Abstract:
A hand tool ( 100 ) including a replaceable knife cartridge ( 110 ) is disclosed herein. The body ( 120 ) of the hand tool operatively engages the knife cartridge such that the blade ( 111 ) of the cartridge is positioned for cutting packaging such as blister pack without damaging contents contained by the packaging.

Description:
FIELD  
       [0001]    This disclosure relates to hand tools for opening packages, and particularly to hand tools having replaceable knife cartridges. 
       BACKGROUND  
       [0002]    Blister pack is a type of packaging used for small consumer goods such as electronics, toys and hardware. One type of blister pack is the clamshell blister in which clear molded plastic sheeting is folded over onto itself to enclose the item(s) being packaged, and the sheeting is then fused at the edges. Other similar types of blister packs utilize two or more pieces of molded plastic sheeting to enclose the item(s). In general, blister packs are used extensively in industry for a variety of reasons, particularly because they are tamper resistant and deter package pilfering. Unfortunately, the average consumer can find it difficult to open this type of packaging. It is not uncommon for a consumer to inflict injury upon himself when opening a blister pack because sharp implements or inappropriate cutting tools are often employed. 
       SUMMARY  
       [0003]    A hand tool comprising a replaceable knife cartridge is disclosed herein. The body of the hand tool operatively engages the knife cartridge such that the blade of the cartridge is positioned for cutting packaging such as blister pack without damaging contents contained by the packaging. 
         [0004]    The knife cartridge includes a cartridge housing and a blade, the cartridge housing having two opposing sides and a plurality of edges, at least one of the edges comprising a guide edge having a substantially planar surface, the cartridge housing holding the blade in a fixed position such that the blade partially protrudes from the guide edge. The hand tool includes a body comprising a grip portion, and an operative portion configured to hold the knife cartridge in a first position in which the knife cartridge is fully encased within the operative portion, and a second position in which the knife cartridge is partially encased within the operative portion such that the cutting edge of the blade protrudes from the operative portion of the body, and the guide edge of the knife cartridge engages with a surface of an item being cut. 
         [0005]    These and other aspects of the invention are described in the detailed description below. In no event should the above summary be construed as a limitation on the claimed subject matter which is defined solely by the claims as set forth herein. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0006]    Advantages and features of the invention may be more completely understood by consideration of the following figures in connection with the detailed description provided below. The figures are schematic drawings of various articles and are not necessarily drawn to scale. 
           [0007]      FIG. 1   a  shows a perspective view of an exemplary hand tool disclosed herein.  FIGS. 1   b - 1   d  show side views of the exemplary hand tool shown in  FIG. 1   a , illustrating first, second and third positions, respectively, of the knife cartridge with respect to the body. 
           [0008]      FIGS. 2   a  and  2   b  show side and edge views, respectively, of an exemplary knife cartridge disclosed herein. 
           [0009]      FIGS. 3   a  and  3   b  show side views of the knife cartridge shown in  FIGS. 2   a  and  2   b , wherein the knife cartridge is used to cut sheeting. 
           [0010]      FIG. 4  shows a side view of an exemplary hand tool disclosed herein, illustrating geometrical relationships between parts of the hand tool. 
           [0011]      FIG. 5  shows a side view of an exemplary hand tool disclosed herein. 
           [0012]      FIG. 6  shows a side view of an exemplary hand tool disclosed herein, illustrating a fourth position of the knife cartridge with respect to the body. 
           [0013]      FIGS. 7   a  and  7   b  show side views of exemplary knife cartridges disclosed herein. 
           [0014]      FIGS. 8   a  and  8   b  show engagement of a cartridge housing with a cartridge holder. 
           [0015]      FIG. 9  shows an exploded perspective view of an exemplary hand tool disclosed herein. 
           [0016]      FIG. 10  shows a tray holding a plurality of knife cartridges. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Referring to  FIGS. 1   a - 1   d , exemplary hand tool  100  comprises knife cartridge  110  and body  120 . The body includes two portions: grip portion  121  for gripping the tool by hand and operative portion  122  for operating the knife cartridge as described further below. In some embodiments, one or more buttons, levers, knobs, or the like may be used in conjunction with the operative portion for engaging the knife cartridge. For the embodiment shown in  FIGS. 1   a - 1   d , button  130  is shown as a generic button, and it is to be understood that any type of element, e.g., button, lever, etc., can be used as long as the operative portion functions as desired. 
