Artificial surface

TECHNOLOGICAL FIELD

Examples of the disclosure relate to a structure, and particularly a structure defining an area for sporting activity.

BACKGROUND

Artificial surfaces are used for various sporting activities. Artificial surfaces are known to be a contributing factor in injuries sustained during sporting activities.

It is desirable therefore to provide artificial surfaces which reduce the risk of injury.

BRIEF SUMMARY

According to various, but not necessarily all, examples of the disclosure there is provided a structure defining an area for sporting activity, wherein the structure comprises:

an upper artificial surface layer;

a shock absorbing layer underlying the upper artificial surface layer; and a support structure layer underlying the shock absorbing layer.

A membrane layer may be provided between the upper artificial surface layer and the shock absorbing layer. The membrane layer provided between the upper artificial surface layer and the shock absorbing layer may comprise felt. The upper artificial surface layer may comprise a textured underside to substantially limit relative movement of the membrane layer. A membrane layer may be provided between the shock absorbing layer and the support layer. The membrane layer provided between the shock absorbing layer and the support layer may comprise a permeable fabric, such as a geotextile, to allow drainage therethrough. The upper artificial surface layer may comprise an infilled artificial turf system. The infilled artificial turf system may comprise a turf and an infill. The infill may comprise a mixture of at least two different materials. Possibly, a first of the at least two different materials is an elastic material and a second of the materials is a non elastic material. The first material may comprise cork. The second material may comprise silica sand. The ratio of first material to second material in the infill may be from 1 to 15 to 1 to 20 (dry weight).

The turf may be filled with infill to a height of 10 mm to 35 mm, and more particularly to a height of 25 mm to 30 mm.

The turf may comprise a mixture of different length fibres, and may comprise at least two different length fibres. Possibly the relatively longer fibres have a length of 40 mm, and the relatively shorter fibres have a length of 20 mm. The relatively shorter fibres may have a wavy profile. Alternatively, the turf may comprise only fibres of substantially the same length. The fibres may all have a length of 40 mm.

The shock absorbing layer may comprise at least one sub layer. Each of the at least one sub layers may comprise a plurality of shock absorbing units. The shock absorbing units may comprise a shock absorbing material. The shock absorbing material may be a foam.

The shock absorbing layer may comprise a plurality of sub layers. Possibly, each of the sub layers comprises a plurality of shock absorbing units. Possibly, each of the plurality of shock absorbing units comprise a shock absorbing material. The shock absorbing material may be a foam.

Drainage channels may be provided between adjacent shock absorbing units.

A sub layer with a greater thickness and a lesser density may be provided between sub layers with a lesser thickness and greater density.

The shock absorbing layer may comprise three sub layers, wherein two of the sub layers have a first thickness, and one of the sub layers has a second thickness, wherein the second thickness is greater than the first thickness. The sub layers with the first thickness may have a greater density than the sub layer with the second thickness. The sub layer with the second thickness may be provided between the sub layers with the first thickness. The first thickness may be 10 mm and the second thickness may be 16 mm.

The support structure layer may comprise a frame, wherein the frame comprises a plurality of cavities. The frame may be formed of a plastics material. The frame may comprise cavities of different shapes and volumes.

In some examples, at least a selection of the plurality of cavities are filled with a shock absorbing material. All the cavities may be filled with a shock absorbing material. The shock absorbing material may comprise a foam. Drainage channels may be provided in the frame between adjacent cavities.

In other examples, the support structure layer may comprise a particulate material. The particulate material may comprise limestone, and may comprise compressed limestone. The particulate material may be configured to permit drainage therethrough.

According to various, but not necessarily all, examples of the disclosure there is provided a method of providing a structure defining an area for sporting activity, wherein the method comprises: providing a support structure layer as a lowermost layer; providing a shock absorbing layer overlying the support layer; and providing an upper artificial surface layer as an uppermost layer.

According to various, but not necessarily all, examples of the disclosure there is provided an infilled artificial turf system, wherein the system comprises an artificial turf and an infill, wherein the infill comprises a mixture of at least two different materials, wherein a first material comprises cork, and a second material comprises a solid particulate.

