GB2474711A

GB2474711A - Synthetic grass cricket mat

Info

Publication number: GB2474711A
Application number: GB0918730A
Authority: GB
Inventors: Steve Foxon; Nicholas James Mclaren
Original assignee: NOTTS SPORT Ltd
Current assignee: NOTTS SPORT Ltd
Priority date: 2009-10-26
Filing date: 2009-10-26
Publication date: 2011-04-27
Anticipated expiration: 2029-10-26
Also published as: GB0918730D0; GB2474711B

Abstract

A cricket neat comprises a base layer 1 of foam or rubber adhered to an upper carpet layer 2 of synthetic grass piles, wherein the mat can be rolled for storage and unrolled for use. The invention also concerns a playing surface comprising a mat and one or more edging strips (10, figure 4) arranged for connection to an edge of the mat. Also disclosed is a method of forming a cricket pitch which comprises laying a mat over an artificial playing surface.

Description

A PLAYING SURFACE AND METHOD OF LAYING A PLAYING

SURFACE

This invention concerns a playing surface and method of laying a playing surface. The invention has particular, but not exclusive, application to a mat and a method of laying a mat on an artificial playing surface, such as artificial turf comprising an inf ill of rubber particles and sand, for forming a cricket pitch.

Artificial turf comprising artificial grass pile and an infill of rubber particles and sand embedded in the pile is known, often called third generation (3G) pitches. These pitches are particular suitable for games such as football (soccer) and rugby. However, such playing surfaces are unsuitable for sports involving a hard ball that is bounced on a surface as part of the game, such as cricket, as the presence of the rubber particulate infill makes the hard ball bounce unnaturally and dangerously from the artificial surface. However, with the prevalence of 3G pitches it is desirable to use these pitches for a wider range of sports than is currently possible.

According to a first aspect of the invention there is provided a cricket mat comprising a base layer of foam or rubber adhered to an upper carpet layer of synthetic grass piles, wherein the mat can be rolled for storage and unrolled for use.

In this way, the cricket mat can be rolled over at least part of an artificial playing surface that has unsuitable bounce characteristics for a cricket ball, the mat negating the effect of the underlying artificial playing surface such that suitable bounce characteristics for a cricket ball are achieved. The cricket mat may comprise markings of a cricket pitch, for example markings delineating the creases, and the dimensions of the mat may be of the order, or at least only slightly larger or smaller (such as a few metres more or less), than a standard cricket pitch, for example of the order of 20 to 28m long and im to 4m wide. In one embodiment, the cricket mat is 24m long and 2m wide. A cricket mat slightly longer than the standard cricket pitch length of 20.12m (22 yards) accommodates for a few strides of the bowler's run-up giving the bowler surer footing immediately before the bowler delivers the ball.

The effectiveness of the cricket mat in negating the effects of the underlying surface on the bounce of the cricket ball and providing a bounce that adequately mimics the bounce from a grass cricket pitch is dependent on the nature of the base layer and upper carpet layer.

It has been found that a base layer of foam having a density of 50 to 90kg/rn3 provides bounce characteristics that approximate the bounce of a cricket ball on a grass wicket. In particular, foam having a density within this range is stiff enough to generate a suitable bounce for a cricket ball but not too stiff to prevent the mat from being rolled for storage. The foam may be a closed cell foam such that it does not absorb moisture and may be polyethylene. As an alternative, the foam may be polyurethane.

The base layer may have a thickness of 6 to 12mm and preferably 10mm.

The foam base layer may comprise slits extending there-through, the slits allowing for expansion of the foam. The slits may be arranged in two directions, preferably perpendicular directions. The slits may extend at an angle, preferably at an angle between 30° to 70°, and most preferably 40° to 50°. Alternatively, the slits (e.g. all the slits) may be parallel but offset from one another. The foam base layer may comprise slits as disclosed in W02008/046912A1.

A base layer of foam is desirable as it results in a lightweight mat that can be lifted easily. However, in another embodiment, the base layer is rubber arranged to provide a suitable bounce. Rubber is less desirable than foam because a mat comprising a rubber base layer is heavier and may be difficult to lift during storage and laying of the mat.

The upper carpet layer may comprise a resin impregnated textile layer, for example the carpet layer may comprise a resin impregnated backing.

The carpet layer may comprise a pile having a height of between 4 to 9mm and preferably between 6 to 8mm. A carpet layer having a pile height longer then 9mm may need to be filled with sand making the mat unsuitable for rolling and unrolling.