         [0018]    Knife cartridge  110  comprises blade  111  and cartridge housing  112  which holds the blade in a fixed position relative to the housing.  FIG. 1   b  shows a first position in which the knife cartridge is fully encased within the operative portion of the body as indicated by the dotted lines.  FIG. 1   c  shows the knife cartridge in a second position in which the knife cartridge partially protrudes from the operative portion of the body with dotted lines indicating a portion of the knife cartridge that is encased within the operative portion. Hand tool  100  is designed to be used to open packaging when blade  111  is visible outside of the body, for example, as shown in  FIG. 1   b .  FIG. 1   d  shows the knife cartridge in a third position in which the knife cartridge protrudes farther from the operative portion as compared to the knife cartridge in the second position. In some embodiments, the third position comprises a releasable and/or removeable position for the knife cartridge with respect to the body. After positioning the knife cartridge in the third position, a user can remove the knife cartridge from the body and replace it with a new knife cartridge. 
         [0019]      FIGS. 2   a  and  2   b  show side and edge views, respectfully, of exemplary knife cartridge  110 . Cartridge housing  112  generally comprises two opposing sides such as  113   a  and  113   b  which are major surfaces of the housing. A plurality of edges define the perimeter of the cartridge housing. In general, the cartridge housing has three or more edges that define the perimeter of the cartridge housing, for example, cartridge housing  112  comprises six edges. The distance between the two opposing sides defines width, W, of the cartridge housing. At least one of the edges comprises a guide edge having a substantially planar surface, for example, cartridge housing  112  comprises guide edge  114 . 
         [0020]    Blade  111  partially protrudes from and is generally perpendicular to the planar surface of guide edge  114 . The blade itself is planar and protrudes from the cartridge housing such that a blade tip and two or more edges, at least one edge comprising a cutting edge, can be utilized for cutting. The visible portion of the blade that protrudes from the cartridge housing defines a planar cutting area. As shown in  FIG. 2   a , blade  111  comprises cutting edge  115   a , edge  115   b  which can comprise a second cutting edge, and blade tip  115   c  formed by the edges. Guide edge  114 , cutting edge  115   a , edge  115   b  and blade tip  115   c  define planar cutting area  116 . 
         [0021]    The cutting area of the blade and its relationship to the substantially planar surface of the guide edge of the cartridge housing is a characteristic of the hand tool that enables the average consumer to open plastic clamshell package with ease relative to known hand tools designed for cutting. The distance from guide edge  114  to blade tip  115   c  defines length, L, and this distance is long enough such that plastic sheeting used for clamshell packaging can be cut and short enough such that little or no portion of the cutting area extends through the thickness of the sheeting.  FIGS. 3   a  and  3   b  show exemplary knife cartridge  110  used to open plastic sheeting  300  and  302 , respectively, wherein plastic sheeting  300  is thicker than plastic sheeting  302 . In  FIG. 3   a , blade tip  115   c  extends through the thickness of film  300  but not beyond the film, and in  FIG. 3   b , the blade tip extends through the thickness of film  302  such that this film is slightly punctured without damaging contents enclosed by the film. The distance from guide edge  114  to blade tip  115   c  can be any useful length, for example, anywhere from about 0.015 to about 0.375 inches, from about 0.015 to about 0.08 inches, from about 0.04 to about 0.08 inches, or from about 0.08 to about 0.375 inches. 
         [0022]    Referring again to  FIG. 2   a , the cutting area of the blade can be characterized as having a blade angle, α, formed by the edges that define the blade tip. The blade angle can be any useful angle as long as the knife cartridge and hand tool can function as desired. For example, the blade angle may be within a particular range of angles such that the blade tip can facilitate penetration of the blade into the plastic sheeting. For example, the blade angle can be from about 20 to about 120 degrees, or from about 80 to about 100 degrees. 
         [0023]    As shown in  FIG. 2   a , cutting area  116  of the blade is related to guide edge  114  according to cutting angle, β, formed by cutting edge  115   a  and the guide edge. The cutting angle can be any useful angle as long as the knife cartridge and hand tool can function as desired. For example, the cutting angle can be from about 30 to about 160 degrees, or from about 100 to about 160 degrees. 
         [0024]    Returning to  FIGS. 1   a - 1   d , body  120  comprises an elongated housing typically formed by injection molding of a polymeric material. The particular choice of polymeric material is not particularly limited as long as the housing can be manufactured as desired and can function as desired once the tool is put together. The elongated housing may also be made by metal injection molding, die-casting, forming, machining and the like. The elongated housing may comprise more than one material as shown in  FIG. 1   a ; a hard rigid polymer material may be used to form portion  120   a  of the elongated housing, and a soft polymeric material may be used to form portions  120   b , as desired, for comfort when the hand tool is being gripped. The elongated housing can be an ergonomic elongated housing as shown in  FIG. 1   a.    
