[0001] The present invention relates to containers for transport, storing and handling of
liquids, and more closely to a container shaped as a cylinder and made of sheet material,
placed edgeways on a load transporting platform and containing a liquidproof insert
in the form of a plastic sack or similar.
[0002] 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 faced
upwards.
[0003] 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 breakes.
[0004] 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.
[0005] 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.
[0006] 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.
[0007] 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 claims from which claims
also the especially characterizing features of the invention are clear.
[0008] 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.
[0009] 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 sack for containing
the liquid for which the container 1 is to be used is mounted in the cylinder 2.
[0010] 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.
[0011] The cylinder 2 consists of double walls, an inner wall 8 and an outer wall 9 both
of which are of fibre 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.
[0012] The outer cylinder wall is formed in the same way as the inner one but it is so much
bigger that it without play worth mentioning can be threaded outside the inner cylinder
wall 8. In order to avoid the laps from 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 ought
to be displaced so much from each other that the shock impacts which might appear
can act only against one lap at a time. In this connection, the laps should neither
be located opposite each other but a displacement between 45 and 9
0° between the laps is suitable.
[0013] 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.
[0014] Ln 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 Lnsert especially adapted for the actual container and for the material
which it is intended 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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 baord while the other or
the rest may be made from cardboard containing several layers or not reinforced fibre
board.
[0019] 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.
[0020] 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 moves 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.
[0021] 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.
[0022] In order to keep the portions of the container 1 together there is preferably used
some type 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.
[0023] 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.
1. Container (1) including a pipe-shaped wall (2) of sheet material and a bottom (4)
which is loose in relation to the pipe-shaped wall (2), the bottom (4) and the pipe-shaped
wall (2) being intended to be supported upon a load transporting platform (3), characterized
by the fact that the pipe-shaped wall (2) consists of at least two in relation to
each other loose cylinder-shaped walls (8, 9) located one within the other.
2. Container in accordance. with claim 1, characterized by the fact that an insert
(6) of flexible material is arranged in the compartment delimited by the pipe-shaped
wall (2) and the bottom (4).
3. Container in accordance with claim 2, characterized by the fact that the insert
is constituted by a sack (6) of at least one layer which is adapted to the shape of
said compartment.
4. Container in accordance with claim 2 or 3, characterized by the fact that the insert
is provided with a sleeve which extends over the upper edge of the inner wall (8)
of the pipe-shaped wall (2) and into the space between two adjacent walls (8, 9).
5. Container in accordance with claim 2, 3 or 4, characterized by the fact that the
insert (6) is provided with a skirt extending in between the bottom (4) and the adjacent
wall (8).