Abstract:
A fixed blade knife, includes a handle, and a blade, coupled to the handle. The blade has a tang received within the handle. A plurality of lashing points defined by passages extending through both the handle and the tang are provided. The knife may be carried in a sheath with a knife sharpener removably coupled to the sheath.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a hand held knife having a fixed blade and a corresponding sheath. In particular, the present invention relates to a fixed blade knife system adapted for rugged use.  
       BACKGROUND OF THE INVENTION  
       [0002]     Fixed blade knives have a sharpened blade that is attached to a handle in any one of a variety of ways known in the art. In order to provide a secure feel and strong design, the blade typically has a tang portion that extends well into the handle. The handle sides are secured to the tang of the blade with screws or other fasteners or with an adhesive.  
         [0003]     One challenge associated with fixed blade knives relates to adapting the knives for rugged use. The rigors and strain that a fixed blade knife experiences during rugged use may damage the knife, causing the various components to become dislodged. Also, in some situations it is difficult to lash or couple a knife to a pole for use as a spear, or use the end of the knife handle as a hammer when it would be advantageous to do so. Further, a situation may arise in which the knife handle must be used to break a window, such as to aid a member of an aircrew in escaping from a disabled aircraft. Conventional knife handles may not be suited to such functionality, especially when the window is constructed of break resistant material, such as plexiglasss. Further still, many fixed blade knives are limited in that the knives cannot be safely used to cut live electrical wires.  
         [0004]     Fixed blade knifes may also be used in conjunction with sheaths. While sheaths have been provided with sharpeners for sharpening the blade of the knife, the sharpeners typically lose a certain degree of effectiveness with use.  
         [0005]     Accordingly, there is a need for a fixed blade knife that provides a stronger connection between the tang and the handle to prevent dislodging of the blade during rugged use. Further, there is a need for a fixed blade knife that can be easily and securely lashed to a pole for use as a spear. Also, there is a need for a fixed blade knife that may be used for hammering, especially hammering to break plexiglass, while minimizing the damage such use causes to the knife. There is also a need for a knife that can be safely used to cut live electrical wires. Further, there is a need for a fixed blade knife system including a sheath with an integral blade sharpener that is configured to address the issue of the loss of effectiveness of the blade sharpener.  
         [0006]     It would be desirable to provide a system and/or method that provides one or more of these or other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments that fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.  
       SUMMARY OF THE INVENTION  
       [0007]     The invention relates to a knife including a blade that is coupled to a handle. The blade includes a tang that is received within the handle. The knife also includes a plurality of lashing points defined by passages extending through both the handle and the tang.  
         [0008]     The invention further relates to a knife system including a knife, a sheath, and a knife sharpener coupled to the sheath. The knife sharpener has a housing and a number of sharpener inserts received within the housing. The sharpener inserts may be easily removed from the housing to be replaced.  
         [0009]     The invention further relates to a fixed blade knife with a handle having a body portion and a buttcap. A blade is coupled to the handle, and the handle includes a first recess in the body portion sized to receive a portion of a spear. A second recess in the buttcap is sized to receive a portion of the spear and the second recess is on the same side of the handle as the first recess.  
         [0010]     The invention is capable of other embodiments and of being practiced or being carried out in various ways. Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The invention will become more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like elements, in which:  
         [0012]      FIG. 1  is a perspective view of a fixed blade knife.  
         [0013]      FIG. 2  is a sectional view taken generally along line  2 - 2  of  FIG. 1 .  
         [0014]      FIG. 3  is a cut-away perspective view of a fixed blade knife.  
         [0015]      FIG. 4  is a top exploded view of a fixed blade knife.  
         [0016]      FIG. 5  is an elevation view of a buttcap for a fixed blade knife.  
         [0017]      FIG. 6  is an elevation view of a sheath for a fixed blade knife.  
         [0018]      FIG. 7  is a perspective view of a sharpener insert. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0019]     Referring to  FIG. 1 , according to an exemplary embodiment of the present invention, a knife  10  has a blade  12 , and a handle  14 . According to an exemplary embodiment, blade  12  may be coated or colored to reduce the visual signature of knife  10 . The handle  14  includes an outer surface  16  having a recess  18  on one or both sides of the handle  16 . Recess  18  serves to receive and align a pole or other similar object (not shown) when knife  10  is used as a spear. Handle  14  also includes guards  20  for preventing the hand of the operator from moving past handle  14  when the knife  10  is in use.  
         [0020]     Further referring to  FIG. 1 , guards  20  are provided with lashing points, shown as apertures  22  that pass through guards  20  from one side of handle  14  to the opposite side of handle  14 . Apertures  22  serve to receive rope, twine, or other bindings that may be used to secure knife  10  to a pole when knife  10  is used as a spear. The use of apertures  22  provides a more secure connection between knife  10  and the pole than simply tying a binding around knife  10  and a pole.  
         [0021]     Further referring to  FIG. 1 , a buttcap  24  is coupled to handle  14 . According to an exemplary embodiment, buttcap  24  is made of metal such as stainless steel, but other suitable materials are known in the art. Buttcap  24  is provided with an aperture  26  for receiving a lanyard and securing the lanyard to the knife. Buttcap  24  includes a dished surface  28  that defines a recess to receive a portion of a pole when the knife is used as a spear. The creation of a recess in buttcap  24  also reduces the amount of material needed to construct buttcap  24 . Buttcap  24  includes hammering surface  31  for contacting and applying a force to objects when knife  10  is used as a hammer. Buttcap  24  further includes an impact point  33 . Impact point  33  provides a small surface area over which the force of a hammering blow may be applied, permitting knife  10  to be used to break window material such as plexiglass. Such a functionality is especially useful for air crewmen who may need to break plexiglass windows to escape a downed helicopter, or for police and fire personnel to gain entry into buildings in an emergency.  
