Patent Publication Number: US-10315325-B2

Title: Blade cartridges and lockable safety covers

Description:
The application is a continuation-in-part of U.S. patent application Ser. No. 14/931,093, filed on Nov. 3, 2015. This and all other publications referenced herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. 
    
    
     FIELD OF THE INVENTION 
     The field of the invention is utility knives. 
     BACKGROUND 
     The background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art. 
     Safety has been an important concern when using utility knives as many users inadvertently cut themselves with the exposed blades. Some efforts have been made to address this safety concern. 
     For example, U.S. Pat. No. 8,347,509 teaches a blade cartridge with a blade cover that defaults to a closed position in which the blade cover surrounds the otherwise exposed portion of a blade. A spring is used to push the blade cover into the closed position, and the blade cover remains in the closed position until pressure is applied to push the cover to an open configuration where the blade is exposed for use. 
     This and all other publications referenced herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. 
     Unfortunately, the &#39;509 Patent&#39;s blade cartridge and blade cover fails to address several other safety issues, for example, injuries that can occur from an inadvertent detaching of the cartridge or blade from a tool handle. 
     U.S. Pat. Nos. 7,475,480 and 8,099,868 each strive to solve this problem by featuring a flexing latch to secure the handle to the cartridge. While the cartridge is inserted into the handle, the latches flex into a strained position in order to fit into the receiving channel of the handle. Once the cartridge has been fully inserted into the handle, the latches then return to a relaxed, unstrained position by pushing through openings on either side of the handle. Such a latching mechanism is useful in securing the blade. 
     Unfortunately, the cartridge is at risk of inadvertent detachment from the handle because the latches are positioned on the handle at a place where users commonly squeeze their thumb and first finger together to grip and manipulate the tool. 
     Thus, there is still a need for improved and safer utility knives and utility knife components. 
     SUMMARY OF THE INVENTION 
     The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art. 
     The inventive subject matter provides apparatus, systems, and methods in which a utility knife includes a blade cover that is movable from a locked position to an unlocked position relative to at least one of a blade cartridge, a blade holder, and a tool handle. When the blade cover is in an unlocked position, the blade cover can advantageously be moved (e.g., rotate (partially or fully), pivot, slide, swivel, turn, bend, flex) from a blade covering configuration to a blade exposing configuration. 
     The blade cover could be biased towards the blade covering configuration, for example, via a spring, such that a force (e.g., from a cutting surface or a user) is required to move to the blade exposing configuration. 
     In some aspects, contemplated utility knives could comprise a cartridge that is coupled to or includes a blade, and a blade cover coupled to the cartridge. The cartridge could comprise a stem that extends from an end of the cartridge opposite the blade. The stem could include one or more flexible spring arms that each includes a locking member sized and dimensioned to be releasably received by a catch of a tool handle. Advantageously, the spring arms could be configured to flex in opposite directions and towards one another such that the cartridge could readily be removed from the tool handle when desired. Additionally or alternatively, the catches that receive the locking mechanisms could be positioned on top and bottom portions of the tool handle (when the tool is being used), such that unintentional release of the cartridge from the handle during use can be avoided. 
     In some aspects of the inventive subject matter, utility knives having hook-type cutters are provided. Knives having hook-type cutters can advantageously protect users from inadvertent cuts, since the blade&#39;s edge is recessed relative to other portions of the cutter. Viewed from another perspective, the blade&#39;s cutting edge is covered on both ends by material that extends out further than the blade&#39;s cutting edge. In this manner, the end materials act as a barrier or block to the blade edge for objects that are larger than the narrow space (e.g., less than 20 mm, less than 15 mm, less than 10 mm, less than 5 mm) between the end materials. 
     Such hook-type cutters have been found to be especially useful in cutting shrink wrap, bubble wrap, straps, bands, cardboard, and other items that are thin and can readily fit within the narrow space between the end portions. Additionally, one or more end portions could include a piercer such that an object can be pierced and cut open with a single swipe or other movement. 
     Contemplated utility knives could include a cartridge including a movable member, a blade holder portion, a blade, and a hook-type cutter. A blade cover could be movably coupled to the cartridge, and include an opening member that cooperates with the cartridge&#39;s movable member to adjust the blade cover between blade covering and blade exposing configurations. For example, the opening member could modify a position or a shape of the movable member relative to the rest of the cartridge. 
     In some other aspects, a utility knife comprises a cartridge coupled to a blade and including a first blade holder that partially encloses a first side of the blade. A second blade holder (e.g., a blade tip cap) can partially enclose a second side of the blade opposite the first side. The blade can advantageously be recessed relative to the first and second blade holders, thereby forming a hook-type cutter. 
     The second blade holder could be permanently coupled to the blade (fixedly or movably—e.g., rotatably, pivotably), or could be removably coupled to the blade. For example, the first and second blade holders could be coupled to one another via a flexible connector. When the user wishes to access the portion of the blade covered by the second blade holder, the user could pull the second blade holder away from the blade. The second blade holder being connected to the first blade holder (cartridge) via the connector reduces the risk that the blade tip cover will be lost. 
