Patent Publication Number: US-11376751-B2

Title: Blade assembly and knife therefor

Description:
FIELD OF THE INVENTION 
     According to a first aspect, the invention relates to a blade assembly comprising a blade support and a blade. Such blade assemblies are usually part of knives, in particular utility knives. 
     The blade assembly e.g. comprises a blade support and a blade that can be detachably fastened in the blade support. The blade support is provided with a blade seat having a contact face for a first blade face. A second blade face opposite the first blade face is substantially freely accessible or abuts a contact face of the blade cover. 
     The blade support has a holder for holding the blade in the blade seat, comprising first interlocking formation associated with the blade support and second interlocking formation associated with the blade that interlock and hold the blade at least in a plane parallel to the contact face. The interlocking formation are designed such that the blade has at least one degree of freedom in one direction in order to be detached from the blade seat. 
     The blade can e.g. be mounted between a contact face of the blade support and a contact face of a blade cover retained on the blade support. Alternatively, a blade cover may not be provided, such that a blade face of the blade abuts a contact face of the blade support and the opposing blade face is open. 
     The holder has a latch having at least one bolt element that is movable between a bolted position and a released position, engages over a region of the second blade face or the blade cover, and locks movement of the blade in the direction of the degree of freedom. In other words, it is not possible to move the blade out of the blade seat in the bolted position of the latch, since the degree(s) of freedom of the blade is/are blocked by the bolt. The latch is e.g. retained on the blade support. The bolt may directly engage over at least one region of the second blade face or may engage over at least one region of a blade cover, wherein the blades 
     The first interlocking formation and the second interlocking formation are e.g. designed such that the blade has only one degree of freedom in the pivoting direction. The bolt may e.g. be in contact with the blade at an end remote from the pivot axis, such that, due to the lever arm, low retaining forces are required to retain the blade securely in its blade seat. 
     The first interlocking formation e.g. comprise at least one projection that interlockingly interacts with a complementary cut-out of the second interlocking formation, such that the blade can be threaded onto the projection by the cut-out. For example, the first interlocking formation comprise two projections, each projection interlockingly interacting with a cut-out of the blade. In this case, the blade support thus has e.g. two projections and the blade has two cut-outs. 
     The first interlocking formation comprise e.g. at least one hook-shaped projection of the blade support that detachably engages through a cut-out of the blade, the shape of the cut-out approximately corresponding to the cross section of the hook-shaped projection. The blade is e.g. detachably arranged between a surface of the projection facing the second blade face and a contact face of the blade support. 
     According to an embodiment of the invention, the blade is detachably arranged between a holding surface of the projection facing the second blade face and a contact face of the blade support. 
     An embodiment is characterized in that the bolt element is designed as a wire or plate. In this way, the bolt provides a small surface area for depositing particles, which could impair the function of the knife. Within the meaning of the invention, the terms “wire” or “plate” are to be understood to mean that they may consist of a metal, but that other material, such as plastics materials or composite materials, also come into consideration for this purpose. The properties according to which, for example, a small deposit surface is formed and/or according to which good spring properties of the material are provided, as is the case for certain metals, for example, are essential. 
     The bolt is designed as a spring, for example. For example, the bolt is formed by a first leg of a torsion spring. 
     The bolt e.g. has a bolt region and a bearing region, the bearing region being movably mounted in a bearing receptacle of the blade support. For example, the bearing region is pivotally mounted in the bearing receptacle. The bearing region is e.g. formed by a second leg of a torsion spring that is pivotally retained in a bearing receptacle of the blade support. 
     The bolt can e.g. be detachably brought into engagement with a receptacle that is retained on the blade support. For example, the receptacle has a seat for the bolt element. The bolt is e.g. retained in the seat such that it cannot become inadvertently detached from the seat. For example, a region of the bolt is latched in the seat. Alternatively or additionally, the bolt is loaded into the seat by a spring force. 
     For example, the receptacle is provided with an oblique surface that, when the bolt moves into the seat, deflects a force that acts on the bolt element in a first direction, in a second direction that is directed orthogonally to the second blade face. The force may be formed by a spring force, for example. In this way, the blade is loaded by the bolt against the contact face of the blade seat. 
