Patent Publication Number: US-6209741-B1

Title: Collapsible container

Description:
DESCRIPTION OF INVENTION 
     This invention relates to a container of the type having a base and four side walls (normally four) upstanding from sides of the base, wherein the side walls are hinged for movement relative to the base and which side walls may accordingly occupy positions in which they upstand from the base or in which they overlie the base by inwardly folding the side walls relative to the base. 
     A variety of such containers are known, and a particularly suitable construction of such has previously been found to be of the type whereby the entire container, i.e., the base and the side walls, are formed from a unitary plastics moulding. In such a construction, conveniently a “live” hinge is utilised in which adjacent parts of the container, whilst being formed in one piece, are separated by a “score” or line of reduced thickness, about which the adjacent parts may be relatively pivoted. On the one hand, such a construction enables relatively fast manufacture and assembly of a container, but on the other hand the moulds required for such construction are by necessity complex and accordingly expensive to manufacture and maintain. Additionally if part of the container should be irreparably damaged it may be necessary to replace the entire container. 
     It is accordingly an object of the present invention to provide an improved container which overcomes or reduces the problems outlined above. 
     According to a first aspect of the invention, there is provided a container having a base and side walls extending from sides of the base, wherein at least some of the side walls are movable relative to the base to enable the container to be folded, and wherein at least some of the side walls are moulded separately from the base. 
     Preferably, all the side walls are movable relative to the base, and conveniently all the side walls are each moulded in one piece separately from the base. 
     The side walls moulded separately from the base are preferably engageable with the base so as to form a substantially rigid connection between part of the side walls and the base. 
     The side walls are preferably movable relative to the base by virtue of hinges, which may be provided on or which may be integral with the base. Preferably however the hinges are provided on or are integral with the side walls. 
     Thus conveniently, the base has first engaging means along some at least of the sides of the base, and some at least of the associated side walls have a fixing portion provided with second engaging means, the first and second engaging means being capable of engagement to secure the side walls to the base, there being provided a side wall portion hinged to each fixing portion. 
     Conveniently the first and second engaging means enable the fixing portions and base to be substantially rigidly secured together. 
     Advantageously first engaging means are provided on all sides of the base, and all side walls are provided with a fixing portion as aforesaid. 
     The side walls may be secured to the base in a substantially permanent manner, as for example by welding, conveniently by ultrasonic welding. 
     Preferably, however, the second engaging means of the side walls are engageable with receiving apertures of the base, and conveniently such engagement may include a snap fitting engagement. In such a case, the first engaging means may comprise recesses or apertures provided in the sides of the base, and the second engaging means may comprise engaging formations such as tongues or like protrusions adapted to be insertable into the recesses or apertures by causing resilient deformation of material surrounding the recess or aperture, and/or by the engaging formations undergoing resilient deformation themselves. Preferably, the tongues or like protrusions may generally only pass through the recess or aperture in one direction, such that they become retained in position once such insertion is complete and are thus prevented from removal. 
     The tongues or like protrusions adapted for such snap fitting engagement may comprise a rearwardly facing surface (when taken in the direction of insertion), providing an abutment surface, which when the tongue is inserted into the recess or aperture abuts part of the material surrounding the recess or aperture, thus hindering or preventing removal of the tongue or like protrusions, by movement in an opposite direction. 
     Thus, the tongue or like protrusions may be of generally barbed bayonet type configuration, and there may be provided such an abutment surface on one or each side of the tongue. 
     It is envisaged that not all of the tongues or like protrusions may be adapted for such snap fitting engagement, and it may be desirable for some of the tongues or like protrusions to merely be locatable within a corresponding recess or aperture and not necessarily be lockable therein. The corresponding recess or aperture may be provided at a lower position relative to the side of the base than the recesses or apertures adapted for snap fitting engagement. 
     Those tongues or like protrusions which are not provided with such a bayonet type configuration may comprise a tapered end part to facilitate location within the corresponding recess or aperture. 
     The container may be square in plan view. Preferably however, the base of the container is rectangular in plan view. In such a case, the fixing portions of a first pair of opposite side walls are preferably mounted at a higher level relative to the base than those of a second pair of opposite side walls. Accordingly, the second pair of opposite side walls shall henceforth be referred to as the “end walls”. Accordingly, the second pair of opposite side walls shall henceforth be referred to as the “end walls”. 
     Conveniently, the side walls of the first pair are longer than those of the second pair, and for the sake of convenience herein shall be henceforth referred to as the “longer” side walls. 
