Ball Rebound Apparatus
FIELD OF THE EWENTION
This invention relates to a ball rebound apparatus, and in particular, but not exclusively to a ball rebound apparatus having two distinct rebound surfaces for use in ball-skills training.
BACKGROUND
The inventors of the present invention are also the inventors of the rebound apparatus which is the subject of New Zealand Patent number 335024, this apparatus having a rebound surface that is designed to produce an unpredictable angle of ball return. This apparatus has been very successful and is used by many sportspeople to improve their ball handling skills. Among the sportspeople who use their apparatus are a number of international cricketers, and rugby, soccer and hockey players.
However, while a rebound apparatus with an unpredictable rebound is useful in some circumstances, in other situations a rebound apparatus with a predictable rebound would be of more use. This has lead to a need for a rebound apparatus that can perform both functions.
Similarly, for the purposes of skills training it is sometimes useful to have rebound nets that are capable of differing rates of ball return.
It is common to manufacture a rebound apparatus by suspending a rebound surface within a frame, and the surface is connected to a frame by springs or bungee cords. Suspending two different rebound surfaces from the same frame however has not been particularly successful as the two different rebound surfaces tend to interact with each other.
OBJECT
It is therefore an object of the present invention to provide a ball rebound apparatus which will at least go some way towards overcoming the above mentioned problem, or
at least provide the public with a useful choice.
STATEMENTS OF THE INVENTION
Accordingly, in a first aspect, the invention may broadly be said to consist in a ball rebound apparatus, including a frame having a first and a second face, and a first and a second rebound surface, each rebound surface being configured to produce a unique ball rebound characteristic, and each rebound surface being operatively connected to the frame, wherein the first and the second rebound surfaces are separated by at least one spacer that is so sized, shaped and located on or within the apparatus as to at least partially maintain the unique ball rebound characteristic of each rebound surface when in use.
Although the or each spacer could be independent of the frame, or be directly connected to the frame, preferably the spacer forms at least part of the frame.
Each rebound surface could be directly connected to the frame, however preferably each rebound surface is operatively connected to the frame by one or more resilient members.
Although the or each resilient member could be used to operatively connect each rebound surface to the frame separately, optionally the or each resilient member operatively connects both rebound surfaces to the frame.
Preferably the or each resilient member is arranged such that the first rebound surface is substantially aligned with the first face and the second rebound surface is substantially aligned with the second face.
Optionally the or each resilient member spans the width of the frame and is operatively connected to the first rebound surface substantially in a plane of the first face, and is operatively connected to the second rebound surface substantially in a plane of the second face.
Although it is conceivable that the two rebound surfaces could be side by side, or at an angle to one another, preferably both rebound surfaces are in a substantially overlying relationship with one another.
Preferably the overlying relationship is parallel.
While the or each resilient member can be a spring, preferably the or each resilient member is an elastic cord or cords, for example an elastic cord commonly known as bungee cord or shock cord. . '
Optionally the first and the second rebound surfaces are held apart by spacer members situated between the rebound surfaces.
Preferably at least one of the rebound surfaces is adapted to cause an unpredictable angle of rebound.
Preferably the unpredictable rebound surface comprises at least two layers of net material.
Optionally the first and the second rebound surfaces are held within the frame under differing tensions.
In a second aspect, the invention may broadly be said to consist in a ball rebound apparatus, comprising two rebound surfaces arranged substantially parallel to one another, wherein each surface is configured to produce a unique ball rebound characteristic, and both rebound surfaces are supported by a common frame.
In a third aspect, the invention may broadly be said to consist in a training apparatus incorporating at least one ball rebound apparatus as specified herein.
DESCRIPTION
The invention may also broadly be said to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of the parts, elements or features, and where specific integers are mentioned herein which have known equivalents, such equivalents are incorporated herein as if they were individually set forth.
