The present invention relates to containers and in particular to collapsible containers (see for example WO 98/56668 A).
Collapsible containers are known for use in many applications, including retail delivery. Fig. 1 is a highly schematic and simplified perspective view of a collapsible retail delivery container 2, having a base 4 from which four walls 6 are upstanding. In the erect condition (Fig. 1) the walls 6 extend up from the base 4 to define an open-topped container. When not in use (such as for return after a delivery) the walls 6 can be collapsed by folding them over the base in the directions of the arrows 8 (Fig. 2). In the illustrated example, the base 4 is rectangular, but it is readily apparent that the same principles can be used to design a square container and for this reason, the term "rectangular" is used herein to encompass containers with a square or rectangular base.
The invention provides a collapsible container according to claim 1.
The stacking members are preferably movable between the stacking and filling positions by means of a first type movement, wherein manual intervention causes the stacking members to undertake second type movement which results in the locking arrangements being released. The second type movement is preferably begun by manual intervention. Preferably manual intervention is required while the stacking member is moving from the filling to the stacking position or before the stacking members leave the filling position. Second type movement is preferably begun by depressing the stacking member relative to the container walls.
The container may comprise inter-engaging formations of the stacking members and walls, the inter-engaging formations serving to guide the stacking formations to first type movement except as a result of manual intervention. The guide surfaces may be fixed relative to the walls, and operable to deflect a moving stacking member to first type movement. There may be second guide surfaces carried by stacking members to ride across the fixed guide surfaces to cause stacking members to continue to execute first type movement. The stacking member may carry a land which engages the fixed guide surface to be guided along first type movement, and which enters a slot defining second type movement, upon manual intervention as aforesaid.
The stacking member may be resiliently mounted to allow the stacking member to be deflected against the resilience during first type movement, the deflection causing the fixed guide surface to be missed, to allow the stacking member to execute second type movement. The resilient mounting may comprise a resilient member which supports the weight of the stacking member and is mounted on a first wall to releasably engage a second wall when deflected. The resilient mounting may incorporate the locking arrangement, whereby deflection of the stacking member causes the locking arrangement to be released. The resilient member may comprise a spring finger having a hook member which engages the second wall when relaxed, and is disengaged when pressed by the stacking member while executing second type movement.
Alternatively, the locking arrangement may be a snap-fit arrangement and the stacking member may comprise cam means operable to force the locking arrangement to release by camming action during second type movement.
Preferably the stacking members are stacking bars. The stacking members are preferably mounted on opposed relatively short walls of the container.
An embodiment of the present invention will now be described in more detail, by way of example only, and with reference to the remaining drawings, in which:
Turning first to Fig. 3, there is shown a container 10 having a base 12 which is rectangular. Four walls 14, 16 are upstanding from the base 12, namely relatively short end walls 14, and relatively long side walls 16. The walls 14, 16 are attached by hinge arrangements 18 along their lower edge, to the base, to allow the container to collapse by hinging the walls over the base 12, generally in the manner described above in relation to Figs. 1 and 2.
The container 10 further comprises stacking members in the form of stacking bars 20 which are movable between stacking and filling positions when the container is erect, as will be described.
Fig. 3 shows the stacking bars 20 in the stacking position. Each lies across the upper mouth of the container 10 to provide support for the base of another container stacked on the container 10. In particular, the stacking bars 20 will support the base of another similar container or of a nesting container (not shown) having the same overall dimensions in plan as the container 10 (typically 400 mm by 600 mm), but designed for nesting with itself, and therefore having a base which is smaller than the overall plan dimensions, and tapering side walls. When in the stacking position of Fig. 3, the stacking bars 20 are sufficiently close to allow the base of a nesting container to bridge between the bars 20, thereby supporting the upper container.
The mounting of the bars 20 on the container 10 can be explained in more detail, commencing with reference to Figs. 4 and 5. These show one corner of the container 10. Equivalent structures are provided at each of the four corners, but only one corner will be described in detail.
