Abstract:
A plastic container includes at least two foldable sidewalls articulated to a container base by at least two hinge connections, each including a hinge bolt or pin for pivoting in a receiving gap of the base frame. The receiving gap has an elongate opening to allow the hinge bolt to move in the receiving gap from a lower to an upper end position. The opening has a length at least corresponding to the thickness of the sidewall which is thus liftable vertically by at least the thickness. At least two guide elements are formed at the sidewall and received in the base frame in recesses which have a nose defined by an upper edge spaced from an upper edge of the base frame by a distance which corresponds to a length of the guide element from a lower edge of the sidewall to a lower edge of the guide element.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the priority of Swiss Patent Application, Serial No. CH 00446/11, filed Mar. 17, 2011, pursuant to 35 U.S.C. 119(a)-(d), the content of which is incorporated herein by reference in its entirety as if fully set forth herein. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a foldable transport and storage container of plastic. 
     The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention. 
     Foldable containers for transporting and storing goods are known which include sidewalls that can be fully folded inwardly or outwardly in order to adjust the container volume to the need at hand. Containers of this type are also known as folding box and typically include a container base to which the sidewalls are linked through hinges. When folding the container, the shorter transverse sidewalls are first folded inwards and then the longitudinal sidewalls are folded inwards. When the sidewalls are taller than half the length of the adjacent side of the folding box, the neighboring sidewalls as well as the respectively opposite sidewalls are placed on top of one another. As a consequence, the hinges of the individual sidewalls in the container base must be arranged at different levels or the sidewalls have varying heights in order for the foldable sidewalls to lie flatly upon one another and to form with the container base a compact stack. The presence of sidewalls of different heights, especially those that oppose one another, as well as the presence of hinges arranged on the container base at different heights adversely affect production and manufacturing costs of folding boxes of this type. 
     DE 10 2009 005 212 A1 discloses a foldable container having a linkage of the foldable sidewalls to the container base using hinges which have hinge bolts articulated in hinge bolt receivers having recesses in such a way that the hinge bolts are movable in the hinge bolt receivers from a lower end position to an upper end position so that a planar placement of two sidewalls on top of one another is facilitated. As the hinge bolts in the hinge bolt receivers not only pivot but also move vertically, the sidewall oftentimes is caused to tilt during folding up. In other words, the pivot axis of a sidewall does not extend parallel to the base of the folding box during folding up. 
     It would be desirable and advantageous to provide an improved foldable storage and transport container to address prior art problems and to obviate other prior art shortcomings. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention, a foldable storage and transport container of plastic includes a container base comprised of a base frame and a base plate, at least two sidewalls foldable on top of one another, each sidewall having a defined thickness, and at least two hinge connections for articulating each sidewall to the base frame, each hinge connection comprising a hinge bolt or a hinge pin for pivot engagement in a receiving gap of the base frame, with the receiving gap having an elongate opening extending substantially perpendicular to a plane of the base plate to allow the hinge bolt or the hinge pin to move in the receiving gap from a lower end position to an upper end position, with the opening having a length sized to at least correspond to the thickness of the sidewall so that the sidewall is liftable in a vertical direction by at least the thickness thereof, wherein at least two guide elements are formed at the foldable sidewall which are received in corresponding recesses in the base frame, wherein the recesses have a nose defined by an upper edge spaced from an upper edge of the base frame by a distance which corresponds to the length of the guide element from the lower edge of the sidewall to the lower edge of the guide element. 
     The provision of guide elements in accordance with the present invention for engagement in recesses of the base frame maintains the pivot axis during folding up of the sidewall in parallel relationship to the upper edge of the base frame so that a tilting of the sidewall becomes impossible. A benefit of the present invention resides in the interaction between the sidewalls and the container base via hinge connections and the interaction between the guide elements on the sidewalls and the complementary recesses on the container base. As a result of the hinge connections between the sidewalls and the container base, foldable opposite sidewalls can be made identical and can be placed flatly upon one another so as to form a compact stack jointly with the container base. The sidewalls can easily and quickly be mounted to the container base and easily and quickly be replaced so that overall manufacturing costs are decreased 
     According to another advantageous feature of the present invention, the guide element may have a depression for locking engagement by a projection of the base frame in an area of the upper edge of the base frame. 
     According to another advantageous feature of the present invention, the hinge bolts or hinge pin are formed at the lower end of the guide element which are received in the receiving gaps of the base frame. 
     According to another advantageous feature of the present invention, the guide element may have two incisions to divide the guide element in three sections comprised of two outer rail-like hinge arms formed with the hinge bolts or hinge pin, and a center part extending between the hinge arms and having a U-shaped configuration. 
     According to another advantageous feature of the present invention, partition walls may be provided on opposite sides of the nose in the recesses of the base frame for engagement with the incisions of the guide element. 
     According to another advantageous feature of the present invention, the receiving gap for the hinge bolts or hinge pin may be formed by inner surfaces of front and rear walls of the base frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which: 
         FIG. 1  is a schematic exploded view of a storage and transport container according to the present invention, showing a portion of a container base and a portion of a sidewall with guide elements; 
         FIG. 2  is a schematic perspective view of the container base with attached sidewall in a folded up position, showing in detail the area of a hinge connection between the sidewall and the container base, wherein the hinge elements are integrated with the guide elements; 
         FIG. 3  is a schematic perspective view of the container base with a first part of the hinge connection; 
         FIG. 4  is a schematic perspective view of the sidewall with a second part of the hinge connection, corresponding to the first part; 
         FIG. 5  is a schematic perspective view of the container base, partly cut away, with attached sidewall in a folded down position and in a lower position; and 
         FIG. 6  is a schematic perspective view of the container base with attached sidewall in a folded down position and in an upper position. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Throughout all the figures, same or corresponding elements may generally be indicated by same reference numerals. These depicted embodiments are to be understood as illustrative of the invention and not as limiting in any way. It should also be understood that the figures are not necessarily to scale and that the embodiments are sometimes illustrated by graphic symbols, phantom lines, diagrammatic representations and fragmentary views. In certain instances, details which are not necessary for an understanding of the present invention or which render other details difficult to perceive may have been omitted. 
     Turning now to the drawing, and in particular to  FIG. 1 , there is shown a schematic exploded view of a storage and transport container according to the present invention, showing a portion of a container base, generally designated by reference numeral  1 , and a portion of a sidewall  4  which is connectable to the container base  1  via a hinged connection, as described e.g. in DE 10 2009 005 212 A1. The container base  1  includes a base frame  2  and a base plate  3  which may be made in one piece with the base frame  2 . The base frame  2  includes a recess  5  for receiving a guide element  11  of the sidewall  4 . Arranged in the recess  5  is a nose  6  having an upper edge  7  which is spaced from an upper edge  8  of the base frame  2  at a distance Db. The guide element  11  is formed onto the sidewall  4  and has a length Ds as measured from a lower edge  12  of the sidewall  4  to a lower edge  13  of the guide element  11 . The length Ds of the guide element  11  corresponds to the distance Db in the base frame  2 . When the sidewall  4  articulated to the base frame  2  is positioned in a vertical alignment, the lower edge  12  of the sidewall  4  bears upon the upper edge  8  of the base frame  2 . In addition, the lower edge  13  of the guide element  11  bears upon the upper edge  7  of the nose  6 . 
     An imaginary connection line in this position of separate hinge members, such as hinge bolts or hinge pin (not shown), of the sidewall  4  defines a pivot axis A. The nose  6  is arranged in the recess  5  in such a manner that the pivot axis A extends through the upper edge  7  of the nose  6 . 
     The guide element  11  has a depression  9  for engagement by a projection  10  of the base frame  2  in the area of the upper edge  8 . In a horizontal position of the sidewall  4 , i.e. substantially parallel to the base plate  3 , and with the hinge members assuming their lower end positioned in receiving gaps of the base plate (not shown), the lower edge  13  and part of the front surface  14  of the guide element  11  bears upon the upper edge  7  of the nose  6 . 
     At least two guide elements  11  with associated recesses  5  are provided per sidewall  4  so that the pivot axis A extends parallel to the upper edge  8  of the base frame  2 . When now folding up the sidewall  4 , the lower edges  13  of the guide elements  11  bear upon the upper edges  7  of the noses  6 , respectively, and the sidewall  4  can be swung without tilting. When a folded down sidewall  4  occupies a position above the base plate  3  in which the hinge members  19  assume their uppermost end position or assume a position between the uppermost and lowermost positions, the backside  16  of the guide element  11  impacts the front edge  17  of the projection  10 , when the sidewall  4  is folded up. The sidewall  4  is swung about the front edge  17  and since the hinge members  19  can only be shifted vertically in the receiving gaps  15 , the sidewall  4  and thus also the lower end of the sidewall  4  are pushed downwards until the lower edge  13  of the guide element  11  bears upon the upper edge  7  of the nose  6 . In this position, the backside  16  of the guide element  11  bears no longer on the front edge  17  of the projection  10 , and the projection  10  engages in the depression  9 . 
     In the schematic illustration of  FIG. 1 , the recess  5  and the guide element  11  have symmetric configuration so that the guide element  11  has on both sides a depression  9 . Of course, a symmetric configuration is not necessarily required. 
     In the following, a further embodiment of a foldable storage and transport container, wherein the guide elements are combined with the hinge elements, will be described in greater detail. 
       FIG. 2  shows a schematic perspective view of the container base  1  with attached sidewall  4  in a folded up disposition, showing in detail the area of the complementing hinged connection between the sidewall  4  and the container base  1 . The base frame  2  has a double-walled configuration and the hinge element is integrated with the guide element  11 . The guide element  11  has a defined thickness which substantially corresponds to a thickness of the sidewall  4 . The guide element  11  has a lower end  18  which is formed with hinge bolts  19  which project into the receiving gaps  15  of the base frame  2 . The receiving gap  15  is formed by inner surfaces of the front and rear walls  21 ,  22  of the base frame  2 . 
       FIG. 3  shows a schematic perspective view of the container base  1  with the recess  5  in the base frame  2 , without illustration of the sidewall  4 . The nose  6  is arranged in midsection of the recess  5 . The arrangement of the nose  6  in the recess  5  is selected in such a way that the pivot axis A intersects the upper edge  7  of the nose  6 , when the lower edge  13  of the guide element  11  bears upon the upper edge  7  of the nose  6  and the lower edge  12  of the sidewall  4  bears upon the upper edge  8  of the base frame  2 . The projection  10  with the front edge  17  can be seen at the upper end of the recess  5 . The recess  5  has symmetric configuration so that both sides of the recess  5  have a projection  10  extending into the recess  5 . At least two such recesses  5  are provided along each side of the base frame  2  of the storage and transport container. 
       FIG. 4  shows a schematic perspective view of the sidewall  4  in the area of the hinge connection, with the guide element  11  being formed on the sidewall  4 . The depression  9  of the guide element  11  is arranged adjacent to the lower edge  12  of the sidewall  4 . In the non-limiting example shown here, the guide element  11  has a thickness substantially corresponding to the thickness of the sidewall  4 . The guide element  11  has two incisions  23  so as to establish a three-part configuration, comprised of two outer rail-like hinge arms  24 ,  25  with respectively formed hinge bolts  19 . Arranged between the hinge arms  24 ,  25  is a center part  26  of U-shaped configuration which defines the lower edge  13  of the guide element  11 . The hinge arms  24 ,  25  as well as the U-shaped center part  26  are rounded at the lower ends. 
     When the sidewall  4  is articulated to the base frame  2 , the hinge bolts  19  engage into the receiving gaps  15 . When the sidewall  4  is folded up, the lower edge  12  of the sidewall  4  bears upon the upper edge  8  of the base frame  2 . In this position, the lower edge  13  of the guide element  11  bears upon the nose  6 . When the sidewall  4  is folded down, the nose  6  engages the U-shaped center part  26 . Partition walls  20  ( FIG. 3 ) arranged on both sides of the nose  6  prevent the hinge bolts  19  from being pushed out of the receiving gap  15 . The partition walls  20  are sized to extend shy of the entire length of the incision  23  of the guide element  11  in order to allow insertion or removal of the hinge bolts  19  to or from the receiving gaps  15  by pushing the hinge arms  24 ,  25  away to the side, when the folded down sidewall  4  assumes the uppermost position. To facilitate the insertion of the hinge bolts  19  in the receiving gap  15 , the hinge bolts  19  are formed with a bevel  27  and the side surfaces ( FIG. 5 ) of the recess  5  of the base frame  2  are also beveled in an upper area  28 . 
     To prevent the sidewall  4  from folding down, when assuming the folded up position, safeguards are provided on the lower edge  12  of the sidewall  4  and on the upper edge  8  of the base frame  2 . These safeguards involve recesses  29  in the upper edge  8  of the sidewall  4  and locking lugs or projections  30  projecting from the lower edge  12  of the sidewall  4  for engagement in the depressions  29 . 
       FIG. 5  shows a schematic perspective view of the container base  1  with attached sidewall  4  in folded down disposition and in a lower position, with the section plane extending vertically through the nose  6 . The U-shaped center part  26  of the guide element  11  bears upon the upper edge  7  of the nose  6 . The partition walls  20  project into the incisions  23  of the guide element  11 . When folded up, the sidewall  4  swings about the pivot axis A, defined by the hinge bolts  19  and the upper edge  7  of the nose  6  until the locking lugs  30  snap into the depressions  29  on the upper edge  8  of the base frame  2 . 
       FIG. 6  shows a similar schematic perspective view as in  FIG. 5 , wherein the sidewall  4  is in the upper position. The vertical section plane extends between the hinge arm  25  and the partition wall  20 . As can be seen, the backside  16  of the guide element  11  contacts the inner side of the projection  10  and the lower edge  13  bears upon the rear wall  22 . When the sidewall  4  is folded up from the front, the edge  17  acts as pivot axis for the sidewall  4  and since the hinge bolts  19  can only be moved vertically as a result of their guidance in the receiving gaps  15 , the hinge bolts  19  are pushed down. As the sidewall  4  is provided with at least two guide elements  11 , the axis through the hinge bolts  19  shifts in parallel relation to the upper edge  8  of the base frame  2  downwards until the lower edge  13  of the U-shaped center part  26  bears upon the nose  6 . When the sidewall  4  assumes an intermediate position between lowermost and uppermost positions, the sidewall  4  is initially pivoted until the backside  16  of the guide element  11  impacts the edge  17 . Subsequently, the hinge bolts  19  are again pressed downwards until the lower edge  13  of the U-shaped center part  26  bears upon the nose  6 . 
     The storage and transport container according to the present invention allows a collapsing of the sidewalls and a placement of the sidewalls flatly upon one another. As the sidewalls are folded up, tilting of the sidewalls is prevented by the guide means on the base part and the sidewalls. 
     While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit and scope of the present invention. The embodiments were chosen and described in order to explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.