Patent Publication Number: US-9896263-B2

Title: Collapsible containers

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. Ser. No. 13/143,339, filed 23 Feb. 2012 entitled “Collapsible Containers,” which is a national phase entry under 35 U.S.C. § 371 of International Patent Application No. PCT/AU2009/001704, filed 24 Dec. 2009, entitled “Collapsible Containers,” which designates the United States of America, and which claims priority to Australian Patent Application No. 2009900025, filed 5 Jan. 2009, the entire contents and disclosures of which are hereby incorporated by reference in their entireties. 
    
    
     FIELD OF THE INVENTION 
     THIS INVENTION relates to collapsible containers. 
     The invention particularly relates, but is not limited to, containers for holding items therein, and which are collapsible (for storage and/or transport) when empty. 
     PRIOR ART 
     Containerisation, including the development and standardization of freight containers and of complementary specialized container-handling equipment, was a quantum leap in the field of materials handling. 
     The containers are used to hold items, both while in storage and while being transported between destinations by vehicles including trucks, trains, aircraft, ships, or other transport vehicles. 
     The costs of storage and transportation of the goods in containers are based on the respective volumes occupied by the containers; and so the costs are the same even if the containers are empty or partially-filled to capacity. 
     In many instances, the containers are only used once, eg., when used to transport goods to destinations which have little, if any, goods to be transported in return, or to other destinations. With a manufacturing cost of approximately USD 4000.00, any containers which are dumped and not re-used reflect of waste of manufacturing resources and money. 
     When empty containers are returned to their original destinations, or forwarded to other destinations, the transportation costs are the same as if the containers are full; and the operations of many ships or other transport vehicles are effectively wasted as they are transporting no more than big boxes of air. 
     While the empty containers are awaiting re-use, they typically occupy valuable storage space eg. on wharves, in railway yards, or at remote storage sites; and typically incur additional transportation costs to and from the storage sites. 
     To reduce storage and/or transportation costs for the empty containers, it is desirable to have containers that can be collapsed during storage and in transport. Collapsible containers have previously been proposed; and examples are disclosed in (i) International Application PCT/AU89/00354 (International Publication No. WO 90/02084=U.S. Pat. No. 5,190,179) (Richter et al) and (ii) International Application PCT/AU2005/001333 (International Publication No. WO 2006/024104) (Container Technology Pty Ltd et al)). (The contents of those respective disclosures are included in the present disclosure by way of reference.) 
     However, the prior art collapsible containers, including those disclosed in (i) WO 90/02084 and (ii) WO 2006/024104 do not meet the stringent container standards set by the transportation authorities and international insurance bodies around the world. These standards require the containers pass various structural strength tests, such as shock tests in relation to dropping from a height above floor level, tipping, rolling, stacking, racking, etc. When erected, the standards set minimum compressive loads which can be sustained when the containers are stacked, or tensile loads when the containers are being lifted; and the container standards also set minimum compressive and tensile loads for the collapsible containers, when collapsed, for storage or transit. The containers must at least meet, and more preferably exceed, the minimum standards, whether full, empty or partially-filled. 
     The standards also require the containers to be spray- or water-proof to protect the goods stored therein (and to minimize structural failure or other damage as a result of internal corrosion). 
     None of the known collapsible containers pass all these tests. 
     In addition, the manufacturing costs of any collapsible containers must be such that any additional manufacturing costs over those of conventional (rigid) containers must be more than offset during the expected life cycle of the collapsible containers, due to savings from reduced storage and/or transport costs when collapsed. 
     SUMMARY OF THE PRESENT INVENTION 
     It is an object of the present invention to alleviate, or to at least reduce, one or more of the disadvantages of the known collapsible containers. 
     It is a preferred object of the present invention to provide a collapsible container which is stable and meets the container standards when erected (and up to fully loaded) and/or when collapsed. 
     It is a further preferred object to provide a collapsible container which can be collapsed to occupy a volume no greater than 50% of the volume of the container when erected. 