     Having a hook-type cutter as described above could help prevent accidents from occurring. For additional safety, a movable cover could be coupled to the cartridge, and be adjustable between two or more positions or configurations. 
     In still further aspects, a utility knife could comprise a blade at least partially embedded in a blade holder. The blade could comprise first and second ends, and a cutting edge extending there-between. The knife could additionally include a blade cap that is sized and dimensioned to receive a portion of the blade not covered by the blade holder. The blade cap could advantageously be coupled to at least one of the blade and the blade holder in a manner that allows the blade cap to move between first and second positions, wherein the blade cap covers more of the blade&#39;s cutting edge when in the first position relative to the second position. 
     The blade cap could be a separate piece of material that is removable from the blade and blade holder. Additionally or alternatively, the blade cap could be a separate piece of material that is connected to the blade holder (or other portion of a knife cartridge) via a connector. Additionally or alternatively, the blade cap could be attached to the blade holder, blade, or other portion of the cartridge in a manner that allows the blade cap to pivot or rotate relative to the blade edge. In these and other embodiments, the blade cap could be biased to a position that covers more of the blade&#39;s edge that when pivoted or rotated using force. 
     Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1A  illustrates a blade cartridge and cover of the inventive subject matter, wherein the cover is in a locked position. 
         FIG. 1B  illustrates the blade cartridge and cover of  FIG. 1A , wherein the cover is in an unlocked position. 
         FIG. 1C  illustrates the blade cartridge and cover of  FIGS. 1A-1B , wherein the cover is in a blade exposing configuration. 
         FIG. 2A  illustrates another blade cartridge and cover of the inventive subject matter, wherein the cover is in an unlocked position and a blade covering configuration. 
         FIG. 2B  illustrates the blade cartridge and cover of  FIG. 2A , wherein the cover is in an unlocked position and a blade exposing configuration. 
         FIG. 3  illustrates a utility knife of the inventive subject matter. 
         FIG. 4  illustrates another utility knife of the inventive subject matter. 
         FIG. 5A  illustrates another embodiment of a utility knife, including a blade cartridge and a tool handle. 
         FIG. 5B  illustrates the utility knife of  FIG. 5A , wherein the blade cartridge is locked into the tool handle. 
         FIG. 6A  illustrates yet another embodiment of a utility knife, including a blade cartridge and tool handle. 
         FIG. 6B  illustrates the utility knife of  FIG. 6A , wherein the cartridge is locked into the tool handle. 
         FIGS. 7A-7D  illustrate a utility knife of the inventive subject matter having a hook type cutter. 
         FIG. 8  illustrates a utility knife having a blade tip cap. 
         FIG. 9  illustrates another utility knife having a blade tip cap. 
         FIG. 10  illustrates yet another utility knife having a blade tip cap. 
         FIGS. 11A-11C  illustrate a utility knife having a blade tip cap and a blade cover. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The inventive subject matter provides utility knives with a safety cover that is movable from a locked position to an unlocked position (and vice versa), and from a biased unexposed blade configuration to an exposed blade configuration (and vice versa). The utility knives can include a cartridge for a blade and blade cover, and a tool handle that is configured to securely and releasably receive the cartridge. 
     The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed. 
       FIGS. 1A-1C  illustrate a utility knife cartridge  100  of the inventive subject matter. Cartridge  100  comprises blade holder or blade holder component  110 , blade  65 , stem  90 , and blade cover  30 . Blade holder  110  and stem  90  could be made from a single piece of material (e.g., injected molded plastic, metal). In other contemplated embodiments, blade holder  110  and stem  90  could be made from separate pieces of material. 
     Where a separate tool handle is not used with a cartridge of the inventive subject matter, stem  90  could be replaced with or otherwise include a handle. Here, cartridge  100  is one of many cartridges that can be used in combination with a tool handle (e.g.,  350  of  FIG. 3 ). In order to allow cartridge  100  to be releasably coupled to the tool handle, stem  90  includes a first arm  40  with a first stem locking member  40 A, and a second arm  45  with a second locking member  45 A. Each locking member is configured to mate with a catch of a tool handle as further described below. 
     Blade cover  30  is advantageously configured to move (e.g., slide) relative to the blade holder from a locked position, as shown in  FIG. 1A , to an unlocked position, as shown in  FIG. 1B . Blade holder  110  comprises a lock protrusion  50  that is configured to cooperate with blade cover&#39;s lock opening  55 . This allows the blade cover  30  to be locked in a safe position that keeps the blade from being inadvertently exposed, regardless of whether or not the cartridge has been inserted into a tool handle. 
     Additionally, blade cover  30  is configured to move (e.g., rotate) relative to the blade holder and blade from a blade covering configuration, as shown in  FIG. 1B , to a blade exposing configuration, as shown in  FIG. 1C . Blade holder  110  comprises a movement protrusion  70  that is configured to cooperate with blade cover&#39;s angled channel  105  to allow for rotation of blade cover  30  when it is in an unlocked position. 
     Here, lock opening  55  and angled channel  105  are shown as extending through a thickness of blade cover  30 . However, it should be appreciated that lock protrusion  50  and movement protrusion  70  could additionally or alternatively cooperate with recessed portions or grooves on an inner surface of blade cover  30 . 