Five examples of the invention will now be described, by way of example only, with reference to the accompanying drawings in which,
FIGIIRE 1 is a perspective view of a ball rebound apparatus according to a first example,
FIGURE 2 is a partial cross sectional view AA as defined in figure 1,
FIGURE 3 is a close-up perspective view showing a portion of the lacing pattern for the ball rebound apparatus of the first example,
FIGURE 4 is a view showing the lacing pattern along one complete edge of the ball rebound apparatus of the first example,
FIGURE 5 is a view showing a second example of a net separation system using separate spacer members,
FIGURE 6 is a partial cross sectional view BB as defined in figure 5,
FIGURE 7 is a perspective view of a section of a ball rebound apparatus according to a third example,
FIGURE 8 is a perspective view of a section of a ball rebound apparatus according to a fourth example,
FIGURE 9 is a cross sectional view of an alternate frame profile which can be used in the third and fourth examples,
FIGURE 10 is a cross sectional view of another alternate frame profile which can be used in the third and fourth examples, and
FIGURE 11 is a perspective view showing a fifth example of a rebound apparatus using two frames linked together.
FIRST EXAMPLE
With reference to Figures 1 and 2, a first example of a ball rebound apparatus (10) is shown comprising at least a frame (11) which supports both a first rebound surface (13) and a second rebound surface (15). Both of the surfaces (13) and (15) are operatively connected to the frame (11) by a resilient member in the form of an elastic cord (17) which is laced through each surface (13) and (15) and around the frame (11). The
details of this lacing are explained in further detail below. The frame (11) is supported at any suitable angle relative to the ground by a base (19) and an adjustable support (21).
In each of the examples described herein, the first rebound surface (13) is a surface comprising two layers of mesh which are held together, the mesh comprising squares having approximately 57 millimetre (mm) sides. The second rebound surface (15) is a surface comprising a single layer of mesh, the mesh comprising squares having approximately 30 mm sides. The 57 mm mesh provides an unpredictable or "insane" surface, and the 30 mm mesh provides a predictable or "sane" surface, for a ball approximately the size of a cricket ball, that is a ball with a 225 to 230 mm circumference. The mesh can be made from a polyethylene material for example. However, many other rebound surfaces could be used to replace either the first of the second rebound surface, (13) or (15), or both, for example rebound surfaces made from nets with different mesh size, nets made of different materials, or a resilient sheet material, etc.
The resilient member used in this example is an elastic cord (17) which has an elastic core material and a fabric outer sheath, and is commonly known as shock cord or bungee cord.
In figure 2 it can be seen that the rebound surfaces, (13) and (15), are held apart by a distance X. This distance X is achieved because the frame (11) acts as a spacer. The elastic cord (17) spans across the width of the frame (11) and connects to each rebound surface, (13) and (15), separately. In this example, the distance X is distance between the first face (Ha) and the second face (lib) of the frame (11), and the distance can be any distance which is sufficient to prevent significant interaction between the two rebound surfaces, (13) and (15). The inventor has found that for a rebound apparatus having a frame which is approximately 600 millimetres (mm) square that a distance X of approximately 25 mm is sufficient. It is anticipated that depending on the size of the apparatus and the tension in each rebound surface, that a distance X of between 15 and 100 mm would usually suffice.
In this first example the two rebound surfaces (13) and (15)" are arranged on a single frame (11) such that the two surfaces substantially overly one another. The first and the
second rebound surfaces, (13) and (15), each lie substantially in the same plane as the first and second faces (1 Ia) and (1 Ib), respectively, and are substantially parallel to one another.
With reference to Figures 3, the lacing is shown in greater detail on a short section of the frame (11). The style of lacing shown in this figure is used over a significant portion of the length of each side of the frame (11). While the same lacing pattern can be used around the corners of the frame (11), it has been found that simple spiral lacing can be used in the corners without significantly reducing the performance of the apparatus. This aspect is explained in more detail with reference to figure 4 below.
The lacing shown in figure 3 is referred to herein as "face to face lacing", since the lacing extends from the first face (1 Ia) to the second face (1 Ib) of the frame (11) before extending to the second rebound surface (15), and then back to the first face (1 Ia) before connecting to the first rebound surface (13), to produce spaced apart rebound surfaces.
The face to face lacing is produced by lacing the elastic cord (17) in such a manner that the cord passes around the outer surface of the frame (11) to a first face (Ha) of the frame (11) and then extends to and connects to the first rebound surface (13) and then passes back to the first face of the frame and over the outer surface of the frame to a second face (1 Ib) of the frame and then extends to and connects with the second rebound surface (15), before passing back to the second face of the frame and over the outer surface of the frame (11) again to repeat the process. This produces more of a
"zig-zag" lacing pattern as opposed to a spiral shaped lacing pattern that is commonly used on rebound nets.
