Abstract:
A guided utility knife that alternates between a carton tray cutter and a conventional utility knife is provided herewith. The knife comprises two rotatable guide portions that are hingedly attached to the housing. Each guide portion flips laterally, away from the cutting blade from its unfolded position to its folded position. Each guide portion further occupies a channel on the exterior surface of the housing. Magnets are provided in the housing to secure the guide portions in both the folded and unfolded positions.

Description:
FIELD OF INVENTION 
       [0001]    The present application relates to utility knives. More specifically, the invention involves a guided utility knife for separating a corrugated carton top from its body. Even more particularly, the invention relates to an ambidextrous retractable utility knife having hinged guides, each guide being adapted to slide along a carton surface while a blade cleanly and professionally slices the carton top off to leave a topless carton, in a precise and consistent manner. 
       BACKGROUND OF THE INVENTION 
       [0002]    Utility knives and in particular box cutting knives have been widely used for a number of years. However, many box cutting knives that are common in the industry suffer from a number of major drawbacks. One drawback for some of the knives, such as the ones disclosed in U.S. Pat. Nos. 5,386,632 and 5,613,300, is that they are constructed to be used by either right- or left-handed individuals, but not both. For example, right-handed versions of such a knife are constructed with an immobile guide that is firmly fastened or, in some cases, integrally molded to the left side of the knife, and conversely, left-handed versions of the knife are constructed with an immobile guide that is fastened to the right side. This requires retail or wholesale establishments that sell or use such utility knives to keep stock of both to suit the needs of individual workmen. 
         [0003]    While there exist some guided box cutting knives which provide for use by both right- and left-handed individuals, such as the one disclosed in U.S. patent application Ser. No. 11/735,997 having Pub. No. U.S. 2007/0209209 (“Davis”), many of these have a number of other deficiencies. One deficiency includes the incorporation of guides on either side of the knife that are meant to slide forward as a result of applying pressure to the guide with a thumb. In some instances however, the guides are overly impeded by the construction of the knife as a whole, requiring a larger amount of force in order to slide the guide forward and into a guiding position. When this occurs, a user&#39;s thumb may slip forward against a blade that is extended from the cutter, causing a gash or other serious injury to the user. Another deficiency in the Davis knife is that it is grip-activated, that is, when the knife is gripped, the blade is extended. This requires the knife to be held for safety in a holster, and prevents a user from placing it in a pants or apron pocket where the blade may extend if pressure is accidentally applied to the grip while in the pocket. 
         [0004]    Yet another problem with Davis is that the guides on either side of the knife do not extend sufficiently forward beyond the edge of the knife housing. In the context of box cutting, this results in guides being routinely driven into and hooking onto the sides of the boxes, rather than proceeding smoothly and easily along the surface of the box as intended. In most instances, this results in uneven cutting of the box, or damage to merchandise inside the box, and/or possibly injury to a user who must use additional force to free the blade and guide from the box. 
         [0005]    Another particularly major drawback with current utility knives that have a selectively extendable/retractable guide is that the guide&#39;s movement is severely restricted such that it may only extend straight forward and retract straight back, usually parallel to the cutting blade. This restriction may cause severe injury, particularly in the context of forcing the guide rearward into a retracted position. For example, if the cutting blade is extended forward, an unwary user pushing the guide back into its retracted position may force his finger(s) directly onto the sharp blade. 
       SUMMARY OF THE INVENTION 
       [0006]    In view of the deficiencies and drawbacks in the prior art, it is a primary object of the present invention to provide an improved guided utility knife for use in removing corrugated box tops cleanly and efficiently leaving an open-topped carton while minimizing risk of injury to a user. 
         [0007]    Another primary object of the present invention is to provide an improved utility knife with guides that rotate and/or fold towards and fold away from a sharp cutting blade (rather than extending straight forward and retracting straight back) to prevent risk of injury to a user. 
         [0008]    Still another object of the present invention is to provide a cutting instrument with selectively rotatable guides that pivot between an extended or unfolded position that allows for precise boxtop cutting, and a retracted or folded position that allows for other conventional utility knife usage. 
         [0009]    It is a further object of the present invention to provide an improved utility knife with guides that extend sufficiently forward to prevent uneven cutting, damage to merchandise and unintentional injury to a user. 
         [0010]    Yet another object of the present invention is to provide an improved guided utility knife that is suitable for both right- and left-handed users. 
         [0011]    Additional objectives will be apparent from the description of the invention that follows. 