     Still further, while blade holder  110  is shown to have the lock and movement protrusions, and blade cover  30  is shown to have the lock opening and angled channel, it should be appreciated that one or more of the protrusions could be included on the blade cover, and one or more of the openings or channels could be included on the blade holder. 
     In the embodiment shown, lock opening  55  is peanut or nephroid shaped, and includes a narrow central portion between two wider ends. Lock protrusion  50  can be positioned, sized and dimensioned to snugly fit through the narrow central portion when a force towards one of the wider ends is applied by a user. Viewed from another perspective, a user could use at least one of a thumb and forefinger to hold the blade cover and move it towards the stem  90  to unlock the blade cover. Additionally or alternatively, the user could move the blade cover towards the blade  65  to lock the blade cover. 
     One or more slots (e.g.,  60 ) could be included on blade cover  30  to allow the central portion of lock opening  55  to widen and allow lock protrusion  50  to pass through. Additionally or alternatively, one or more slots could be included on blade cover that allows a user to see blade  65  (or other tool) when blade cover is in a blade covering configuration. 
     In some embodiments, the lock protrusion  50  could have a varying thickness, and include at least one thinner portion and at least one wider portion. The wider portion(s) could be wider than the narrow central portion of lock opening  55 , and thus not sized and dimensioned to pass through the narrow central portion. The thinner portion(s) could be positioned further away from blade holder  110  than the wider portion, such that lock protrusion  50  could be pushed in, and the thinner portion could pass through the narrow central portion of lock opening  55 . Additionally or alternatively, the thinner portion could be positioned closer to the blade holder such that the lock protrusion could be pulled out, and the thinner portion could pass through the narrow central portion. 
     When the blade cover is moved from a locked position (as shown in  FIG. 1A ) to an unlocked position (as shown in  FIG. 1B ), movement protrusion  70  could be positioned at a corner of channel  105  such that blade cover  30  can move from a blade covering configuration (as shown in  FIG. 1B ) to a blade exposing configuration (as shown in  FIG. 1C ). As illustrated in  FIGS. 1A-1C , the channel  105  can include a first sub-channel and a second sub-channel. The movement protrusion  70  could move through first sub-channel when blade cover  30  moves between a locked position and an unlocked configuration. The movement protrusion  70  could move through the second curved sub-channel when blade cover  30  moves between a blade covering configuration and a blade exposing configuration. 
     In some embodiments, blade cover  30  could be biased towards the blade covering configuration (e.g., via a spring). An exemplary spring biasing mechanism is the curved spring carried in a groove and described in U.S. Pat. No. 8,099,868 to Votolato. When blade cover  30  is in an unlocked position, a user could apply a pressure to a portion of the blade cover, for example, via a cutting surface, and cause the blade to be exposed to apply a cut to the cutting surface (item to be cut). When the pressure is released (e.g., when the knife is moved away from a cutting surface), blade cover  30  could automatically move back to a blade covering configuration. 
     It should be appreciated that the locking feature (lock opening  55  and lock protrusion  50 ) can allow a user to repeatedly lock and unlock the cover with a simple movement. A user can simply grab the blade cover with a forefinger and thumb, and pull or push the blade cover slightly away from or towards the knife handle. This can prevent accidental exposure to the cartridge blade when the knife is not in use (e.g., when it is in a pocket of a user, is placed in a toolbox or left unattended, when the cartridge is being coupled to, or removed from, a tool holder. 
     It is contemplated that cartridge  100  could be replaced with another blade cartridge, for example, when blade  65  becomes dull. Additionally or alternatively, cartridge  100  could be replaced with a different tool cartridge (e.g., screw driver cartridge, saw cartridge, scraper cartridge). The different tool cartridges could be the same as utility knife cartridge  100 , except that blade  65  is replaced with a different tool. 
       FIGS. 2A-2B  illustrate another utility knife cartridge  200  of the inventive subject matter. Cartridge  200  includes blade holder  235  having a stem, blade  230 , and a partially transparent blade cover  210 . Cartridge  200  includes a lock opening and lock protrusion similar to those described in  FIGS. 1A-1C . Cartridge  200  also includes slots  220 A and  220 B that provide some flexibility to blade cover  210 . Furthermore, cartridge  200  includes a movement protrusion  240  that cooperates with channel  215  to allow blade cover  210  to adjust between locked and unlocked positions, and between blade covering (closed) and blade exposing (open) configurations. 
     In some embodiments, a cartridge blade cover could default/be biased to a closed position in which the blade cover surrounds the otherwise exposed portion of a blade. A spring (e.g., a curved spring) could be included, which pushes the blade cover into the closed position. The blade cover could remain in the closed position until pressure is applied to push the cover to an open configuration where the blade is exposed for use. 
     Additionally or alternatively to a spring, cartridge  200  could include a movable member  245  that can bias the blade cover in the closed position. When blade cover  210  is moved to an open configuration by a cutting surface or other force, blade cover  210  can cause movable member  245  to flex or straighten to a strained position within through-hole or recessed portion  225  in which movable member  245  is positioned (as shown in  FIG. 2B ). 