     It is a still further preferred object to provide a collapsible container when can be handled by conventional container handling equipment when collapsed. 
     It is a still further preferred object to provide a collapsible container where adjacent components can be securely locked together when the container is erected, but allow easy release when the container is to be collapsed. 
     Other preferred objects of the present invention will become apparent from the following description. 
     Hereinafter throughout the specification, the term “a collapsible container as hereinbefore defined” will mean “a collapsible container of the type including: a base structure; a top structure; opposed side covers arranged between the base structure and top structure, each said side cover having a lower section frame pivotally connected to the base structure and a top section frame pivotally connected to the top structure; a central hinge arrangement configured so that the top section frame is pivotally movable relative to the lower section frame, whereby the side covers are selectively positionable between an erected position in which the top structure is remote from the base structure, and a collapsed position in which the top structure is at or adjacent to the base structure; the container when erected defining an interior space between the base structure and top structure; and end covers at opposed ends of the container, arranged to be pivotally movable between an upright position for covering respective ends of the container, and a lowered position for allowing the side covers to be moved to the collapsed position”. 
     In one aspect, the present invention resides in base frame/end cover engagement assembly, for a collapsible container as hereinbefore defined, the assembly including: 
     a corner post located at a corner of the base frame and extending upwardly therefrom; 
     a lower lifting restraint extending laterally from the corner post, towards the interior space, and spaced above the base frame, the lower lifting restraint having, at a distal end, a downwardly-directed concave abutment face; 
     a stile of an end cover frame pivotally mounted on the base frame adjacent the corner post; 
     a lower lifting restraint block on the stile, the lower lifting restraint block having an upwardly-directed convex abutment face complementary to the concave abutment face on the lower lifting restraint; and 
     a latch member on the corner post, or the stile, operable to releasably engage a stop member on the stile, or corner post, to releasably lock the stile in a substantially vertical position when a respective end cover is in an erected position; so arranged that: 
     in the erected position, the respective abutment faces of the lower lifting restraint and of the lower lifting restraint block are engaged to increase the load strength of the collapsible container, in the vertical direction, when erected. 
     Preferably, the corner post is formed integrally with the (hollow) base corner casting, operable to receive the twist-locks of adjacent container(s). 
     The lower lifting restraint may extend, and be fixed, to a vertical side plate of the base frame extending along one side thereof. 
     The lower lifting restraint block may be mounted on a bottom rail or plate of the end cover frame &amp; fixed to the adjacent stile; where the axis of the curvature of the convex abutment face is preferably co-axial with the pivotal mounting of the end cover frame on the base frame. 
     At least one end cover frame comprises a door frame operable to support at least one door to provide selective (preferably lockable) access to the interior space. 
     Preferably, spring attachment plate(s) extend from the end cover frame, below the pivotal connection, and are operably connected to one or more (preferably tension) springs (preferably) mounted (in respective cylinders or housings) on the base frame to assist the movement of the end cover frame to its erected position. 
     Alternatively, attachment plate(s) extend from the end cover frame, below the pivotal connection, and are operably connected to a winch system having an operating bar slidably mounted on parallel guides on the base frame, the operating bar being movable relative to the base frame by a screw-threaded connection with an operating shaft rotatably journalled in the base frame, selective rotation of the operating shaft by a handle being operable to move the end cover frame between the raised and lowered positions. 
     In a second aspect, the present invention resides in a frame for an end cover, for a collapsible container as hereinbefore defined, the frame including at least two stiles connected by a head rail and a bottom rail, respectively, wherein: 
     a respective corner block is provided at the junction of a stile and the head rail, the corner block having body with an elongate slot or groove operable to receive, and engage, a spigot extending from the adjacent end wall when the end cover frame and the side wall are both in their erected positions. 
     Preferably a latch plate on the stile is releasably engageable with the spigot to releasably lock the end cover frame to the side wall. 
     The end cover frame may comprise a door frame, having at least one door hingedly mounted thereto to enable selective access to the interior space. 
