Patent Publication Number: US-11020863-B1

Title: Locking device for a folding knife

Description:
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 there within when not in use. Such folding knives have blade engagement locking devices to secure, 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 the upper back edge of the knife and requires a manual depression at one end to release the free end from direct engagement within a retaining lock notch formed in the blade inwardly of 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, 6,918,184, 7,222,429 and 7,469,476. 
     In U.S. Pat. No. 5,093,995 a knife locking mechanism is disclosed that uses a preassembled 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 notch 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 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 an inadvertent closing of the knife blade as well as over extension of the blade during use. 
     U.S. Pat. No. 6,751,868 shows 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 of the heal of the blade preventing the blade from rotation locking same. 
     U.S. Pat. No. 7,222,429 discloses a folding knife with a locking pin engagement with a locking bar. The locking pin in one form is tapered so as to provide adjustable diameter pin surface that engages the locking bar partially there against. 
     Applicant&#39;s U.S. Pat. No. 7,469,476 discloses an improvement to a folding knife locking reinforcement wherein an improved safety pin is disclosed with an elongated bar pivot point opening and an extended locking bar free end portion that overrides the pin. 
     SUMMARY OF THE INVENTION 
     An improved locking reinforcement mechanism for a folding knife utilizing a contoured reinforcement pin that transfers load pressures from the lock pivot pin of the locking bar and an enhanced locking bar pivot position by both longitudinal and vertical bar displacement under activation obviating knife lock failure and maintaining operational use and safety. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view of the folding knife with portions broken away in opened locked position with reinforcing pin and locking bar of the invention. 
         FIG. 2  is an enlarged partial top plan view with portions broken away of the reinforcing pin and repositional pivot position of the locking bar. 
         FIG. 3  is a side elevational view with portions broken away of the folding knife in full closed position. 
         FIG. 4  is a partial side elevational view with portions broken away of the reinforcing pin and locking bar equipped knife in unlocked partial deployed position. 
         FIG. 5  is an enlarged perspective view of the improved reinforcing pin. 
         FIG. 6  is a large top plan view thereof. 
         FIG. 7  is an enlarged end elevational view on lines  7 - 7  of  FIG. 5 . 
         FIG. 8  is an enlarged partial side elevational view of the improved locking bar and pivot pin readjustable positions therein shown in broken lines. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIG. 1  of the drawings, a folding knife  10  of the invention 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 a frame member  13  with a pivoted locking bar  14  and independent spring element  15  extending from the handle support portion  12  for engagement therewith. 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  which is removably disposed within a blade retention slot  18  defined within the handle support  12  so that the sharpened edge  17 A of the blade  17  is safely enclosed therewithin. The blade  17  has a shank portion  19  apertured at  20  through which the blade hinge pin  16  extends. The shank portion  19  has an arcuate end edge  21  that defines at its upper terminus a shank hook  22  formed within. 
     The locking bar  14  has a corresponding engageable notched end portion  23  with a contoured angle surface  23 A and a corresponding contoured angle notched surface  23 B that is registerably engaged with the shank hook  22  when in folded open locked portion. The pivoting lock bar  14  has an enlarged preferably annual shaped pivot pin receiving opening at  24  for a bar lock pivot pin  25 , best seen in  FIGS. 1, 2 and 8  of the drawings. It will be seen that the orientation of the locking bar pivot pin  25  within the enlarged opening  24  during bar activation shown in broken lines in  FIG. 1  and solid lines in  FIG. 8  of the drawings provides for an adjustable repositioning of a pivot point thereby a true adjustable pivot point PP is achieved for the locking bar  14 . It will be seen that the adjustable pivot point PP will in turn provide and accommodate for user wear and for manufacturing variations inherent in such knife use and manufacturing which effects both its longevity and vertical angular orientation. This adaptable repositioning of the pivot point PP generally indicated by broken directional arrows P in  FIGS. 1 and 8  of the drawings assures proper locking bar safety repositioned pin and shank hook engagement during operational open lock and release parameters. 