The solid particulate may comprise silica sand. The ratio of cork to silica sand in the infill may be from 1 to 15 to 1 to 20 (dry weight). According to various, but not necessarily all, examples of the disclosure there is provided an infill for an artificial turf system, wherein the infill comprises a mixture of at least two different materials, wherein a first material comprises cork, and a second material comprises silica sand. The artificial turf system comprises a turf and the infill

The ratio of cork to silica sand in the infill may be from 1 to 15 to 1 to 20 (dry weight).

According to various, but not necessarily all, examples of the disclosure there is provided a support structure comprising a frame, wherein the frame comprises a plurality of cavities, wherein at least a selection of the plurality of cavities are filled with a shock absorbing material.

The frame may be formed of a plastics material. The shock absorbing material may comprise a foam. All the cavities may be filled with a shock absorbing material.

According to various, but not necessarily all, examples of the disclosure there may be provided examples as claimed in the appended claims.

BRIEF DESCRIPTION

For a better understanding of various examples that are useful for understanding the detailed description, reference will now be made by way of example only to the accompanying drawing in which:

Fig. 1 illustrates a cross section of a structure; and

Fig. 2 illustrates a cross section of another structure.

DETAILED DESCRIPTION

As illustrated in the figures, examples of the disclosure provide a structure 10 defining an area for sporting activity. The figures illustrate only a section of a structure 10, which may extend to cover an entire playing surface, i.e. an entire area, used in a particular sporting activity. The structure 10 comprises: an upper artificial surface layer 12; a shock absorbing layer 14 underlying the upper artificial surface layer 12; and a support structure layer 16 underlying the shock absorbing layer 14.

The structure 10 may have a thickness of 100 to 150 mm.

Example structures 10 define an area suitable for a range of different sporting activities, including for example, equestrian sports, football, hockey, children’s playground, or multi-sports applications.

In some examples, a membrane layer 18 is provided between the upper artificial surface layer 12 and the shock absorbing layer 14. A membrane 19 may also be provided between the shock absorbing layer 14 and the support layer 16. The membrane 18, 19 may be held in place by friction.

With regard to the membrane layer 18 between the upper artificial surface layer 12 and the shock absorbing layer 14, in some example this may comprise felt. The felt membrane layer 18 may be held under tension. The felt membrane layer 18 may be held in place by friction. For example, the underside of the upper artificial surface layer 12 may have a contacting surface which is textured to substantially limit relative movement of the felt membrane layer 18. The textured surface may comprise ridges.

The felt membrane layer 18 provides a cushioning effect and distributes impact force. The felt membrane layer 18 may have a thickness of up to 5 mm.

The felt may be dense engineering felt. The felt may comprise polyester.

The membrane, for example, felt may provide dimensional stability, and may reduce vibrations.

The membrane layer 19 provided between the shock absorbing layer 14 and the support layer 16 may comprise a permeable fabric, such as a geotextile, to allow drainage therethrough. The membrane layer 19 may be held in place by friction. The membrane layer 19 may have a thickness of 1 mm. The membrane 19 may be non-woven. The membrane 19 provides a barrier which prevents the shock absorbing layer 14 being damaged by the support layer 16, or at least substantially limits such damage.

As noted above, the structure 10 comprises an upper artificial surface layer

12.

In some examples, the upper artificial surface layer 12 comprise an infilled artificial turf system 20. The infilled artificial turf system 20 comprise a turf 22, for example, an artificial turf 22 comprising synthetic fibres 26, 28, and an infill 24. Synthetic fibres 26, 28 are artificial grass fibres.

In some examples, the infill 24 comprises a mixture of at least two different materials. A first of the at least two different materials may be an elastic material and a second of the materials may be a non-elastic material. In some examples, the first material is cork, and in particular granulated cork, and the second material is silica sand, and in particular washed silica sand. The sand may be play sand, for example comprising crystalline silica.

An elastic material is a material which is resiliently deformable, i.e. able to resume its normal state spontaneously after being compressed.

