be used without deviating from the principles of the present invention, such as plastic or polymer, metal or metal alloy, natural or synthetic fibers or fabrics, or a composite material including metals, ceramics, fabrics, fibers, polymers, or any combination thereof.  
         [0025]    As shown in FIG. 1D, the suspension strap  210  is angled with respect to the sheath body  200  with respect to the centerline axis of the sheath body  200 . The knife handle securing mechanism or strap  215  is shown as a strip of Cordura nylon passed through an opening  225  defined by the upper end of the suspension strap  210 . Although the securing strap  215  is shown as being freely slidable through the opening  225 , it can alternatively be fixedly secured thereto. Hook and pile fasteners  230  and  235 , respectively, are disposed on opposing sides of the securing strap  215  so as to be engagable when the securing strap  215  is formed into a loop.  
         [0026]    [0026]FIGS. 2 through 7 illustrate additional views of the knife sheath, wherein FIG. 2 is a view from the sheath tip  204 ; and FIG. 3 is a view from the top edge  250  of the suspension strap  210 . FIG. 4 is a plan view of the opposite side of the knife sheath presented in FIG. 1D, and FIG. 5 is a plan view of the knife sheath side as presented in FIG. 1D. FIG. 6 depicts the knife sheath from the front edge  202 , and FIG. 7 shows the opposite back edge  203  of the knife sheath.  
         [0027]    [0027]FIG. 2 shows the sheath from the top, illustrating the open mouth  270  of the sheath body  200 . The mouth  270  may be any form of opening or channel defined by the top edge  205  of the sheath body  200  so as to allow for the entry of a blade. FIG. 3 shows the sheath from the bottom, wherein the tip  204  is sown or closed. It is understood however, that the particular configuration of the mouth  270  and tip  204  may vary widely depending on the particular shape of the knife and knife blade, and is by no means limited to the particular geometries displayed in the Figures.  
         [0028]    [0028]FIG. 4 illustrates the advantageous configuration of the knife sheath shown in FIG. 1D. As shown in FIG. 4, body  200  has a longitudinal axis  300 . The top edge  250  of the securing strap  215  has a transverse axis  310  tangent to the top edge  250  of the suspension strap  210 . A second transverse axis  320 , parallel to transverse axis  310  is also shown. Each of transverse axes  310  and  320  are orthogonal to the longitudinal axis  330  of the suspension strap  210 . An additional tangential axis  340  is shown, it being tangent to the top edge  205  of the body  200 .  
         [0029]    An angle α is therefore formed between the longitudinal axis  300  of the body  200  and the longitudinal axis  330  of the suspension strap. Another angle β is formed between the tangential axis  340  and the transverse axis  320 . Although the embodiment depicted in FIGS.  1 - 7  bears the particular angles and configuration shown, the angles and relative orientation of the axes discussed herein may be varied without deviating from the principles of the invention. Angle α may vary from zero to forty-five degrees or more. Angle β may vary from zero to forty-five degrees or more. One practical range for both angles α and β is approximately two to twenty-five degrees for each. Another exemplary, yet more narrow, range for angle α would be approximately eight to fifteen degrees, while a narrower exemplary range for angle β would be approximately ten to twenty degrees. The angle α shown in FIG. 4 is approximately 10 degrees, while the angle β is approximately twelve degrees.  
         [0030]    The sheath may be utilized such that a user inserts a belt (not shown) through the loop  225  formed by the suspension strap  210 . The belt may be, for example, in alignment with transverse axes  310  and  320  and may fit therebetween. If the sheath were thus to hang from the belt, the longitudinal axis  330  of the suspension strap  210  would be in substantial alignment with a gravity vector {right arrow over (g)}. Thus the angle that the body  200  would make with gravity would be angle α, while the angle that the top edge  205  of body  200  would make with the horizontal to gravity would be angle β. It is also apparent from FIG. 4 that the tangential axis is aligned with neither the transverse axis  320 , or with a separate axis (not shown) transverse to the longitudinal axis  300  of the sheath body  200 . This easily confirmed by inspection of an angle γ between the axes  300  and  340 , in that angle γ is always less than a right angle.  
         [0031]    It is precisely because angles α and β are orientated with respect to a gravity vector {right arrow over (g)} that the knife sheath has its advantageous qualities. First, because of angle α deviating from zero degrees, a user of the sheath may be able the easily insert a curved or angled knife into the sheath using a more natural motion rather than a straight up and down motion aligned with the gravity vector. Second, because of angle β deviating from zero degrees, the handle portion of a curved or angled knife may be more easily buttressed against the top edge  205  of the sheath body  200 .  
         [0032]    [0032]FIG. 5 illustrates another plan view of the sheath shown in FIG. 4, including the body  200 , suspension strap  210  and securing strip  215 . This view of the present invention emphasizes that strap  210  may not be a loop at all, but may be a roughly “two-dimensional” carrying member, such as a simple rectangular strip as the securing strip  215 . The securing strip  215  may for example be affixed to the upper or proximal end portion of the carrying member  210  at a right angle, while the lower or distal end portion of the carrying member  210  may be affixed to the upper or proximal end portion of the body  200  at an angle commensurate with the alignments discussed above with regard to and illustrated in FIG. 4. Or the securing member  215  may be omitted entirely, and the carrying member may be provided with a hole, hook, or some other mechanism for connecting to a junction or point for carrying the sheath, wherein the sheath may then freely hang such that the axis longitude  330  of the carrying member is not aligned with the axis of longitude  300  of the sheath body or scabbard  200 .  
         [0033]    [0033]FIG. 6 is a view of the sheath from the front edge  202 . FIG. 6 also shows a knife  400  positioned alongside the sheath yet with the blade  440  outside the body  200  for ease of viewing. The knife  400  includes a handle portion  420 , which is disposed substantially parallel to and against the suspension strap  210 , such that ends of the securing strip  215  may be wrapped around the handle  420  in the direction of the arrows D as shown.  
         [0034]    [0034]FIG. 7 shows the sheath from the back edge  203  of the body  200 .  
         [0035]    Finally, FIG. 8 is a transverse sectional view of the sheath body  200 , taken along section  8 - 8  in FIG. 4. The body  200  includes an outer shell  500 , and may further include an inner shell  510  enclosing the interior space  520  of the sheath body  200 . A knife blade (not shown) inserted into the sheath body  200  will be thus disposed inside of the space  520 . The outer shell  500  may be made of a robust material such as Cordura nylon, or some other fiber, fabric, composite, or other suitable material. The outer shell  500  may be rigid or flexible, yet substantially non-deformable. The inner shell  510  may in turn be more rigid, and may be made of a suitably rigid material such as a polymer such as polyvinylchloride (PVC).  
         [0036]    The sheath may also include a series of ridges  530 , which resemble linear “bumps” or strips that run the length of the body  200  parallel to longitudinal axis  300 , and are positioned on the inner surface of inner shell  510  as shown in FIG. 8. The ridges are preferably made of a softer PVC-like material, and have a sufficient adhesive property to grip a smooth metal blade through static friction. The frictional grip imposed by the ridges  530  runs along the length of a blade, and hence provides an improved means of gripping the blade and keeping the knife inside of the sheath as desired.  
         [0037]    It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.

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