         [0022]     In the embodiment depicted in  FIG. 1 , knife  10  is a fixed blade knife adapted for rugged use. In a typical knife construction, blade  12  is made of metal, such as steel or aluminum, and the handle components may be made of a variety of materials including wood, plastic, metal, or various composites. The term “blade” is not intended to be limiting and may include various types of blades and tools, such as knife blades, saws, skinners, and so forth as is known in the art. Further, the term “handle” is intended to be a generic term referring to all of the components in the handle portion of the knife including various liners, handle sides, bolsters, frames, substrates, buttcaps, receivers, and so forth as is known in the art.  
         [0023]     Referring to  FIG. 2 , blade  12  may be integrally formed with tang  29 . Tang  29  includes lateral extensions  30 . Extensions  30  are provided with apertures  32  that align with apertures  22  in handle  14 .  
         [0024]     Further referring to  FIG. 2 , handle  14  includes a base having a substrate  34 . Substrate  34  may be made of a glass filled nylon material. The substrate  34  is covered by overmolding  36 . The overmolding  36  may be made of thermoplastic vulcanizate (TPV) or other suitable material. Tang  29  includes contact points such as indentations or negatives  38  that engage corresponding protrusions or positives  40  in substrate  34  and provide for a more secure connection between tang  29  and handle  14 . According to an alternative embodiment, the contact points could be positives extending from the tang and used to engage negatives in the substrate  34 . Tang  29  is also provided with an aperture  42  that receives a connector that is shown as, but not limited to, stud  44 . A metal screw may be used to couple substrate halves  34 , with the screw passing through aperture  42  in tang  29 . In such an embodiment, substrate material may be used to surround the screw and electrically isolate the screw from tang  29 .  
         [0025]     Further referring to  FIGS. 2 and 4 , substrate  34  physically separates tang  29  from buttcap  24 . Substrate  34  serves to absorb the shock created when knife  10  is used as a hammer. Also, substrate  34  electrically isolates tang  29  from buttcap  24  to prevent the corrosion that would be hastened by the presence of an electrochemical potential between the metal tang  29  and the metal buttcap  24 . Electrically isolating buttcap  24  from tang  29  also prevents the user&#39;s hand from being electrically coupled to the blade via the exposed metal buttcap and thus reduces the possibility of an electric shock to the user if knife  10  is used to sever an electric wire. Buttcap  24  is also provided with an aperture  48  that receives a connector that is shown as, but not limited to, stud  50 . In a particularly exemplary embodiment, a metal screw may be used to couple substrate halves  34 , with the screw passing through aperture  48  in buttcap  24 . In such an embodiment, substrate material may be used to surround the screw and electrically isolate the screw from buttcap  24 . FIG. 4  does not show the overmolding.  
         [0026]      FIG. 3  shows a cutaway view of knife  10  where one substrate half is removed to show the relative positions of buttcap  24 , substrate  34 , and blade  12 . Referring to  FIGS. 3 and 5 , buttcap  24  includes a protrusion  52 . An extension in the form of locking portion  54  extends from protrusion  52  and engages substrate  34  to secure buttcap  24  to handle  14 . Locking portion  54  may be a ring of positive material or other suitable device for interlocking with a corresponding recess in the substrate  34 .  
         [0027]     Referring to  FIG. 6 , sheath  60  is provided with tie-down points  62  for securing the sheath to an article of clothing or other object (not shown). Alternatively various clips, snaps, loops, and the like could be used as are known in the art. Sheath  60  may be constructed of a glass filled nylon material, covered with an overmolding  64 . Overmolding  64  may be made of thermoplastic vulcanizate (TPV) or other suitable material that reduces the sound created by the sheath contacting clothing or other objects. Tab  66  serves to lock knife  10  in sheath  60  by applying a force against handle  14 .  
         [0028]     Further referring to  FIG. 6 , sheath  60  is provided with a slot  68  that accommodates blade  12  when sharpening. Insert cap  70  houses sharpener inserts (see  FIG. 7 ) that contact blade  12  when sharpening. Insert cap  70  is removably coupled to sheath  60  by fastener  72 . Fastener  72  may be a screw or other such fastener that allows for relatively easy removal of insert cap  70 , and therefore creating a knife sharpener having sharpening inserts that are removably coupled to the sheath for ease of replacement. Alternatively, insert cap  70  could be placed in a receiving slot and held in place by friction.  
         [0029]     Referring to  FIG. 7 , sharpener insert  74  has a sharpening plane  76 . Sharpener insert  74  may be made of a carbide material or other suitable abrasive material. When used in sheath  60 , two inserts  74  are used in conjunction and placed such that the sharpening planes  76  form a “V” for receiving blade  12 .  
         [0030]     While the detailed drawings and specific examples given herein describe various exemplary embodiments, they serve the purpose of illustration only. It is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the preceding description or illustrated in the drawings. For example, the particular lashing points and recesses are but one way of creating a more secure connection between the knife and a pole when the two are used as a spear. Further, removable insert cap that is secured to the sheath by fasteners is shown in one embodiment, but may take other forms that permit the replacement of the sharpener. Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangements of the exemplary embodiments without departing from the scope of the invention as expressed in the appended claims.