Transport of liquid takes place to a great extent in transportable reusable receptacles that often are filled in one place and emptied at another place at greater or smaller distance from the first place. The emptied receptacles obviously weigh less than the full ones but the space they occupy is the same when the containers are permanent which e. g. is the case with steel tanks. These permanent receptacles are therefore costly and difficult to return when they are to be filled again.

In order to make good this deficiency, liquid containers have been devised that after emptying can be made to assume a highly reduced volume. These containers each consist of a flexible liner in form of a large bag and a box with wall- shaped sections hinged on a pallet-like base section. The sections can be folded up around the liner and thereby support the liquid-filled, flexible liner on all sides.

When the liner is empty, the sections can be collapsed into a stack over the base section and the liner laid flat. In this state, the container occupies relatively little space.

In the base section is normally a plate-shaped base for supporting the weight of the liquid in a filled liner. This base is typically welded onto the base section. However, this job is costly and difficult especially when the base section and its base are made of galvanised iron which often is the case.

Alternatively, the base can be riveted or screwed onto the base section but this job is time-consuming and therefore also costly.

The object of the invention is to provide a base section of the kind mentioned in the opening paragraph, that has a base which is less expensive and easier to fasten in the base section than hitherto known.

The novel and unique features according to the invention, whereby this is achieved, is the fact that along two opposite sides on the base are made vertical flanges which, in the free state of the base, have a mutual spacing at the top edges that is larger than the base is wide, that the opposite side faces of the side bars have a lower section which, at a given location along the side bars, are extending upwards from the cross bars to a height that mainly corresponds to the height of the base flanges at the same location in the longitudinal direction, and an upper section extending upwards in tandem with the lower section, that the mutual spacing between the opposite side faces of the side bars is larger than the width of the base at both the lower and the upper section whereas the mutual spacing between the two lower sections is smaller than the mutual spacing between the top edges of the flanges in the free state of the base. Thereby, the base can be pressed down into the base section in one simple operation where it then will be automatically locked.

The locking is effectively secured when the lower section passes into the upper section along a transverse edge area extending crosswise to the respective side face.

The base will be particularly inexpensive to manufacture when the flanges and the base are made in one piece of the same plate. This can e. g. take place by edge bending of the plate.

Depending on the properties of the plate material used, the place can in some cases be bent an angle of about 90° whereby the natural resilience of the plate will ensure that the spacing between the top edges of the flanges will be a little larger than the width of the base.

It is advantageous when the base forms an acute angle with each flange of between 60° and 89°, preferably between 75° and 89°, and especially between 85° and 89°.

In a preferred embodiment the two opposite side bars can each consist of a lower and an upper bar whereby the transverse edge area is formed by a piece of the underside of the upper bar extending out over the lower bar.

In order to facilitate the emptying of a filled liner, the base can advantageously be placed inclined towards an end bar in which is made an opening for a discharge spout for the liner of the container.

The base is locked in the base section extra well when other vertical flanges are made along the two other opposite sides on the base, and when said flanges are arranged to cooperate with the opposite side faces of the side bars in the same way as the first opposite sides on the base cooperate with the opposite side faces of the side bars.

The invention will be explained in greater detail below, describing only an exemplary embodiment with reference to the drawing, in which fig. 1 is a perspective view of a collapsible container with a base section according to the invention, fig. 2 is a perspective exploded view of the base section in fig. 1 with a base and a base frame, fig. 3 is a sectional view through the base, fig. 4 is a sectional view through the base frame, and fig. 5 is a view of the base and the base frame in assembled state.

The collapsible container in fig. 1 is intended for storing and transporting a liquid which during this is filled in a liner in form of a large bag of e. g. plastic. The filled liner is not dimensionally stable in itself and it is therefore supported along its total outer side by a total of six sections in form of solid walls pivotally connected to each other and, in unfolded state, forming a closed box with a chamber for containing the liner.

