A collapsible container

Abstract

 A collapsible container especially for the containerized shipment of bulk goods. The container comprises a pallet-like base (2), four walls members (4), the lower horizontal edges of which are provided with first locating means (24) engaging, in the assembled state of the container, second locating means (22) disposed in the base (2) adjacent the periphery thereof, abutment means (10,12) along the vertical edges of the wall members (4) to define and delimit the verticality of the walls in the assembled state of the container. At least some of the first and second locating means (22,24) are engageable and disengageable only when the walls are in an outwardly tilted position relative to the base. Means (32) are provided to maintain the integrity of the container when assembled.

Description

[0001] This invention relates to a collapsible container.

[0002] Containerization is increasingly becoming the accepted and, indeed, the only economically viable mode of long- distance transport of goods. As with this system costs are a function of size and volume rather than of weight, packaging such as boxes and crates must be non-returnable, since the return shipment of empties would be even costlier than the waste of these millions of containers.

[0003] The problem to be solved by the present invention is to provide a reusable, stackable container that is also collapsible and, in the collapsed state, takes up a small proportion of its space requirements when fully assembled. Such a container must also be adjustable for use with forklift trucks. The return shipment of such containers in the collapsed state would therefore be economically feasible.

[0004] The problem is solved in accordance with the present invention by the provision of a pallet-like base, four wall members the lower horizontal edges of which are provided with first locating means engaging, in the assembled state of said container, second locating means disposed in said base adjacent the periphery thereof, abutment means along the vertical edges of each of said wall members to define and delimit the verticality of said walls in the assembled state of said container, at least some of said first and second locating means being engageable and disengageable only when said walls are in a tilted position relative to said base, and means to maintain the integrity of said container when assembled.

[0005] Containers embodying the invention will now be described by way of example, with reference to the accompanying diagrammatic drawings, in which:

Figure 1 is a perspective view of a first container embodiment according to the invention;

Figure 2 is a front view of the first embodiment;

Figure 3 shows a top plan view of the first embodiment;

Figure 4 is a cross-section on line I-I of Figure 1;

Figure 5 is a fragmentary top plan view of matching edges of two adjacent walls;

Figure 6 is a cross-section on the line II-II of Figure 1, with a hooping strap in position;

Figure 7 is a cross-section of the container of Figure 1, showing the final position of a hooping strap;

Figure 8 is a top plan view of the assembled walls of a second embodiment of container according to the invention; and

Figure 9 is a top plan view of the base of the embodiment of Figure 8.

[0006] The basic container is bedt understood from Figure 1, where there is seen a pallet-like base 2, on which are detachably mounted four walls 4, one of which is shown in a tilted position characteristic of the way in which, as will be explained below, the container is assembled as well as collapsed. Grooves or passages 6 extend across the underside of the base 2 in two directions and serve to accommodate the forks of fork trucks. The lower edges 8 of the base 2 are stepped or otherwise recessed, to allow the containers to be stacked, and each wall 4 incorporates one of the corners 10 of the assembled container, and is provided with abutment means along its vertical edges 12, which, in conjunction with matching abutment means of adjacent walls, define and delimit the verticality of the walls 4 in the assembled state of the container (see

[0007] Figure 5). Connecting each wall 4 to the base 2 are locating means, not shown in Figure 1, which will be described further below, as will be the hoop-like straps which are used to maintain the integrity of the container once assembled.

[0008] Details of the container are shown in Figures 1 to 6.

[0009] Both the base 2 and the walls 4 are plastics mouldings, preferably of a thermoplastic material, for example, polyethylene. As is best seen in Figure 4, both the walls 4 and the base 2 are hollow, mechanical strength being provided by reinforcing features which, in the walls 4, are in the form of a plurality of stays 14 which, at selected points, connect the inner and outer faces of the walls 4 and are of course an integral part of the moulding. Air spaces 16 between the inner and outer faces of the walls 4 also serve for thermal insulation, especially for frozen goods, for example deep-frozen fruit-juice concentrates which are transported in plastics bags. Similar, rib-like, stiffening means 18 can be seen in the base 2 (see also Figure 3). In addition, the base 2 is also provided with diagonally extending reinforcing members in the form of moulded-in metal tubes 20 (Fig.3).

