Patent Publication Number: US-2009223063-A1

Title: Dual bladed utility knife

Description:
BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a utility knife in accordance with one exemplary embodiment. 
       FIG. 2  is an exploded assembly view of the utility knife of  FIG. 1 . 
       FIG. 3  is a perspective view of a portion of the utility knife of  FIG. 1  showing the position of both blades when contained in the housing. 
       FIG. 4  is a perspective view of a portion of the utility knife of  FIG. 1  showing the position of the first blade when it extends from the housing. 
       FIG. 5  is a perspective view of a portion of the utility knife of  FIG. 1  showing the position of the second blade when it extends from the housing. 
       FIG. 6  is a perspective view of the utility knife of  FIG. 1  in which a first blade detachment member is actuated to effect removal of the first blade. 
       FIG. 7  is a perspective view of the utility knife of  FIG. 1  in which a second blade detachment member is actuated to effect removal of the second blade. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
     An exemplary embodiment of the present invention provides for a dual bladed utility knife  10  with a thumb slide button  28 . The arrangement of utility knife  10  enables a user to extend and retract blades  22  and  24  with one hand, without having to touch the blades  22  or  24 . Further, the utility knife  10  eliminates the need to carry more than one knife should various types of blades  22  and  24  be desired, and the utility knife  10  may be arranged so as not to require use of both hands to change the blades  22  and  24 . Reference will now be made in detail to the embodiments of the invention, examples of which are illustrated in the drawings. 
       FIG. 1  illustrates a first embodiment of a utility knife  10 , in a non-operational position. An opening  88  may be defined on the top of a housing  12  of the utility knife  10 . Opening  88  may be along the length of housing  12 . A button  28  is present and has a portion that may be disposed into the housing  12  through the opening  88 . The button  28  may be capable of sliding along a longitudinal direction  14  of the housing  12 . Further, the button  28  may be capable of moving along a transverse direction  16  of housing  12 . The button  28  may be pushed by the thumb of the user to slide with respect to the housing  12  in the longitudinal direction  14  and the transverse direction  16 . 
     Referring to  FIG. 2 , the housing  12  of the utility knife  10  has a left housing-half  12 ( a ) and a right housing-half  12 ( b ). Both the left housing-half  12 ( a ) and the right housing-half  12 ( b ) have a convex inner side and a concave outer side. The opening  88  is a combination of a left opening-half  88 ( a ) and a right opening-half  88 ( b ). The left opening-half  88 ( a ) is defined on the top of the left housing-half  12 ( a ), and the right opening-half  88 ( b ) is defined on the top of the right housing-half  12 ( b ). The left housing-half  12 ( a ) may be coupled with the right housing-half  12 ( b ) such that the concave inner side of the left housing-half  12 ( a ) faces the concave inner side of the right housing-half  12 ( b ). As the left opening-half  88 ( a ), on the top of the left housing-half  12 ( a ) is aligned with the right opening-half  88 ( b ), on the top of the right housing-half  12 ( b ), the opening  88  is defined on the top of housing  12 , as illustrated in  FIG. 1 . The left housing-half  12 ( a ) may have an aperture  86  which may be aligned with an aperture  87  present on the right housing-half  12 ( b ). A threaded screw  84 , or the like, may be extended through the aligned apertures  86  and  87  to couple the left housing-half  12 ( a ) with the right housing-half  12 ( b ). The apertures  86  and  87  may be present near a second end  20  of the housing  12 , or anywhere else along the length of the utility knife  10  to securely couple the left housing-half  12 ( a ) with the right housing-half  12 ( b ). Additional screws and apertures may also be present at other locations along the housing  12  in order to further secure the left housing-half  12 ( a ) with the right housing-half  12 ( b ). Other coupling means may be employed for coupling the left housing-half  12 ( a ) with the right housing-half  12 ( b ). For example a U-shaped clamp, adhesives, magnetic fasteners, or other mechanical fasteners may be employed in accordance with other exemplary embodiments. 
