Pressure-tight transport container for flowable goods

Abstract

The invention relates to a pressure-tight transport container for flowable goods of the kind comprising two end walls with corner fittings for stacking and lifting, an envelope having at least two part-cylindrical sections providing a pair of intersection lines extending between the end walls, elongated support members which extend between the end walls and are contiguous to the exterior of the envelope wall, and reinforcing elements arranged inside the container so as to be stressed at least in tension. The invention provides each said support member substantially in the plane of said pair of intersection lines of the envelope which are lines opposite to each other, and the reinforcing elements comprise elongated members arranged in this plane with the ends thereof penetrating the intersection lines in a fluid-tight manner and rigidly connected to said support members.

Description

The invention relates to pressure-tight transport containers for flowable goods of the kind comprising a fluid-tight container, which is formed by two end walls with corner fittings for stacking and lifting and an envelope having at least two intersecting part-cylindrical sections providing a pair of intersection lines extending between the end walls, elongated support members which extend between the end walls and are contiguous to the exterior wall of the envelope and reinforcing elements arranged inside the container so as to be stressed at least in tension.

In one previously proposed transport container of this kind the support members extend along the sides of the container approximately half way up the container height. They serve the purpose of taking the external tensile- and compressive stresses acting along the container, as well as the bending stresses which appear especially during lifting. The internal pressure on the other hand which tends to expand the container, is taken solely by the reinforcing elements attached in the plane of two oppositely disposed intersection lines, which elements are in the form of at least one continuous intermediate wall with discrete apertures. The intermediate wall is welded directly at the lines of intersection between mutually abutting exterior wall sections, and gusset sections of suitable cross-sectional shape may be inserted for the purpose of providing additional strength. Although such intermediate walls provide very uniform load distribution, they require a large amount of material which, depending upon the nature of the flowable material, may be required to be corrosion resistant and make the cleaning of the container more difficult.

An object of the invention is to provide a transport container with a good utilisation of the space available within the prescribed external dimensions which, whilst being economical to construct, possesses a high degree of pressure resistance and is easy to clean.

According to the invention, in a pressure-tight container of the kind referred to hereinbefore, each support member lies substantially in the plane of said pair of intersection lines of the envelope which are disposed so as to lie opposite each other, and the reinforcing elements are in the form of elongated members arranged in this plane and the ends of which penetrate the intersection lines in a fluid-tight manner and are joined to said support members.

Preferably the ends of the reinforcing elements which penetrate the container are of flat configuration. In this way the ends of the reinforcing elements can be readily welded to the limbs of the support members. These ends can be of different shapes, which can be chosen from the points of view of welding technology and structural strength. Ends of the reinforcing elements which are inclined in the form of a trapezium have been found particularly satisfactory.

Conveniently, the elongated support members are of U-shaped cross-section and one limb thereof is arranged in the plane of the intersection lines to which the respective ends of the reinforcing elements are attached.

Thus, if a smooth exterior surface is preferred for the support members, it is possible to provide cut-outs in the attachment limbs of the U-shaped support members and to insert the ends of the reinforcing elements therein.

In the simplest case, the reinforcing elements consist of individual sheet metal strips. These may be subjected to tensile stresses and thereby endow the container with the desired strength to stand up to internal pressure.

If the reinforcing elements are required to assist the support members also with regard to the stresses imposed on the container from outside, they have to be capable of withstanding tension, pressure and buckling. To a certain extent the buckling strength may be increased by the use of sheet metal strips twisted in screw-like fashion; these moreover have the advantage of taking up little room, being easy to clean and having a surge-inhibiting effect on the fluid inside the container. The bending strength of the container may be increased by using reinforcing elements consisting of rods or tubes with flattened ends. In this case the support members together with the adjacent regions of the wall envelope would behave like the upper and lower flanges of a double-T-beam which is resistant to bending.

Preferably the end walls of the transport container each have a frame into which at least one cylindrically or spherically curved wall element is sealingly inserted. The end edges of the wall envelope are abuttingly secured to the flat surfaces of the frames. In this way a design is achieved which is distortion-resistant and easy to clean and has welding seams which are easy to produce.

In the case of square frames, a single spherically curved wall element suffices for the end closure of the container. Where the dimensions are such as to produce a rectangle, it is preferable to use two or more adjacent part-cylindrical or spherical end wall elements, whose lines of intersection may, if desired, be stiffened by reinforcing strips applied thereto or therebetween.

Since the transport container is subjected to the highest bending stress when it is being lifted at its four corners as a result of oscillations induced in transit, it is advisable to provide two support members arranged along the floor and the top of the container. These may, for the purpose of disposing of the forces due to acceleration and braking acting on the corner fittings be supported by oblique struts at the end walls. At the top of the container, two such oblique struts may, together with a support member which stops short of that end of the container and a transverse support member of the end wall provide an area for location on the manhole and a catchment trough surrounding the manhole.

If the container envelope consists of two exterior sections and a central section of the exterior walls, i.e. if it is of triple-shell construction with two pairs of intersection lines in parallel planes, U-shaped support members are preferably arranged symmetrically, i.e. the limbs of the support members are each arranged in one of the two parallel planes.

If, on the other hand, the exterior envelope of the container consists of two adjacent sections of the exterior wall, the two support members are preferably arranged asymmetrically relatively displaced in such a way that one of their limbs is located in the plane of the pair of intersection lines.

If the transport container is of square cross-section, an arrangement is preferably employed in which the part-cylindrical curves of the wall envelope are arranged symmetrically relative to the centre about the container axis and secured by their end edges to square end wall frames into which substantially spherical end walls are fitted. In this way the space utilisation is considerably improved as compared with a wall envelope of circular-cylindrical configuration. Preferably four such curves are provided to provide a crosssection in the form of a four-leaf clover. With this design the reinforcing elements which cross inside the container may be arranged in adjacent pairs which are connected together, for example, by a tube extending along the axis of the container. Here also the support members may be arranged asymmetrically.

The asymmetrically arranged support members may, however, be joined to flat or angled reinforcing plates which extend beyond the attachment limbs and are attached to the part-cylindrical envelopes. In this way a substantially symmetrical construction providing increased bending strength is achieved.

With a view to a further increase in the strength of the container in relation to external pressure, reinforcing rings may extend at right-angles to the axis of the container and may be applied at various points of the latter. Preferably their ends do not, at the re-entrant portion in the vicinity of the intersection lines of the wall envelope follow the curvature of said envelope but extend in the direction of maximum tension, so as in this way to accommodate the acting forces in the most beneficial manner.

The support members arranged along the floor and top of the container have a variety of uses. Apart from the advantages of increasing the bending- and compression strength of the transport container already mentioned, and of defining seats for the reinforcing rings, the upper support member may also serve the purpose of a platform for servicing as well as a means for applying and covering insulating means. The lower support member may, together with lateral rails secured to the floor of the container, be constructed in the form of a longitudinally extending trough for centring the container via a superstructure on a lorry for removable containers and in the form of a frame of a "gooseneck-channel.

Several embodiments of the invention will now be described, by way of example, with reference to the accompany drawing, in which:

FIG. 1 is a perspective view of a first embodiment of the invention;

FIG. 2 is a fragmentary view of a modified embodiment;

FIG. 3 is a perspective view of a further embodiment;

FIG. 4 is a similar view of a further embodiment;

FIGS. 5 to 8 are fragmentary views of different forms of reinforcing elements; and

FIG. 9 is a fragmentary view of a further embodiment viewed from below.

In all the embodiments, the transport container has two end walls 1, which have two horizontal transverse support members 2 and two vertical struts 3. At the joints of the latter, corner fittings 4 in accordance with ISO-TC 104 for lifting and securing the transport container are inserted.

In the embodiment according to FIG. 1, the closed frame formed by the transverse support members 2 and the struts 3 is subdivided by one or more (in the example two) reinforcing members 5 into separate fields, into which part-cylindrically curved wall elements 6 with vertical axes of curvature are fitted in fluid-tight manner. These wall elements and the frame which surrounds them form an inseparable part of the fluid container and at least those of their portions which can come into contact with the contents of the container are made of a material which is chemically resistant to this content.

Part-cylindrical wall sections 7 and 8, curved about horizontal longitudinal axes are butt-welded to the transverse support members 2 and supports 3 which are of appropriate width. These wall sections together with the end walls just described form the fluid container proper. They merge into each other at the lines of intersection 9 at which they abut.

By suitable choice of the relationship between the radii of curvature and the wall thicknesses of the lateral and the central cylindrical sections, the shape of the container may readily be adapted in optimum manner to the relationship between width and height required for any particular transport container. The relatively oppositely disposed lines of intersection 9 of the central and lateral exterior wall sections are joined together by vertical reinforcing elements 10. These reinforcing elements are in the form of elongated members and consist, for exaample, of sheet metal strips, whose ends 30 penetrate in fluid-tight manner through the intersection lines 9.

