Container for fluids, solids having flow properties of the like

A container for fluids, solids having flow properties or the like, and comprising a box of a conventional packing material, such as cardboard, a supporting frame of a material that is stronger and of greater dimensional stability, such as wood, and an inner bag (4) of a conventional packing material, such as a flexible synthetic plastics, for containing the material being packed. The container comprises four opposed frame sidewalls (1, 2), each including a pressure face (8, 13) extending the full height of the respective sidewall. A sleeve (3) of a relatively thin material having a high tensile strength and relatively low stretch, such as paper, a ribbon fabric of plastics, or the like, is provided to extend on the outside of, and around, the pressure faces (8, 13), and from one side of a pressure face (8, 13) substantially direct to the adjacent side edge of the pressure face (13, 8) of the adjacent sidewall, thus cutting the frame corners.

This invention relates to a container for fluids, solids having flow 
properties or the like, of the kind comprising a box of a conventional 
packing material, such as cardboard, a supporting frame of a material that 
is stronger and of greater dimensional stability, such as wood, and an 
inner bag of a conventional packing material, such as a flexible synthetic 
plastics, for containing the material being packed. 
With a container of this kind, problems may occur as a result of bulging of 
the box sidewalls, in spite of the provision of the supporting frame. 
Bulging has various disadvantages. Major disadvantages are a decrease in 
effectively utilizing transport volume, and an increase in the risk of 
damage to the container. The reduction in transport volume to be 
effectively used is a result of the fact that bulges prevent boxes being 
placed in close surface-to-surface contact with each other, so that voids 
are formed between boxes placed next to each other. Especially in the case 
of long transport routes, for example, by sea, this can be a considerable 
disadvantage which greatly increases the cost of transport, certainly in 
the case of materials to be shipped under particular conditions, for 
example, in refrigerated spaces. The increased risk of damage is a result 
of the bulging walls, which are often made of a less strong material, for 
example, cardboard, projecting outside of the supporting frame. Damage to 
that wall may rapidly lead to damage to the inner bag as well, which is 
pressed against the box wall by the packed material, so that the materials 
packed are released and become lost. To prevent these adverse effects the 
art has already resorted to measures which make the manufacture of the 
container considerably more complicated and expensive, such as covering 
the supporting frame with sheeting material of relatively high strength, 
such as wood products, or making double walls with cavities between them, 
which it is true reduce the risk of damage, but reduce the effective 
shipping space and in addition complicate the design and manufacture of 
the box and make these more expensive. Covering the supporting frame with 
relatively rigid and strong members does reduce the useful shipping space 
to a lesser extent, but is considerably more expensive and in addition 
adds to the weight of the container, which is less desirable from the 
point of view of shipping. 
It is an object of the present invention to improve a container of the kind 
described in such a manner as to produce a reliable, non-bulging 
construction by a small number of relatively inexpensive means, and 
minimizing ineffective shipping volume. 
This is achieved, according to the present invention, by providing a 
container of the kind described which is characterized in that four 
opposed frame sidewalls each include a pressure face extending the full 
height of the respective sidewall but having a width less than that of the 
respective sidewall, and a sleeve of a relatively thin material of high 
tensile strength and relatively low stretch, such as paper, a ribbon 
fabric of plastics, or the like is provided to extend on the outside of, 
and around, the pressure faces, and from one side of a pressure face 
substantially direct to the adjacent side edge of the pressure face of the 
adjacent sidewall, thus cutting the frame corners. 
By virtue of these measures, a construction is obtained which when filled 
with a fluid tensions and stiffens itself owing to the pressure exerted by 
the material introduced into the inner bag. This beneficial effect is the 
result of the provision of the sleeve, which limits and correlates the 
outward deflection of the pressure faces. The circumference of the sleeve 
in loaded condition dictates how far the pressure faces can move outwards, 
whereby the sleeve is only subjected to tensile loads and thus can be made 
from a light and thin material, such as paper. Voids only form in the 
corners of the box, that is to say, at the places where the sleeve extends 
cutting the frame corners. These corner regions are as small as possible 
and distributed as effectively as possible in a further embodiment of the 
present invention, in which the pressure faces leave, on their two sides, 
equal parts of the frame sidewalls uncovered. If desired, stiffening 
members, for example, for enhancing the stacking strength, may be provided 
in the corners. 
The pressure faces are to be seen as determinative of the outer faces of 
the container. To keep the outer faces flat, the pressure faces may take 
the form of relatively rigid, non-budging elements. It is true that one of 
the disadvantages of the known stiffening constructions is again partly 
introduced, namely the use of a more expensive, heavier material. 
Preferably, therefore, and in accordance with a further embodiment of the 
present invention, the pressure faces are made of a thin material of high 
tensile strength and relatively low stretch, such as paper, which pressure 
faces are kept at least locally spaced from the sleeve by interposed rigid 
support members, for example, wooden strips. 
In a further advantageous manner, the rigid support members form the 
horizontal and vertical parts of the support frame in a further preferred 
embodiment of the invention, in which the frame comprises four basically 
independent frame walls each composed of a pressure face and at both the 
top and the bottom of the pressure face rigid frame edge members 
projecting from the pressure face on opposite sides thereof a distance 
corresponding with the desired peripheral dimensions of the frame. This 
construction is rendered possible by the use of the sleeve, which forms 
the connecting element for the four pressure faces and hence the support 
frame sidewalls. This embodiment has the further, additional and 
particular advantage that the container can be supplied in flat collapsed 
condition at the site where the container is to be filled, and no 
carpentry work is needed to obtain a firm support frame. To the extent 
this has not yet been done, the support frame sidewalls only need to be 
shifted into the sleeve; the desired strength of the whole is 
automatically obtained as the container is being filled. 
When, in accordance with a further embodiment of the invention, at both the 
top and the bottom, one pair of opposed frame edge members have such a 
length that their end faces abut with the inner sides of the other pair of 
opposed frame edge members, the container can be set up or unfolded into a 
first rough form, which facilitates its filling to produce the ultimate 
desired form and strength. Both this initial shaping and the realization 
of the ultimate desired shape during filling is influenced in an 
advantageous manner when, in accordance with a further embodiment of the 
present invention, the ends of said one pair of frame edge members can 
slide along the inner sides of said other pair of frame edge members. To 
optimize the pattern of forces it is preferable, in this embodiment, that 
the support members connected to said one pair of frame edge members are 
secured thereto on the inside thereof and the support members connected to 
said other pair of frame edge members are secured thereto on the outside 
thereof. Owing to these features, the pressure faces carrying said one 
pair of frame edge members are pressed outwardly during filling, and the 
pressure faces carrying the other pair of frame edge members are loaded 
inwardly by the sleeve, the result of which is that, as the container is 
being filled, the frame edge members are going to reach their ultimate 
desired position and finally, in their end position determined be the 
sleeve, are positively pressed together by the same sleeve, and thus are 
locked in a rectangular bracing, which basically does not require fixing 
the frame edge members by fastening means. 
In order to enhance the stacking strength and to reduce the risk of damage 
to the bottom of the container, it may in certain cases be preferable 
that, at the bottom, the frame edge members of said other pair are each 
secured to a plate-like bottom of a rigid material, such as wood. In a 
construction with support frame walls which are independent from each 
other and have sliding frame edge members, the plate-like bottom can be 
placed in position at any desired moment without adversely affecting, or 
preventing, the desired operation of the container during filling. 
Naturally, a plate-like cover can further be provided after the completion 
of the filling operation.

In order that the construction and operation of the various parts of the 
container may be better understood, the container is shown in the drawings 
without a box which normally, at least in the shipping situation, envelops 
it, which is made of a conventionaI packing material, such as cardboard or 
the like. Forming part of the container shown, therefore, is a universally 
known rectangular box which can be made in any given known manner, and is 
therefore not described in any further detail herein. 
The parts of the container shown in the drawings comprise a first pair of 
opposing walls 1, a second pair of opposing walls 2, extending at right 
angles to the first pair of walls 1, a sleeve 3, an inner bag 4 and a 
bottom plate 5. 
Walls 1 are each composed of an upper frame edge member 6 and a lower frame 
edge member 7, which all have a length corresponding to an inner main 
dimension of an enveloping box, in the present case the shorter legs, as 
viewed in cross-section of the box. Extending vertically between each pair 
of upper and lower frame edge members is a pressure face 8, built up from 
two support members 9, between which a layer 10 of paper is tensioned. The 
support members are positioned on the outsides of the frame edge members 6 
and 7 and secured thereto with the layer 10 between them. 
Walls 2 are also composed each of an upper frame edge member 11 and a lower 
frame edge member 12, all having a length which together with the 
thickness of the two frame edge members 6, 7, corresponds with an inner 
main dimension of an enveloping box, in the present case the longer leg, 
as viewed in cross-section, of the box. Extending vertically between each 
pair of upper and lower frame edge members is a pressure face 13, built up 
from two support members 14, between which a layer 15 of paper is 
tensioned. Support members 14 are secured to the inner sides of the frame 
edge members 11 and 12, with layer 15, in turn, being secured to the 
inside of support members 14. 
