EP0106821B1

EP0106821B1 - Container for transport, storing and handling of liquids

Info

Publication number: EP0106821B1
Application number: EP19830850265
Authority: EP
Inventors: Helge Engström
Original assignee: SWEDEBOARD VRENA AB
Current assignee: SWEDEBOARD VRENA AB
Priority date: 1982-10-11
Filing date: 1983-10-05
Publication date: 1987-04-01
Also published as: SE8205779D0; SE8205779L; DE3370610D1; EP0106821A1

Description

The present invention relates to containers for transport storing and handling of liquids according to the preamble of claim 1 (known from US-A-4 165 024), and more to a container shaped as a cylinder and made of sheet material, placed edgeways on a load transporting platform and containing a liquid-proof insert in theform of a plastic sack or similar.
The basic type of container to which the present invention refers is clear from e.g. Swedish patent specification Ser. No. 347.716. This known container consists of a cylinder of sheet material such as fibre board, cardboard, plastic or similar which cylinder is placed edgeways on a load transporting platform such as a pallet, around a bottom located upon this platform. A conventional lid closes the end of the cylinder facing upwards.
Although it has been suggested in said specification that such a known container should be possible to use also for handling of liquids, it has, however, been obvious that this involves not expected problems and up to now, the known container has not successfully been useful for liquids. It has namely been realized that the shock impacts which appear when the liquid within the container is subjected to movements during the transport of the container, are so powerful that the thin cylinder cannot resist such impacts but breaks.
A container of the type mentioned is cheap and is of a low weight empty, it is good for the environment and can easily be refused e.g. by firing. If any portion of the container is broken such as by outer mechanical damages this portion can easily be substituted without any special measures or tools while remaining portions of the container can be further used in the condition in which they are. Regardless of whether the container is used as a container of disposable type or a container to be used several times it is of such evident advantages that an enlargement of the use thereof is highly desirable.
Another example of prior art containers according to the preamble of claim 1 is disclosed in US-4 165 024. The container described therein comprises a cylindrical side wall structure and a disposable interior lining.
The problem of handling liquids within the container of the type mentioned is, accordingly, to get the cylinder wall to resist the shock impacts appearing when the liquid within the container is subjected to movements. The unsophisticated solution of this problem would apparently be a reinforcement of the cylinder wall in some way, such as by increasing the thickness of the wall, by stretching a band around the _'cylinder or by arranging reinforcing ridges.
However, it has been shown that none of the mentioned measures has given the desired result but either given rise to other problems such as difficulties in forming the thicker material to a cylinder or also been too expensive to be a useful alternative.
The object of the present invention is to remove the above problems. This object is reached by a container of the type referred to in the characterizing part of claim 1.
The invention is closer described in the following with reference to the attached drawing showing a partly sectioned view of a container in accordance with the invention.
The container 1 shown in the drawing consists of a cylinder 2 of sheet material, preferably fibre sheet or fibre board, which is placed edgeways around a bottom 4 on a load transporting platform 3 in the shape of a pallet. A lid 5 closes the upper end of the cylinder 2 and an insert 6 in the shape of a plastic sackfor containing the liquid for which the container 1 is to be used is mounted in the cylinder 2.
The bottom 4 is in the shown embodiment constituted by a circular plate of plywood, fibre board or similar material and around the periphery thereof there is a profile which is L-shaped in cross section, the one leg of which extends under the bottom 4 and the other leg of which extends upwards a distance above the upper plane of the bottom 4. In order to avoid displacement of the container 1 on the pallet 3 the bottom 4 is preferably attached thereto e.g. by nailing.
The cylinder 2 consists of double walls, an inner wall 8 and an outer wall 9 both of which are offibre board having a thickness of between 2 and 5 mm. The starting material is a rectangular sheet which has been bent or shaped to a cylinder and the overlapping edge portions of which are locked to each other by stapling, riveting, screwing or the like. The inner cylinder wall 8 has, in this connection, an inner diameter which is substantially the same as the outer diameter of the bottom 4 so that it easily can be threaded over the L-shaped profile delimiting the periphery of the bottom 4.
The outer cylinder wall is formed in the same way as the inner one but it is so much biggerthan it without play worth mentioning can be threaded outside the inner cylinder wall 8. In order to avoid the lapsfrom gripping each other and giving rise to damages of the cylinders during the movements of the,walls in relation to each other when the container is in use the laps must be displaced a distance from each other. Further, in order to obtain such a good strength as possible in the cylinder the laps should be displaced so much from each other that the shock impacts which might appear can act only against one tap at a time. In this connection, the laps should neither be located opposite each other by a displacement between 45 and 90° between the laps is suitable.
The lid 5 consists of a plate 10 preferably of the same structure as the bottom 4 but having a diameter corresponding to the outer diameter of the cylinder 2. A L-shaped profile 11 is extended around its periphery having one leg extending in over the plate 10 and the other leg down around the cylinder 2.