Short extension leg 22 is carried at the end of the bar 20, extending generally perpendicular to the length of the bar 20 and carrying a boss 24 (Fig. 3) which runs in a generally vertical slot 26 in the side wall 16. As the boss 24 approaches the top of the slot 26, the bar 20 may swing over to the position shown in Figs. 4 and 5, with the end of the bar 20 supported in a seating indicated generally at 28, provided on the side wall 16. This provides support to bear the weight of a second container sitting on the bar 20,
The bar 20 can also be manipulated to a second, filling condition illustrated in Fig. 6, in which the bar 20 has moved clear of the mouth of the container 10. This improves access to the container, for instance during filling, and is thus termed the "filling" position, but it is to be understood that the bars could be moved to this position for other reasons.
The filling condition of Fig. 6 is achieved from the stacking condition of Figs. 3 and 4 by lifting the bar 20 and swinging it to bring the leg 22 to a position approximately vertical and below the bar 20, and then allowing the boss 24 to run down the slot 26 until the position of Fig. 6 is reached.
It is important to note from Fig. 6 that in the filling condition, the boss 24 is not at the lowermost extremity of the slot 26. The significance of this feature will be explained below.
The boss 24 is located to run in the slot 26, as has been described, and is retained therein by a flange 34 (Fig. 7A) which captures the leg 22 between the flange 34 and the wall 36 in which the slot 26 is formed. The flange 34 and the wall 36 together form a short projection from the plane of the end wall 14, as can be seen in Fig. 4.
A guide slot 38 is formed near the top of the flange 34, opening away from the side wall 16 and leaving a relatively small nose 40 of flange material above the guide slot 48. The nose 40 has a flat upper surface 42 and a sloping forward surface 44 forming a lead-in surface, for reasons to be described. The guide slot 38 is slightly sloped to be lower at its inner end 46 than at its mouth 48.
The guide slot 38 and nose 40 are provided to inter-work with a land 5 0 carried by the leg 22 at a position indicated in Fig. 7, and clearly visible in Fig. 4. The land 50 is shaped so that when the bar 20 is in the filling position (Fig. 7), the land 50 opposes the nose 40, having a sloping under-surface 52, rounded at 54 to meet the upper surface 56 of the land 50. The height of the rounded edge 54 is slightly higher than the height of the front edge of the nose 40 when the bar 20 is at rest in the stacking position (as illustrated in Fig. 7), so that when the bar 20 is pushed horizontally, the land 50 will be pushed against the nose 40, engaging the under-surface 52 with the lead-in surface 44 and causing the land 50 to ride up the lead-in surface 44 and across the upper surface 42, so guiding the bar 20 to move out to the stacking position illustrated in Figs. 3 to 5. In doing so, the bar 20 will pass through an intermediate position illustrated in Fig. 8, in which the boss 24 has risen up the slot 26 and the land 50 has ridden along the upper surface 42. The bar 20 can then be picked up and moved to the seating 28.
It will readily be understood from the above, that when the bar 20 is in the stacking position and is pushed out toward the end wall 14, the reverse operation can occur, in which the land 50 rides over the upper surface 42 until dropping down behind it, to the position illustrated in Figs. 7 and 7A.
In normal use of the container, while the container remains in the erect condition, the bars 20 will be moved between the stacking and filling conditions, as required, in the manner described above. During this use, the walls 14, 16 remain locked together in a manner which can now be described in more detail, as follows. Again, only the structures at one corner will be described; equivalent structures are provided at each of the four corners of the container.
The flange 34 and wall 36 which extend from the plane of the end wall 14 are accommodated in a rebate 58 toward the top of the side wall 16, when the container 10 is erect. The lower edge 60 of the rebate 58 carries a spring finger 62 which extends under the lower edge of the flange 34 and carries a hook portion 64 which serves to engage behind the flange 34, preventing the side wall 16 hinging down over the base 12. The hook portion 64 also provides a support on which the lowermost extremity of the leg 22 will sit when the bar 20 is in the filling condition, so sharing the weight of the bar 20 with the corresponding structures at the other end. The resilient strength of the spring finger 62 is sufficient to hold the land 50, relative to the nose 40, at the position described above. However, manual intervention by way of downward force applied to the bar 20, will be transmitted along the leg 22 to cause the spring finger 62 to flex downwardly, as illustrated in Figs. 9 and 9A. This allows the land 50 to move down, relative to the nose 40. A position is eventually reached at which the rounded edge 54 of the land 50 is clear below the front edge of the nose 40, so that the land 50 can move into the slot 38 (Figs. 10 and 11). The result of this downward movement is that the hook portion 64 is pushed below and clear of the lower edge of the flange 34, thus unlocking the side wall 16 from the end wall 14, and allowing the side wall to be folded down over the base 12. As the side wall folds down, the finger 62 moves clear of the flange 34, as seen in Fig. 10 and 11.
