Patent Publication Number: US-2023143431-A1

Title: Blade cover and axe assembly

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS 
     This application claims the benefit of priority to European patent application number 21206680.7, filed on Nov. 5, 2021, the complete disclosure of which is hereby incorporated by reference in its entirety. 
     FIELD 
     The present invention relates to a blade cover and an axe assembly, and more particularly to a blade cover with a locking mechanism. 
     BACKGROUND 
     The axe has many forms and specialized uses. The axe can be for example a splitting axe or a hatchet, also known as a camping axe. The most common form of the axe typically has a long handle with a steel head. The steel head may have a sharp edge and a poll. The splitting axe can be used with two hands, whereas the hatchet is a one-handed striking tool with a sharp edge on one side used for cutting and splitting wood, and a hammer head on the other side for striking purposes. Hatchets are lighter and has smaller size compared to usual axes making them easy to storage and travel. 
     Conventional blade covers usually cover both the sharp edge and the hammer head. Therefore, when using the hammer head of the axe, the user needs to take off the blade cover. This exposes the sharp edge of the axe and causes a significant risk of cutting something unintentionally, or in a worst-case scenario, getting severely injured. 
     SUMMARY 
     An object of the present invention is to provide an arrangement to reduce the risk of unintentional use of the sharp edge while allowing the hammer head to be used. 
     The invention is based on the idea of providing a blade cover for the sharp edge with a locking mechanism and a hatchet assembly. The locking mechanism prevents the blade cover to fall off during the usage of the hammer head and simultaneously prevents the sharp edge to be utilized accidently. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following the invention will be described in greater detail by means of preferred embodiments with reference to the attached drawings, in which 
         FIG.  1    shows an axe assembly according to an embodiment; 
         FIG.  2    shows an example of an axe with a through hole; 
         FIG.  3    shows a blade cover with a rotatable switch attached; 
         FIG.  4    shows a back view of the blade cover; and 
         FIG.  5    shows a blade cover, where the rotatable switch is separated from a receiver. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention pertains to an axe assembly. The axe assembly comprises an axe  1  and a blade cover  2 . The axe  1  may be any kind of axe with a handle  10  and a tool head  11  but in the present Figures, the axe  1  is illustrated as a hatchet. 
       FIG.  1    shows the axe assembly according to an embodiment and  FIG.  2    shows an example of the axe  1  with a through hole  12 . The axe  1  comprises a handle  10  and a tool head  11 . The tool head  11  comprises a sharp edge  13  on one side and a hammer head  14  on the other side. Between the sharp edge  13  and the hammer head  14  comprises a through hole  12 , where an axis of the through hole  12  is preferably perpendicular to a longitudinal axis of the handle  10 . 
     The tool head  11  is made of a first material, preferably steel, and at least part of the handle  10  is made of a second material, preferably polymer or composite material by injection molding, wherein the second material at least partially surrounds the tool head  11  and the through hole  12 . 
     The tool head  11  is preferably made with forging but other manufacturing methods may be implemented, such as casting and hot rolling. An initial through hole may be circular or an open circle with a slot for facilitating the connection between the tool head  11  and the second material. 
     The handle  10  may be hollow, semi-hollow or solid. The whole handle  10  may be made of the second material, or a grip portion  10   a  of the handle  10  may be made of a third material while the second material connects the tool head  11  and the grip portion  10   a  together. The third material can be made of softer material such as thermoplastic elastomer or wood, for example. 
     The tool head  11  may comprise a first groove  15  around the tool head  11  separating the hammer head  14  portion from a cheek  16  of the tool head  11 . The tool head  11  may comprise a second groove  17  around the tool head  11  separating a blade portion  18  from the cheek  16 . Said grooves  15 ,  17  may facilitate injection molding of the second material and determine the final appearance. The area between said grooves  15 ,  17  may define the injection molding area and the areas outside the grooves  15 ,  17  remain exposed with the first material. The second material may form a bevel  19  around the through hole  12  for softening the edge of the through hole  12  and to facilitate attaching the blade cover  2 . 
     The through hole  12  is preferably within the width of the handle  10  for a better ergonomic use. However, in some embodiments, the through hole  12  may locate partially or completely outside the width of the handle  10 . 
     The through hole  12  may have different shapes. The initial through hole in the tool head  11  can be circular or the open circle and is preferably co-manufactured with the tool head  11  by forging. However, the initial hole may also be post-manufactured by drilling or machining. During the injection molding of the second material, the second material may form a minor segment inside the initial through hole altering the shape of the final through hole  12 . As shown in  FIG.  2   , the second material has formed two circular segments as rims  20  on each side of the through hole  12  so the final through hole  12  is oval shaped. In another embodiment, the final shape of the through hole  12  may be for example square, rectangle, triangle, circle, semicircle, pentagon, hexagon, etc. 