In the shown embodiment a plane plastic sack 6 is inserted in the container 1 which sack in a conventional way has its upper portion tied. However, it is sometimes suitable to have the insert especially adapted to contain. Such an insert sack may be provided with a sleeve which is folded down over the upper edge of the inner cylinder wall 8 and in this connection, the sleeve is clamped between the two cylinder walls 8 and 9 and depending on the material in the sleeve as well as the distance it extends inwards in the interspace it can add to keep the friction low between the abutting walls. In the same way a skirt may exist at the bottom of the insert sack, which skirt is clamped between e.g. the upwards extending leg of the L-shaped profile 7 and the internal side of the inner cylinder wall 8.
An emptying valve, not shown, may be arranged in the bottom of the container and this valve opens then preferably in the most central space 12 in the pallet 3 where the portions of the valve are well protected for damage.
As is clear from what is stated above the container in accordance with the present invention differs from previously known containers of similar type primarily by the fact that the cylinder 2 is constituted by a double wall. As mentioned in the preamble it would be normal to increase the thickness of the wall or to provide the wall with reinforcements in order to increase the strength of the wall. Tests in that direction have, however, not given the desired result. One is in this connection neither allowed to disregard the advantages residing in the fact that it is possible to make use of a material which is relatively easy to shape and which is of low weight in comparison with the strength thereof.
Hence, suitable material for the cylinder walls are different types of sheet material such as fibre board, board consisting of several layers of cardboard and similar, like such boards as glass fibre reinforced fibre board.
For certain types of use it might also be preferable to have more than two cylinder walls and it is neither necessary to have such boards made from one and the same material but one may be made from e.g. glass fibre reinforced fibre board while the other or the rest may be made from cardboard containingseveral layers or not reinforced fibre board.
However, what is surprising in the present invention is the unexpected strength which the container obtains due to such a simple measure as making the cylinder wall from two or more layers. Then, that a container constructed in this way is useful for handling liquids having the special problems which relate to such handling and which have been previously mentioned is completely unexpected. The unexpected strength which the present structure gives rise to emanates most likely from the fact that the combined wall may move in a more flexible way than a corresponding wall of homogeneous type. Due to the fact that the separate walls of the combined wall can be kept thin there appear neither any stresses therein worth mentioning when they are shaped to a cylinder or a pipe which, on the contrary, is the case in connection with thicker walls. Reinforcements such as ridges, bands and similar give easily rise to indications of fractures as the wall obtains different bending and tensioning strength in different portions.
Further to the fact that the initial tensions in the wall are equally spaced and that added stresses are distributed substantially equal in the wall, the fact that the stresses move in steps from wall to wall in the combined wall appears to add to the increased strength simultaneously as the separate walls are movable in relation to each other.
Most likely also the fact that the cylinder walls 8, 9 are loose not only in relation to each other but also in relation to the bottom 4 and the lid 5 adds to the good strength. This gives rise to the fact that there are no points which are fixed and which, accordingly, may constitute the reason to fractures which otherwise easily starts from such fixed points. Such fixed points might exist if the lid was fastened to the cylinder wall 2 and if said wall in turn was fastened to the bottom 4. The fact that all portions are loose in relation to each other is, hence, an important feature of the invention.
In order to keep the portions of the container 1 together there is preferably used some types of bundle straps. Such bundle straps may extend into and through the pallet 3 and up along the cylinder wall 2 and above the lid 5, the bundle straps crossing each other under the bottom 4 and upon the lid 5.
As is clear from the above the problems mentioned in the preamble have been removed by the present invention and an extremely simple and effective packing means has been obtained. For the men skilled in the art it is, however, clear that the invention can be modified in some details, such as in connection with the shaping of the insert and the connection between the bottom and the lid to the cylinder wall as well as the cross sectional shape of the cylinder wall but such modifications are fully within the scope of the invention as it is defined in the attached claims.

Claims

1. Container (1) comprising a cylinder (2) of sheet material and a bottom (4) which is free to move relative to the cylinder, wherein the cylinder (2) consists of at least two relative to each other, movable cylindrical walls (8, 9) placed one within the other, the bottom (4) and the cylinder (2) being adapted to be supported on a load transporting platform (3), the container further comprising an insert (6) of flexible material that is arranged in the compartment delimited by the cylinder (2) and the bottom, characterized in that the insert (6) is provided with a sleeve which extends over the upper edge of the inner cylindrical wall (8) of the cylinder (2) and into the space between two adjacent walls (8, 9).

2. Container according to claim 1, characterized by the fact that the insert (6) is provided with a skirt extending in between the bottom (4) and the adjacent wall (8).