Patent Publication Number: US-8109402-B2

Title: Collapsible container for transport and storage

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part application of U.S. application Ser. No. 10/491,624 filed on Aug. 11, 2004, now U.S. Pat. No. 7,347,328, which in turn was a 35 U.S.C. 371 National Stage Application of PCT/SE02/01784, filed Oct. 1, 2002; claiming benefit of Swedish Application 0103332-2, filed Oct. 4, 2001, the entire disclosures of which are incorporated herein by reference in their entirety. 
    
    
     The present invention relates to collapsible container such as a collapsible pallet containers for transport and storage. 
     Collapsible containers of the foldable pallet container type, are rather popular since they will make a radical saving of the empty return transport volume possible. Foldable pallet containers are advantageously made of thermoplastic materials which will give light and still sturdy containers which are easy to keep clean. Another advantage is that the tare-weight of such containers is very stable which is not the case with, for example, wood containers where the tare-weight can double when the wood becomes wet. Yet another advantage is that thermoplastic materials do not corrode, which is the case with containers made from metal such as steel and aluminum. Most thermoplastic materials furthermore have a good resistance to chemical substances such as acids and bases, which is not the case with most metals. 
     Most collapsible containers available suffer from the disadvantage that they are bulky, inflexible when handled. 
     Through the present invention a novel collapsible container with great flexibility has been achieved. The invention relates to a collapsible container, preferably a collapsible pallet container for transport and storage. The collapsible container includes a base member and collapsible side walls, which adjacent side walls arc inter-connectable. The invention is characterised in that the base member is provided with feet members a circumambient edge and a mainly horizontal load surface whereby the load surface is provided with recesses extending downwards from the load surface. Said recesses are arranged adjacent the edge. At least one side wall is provided with downwards extending protrusions, said protrusions being arranged to interact with said recesses. Said at least one side wall engages the base member through vertical motion. 
     According to one embodiment of the invention the side wall is provided with a claw while the circumambient edge is provided with a void, said claw and void being arranged to interact so that an erected side wall will be prevented from being unintentionally disengaged from the base member. The claw of the side wall is preferably disengaged from the void of the circumambient edge through the process of by being angled slightly inwards followed by lifting the side wall. 
     The side walls are suitably provided coupling means at their respective vertical edges, said coupling means being intended to lock adjacent side walls together when they are in erected position. Said coupling means locking being disengaged by lifting said side wall and said coupling means being engaged by allowing said side wall to move downwards when erected in correct position adjacent other erected side wall. At least two side walls, arranged on opposite sides of the container, are suitably provided with locking means. Said locking means are used for locking adjacent side walls together when the side walls are in erected position. 
     The protrusions are according to one embodiment of the invention movably attached to the side wall via a hinge member. 
     According to one embodiment of the invention the protrusions are provided with snapping heels while the recesses are provided with undercuts. The snapping heels and undercuts are adapted to interact limiting the vertical movement of the protrusions and thereby the side wall. The recesses, the undercuts, the protrusions and the snapping heels are suitably arranged to allow a limited vertical movement so that the protrusion, and thereby the side wall, will be located in a lowermost position when the side wall is in erected position and in a higher position when the protrusion, and thereby the side wall, is in folded position. The side wall is suitably provided with a claw while the circumambient edge is provided with a void, said claw and void being arranged to interact so that an erected side wall will be prevented from being unintentionally disengaged from the base member. The claw of the side wall is disengaged from the void of the circumambient edge through the process of being angled slightly inwards followed by lifting the side wall. 
     According to one embodiment of the invention the lower end of the side wall is provided with a stabilising low rib intended to interact with a groove arranged on the base member. Said stabilising low rib will hereby fall into said groove when said side wall is in erected position. The side wall is hereby folded through the process of being lifted slightly to disengage the stabilising low rib front the groove before folding said side wall from erected position to folded position. 
     At least two opposite side walls arc each provided with a first and a second horizontal folding line by being provided with hinges. The first horizontal folding line constitutes a lower end of the side wall at which the side wall connects with the base member. The second horizontal folding line, which divides the side wall into an upper side wall part and a lower side wall part, is placed at a distance from the first horizontal folding line, between the lower end and an upper rim of the side walls. The two horizontal folding lines are mainly parallel. 
     The invention also relates to a process where the collapsible container is folded sequentially by folding the upper side wall part towards the lower side wall part. Said wall parts hereby becomes mainly parallel. The partly folded side wall is then folded towards the load surface. The procedure is repeated for the opposite side wall whereupon the two remaining side walls are, one after the other, folded on top of the two, first folded, side walls. 
     According to an alternative embodiment of the invention the collapsible container is folded sequentially by folding the upper side wall part towards the lower side wall part so that said wail parts becomes mainly parallel. The procedure is repeated for the opposite side wall whereupon the two remaining side walls are, one after the other, folded towards the load surface. Said two side walls, consisting of upper and lower side wall parts, are then folded on top of the side walls already arranged on the load surface. 
     The collapsible container is according to one special embodiment folded sequentially by folding the upper side wall part towards the lower side wall part so that said wail parts becomes mainly parallel. The folded side wall is then folded towards the load surface. The procedure is repeated for the opposite side wall whereupon the two remaining side walls, which are also divided into upper side wall parts and lower side wall parts, are folded, one after the other, on top of the two first folded side walls by repeating the procedure of the first side wall. 
     The divided side walls are suitably provided with a link member used for movably connecting the upper side wall part to the lower side wall part. The upper edge of said lower side wall part and the lower edge of said upper side wall part are provided with protrusions and matching recesses which are intended to interact. Said link member is attached to at least one of said side wall parts via an oblong hole allowing the protrusions and recesses of the side wall parts to be distanced from each other by forcing them apart thereby allowing folding of said upper side wall part and that stability is achieved when said divided side wall is in erected state. 
     The side walls are suitably also provided coupling means at their respective vertical edges, said coupling means being intended to lock adjacent side walls together when they are in erected position. Said coupling means locking are disengaged by lifting said side wall and said coupling means being engaged by allowing said side wall to move downwards when erected in correct position adjacent other erected side wall. 
     According to one embodiment of the invention the side walls are provided coupling means at their respective vertical edges. Said coupling means are intended to lock adjacent side walls together when they are in erected position. Said coupling means locking is disengaged by lifting the upper side wall part and said coupling means is engaged by allowing said side wall to move downwards when erected in correct position adjacent other erected side wall. 
     The divided side wall is suitably provided with a clamping means being arranged at the second horizontal folding line. Said clamping means are used for clamping the upper side wall part and the lower side wall part together at times where folding is not desired. These clamping means are suitably movably integrated with the side wall. 
     At least two side walls, arranged on opposite sides of the container, are suitably provided with locking means. Said locking means are used for locking adjacent side walls together when the side walls are in erected position. 
     The base part preferably has the basic shape of a pallet provided with feet and skids making it possible to handle the container with mechanical means such as a fork lift. 
     A collapsible container according to the present invention is preferably manufactured through injection moulding, vacuum moulding, blow moulding or press moulding of one or more polymeric materials such as polyethylene, polypropylene, polybutene, polyvinylchloride, polyalkylene-therephtalate acrylonitrile-butadiene-styrene copolymer, polyamide, polycarbonate or the like. Since the desired material characteristics of the different parts that the container is made up of can vary from part to part it is possible to add, different additives to the thermoplastic material that will make this possible. As examples of such known additives can be mentioned ethylene-vinyl-acetate and rubber beads which will make the material more ductile and more impact resistant, but on the other hand more disposed to thermal creepage, or glass fibre, carbon fibre, steel fibre or aramide fibre which will make the material more rigid, less disposed to thermal creepage but on the other hand more brittle. 
    
