Abstract:
A folding knife having an improved locking mechanism that keeps the knife in an open extended use position until specific close actions are initiated. The improved locking mechanism provides a safety pin that is secured within the frame elements so as to be positioned between the knife blade and the free end of a locking bar that is spring urged thereagainst imparting improved force transfer locking structure thereto with wear adjustably pivot engagement points of the locking mechanism under spring urged locking engagement.

Description:
This is a continuation in part patent application of Ser. No. 11/506,937, filed Aug. 21, 2006. 

   BACKGROUND OF THE INVENTION 
   1. Technical Field 
   This invention relates to folding knives that provide a compact configuration in which the knife blade is pivotally attached to the handle and can be folded therewithin when not in use. Such folding knives have blade engagement locking devices to securely lock and hold the blade in extended longitudinal position with the handle for use. A typical locking element is commonly referred to as a lock bar that extends along the upper back edge of the knife and requires a manual depression at one end to release the free end from direct engagement with a retaining lock notch formed in the blade inwardly from its primary pivot attachment point with the handle frame elements. 
   2. Description of Prior Art 
   Prior art folding knives of this type have a variety of blade locking engagement structures to afford a number of blade lock and release positions, see for example U.S. Pat. Nos. 5,093,995, 5,685,079, 6,574,869, 6,751,868, and 6,918,184. 
   In U.S. Pat. No. 5,093,995 a knife locking mechanism is disclosed that uses a pressable lock pin having a notch therein to be resiliently engaged with a corresponding notch in the blade, locking same in extended use position. 
   U.S. Pat. No. 5,685,079 claims a locking mechanism for a folding knife in which a lever is movable between two positions using a notched cylinder body to selectively engage a portion of the blade. 
   U.S. Pat. No. 6,574,869 is directed to a folding pocket knife with a lock having a locking pin that is slidably positioned to engage a shoulder on the blade. 
   U.S. Pat. No. 6,918,184 discloses a knife with an integral stop pin of a locking mechanism is used to prevent the inadvertent closing of the knife blade as well as over extension of the blade during use. 
   Finally, in U.S. Pat. No. 6,751,868 a folding knife with a spherical locking mechanism is illustrated having a ball biased by a coil spring. The ball selectively engages a tongue portion on the heel end of the blade preventing the blade from rotation, locking same. 
   SUMMARY OF THE INVENTION 
   A locking reinforcement mechanism for a folding knife utilizing a reinforcement pin that transfers the associated load pressure from the lock pivot pin of the lock bar and imparts a safety prevention feature by reducing the possibility of shearing of the lock bar engagement hook portion on the knife blade heretofore associated with the knife lock failure under extreme load induced stress. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational view of the folding knife in open locked position with the reinforcing pin of the invention; 
       FIG. 2  is an enlarged partial top plan view of the reinforcing pin and adjacent knife elements thereof; 
       FIG. 3  is a side elevational view of the reinforcing pin equipped knife in unlocked partial folded position; 
       FIG. 4  is an enlarged perspective view of the reinforcing pin of the invention; 
       FIG. 5  is a partial side elevational view of a prior art folding knife locking mechanism. 
       FIG. 6  is a partial side elevational view of an alternate configuration of the invention. 
       FIG. 7  is a partial side elevational view of a second alternate configuration adjustable lock bar pivot point. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to  FIG. 1  of the drawings, a folding knife  10  can be seen in unfolded locked position. The knife  10  has a blade portion  11  pivotally secured to a handle support portion  12 . The handle support portion  12  has frame members  13  with a pivoted locking bar  14  and interengaging spring element  15 . The blade portion  11  is pivotally secured via a hinge pin  16  therethrough as that which is manually deployed for a folding knife configuration. The blade portion  11  defines a blade  17  is accordingly removably disposed within a blade retention slot  18  defined within the handle support portion  12  so that a sharpened edge  17 A of the blade  17  is safely enclosed therewithin. The blade  17  has a shank portion  19  which is apertured at  20  through which the hinge pin  16  extends pivotally securing the blade  16  to the handle support portion  12  as hereinbefore described. 
   The shank portion  19  has an arcuate end edge  21  that defines at its upper terminus a shank hook  22  formed therein. The locking bar  14  has a correspondingly engageable notched free end portion  23  that is registerably engaged to the shank hook  22  when in unfolded locked position. The hereinbefore described folding knife structure is typical of a prior art knifes  23 A illustrated for comparison in  FIG. 5  of the drawings. 
   The improvement is directed to a safety reinforcement pin  24  of the invention, best seen in  FIG. 4  of the drawings, that has a main cylindrical body portion  25  with an integral monolithic oppositely disposed axially aligned cylindrical mounting lugs  26 A and  26 B extending respectively therefrom. The mounting lugs  26 A and  26 B are set into the corresponding rail frame elements  13  as best seen in  FIG. 2  of the drawings. 
   During the blade  17  deployment from within the handle support portion  12 , the blade shank portion  19  arcuate edge  21  will engage the notched end portion  23  of the locking bar  14  which is pivotally deployed via a pivot pin  14 A against the resilient spring element  15  as seen in  FIG. 3  of the drawings which upon the blade  17  full deployment maintains a locking relationship with the shank hook portion  22  as seen in  FIG. 1  of the drawings. 
   An alternate modified configuration can be seen in  FIG. 6  of the drawings in which a knife  28  is illustrated having an extended free end portion  28 A that overlies the reinforcement pin  24 . This feature hides the pin  24  from view which may be desirable in some applications. 
   It will be seen therefore that a parallel abutting relationship is defined between a forward edge portion  19 A of the shank from the hook  22  with an engagement end surface  23 B of the end portion  23  of the locking bar  15  in fully deployed (open position. The reinforcing pin  24  will registerably engage the end surface  23 B of the locking bar  14  and under applied to positive or negative pressure indicated by load arrows  27 , a load transfer will occur correspondingly relieving the lock bar pivot pin  14 A of failure inducing pressure preventing the lock bar portion  23  from shearing off as is previously the case common within the prior art. 
   Referring now to  FIG. 7  of the drawings, a second alternate form of the invention can be seen at  30  in which a modified lock bar  31  improvement is disclosed having a central body member  32 , defining a resilient engagement portion  33  with a shank extending hook portion  34  formed on the oppositely disposed end thereof. The shank extension hook  34  has a safety reinforcing pin engagement surface  32 A and a shank hook engagement surface  32 B. The safety reinforcement pin engagement surface  32 A and the shank hook engagement surface  32 B are both of a co-parallel arcuate angular inclination as illustrated. A safety reinforcement pin  35  the same as previously disclosed pin  24  is positioned and used in the same manner to transfer load input indicated by directional arrows to a lock bar pivot pin  36 . In this improved alternate form of the invention, an elongated opening at  37  in the lock bar  31  is provided through which the pivot pin  36  extends. This engagement will allow for an effective adjustable “pivot point” relative to the lock bar  31  position on its longitudinal axis. The adjustable “pivot point” will in turn provide for wear compensation of the critical engagement surfaces during long term use keeping the effective engagement surfaces in proper engagement orientation in which the respective angular safety reinforcement pin engagement surface  32 A and corresponding angular shank hook engagement surface  32 B will effectively maintain the lock bar  31  secure engagement between the safety reinforcement pin  35  and a shank hook  38  extending from the shank maintaining the blade  39  in a secure lock extended open position resistant to bi-lateral force input by transfer to said lock bar pin  36 . 
   It will be seen that with the addition of the safety reinforcement pin  24  and of the invention within a modified folding knife locking assembly as hereinbefore illustrated and described, that an improved and enhanced folding knife  10  has been achieved. 
   It will thus be seen that a new and novel folding knife configuration of an improved locking mechanism has been illustrated and described and it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention.