Patent Abstract:
A pocketknife puzzle or kit is provided having a blade and spring, sandwiched between two handle sections and held in place by three pins. The pins are held in place by friction, resulting from the tension of the spring against the pivoting end of the blade. The pocketknife may be assembled and disassembled without tools.

Full Description:
[0001]    This application claims priority to provisional patent application Ser. No. 61/162,890, filed Mar. 24, 2009. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to a pocketknife puzzle or kit for making a pocketknife. The component parts may be assembled into a pocketknife, useful as a toy, letter opener or the like, and then disassembled again, as desired. 
         [0003]    Pocketknives useful as tools are well known in the prior art. The blade, spring and handles are made of metal. Rivets are employed to hold the component parts together. The pocketknives are sold assembled and are intended to remain assembled. Such a pocketknife may be disassembled only with difficulty, such as by removing the rivets with a punch, thereby damaging or destroying them. 
         [0004]    Prior art toy pocketknives have typically been sold pre-assembled and are not intended to be disassembled. Furthermore, many toy pocketknives lack features, such as a spring, to engage the pivoting end of the blade and hold the blade in a desired position, for example, open or closed. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is a three-dimensional puzzle or kit for making a pocketknife. The component parts of the pocketknife are a blade, a spring, first and second handle sections and three cylindrical fasteners. The blade has a pivoting end, with a hole therein, and a swinging end, opposite the pivoting end. The pivoting end of the blade may have a cam-shaped outer surface (cam surface). The blade need not be pointed at the swinging end or sharp, but it can be pointed and sharpened, as desired. 
         [0006]    The spring has an anchoring end, with a first hole therein, a deflecting end, opposite the anchoring end, and a second hole, positioned between the anchoring end and the deflecting end. The deflecting end of the spring is urged against the pivoting end of the blade, when the pocketknife is assembled. 
         [0007]    The handle of the pocketknife is in two sections. The first handle section has a first end, with a first hole therein, a second end, opposite the first end, with a second hole therein, and a third hole, positioned between the first and second holes. The second handle section has a first end, with a first hole therein, a second end, opposite the first end, with a second hole therein, and a third hole, positioned between the first and second holes. Three cylindrical fasteners are provided, which are configured to engage the first, second and third holes in the first and second handle sections. 
         [0008]    When the pocketknife is assembled, the blade and spring are sandwiched between the first and second handle sections. One of the cylindrical fasteners extends through the first holes in the handle sections and the hole in the pivoting end of the blade. The second cylindrical fastener extends through the second holes in the handle sections and the hole in the anchoring end of the spring. The third cylindrical fastener extends through the third holes in the handle sections and the second hole in the spring. 
         [0009]    In one embodiment of the invention, the cylindrical fasteners are selected to allow the pocketknife to be assembled and disassembled, multiple times and without damage to the fasteners. By way of example, the cylindrical fasteners may be metal pins or bolts, the bolts having a threaded end to engage a nut. The use of pins has the advantage that the component parts may be assembled to make a pocketknife, and disassembled again, without the use of tools. The pins are held in place solely by frictional engagement, as the spring is under tension itself and the spring applies tension to the pivoting end of the blade. 
         [0010]    In one embodiment of the invention, the blade, spring, first and second handles, and first, second and third cylindrical fasteners are provided unassembled in a package. This provides a child with the challenge of assembling the component parts to make a pocketknife, by following the instructions provided therewith. Preferably, the package is re-usable and is proportioned to store both the unassembled component parts or the assembled pocketknife. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is an exploded view of the pocketknife. 
           [0012]      FIG. 2  is a perspective view of the assembled pocketknife. 
           [0013]      FIG. 3  is a perspective view of an alternative embodiment of the cylindrical fasteners used to hold the pocketknife together, namely bolts and nuts. 
           [0014]      FIG. 4  is an example of suitable packaging for the component parts of the pocketknife, namely a re-usable tin box. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Without intending to limit the scope of the invention, the preferred embodiments and features are hereinafter set forth. 