     The spring element  15  as seen extending from the frame  13  is engaged on the locking bar  14  portion in spaced longitudinal relation to the pivot pin  25  bar engagement providing spring urged return action to the locking bar during use. 
     Referring now to  FIGS. 1 and 5-7  of the drawings, a modified improved safety reinforcement pin  27  of the invention can be seen having a main cylinder body portion  28  with integral monolithic oppositely disposed axially aligned cylindrical mounting lugs  29 A and  29 B of reduced diameter extending respectively therefrom. The mounting lugs  29 A and  29 B are correspondingly registerable in spaced opposing mounting apertures AP in the real frame elements  13 , best indicated and seen in  FIG. 2  of the drawings. 
     The main cylinder body portion  28  has a contoured relief portion  28 A formed therein extending laterally a distance equal to the corresponding reduced transverse diameter of the hereinbefore described mounting lugs  29 A and  29 B indicated graphically by broken dimensional equivalent lines DL in  FIG. 7  of the drawings. 
     Referring to  FIG. 1  of the drawings, it will be seen that the locking bar contoured end surface  23 A will registerably engage the safety reinforcement relief surface  28 A. Correspondingly, the engagement surfaces  23 A and  23 B of the locking bar are both of a co-parallel arcuate angular inclination as illustrated effecting a positive engagement between the safety reinforcement pin  27  and the blade&#39;s shank hook  22 . The safety reinforcement pin  27  is used therefore to transfer load input indicated by directional arrows to the lock bar fixed pivot pin  25  within the lock bar receiving opening  24 . 
     It will be seen as such that under operational user input, the lock bar will move about the fixed pivot pin  25  from a bottom center position creating an effective alternate pivot point location indicated graphically in  FIG. 8  of the drawings. This re-orientation of the effective lock bar pivot point PP provides release from the under-cut engagement of the shank hook engaged surface  22 . 
     It will also be seen that the corresponding engagement of the lock bar engagement surface  23 A with the safety reinforcement pins main cylinder body&#39;s relief contoured surface  28 A affords a more positive engagement when in locked position. This combination assures that the locking mechanism won&#39;t jam or be difficult to use with improved locking and unlocking prerequisites despite variations in manufacturing tolerances and extended use wear which occurs in such products. 
     During the blade  17  deployment from within the handle support portion  12 , best seen in  FIGS. 3 and 4  of the drawings, the blade shank portion arcuate edge  21  will rotatably engage the notched end portion  23  of the locking bar  14  which is pivotally displaced on the locking bar pivot pin  25  within the bar&#39;s enlarged pin receiving opening at  24  against the resilient spring bar  15 . The locking bar  14  end portion&#39;s contoured end surfaces  23 A and inner surface  23 B will thereby registerably engage respectively against the corresponding safety reinforcement pin relief surface  28 A and blade shank hook surface  22  as seen in  FIG. 1  of the drawings. The locking bar contoured engagement surface  23 A and spaced inner engagement surface  23 B are of a co-parallel arcuate angular inclination to one another as hereinbefore described. 
     To unlock and close the folding knife  10  of the invention, the user, not shown, applied force is applied to the lock bar  14  indicated by force arrow FA position in  FIGS. 1 and 4  of the drawings repositioning the effective lock bar pivot point PP within the enlarged annular opening  24  as seen graphically in  FIG. 8  of the drawings. This pivot point PP re-orientation on multiple axis allows clearance needed in respect to the notch bars end portion  23  surface to disengage as indicated in broken lines in  FIGS. 1 and 4  of the drawings. 
     It will be seen that with the modified safety reinforcement pin  27  and repositional pivot point of the lock bar  14  in both longitudinal and vertical axis imparted by the lock bar&#39;s fixed pivot pin  25  within the enlarged annular opening  24  as hereinbefore illustrated and described that an improved and enhanced locking mechanism has been illustrated and described and it will be apparent to those skilled in the art that various changes and modification may be made therein without departing from the spirit of the invention. Therefore, I claim: