Abstract:
A foldable knife having a handle and a blade holder movably mounted on the handle for movement from an unfolded position to a folded position. The handle has a space adapted to receive the blade holder when the blade holder is in its folded position. The blade holder has a blade locking mechanism.

Description:
BACKGROUND 
       [0001]    The present invention relates to a folding knife and more particularly to a foldable utility knife in which the blade may be folded into the handle when the knife is not in use. The application is an improvement over U.S. patent application Ser. No. 10/750,134 filed Dec. 13, 2003 and now U.S. Pat. No. 6,968,622 and Ser. No. 10/437,089 filed May 13, 2003 and now U.S. Pat. No. 7,040,022. 
         [0002]    Utility knives have been in use for a number of years. Some of these utility knives have blades that are mounted on a blade holder which is foldable within a handle when the knife is not in use. However, some of these utility knives have many movable parts which makes them difficult to use and expensive to manufacture. In some of these utility knives replacement of the blade is a complicated operation which may require the use of special tools. In addition, some existing utility knives do not have means to support a finger when the knife is in use nor do they have adequate means to store extra blades. 
       OBJECTS 
       [0003]    The present invention overcomes these problems and has for one its objects the provision of an improved utility knife in which the blade holder may be easily folded into the handle. 
         [0004]    Another object of the present invention is the provision of an improved utility knife in which the blade is held securely on the blade holder. 
         [0005]    Another object of the present invention is the provision of an improved utility knife in which improved means are provided for replacing the blade on the blade holder. 
         [0006]    Another object of the present invention is the provision of an improved utility knife which is simple to use and inexpensive to manufacture and maintain. 
         [0007]    Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to described, or will be indicated in the appended claims and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. 
     
     
       DRAWINGS 
         [0008]    A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification, wherein: 
           [0009]      FIG. 1  is an exploded perspective view of a utility knife made in accordance with the present invention. 
           [0010]      FIG. 2  is a perspective view of the utility knife of the present invention. 
           [0011]      FIG. 3  is a top plan view thereof. 
           [0012]      FIG. 4  is a sectional view taken along the line  4 - 4  of  FIG. 2 . 
           [0013]      FIG. 5  is an enlarged sectional view of the blade locking mechanism of the present invention. 
           [0014]      FIG. 6  is a side elevational view showing the blade being removed. 
           [0015]      FIG. 7  is an enlarged perspective view of the blade locking mechanism of the present invention. 
           [0016]      FIG. 8  is a side elevational view of the present invention showing the blade storage component in a closed position. 
           [0017]      FIG. 9  is a view similar to  FIG. 8  showing the blade storage compartment in an open position. 
           [0018]      FIG. 10  is an enlarged fragmentary sectional view showing the storage compartment cover release mechanism in a locked cover closing position. 
           [0019]      FIG. 11  is an enlarged fragmentary sectional view similar to  FIG. 10  showing the storage compartment cover release mechanism in an unlocked cover opening position. 
           [0020]      FIG. 12  is a sectional view taken along line  12 - 12  of  FIG. 3  showing the utility knife in an open position. 
           [0021]      FIG. 13  is a sectional view similar to  FIG. 12  showing the utility knife a partially folded position. 
           [0022]      FIG. 14  is a sectional view similar to  FIG. 12  showing the utility knife in a fully folded position. 
           [0023]      FIG. 15  is a plan view of the opposite side of the utility knife. 
       
    
    
     DESCRIPTION 
       [0024]    Referring to the drawings, the utility knife  1  of the present invention comprises a handle assembly  2  and a blade holder  3 . The blade holder  3  is pivotally mounted on the handle  2  by means of a pivot assembly  22  from an open position to a closed position. 
         [0025]    The handle assembly  2  comprises a side wall  4  having an upper edge  7  and a lower edge  9 . A U-shaped blade storage compartment  5  having an inner wall  15  is provided and attached to the side wall  2  through the intermediation of a spacer  6  extending inwardly from side wall  4  and preferably integral therewith. The spacer  6  creates a space  8  ( FIG. 4 ) between side wall  2  and the inner wall  15  of the blade storage compartment  5 . The spacer  6 , the side wall  2  and the blade holding compartment  5  are held together by fasteners  10  and  11  which extend through the spacer  6 , the side wall  2  and the inner wall  15  of the blade holding compartment  5  in order to hold them together. The upper edge  7  of the side wall  2  has a finger notch  12  therein. 
         [0026]    The blade storage compartment  5  is unshaped and has a pair of spaced inner and outer walls  15  and  16 , respectively, a bottom wall  17  connecting the inner and outer walls  15 - 16  together, and an open top  18 . The upper edge  7 A of the inner wall  15  is shaped similarly to and conforms with the shape of the upper edge  7  of the side wall  2  and has a notch  12 A therein which preferably conforms in location, size and shape to the notch  12  in the side wall  2 . The outer wall  16  has an upper edge  16 A having a downwardly curved cut out to form a concave edge portion  19 . 
         [0027]    The open top  18  of the blade storage compartment  5  is adapted to be closed by a cover assembly  20  having a front portion  21  which is interposed between and pivotally mounted to the inner and outer walls  15  and  16  by means of a pivot assembly  22  and a rear portion  21 A. The cover assembly  20  has a top surface  7 B and a notch  12 B which conform in location, shape and size to the top edges  7  and  7 A and the notches  12  and  12 A in the side wall  2  and the inner wall  15 , respectively. A skirt  25  depends from the top surface  7 B and has a lower curved convex edge  26  which conforms to and mates with a concave edge  19  in the outer wall  16  when the cover assembly  20  closes the blade storage compartment  5 . A spring  30  having diverging arms  31  and  32  is mounted within the blade storage compartment  5  between inner and outer walls  15 - 16  and around the pivot assembly  22  with its arms  31  and  32  biased outwardly between the cover assembly  20  and the bottom wall  17  so that the spring  30  will normally raise the cover assembly  20  to open the blade storage compartment  5 . 
         [0028]    The rear portion  21 A of the cover assembly  20  has a hook  33  extending downwardly therefrom. The spacer  6  has a spring pressed latch  35  slidably mounted in slot  35 A which is normally biased toward the rear of the outer wall  16  by means of a spring  36 . The latch  35  has a finger bottom  35 B extending through an opening  35 C in the outer wall  16 . When the cover assembly  20  is in its closed position, the latch  35  is positioned over the hook  33  to keep the cover assembly  20  in it closed position ( FIG. 10 ). When the latch  35  is moved by the finger button  35 B against the spring  36  it is moved from beneath the hook  33  to release the cover assembly  20  to cause it to spring up under the influence of the spring  30  to open the blade storage compartment  5  ( FIG. 11 ). To close the blade storage compartment  5 , the cover  20  is moved down against the bias of the spring  30  until the hook  33  snaps under the latch  35  to hold the cover assembly  20  of the storage blade compartment  5  in a closed position. A plurality of blades B may be stored within the blade storage compartment  4  each of which can then be removed when it is desired to replace an old blade B with a new blade B. 
         [0029]    Mounted in the space  8  formed between the side wall  2  and the inner wall  15  of the blade storage compartment  5  and along their upper edges  7  and  7 A there is provided a lock lever assembly  40  which is pivotally mounted between the side wall  2  and the inner wall  15  on the pivot  11  which extends through the side wall  2 , the inner wall  15  and the lock lever assembly  40 . The lock lever assembly  40  is preferably a two arm lever having front and rear arms  42  and  43 , respectively. The front arm  42  is provided with a downwardly extending lock finger  44 . Below the rear arm  43  of the lock lever assembly  40  there is provided a leaf spring  45  which is mounted on the spacer  6  and which normally bears against the bottom edge of the rear arm  43  to force the rear arm  43  upwardly and the front arm  42  downwardly around the pivot  11  so that rear arm  43  normally protrudes above the notches  12 ,  12 A and  12 B in the side wall  2 , inner wall  15  and top edge  7 B, respectively. It will be seen that when the rear arm  43  of the lock lever assembly  40  is pressed down manually at the notches  12 ,  12 A and  12 B against the action of spring  45 , the front arm  42  will be raised together with its lock finger  44 . 
         [0030]    The blade holder  3  of the present invention comprises a rear end  51  and a front end  52  which are preferably integral with each other. The blade holder  3  has a rear edge  51 A, a bottom edge  51 B and an upper edge  51 C. The blade holder  3  is pivotally mounted in the space  8  between side wall  4  and inner wall  15  on the pivot pin assembly  22 . The upper edge  51 C has a groove  53  therein into which the downwardly extending lock finger  44  of the lock assembly  40  is adapted to enter when the blade holder  3  is in its extended or unfolded position. 
         [0031]    The front end  52  of the blade holder  3  has an upper edge  52 A and comprises a main wall  54  and a thin guard wall  55  movable relative to main wall  54  and preferably pivotally mounted on the main wall  54  on pivot pin  56 . The main wall  54  has a blade holding area  54 A having a top ledge  54 D and a bottom ledge  54 B and a rear ledge  54 C and is adapted to hold a blade B which preferably comprises a lower cutting edge  57  seated on lower ledge  54 C, rear edge  57 A and top edge  59  abutting rear ledge  54 C and top ledge  54 D, respectively, and spaced notches  58  in its top edge  59  which enter into protrusions  54 E in the upper ledge  54 D. The movable guide wall  55  has a hook  60  extending upwardly therefrom. It will be seen that when the guard wall  55  is in its closed raised position it covers and holds the blade B in place but when the guard wall  55  is in its open downward position, it exposes the blade B to permit its removal and replacement. 
         [0032]    The front end  52  is also provided with an elongated slot  61  located below its upper edge  53  and terminates in a space  61 A above the slot  61 . The hook  60  of the moveable guard wall  55  is adapted to enter the space  61 A above the slot  60 . 
         [0033]    A blade lock assembly  65  is mounted along the upper edge  52 A of the front end  52  of the blade holder  3 . The blade lock assembly  65  comprises a pair of opposed side plates  68  and  69  mounted on opposite sides of the front end  52  adjacent the upper edge  52 A by means of fasteners  67 . The side plate  68  has a slot  66  which is alignment with and at the slot  61  in the front end  52 . A lock finger  62  slidably mounted in slot  61  and is biased forwardly by a spring  63 . The lock finger  62  has a side finger knob  64  extending through the slot  66  in the side plate  68 . The lock finger  62  is adapted to be placed under the hook  60  when the guard wall is in its upper position to hold the guide wall  55  in its raised position, one main wall  54 . When the lock finger  62  is moved back against the bias of spring  63  by means of the finger knob  64 , it is moved out from under the hook  60  to release the guide wall  55  and permit it to pivot away from the main wall  54 . Thus when it is desired to remove and replace the blade B, the lock finger  62  is moved away from under the hook  60  to release the guide wall  55 . This permits the guard wall  55  to be pivoted relative to main wall  54  away from the blade B (as shown in  FIG. 7 ) in order to expose the blade B and permit the blade B to be removed and replaced. 
         [0034]    If desired, a finger support assembly  80  may be mounted on the upper edges  52 A of the blade holder  3  and may comprise soft finger pad  81  mounted on a platform  82  and has a downwardly extending side walls  83  which are mounted on either side of the upper edge  52 A of the blade holder  3 . This finger support assembly  80  permits the user to bear down on the blade holder  3  with his finger without any danger of being injured. 