         [0016]      FIG. 1  is an exploded view showing the individual component parts of the pocketknife puzzle and how the components fit together. Blade  1  has a swinging end  2  and a pivoting end  3 , shown with a point. Pivoting end  3  has a hole  4  and a cam surface  5 . 
         [0017]    Spring  6  has an anchoring end  7  and a deflecting end  8 . Spring  6  has a first hole  9  in the anchoring end  7  and a second hole  10  between the anchoring end  7  and the deflecting end  8 . The first hole  9  and second hole  10  are spaced apart to provide leverage, when the parts are assembled, whereby deflecting end  8  may be resiliently deflected, but spring  6  does not pivot about hole  10 . 
         [0018]    Blade  1  and spring  6  are sandwiched between handle sections  11  and  12 , whereby deflecting end  8  of spring  6  is urged against cam surface  5 , as blade  1  is pivoted. The force applied to the pivoting end  3  of blade  1  by spring  6  holds blade  1  in position (closed or open), as well as creates sufficient force to frictionally engage pin  13 , which is inserted through holes  14  and  15  in handles  11  and  12 , respectively, and hole  4  in blade  1 . 
         [0019]    Pin  16  is inserted through hole  17  in handle  11 , hole  9  in spring  6  and hole  18  in handle  12 . Pin  19  is inserted through hole  20  in handle  11 , hole  10  in spring  6  and hole  21  in handle  12 . The force applied to the deflecting end  8  of spring  6  by the pivoting end  3  of blade  1  is transmitted along spring  6  creating sufficient force to frictionally engage pins  16  and  19 , when the parts are assembled. 
         [0020]    Optionally, inlays  22  and  23  are provided, which conform to recesses in the outer surfaces of handles  11  and  12 , respectively. Inlays  22  and  23  are provided with holes  24  and  25 , respectively, which allows the inlays to fit over pin  19 . Inlays  22  and  23  are not frictionally engaged by pin  19 , but can be glued to the handles. 
         [0021]    Referring to  FIG. 2 , the assembled pocketknife  26  is shown. In one embodiment of the invention, each of pins  13 ,  16  and  19  is a metal rod having a uniform diameter along its length. Accordingly, the pins and other parts of the pocketknife (blade, spring and handles) can slide relative to each other, allowing the pocketknife to be assembled and disassembled without tools, and without damaging the pins. 
         [0022]    In an alternative embodiment, pins  13 ,  16  and  19  may be replaced by bolts  27  and nuts  28 , shown in  FIG. 3 . For example, nuts  28  may be inserted in handle  11  or  12 , to facilitate assembly. The bolts  27  can be unscrewed to disassemble the knife, as desired, without damaging the bolts and nuts. The cylindrical fasteners may also be a non-metal dowel or peg, or metal cotter pin. 
         [0023]    The blade, spring and handles may be made of the same or different material. By way of example, the material of construction for the blade, spring and handle may be selected from wood, thermoplastic resin, thermosetting resin or metal. The resin may be a composite, having a filler or fiber reinforcement incorporated therein. Wooden parts may be manufactured using a computer guided laser or router. For use as a child&#39;s puzzle, the blade, spring and handle are preferably non-metal. 
         [0024]    The parts of pocketknife  26  can be sold unassembled in a package. The term “package” is intended to encompass containers, such as a tin box  29 , shown in  FIG. 4  and other re-usable metal, textile and synthetic resin containers, which can accommodate all of the parts or the assembled pocketknife, as well as disposable packaging such as plastic bags or molded plastic sheets. 
         [0025]    Optionally, the pocketknife kit components can be glued together for permanency. The blade can be left dull or can be sharpened to a point. The blade may be waxed for ease of opening and closing of the blade. The components may be painted, stained or varnished before or after assembly. 
         [0026]    The invention may be further understood by reference to the following claims.

Technology Classification (CPC): 1