Patent Publication Number: US-7716839-B2

Title: Folding knife with removable blade

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation-in-part of U.S. patent application Ser. No. 10/631,920, filed Jul. 30, 2003, now U.S. Pat. No. 7,370,421 which claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/399,772 filed Jul. 30, 2002, where these applications are incorporated herein by reference in their entireties. 

   BACKGROUND OF THE INVENTION 
   Field of the Invention 
   The present invention relates generally to folding knives, and more specifically, to a folding knife with a removable blade. Folding knives are disclosed in a number of U.S. patents, including U.S. Pat. Nos. 6,145,202, 5,802,722, and 5,815,927, the disclosures of which are hereby incorporated by reference. Knives with removable blades are shown in U.S. Pat. Nos. 1,706,251, 2,265,775, 3,851,986, 3,896,546, 4,408,394, 4,918,820, 5,979,065, 6,134,788, and 6,354,007, the disclosures of which are incorporated herein by reference for all. 
   BRIEF SUMMARY OF THE INVENTION 
   According to an embodiment of the invention, a folding knife is provided, including a handle having first and second side pieces coupled in a spaced-apart relationship and rotatable, relative to each other, around a first pivot axis between an open and a closed position; a blade coupled to the handle and configured to rotate around a second pivot axis, relative to the handle, between an extended and a folded position, and configured to be removable from the handle while the first and second side pieces are rotated away from the closed position; and a fastener coupled to the second side piece and configured to rotationally lock the first and second side pieces in the closed position, and further configured to release the first side piece for rotation away from the closed position, with the fastener remaining coupled to the second side piece. 
   The fastener comprises a post coupled to the second side piece and having a pivot neck of a first diameter and a pivot collar of a second diameter, greater than the first diameter. The blade includes a pivot aperture having a diameter greater than the second diameter and a slot extending from the pivot aperture to an edge of the blade, the slot having a width greater than the first diameter but less than the second diameter, such that the blade can receive the pivot collar in the pivot aperture without permitting the post to slide through the slot. If the blade is moved such that the pivot neck is within the pivot aperture, the blade can be removed from the handle by sliding the post through the slot. 
   While the first and second side pieces are in the closed position the blade is held such that a portion of the pivot collar is within the pivot aperture. While the first and second side pieces are rotated away from the closed position, the blade is translatable to a position in which only the pivot neck is within the pivot aperture, such that the blade can be removed from the handle. 
   The first side piece includes a handle slot extending from the second pivot axis to an edge of the first side piece, a seat centered on the second pivot axis and recessed to a first depth, and a channel centered over the slot and extending from the seat to the edge of the side piece, the slot being recessed to a second depth less than the first depth. The knob is configured to move between an engaged position, wherein the knob bears against the seat, and a disengaged position, where the knob at least clears the channel such that the second side piece can be rotated away from the closed position, the post passing through the handle slot, thus allowing removal of the blade as previously described. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a side view of a folding knife according to an embodiment of the present disclosure. 
       FIG. 2  is a top view of the folding knife of  FIG. 1 . 
       FIG. 3  is an exploded isometric view of the folding knife of  FIG. 1  shown in the open position. 
       FIG. 4  is a side view of the folding knife of  FIG. 1  showing partial disassembly of the knife. 
       FIG. 5  is an enlarged fragmentary bottom view of a portion taken along line  5 - 5  of the folding knife shown in  FIG. 4 . 
       FIG. 6  is a side view of the folding knife of  FIG. 1  with the blade in a closed position. 
       FIG. 7  is an enlarged fragmentary isometric view of the opposing side of the folding knife of  FIG. 4 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to the drawings, and more specifically to  FIG. 1 , a folding knife according to an embodiment of the present disclosure is shown generally at  10 . Folding knife  10  includes a handle  12  and a blade  14 . Distal end  16  of blade  14  typically includes a sharp point or tip  18 , but may include a blunt end or other tool head. In some embodiments, the blade may be serrated or notched. Blade  14  is adapted to be folded or otherwise positioned in an open position, where the blade substantially extends from the handle  12  as shown in solid lines in  FIG. 1  and a closed position where at least a portion of the blade is received within the handle as shown by the dashed lines in  FIG. 1 . 
   In the illustrated embodiment, blade  14  includes a tang  20  that is pivotally connected to handle  12  at a pivot point  22 . Blade  14  is adapted to pivot about pivot point  22  between an open (fully-extended) position and a closed position as indicated by the arrow A. Although only an open fully-extended position and a closed position are illustrated, it should be appreciated that in some embodiments, the knife may be positioned in any number of various open and/or closed positions. 
