The Specification
5 The Specification explains that the invention is related to "bulk transport containers, and in particular to containers used in road and rail transportation".
6 The Specification then discusses the prior art. It explains (as at 1998 when it was written) that the present designs used by Australian and international transportation companies are at least twenty years old. The Specification provides that an object of the invention is "to provide a container for bulk product transportation that is more efficient and cost effective than existing containers". It then contains the following consistory statement:
With the above object in mind the present invention provides a container for transporting bulk material including two side walls, two end walls and a base, wherein at least one said side wall includes at least one ridge running along said at least one side wall between said end walls, and wherein said ridge is integrally formed within said at least one side wall and the distance from which said ridge projects from said side wall is greater than the thickness of said side wall.
Another form of the present invention provides a container for transporting bulk material and for rotary or side tip unloading, the container including two side walls, two end walls and a base, wherein at least one said side wall includes at least one internal ridge running along said at least one side wall between said end walls, the at least one internal ridge including a first wall portion and the material flows across the at least one ridge when unloading the container, and wherein said at least one ridge is integrally formed within said at least one side wall and said internal ridge has a depth greater than the thickness of said side wall.
7 The Specification then describes a number of the preferred features of the invention. These include the following:
• Preferably, there will be at least one internal ridge between each of the reinforcing members;
• Preferably, there will be at least one internal ridge between an end wall and a first reinforcing means;
• In some instances, extra reinforcing members might be required to satisfy the structural strength of any or all panels on the side wall and/or floor and/or end wall;
• Ideally, the internal ridge includes a first wall portion angled from the wall towards the interior of the container, and a second wall portion rejoining the first wall portion to the wall. The angle of the first wall portion is in the direction of flow during unloading of the material to be transported. Alternatively, the internal ridge includes a first wall portion deflected inwardly a progressively increased degree relative to the intersection of the side wall and the base, and a second wall portion extending from the first wall portion and being deflected outwardly a progressively decreased degree relative to the intersection of the side wall and the base;
• The angle of the first wall portion may be determined by subtracting the natural angle of repose of the transported product, from the angle the container is rotated during unloading. Whilst the first and second wall portions may be symmetrical, they may also be of uneven length;
• In further embodiments, the internal ridge may also include a third wall portion between the first wall portion and the second wall portion. This third wall portion may be flat or concave. Any such flat third wall portion may additionally be parallel to the side wall;
• In some applications, a partial internal ridge may extend along the top edge or rim of the side walls. Such a partial internal ridge may consist of the first wall portion of the internal ridge. In this case, an additional strengthening member along the edge or rim of the side wall would be included; and
• In a preferred embodiment, the base of the container also includes at least one internal ridge extending substantially along the length of the base.
8 The Specification then provides for another form of the invention. It says:
A further form of the present invention provides a container for transporting bulk material and for rotary tor tipping unloading, the container including two side walls, two end walls, and a base; said side walls including a plurality of vertical reinforcing members spaced along the length of each said side wall, wherein a section of said side wall between at least one adjacent pair of said reinforcing members includes at least one internal ridge running therebetween, the said at least one internal ridge including a first wall portion angled towards an interior of the container, wherein the angle is in the direction of flow of the material during the rotary or tipping unloading, and wherein said at least one internal ridge is integrally formed within said side wall and said at least one internal ridge has a depth greater than the thickness of said side wall.
It will be convenient to further describe the invention by reference to the accompanying drawings which illustrate possible embodiments of the invention and improvements over the prior art. Other embodiments of the invention are possible and consequently the particularity of the accompanying drawings is not to be understood as superseding the generality of the preceding description of the present invention.
9 The Specification then refers to the Figures which are used in the Specification to illustrate the preferred embodiment of the invention. Those Figures are annexures to these reasons with the same descriptions as they contain in the Specification.
10 The Specification explains the constraints upon conventional containers. The basic container includes two side walls, a base, and two end walls. Neither the height nor the width of the container can exceed pre-defined dimensions. Those dimensions are determined by rail and road standards and also the practical limitations of loading and unloading facilities. This means that it is not possible to increase the size of the containers without decreasing their strength.
