Playing surface for sports

Abstract

 A playing surface with selected bounce characteristics is constructed by confining particulate material preferably sand or fine soil in a shallow trench. For indoor use a flexible sheet is rested on the top layer of the particulate material thereby spreading the load produced by the ball during bouncing and the feet of the players thereby preventing excessive bumps being formed in the surface. The particulate material must be kept dry to achieve the constant characteristic and thereby for outdoor use the flexible sheet and shallow trench must be waterproof.

Description

[0001] This invention relates to a playing surface for sports, for example for use as the wicket of a cricket pitch.

[0002] The bounce characteristics of a particular artificial turf surface are often extremely important especially for certain types of ball game such as tennis or cricket. It is difficult both indoors and outdoors to produce a surface with desired and substantially constant bounce characteristics and it is an object of the present invention to provide such a surface.

[0003] Accordingly the present invention provides a playing surface for sports comprising a body of fine particulate material characterised in that the body of fine particulate material is surrounded by and distributed in a layer on water impermeable material and in that the body of fine particulate material is covered with a flexible sheet resting on the upper surface of the layer.

[0004] The flexible sheet may be an artificial turf material, or a resilient pad or mat, with or without an artificial turf layer on top.

[0005] The water-impermeable material may be concrete or tarmac, for example, but the surface may also be provided by cutting a shallow trench or the like out of a natural turf surface, lining the sides and bottom of the trench with an impermeable plastics foam, for example dense polyethylene foam 1 to 5 mm, preferably 3 mm, thick, and then filling the cavity so formed with sand or other particulate material.

[0006] Playing surfaces in accordance with the invention are consistent in their bounce characteristics when used for ball games such as cricket, are simple to construct and maintain, and are particularly useful for indoor sports surfaces such as in indoor cricket practice nets.

[0007] Reference is made to the drawings, in which:

Figure 1 is a section through a playing surface in accordance with the first embodiment of the invention; and

Figure 2 is a section through a playing surface in accordance with a second embodiment of the invention.

[0008] Referring first to Figure 1, a concrete floor 1 has a recess 3 therein, the base of which is lined with a rough membrane 5, for example a bonded fibre film or mat, to reduce the rolling of the sand on the smooth concrete surface. Alternatively, the surface of the concrete may be roughened. A layer of sand 7, approximately 25 to 50 mm thick, is laid on the membrane 5 and a second membrane 9, similar to the first membrane 5, is laid on the surface of the sand. It will be observed that Figure 1 is not drawn to scale for a surface usable as a cricket practice surface. A layer of a resilient material 11 is placed over the second membiane 9. The resilient material may be a mat formed of bonded rubber particles, or a bonded fibre felt material. The layer of resilient material 11 is preferably pinned to the floor 1 at appropriate spacing distances all round the recess 3 by for example masonary nails 4. The thickness of the layer 11 is preferably in the range of 1 to 4 mm, a larger thickness being preferable if no further layer is used on top. A final layar 13, which may be an artificial turf material or any other suitable surfacing material is normally laid over the pad 11. The final layer may be pinned to the floor 1 at appropriate spacing distances by for example masonary nails 6. It is has been found that this arrangement simulates a natural pitch for cricket practice indoors, the playing characteristics of the surface remaining consistent.

[0009] The surface illustrated in Figure 2 is intended for use as an outdoor surface, for example a cricket pitch or a practice area in nets. A shallow trench 20 is cut out of a natural turf surface 22 and the trench 20 is lined with a dense water-impermeable polyethylene foam material 24 having a thickness of approximately 3 mm in the base of the trench and a greater thickness at the sides of the trench. The lined trench is filled with a fine dry sand 26, the depth of the sand being approximately 25 mm, and an underlay 28 is then laid over the trench and resting on the upper surface of the sand 26. The upper surface 25 of the box formed by material 24 is preferably roughened to prevent undue movement of the particulate material 26. The underlay is fastened to the soil surrounding the trench by means of pins 27. Finally, an artificial turf material is laid over the underlay and fastened at the junction with the natural turf 22. The underlay may be formed of a bonded particulate rubber mat, or water-impermeable polyethylene foam, or any other suitable resilient water-impermeable material. A preferred thickness range is from 1 to 4 mm for the underlay. The artificial turf may be of any known type, for example formed of polypropylene and is preferably fastened to the soil by means of pins 29.

[0010] The playing surface formed is consistent in its bounce characteristics for cricket balls, for example, and requires little or no maintenance, regardless of weather conditions. It is also very simple in construction and may therefore may readily be used in place of natural turf pitches and the like.

[0011] Although the invention has been described in relation to cricket pitches, it will be understood that surfaces in accordance with the invention may be used for a wide variety of sports where a controlled consistent resilience of the surface is desired.

Claims

1. A playing surface for sports comprising a body of fine particulate material characterised in that the body of fine particulate material (7) is surrounded by and distributed in a layer on water impermeable material (3, 24) and in that the body of fine particulate material (7) is covered with a flexible sheet (11) resting on the upper surface of the layer.

2. A playing surface for sports as claimed in Claim 1 characterised in that the flexible sheet (11) is water impermeable.

3. A playing surface for sports as claimed in Claim 1 or Claim 2 characterised in that a sheet of artificial turf material (13) is laid on the flexible sheet (11).

4. A playing surface for sports as claimed in any one of Claims 1 to 3 characterised in that the water impermeable material (3) comprises a shallow concrete trench.

5. A playing surface as claimed in any one of Claims 2 or 3 characterised in that the water impermeable material (24) comprises a shallow trench (20) excavated in open ground and lined with a plastics material (24).

6. A playing surface as claimed in Claim 5 characterised in that the plastics material (24) comprises a dense water impermeable polyethylene foam material forming an open shallow box, the sides of the the box being of thicker material than the base.

7. A playing surface as claimed in Claim 6 characterised in that the flexible sheet (11) is fixed to the ground surrounding the shallow box to effectively enclose the fine particulate material completely in a water-tight manner thereby maintaining a constant bounce characteristic for the playing surface.

8. A playing surface as claimed in Claim 3 in which the surface of the floor of the trench (3) is roughened to prevent undue movement of the particulate material.

9. A playing surface as claimed in Claim 6 in which the surface of the floor of the box is roughened to prevent undue movement of the particulate material.

Drawing