     The projection e.g. simultaneously forms the receptacle for the bolt element when it is arranged in the bolted position. In this case, a separate element for the seat of the bolt element does not have to be produced. In this way, space can also be freed up for structural elements on the blade support. 
     In the bolted position, the bolt element for example surrounds the blade or engages through a cut-out of the blade and abuts the second blade face. 
     The invention also relates to a knife having a blade assembly  10  according to the first aspect of the invention. 
     The knife has, for example, a mechanism having a first part and a second part that is movable relative to the first part in order to move a blade assembly between a stowed position in which a blade of the blade assembly is moved relative to a protector such that the user cannot come into contact with a cutting edge of the blade assembly and an operating position which the blade is moved relative to the protector such that a cutting process is possible. 
     In terms of the advantages of the knife, reference is made to the advantages of the first aspect of the invention. 
     One embodiment of the invention is described by way of example in the following description of the figures, also with reference to the schematic drawings. Here, for the sake of clarity, even if different embodiments are involved, identical or comparable parts or elements have been denoted by identical reference signs, sometimes with the addition of lower case letters. 
     Features that are only described, set out or disclosed in relation to one embodiment can also be provided in any other embodiment of the invention within the scope of the invention. Even if they are not shown in the drawings, such amended embodiments are covered by the invention. 
     All the features disclosed are essential to the invention per se. The content of the disclosure of the cited documents and the prior art devices described are hereby incorporated into the disclosure of the application in their entirety, also for the purpose of incorporating individual features or a plurality of features of the subjects disclosed therein into one or more claims of the present application. Even if they are not shown in the drawings, such amended embodiments are also covered by the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       In the drawings: 
         FIG. 1  is a side view of a knife in the stowed position, 
         FIG. 2  is a side view of the knife in an operating position, 
         FIG. 3  is a side view of the knife in a blade-changing position, 
         FIG. 4  is a side view of a blade assembly of the knife, having a blade support and a blade retained thereon, a latch being in a bolted position, 
         FIG. 5  is a sectional view along sectional line A-A in  FIG. 4 , 
         FIG. 6 a    is a detail according to detail line C in  FIG. 5 , 
         FIG. 6 b    is a detail according to detail line D in  FIG. 5 , 
         FIG. 7 a    is a view from the direction of the arrow B in  FIG. 4 , 
         FIG. 7 b    is a section taken along section line G-G of  FIG. 7   a;    
         FIG. 8  is an oblique perspective rear view of the blade support according to  FIG. 4 , 
         FIG. 9  is an oblique perspective front view of the blade support according to  FIG. 4 , 
         FIG. 10  is a side view of the blade support according to  FIG. 4 , a latch being in the released position, 
         FIG. 11  is a view from the direction of the arrow E in  FIG. 10 , 
         FIG. 12  is a view from the direction of the arrow F in  FIG. 10 , 
         FIG. 13  is an oblique perspective rear view of the blade support according to  FIG. 10 , 
         FIGS. 14 a  to 14 d    show the method for mounting the blade on the blade support, 
         FIG. 15  is an exploded view of the blade support, 
         FIG. 16  is an exploded view of a second embodiment of the blade support, 
         FIG. 17  is a perspective view of the blade support, the latch being in a bolted position, 
         FIG. 18  is a perspective view of the blade support, the latch being in the released position, 
         FIG. 19  is a perspective view of the blade support, the latch being in the released position, 
         FIG. 20  is a side view of the blade support in the bolted position of the latch, 
         FIG. 21  is a sectional view along sectional line F-F in  FIG. 20 , 
         FIG. 22  is a view from the direction of the arrow G in  FIG. 20 . 
     
    
    
     SPECIFIC DESCRIPTION OF THE INVENTION 
     The knife as a whole according to  FIG. 1  is denoted by reference sign  10  in the drawings. 
