Takraw balls

A takraw ball having a relatively soft, or elastically deformable, surface and conventional rebound characteristics. The takraw ball may be woven from composite strips, one component of which is elastically deformable material and forms the ball surface and the another component of which is a springy material. The elastically deformable material and the springy material are selected to produce a desired rebound characteristic. The strips have a wide variety of shapes and compositions. In an alternative embodiment the springy material component forms the ball surface and the elastically deformable material provides reinforcement for the strip.

BACKGROUND OF THE INVENTION 
This invention relates to takraw balls and it particularly relates to an 
improved takraw ball with regard to playability and safety. 
Sepak Takraw is played by opposing teams passing a takraw ball across a 
chest-high net using feet, knees, head, shoulders etc., i.e. every part of 
the body except the player's hands and arms. The object of the game is to 
ground the ball in the opposing team's court; the rules of the game are 
similar to volleyball. Another form of takraw is hoop takraw, only one 
team plays at a time and the players co-operate to get the ball into a 
vertically orientated hoop some 5 meters above the ground. 
United Kingdom Patent Specification No. 2,196,861 (Lorhpipat) describes the 
manufacture of traditional takraw balls by conventionally weaving split 
rattan strips into a spherical basket and the manufacture of takraw balls 
by forming strips of plastics material into interwoven hoops. As shown by 
FIG. 1, a takraw ball 1 has a spherical woven structure with a regular 
array of openings 2. 
It is an essential characteristic of the takraw ball for it to be as 
inelastic as possible; this is to obtain the maximum energy transfer when 
the ball is struck so that the ball's flight or trajectory is as far, fast 
or high as possible. A takraw ball's bounce characteristic is much closer 
to the essentially inelastic collision between billiard balls than the 
elastic collision between a squash ball and racket. The woven structure of 
a takraw ball modifies its bounce characteristic, there is a small amount 
of relative movement between the strips that contributes to the essential 
"feel" of the ball, without which the ball is not a takraw ball. 
A takraw ball may be defined by the below listed parameters: 
weight=100 to 250 gm 
circumference=380 to 460 mm 
bounce=a first rebound of between 100 and 150 cm when dropped in free fall 
from a height of 330 cm. 
A competition sepak takraw ball must have the following parameters: 
weight=170 to 180 gm 
circumference=420 to 440 mm 
bounce=a first rebound of between 130 to 135 cm and within a solid angle of 
15.degree. when dropped in free fall from a height of 330 cm. 
The drawback of both the conventional rattan takraw ball and the 
above-described plastics takraw ball is that their essential inelasticity 
makes them hard and playing takraw can be quite painful; especially for 
the novice. Clearly, this limits the popularity of the game as a 
participation sport. In addition, the hardness of the takraw ball can be 
dangerous. In conventional balls the rattan can unexpectedly break or 
splinter and cut the skin of a player. Similarly, the plastics takraw ball 
can break. Takraw can be played on almost any surface, not just the 
gymnasium floor of competition events, and some surfaces, such as 
concrete, can rapidly abrade/wear the surface of both types of ball; it is 
this that can lead to ball breakage. 
U.S. Pat. No. 5,224,959 (Kasper) discloses a woven skeleton ball which is 
limited to "a plurality of loops woven together into a hollow spheroidal 
skeletal grid, said ball having an outer surface which is predominantly 
open space and thus making said ball suitable for allowing a user's 
fingers to pass through said surface and grip said loops" (see column 7 
line 66 to column 8 line 2). This skeleton ball is clearly not a takraw 
ball, which is stated to have "a predominantly closed smooth surface with 
relatively few small openings" (see column 2, lines 37 to 39). It is 
evident that this skeleton ball cannot function or be used as a takraw 
ball. Its deformability or shape changing characteristic means that it 
cannot have an inelastic bounce characteristic. It probably has no bounce 
characteristic at all; whereas a takraw ball has to restore its original 
spherical shape after each collision. 
U.S. Pat. No. 5,224,959 discloses composite materials, see FIGS. 3C and 3D 
and the related description at column 5 lines 8 to 27; however, there is 
no disclosure of the skeleton ball being bounceable, let alone selection 
of materials to produce a given bounce characteristic as required by the 
present invention. 
It is one object of the present invention to provide a softer takraw ball 
whilst retaining the ball's essential characteristics. Conventional takraw 
balls are traditionally treated with coconut oil both to prevent the ball 
from rotting and to reduce the brittleness of the rattan, i.e. to make it 
softer and more playable. Experiments to simply make a plastics takraw 
from softer material were unsuccessful because the necessary bounce 
characteristic could not be achieved and the ball would not retain its 
woven structure when played, strips moved and overlapped one another. 
Another object of the present invention is to provide a safer takraw ball. 
SUMMARY OF THE INVENTION 
According to the present invention, a takraw ball is woven from strips at 
least a majority of which are composite strips having one component part 
of soft material and another component part of springy material; the soft 
material and the springy material being selected to produce a given bounce 
characteristic. By springy is meant a material that is essentially stiff 
or rigid but also resilient such that, if deflected under applied load it 
will return to its original shape or position. 
According to an embodiment of the present invention, the composite strip is 
formed and arranged such that, when woven into a ball, at least the 
exposed outer surface of the ball is constituted by said soft part. 
Surprisingly, a takraw ball in accordance with this embodiment of the 
present invention can have a significantly softer outer surface than known 
takraw balls and still have essentially the same bounce characteristics; 
such a ball will have the surface softness of, for example, a soccer ball 
and yet be fully playable. 
According to a further embodiment of the present invention, the soft part 
of the composite strip is continuous. 
According to another embodiment of the present invention, the soft part of 
the composite strip is discontinuous, being limited to only those areas of 
the composite strip that, when woven, will constitute the exposed outer 
surface of the ball. The effect of this is that the soft part of the 
composite strip will not occur under woven intersections. This permits 
higher coefficient of friction soft material to be used; the relative 
movement at woven intersections that occurs when the ball bounces or is 
struck will be between the low coefficient of friction springy parts. 
Additionally or alternatively, the soft component part can provide a safety 
surface layer, guarding a player against the ball becoming damaged; the 
springy component part may be brittle and liable to break or fracture and 
the elastic surface can prevent sharp spring parts from protruding through 
the surface. 
According to yet another embodiment of the present invention, the soft part 
of the composite strip is in the form of a backing layer for a springy 
outer layer or is in the form of a core within a springy body. This 
produces a conventionally hard takraw ball but the backing layer or core, 
being soft or flexible, holds the strip together should the springy outer 
layer or body fracture or break. 
The composite strip generally takes two different forms: 
a continuous or discontinuous outer layer of soft material with a springy 
backing; or 
a springy core embedded in a soft body. 
Examples of suitable springy materials are: 
spring metal, nylon fibre, glass fibre, carbon fibre, engineering plastics. 
Examples of suitable soft materials are: 
rubber, elastomer, thermoplastics elastomer (TPE), polyurethane, silicon 
rubber. 
A takraw ball could be manufactured from composite strips in accordance 
with the present invention and having the general form described in United 
Kingdom Patent Specification No. 2196861. Alternatively, a takraw ball 
could be conventionally woven from composite strips of synthetic rattan in 
accordance with the present invention.

As shown by FIG. 2, a composite side hoop strip 20 comprises a thin, flat 
springy backing 22 of, for example an engineering plastic, and a soft 
outer layer 24, of for example TPE; as can be seen the spring extends over 
the whole width of the side strip. The plan shape of the springy backing 
22 is shown in FIG. 3. The side hoop strip 20 is formed by suspending a 
spring in a mould and then injecting the outer layer material onto the 
spring; the final shape of the thus formed composite side hoop strip being 
shown in FIGS. 4, 5 and 6. The spring and outer layer materials are 
compatible so that they will bond together during the injection moulding 
process. 
As shown by FIG. 7 a composite centre strip 26 comprises a thin, fiat 
springy backing 28 having a soft outer layer 30. As can be seen the 
springy backing 28 extends over the whole width of the centre strip 26. 
The plan shape of the springy backing 28 is shown in FIG. 8. The spring is 
made from the same material as side strip backing 22. The outer layer 30 
is of the same material as side strip outer layer 24 and the centre strip 
is also injection moulded to have the final shape shown in FIGS. 9 and 10. 
Side strips 20 and centre strips 26 are then woven to form a takraw ball in 
the same manner as described in United Kingdom Patent Specification No. 
2196861. The resulting takraw ball is similar in appearance to the takraw 
ball shown in FIG. 1 but has a soft outer covering, formed by strip layers 
24 and 30. This soft outer surface is considerably softer than the surface 
of previous plastic takraw balls and is thus easier to play with. In 
addition the softer outer layers enable interwoven bands I, II and III to 
fit more closely and tightly at a cross-over IV (see FIG. 1); further 
improving the spherical shape of the ball. 
FIG. 11 illustrates an alternative to bonding between the composite 
materials, the upper surface 32 of the springy backings, 22 or 28, is 
shaped, such as by undercutting 34, to enable the outer layers, 24 or 30, 
to mechanically key with the backings. 
FIGS. 12 to 15 illustrate an alternative embodiment wherein the soft side 
and centre hoop strip outer layers 36, 38 are discontinuous. The outer 
layers 36 are limited to five specially shaped areas on each backing strip 
22, 28, as indicated by stippling in the figures. The effect of this is 
that, unlike the embodiment of FIGS. 2 to 11 where the outer layers are 
continuous and the intersections of the woven ball effectively have four 
layers (soft, springy, soft, springy), the meeting surfaces at woven 
intersections are constituted solely by the backing strips. This greatly 
extends the range of suitable soft materials; as high coefficient of 
friction, more abrasion-resistant or softer materials can be chosen. With 
lower coefficient of friction springy backing material enabling the strips 
to ready slide over one another at woven intersections. 
FIG. 16 shows an alternative form of composite side strip 40 to comprise 
four steel wire spring cores 42 embedded in a soft body 44. The side strip 
40 is formed by suspending spring cores in a mould and then injecting the 
body material about the spring cores; the final shape of the thus formed 
composite side strip again being essentially the same as shown in FIGS. 4, 
5 and 6. In this case it may not be necessary to bond the spring cores and 
the body; the cores may simply be trapped within the body. 
FIG. 17 shows an alternative form of composite centre strip 46 to comprise 
two steel wire spring cores 48 embedded in a soft body 50 and it is formed 
by co-extruding the body about the spring cores; again the final shape of 
the thus formed composite centre strip is the same as that shown by FIGS. 
10 and 11. Again, it may not be necessary to bond the spring cores and the 
body; the extrusion process may tightly shrink the body onto the spring 
cores to firmly hold them in place. The surface of the spring cores could 
be roughened to improve the mechanical key between core and body. 
FIG. 18 shows another variant 52 of the composite side hoop strip of FIG. 
2; in this variant, the spring 54 is a strip of spring steel and is wholly 
embedded as a core within a body 56 so that the spring can be mechanically 
retained within the body. The plan shape of the spring strip can vary from 
a simple curve-sided bow to more complex shapes. An equivalent composite 
centre hoop strip (not shown) could be provided. 
It is, of course, possible to weave takraw balls from different 
combinations of side and centre hoop strips; for example by combining side 
hoop strips 20 with centre hoop strips 46. It is also possible to use 
different composite materials for the side and centre hoop strips. 
A synthetic rattan strip for the manufacture of conventionally woven takraw 
balls is shown by FIG. 19 to be a composite 58 of generally 
rectangular-like cross-section that has a soft outer layer 60 and a 
springy backing layer 62. The two layers are co-extruded and the materials 
are chosen so that they will bond together during the extrusion process. 
Alternatively, the upper surface of the backing layer could be shaped to 
mechanically key with the outer layer. The composite strip 58 is 
dimensionally the same as split rattan stalk; i.e. approximately 3 to 4 
millimeters wide and thick. Lengths of this synthetic rattan strip can 
then be woven into a takraw ball in the conventional, traditional manner, 
to produce a takraw ball as shown in FIG. 20. 
A takraw ball woven from this synthetic rattan material has all the 
advantages of a plastics takraw ball in consistency of performance etc, 
has the player friendly soft/safe outer covering and is a more accurate 
reproduction of a traditional takraw ball; thus making it especially 
suitable for playing takraw through the hoop. In addition, the 
deformability of the outer layer enables the ball to be woven into a more 
uniform, spherical shape. 
FIG. 21 shows an alternative form of synthetic rattan strip 64, wherein a 
soft, outer body 66 is co-extruded about an inner core 68 of spring steel 
wire; in much the same manner as centre hoop strip 46. 
FIG. 22 shows a further form of synthetic rattan strip 70, wherein a soft 
outer body 72 is moulded in a U-shaped channel section spring 74. 
All the above described forms of synthetic rattan have a continuous outer 
body. It is equally possible to produce a synthetic rattan strip having a 
discontinuous outer body, such that there is only direct contact between 
springy backing layers at woven intersections. 
As mentioned above, abrasion and wear of takraw balls leads to their 
breakage and the danger of hurting players. Wear indicators, for example a 
colour change, can be incorporated into the outer layer of any of the 
above composite strips to indicate when the ball has become dangerously 
worn. 
FIG. 23 is a graph of free fall first-rebounce height of prior art takraw 
balls and takraw balls in accordance with the present invention; tabulated 
below: 
______________________________________ 
BOUNCE 
TYPE HEIGHT MATERIAL REMARKS 
______________________________________ 
MT101 107.50 cm Polyolefin Blend* 
PRIOR ART 
MT102 112.50 cm Polyolefin Blend* 
PRIOR ART 
MT201 127.50 cm Polyolefin Blend* 
PRIOR ART 
MT301 132.50 cm Polyolefin Blend* 
PRIOR ART 
MALAY1 112.50 cm Competitor's product 
PRIOR ART 
MALAY2 122.50 cm Competitor's product 
PRIOR ART 
SYN.RAT1 
132.50 cm Polyolefin Blend* 
PRIOR ART 
SYN.RAT2 
137.50 cm Polyolefin Blend* 
PRIOR ART 
SYN.RAT3 
142.50 cm Polyolefin Blend* 
PRIOR ART 
MT201/N 122.50 cm Polyolefin/Nylon 
INVENTION 
composite 
MT201/W 127.50 cm wire-reinforced 
INVENTION 
Polyolefin 
RATT1 137.50 cm NATURAL PRIOR ART 
RATTAN 
RATT2 132.50 cm NATURAL PRIOR ART 
RATTAN 
MT301/N 127.50 cm Polyolefin/Nylon 
INVENTION 
composite 
MT301/C 112.50 cm Elastomer coated 
INVENTION 
Polyolefin 
MT201/C 117.50 cm Elastomer coated 
INVENTION 
Polyolefin 
______________________________________ 
*"Polyolefin Blend" this term is adopted to defined a homogeneous blend 
including polyethylene and polypropylene the proportions of which are 
varied to suit the particular application for which the takraw ball is to 
be used; from beginners, amateurs to professional competition players. 
Of the takraw balls in accordance with the invention, types MT201/N and 
MT201/W are wire reinforced, composite synthetic rattan, conventionally 
woven takraw balls and types MT301/N, MT301/C and MT201/C are composite 
strip plastic takraw balls, from interwoven hoops. As can be seen, both 
types of composite strip takraw ball meet the bounce requirement. 
In another, unillustrated application of the present invention the outer 
layer or body of the composite strip can be of the hard, springy 
polyolefin blend currently used for plastic takraw balls but the backing 
layer or core is of a soft material, such as nylon, and this acts to keep 
the ball together in the event that the outer layer or body breaks. 
Although composite strips consisting of two separate parts have been 
described, it is the intention of this application to include a strip 
formed from a material that exhibits the characteristics of two different 
materials, soft and springy, within the definition of a composite strip.