     In a third aspect, the present invention resides in a locking mechanism to releasably lock a frame of an end cover to a side wall, of a collapsible container as hereinbefore defined, the locking mechanism including: 
     a striker plate mounted on, and extending from, the side wall; 
     a backing plate mounted on a stile of the end cover frame; 
     a sliding plate, extending laterally from the backing plate and operable to intersect the striker plate, the sliding plate being mounted on the backing plate between a released position and an engaged position; and 
     a safety flap operable to restrain the sliding plate in the engaged position; 
     the striker plate having an upwardly-directed slot and/or the sliding plate having a downwardly directed slot, so arranged that, when in the engaged position, the sliding plate engages the striker plate to releasably lock the end cover frame to the side wall. 
     In a fourth aspect, the present invention resides in a collapsible container, as hereinbefore defined, having the features of any one or more of the first to third aspects hereinbefore described. 
     Other aspects of the present invention will become apparent from the following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To enable the invention to be fully understood, preferred embodiments will now be described with reference to the accompanying drawings, in which: 
         FIGS. 1 and 2  are respective front isometric and end elevation views of a collapsible container, in accordance with the present invention, in its erected configuration; 
         FIGS. 3, 4 and 5  are respective front isometric, end elevation and front elevation views of the collapsible container in its collapsed configuration; 
         FIG. 6  is a sectional view on line A in  FIG. 5 ; 
         FIGS. 7, 8 and 9  are respective front isometric, end elevation and front elevation views of a plurality of the collapsible containers stacked together in their collapsed configurations; 
         FIG. 10  is a front isometric view of the base assembly for the collapsible container; 
         FIG. 11  is a similar view of the roof assembly for the collapsible container; 
         FIGS. 12 and 13  are respective internal and external isometric views of a corner of the base assembly of  FIG. 10 ; 
         FIGS. 14 and 15  are respective sectional views of the corner of  FIGS. 12 and 13 ; 
         FIG. 16  is an isometric front view of an end cover, including a pair of hingedly-mounted doors, for the collapsible container; 
         FIG. 17  is a schematic isometric view of one corner of the end cover of  FIG. 16 ; 
         FIGS. 18 &amp; 19  are respective isometric views of a base corner of the collapsible container viewed externally and internally; 
         FIGS. 20 and 21  are similar views of a roof corner of the collapsible container; 
         FIGS. 22 and 23  are respective front isometric views of a locking assembly, for the side walls, in the released and locked positions; 
         FIG. 24  is a front isometric external view of a roof corner of the collapsible container; 
         FIG. 25  is a similar view on an enlarged scale; 
         FIGS. 26 and 27  are respective front isometric views of a twist-lock assembly for the collapsible container, with the twist-locks in the released and locking positions; 
         FIGS. 28 and 29  are respective front elevation and front isometric views of a side wall for the collapsible container; 
         FIG. 30  is a sectional view on line “A” on  FIG. 28 ; 
         FIG. 31  is an enlarged end view of the details (1) to (3) on  FIG. 30 ; 
         FIG. 31A  is an enlarged isometric view of a hinge plate for the side wall; 
         FIG. 32  is a top plan view of one end of the base frame illustrating a winch system for the door at that end; 
         FIG. 33  is an end elevational view thereof; 
         FIG. 34  is a side elevational view taken on line “A” on  FIG. 32 ; and 
         FIG. 35  is a similar view taken on line “B” on  FIG. 32 . 
     
    
    
     NB: Any notations, including dimensions, on the drawings, are not limiting to the scope of the present invention, and are as guidance and by way of example only. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1 to 9 , the collapsible containers  10  of the present invention have base assemblies, roof assemblies, side walls and end covers (including doors) generally of the nature of the prior art collapsible containers of International Publications (i) WO 90/02084 and (ii) WO 2006/024104 discussed above, except where the specific advantageous features of the collapsible containers  10  of the present invention are hereinafter described in detail, with reference to the accompanying drawings. 
     The selection of specific materials/dimensions for the components for the containers  10  will be subject to design criteria enabling the collapsible containers  10  to meet, and preferably exceed, the internationally accepted standards for containers, whether rigid or collapsible. 
