Inflatable ball

Abstract

To provide a ball, in particular a soccer ball, having good properties including an improved control level at a shoe and also a balanced magnus effect in the air leading to a controlled swerve degree which reduces so-called fluttering.SOLUTION: The invention relates to an inflatable ball, particularly a soccer ball, that has an outer shell comprising panels. The panels include at least one surface texture. At least a subset of the panels includes indentations in addition to the surface texture. The indentations have a shape which is different from a shape of the surface texture.SELECTED DRAWING: Figure 1a

Description

Technical Field

[0001] The present invention relates to an inflatable ball having an outer shell including panels, and more particularly to a soccer ball.

Background Art

[0002] High-quality balls generally comprise an outer shell composed of a number of prefabricated panels. The panels are understood hereinafter as being separately prefabricated parts that form less than half of the ball shell.

[0003] The panels must be properly joined to each other, for example, by stitching their edges or by adhesion to the surface of the carcass. Direct adhesion or (laser) welding of the edges of the panels to each other is also possible. For simplicity, regardless of whether the panels are actually stitched to each other in a standard manner or whether they are fixed to each other in another way to provide the outer shell of the ball, the area where two adjacent panels contact each other is simply referred to hereinafter as a "seam".

[0004] In the past, the shell of a soccer ball typically consisted of 32 panels having pentagonal and hexagonal shapes respectively. Due to the large number of small panels, a significant portion of the time for ball manufacturing was required for stitching. Stitching is often a labor-intensive step in the manufacturing process that is performed manually to provide a high-quality ball. However, it has also been recognized that balls with large panels can have negative flight characteristics, for example, they can cause instability. Nevertheless, the trend is clearly towards fewer and larger panels. However, due to aerodynamic effects, there can be an unintended and unpredictable flutter motion in balls with larger, smooth surface panels. Such aerodynamic effects can quickly be seen to essentially impair controlled play and precise shots. Additionally, the smooth surface of the panel also reduces the level of control of the ball in the shoe by, for example, a soccer player during dribbling. Similar problems also occur with inflated balls for other sports such as handball, volleyball, etc.

[0005] Several attempts have been made in the past to improve the aerodynamic characteristics of the ball. For example, the prior art document, U.S. Patent No. 4,318,544, discloses a soccer ball having an outer shell with a plurality of indentations arranged to provide an air duct configuration to assist in the aerodynamic control of the ball. The prior art document, Belgian Patent No. 1,016,122, relates to a football having panels with recessed regions in the form of holes, embossed areas, or grooves. Further, the prior art documents, U.S. Patent Application Publication No. 2020 / 0230468 and U.S. Patent No. 8,617,011, show large elongated rib-like indentations. The plurality of indentations can include a plurality of peripheral flow paths or seams as well as a plurality of internal flow paths.

[0006] Furthermore, the prior art document, U.S. Patent Application Publication No. 2004 / 0142780, discloses a sports ball having an external pattern applied over the entire outer surface of the ball, the pattern being constituted by a plurality of cavities of the same size that are evenly spaced apart. Similarly, the prior art document, U.S. Patent Application Publication No. 2007 / 0117662, relates to a soccer ball having a plurality of air turbulence generating indentations distributed over most of the outer surface of the outer skin.

[0007] Further prior art can be found in: Hong Sungchan et al., Effect of a soccer ball's surface texture on its aerodynamics and trajectories, 2018; Rogers David, A study of the relationship between surface features and the in-flight performance of footballs, UK 2011; Ward Matthew et al., Comparing the aerodynamic behaviour of real footballs to a smooth sphere using tomographic PIV, 2020; Belgian Patent No. 1016110; Belgian Patent No. 1016122; U.S. Patent No. 8617011; U.S. Patent Application Publication No. 2020 / 0230468.

