AU2008255231B2

AU2008255231B2 - Water tank improvements

Info

Publication number: AU2008255231B2
Application number: AU2008255231A
Authority: AU
Inventors: Peter John Snelling
Original assignee: THIN TANKS Pty Ltd
Current assignee: THIN TANKS Pty Ltd
Priority date: 2008-09-17
Filing date: 2008-12-11
Publication date: 2016-01-21
Anticipated expiration: 2028-12-11
Also published as: AU2008255231A1

Abstract

A thin tank comprised of plastics material in which there is at each end of the tank a channel extending from a bottom to the top of the tank and adapted to receive in nested alignment either a post which can extend beyond either the 5 bottom or top of the tank or a bracket a portion of which can engage into the channel, and a plurality of laterally extending channels which are variably spaced apart with internally molded ties between the respective oppositely positioned channels. Nti CY) 0n

Description

1 WATER TANK IMPROVEMENTS This invention relates to a water tank and in particular to one formed from plastics material and is dimensioned so that it can be generally described as a "thin" tank. 5 With the current prospect of global warming and fears of increasing lack of potable water, water tanks that can be located in some more difficult locations is desirable. This is particularly the case with a tank that has a relatively small width so that it can be located in places where space is very limited or in places where it is 10 convenient to have a relatively thin barrier as for instance in a fencing application. One of the difficulties with tanks in general is that in order to store a reasonable quantity of water, they will need to have a relatively deep storage area and the difficulty here is that this will cause relatively high pressures at and toward the 15 bottom of the tank when filled with water due simply to the head of water within the tank. Another and perhaps more significant problem relates to appearance. One known example of a thin tank comprises of a plastics wall has external metal bracing across its broad face in order to have the plastic walls retained 20 without distortion against any reasonable head of water in the tank. External bracing implicitly contributes significant mechanical parts to the visual appearance and to many people is undesirable purely from an appearance point of view. Internal bracing at first sight is not an option because of the narrowness between the broad sides which limits access at least for 25 subsequent installation.

2 Further however, in order to achieve adequate bracing strength, the elements providing such bracing must be substantial and any plastic wall in order to accommodate such bracing has either to be moulded to allow for a substantial insetting of such reinforcing members or if they are positioned to extend proud 5 of a side wall, then these can add significantly to the overall width of such a tank and can thereby implicitly destroy or at least reduce its advantage of being thin and still hold a reasonable quantity of water. An object of this invention then is to propose a tank comprised of plastics material which at least provides the public with a useful alternative. 10 According to this invention then, there is provided a thin tank comprised of plastics material in which there is at each end of the tank a channel extending from a bottom to the top of the tank and adapted to receive in nested alignment either a post which can extend beyond either the bottom or top of the tank or a bracket a portion of which can engage into the channel. 15 If such an arrangement using the post is placed at both ends of a tank, it is then possible for a post to be held independently of the tanks, for instance embedded in the ground or otherwise supported and one or more of the tanks then to a large extent cover the post which can provide thereby support strength where otherwise such a tank might by unstable. 20 This allows the length of a tank to be chosen to allow for sufficient strength in line with head height but not having to suffer undue interruptions within a visual appearance. In simple terms then, by having means to effect embedding of vertical posts at each end, there can be presented a continuous face on each side of a tank line 25 where there might be two or more such tanks abutting one against the other with of course a post nesting and holding the relative adjoining ends.

3 In the event that the tank is located to lie against a wall then use of a bracket with one at preferably both ends of the tank allows a portion of the bracket to interlock with the channel and a further portion can then be attached to the wall. This can also apply to two abutted tanks where the bracket then has a portion 5 that interlocks with both adjacent channels of two tanks while a further portion is attached to the wall or of course other support structure. The next difficulty however is that it becomes extremely difficult with a very thin tank and by thin we might mean in the order of 200 to perhaps 300 mm width, although it is not intended that such a width be a limiting range at this stage, 10 that it is difficult to provide internal ties or bracing. This is not a problem if you have external bracing but there is a visual price to be paid with external bracing. In a further preferred embodiment in accordance with this invention then, there is proposed that there be a plurality of laterally extending vertically spaced apart 15 embedded channels which are formed in each side wall and extend from end to end. Such inset channels can be relatively straightforwardly moulded from plastic by using for instance a rotational moulding technique and by having such channels moulded at spaced apart intervals in a vertical spaced alignment, means that 20 the spacing can be selected and the depth of the channel selected to accord with the head height and length of a tank which can then be chosen in accordance with a desirable storage capacity. It has been discovered that if one uses this technique, some advantage can be obtained by increasing the vertical spacing apart of the laterally extending 25 reinforcing channels at an upper part of the tank as compared to a lower part of the tank.