   Blade  14  further includes a tang-protruding portion  24 . Tang-protruding portion protrudes from handle  12  when the blade is in a closed position. Tang-protruding portion  24  is adapted to aid a user in opening blade  14  from the closed position. For example, a user may push protruding portion  24  into the handle, thereby urging blade  14  out of handle  12  into the open position. Blade  14  also includes a thumb stud  26  located on one or both sides of blade  14 . Thumb stud  26  allows a user to apply a force to blade  14  further aiding in opening and/or closing of the blade. Such features are useful in one-handed assisted-opening devices and are further described in U.S. Pat. Nos. 6,145,202 and 5,802,722, the disclosures of which are incorporated by reference above. 
   It should be appreciated that the blade may be maintained in the open position by any suitable locking or retention mechanisms. For example, liner locks, sliding locks, spring locks, etc. may be used to retain the blade in a selected position. Additionally, the handle may include features which further operate to lock the blade in an open position. For example, in the embodiment shown, handle  12  includes an indentation  28  adapted to receive thumb stud  26  of blade  14  when the blade is in the open position. Indentation  28  acts as a stop for blade  14  preventing the blade from being moved or rotated beyond the fully-extended open position. Thus, in the open position, thumb stud  26  is cradled within indentation  28  of handle  12 . 
   As described in more detail below, the handle  12  includes first and second side pieces  42 ,  44 . A fastening device  30  disposed on the handle  12  is adapted to secure the first side piece  42  to the second side piece  44  and to secure the blade  14  to the handle  12 . In some embodiments, including the embodiment shown in  FIG. 1 , fastening device  30  is disposed about pivot point  22  on the front end of handle  12 . Regardless of location, fastening device  30  is adapted to be manually released by a user&#39;s hand. 
   As used herein, a manually-releasable fastening device or manipulable device includes a device that may be operated by using human force rather than mechanical force. Human force includes operation or control by skilled use of hands. For example, a manually-releasable fastening device may include a fastener adapted to be released without the use of machines or tools, such as, but not limited to, screwdrivers, wrenches, pliers, etc. 
   In the embodiment of  FIG. 1 , fastening device  30  is shown to include a knob  32 . Knob  32  may be a manipulable switch, dial, collar, socket, or lever. Manipulation of knob  32  includes rotation of the knob by the hand of the user. Rotation effectively loosens or disengages the fastening device  30  from the handle, and consequently enables the blade to be released from the handle. Counter-rotation of knob  32  functions to secure the blade to the handle. 
   In the embodiment shown in  FIG. 1 , handle  12  is adapted to interact with fastening device  30 . Handle  12  includes a receiving slot, also referred to herein as a handle slot  34 , located on the handle. The receiving slot is adapted to engage a portion of the fastening device  30 . 
   As described in more detail below, handle  12  further includes a rear connector  40  located at a rear end  38  of handle  12 , where rear end  38  is distal to pivot point  22 . The rear connector acts to secure components of the handle together. It should be noted that rear connector  40  may be capable of being selectively released to enable assembly/disassembly of handle  12 . 
   Referring to  FIG. 2 , handle  12 , first side or first side piece  42  and second side or second side piece  44  are shown. The first side piece  42  is removably coupled to the second side piece  44 . The side pieces  42 ,  44  are linked by a plurality of connectors and/or spacers. For example, the side pieces are spaced apart by a mid-anchor connector  46  and spacers  48  and  50 , which may be attached to one or both sides of handle  12 . The connectors/spacers define a hollow region or blade-receiving space  52  for receiving a portion of blade  14  when blade  14  is in a closed position relative to handle  12 . 
   As briefly described above, first side piece  42  and second side piece  44  of handle  12  are additionally connected by a rear connector  40  substantially disposed toward the rear end  38  of handle  12 . Rear connector  40  is shown to be a pin connector but may also be a bolt, a screw, a rivet, or any fastening device, and may be adapted to be released manually. It should be appreciated that other connectors may function in a similar manner as rear connector  40 . 
   In the embodiment shown, a liner  54  is disposed beside the second side piece  44  such that the liner is positioned adjacent hollow region  52 . Liner  54  includes a displaceable portion  56  that operates to lock blade  14  in an open position. The displaceable portion is biased such that the displaceable portion moves into the path of blade  14  once blade  14  has moved to a substantially-open position. The displaceable portion thus operates as a liner lock. Closing blade  14  includes disengaging or otherwise moving displaceable portion  56  of liner  54  out of the path of blade  14 . Liner locks are well known in the art. 
