Abstract:
This invention relates to an actuator in a knife that controls the movement of the blade between an open and alternatively closed position. The knife generally consists of a blade having a tang extending outwardly from the blade; a handle having a guide; a bar connecting the tang and the handle; an actuator engaging the blade, wherein movement of the actuator is limited by the guide of the handle. In another embodiment, the handle includes an arrestor which impedes the movement of the blade or actuator until sufficient force is applied to break past the arrestor. Generally, in the present invention, force must be applied to the actuator to initiate movement of the blade whereupon the actuator moves into a position to stop the blade from further movement.

Description:
CROSS REFERENCE  
       [0001]     This patent application claims priority to U.S. Provisional Application No. 60/687,004 filed Jun. 4, 2005 entitled “Knife Blade Arrestor.” 
     
    
     BACKGROUND OF INVENTION  
       [0002]     1. Field of Invention  
         [0003]     Generally, this invention relates to cutlery implements which are foldable or otherwise retractable into the handle to protect the blade while not in use. Specifically, this invention relates to implements in which a means is provided for positively moving the blade from the handle and locking the blade in either in an open or closed position.  
         [0004]     2. Description of Related Art  
         [0005]     In the cutlery industry, a folding or sliding knife includes a housing or handle to support the blade in the open position and for receiving the blade in the closed position. Challenges lie in the starting and stopping the movement of a knife blade as well as keeping a knife blade in a desirable position, such as open, locked or closed positions.  
         [0006]     Controlling movement of a pivoting knife blade is generally known and examples of such control can be found in Collins U.S. Pat. No. 5,815,927, Glesser U.S. Pat. No. 6,918,184, Leatherman&#39;s flipper knife models E306x and E307x, Onion U.S. Pat. Nos. 6,591,504, and 6,145,202, and Onion U.S. Patent Application Publication 2005/0132576. It is generally known how to lock a knife blade when in the open position. Examples of such locking mechanism are found in Neely U.S. Pat. No. 5,060,379 and Wiethoff U.S. Pat. No. 4,404,748.  
         [0007]     The actuator and stop mechanism of the present invention overcomes the various deficiencies of folding knives and opening and closing mechanisms presently known in the knife and cutlery industry by providing positive opening and stopping assistance while enabling such opening and closing to be performed with only a single hand of the user.  
       BRIEF SUMMARY OF THE INVENTION  
       [0008]     This invention generally provides for a folding knife mechanism comprising a blade, a handle for receiving and supporting the blade and an actuator located within the handle that engages with the blade and provides positive assistance for opening the blade. The mechanism generally includes an actuator coupled to a guide formed in the interior of the handle. The actuator is substantially coplanar to said blade and pushes against the blade to move it from a closed to an open position. Generally, in the present invention, force, typically from the user, is applied to the actuator to initiate movement of the blade whereupon the actuator moves into a position to stop the blade from further movement, hence the name of the invention, blade actuating stop.  
         [0009]     An arrestor may be incorporated into the knife to prevent accidental opening of the blade and requires further positive force to begin movement of the blade. The arrestor is attached to the handle or sub-components of the handle and positioned to interfere with the movement of the blade or actuator until sufficient force is applied to the blade or actuator to break past the arrestor.  
         [0010]     Likewise, a locking means, such as a lock situated in the handle, may be provided to prevent accidental closing of the blade. The blade of the present invention, when in an open position, is securely held in position between the lock and the actuator. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0011]      FIG. 1  depicts a profile view of the prior art with the blade in a closed position.  
         [0012]      FIG. 2  depicts a profile cutaway view of the prior art with the blade in a closed position.  
         [0013]      FIG. 3  depicts a profile cutaway view of the prior art with the blade in a partial open position.  
         [0014]      FIG. 4  depicts a profile cutaway view of the prior art with the blade in a fully open and locked position.  
         [0015]      FIG. 5  depicts a profile view of an embodiment of the present invention with a blade in a closed position and an exposed digit tab of a blade actuating stop.  
         [0016]      FIG. 6  depicts a cutaway profile view of an embodiment of the present invention with a blade in a closed position and an exposed digit tab of a blade actuating stop.  
         [0017]      FIG. 7  depicts a cutaway profile view of an embodiment of the present invention with a blade in a partial open position engaged with a blade actuating stop.  
         [0018]      FIG. 8  depicts a cutaway profile view of an embodiment of the present invention with a blade in a partial open position and a blade actuating stop operatively coupled to an arcuate guide groove and positioned to stop blade movement.  
         [0019]      FIG. 9  depicts a cutaway profile view of an embodiment of the present invention with a blade in a full open and locked position between a blade actuating stop and a liner lock.  
