Abstract:
A bi-fold knife locking mechanism is provided which maintains the open and closed positions associated with the bi-fold knife. A locking and release mechanism for changing the bi-fold knife from the closed to the open position is also disclosed. An aperture in the blade portion of the bi-fold knife for ergonomically gripping the bi-fold knife is also disclosed. A locking plate for securing the locking and release mechanism and bi-fold knife in the closed position is also disclosed.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present invention claims the benefit of U.S. patent Ser. No. 29/280,614, filed Jun. 1, 2007 which is incorporated by reference in its entirety herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is related to cutting instruments, and more specifically bi-fold knives with locking and release mechanisms to maintain open and closed positions associated with the bi-fold knife. 
       BACKGROUND OF THE INVENTION 
       [0003]    Cutting instruments have been used for centuries by craftsmen, hunters, and others requiring a sharp cutting instrument. More recently, fixed length knives have been replaced with popular folding knives, including bi-fold knives, which generally have two positions. In a first extended position of use, the knife cutting blade is extended to expose the blade cutting edge and permit cutting therein. In a second closed position, the cutting edge of the blade is stored within a cavity or recess in the handle portion of the knife, thus preventing the blade from being exposed. The folding mechanism further provides a cutting instrument which is much shorter in length than a typical fixed blade knife. As discussed herein, the term “bi-fold” refers to a folding knife where the blade rotates at a hinge point on the handle and is positioned adjacent to the handle portion as depicted herein in the drawings. Although these types of knives are extremely convenient, they can potentially become dangerous if the cutting blade does not have a locking mechanism to securely keep the knife blade in the first extended position of use. Likewise, it is often convenient to have a locking mechanism or some form of frictional ball detente apparatus to prevent the knife from inadvertently opening when the knife blade is in the second closed position. 
         [0004]    Although there are other types of locking mechanisms used to prevent the inadvertent closure of a folding knife blade, none are simplistic to use, inexpensive to manufacture and are essentially fail-proof. Thus, there is a need for a type of bi-fold folding knife locking mechanism which is simplistic to use, inexpensive to manufacture, and provides substantial strength to prevent any inadvertent failure. 
       SUMMARY OF THE INVENTION 
       [0005]    It is thus an object of the present invention to provide a bi-fold knife locking mechanism which is secure and easily activated when the blade is in an extended position of use. It is a further object of the present invention that the bi-fold knife locking mechanism be designed to use a minimum number of components, thus making the locking mechanism inexpensive to manufacture, simplistic in design, and encompassing a variety of different embodiments of a bi-fold knife. 
         [0006]    Thus, in one aspect of the present invention, a bi-fold knife is provided which includes a locking mechanism for preventing movement of a folding mechanism, such as a hinge, thereby securing the bi-fold knife in an opened position. 
         [0007]    In another aspect of the invention, the locking mechanism is in operable contact with a latching mechanism, such as a detente mechanism, for securing the hingedly connected portions to one another in a closed position. 
         [0008]    In yet another aspect of the invention, the locking mechanism may be secured in its latched position (corresponding to the bi-fold knife in its closed position) by engaging a locking plate, which shifts from a first position to a second position to secure the locking mechanism from movement to release the detente mechanism. 
         [0009]    Thus, in one particular aspect or embodiment of the present invention, a bi-fold knife is provided which generally comprises: 
         [0010]    a blade having a front end and a tang; 
         [0011]    a handle having a front end and a rear end, said tang end of said blade rotatably interconnected to said front end of said handle by a hinge; 
         [0012]    a slot positioned in at least one of said hinge and said tang; 
         [0013]    a detente mechanism extending from said blade; 
         [0014]    a locking mechanism for locking said blade in a open position or a closed position, said locking mechanism rotatable about a pivot point from a first position to a second position; and 
         [0015]    wherein a latch on said locking mechanism engages said slot in said first position for locking said bi-fold knife in said open position, wherein said latch is released from said slot to allow the rotation of said blade and said handle to said closed position, and wherein said detente mechanism contacts and engages said locking mechanism for locking said blade in said closed position. 