     As discussed above, cartridges of the inventive subject matter could include stems that are configured to be releasably received by one or more tool handles of the inventive subject matter.  FIG. 3  illustrates a utility knife  300 , which includes a cartridge  310  releasably locked into place on tool handle  350 , and an anti-tamper guard. 
     Cartridge  310  includes a blade holder, blade  320 , blade cover  315 , and a stem that includes two flexible arms that include two locking members ( 325 ,  330 ). In one embodiment, the stem and flexible arms are configured such that considerable pressure is required to depress the two flexible arms. In another embodiment, only slight pressure is required to depress the two flexible arms. Further, in some embodiments, after pressure is released from the two flexible arms, the arms return back to their original positions. In a further embodiment, only when the two flexible arms are depressed is cartridge  310  able to fit into tool handle  350 , while in another only one flexible arm must be depressed. 
     Tool handle  350  includes a first catch  355  sized and dimensioned to receive a first locking member (e.g.,  40 A,  325 ), and a second catch  360  sized and dimensioned to receive a second locking member (e.g.,  45 A,  330 ). In the embodiment shown, catch  355  is located on a bottom edge of knife  300 , and catch  360  is located on a top edge of knife  300 . When cartridge  310  is locked with tool handle  350 , the two flexible arms can be flexed towards each other (away from their resting positions) to allow locking members  325  and  330  to snap into catches  355  and  360 , respectively. From another perspective, the flexible arms of cartridge  310  could be configured such that, in a relaxed position, locking members  325  and  330  rest snugly and securely within catches  355  and  360 . 
     The receiving end of the opening of the tool holder can be sized and dimensioned to receive the arms of cartridge  310  in a way that momentarily depresses those arms, allowing for locking members  325  and  330  to slide into the tool handle opening, and then to snap back to lock into place in catches  355  and  365  located on the vertical plane or spine of the handle. 
     When removing cartridge  310  for replacement, a user can simply squeeze or pinch the stem arms together via locking members  325  and  330 , allowing cartridge  310  to be pulled out from tool handle  350 . In some embodiments, the force required to depress the stem arms is great, while in others slight pressure is sufficient. 
     Cartridge  310  can further be configured such that, while inserting cartridge  310  into tool handle  350 , cartridge  310  is shifted into a locked configuration where blade cover  315  cannot move in relation to blade  320 . This can be accomplished, for example, by reversing the orientation of angled channel  105  such that a pushing motion along blade cover  315  toward tool handle  350  slides the lock protrusion along the angled channel into a locked conformation. 
     Cartridge  310  can further be configured such that, while removing cartridge  310  from tool handle  350 , cartridge  310  is shifted into a locked configuration where blade cover  315  cannot move in relation to blade  320 . This can be accomplished, for example, by using the orientation of angled channel  105  such that a pulling motion along blade cover  315  away from tool handle  350  slides the lock protrusion along the angled channel into a locked conformation. 
     Whereas known utility knives included spring arms protruding along the horizontal axis and perpendicular to the orientation of the blade, cartridges of the inventive subject matter can advantageously include flexible arms on the vertical plane, and in the same direction as the orientation of the blade. Viewed from another perspective, when knife  300  is used to make a cut, a user can grab left and right sides of the blade without inadvertently releasing the cartridge from the tool handle. 
     Furthermore, knife  300  additionally includes an anti-tamper guard  375 , which protects blade cover  315  from being tampered with or taken off of cartridge  310  when cartridge  310  is coupled with tool handle  350 . As illustrated, tool handle  350  could comprise anti-tamper guard  375 , which could at least partially surround first and second side surfaces of blade cover  315 . More specifically anti-tamper guard  375  can include a first side portion  375 A and a second side portion substantially parallel to front side portion  375 A. The first and second side portions form a gap sized and dimensioned to receive a thickness of cartridge  310 , including a portion of blade cover  315 . 
     The outer surface of one or both of the side portions could include a logo, design or other marking. The inner surface of one or both side portions could include protrusions that are sized and dimensioned to couple with an aperture or recesses of a lock protrusion (e.g.,  50  in  FIG. 1A ). For example, each of the two portions could include a protrusion such that the two protrusions face one another. These two protrusions could couple with a through-hole or recessed portions of a lock protrusion via a snap fit or any other suitable mechanism. 
     An anti-tamper guard as described above could advantageously protect against unwanted tampering of the blade cover, yet allow the blade cover to move between unlocked, locked positions, and closed and open configurations. Anti-tamper guards are further described and shown in  FIGS. 7A-7D . 
       FIG. 4  illustrates another utility knife  400  of the inventive subject matter. Knife  400  includes handle  455  and cartridge  450 . Cartridge  450  includes a blade holder, blade, blade cover  410 , and two flexible arms including locking members  435  and  440 . Handle  455  includes first and second catches  460  and  465 , which are sized and dimensioned to block locking members  435  and  440  in place. 