4 This of course is because the burst pressure of a head of water is directly proportional to the depth of water. In a next improvement, there is moulded between oppositely positioned channels, an interconnecting link whereby there is during the moulding process 5 a member passing from one side of an expected channel position to another and there is moulded thereby around such a member and integrating with the channels therein, such a form which thereby acts as an internal bracing between the respective sides. In preference, there is at least one of these ties but in practical terms one would 10 expect that these can be distributed throughout these channels so there might be for instance three, four or more of these between each respective oppositely positioned channels. A further advantage in relation to shaping a wall which now has a plurality of segments which are extending horizontally, is that the external wall is arcuate in 15 cross section and is thereby of a consistent arcuate shape throughout its length. This has the advantage that it does implicitly stiffen the wall segment thus shaped but it also relieves the view of seeing a perfectly planar surface where any bulging will be much more apparent than if there is in effect a slight bulging on a controlled basis where a little more bulging will not be so apparent. 20 For a better understanding of this invention it will now with reference to an embodiment which will be described with the assistance of drawings wherein, Figure 1 is a perspective view of the tank according to the first embodiment, Figure 2 is a further perspective view of the same tank viewed from slightly below the tank, 25 Figure 3 is a cross sectional view through the tank, 5 Figure 4 illustrates two tanks joined together, Figure 5 illustrates two tanks where the separate parts including posts are separated, and Figure 6 is an assembly illustrating the details of a combination of two tanks 5 supported by inverted posts. Figure 7 is a cross sectional view of an end portion of a tank with a further fitting according to a second embodiment, Figure 8 is an end elevation of the tank as in figure 7, and Figure 9 is a cross sectional view of a further embodiment using a bracket 10 attached to a wall where there are two abutted tanks jointly held by having the bracket interlock within each respective end channel. Referring specifically to the drawings Figs 1 through 6, a tank 1 is moulded by rotational moulding and to have dimensions where the width in this case is approximately 230 mm, a height of 1850 mm and a length of 2400 mm. 15 These dimensions provide capacity in the tank for approximately 1000 litres of water. However, each tank has at an end 2 an embedded main or primary channel 3 at one end and 4 at the other which extends fully from a bottom 5 of the tank to a top of the tank 6. 20 Extending laterally between the ends 2 of the tank, are a plurality of secondary channels shown typically at 7 these extending along on both sides of the tank and being embedded within the wall of the tank so as to provide a rigid reinforcing shape.

6 In accordance with the vertical spacing, the ridges shown say at 8 are spaced closer together than those nearer the top for instance to allow for a variation in the head pressure that the tank must resist. A further feature of the tank is that between oppositely positioned channels in 5 respective sides of the tank there is a moulded bracing shown most clearly at 10 in Figure 3 where there is moulded a conduit from one side to the other but which then provides connecting walls between respective strengthening channels such as at 7. This is achieved by having a member placed in position around which the 10 plastic is molded and then as appropriate this is removed but leaving a hollow tubular conduit which none the less acts as an internal bracing. A further feature is that each outer segment shown let us say typically at 11 is of outwardly arcuate shape or when viewed from outside has a slightly bulbus or convex shape which is consistent along the length of the tank and this provides 15 a further stiffening but also visually reduces the sensitively of planar surfaces showing even slight bulbus distortion. By using these techniques, an external face which presents as generally a large generally planar area can have all of this stiffening without being visually distasteful. 20 Further however, the length of each tank can now be chosen in accordance with the ability to strengthen and stiffen the side walls and any number of such tanks can now be joined one to another where the supporting post between them can be hidden. This then makes them ideal for applications such as providing fencing panels or 25 for being located as a barrier or shield.

7 These applications are more apparent when the further illustrations are seen for instance in Figure 6 the posts 13, 14 and 15 are embedded so that visually they are not prominent and the visually external appearance is generally of a planar barrier while usefully large quantities of water can be stored in these relatively 5 thin tanks. Interconnections between the tanks are of course according to standard techniques and do not need to be described in detail here. Now referring to figures 7 and 8, there is a bracket 16 having a portion 17 interlocking with the end channel 18 of a tank 19. 10 A further portion 20 of the bracket 16 is attached to a wall by masonry bolts shown typically at 21. In a further example there are two tanks 22 and 23 which are abutted together with a bracket 24 attached at one portion 25 to a wall 26 by masonry bolts 28 and at a further end a portion 27 extends into both channels 28 and 29 holding 15 the tanks 22 and 23 together with imperceptible visual disruption.

Claims

1. A thin tank comprised of plastics material in which there is at each end of the tank a primary channel extending from a bottom to the top of the tank and adapted to receive in nested alignment either a post which can 5 extend beyond either the bottom or top of the tank or a bracket a portion of which can engage into the channel, including; a plurality of laterally extending vertically spaced apart embedded secondary channels which are formed in each side wall and these in at least one case extend fully from one side to the opposite side of the tank; 10 further characterised in that the external wall between each secondary channel is arcuate in cross section and is of a consistent arcuate shape along its length and; where there are two vertically spaced apart laterally extending reinforcing secondary channels at an upper part of the tank which are 15 further apart than two vertically spaced apart laterally extending reinforcing secondary channels at a lower part of the tank

2. A thin tank as in anyone of the preceding claims where the vertically spaced apart embedded secondary channels are positioned in opposedly correspondingly located locations on both broad sides of the tank 20

3. A thin tank as in any one of the preceding claims further characterised in that there is moulded integrally between at least one set of oppositely positioned secondary channels, an interconnecting tie.

4. A thin tank as in the immediately preceding claim further characterised in that there are a plurality of interconnecting ties and at least one 25 between each respective oppositely positioned secondary channel. 9

5. A method of molding a thin tank as in any one of the preceding claims where the molding is by rotamolding.

6. A method of molding as in the immediately preceding claim where there is, during the moulding process, a member passing from one side of an 5 expected channel position to another and there is moulded thereby around such a member and integrating with the channels therein, such a form which thereby acts as an internal bracing between the respective sides.