[0008] All of these existing structures generally attempt to affect flight characteristics or ball control, but they result in either a ball with a significantly increased swerve or a trajectory with little swerve. Additionally, parallel grooves also affect aimed shots based on whether a player's shoe hits directly into such a groove or into a smoother area of the shell. So far, an ideal balance has not been found.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Non-Patent Documents

[0010]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0011] Accordingly, it is an underlying problem of the present invention to provide a ball, in particular a soccer ball, having good properties including an improved control level in a shoe, but also providing a controlled swerve degree that reduces so-called fluttering, including a well-balanced Magnus effect in the air. Such a ball enables more precise play, thereby at least partially overcoming the disadvantages outlined above in relation to the prior art.

Means for Solving the Problems

[0012] The above problems are solved by the subject matter of the independent claims of the present invention. Exemplary embodiments of the present invention are defined in the dependent claims.

[0013] In one embodiment, the present invention provides an inflatable ball, in particular a soccer ball, having an outer shell including panels. The panels include at least one surface texture, and at least a subset of the panels includes indentations in addition to the surface texture. The indentations further have a shape different from the shape of the surface texture.

[0014] Generally, a moving object, such as a ball flying through the air, has a high-pressure area on its front side compared to its rear side. Air flows smoothly over the front contour and finally separates from the ball at the rear side. A flying ball also leaves behind a turbulent wake region where the air flow fluctuates or oscillates, creating a lower pressure behind it. The size of the wake affects the amount of drag force on the object. One or more surface textures on the outer shell of the ball create a thin turbulent boundary layer of air that clings to the surface of the ball. This allows the smoothly flowing air to follow the surface of the ball a little further around the rear side of the ball, thereby reducing the size of the wake. Therefore, at least one surface texture results in a reduction in the drag force of the ball compared to a ball with a smooth surface, which can result in a longer shot.

[0015] Despite the possibility of longer shots based on the surface texture of the panel, the inventors have found that by additionally incorporating indentations on at least a subset of the panels, the accuracy of the ball's flight can be significantly improved. For example, the prediction of the ball's trajectory, which is very important for all players on the field, including the goalkeeper, is greatly improved. However, it also allows live and television viewers to more easily follow the game visually, providing a more engaging and enjoyable experience. Even the shooter himself can more reliably trust the flight behavior of the ball, enabling more accurate shots. Additionally, unintended fluttering of the ball can be reduced by the indentations. Therefore, for example, the difficult decision-making of players attempting high-risk long-distance shots is facilitated, and the game becomes more exciting with the inflatable ball of the present invention.

[0016] Furthermore, not only does the flight behavior improve, but at least one surface texture of the panel also results in an inflatable ball having an improved control level in shoes, enabling better dribbling with the ball.

[0017] In some embodiments of the present invention, only a subset of the panels may include indentations in addition to the surface texture. Thus, by carefully selecting the number of panels in the subset, the flight behavior of the inflatable ball can be precisely optimized. Furthermore, carefully arranging the subset of panels on the outer shell of the inflatable ball allows for further adjustment of the flight behavior of the inflatable ball, particularly the predictability of the flight behavior.

[0018] Alternatively, all panels may include indentations in addition to the surface texture. An increase in the number of panels having indentations can increase the Magnus effect of the ball in the air. This results in an increase in the swerve of the inflatable ball.

[0019] The surface texture and the indentations can be arranged independently of each other on the panel. Therefore, the pattern of the surface texture does not have to be interrupted or significantly changed in the indentations. Thus, it is possible for the surface texture to be present within the indentations and vice versa.

[0020] The indentations can be polygonal, in particular, essentially kite-shaped, rhombus-shaped, or even square-shaped. Additionally, or alternatively, elliptical indentations, in particular, essentially circular indentations, may also be applicable. The inventors have found that the shape of the indentations affects the flight behavior of the expandable ball. Both types of indentation shapes, whether polygonal or elliptical, improve the predictability of the trajectory of the ball according to the present invention. The inventors have further found that polygonal indentations provide a slightly higher level of predictability. On the other hand, elliptical indentations allow for a slightly higher speed of the ball. The term "essentially" when used in the present invention should be understood to include small deviations within the range of 5 to 10%. The deviations can be based, for example, on material properties and / or manufacturing uncertainties well known to those skilled in the art.

[0021] The indentations do not have to be in contact with the panel edge and / or can be arranged essentially within the central region of the panel. For example, the indentations can have a minimum distance of at least 10 mm, preferably 15 mm, from the panel edge. Thus, the indentations do not interfere with or adversely affect the seam between two panels. Furthermore, the seams of the outer shell of the expandable ball are generally positioned within a slight depression compared to the central region of the panel, but the indentations arranged within the central region of the panel can have a greater impact on the flight behavior of the ball.

[0022] The depressions may be in-homogeneously distributed over each panel having depressions. The term "in-homogeneously distributed", as used in the present invention, can be understood to mean that each panel may include a region having a greater amount of depressions, as well as a region having fewer depressions or even no depressions. The inhomogeneous distribution of depressions can also be defined based on the average spacing between adjacent depressions. Therefore, the average spacing between adjacent depressions may be different within a first subset than within a second subset. Thus, the density of depressions can be varied across the panel. The term "density", as used in this application, refers to the number of depressions per unit of surface area. The inhomogeneous distribution of depressions can result in an optimized flight behavior for the inflatable ball. The distribution of depressions can be further individually adapted to the preferred flight behavior.

[0023] In an alternative embodiment according to the present invention, the depressions may be uniformly distributed over each panel having depressions. In a uniform distribution, the average distance between adjacent depressions can be essentially constant. It should be noted that a deviation in the average distance on the order of 5% between depressions on the same panel can still be referred to as a uniform distribution. Preferably, but not limited to, depressions having an elliptical shape can be uniformly distributed over each panel of the subset. However, a uniform distribution of polygonal-shaped depressions is also applicable.

[0024] Depending on the embodiment, each panel may include only one surface texture. The surface texture can be distributed essentially uniformly over each of the panels. The shape of the surface texture may vary across the various panels, and in particular, each panel can have a different surface texture. Thus, a precise selection of the various surface textures and / or the arrangement of different surface textures across the various panels can result in a high degree of individual adjustment of the inflatable ball to the preferred flight behavior.

[0025] The surface texture can have a plurality of different shapes. The different shapes can be grouped relative to each other and may form formations. A plurality of formations may be at least partially distributed across the panel, such that the distribution of the different shapes may repeat identically within the plurality of formations.

[0026] The shape of the surface texture can be the same on each panel. Therefore, the level of ball control in the shoe can be substantially the same regardless of the location of the contact area on the outer shell. Preferably, each panel of the inflatable ball can include a surface texture.

[0027] Alternatively, at least some panels can include more than one surface texture. At least two surface textures on the same panel can be at least partially overlapped with each other or arranged adjacent to each other. Different surface textures on the same panel can result in a more specific adaptation of the surface of the inflatable ball with respect to flight behavior, control in the shoe, and other characteristics.

[0028] The maximum extent of at least one surface texture perpendicular to the surface of the inflatable ball can be less than the maximum depth of the indentation. As described above, at least one surface texture can create a thin turbulent boundary layer of air that clings to the surface of the ball, especially when it is essentially uniformly distributed over each of the panels. At this time, a greater depth of the indentation can intentionally disrupt the thin boundary layer of air in the panel having the indentation, creating the ability to affect the flight behavior of the ball according to the present invention. Therefore, depending on the depth of the indentation, a higher stability of the ball in the air can be created.

[0029] Each panel having indentations can have at least 2, preferably at least 3, and more preferably at least 4 distinct indentation depths, indentation lengths, indentation widths, or combinations thereof. In a preferred embodiment, on each panel having indentations, the indentation depth, indentation length, indentation width, or combinations thereof can decrease on average in the direction from the inner region of the panel to the outer / edge region. It should be noted that the term "decrease on average in the direction from the inner region to the outer / edge region" can generally allow adjacent indentations having the same but non-increasing sizes in the defined direction. Carefully changing the parameters of each indentation or group of indentations on the panel can be used to have a favorable effect on the flight behavior of the inflatable ball. The optimized parameters can be found, for example, by standard experiments (in a laboratory, wind tunnel, etc.) or calculated using a theoretical model.

[0030] The indentation length can vary from 1.0 to 30.0 mm, preferably from 1.5 to 20.0 mm, and more preferably from 2.0 to 10.0 mm. The term "length", when used in the present invention, relates to the range of the indentation between two points, and the larger of the two dimensions parallel to the surface of the inflatable ball corresponds to the length. For example, for a (convex) kite-shaped indentation, the length corresponds to the range along the axis of symmetry. For a circular indentation, the length corresponds to the diameter, and for an elliptical shape, the length corresponds to twice the semi-major axis. The indentation depth can vary from 0 to 10 mm, preferably from 0 to 8 mm, and more preferably from 0 to 6 mm. The indentation width can vary from 0.1 to 15.0 mm, preferably from 0.2 to 7.5 mm, and more preferably from 0.4 to 2.5 mm. Similar to the definition of length, the width corresponds to the smaller of the two dimensions along the surface. For example, for a kite-shaped indentation, the width corresponds to the maximum extension between two corners perpendicular to the main extension direction. For an elliptical shape, the width corresponds to twice the semi-minor axis. The inventors have found that the recited ranges result in indentations that are not so small as to have no effect on the flight behavior, but also not so large / deep as to cause different responses on the shoe depending on whether the contact area is on a subgroup of the panel.

[0031] The flight behavior of the inflatable ball, in particular the predictability of the flight behavior, can depend on one of the position of the indentation on the panel, the shape of the indentation, the depth of the indentation, the distance between the indentations relative to each other, or a combination thereof. Preferably, the shortest distance between two adjacent indentations on the same panel can be from 0.5 to 45.0 mm, preferably from 1.0 to 30.0 mm, and most preferably from 1.5 to 15.0 mm. Thus, the indentations optimally cooperate to favorably influence the flight behavior, in particular the predictability of the flight behavior.

[0032] Each panel may include an outer layer containing polyurethane (PU). Each panel may include an inner layer of a foamed material, preferably ethylene propylene diene monomer (EPDM). According to embodiments of the present invention, at least some of the indentations on each panel having indentations may extend partially into the upper surface of the inner layer. At least one surface texture may extend only within the outer layer.

[0033] The inflatable ball may further comprise a carcass. The carcass covers the surface of the inner bladder. The inner bladder provides the required airtightness of the ball, and the carcass stabilizes the bladder and protects it from external impacts. The carcass further provides a contracting force towards the inner bladder.

[0034] According to embodiments, the panels and the carcass may be at least partially spray-coated with an adhesive, preferably containing latex. The panel edges of adjacent panels may be connected to each other via heat-activated bonding.

[0035] The indentations may be applied after the panel forming process. The panel forming process corresponds to the process in which the inner and outer layers of each panel are joined together. To manufacture the inflatable ball according to the present invention, no modification of the representative machines for panel production is required, thereby improving the cost efficiency of the manufacturing process. Furthermore, by reusing existing machines, the total carbon footprint of the manufacturing process is reduced. Preferably, the indentations may be created by pressing a plate having protrusions onto at least one panel.

[0036] The subset may include fewer than 32 panels, preferably fewer than 24 panels, and most preferably 12 panels. Preferably, the number of panels not within the subset may be fewer than 24 panels, preferably fewer than 16 panels, and most preferably 8. As described above, fewer and larger panels reduce the amount of stitching required during manufacturing, making the inflatable ball of the present invention more cost-effective.

[0037] The maximum extent of at least one surface texture perpendicular to the surface of the expandable ball can be less than 1.5 mm, preferably less than 1.0 mm, and more preferably less than 0.5 mm. The shape of the at least one surface texture can be polygonal, preferably quadrilateral. The maximum length of the sides of the polygonal surface texture can be less than 20 mm, preferably less than 15 mm, and more preferably less than 10 mm.

[0038] The total roughness volume of the surface of the expandable ball is 7000 - 30000 mm 3 , preferably 14000 - 25000 mm 3 , and more preferably 18000 - 22000 mm 3can extend to the range. The total roughness volume according to the present invention can be most preferably explained starting from the base sphere. The base sphere corresponds to the smallest sphere possible that surrounds an (ideal) inflatable ball having a smooth panel, i.e., having no surface texture and indentation in particular. At this time, the total roughness volume corresponds to the absolute value of the volume difference between the base sphere and the volume of the inflatable ball defined by the surface of the ball. It should be noted that the total roughness volume can include a volume difference based on a first volume inside the base sphere, for example, seams, indentations, and / or a sunken surface texture of the inflatable ball. The total roughness volume can further include a volume difference based on a second volume outside the base sphere, for example, a volume difference based on one or more protruding surface textures. In these embodiments, the total roughness volume corresponds to the sum of the absolute values of the first and second volumes. Alternatively, the total surface texture may consist only of the first volume, especially for the sunken surface texture. Therefore, the total roughness volume depends at least on indentations, surface texture, and / or seams. The inventors have found that for a ball having a total roughness volume within a defined range, the critical Reynolds number of the ball when flying in the air can be shifted to a lower speed where the flight behavior of the ball does not essentially depend on its drag. As a result, at a higher speed where the drag is appropriate for the flight behavior of the ball, an essentially constant drag can be achieved over various speeds. In this way, the prediction of the ball's trajectory can be greatly improved. In addition, the unintentional fluttering of the ball can be reduced.

[0039] For example, when developing a new inflatable ball according to the present invention, the roughness volume of the seam can be determined first. Next, a plurality of indentations and / or at least one surface texture can be added to match the required amount of roughness volume so as to produce a total roughness volume within the above-mentioned preferably defined range. The indentations and / or at least one surface texture preferably correspond to the indentations and surface textures as described herein.

[0040] Aspects of the present invention will be described in more detail below with reference to the accompanying drawings. These drawings show the following:

Brief Description of the Drawings

[0041]

Figure 1a

Figure 1b

Figure 1c

Figure 2a

Figure 2b

Figure 2c

Figure 3

Figure 4a

Figure 4b

Figure 5a

Figure 5b

Figure 6

Modes for Carrying Out the Invention

[0042] In the following, exemplary embodiments of the present invention will be described in more detail with reference to an inflatable ball. It should be understood that while specific combinations of features are described below with respect to exemplary embodiments of the present invention, the present disclosure is not limited to such embodiments. Specifically, not all features need to be present to implement the present invention, and embodiments can be varied by combining specific features of one embodiment with one or more features of another embodiment.

[0043] Figures 1a - 1c show an embodiment of an inflatable ball 100 according to the present invention from three different viewpoints. The ball 100 can be a soccer ball. Although the features of the present invention are mainly described with respect to a soccer ball, those skilled in the art can easily apply these features to balls for various other sports, such as volleyballs, handballs, or others. The ball 100 has an outer shell including various panels 140, 150. The panels 140, 150 include a surface texture 120 on the outer layer. The surface texture 120 represents a regular pattern uniformly distributed on each panel. It can be understood that the panel edges 130 represent an interruption of the regular pattern. When assembling the pre - manufactured panels 140, 150, the panel edges 130 can be joined to each other using an adhesive, via thermally activated bonding, by stitching or sewing. The shape of the surface texture 120 is essentially quadrilateral with a longest side length of approximately 5 mm. The extent of the surface texture 120, which represents the maximum distance in the height profile of the surface texture 120, is less than 1 mm. Figures 1a - 1c show one embodiment having a single uniformly distributed surface texture 120, but it should be noted that according to the present invention, different surface textures on the same panel or on adjacent panels are also applicable.

[0044] A subset of panel 150 includes indentations 110 in addition to the surface texture 120. Panel 140 that is not within the subset of panel 150 does not include such indentations 110. As shown in FIGS. 1a - 1c, the indentations 110 have a shape much like that of a kite. Generally, the shape belongs to a group of (mathematically) polygons. The indentations 110 are mainly distributed within the central region of the subset of panel 150, while the edge region 170 close to the seam or edge 130 of panel 150 does not have indentations 110. Therefore, compared to the regular surface texture 120, the indentations 110 are non - uniformly distributed on each panel 150. The non - uniform distribution of the indentations can also be understood based on the average spacing between adjacent indentations. As shown in FIGS. 1a - c and, similarly, in FIG. 3, the average spacing between adjacent indentations within the central region of the panel is smaller than that within the edge or the region close to the edge. Thus, the density of the indentations is varied across the panel. In another embodiment of the present invention (not shown), a uniform distribution of the indentations is also envisioned. This can be particularly beneficial for indentations having an elliptical shape (see indentations 211 in FIGS. 2a - 2c).

[0045] The inflatable ball 100 further comprises a bladder that can be covered by a carcass (not shown). For example, a sealable opening 160 connected to the internal bladder is guided through the carcass and the outer shell to inflate the ball 100 using an air pump or a compressor. During the manufacture of the ball 100, the panels 140, 150 and the carcass are preferably spray - coated with an adhesive and, in a subsequent step, bonded to each other. The adhesive can include latex.

[0046] All of the various features of the inflatable ball 100 described above, particularly the combination of the indentation 110 and the surface texture 120, contribute to the ball 100 having improved controllability and more reliable flight behavior. Thus, the surface texture 120 not only increases the controllability of the ball 100 in a shoe, but also actively increases the possible range of a shot. Based on the small vertical range and essentially regular pattern of the surface texture 120, a thin turbulent boundary layer of air that adheres to the surface of the ball is created, reducing the drag force of the ball 100 compared to balls known in the art having a smooth outer surface. In addition, these known balls are particularly prone to fluttering during long-distance shots, especially when made of fewer but larger panels, but these effects are very well suppressed by the inflatable ball 100 according to the present invention. The indentation 110 of the panel 150 produces a more balanced Magnus effect in the air, resulting in a controlled and stable degree of swerve. This can be understood as the main reason for reducing the fluttering of the inflatable ball 100. In this regard, for example, the arrangement of the indentations 110 on the panel 150, the polygonal shape of the indentations 110, the depth of the indentations 110, the distance between the indentations relative to each other, or combinations thereof, as can be depicted from FIGS. 1a to 1c, result in a more stable and more reliably predictable trajectory of the ball 100.

[0047] The inventors have found that between 7000 and 30000 mm 3For balls having a total roughness volume within the range, it has been found that the critical Reynolds number of a ball flying in air can be shifted to lower speeds where the flight behavior of the ball does not essentially depend on its drag or the degree to which the flight behavior of the ball depends on its drag is quite small. This can be based on the exponential relationship between the aerodynamic force and the atmospheric velocity. As a result, at higher speeds where the drag is related to the flight behavior of the ball, an essentially constant drag can be achieved over various speeds. Thus, the prediction of the ball's trajectory can be greatly improved. In addition, the unintentional fluttering of the ball can be reduced. For example, when developing a new inflatable ball according to the present invention, the roughness volume of the seam can be determined first. Next, a plurality of indentations and / or at least one surface texture can be added to yield the required roughness volume amount so as to produce a total roughness volume within the above-mentioned advantageously defined range. The indentations and / or at least one surface texture preferably correspond to the indentations and surface textures as described herein.