The pile may comprise a mix of fibres comprising a first set of fibres having a first denier per filament, for example a denier per filament of 60 to 80, and a second set of fibres having a second denier per filament different to the first denier per filament, for example a denier per filament of 100 to 120. The total fibre weight may be 1000 to 1300 grams/m2. It has been found that carpet layer with this pile height, denier and weight provides suitable bounce characteristics for a cricket ball.

The fibre may be a suitable plastic fibre, such as UVF polypropylene.

The carpet layer may be a resin impregnated carpet layer having a resin impregnated backing. The resin impregnated backing may have a thickness of between 2 and 6mm and preferably 4mm. The resin impregnated backing of the carpet layer may have a denier of between 12 and 18 denier and preferably 15 denier.

A suitable bounce characteristic for a cricket ball may be a rebound height of between 240 to 560mm when a cricket ball (complying with BS5993) is dropped on a surface from a height of 2000mm.

The carpet layer may comprise a stabilising layer, such as a scrim, through which the fibres extend. The carpet may be formed by needle punching the fibres through the stabilising layer. The stabilising layer may be made of polyester and the fibres may be needle punched through the stabilising layer.

The base layer may be adhered to the carpet layer by way of melting and setting the base layer to the carpet layer. This provides a simple way to attach the two layers together without requiring a separate adhesive.

An anti-slip layer having an abrasive surface may be attached to the lower surface of the base layer. The anti-slip layer grips an underlying surface on which the mat is placed to reduce the chances of the mat from moving in use.

According to a second aspect of the invention there is provided a cricket pitch assembly comprising a mat according to the first aspect of the invention and one or more edging strips arranged for connection to an edge of the mat.

The weight of the edging strips may prevent the edges of the mat from curling up when the mat is laid on a surface. Furthermore, the edging strips may provide a smooth transition from the surface on which the mat is laid and the upper surface of the mat. Accordingly, in one embodiment, the edging strips comprise a wedge shape. Each edging strip may further comprise a recess into which the mat can be inserted to secure the edging strip to the mat.

The edging strips may be made of rubber material or the like that can be easily moulded to the required shape and has sufficient weight to prevent the edges of the mat from curling up. In one embodiment, the edging strips have a weight of between 1.5 and 2.5 kg per linear m.

According to a third aspect of the invention there is provided a method of forming a cricket pitch comprising laying a mat over an artificial playing surface comprising an infill of rubber particles and sand embed in the pile of the playing surface, wherein the mat is arranged such that a bounce of a cricket ball on the mat is different relative to a bounce of a cricket ball on the artificial playing surface.

In this way, the artificial playing surface can be used for games, such as cricket.

The mat may be a mat according to the first aspect of the invention. This is advantageous as such a mat may provide a bounce for a cricket ball that is similar to the bounce of a cricket ball on a grass cricket pitch.

The method may further comprise securing edging strips to the mat.

According to a fourth aspect of the invention there is provided a method of forming a cricket pitch comprising laying a mat according to the first aspect of the invention on a surface.

The surface may be an artificial playing surface or may be "natural" playing surface such as grass.

According to a fifth aspect of the invention there is provided a kit for forming an artificial playing surface, the kit comprising a mat for laying on a surface and edging strips, each edging strip arranged for receiving an edge of the mat to prevent the edges of the mat from curling and providing a slope to guide a ball onto the mat from a surface on which the mat has been laid.

According to a sixth aspect of the invention there is provided a method of forming an artificial playing surface comprising laying a mat on a surface and inserting edges of the mat into edging strips, the edging strips preventing the edges of the mat from curling and providing a slope to guide a ball onto the mat from the surface on which the mat has been laid.

In this way, the chances of a person tripping over an edge of the mat or the ball being stopped or undesirably deflected by the edge of the mat is reduced.

The edging strips may comprise a recess for receiving the mat and the method comprises inserting the edges of the mat into the recesses of the edging strips.

The method may comprise unrolling the mat onto the surface. As the mat is laid on the surface from a rolled condition, there is a tendency for the edges of the mat to curl up and the provision of edging strips reduces and/or eliminates curled edges on the laid mat. The method may further comprise rolling the mat back into a rolled condition when not in use.

