[0001] The present invention relates to sports aids which provide a rebound surface for
a ball, and more particularly but not exclusively to a tennis practice aid.
[0002] There are commercially available tennis practice aids which provide a rebound surface
in the form of a flexible sheet material or solid surface The surfaces are basically
upwardly extending and planar. However, rebound surfaces having a non-planar configuration,
are disclosed in Australian Applications 71012/87 (USA Application No. 033 224 filed
1 April 1987).
[0003] Typical rebound surfaces are described in US Patents 4 489 941; 4 239 235; 3 563
455; 3 180 643; 2 333 098; as well as British Patent 18900 and German Patent 2 248
933. The devices disclosed in these publications all possess a rebound surface which
is uniform and accordingly, the rebound qualities of the ball are predictable. Although
in some instances the rebound surface may be divided into sub-surfaces, again the
sub-surfaces are generally uniform and accordingly the return qualities of the ball
are again predictable.
[0004] The above discussed rebound surfaces which are of a woven mesh (or sheet material)
or provided by a solid surface, have the disadvantage that the ball return is substantially
predictable and therefore does not similate a true tennis return where the opponent
tries to vary the type of shot played.
[0005] It is the object of the present invention to overcome or substantially ameliorate
the above disadvantage.
[0006] There is disclosed herein a rebound device for a ball game, said device comprising
a frame to rest upon a support surface, a rebound surface supported by the frame and
against which the ball may be hit to be returned to a user, said rebound surface being
defined by a generally planar sheet material which is deformed by the ball impacting
thereagainst, and rebound varying means fixed to said rebound surface and adapted
to influence the projection and/or velocity of a rebounding ball having impacting
against the rebound surface at or adjacent said rebound varying means as compared
to a ball impacting against said rebound surface at a position remote from said rebound
varying means.
[0007] There is further disclosed herein a rebound damper to be fixed to a flexible rebound
sheet of a rebound device, which sheet has a front rebound surface against which a
ball impacts to be returned by the device, and a rear surface; said damper having:
a head portion to abut said rebound surface so as to project away from said rebound
surface;
a securing portion to abut said rear surface;
a neck joining said head portion and securing portion, which neck portion is adapted
to pass through said rebound sheet; and
wherein said head portion has outwardly facing surface irregularities which engage
the ball to vary the projection and/or velocity of the rebounding ball.
[0008] A preferred form of the present invention will now be described by way of example
with reference to the accompanying drawings, wherein:
Figure 1 is a schematic perspective view of a tennis practice aid;
Figure 2 is a schematic perspective view of the net base portion of the tennis practice
aid of Figure 1;
Figure 3 is schematic front perspective view of a rebound damper employed with the
tennis practice aid of Figure 1;
Figure 4 is a schematic rear perspective view of the rebound damper of Figure 3;
Figure 5 is a schematic front elevation of the rebound damper of Figure 3;
Figure 6 is a schematic rear elevation of the rebound damper of Figure 3;
Figure 7 is a schematic side elevation of the rebound damper of Figure 3;
Figure 8 is a schematic sectioned side elevation of the rebound damper as illustrated
in Figure 5 sectioned along the line 8-8;
Figure 9 is a schematic side elevation of the rebound damper of Figure 5 as sectioned
along the line 9-9; and
Figure 10 schematically depicts various rebound dampers which may be used in combination
with, or as alternatives to, the rebound damper of Figures 3 to 9.
[0009] In Figures 1 and 2 there is schematically depicted a tennis practice aid 10 to rest
on a ground surface. The tennis practice aid 10 consists of a frame 11 which supports
a sheet of woven mesh 12 providing a rebound surface 15 against which a tennis ball
is hit, to return the tennis ball to the user. When the tennis ball impacts against
the mesh 12, the mesh 12 is deformed and deflected thereby.
[0010] The frame 11 includes a rectangular sub-frame 13 which directly supports the mesh
12. The frame 11 further includes a pair of upright frame members 14 which directly
support the sub-frame 13 and attach to the net base 16. The rectangular sub-frame
13 includes horizontal frame members 17 and vertical frame members 18. The frame members
14 are attached adjacent their upper and lower portions to the vertical frame members
18.
[0011] The net base 16 includes a frame 19 which includes two side sub-frames 20 of generally
triangular configuration, with each sub-frame 20 having a wheel 21. A cross member
22 extends between the two sub-frames 20, as well as a pair of brace members 23.
[0012] Extending between the sub-frames 19 and 20 is a net 24 which has its upper edge positioned
so as to approximate the upper edge of a normal tennis net.
