GB2314778A

GB2314778A - Sports training ball

Info

Publication number: GB2314778A
Application number: GB9613849A
Authority: GB
Inventors: Simon William Griffin
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-07-02
Filing date: 1996-07-02
Publication date: 1998-01-14
Also published as: GB9613849D0

Abstract

A sports training ball 1 comprises a high drag coefficient component 2 and a low drag coefficient component 4 which together give the ball an inherent swing capability when it is projected through the air. The high and low coefficients of drag can be obtained by surface indents 3, protuberances, bristles and other means. The ball can be used for training in cricket, golf, tennis, football, baseball. The ball 1 can also be provided with a circumferential seam 5.

Description

SPORTS TRAINING BALL This invention relates to a sports training ball. More particularly, but not exclusively, this invention relates to a cricket training ball.

One object of the present invention is to provide a training ball which permanently and accurately simulates the "swing and seam" effect of a real cricket ball without having to be polished or abraded.

According to the present invention there is provided a sports training ball comprising a high drag coefficient component and a low drag coefficient component which together give the ball an inherent swing capability when it is projected through the air.

The degree of swing capability of the ball of the invention is determined by the ratio of the two coefficients of drag.

In one embodiment of the invention, the high drag component is provided with a plurality of indents on its outer surface and the lower drag component has a smooth outer surface.

Alternatively, the low drag component may also have a plurality of indents on its outer surface but of lower number than the indents on the high drag component.

Preferably, the indents are concave in shape.

In another embodiment of the invention, the high drag component is provided with a plurality of protuberances on its outer surface and the low drag component has a smooth outer surface.

Alternatively, the low drag component may also have a plurality of protuberances on its outer surface but of lower number than the protuberances on the high drag component.

Preferably, the protuberances are convex in shape.

The aforementioned indents and protuberances can be moulded or cut into the surface of the ball and they can be of any shape, size or number.

In yet another embodiment of the invention, the ball may be made of two different materials, one having a higher coefficient of drag than the other.

Alternatively, one material may have a higher density than the other.

The sports ball of the invention may have a partial high drag bristled outer surface as in a tennis ball and the remainder of the outer surface may be smooth From another aspect, the sports ball of the invention may be of hollow structure with the high drag component having a wall thickness greater than the low drag component.

From yet another aspect, the high drag component may be larger than the low drag component.

In a further embodiment of the invention, the ball may consist of a sphere provided with an outer cover which has a high drag surface and a low drag surface.

Alternatively, the sphere may be provided with a partial cover which has a coefficient of drag higher or lower than the surface of the sphere.

Preferably, the sports ball of the invention comprises two hemispheres, one hemisphere having a higher coefficent of drag than the other.

The ball can be manufacturered in a variety of polymeric materials such as (but not exclusively) polyurethanes, polyisoprenes, polybutenes and PVC. The ball may also be made of a blend of polymers or be made of natural products such as cork or leather.

The ball can be made in a variety of hardnesses from very soft like a tennis ball to very hard like a cricket ball.

The soft ball can be used on hard surfaces without damaging the ability of the ball to swing and without the need for expensive protective equipment for the batsman.

The hard ball can be used in cricket practice nets and bowling machines without the constant need for polishing.

The material composition of the ball can be altered during manufacture to produce different rebound heights depending on the surface the ball is to be used on.

The ball can be provided with a seam with the necessary dimensions to provide deviation like a real cricket ball. However, the seam is not essential for the ball's ability to swing and the ball can be produced without a seam if required. The seam can also be used to guide the ball into a bowling machine down a groove in a hopper enabling the ball to be delivered "seam-up" to the batsman.

As stated above, in a preferred embodiment the ball consists of two hemispheres, one hemisphere having a permanently higher coefficient of drag than the other. When the ball is thrown or fired through the air in the correct manner so as to induce swing, the ball will deviate from its original trajectory or curve or swing in a manner similar to a real cricket ball.

