AU2010212425A1

AU2010212425A1 - Artificial grass system

Info

Publication number: AU2010212425A1
Application number: AU2010212425A
Authority: AU
Original assignee: RPS Industries Pty Ltd
Current assignee: RPS Industries Pty Ltd
Priority date: 2009-08-18
Filing date: 2010-08-18
Publication date: 2011-03-10

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant(s): RPS Industries Pty Ltd Invention Title: ARTIFICIAL GRASS SYSTEM The following statement is a full description of this invention, including the best method for performing it known to me/us: -2 ARTIFICIAL GRASS SYSTEM The present invention relates to an artificial 5 (sometimes referred to in the industry as "synthetic") grass system that has a capability to capture and store rainwater that falls on the surface of the system. The present invention relates particularly, 10 although by no means exclusively, to an artificial grass system that can be used for recreational playing fields for sports, such as cricket, hockey, soccer, rugby, and football, that are exposed to the elements all of the time or for part of the time in the case of playing fields in 15 stadiums that have roofs that can be opened and closed. The present invention also relates to a recreational playing field for sports, such as cricket, hockey, soccer, rugby, and football, that includes such an 20 artificial grass system. The present invention also relates to a method of constructing such an artificial grass system. 25 According to the present invention there is provided an artificial grass system that comprises: (a) a layer of artificial grass on an area of ground; and 30 (b) at least one underground water storage tank for storing rainwater that falls on the artificial grass layer and flows downwardly through the artificial grass layer. 35 The above-described artificial grass system makes it possible to harvest and store for use (as required) a 1731145_1 ( Mattera) 18/08/10 -3 substantial part, if not all, of the rainwater that falls on the artificial grass surface. Artificial grass does not retain water - consequently substantially all, if not all, of the rainwater that falls on the artificial grass 5 flows downwardly through the grass layer and is potentially available for harvesting and subsequent use. Hence, in a situation in which the artificial grass system forms a recreational playing field, the invention can harvest water for use beneficially, for example for 10 watering and thereby maintaining gardens or natural grass recreational playing fields in the general area of the artificial grass playing field and/or for other end use applications. 15 The artificial grass may be any suitable artificial grass for a given end use activity, such as cricket and/or football. The artificial grass system may comprise a water 20 collection element between the artificial grass layer and the water storage tank that extends below at least a substantial section of the area of the artificial grass layer and is adapted to direct downwardly flowing rainwater to flow into the water storage tank. In this 25 regard, it is relevant to note that in many applications of the artificial grass system of the present invention the artificial grass layer may have a substantially larger surface area, i.e. footprint, than that of the water storage tank. The water collection layer is necessary in 30 such situations to direct downwardly flowing rainwater to the water storage tank for collection and storage in the tank. The water collection element may comprise a 35 plurality of water flow passages that can receive water that flows downwardly onto the element and can direct the water to the water storage tank or be otherwise formed to 17311451 (GHMatters) 18/08/10 - 4 direct water that contacts the water collection element into the water storage tank. The artificial grass system may comprise a shock 5 absorption element between the artificial grass layer and the water storage tank that allows water to flow through the element and is adapted to absorb impact energy of players to minimise impact injuries to players. 10 The shock absorbing element may be formed from a shock absorbing material. The shock absorption element may allow water to flow downwardly through the element. 15 The shock absorption element may allow water to flow downwardly and laterally through the element. The shock absorption element may be between the 20 artificial grass layer and the water collection layer. The shock absorption element may be made from a permeable material that allows rainwater to flow through the material. 25 The shock absorption element may be formed with passageways that allow rainwater to flow through the material. 