Abstract:
A knife is provided. The knife comprises a handle and a blade configured to pivot with respect to the handle between an open position wherein a cutting edge of the blade is exposed and a closed position wherein the cutting edge of the blade is disposed within the handle, the blade including an abutting surface. The knife may further comprise a locking assembly configured to releasably lock the blade in the open position, the locking assembly comprising a biased, rotatable member having a canted surface for engaging a corresponding surface on the blade, wherein the canted surface and the corresponding surface are configured to secure the blade relative to the handle in the open position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Embodiments of the present invention generally relate to hand tools, and more specifically to a folding knife having a blade lock and release mechanism. 
     2. Description of the Related Art 
     Conventional folding knives have various locks for locking the blade in the open position. For example, a conventional “lock back” style of folding knife provides for the blade to be locked in the open position, and the blade is released by depressing a lever into a cutout in the rear of the handle. However, this arrangement requires substantial repositioning of the entire knife in the user&#39;s hand in order to provide access and leverage for depressing the lever. 
     Furthermore, conventional folding knives do not necessarily lock the blade in the closed position. Thus, the knife may inadvertently open at inopportune times, presenting a hazard to the user. 
     SUMMARY OF THE INVENTION 
     According to aspects of the present invention, a knife is provided. The knife comprises a handle and a blade configured to pivot with respect to the handle between an open position wherein a cutting edge of the blade is exposed and a closed position wherein the cutting edge of the blade is disposed within the handle, the blade including an abutting surface. The knife may further comprise a locking assembly configured to releasably lock the blade in the open position, the locking assembly comprising a biased, rotatable member having a canted surface for engaging a corresponding surface on the blade, wherein the canted surface and the corresponding surface are configured to secure the blade relative to the handle in the open position. 
     According to another aspect of the present invention, a knife is provided. The knife may comprise a handle having a first side and a second side and a blade disposed between the first and second sides and pivotally movable relative to the handle between an open position and a closed position. The knife may further comprise a locking assembly for releasably locking the blade in the open position, the locking assembly comprising a rotatable member having a gripping portion accessible via an aperture in one side of the handle and a canted surface for engagement with the blade, and wherein the rotatable member is pivotally movable with respect to the handle between a locked position and an unlocked position. 
     According to another aspect of the present invention, a knife is provided. The knife may comprise a handle having a first side and a second side and a blade disposed between the first and second sides and pivotally movable relative to the handle between an open position and a closed position. The knife may further comprise a locking means for releasably locking the blade in the open position and in the closed position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIG. 1  is a perspective view of a folding knife according to certain embodiments of the present invention. 
         FIG. 2  illustrates an exploded view of a folding knife according to certain embodiments of the present invention. 
         FIG. 3  illustrates a partial view of a folding knife with the blade in an open, locked position, according to certain embodiments of the present invention. 
         FIG. 4  illustrates a pivoting end of a blade of a folding knife according to certain embodiments of the present invention. 
         FIG. 5  illustrates a side view of a rotatable member for locking the blade of a folding knife according to certain embodiments of the present invention. 
         FIG. 6  illustrates a perspective view of a rotatable member for locking the blade of a folding knife according to certain embodiments of the present invention. 
         FIG. 7  illustrates a cross section view of a folding knife with the blade in an open, locked position, according to certain embodiments of the present invention. 
         FIG. 8  illustrates a cross section view of a rotatable member and a blade of a folding knife in an opened, locked position, according to certain embodiments of the present invention. 
         FIG. 9  illustrates a partial view of a folding knife with the blade in a pivoting, unlocked position, according to certain embodiments of the present invention. 
         FIG. 10  illustrates cut away view of a folding knife with the blade in a pivoting, unlocked position, according to certain embodiments of the present invention. 
         FIG. 11  illustrates a partial view of a folding knife with the blade in a closed, locked position, according to certain embodiments of the present invention. 
         FIG. 12  illustrates cut away view of a folding knife with the blade in a closed, locked position, according to certain embodiments of the present invention. 
         FIG. 13  illustrates a perspective view of a folding knife according to an alternative embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring specifically to the Figures in which identical or similar parts as designated by the same reference numerals throughout, and further referring to  FIG. 1 , the folding knife in accordance with the present invention is generally designated by reference numeral  100 . 
       FIG. 1  is a perspective view of the folding knife  100  according to certain embodiments to the present invention.  FIG. 2  is an exploded view of the folding knife  100 . Folding knife  100  includes blade  102 , which is pivotally mounted to handle  104   a, b , locking assembly  106  for retaining the blade in an open and closed position, interconnecting bolt  116   a  and mating interconnecting nut  116   b  for maintaining the blade in the handle, rear support  118 , fasteners  120 , and gaskets  136 . 
     The handle  104  may be comprised of two parts  104   a, b  as shown. Locking assembly  106  is mounted with the handle  104  for locking the blade  102  in an open position, as shown in  FIG. 1 , and closed position. Lock support  114  (which is part of locking assembly  106 ) and rear support  118  are disposed between two parts of the handle  104 . The space between the two parts  104   a, b  of the handle  104  due to lock support  114  and rear support  118  allow for pivoting end of the blade  102  to be located within the handle. In alternative embodiments, the handle  104  may be comprised of a single part forming both sides of the knife  100 , with the locking assembly  106  integrated into the handle  104  with fasteners  120 . 
     As seen in  FIG. 2 , folding knife  100  includes locking assembly  106 . Locking assembly  106  comprises a rotatable member  108 , coiled spring  110 , pivot pin  112 , and lock support  114 . Pivot pin  112  attaches the rotatable member  108  to the lock support  114  and allows rotatable member  108  to rotate with respect to lock support  114 . Coiled spring  110  is disposed between the rotatable member  108  and lock support  114  so that rotatable member  108  is rotationally biased with respect to lock support  114 . For example, the coiled spring  110  may rotationally bias the rotatable member in the direction indicated by arrow  144  in  FIGS. 5 and 6 . According to alternative embodiments, the biasing force could be provided from a suitable structure other than coiled spring  110 , such as a flexible member or a compressible member, for example. 
     The lock support  114  is disposed between the two portions of the handle  104   a, b  and connected thereto with fasteners  120 . Lock support  114  may include a gripping portion to improve a user&#39;s grip on the folding knife  100 . In the embodiment shown, rotatable member  108  includes serrations on one side to enable a user to apply a force to overcome the bias due to coiled spring  110 . The serrations are arranged to protrude from the inside of the handle  104  through a large aperture  138  formed in the handle part  104   a  so that a user can apply a force against the biasing force of coiled spring  110  from the exterior of the folding knife  100 . The portion of the rotatable member  108  opposite the serrations extends into a small aperture  140  formed in handle part  104   b . However, the portion of the rotatable member  108  opposite the gripping portion may not protrude entirely through the small aperture  140 . For example, as can be seen in  FIG. 7 , discussed further below, the rotatable member  108  does not extend to the exterior of handle portion  104   b.    
     Interconnecting bolt  116   a  connects through the handle  104 , gaskets  136 , and blade  102 , with interconnecting nut  116   b  to hold the blade  102  in pivoting arrangement to handle  104 . Gaskets  136  may provide for smooth pivoting movement of the blade  102  with respect to handle  104  and are therefore made of a suitable material such as durable plastic, rubber, silicon or the like. Rear support  118  is disposed between the two halves of the handle  104  with fasteners  120 . 
       FIG. 3  is a partial view of the folding knife  100  according to aspects of the present invention, in which blade  102  is locked in an open locked position by the locking assembly  106 . In  FIG. 3 , one side of the handle  104  has been omitted to illustrate the arrangement between the blade  102  and locking assembly  106 . A blade stop surface  126  on the blade  102  abuts a lock support stop surface  128  on the lock support  114 , thus preventing the blade from rotating any further in an open direction. The biasing force of coiled spring  110  urges the rotatable member into the open locked position, which in turn, urges the blade  102  in the direction indicated by the arrow  142  in  FIG. 3 , so that blade stop surface  126  is firmly urged against lock support stop surface  128 . This arrangement provides for a more secure locked position for the blade in the open position with respect to the handle. 
     As shown in  FIG. 4 , blade  102  includes a canted blade surface  122  having an angle A relative to the thickness of the blade  102 . As shown in  FIGS. 5 and 6 , rotatable member  108  includes a corresponding canted blade lock surface  124 . Canted blade lock surface  124  has an angle B relative to the plane perpendicular to the thickness of rotatable member  108 . The coil spring  144  biases the rotatable member  108  in the direction of arrow  144  shown in  FIG. 5 . 
       FIG. 7  is a cross-section of folding knife  100  viewed from a plane perpendicular to the length of the folding knife  100  through the point at interconnecting bolt  116   a  and interconnecting nut  116   b , and illustrates the locking arrangement between the blade  102  and the locking assembly  106  when the blade is in the open locked position. In  FIG. 7 , the canted blade lock surface  124  (having an angle B) of rotatable member  108  is disposed against canted blade surface  122  (having an angle A) of blade  102 . Rotatable member  108  is biased against blade  102  due to the force from coiled spring  110  (not shown in  FIG. 7 ). Due to their geometry, the canted blade surface  122  is biased against the canted blade lock surface  124 , urging the blade  102  in the open direction. Blade stop surface  126  prevents the blade from opening further due to its abutment to lock support stop surface  128 , as illustrated in  FIG. 3 . 
     The tension created by coiled spring  110  biasing the rotatable member  108  into the position shown in  FIG. 7  creates tension that causes the blade to remain in a locked and secured, immobile position relative to the handle  104 . This immovable arrangement is due to the interaction of canted blade lock surface  124  with the canted blade surface  122  of blade  102 , and keeps the blade secured in the locked position even as components may be worn over time, and without requiring excessively precise manufacturing tolerance. 