         [0016]    In another embodiment, a bi-fold knife is provided which generally comprises: 
         [0017]    a first portion comprising at least one blade and a hinge; 
         [0018]    a second portion connected to said first portion by said hinge; 
         [0019]    a locking post extending from said first portion; 
         [0020]    a locking mechanism attached to and pivotable about at least a part of said second portion for locking said folding knife in a open position or a closed position; and 
         [0021]    wherein said locking mechanism is in operable contact with said first portion in one position for locking said folding knife in said open position, and wherein said locking mechanism is in operable contact with said locking post in another position for locking said folding knife in said closed position. 
         [0022]    In another embodiment of the present invention, an aperture in the blade portion is adapted for receiving a user&#39;s finger, wherein a portion of the knife blade is effectively used as a portion of the knife handle for gripping the cutting instrument. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is a front perspective view of a bi-fold knife, according to one embodiment of the invention; 
           [0024]      FIG. 2  is a top plan view of the bi-fold knife of  FIG. 1 ; 
           [0025]      FIG. 3  is a front elevation view of the bi-fold knife of  FIG. 1 ; 
           [0026]      FIG. 4  is a bottom plan view of the bi-fold knife of  FIG. 1 ; 
           [0027]      FIG. 5  is a rear elevation view of the bi-fold knife in  FIG. 1 ; 
           [0028]      FIG. 6  is a left elevation view of the bi-fold knife in  FIG. 1 ; 
           [0029]      FIG. 7  is a right elevation view of the bi-fold knife of  FIG. 1 ; 
           [0030]      FIG. 8  is a front elevation view of the bi-fold knife of  FIG. 3  in a closed position; 
           [0031]      FIG. 9  is a rear elevation view of the bi-fold knife of  FIG. 5  in a closed position; and 
           [0032]      FIG. 10  is a front elevation view of the bi-fold knife of  FIG. 1  with the locking mechanism in a second or released position. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    As described in detail below, various embodiments of the present invention include novel bi-fold knife designs and configurations, comprising one or more locking and release mechanisms and/or other features. Referring now to the drawings,  FIG. 1  represents one particular embodiment of the present invention and generally depicts a bi-fold knife in a first open position with the knife blade available for use. In general, the bi-fold knife  2  comprises a blade portion  44  hingedly connected to a handle portion  46 . The blade portion  44  generally comprises a blade  4  opposite a spine  14  towards its forward end. The blade portion  44  may further comprise a finger aperture  12  and a serrated edge  20 , as shown in  FIG. 1 . The handle portion  46  comprises a handle  30  and a locking mechanism  16 . The handle portion  46  is connected to the blade portion by a hinge  10  and a hinge pin  32 . The handle  30  further comprises contours  48  for placement of individual fingers to grasp the bi-fold knife  2 . 
         [0034]    Referring now to  FIG. 2 , the bi-fold knife  2  in an open position is shown in a top plan view. In one embodiment, the geometry of the bi-fold knife  2  is such that the blade portion  44  is substantially symmetrical with the handle portion  46  about an axis centered through the hinge pin  32 . The geometry of the assembly is such that when bi-fold knife  2  is in an open position, the handle portion  46  is approximately the same length as the blade portion  44 . In other words, the distance from the hinge pin  32  to the distal end of the handle portion  46  is approximately equal to the distance from the hinge pin  32  to the distal end of the blade portion  44 . As shown in  FIG. 2 , the handle portion  46  comprises a first extension  50  which creates a recessed portion for accommodating a safe placement of the blade  4  when the bi-fold knife  2  is in a closed position. The blade portion  44  in one embodiment further comprises a clip  26  for attaching to an article of clothing or a belt or the like. Also shown in  FIG. 2 , a detente mechanism  22  extends outwardly from the surface of the blade portion  44  and is positioned to contact the locking mechanism  16  to secure the bi-fold knife  2  in a closed position as described in greater detail below. 
         [0035]    As shown in  FIGS. 1 and 2 , the blade portion  44  and the handle portion  46  of bi-fold knife  2  are hingedly connected near the tang  6  of blade portion  44  by hinge  10 . The hinge  10  extends throughout the minor axis of bi-fold knife  2 , thereby allowing movement of the blade portion  44  and the handle portion  46  relative to one another such that bi-fold knife  2  may be positioned in an opened or a closed position. Hinge  10  further comprises a biasing member  38 , causing the blade portion  44  and the handle portion  46  to move axially about the hinge  10  relative to one another, which biases the bi-fold knife  2  to a normally opened position. 