FIG. 2 shows tow different situations. In the upper half, the starting 
position prior to filling, and in the lower half, the situation after 
filling are shown. With particular reference to the upper half of FIG. 2, 
it is noted that the four walls 1 and 2 are basically independent of each 
other and of sleeve 3, which means that the four walls can in fact each be 
removed independently from sleeve 3, so that the container can be supplied 
to the filling site in fully flat condition, which shipping advantage is 
not nullified by the enveloping box, which, as is well known, can also be 
supplied in flat condition. With particular reference to FIG. 2, there 
will now follow a more detailed description of what happens with the 
container as it is being filled. 
Depending on the condition in which the container is supplied to the 
filling site, it should first be set up until the position shown in the 
upper half of FIG. 2 is realized. Examples of operations to be performed 
for this purpose are inserting the four independent walls 1 and 2 into the 
sleeve, placing the frame edge members 11 and 12 at right angles to, and 
within, the frame edge members 6 and 7, placing the inner bag 4 in the 
space surrounded by walls 1 and 21 and, if desired, fastening the lower 
frame edge members 7 to the bottom plate 5. 
When the container has thus been set up, its filling can be started by 
introducing the material being packed into the inner bag 4. Owing to the 
material introduced, the inner bag 4 is stretched and thus comes into 
contact with the pressure faces 8 and 13 as well as with sleeve 3. 
According as more material is contained within inner bag 4, this bag, 
which has hardly, if at all, any stiffness of its own, tends to move 
further outwardly, the result of which is that in particular the pressure 
faces are loaded. As a consequence, the pressure faces 13 will move from 
the position shown in the upper half of FIG. 2 to the position shown in 
the lower half, whereby the sleeve 3, which initially extended loosely 
around walls 1 and 2, is gradually being tensioned until the position 
shown in the lower half of FIG. 2 is reached, in which the frame edge 
members 6 and 11, and 7 and 12, form a rectangular upper and lower support 
frame, and sleeve 3 is tautly in its tensioned position and in fact cannot 
be deflected any further. In that position, the pressure faces 8 and 13 
have been deformed into a slight outward deflection, as shown in the lower 
half of FIG. 2, without, however, forming any objectionable bulges outside 
the circumference of the container. 
The position shown in the lower half of FIG. 2 can be reached from that 
shown in the upper half by virtue of the ends of the frame edge members 11 
and 12 sliding along the inner sides of frame edge members 6 and 7. In 
this way, the pressure faces 13 are pressed outwardly during filling, 
which outward movement is counteracted, from a given moment, by the sleeve 
as it is gradually brought under tension, and which in turn is limited in 
its possibilities of movement by the support members 9 connected to the 
frame edge members 6 and 7, which are kept at a fixed spaced 
interrelationship by the frame edge members 11 and 12. During the 
deflection of the pressure faces 13, the frame edge members 6 and 7 are 
pulled together by the tensioned sleeve 3 which, in this way, provides for 
a stiffening of the container which in principle is composed of loose 
parts. As shown in the lower half of FIG. 2, the inner bag 4 will 
ultimately closely conform to the shape of the pressure faces 8 and 13 
and, between these pressure faces, the shape of sleeve 3. When the 
container has been filled to completion, the inner bag is closed in a 
fluid-tight manner, which is effected by sealing or any different method 
depending on the material of the inner bag. There is thus obtained a 
container which, except for four small corner regions, can fill a 
rectangular cross-section without exhibiting bulges. It will further be 
clear that the container shown in the lower half of FIG. 2 can be shifted 
into an enveloping rectangular box of suitable dimensions without any 
problems, which box may be of relatively light construction because it 
need not absorb any forces from the packaged material, which in fact are 
fully taken up in the construction shown in FIG. 2. It will thus also be 
clear that the box will not be going to exhibit any bulges either, so that 
optimum stacking in a shipping space can be effected. Support members 9 
and 14, and frame edge members 6, 7, 11 and 12 will generally impart 
sufficient stiffness and strength to the container for it to withstand 
stacking forces. In cases where additional reinforcement would be 
required, this can be realized in a simple manner by sliding such 
reinforcements and rigidifications into the corner regions, which remain 
free, after filling the container. 
Naturally, many modifications and variants are possible without departing 
from the scope of the invention. Thus the frame edge members may all be of 
shorter length, for example, not longer than the width of the associated 
pressure face, whicb in turn could consist of a plate-like member, so that 
the construction need not necessarily present separate support members and 
frame edge members. Furthermore, a plate-like cover member, similar to the 
plate-like bottom member 5 could be provided. This latter is of course 
also possible for that matter, in the construction shown in the 
accompanying drawings. Furthermore, the various parts can be made of any 
given suitable material. If desired for considerations of strength and 
stiffness, it is equally possible to provide further intermediate frame 
edge members between the upper and lower frame edge members. The same 
applies of course with regard to the support members.