[0013] The frame members 14 are telescopically received within the tubular portions 25 of
the sub-frames 19 and 20. Accordingly, the frame 11 may be removed from the net base
16 so that the net base 16 may be used solely as a net with a player on each side.
This configuration is depicted in Figure 2.
[0014] Mounted on the mesh 12 is a plurality of rebound dampers 26, described in more detail
with reference to Figures 3 to 9.
[0015] The rebound dampers 26 have a head portion 27 and a securing portion 28 joined by
a neck 29. The head portion 12 is provided with surface irregularities 30 in the form
of projections 31 which extend away from the mesh 12. In this particular embodiment,
the projections 31 are ridges which extend radially from the centre of the head portion
27. The projections 31 have longitudinally extending apexes 32, with the cross section
of each projection 31 diminishing radially from the centre of the head portion 27.
Preferably, each projection 31 has generally planar side surfaces 33 inclined by an
angle of approximately 50 to 70 degrees, but more preferably 60 degrees. In this particular
embodiment, there are five projections 31.
[0016] Defined between the head portion 27 and the securing portion 28 is an annular recess
34 within which strands 35 of the mesh 12 are located so that the rebound damper 26
is secured in position. Preferably the rebound damper 26 is moulded from plastics
material or a natural or synthetic rubber.
[0017] The rebound damper 26 can be arranged in any desired pattern on the mesh 12.
[0018] In use of the above described tennis practice aid 10, a user upon directing a ball
at the mesh 12, will not be able to anticipate all the ball returns since a ball impacting
against or adjacent one of the rebound dampers 26 will not behave in a predictable
manner. For example, if a ball lands directly on one of the rebound dampers 26, the
ball may drop very rapidly and/or change in direction, relative to a ball which would
strike the mesh at a position spaced from the rebound dampers 26.
[0019] As an alternative to the rebound dampers 26, dampers 35 (Figure 10A) may be used.
The dampers 35 have a front surface 36 and a central aperture 37.
[0020] In Figures 10(a), (b), (c), (d) and (g), alternative rebound altering devices are
shown. They have varying characteristics and may be positioned on the surface 15 to
provide a pattern of return required. In Figure 10(d) the altering device is an increased
weave density over a predetermined area.
1. A rebound device 10 for a ball game, said device 10 comprising a frame 11 to rest
upon a support surface, a rebound surface 15 supported by the frame 11 and against
which the ball may be hit to be returned to a user, said rebound surface 15 being
defined by a generally planar sheet material 12 which is deformed by the ball impacting
thereagainst, and rebound varying means 26 fixed to said rebound surface 15 and adapted
to influence the projection and/or velocity of a rebounding ball having impacting
against the rebound surface 15 at or adjacent said rebound varying means 26 as compared
to a ball impacting against said rebound surface 15 at a position remote from said
rebound varying means 26.
2. The rebound device 10 of Claim 1, wherein said rebound surface 15 is provided by
a mesh 12, and said rebound varying means 26 is a plurality of rebound dampers 26
secured to said mesh 12.
3. The device 10 of Claim 2, wherein each rebound damper 26 has a head portion 27
against which a ball may impact, and a securing portion 28 located on the other side
of said mesh 12, and a neck portion 29 extending through the mesh 12 and joining said
head portion 27 and securing portion 28.
4. The rebound device 10 of Claim 3, wherein each rebound damper 26 has an annular
groove 34 within which portions of the mesh 12 are located to retain the rebound dampers
26 in position.
5. The rebound device 10 of Claim 4, wherein the head portion 27 of each rebound damper
26 has ridges 30 against which a ball may impact.
6. A rebound damper 26 to be fixed to a flexible rebound sheet 12 of a rebound device
10, which sheet 12 has a front rebound surface 15 against which a ball impacts to
be returned by the device, and a rear surface; said damper 26 having:
a head portion 27 to abut said rebound surface 15 so as to project away from said
rebound surface 15;
a securing portion 28 to abut said rear surface;
a neck 29 joining said head portion 27 and securing portion 28, which neck portion
29 is adapted to pass through said rebound sheet 12; and
wherein said head portion 27 has outwardly facing surface irregularities 30 which
engage the ball to vary the projection and/or velocity of the rebounding ball.
7 The rebound damper 26 of Claim 6 wherein said surface irregularities 30 are projecting
ridges 30.
8. The rebound damper 26 of Claim 7 wherein said ridges 30 are elongated and extend
radially from a central portion of said head portion 27.
9. The rebound damper 26 of Claim 8 wherein each ridge 30 has a triangular transverse
cross section which diminishes in area from said central portion.