With reference to Figure 4, the lacing along a complete side of the frame (11) is shown. Between each corner of the frame (23), the lacing is in three sections, two outer sections (25) and a centre section (27). Simple lacing, or spiral lacing, in which both surfaces (13) and (15) are included in the lacing each time the elastic cord (17) passes around the tubing of the frame (11), is used in the outer sections (25). Face to face lacing, as described with reference to figure 3 above, is used in the centre section (27).
This lacing method, which includes simple spiral lacing adjacent to the corners, does not significantly reduce the gap between the surfaces (13) and (15) over most of the rebound
apparatus (10) surface, allowing the surfaces (13) and (15) to act substantially independently, and yet this lacing method allows the apparatus (10) to be manufactured at a lower cost, compared to an apparatus made using face to face lacing all around the frame (11). The surfaces (13) and (15) do come together at the corners where the simple lacing is used, but this does not adversely affect the performance of the rebound apparatus (10), since the surfaces (13) and (15) are held apart over the majority of their respective areas.
The rebound apparatus (10) described herein is suitable to provide a challenge for all skill levels, from 3 year olds having their first throwing and catching experiences to international athletes. Also it allows the added versatility of a rebound net that can be used for a wider range of skill training activities where both predictable and unpredictable rebounds are required. The predictable ball return is suitable for beginners, or general training, and the unpredictable ball return provides an excellent visual skills training aid that mimics many of the visual skill sets required in match play in a wide range of sports. This unpredictability is at its optimum when the mesh cell size perimeter approaches the ball circumference and is the same for both layers of mesh, and when a hard ball such as a cricket ball or baseball is used, as compared with a softer ball.
Below is a study of the development process which lead to the rebound apparatus (10) as described above. Initially a simple lacing pattern was used about the entire frame, and the rebound surfaces were not spaced apart. While this configuration worked it was not considered ideal. It produced a compromise situation where, to get a high degree of unpredictability on the "insane" side of the apparatus, a degree of unpredictability is also produced on the "sane" side. Also, the ball return speed is decreased slightly on the "sane" side. Alternatively, it is possible to achieve an increased level of predictability on the "sane" side but only by sacrificing some of the unpredictability on the "insane" side. However, it is often important to retain good unpredictability. This has been supported by leading international sports players and one of the worlds leading sports visual skills experts who works with many international sports sides including England rugby and Spanish hockey. And yet, at the same time it is advantageous to have a predictable side to the apparatus for the practise of various skills where a very predictable rebound is desirable.
Initial trials to try and produce an apparatus that retained two distinct rebound surfaces centred around identifying the optimum tension on the two. Variations in tension were achieved by varying the mesh size used for the surface on the "sane" side. However this did not solve the problem adequately.
Subsequent trials included the use of alkathene tubing and high density foam which was slid between the two surfaces to create a gap. This method of construction had some potential, especially with the use of foam, but was not considered the optimal solution for rebound surface performance. This option is explained further with reference to figures 5 and 6 below.
It was after these trials that a new lacing technique was investigated. Initially this involved the use of face to face lacing around the whole frame. While this achieved the purpose of providing separation of the two surfaces, the method was more time consuming, more complicated and put more pressure on the surfaces at the corners of the frame. Continued perseverance produced a compromise solution, requiring minimal additional labour and yet providing excellent results in terms of performance. This compromise solution is that shown with reference to figure 4 above.
This system of lacing involving simple spiral lacing of both surfaces around the corners of the frame, and face to face lacing along the majority of each straight edge of the frame produced an apparatus having the following characteristics in comparison to the earlier trials involving simple spiral lacing of both surfaces around the entire frame;
1 A significant increase of unpredictability on the "insane" side and with equal or increased speed of ball return.
2 A very predictable return on the "sane" side for a ball of the same optimum diameter for an "insane" ball return, on the "insane" side.
3 A significant increase in the ball return speed on the "sane" side.
4 A design where a more consistent rebound performance can be achieved between one rebound apparatus and another. This is important because with the net manufacture there is typically some slight variation in the mesh. size. This variation in mesh size can influence the rebound
performance when simple lacing is used with rebound surfaces of more than one net layer, but has a lesser effect when face to face lacing is used.
