This invention relates to balls woven from strip-shaped subassemblies, as well as to these strip subassemblies themselves and the methods of weaving the strip subassemblies to form a ball. It includes synthetic takraw balls, their component parts and their methods of assembly, although is not limited to these exclusively.
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, where only one team plays at a time and the players co-operate to pass the ball through a vertically orientated hoop some 5 meters above the ground.
Traditional takraw balls are manufactured by conventionally weaving split rattan into a spherical basket. Rattan stalk is split into long strands of 3 to 4 millimetres wide and 3 to 4 millimetres thick. Then these rattan strands are plaited spirally to form a circular band, like a spring coil of 8 to 12 turns. The number of turns will be determined from the width of the rattan strands used and the final tightness of the ball required. Newly woven rattan takraw balls are not round and have to be pressed by big tongs to force the rattan strands to squeeze into each other and form a substantially round ball. This is then treated with coconut oil to prolong storage life.
Synthetic takraw balls are manufactured by forming strips of plastic material into interwoven hoops. There are two main woven structures for existing synthetic takraw balls, those with completed hoops formed just from two side strips and those with completed hoops formed from two side strips and a centre strip. To assemble the takraw ball, six hoops of just one side strip are first interwoven and then the next set of six side strips are interwoven into the assembly to make a further six hoops next to the first six. In the case where centre strips are used, these are then interwoven to form a further set of six hoops between the opposing side strips. All of this interweaving is labour intensive, requires dexterity and is quite hard work. Particularly weaving in the last strips and joining their ends to form hoops requires strong fingers. The resulting ball is described in GB2196861.
It is an important handling characteristic of the takraw ball for it to be resilient but stiff. This is to obtain the maximum kinetic 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 hard, low strain, kinetic energy conserving collision between billiard balls than the softer, higher strain, kinetic energy absorbing 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.
A regulation Sepak takraw ball is defined as “spherical of one woven layer having 12 holes, 20 intersections. It shall be made of synthetic fibre or natural rattan. If it is made of rattan, it shall consist of 9-11 strains. For a competition ball, the circumference shall not be less than 0.42 m and not more than 0.44 m (0.43 m to 0.45 m for women). The weight before play shall not be less than 170 gm. and not more than 180 gm. (150 gm. to 160 gm. for women).”
Document WO95/28206 describes a takraw ball woven from strips of composite material of which one part is of soft material and another part of springy material. As shown in and described with reference to FIGS. 12-15 of that document, the strips provide subassemblies in accordance with the pre-characterising portion of claim 1.
Document WO2006/051248 describes a takraw ball woven from strips of springy material having soft material pads moulded into recesses in a strip outer face.
Document GB2494478 describes a takraw ball woven from strips of plastics material with one side edge of undulating profile having troughs and peaks. The strip is shaped or otherwise constructed to be preferentially longitudinally flexible in peak regions, so that the strip naturally adopts a more circular shape when bent into a hoop.
Document GB2513862 describes a takraw ball woven from plastic side strips, and, optionally, plastic centre strips; both having through-going slots so that the outer surface of the woven ball is essentially composed of synthetic rattan-like slivers. The slivers provide reduction of pain for a player, improved bouncing properties, a measure of independent transverse sliver movement and improved sphericity.
A “playability” problem of both the conventional rattan takraw ball and the above-described synthetic takraw balls is that their stiffness 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.
A “durability” problem is that 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 plastic takraw ball can break. Takraw can be played on almost any surface, not just the gymnasium floor of competition events or sand for beach takraw, and some surfaces, such as concrete, can rapidly abrade/wear the surface of both types of ball; it is this that can particularly lead to ball breakage.
Documents WO-A-95/28206 and WO-A-2006/051248 address the playability problem by providing soft or springy material outer surfaces. However these soft/springy surfaces affect the durability and handling characteristics of the takraw ball. Document GB-A-2196861 addresses the durability problem of conventional rattan balls by using plastic strips and WO-A-2006/051248 protects the soft material pads by moulding the pads into recesses in the outer face of the strip. None of these give much variability in playing characteristics to suit different user groups, i.e. novice/casual/amateur players vs. traditional/serious/professional players, children vs. adults, etc. There are also assembly difficulties as noted above.
The present invention seeks to provide a synthetic takraw or similar ball having one or more of improved playability, durability, handling characteristics and ease of manufacture.
The present invention provides a strip subassembly for weaving to form a ball, as set out in claim 1. The invention correspondingly provides a ball, such as a takraw ball, woven from such strip subassemblies, as set out in claim 11. Further optional and inventive features are set out in the dependent claims.
In takraw balls of the prior art, the interwoven side and centre strips form both the structure and the surface of the ball. In contrast, when the strip subassemblies of the present invention are assembled to form a ball, the backbone struts form the internal structure of the ball and the pads form the surface of the ball. The backbone struts therefore need not be exposed at the surface of the ball.
In the prior art takraw balls, the ball surface together with the ball structure are woven by bending and pushing a free end of one strip up and down and in and out of other strips, crossing the other strips to form a spherical basket. Then the ends of each strip are joined to make interwoven hoops to form a takraw ball. With the present invention, the pads can be positioned and arranged on the backbone struts so that when the strip subassemblies are assembled to form the ball (with the backbone struts crossing one another and neighbouring pads on one backbone strut positioned next to, and on either side of, a pad on another, crossing backbone strut), the pads are arranged with their outer surfaces arranged to lie aligned on a sphere or regular polygon. In such an arrangement, the outer surfaces of the pads may be aligned with each other and the pads need not jut out one relative to another or cross over or overlap one another.
Because the prior art strips have springy stiffness, during the ball weaving process, the surface of a strip always has friction and rubs against other strips as the strip is bent and pushed/pulled to go under or over the other strips. The visible surfaces of the strips can therefore be scuffed, scratched or otherwise damaged, or subjected to stress whitening, if woven carelessly or inexpertly or in a dirty or gritty environment. But when using the subassemblies of the present invention to form a ball, the pads themselves are not pulled past other pads or other components in the interlocking assembly process and therefore the pad outer surfaces are not subjected to friction or abrasion during assembly of the ball. Furthermore, ball assembly is faster and easier than when using the prior art side and centre strips or traditional rattan strands.
It is the pads which make up the shaped (outer) playing surface of the ball formed from the subassemblies of the present invention. In previous takraw ball designs and structures, the ball's surface comprises crossing and adjacent side strips and centre strips, or crossing and adjacent rattan strands. When such a ball strikes a player's skin, each strip or strand has a different shape, deformed out of its generally circular, rest-state shape. Even absent such deformation, protruding edges of the woven structure can create pressure points which cause pain to a player. After the ball bounces back, the deformed circular strips try to go back to their original places, and the closing gaps between different deformed strips can nip the skin or hair of the player. With the woven structure of prior art takraw balls, it is unavoidable that one strip or strand overlies another in layers, creating relatively sharp edges or corners at the upper layer and creating spaces between layers, strips and strands, which open/close/nip as the ball deforms and recovers its original shape during play. A generally smooth spherical surface cannot be made, so the prior art takraw ball structures can cause pain to a player upon impact. The present invention is able to provide a homogeneous, single-layered, non-overlapping, uniformly and synchronously deformable outer surface, devoid of sharp edges, corners or pinch points in play.
Therefore balls constructed from the subassemblies of the present invention may have a surface which is more smooth, more round, and may be formed from soft, sensitive surface materials, e.g. low density material with air bubbles like resilient foam or sponge. The properties of the pads and hence the ball surface layer may be varied to suit different games and different types of players. The surface formed by the pads determines the feel and control of the ball while the backbone struts maintain the roundness and structural strength of the ball. Some properties such as resiliency and damping can be controlled or adjusted by selecting the material properties of either or both of the pads and the backbone struts. With the new method of construction and assembly the backbone struts can also be hidden once the ball assembly is complete. This allows the surface of the ball to be fully padded with softer shock absorbent material while the backbone struts can be formed from e.g. a much harder highly resilient material (including composites) to control bounciness and propulsion of the ball after impact. Utilizing suitable materials having different properties in the subassembly means balls can be made to travel fast for a thrilling game but they will land with softer shock upon impact with the body and limbs.
A greater understanding of the invention, and some of its optional features and advantages, may be had from the following description of illustrative and non-limiting embodiments, made with reference to the drawings.
The present disclosure relates to a strip subassembly comprising a backbone strut and one or more pads threaded or otherwise formed onto the backbone strut, as well as a ball, such as a takraw ball, woven from such strip subassemblies and a method of weaving a ball from such strip subassemblies. The ball of the present invention is a development of the takraw balls described in documents GB2196861, WO95/28206, GB2494478 and GB2513862.
GB2513862 describes a takraw ball made up of synthetic rattan-mimicking side strips, which form the main structure of the ball, and narrower centre strips, which act as wedging parts to achieve the final, tightly woven ball. The present invention, on the other hand, is made up only of relatively narrow struts which act as the “backbones” of the structure and which have pads threaded or otherwise formed onto or attached to them.
Each backbone strut 4 shown in
The final pads 6 may have one or more holes or passages 14 running through them longitudinally, through which the backbone strut(s) 4 are threaded or otherwise run, and may have one or more channels 16 running across them transversely which intersect the longitudinal hole(s) or passages 14, allowing the backbone strut(s) 4 to overlap and directly contact each other. This occurs at a 60°/120° angle in the takraw ball shown in
When formed separately from the struts 4, the pads 6 may be moulded in one piece or may be of laminated construction to provide the required hole or passage 14 and channel 16. Several pads 6 or their component parts may be multi-moulded together in a single operation to reduce the flash, and then cut along linking web portions to form the individual pads or pad pieces. The pieces are then laminated together if required, e.g. using a suitable adhesive, to form the individual pads 6. The pads 6 (five such pads for a regulation takraw ball) may be glued to the backbone strut or struts 4 onto which they are threaded to form a strip subassembly 2. Alternatively, the pads 6 may be co- or insert-moulded on the strut(s) 4, to form the strip subassemblies 2, as described above. In yet another embodiment, as shown in
arranged to lie aligned on a sphere or regular polygon so as to provide the advantages of improved player comfort as discussed above.
A number (six for a regulation takraw ball) of strip subassemblies 2 are woven together to form a ball. During such weaving, the pads 6 are not dragged past one another or past other parts of other strip subassemblies, so there is no frictional damage to the pads and assembly is much easier than is the case for prior art takraw ball weaving methods. Nevertheless, the movement of the pads 6 and/or struts 4 against each other during play can still give a similar sound and feel to a traditional takraw ball made of rattan fibres. When desired, however, the pad material can be chosen to provide softer, less painful player contact in use.
The plan shapes of the pads 6 threaded onto the backbone struts 4 may be any suitable shape tessellating to form the outer surface of the ball, or partly tessellating to provide a ball surface which has holes or gaps in it. For example, the plan shapes of the pads 6 may be parallelograms, each parallelogram having a major internal angle of 120° on one pair of opposing vertices and a minor internal angle of 60° on the other pair of opposing vertices. Each parallelogram may have a long and a short side and the five pads 6 on each backbone strut 4 may be spaced apart by the transverse width of a parallelogram, such that when two subassemblies 2 are crossed over each other, the pad 6 of one subassembly 2 fits in between two of the pads 6 of the other subassembly 2 in a perpendicular orientation. At each point 18a (
Other fully or partly tessellating pad shapes are also possible, as are other numbers of pads 6 per strip subassembly 2 and other numbers of strip subassemblies 2 per ball.
The ball structures and constructions described above provide functions including:
A. Reduction of pain for a player. The side strips described in any of documents GB2196861, WO95/28206 and GB2494478 are relatively rigid, especially in the exposed peak regions, such that, when a ball hits any part of a player's body, the contact area is likely to be a concentrated point with consequent high loading. The problem is exacerbated by the relatively sharp edges and corners produced where one strip overlaps another. There is also a problem of relative movement of the strips as the ball deforms, pinching the player's skin or hair as the ball springs back to its original shape. The slivers in GB2513862 deflect transversely away from one another under load to spread out the contact area, transmitting a lighter force per area to the player. In the present invention, there are no interwoven side strips to hold the backbone struts rigid, so these deform more on impact than the side and centre strips of previous synthetic takraw balls. The pads themselves also deform on impact due to the properties of the material from which they are made, transmitting an even lighter force per area to a person striking or struck by the ball. There is no overlapping of pads, with consequent reduction or elimination of the prior art protruding edges and corners and the nipping or pinching phenomenon. This enables takraw or other sports and games to be played barefoot without considerable discomfort to the players and particularly promotes amateur involvement in the game.
B. Lower density material can be used to make the pads when desired, so the entire ball may weigh less than previous models, further reducing the pain for the player upon impact, as well as making the ball easier to throw and catch, particularly benefitting newer players. On the other hand, the weights of the ball components can be designed and adjusted to achieve any desired ball weight or range of ball weights, including those specified for regulation takraw balls.
C. Ease of manufacture. The lack of side strips significantly reduces the amount of time and effort that goes into assembling the ball, since it reduces the weaving steps and makes the remaining weaving steps easier, as well as potentially reducing the number of fasteners from eighteen to six, in the case of a regulation takraw ball. The potential for scratching, abrading or otherwise damaging the ball's exposed surface during its assembly is reduced or eliminated.
D. Reduced use of plastic. The same size of ball is achieved with less plastic since there is no overlap of the pads as there is of the side strips of the previous models.
E. Greater durability. The pads of the present invention deform on impact, reducing the likelihood of abrasion of the surface of the ball. The backbone struts are also unlikely to splinter since they are protected by the pads. The pads may be provided with a tougher surface layer if desired.
F. More even stiffness and deformation in play over the whole ball. There is less overlapping of pieces (overlapping being a feature which gives variation of stiffness), so there is a more even stiffness over the entire ball. It is also under less internal stress than the models with overlapping side strips, due to the relative lack of overlapping pieces. Less overlap means lower stress at the point where three pads meet, compared with the equivalent point on the earlier models, the point where three plastic hoops cross. The stress at the point is spread across the entire edge of each of the three pads, whilst in the earlier models it is concentrated at the point of intersection of the hoops. Less concentrated stress at any one point means that the ball is less likely to come apart during play. No overlaps means no nipping or pinching of the player's skin or hair as the ball deforms and then resiliently recovers, and no raised or sharp edges or corners to concentrate impact stresses; all of which makes the ball more comfortable to play with.
G. Improved control of frictional damping and sound of the ball in play. Unlike the side and centre strips of previous models, the pads do not overlie one another. This permits greater ball flexibility and greater design freedom in controlling frictional damping within the ball structure, and hence greater design freedom in controlling the bounce characteristics, sound and feel of the ball in play.
Number | Date | Country | Kind |
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1713030.3 | Aug 2017 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/GB2018/052241 | 6/8/2018 | WO | 00 |