     FIG. 3  further illustrates the components of knife  10 . As described above, knife  10  includes a handle  12  including a plurality of connectors/spacers, such as mid-anchor connector  46 , spacers  48 ,  50 , rear connector  40 , etc. The connectors/spacers may be any suitable pin, screw, bolt, etc. that operate to define a blade-receiving space or hollow region  52  linking the sides of the handle together. According to an embodiment of the invention, the spacers  48 ,  50  are affixed to the second side piece via respective fasteners such that, when the knife  10  is disassembled, the fasteners  48 ,  50  remain attached, and also serve to hold the liner  54  in position relative to the second side piece  44 . Likewise, the mid-anchor connector  46  and the rear connector  40  are affixed to the first side piece  42  such that, when the knife  10  is disassembled, the mid-anchor connector  46  and the rear connector  40  remain attached to the first side piece  44 . 
   As shown in  FIG. 3 , mid-anchor connector  46  is configured to couple with the mid-region of the handle side pieces  42 ,  44  together by fitting into a receiving cavity  64  within handle side piece  44  and engaging a shoulder  65  therein. 
   The first side piece  42  includes a recessed seat  35  positioned concentric with the pivot point  22 , and a channel  36  extending between the seat  35  and the edge of the side piece  42 . The channel  36  is recessed to a first depth and the seat  35  is recessed to a second depth, greater than the first depth. The seat  35  is configured to receive the knob  32  as described hereafter. The slot  34  extends from the pivot point  22  to the edge of the knife, as shown in  FIGS. 3 and 4 . The second side piece  44  and the liner  54  each include an aperture  37  positioned concentric with pivot point  22 . 
   Fastening device  30  includes the knob  32  coupled with a retention pin or post  58 . Retention post  58  includes a head  67 , a pivot collar  68 , a pivot neck  70 , a threaded collar  66 , and a threaded retention aperture  69 . The retention post is press fit or otherwise fixed in the aperture  37  of the second side piece  44 . Knob  32  includes a knob recess  33  penetrating from a first side of the knob a portion of the thickness of the knob  32 , and a threaded aperture  31  between the knob recess  33  and a second side of the knob  33 . The threaded aperture  31  is adapted to engage the threaded collar  66  of retention post  58 . A threaded limiting fastener  71  is configured to engage the retention aperture  69  of the retention post  58  and serve to prevent the knob  32  from being fully removed from the post  58  when loosened. 
   A back washer  29  is shown positioned on the retention post  58  between the blade  14  and the liner  54 . While not shown, a front washer may also be included, positioned between the blade  14  and the first side piece  42 . 
   In the disclosed embodiment, the retention post  58  is received in the apertures  37  such that it extends toward the first side piece  42 . Blade  14  includes an inlet  59 , which includes a blade slot  60  and a pivot aperture  62 . Inlet  59  is adapted to engage retention post  58  via blade slot  60  in the tang of the blade. Blade slot  60  terminates in the pivot aperture  62  which is adapted to be seated around pivot collar  68  as described in more detail below. Blade  14  pivots about retention post  58  between an open and a closed position. Retention post  58  further functions to couple handle side pieces  42  and  44  together. Retention post  58  extends through apertures  37  of the second side piece  44  and liner  54 , pivot aperture  62  of the blade  14 , and slot  34  of the first side piece  42 . 
     FIGS. 4 and 5  illustrate a method of manual assembly/disassembly of blade  14  from handle  12 . The handle pieces and blade are in an engaged position when they are secured in an operable fashion by the fastening device  30 . In the embodiment shown, release of fastening device  30  is achieved by turning knob  32  in a counter-clockwise direction, as indicated by arrow R. The knob  32  is movable between an engaged position in which the knob bears against the recessed seat  35 , and a disengaged position in which an inner surface of the knob recess  33  bears against the limiting fastener  71 . Rotation of knob  32  in the counter-clockwise direction enables knob  32  to rise upwards on the threaded collar  66  of post  58  and move to the disengaged position from recessed seat  35 . 
   It should be noted the while the direction indicated for rotation of knob  32  is in the counter-clockwise direction, it is possible that device  30  may alternatively be released from the engaged position by clockwise rotation of knob  32 . Moreover, other mechanisms for releasing knob  32  may be used without departing from the scope of the invention. 
   When the knob  32  rises on the post  58  a distance exceeding a difference between the depth of the recessed seat  35  and the depth of the channel, the first side  42  of the handle is able to be rotated or pivoted away from the fastening device  30  as the retention post  58  passes through the handle slot  34 . Rotation of handle side  42  away from handle side  44  is illustrated by arrow S in  FIG. 4 . 
   After rotation of handle side  42  from handle side  44 , the blade may be disengaged from the fastening device. As described in more detail in relationship to  FIG. 5 , the blade may be slid off of or otherwise disconnected from retention post  58  of fastening device  30 . Removal of blade  14  from fastening device  30  is indicated by dashed arrow T. 