Above and below the central wall sections 8, the exterior longitudinal support members 11 of U-shaped crosssection are provided. In accordance with the present invention the vertical limbs 12 of these support members are disposed in the planes of the reinforcing elements 10. The limbs 12 are provided with cut-out portions 13, into which the ends 30 of the reinforcing elements 10 fit. The edges of the limbs 12 are then welded to the ends of the reinforcing elements 10 and to the container wall sections 7 and 8 which abut at the intersection lines concerned. Depending on the length of the welding seam desired, the cut-out portions 13 and the appropriate ends 30 of the reinforcing elements may by made longer or shorter. Alternatively the ends 30 of the reinforcing elements may also simply be welded to the limbs 12 of the longitudinal members 11 (c.f. FIG. 4).

Depending on the length of the transport container, one or more reinforcing rings 14 are provided, which join the upper and the lower longitudinal members 11 and, if desired, merge into saddles 15. At their upper and lower end portion 29, they do not follow the curvature of the wall sections, but lead directly into the longitudinal support members 11.

For the purpose of providing room for the filling aperture or manhole 16, located at one end of the container, the upper longitudinal support member 11 merges directly into the end wall only at the other end of the transport container. The end of the longitudinal support member 11 facing the manhole forms a shoulder 17 from which oblique struts in the form of rectangular beams 18 lead to the corners of the end wall 1. The space between the shoulder 17 of the longitudinal support member, the beams 18 and the transverse support member 2 of the end wall 1 may be constructed so as to define a catchment trough 19.

Oblique corner struts may also lead from the other corners of the container end walls to the central longitudinal support members, for the purpose of disposing of the forces due to acceleration and braking acting on the corner fittings. These struts may, for example, take the form of further rectangular beams 17, as in FIG. 1, or triangular gussets 20 as in FIG. 2. Moreover, they may either terminate short of the corner fittings 4, as in FIG. 1, or they may fully encompass the corner fittings, as do the gussets 20 in FIG. 2.

The discharge fittings may in known manner be provided at the centre of an end wall. They may, however, alternatively, be accommodated behind one of the corner fittings 4 and be in the form of a box structure 21 as shown diagrammatically in FIG. 2.

The embodiment according to FIG. 3 is no different from those according to FIGS. 1 and 2 so far as the design of the end wall frames is concerned. In this case, however, only part-cylindrical sections 22 and 23 with horizontal axes are provided, which are welded together along the upper and lower intersection lines 24 for fitting reinforcing elements 10 therebetween. The ends 30 of the reinforcing elements 10 which penetrate the container are inserted into appropriate cut-outs in a limb 26 of the upper and lower longitudinal support members 27 respectively, which again are of U-shaped cross-section. The longitudinal support members 27 are arranged somewhat off-centre and relatively displaced; and their other limbs 28 are butt-welded directly to their respective wall sections 22 and 23 as shown. This asymmetrical construction is of interest particularly for tall containers. In this embodiment two spherical wall elements 55 are fitted into the rectangular end wall frames 1. The vertically disposed intersection line 56 between the wall elements 55 either defines a simple welding seam, as in FIG. 3, or it is provided, as in FIG. 1, with a straight or curved reinforcement 5. The provision of spherical wall elements 55 has the advantage of lower weight as compared with the end wall design of FIG. 1.

The oblique struts have, in the embodiment shown in FIG. 3, been dispensed with. In other respects the construction of the container, including the various possible modifications corresponds to that of FIGS. 1 and 2.

The transport container according to FIG. 4 has two end walls 1 of square circumference.

A spherically curved floor 35 is inserted in fluid-tight manner in each of the closed frames formed by the transverse support members 2 and the supports 3. Four part-cylindrical envelopes 36 which are curved about horizontal longitudinal axes are butt-welded to the transverse support members 2 and the supports 3, which are of appropriate width. These envelopes form the fluid container proper, and merge mutually at the intersection lines 37 where they abut. The envelopes are of symmetrical construction; i.e. they all have the same radius of curvature and thus present a crosssection in the form of a four-leaf clover, whereby the square frame cross-section is utilised effectively.

The relatively oppositely disposed intersection lines 37 of any two abutting envelopes are joined by horizontal and verticial reinforcing elements 38 and 39. In the embodiment according to FIG. 4, these reinforcing elements again consist of flat sheet metal strips, whose ends 40 penetrate in a fluid-tight manner, to the exterior through the intersection lines 37.

