Abstract:
A knife system including a mechanism for automatically advancing a cutting blade. The knife system includes a click mechanism that a user is capable of selectively actuating. Each actuation of the click mechanism causes the cutting blade to become either exposed or unexposed. The knife system also includes a break off mechanism that aids a user in removing individual blade segments from the cutting blade.

Description:
[0001]     The present application claims priority to U.S. Provisional Patent Application No. 60/621,218, filed Oct. 21, 2004 and incorporated by reference herein in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to utility knives. More particularly, the present invention relates to utility knives with blades that can be incrementally extended from the device by a user.  
       BACKGROUND OF THE INVENTION  
       [0003]     A number of knives using “break off” blades are conventionally known. In these knives, a user is capable of manually extending the blade as necessary and physically removing the front portion of the blade when the front portion becomes dulled, bent, or otherwise unusable.  
         [0004]     Although such knives are known in the art, each have their own respective drawbacks. In several conventional knife systems, the user must literally take apart the knife to move the blade forward in order to have the blade exposed after a front segment has been removed. This is time consuming and also exposes the user to potential injury during this process. Other systems, while incorporating a rudimentary “blade advance” feature, are only capable of moving the blade forward and backward by a predetermined amount and are not able to incrementally move the blade forward such that a front segment can be broken off, while leaving the next segment of the blade exposed for immediate use. Furthermore, many conventional knife systems do not have any built-in mechanism for breaking off individual blade segments, instead requiring the user to break off the segments using his or her hands. This creates additional safety concerns.  
         [0005]     It would therefore be desirable to develop a knife system that is easy to use, while addressing the above-identified shortcomings.  
       SUMMARY OF THE INVENTION  
       [0006]     It is therefore an object of the invention to provide an improved knife system that enables a user to quickly and easily extend a cutting blade from the unit as front segments of the blade become dulled, damaged, or otherwise unusable.  
         [0007]     It is another object of the invention to provide an improved knife system that enables a user to extend a cutting blade without having to opening the unit.  
         [0008]     It is still another object of the invention to provide an improved knife system that reduces the potential for user injury when the user is in the process of extending a cutting blade.  
         [0009]     It is yet another object of the invention to provide an improved knife system that provides a mechanism for enabling a user to quickly and easily remove individual segments of a cutting blade.  
         [0010]     In accordance with the above-identified objects, the present invention comprises a knife system including a “click assembly” that enables a user to quickly and easily extend a cutting blade that is operatively connected to the assembly. The click assembly is operatively connected to a blade advance biasing member. Actuation of the knob of the click assembly causes the cutting blade to alternately become available and unavailable for use.  
         [0011]     The present invention provides a number of benefits not found in conventional systems. For example, the advancing mechanism used in the present invention provides a limited blade advancement system for everyday use, as well as virtually unlimited blade advancing and retracting for blade changing or breakoff. This is in sharp contrast to conventional systems, where the click function is typically used only for a fixed blade that is not capable of having individual segments removed or snapped off.  
         [0012]     These and other objects, advantages and features of the invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described below. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view of a utility knife according to one embodiment of the present invention;  
         [0014]      FIG. 2  is a right side view of the utility knife of  FIG. 1 ;  
         [0015]      FIG. 3  is a top view of the utility knife of  FIG. 1 ;  
         [0016]      FIG. 4  is a left side view of the utility knife of  FIG. 1 ;  
         [0017]      FIG. 5  is a bottom view of the utility knife of  FIG. 1 ;  
         [0018]      FIG. 6  is a front view of the utility knife of  FIG. 1 ;  
         [0019]      FIG. 7  is a back view of the utility knife of  FIG. 1 ;  
         [0020]      FIG. 8  is an exploded view of the utility knife of  FIG. 1 ;  
         [0021]      FIG. 9  is a sectional side view of the rear portion of the utility knife of  FIG. 1 ;  
         [0022]      FIG. 10  is a side view of the click assembly of the utility knife of  FIG. 1 ;  
         [0023]      FIG. 11  is a sectional side view of the click assembly taken along lines A-A of  FIG. 10 ;  
         [0024]      FIG. 12  is a rear view of the click assembly of  FIG. 10 ;  
         [0025]      FIG. 13  is a perspective view of a portion of a click assembly body according to one embodiment of the present invention;  
         [0026]      FIG. 14  is a perspective view of an indexer according to one embodiment of the present invention;  
         [0027]      FIG. 15  is a perspective view of a positioner according to one embodiment of the present invention;  
         [0028]      FIG. 16  is a perspective view of a click mechanism when the click mechanism is in the retracted position;  
         [0029]      FIG. 17  is a perspective view of the click mechanism of  FIG. 16  as the knob is in the process of being actuated and moved towards the positioner and the indexer;  
         [0030]      FIG. 18  is a perspective view of the click mechanism of  FIG. 16  as the knob is fully actuated;  
         [0031]      FIG. 19  is a perspective view of the click mechanism of  FIG. 16  as the knob is in the process of being retracted;  
         [0032]      FIG. 20  is an exploded view of an additional embodiment of the click system of the present invention; and  
         [0033]      FIG. 21  is a view of the knife of  FIG. 20  with the second body portion removed. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]     A knife assembly constructed in accordance with the principles of the present invention is shown at  20  in  FIGS. 1-8 . The knife assembly  20  includes a housing  21  having a first body portion  22  and a second body portion  24 . A cutting blade  26  is positioned between the first body portion  22  and the second body portion  24  and is extendible through the front end of the knife assembly  20 . As shown in  FIGS. 1, 2  and  4 , the cutting blade  26  can include a plurality of cutting blade segments  28 . The cutting blade segments  28  are capable of being physically broken off from the remainder of the cutting blade  26 , so that the user can continue to use the cutting blade in the event that an individual cutting blade segment becomes bent, dulled, or otherwise unusable.  