30 The shock absorption element may have a shape that promotes shock absorption. For example, the shock absorption element may comprise voids that promote shock absorption. 35 By way of further example, the shock absorption element may comprise an upper wall and a plurality of side 1731145_1 (GHMatters) 18/08/10 -5 walls that extend downwardly from the upper wall and a plurality of open voids defined by the upper wall and the side walls. 5 The shock absorption element may be formed from a shock absorbing material, such as rubber or an ethylene vinyl acetate (EVA). The water storage tank may be located below a 10 section of the layer of artificial grass. The water storage tank may also be located away from the area of ground on which the layer of artificial grass is located. There may be situations in which it is 15 not possible to locate the water storage tank below the artificial grass layer and locating the tank away from the area of ground may be necessary. The water storage tank may comprise a framework 20 that defines a water storage chamber and an outer liner of a water impermeable material. The framework may comprise a base and sides. 25 The liner may be positioned under the base and extend up the sides of the framework. The artificial grass system may comprise a filter element above the water storage tank to prevent 30 contaminants, such as animal faecal matter, entering the water storage tank. The purpose of the filter element is to remove impurities that may significantly limit subsequent use of the water in the water storage tank. 35 The artificial grass system may comprise a water impermeable liner, for example defined by a plastic material membrane, below the water storage tank. The 1731145_1 (GHMatters) 18/08/10 - 6 purpose of the water impermeable liner is to at least partially close the system. More particularly, the artificial grass system 5 may be a completely closed system so that there is no loss of water from the system into the surrounding ground. The artificial grass system may comprise a water distribution system for distributing water in the water 10 storage tank to end-use applications for the water. According to the present invention there is also provided an artificial grass system that comprises: 15 (a) a layer of artificial grass on an area of ground; and (b) a shock absorption element beneath the artificial grass layer that allows water to flow through 20 the layer and is adapted to absorb impact of players and/or equipment on the artificial grass layer. The shock absorbing element may be formed from a shock absorbing material. 25 The shock absorption element may allow water to flow downwardly through the element. The shock absorption element may allow water to 30 flow downwardly and laterally through the element. The shock absorption element may be made from a permeable material that allows rainwater to flow through the material. 35 The shock absorption element may be formed with passageways that allow rainwater to flow through the 17311451 (GHMatters) 18/08/10 -7 material. The shock absorption element may have a shape that promotes shock absorption. 5 For example, the shock absorption element may comprise voids that promote shock absorption. By way of further example, the shock absorption 10 element may comprise an upper wall and a plurality of side walls that extend downwardly from the upper wall and a plurality of open voids defined by the upper wall and the side walls. 15 The shock absorption element may be formed from a shock absorbing material, such as rubber or an ethylene vinyl acetate (EVA). According to the present invention there is also 20 provided a recreational playing field for sports, such as cricket, hockey, soccer, rugby and football, that comprises the above-described artificial grass system. In a situation in which the artificial grass 25 system covers the whole of the playing field, the water storage tank may be adapted to store at least 2 million litres of water. According to the present invention there is also 30 provided a method of constructing the above-described artificial grass system on an area of ground that comprises: (a) excavating the area of ground; 35 (b) locating at least one water storage tank in the excavated area; and 17311451 (GHMatters) 18/08/10 - 8 (c) laying artificial grass on the area of ground. 5 According to the present invention there is also provided a method of constructing the above-described artificial grass system on an area of ground that comprises: 10 (a) excavating the area of ground; (b) locating a shock absorption element in the excavated area, the element being adapted to allow water to flow through the layer and to absorb impact of players 15 and/or equipment on artificial grass ultimately laid on the element; and (c) laying artificial grass on the area of ground. 20 The present invention is described further by way of example with reference to the accompanying drawings, of which: 25 Figure 1 is a partially cut-away perspective view of one embodiment of an artificial grass system in accordance with the present invention; Figure 2 is a vertical cross-section that further 30 illustrates the artificial grass system shown in the Figures; Figure 3 is another vertical cross-section that further illustrates the artificial grass system shown in 35 the Figures; Figure 4 is a top plan view of a section of the 1731145_1 (GHMatters) 18/08/10 - 9 shock pad layer of the artificial grass system shown in the Figures; Figure 5 is a side view of the long side of the 5 shock pad layer shown in Figure 4; and Figure 6 is a side view of the short side of the shock pad layer shown in Figure 4. 10 The Figures illustrate one embodiment of an artificial grass system in accordance with the present invention that forms a playing surface of a recreational playing field for sports, such as cricket, soccer, hockey, rugby, and football, that is exposed to the elements all 15 of the time or for part of the time as is the case of playing fields in stadiums that have roofs that can be opened and closed. With reference to Figures 1 to 3, the artificial 20 grass system is constructed by excavating a suitable area to form the playing field and the below-ground elements of the artificial grass system and then positioning the following elements in the order set out below into the excavated area to form the artificial grass system: 25 (a) a water impermeable liner 3, for example in the form of a plastic membrane 3 that is impermeable to water, that is located on the base and sides of the excavation (see Figure 3) and is designed to close the 30 system and retain water in the system, for example for environmental reasons; (b) a layer 5 of permeable material, typically a 150 mm layer of washed river sand or crushed glass, on 35 top of the membrane 3; (c) a layer 7 of a geotextile material or other 1731145_1 (GHMatters) 18/08/10 - 10 suitable that filters contaminants, such as animal faecal matter, (d) at least one underground water storage 5 chamber 9 for storing rainwater that falls on the artificial grass layer system and flows downwardly through the system - the chamber is defined by a framework of milk crates stacked on top of each other, although it is emphasised that this is only one of a number of options 10 for the framework; (e) a layer 11 of a geotextile material or other suitable material that extends over the upper wall of the chamber 9 and filters contaminants, such as animal 15 faecal matter, and purifies the water flowing into the chamber 9; (f) a layer 15 of permeable material, typically a 300 mm layer of washed river sand or crushed glass that 20 filters contaminants, such as animal faecal matter, and purifies the water flowing downwardly; (g) a layer 17 of a geotextile material or other suitable material that filters contaminants, such as 25 animal faecal matter, and purifies the water flowing downwardly; (h) a water collection element 19 that extends substantially under the whole of the footprint of the 30 playing field and directs downwardly flowing water to the water storage chamber 9 for collection and storage in the chamber - typically, the layer has a 1*-3* fall to the water storage chamber 9 footprint - the cross-section shown in Figure 3 shows that the water storage tank does 35 not extend below the whole of the surface of the layer of artificial grass and, as a consequence, the water collection layer is necessary and important in such 17311451 (GHMatters) 18/08/10 - 11 situations to maximise the harvesting of rainwater from the whole of the surface of the layer of artificial grass; (i) a layer 21 of a geotextile material or 5 other suitable material that filters contaminants, such as animal faecal matter, and purifies the water flowing downwardly; (j) a shock absorption element 23 shown in more 10 detail in Figures 4 to 6 that is adapted to absorb impact of players to minimise impact injuries to players; (k) a layer 25 of a geotextile material or other suitable material that filters contaminants, such as 15 animal faecal matter, and purifies the water flowing downwardly; and (1) a layer 27 of artificial grass that forms the playing surface of the field. 