     In  FIGS. 7 to 9 , three (3) collapsible containers  10  are shown stacked together, when collapsed, to occupy a volume of approximately one (1) of the collapsible containers  10  when erected. It is preferred that at least two (2) of the collapsible containers  10  will occupy the volume occupied by one (1) of the collapsible containers  10  when erected. 
     The containers  10  include a base assembly  20 , a roof assembly  30 , end covers  40  and side walls  50  to be hereinafter described in more detail. 
     Stacked collapsible containers  10 , whether collapsed or erected, are releasably interconnected via the twist locks  90  (to be hereinafter described in more detail with reference to  FIGS. 25 to 27 ) mountable on the roof assemblies  30  of the lowermost of the stacked collapsible containers  10 . 
     Referring to  FIGS. 10, 12 to 15 , each base assembly  20  has a pair of side rails  21  (e.g., formed of RHS) interconnected by a plurality of cross beams  22  (eg., of C-section steel) and tubular end rails  23 . A pair of tubular cross beams  24 , which are open at their respective ends, are adapted to receive the lifting forks of a forklift or like materials handling machines. 
     Side plates  25  extend along each side of the base assembly  20 , surmounting the side rails  21 . 
     Cast lock housings  27 , operable to receive the twist locks  90  from adjacent containers, or on materials- or transport-machines, are provided at each corner of the base assembly  20 . 
     As shown more clearly in  FIGS. 12 to 14 , a corner post  70 , of substantially L-shape, extends upwardly from a respective lock housing  27  and is fixed, e.g., welded, to the adjacent side rail  21  and side plate  25 . 
     A lower lifting restraint  71  is provided on the inner face of the corner post  70 , i.e. directed into the interior space of the collapsible container  10  and may also be fixed to the adjacent side plate  25  for increased strength. 
     The lower lifting restraint  71  has a downwardly-directed concave face  72 , extending from the distal end of the lower lifting restraint  71 , where the radius of curvature of the concave face  72  is measured from the centre line of a hinge tube  73 , for the hinged mounting of an end cover  40 , to be hereinafter described. 
     The other end of the corner post  70  has a base closure support finger  74  which assists in locating and supporting the adjacent end cover  40 , when erected, or in the roof assembly  30  when the collapsible container  10  is collapsed. 
     A latch plate  75  is pivotally mounted on the external face of the corner post  70  and is operable to engage a headed stop, to be hereinafter described, on the end cover  40  when the latter is erected, or on a similar stop on the roof assembly  30  when the container  10  is collapsed. 
     Referring to  FIGS. 16 and 17 , normally, one end cover  40  has a “solid infill” end panel, while the second end cover  40  has a door frame  41  hingedly mounting a pair of doors  42 , mounted on hinges  43  and lockable by lock mechanisms  44  in the manner of existing containers. 
     Each door frame  41  has a pair of stiles  45  (which are vertical when the container is erected) interconnected by a head rail  46  and a bottom rail  47 ; while a corner block  48  is provided at the junction of the head rail with each stile). 
     The bottom rail  47  of the door frame  41  may be formed of steel aluminium plate, with a door frame step  49  extending downwardly from the outer side thereof, the latter terminated by a pair of end seal plates  76  adapted to lie adjacent the respective lock housings  27  when the door frame  41  is erected. 
     Respective hinge tubes  77  on the inner side of the bottom rail  47  are adapted to be aligned with the hinge tubes  73  on the respective end rails  23  of the base assembly  20  and to receive suitable hinge pins (not shown). 
     The bottom rail  47  extends past the respective stiles  45  and the upper face of each extension  78  is provided with a lower lifting restraint block  79  which has an upwardly directed convex face  80  complementary to the concave face  72  of the respective lower lifting restraint  71  on an adjacent corner post  70 . 
     When the door frame  41  (or end cover frame) is moved to the erected position, the lower lifting restraint block  79  engages the lower lifting restraint  71  on the base assembly  20  to provide a releasable connection which provides both lateral stability, but more importantly, improved load transfer in the vertical direction when the container  10  is erected and being lifted. 
