Abstract:
A substantially planar shipping container blank is configured for planar stacking to permit compact packaging but simplifies the ease of assembly into a triangular shipping container. The container blank is foldably divided into a rectangular longitudinal section, two end sections, and a closure tab. The interior surfaces of certain portions of the end sections are pre-mounted to the interior surface of the longitudinal section. By folding the longitudinal section of the blank along two pre-pressed longitudinal fold lines, the end sections of the blank automatically fold along pre-pressed angular fold lines to form a triangular shipping container. The container can thereafter be fastened shut by folding the closure tab along a third pre-pressed longitudinal fold line and affixing the tab to the exterior of the container.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
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   STATEMENT REGARDING FEDERALLY-SPONSORED RESEARCH AND DEVELOPMENT 
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   REFERENCE TO AN APPENDIX 
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   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates generally to the field of shipping containers and relates more particularly to a shipping container blank that is configured for easy assembly into a triangular shipping container and a method for preparing the same. 
   2. Description of the Related Art 
   Triangular containers for shipping and storing various items are well known in the art. To conserve space and simplify handling, such containers are themselves typically shipped and stored in the form of unassembled planar blanks that must be folded and glued, taped, and/or stapled to produce complete, assembled containers. Assembly of a container often requires numerous portions of a blank to be folded and fastened together, which can be time consuming and labor intensive. This folding and fastening of the prior art blanks is ordinarily entirely performed immediately before the object to be shipped is placed in them by the user. If the blanks were folded by their manufacturer before being packaged and shipped to the user, the blanks become bulky and therefore inefficient and more expensive to package, inventory and ship. 
   It would therefore be desirable to have a shipping container blank that is substantially planar so it can be compactly and efficiently packaged and stored before use but additionally is constructed in a way that reduces the amount of folding and fastening manipulations that the user must perform in order to assemble it into a triangular shipping container. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention relates to a pre-configured shipping container blank that can be assembled into a triangular shipping container quickly and with relatively little effort. 
   In accordance with the preferred embodiment of the present invention, there is provided a container blank that is preferably formed of a material commonly called cardboard but more accurately is called corrugated fiberboard or corrugated paperboard. 
   The container blank has a rectangular base panel, a rectangular rear panel foldably connected to the rectangular base panel along a first longitudinal fold line, and a rectangular front panel foldably connected to the rectangular base panel along a second longitudinal fold line opposite the first longitudinal fold line. Preferably, a closure tab is foldably connected to the front panel along a third longitudinal fold line opposite the second longitudinal fold line. 
   An end section is formed at each end of the blank and each comprises two triangular panels and preferably an additional “mounting” panel. A first triangular panel is foldably connected to the base panel along a first transverse fold line. A second triangular panel is foldably connected to the first triangular panel along a first angled fold line and is foldably connected to the interior surface of the rear panel along a second angled fold line. A third triangular panel is foldably connected to the base panel along a second transverse fold line opposite the first transverse fold line. A fourth triangular panel is foldably connected to the third triangular panel along a third angled fold line and is foldably connected to the interior surface of the rear panel along a fourth angled fold line. 
   Preferably, the way of foldably connecting the second and fourth triangular panels to the interior surface of the rear panel along a second angled fold line is to connect each of these two triangular panels to its own mounting panel that is mounted to the surface of the rear panel. Specifically, a first mounting panel is foldably connected to the second triangular panel along the second angled fold line and is flatly mounted to the interior surface of the rear panel for foldably connecting the second triangular panel to the interior surface of the rear panel along the second angled fold line. Similarly, a second mounting panel is preferably foldably connected to the fourth triangular panel along the fourth angled fold line and is flatly mounted to the interior surface of the rear panel for foldably connecting the fourth triangular panel to the interior surface of the rear panel along the fourth angled fold line. The preferred manner of flatly mounting the mounting panels to the interior surface of the rear panel is by the application of an adhesive. 
   By mounting these panels as described above before shipping, the blanks are essentially planar for compact storing, packaging and shipping, but are very easily and quickly assembled. By folding the longitudinal section of the blank along the longitudinal fold lines, the end sections of the blank are caused to automatically fold along the angled fold lines to form a triangular shipping container. The container can thereafter be fastened shut by folding the closure tab along the third longitudinal fold line and affixing the tab to the exterior of the container with glue, tape, or similar fastening means. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is a front view illustrating the preferred embodiment of the present invention with the end sections shown unfolded for clarity. 
