Abstract
A strip subassembly (2) which may be used to form a takraw ball or a similar woven ball, includes a backbone strut (4) and one or more pads (6) attached to the backbone strut (4). In the woven ball, the pads (6) form an even surface which is comfortable for the player.
Claims
1. A strip subassembly for weaving together with other such strip subassemblies for forming a ball, the strip subassembly comprising: a resilient, elongate backbone strut having ends which are configured for fastening together so as to form the strip subassembly into a hoop; and a plurality of cushioning pads attached to the backbone strut and spaced apart along the length of the backbone strut; wherein the cushioning pads are configured so that when a plurality of such strip subassemblies are woven together to form the ball, the cushioning pads will interlock to form the outer surface of the ball and the backbone struts will form an internal structure of the ball which is not exposed at the outer surface of the ball; and wherein each cushioning pad comprises a unitary body of cushioning material having: (a) a hole or passage running through the unitary body longitudinally and through which the backbone strut passes; and (b) a channel running within and across the unitary body transversely whereby the backbone strut of another such strip subassembly forming the ball is receivable in the channel.
2. The strip subassembly claim 1, wherein channel intersects the longitudinal hole or passage whereby the backbone strut of the another such strip subassembly forming the ball is receivable in the channel so as to directly contact the backbone strut passing through the hole or passage.
3. The strip subassembly of claim 2, wherein the passage and the channel are positioned and configured so that when two or more such subassemblies are woven together to form the ball, outer surfaces or edges of their cushioning pads are aligned along a spherical or regular polygonal surface.
4. The strip subassembly of claim 1, wherein the backbone strut comprises a non-linear shape.
5. The strip subassembly of claim 1, wherein the backbone strut comprises a roughened or textured surface or surface portion(s).
6. The strip subassembly of claim 1, wherein each cushioning pad is secured to more than one backbone strut in parallel.
7. The strip subassembly of claim 1, wherein the cushioning pads are glued onto the backbone strut(s), co-moulded with the backbone struts, or are insert moulded onto the backbone struts.
8. The strip subassembly of claim 1, wherein the cushioning pads are parallelogram shaped.
9. The strip subassembly of claim 1, wherein the cushioning pads are spaced apart on the backbone strut by a transverse width of the cushioning pad, such that when two such strip subassemblies cross each other the cushioning pad of one strip subassembly abuts two of the cushioning pads on the other strip subassembly.
10. The strip subassembly of claim 1, wherein there are exactly five cushioning pads attached to the backbone strut.
11. A ball assembled from strip subassemblies as claimed in claim 1, by weaving a plurality of the strip subassemblies together.
12. The ball of claim 11, wherein edges of adjacent cushioning pads on different backbone struts closely abut one another over at least a part of their length.
13. The ball of claim 12, wherein the cushioning pads are parallelogram shaped and three of the cushioning pads meet at a point at the major internal angles of the parallelogram shapes; and/or wherein the minor internal angles of five cushioning pads lie adjacent to one another at a pentagon-shaped gap in the ball or meet at a point.
14. The ball of claim 11, wherein the ball is a takraw ball.
15. The ball of claim 13, in which the cushioning pads do not overlap.
16. The ball of claim 15, wherein the ball is assembled from exactly six of the strip subassemblies.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIGS. 1A and 1B are respectively a top (outside surface) plan view and a bottom (inside surface) plan view of a strip subassembly of a backbone strut and five pads which may be used together with identical subassemblies to weave a takraw ball embodying the invention;
(2) FIGS. 2A and 2B are respectively a top (outside surface) plan view and a bottom (inside surface) plan view of one pad of the strip subassembly of FIGS. 1A and 1B, without the backbone strut in place;
(3) FIG. 3 is a bottom (inside surface) view of one pad attached to the backbone strut of the strip subassembly of the backbone strut and pads of FIGS. 1A and 1B:
(4) FIG. 4 is a bottom (inside surface) view of an alternative embodiment to FIG. 3, showing one pad attached to two backbone struts forming a section of a strip subassembly;
(5) FIG. 5A is a bottom (inside surface) view of an alternative crossover arrangement of a strip subassembly to FIGS. 1 to 5, showing one pad attached to a backbone strut by means of attachment hoops through which the backbone strut runs, with a further backbone strut crossing over it;
(6) FIG. 5B is a top (outside) plan view of an alternative form of backbone strut from those used in FIGS. 1A, 1B, 3, 4 and 5A;
(7) FIG. 5C shows the backbone strut of FIG. 5B with pads attached, but before it is woven into a ball and secured to form a hoop;
(8) FIG. 6 shows a first stage, requiring five of the subassemblies of FIGS. 1A and 1B, in the weaving of six of the subassemblies to form a takraw ball;
(9) FIG. 7 shows the sixth subassembly of FIGS. 1A and 1B required in the weaving of six of the subassemblies to form a takraw ball, bent into a hoop and fastened by a press-in plastic fastener;
(10) FIG. 8 shows a further stage in the ball weaving process of six of the subassemblies of FIGS. 1A and 1B to form a takraw ball;
(11) FIG. 9 shows yet a further stage in the ball weaving process of six of the subassemblies of FIGS. 1A and 1B to form a takraw ball;
(12) FIG. 10 shows the finished takraw ball after the weaving process of FIGS. 6 to 9 is complete;
(13) FIG. 11 is a bottom (inside surface) plan view of an alternative embodiment of a strip subassembly to FIGS. 1A to 10, comprising a backbone strut and four pentagon-shaped pads which may be used together with identical subassemblies to weave a ball embodying the invention; and,
(14) FIG. 12 shows the finished ball woven from three of the strip subassemblies of FIG. 11.