A trial was carried out using a hard cricket ball thrown from a set distance of 4 metres at a constant speed. The variation of the rebound was recorded with 100 results for each by measuring the level of variation from the expected in terms of degrees. The percentage of ball returns in each category is recorded in the tables below. The results are as follows:
This shows the significant increase in unpredictability with the new prototype. Over half the balls had a greater than 12° change in ball flight path on the rebound compared to what would be expected with a totally predictable rebound.
This highlights the superior predictability of the ball return on the "sane" side. The ball return was also significantly faster.
Using the face to face lacing system produces a far higher level of independence hi the performance of the two rebound surfaces. This is achieved because of the space
between the two surfaces or nets. In these trials it was found that the spacing should ideally be at least 25mm for maximum benefit.
Shock cord represents 15% of the total material costs and 50% more is used with the face to face lacing method. The time to produce the face to face lacing is increased by 250% over the simple lacing, as it involves double the amount of threading and is much more intricate. Added to this, the frame is loaded with almost double the inwards pull pressure, and for this reason each side of the frame is constructed having an outward curvature to improve its resistance to the forces applied by the shock cord.
While there are increased costs over a single surface rebound apparatus, the rebound apparatus described above is cheaper than the manufacture of two single surface rebound apparatus, each having different rebound surface characteristics. And the double sided rebound apparatus is more compact to store and transport.
EXAMPLE 2
With reference to Figures 5 and 6 a second example of a rebound, apparatus (30) is shown which uses a different method to achieve separation of the two rebound surfaces than that shown with reference to figures 1 to 4. This method does not rely on a particular lacing system, but instead uses a spacer or a system of spacers which are placed between the rebound surfaces. A suitable spacer (33) in the form of a foam rubber tube is shown between the first rebound surface (13) and the second rebound surface (15).
In this example the first rebound surface (13) and the second rebound surface (15) are both supported from a common frame (31) and are connected to the frame (31) using an elastic cord (17) using a simple spiral lacing method.
Whilst the spacer (33) shown is a hollow foam rubber tube, the spacer (33) could take a number of forms, for example a rigid plastics tube, a line of springs, a series of foamed rubber blocks, or rubber balls, etc. However, preferably the spacer (33) is formed from a resilient material, since a resilient material is less likely to cause interactions between the first rebound surface and the second rebound surface.
Figure 5 shows a preferred layout for the system of spacers. The spacers (33) can be arranged in any manner, however, preferably the spacers (33) are arranged substantially adjacent to, and inboard of, the perimeter of the rebound surfaces. Optionally the or each spacer (33), or additional spacers (33), can be arranged nearer to the centre of the rebound surfaces (13) and (15), to ensure adequate separation of the rebound surfaces (13) and (15) nearer the centre, and/or to provide a target for users.
Testing indicates that some efficiency of the rebound apparatus (10) is lost using this method, that is, the ball return speed can be slightly slower in comparison to a rebound apparatus manufactured using the face to face lacing method as described in the first example. However, this method has the advantage that it can be quicker, and therefore cheaper, to manufacture, than the face to face lacing method. The use of spacers also has the advantage that the spacers can be placed nearer to the centre of the rebound surfaces reducing the likelihood of the two rebound surfaces contacting one another when a ball impacts one or other surface.
Other aspects of the rebound apparatus (30) are similar to those described in the first example.
THIRD EXAMPLE
With reference to Figure 7 a small section of a third example of a rebound apparatus (50) is shown including a frame (51), and a first and a second rebound surface, (13) and (15). While only a short section of the frame (51) and a small section of each rebound surface (13) and (15) is shown, clearly the construction method can be used to construct a rebound apparatus having a similar shape to that shown with reference to figure 1.
In this example the frame (51) has a substantially "C" or "U" shaped cross section and each rebound surface (13) and (15) is connected to separate legs (51a) or (51b) of the cross sectional shape. In this example each rebound surface (13) and (15) is connected to the frame (51) by a resilient member in the form of an elastic cord (17) which connects to lugs (53) which are provided on the opposing internal faces of each of the legs (51a) and (51b) of the frame (51). The width of the frame cross section essentially forms the spacer which holds the two rebound surfaces apart.
FODRTH EXAMPLE
With reference to Figure 8 a small section of a fourth example of a rebound apparatus (70) is shown including a frame (71), and a first and a second rebound surface, (13) and (15). While only a short section of the frame (71) and a small section of each rebound surface (13) and (15) is shown, clearly the construction method can be used to construct a rebound apparatus having a similar shape to that shown with reference to figure 1.
In this example the frame (71) has a substantially "C" or "U" shaped cross section and each rebound surface (13) and (15) is connected to separate legs (71a) or (71b) of the cross sectional shape. In this example each rebound surface (13) and (15) is connected to the frame (71) by a number of resilient members in the form of springs (75) which are connected to holes (73) which are provided in each of the legs (71a) and (71b) of the frame (71). The width of the frame cross section essentially forms the spacer which holds the two rebound surfaces apart.
Figures 9 and 10 show two alternative frame constructions which could be used in either the third example, or with minor modifications, in the fourth example. Both figures show a frame cross section made of two halves.
In figure 9 the first alternative frame cross section (81) is shown comprising two similarly profiled frame halves (83) which can be joined together using a suitable fastening system, and in this case a bolted (85) joint is shown. Each frame half is shown having lugs (53) which can be used to connect with the elastic cord (17) of a rebound apparatus.
In figure 10 the second alternative frame cross section (91) is shown comprising a first frame half (93) and a second frame half (95) which are adapted to provide a snap fit (97) which can be used to join the two halves together. Such a frame cross section (91) could be advantageous in providing a rebound apparatus in which the rebound surfaces could be changed quickly by simply removing one frame half (93) or (95) and replacing it with another which has a different rebound surface attached. Each frame half is shown having lugs (53) which can be used to connect with the elastic cord (17) of a rebound apparatus.
FIFTH EXAMPLE
With reference to figure ll a fifth example of a rebound apparatus (100) is shown having a first and a second frame (101) and (103) which are joined together. The first frame (101) supports the first rebound surface (13) and the second frame (103) supports the second rebound surface (15). Each rebound surface (13) and (15) is joined to its respective frame, (101) or (103), by an elastic cord (17) which can be laced using a simple spiral method.
While the two frames can be joined together along all of their respective edges, in the example shown the two frames (101) and (103) are only joined along one edge and are fastened together with bolts (105) to form an "A" frame shape which is able to stand up on its own. Alternative fastening systems could be used, for example plastic clips or Velcro tape. In this example the two rebound surfaces, (13) and (15), are held apart by the joined frames (101) and (103).
VARIATIONS
Clearly any combination of the construction methods shown in the above five examples could be used, for example a rebound apparatus (10) having face to face lacing and a spacer (33) situated near to the centre of the rebound surfaces. Also, lugs or similar features can be provided on the outside of a tubular frame allowing a lacing pattern similar to that used in the third example but where the lacing is external to the frame.
Suitable clips could be used to assist with the connection of the resilient members to the rebound surfaces, for example "C" shaped clips, which at one end could engage with the rebound surface and at its other end with an elastic cord, eliminating the requirement to thread the elastic cord through any openings in a the rebound surface.
While the above examples show various rebound apparatus having square or rectangular frames, clearly the frame shape could be any number of shapes, for example circular, octagonal, etc
Many variations of rebound surfaces can be used in each of the above examples. Some examples of alternative rebound surface configurations are shown in the following table:
However, clearly any combination of rebound surfaces could be used and sheet materials can be used in the place of mesh or net for certain purposes.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.
ADVANTAGES
Such an apparatus in which the two rebound surfaces are spaced apart provides an apparatus in which two distinct rebound characteristics can be achieved. This is because
the distance between the rebound surfaces significantly reduces the affects of any interaction between the two surfaces which can affect the return of a ball.
Such a rebound apparatus provides the advantage of a single item of training equipment that can be used for two types or levels of training. For example, one of the rebound surfaces can be configured to produce an unpredictable rebound, while the other surface can be configured to produce a predictable rebound.
In addition, such an apparatus can include rebound surfaces having different rebound surface materials, and/or tensioning, which can also produce variations in rebound characteristics, for example rebound speed.
The legs of the cross sections used to make the frames in the third and the fourth examples can be advantageous in that they can provide some degree protection to the elastic cord (17) which could help to extend its life, for example the legs can provide ultra violet (UV) protection, or simply protection from knocks and abrasion.
DEFINITIONS
Throughout this specification the word "comprise" and variations of that word, such as "comprises" and "comprising", are not intended to exclude other additives, components, integers or steps.
The terms "sane" and "insane" as used herein are intended to describe a surface that produces a predictable or an unpredictable ball return, respectively.