         [0020]      FIG. 10  depicts a cross sectional view of an embodiment of the present invention with a blade actuating stop coupled to a guide rail.  
         [0021]      FIGS. 11   a  and  11   b  depict cutaway profile views of an embodiment of the present invention with a blade actuating stop, spring and arrestor in the form of a tab.  
         [0022]      FIGS. 12   a  and  12   b  depict cutaway profile views of an embodiment of the present invention with a blade actuating stop and spring.  
         [0023]      FIGS. 13   a  and  13   b  depict cutaway profile views of an embodiment of the present invention with a blade actuating stop operatively coupled to a linear guide groove.  
         [0024]      FIGS. 14   a  and  14   b  depict cutaway profile views of an embodiment of the present invention with an arrestor in the form of a tab to impede blade movement.  
         [0025]      FIG. 15  depicts a cutaway profile view of an embodiment of the present invention with an arrestor in the form of an axially compressive member to impede blade movement.  
         [0026]      FIGS. 16   a  and  16   b  depict cutaway profile views of an embodiment of the present invention with an arrestor in the form of a spindled flexible shaft to impede blade movement. 
     
    
     DETAILED DESCRIPTION  
       [0027]     To appreciate the present invention an understanding of the prior art is in order. Referring to  FIGS. 1 through 4 , the prior art folding knife  5  provides for a handle  10  with side parts  102 , a bottom  103 , rear end  104  and a front end  106 . Fasteners  116  hold the side parts  102  of handle  10  together. See  FIG. 1 . A central cavity  112  is formed in the handle  10  to receive a blade  30 . See  FIG. 2 . An actuator plate  200  and a blade  30  pivotally connected by a bar  118  to a handle  10 . See  FIGS. 2 through 4 . A tang  32  projects from one end region of blade  30 . See  FIGS. 2 through 4 . The actuator plate  200  and blade  30  are pivotably connected to the handle  10  by a common bar  118  such that actuator plate  200  is disposed between one side of handle  10  and blade  30 . See  FIGS. 1 through 4 .  
         [0028]     The actuator plate  200  includes a finger tab  220  and a tang contactor  240 . See  FIGS. 2 through 4 . Finger tab  220  projects away from the periphery of the actuator plate  200  and extends above a portion of handle  10  through a part of its arc of rotation about bar  118 . See  FIGS. 2 through 4 . Tang contactor  240  projects away from one side of the actuator plate  200  to engage tang  32  when actuator plate  200  is rotated through a portion of its arc of rotation about bar  118 . See  FIGS. 2 through 4 .  
         [0029]     Movement of blade  30  out of the central cavity  112  occurs when user force applied to finger tab  220  causes actuator plate  200  to rotate about bar  118  to engage and push tang contactor  240  against tang  32 . The blade  30  is pushed towards an open position while tang contactor  240  is engaged against tang  32 . This positive push of the blade by tang contactor  240  continues until finger tab  220  rotates into handle  10 . A thumb pin  31  attached to and projecting from blade  30  provides an alternative means to open a blade  30 . See  FIGS. 1 through 4 .  
         [0030]     Variations in the required spacing between actuator plate  200 , blade  30  and handle  10  affect the amount of effort required to move blade  30  out of handle  10  as well as the effectiveness of tang contactor  240  engaging tang  32 . The arc of actuator plate  200  rotation and amount of force required to move blade  30  is dependent upon the placement of the finger tab  220  in relation to bar  118 . The larger the distance between bar  118  and finger tab  220 , the greater the leverage to move blade  30  out of handle  10  but at the increased risk of finger tab  220  become entangled in articles of clothing or other objects which may further cause inadvertent movement of blade  30 . Effective engagement of tang contactor  240  against tang  32  requires proper alignment of the pivotal connection of actuator plate  200  against blade  30  by bar  118 . Wear of tang contactor  240  or bar  118  reduces the effectiveness of the engagement between the tang contactor  240  and tang  32 . Tang contactor  240  may ride over and slide against tang  32  if the distance between blade  30 , handle  10  and actuator plate  200  deviates from the desired tolerances and/or by virtue of excessive wear of the tang contactor  240  itself. The present invention overcomes these issues as described below.  
         [0031]     The present invention of a knife  5  generally includes a handle  10  with a bottom  103 , rear end  104  and a front end  106 . See  FIG. 5 . A central cavity  112  is formed in handle  10  to receive blade  30 . See  FIGS. 6 and 10 . The interior of the central cavity  112  is shaped according to the form of the blade  30  and forms a stop for the blade  30  when placed in the closed position. In one embodiment, handle  10  includes side parts  102  and liners  108 . See  FIGS. 6 through 9 . Each side part  102  and liner  108  has a plurality of holes  114  that receive fasteners  116  which secure side parts  102  together and an opening for a pivot of bar  118 . See  FIGS. 5, 8  and  9 .  