         [0036]    The locking mechanism  16  provides limited movement about the lock pivot point  24  to accommodate locking of the bi-fold knife  2  in an opened position and/or release of the locking mechanism  16  to allow the bi-fold knife  2  to be closed. Locking mechanism  16  may be biased by a spring  8  located at lock pivot point  24  such that spring  8  normally biases the locking mechanism  16  in a clockwise direction. This positive rotation causes the locking mechanism  16  to become engaged with a slot  42  in hinge  10  when the bi-fold knife  2  is in a fully opened position. When locking mechanism  16  is engaged with slot  42 , the hinge  10  may not operate and the bi-fold knife  2  is maintained in an open position. Thus, bi-fold knife  2  may not be closed without first rotating locking mechanism  16  about lock pivot point  24  to disengage the locking mechanism  16  from slot  42  to allow rotation of the blade portion  44  and the handle portion  46  about the hinge pin  32 . 
         [0037]    Referring now in detail to  FIG. 3 , a front elevation view of the bi-fold knife  2  is shown. In this embodiment, the locking mechanism  16  is pivotally connected to the handle  30  at the lock pivot point  24 . Thus, the locking mechanism  16  is movable from a first position to a second position by the insertion of a finger into the finger aperture  12  and movement against a finger engagement surface  18 . This movement causes rotation of the locking mechanism  16  from a first position to a second position. Thus, the locking mechanism  16  and finger engagement surface  18  allow a finger of a user to be inserted into the finger aperture  12  of the handle portion  46  of the bi-fold knife  2 , and allow rotation of the locking mechanism  16  to become disengaged from the slot  42  to operate the hinge  10  and close the bi-fold knife  2  (as shown in relation to  FIG. 10  below). 
         [0038]    Referring now to  FIG. 4 , the locking mechanism  16  in this embodiment may further comprise an extended portion or latch for engaging the slot  42  when the locking mechanism  16  is in a second position, thereby maintaining the bi-fold knife  2  in an open position. The insertion of this extended portion of the locking mechanism  16  in the slot  42  of hinge  10  thus prevents the hinge  10  from rotating and allowing the bi-fold knife  2  to close. Once a user inserts their finger into the handle aperture and moves the locking mechanism  16  by rotation about the lock pivot point  24 , the locking mechanism  16  is removed from the slot  42 , thus allowing hinge  10  to operate and collapse the bi-fold knife  2  into a closed position. 
         [0039]    Referring now in detail to  FIG. 5 , a rear elevation of the bi-fold knife  2  is shown. The bi-fold knife  2  also comprises on the handle portion  46  a finger lock  36  positioned on the handle  30 . This finger lock  36  is movable from a first position to a second position and allows the bi-fold knife  2  to become locked in a closed position upon engagement of the detente mechanism  22  with the locking mechanism  16 , as described in greater detail below in reference to  FIGS. 8 and 9 . Also shown in  FIG. 5 , the finger aperture  12  is aligned with the contours  48  of the handle  30  such that the hand of a user may easily grip the bi-fold knife  2  such that fingers may be placed on the contours  48  shown on the handle portion  46  and one finger may be extended through the finger aperture  12  for easy purchase on the bi-fold knife  2 . This improves the ability of a user to grasp and control the bi-fold knife  2 . 
         [0040]    Referring now in detail to  FIGS. 6 and 7 , a left elevation view and right elevation view of the bi-fold knife  2  in one embodiment of the invention is shown.  FIGS. 6 and 7  depict the bi-fold knife  2  in an open position, with  FIG. 6  depicting an elevation view of the left side or the forward end of the blade portion  44  of the bi-fold knife  2 , and  FIG. 7  depicting an elevation view of the right side or rear end of the handle portion  46 . 
         [0041]    Referring now to  FIG. 8 , the bi-fold knife  2  in accordance with one embodiment is shown in a closed position. The handle  30  has been collapsed against the blade portion  44  such that the handle portion  46  is connected to the blade portion  44  by engagement of the détente mechanism  22  with the locking mechanism  16 . In one embodiment, the détente mechanism  22  is a post, which comprises a knob or other extended surface for achieving latching contact with the locking mechanism  16  when the blade portion  44  is folded to a closed position against the handle portion  46 . A finger lock  36  is provided for locking the bi-fold knife  2  in a closed position once the locking mechanism  16  is moved to a second position as shown in  FIG. 8 . A locking plate  52  (as shown ill  FIG. 3 ) is coupled to the finger lock  36 , which may be moved from a first normal position to a second locked position. In the second locked position, locking plate  52  is positioned against locking mechanism  16  to prevent further counterclockwise rotation, thereby preventing bi-fold knife  2  from being opened accidentally. This is achieved by contact between the locking plate  52  and the locking mechanism  16  in its second position to prevent the locking mechanism  16  from pivoting about the lock pivot point  24  to release the détente mechanism  22 . Once the finger lock  36  is moved back to its first normal position (and correspondingly, the locking plate  52  is moved back to its first normal position), the locking mechanism  16  is free to pivot and allow a user to open the bi-fold knife  2  to a position of use. 
         [0042]    Referring now to  FIG. 9 , another view of the bi-fold knife  2  according to one embodiment of the invention is shown in a closed position. The hinge  10  allows the blade portion  44  of the bi-fold knife  2  to fold and collapse against the handle portion  46  and the handle  30  of the bi-fold knife  2 , allowing the blade  4  to become recessed against the handle  30  and the first extension  50  such that the blade  4  is protected and shielded from contact with the user. The détente mechanism  22  engages with the locking mechanism  16  such that the locking mechanism  16  overlaps the extended portion of the détente mechanism  22  after the détente mechanism  22  contacts and slides past a sloped surface  34  of the locking mechanism  16  and engages the rear surface of the locking mechanism  16  as described in greater detail below. The détente mechanism  22  thus creates a frictional latching connection with locking mechanism  16  to retain bi-fold knife  2  in a closed position. 
         [0043]    Referring now to  FIG. 10 , another view of the bi-fold knife  2  according to one embodiment of the invention is shown with the locking mechanism  16  rotated to a position so as to disengage from hinge  10 . As can be seen from the drawing, locking mechanism  16  in one embodiment comprises an extended portion or latch  58  for engaging the slot  42  in hinge  10  when the locking mechanism  16  is in a closed or released position (as shown in  FIG. 4 ). Referring again to  FIG. 10 , however, locking mechanism  16  has been rotated so that the latch  58  is no longer engaged with slot  42 , thus allowing the hinge  10  to operate by the force provided by biasing member  38  and the bi-fold knife  2  to become closed. Furthermore, the locking mechanism  16  may be rotated to this position to release the détente mechanism  22  and return the bi-fold knife  2  to an open position after being latched in a closed position. 
         [0044]    In operation, a user may insert a finger into the finger aperture  12  and rotate the locking mechanism  16  by exerting force against the finger engagement surface  18 , thereby causing locking mechanism  16  to rotate about the lock pivot point  24  and become disengaged from the slot  42  in hinge  10 . The bi-fold knife  2  may be folded or collapsed by moving the blade portion  44  and the handle portion  46  axially so that the front surface of the blade portion  44  abuts the front surface of the handle portion  46 . The biasing member  38  exerts minimal force such that movement of the blade portion  44  and handle portion  46  axially about hinge pin  32  is easily achieved. As shown in  FIGS. 8 and 9 , the bi-fold knife  2  is maintained in a closed position by engaging the détente mechanism  22  with the locking mechanism  16 . The détente mechanism  22  is positioned on the blade portion  44  such that once bi-fold knife  2  is folded to a closed position, the détente mechanism  22  comes into contact with the sloped surface  34  of locking mechanism  16 . As the détente mechanism  22  contacts sloped surface  34 , locking mechanism  16  is biased in a generally counter-clockwise direction, allowing the détente mechanism  22  to slide along the sloped surface  34  of locking mechanism  16  and become engaged with the rear surface of locking mechanism  16 . The spring  8  about lock pivot point  24  forces locking mechanism  16  to move slightly in a generally clockwise direction after the détente mechanism  22  has contacted the sloped surface  34 , and thus the bi-fold knife  2  is secured in a closed position by latching of the détente mechanism  22  with the locking mechanism. 
         [0045]    Similarly, the bi-fold knife  2  may be easily opened and the locking mechanism  16  securely inserted into the slot  42  for maintaining the bi-fold knife  2  in an opened position. This is accomplished by contacting the finger engagement surface  18  and rotating locking mechanism  16  slightly so that it becomes disengaged with the détente mechanism  22 , thereby causing the biasing member  38  to force hinge  10  to rotate, locking mechanism  16  to engage slot  42  of hinge  10 , and bi-fold knife  2  to be secured in a position of use. 
         [0046]    To provide further clarity to the detailed description provided herein in the associated drawings, the following list of components and associated numbering are provided as follows: 
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                 Component No. 
                 Component 
               
               
                   
               
             
             
               
                 02 
                 Bi-Fold Knife 
               
               
                 04 
                 Blade 
               
               
                 06 
                 Tang 
               
               
                 08 
                 Spring 
               
               
                 10 
                 Hinge 
               
               
                 12 
                 Finger Aperture 
               
               
                 14 
                 Spine 
               
               
                 16 
                 Locking Mechanism 
               
               
                 18 
                 Finger Engagement Surface 
               
               
                 20 
                 Serrated Edge 
               
               
                 22 
                 Detente Mechanism 
               
               
                 24 
                 Lock Pivot Point 
               
               
                 26 
                 Clip 
               
               
                 28 
                 Screws 
               
               
                 30 
                 Handle 
               
               
                 32 
                 Hinge Pin 
               
               
                 34 
                 Sloped Surface 
               
               
                 36 
                 Finger Lock 
               
               
                 38 
                 Biasing Member 
               
               
                 42 
                 Slot 
               
               
                 44 
                 Blade Portion 
               
               
                 46 
                 Handle Portion 
               
               
                 48 
                 Contours 
               
               
                 50 
                 First Extension 
               
               
                 52 
                 Locking Plate 
               
               
                 58 
                 Latch 
               
               
                   
               
             
          
         
       
     
         [0047]    The foregoing description of the present invention has been presented for illustration and description purposes. However, the description is not intended to limit the invention to only the forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention. 
         [0048]    As used herein, “at least one,” “one or more,” and “and/or” are open-ended expressions that are both conjunctive and disjunctive in operation. For example, each of the expressions “at least one of A, B and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C” and “A, B, and/or C” means A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B and C together. 
         [0049]    Consequently, variations and modifications commensurate with the above teachings and skill and knowledge of the relevant art are within the scope of the present invention. The embodiments described herein above are further intended to explain best modes of practicing the invention and to enable others skilled in the art to utilize the invention in such a manner, or include other embodiments with various modifications as required by the particular application(s) or use(s) of the present invention. Thus, it is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.