Embodiments of the invention will now be described, by example only, with reference to the accompanying drawings, in which:-FIGURE 1 is a perspective view of a section of a cricket mat according to an embodiment of the invention; FIGURE 2 is a cross-sectional view of a section of the cricket mat shown in Figure 1; FIGURE 3 is a plan view of a bottom of a section of the cricket mat shown in Figures 1 and 2 with the anti-slip layer removed; FIGURE 4 is a perspective view of the cricket pitch assembly comprising a cricket mat as shown in Figures 1 to 3, assembled to form a cricket pitch; FIGURE 5 is a perspective view of an end of an edging strip to be assembled with a cricket mat.

Referring to the Figures 1 to 5, a cricket mat 9 according to one embodiment of the invention comprises a base layer 1 of foam, in this embodiment closed cell polyethylene foam, adhered to an upper carpet layer 2 of synthetic grass piles.

An anti-slip layer 3, in this embodiment a scrim, having an abrasive lower surface 3a is attached to the lower surface of the base layer 1. The anti-slip layer 3 grips an underlying surface on which the mat is placed to reduce the chances of the mat moving in use compared to a mat wherein the lower surface is the polyethylene foam of the base layer 1.

The upper carpet layer 2 comprises a textile layer of UVF polypropylene fibres 5 needle punched through a scrim 4, the fibres rearward of the scrim bonded together by a resin to form resin impregnated backing 6.

The carpet layer comprises a pile having a height of 6mm and a mixture of fibres, a first set of fibres having a denier per filament of 70 and a second set of fibres having a denier per filament of 110.

The resin impregnated backing layer 6 is 4mm thick. The scrim 4 is spunbond polyester weighing lOOg/m2.

The base layer 1 is made of foam having a density of 70kg/rn3. As can be seen most clearly in Figure 3, the base layer 1 comprises a plurality of slits 7 extending there-through, the slits 7 allowing for expansion of the foam. The slits 7 are arranged in two perpendicular directions with each slit 7 located between but not intersecting two slits extending in a perpendicular direction to the slit. The slits 7 are located such that if the slits did intersect, each slit 7 would intersect a midpoint of each of the two perpendicular slits 7. It will be understood however that in another embodiment the base layer 1 may not have slits therein.

During manufacture, the base layer 1 is adhered to the carpet layer 2 by way of melting and setting the base layer 1 to the carpet layer 2.

As can be seen in Figure 4, the cricket mat comprises markings of a cricket pitch, in this embodiment, markings 8 delineating the creases. In this embodiment, the dimensions of the mat are slightly larger than a cricket pitch.

In use, the cricket mat forms part of a cricket pitch assembly comprising the mat 9 and edging strips 10 arranged for connection to an edge of the mat 9. The edging strips 10 are wedge shaped, each edging strip 10 comprising a recess 11 into which an edge of the mat 9 can be inserted.

The edging strips 10 are made of rubber material and, in this embodiment, each edging strip has a length of between 1 and 3 metres.

The edging strips 10 of the cricket pitch assembly when assembled with the mat extend only over some, but not all, of the edges of the mat 9. It has been found that edging strips are not required for all edges of the mat 9 as the edges of the mat 9 will not significantly curl to cause a trip hazard if edging strips are provided to cover a significant portion, but not all, of the edges of the mat 9. In particular, it has been found that by positioning edging strips 10 at (very close to) the corners of the mat 9, but having gaps between edging strips 10 along the edges away from the corners (as shown in Figure 4), significant curl of the mat 9 that could cause a trip hazard is avoided. Six edging strips 10 are shown in Figure 4, but it will be understood that the cricket mat assembly may comprise more than six edging strips 10.

In use, the edges of the mat 9 are inserted into recesses 1 of the edging strips 10, with one edging strip provided at either end (only one of which is shown in Figure 4) and two edging strips 10 along either longitudinal edge. The weight of the edging strips 10 prevent the edges of the mat from curling up when the mat is laid on a surface. Furthermore, the edging strips 10 provide a smooth transition from the surface on which the mat 9 is laid and an upper surface of the mat 9.

The mat is particularly suitable for laying over an artificial playing surface comprising an infill of rubber particles embedded in the pile of the playing surface as the composition of the mat negates the effects of the underlying artificial surface and produces a bounce of a cricket ball that approximates the bounce that that would be expected from a grass cricket pitch. In this way, the artificial playing surface with an infill of rubber particles can be used for games, such as cricket.