Silica sand adds weight to the upper artificial surface layer 12, provides slip resistance and supports the artificial grass fibres 26, 28. The combination of silica sand and cork effectively dissipates impact force. For example, in an equestrian application, the impact force of a hoof strike is dissipated providing shock absorption and stability to the horse’s foot balance with minimal vertical deformation of the upper surface layer 12. The infill 24 comprising silica sand and cork also provides energy restitution, and a rapid infiltration rate. Furthermore, cork provides a micro climate, frost resistance, prevents overheating and releases beneficial gases. What is more, cork is a renewable resource and therefore environmentally friendly.

Infill 24 according to examples of the disclosure may be natural infill 24, that is, the infill 24 only comprises materials found in nature. The infill 24 does not comprise synthetic materials, such as synthetic rubbers or other synthetic polymers. The infill 24 may be premixed and pre-soaked to a specific moisture content.

In some examples, the ratio of first material to second material in the infill may be from 1 to 15 to 1 to 20 (dry weight). For example, in applications where a relatively stiffer surface is required, the ratio of cork to silica sand in the infill 24 is 1 to 20 (dry weight), which is 1 to 10 (wet weight once the cork has been wetted). In other applications, for example when a relatively more springy surface is required, the ratio of cork to silica sand in the infill 24 is 1 to 15 (dry weight).

An example infill 24 is now described. The example infill 24 comprises high quality silica sand with sub rounded grains (play sand). The sand has been multi- washed, screened, and officially graded to comply with BSEN 71-3 2013 for chemical toxicity and BSEN 1177 2008 for impact absorption. The selected sand is a durable, light, golden yellow, soft-textured, free-flowing, non-straining material, with excellent drainage and very low abrasion on skin contact. The example infill 24 also comprises premium granulated cork (1-2 mm grain size). The selected cork has no chemical contaminate, is an eco-safety product, has high elasticity (returning to original shape after compression), is a durable flexible aggregate, is buoyant, is decay resistant, has high fire resistance, and can decrease surface temperature by 30%. In use, the selected sand and cork are pre-mixed before applying to artificial turf to a depth of 15 to 20 mm. The infill 24 is then sprayed with water to wet the cork granules which increase in volume by up to 100% and become more elastic when fully hydrated. The ratio of water to be applied is 25% of the combined weight of the dry infill ingredients.

In some examples, the turf 22 comprises a mixture of different length fibres 26, 28, and may comprise at least two different length fibres 26, 28. In some examples, the longer length fibres 26 are about double the length of the shorter length fibres 28. For example, the relatively longer fibres may have a length of 40 mm, and the relatively shorter fibres 28 may have a length of 20 mm.

The relatively shorter fibres 28 may provide an underlayer of fibres at the root base of the relatively longer fibres 26 to reduce splash of infill on impact, and this effect may be enhanced in examples where the relatively shorter fibres 28 have a wavy profile. Fig. 1 illustrates an example in which the relatively shorter fibres 28 have a wavy profile and the relatively longer fibres 26 have a substantially straight profile, i.e. non wavy profile. The wavy profile of the relatively shorter fibres 28 acts to trap pockets of infill 24. A wavy profile means that each relatively shorter fibre curves in and out in the form of a wave.

The turf 22 may comprise a mixture of relatively harder fibres 26 and relatively softer fibres 28. In the illustrated example, the relatively harder fibres 26 have a greater length than the relatively softer fibres 28. The relatively harder fibres 26 may have length about double that of the relatively softer fibres 28. In some example, the relatively harder fibres 26 have a length of 40 mm, and the relatively softer fibres 28 have a length of 20 mm.

In other examples, the turf 22 comprises only fibres of substantially the same length. For instance, figure 2 illustrates an example comprising only relatively longer fibres 26. In such examples, the fibres 26 may all have a length of 40 mm.

The turf 22 may comprise artificial grass fibre 26, 28 having a thickness of 360 microns or of at least 360 microns. The turf 22 may be artificial 3G grass fibre.

The turf 22 may be filled with infill 24 to a height of 10 mm to 35 mm, and more particularly may be filled to a height of 25 mm to 30 mm. It is to be understood that the average height of the infill across the area is within the stated range.