         [0035]    In operation, the utility knife  1  is placed in its operative unfolded position with the blade holder  3  unfolded and ready to be used. The blade B is held between the main wall  54  and the guard wall  55  of the blade holder  3  by protrusions  54 E extending into notches  58  in the top edge  59  of the blade B and between ledges  54 B,  54 C and  54 D. The hook  60  on guard wall  55  is in place in the space  61 A and the slide lock  62  is under the hook  60  to hold the guard wall  55  in position over the main wall  54 . The lock finger  44  of the front arm  42  of the lock lever assembly  40  is in its lower position (because of the pressure of spring  45  on rear arm  43 ) and is positioned in the groove  53  in the blade holder  3  in order to hold the blade holder  3  in its unfolded position. The rear arm  43  of the lock lever assembly  40  is in its raised position and protrudes above the finger notches  12 ,  12 A, and  12 B in the top edges  7 ,  7 A and  7 B of the handle  2 . 
         [0036]    When it is desired to place the utility knife  1  into its folded inoperative position, the rear arm  43  of the lock lever assembly  40  is pressed down manually at the notches  12 ,  12 A, and  12 B against the bias of the spring  45 . This causes the front arm  42  of the lock assembly  40  to be raised thereby moving the lock finger  44  out of the groove  53  to release the blade holder  3  and permit it to pivot downwardly around the pivot pin  22  ( FIG. 12 ). If desired, this may be accomplished by pushing down on the finger support assembly  80 . The blade holder  3  is then pivoted down completely and is moved into the space  8  between the side wall  2  and the inner wall  15  ( FIGS. 13 and 14 ) When pressure on rear arm  43  of the lock lever assembly  40  is released, the spring  45  moves the rear arm  40  back to its original raised position. This causes the lock finger  44  to bear against the rear edge  51 A and lower edge  51 B of the blade holder  3  ( FIG. 13 ) thereby assisting in holding the blade holder  3  in its folded position. 
         [0037]    When it is desired to use the blade B, the reverse procedure is followed. The blade holder  3  is pivoted in the opposite direction (again with the use of finger support assembly  80 , if desired). It may be desirable for the rear arm  43  of the lock lever assembly  40  to again be depressed manually at the notches  12 ,  12 A, and  12 B to assist in unfolding the blade holder  3 . The blade holder  3  is continued to be rotated counter-clockwise (as seen in  FIG. 13 ) until the lock finger  44  of the front arm  42  enters into the groove  53  in the rear end  51  of the blade holder  3  in order to hold the blade holder  3  in its extended position. 
         [0038]    When it is desired to replace a blade B, the blade holder  3  is placed in its unfolded position (as shown in  FIG. 4 to 6 ) and the slide lock  62  is moved back from under the hook  60  (by finger knob  64 ) against the action of the spring  63  thereby the releasing of guard wall  55  and permitting it to be pivoted downwardly relative to main wall  54  around pivot  56  to expose the blade B. The blade B can then be moved out of the blade holder  3  and a new blade B can be placed therein. After replacement, the guard wall  55  is again pivoted upwardly back into position over the blade B. The lock  60  is moved in the space  61 A in the front of the slot  61 . The slide lock  62  moves forward by spring  62  to a position beneath lock  60  to lock the guard wall  55  in position over the main wall  54 . 
         [0039]    The new blade B can be obtained from stored blades B in the blade storage compartment  4  which is opened by moving the latch  35  away from the hook  33  to permit the cover  20  of the blade storage compartment  4  to spring open under tension of spring  30 . A blade B can then be removed from the blade storage compartment  4  and placed in the blade holder  3  as set forth above. The blade storage compartment  4  can then be closed by moving it down against bias of spring  30  until the spring pressed latch  35  enters the hook  33  to hold the cover  20  assembly in its closed position. 
         [0040]    It will be seen that the present invention provides a utility knife in which the blade holder may be easily folded into a handle in which improved means are provided for securing the blade on the utility knife, for replacing the blade on the knife and which is simple to use and inexpensive to manufacture and maintain. 
         [0041]    As many and varied modifications of the subject matter of this invention will become apparent to those skilled in the art from the detailed description given hereinabove, it will be understood that the present invention is limited only as provided in the claims appended hereto.