When the liner has been emptied, these walls can be collapsed so that they will lie stacked on top of each other (not shown). In this collapsed state, the container occupies relatively little space, and it can therefore now be returned in a convenient and economically advantageous manner to be filled again.

The six walls of the container are a base section 1, two opposite end sections 2 ; 3, two opposite side sections 45, and a top wall 6 which in fig. 1, as indicated with the arrow, is

being taken to its final position on top of the end and side sections.

The base section is constructed as a pallet with legs 7 allowing for insertion of the fork arms of a fork-lift truck (not shown) under the base section so that the fork-lift truck can lift the container.

The collapsible container is described in detail in the applicant's simultaneously filed Danish patent applications, "Collapsible container for transporting a liquid"and "Collapsible container with unbroken top wall"which both are incorporated by reference in the present Danish patent application.

The base section 1 comprises a base frame 8 with two opposite end bars 9 and 10, two opposite side bars 11 and 12, a number of cross bars 13 connecting the side bars, and a plate-shaped base 14 resting on. the cross bars (fig. 5) and inclining towards a discharge point 15 for the discharge spout (not shown) at the foremost end bar 9.

The base 14 is made of a plate of e. g. metal, such as galvanised iron. As shown in figs. 2 and 3, the plate has a bent flange 16 with top edges 17 along each side of the base.

The height h of the flanges is so much higher at the front edge of the base than at the its rear edge that the top edges will be positioned mainly horizontally when the base is in position in the base frame. At the front edge, the base furthermore has a cut-out section 18 for the discharge spout of the liner.

As shown in fig. 3, the spacing a between the top edges 17 of the flanges 16 is larger than the width b of the base, each flange 17 forming an acute angle with the base 14.

The opposite side faces 19,20 of the side bars 11; 12 have a lower section 19 extending upwards to a height h'from the inclined plane that the cross bars 13 are forming, and an upper section 20 extending upwards via a transverse edge area 21 in tandem of the lower section 19.

Just as the height h of the base flanges, the height h'of the lower section is greater at the front edge of the base than at its rear edge. At the same position seen in longitudinal direction, the height h'of the lower section is equal to or slightly higher than the height h of the base flanges.

The spacing d between the two opposite lower sections 19 is larger than the spacing c between the two opposite upper sections 20. The spacing d between the two opposite lower sections 19 is furthermore smaller than the spacing a between the top edges 17 of the flanges 16.

As shown in figs. 3 and 4, the base 14 is pushed in the direction of the arrow down into the base frame at mounting.

During this the base can pass between the two upper sections 20 as the spacing c between these is larger than the width b of the base.

Even if the spacing a between the top edges 17 of the flanges 16 is larger than the spacing c between the two upper sections 20, the flanges can still pass between these sections as the flanges 16 during this are bent resiliently in towards each other.

As the height h'of the lower section 19 at any location in the longitudinal direction is equal to or slightly higher than the height h of the base flanges 16 at the same location, the flanges 16 will now spring resiliently in towards the lower sections 19 with the top edges 17 of the flanges located under the transverse edge areas 21. The flanges now function as a

kind of barbs that effectively lock the base in the base frame 8.

When the width e of the transverse edge areas 21 correspond to the thickness t of the base flanges, a smooth and even transition is advantageously obtained between the side faces of the upper sections 20 and the internal side of the flanges 16.

As it appears, the base has now been mounted in this way in the base frame quickly and easily without any kind of costly joints, such as welded joints, screwed joints or rivet joints.

In the case shown, the side bars 11 and 12 each consist of a lower bar 22 and an upper bar 23. The transverse edge area 21 that locks the base 14 to the base frame 8 is formed by a piece of the underside of the upper bar 23 which is extending out over the lower bar 22.

In the example described above and shown in the drawing, the base was only locked along the side bars 11 and 12.

Alternatively, the base can correspondingly be locked along the end bars 9 and 10.

The base does not have to be inclined towards a discharge point in the container either. In such case, the base flanges have the same height in their entire longitudinal extent.

Furthermore, the base section according to the invention can advantageously be used for collapsible containers for transporting solid goods.