     While the respective concave and convex faces  72 ,  80  of the lower lifting restraint  71  and lower lifting restraint block  79 , respectively, could be substituted by complementary “wedged” faces, the curved faces provide improved release and engagement between the components. 
     To assist in the raising and lowering of the end covers  40 , a pair of tension springs (not shown) are provided in tubular spring housings  81  mounted in the cross beams  22  of the base assembly  20  and have piston rods  83  connected via suitable linkages  84  to door closure attachment plates  85  extending inwardly from the door frame step  49  (below the bottom rail) of the end covers  40 . 
     When the end covers  40  are moved to the collapsed position, the door closure attachment plates  85  and linkages  84  pull the piston rods  83  to cause the tension springs to be tensioned. As the door covers are being raised, the tension springs compress towards their “neutral” position and thereby provide a force assisting in raising the end covers  40  to their erected positions. 
       FIG. 11  illustrates the roof assembly for the collapsible container; while  FIGS. 20, 21, 24 and 25  illustrate the connection of the roof assembly  30  and the side walls  50  to the end covers  40 . 
     The upper edges of the side walls  50  are hingedly connected to the roof assembly  30  by a plurality of spaced hinges to be hereinafter described. 
     A headed spigot  86  on the roof assembly  30  can either extend through an aligned hole in the corresponding stile  45  of the end cover  40 , or through the respective corner block  48  of the end cover  40  and be releasably engaged by a closure latch plate  87  hingedly mounted on the stile  45  and prevented from accidental release by a hinged keeper  88  pivotally mounted on the spigot  86 . 
     The corner blocks  48  at the upper corners of the end covers  40  provide strength and rigidity to the door frames  41  to assist and prevent lateral twisting of the container  10  when erected and to assist in providing effective transfer of vertical loads from the stiles  45  to the roof assembly  30 . 
     As particularly illustrated at  FIGS. 24 and 25 , a twist lock assembly  90  can be provided for releasable engagement with a roof corner lock casting  89  to enable releasable engagement with a container  10  stacked thereon. 
     The corner lock casting  89  provides a strong junction between the side and end rails  31 ,  32  of the roof assembly  30 . 
     As shown in more detail in  FIGS. 26 and 27 , the twist lock assembly  90  has a body  91 , eg., of cast steel or aluminium with upper and lower lugs  92 ,  93  arranged for engagement in complementary holes in the corner lock housings  27 ,  89  of the containers  10 . 
     A shaft  94  is rotatably journalled in the body  91  and is selectively rotatable between an unlocked position, where the operating handle  95  is received within a slot  96  in the body, as shown in  FIG. 26 ; and an operating position, where the handle  95  extends from the slot  96 , as shown in  FIG. 27 . 
     Respective twist lock knobs  97 ,  98  are secured to the shaft  94  and are rotatable therewith for releasable engagement between adjacent containers. 
     As illustrated in  FIGS. 28 to 30 , each side wall assembly  50  has an upper wall portion  51  and a lower wall portion  52  interconnected by a plurality of cast double-hinge members  53  which are provided at spaced intervals to enable hinged interconnection between the upper and lower wall portions  51 ,  52 . 
     The upper and lower wall portions  51 ,  52  are respectively hingedly connected to the roof assembly  30  and base assembly  20  by spaced hinges  54 ,  55 ; and as illustrated in  FIGS. 4, 6 and 8 , the central wall portion  56  may be moved inwardly to enable the roof assembly  30  to be moved towards the base assembly  20  to enable the container to be collapsed; or vice versa. 
     As illustrated, by way of example, the double-hinge members  53  may have flanges or extensions  58  operable to engage the wall  59  of the central wall portion  56  so that the upper and lower wall portions  51 ,  52  are maintained in vertical alignment when the container  10  is erected; and to oppose any deflection of the side walls  50  when load is applied thereto through the roof assembly  30 . 
     To further stabilize the side walls  50 , a respective locking mechanism  100 —see  FIGS. 22 and 23 , is provided to releasably lock the door frame  41  of an end cover  40  to the adjacent side wall  50 . 
     NB: While the locking mechanism  100  is preferably provided between the end cover  40  and the lower side wall portion  52 , respective locking mechanisms  100  could be provided between the end cover  40  and both the upper and lower side wall portions  51 ,  52 . 
     The locking mechanism  100  has a striker plate  101  mounted on, and extending from, the side wall  50  lying parallel to and spaced a small distance from, the end frame member  52 A of the lower side wall portion  52 . 
     A backing plate  102  is mounted on the inner face of the adjacent stile  45  of the end cover  40  and slidably mounts a sliding plate  103 , of substantially inverted L-shape in end view, where an elongate slot  104  in the body  105  of the sliding plate  103  receives a pair of support pins  106  extending from the backing plate  102 . 
     The sliding plate  103  has a substantially L-shaped finger  107  extending laterally from the body  105  of the sliding plate  103  with a downwardly directed slot  108  which is aligned with a complementary upwardly directed slot  109  in the top face of the striker plate  101 . A safety flap  110  is pivotally mounted on the sliding plate  103  and is movable between a first position where it engages the uppermost of the pins  106  in the backing plate  102  so that the finger  107  is released from engagement from the striker plate  101 ; and a second position disengaged from the pin  106 , allowing the sliding plate  103  to be lowered so that the finger  107  releasably engages the striker plate  101 . 
     The striker plate  101  and finger  107  together form an interlocking cruciform assembly which prevents movement in all three axes between the side wall portion  52  and the adjacent end cover  40 . This, of course, prevents unwanted “bowing” of the side wall  50  when vertical loads are applied to the roof assembly  30  of the container  10  (and indeed also assists in load transfer between the side wall  50  and the end cover  40  when the container  10  is being lifted while erected—irrespective of whether or not the container has any contents). 
       FIGS. 32 to 35  illustrate a winch system  110  may be provided at one end, or both ends, of the base assembly  20  to raise/lower the end cover  40  when the container  10  is to be erected/collapsed, respectively. 
     The winch system  110  has an operating shaft  111  rotatably journalled in bearings (or bushes)  112  in cross beams  22  of the base assembly  20 , and has a detachable (or foldable) handle  113  at its distal end. (A “universal joint” may interconnect the handle  113  to the operating shaft  111 .) 
     The inner end of the operating shaft  111  has a screw-threaded portion  114  operably engaged by a travelling screw  115  on a transverse operating bar  116  which is guided by sliding bushes  117  engaged on parallel guides  118  interconnecting adjacent cross beams  22 . 
     Operating links  119  are interposed between the door closure attachment plates  85 , connected to the end covers  40  (as hereinbefore described), and respective pairs of operating plates  120  adjacent the respective ends of the operating bar  116 . 
     Each full rotation of the operating shaft  111  moves the operating bar e.g. 10 mm, where total travel of e.g. 150 mm is required to fully raise or lower the end cover  40  connected thereto. 
     The skilled addressee will appreciate the raising of the end cover  40  may additionally be assisted by the tension springs also connected to the door closure attachment plates  85 , as hereinbefore described. 
     Alternatively, the handle  113  may be substituted by releasable connection of the distal end of the operating shaft  111  to the output shaft of a portable “power-pack” (not shown), such as a hydraulic motor connected to a engine-driven pump, which is selectively operate to rotate the operating shaft  111  to raise or lower the end cover  40 . The use of such a “power-pack” enables the containers  10  to be quickly and easily erected or collapsed, as required. 
     The collapsible container  10  of the present invention can be easily collapsed for storage or transport when empty; but equals or exceeds the international standards for shipping containers when erected; and any additional manufacturing cost can be quickly recovered by the reduced storage or transport costs when the containers are collapsed; and their re-use over many storage/transport cycles, rather than being dumped as a “use once only” item. 
     Various changes and modifications may be made to the embodiments described and illustrated without departing from the present invention.