     Each side wall portion is preferably hinged to a respective fixing portion by a film of plastics material, such a hinge being commonly known as a “live” hinge. Preferably the side walls are formed from the same material as the hinge, and conveniently, the entire container may be formed from such a material. A particularly suitable material has been found to be the plastics material polypropylene, although it is envisaged that any other suitable material may be employed without detracting from the scope of the invention. Thus, the side walls are preferably formed as a single moulding, the side wall portion, the “live” hinge and the fixing portion thus preferably being integral with each other. 
     The longer side wall portions may have upper parts configured to permit one longer side wall portion to partially overlie the other when in an inwardly folded position, whilst still presenting a generally planar outwardly facing surface. To this end, the upper parts may be asymmetrical with respect to each other, and conveniently the asymmetric parts may comprise parts of reduced thickness. 
     It is anticipated that the parts of reduced thickness on the upper parts of the longer side wall portions may be tapered parts, the parts tapering generally towards the base of the container when the side walls are in a generally upstanding condition. 
     Accordingly, when it is desired for the side walls to be folded inwardly towards the base, so as to provide a collapsed condition of the container, the longer side walls are preferably folded after the end walls such that the longer side walls each partially overlie the end walls and partially overlie each other. 
     Preferably, ends of the longer side walls are provided with attachment formations such as clips or hooks adapted for engagement with corresponding parts on the end walls. Preferably, the longer side walls are provided at their ends with inturned formations, said formations being inturned towards the interior of the container, said attachment formations being provided on said inturned formations. Conveniently, the inturned formations lie generally in the same plane as the adjacent end wall when the side walls are in a generally upstanding condition, so that in an erected condition, the end wall may be brought into abutment with the inturned formations enabling the attachment formations to engage with corresponding parts on the end wall. Preferably, the or each attachment formation comprises a clip and the corresponding part on the adjacent end wall comprises an aperture or recess. Conveniently, the clip is adapted to resiliently deform during insertion into the apertures or recesses. Additionally, part of the end wall adjacent or surrounding the recess or aperture may also resiliently deform during insertion of the clip. The clip may be configured such that insertion of the clip into the recess or aperture is easier than removal of the clip. Such an arrangement provides that engagement of the clip and aperture may readily be achieved, whereas releasing the clip from the aperture is hindered. 
     Preferably, the engagement between the attachment formations and the apertures is such that by relative generally vertical displacement of the longer side wall and adjacent end wall, the engagement may be released. Preferably, such relative displacement comprises relative upward movement of the longer side wall, and relative downward movement of the adjacent end wall. Such relative vertical displacement is preferably achieved by flexing or compression of the base, longer side walls and end walls. In particular, it is envisaged that there may be provided a section of reduced strength, for example a cut away section on the base, generally below a corner defined by a longer side wall and an adjacent end wall. Preferably, such a portion of reduced strength permits parts of the base adjacent the portion to be displaced generally vertically relative to each other, and since the side walls are engaged with recesses or apertures at that part of the base, relative vertical displacement of the side walls is permitted. Additionally, it is envisaged that the “live” hinge by which the side wall portions are hinged to the fixing portions may not extend to the corners of the base. In particular, the hinge may terminate approximately 30 mm from each corner. This further enables relative vertical movement of the side walls to be achieved. 
     Each side wall of the container may be provided with one or more ventilation holes, and it is anticipated that each side wall may have a “fluted” configuration in order to provide resistance to distortion caused by compression forces acting from above the side walls. To reduce the effect of any bending which may occur to the side walls, reinforcing cross members may be provided generally horizontally, through or along each side wall. 
     According to a second aspect of the invention, there is provided a container having a base and side walls extending from sides of the base, wherein at least some of the side walls are movable relative to the base to enable the container to be folded, and wherein at least one pair of opposite side walls partially overlie each other when the container is in a folded condition, and wherein the pair of opposite side walls have mutually interfitting formations to enable the side walls to substantially interfit when in a folded condition. 
    
    
     The invention will now be described in greater detail and by way of example only by reference to the accompanying drawings wherein: 
     FIG. 1 is a schematic view illustrating the engagement of a side wall with a side of the base of the container, 
     FIG. 2 is a side schematic view showing the side wall portion in upright and inwardly folded positions relative to the fixing portion and base, 
     FIG. 3 is a similar view to that shown in FIG. 1 but in respect of an end of the container, 
     FIG. 4 is a cross section of a container with end walls and longer side walls in an inwardly folded position, and 
     FIG. 5 is an underside plan view of a base of a container showing a cut away section permitting of flexing of a corner of the container, 
     FIG. 6 is a view of an alternative embodiment of part of the base and adjacent side thereof, 
     FIG. 7 shows an alternative embodiment of a side wall, 
     FIG. 8 shows an assembled container with one end wall in a partially inwardly folded condition, and 
     FIG. 9 shows a different sized container in an almost fully folded condition. 