       FIG. 2   a  is a partial front view illustrating a pre-folded and pre-glued end of the preferred embodiment of the present invention shown in  FIG. 1 . 
       FIG. 2   b  is a partial view in perspective illustrating the end of the preferred embodiment of the present invention shown in  FIG. 2 . 
       FIGS. 2   c - 2   g  are partial views in perspective illustrating the progressive folding of the end section of the preferred embodiment of the present invention shown in  FIG. 2 . 
       FIG. 3  is a perspective view illustrating a completed triangular container formed of the container blank of the preferred embodiment of the present invention shown in  FIG. 1 . 
       FIG. 4   a  is a partial front view illustrating an unfolded end of an alternative embodiment of the present invention. 
       FIG. 4   b  is a partial view in perspective illustrating the end of the alternative embodiment shown in  FIG. 4   a  wherein the end has been folded and fastened. 
       FIG. 5   a  is a partial front view illustrating an unfolded end of another alternative embodiment of the present invention. 
       FIG. 5   b  is a partial view in perspective illustrating the end of the alternative embodiment shown in  FIG. 5   a  wherein the end has been folded and fastened. 
       FIG. 6   a  is a partial front view illustrating an unfolded end of another alternative embodiment of the present invention. 
       FIG. 6   b  is a partial view in perspective illustrating the end of the alternative embodiment shown in  FIG. 6   a  wherein the end has been folded. 
       FIG. 6   c  is a partial view in perspective illustrating the end of the alternative embodiment shown in  FIG. 6   a  wherein the end has been folded and fastened. 
       FIG. 7   a  is a front view illustrating an alternative embodiment of the present invention wherein the closure tab has been omitted. 
       FIG. 7   b  is a perspective view illustrating a completed triangular container formed of the container blank of the alternative embodiment of the present invention shown in  FIG. 7   a.    
   

   In describing the preferred embodiment of the invention which is illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific term so selected and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word connected or terms similar thereto are often used. 
   DETAILED DESCRIPTION OF THE INVENTION 
   Referring to  FIG. 1 , a shipping container blank  10  in accordance with the present invention is illustrated. The blank  10  is shown completely unfolded in  FIG. 1  for clarity, and the blank  10  is shown in its inventive, pre-folded and pre-glued form (described in greater detail below) in  FIGS. 2   a - 2   g . It is preferred that the container blank  10  be formed of conventional corrugated fiberboard, although is contemplated that the blank  10  can be formed of any other material that is suitable for making a shipping container or point of purchase display, including, but not limited to folding carton stock, wood, metal, plastic, and various composites. For the sake of convenience and clarity, terms such as “top”, “bottom”, “length,” “width,” “inwardly,” “outwardly,” “lateral,” and “longitudinal” will be used herein to describe the relative size and orientation of various components of the invention, all with respect to the geometry and orientation of the blank  10  as it appears in  FIG. 1 . This terminology will include the words specifically mentioned, derivatives thereof, and words of similar import. 
   The container blank  10  is generally planar with an interior surface  12  and an opposing exterior surface  14  (not within view). The blank  10  includes a longitudinal section  16  and two end sections  18  and  20 . Three longitudinal fold lines  22 ,  24 , and  26  are formed in the longitudinal section  16  of the blank  10  in a substantially parallel relationship for foldably separating the longitudinal section  16  into a base panel  28 , a rear panel  30 , a front panel  32 , and a closure tab  34 . The fold lines  22 ,  24 , and  26  may be scored and/or depressed into the interior surface  12  of the blank  10  in a conventional manner that will be appreciated by those skilled in the art. The base panel  28 , rear panel  30 , and front panel  32  are generally rectangular in shape and are preferably equal to one another in dimension to form a container having an equilateral, triangular cross section (described in greater detail below). The longitudinal section  16  of the container blank  10  can have any length desired, as indicated by the broken lines in the longitudinal section  16 , although lengths under about 6 feet are generally preferred for forming a container with sufficient axial rigidity. Container blanks formed of materials other than fiberboard may, however, offer sufficient axial rigidity at maximum lengths greater or lesser than that of the preferred embodiment. It is generally required that the panels  28 - 32  be of substantially equal length, although embodiments of the invention are contemplated in which the panels  28 - 32  have unequal widths for forming triangular containers that are not equilateral. 