20 In effect, the liner 3, the layer 5 of permeable material, the layer 7 geotextile material, the water storage chamber 9, the layer 11 of geotextile material, and the layer 15 of permeable material define an assembly 25 of a water storage tank and a filter system for filtering water flowing into the tank. The artificial grass system also comprises a water distribution system (not shown) that comprises, by 30 way of example, water pipes (not shown) and pumps (not shown) that can distribute water from the water storage tank 9 to gardens or natural grass playing fields or other end-use applications in the vicinity of the artificial grass playing field. 35 By way of example only, the total excavation depth is approximately 1.4 m and the water storage tank 17311451 (GHMatters) 18/08/10 - 12 has a 3 million litre capacity. Typically, the dimensions of the tank are: 80 m long, 46 m wide and 0.88 m deep. With reference to Figures 4 to 6, the shock 5 absorption element 23 for this embodiment of the present invention comprises a plurality of mats 31 that are laid on the surface of the geotextile layer 21 to form a continuous element 23. Each mat 31 is made from a shock absorbing material such a rubber or an EVA that is moulded 10 into a shape that promotes shock absorption. Specifically, each mat 31 comprises voids that promote shock absorption. More specifically, each mat 31 comprises a combination of a moulded shock absorbing material structure that includes voids, whereby the 15 combination of the properties of the material and the shape of the mats (including the voids) promotes shock absorption. With particular reference to Figures 4 to 6, each mat 31 comprises an upper wall 33 and a plurality of downwardly depending side walls 35 and a plurality of open 20 voids 37 defined by the upper wall 33 and the side walls 35. The above-described artificial grass system is an effective system for collecting rainwater that falls on 25 the artificial grass layer 27 so that the water can be used as required beneficially and does not simply drain away. Many modifications may be made to the present 30 invention as described above without departing from the spirit and scope of the invention. By way of example, whilst the embodiment of the artificial grass system is described with reference to the 35 Figures in the context of use for recreational playing fields for playing sports, such as cricket, soccer, hockey, rugby and football, the present invention is not 1731145 1 (GHMattera) 18/08/10 - 13 so limited and extends to other uses of artificial grass systems, such as artificial lawn areas in garden settings. By way of further example, whilst the embodiment 5 of the artificial grass system is described with reference to the Figures comprises a water storage tank, the present invention is not so limited and extends to systems that do not include tanks and do not otherwise harvest water. In particular, the present invention also includes 10 embodiments that are based on the combination of a shock absorption element (such as the element 23 in the Figures) and an artificial grass layer (such as the layer 27 in the Figures). 15 By way of further example, whilst the embodiment of the artificial grass system is described with reference to the Figures in the context of a single water storage tank, the present invention is not so limited and extends to the use of a plurality of such tanks positioned under 20 the artificial grass. By way of further example, whilst the embodiment of the artificial grass system described with reference to the Figures comprises a single water storage tank located 25 below the artificial grass layer 27, the present invention is not so limited and extends to arrangements in which the water storage tank is located outside the area covered by the artificial grass layer 27. As discussed above, this may be appropriate in a number of situations, for example, 30 where there are constraints on excavating in the ground on which the artificial grass layer 27 is required. By way of further example, whilst the embodiment of the artificial grass system described with reference to 35 the Figures comprises harvesting rainwater that flows onto and through the artificial grass layer 27, the present invention is not so limited and extends to harvesting 1731145_1 (CHMatters) 18/08/10 - 14 rainwater from a range of urban surfaces, such as roofs of buildings and carparks, and from stormwater systems. Specifically, in addition to being a range to receive rainwater flowing downwardly through the artificial grass 5 layer 27, the water storage tank may also be connected to harvest water from these urban surfaces and stormwater systems. 1731145_1 (GHMatters) 18/08/10

Claims

1. An artificial grass system that comprises: 5 (a) a layer of artificial grass on an area of ground; and (b) at least one underground water storage tank for storing rainwater that falls on the artificial grass 10 layer and flows downwardly through the artificial grass layer.

2. The artificial grass system defined in claim 1 comprises a water collection element between the 15 artificial grass layer and the water storage tank and extends below at least a substantial section of the area of the artificial grass layer and is adapted to direct downwardly flowing rainwater to flow into the water storage tank. 20

3. The artificial grass system defined in claim 2 wherein the water collection element comprises a plurality of water flow passages that can receive water that flows downwardly onto the element and can direct the water to 25 the water storage tank.

4. The artificial grass system defined in any one of the preceding claims comprises a shock absorption element between the artificial grass layer and the water storage 30 tank that allows water to flow through the layer and is adapted to absorb impact of players and/or equipment on the artificial grass layer.

5. The artificial grass system defined in claim 4 35 wherein the shock absorption element is between the artificial grass layer and the water collection layer. 1731145_1 (GHMatters) 18/08/10 - 16

6. The artificial grass system defined in claim 4 or claim 5 wherein the shock absorption element is formed from a shock absorbing material 5

7. The artificial grass system defined in any one of claims 4 to 6 wherein the shock absorption element allows water to flow downwardly through the element. 10

8. The artificial grass system defined in any one of claims 4 to 7 wherein shock absorption element allows water to flow downwardly and laterally through the element. 15

9. The artificial grass system defined in any one of claims 4 to 8 wherein the shock absorption element is made from a permeable material that allows rainwater to flow downwardly through the material. 20

10. The artificial grass system defined in any one of claims 4 to 9 comprises an upper wall and a plurality of side walls that extend downwardly from the upper wall and a plurality of open voids defined by the upper wall and the side walls. 25

11. The artificial grass system defined in any one of the preceding claims wherein the water storage tank is located below a section of the artificial grass. 30

12. The artificial grass system defined in any one of claims 1 to 10 wherein the water storage tank is located away from the area of ground on which the layer of artificial grass is located. 35

13. The artificial grass system defined in any one of the preceding claims comprises a filter element above the water storage tank to prevent contaminants, such as animal 1731145_1 (GHMatters) 18/08/10 - 17 faecal matter, entering the water storage tank.

14. The artificial grass system defined in any one of the preceding claims comprises a water impermeable layer, 5 for example defined by a plastic material membrane, below the water storage tank.

15. The artificial grass system defined in any one of the preceding claims comprises a water distribution system 10 for distributing water in the water storage tank to end use applications for the water.

16. An artificial grass system that comprises: 15 (a) a layer of artificial grass on an area of ground; and (b) a shock absorption element beneath the artificial grass layer that allows water to flow through 20 the layer and is adapted to absorb impact of players and/or equipment on the artificial grass layer.

17. The artificial grass system defined in claim 16 wherein the shock absorbing element is formed from a shock 25 absorbing material.

18. The artificial grass system defined in claim 16 or claim 17 wherein the shock absorption element is made from a permeable material that allows rainwater to flow 30 through the material.

19. The artificial grass system defined in any one of claims 16 to 18 wherein the shock absorption element allows water to flow downwardly through the element. 35

20. The artificial grass system defined in any one of claims 16 to 18 wherein the shock absorption element 1731145_1 (GHMatters) 18/08/10 - 18 allows water to flow downwardly and laterally through the element.

21. The artificial grass system defined in any one of 5 claims 16 to 20 wherein the shock absorption element is formed with passageways that allow rainwater to flow through the material.

22. The artificial grass system defined in any one of 10 claims 16 to 21 wherein the shock absorption element has a shape that promotes shock absorption.

23. The artificial grass system defined in any one of claims 16 to 22 wherein the shock absorption element 15 comprises voids that promote shock absorption.

24. The artificial grass system defined in any one of claims 16 to 23 wherein the shock absorption element comprises an upper wall and a plurality of side walls that 20 extend downwardly from the upper wall and a plurality of open voids defined by the upper wall and the side walls.

25. The artificial grass system defined in any one of claims 16 to 24 wherein the shock absorption element is 25 formed from a shock absorbing material, such as rubber or an ethylene-vinyl acetate (EVA).

26. A recreational playing field for sports that comprises the artificial grass system defined in any one 30 of the preceding claims.

27. A method of constructing the artificial grass system defined in any one of claims 1 to 15 on an area of ground comprises: 35 (a) excavating the area of ground; 1731145_1 (GHMatters) 18/08/10 - 19 (b) locating at least one water storage tank in the excavated area; and (c) laying artificial grass on the area of ground. 5

28. A method of constructing the artificial grass system defined in any one of claims 16 to 25 on an area of ground comprises: 10 (a) excavating the area of ground; (b) locating a shock absorption element in the excavated area, the element being adapted to allow water to flow through the layer and to absorb impact of players 15 and/or equipment on artificial grass ultimately laid on the element; and (c) laying artificial grass on the area of ground. 1731145_1 (GHMatters) 18/08/10