This application represents the national stage entry of PCT International Patent Application No. PCT/EP2021/072531 filed on Aug. 12, 2021 and claims priority to German Patent Application No. 10 2020 127 721.0 filed on Oct. 21, 2020. The contents of each of these applications are hereby incorporated by reference as if set forth in their entirety herein.
The present disclosure relates to a transport and storage container for liquids comprising a pallet-type understructure for an inner container made of plastic, the inner container having four side walls, a lower and an upper bottom, a sealable filling socket which is formed on the upper bottom and an outlet socket which is formed on the lower portion of a side wall, said outlet socket having a tapping fitting, the transport and storage container comprising a cage having horizontal and vertical bars made of metal for receiving the inner container, ends of the vertical bars, which are formed by a hollow profile, being welded to a lower and an upper circumferential edge profile of the cage, the upper ends of the vertical bars having a connecting portion in order to be connected to the upper edge profile, said connecting portion having a flat section which is formed from the hollow profile by deforming, at least two vertical bars, which are disposed on opposite side walls, being connected at the connecting portions by means of a traverse bar which extends over the upper bot-tom of the inner container and which is formed by a hollow profile, a connecting portion of a vertical bar being connected to a connecting portion formed on the ends of the traverse bar by deforming the hollow profile to a flat section via a screwed joint in each case, the connecting portions of the traverse bar being bent open with respect to a longitudinal portion, which extends over the upper bottom of the inner container, and extending towards the connecting portions of the vertical bars, and the connecting portions of the traverse bar having a fastening opening with a wall for forming a threaded engagement with a connecting screw, which is guided through a passage opening of the connecting portion of the vertical bar.
Transport and storage containers of the make mentioned above are subject to a compliance inspection depending on their type to ensure that defined safety standards are adhered to when using the transport and storage containers, which are also referred to as IBCs. In the course of such compliance inspections, in particular the compressive strength of the transport and storage containers is inspected by applying increased hydraulic internal pressure to the inner container with the result that corresponding deformation forces which act on the inner container must be absorbed by the cage which receives the inner container. The screwed joints which are formed between the connecting portions of the vertical bars and the connecting portions of the traverse bar are subjected to excessive stress since shear forces act on the screwed joints in the area of the connecting portions, which can cause a widening of the threaded hole formed in the connecting portions of the traverse bar, with the result that the threaded engagement between the connecting screws and the connecting portions of the traverse bar is disengaged, resulting in a corresponding component failure.
The object of the present disclosure is to propose a transport and storage container which is characterized by an improved safety against failure regarding the screwed joint formed between the traverse bars and the cage.
This object is attained by the transport and storage container according to the disclosure having the features of claim 1.
According to the disclosure, the vertical bars which are connected to each other via the traverse bar or the traverse bar have/has a cross section recess for decreasing a shear force acting on the connecting screw in transition portions, which are formed adjacent to the connecting portions in the transition area towards the hollow profile.
Tests have shown that the shear forces relevant for the component safety of the screwed joint are essentially caused by the fact that a deforming of the traverse bar occurs when the inner container expands because of increased hydraulic internal pressure, said deforming occurring in such a manner that the transition portion which is adjacent to the connecting portion of the traverse bar comes into contact with the screw end protruding from the fastening opening of the connecting portion of the traverse bar, such that deformation forces act on the connecting screw as shear forces via the transition portion and, as a result of the widening of the wall of the fastening opening, the threaded engagement between the connecting screw and the connecting portions of the traverse bar is disengaged.
By means of the cross section recess according to the disclosure, which can be formed in the transition portions of the vertical bars or in the transition portions of the traverse bar or both in the transition portions of the vertical bars and in the transition portions of the traverse bar, the forming of a physical contact between the transition portions of the traverse bar and the connecting screw can be prevented, such that corresponding harmful shear forces on the connecting screw can be avoided.
According to a preferred embodiment of the disclosure, the cross section recess in the transition portions of the traverse bar is formed opposite a screw end protruding from the fastening opening and serves to receive the screw end when the transition portion approaches the screw end. Such an embodiment of the cross section recess enables the deformation path of the traverse bar to increase as a result of an expansion of the inner container without the traverse bar and the screw end being able to come into contact. Thus, a physical contact between the traverse bar and the screw end is avoided or the possible deformation path of the traverse bar is increased before a physical contact is formed.
The cross section recess in the transition portions of the traverse bar can be formed as a depression or a recess which is formed between longitudinal edges of the traverse bar. A depression is particularly advantageous, such that in contrast to a recess or a hollow extending over the total width of the transition piece, an increased bending stiffness of the traverse bar is maintained in the area of the transition portions.
According to another preferred embodiment of the disclosure, the cross section recess in the transition portions of the vertical bars forms a predetermined bending point which allows a pivoting of the connecting portions away from the inner container around the predetermined bending point and outwards around an axis which is parallel to the upper edge profile when a shear force acts on the connecting portions via the traverse bar. In such an embodiment, a physical contact between the traverse bar and the screw end, which would be harmful to the strength of the screwed joint, is prevented from forming or is delayed because the decreased bending stiffness of the transition portion of the vertical bars causes the connecting portions of the vertical bars to perform an outward pivoting motion around the predetermined bending point in the same direction as the deformation of the traverse bar.
It has proven to be particularly advantageous if the predetermined bending point is formed as a groove which his disposed on an outer surface of the vertical bars in the transition portion and which extends parallel to the upper edge profile, such that a reduced bending stiffness desired in the area of the predetermined bending point is achieved.
Hereinafter, preferred embodiments of the disclosure will be described in more detail with reference to the drawings.
As
As in particular
To form the force fit, connecting screw 39 is screwed into fastening opening 41, which is formed as a threaded hole, with a screw end 42, which penetrates fastening opening 41, in such a manner that a threaded engagement is produced between a wall 43 of fastening opening 41 and screw end 42.
In particular
To explain the advantageous effect of depression 44 and groove 46 in a case where an inner container 11 is subject to increased hydraulic internal pressure,
Furthermore, a comparison between the illustrations in
As can be derived from the above, both the forming of depression 44 in transition portion 35 of traverse bar 30 and the forming of groove 45 in transition portion 36 of vertical bar 24 allow avoiding a physical contact between transition portion 35 of traverse bar 30 and screw end 42, the simultaneous forming of depression 44 and groove 46 in the illustrated embodiment allowing a particularly advantageous overlapping of the effects.
Number | Date | Country | Kind |
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10 2020 127 721.0 | Oct 2020 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/072531 | 8/12/2021 | WO |