[0048] Figures 2a - 2c show an embodiment according to the invention of a ball 200 with an outer shell having panels 240, 250 connected at the edge 230 of the panel. Panel 240 includes a surface texture 220 and provides the same advantages described for panel 140. Panel 250 includes a recess 211 and provides advantages very similar to those described for panel 150. Compared to panel 150, panel 250 includes an essentially circular recess 211 that can generally be elliptical depending on manufacturing uncertainties. Recess 211 is mainly distributed within the central region of panel 250, while the seam or edge region 270 near the edge 230 of panel 250 does not have recess 211. Thus, similar to recess 110 of ball 100, recess 211 of ball 200 is also non-uniformly distributed over each panel 250. This can be seen as a decrease in recess density proceeding from the central region to the edge region 270 of panel 250. For example, as shown in FIG. 2a, surface texture 220 and recess 211 can be arranged independently of each other on panel 250. Thus, the pattern of surface texture 220 is not interrupted or significantly altered in recess 211. In this way, surface texture 220 can be present within recess 220 and vice versa, which also applies to other embodiments described herein, for example, the inflatable ball 100 with recess 110 and surface texture 120. The inflatable ball 200 further comprises a bladder that can be covered by a carcass (not shown). For example, a sealable opening 260 connected to the internal bladder is guided through the carcass and the outer shell to inflate the ball 200 using an air pump or compressor. Similar to ball 100, the flight behavior of ball 200 depends on the various parameters of recess 211 listed above with respect to recess 110.

[0049] Figure 3 schematically shows an embodiment according to the invention of a panel configuration 300. The panel configuration 300 shows a two-dimensional configuration of various panels 340, 350, similar to a development of a polyhedron. In geometry, a development of a polyhedron is a configuration of non-overlapping edge-joined polygons in a plane that can be folded (along the edges) to become the faces of the polyhedron. Thus, by aligning adjacent panel edges 330 on a bladder or carcass like the folding steps of a polygon and attaching the panels 340, 350 to the bladder or carcass, an inflatable ball according to the invention can be formed. The panel configuration 300 includes twelve panels 350 having indentations 310. The indentations 310 are essentially arranged within the central region of the panel 350. Thereby, the edge region 370 does not contain any indentations 310 at all. In other words, the density of the indentations 310 is highest within the central region of the panel 350 and decreases in the direction towards the panel edge 330. The panel configuration 300 further includes eight panels 340 that do not contain any indentations 310 at all. In addition to the indentations 310 on a subset of the panels 340, all the panels 340, 350 of the panel configuration 300 include a surface texture (not shown in FIG. 3). The advantageous synergistic effect brought about by the combination of the indentations 310 and the surface texture has been described above with respect to FIG. 1 and applies here as well.

[0050] Figure 4a shows a partial view of an experimental apparatus of a goal 400 showing true-to-scale collision zones 490 - 495 of various balls. The goal 400 includes bars 480 and posts 482 that create 90° corners at their connections. The height 281 of the goal 400 is 2.44 m, in accordance with standard FIFA (trademark) regulations. The inventors conducted various experiments under laboratory conditions comparing known balls in the art with the inflatable ball according to the present invention. In a first experiment, a swerve kick was performed using a typical soccer shoe attached to the experimental apparatus, similar to the movement of a player's leg while kicking a ball. The speed of the shoe was set at 20 m / s, which resulted in a ball speed of approximately 90 km / h (i.e., 25 m / s) or so. Each kick using each ball was repeated 18 times using six different contact points of the shoe on each ball. The contact points varied, for example, between the center of the panel, the edge / seam of the panel, the edge / seam point of more than two panels, etc. The trajectory of each ball was determined by video analysis. The air pressure of each ball was set at 0.8 bar.