       FIGS.  3 - 5    shows a blade cover  2  according to an embodiment.  FIG.  3    illustrates a blade cover  2  with a rotatable switch  3  attached,  FIG.  4    illustrates a back view of the blade cover  2 , and  FIG.  5    illustrates a blade cover  2 , where the rotatable switch  3  is separated from a receiver  4 . 
     The blade cover  2  comprises a protective portion  5  arranged to cover the sharp edge  13  of the tool head  11  and a locking mechanism  6  releasably attachable to the tool head  11 . The protective portion  5  is preferably on one end of the blade cover  2  and the locking mechanism  6  is on the other end of the blade cover  2 , opposite the protective portion  5 . In the accompanying Figures, the blade cover  2  is illustrated as paddle shaped with optimal rigidity and material application but it may have a different shape in other implementations. 
     The locking mechanism  6  may comprise a rotatable switch  3  and a receiver  4  fitted to receive the rotatable switch  3 . The locking mechanism  6  is arranged to align with the through hole  12  so the through hole  12  and the rotatable switch  3  may have coinciding axis A when the blade cover  2  is attached to the tool head  11 . 
     The rotatable switch  3  is arranged to be rotatable in relation to the receiver  4  when fastened to the receiver  4  and comprises a holder portion  31  to which the user can hold between fingers. The holder portion  31  can be a protrusion, or it can be flat or rounded knob. In the accompanying Figures, the holder portion  31  is illustrated as a flange extending outward from an exterior surface of the rotatable switch  3 . The rotatable switch  3  may additionally comprise a shaft  32  with a snap lock pin  33 . 
     The rotatable switch  3  is fastened to the receiver  4  preferably by snap fastening, but other mechanical fastening means may be implemented for allowing the rotatable switch  3  to rotate about the axis A, such as a threaded element. According to the embodiment illustrated in  FIG.  5   , the receiver  4  comprises a frustum surface  41  made of at least two parts for tolerating elastic deformation and the rotatable switch  3  comprising the snap lock pin  33 , wherein the rotatable switch  3  is snap fastened to the receiver  4  by guiding the snap lock pin  33  between said at least two parts of the frustum surface  41  and overcoming the elastic deformation threshold. The frustum surface  41  in this context refers to a truncated cone or pyramid shape having a discontinuous inner surface. 
     The snap lock pin  33  is illustrated as an elongated stem with an end having larger cross-section than the remaining stem preventing the snap lock pin  33  to disengage from the receiver  4  but allowing the rotatable switch  3  to rotate in relation to the receiver  4 . The receiver  4  may alternatively comprise a tubular surface and the snap lock pin  33  may comprise at least one outward hook for engaging with an outer end of the tube. 
     In another embodiment features of the rotatable switch  3  and the receiver  4  may be reversed as the receiver  4  may comprise the snap lock pin  33  and the rotatable switch  3  may comprise the frustum or tubular surface. 
     The locking mechanism  6  may comprise a recess  61  fitted to accommodate the rim  20  of the through hole  12  when the blade cover  2  is attached to the tool head  11 . This contact may facilitate positioning the locking mechanism  6  to the optimal spot in relation to the through hole  12 . 
     The receiver  4  may comprise at least one additional support element  42  for supporting the receiver  4  to the locking mechanism  6 . The additional support element  42  may be a plate connecting the outer surface of the receiver  4  to the back side of the locking mechanism  6 .  FIG.  4    shows four additional support elements  42  evenly supporting the receiver  4  but other embodiments may comprise more or less additional support elements  42 . 
     The rotatable switch  3  is rotatable between two positions, wherein in a first position the blade cover  2  is fixedly securable to the tool head  11 , and in a second position the blade cover  2  is releasably attachable to the tool head  11 . The first position is switched to the second position by rotating the rotatable switch  3  around the axis A. The rotatable switch  3  is arranged to pass through the through hole  12  in the second position. 
     In the accompanying Figures, the rotatable switch  3  is arranged to rotate approximately 90 degrees to change between the first position and the second position. However, depending on the shape of the through hole  12 , the rotation rate may vary. For instance, it can be 45 degrees for a triangle shaped through hole, or 180 degrees for a semicircle shaped through hole. 
