[0001] The invention refers to a anti-bending stepped system for metallic containers, the
aim of which is to prevent the usual bending that normally appears in the metallic
containers during the expansion operations carried out to obtaining or manufacturing
such containers.
[0002] The anti-bending system can be applied to all kind of metallic containers of a shape
that can be either trunco-pyramidal, parallelopipedic, elliptical, etc.
[0003] As everybody knows, when the body of a metallic container is expanded, a deformation
occurs due to stress of the material. Such deformation is called "bending" and happens
in the bottom causing an uneven distribution of material in the periphery of the body
of the container.
[0004] In the light of the above and to proceed with the manufacturing of the container
it is necessary to correct such bending so that the whole periphery of the container
is parallel, thus enabling such deformation to disappear.
[0005] Currently, there are two systems aimed to achieve the correction of the bending.
The first one consists of cutting the material with its periphery already compensated
prior to proceed to weld the body and its subsequent expansion. The second system
consists of expanding the body of the container with concave expanding tools so that
they can proportionately compensate the subsequent deformation.
[0006] In the first case, we find the inconvenience of the loss of material, while in the
second one the inconvenience stems from a bad or defective configuration of the container
itself.
[0007] The system proposed has been conceived to satisfactorily solve all those problems
on the basis of a simple and efficient solution which the added advantage - when compared
with the first conventional system referred above - of a better use of the raw material
which, in turn and compared with the second conventional system, enables to obtain
a more even and straight configuration of the wall of the container which makes the
storage of the containers much easier.
[0008] These features or advantages are achieved by using the system which is the object
of this invention. This consists of making two or more steps of a certain dimension
and at a specific place so that such steps determine the folding of the excess material
just in the areas where such excess has been produced.
[0009] Once the deformation or bending has been corrected, it is possible to continue with
the following stages of the normal manufacturing process of the container.
[0010] To complement this description and in an effort to better understand the main characteristics
of the invention, a set of drawings is attached to this descriptive report forming
an integral part of it and where, as an illustration and without limitation, the following
has been represented:
[0011] Figure 1 shows a schematic view of the side of a container. One of the halves incorporates
the preconized stepping and the other half is shown without such stepping and presents
the relevant bending.
[0012] Figure 2 shows a plan view of a rectangular container with stepping in one of its
corners.
[0013] Figure 3 finally shows a section view of the steps made on the wall of a container
presenting the compensation of excess material compared with non-stepped wall shown
in the same figure.
[0014] In such figures, the numbering system correspond to the following parts and elements:
1. Container
2. Bending
3. Steps
4. Stepped wall
4'. Non-stepped wall
a. Bending size
b. Size or depth of the steps (3).
[0015] As it can be observed in such figures, and specifically in the right half of figure
1, the container (1) when expanding suffers a bending deformation (2) which causes
an uneven distribution of the material across the periphery of the container (1) itself
so that to continue with the manufacturing of the container it is necessary to correct
such bending (2) in order that the whole periphery of the container is parallel and
the "a" deformation disappears.
[0016] Such disappearance or correction of the bending is achieved by means of a series
of steps (3) the number of which depends on the size of the "a" deformation referred
to above. Such steps are located at or affect specific areas as shown in figures 1
and 2 and all have the same dimension which corresponds to the size of the steps "b"
so that such steps (3) fold the excess material at those areas where they have been
made. The correction achieved with the steps (3) on the wall (4) of the container
(1) with respect to the wall (4') with no steps can be compared in figure 3.
1. Anti-bending stepping system for metallic containers which can be applied to all kind
of metallic containers of a shape that can be either trunco-pyramidal, parallelopipedic,
elliptical or similar to correct the usual bending produced when the body of the container
is expanded, essentially characterized because it comprises two or more steps on certain
areas of the side wall of the body of the container, the number of steps and their
depth depending on the size of the relevant deformation causing the bending. It has
been foreseen that the steps are parallel to the base to absorb the excess material
originated during the manufacturing expansion stage of the container itself.