    
    
     Referring first to FIG. 1, there is shown a side wall  10  of a container having a fixing portion  11  and a side wall portion  12  hinged to the fixing portion  11  by a “live” hinge  13  which in this example is in the form of a polypropylene plastics film hinge. The fixing portion  11  comprises clip hooks  14  (one of which is shown) and under hooks  15  adapted for engagement with receiving apertures  33  and  32  of an associated base  31 . It is envisaged that the receiving apertures be generally elongate, wherein the plastics material surrounding at least those apertures  33  adapted for insertion of the clip hooks  14  is resiliently deformable so as to permit insertion of the clip hook, but by virtue of shoulder  16 , on the clip hook, hinder release of the clip hook from the aperture. Alternatively, the material from which the clip hook is formed may be resiliently deformable to enable such engagement. 
     Whilst in the drawings, the clip hook  14  is shown with one shoulder  16 , it is envisaged by the applicants that a corresponding shoulder may be provided on the other side of the clip, in the region indicated generally at  16   a  so as to provide a barbed “bayonet” type construction, offering increased resistance against removal of the clip hook  14  from the aperture  33 . 
     There is shown a side part  30  of a base  31  of a container, the side part  30  being angled generally upwardly relative to the base so as to raise the position of side wall  10  relative to the base. The side part  30  has the apertures  32  and  33  along its length. It can be seen that in the case of clip hook  14 , there is provided clearance either side of the clip hook, although in the case of underhook  15 , the associated aperture  32  is substantially the same length as the underhook such that lateral movement of the side wall relative to the side part  30  is restricted. Of course, by virtue of the shoulders  16  provided on clip hooks  14 , movement in a direction perpendicular to this, i.e. inwardly of the container, is prevented. Accordingly, once the side wall  10  has been “snap fitted” into the side part  30  of base  31  the side wall remains securely attached and only the side wall portion  12  is movable, by virtue of the live hinge  13 . 
     Referring next to FIG. 2, the side wall  10  shown in FIG. 1 is illustrated in schematic side view. The live hinge  13  is located towards a rear part  20  of the fixing portion  11  such that when the side wall portion is in an upright position as shown in solid outline at  12   a , the side wall portion lies generally flush with rear faces  21  of the clip hook  14  and underhook  15 . Braces  22  are provided to give increased strength and resistance to outward bending of the side wall. It is envisaged that the braces may be in the form of fins and one or more may be disposed along the outward face  23  of the side wall portion. The side wall portion when in an inwardly folded position is shown in dotted outline at  12   b  (braces  22  not shown). 
     Referring now to FIG. 3, a similar arrangement to that shown in FIG. 1 is illustrated, although FIG. 3 illustrates a construction at an end part of a container, rather than of a longer side wall part as shown in FIG.  1 . 
     An end support part  40  of base  31  is shown which is analogous to side part  30  as shown in FIG. 1, although end support part  40  is mounted lower relative to the base than is side part  30 . Accordingly, underhook  15  is introduced into an aperture  41  in the base  31 , where the aperture  41  corresponds to aperture  32  of FIG. 1, although aperture  41  is generally coplanar with the base, whereas aperture  32  is generally perpendicular to the base. Similarly, there is provided an aperture  42  for insertion of clip hook  14  and again, aperture  42  is located relatively lower than corresponding aperture  33  as shown in FIG.  1 . 
     Referring now to FIG. 4, there is shown a cross-sectional side view of a container having end walls and longer side walls in an inwardly folded position. For the sake of clarity, the folded end walls are not shown, although it should be appreciated that the folded end walls lie below the folded longer side walls in the space generally indicated at  50 . The base  31  is not illustrated in great detail, since the construction of the majority thereof does not form part of the present invention. 
     Longer side walls  51  are shown in an inwardly folded position, the side walls  51  having fixing portions  52  as illustrated by reference number  11  in FIGS. 1 and 2. Side part  30  of the base  31  is clearly shown, and it can be seen that by virtue of side part  30 , the longer side walls  51  are hinged relatively higher than the end walls which when folded occupy the space  50 . Upper parts  53  of the longer side walls  51  are tapered as indicated at  54  such that when in an inwardly folded position, the upper parts of the side walls  51  may overlie each other whilst presenting a generally planar outer surface  55 . The side walls  51  comprise braces  22  as illustrated in FIGS. 1 and 2 and are also provided with generally horizontally extending support ribs  56  which provide further strength to the side walls. 