A locking arrangement of the type described above is provided at each of the four corners of the container 10, with each bar 20 serving to disconnect a locking arrangement at each end, in the manner described. Thus, by downward pressure on both bars 20, all four locks can be released, allowing the side walls 16 to fold down over the base 12, and then the end walls 14 to fold down over the side walls, to complete the collapse of the container 10.
In order to erect the container, the reverse sequence is executed, with the end walls 14 being first raised, and then the side walls 16 being raised until the spring fingers 62 engage the lower edges of the flanges 34. The hook portions 64 will deflect to ride under the flanges 34 and then snap behind them to lock the side walls 16 in place. As the spring finger 62 snaps past the flange 34, it will engage the lower end of the leg 22, slightly lifting the bar 20, to resume the filling position of Fig. 7.
In the arrangements described above, movement of the stacking bar 20 acts directly, by means of the extension legs 22, to press and release the spring finger 52. Figs. 12 and 12A illustrate an alternative arrangement in which indirect action is achieved, as set out below. Many features illustrated in Figs. 12 and 12A correspond closely to features of the other Figures and are thus given the same reference numerals.
In this example, the stacking bars 20 are again mounted by means of extension legs 22 which extend down between a flange 34 and a slot 36 in which a guide slot 38 accommodates a boss 24. The flange 34 and wall 36 are again accommodated in a rebate 58 in the side wall 16, and the lower edge 60 of the rebate 58 again carries a spring finger 62, which is able to extend under the lower edge of the flange 34 to hook behind it and thus lock the walls 14, 16 together, preventing the container from collapsing.
In this example, the weight of the stacking member 20 is supported by a resilient ledge 65 on which the lower end of the extension leg 22 rests.
The hook portion 64A, shown in Fig. 12A, is much more rounded than the hook portion 64 of earlier Figures. Consequently, whereas the hook portion 64 cannot be released from the flange 34 without being forced downwardly, the rounded hook portion 64A can be pulled away from the flange 34 by the application of adequate force in a generally horizontal direction, (tending to fold down the wall 16). This force is provided, in use, by means of a cam arrangement, as follows.
Comparison of Fig. 12 and Fig. 7, for instance, illustrates that in Fig. 12, the leg 22 is carrying a stub 66 which extends generally horizontally away from the end wall 14. The stub 66 has a sloping lower face 68. The stub 66 projects out from between the flange 34 and wall 36 and into a slot 69 formed in the edge of the wall 16. The slot 69 has a sloping floor 70.
In use, when the container is to be collapsed, the stacking bar 20 is pushed down to release the walls, generally in the manner described above, and against the resilience of the ledge 65. The downward force applied to the stacking bar 20 presses the bar 20 and the legs 22 down against the resilience of the ledge 65, allowing the land 50 to move clear below the nose 40, as described above. The stub 66 will reach a position at which the lower face 68 bears on the floor 70. The sloping nature of both surfaces causes a camming action which converts the downward force on the slacking bar 20 into a generally horizontal force pushing the wall 16 to fold down. As downward force on the stacking bar 20 increases, this horizontal force increases until eventually, the finger 62 is snapped from under the flange 34, releasing the wall 16 to collapse. As it does so, the stub 66 leaves the slot 69 through an exit aperture at 72.
When the wall 16 is subsequently raised again, the rounded hook portion 64A can snap under the flange 34 to lock the walls together again. The stub 66 re-enters the slot 69 and thereafter assists in bracing the joint to hold the side and end walls together.
There are thus provided containers which can be operated to provide stacking with a similar container or a nestable container, using bars which can be moved substantially clear of the mouth when not required for stacking, and which can be collapsed, when not required to contain goods, but which is secure against collapse except when deliberate manual intervention occurs.
Many variations and modifications can be made to the container described above, without departing from the scope of the invention. In particular, many different sizes, shapes, relative sizes and other design details can be varied. It is envisaged that the container can be made as a set of plastics components, such as by injection moulding, for subsequent assembly.
References above to directions are solely for reasons of clarity. However, it is expected that in normal use, the container will have the orientation shown and described.