11 The Specification explains that when bulk product is transported in the containers, it places extreme stress on the walls of the containers. This requires a number of support or reinforcing members to strengthen the walls. The walls of the containers therefore do not extend to the maximum possible dimensions. The support or reinforcing members conveniently takes the form of a number of "ribs" which extend around the body of the container. The ribs cause the container to be much heavier and they decrease the aerodynamics of the container with both fill and cost implications on its profitability. Further, structural maintenance and repairs to the containers are both frequent and expensive and they do not guarantee that the operational life of the container will be significantly increased. Larger containers also require more ribs or reinforcing members.
12 The Specification then continues, explaining that the invention reduces the number of ribs that are required when compared with a conventional container of equal size. The Specification refers to the preferred embodiment of the invention which although containing two side walls (5), two end walls (7), and a base (6), differs from conventional containers because it also includes at least one internal ridge (8). Each of these features can be seen in Figures (2), (3), and (4b) with the numbers in brackets indicating each of those features. The Specification provides that the "main element of this internal ridge" (8) is "a first portion (8a)" which the specification describes as extending "from the wall at an angle towards the interior of the container". A second portion (8b) "can be adapted to complete the internal ridge (8), by rejoining the wall (5), to the end of the first portion (8a)".
13 The Specification then provides that in some circumstances the internal ridge could be supplemented by extra reinforcing elements to add structural strength. It explains that the extra reinforcement "may be added to the internal ridge between each strengthening rib" or could be added to the internal ridge in at least one of the wall sections. The extra reinforcement could be shaped similarly to the shape of the internal ridge.
14 The Specification then provides for some detail about the angle at which the first portion of the internal ridge extends from the wall towards the interior of the container. It provides that the dimensions of the internal ridge are also determined as a function of the structural strength required and the natural angle of repose of the material that is to be transported.
15 The Specification provides that for a "bottom dumping container" the internal ridge "can be configured to extend away from the interior of the container". It provides that such an arrangement "will not provide the same increased payload as a ridge which extends towards the interior of the container" (our emphasis). The Specification says that even where the internal ridge extends towards the interior of the container it will provide substantial gains in cost reduction of fabrication from conventional containers which merely provide an additional strengthening member along the exterior of a standard container.
16 The Specification provides detail concerning the length and shape of the internal ridge as follows:
The length and shape of the internal ridge 8, will depend on the structural requirements of the side walls 5 and the base 6. It will also depend on the spacing between supporting frame members 9, and the natural angle of repose of the material. As the distance or spacing between the supporting frame members 9 increases, it will be necessary to increase the depth 16 of the internal ridge 8, to ensure the necessary structural strength. Accordingly, it is possible to design a container specifically for a certain type of material to be transported, by considering the mass of the material and the pressure the material will place on the walls of the container.
A container constructed with an internal ridge of the present invention provides a container that is able to transport bulk product. Furthermore, the internal ridge acts as an in-built longitudinal structural stiffener. This internal ridge, then ensures that the structural requirements, such as strength, fatigue, resistance, and buckling capacity, are met, while ensuring that more product can be loaded into a container that has the same exterior dimensions as a conventionally designed container. This difference in carrying capacity can be seen in Figure 5, where the shape of a new container of the present invention is superimposed over a conventional container.
17 Towards the end of the specification there is a description of the benefit of the internal ridge as follows:
By the addition of at least one internal ridge in the wall of the container, the present invention results in a container that is lighter than conventional containers as the side wall containing the internal ridge does not require as many structural reinforcements as conventional containers, since the internal ridge itself adds to the structural strength of the wall. Again this can be seen by comparison of Figures 1 and 2, whereby the number of ribs or strengthening elements is less than in the original design. The decrease in the number of ribs 9 also leads to a cheaper container. The decrease in the number of vertical elements, and protruding parts generally improves the aerodynamic shape of the container, thereby making a more efficient and economical container. Further, because fewer welds are required the design ensures that there are fewer areas of stress concentration, thereby making the improved container more fatigue resistant.