A limb 41 of a U-shaped longitudinal support member 42 having limbs of unequal length, extends along each intersection line 37. The other, short, limb 28 of this longitudinal support member rests on one of the adjacent cylindrical envelopes 36 and is welded thereto. The protruding ends 40 of the reinforcing elements 38 and 39 are welded to the limb 41. In the interests of optimum distribution of the stresses, the ends 40 are inclined in the form of a trapezium.

The horizontal and vertical reinforcing elements 38 and 39 are joined together inside the container. Either the various reinforcing elements are joined together in pairs at their crossing points with the aid of gussets 43, as shown in FIG. 4 or a central longitudinally extending tube 34 to which the various tie elements are secured is provided inside the container as shown in FIG. 5.

For the purpose of further increasing the pressure-tightness, the longitudinal support members 42 may, if desired, be joined to reinforcing plates 44, as shown in FIGS. 4 and 5, which may be flat or provided with angled edges and those of their ends which reach over the longer limbs 41 may be joined to the cylindrical envelopes 36. Such reinforcing plates may also be used at the transport container according to FIG. 3.

The transport container is, in the usual manner, provided with a manhole 45, an air equalisation duct 46 and a charging- and discharging device with a transverse trough and transverse pipe (not shown), preferably accommodated in the region of one of the lower corners of the container.

Thanks to the arrangement of two oppositely disposed longitudinal support members 42, which are joined by reinforcing elements 38 and 39, the transport container also has a certain degree of rigidity with respect to external pressures, since the parts mentioned, together with the adjacent shell regions, act like a double-T-beam. By appropriate dimensioning of the reinforcing plates 44, this beam-like effect can be increased almost to any desired extent.

In order to increase the resistance to buckling of the reinforcing elements 38 and 39, the latter can take the form of sheet metal strips, twisted in screw-like fashion. Such reinforcing elements 50 are shown in FIG. 6, the ends of the elements being relatively twisted through 180.degree. or a multiple thereof, so that they lie in the planes of the intersection lines 37 (FIG. 4) and may be welded to the limbs 41 of the longitudinal support members 42. The twisted constructon has the effect that, when cleaning the container by jets of liquid, the latter impinge on all four flanks of the element. Following the gradient and the twist, the cleaning liquid thereby runs and rises along the parts of the flanks remote from the spray head from which the jets emanate.

The bending moment and buckling strength of the reinforcing element shown are greater than in the case of a flat metal section. The twisted construction also exhibits a greater surge inhibiting effect than a metal strip of flat section.

With a view to increasing their bending and buckling strength, the reinforcing elements may also take the form of tubes or rods. In order that their ends may, in the plane of the joint seams, penetrate said seams, these ends are preferably flattened. This is particularly easy to accomplish in the case of a tube. Thus tubular reinforcing elements are shown in FIGS. 7 and 8. They are flattened at their ends 51. By way of example, circular tubes 52 (FIG. 7) or tubes 53, 54 partially flattened into an oval shape (FIG. 8) are shown in different orientations. Such reinforcing elements of increased buckling- and compression strength may of course also be used in the transport containers according to FIGS. 1 to 3.

FIG. 9 shows the view from below of a transport container which may be constructed in accordance with any one of the embodiments described hereinbefore. The lower longitudinal support member 27 is provided with a horizontal floor plate 61 which, for example, may comprise a reinforcing plate such as 44 (FIGS. 4 and 5). The floor plate 61 together with laterally disposed rails 62 mounted thereon and extending the full length of the container defines a longitudinal channel 64, whose width and depth correspond to the prescribed dimensions of centring channels of superstructures on lorries for carrying the containers. In this way a stable design of the channel is provided and the containers can readily be loaded onto the lorries in a predetermined position.

It will be appreciated that all the individual features described and shown in the different embodiments may be combined and relatively exchanged in any desired manner which appears appropriate.

Claims

I claim:

1. A pressure-tight transport container for flowable goods comprising two end walls with corner fittings for stacking and lifting, an envelope having an exterior surface and at least two part-cylindrical wall sections providing a pair of intersection lines extending between the end walls, elongated support members extending between the end walls contiguous to the exterior surface of the envelope, and reinforcing elements arranged inside the container so as to be stressed at least in tension, wherein the improvement comprises each said support member having at least a portion thereof lying substantially in the plane of said pair of intersection lines of the envelope which are lines opposite to each other, and the reinforcing elements comprise elongated members arranged in this plane with the ends thereof penetrating the intersection lines in a fluid-tight manner and rigidly connected to said support members.

2. A transport container according to claim 1, wherein the elongated support members are of U-shaped cross-section and one limb thereof is arranged in the plane of the intersection lines to which the respective ends of the reinforcing elements are attached.

