Patent Publication Number: US-10307916-B2

Title: Interchangeable backspacer assembly for a knife

Description:
This application claims the benefit of U.S. Provisional Application No. 62/279,875 filed Jan. 18, 2016, the disclosure of which is hereby incorporated by reference. 
     This invention relates to knives and in particular a knife having an interchangeable back spacer assembly. 
    
    
     BACKGROUND AND SUMMARY OF THE INVENTION 
     Knife handles often use “standoffs” and “backspacers” interposed between two side members of the handle. In folding knives, standoffs and back spacers are simply used to provide the open space between the handle sides for receiving a folding blade when closed. In fixed blade knifes, standoffs and backspacers provide weight or structural integrity to the handles of fixed blade knives. 
     The interchangeable backspacer assembly of this invention allows different backspacers to be readily interchanged to selectively incorporate additional functionality into the handle of a knife. The interchangeable backspacer assembly includes a pair of standoffs and interchangeable backspacers. Different backspacers may be configured to incorporate different features and functionality, such as lanyard loops, screwdriver heads, glass breakers, pry tools, and the like. The standoffs are incorporated into the knife handle between the side members of the knife handle to form an open interior for receiving the back spacers at the distal end of the handle. Each backspacer has a pair of slots spaced and dimensioned to receive one of the standoffs. When the backspacer is inserted into the handle opening, both standoffs are seated within the slots formed in the backspacers. The backspacers are secured between the standoffs and locked in place by a single locking set screw, which abuts one of the standoffs. The standoffs provide the space for receiving the interchangeable backspacers, while maintaining the structural integrity of the knife handle when the spacer is removed. 
     The above described features and advantages, as well as others, will become more readily apparent to those of ordinary skill in the art by reference to the following detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention may take form in various system and method components and arrangement of system and method components. The drawings are only for purposes of illustrating exemplary embodiments and are not to be construed as limiting the invention. The drawings illustrate the present invention, in which: 
         FIG. 1  is a left side view of a conventional folding knife incorporating an exemplary embodiment of the interchangeable backspacer assembly of this invention; 
         FIG. 2  is an exploded perspective view of the interchangeable backspacer assembly of  FIG. 1 ; 
         FIG. 3  is a side view of the standoffs used in the interchangeable backspacer assembly of  FIG. 1 ; 
         FIG. 4  is a perspective view of the standoffs used in the interchangeable backspacer assembly of  FIG. 1 ; 
         FIG. 5  is a partial side view of the knife of  FIG. 1  with a portion cutaway showing the backspacer removed from the knife handle; 
         FIG. 6  is a partial side view of the knife of  FIG. 1  with a portion cutaway showing the backspacer fitted to the knife handle; 
         FIG. 7  is another partial side view of the knife of  FIG. 1  with a portion cutaway showing the backspacer fitted to the knife handle; 
         FIG. 8  is a partial top view of the knife of  FIG. 1  with a portion cutaway showing the backspacer fitted to the knife handle; 
         FIG. 9  is a side view of a second embodiment of the backspacer; 
         FIG. 10  is a side view of a third embodiment of the backspacer; 
         FIG. 11  is a side view of a fourth embodiment of the backspacer; 
         FIG. 12  is a side view of a fifth embodiment of the backspacer; and 
         FIG. 13  is a side view of a sixth embodiment of the backspacer. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical, structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
     Referring now to the drawings,  FIGS. 1-8  illustrate an exemplary embodiment of the interchangeable backspacer assembly  100 , which is incorporated into a conventional folding knife  10 . As shown, knife  10  includes a blade  20  pivotally coupled to a handle  30  for rotation between an open position and a closed position. Handle  30  consists of a pair of side members  32  (left and right sides) that are spaced apart to form an area  31  for receiving blade  20  therein in the closed position. Knife  10  is illustrated as a “frame-lock” style folding knife, although, other styles of folding knives, including but not limited to “lock-back” and “liner-lock” style knives may be modified within the teachings of the present invention. In addition, the teachings of this invention may be readily applied to fixed blade knives, as well. For ease of explanation, many commonly known features of folding knives are omitted in the figures and description of embodiments of the invention. For example, fasteners, such as machine screws, bolts, rivets, pins, washers, etc. are well known in the art and need not be discussed in detail. Other features are described to provide context for the embodiment described, but are not essential to the invention or particular embodiment described and are not to be construed as being essential to the claimed embodiment unless so indicated. 
     Interchangeable backspacer assembly  100  includes a pair of standoffs  110 , a removable backspacer  120  and a locking screw  140 . Standoffs  110  are integrated in the knife handle  30  between side members  32 . Backspacer  120  connects to standoffs  110  and is held within handle  30  by locking screw  140 . 
     Standoffs  110  are cast, machined or otherwise formed from a suitable metal, such as steel, brass, copper, aluminum or titanium, but may be formed from a suitable composite ceramic or polymer material. Each standoff  110  includes a cylindrical central barrel  112  and a pair of spaced annular flanges  114 . Standoffs  110  are affixed to handle  30  by a pair of screws  118 , which extend through holes in the handle side members  32  and turn into thread axial bores in the standoffs. As shown in  FIGS. 1 and 5-8 , standoffs  110  are positioned near the distal end of handle  30  and spaced apart from each other along the back edge of handle  30 . Standoffs  110  are connected between handle side members  32  to provide an opening  33  for receiving backspacer  120  at the distal end of handle  30 . 
     Backspacer  120  may be cast, cut, stamped, machined or otherwise formed from a suitable metal, but may be formed from a suitable composite ceramic or polymer material. Backspacer  120  is generally cut or stamped from a suitable sheet metal, such as steel, brass, copper, aluminum or titanium as a flat piece cut and shaped to seat between handle side members  32  and standoffs  110 . Backspacer  120  is configured to restrictively seat within handle opening  33  and conform to the shape and contour of handle  30 . Backspacer  120  has flat opposed sides and is configured to have proximal and distal ends  122  and  124 , a back edge  126  and an inner edge  128 . As shown, back edge  126  and distal end  124  of backspacer  120  are configured to correspond to and align with the contour of the top and end of handle  30  when backspacer  120  is fitted to the handle. Backspacer  120  has a pair of open-ended standoff slots  121  and  123  dimensioned to restrictively receive the central barrels  112  of standoffs  110 . Slot  121  is formed near the proximal end of backspacer  120  and slot  123  is formed near the distal end of backspacer  120 . As shown, the slots  121  and  123  are oriented to be longitudinally parallel to but spaced from each other with their open ends facing towards the proximal end of backspacer  120 . Back spacer  120  also has a set screw slot  125  formed in back edge  126  and a threaded bore  127  that extends through the body backspacer  120  between screw slot  125  and standoff slot  123 . 
     As shown in  FIGS. 1, 5-8 , backspacer  120  is removably fitted to handle  30  within handle opening  33  and secured by locking set screw  140 . Backspacer  120  slides into handle opening  33  from the rear of handle  30  ( FIG. 5 ). When fully inserted into handle opening  33 , Central barrels  112  are seated with standoff slots  121  and  123  ( FIG. 6 ). Locking set screw  140  is turned into a threaded bore  127  to secure the backspacer within handle opening  33  ( FIG. 7 ). Set screw  140  extends partially from the threaded bore  127  to abut central barrel  112  of the rearmost standoff  110 , which holds and locks backspacer  120  within handle opening  33 . Backspacer  120  is removed by simply turning locking screw  140  to retract the screw end out of engagement with the rearmost standoff  110  and manually sliding the backspacer rearward from handle  30 . 
     The backspacer assembly of this invention allows backspacers to be readily interchanged to provide varying features and functionality to the knife handle. Different backspacers can be uniquely configured with different features or functions. As shown in  FIGS. 1-8 , backspacer  120  is configured to have an integral lanyard loop  130 . Lanyard loop  130  has a slotted opening  131  for receiving a lanyard cord or other retaining device.  FIG. 9  illustrates backspacer  220  having an integral glass punch  240  extending from its distal end.  FIG. 10  illustrates backspacer  320  having an integral flat screwdriver or pry head  330  extending from the distal end.  FIG. 11  illustrates backspacer  420  includes an integral hex head  430  for use with a drive sockets.  FIG. 12  illustrates backspacer  520  having a straight distal end, which aligns flushly with the end of handle  30 , but includes central cutout  531  that houses a bit tool  530  for storage within handle opening  33 .  FIG. 13  illustrates backspacer  620  having an integral phillips head screwdriver head  630 . 
     One skilled in the art will note several advantages of the backspacer assembly of this invention. The assembly allows additional functionality to be added to the knife by interchanging backspacers. The backspacers can be configured to have different functionality, by integrating tools and features into the body and end of the backspacer. Embodiments of the back spacer may include lanyard loops, screwdriver heads, and pry tool heads. The backspacers are secured between the standoffs and locked in place by a single locking set screw. The standoffs provide the space for receiving the interchangeable backspacers in the knife handle while maintaining the structural integrity of the knife handle when the spacer is removed. 
     The embodiment of the present invention herein described and illustrated is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is presented to explain the invention so that others skilled in the art might utilize its teachings. The embodiment of the present invention may be modified within the scope of the following claims.