     Cartridge  450  is similar to the cartridges shown in  FIGS. 1A-1C  and  FIGS. 2A-2B , and includes mechanisms that allow blade cover  410  to move between locked and unlocked positions, and between closed and open configurations. As illustrated, blade cover  410  is in a locked position. A user could use his thumb and forefinger, a cutting surface, or any other suitable force to move blade cover  410  towards handle  455  such that locking protrusion  415  moves to an opposite end of lock opening  420  (unlocked position). This would position moving protrusion  430  within the corner of angled channel  425 , and allow a user to rotate blade cover  410  to a blade exposing (open) configuration. Some contemplated channels allow blade cover  410  to rotate between 25-75 degrees, more preferably between 25-65 degrees, and even more preferably between 25-55 degrees. 
       FIGS. 5A and 5B  illustrate yet another utility knife  500  of the inventive subject matter.  FIG. 5A  shows cartridge  510  and handle  550  separated from one another, and  FIG. 5B  shows the components coupled together. 
     Cartridge  510  includes a blade holder (or blade holder portion)  515 , blade  520 , blade top shield  525 , and a stem  530  that includes two flexible arms  530 A,  535 A having two locking members  530 B,  535 B. The stem  530  and flexible arms  530 A,  535 A are configured such that a pressure is required to depress the two flexible arms  530 A,  535 A. After a pressure is released from the two flexible arms  530 A,  535 A, they return back to their original positions. It is contemplated that one or both of the flexible arms  530 A,  535 A will need to be squeezed towards one another in order to releasably couple with handle  550 &#39;s catches  540  and  545 . 
     Tool handle  550  includes a first catch  540  sized and dimensioned to receive a first locking member  535 B, and a second catch  545  sized and dimensioned to receive a second locking member  530 B. In the embodiment shown, catch  545  is located on a bottom edge of knife  500 , and catch  540  is located on a top edge of knife  500 . When cartridge  510  is locked with tool handle  550  as shown in  FIG. 5B , the two flexible arms can be flexed towards each other (away from their resting positions) to allow locking members  535 B and  530 B to snap into catches  540  and  545 , respectively. From another perspective, the flexible arms of cartridge  510  could be configured such that, in a relaxed position, locking members  535 B and  530 B rest snugly and securely within catches  540  and  545 . 
     The receiving end  560  of the opening of the tool handle can be sized and dimensioned to receive the arms of cartridge  510  in a way that momentarily depresses those arms, allowing for locking members  530 B and  535 B to slide into the tool handle opening, and then to snap back to lock into place in catches  540  and  545  located on the vertical plane or spine of the handle. 
     When removing cartridge  510  for replacement, a user can simply squeeze or pinch the stem arms  535 A and  530 A together via locking members  535 B and  530 B, allowing cartridge  510  to be pulled out from tool handle  550 . 
     It should be appreciated that a blade cover as described in  FIGS. 1-4  (e.g., blade cover  315 ) could advantageously be used with cartridge  510 . Cartridge  510  could include a lock protrusion (e.g.,  50  in  FIG. 1A ), which could be coupled with a blade cover lock opening (e.g.,  55  in  FIG. 1A ). Cartridge  510  could also include a movement protrusion (e.g.,  70  in  FIG. 1A ), which could be coupled with a blade cover channel (e.g.,  105 ) as described above. Viewed from another perspective, cartridge  510  could be identical to cartridges  100 ,  310  or  200 , which include blade covers, except for the positioning of blade  520  and the inclusion of blade top shield  525 . 
     As shown in  FIGS. 5A-5B , blade holder  515 , blade  520 , blade top shield  525  are configured such that a blade cover may not be required. An edge of blade holder  515  and an edge of blade top shield (referred to herein from time to time as blade cap, second blade holder, or blade tip cap)  525  define a recessed area that includes blade  520 . Only a small portion of blade  520 &#39;s edge is exposed (e.g., less than 2 cm, less than 1.5 cm, less than 1 cm), and the exposed edge portion is recessed relative to an end of blade top shield  525 , which could comprise a piercer or a blunt tip. Viewed from another perspective, cartridge  510  is configured such that an object will not be cut by blade  520  unless placed within a recess defined by an edge of a blade holder and an edge of a blade top shield. In preferred embodiments, blade top shield  525 &#39;s end or tip could extend at least 1 mm, at least 2 mm, at least 5 mm, or even at least 10 mm or more further towards the cartridge stem than blade  520 &#39;s edge. Additionally or alternatively, blade holder  515 &#39;s tip  515 A could extend further away from the cartridge stem than blade top shield (e.g., at least 1 mm, at least 2 mm, at least 5 mm or even more), and could comprise a pointed tip that acts as a piercer. 
       FIGS. 6A-6B  illustrate yet another utility knife  600 , which can be used with or without a blade cover. Utility knife  600  is similar to knife  500 , and includes a cartridge  610  and tool handle  650 . Cartridge  610  comprises a blade holder  615  and a stem  640  including two flexible arms  645 A,  640 A having locking members  645 B and  640 B. Handle  650  comprises two catches  660  and  655  that are sized and dimensioned to receive locking members  645 B and  640 B, respectively. Cartridge  610 , however, includes two blade top shields  635  and  630 , each of which are coupled to blade holder  615  and at least partially define a recess. 