DETAILED DESCRIPTION OF THE INVENTION
(15) 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.
(16) 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.
(17) FIGS. 1A and 1B are plan views of the outside and inside surfaces respectively of a strip subassembly 2 of the present invention. The subassembly consists of a backbone strut 4 and five pads 6, which may be used together with identical subassemblies 2 to weave a ball, such as a takraw ball, of the invention. For the prototype ball shown in FIGS. 1 to 4, 5A and 6 to 10, for convenience the centre strips of GB2513862 have been used as the backbone struts 4. However this is not essential and backbone struts 4 of other transverse cross-sectional shapes and/or materials may be used as well or instead. An example of another backbone strut 4 is shown in FIGS. 5B and 5C, which are discussed in more detail below. Returning to FIGS. 1A and 1B, the upper face of a backbone strut 4 as shown has one or more longitudinal grooves 8 and the lower face has a large rectangular sectioned groove which lends an overall, generally U-shaped transverse cross-sectional profile to the backbone strut 4, but this need not be the case for the backbone struts 4 of the present invention. In the finished ball, the upper face of the backbone strut faces outwardly and the bottom face of the backbone strut faces inwardly.
(18) Each backbone strut 4 shown in FIGS. 1A and 1B is approximately 43.5 cm long and is moulded from a suitable plastic material (such as polypropylene, high density polyethylene, nylon, or plasticised PVC), to have straight side edges. It may be U-profiled in transverse cross-section as described above, or otherwise non-circular, to prevent the pads 6 from rotating about the strut longitudinal axis and to allow for better bending into the spherical shape of the ball. Another option to prevent the pads from rotating about the strut longitudinal axis is to thread the pads 6 onto more than one backbone strut 4 in parallel, as shown in FIG. 4 and discussed in more detail below. In general, the backbone struts may have any suitable cross-sectional profile to provide the desired weight, stiffness and resiliency characteristics in the finished ball. For example, the strut transverse cross-sectional profile may be round, half-round or the like, rectangular, X or cross-shaped, I-beam, or hollow (e.g. tubular or box-section). Through holes 10 are provided proximate each end of a backbone strut 4 suitable for receiving press-in plastic fasteners 12 or other suitable fasteners, such as pop rivet and washer assemblies, to hold the two ends together in a hoop. Where the strut 4 is made from a suitably plastically deformable material such as metal wire, the ends of the strut may simply be twisted together to secure them to form the hoops. The twisted ends can be tucked inside the hollow interior of the finished ball, or hidden within the pad 6 interiors. Any other suitable end fastening means can be used, e.g. an integrally moulded, snap-in spigot and socket connection. Additionally or alternatively, as shown in FIGS. 5B and 5C and discussed in more detail below, the backbone struts 4 may have grooves or other features providing texture to their surfaces, and/or may have a non-linear shape, for purposes discussed below.
(19) FIGS. 2A and 2B show the pad 6, from above and below respectively, of the strip subassembly of FIGS. 1A and 1B, without the backbone strut 4 in place. Each backbone strut 4 has five pads 6 threaded or otherwise formed (e.g. co- or insert-moulded) or fixed onto it, which may be polymer foam pads, such as of ethylene-vinyl acetate (EVA) foam, or any other suitable foamed plastic or elastomeric material. The properties of the foam can be adjusted, for example by a foaming agent, to give the correct hardness/softness or a range of hardnesses/softnesses depending on who will be using the ball, and the requirements of the game in winch the ball is being used. The pads therefore define cushioning pads comprising a unitary body of cushioning material.
(20) 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 FIG. 10, but may occur at other angles in other embodiments. The channels 16 may be wider than the backbone struts, to make assembly of the ball easier. The additional width of the channels also allows movement of the backbone struts relative to and against each other at their crossover points, which makes the ball more flexible. Rubbing movement of the backbone struts against each other and against the adjacent pads provides frictional damping and sounds in play, which can be used for example to mimic properties of a rattan takraw ball. FIG. 3 shows the prototype arrangement of the backbone strut 4/channel 16/longitudinal hole 14 arrangement which allows the overlapping of strip subassemblies 2. The depth of the channel 16 and the depthwise positioning of the hole or passage 14 may be arranged so that, in the finished ball, the outer surfaces of all the pads 6 are homogeneously co-aligned, e.g. arranged along a spherical or regular polygonal surface. The pads need not overlap, avoiding or reducing any protruding edges or corners which could be painful when the ball hits a player, and/or having the potential to trap and pinch the player's skin or hair as different parts of the ball deform by different amounts and then recover during play.
(21) FIG. 4 shows an embodiment otherwise similar to that of FIG. 3, but in which one pad 6 is attached to two backbone struts 4 of a strip subassembly 2, through correspondingly two longitudinal hole(s) or passages 14, which are intersected by two channels 16 for receiving the two backbone strips 4 of another such strip subassembly 2. In both FIGS. 3 and 4, the position of the backbone strut(s) 4 running through the pad is indicated by a dotted line continuing on from the solid line of the visible portion of the backbone strut(s) 4. The arrangement of backbone struts 4 contacting each other at their crossing points, made possible by the intersection of the pad channels 16 with the pad through holes or passages 14, allows the interwoven, hooped struts 4 to assume a substantially circular shape in the finished ball, with all of the pads aligned to form a regular shell, for example with their outer edges and outer surfaces arranged to lie aligned on a sphere or regular polygon, providing the same lack of protruding edges and pinch points, and hence the same advantages over the prior art, as described above.
(22) 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 FIG. 5A, the pads 6 may be attached to the backbone strut 4 by means of one or more attachment lugs 15 or other structures situated on or projecting from the rear or inner face of each pad 4, which have a hole or passage 17 through which the backbone strut 4 runs. Where each pad is attached to more than one backbone strut (similar to the arrangement shown in FIG. 4), the number and positioning of the lugs 15 or other structures is modified accordingly. The lugs 15 and their holes or passages 17 may be configured and positioned so that when the resulting subassemblies are assembled into a ball, the outer surfaces and edges of the pads are again arranged to lie aligned on a sphere or regular polygon so as to provide the advantages of improved player comfort as discussed above.
(23) FIG. 5B shows an alternative form of backbone strut 4, whilst FIG. 5C shows this form of backbone strut 4 with pads 6 attached to form a strip subassembly 2. In this embodiment, the backbone strut 4 comprises a generally flat strip which has asymmetrically staggered notches 50 cut, moulded or otherwise formed in the sides so that its overall shape is non-linear. The non-linear shape may help to hold the pads 6 in position on the backbone strut 4 and prevent them from slipping longitudinally. Broader, un-notched parts of the backbone strut 4 are received inside the pads 6 help to support them, reducing impact stresses and also prevent the pads from twisting on the backbone strut 4. Adjacent pairs of the notches 50 in opposite sides of the backbone strut 4 make a narrower, sloping portion which can fit into the groove 16 on the bottom of a pad 6 attached to a crossing backbone strut 4, this groove being at substantially 90 degrees to the long edges of the pad 6 in which it formed (or at any other desired angle as dictated by the notch shapes and relative positions). The non-linear shape of the strut 4 may also cause the pads 6 to tilt slightly relative to one another when the strip subassembly 2 is bent into a hoop, helping the outer surfaces of the pads 6 to align in a more spherical shape. The non-linear shape (where present) and/or broader and narrower sections (where present) of the backbone strut 4 may take other forms (e.g. zig-zag or sinuous) and may be achieved in other ways than by use of notches such as 50. FIGS. 5B and 5C further show how a backbone strut 4 may be provided with one or more grooves 51 or other features providing texture or roughening on their surfaces (upper or lower or both), which may help to hold the pads 6 in position on the backbone strut 4 and may help to prevent them from rotating around the longitudinal axis of the backbone strut 4, due to the extra friction caused thereby. The texture or roughening at the crossing points of the backbone struts in the finished ball can be used to vary or adjust the frictional damping and sounds produced as the struts rub against each other in play as described earlier.
(24) 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.
(25) FIG. 6 shows a first stage in the weaving of strip subassemblies 2 to form a takraw ball. Five of the six strip subassemblies 2 are laid on top of each other to create a pentagon-shaped gap 18 surrounded by pads 6a, which correspondingly create a star shape. Each strip subassembly 2 is laid respectively over and under the two strip subassemblies 2 immediately adjacent it, creating ten loose ends radially arranged. As shown in FIG. 7, the sixth strip subassembly 2 is bent and its ends are fastened together, for example with a plastic press-in fastener 12 in the through holes 10 at either end of the backbone strut 4a, to form a hoop. FIGS. 8 and 9 show further stages in the ball weaving process of six strip subassemblies 2 to form a takraw ball. Five of the ten loose ends of the five strip subassemblies 2, always those ends where the strip subassembly is underneath an adjacent strip subassembly, are bent into the middle above the pentagon-shaped gap 18 and the sixth hoop is placed over them and clicked into place, the pads 6 determining the exact position in which it sits (FIG. 8). The now shorter ten loose ends are fitted together to make another star shape at the opposite side of the ball to the first one (FIG. 9). Each strip subassembly 2 has its ends fastened together, for example by a plastic press-in fastener 12 in the through holes 10 at either end of the backbone strut(s) 4, to create six whole hoops interwoven into a sphere, making up the completed takraw ball as shown in FIG. 10. Referring back to FIG. 9, strut end 4b is tucked beneath pad 6b and is fastened to the opposite end 4c of the same backbone strut; strut end 4d is tucked beneath pad 6c and is fastened to opposite end 4e of the same backbone strut; strut end 4f is tucked beneath pad 6d and is fastened to the opposite end 4g of the same backbone strut; strut end 4h is tucked beneath pad 6e and is fastened to the opposite end 4i of the same backbone strut; and strut end 4j is tucked beneath pad 6f and is fastened to the opposite end 4k of the same backbone strut. The outside of the pads 6 may be profiled, contoured, textured or roughened as desired to give any surface texture or pattern, such as for example surface striations 20 to mimic the appearance of natural rattan fibres. Different pads or different parts of pads may be differently coloured to produce different coloured surface patterns in the finished ball.
(26) 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 (FIG. 10) where three pads 6b, 6c, 6g meet, they meet at the major internal angle, the long edge of the first pad 6b contacting the short edge of the second pad 6c, the long edge of the second pad 6c contacting the short edge of the third pad 6g and the long edge of the third pad 6g contacting the short edge of the first pad 6b. There are twenty such meeting points, corresponding to the twenty weaving crossover points in a traditionally woven rattan takraw ball. The minor internal angles of five pads 6b, 6c, 6d, 6e, 6f meanwhile, almost meet such as to form a star shape with a central gap, which may be a pentagon-shaped gap 18. If six subassemblies 2 are being used, this occurs at twelve points on the ball, creating twelve pentagon-shaped gaps 18. Alternatively, the “long” and “short” edges of the parallelogram-shaped pads may be made of equal length, so that the pentagon-shaped gaps 18 become meeting points. Thus, rather than having twenty meeting points 18a and twelve gaps 18, the ball may be substantially completely closed, with thirty-two meeting points and no gaps. At twenty of those points the major internal angles of three adjacent parallelogram-shaped pads 6 meet. At the other twelve of those points the minor internal angles of five adjacent parallelogram-shaped pads 6 meet.
(27) 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. FIG. 11, for example, shows an alternative embodiment of a strip subassembly 2 comprising a backbone strut 4 and four pentagon-shaped pads 6. Three of these strip subassemblies 2 may be woven together to produce a dodecahedron-shaped ball, as shown in FIG. 12, with twelve faces, thirty edges and twenty vertices, each vertex being the meeting point 18a of three of the pentagon-shaped pads 6. Other non-limiting examples of possible shapes for balls woven from strip subassemblies 2 according to the disclosure include a tetradecahedron (14 sides), an icosahedron (20 sides), a rhombicuboctahedron (26 sides), an icosidodecahedron (32 sides) and a rhombicosidodecahedron (62 sides). Any holes or gaps in the surface of the ball produced by partly tessellating pads 6 may have any desired shape. For example, referring to FIG. 10, the parts of the pads 6 bounding the gap 18 may be given an arcuate shape, centred on the centre of the gap 18, so that the gap 18 produced by the partly tessellating pads 6 is circular. Rather than being straight, the edges of neighbouring interlocking pads may be provided with complementary interlocking recesses and protrusions.
(28) The ball structures and constructions described above provide functions including:
(29) 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.