    
     
       The invention is illustrated further through the enclosed figures slowing embodiments of the invention whereby, 
         FIG. 1  shows schematically and in perspective and exploded view a collapsible container  1  according to first embodiment of the invention. 
         FIG. 2  shows schematically and in perspective view a collapsible container  1  according to second embodiment of the invention. 
         FIG. 3  shows schematically and in perspective view corner parts of a base member  2  and lower portions of a side wall  3  of a collapsible container  1  according to the invention. 
         FIG. 4  shows schematically and a perspective view, seen from the outside, upper corner parts of a collapsible container  1  where two side walls  3  are connected to one another. 
         FIG. 5  shows schematically and in perspective view, seen from the inside, upper corner parts of a collapsible container  1  where two adjacent side walls  3  are in the process to be connected to one another. 
         FIG. 6   a  and  6   b  show schematically and in cross-section lower portions of a collapsible container  1  according to the invention where a side wall  3  is movably connected to a base member  2 . 
         FIG. 6   c  is a schematic, cross-section view of lower portion of collapsible container  1 , according to the invention where a side wall  3  must first be tilted slightly outwards and then be pulled up from the engagement with the base. 
         FIG. 7  shows schematically and in perspective view, seen from the outside, parts of a collapsible container  1  according to the invention where an upper side wall part  3   u  and a lower side wall part  3   L  are movably connected to one another. 
     