     With reference to  FIG. 2 , a first blade  22  can be extended and retracted from the housing  12  of the utility knife  10  through a blade-slot  76  present at a first end  18  of the housing  12 . Alternatingly, a second blade  24 , can be extended and retracted from the housing  12  of the utility knife  10  through a blade-slot  78  present at the first end  18  of the housing  12 . The first blade  22  may have, for example, a straight cutting surface. Additionally, the second blade  24  may have a hook-shaped cutting surface. The first blade  22  and second blade  24  may have varying shapes in order to provide various cutting capabilities as desired. Further, in alternative embodiments, the profiles of the first blade  22  and the second blade  24  may be similar. 
     To operate the utility knife  10 , an actuator  26  shown in  FIG. 2 , may be utilized. As illustrated in  FIG. 2 , the actuator  26  may be an assembly that includes the button  28  which is disposed into the housing  12  through the opening  88 , a track  30  on which the button  28  may slide, a sliding member  38 , a first blade engagement member  44 , and a second blade engagement member  48 . 
     As seen in  FIG. 2 , the track  30  may have a slot  32  that is wider at one end so as to accommodate the button  28 . The button  28  may have an upper block  28 ( a ) and a lower stem  28 ( b ). A spring  36  may be coiled around the lower stem  28 ( b ). The sliding member  38  may include a sliding member body  40  which may be generally rectangular in shape with a slant side  90 . A button engagement member  42  may also be present on the sliding member  38  which may be cuboidal in nature. The button engagement member  42  may be removably attached at the center of the sliding member body  40 . The sliding member  38  is placed in the housing  12 , along the length of the housing  12 , and the button engagement member  42  is capable of pivoting along the transverse direction  16 . The button engagement member  42  may have a cavity at the top  92  to matingly receive the lower stem  28 ( b ) of the button  28 . 
     Referring to  FIG. 3 , on one side of the sliding member body  40 , the first blade engagement member  44  may be positioned to carry the first blade  22 . On the opposite side of the sliding member body  40 , the second blade engagement member  48  may be positioned to carry the second blade  24 . The first blade engagement member  44  may have a first blade engagement member recess  46  formed at its center. The first blade engagement member  44  may be provided with a ledge  96  on the front surface which defines the position for placing the first blade  22 . For accurate positioning of the first blade  22 , a pair of projections  52  may protrude from the first blade engagement member  44 . The projections  52  on the first blade engagement member  44  may be sized to securely fit in a pair of notches  94  formed on the first blade  22  illustrated in  FIG. 3 . The projections  52  prevent displacement of the first blade  22  from its defined position on the first blade engagement member  44 . The projections  52  may be capable of being depressed towards the first blade engagement member  44  so that the first blade  22  becomes free to slide along the length of the first blade engagement member  44 . 
     The second blade engagement member  48 , positioned on the opposite side of the sliding member body  40 , carries the second blade  24 . The second blade engagement member  48  may have a second blade engagement member recess  50  formed at its center. The second blade engagement member  48  may be provided with a ledge  97  on the front surface which defines a position for placing the second blade  24 . For accurate positioning of the second blade  24 , a pair of projections  54  may protrude from the second blade engagement member  48 . The projections  54  on the second blade engagement member  48  may be sized to securely fit in a pair of notches  95  formed on the second blade  24  illustrated in  FIG. 3 . The projections  54  prevent displacement of the second blade  24  from its defined position on the second blade engagement member  48 . The projections  54  may be capable of being depressed towards the second blade engagement member  48  so that the second blade  24  becomes free to slide along the length of the second blade engagement member  48 . 
     The first blade engagement member  44  and the second blade engagement member  48  may be positioned on opposite sides of the sliding member body  40 . The front surface of the first blade engagement member  44 , which has the pair of notches  94  and the ledge  96  may not face the sliding member body  40 . However, other embodiments are possible in which the front surface may in fact face the sliding member body  40 . The first blade engagement member recess  46  can be aligned with the button engagement member  42 . Similarly, the front surface of the second blade engagement member  48  that has the pair of notches  95  and the ledge  97  does not face the sliding member body  40 . The second blade engagement member recess  50  can be aligned with the button engagement member  42 . With this arrangement, the first blade engagement member recess  46 , the button engagement member  42  of the sliding member  38  and the second blade engagement member recess  50  are aligned parallel to each other in subsequent order. This arrangement is illustrated with reference to  FIG. 3 . 
     The actuator  26  is positioned in the housing  12 . Referring to  FIG. 2 , the track  30  can be positioned on a pair of arched mounting posts (not shown) provided in the left housing-half  12 ( a ) beneath the opening  88  in the housing  12 . The button  28  can be placed on track  30  so that the lower-stem  28 ( b ) passes through the slot  32  and is thus disposed into housing  12 . The upper-block  28 ( a ) remains on top of the housing  12 . A biasing member  56  may be provided on the concave side of the left housing-half  12 ( a ). The biasing member  56  may be a push-button in accordance with certain exemplary embodiments. The first blade engagement member  44  can be positioned along the length of the left housing-half  12 ( a ) in contact with the biasing member  56 . The first blade engagement member  44  is positioned so that the biasing member  56  lies in the first blade engagement member recess  46 . The biasing member  56  may be sized so that it fits in the first blade engagement member recess  46 . When the biasing member  56  is not depressed, it prevents sliding of the first blade engagement member  44  in the longitudinal direction  14 . The biasing member  56  may be depressed, so that the first blade engagement member  44  is free to slide along the length of the housing  12  in the longitudinal direction  14 . A user may push the button  28  in the transverse direction  16  so as to be inserted into the first blade engagement member recess  50  to depress the biasing member  56  to allow for movement in the longitudinal direction  14 . 
     As explained above, next to the first blade engagement member  44 , the sliding member  38  is positioned. On the opposite side of the sliding member  38 , the second blade engagement member  48  is positioned. A first blade storage area  64  may be present in the left housing-half  12 ( a ) closer to the first end  18  for use in storing the first blade  22 . Access to the first blade storage area  64  may be gained by removing a cover  80  present on the convex outer side of the left housing-half  12 ( a ) as illustrated in  FIG. 1 . A first biasing member  68  may be present in the first blade storage area  64  on the concave inner side of the left housing-half  12 ( a ). The first biasing member  68  may have a spring arranged to urge the first blade  22  stored in the first blade storage area  64  towards the first blade engagement member  44 . Urging of the first blade  22  towards the first blade engagement member  44  causes the first blade  22  to be captured by the first blade engagement member  44 . 
     Referring to  FIG. 3 , a biasing member  58  may be provided on the concave side of the right housing-half  12 ( b ). The biasing member  58  may be a push-button in accordance with one exemplary embodiment. The second blade engagement member  48  can be positioned next to sliding member body  40  in contact with the biasing member  58 . The second blade engagement member  48  is positioned such that the biasing member  58  lies in the second blade engagement member recess  50 . When the biasing member  58  is not depressed, it prevents sliding of the second blade engagement member  48  along the length of the right housing-half  12 ( b ) in the longitudinal direction  14 . The biasing member  58  may be depressed so that the second blade engagement member  48  becomes free to slide along the length of the right housing-half  12 ( b ). The biasing member  58  may be depressed upon a user pushing the button  28  in the transverse direction  16  so that the spring force of the biasing member  58  is overcome. 