   The closure tab  34  is preferably trapezoidal in shape and has a width that is substantially equal to the widths of the base, rear, and front panels  28 - 32 . However, the closure tab  34  can have any suitable size or shape, including, but not limited to rectangular, triangular, or rounded. Alternatively, the closure tab  34  can be replaced by two or more smaller tabs that are longitudinally spaced apart from another. The closure tab  34  can alternatively be foldably connected to the rear panel, as indicated by the phantom line shown in  FIG. 7   a . Still further, the closure tab can be entirely omitted (see  FIGS. 7   a  and  7   b ). 
   Still referring to  FIG. 1 , first and second transverse fold lines  36  and  38  are formed in the container blank  10  in a substantially parallel relationship at opposing longitudinal ends of the longitudinal section  16 . The transverse fold lines  36  and  38  foldably separate the longitudinal section  16  of the blank  10  from the end sections  18  and  20  and allow the end sections  18  and  20  to be folded approximately 180 degrees relative to the interior surface of the longitudinal section  16 . 
   A first angled fold line  40  and a second angled fold line  44  are formed in the end section  18  for foldably separating the end section  18  into a first triangular panel  48 , a second triangular panel  52 , and a first mounting panel  56 . Similarly, a third angled fold line  42  and a fourth angled fold line  46  are formed in the end section  20  for foldably separating the end section  20  into a third triangular panel  50 , a fourth triangular panel  54 , and a second mounting panel  58 . 
   It is critical that the edges of the first and third triangular panels  48  and  50  that lie along the first and second transverse fold lines  36  and  38  extend from the top edge of the base panel  28  to the bottom edge of the base panel  28 . It is generally preferred that the first and third triangular panels  48  and  50  be equilateral, with each edge of the panels  48  and  50  being substantially equal in length to the widths of the base, front, and, rear panels  28 - 32  for forming an assembled shipping container with an equilateral cross-section. While the lengths of the edges of the first and third triangular panels  48  and  50  can be made unequal for forming a triangular container that is not equilateral, it is generally required that the lengths of the top edges of the panels  48  and  50  be substantially equal to the width of the front panel  32 , that the lengths of the bottom edges of the panels  48  and  50  be substantially equal to the width of the rear panel  30 , and that the lengths of the edges of the panels  48  and  50  that lie along the first and second transverse fold lines  36  and  38  be substantially equal to the width of the base panel  28 . 
   The second and fourth triangular panels  52  and  54  are preferably identical in size and shape to the first and third triangular panels  48  and  50 , although it is contemplated that the edges of the second and fourth triangular panels  52  and  54  that lie along the first and third angled fold lines  40  and  42  can be shorter than the edges of the first and third triangular panels  48  and  50  that lie along the first and third angled fold lines  40  and  42  and that the edges of the second and fourth triangular panels  52  and  54  that lie along the second and fourth angled fold lines  44  and  46  can be longer or shorter than the edges of the first and third triangular panels  48  and  50  that lie along the second and fourth angled fold lines  44  and  46 . The outermost edges of the second and fourth triangular panels  52  and  54  can alternatively be rounded, notched, or irregularly-shaped. 
   The first and second mounting panels  56  and  58  are preferably trapezoidal in shape and extend downwardly from the second and fourth angled fold lines  44  and  46  to the bottom edge of the rear panel  30 . The first and second mounting panels  56  and  58  can have a variety of other shapes and sizes, as will be discussed later herein. Preferably, relief holes  57  and  59  are formed through each of the end sections  18  and  20  at the intersection of the three panels that make up an end section. These holes make is easier to fold the material along the fold lines. 
   Referring now to  FIGS. 2   a  and  2   b , the container blank  10  is shown in its inventive, pre-folded and pre-glued form. The end sections  18  and  20  of the blank  10  are substantially identical minor images of one another, and will now be described with reference to the left end section  18  only. It is a first critical feature of the invention that the end section  18  of the blank  10  is folded inwardly, with the interior surface of the end section  18  flatly abutting the interior surface of the longitudinal section  16 . It is another critical feature of the invention that the bottom edge of the second triangular panel  52  is foldably secured against the interior surface of the rear panel  30  for allowing the second triangular panel  52  to fold approximately 180 degrees relative to the rear panel  30  about the second angled fold line  44 . In the preferred embodiment of the invention, both of the above described critical features are achieved by gluing the interior surface of the first mounting panel  56  to the interior surface of the rear panel  30  (glue is indicated by the dashed trapezoidal outlines in  FIGS. 2   a  and  2   b , and by the shaded trapezoids in  FIG. 1 ). Although it is preferred that the interior surfaces of the first mounting panel  56  and the rear panel  30  be glued together, the panels  56  and  30  can be secured to one another by any other conventional means, such as by taping, stapling, or by Velcro. 