         [0025]      FIG. 4  shows a schematic side view of exemplary hand tool  400  comprising knife cartridge  410 , body  420  and button  430 .  FIG. 4  illustrates an exemplary geometric relationship between the body and the guide edge of the knife cartridge. For hand tool  400  in side view: longitudinal axis, a, is defined by the longest distance between any two ends of body  420  without any portion of the longitudinal axis outside the perimeter of the body; guide edge axis, b, is defined by an axis parallel to the guide edge; and normal guide edge axis, c, is defined by an axis perpendicular to the guide edge axis. The longitudinal axis and the normal guide edge axis form guide angle, γ, which may be from about 30 to about 180 degrees, or from about 90 to about 120 degrees. 
         [0026]    The hand tool may be designed such that any portion of the knife cartridge does not extend beyond the maximum length of the body; this embodiment is shown in  FIGS. 1   a - 1   d . In some embodiments, the hand tool may be designed such that a portion of the knife cartridges does extend beyond the maximum length of the body. For example,  FIG. 5  shows a schematic side view of exemplary hand tool  500  comprising body  520 , button  530  and a knife cartridge comprising blade  511  and cartridge housing  512 . A portion of the knife cartridge extends beyond the maximum length of body  520 . The hand tool may be designed such that the blade and a portion of the cartridge housing extend beyond the maximum length of body  520 , or such that only the blade extends beyond the maximum length, and the cartridge housing does not. 
         [0027]    In some embodiments, the knife cartridge is held in a fourth position which may define another position for the cartridge to engage in cutting.  FIG. 6  shows a side view of exemplary hand tool  600  comprising body  620 , button  630  and knife cartridge  610  in a fourth position. In this fourth position, the knife cartridge is partially encased within the operative portion such that only the blade with blade tip  611  protrudes from the body and cartridge housing  112  does not. In this forth position shown in  FIG. 6 , the body can be used as the guide edge. 
         [0028]      FIGS. 7   a  and  7   b  shown embodiments of the knife cartridge, particularly embodiments of the cartridge housing. In  FIG. 7   a , knife cartridge  710  comprises blade  711  and cartridge housing  712  that comprises feature  713  that engages or couples with the operative portion of the body. In  FIG. 7   b , knife cartridge  720  comprises blade  721  and cartridge housing  722  that comprises three features  723  that engage or couple with the operative portion for holding the knife cartridge in three different positions. 
         [0029]    The knife cartridge and the operative portion of the body can engage or couple in any useful way as long as the hand tool can function as desired. Referring to  FIGS. 8   a  and  8   b , an embodiment is shown in which a portion of cartridge holder  802  having tabs  803  is shown, along with cartridge housing  812  having indentations  813  on opposing major surfaces (only one indentation is shown).  FIG. 8   b  shows indentations  813  mated with tabs  803  such that the knife cartridge is held in a fixed position relative to the cartridge holder. The cartridge holder itself can be configured with grooves  804  and protrusions  805 . 
         [0030]    Referring to  FIG. 9 , exemplary hand tool  900  comprises knife cartridge  910 , body  920  and a combination contoured button/cartridge holder  935 . The cartridge housing of the knife cartridge comprises features on each side, the features comprising a single slot and indentations. The body is comprised of two separate parts  920   a  and  920   b  that mate together as shown by the dotted lines. The body includes operative portion  922  comprising multiple slots and grooves that engage with combination contoured button/cartridge holder  935 . The multiple slots and grooves can be configured to hold the knife cartridge in the desired number of positions and optionally for releasing and/or removing the knife cartridge from the operative portion. For example, the multiple slots and grooves can be configured to hold the knife cartridge in the first and second positions as described for  FIGS. 1   b  and  1   c , and optionally the multiple slots and grooves can be configured to hold the knife cartridge in the third position as described for  FIG. 1   d.    
         [0031]    In some embodiments in which the knife cartridge can be held in a third position, the hand tool is designed such that for the first, second and third positions, the blade is aligned along an axis. In some embodiments in which the knife cartridge can be held in a third position, the hand tool is designed such that for the first, second and third positions, the blade is aligned along a curve. 
         [0032]    Although specific embodiments have been illustrated and described herein, alternative or additional embodiments can be envisioned by one of ordinary skill in the art without departing from the scope of the invention disclosed herein.