     A second blade storage area  70  for storing the second blade  24  may be provided on the concave inner side of right housing-half  12 ( b ) proximate to the first end  18 . A cover  82  illustrated in  FIG. 3 , may be removed to gain access to the second blade storage area  70 . The right housing-half  12 ( b ) may define a blade-slot  76  and a blade-slot  78  defined in a lid  98  present at the first end  18  of the right housing-half  12 ( b ). The lid  98  may be removably or fixedly attached at the first end  18 . Upon operation, the first blade  22  and the second blade  24  extend out from the blade-slots  76  and  78 , respectively. 
       FIG. 4  shows extension of the first blade  22  from the housing  12 . This action involves co-operation between the first blade engagement member  44 , the sliding member  38 . Depression of the button  28  causes a spring  36 , which is wound around the lower-stem  28 ( b ) of the button  28 , to become compressed. The lower-stem  28 ( b ) of the button  28  is inserted deeper into the button engagement member  42 . The button  28  may be depressed and pushed along the transverse direction  16 , towards the left housing half  12 ( a ), to engage the button engagement member  42  with the first blade engagement member recess  46 . This action functions to depress the biasing member  56  present in the left housing-half  12 ( a ). Thus, as the button  28  slides along the longitudinal direction  14  towards the first-end  18  of the housing  12 , the first blade engagement member  44  also slides towards first end  18 . The first blade  22 , carried by the first blade engagement member  44 , extends out from the blade-slot  76  present at the first end  18  of the housing  12 . The second blade engagement member  48  is secured inside the housing  12  by the biasing member  58 . The first blade  22  may be retracted into the housing  12  by depressing the button  28  and sliding it in the opposite direction towards the second end  20  along the longitudinal direction  14 . 
     The button  28 , which is in a neutral position in  FIG. 3 , may be used to extend and retract the first blade  22  and the second blade  24  from the utility knife  10 . Referring to  FIG. 5 , for extending the second blade  24 , the button  28  may be depressed and pushed along the transverse direction  16 , towards the right housing-half  12 ( b ). This also causes the track  30  to move along the arched mounting posts (not shown) towards the right housing-half  12 ( b ). The biasing member  58  is compressed out of the second blade engagement member recess  50  by the button button engagement member  42  of the button  28  to allow movement in the longitudinal direction  14 . Thereafter, the button  28 , in the depressed position, is slid in the longitudinal direction  14 , towards the first end  18  of the housing  12 , thus extending the second blade  24  from the housing  12 . 
     Movement of the button  28  in the transverse direction  16  towards the right housing-half  12 ( b ) causes the button engagement member  42  to pivot towards the right housing-half  12 ( b ) and become inserted into the second blade engagement member recess  50 . The second blade engagement member recess  50  may be sized to receive the button engagement member  42 . Due to the movement of the button engagement member  42  towards the right housing-half  12 ( b ), the biasing member  58  becomes depressed and the second blade engagement member  48  becomes free to slide along the length of the housing  12  in the longitudinal direction  14 . Thus, as the button  28 , in the depressed position, is slid on the track  30  in the longitudinal direction  14 , the second blade engagement member  48  is slid along with the sliding member  38  in the same direction. The second blade engagement member  48  is carried along with the sliding member  38  in the longitudinal direction  14  towards the first end  18  of the housing  12 . When this occurs, the first blade engagement member  44  stays securely positioned inside the housing  12 . Sliding motion of the first blade engagement member  44  is prevented by the biasing member  56 . The second blade engagement member  48 , carrying the second blade  24 , thus slides in the longitudinal direction  14  towards the first end  18  of the housing  12 . The second blade  24  extends out of the housing  12  from the blade-slot  78  present at the first end  18 . To retract the second blade  24 , the button  28  may be depressed and slid towards the second-end  20  in the opposite direction in the longitudinal direction  14 . This causes the second blade engagement member  48 , carrying the second blade  24 , to slide towards the second-end  20  of the housing  12 . Thus, the second-blade  24  is retracted into the housing  12 . 