In some examples, wherein the turf 22 comprises only fibres of substantially the same length, wherein the length of the fibres is 40 mm, the height of the infill is 25 mm to 30 mm. It had been found that this particular arrangement has excellent slip resistance.

In some example, drainage holes (not illustrated) are provided in the upper artificial surface layer 12. The drainage holes may be evenly spaced, and in some examples are evenly spaced 10 cm apart.

As noted above, the structure 10 comprises a shock absorbing layer 14. The shock absorbing layer 14 absorbs and dissipates at least some of the energy of a shock or impact, provides energy absorption over a large area, and provides return energy.

The shock absorbing layer 14 comprises at least one sub layer 30. In some examples, the shock absorbing layer 14 comprises a plurality of sub layers 30. Each respective sub layer 30 comprises an upper portion 32 and a lower portion 34. The plurality of sub layers 30 may be separate and discrete from one another. In some examples, each respective sub layer 30 comprises a plurality of shock absorbing units 36. The upper portion 32 may comprise a plurality of shock absorbing units 36. The lower portion 34 may comprise a plurality of shock absorbing units 36. Adjacent shock absorbing units 36 may be connected. The shock absorbing units 36 comprise a shock absorbing material. The shock absorbing material may be a foam.

Drainage channels 38 may be provided between adjacent shock absorbing units 36. Each respective drainage channel 38 may extend substantially perpendicular relative to the shock absorbing layer 30. Drainage channels 38 provided in the upper portion 32 may be offset from drainage channels 38 provided in the lower portion 34.

In examples of the disclosure comprising a plurality of sub layers 30, the respective plurality of sub layers 30 may be configured such that drainage channels 38 provided in the lower portion 34 of a first sub layer 30 are offset from drainage channels 38 provided in the upper portion 34 of a second sub layer 30, wherein the second sub layer 30 underlies the first sub layer 30.

In some examples, the shock absorbing layer 14 comprises a plurality of sub layers 30, wherein each respective sub layer 30 provides a different level of shock absorption. The level of shock absorption may be determined, for example, by the density, thickness and material of the sub layer 30.

Each respective unit 36 may form a tile.

In some examples, each respective sub layer 30 may have a substantially similar thickness, for example, of 20 mm. In the illustrated examples, the shock absorbing layer 14 comprise three sub layers 30, and therefore the shock absorbing layer 14 has a thickness of 60 mm. In other examples, the shock absorbing layer 14 may comprise a single sub layer 30, and is therefore a single layer.

In some examples, the shock absorbing layer 14 comprises at least two sub layers 30, each with a different thickness. In other examples, the shock absorbing layer 14 comprises at least three sub layers 30, wherein two of the at least three sub layers 30 have a first thickness, and a one of the at least three sub layers 30 has a second thickness. In some examples, the second thickness is greater than the first thickness. In other examples, the first thickness is greater than the second thickness. In such examples, the sub layer 30 with the lesser thickness may have the greater density. The sub layer 30 with the lesser density may be relatively softer.

In some examples, a sub layer 30 with a greater thickness and a lesser density is provided between sub layers 30 with a lesser thickness and greater density. In such examples, the cushioning provided by the shock absorbing layer 14 and the return energy is optimally balanced.

In one example, the shock absorbing layer 14 comprises three sub layers 30, wherein two of the sub layers 30 have a first thickness, and one of the sub layers 30 has a second thickness. The second thickness is greater than the first thickness. The sub layers 30 with the first thickness have a greater density than the sub layer 30 with the second thickness. The sub layer 30 with the second thickness is provided between the sub layers 30 with the first thickness. The sub layer 30 with the second thickness is therefore sandwiched between the sub layers 30 with the first thickness. In some examples, the first thickness is 10 mm and the second thickness is 16 mm.

The shock absorbing material is also resiliently deformable, i.e. able to resume its normal state spontaneously after being compressed.

As noted above, the structure 10 comprises a support structure layer 16.