   Referring to  FIG. 5 , the circumference of pivot collar  68  is greater than the circumference of pivot neck  70 . Pivot aperture  62  of blade  14  is sized to receive pivot collar  68 . When pivot collar  68  is received within pivot aperture  62 , and clamped between the side pieces  42 ,  44  of the handle  12  via fastening mechanism  30 , blade  14  is unable to slide off of post  58  because blade slot  60  is sized to prevent pivot collar  68  from passing through slot  60 . 
   Removal of blade  14  from retention post  58  includes moving blade  14  upward in direction of arrow U and onto the comparatively narrower neck  70  of retention post  58 . Although blade slot  60  is too narrow to allow base  68  to pass through, blade slot  60  is sized such that neck  70  may pass through. Thus, upward movement of blade  14  aligns slot  60  with neck  70  such that the blade may be slid off of neck  70  and removed from retention post  58 . This can only occur when the first side piece  42  has been rotated away from the retention post  58 . 
     FIG. 5  further illustrates friction grips  72  adapted to assist a user in the release of the fastening device. For example, the friction grips may enable a user to more easily turn knob  32  by hand without the use of any tools. 
   It should be noted that in some embodiments the handle side pieces  42 ,  44  may be assembled and disassembled manually. For example, and as discussed above, the side pieces of the handle may be coupled via a rear connector  40 . Referring back to  FIG. 3 , rear connector  40  is shown to include a pin  74  which extends through a receiving aperture  76  in the first side piece  42  handle, through the rear spacer  80 , and an aperture in liner  54  to a pin slot  78  on the second side piece  44 . 
     FIG. 6  illustrates the position of the pin relative the pin slot when the knife is assembled. Specifically, pin  74  extends substantially transverse to or otherwise off set from the pin slot  78  such that the first and second side handles are secured together.  FIG. 7  illustrates a method of manually disengaging the first side piece  42  from the second side piece  44 . Specifically, first side piece  42  is rotated relative to second side piece  44 . In the rotated position, pin  74  aligns with pin slot  78  such that pin  74  may pass through pin slot  78 , thus enabling the separation of the first side piece from the second side piece. 
     FIG. 6  also illustrates mid-anchor  46  positioned within receiving cavity  64  and engaging shoulder  65 . It should be appreciated that the receiving cavity  64  is shaped to enable the rotation of the first side piece and mid-anchor  46  out of receiving cavity  64 . 
   Assembly of the knife generally follows the reverse of the disassembly method described above: the first and second side pieces  42 ,  44  are aligned in the rotated position shown in  FIG. 7 . such that the pin  74  may be inserted into pin slot  78 , after which the first side piece  42  is rotated toward engagement with the fastening device  30 , thereby securing the side pieces  42 ,  44  together. 
   The blade is attached to the handle  12  by sliding the blade slot  60  over the neck  70  of retention post  58 . Pivot aperture  62  of blade  14  is then seated onto the pivot collar  68  of retention post  58 . As the first and second side pieces  42 ,  44  are rotated toward parallel alignment, as shown in  FIG. 4 , retention post  58  is received within handle slot  34  of side piece  42 . Knob  32  is moved from the disengaged to the engaged position on retention post  58  and bearing against the seat  35  thereby securing first and second side pieces in parallel alignment, and the knife blade  14  to the handle  12 . It should be appreciated that rotation of the handle pieces into alignment causes pin  74  to rotate perpendicular to pin slot  78 , thus preventing the disengagement of handle side pieces from each other. 
   It will be appreciated that the knife  10  of the disclosed embodiment has several advantages over conventional folding knives: It can be disassembled without the use of tools; disassembly and reassembly is uncomplicated and straightforward; and when disassembled, there are no small parts that become separated from the knife  10 , inasmuch as all fasteners, washers, and spacers, are affixed to one or the other of the side pieces  42 ,  44  or held by the retention post  58 , with the knob  32  being retained by the pivot fastener  71 . These advantages make the knife  10  ideal for use in harsh environments or under conditions where it becomes necessary to service the knife in the field. For example, a user might find it necessary to disassemble the knife  10  to be thoroughly cleaned at a stream-side or in a camp. A convention knife would present difficulties, first, in disassembly without tools, and, second, in the likelihood of lost parts. 
   In describing disassembly of the knife  10 , above, a description of a field disassembly is provided. It will be recognized that a complete disassembly would include the separation of fasteners, spacers, washers, etc., from the larger components, which can be accomplished with the appropriate tools. 
   All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety. 
   From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.