Patent Publication Number: US-2022212356-A1

Title: Folding knife with frame lock guard

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. application Ser. No. 16/573124, filed on Sep. 17, 2019, which claims the benefit of and priority to U.S. Provisional Application No. 62/732,926, filed Sep. 18, 2018, all of which are incorporated herein by reference in their entireties. 
    
    
     BACKGROUND 
     The present invention relates generally to knives. More specifically, the present invention relates to folding knives and in particular to frame lock folding knives. 
     Frame lock folding knives typically include an over-rotation inhibiting disc that is coupled to a handle, which inhibits the over rotation of a locking mechanism. However, over-rotation inhibiting discs do not inhibit a user from inadvertently actuating the locking mechanism while opening or closing the knife. This can lead to reduced user satisfaction. 
     SUMMARY 
     One embodiment relates to a knife that includes a blade and a handle assembly rotatably coupled to the blade. The handle assembly includes a side frame, a locking arm coupled to the side frame and movable between a locked position and an unlocked position and a guard. The locking arm defines an arm length. The guard is coupled to the side frame and overlays at least a portion of the locking arm. The guard defines a guard length in a direction parallel to the arm length, and a ratio of the guard length to the arm length is greater than seventy-five percent (75%). 
     Another embodiment relates to a knife that includes a blade, and a handle assembly rotatably coupled to the blade and defining a longitudinal axis. The handle assembly includes a side frame, a locking arm coupled to the side frame and movable between a locked position and an unlocked position, and a guard. The locking arm defines an arm width in a direction perpendicular to the longitudinal axis. The guard is coupled to the side frame and overlays at least a portion of the locking arm. The guard defines a guard width in a direction perpendicular to the longitudinal axis, and a ratio of the guard width to the arm width at any given position along the longitudinal axis is greater than thirty percent (30%). 
     Another embodiment relates to a knife that includes a blade, and a handle assembly rotatably coupled to the blade and defining a longitudinal axis. The handle assembly includes a handle frame, a side frame coupled to the handle frame, and a locking arm coupled to the side frame by a living hinge and movable between a locked position and an unlocked position. The living hinge biases the locking arm toward the locked position. The locking arm defines an arm width in a direction perpendicular to the longitudinal axis and an arm length in a direction parallel to the longitudinal axis. A guard is coupled to the side frame and overlays at least a portion of the locking arm. The guard defines a guard width in a direction perpendicular to the longitudinal axis and a guard length in a direction parallel to the longitudinal axis. A ratio of the guard width to the arm width at any given position along the longitudinal axis is greater than thirty percent (30%), and a ratio of the guard length to the arm length is greater than seventy-five percent (75%). 
     Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements, in which: 
         FIG. 1  is a front view of a knife in an open or deployed position, according to an exemplary embodiment. 
         FIG. 2  is a back view of the knife of  FIG. 1  in the open position. 
         FIG. 3  is a perspective detail view of the knife of  FIG. 1  in the open position. 
         FIG. 4  is an exploded view of the knife of  FIG. 1 . 
         FIG. 5  is a front view of the knife of  FIG. 1  is a closed, or stowed position. 
         FIG. 6  is a back view of the knife of  FIG. 1  in the closed position. 
         FIG. 7  is a sectional view of the knife of  FIG. 1  taken along line  7 - 7  of  FIG. 6  with a blade removed. 
         FIG. 8  is a side view of a frame lock guard of the knife of  FIG. 1 . 
         FIG. 9  is a front view of the frame lock guard of  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. 
     Referring generally to the drawings, a folding knife is shown and described that includes a blade pivotably coupled to a handle assembly and movable between a deployed, or “use” position and a stowed, or “storage” position. The handle assembly includes a side frame, a liner, and a handle frame. A locking arm is connected to the side frame by a living hinge. The locking arm is structured to move between a locked position and an unlocked position and is biased toward the locked position by the living hinge. A lock guard is connected to the side frame and partially covers the locking arm. The lock guard is positioned to inhibit a user from actuating or pressing on the locking arm while moving the blade between the use position and the storage position. 