   Container blanks are stacked and packaged with both of their end sections folded and secured as illustrated in  FIGS. 2   a  and  2   b . In order to convert the pre-folded, pre-glued container blank  10  into an assembled shipping container, the blank  10  must be folded along the first and second longitudinal fold lines  22  and  24  as indicated by the curved, outlined arrows shown in  FIGS. 2   c - 2   e . Referring to  FIGS. 2   c - 2   f , the rear panel  30  is preferably first folded inwardly about the first longitudinal fold line  22  toward the interior surface of the base panel  28 . As the rear panel  30  is pivoted, the end section  18  of the blank  10  is caused to automatically fold along the first and second angled fold lines  40  and  44  in the manner of a pop-up book, as indicated by the dashed arrows in  FIGS. 2   c - 2   e . Specifically, the exterior surface of the first mounting panel  56  automatically pivots about the second angled fold line  44  toward the exterior surface of the second triangular panel  52 , and the interior surface of the second triangular panel  52  automatically pivots about the first angled fold line  40  toward the interior surface of the first triangular panel  48 . The first triangular panel  48  is thereby caused to automatically pivot about the first transverse fold line  36  outwardly, away from the base panel  28 . 
   Referring to  FIG. 2   f , the rear panel  30  is folded until the lateral edge of the rear panel  30  meets the bottom edge of the first triangular panel  48 . Optionally, the exterior surfaces of the mounting panel  56  and the second triangular panel  52  may then be fastened together with glue, tape, staples, or any other suitable fastening means. At this point, any items that are to be stored or shipped in the container should be placed inside the assembled portion of the container (i.e., within the V-shaped crotch formed by the base panel  28  and the rear panel  30 ). 
   Referring now to  FIGS. 2   f  and  2   g , the assembly of the shipping container is completed by pivoting the front panel  32  about the second longitudinal fold line  24  toward the base panel  28  until the lateral edge of the front panel  32  meets the top edge of the first triangular panel  48 . Referring to  FIG. 2   g , the closure tab  34  is then folded about the third longitudinal fold line  26  over the rear panel  30  until the interior surface of the closure tab  34  is brought into contact with the exterior surface of the rear panel  30 . The closure tab  34  is then preferably fastened to the rear panel  30  with glue, although all other suitable fastening means, such as tape, staples, or Velcro, are contemplated. Referring to  FIG. 3 , the completed triangular shipping container  60  is sealed and ready to be shipped. 
   Although it is preferred that the first mounting panel  56  be trapezoidal in shape and that it extends from the second angled fold line  44  to the bottom edge of the rear panel  30 , the first mounting panel  56  can have a variety of alternative shapes and sizes, or it can be omitted entirely. For example, referring to  FIGS. 4   a  and  4   b , the left end section of an alternative embodiment of the invention is illustrated in which the mounting panel  70  is a narrow tab. Referring to  FIGS. 5   a  and  5   b , another embodiment of the invention is illustrated in which the mounting panel is omitted, and wherein the bottom edge of the second triangular panel  80  is foldably secured against the rear panel  82  with a piece of tape  84 . Referring now to  FIGS. 6   a - 6   c , yet another embodiment of the invention is illustrated wherein the mounting panel is omitted, and wherein the exterior surface of the second triangular panel  90  is foldably connected to the exterior surface of the rear panel  92  by a piece of tape  94  that extends through a narrow slit  96  formed in the rear panel  92 . Although the embodiment illustrated in  FIGS. 6   a - 6   c  is not preferred because it lacks the strength of the preferred embodiment, it is included to show that many different methods for foldably connecting the second triangular panel  52  to the rear panel  30  are possible. 
   If the closure tab  34  is omitted, as in the embodiment of the invention shown in  FIGS. 7   a  and  7   b , one or more pieces of tape  100  or any other suitable fastener can be used to fasten the exterior surface of the front panel  102  to the exterior surface of the rear panel  104  for holding the assembled container  106  closed. As a further alternative, a closure tab  108 , similar to the closure tab  34 , may optionally be hinged along a fold line to the rear panel  110 . 
   This detailed description in connection with the drawings is intended principally as a description of the presently preferred embodiments of the invention, and is not intended to represent the only form in which the present invention may be constructed or utilized. The description sets forth the designs, functions, means, and methods of implementing the invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and features may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention and that various modifications may be adopted without departing from the invention or scope of the following claims.