    
    
       FIG. 1  shows schematically and in perspective and exploded view a collapsible container  1  according to first embodiment of the invention. The collapsible container  1  includes a base member  2  and collapsible side walls  3 . The base member  2  is provided with feet members  21 , a circumambient edge  22  and a mainly horizontal load surface  23 . The load surface  23  is provided with recesses  24  extending downwards from the load surface  23 . The recesses  24  are arranged adjacent the edge  22 . All four side walls  3  (only two shown) are provided with downwards extending protrusions  31  said protrusions  31  being arranged to interact with said recesses  24 . The side walls  3  engages the base member  2  through vertical motion. The lower ends of the side wails  3  are provided with a stabilising low rib  33  (see  FIG. 3 ) intended to interact with a groove  25  (see  FIG. 3 ) arranged on the base member  2  wherein said stabilising low rib  33  falls into said groove  25  when said side wall  3  is in erected position. Portions of the circumambient edge  22  has for the reason of clarity been cut away in  FIG. 3 . The side walls  3  are further provided coupling means  35  (see  FIG. 4 and 5 ) at their respective vertical edges. The coupling means  35  are intended to lock adjacent side walls  3  together when they are in erected position. The coupling means  35  locking is disengaged by lifting said side wall  3  a specified distance whereby said side wall  3  is tilted. The coupling means  35  are engaged by allowing said side wall  3  to move downwards when erected in correct position adjacent other erected side wall  3 . Two side walls  37  arranged on opposite sides of the container  1 , may also be provided with locking means. Said locking means being used for locking adjacent side walls together when the side walls  3  are in erected position. Two of the side walls  3 , preferably arranged on opposite sides, may also be provided with claws  310 ′ as shown in  FIG. 6   a  and  6   b  while the circumambient edge  22  is provided with a void  240 ′ also shown in  FIG. 6   a  and  6   b . The hinge member  32  isn&#39;t present in this special embodiment. The claws  310 ′ and voids  240 ′ are arranged to interact so that an erected side wall  3  will be prevented from being unintentionally disengaged from the base member  2 . The claws  310 ′ are disengaged from the voids  240 ′ by tilting the side wall  3  inwards after having removed or folded tie adjacent side walls  3 . 
       FIG. 2  shows schematically and in perspective view a collapsible container  1  according to second embodiment of the invention. The collapsible container  1  includes a base member  2  and collapsible side walls  3 . The base member  2  is provided with feet members  21 , a circumambient edge  22  (see  FIG. 1 ) and a mainly horizontal load surface  23 . The load surface  23  is provided with recesses  24  (see  FIG. 1 ) extending downwards from the load surface  23 . The recesses  24  are arranged adjacent the edge  22 . All four side walls  3  are provided with downwards extending protrusions  31  (see  FIG. 1 ) said protrusions  31  being arranged to interact with said recesses  24 . The side walls  3  engages the base member  2  through vertical motion. The lower ends of the side walls  3  are provided with a stabilising low rib  33  (see  FIG. 3 ) intended to interact with a groove  25  (see  FIG. 3 ) arranged on the base member  2  wherein said stabilising low rib  33  falls into said groove  25  when said side wall  3  is in erected position. Two opposite side walls  3  are each provided with a first and a second horizontal folding line  3   1  and  3   11  respectively by being provided with hinges. The first horizontal folding line  3   1  constitutes a lower end of the side wall  3  at which the side wall  3  connects with the base member  2 . The second horizontal folding line  3   11 , which divides the side wall  3  into a upper side wall part  3   u  and a lower side wall part  3   L , is placed at a distance from the first horizontal folding line  3   1 , between the lower end and the upper rim of the side walls  3 . The two horizontal folding lines  3   1  and  3   11  respectively are mainly parallel. The divided side walls  3  are provided with a link member  34  (see  FIG. 7 ) used for movably connecting the upper side wall part  3   L  to the lower side wall part  3   L . The upper edge of said lower side wall part  3   L  and the lower edge of said upper side wall part  3   u  are also provided with protrusions  34 ′ and matching recesses  34 ″ which are intended to interact. Said link member  34  is attached to the side wall parts  3   u  and  3   L  respectively via oblong holes allowing the protrusions and recesses of the side wall parts  3   u  and  3   L  respectively to be distanced from each other by forcing them apart thereby allowing folding of said upper side wall part  3   u . Stability is achieved when said divided side wall  3  is in erected state. The divided side walls  3  may also be provided with a clamping