In some examples, the support structure layer 16 comprises a frame 40, wherein the frame 40 comprises a plurality of cavities 42. The frame 40 defines a grid. The frame 40 may be formed of a plastics material. The frame 40 may comprise a plurality of discrete cavities 42. As illustrated in Fig. 1 , the frame 40 may comprise cavities 42 of different shapes and volumes. For example, a selection of the cavities 42 may define a first volume and a selection of the cavities 42 may define a second volume, wherein the first and second volumes are different.

In some examples, at least a selection of the plurality of cavities 42 are filled with a shock absorbing material. All the cavities 42 may be filled with a shock absorbing material. The shock absorbing material may comprise a foam. The support structure layer may comprise drainage channels 44. The drainage channels 44 may be provided in the frame 40 between adjacent cavities 42.

In other examples, the support structure layer 16 may comprise a particulate material 46. Drainage channels 44 may be defined by the gaps between the particulate material 46. Accordingly, the particulate material 46 is configured to permit drainage therethrough. The particulate material 46 may comprise limestone, and may comprise compressed limestone.

In other examples (not illustrated), the support structure layer 16 may comprise a particulate material 46 (as illustrated in Fig. 2) underlying a frame 40 comprising a plurality of cavities 42 (as illustrated in Fig. 1).

The support layer may have a thickness of 50 mm.

Examples of the disclosure also provide a method of providing a structure 10 defining an area for sporting activity. The method comprises providing a support structure layer 16 as a lowermost layer, providing a shock absorbing layer 14 overlying the support layer 16, and providing an upper artificial surface layer 12 as an uppermost layer.

The support structure layer 16 may be laid as a first step. In examples where the support structure layer 16 comprises a particulate material 46 (Fig. 2), the particulate material 46 may be provided to the required depth. In examples where the support structure layer 16 comprises a frame 40 (Fig. 1), the frame 40 may be provided as a plurality of parts which are assembled in use to cover an area. The parts may interlock. In some examples, a membrane 19 is laid over the support structure layer 16. A shock absorbing layer 14 is subsequently provided overlying the membrane 19 if present, or directly overlying the support layer 16. The shock absorbing layer 14 may be provided as a plurality of parts which are assembled in use to cover an area.

In some examples a felt membrane layer 18 is laid over the shock absorbing layer 14. The felt membrane layer 18 may be tensioned over the shock absorbing layer 14. Subsequently, an upper artificial surface layer 12 is provided as an uppermost layer. The upper artificial surface layer 12 may be tensioned over the felt membrane layer 18 if present, or directly over the shock absorbing layer 14.

Examples of the disclosure also provide an infilled artificial turf system 20. The system 20 comprises an artificial turf 22 and an infill 24. The infill 24 comprises a mixture of at least two different materials, wherein a first material comprises cork, and a second material comprises a solid particulate.

The solid particulate may comprise silica sand.

Examples of the disclosure also provide a support structure 16 comprising a frame 40. The frame 40 comprises a plurality of cavities 42. At least a selection of the plurality of cavities 42 are filled with a shock absorbing material. The frame 40 may be formed of a plastics material.

The shock absorbing material may comprise a foam. All the cavities 42 may be filled with a shock absorbing material. The cavities may be filled with a shock absorbing material by injection moulding.

Examples of the disclosure provide a number of advantages as detailed above. Furthermore, structures 10 reduce the risk of injury because the particular combination of layers and materials provides an optimum balance of impact resistance and return energy. For equestrian applications, the structure 10 provides the required levels of shock absorption and torque to provide an optimum surface for a galloping horse. Furthermore, the structure 10 could be readily and quickly put together to provide a temporary surface, and readily and quickly dismantled when no longer required. Alternatively, the structure 10 is robust and could therefore provide a permanent surface. The structure 10 provides an allweather surface for sporting activities. The structure requires minimal maintenance.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed.

Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

The term “comprise” is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use “comprise” with an exclusive meaning then it will be made clear in the context by referring to“comprising only one...” or by using“consisting”.

In this brief description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term“example” or “for example” or“may” in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus“example”,“for example” or“may” refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub class of the class that comprise some but not all of the instances in the class. It is therefore implicitly disclosed that features described with reference to one example but not with reference to another example, can where possible be used in that other example but does not necessarily have to be used in that other example.

Whilst endeavoring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

I/we claim: