GB2337820A

GB2337820A - Detecting the location of impacts on a target.

Info

Publication number: GB2337820A
Application number: GB9912360A
Authority: GB
Inventors: Edward Frederick Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-05-29
Filing date: 1999-05-28
Publication date: 1999-12-01
Anticipated expiration: 2019-05-28
Also published as: GB2337820B; GB9912360D0

Abstract

Apparatus for indicating the position of the point of impact of an object in a selected area comprises a pad (1) defining the selected area and capable of being placed in a required position, a plurality of impact sensitive devices (2) distributed within the pad, and means associated with each impact sensitive device for generating an output signal when the device is impacted by an object (7). Preferably the pad (1) is portable. Applications include sports such as cricket, where the device could be used to test bowling accuracy.

Description

SMITH 01199 2337820 CRICKET BALL BOWLING TEST APPARATUS The present

invention relates to apparatus for indicating the position of the point of impact of an object failing in a selected area. The invention has a particular application in testing the accuracy of the bowling of a cricket ball by a bowler into a selected area of a cricket pitch or practice area.

In order to improve the accuracy of the bowling action of a bowler it is common practice for the bowler to bowl cricket balls repeatedly into a selected area on a cricket pitch or other surface. While it is possible for an observer to observe the position in which the ball strikes the ground it is not easy to determine accurately where this position is or how it changes with successive bowling operations or changes in the bowling action. It is useful to determine accurately changes in the position as the bowler tries to repeat his bowling action or to change his bowling action in a particular way.

It is also useful to have an apparatus for testing the accuracy of a bowling action which is portable so that the apparatus can be taken to any cricket pitch or other surface both indoors and outdoors.

The object of the present invention is to provide an improved apparatus for indicating the position of the point of impact of an object such as a cricket ball in a selected area.

According to the present invention apparatus for indicating the position of the point of impact of an object in a selected area comprises a pad defining the selected area and capable of being placed in a required position, a plurality of impact sensitive devices distributed within the pad, and means associated with each impact sensitive device for generating an output signal when the device is impacted by an object.

1 SMITH 01199 The apparatus may also include an indicating device which, on receipt of an output signal from any one of the impact sensitive devices, indicates which device has been impacted and the position of the device within the pad.

Preferably the pad and the indicating device (if included) are portable so that the whole apparatus can be used in different places.

In order that the invention may be more readily understood an embodiment will now be described with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a pad including a plurality of impact sensitive devices, Figure 2 is a side view in section of one type of one of the impact sensitive devices illustrated in Figure 1, Figure 3 is a side view in section of another type of one of the impact sensitive devices illustrated in Figure 1, Figure 4 is a plan view, partly in section, of a further type of one of the impact sensitive devices illustrated in Figure 1, Figure 5 is a side view in section of the impact sensitive device illustrated in Figure 4, and Figure 6 is a side view in section of another version of the impact sensitive device illustrated in Figures 4 and 5, and Figure 7 is a diagrammatic illustration of an indicating device which will indicate which of the impact sensitive devices in the pad of Figure 1 has been impacted.

SMITH 01199 With reference to Figure 1 a pad 1 is formed with a plurality of impact sensitive devices 2. The devices 2 are square or rectangular in plan view and abut against each other so as to cover the whole area or a selected part of the area of the pad 1. Alternatively, the devices 2 may be hexagonal in plan view or have other shapes or combinations of shapes such as octagons and squares so that the devices 2 can abut against each other and fully cover the whole area of the pad 1. The devices 2 are positioned either on the surface of the pad 1 or within the body of the pad 1. The devices 2 are not necessarily all the same size or shape or type.

The devices 2 may be distributed within the pad 1 in accordance with a selected pattern. For example smaller devices 2 may be used in some parts of the pad 1 while larger devices 2 may be used in other parts of the pad 1 so as to have different sensitivities and resolution characteristics in different parts of the pad 1. Devices 2 of different types may be used in different parts of the pad 1.

With reference to Figure 2, according to one embodiment of the invention, each impact sensitive device 2 comprises two layers 3, 4 of rigid or flexible material with a piezo electrical element 5 positioned between the two layers 3, 4 and an output cable 6 from the element 5. When the layers 3, 4 are compressed together by the impact of a body 7 on the surface 8 of one of the layers 3, the piezo electric element 5 will generate an output electrical signal in the cable 6.

With reference to Figure 3, according to another embodiment of the invention, each impact sensitive device 2 comprises two layers 11, 12 of a rigid or flexible material separated by a gap 13. On the surface of the layer 11 adjacent to the gap 13 is a layer 14 of an electrically conducting material and on the surface of the layer 12 adjacent to the gap 13 is another layer 15 of electrically conducting material. Output cables 16, 17 are connected to the conducting layers 14, 15 respectively. The layers 14, 15 of electrically conducting material may be painted onto the surfaces of the layers 11, 12.

If the two layers 11, 12 are moved towards each other by the impact of a body 7 on the surface 8 of the layer 11, part of the conducting layer 14 will move into 3 SMITH 01199 contact with the conducting layer 15 so as to complete the circuit between the cables 16, 17 and to generate an output electrical signal.

With reference to Figures 4 and 5, according to another embodiment of the invention each impact sensitive device 2 comprises two flat elements 33, 34 made of a flexible electrically conducting material spaced apart by an annular member 35 made of a rigid or flexible electrically insulating material. The material of the elements 33, 34 may be a rubber based material or other electrically insulating material with particles of an electrically conducting material dispersed therein. The flexible elements 33, 34 and the annular member 35 are sealed together, for example by an adhesive or by welding, so as to form a sealed chamber 36. The chamber 36 contains a gas, such as air, under sufficient pressure so that the flexible elements 33, 34 are normally spaced apart but will move into contact when the device 2 is impacted by an object 7, such as a cricket ball, on the surface 40 of the element 33.

'ZA Electrical conductors 37, 38 are connected to the elements 33,, respectively and a valve 39 connects with the chamber 36 to allow gas to be supplied into the chamber 36. If the two electrically conducting elements 33, 34 are moved towards each other by the impact of an object 7 on the surface 40 of the device, provided the impact is of sufficient force parts of the two electrically conducting elements 33, 34 will move into contact with each other so as to complete the circuit between the two conductors 37, 38 for a short time period.

The adhesive or welding used to attach the elements 33, 34 and the annular member 35 together must be sufficiently powerful to ensure that the elements 33, 34 do not become detached from the annular member 35 allowing gas to leak out of the chamber 36 during normal use of the device.

If required, a protective strip 41 of a rigid or flexible electrically insulating material may be placed around the device 2 over the joints between the elements 33, 34 and the annular member 35.

4 SMITH 01199 In an alternative arrangement illustrated in Figure 6, the elements 33, 34 of electrically conducting material are replaced by two layers 42, 43 of flexible electrically insulating material with two layers 44, 45 of electrically conducting material on the surfaces of the layers 42, 43 facing into the chamber 36. The conducting layers 44, 45 may be continuous and formed for example from electrically conducting paint or in the form of a mesh of electrically conducting material. The layers 44, 45 are spaced apart by an annular member 35 of the type illustrated in Figure 5.

If the two electrically insulating layers 42, 43 are moved towards each other by the impact of an object 7 on the surface 40 of the layer 42, provided the impact is of sufficient force parts of the two electrically conducting layers 44, 45 will move into contact with each other so as to complete the circuit between the two conductors 37, 38 for a short time period.

The device 2 illustrated in Figures 4, 5 and 6 is preferably easily portable and can have dimensions of the order of 60 cms x 60 cms by 2 cms thick. The material from which the pairs of elements 33, 34 and the layers 42, 43 are made is preferably hard wearing and resistant to impact by an object 7. All materials used are also preferably sufficiently flexible to allow the device 2 to be rolled up for transporting.

The output signals from the impact sensitive devices 2 may be coded in accordance with the position within the pad 1 of the device 2 in which they are generated.

Alternatives to the types of impact sensitive devices 2 described above are:

- magnetic elements which generate magnetic output signals when moved relative to each other.

- pneumatic or hydraulic elements which generate respectively pneumatic and hydraulic output signals.

- transducers which generate audible output signals. With this arrangement, when the apparatus is used to test the accuracy of the bowling action of a bowler, each element 2 or group of elements can generate a distinctive audible sound so 5 SMITH 01199 that it can be immediately apparent to the bowler which area of the pad 1 has been impacted by the cricket ball without the use of a separate indicating device 21 (see below in connection with Figure 7). The transducers may need to have their own sources of power.

- electronic elements, for example those including semi conductor devices andlor integrated circuits which generate electronic output signals.

- optical elements which generate light or other radiation output signals which can be coupled directly to the indicating device 21 by an optical fibre cable or otherwise.

The generation of an output electrical signal in the cable 6 (Figure 2) or the cables 16, 17 (Figure 3) or the cables 37, 38 (Figures 4, 5 and 6) can be detected in an indicating device 21 of the type illustrated in Figure 7.

With reference to Figure 7 the indicating device 21 comprises a set of visual elements 22 arranged in a pattern identical to the pattern of the impact sensitive devices 2 in the pad 1 of Figure 1. Each of the visual elements 22 is connected to the output cable 6 or cables 16, 17 of cables 37, 38 of a respective one of the impact sensitive devices 2 via a multicore cable 23 so that it receives the output signal generated in the respective device 2. Each visual element 22 will produce a visible output when the corresponding impact sensitive device 2 produces an output on the cable 6 (Figure 2) or the cables 16, 17 (Figure 3) or the cables 37, 38 (Figures 4, 5 and 6). The cable 23 may be an electrical cable or an optical fibre cable or any other suitable type of connecting cable or structure. A radio or other radiation link, for example an infra red radiation link, may be used in place of the cable 23.

The visual elements 22 may produce a light output or may change colour, for example, when energised.

A battery 24 may be used to provide electrical power to the indicating device 21 and to the impact sensitive devices 2 through the cable 23.

6 SMITH 01199 If the impact sensitive devices 2 are used with an indicating device such as the device 21 illustrated in Figure 7, the indicating device can usefully include components to convert the relatively short signals generated by the impact sensitive devices into longer signals. As a result the visual or other element corresponding to each impact sensitive device will produce a relatively long output signal which can be seen for a longer time period.

In use, the pad 1 can be placed in a selected position on a cricket pitch, for example at one end adjacent to the stumps. The indicating device 21 can be positioned at the other end of the pitch and connected to the pad 1 by the cable 23. If a bowler bowls a ball towards the pad 1 and the ball strikes the pad 1, the impact sensitive device 2 which is struck by the ball will generate an output signal. This will result in the corresponding visual element 22 in the indicating device 21 producing a visible output.

If the output signal is visible (device 21), it will then be apparent to the bowler, or a coach near to the bowler, the position of impact of the ball on the selected area defined by the pad 1. The bowler can then maintain his bowling action or change his action to see if the position of impact changes or remains constant.

In the alternative arrangement described above in which the transducers in the devices 2 produce audible signals it will not be necessary to use the indicating device 21 since the audible signals will be heard by the bowler or the coach.

The indicating device 21 is preferably relatively small and portable so that it can be held in the hand of a coach or other person standing close to a bowler who is bowling cricket ball towards the pad 1 so that he can see on which portion of the pad 1 the bowled balls are failing and give instruction if required. Alternatively, the indicating device 21 may be adapted to be supported on a structure adjacent to the bowler. In this arrangement the bowler himself can see where the bowled balls are failing and can adjust his bowling action accordingly.

7 SMITH 01199 In another alternative form of the apparatus each of the visual elements 22 in the indicating device 21 can be associated with a numerical value which is different for each visual element or groups of visual elements in accordance with the positions of their associated impact sensitive devices 2. With such an arrangement a game or competition using the apparatus can be devised. In this a bowler will score for each ball bowled in accordance with the numerical value associated with the visual element 22 which produces an output indicating where a bowled ball has fallen. Each person playing the game or entering the competition will bowl a selected number of balls and his total score will be calculated in the indicating device 21 by, for example, a calculating device 25 included in the indicating device 21.

The portable indicating device 21 may be replaced by a large display board so that spectators can see how each competitor is scoring in the game or competition.

In a practical example of the apparatus the pad 1 is approximately 1000 mm x 600 mm by 20 mm thick, each impact sensitive device 2 is approximately 100 mm x 100 mm and each visual element 22 is approximately 20 mm x 20 mm. The materials used in the pad 1 and the impact sensitive devices 2 and the indicating device 21 are preferably chosen so that the complete pad 1 and the indicating device 21 and the battery 24 can easily be carried by one person in a suitable container. Preferably the pad 1 can be rolled up so that it can be carried and stored easily and without damaging the pad 1 or the devices 2.

8 SMITH 01199

Claims

1. Apparatus for indicating the position of the point of impact of an object in a selected area comprising a pad (1) defining the selected area and capable of being placed in a required position, a plurality of impact sensitive devices (2) distributed within the pad, and means (6; 16,17; 37, 38) associated with each impact sensitive device for generating an output signal when the device is impacted by an object (7).

2. Apparatus as claimed in Claim 1 comprising an indicating device (21) adapted to receive said output signals and including a plurality of indicating elements (22) to indicate from which impact sensitive device each output signal is received.

3. Apparatus as claimed in Claim 2 in which each of said indicating elements (22) produces a visible output.

4. Apparatus as claimed in Claim 3 comprising means for associating a numerical value with each of said indicating elements (22).

5. Apparatus as claimed in any one of the preceding claims in which said pad (1) and said indicating device (21) are portable.

6. Apparatus as claimed in Claim 5 in which said pad (1) can be rolled up for carrying and storage.

7. Apparatus as claimed in any one of the preceding claims in which each of said impact sensitive devices comprises piezoelectric elements.

8. Apparatus as claimed in any one of Claims 1 to 6 in which each of said impact sensitive devices comprises pairs of electrical contacts.

9 SMITH 01199 9. Apparatus as claimed in any one of Claims 1 to 6 in which each of said impact sensitive devices comprises magnetic elements.

10. Apparatus as claimed in any one of Claims 1 to 6 in which each of said impact sensitive devices comprises pneumatic or hydraulic elements.

11. Apparatus as claimed in any one of Claims 1 to 6 in which each of said impact sensitive devices comprises elements which emit audible signals.

12. Apparatus as claimed in any one of Claims 1 to 6 in which each of said impact sensitive devices comprises electronic elements including semi conductor devices andlor integrated circuits.

13. Apparatus as claimed in any one of Claims 1 to 6 in which each of said impact sensitive devices comprises optical elements which emit light or other radiation.

14. Apparatus as claimed in any one of Claims 1 to 6 in which each of said impact sensitive devices comprises two electrically conducting elements separated by a space containing a gas at a sufficient pressure so as normally to keep the elements apart but to allow the elements to move into contact when the device is impacted by an object.

15. Apparatus as claimed in Claim 14 in which each electrically conducting element is made from a flexible electrically conducting material.

16. Apparatus as claimed in Claim 14 in which each electrically conducting element is made from a flexible electrically insulating material with a layer of an electrically conducting material on one surface.