     The knife  10  comprises a first part  11  and a second part  12 . The first part  11  and the second part  12  are part of a mechanism  13  that can move a blade assembly  40  having a blade support  14  and a blade  17 , can be moved between a stowed position and an operating position. The stowed position is shown in  FIG. 1 . Owing to movement of the second part  12  in the direction u 1  about a pivot axis a 1  relative to the first part  11 , the blade support  14  can be pivoted from the stowed position into an operating position. The operating position is shown in  FIG. 2 . The second part  12  can be moved relative to the first part  11  in the direction u 2  out of the stowed position according to  FIG. 1 , the knife  10  being moved into a blade-changing position according to  FIG. 3 . In the blade-changing position, the blade support  14  is accessible and the blade can be changed. 
     According to  FIG. 4 , the blade support  14  has a rear projection  15  for articulated support on the mechanism  13 . In order to form the pivot joints, the projection  15  has openings  19   a  and  19   b . In addition, the blade support  14  has a blade seat  16  for fastening a blade  17  that is provided with a cutting edge  18 , and a first blade face  43  and a second blade face  44  opposite the first blade face  43 . A latch  30  detachably secures the blade  17  to the blade support  14 . Projections  21  and  22  are retained on the blade support  14  that, in the present embodiment, are cut out from the blade support  14  and project out of a plane E of the blade seat that has an x/z direction, such that they have a region projecting in the direction y 1  and a region that is parallel to the plane E. The projections  21  and  22  engage through cut-outs  23  and  24  in the blade  17 . The projection  22  forms a seat  45 . 
     A region  31  of the projection  21  extending in parallel with the plane E has a width K 1  that is greater than the width K 2  of the opening  23 . The cross section of the projection  21  approximately corresponds to the dimensions of the cut-out  23  in the x direction and z direction, or is slightly smaller. For this reason, the blade  17  cannot readily be detached from the projection  21  in the direction y 1 . Instead, a pivoting movement of the blade in the direction v 1  according to  FIG. 5  is required. The cut-out  24  in the blade is formed such that the blade  17  can be moved away over the region  32  of the projection  22  when pivoting in the direction v 1 . The pivoting guidance is predetermined by the shape of the projection  21 . 
     A bolt that prevents movement of the blade  17  in the direction v 1  is arranged between a holding surface  33  of the projection  22  and the outer surface  44  of the blade  17  (see  FIG. 4 ). In the present embodiment, the bolt is formed by a leg  27  of a spring  25 , the other leg  26  of which is pivotally retained in a bearing device  35  of the blade support  14 . 
     In the present embodiment, the bearing device  35  has a projection  36  of the blade support  14  (see e.g.  FIG. 8 ), from which two arms  29   a  and  29   b  project in the direction y 1 . An opening  37   a  is formed in the arm  29   a  and an opening  37   b  is formed in the arm  29   b . The openings  37   a  and  37   b  align with one another. The leg  26  engages through the openings  37   a  and  37   b , such that a pivot axis a 2  is formed, about which the spring  25  can be pivoted. An end region  38  of the leg  26  is approximately bent at right angles to the longitudinal extension of the leg  26  such that the spring  25  cannot be detached from the bearing device  35 . A wound central region  39  of the spring  25  prevents movement of the spring in the direction x by the contact with the arm  29   a.    
     An end region  41  of the spring leg  27  is bent such that it can be easily grasped, making it easy for the user to actuate. 
     The spring leg  27  is subjected to pretension about a pivot axis a 3  of the spring  25  in the direction w 1  in engagement with the projection  22 . Owing to movement of the leg  27  counter to the spring force in the direction w 2  and subsequent pivoting about the pivot axis a 2  in the direction p 1  into the position shown in  FIGS. 10 to 13 , the locking can be released such that the blade  17  can be removed from the blade seat  16 . 
     In the unlocked position according to  FIGS. 10 to 13 , the blade  17  only has one degree of freedom in the pivoting direction v 1 . The blade can then be removed from the blade seat  16  by pivoting in the direction v 1  and can optionally be replaced with another blade  17 . 
     The blade  17  can be mounted again by, according to  FIG. 14 a   , the cut-out  23  being brought into engagement with the projection  21  and the blade  17  then being pivoted onto the projection  21  in the direction v 2  (see  FIGS. 14 b  and 14 c   ) until the projection  22  engages through the cut-out  24  and the first blade face  43  comes into contact with the contact face  42 . 