     An edge of blade holder  615  and an edge of blade top shield  635  define a recessed area that includes blade  625 . Only a small portion of blade  625 &#39;s edge is exposed (e.g., less than 2 cm, less than 1.5 cm, less than 1 cm), and the exposed edge portion is recessed relative to an end of blade top shield  635 , which could comprise a piercer or a blunt tip. 
     Viewed from another perspective, cartridge  610  is configured such that an object will not be cut by blade  625  unless placed within a recess defined by an edge of a blade holder and an edge of a blade top shield. A different edge of blade holder  615  and an edge of blade top shield  630  define a recessed area that includes blade  620 . Only a small portion of blade  620 &#39;s edge is exposed, and the exposed edge portion is recessed relative to an end of blade top shield  630 , which could comprise a piercer or a blunt tip. 
     Similarly to utility knife  500 , each blade top shield  635  or  630 &#39;s end or tip could extend at least 1 mm, at least 2 mm, at least 5 mm, or even at least 10 mm or more further towards the cartridge stem than blade  625  or  620 &#39;s edge. 
     In some aspects of the inventive subject matter, a cartridge can include a movable member, a blade holder, and a blade. A blade cover coupled to the cartridge can include an opening member, and be configured to move from a closed configuration to an open configuration via an interaction of the opening member and the movable member. Additionally or alternatively, the blade could compose a hook-type cutter, and include an exposed edge portion that is recessed relative to at least one of the blade holder and a blade tip cover.  FIGS. 7A-7D  illustrate a utility knife  700  having such features. 
       FIG. 7A  is a top view of knife  700 , which includes handle  750 , cartridge  710  removably coupled to handle  750 , anti-tamper guard  775  having first and second sides ( 775 A,  775 B), and blade cover  715 . As can more clearly be seen in the bottom view of  FIG. 7B  and the side views of  FIGS. 7C and 7D , the first and second sides  775 A,  775 B of anti-tamper guard  775  form a gap that is sized and dimensioned to receive at least portions of cartridge  710  and blade cover  715 . 
     Anti-tamper guard  775  protects blade cover  715  from being tampered with or taken off of cartridge  710  when cartridge  710  is coupled with tool handle  750 . First and second sides  775 A,  775 B are substantially parallel to one another, and positioned, sized and dimensioned to receive a thickness of blade cover  715 . 
     It should be appreciated that the cartridge and blade cover of knife  700  could function similarly to the cartridge and blade cover shown in  FIG. 1A . For example, cartridge  710  could include a blade holder, a blade, a stem having two flexible arms, and a lock protrusion (e.g.,  50  of  FIG. 1A ). Blade cover  715  could include a lock opening (e.g.,  55  of  FIG. 1A ), and be configured to move (e.g., slide) relative to the blade holder from a locked position, as shown in  FIG. 1A , to an unlocked position, as shown in  FIG. 1B . In this manner, blade cover  715  can be locked in a safe position that keeps the blade from being inadvertently exposed, regardless of whether or not the cartridge has been inserted into a tool handle. 
     Additionally or alternatively, blade cover  715  could be configured to move (e.g., rotate) relative to the blade holder and blade from a blade covering configuration, as shown in  FIG. 1B , to a blade exposing configuration, as shown in  FIG. 1C . For example, the blade holder could comprise a movement protrusion (e.g.,  70  of  FIG. 1A ) that is configured to cooperate with blade cover&#39;s angled channel (e.g.,  105  of  FIG. 1A ) to allow for rotation of blade cover  715  when it is in an unlocked position. 
     In some other embodiments, blade cover  715  could be configured to move from a blade covering configuration to a blade exposing configuration, but not be configured to move between a locked position and an unlocked position. Additionally, the blade cover could be biased to a blade covering configuration (e.g., via a spring). 
     In some other embodiments, blade cover could be configured to move between only two positions—away and towards a cartridge stem via a lock opening of the blade cover and a lock protrusion of the cartridge, or vice versa. When blade cover is positioned towards the cartridge stem, the blade edge could be entirely covered by the blade cover. When blade cover is positioned away from the cartridge stem, the blade edge could be exposed. The blade cover could be biased towards a blade covering position, wherein the lock protrusion could be positioned within one wide end of the nephroid lock opening, similar to what is shown in  FIG. 1B . When a force is applied, the blade cover could move towards a blade exposing position, wherein the lock protrusion could be positioned within the other wide end of lock opening, similar to what is shown in  FIG. 1A . 
     The outer surface of one or both of the first and second sides  775 A,  775 B could include a logo, design or other marking (as shown in  FIGS. 7C and 7D ). An inner surface of one or both sides could include a protrusion that is sized and dimensioned to couple with an aperture or recess of a lock protrusion (e.g.,  50  in  FIG. 1A ). For example, each of the two portions could include a protrusion, and the two protrusions could face one another. These two protrusions could couple with a through-hole or recessed portions of a lock protrusion via a snap fit or any other suitable mechanism. 