       FIG. 8  also illustrates the arrangement between rotatable member  108  and blade  102  in the open, locked position. As indicated by the arrow  146 , the rotatable member  108  is urged towards the locking position due to the biasing action of coiled spring  110 . This urges the blade  102  to rotate as indicated by the arrow  148  into the open position, while rotation is stopped in the open locked position due to the blade stop surface  126  abutting lock support stop surface  128 . 
       FIG. 9  illustrates the blade  102  in the unlocked, pivoting position in which the blade  102  in a partially open position and free to pivot with respect to the handle  104 . In order to move the blade  102  from the locked position, as shown in  FIG. 3 , to the unlocked, partially open position shown in  FIG. 9 , the user rotates rotatable member  108  against the biasing force of coiled spring  110  so that the canted blade lock surface  124  is no longer engaged with canted blade surface  122 . Rotatable member  108  may be disposed on one side of the blade handle (rather than the top, for instance), so that it can be readily moved from the locked to the unlocked, partially open position with a user&#39;s thumb. Thus, according to some embodiments, the rotatable member  108  and the large aperture  138  may be located in an ergonomic position with respect to the handle  104  for ease of safe engagement by a user. In alternative embodiments, the rotatable member  108  and large aperture  138  may be located on a side of the handle suitable for ease of use by a left-handed user. 
       FIG. 10  is a cross section view illustrating this unlocked, partially open position of the rotatable member  108 . In some embodiments, the user must continue to overcome the biasing force of coiled spring  110  to allow the blade to freely pivot in the range between the two locked positions. In other embodiments, blade  102  may be free to pivot even if the user is not overcoming the biasing force of coiled spring  110 . In other words, the biasing force of coiled spring  110  urges the rotatable member  108  against the blade  102 , but without excessive force that would prevent blade  102  from pivoting with respect to handle  104 . Thus, the canted blade lock surface  124  of rotatable member  108  is urged against the blade  102  without locking the blade  102  as the blade pivots so long as the blade is not pivoted to the open or closed locked position, i.e., into engagement with canted blade surface  122  or blade lock detent  122 . 
       FIGS. 11 and 12  illustrate the folding knife  100  in the closed locked position. If the biasing force of coiled spring  110  is not overcome, rotatable member  108  is urged towards the locked position. When the blade  102  pivots all the way to the closed position shown in  FIG. 11 , coiled spring  110  urges canted blade lock surface  124  of rotatable member  108  into the blade stop detent  132  of blade  102 . This locks the blade in the closed locked position, and the user must overcome the biasing force of coiled spring  110  on rotatable member  108  in order to unlock and open the blade. When the user overcomes the biasing force of coiled spring  110  and moves the rotatable member  108  out of the locked position, the blade is free to pivot between the closed and open positions, as shown in  FIG. 10 . In the embodiments shown, there is no blade lock position on the blade  102  between the open locked position and the closed lock position. 
     Blade stop knob  130  prevents the blade  102  from pivoting further into handle  104 , thus preventing blade edge  134  from contacting the inner components inside the handle  104 , such as rotatable member  108  or lock support  114 , for example. This prevents the blade edge  134  from being unnecessarily dulled or damaged as it is moved to the closed, locked position or while the folding knife  100  is carried in the closed, locked position. 
       FIG. 12  is a cross section view of the folding knife  100  in the closed locked position. Rotatable member  108  is biased in the counterclockwise direction in the locked position due to the force from coiled spring  110 . The rotatable member  108  is disposed in blade stop detent  132  and prevents the blade  102  from opening. Blade stop knob  130  abuts rotatable member  108 , thereby preventing the blade  102  from pivoting further into the handle, thereby protecting blade edge  134 , as discussed above. 
     In the figures, blade  102  is depicted as a sporting-type blade. However, the blade  102  could be any suitable type of blade, such as a saw blade or a tanto-type blade, for example. 
     Another example is shown in  FIG. 13 . The blade  102  may be a utility blade  150  mounted in a blade carrier  152 . In the arrangement shown in  FIG. 13 , the utility blade and corresponding blade carrier pivot together with respect to the handle  104 . A blade release member  154  is biased to releasably lock the utility blade  150  to the blade carrier  152 . In the biased, locked position, the blade release member  145  engages a mounting notch (not shown) in the utility blade  150 . A user may overcome the biasing force so that the blade release member  145  no longer engages the mounting notch in the utility blade  150 , thereby allowing the blade  150  to be easily removed and replaced from the front of the blade carrier  152 . The biasing force on blade release member  154  may be provided by a spring or other suitable biasing member. Other suitable blade lock mechanisms for releasably locking the utility blade  150  to the blade carrier  152  may be utilized without departing from the scope of the present invention. For example, a suitable blade lock mechanism for releasably locking a utility blade to a blade carrier is disclosed in U.S. Pat. No. 7,520,059, which is herein incorporated by reference. 
     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.