         [0012]    In summary, there is provided an improved guided utility knife or carton tray cutter comprising a first housing portion and a second housing portion which are selectively separable from one another by use of a releasable housing lock. The first and second housing portions together form an enclosed housing which accommodates a retractable cutting blade. The improved utility knife further comprises a first guide portion and a second guide portion attached to each of the first and second housing portions, respectively. Preferably, each of the first and second guide portions are hingedly and rotatably attached to the first and second housing portions, respectively. Significantly, the pivot connection allows each guide to rotate between an extended or unfolded position, where the guide extends forward beyond the front edge or head of the utility knife, and a retracted or folded position, where the guide is folded back when not in use or to use the device as a conventional utility knife. In a preferred embodiment, each guide is secured both in the extended position and retracted position by one or more magnets located on the housing portion to which the guide is attached. The ability of each guide to rotate laterally, away from the cutting blade when the guide is tucked back into the folded position is particularly advantageous in preventing injuries. 
         [0013]    As a carton tray cutter, the device is used to cleanly, precisely and safely cut and remove the tops off corrugated cartons or containers so as to leave a topless carton, as is required in many supermarkets, convenience stores, hardware stores and other venues that receive stock in boxes or bulk containers. By cleanly removing the carton top, a stock clerk is able to label or place price stickers on the items contained in the topless carton without destroying the stability of the remaining open carton. Notably, the carton tray cutter is quickly and safely converted into a conventional utility knife by folding the guide(s) away from the cutting blade. Thus, with the same cutting instrument, a clerk is not only able to remove the carton top to expose a topless carton, but is also able to carve a “cut down tray carton” by slicing the front and sides of the carton in order to display its contents on a shelf for shoppers to see. Similarly, the device may be used to accomplish other tasks for which a conventional utility knife is typically utilized. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    With reference to the attached drawings: 
           [0015]      FIG. 1  is a perspective view of a preferred embodiment of the inventive utility knife showing the top, front and left side thereof, with the left and right guides in a folded position and the blade retracted in the housing (in the safe carrying position); 
           [0016]      FIG. 2  is a partial cross sectional view, showing the guide partially rotated from a folded or retracted position toward an unfolded position, taken along line  2 - 2  of  FIG. 1 ; 
           [0017]      FIG. 2A  is perspective view of the utility knife with the guide being rotated from a folded or retracted position toward an unfolded position; 
           [0018]      FIG. 3  is a perspective view of the utility knife shown in  FIG. 1  showing the top, front and right side thereof, with the right and left guides in a folded position and the blade retracted in the housing; 
           [0019]      FIG. 4  is a perspective view of the utility knife with the left guide in the unfolded position and the cutting blade partially extended from the housing ready for use as a right-hand tray cutter; 
           [0020]      FIG. 5  is a partial cross sectional view, showing the guide partially rotated from an unfolded or extended position toward a folded position, taken along line  5 - 5  of  FIG. 4 ; 
           [0021]      FIG. 6  is a perspective view of the utility knife with the right guide in the unfolded position and the blade partially extended from the housing ready for use as a left-hand tray cutter; 
           [0022]      FIG. 7  is a perspective view of the right hand of a right-handed user precisely cutting a corrugated box top with a preferred embodiment of the inventive utility knife with the left guide in an unfolded position; 
           [0023]      FIG. 8  is a partial cross sectional, close-up view taken along line  8 - 8  of  FIG. 7  of the thumb area of the right hand of a right-handed user cutting a corrugated box top with a preferred embodiment of the inventive utility knife with the left guide in the unfolded position  FIG. 9  is a partial cross sectional, close-up view of a left-handed user cutting a corrugated box top with a preferred embodiment of the inventive utility knife with the right guide in the unfolded position; 
           [0024]      FIG. 10  is a top view of the utility knife with both guides in their folded positions and the cutting blade in the fully extended position cutting a corrugated box and being used as a conventional (retractable) utility knife; 
           [0025]      FIG. 11  is an alternate embodiment of the utility knife with the actuating button along the top edge; and 
           [0026]      FIG. 12  is a preferred embodiment of the blade carrier. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    With reference to  FIGS. 1 through 10 , there is shown a preferred embodiment of the guided utility knife or carton tray cutter  10  having a first housing portion  12  and a second housing portion  14 . The first housing portion  12  and second housing portion  14  together form an enclosed housing  16  for accommodating at least one conventional cutting blade  18  which is typically mounted on a plastic carrier, such as the carrier  80  shown in  FIG. 12 , and which extends from a narrow blade opening  20  at the front end  22  of the guided utility knife  10 . The carrier  80  is integrally molded to an actuating button  27  which slides the carrier  80  and blade forward and back along the length of a slot  28  in the first housing portion  12 . The housing portions  12 ,  14  are selectively separable from one another to allow for replacement and storage of cutting blades, and are also secured by a housing lock  26  at the rear end  24  of the utility knife. 
         [0028]    Although one preferred embodiment of the knife  10  comprises a side actuating button  27 , it should be understood that an alternate embodiment can be created, where the actuating button is placed on top of the knife  110  (rather than on the sides of the knife), as shown in  FIG. 1   1 . When the button  127  is located on the top of the knife  110 , between the two housing portions  112 ,  114  and/or equidistant from each of the guides  132 ,  134 , the utility knife  110  is used in the same manner by both right- and left-handed users. 
         [0029]    Other details regarding the structure, construction and features of housings, blade carriers, releasable housing locks and other components that may optionally be utilized in conjunction with modifications to the preferred embodiment described herein can be found in U.S. Pat. Nos. 5,813,121 and 7,325,313, which are incorporated herein by reference. Furthermore, although the preferred embodiment is shown and described in the context of a guided utility knife  10 ,  110  having separable housing portions  12 ,  14 , it should be understood that the invention may optionally utilize a non-separable housing or non-separable housing portions as well. 
         [0030]    The first housing portion  12  comprises a first guide  32  that is preferably formed of metal or hard plastic material. The broad side  36  of the first guide  32  is substantially smooth and flat to allow the first guide  32  to slide along the top of a carton with relative ease. Optionally, the first guide  32  may have inscribed instructions on either of its broad sides  36 ,  37 , such as “Flip for Right Hand” when the first guide  32  is in the folded position (i.e., on the external side  36  of the first guide  32 ), or “Hold Down to Cut” when the first guide  32  is in the extended position (i.e., on the internal side  37  of the first guide  32 ). The foregoing similarly applies to the second guide  34  located at and connected to the second housing portion  14 . Each guide  32 ,  34  may be flipped with either the top or bottom of a finger, and preferably the thumb or index finger. 
         [0031]    Each of the guides  32 ,  34  are connected to each of the respective first and second housing portions  12 ,  14  with hinges  42 ,  44 . In particular, the hinges  42 ,  44  comprise sockets  41  on the guides  32 ,  34  which receive pins  43  extending from the respective housing portions  12 ,  14 . Alternatively, it should be understood that the pins may extend from the guides  32 ,  34 , and the housing portions  12 ,  14  may have the sockets, or optionally, one of each, respectively. As shown in  FIGS. 2 ,  2 A and  5 , a user simply flips or pivots the guide from the folded position to the extended position with either the thumb or a forefinger, or conversely from the extended position back to the folded position. In so doing, each guide rotates on an axis formed by the sockets and pins. The hinged connection allows the knife  10  to alternate between a standard utility knife when the guides  32 ,  34  are both folded back, (as shown in  FIG. 10  with the blade optionally extended fully forward), and a guided carton tray cutter when one of the guides  32 ,  34  are extended forward. Furthermore, as previously mentioned, the hinged connections that require a user to outwardly flip the guides  32 ,  34  laterally and away from the blade help prevent serious injuries by keeping the fingers of the user away from the blade. 
         [0032]    The first guide  32  occupies a channel  46  formed in the first housing  12 . Likewise, on the opposite side of the utility knife  10 , the second guide  34  occupies a channel  48  formed in the second housing  14 . Each channel  46 ,  48  has a top-side wall  47 A, a bottom-side wall  47 B and a floor  47 C. The channel  46  has a length that runs from the front end  22  of the guided knife  10  to a location between the actuating button  27  and housing lock  26 . As shown in  FIG. 3 , since there is no actuating button projecting from the second housing portion  14 , the length of the channel  48  in the second housing portion  14  is less than the length of the channel  46  on first housing portion  12  but enough to accommodate the second guide  34 . 
         [0033]    The broad sides  36 ,  37  of the first guide  32  occupy the width of the channel  46 , allowing enough space for the first guide  32  to rotate or flip between folded and unfolded positions without impediment. When the guide  32  is in the folded position, it is considered to be positioned entirely within the walls  47 A,  478  of the channel  46  (even though the bent lead or tongue  62 , which is discussed further below, is not within the channel  46 ). When the guide  32  is in the unfolded position, it remains at least partially, and preferably at least 50%, within the channel. The same likewise applies to the second guide  34  and channel  48 . 
         [0034]    Within the channel  46  of the first housing portion  12  there are located two magnets  52 A,  52 B. Rearward magnet  52 A is slightly raised within a circular case  53  that is integrally molded to the first housing portion  12 . When the first guide  32  is made of metal and is in the folded position, the magnet  52 A magnetically holds the first guide  32  in the folded position. Conversely, forward magnet  52 B is preferably flush with the first housing portion  14 . When the first guide  32  is in the extended position, the magnet  52 B holds the first guide  32  in the extended position. In the event that first guide portion is made of plastic or other non-magnetic material, a conventional clip or snap may be utilized in place of a magnet to hold the first guide in place. 
         [0035]    Similarly, within the channel  48  of the second housing portion  14  there are two magnets  54 A,  54 B. Rearward magnet  54 A is slightly raised within a circular case  55  that is integrally molded to the second housing portion  14 . When the second guide  34  is made of metal and is in the folded position, the magnet  54 A magnetically holds the second guide  34  in the folded position. Conversely, forward magnet  54 B is preferably flush with the second housing portion  14 . When the second guide  34  is in the extended position, the magnet  54 B holds the second guide  34  in the extended position. In the event that second guide portion is made of plastic or other non-magnetic material, a conventional clip or snap may be utilized in place of a magnet to hold the first guide portion in place. So that the magnets  52 A,  52 B,  54 A,  54 B do not unintentionally magnetically pull the blade from position within the housing when, for example, the housing portions  12 ,  14  are separated from one another, insulation, such as additional plastic or rubber, is preferably provided on the inside of the housing portions  12 ,  14 . Although the preferred embodiment has two magnets on each of the housing portions  12 ,  14 , it should be understood that a single magnet may be used to keep a guide in the folded position, keep a guide in the extended position, or both. 
         [0036]    When the guides  32 ,  34  are folded back, the slightly raised cases  53 ,  55  leave a small gap between the internal broad sides  37 ,  39  (of the first and second guide portions  32 ,  34 ) and the channels  46 ,  48  (of the first and second housing portions  12 ,  14 ), respectively. This small gap allows a user to have sufficient leverage and reach with his thumb or other fingers beneath the guides  32 ,  34  to easily flip them forward when needed, see e.g.,  FIG. 2A . 
         [0037]    The first guide  32  has a corresponding bent lead or tongue  62 . The rolled up edge of the tongues  62  helps the knife  10  and first guide  32  glide smoothly and with less friction over the top of a carton as a thumb of a right-handed user is pressed downward applying force against the first guide  32 . The second guide  34  has a corresponding bent lead or tongue  64  which functions similarly in the case of a left-handed user. 
         [0038]    In the preferred embodiment, when the first guide  32  is in the extended position, the tongue  62  is co-extensive with the front edge  22  of first housing portion  12  (and the bottom-side wall  47  of the channel  46 ) such that when the first housing portion ends, the tongue begins. This helps ensure that the thumb of a user does not accidentally slip off the knife and injure itself. 
         [0039]    In the preferred embodiment, the first housing portion  12  has a pocket or groove  66  in wall  47 B and the second housing portion  14  has a pocket or groove  68  in wall  47 B. The tongues  62 ,  64  of the first and second guide portions  32 ,  34  are curved and fit into the pockets  66 ,  68  on the first housing portion  12  and second housing portion  14  respectively. Significantly, the curvature of the tongues  62 ,  64  match or correspond to the side and bottom handle curvature of the first housing portion  12  and second housing portion  14 , respectively, such that they do not significantly project outward. This feature allows a user to more easily handle the guided utility knife  10  when the first and second guide portions  32 ,  34  are folded back. 
         [0040]    Notably, the tongue  66  on the first guide  32  serves another function. In particular, when the first guide  32  is in the extended or unfolded position, it is seated adjacent to or against the front end of the second housing portion  14 . Since the tongue  66  is hinged to the first housing portion, the housing portions  12 ,  14  of the knife  10  cannot accidentally separate when the first guide  32  is in the extended position. 
         [0041]    As shown in  FIGS. 7 through 9 , during use as a carton tray cutter, the blade  18  is extended by means of the actuating button  27  approximately half of its fully extendable length such that it is partially hidden or protected behind the first guide  32 , as shown in  FIG. 4  (or behind the second guide  34 , as shown in  FIG. 6  in the case of a left-handed user). After the blade  18  is partially extended, the thumb is placed over the first guide  32 , such that the edge of the thumb is positioned at or just shy of the edge of the first guide  32 , and the tool  10  is drawn across the top edge of the carton on its four sides. The flat top of the carton is slit on its four sides and removed leaving a “tray” or topless carton, see  FIG. 8 . 
         [0042]    As further shown in  FIGS. 7 through 9 , when either of the two guides  32 ,  34  are in the unfolded position ready for carton tray cutting, they are preferably spaced about 3/16 to ¾ of an inch from the extended cutting blade  18 . The spacing between the blade  18  and either of the first and second guide portions  32 ,  34  corresponds to the thickness of the corrugated carton being cut, allowing the blade  18  to cut just below the edge without damaging merchandise as shown in  FIGS. 8 and 9 . A significant additional amount of space between the guides  32 ,  34  and the blade  18  would lead to damage or puncture merchandise located in the box that is cut. 
         [0043]    Although the invention is described in terms of particular embodiments, it is to be understood that the embodiments are merely illustrative of an application of the principles of the invention. Numerous modifications may be made and other arrangements may be devised without departing from the spirit and scope of the invention.