Each half of the ball can be coloured differently so that when a bowler is being trained, he or she will see by rotation of the ball whether or not the ball is being delivered in the correct manner to induce swing.

A version of the ball can be used for baseball practice. It will enable an inexperienced pitcher to pitch "curved" balls at a trainee pitcher.

Variations of the ball may also be used in golf, tennis and football.

An embodiment of the invention will now be described by way of example only, with reference to the accompanying drawing.

A cricket training ball 1 is manufactured from foamed polyurethane which is cured by means of an amine system. The ball 1 is moulded in a metal mould. The ball composition is prepared as a solution containing the gas producing chemicals and other well known chemicals necessary for environmental resistance and ease of processing. This is poured into the mould which has been preheated to 40-50 degree C. The mould is rotated during insertion of the ball composition to ensure conformity of product and a hollow centre. The ball composition is allowed to remain in the mould for 3.5 to 4 minutes to allow for full curing and foaming.

The hardness of the final composition is 46 to 52 (shore C). The final rebound of the ball 1 is 38 to 43e. The final weight of the ball 1 is 80 to 90 g.

One half 2 of the ball 1 is moulded so that the surface is covered with hemispherical indents 3 with a radius of 3mm. There are 142 indents evenly distributed over the surface of half 2. The other half 4 of the ball 1 is left as smooth as possible.

The ball 1 is moulded with ridged seam 5 running round its full circumference. The seam 5 acts as a dividing line between the indented half 2 and the smooth half 4. The seam 5 has a radius of about 5.9mm and a height of about 1.5mm.

Claims

1. A sports training ball comprising a high drag coefficient component and a low drag coefficient component which together give the ball an inherent swing capability when it is projected through the air.

2. A ball as claimed in claim 1 whose inherent degree of swing is determined by the ratio of the coefficient of drag of the two components.

3. A ball as claimed in claim 1 or claim 2 wherein the high drag component is provided with a plurality of indents on its outer surface and the low drag component has a smooth outer surface.

4. A ball as claimed in claim 1 or claim 2 wherein the high drag component is provided with a plurality of indents on its outer surface and the low drag component is provided with a lower number of indents on its outer surface.

5. A ball as claimed in claim 3 or 4 wherein the indents are concave in shape.

6. A ball as claimed in claim 1 or 2 wherein the high drag component is provided with a plurality of protuberances on its outer surface and the low drag component has a smooth outer surface.

7. A ball as claimed in claim 1 or claim 2 wherein the high drag component has a plurality of protuberances on its outer surface and the low drag component is provided with a lower number of protuberances on its outer surface.

8. A ball as claimed in claim 6 or 7 wherein the protuberances are convex in shape.

9. A ball as claimed in claim 1 or 2 wherein the high drag component has a bristled outer surface and the low drag component has a smooth outer surface.

10. A ball as claimed in claim 1 or 2 wherein the high drag component and the low drag component are made of separate materials having different coefficients of drag.

11. A ball as claimed in claim 1 or 2 wherein the high drag component and low drag component are made of separate materials having different densities.

12. A ball as claimed in claim 1 or 2 wherein the high drag component has a greater wall thickness than the low drag component.

13. A ball as claimed in claim 1 or 2 wherein the high drag component is larger than the low drag component.

14. A ball as claimed in claim 1 or 2 comprising a sphere provided with a cover which has a high drag surface and a low drag surface.

15. A ball as claimed in claim 1 or 2 comprising a sphere provided with a partial cover which has a higher or lower coefficient of drag than the sphere.

16. A ball as claimed in any one of the preceding claims comprising a high drag hemisphere and a low drag hemisphere.

17. A ball as claimed in any one of the preceding claims which is provided with a circumferential seam.

18. A ball as claimed in any one of the preceding claims made of a polyurethane, a polyisoprene, a polybutene, a polyvinyl chloride, a blend of polymers, cork or leather.

19. A ball as claimed in any one of the preceding claims which is a training ball for cricket, tennis, golf, football or baseball.