Abstract:
Folding knives of the double action type in which a pivoted blade can be moved from the sheathed position within the handle and lock automatically in the unsheathed use position in two different ways at the option of the user, namely, (a) to snap the blade into the use position via spring action by movement of a release trigger or (b) to silently unfold the blade manually into the use position, are improved by providing the knives with hidden release triggers, i.e., triggers that are not apparent to viewers in normal inspection of the knives. A unique form of trigger release is disclosed.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This application relates broadly to folding knives that have a blade pivoted at one end to fold into a sheath handle. More particularly, it concerns such knives that are of the double action type and which have a hidden trigger for automatic release of the blade from the handle to move and lock in the use position.  
           [0003]    2. Description of the Prior Art  
           [0004]    Double action folding knives are a known class in which the pivoted blade can be moved from the sheathed position within the handle and lock automatically in the unsheathed use position in one of two ways at the option of the user (see U.S. Pat. No. 5,819,414). Thus, the user may choose (a) to snap the blade into the use position via spring action by manipulating a release trigger or (b) to silently unfold the blade manually into the use position.  
           [0005]    The double action folding knives were preceded by many versions of single action folding knives that lock a pivoted blade in the use position upon manual movement from a sheathed position to a use position (see U.S. Pat. Nos. 4,837,932, 5,502,895, 5,511,310, 5,694,692, 5,737,841, 5,755,035, 5,875,552 and 5,964,035).  
           [0006]    Moreover, forms of single action folding knives are known that use trigger means, rather than manual movement, to move the blade from a sheathed position within the handle into the use position (see U.S. Pat. Nos. 4,811,486, 5,331,741 and 5,822,866).  
         OBJECTS  
         [0007]    A principal object of the invention is the provision of improved folding knives of the double action class, namely, that enable the user to move the blade from its sheathed position to locked use position in two different ways, i.e., manual movement and spring means movement.  
           [0008]    Another object is the provision of improved double action folding knives that have a hidden trigger, i.e., triggers that are not apparent to viewers in normal inspection of the knives.  
           [0009]    A further object is the provision of improved double action folding knives that enable a snap action means to remain cocked when the blade is manually unsheathed, i.e., moved simply by hand into its use position.  
           [0010]    Other objects and further scope of applicability of the present invention will become apparent from the detailed descriptions given herein; it should be understood, however, that the detailed descriptions, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent from such descriptions.  
         SUMMARY OF THE INVENTION  
         [0011]    The stated objects are accomplished in accordance with the invention by the provision of a double action folding knife comprising a longitudinal sheath handle, a blade that pivots about one end from a sheathed position within the handle to a use position external of the handle, spring means to rotate the blade from the sheathed position into the use position and hidden trigger means for automatic movement of the blade from the sheathed position to lock in the use position.  
           [0012]    The longitudinal sheath handle has a first end, a second end and a channeled body portion integrally joining the first and second ends.  
           [0013]    The blade has a pivot end, a free end and an integral central body portion all lying in a common plane. The pivot end is pivoted to the handle first end about an axis normal to the common plane enabling the blade to move between the sheathed position within the handle through an arc to the use position external of the handle.  
           [0014]    Pivot means upon which the blade is pivoted enables the blade to be manually moved between the sheathed position and the use position.  
           [0015]    The knife handle is constructed of an assembly, in turn from its right hand side to its left hand side, of a right bolster and right scale as a first layer, a right liner as a second layer, the blade, a leaf spring and a spacer spine as a third layer, a left liner as a fourth layer, a left bolster and left scale as a fifth layer.  
           [0016]    There is lock means to automatically lock the blade in the use position upon completion of the movement thereof into the use position and to be manually unlocked for manual return of the blade from the use position to the sheathed position.  
           [0017]    Further, there is spring means that is cocked by manual rotation of the blade from the use position to the sheathed position and can be uncocked for automatic rotation of the blade by such spring means forcibly from the sheathed position to the use position.  
           [0018]    Additionally, there is hidden trigger means that holds the spring means in its cocked mode and un-cocks the spring means for automatic blade rotation when manipulated by the user of the knife.  
           [0019]    In preferred embodiments of the invention, the hidden trigger means comprises a bolster that is pivoted to reciprocate in a plane parallel to the common plane between a spring cocked position and a spring un-cocking position, a cavity in the right hand bolster, a catch fixed in the cavity and a sear that engages the catch when the blade is returned to the sheathed position and disengages from the catch when the right hand bolster is moved into its spring un-cocked position.  
           [0020]    The new knives may include a belt clip, a lanyard, scale engravings or ridges and like embellishments know to the art. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]    A more complete understanding of the invention can be obtained by reference to the accompanying drawings of an embodiment of a knife in accordance with the invention in which:  
         [0022]    [0022]FIG. 1 is an exploded isometric view of the knife.  
         [0023]    [0023]FIG. 2 is side view of the left hand side of the knife with the blade in the opened use position. In the knife art, the left hand side of a knife means that side which a viewer sees when the knife is held in the left hand with the blade edge pointing downward.  
         [0024]    [0024]FIG. 3 is the left side view of the knife with the blade in the closed sheathed position.  
         [0025]    [0025]FIG. 4 is side view of the right hand side of the knife with the blade in the opened use position. In the knife art, the right hand side of a knife means that side which a viewer sees when the knife is held in the right hand with the blade edge pointing downward.  
         [0026]    [0026]FIG. 5 is the right hand side view of the knife with the blade in the closed sheathed position.  
         [0027]    [0027]FIG. 6 is a plan view of the outside of the left scale of the knife.  
         [0028]    [0028]FIG. 7 is a plan view of the inside of the left scale of the knife.  
         [0029]    [0029]FIG. 8 is a plan view of the outside of the right scale of the knife.  
         [0030]    [0030]FIG. 9 is a plan view of the inside of the right bolster of the knife.  
         [0031]    [0031]FIG. 10 is a plan view of the outside of the left bolster of the knife.  
         [0032]    [0032]FIG. 11 is a plan view of the inside of the left bolster of the knife.  
         [0033]    [0033]FIG. 12 is a plan view of the outside of the right bolster of the knife.  
         [0034]    [0034]FIG. 13 is a plan view of the inside of the right bolster of the knife.  
         [0035]    [0035]FIG. 14 is a plan view of the outer side of the left liner of the knife.  
         [0036]    [0036]FIG. 15 is a plan view of the inner side of the left liner of the knife.  
         [0037]    [0037]FIG. 16 is a plan view of the outer side of the right liner of the knife.  
         [0038]    [0038]FIG. 17 is a plan view of the inner side of the right liner of the knife.  
         [0039]    [0039]FIG. 18 is a lateral view of a pin spine of the knife.  
         [0040]    [0040]FIG. 19 is a lateral view of the blade bushing of the knife.  
         [0041]    [0041]FIG. 20 is an end view of the blade pin of the knife.  
         [0042]    [0042]FIG. 21 is a lateral view of a blade pin of the knife.  
         [0043]    [0043]FIG. 22 is a lateral view of the spring retainer pin of the knife.  
         [0044]    [0044]FIG. 23 is a lateral view of the male stud of the knife.  
         [0045]    [0045]FIG. 24 is an end view of the male stud of the knife.  
         [0046]    [0046]FIG. 25 is a lateral view of the female part of the stud of the knife.  
         [0047]    [0047]FIG. 26 is an end view of the male part of the stud.  
         [0048]    [0048]FIG. 27 is an end view of the sear of the knife.  
         [0049]    [0049]FIG. 28 is a lateral view of the sear of the knife.  
         [0050]    [0050]FIG. 29 is a lateral view of the blade stop pin of the knife.  
         [0051]    [0051]FIG. 30 is a lateral view of the un-notched side of the trigger catch of the knife.  
         [0052]    [0052]FIG. 31 is a side view of the trigger catch of the knife.  