         [0032]     The blade  30  has a distal end  34  and a proximal end  36 , with tang  32  adjacent to the proximal end  36 . See  FIGS. 6 and 7 . The tang  32  has a hole for receiving a bar  118 . It is contemplated that blade  30  may include a thumb opener  38  which provides an alternative blade opening means. See  FIGS. 5 through 9 . Thumb opener  38  can be in the form of a pin  31  as shown in  FIGS. 13   a  through  15 . In addition to being an opening form in the blade  30  or a pin  31 , thumb opener  38  can be in the form of a disc as known to those in the cutlery arts.  
         [0033]     A portion of liner  108 , indicated in  FIG. 9  as liner portion  109  is separate from the liner  108  at the front end  106  of the handle  10  and is displaceable. Liner portion  109  is biased like a leaf spring so that it extends into the central cavity  112  of the handle  10  when the blade  30  is placed in the open position, as shown in  FIG. 9 . The forward end of liner portion  109  communicates with the tang  32  of the blade  30  when the blade  30  is in the open position so as to prevent folding of the blade  30  into the central cavity  112  because forward end of liner portion  109  is in the path of travel of tang  32 . The user can move the forward end of liner portion  109  out of the path of travel of tang  32  to allow blade  30  to fold into the central cavity  112 .  
         [0034]     A guide  12  within handle  10  is located near tang  32  when blade  30  is in a closed position. See  FIGS. 7, 8 ,  10 ,  11   a ,  12   a ,  13   a ,  13   b ,  14   a  through  16   b . Guide  12  is operatively coupled to an actuator  20  which is coplanar with blade  30 . See  FIGS. 6 through 9  and  11   a  through  13   b . As depicted in  FIGS. 5 through 12   b , actuator  20  includes a digit tab  22  which projects beyond a portion of handle  10  when blade  30  is in a closed position and is flush with handle  10  when blade  30  is in an open position. In another embodiment, as depicted in  FIGS. 13   a  and  13   b , actuator  20  includes a digit tab  22  that is substantially flush with handle  10  regardless of the position of blade  30 .  
         [0035]     The shape of guide  12  can be arcuate, linear or a combination of the two. See  FIGS. 8 and 13   a . In one embodiment, guide  12  is a groove or channel formed in the liner  108 . See  FIG. 8 . Operative coupling with actuator  20  is achieved by at least one pin  26  riding in grooved guide  12 . See  FIG. 8 . In another embodiment, operative coupling with actuator  20  is achieved by a groove  28  formed in actuator  20  riding on guide  12  in the form of a rail. See  FIG. 10 . In each of the embodiments, once blade  30  is moving towards an open position, actuator  20  is moved into a position to stop blade  05  from further movement past the open position. See  FIGS. 8, 11   b ,  12   b  and  13   b.    
         [0036]     The actuator mechanism  20  can be augmented with a spring  25  that imparts force to the actuator  20  and in turn blade  30 . See  FIGS. 11   a  through  12   b . In the embodiments of  FIGS. 11   a  and  11   b , spring  25  urges the actuator  20  into a pre-determined position, preferably such that digit tab  22  is flush with (or in) handle  10 . In  FIGS. 11   a  and  11   b , spring  25  includes at least one bend and is fixed to handle  10  (or liner  108 ). In  FIGS. 12   a  and  12   b , spring  25  is attached at one end to actuator  20  and handle  10  (or liner  108 ) at the other end, such that spring  20  is stretched when digit tab  22  extends beyond handle  10 . In such an embodiment, the length of guide  12  and placement of spring  20  can be such as to generate a force that urges actuator  20  into a pre-determined position about the guide  12 . See  FIG. 11   b . In another embodiment, the spring  25  and guide  12  are positioned in the handle  10  to align the force from spring  25  to impede movement of the actuator  20  at one end region of guide  12 . See  FIG. 11   a.    
         [0037]     As depicted in  FIGS. 11   a ,  11   b , and  14   a  through  16   b , an arrestor  40  is attached to the handle  10  or liner  108  and positioned to impede movement of the actuator  20  (See  FIGS. 11   a  and  11   b ) or blade  30  (See  FIGS. 14   a  through  16   b ) until sufficient force is applied to the actuator  20  or blade  30  to break by the arrestor  40 . Arrestor  40  can be a simple tab  42  as shown in  FIGS. 11   b ,  14   a , and  14   b  or can be an axially compressible member  44  as shown in  FIG. 15  or a spindled flexible shaft  46  as depicted in  FIGS. 16   a  and  16   b.    
         [0038]     The break by force required to move past arrestor  40  can be varied by altering the coefficient of friction in the contact region between arrestor  40  and blade  30  or actuator  20 . This can be achieved by polishing (or roughing up) at least one surface of the contact region and/or applying a layer or coating of a different material to at least one surface on the contact region.  
         [0039]     As stated above, arrestor  40  may include a tab cut from the same material as the handle  10  or liner  108  (See  FIGS. 11   a ,  11   b ,  14   a  and  14   b ). It is further contemplated that arrestor  40  in the form of a tab  42  can be manufactured from a material different from handle  10  or liner  108  and fixed (permanently or otherwise) to handle  10  or liner  108 .  
         [0040]      FIGS. 11   a  and  11   b  depict an embodiment of the present invention wherein the movement of blade  30  is limited when arrestor  40  impedes the movement of pin  26  causing actuator  20  to function as a blade stop until sufficient force is applied to either blade  30  or actuator  20  to make pin  26  break past arrestor tab  42 .  FIGS. 14   a  through  16   b  depict another embodiment in which a stub  117  projecting away from blade  30  is operatively coupled to a guide  12  formed in handle  10  or liner  108 . In such an embodiment, tab  42  arrests the movement of blade  30  until sufficient force is applied to stub  117  to break past arrestor  40 . In another embodiment, arrestor  40  includes an axially compressible member  44  attached to handle  10  or liner  108  that positions an end of arrestor  40  in the path of blade  30  or actuator  20  to impede movement of blade  30  or actuator  20  until it breaks by the arrestor  40 . See  FIG. 15 . An axially compressible member  44  can include a spring or a compressible material, like rubber.  
         [0041]     In yet another embodiment, arrestor  40  includes a spindled flexible shaft  46  attached to handle  10  or liner  108  in which at least a portion of spindled flexible shaft  46  is positioned to impede the movement of blade  30  until sufficient force is applied to blade  30  or actuator  20  to break past arrestor  40 . See  FIGS. 16   a  and  16   b . In such an embodiment, spindled flexible shaft  46  includes a shaft  462  of flexible material, such as NITINOL, surrounded (in part or wholly) by a spindle  464  or a part thereof. It is further contemplated that shaft  462  is fixed or coupled to spindle  464 . The force required to break past an arrestor including a spindled flexible shaft  46  can be varied as described above or by allowing spindle  464  or shaft  462  to rotate about the longitudinal axis defined by shaft  462 .  
         [0042]     In operation, a folding knife  05  in a closed position is grasped with the rear end  104  of the handle  10  oriented towards the user&#39;s wrist and the bottom  103  of the handle  10  resting in the palm resulting in a user&#39;s finger (typically the forefinger) being in close proximity to digit tab  22 . Pressure is applied to the digit tab  22  as the finger is drawn toward the rear end  104  of handle  10 , causing the actuator  20  to engage a portion of the tang  32  to rotate or slide the blade  30  out of its closed position in the central cavity  112 . The blade  30  is pushed out of the central cavity  112 , once the blade  30  (or actuator  20 ) breaks past an arrestor  40 , if present, resulting in the blade  30  moving into an open position and the actuator mechanism  20  moving into position to stop the blade  30  from travel beyond the desired open position. The liner portion  109  extends into the central cavity  112  as the blade  30  clears approaches the fully open position and further becomes lodged against the tang  32 , thereby preventing the blade  30  from closing.  
         [0043]     To close the knife  05 , pressure is applied to the moveable liner portion  109 , dislodging the end of the lining from the tang  32 , placing the liner portion  109  in linear arrangement with the lining  108 . The blade  30  is then moved towards the central cavity  112 . Blade  30  or actuator  20  breaks past arrestor  40 , if present at blade approaches central cavity  112 . In the closed position, the arrestor  40  and/or catch  111  prevents blade  30  from opening accidentally.  
         [0044]     It will be appreciated that an actuator  20  operatively coupled to a guide  12  allows a knife designer the freedom to design the movement or throw of digit tab  22  for a particular purpose without being limited to a blade&#39;s range of motion about its pivot point as seen in conventional flipper folding knives with the finger tab fixed to the blade or detached but pivotally constrained by bar  118  as depicted in the prior art discussed above. It is contemplated that the present invention of an actuating stop and arrestor provide novel solutions to stopping and/or arresting blade  30  movement.  
         [0045]     It will be understood that certain features and some combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of the Claims. Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.