     Knife  700  could also include a blade tip cover  780 , which can be sized and dimensioned to receive at least a portion of blade  785 . Blade tip cover  780  could be fixedly attached to blade  785 , movably but permanently attached to blade  785  or other portion of cartridge  710 , or removably coupled to blade  785  via a suitable mechanism. Some exemplary knives having different blade tip covers are illustrated in  FIGS. 8-10 , but it should be appreciated that any suitable cover that is sized and dimensioned to securely receive a portion of a blade that not secured within a cartridge blade holder is contemplated. 
       FIG. 8  illustrates utility knife  800 , which includes a handle  850  and cartridge  810 . Cartridge  810  includes a blade holder  815 , which secures blade  820  in place, and blade tip cap  870 , which advantageously provides protection against inadvertent cuts by creating a hook-type cutter with blade  820  and blade holder  815 . Cartridge  810  also includes a moving member or biasing member  880  positioned within a recess or through-hole of cartridge, which is configured to flex when a pressure is applied, for example, by a blade cover&#39;s opening member. Stem  830  of cartridge  810  includes two flexible arms  830 A,  835 A, each of which include a locking member  830 B,  835 B, respectively. 
     Stem  830  is sized and dimensioned to be received by an opening  860  of handle  850 . Arms  835 A and  830 A can be squeezed towards one another to allow locking members  835 B,  830 B to pass through opening  860 , and snap or otherwise be released into first and second catches  840 ,  845 , respectively. 
     The portion of blade  820  that is not secured within blade holder  815  is triangular in shape and includes a pointy end. Blade tip cap  870  is similarly triangular in shape, and is sized and dimensioned to receive the pointy end of blade  820 , leaving an exposed blade portion between blade holder  815  and blade tip cap  870 . Viewed from another perspective, the exposed portion of blade  820 &#39;s edge is recessed relative to blade holder  815  and blade tip cap  870 , and forms a hook-type cutter. 
       FIG. 9  illustrates another utility knife  900  including a hook type cutter. Cartridge  910  includes a blade holder  915 , which secures blade  920  in place, and blade tip cap  970 . Cartridge  910  also includes a biasing member  980  positioned within a recess or through-hole of cartridge, which is configured to flex when a pressure is applied, for example, by a blade cover&#39;s opening member. Stem  930  of cartridge  910  includes two flexible arms  930 A,  935 A, each of which include a locking member  930 B,  935 B, respectively. 
     Stem  930  is sized and dimensioned to be received by an opening  960  of handle  950 . Arms  935 A and  930 A can be squeezed towards one another to allow locking members  935 B,  930 B to pass through opening  960 , and snap into first and second catches  940 ,  945 , respectively. 
     The portion of blade  920  that is not secured within blade holder  915  is trapezoidal or trapezium in shape, and includes two pointy ends. A first pointy end is sharp and includes the blade&#39;s cutting edge. A second pointy end has a greater thickness, and is not typically used to create a cut. Blade tip cap  970  can comprise any suitable shape, and is sized and dimensioned to receive the first and second pointy ends of blade  920 , leaving an exposed blade portion between blade holder  915  and blade tip cap  970 . 
       FIG. 10  illustrates yet another utility knife  1000  including a hook type cutter. Cartridge  1010  includes a blade holder  1015 , which secures blade  1020  in place, and blade tip cap  1070 . Blade holder  1050  and blade tip cap  1070  cooperate to cover the entirety of blade  1020 , exclusive of a portion of a cutting edge. 
     Cartridge  1010  also includes a biasing member  1080  positioned within a recess or through-hole of cartridge, which is configured to flex when a pressure is applied, for example, by a blade cover&#39;s opening member. It should be appreciated that biasing member  1080  is optional, and may not be included in embodiments not including a rotating blade cover. Stem  1030  of cartridge  1010  includes two flexible arms  1030 A,  1035 A, each of which include a locking member  1030 B,  1035 B, respectively. 
     Stem  1030  is sized and dimensioned to be received by an opening  1060  of blade holder  1050 . Arms  1035 A and  1030 A can be squeezed towards one another to allow locking members  1035 B,  1030 B to pass through opening  1060 , and release into first and second catches  1040 ,  1045 , respectively. 
     Blade  1020  is a quadrilateral, but could alternatively comprise any other suitable shape. Blade  1020  includes an outer perimeter, at least part of which comprises a cutting edge. Blade tip cap  1070  extends from blade holder  1015  and around the outer perimeter of blade  1020  that is not covered by blade holder  1015 , leaving only a small portion of blade  1020 &#39;s cutting edge accessible. The accessible portion of blade  1020 &#39;s cutting edge could have any suitable length, including for example, between 1-20 mm, between 1-15 mm, between 1-10 mm, between 5-15 mm, or between 5-10 mm, 10-15 mm. Viewed from another perspective, it is contemplated that blade holder  1015  and blade tip cap  1070  could enclose at least 50%, at least 70%, at least 80%, or even 90% or more of blade  1020 &#39;s outer perimeter. 
     In some preferred embodiments, the blade is positioned relative to the blade holder  1015  and blade tip cap  1070  such that the exposed blade edge portion is recessed, thereby forming a hook type cutter. Viewed from another perspective, the blade tip cap and an edge of blade holder  1050  each extend further towards the cartridge stem  1030  than blade  1020 &#39;s cutting edge. Viewed from yet another perspective, the blade holder and blade tip cap form a notch or recess in which blade  1020  (including its cutting edge) is disposed. 
     It should be appreciated that the knives of  FIGS. 8, 9 and 10  could each include an anti-tamper guard, or any other feature described throughout the application. 
       FIGS. 11A-11C  illustrate a utility knife of the inventive subject matter similar to the knives of  FIGS. 8-10 , and including a blade cover  1005  that is configured to rotate relative to cartridge  1110 .  FIG. 11A  illustrates blade cover  1105  in a closed position, with cartridge  1110  removed from handle  1150 .  FIG. 11B  illustrates blade cover in a closed position, with cartridge  1110  coupled with handle  1150 .  FIG. 11C  illustrates blade cover in an open position, with cartridge  1110  coupled with handle  1150 . 
     Utility knife  1100  includes cartridge  1110  and tool handle  1150 . Cartridge  1110  includes a blade holder, which secures blade  1120  in place, and blade tip cap  1170 . Cartridge  1110  also includes a biasing member  1180  positioned within a recess or through-hole of cartridge  1110 . Biasing member  1180  is configured to flex when a pressure is applied by blade cover&#39;s opening member  1105 A, as further described below. In some preferred embodiments, the cartridge is sized and dimensioned such that the biasing member can move at least 25 mm in at least one direction, at least 20 mm in at least one direction, at least 15 mm in at least one direction, at least 10 mm in at least one direction, or at least 5 mm in at least one direction. 
     Stem  1130  of cartridge  1110  includes two flexible arms  1130 A,  1135 A, each of which include a locking member  1130 B,  1305 B, respectively. Stem  1130  is sized and dimensioned to be received by an opening  1160  of handle  1150 . Arms  1135 A and  1130 A can be squeezed towards one another to allow locking members  1135 B,  1130 B to pass through opening  1160 , and snap into first and second catches  1140 ,  1145 , respectively. 
     Opening member  1105 A comprises a stem that leads to a nub or protuberance. Biasing member  1180  similarly includes a stem that leads to a nub or protuberance, and the nubs of the two members face one another. When blade cover  1105  is in a closed position, biasing member  1180 &#39;s nub is positioned beneath opening member  1105 &#39;s nub. As a force is applied to blade cover  1105  in order to expose blade  1120 , biasing member  1180 &#39;s nub moves up towards opening member  1105 A&#39;s nub, aligns with opening member  1105 &#39;s nub, and then sits above opening member  1105 &#39;s nub. 
     It should be appreciated that opening member  1105 A could be less flexible than biasing member  1180  such that opening member  1105 A does not change shape when blade cover  1105  is moved. Additionally or alternatively, opening member  1105 A could be positioned on blade cover  1105  such that opening member  1105 A does not or cannot move, even when a pressure is applied. For example, opening member  1105 A could be fixedly attached to, or comprise an extension of, an inner surface of blade cover  1105 . 
     Methods of making cartridges as described are also contemplated. A cartridge as detailed in  FIGS. 1A-11C  can be assembled by fixing a blade to a cartridge. The blade can be made of metal, plastic, ceramic, wood, bone, keratin, enamel, carbon, stone, obsidian, glass, diamond, or any other material suitable for cutting or applying directed pressure. Further, the blade may be straight, curved, round, angled, serrated, sharpened, dulled, or otherwise configured as appropriate for the desired use. The cartridge may be a single piece or the composite of several pieces. The pieces could be of the same material (e.g., injection molded plastic) or of a range of materials. 
     A cartridge as described above can be made by fixing a blade cover to the blade holder. The blade cover can be an integral part of the blade holder and can be made of the same material as the blade holder. For example, the blade cover and blade holder can be made of a single piece of flexible rubber or rigid plastic. Further, the blade cover and blade holder can be made primarily of the same material as an integral piece, while the blade holder is further comprised of other components or materials. The blade cover and the blade holder can also be separate components, and can be made of different materials or the same material. The blade cover can be fixed to the blade holder by means that permit the blade cover to rotate (partially or fully), pivot, slide, swivel, turn, bend, flex or otherwise move in relation to the blade. 
     A cartridge as described above can also be made such that the blade cover and the blade holder are attached at a junction. The junction can be further configured such that a part of the junction prevents or allows the blade cover to move in relation to the blade, while another part of the junction provides the avenue or means for the blade cover to move in relation to the blade. The means of preventing or allowing movement, and restricting the direction of movement, of the blade cover in relation to the blade can be an integral part of the junction between the blade cover and the cartridge, or can be a separate component. Further, the components can be made of the same or different materials. 
     A cartridge as described above can further be made by fixing flexible arms to the blade holder. The flexible arms can be a separate component from the blade holder or can be an integral aspect of the blade holder. The flexible arms and blade holder can be made of the same material or of different materials. The flexible arms can be configured such that they depress while being inserted into a tool handle, and then return to an undepressed position once completely inserted into the tool handle. 
     As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. 
     As used herein, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously. 
     The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention. 
     Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims. 
     It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the scope of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.