     The leg  27  of the spring  25  is then pivoted about the axis a 2  in the direction p 2  and latches in the seat  45  of the projection  22  by the leg  27  being pivoted somewhat counter to the force of the spring  25  in the direction w 2  and then being inserted into the seat  45  in the direction w 1 . 
     The holder  20  according to the invention having the latch  30  is not vulnerable to dirt, since there are barely any structural design aspects, such as undercuts, angles, etc., that promote the accumulation of particles. 
     A second embodiment of a blade assembly  140  is shown in  FIGS. 16 to 22 . Since the knife can be designed in substantially the same way as the first embodiment, except for the blade assembly  140 , the remaining parts are not described. 
     The blade assembly  140  has a blade support  114  and a blade cover  129 . A central longitudinal axis of the blade assembly  140  is denoted by m. The blade support  114  and the blade cover  129  are parts of a holder  120  for a blade  117 . According to  FIG. 16 , the blade support  114  has a rear projection  115  on which bearing pins  119   a  and  119   b  are formed. The blade support  114  is provided with a blade  116 , comprising a contact face  142  of the blade support  114 . Pins  121  and  122  project from the blade support  114 . The pin  121  has a notch  136 . A bearing region  137  of the blade support  114  is provided for pivotally mounting the blade cover  129 . 
     The blade  117  has a cutting edge  118  and two cut-outs  123  and  124 . The blade  117  is e.g. designed as a strip steel blade or ceramic blade. A blade face  143  of the blade  117  interacts with the contact face  142  and a blade face  144  of the blade  117  interacts with a contact face  141  of the blade cover  129  when the blade  117  is in the bolted position in the blade seat  116 . 
     A spring  125  that is designed as a torsion spring in the present example, is part of a latch  130 . It has two end regions  126  and  127 . The spring  125  is mounted on the blade assembly  140  by a bearing device  135 . Here, a bearing region  128  that is designed as a bearing pin  131  and is arranged coaxially with the wound region of the torsion spring is provided on the blade cover  129 . The end region  127  is supported on a stop  132  of the blade cover  129  under pretension. The blade cover  129  also has a projection  133  having a link  134  that is in the form of an opening in the projection  133  here and is provided for restricting the movement of the end region  127  of the spring  125 . The link could, however, alternatively be omitted. 
     The blade cover  129  forms a contact face  141  that is shown in  FIG. 22 . 
     When a blade  117  is mounted in the blade seat  116  such that the blade face  143  abuts the contact face  142 , and the projection  121  engages through the cut-out  123  and the projection  122  engages through the cut-out  124 , the blade cover  129  can be pivoted in a direction o 2  out of the open position according to  FIGS. 18 and 19  about a pivot axis a 4  into the closed position according to  FIGS. 17 and 20 to 22  which the projection  121  engages through a cut-out  138  in the blade cover  129 . Owing to the pretension of the spring  125 , the end region  127  abuts an upper end region  139  of the link  134 . The end region of the link  134  opposite the end region  139  is denoted by  145 . 
     By the end region  127  being somewhat deflected in the direction n 1 , it can be inserted into the notch  136 . The latch  130  is then in the bolted position, i.e. the blade cover  129  is prevented from moving in the direction o 1  into the open position by the end region  127  acting as a bolt. The end region  127  extends over a region of an outer surface  146  of the blade cover  129  and abuts the outer surface  146 . 
     The notch  136  is arranged on the projection  121  such that the end region  127  has to be moved counter to spring force in the direction n 1  in order to move it out of the notch  136 . In this way, the end region  127  is not inadvertently released from engagement with the notch  136 . 
     The notch  136  is designed such that it forms a movement converter, such that the spring force exerted by the end region  127  in the direction n 2  is partially diverted into a force that loads the end region  127  in the direction y 1  (see  FIG. 22 ), such that said region exerts a force on the blade cover  129  in the direction o 2 . In this way, the blade  117  is securely retained between the contact faces  142  and  141  and blades  117  having different thicknesses D can be securely fastened in the blade seat  116 .