[0010] Locating means for keeping the assembled walls in position relative to the base are shown in Figures 3 and 4. Each edge portion of the base 2 is provided with two female-type locating members in the form of slots 22, in which engage, in a manner to be explained further below, two male-type locating members in the form of projections 24 integral with the lower, horizontal, edge of each wall 4.

[0011] The cross-section of these slots and projections 22 and 24 is shown in Figure 4. That wall defining the slot 22 which is closer to the edge of the base 2, is provided with a bulge 26 of a substantially semi-circular cross-section, which reduces-the clear cross-section of the slot 22 to a width b. A wall portion 28 of the projection 24 is complementary to the bulge 26, while another wall portion 30, is also of a part-circular cross-section, all the circular arcs being substantially concentric. If the overall width B of the projection 24 is now measured in a direction perpendicular to the plane of wall 4, it is seen that B > b. In other words, the wall 4 can neither be detached from, nor attached to, the base 2 in a direction perpendicular to the base 2. In order to withdraw the projection 24 from, or introduce it into, the slot 22, the wall 4 has to be tilted, as indicated in Figure 1.

[0012] The walls 4 having been mounted on the base 2 in the above described manner, they now have to be tightly clamped together, so that the container will not disintegrate under the pressure, acting on the inside faces of the walls 4, of its contents. This clamping force is supplied by hoops prepared from ordinary hooping or baling straps 32, a short length of which is shown in Figure 2. To ensure proper location of these hoops, each wall 4 is provided on its outside with a number of spaced, shallow grooves 34 (in the embodiment shown, three grooves) which, upon assembly of the four walls 4 form continuous grooves of a width appropriate to the width of the baling strap 32. After the three hoops have been applied, the container is ready for use.

[0013] For greater safety, however, the straps 32 are not merely wound around the container as would be the standard baling procedure, but are preferably applied as illustrated in Figure 7, where it is seen that, around the corners, the strap 32 is guided over the outside of the container, while between the corners, the strap passes over the inside faces of the walls. This is facilitated by the provision of window-like openings 36, seen to best advantage in Figure 6, through which the strap 32 can be passed from the outside groove 34 to an inside groove 38 and back again through the next opening 36. With this arrangement, the hoops can never slide down the walls 4 when becoming loose for some reason. In particularly critical applications it is of course possible to apply two sets of three hoops each; a first set according to Figure 7, and a second set, on top of the first set, on the outside of the container.

[0014] To collapse the containers, the hoops are simply cut and discarded, after which the walls 4 are tilted outwardly and pulled off the base 2.

[0015] An optional component of the container is a lid,not shown, seatable in a defined position on the rim of the assembled container.

[0016] In the second embodiment, illustrated in Figures 8 and 9, the integrity-of the assembled container is further enhanced by mechanical interlocks which will keep the four walls 4 together even without the help of the baling straps 32.

[0017] In Figure 8, the four walls 4 are seen in the assembled position. The four walls 4 are identical in shape, and each also possesses two of the male-type locating members in the form of projections 24 shown in Figure 4, being integral with the lower horizontal edges of the walls 4. The profile of the vertical edge portions is clearly seen in Figure 8. One of the vertical edge portions 40 of each wall constitutes one of the corners 10 of the container, the other edge portion 42, is stepped down to two levels, forming a projection 44 which fits and engages a matching recess 46 in the corner-constituting edge portion 40 of the neighbouring wall 4, and a recess 48 into which fits, and which is engaged by, a projection 50 at the extreme end of the edge portion 40. It is thus seen that the four walls of the container are mechanically interlocking and, once assembled, cannot be separated by pressure from the inside of the container.

[0018] Collapsing of the container is only possible by vertically sliding or pulling out two oppositely located walls 4, after which the remaining pair of walls 4 can be tilted outwardly and pulled off the base 2 as described in conjunction with the previous embodiment. It-will be remembered, however, that the female-type locating members in the form of slots 22 into which engage the male-type members or projections 24 of the walls 4 are precisely meant to prevent such vertical pulling out of the walls 4 (see Figure 4). To overcome this difficulty, the base 2 has been slightly modified, as shown in Figure 9. While two oppositely located pairs of slots 22 have been left unchanged, the other two pairs 52, have been widened by eliminating the bulge 26 to a width at least equalling B (Figure 4), facilitating removal of the walls associated with these modified slots 52 by pulling them out in a direction perpendicular to the base 2.