Furthermore, as illustrated in Figure 4, the mat 9 can be rolled for storage and unrolled for use. In this respect, the base layer 1 of foam is desirable as it results in a lightweight mat 9 that can be lifted easily.

The bounce characteristics of the cricket mat when laid on a 3G artificial playing surface were tested. The test comprised dropping a cricket ball from 2000mm at three different locations on the mat. The results of the test were as follows: Location 1 Location 2 Location 3 Ball Drop 1 474mm 481mm 471mm Ball Drop 2 493mm 478mm 487mm Ball Drop 3 482mm 460mm 496mm Average 483mm 473mm 485mm As can be seen from the results, the rebound heights fall within the range of 240 to 560mm expected of a cricket ball when bouncing on a standard cricket pitch.

Claims

CLAIMS1. A cricket mat comprising a base layer of foam or rubber adhered to an upper carpet layer of synthetic grass piles, wherein the mat can be rolled for storage and unrolled for use.
2. A cricket mat according to claim 1, comprising markings of a cricket pitch.
3. A cricket mat according to claim 1 or claim 2, wherein dimensions of the mat are of the order of a standard cricket pitch.
4. A cricket mat according to any one of the preceding claims, wherein the base layer is foam
5. A cricket mat according to claim 4, wherein the foam has a density of 50 to 9Okg/m3.
6. A cricket mat according to claim 4 or claim 5, wherein the foam is closed cell foam
7. A cricket mat according to any one of claims 4 to 6, wherein the foam is polyethylene.
8. A cricket mat according to any one of claims 4 to 7, wherein the base layer comprises slits extending there-through, the slits allowing for expansion of the foam.
9. A cricket mat according to claim 8, wherein the slits are arranged in two directions.
10. A cricket mat according to any one of the preceding claims, wherein the upper carpet layer comprises a resin impregnated textile layer.
11. A cricket mat according to any one of the preceding claims, wherein the carpet layer comprises a pile having a height of between 4 to 9mm.
12. A cricket mat according to any one of the preceding claims, wherein the carpet layer has a total denier of between 60 and 120.
13. A cricket mat according to any one of the preceding claims, wherein fibres of the carpet layer comprise plastic fibres.
14. A cricket mat according to any one of the preceding claims, wherein the carpet layer comprise a stabilising layer through which fibres of the carpet layer extend.
15. A cricket mat according to claim 14, wherein the fibres of the carpet layer have been needle punching through the stabilising layer.
16. A cricket mat according to any one of the preceding claims, wherein the base layer is adhered to the carpet layer by way of melting and setting the base layer to the carpet layer.
17. A cricket mat according to any one of the preceding claims, comprising an anti-slip layer having an abrasive surface attached to the lower surface of the base layer.
18. A cricket pitch assembly comprising a mat according to any one of claims 1 to 18 and one or more edging strips arranged for connection to an edge of the mat.
19. A cricket pitch assembly according to claim 19, wherein the weight of the edging strips prevents the edges of the mat from curling up when the mat is laid on a surface with edging strips connected.
20. A cricket pitch assembly according to claim 19 or claim 20, wherein the edging strips comprise a wedge shape.
21. A cricket pitch assembly according to any one of claims 19 to 21, wherein each edging strip further comprises a recess into which the mat can be inserted to secure the edging strip to the mat.
22. A cricket pitch assembly according to any one of claims 19 to 22, wherein the edging strips are made of rubber material.
23. A method of forming a cricket pitch comprising laying a mat over an artificial playing surface comprising an infill of rubber particles and sand embedded in the pile of the playing surface, wherein the mat is arranged such that a bounce of a cricket ball on the mat is different relative to a bounce of a cricket ball on the artificial playing surface.
24. A method according to claim 23, further comprising securing edging strips to the mat.
25. A kit for forming an artificial playing surface, the kit comprising a mat for laying on a surface and edging strips, each edging strip arranged for receiving an edge of the mat to prevent the edges of the mat from curling and providing a slope to guide a ball onto the mat from a surface on which the mat has been laid.
26. A method of forming an artificial playing surface comprising laying a mat on a surface and inserting edges of the mat into edging strips, the edging strips preventing the edges of the mat from curling and providing a slope to guide a ball onto the mat from the surface on which the mat has been laid.
27. A cricket mat substantially as described herein with reference to the accompanying drawings.
28. A cricket mat assembly substantially as described herein with reference to the accompanying drawings.