         [0035]     As is shown in  FIG. 8 , the cutting blade  26  is engageable with a follower  30  via a blade holder  44 . As the blade holder  44  is operatively connected to the cutting blade  26  at one end and the follower  30  at the other end, any movement of the follower  30  results in a commensurate movement of the cutting blade  26 . The follower  30  engages a blade advance biasing member  42  at an end opposite the blade holder  44 .  
         [0036]     The opposite end of the blade advance biasing member  42  engages a click assembly  52 . One embodiment of the click assembly  52  is shown in detail in  FIGS. 9-12 . The click assembly  52 , in one embodiment of the invention, comprises a click assembly body  32 , an indexer  34 , a positioner  36  and a knob  38 . In one embodiment of the invention, the indexer  34  and the positioner  36  are bonded or coupled together so as to capture a portion of the click assembly body  32 . It is also possible for the indexer  34  and the positioner  36  to be coupled to each other by some other mechanism besides bonding. The click assembly body  32  is capable of sliding within the indexer  34  and the positioner  36 . The knob  38  is coupled to an end of the click assembly body  32  opposite the indexer  34  and the positioner  36  such that movement of the knob  38  results in a corresponding movement of the click assembly body  32 . The knob  38  is positioned outside of the first and second body portions  22  and  24  so as to be actuable by the user.  
         [0037]     As can be seen in  FIGS. 13 and 16 - 19 , the click assembly body  32  includes a plurality of body ramps  59  each having a positioner side  60  and an indexer side  62 . As shown in  FIGS. 14 and 16 - 19 , the indexer  34  includes a plurality of indexer ramps  64  for selective engagement with the plurality of the indexer side  62  of the plurality of the body ramps  59 . The indexer  34  also includes a hole  66  so as to permit a click assembly biasing member  40  (see  FIG. 8 ) to contact and bias the click assembly body  32 . As shown in  FIGS. 15-19 , the positioner  36  includes a plurality of extended position slots  54 , as well as a plurality of retracted position slots  56 .  
         [0038]     The operation of the click assembly  52  is generally as follows and as depicted in  FIGS. 16-19 . When the click assembly  52  is in a fully retracted position, shown in  FIG. 16 , each of the body ramps  59  is fully engaged within a respective retracted position slot  56  of the positioner  36  such that each of the positioner sides  60  of the body ramps  59  contact the positioner  36 . In this position, the cutting blade is not exposed outside the remainder of the knife assembly  20 . When the knob  38  is pressed by the user and as represented in  FIG. 17 , the click assembly body  32  moves forward and the plurality of the body ramps  59  move through the retracted position slots  56  and towards the plurality of the indexer ramps  64 . When the body ramps  59  contact the indexer ramps  64 , the indexer  34  and the positioner  36  pivot as the indexer side  62  of each the plurality of the body ramps  59  engage the plurality of indexer ramps  64 . The forward movement of the click assembly body  32  causes the blade advance biasing member  42  to act against the follower  30 , ultimately causing the cutting blade  26  to incrementally advance.  
         [0039]     In the position shown in  FIG. 18 , the body ramps  59  have fully engaged slots defined by the indexer ramps  64 , temporarily fixing the position of the click assembly body  32  relative to the indexer  34  and the positioner  36 . When in this position, the body ramps  59  are slightly offset relative to the extended position slots  54 . When the user releases pressure on the knob  38 , the click assembly body  32  retracts due to the forces exerted by the click assembly biasing member  40 , the positioner side  60  of the body ramps  59  contact the extended position slots  54 . This is shown in  FIG. 19 . The offset between the body ramps  59  and the extended position slots  54  causes the indexer  34  and the positioner  36  to rotate until the body ramps  59  fully side the extended position slots  54 . At this position, the click assembly body  32  is partially, but not fully retracted. As a result, the blade advance biasing member  42  is also partially, but not fully retracted. In this position, the cutting blade  26  is exposed for use.  