     The actuator  26  may be arranged so that it does not allow the simultaneous extension of the first blade  22  and the second blade  24  from the housing  12  of the utility knife  10 . Further, the actuator  26  may be arranged so that it is capable of extending and retracting both the first blade  22  and the second blade  24 . However, it is to be understood that other arrangements are possible in which more than one actuator  26  can be present. A single actuator  26  may thus be employed that allows blades  22  and  24 , that may be configured differently or the same as one another, to be extended and retracted from the housing  12   
     Whenever there is a need for blade replacement, the first blade  22  or the second blade  24  may be removed from the housing  12 . This can be accomplished without removing the covers  80  or  82  to access the first blade storage area  64  or the second blade storage area  70 , respectively. 
     As shown with reference to  FIGS. 6 and 7 , the first blade  22  may extend out from the housing  12 . In order to detach the first blade  22 , a first blade detachment member  60 , which may be present on the left housing-half  12 ( a ) at the position of the eye of the shark, may be actuated in the transverse direction  16 , towards the housing  12  to depress the projections  52  present on the first blade engagement member  44 . Consequently, the first blade  22  disengages from the first blade engagement member  44  and can be pulled out to be completely removed from the housing  12 . Thereafter, the first blade detachment member  60  may again be actuated in the transverse direction  16  towards the housing  12 , and another first blade  22  may be inserted from the blade-slot  76  present at the first end  18  of the right housing-half  12 ( b ). 
     A second blade detachment member  62 , illustrated in  FIGS. 6 and 7  may be present on the right housing-half  12 ( b ) at the position of the eye of the shark. A lower portion of the second blade detachment member  62  is disposed inside the housing  12 . When the second blade  24  extends out from the housing  12 , the second blade detachment member  62  may be actuated along the transverse direction  16 , towards the housing  12 . Consequently, the projections  54  protruding from the second blade engagement member  48  are depressed, which disengages the second blade  24 . The second blade  24  can then be pulled out and completely removed from the housing  12 . Another second blade  24  may be fed into the housing  12 . In one embodiment, the second blade detachment member  62  can be actuated along the same direction and another second blade  24  can be inserted into the blade-slot  78  present at the first end  18  of the right housing-half  12 ( b ). 
     The described mechanism of removal and insertion of first blade  22  and the second blade  24  may be used to extend the life of the first blade  22  and the second blade  24 . Whenever the cutting edge of the either of the first blade  22  or the second blade  24  becomes blunt, the blade  22  or  24  can simply be removed, turned over and then inserted so that the other edge of the blade  22  or  24  can be used. In an alternate embodiment, the first blade detachment member  60  and the second blade detachment member  62  may not be present, wherein replacing the first blade  22  and the second blade  24  requires the user to open the respective covers  80  and  82  present on the outer convex side of the housing  12 . 
     To save the user the trouble of replacing the first blade  22  and the second blade  24 , an alternate embodiment may be used that allows more than one first blade  22  and more than one second blade  24  to be stored in the housing  12 .  FIG. 2  illustrates a plurality  66  of first blades  22  and a plurality  72  of second blades  24 . The plurality  66  of the first blades  22  may be stored in the first blade storage area  64  present in the left housing-half  12 ( a ). The plurality  66  of the first blade  22  may be positioned over the first biasing member  68  present in the left housing-half  12 ( a ). The plurality  72  of the second blades  24  may be stored in the second blade storage area  70 , present in the right housing-half  12 ( b ). The plurality  72  of the second blades  24  may be positioned over the second biasing member  74  present in the right housing-half  12 ( b ). 
     The first-blade  22  may be removed from the housing  12  by the process mentioned above. Consequently, the first biasing member  68  urges a subsequent first blade  22  of the plurality  66  of first blades  22  into engagement with the first blade engagement member  44 . Similarly, if required, the second bade  24  may be removed from the housing  12  resulting in a subsequent second blade  24  of the plurality  72  of the second blades  24  being urged into engagement with the second blade engagement member  48  by the second biasing member  74 . In an additional alternate embodiment, there may be another first blade storage area  64  and another second blade storage area  70  present near the second end  20  of the housing  12  for purposes of storing extra first blades  22  and extra second blades  24 . 