3. A transport container according to claim 1, wherein at least one reinforcing ring extends at right angles to the axis of the container and is joined to the support members, the external profile of the ring encompassing the envelope in a manner providing the most favourable tensile stress conditions, without following the re-entrant portions determined by the curvature of the envelope intersection lines.

4. A pressure-tight transport container for flowable goods comprising:

two end walls with corner fittings for stacking and lifting, an envelope having an exterior surface and an even number of part-cylindrical wall sections each providing a pair of intersection lines extending between the end walls, elongated support members which extend between the end walls and are contiguous to the exterior surface of the envelope, and reinforcing elements arranged inside the container so as to be stressed at least in tension, wherein each said support member comprises at least one limb lying substantially in the plane of a pair of said intersection lines which are disposed opposite to each other, and the reinforcing elements comprise elongated members arranged substantially in said plane of said pair of intersection lines, the ends of said reinforcing elements penetrating the intersection lines in a fluid-tight manner and being rigidly attached to said limbs.

5. A transport container according to claim 4, wherein the ends of the reinforcing elements are of flat configuration.

6. A transport container according to claim 5, wherein the reinforcing elements consist of rods or tubes with flattened ends.

7. A transport container according to claim 4, wherein the ends of the reinforcing elements are welded to the support members.

8. A transport container according to claim 4, wherein the ends of the reinforcing elements are inclined in the form of a trapezium.

9. A transport container according to claim 4, wherein the reinforcing elements consist of metal strips.

10. A transport container according to claim 9, wherein the metal strips are twisted in screw-like fashion for withstanding tensile, compressive and buckling stresses in a plurality of axial directions.

11. A transport container according to claim 4, wherein the ends of the reinforcing elements are inserted in suitable cut-outs in the limb of their respective support members to which the reinforcing elements are attached.

12. A transport container according to claim 4, wherein the end walls each have a frame into which an end wall element is sealingly inserted and to which a respective edge of the envelope is abuttingly secured.

13. A transport container according to claim 10, wherein the end wall element comprises at least one part-cylindrically curved sheet.

14. A transport container according to claim 12, wherein the end wall element comprises at least one spherically curved sheet.

15. A transport container according to claim 14, wherein the end walls thereof comprise square end wall frames, and wherein said substantially spherical curved sheets are fitted in said end wall frames.

16. A transport container according to claim 15, wherein the support members are of U-shaped cross-section and disposed on opposite sides of the container, the support members are arranged in asymmetrically relatively displaced fashion.

17. A transport container according to claim 14, wherein a plurality of end wall elements are provided for each end wall and the intersection lines of adjacent end wall elements are stiffened by reinforcing strips.

18. A transport container according to claim 4, including a floor and roof, wherein oblique struts extend from the corner fittings of the end walls to the support members which overlie a pair of intersection lines disposed along the floor and the roof of the container.

19. A transport container according to claim 16, wherein the support member on the roof of the container stops short of one end wall and is attached to the latter by two oblique struts, and a manhole for the container is located within the area between said one end wall, the oblique struts and the support member, said area constituting a catchment trough around said manhole.

20. A transport container according to claim 4, with two exterior wall sections and a central wall section defining the envelope and providing two pairs of intersection lines disposed in parallel planes, wherein each limb of the elongated U-shaped support members lies in a different one of said two parallel planes and is attached to the ends of its respective set of reinforcing elements.

21. A transport container according to claim 4, with two adjacent wall sections providing a pair of oppositely disposed intersection lines, and wherein two U-shaped support members are provided on opposite sides of the container and are asymmetrically relatively displaced in such a way that a common one of their limbs is disposed in the plane of the intersection lines.

22. A transport container according to claim 4, wherein a plurality of pairs of oppositely disposed intersection lines in crossing planes are provided by the part-cylindrical wall sections of the envelope, and the reinforcing elements of the different pairs of intersection lines extend in adjacent crossing pairs which are joined together.

23. A transport container according to claim 22, wherein a tube extends along the axis of the container and joins together the reinforcing elements which cross inside the container.

24. A transport container according to claim 4, wherein reinforcing plates are joined to the U-shaped support members so as to provide a further limb, and the other limb of the U-shaped support members and said further limb are joined to the part-cylindrical wall sections on each side of said one limb of the U-shaped support members.

25. A transport container according to claim 4, including a floor, wherein rails are secured to the floor to form a channel for removable co-operation with a positioning structure on a vehicle adapted for carrying said containers.