means being arranged at the second horizontal folding line  3   11 . The clamping means is used for clamping the upper side wall part  3   u  and the lower side wall part  3   L  together at times where folding is not desired. The upper part of the side walls  3  adjacent to the divided side walls  3  as well as the upper side wall part  3   u , may further be provided coupling means  35  (see  FIG. 4 and 5 ) at their respective vertical edges. The coupling means  35  are intended to lock adjacent side walls  3  together when they are in erected position. The coupling means  35  locking is disengaged by lifting said upper side wall part  3   u  a specified distance whereby said upper side wall part  3   u  is tilted. The coupling means  35  are engaged by allowing said upper side wall part  3   u  to move downwards when erected in correct position adjacent other erected side wall  3 . 
     The remaining parts of the side walls  3  may also be provided coupling means  35  (see  FIG. 4 and 5 ) at their respective vertical edges. The coupling means  35  are intended to lock adjacent side walls  3  together when they are in erected position. The coupling means  35  locking is disengaged by lifting said side wall  3  a specified distance whereby said side wall  3  is tilted. The coupling means  35  are engaged by allowing said side wall  3  to move downwards when erected in correct position adjacent other erected side wall  3 . Two side walls  3 , arranged on opposite sides of the container  1 , may also be provided with locking means. Said locking means being used for locking adjacent side walls together when the side walls  3  are in erected position. Two of the side walls  3 , preferably arranged on opposite sides may also be provided with claws  310 ′ as shown in  FIG. 6   a  and  6   b  while the circumambient edge  22  is provided with a void  240 ′ also shown in  FIG. 6   a  and  6   b . The hinge member  32  isn&#39;t present in this special embodiment. The claws  310 ′ and voids  240 ′ are arranged to interact so that an erected side wall  3  will be prevented from being unintentionally disengaged from the base member  2 . The claws  310 ′ are disengaged from the voids  240 ′ by tilting the side wall  3  inwards after having removed or folded the adjacent side walls  3 . 
       FIG. 6   a  and  6   b  show schematically in cross-section a special embodiment of protrusions  31  and recesses  24 . The protrusions  31  are movably attached to the side wall  3  via a hinge member  32 . The protrusions  31  are furthermore provided with snapping heels  310  while the recesses  24  are provided with undercuts  240 . The snapping heels  310  and undercuts  240  are adapted to interact, limiting the vertical movement of the protrusions  31  and thereby the side wall  3 . The undercuts  240 , the protrusions  31  and the snapping heels  310  are arranged to allow a limited vertical movement so that the protrusion  31 , and thereby the side wall  3 , will be located in a lowermost position when the side wall  3  is in erected position (see  FIG. 6   a ) and in a higher position when the protrusion  31 , and thereby the side wall  3 , is in folded position (see  FIG. 6   b ). The side wall  3  may furthermore be provided with a claw  310 ′ while the circumambient edge  22  is provided with a void  240 ′. Said claw  310 ′ and void  240 ′ are arranged to interact so that an erected side wall  3  will be prevented from being unintentionally disengaged from the base member  2 . The claw  310 ′ of the side wall  3  is disengaged from the void  240 ′ of the circumambient edge  22  by being angled slightly inwards followed by lifting the side wall  3 . 
     Containers produced according to the embodiment of  FIG. 6   c  can be emptied by turning them upside down. During the emptying it is important that the sidewalls stay on the container without having to rely on tensional strapping or similar contraptions. Such containers can be used to transport, for example, unrefined or semi-refined rubber blocks. Between a half dozen to a dozen of these rubber blocks are pressed into the container. The possibility to angle the sidewalls, even if ever so slightly, outwards, makes it easier to empty the container. Thus, as shown in  FIG. 6   c , sidewalls  3  hang on snapping heel  310  and undercuts  240  which permit the sidewalls  3  to flex outwardly while still being attached to the base member  2 . As with the other embodiments, feet members  21  are also provided with the embodiment of  FIG. 6   c . 
     The present invention is not limited by the embodiments shown as it is possible to make different alternatives within the scope if the invention. It for example is possible to provide a container according to the invention with three side walls  3  connected to the base member  2  via hinged protrusions  31  as shown in figures  6   a  and  6   b  while the fourth side wall is provided with solid protrusions as shown in  FIGS. 1 and 3 . This will facilitate loading and emptying of such a collapsible container  1  as one of the side walls  3  can be removed during handling.