     An additional alternative exemplary embodiment of the utility knife  10  is explained hereinafter. This additional embodiment is similar to a previously mentioned embodiment except that the first blade  22  and the second blade  24  may be extended simultaneously from the housing  12  of utility knife  10 . To achieve this feature, the first blade engagement member  44  and the second blade engagement member  48  may be fixedly or removably attached at the opposite sides of the sliding member body  40 . This arrangement eliminates the biasing members  56  and  58  present in the housing-halves  12 ( a ) and  12 ( b ), respectively. The present embodiment does not include movement of the button  28  along the transverse direction  16 . The button  28 , when in the neutral position, may only be slid in the longitudinal direction  14  towards the first end  18  of the housing  12 . This movement of button  28  causes the sliding member  38  to slide along with the first blade engagement member  44  and the second blade engagement member  48 . The first blade  22  and the second blade  24  are positioned on the first blade engagement member  44  and the second blade engagement member  48 , respectively. Consequently, the first blade  22  and the second blade  24  simultaneously extend from their respective blade-slots  76  and  78  present at first end  18  of housing  12 . This exemplary embodiment may find utility in situations which require both the blades  22  and  24  to operate simultaneously. Although described as being capable of simultaneously extending from the housing  12 , it is to be understood that various exemplary embodiments exist in which the blades  22  and  24  can only extend one at a time from the housing  12  as previously discussed. In this regard, the actuator  26  is configured so that only one of the blades  22  or  24  can be extended as previously mentioned. 
     Additional modifications to the above mentioned embodiments are possible to yield still further embodiments. For example, the utility knife  10  may employ a mechanism which allows the extension of the first blade  22  and the second blade  24  from the second end  20  as well as from the first end  18  of the housing  12 . In such a mechanism, the ledge  96  as well as the projections  52  and the ledge  97  as well as the projections  54  may be formed on both the ends of the first blade engagement member  44  and the second blade engagement member  48 , respectively. The first blade storage area  64  and the second blade storage area  70  may be present at both ends of the housing  12  which may be accessed by removing the covers  80  and  82 . The first blade  22  and the second blade  24  may be positioned on the opposite ends of their respective blade engagement members  44  and  46 . In this regard, the first blade  22  and the second blade  24  can be located in the first blade storage area  64  and the second blade storage area  70  defined at the second end  20  of the housing  12 . The button  28  may be placed at the longitudinal center of the slot  32  to achieve the non-operational neutral position. The button  28  may be moved along the transverse direction  16  towards either the left housing-half  12 ( a ) or the right housing-half  12 ( b ). Next, the button  28  can be moved along the longitudinal direction  14  towards the second end  20  of the housing  12 . Consequently, the respective blade  22  or blade  24  is extended from the respective blade-slot  76  or  78  present at the second end  20  of the housing  12 . Simultaneous extension of first blade  22  and the second blade  24  from the second end  20  may be achieved if the first blade engagement member  44 , the sliding member  38  and the second blade engagement member  48  are fixedly or removably attached to each other as previously described. 
     An additional exemplary embodiment of the utility knife  10  may exist in which the first blade  22  and the second blade  24  may be simultaneously extended from the first end  18  and the second end  20 . To achieve this arrangement, a pair of actuators  26  may be present. The actuators  26  can be connected in back-to-back fashion. It is to be understood that the actuators  26  can be configured as in a previously discussed embodiment and may be configured the same as one another or different from one another. This embodiment allows the two actuators  26  to work independent of one another. Hence any blade  22  or  24  from any end  18  or  20  may be extended from the housing  12  without affecting the movement or position of the other blades  22  or  24 . 
     While the embodiments of the present invention have been described, it is to be understood that the claimed invention is not to be limited in scope to the aforementioned and described embodiments.