     Referring to  FIG. 1 , a knife  20  includes a blade  24  that is rotatably coupled to a handle assembly  28 . In some examples, the blade  24  is secured to the handle assembly  28  using an axle, shown as pivot pin  32 . The blade  24  is configured to rotate about the pivot pin  32  between a stowed position (shown in  FIG. 5 ) and a deployed position (shown in  FIG. 1 ). The blade  24  can be formed of a hardened or otherwise rigid material, and is adapted for cutting, chopping, and/or slicing objects. The blade  24  can include an opening feature, shown as an opening aperture  36 , along with a cutting edge  40  and a finger choil  44 . The opening aperture  36  can be formed through the top section of the blade  24 , for example, and serves as a gripping feature to help a user grab and control the blade  24 . For example, the opening aperture  36  can be sized to receive a portion of the user&#39;s thumb for actuating the blade  24  between a deployed position and a storage position. The shape and location of the opening aperture  36  can also be varied to accommodate different blade shapes and sizes. Although shown as a negative feature (i.e., a recess or aperture), positive shapes and/or protrusions can also be incorporated into or otherwise coupled to the blade  24  to serve as an opening feature. For example, the opening feature can instead be an opening stud or cylindrical protrusion (not shown). 
     The handle assembly  28  includes a handle frame  48 . The handle frame  48  is shaped to receive at least a portion of the blade  24 , and can be further contoured to provide ergonomic comfort to the user while using and/or grasping the knife  20 . As shown in  FIG. 2 , the handle assembly  28  includes a side frame  52  positioned on an opposite side of the knife  20  from the handle frame  48 . The side frame  52  and handle frame  48  are spaced apart from one another and extend approximately parallel to one another along the length of the knife  20 . The side frame  52  and handle frame  48  together define a cavity  50  that is configured to receive a portion of the blade  24 , including the cutting edge  40 , when the blade  24  is in the storage position. 
     The side frame  52  includes a locking arm  56  connected to the side frame  52  by a living hinge  60 . The locking arm  56  prevents unwanted rotation of the blade  24  from the deployed position into the storage position by blocking the rotation of the blade  24  relative to the handle assembly  28 . The locking arm  56  is actuatable between a locked position (shown in  FIG. 2 ) and an unlocked position (shown in  FIG. 6 ). The living hinge  60  biases the locking arm  56  inward, toward the locked position. The inward bias of the locking arm  56  causes the locking arm  56  to engage the blade  24  in the storage position, creating interference and friction that resists unwanted rotation of the blade  24  away from the handle assembly  28 . Pulling on the blade  24  (e.g., by grabbing the opening aperture  36 ) can overcome the inward bias of the locking arm  56 . As the blade  24  rotates, contact between the blade  24  and locking arm  56  flexes the locking arm  56  outward, toward the unlocked position, which allows the blade  24  to rotate. Once the blade  24  has rotated beyond the locking arm  56 , the natural bias of the living hinge  60  returns the locking arm  56  to the inward, locked position, where the locking arm  56  engages a tang  42  of the blade  24  and resists rotation of the blade  24  relative to the handle assembly  28 . 
     The handle assembly  28  can also include mounting features that allow a user to readily access and stow the knife. For example, a pocket clip  64  can be fastened to the side frame  52 . The pocket clip  64  is sized to engage a pocket of the user&#39;s pants to hold the knife  20  in place. The pocket clip  64  can be secured to the handle assembly  28  using screws or other fasteners, which are anchored to the side frame  52 . The side frame  52  and handle frame  48  can be formed of various materials, including metallic materials (e.g., aluminum), polymeric materials (e.g., G10 nylon), composite materials (e.g., carbon fiber), or some combination of these materials. 
     In addition to the locking arm  56  and pocket clip  64 , the side frame  52  also defines a guard recess  68 . The guard recess  68  can extend into the side frame  52 , and can have a generally concave shape that is sized to receive a frame lock guard  72 . In some examples, the guard recess  68  extends partially, but not entirely through the side frame  52 . An elongate shoulder  70  is then formed inward from an outermost surface  74  of the side frame  52 . In some examples, the perimeter of the elongate shoulder  70  mimics a portion of the frame lock guard  72 . 
     The frame lock guard  72  is positioned within the guard recess  68 . The frame lock guard  72  can be a generally flat, plate-like component that extends over at least a portion of the locking arm  56  to prevent incidental contact and actuation of the locking arm  56 . The frame lock guard  72  can be fastened or otherwise coupled to the side frame  52 . In some examples, the lock guard  72  includes a grip feature. For example, a protrusion or ridge  76  can extend away from a face surface  80  of the frame lock guard  72 . The ridge  76  can extend along a portion of the length of the frame lock guard  72 , and can be defined by a generally constant, semi-circular cross-section, for example. In some embodiments, the ridge  76  is defined by a curvature and extends concentrically with a portion of the outer perimeter of the frame lock guard  72 . The face surface  80  of the frame lock guard  72  can sit substantially flush with an outer surface of the side frame  52 , such that the ridge  76  extends outwardly beyond the side frame  52  to form a stop or grip. The guard recess  68 , which receives the frame lock guard  72 , can be formed with a depth that corresponds to a thickness of the frame lock guard  72  so the face surface  80  of the frame lock guard  72  is flush with the outer surface of the side frame  52 . 
     With continued reference to  FIG. 2 , a longitudinal axis  82  is defined along the length of the knife  20  and a width axis  83  is defined perpendicular to the longitudinal axis  82 . The knife  20  is defined by a series of different length relationships that enable the frame lock knife  20  to function effectively and readily transition between the stowed position and the deployed position, and vice versa. For example, an arm and hinge length  84  is defined by the locking arm  56  and the living hinge  60  and measured parallel to the longitudinal axis  82 . An arm length  88  is defined by the locking arm  56  and measured parallel to the longitudinal axis  82 . A guard length  92  is defined by the frame lock guard  72  and measured parallel to the longitudinal axis  82 . Accordingly, the arm and hinge length  84 , the arm length  88 , and the guard length  92  are defined in parallel relation to one another along a length of the knife  20 , parallel to the longitudinal axis  82 . 
     The relationships between arm and hinge length  84 , arm length  88 , and guard length  92  can be chosen so that the locking arm  56  can provide the necessary bias on the blade  24  without being subjected to unwanted, friction-inducing forces that might otherwise impact the blade  24  from transitioning from the stowed position to the deployed position. For example, the ratio of guard length  92  to arm and hinge length  84  can be less than 100% so that at least a portion of the locking arm  56  and living hinge  60  remain exposed outward beyond the frame lock guard  72 . This arrangement allows the locking arm  56  and hinge  60  to remain movable relative to the frame lock guard  72 , and provides areas of access so that a user can intentionally contact and actuate the locking arm  56  to transition the knife between deployed and stowed positions. In some embodiments, the guard length  92  is about sixty-six percent (66%) of the arm and hinge length  84 , allowing a portion of the living hinge  60  and a portion of the locking arm  56  to extend outwardly beyond each side of the frame lock guard  72 . In some embodiments, a ratio of the guard length  92  to the arm and hinge length  84  is between about fifty percent (50%) and about eighty percent (80%). The frame lock guard  72  can be positioned forward of the living hinge  60  so that the entire living hinge  60  is exposed relative to the frame lock guard  72 . 
     The frame lock guard  72  is designed to cover a significant portion of the locking arm  56 , so that incidental contact between the hands of a user and the locking arm  56  is limited or avoided altogether. The locking arm  56  can straddle the frame lock guard  72  so that a portion of the locking arm  56  extends outwardly from each side (e.g., the front side and back side, determined based upon relative position along the longitudinal axis  82 ) of the frame lock guard  72 . By leaving a portion of the locking arm  56  uncovered by the frame lock guard  72 , a user can intentionally actuate the locking arm  56  by directly contacting the locking arm  56 . In some examples, the frame lock guard  72  is positioned toward the living hinge  60 , so that the distal end of the locking arm  56  remains readily accessible and movable by the fingers of a user. In some embodiments, a ratio of the guard length  92  to the arm length  88  can be about eighty-seven percent (87%). To create the necessary amount of accessibility to the locking arm  56  while still restricting unwanted actuation, the ratio of the guard length  92  to the arm length  88  should be between about seventy-five percent (75%) to about one hundred percent (100%). 
     The longitudinal sizing and positioning, along with the width and latitudinal relationship (i.e., relative to the width axis  83 ) of the frame lock guard  72  and locking arm  56  allow the frame lock guard  72  to prevent or inhibit incidental contact with the locking arm  56  while still allowing access to intentionally actuate the locking arm  56 . A series of dimensional relationships can again determine the frame lock guard&#39;s  72  effectiveness. For example, a locking arm width  96  is defined by the locking arm  56  in a direction parallel to the width axis  83 . The locking arm width  96  varies along the locking arm length  88 . In some embodiments, the locking arm width  96  is at a maximum proximate the living hinge  60 . The locking arm width  96  can be smaller at the distal end of the locking arm  56  than the proximal end of the locking arm  56 . A guard width  100  is defined by both the locking arm  56  and the frame lock guard  72  in a direction parallel to the width axis  83 . The guard width  100  is defined by the distance between the top side  86  of the locking arm  56  to the bottom side  90  of the frame lock guard  72 . The guard width  100  varies along the guard length  92  as well. Like the locking arm  56 , the guard width  100  can be at a maximum nearest the living hinge  60  and at a minimum nearest the distal end of the locking arm  56 . 
     In some embodiments, a ratio of the guard width  100  to the locking arm width  96  at any given position along the guard length  92  is between about forty-five percent (45%) and about seventy percent (70%) to allow a portion of the locking arm  56  to remain exposed below the frame lock guard  72 . In some embodiments, the ratio of the guard width  100  to the locking arm width  96  is about seventy percent ( 70 %) at an end of the frame lock guard  72  distal from the blade  24  (i.e., proximate the living hinge  60 ), and about forty five percent (45%) at an end of the frame lock guard  72  proximate to the blade  24  (i.e., proximate the distal end of the locking arm  56 ). In some embodiments, the ratio of the guard width  100  to the locking arm width  96  is consistent (e.g., ˜50%) along the guard length  92 . In some embodiments, the ratio of the guard width  100  to the locking arm width  96  is between about thirty percent (30%) and about one hundred percent (100%). 
     As shown in  FIG. 3 , the guard recess  68  is sized so that the face surface  80  of the frame lock guard  72  is flush with the outer surface of the side frame  52 . The locking arm  56  can also include an arm recess  104  shaped to receive a portion of the frame lock guard  72 . The arm recess  104  can be formed with a shape complimentary to the bottom side  90  of the frame lock guard  72 , and can be arranged to form a clearance fit around the frame lock guard  72  when the locking arm  56  is biased outward, into the unlocked position (which is located outward from the locked position shown in  FIG. 3 ). In some examples, engagement between the frame lock guard  72  and the base of the arm recess  104  can serve as a stop to prevent the locking arm  56  from being over-actuated outward, beyond the desired unlocked position. A depth of the arm recess  104  can be approximately equal to the thickness of the frame lock guard  72 , so that when the locking arm  56  is moved to the unlocked position, the outer surface of the side frame  52 , the face surface  80 , and the outer surface of the locking arm extend generally flush to one another. 
       FIG. 4  demonstrates the internal structure and fastening architecture of the knife  20 . In some examples, a liner  108  is fastened to the handle frame  48 . Because the handle frame  48  may be formed thinner than the side frame  52 , the liner  108  can be used to help balance and center the blade  24  within the handle assembly  28 . The liner  108  can be spaced apart from the side frame  52  by spacers  112 , which creates the cavity  50  that receives and protects the blade  24  in the storage configuration. While  FIG. 4  shows the components of the knife  20  secured together using a plurality of different removable fasteners, various other coupling mechanisms and techniques can be used to create the knife  20 . In some embodiments, some or all parts of the handle assembly  28  are adhered, welded, brazed, fused, or otherwise connected or coupled without the use of removable fasteners. 
       FIGS. 5 and 6  show the knife  20  in the storage position. The blade  24  is rotated toward the handle assembly  28 , so that the the cutting edge  40  is received within the cavity  50  and hidden within the handle assembly  28 . The portion of the blade  24  positioned within the cavity  50  interferes with the locking arm  56 , and prevents the locking arm  56  from reaching the locked position within the cavity  50 . Instead, the locking arm  56  is rotated about the living hinge  60  outward, into the unlocked position, with an end of the locking arm  56  resting on the blade  24 . The interference between the locking arm  56  resists, but does not prevent rotation of the blade  24  relative to the handle assembly  28  so that a user can still rotate the blade  24  to the deployed position. To deploy the blade  24 , a user can grab onto the blade  24  with one hand and grab onto the handle assembly  28  with the other hand. The opening aperture  36  is exposed and in a position that can be easily engaged by the user&#39;s thumb, and creates a grip point that can be pulled on to begin rotation of the blade  24  outward from the frame assembly  28 . The frame lock guard  72  is positioned so as to provide a gripping location for the user that allows the handle assembly  28  to be securely grasped without pressing on or impinging on the locking arm  56 . Pressing or otherwise forcing the locking arm  56  into the blade  24  can introduce additional friction and interference between the blade  24  and locking arm  56  that resists rotation toward the deployed position, which can be frustrating for a user. The frame lock guard  72  creates a barrier that impedes the hands of a user from contacting the locking arm  56 . In other words, the frame lock guard  72  inhibits accidental actuation of the locking arm  56  toward the locked position. 
     As shown in  FIG. 7  and as explained above, the ridge  76  of the frame lock guard  72  projects outward of the face surface  80 . The ridge  76  protrudes farther from a center line of the handle assembly  28  than the locking arm  56  in the locked position (shown in solid lines) and the unlocked position (shown in dashed lines). The raised profile of the ridge creates a reference point and gripping section for the user, who can know without looking at the handle that his or her hands are positioned properly upon the frame lock guard  72  before deploying the blade  24  of the knife  20 .  FIG. 7  also shows how the frame lock guard  72  is received within the arm recess  104  of the locking arm  56  while the locking arm  56  is arranged in the unlocked position. 
       FIGS. 8 and 9  show additional details of the frame lock guard  72 . Specifically, the ridge  76  is an arcuate projection that protrudes from the face surface  80 . In some embodiments, the grip feature includes a knurled texture, studs, pyramidal protrusions, or a different shaped ridge. Additionally, the frame lock guard  72  is shown as a separate component that is fastened to the side frame  52 . In some embodiments, the frame lock guard  72  can be formed as a part of the side frame  52  or adhered to the side frame  52 , as desired. 
     The frame lock guard  72  advantageously inhibits a user from gripping or pressing on the locking arm  56  unintentionally. For example, as the user engages the opening aperture  36  on the blade  24 , if the user presses inadvertently on the locking arm  56 , the actuation of the blade  24  to the use position (see  FIG. 1 ) is inhibited and feels less than ideal to the user. The frame lock guard  72  inhibits the user from pressing the locking arm  56  inadvertently and avoids situation of less than smooth actuation between the use position and the storage position. 
     The construction and arrangement of the apparatus, systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, some elements shown as integrally formed may be constructed from multiple parts or elements, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure. 
     As utilized herein, the terms “approximately,” “about,” “substantially”, and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges or geometric relationships provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims. 
     While the detailed drawings and specific examples given describe various exemplary embodiments of the camping utensil kit, 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. 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.