     Referring now to FIG. 5, this shows a corner of the underside of the base  31 , the base comprising cross braces  60  meeting generally at right angles at nodes  61 . Apertures  32 ,  33 ,  41  and  42  are shown which receive catch hooks  14  and under hooks  15  (not shown) of fixing portions  11 . 
     It is envisaged that side walls  51  and end walls be engageable with each other by use of a catch arrangement (not shown). The catch arrangement is such that release of the catch may only be achieved by relative generally vertical displacement of the side walls  51  and end walls, and such vertical displacement may be achieved by virtue of the inherent flexibility of a plastics material from which the container is formed, and in particular the flexibility of live hinge  13 . However, it is anticipated that further flexibility may be required in order for such a catch arrangement to be disengaged, and accordingly a cut away  64  is provided towards the corner of the base which enables relative vertical movement of adjacent parts  65  and  66  of the base  31 . The flexibility given by this cut away section is sufficient to allow engagement and disengagement of the catch part on the side and end walls, but is not so great so as to enable the catch parts to become detached accidentally, for example when the container is subjected to a heavy load. If necessary, the bracing section indicated at  67  may be removed in order to provide additionally flexibility at the corner position. 
     Referring now to FIG. 6, part of the base  31  is shown, as is an inside view of side part  30  of the base, comprising apertures  33  to receive clip hooks (not shown) on a corresponding side wall, as shown generally in FIG.  1 . There are provided integrally with intermediate side part  70 , in which the apertures  33  are provided, box like formations  71  located generally within spaces  72  in the side part  30 . The box like formations are of a dimension such that gaps  73  to  75  are provided between the box like formations and adjacent parts of the side part  30 , in which may be received corresponding formations provided on the side wall, as shown in FIG.  7 . 
     Referring now to FIG. 7, there is shown a side wall  80  corresponding generally to the side wall  10  shown in FIG. 1, but wherein the under hook  15  of FIG. 1 is modified and shown at  15   a , by the provision of side supports  81  and  82  and tapered foot  83 , wherein the side supports and tapered foot are configured to locate within gaps  73 ,  75  and  74  respectively in the base side shown in FIG.  6 . 
     Since the side wall  80 , when attached to the base side shown in FIG. 6, makes greater contact with the base side, by virtue of the box like formation, than is the case when the side wall and base are configured as shown in FIG. 1, the side wall and base construction is considerably strengthened. 
     Referring now to FIG. 8, an assembled container  90  is shown having longer side walls  91 ,  92  and end walls  93  and  94  wherein in the figure end wall  93  is partially inwardly folded. The side walls  91  and  92  comprise side wall portions  95  and  96  attached to side parts  97  and  98  of the base  99  by fixing portions (not shown) as generally indicated in FIGS. 1 to  4 . 
     The side wall portions  95  and  96  are hinged to the respective fixing portions by “live” hinges provided in the regions generally indicated at  100  and  101 . 
     The end walls  93  and  94  comprise end wall portions  102  and  103  attached to lower sides of the base, one of which is shown at  104 , in the manner generally indicated in FIG.  3 . 
     Since the end walls are mounted relatively lower to the base than the longer side walls, they may be inwardly folded below the longer side walls to produce a generally flat folded container, as described later in relation to FIG.  9 . 
     The container also comprises guide posts near upper corners of the container, one of which is shown at  105  which enable the container to locate with another container above it when stacking of containers is required. 
     Referring now to FIG. 9, a similar container to that shown in FIG. 8 is shown, but of slightly different dimension. Specifically, the side walls  110  and  111  are of a height, when in an upstanding position, which is greater than half of the width W of the base  112  of the container. 
     Thus, when the side walls  110  and  111  are folded inwardly, upper parts  113  and  114  overlap each other, and the upper parts are configured to allow the upper parts to generally interfit with each other when the side walls  110  and  111  are in an inwardly folded position. In FIG. 9, the configuration is such that the upper part  113  of side wall  110  has a generally concave inner surface  115  whereas the upper part  114  on side wall  111  has a generally convex outwardly facing surface  116 . 
     The invention provides advantages over collapsible containers previously known since whilst the benefits of a one-piece container are obtained, the base and side walls are moulded separately from each other, such that moulding tools are considerably simplified, and production costs accordingly reduced. By virtue of the provision of a separately formed base, side walls of differing dimensions may be added as needs require. 
     Furthermore, should the container become damaged it is possible to replace only that part which is damaged, such as a side wall for example, rather than replacing the complete container. 
     The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.