     The rotatable switch  3  comprises a first mating surface  34 , and the tool head  11  comprises a second mating surface  21 , where the second mating surface  21  may locate at an edge of the through hole  12 . The first mating surface  34  is arranged to abut on the second mating surface  21  in the first position. The first mating surface  34  may be a surface of the outward section extending from the shaft  32  or a surface of the hook of the snap lock pin  33  of the rotatable switch  3  or threaded element formed on the surface of shaft  32  allowing the first mating surface  34  to contact the second mating surface  21  at the edge of the through hole  12 . The second mating surface  21  may locate at the rim  20  inside the through hole  12 . In another embodiment, the second mating surface  21  may locate at an outside rim of the through hole  12 . 
     The first mating surface  34  may locate at a distance away from the holder portion  31  so the second mating surface  21  may fit between the holder portion  31  and the first mating surface  34 . In the present Figures, the rim  20  of the through hole  12  is arranged to abut the rotatable switch  3  in the second position. The second mating surface  21  may respectively be flat or have a threaded formation. 
     In the embodiment illustrated in  FIG.  2   , the second mating surface  21  may comprise a depression  22  allowing a matching projection  35  of the rotatable switch  3  to slide to the ideal first position. 
     When the first mating surface  34  and the second mating surface  21  are in contact with each other, the first mating surface  34  is abutting the second mating surface  21 , the rotatable switch  3  is arranged to be securely fastened to the tool head  11  preventing the blade cover  2  to detach from the tool head  11 . When the rotatable switch  3  is changed to the second position, and the first mating surface  34  and the second mating surface  21  are no longer in contact with each other, the blade cover  2  can be detached from the tool head  11  by passing the rotatable switch  3  through the through hole  12 . 
     The second mating surface  21  may be formed of the second material arranged inside the initial through hole by injection molding. The second material is more moldable to the desired shape and design but is hard and tough enough to withstand impact and stress applied to the tool head  11 . The second material is also lighter compared to steel making the final weight of the axe  1  lighter. 
     Lock and unlock signs  23  may be applied on the second material, for instance on the bevel  19 , to indicate which one is the first position, and which one is the second position of the rotatable switch  3 . 
     The blade cover  2  may be manufactured of same material as the second material, or it can be manufactured of different thermoplastic polymer such as polypropylene (PP) or polyethylene (PE). Both polymers have good chemical and mechanical properties. 
     The protective portion  5  may comprise an edge protecting strip  51  and at least one front sideward extension  52  and at least one back sideward extension  54  extending from respective front side and back side of the edge protecting strip  51 . The protective portion  5  is arranged to receive the blade portion  18  and the edge protecting strip  51  may conform with the shape of the sharp edge  13  surrounding toe  24  and heel  25  portions of the tool head  11 . At least one of the sideward extensions  52 ,  54  may conform with outer surface of a bevel face  26  of the tool head  11  for a snug fitting. However, in some embodiments the fitting may be slightly loose. The edge protecting strip  51  may be reinforced by additional thickness or reinforcement elements  53  to prevent the sharp edge  13  from cracking the blade cover  2 . The additional reinforcement elements  53  may be partially hollow cavities along the edge protecting strip  51 . 
     In the embodiment illustrated in the present  FIGS.  3 - 5   , the back sideward extension  54  may cover one side of the bevel face  26  completely and the protective portion  5  is designed as a half open case. However, in another embodiment, the back sideward extension  54  may cover the bevel face  26  only partially. The front sideward extension  52  may at least partially cover the other bevel face  26  for easier attaching and detaching of the tool head  11 . The front side in this context refers to the same side as the rotatable switch  3 , and the back side refers to the same side as the receiver  4 . 
     A central vertical plane of the edge protecting strip  51  can be on a same vertical plane as one of the mating surfaces  34 ,  21 , when the tool head  11  is in upward position and the handle  10  is in downward position. 
     The back sideward extension  54  may be connected to the locking mechanism  6  via a connecting portion  7 . The connecting portion  7  may comprise a clip or at least two slits  71  for attaching the blade cover  2  to a belt or a strap allowing the axe assembly to be suspended by a strap from a backpack or a belt while trekking. The connecting portion  7  may comprise a protruded portion  72  between the two slits  71 . The protruded portion  72  allows the strap or belt to be inserted and removed more easily through the slits  71  without bending the strap or belt. 
     The protecting portion  5 , the connecting portion  7  and the locking mechanism  6  excluding the rotatable switch  3  may be integrally manufactured as one component, preferably by injection molding. The rotatable switch  3  may be manufactured as a second component to be attached to the receiver  4  afterwards. 
     The blade cover  2  can be attached to the axe  1  at the middle of the tool head  11  leaving the hammer head  14  of the axe  1  uncovered. With the blade cover of the present invention, the blade cover  2  is firmly attached to the axe  1  so that it would not disengage from the tool head  11  while using the hammer head  14 .