[0019] The assembly procedure is the reverse of the collapsing procedure already described: two opposed walls 4 are introduced with their projections 24 into the slots 22, with the walls 4 themselves as yet in the tilted position, after which the walls are righted. What remains to be done now is to slide the remaining two walls 4 drawer- like into the profiled vertical edge portions of the now upright first pair of walls 4. The projections 24 of the thus slid-in two walls will, as explained, freely enter the modified slots 52, serving now as they do only as tenons taking up part of the outwardly directed pressure on the walls 4.

[0020] As the projections 24 of all walls 4 fit both the slots 22 and the modified slots 52, appropriate markings are advantageously provided on the lateral faces of the base 2 to indicate, in the assembled state of the container, below which pair of walls 4 the modified slots 52 are located, that is, which pair of walls 4 can be slid out vertically as a first step to collapsing the container.

[0021] To prevent bulging of the .walls 4 of the container, especially when used for materials with little or no internal friction such as liquids, in which the walls have to take up the full hydrostatic pressure exerted by the charge, it is possible to introduce reinforcing members into the walls, either during or after the moulding process. Such a reinforcing member 54 is indicated in Figure 8 in one of the walls 4. If such reinforcement is required, all four walls are provided with such members 54.

[0022] While primarily intended for the shipment of frozen juice concentrates, the container hereinbefore described are obviously also suitable for solids such as paste goods, cheese, and granular bulk goods of every kind.

Claims

1. A collapsible container
characterized by
a pallet -like base (2), four walls members (4) the lower horizontal edges of which are provided with first locating means (22) engaging, in the assembled state of said container, second locating means (24) disposed in said base adjacent the periphery thereof, abutment means along the vertical edges of each of said wall members to define and delimit the verticality of said walls in the assembled state of said container, at least some of said first and second locating means (22,24) being engageable and disengageable only when said walls are in a tilted position relative to said base, and means (32) to maintain the integrity of said container when assembled.

2. A container as claimed in claim 1,
characterized in that
said first locating means are male-type locating members (24) and said second locating means are female-type locating means.

3. A container as claimed in claim 2,
characterized in that
said male-type locating members (24) are in the form of projections integral with the lower edges of said walls, having one face (28) provided with a concavity of a substantially semi-circular cross-section and an opposite face having a convexity of substantially semi-circular cross-section, both cross-sections being substantially concentric, and in that at least some of said female-type locating means are in the form of slots disposed along at least part of the periphery of said base, the slot walls closer to the edge of said base being provided with a longitudinally extending bulge (26) of a substantially semi-circular cross-section of a radius substantially identical with the radius of the concavity of said male-type locating members (24).

4. A container as claimed in claim 2,
characterized.. in that
at least some of said second locating means are in the form of slots (22) disposed along at least part of the periphery of said base (2) and in that both longitudinal walls defining the width of said slot are plane and substantially parallel.

5. A container as claimed in any one of the preceding claims, characterized in that it is made of plastics mouldings.

6. A container as claimed in any one of the preceding claims, characterized in that the lower edges of said pallet-like base (2) are recessed (at 8) to enable said containers to be stacked.

7. A container as claimed in any one of the preceding claims, characterized in that the underside of said pallet-like base (2) is provided with a plurality of grooves or other passages (6) to accommodate the forks of fork trucks.

8. A container as claimed in any one of the preceding claims, characterized in that said pallet-like base (2) is provided with moulded-in reinforcing members (20).

9. A container as claimed in any one of the preceding claims, characterized in that said integrity-maintaining means (32) is at least one hoop-like strap (32), applied to said container after the assembly thereof and removed from said containemprior to the collapsing thereof.

10. A container as claimed in any one of claims 1 to 8, characterized in that said integrity-maintaining means is constituted by the vertical edge portions (40) of said walls (4) which edge portions are adapted to interlock with one another.

11. A container as claimed in claim 8, characterized in that at least one shallow groove (34) is provided in the faces of said container walls to accommodate and position said hoop-like strap 32).

12. A container as claimed in claim 9, characterized in that at least two window-like openings (36) are provided in at least one of said container walls (4), whereby said strap can be threaded through one of said openings from the outside face of said container wall to the inside face thereof, and through the second of said openings (36) from the inside face of said container wall back to the outside face thereof.

13. A container as claimed in any one of the preceding claims, characterized by reinforcing members (54) located in said walls.

Drawing