The invention relates to a proposal for improvements to an existing design for a new kind of football as described in the Dutch Patent Nr. 1021303, dated 20 Aug. 2007, which has been filed by Pieter Huybers, De Lier, who also is the applicant of the present proposal. This new proposal implies two commutations that lead to a closer approximation of the pursued spherical form than is found following the existing patent. Moreover, the dies that are needed to cut the panels, that comprise the outer skin of the football, are easier to make.
The derivation of the original geometry of the spherical surface is amply described in the aforementioned patent; this will hereby be used as the starting point and be assumed as to be generally of common knowledge.
At the present state of art, a soccer ball consists generally of an inflatable bladder from a flexible material and of an exterior skin from a leathery material which is constructed of smaller parts according a certain geometric pattern. In the aforementioned patent two different basic patterns for the construction of the outer skin are discerned that respectively consist of 32 or 14 parts. However, the mathematical figures or polyhedra, from which they are derived, originally consist of 62 and 26 parts respectively and are called in mathematics:
- 1. Rhombicosidodecahedron, composed of twelve equilateral pentagons, twenty equilateral triangles and thirty squares.
- 2. Rhombicuboctahedron, composed of eighteen squares and eight equilateral triangles.
The dimensions of these figures are determined by the fact, that in both cases all vertices lie on a circumscribed sphere. The centres of the parts are at a certain distance from this sphere, which is different for all kinds of polygons that occur in such a mathematical figure. If one however wishes to create a situation where all centres of the parts have the same distance from the sphere, in the first case all squares are transformed into rectangles where the triangles and the pentagons obtain a form of which all corners are chamfered, and in the second case twelve of the eighteen squares convert to rectangles where the remaining six squares and the triangles become chamfered. The thus found figures can respectively be called: Isodistant Rhombicosidodecahedron and Isodistant Rhombicuboctahedron, where the adjective ‘isodistant’ refers to the fact that all panel centres lie at the same distance from the centre of the whole polyhedron, the system centre, and therefore also from the sphere surface. In order to reduce the sewing length so that the skin is more easily to construct, in the formerly mentioned patent the rectangles are subdivided in two isosceles triangles and two isosceles trapezia. These are combined with adjacent parts following a special pattern to form new entities so that in the first case twelve parts are generated that roughly have the form of a pentagon and twenty parts with roughly the form of a hexagon, and so that in the second case six parts roughly obtain the form of a square and eight parts roughly that of a hexagon. In both cases most of the sides have a form with two slight kinks in length direction. The two bending points of these lines lie at the sphere surface so that these kinked sides more or less follow the curvature of the sphere.
This new patent however indicates a way to let the connection lines between the end points and the bending points of these slightly kinked lines follow an exact circular course. The lines in question thus obtain a more smooth curvature than the respective sides in the old patent and hence follow the curvature of the sphere more closely.
Yet another improvement of the original patent can be accomplished, if all corners of the panels, that basically lie in the plane of the rectangles and thus lie below the sphere surface, are lifted to the level of this sphere. This can easily be realized by a small adaptation of these panels.
The invention shall be explained in more detail with reference to the appended drawings, in which:
FIG. 1. shows the rhombicosidodecahedron1, consisting of twelve flat equilateral pentagons, twenty flat equilateral triangles and thirty flat squares.
FIG. 2. shows theisodistant version2 of the rhombicosidodecahedron1, of which all faces have the same distance from the system centre.
FIG. 3. shows the three kinds of faces that compose the isodistant rhombicosidodecahedron: thirtyrectangles3, twelve chamfered pentagons4 and twentychamfered triangles5.
FIG. 4. shows a subdivision of therectangles3 into four parts: two isosceles triangles6 with apices, that are indicated here as P and Q respectively, and twoisosceles trapezia7. These four parts are added to adjacent faces following a special arrangement, so that two new panel shapes are formed: twelve more or lesspentagonal parts8 and twenty more or lesshexagonal parts9, with which according to the existing patent a soccer ball of the new type can be generated. Theparts8 have five slightly kinkedsides10 where theparts9 have alternatively three kinkedsides10 and three shorter,straight sides11. The position of the points P and Q on therectangular sides3 is chosen such, that thetwisted sides10 of theparts8 and9 are identical. The total sewing length is almost equal to that of the commonly used soccer ball that is composed of twelve equilateral pentagons and twenty equilateral hexagons.
FIG. 5. shows anisometric view12 of theisodistant rhombicosidodecahedron2, of which therectangular parts5 are subdivided.
FIG. 6. shows therhombicuboctahedron13, consisting of eight equilateral triangles and eighteen squares.
FIG. 7. shows theisodistant version14 of therhombicuboctahedron13, in which all faces have the same distance from the system centre and hence from the sphere surface.
FIG. 8. shows the different parts that comprise the isodistant rhombicuboctahedron14: twelverectangles15, eightchamfered triangles16 and sixchamfered squares17.
FIG. 9. shows that therectangles15 also can be subdivided in four parts: twoisosceles triangles18 with apices, that as in the previous case are indicated as P and Q respectively, and twoisosceles trapezia19. These four parts are added to adjacent faces following a special arrangement, so that two new panel shapes are formed: six more or lesssquare parts20 and eight more or lesshexagonal parts21. Theparts20 have four slightly kinkedsides22 where theparts21 have alternatively three kinkedsides22 and three shorter,straight sides23. The position of the points P and Q on therectangular faces15 is chosen such, that the kinkedsides22 of theparts20 and21 are similar. According the existing patent with sixparts20 and eightparts21, soccer balls can be made of a new configuration, but in this case the face centres lie a bit farther away from the sphere surface than in the previous case, so that its use can be suggested for trainings balls in soccer or as balls for other sports where lesser demands count with respect to form and shape retention. A great advantage is, that the sewing length is only one third that of the first version.
FIG. 10. gives anisometric view24 of theisodistant rhombicuboctahedron13, but with subdividedrectangles15.
FIG. 11. shows schematically how according the present patent the slightly kinkedsides10 and22 can be made curved by drawing a circle through the points R, S and T of the kinked side under consideration. These sides will thus follow the curvature of the sphere more precisely than in the old patent.
The describing circles of thesides10 and22 are different and their centres N lie at a considerable distance outside therespective planes8 and9 or20 and21, of which the centre of the circumscribed circles is indicated as M. An extra advantage is, that in a relatively simple way from the centre N of the newly found circle arcs, that replace the kinkedsides10 and22, the positions of the drilling holes for the punching pins can be destined. This method is considerably simpler than the drilling method that must be followed in the case of the kinked sides.
FIG. 12. shows a scheme of therectangular parts3 or15, where the points P and Q, lying in these planes are lifted to the new positions P′ and Q′ on the sphere surface. The circle arc trough V, P′, Q′ and W has the same radius as the sphere. This adaptation will therefore also lead to a better approximation to the sphere form.
FIG. 13. shows theembodiment25 of the ball according the invention based on theisodistant rhombicosidodecahedron12, in inflated state.
FIG. 14. shows theembodiment26, which is based on theisodistant rhombicuboctadron24, in inflated state.