         [0053]    [0053]FIG. 32 is a lateral view of notched side of the trigger catch of the knife.  
         [0054]    [0054]FIG. 33 is a plan view of the small blade washer of the knife.  
         [0055]    [0055]FIG. 34 is a lateral view of the left spring of the knife.  
         [0056]    [0056]FIG. 35 is a plan view of the large blade washer of the knife.  
         [0057]    [0057]FIG. 36 is a lateral view of the spacer spine of the knife.  
         [0058]    [0058]FIG. 37 is a view like right hand view FIG. 4 with the right bolster and right liner removed.  
         [0059]    [0059]FIG. 38 is a view like right hand FIG. 5 with the right bolster and right liner removed.  
         [0060]    [0060]FIG. 39 is a view of the inner side of the right bolster and a portion of the trigger means associated therewith.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0061]    Referring in detail to the drawings, the invention provides a double action folding knife  2  comprising a longitudinal sheath handle  4 , a blade  6  that pivots about one end from a sheathed position within the handle (see FIG. 3) to a use position external of the handle (see FIG. 2), spring means  8 , defined in part by free end  9 , to rotate the blade from the sheathed position into the use position and hidden trigger means  10  for automatic movement of the blade from the sheathed position to lock in the use position.  
         [0062]    Spring means  8  is cocked by manual rotation of the blade  6  from the use position of FIG. 2 to the sheathed position of FIG. 3 and is un-cocked by manipulation of trigger means  10  to produce automatic rotation of the blade from the sheathed position to the use position  
         [0063]    Referring to FIG. 2, the longitudinal sheath handle  4  has a first end  12 , a second end  14  and a channeled body portion  16  integrally joining these ends. The left side  18  of the sheath handle  4  comprises left scale  20  and left bolster  22 .  
         [0064]    Referring to FIG. 4, the right side  19  of sheath handle  4  comprises right scale  21  and right bolster  23 .  
         [0065]    Referring to FIGS. 1,2 &amp;  4 , the blade  6  has a pivot end  24  containing a pivot bore  25 , a free end  26  and an integral central body portion  27  all lying in a common plane. The pivot end  24  is pivoted to the handle first end  12  via pivot means  28  about an axis normal to the common plane enabling the blade  6  to be moved manually by a stud  30  between the sheathed position within the handle through an arc to the use position external of the handle  4 . The stud  30  comprises the male part  30 M and female part  30 F.  
         [0066]    In addition to small screws and like fasteners (not shown), the double action folding knife  2  includes a right liner  32 , left liner  34 , a spacer spine  36 , a blade stop pin  38 , a spring retainer pin  40  and a plurality of spine pins  44 . The spacer spine  36  includes counter-sunk bores  37  to receive screws (not shown) that sandwich it between the right liner  32  and left liner  34 . Typically, the liners are formed from {fraction (1/16)} th   stainless steel sheet and the fasterners are torx head type.  
         [0067]    The pivot means  28  comprises blade pin  46 , blade bushing  48 , large washer  50 , small washer  52  and compression washer  54 .  
         [0068]    The trigger means  10  comprises a cavity  56  in the right hand bolster  23 , the catch  58 , sear  60  and a lug part  62  of the right liner  32 . The sear  60  includes threaded bores  61  and lug part  62  has counter-sunk bores  63  though which screws (not shown) extend to fasten sear  60  to lug part  62 . The catch  58  has a beveled portion  59  that engages a mating beveled portion  65  on sear  60  to function in cocking and un-cocking of the leaf spring  8 . Further, the sear  60  has a lateral extending nib  67  that also functions in cocking and un-cocking of the leaf spring  8 .  
         [0069]    Lock means  64 , that is part of left hand liner  34  and automatically locks the blade  6  in the use position upon completion of the movement thereof into such position and manually unlocks it for manual return to the sheathed position, comprises tongue  66  that is a cantilevered integral part of the left hand liner  34  and has a notched edge  68 . Tongue  66  is bent so that its end  70  protrudes slightly above the plane of the liner  34  providing the lock means  64  with a spring action.  
         [0070]    Left liner  34  (see FIGS. 14 &amp; 15) further comprises bore  72  to receive spring retainer pin  40 , a plurality of larger bores  74 , a plurality of smaller bores  76 , a pair of counter-bored bores  77 , slots  78  and a plurality of threaded bores  79  that serve, inter alia, to receive bolts  80  that fix the left hand scale  20  to the handle  4 .  
         [0071]    Right liner  32 , (see FIGS. 16 &amp; 17), in addition to the lug part  62  mentioned above, comprises trigger spring  82 , a plurality of larger bores  74 , a plurality of smaller bores  76 , a pair of counter-bored bores  77  and a slot  84 .  
         [0072]    Referring to FIGS.  6 - 7 , the left scale  20  contains bores  88  with counter-bores  89  to receive bolts  80  (FIG. 2).  
         [0073]    Referring to FIGS.  8 - 9 , the right scale  21  contains bores  88  with counter-bores  89  to receive bolts  80  (FIG. 4).  
         [0074]    Referring to FIGS.  10 - 11 , the left bolster  22  contains counter-bored bore  90  to receive the male end  91  of pivot means  28 , a counter-bored bore  92  to receive screw  93  (FIG. 3) and a cavity  94  in its inside surface.  
         [0075]    Referring to FIGS.  12 - 12 , the right bolster  23  contains a counter-bored bore  96  to receive the blade pin  46 , a counter-bored bore  97  to receive screw  98  (FIG. 4) and the cavity  56  that chambers parts of the trigger means  10  (FIGS. 1&amp; 37).  
         [0076]    The handling of the new knives of the invention can be explained by reference to the drawings, particularly FIGS.  37 - 39 .  
         [0077]    Obviously, the knife  2  is stowed in a pocket, on a belt, etc. with the blade  6  in the sheathed position (FIGS. 5 &amp; 38). Since the knife  2  is of the double action type, the knife user (not shown) has two choices as to how to open the blade  6  into the use position (FIG. 37). As a first way, the user may open the blade silently by grasping the stud  30  to pull the blade  6  out of the handle  4  until stopped by engagement of the blade pivot end  24  with the stop pin  38 . When the blade  6  reaches such stop position, end  70  of the lock mean  64  will spring behind the pivot end  24  to lock the blade  6  into its use position. During this mode of manual movement of the blade to the use position, the leaf spring  8  is retained in its cocked position by nib  67  of the sear  60  (FIG. 38).  
         [0078]    When the user has finished use of the knife  2 , the blade  6  is returned to the sheathed position by pressing inwardly on the lock means  64 , which is accessible at the side of the bolster  23  as seen in FIG. 5. This unlocks the blade  6  from retention in its use position to enable manual folding of the blade back into the handle  4 . During all this procedure, the leaf spring means  8  remains in the cocked position shown in phantom in FIG. 38.  
         [0079]    In a second way, the user may open the blade automatically by using the trigger means  10 . To do this, the user places the closed knife  2  with the right hand side up first end  12  forward (FIG. 5) in his right hand and with his thumb presses against the side of bolster  23  to move it sideways into the position shown in phantom line in FIG. 5. This movement of bolster  23  causes the nib  67  of sear  60  to disengage the forward end  9  of leaf spring  8  thereby enabling the spring  8  to un-cock causing the blade  6  quickly to jump from the sheathed position (FIG. 38) to the use position while to spring  8  moves into its un-cocked position (FIG. 37). At the same time, lock means  64  will move as described above to lock the blade  6  in its use position.  
         [0080]    When the user has finished use of the knife  2  after applying the trigger means method of blade deployment, the blade  6  is returned to its sheathed position in the same way as described above. However in this case, the un-cocked spring  8  will be forced by the pressure applied to the blade  6  by the user to move into its cocked position (FIG. 38) where nib  67  of sear  60  will slip beneath its free end  9  to maintain the spring means  8  cocked for subsequent release by the trigger means  10 .