         [0040]     When the user presses the knob  38  once more, the same process generally occurs, but the end result (after the knob  38  is released) is that the body ramps  59  have entered retracted position slots  56  (as shown in  FIG. 16 ) instead of extended position slots  58  (as shown in  FIG. 18 ). Because the retracted position slots  56  are deeper than extended position slots  58 , in this position the click assembly body  32  is farther retracted than in the position shown in  FIG. 18 , which ultimately also causes the cutting blade  26  to be retracted into the knife assembly  20 .  
         [0041]     Another exemplary embodiment of the click assembly  52  is shown in  FIGS. 20 and 21 . In the embodiment of  FIGS. 20 and 21 , the click assembly  52  includes the click assembly body,  32 , a knob  38 , a knob biasing assembly  76 , a catch member  70 , and a catch member bias assembly  72 . In one embodiment, the knob  38  and click assembly body  32  are fixedly connected to each other. The click assembly body  32  includes a click assembly body stop  74  for retaining the click assembly body  32  substantially within the knife assembly  20 . The click assembly body  32  is capable of sliding within the knife assembly  20 . The knob  38  is coupled to an end of the click assembly body  32  such that movement of the knob  38  results in a corresponding movement of the click assembly body  32 . The knob  38  is positioned outside of the first and second body portions  22  and  24  so as to be actuable by a user. The knob bias assembly  76  biases the knob  38  and click assembly body  32  to an extended position, where the knob  38  is positioned away from the body portions  22  and  24  and the click assembly body stop  74  is engaging the first and second body portions  22  and  24 . In one embodiment, a coil spring  40  engages the spring stop  78  and the click assembly body stop  74 . The spring stop  78  is fixed in relation to the body portions  22  and  24  so that the spring  40  exerts force on the click assembly body stop  74  to bias the click assembly body  32  and the knob  38  away from the blade  26 . The click assembly body  32  is affixed to the blade advance biasing member  42  and thus in communication with the blade  26  so that movement of the click assembly body  32  slides the blade  26 .  
         [0042]     A catch member  70  is at least partially disposed along a side of either the first body portion  22 , the second body portion  24 , or therebetween. In one embodiment, the catch member extends slightly beyond the body portion in which it resides. The catch member  70  is adapted to engage the click assembly body  32  in order to retain the click assembly body  32  in place when a user depresses the knob  38 . In one embodiment, the click assembly body  32  includes a detent groove  82  for engagement by the catch member  70 . In one embodiment, the click assembly body  32  includes an aperture  84  through which the click assembly body  32  slidably moves when the knob  38  is depressed. A catch member biasing assembly biases the catch member  70  against the click assembly body  32  wherein when the click assembly body  32  has slid sufficiently to align the detent groove  82  with the catch member  70 , the catch member engages the groove  82  and locks the click assembly body  32  (and therefore the blade  26 ) in place. The catch member  70  may be disengaged from the groove  82  by depressing a button portion  88  of the catch member  70  to shift the catch member  70  from the detent groove  82 , allowing the click assembly body  32  to slide (as biased by the click assembly bias assembly  72 ).  
         [0043]     If a user desires to extend the cutting blade  26  in order to expose new ones of the blade segments  28 , the user rotates the entire click assembly  52  by turning the knob  38 . The rotation of the click assembly causes the blade advance biasing member  42  to rotate as well. In this situation, the blade advance biasing member  42  acts as a screw, which causes the follower  30  and connected components to advance.  
         [0044]     In one embodiment, the knife assembly  20  includes a break off portion. In one exemplary embodiment, the break off portion includes a break off lever  46  which is coupled to the second body portion  24  of the knife assembly according to one embodiment of the present invention. When a user needs to remove a cutting blade segment  28  from the cutting blade  26 , the user pulls the break off lever  46  away from a receiving region  48  on the second body portion  24 . This motion causes a break off end  50  of the break off lever  46  to contact the cutting blade  26 . This focused force of the break off lever  46  against the cutting blade  26  causes the blade segments  28  in front of the contact point to break off from the rest of the cutting blade  26 .  
         [0045]     In another exemplary embodiment, the break off portion includes a collar  90  which is removably attachable to the housing  18 . The collar  90  includes a slot  92  adapted to receive the blade  26 . In use, a user removes the collar  90  from the housing  21  and inserts the end of the blade  26  into the slot  92 . The user bends the blade  26  with sufficient force with respect to the collar  90  to remove at least one of the cutting blade segments  28 .  
         [0046]     While several embodiments have been shown and described herein, it should be understood that changes and modifications can be made to the invention without departing from the invention in its broader aspects.