[0051] Figure 4a shows various elliptical collision zones 490-495 located within the junction of post 482 and bar 480 resulting from the video analysis described above. The collision zones 490-495 correspond to the scale-faithful collision zones of various tested balls. For improved visualization of the various zones, each collision zone 490-495 is shown on the left side of Figure 4a so as not to overlap with other collision zones, but still faithfully to scale. Collision zones 490 and 491 correspond to an embodiment of the inflatable ball according to the present invention in which all panels include surface texture and a subset of them additionally include indentations. The indentation of the inflatable ball corresponding to collision zone 490 is kite-shaped, while each indentation corresponding to collision zone 491 is circular. Collision zones 492-495 correspond to balls known in the art. It can be shown that polygonal indentations result in a higher level of predictability. On the other hand, the inventors have found in a second experiment (not shown) that elliptical indentations allow for a slightly higher speed of the ball according to the present invention for straight kicks.

[0052] Figure 4b graphically shows the sizes of each collision zone 490-495. In addition, for each ball, the size in square meters is indicated above each bar in the figure. As can be seen from the figure, the embodiments according to the present invention exhibit the smallest-sized collision zones 490, 491. It should be noted that the small collision zones equivalently mean a highly reliable flight behavior, particularly with regard to the predictability of the flight behavior. The small collision zones further suggest a strong reduction of the fluttering effect known from many balls of the prior art.

[0053] Figures 5a and 5b show an embodiment of the press plate 500 according to the present invention from two perspectives. The manufacturing / fabrication process of the recess according to the present invention can be as follows: Place a pre-manufactured panel on the platen. Next, move a press plate having protrusions 510, for example, the press plate 500, in the direction towards the panel and sandwich the panel between the platen and the press plate 500. As a result, the protrusions 510 of the press plate 500 are pressed into the outer surface of the panel, thereby creating a recess. The press plate 500 exhibits kite-shaped protrusions 510 that result in essentially kite-shaped recesses on the panel. The protrusions 510 are arranged non-uniformly on the press plate 500. Accordingly, based on the press plate edge 570 that does not exhibit the protrusions 510, the corresponding panel will also not exhibit a recess within the edge region of the panel accordingly. The height 511 of the protrusions 510 is approximately 5 mm, creating a recess of 5 mm or less. It should be noted that other shapes, particularly oval shapes, other sizes, other distributions, particularly uniform distributions, or combinations thereof are also applicable for the press plate according to the present invention.

[0054] Figure 6 shows an embodiment of panel 600 according to the present invention. For example, panel 600 can be manufactured using press plate 500. Panel 600 can preferably include an outer layer containing polyurethane and an inner layer containing a foaming material. The inner layer preferably contains ethylene propylene diene monomer (not shown). Panel 600 includes kite-shaped depressions 610 arranged non-uniformly, and the shortest distance 615 of depressions 610 ranges from 1.5 mm to 15.0 mm. Depressions 610 can extend at least into the inner foam layer. Conversely, the range of the surface texture (not shown) can be limited to only the outer layer. Thus, the maximum range of the surface texture perpendicular to the surface of the inflatable ball can be smaller than the maximum depth of the depression. As shown in Figure 6, the size of depressions 610 decreases from the inner or central region to the outer or edge region in direction 675. Generally, the depression depth, depression lengths 612, 613, depression widths 611, 614, or combinations thereof can vary on a single panel. In the embodiment shown in Figure 6, the inner, or largest, depression has a length 613 of 9.2 mm and a width 614 of 2.2 mm. The outer, or smallest, depression has a length 612 of 2.3 mm and a width 611 of 0.5 mm.

[0055] It should be noted that the above-described embodiments and figures mainly show a single surface texture, but more than one surface texture on adjacent panels or even on the same panel is also applicable. Furthermore, embodiments including different panels of the inflatable ball according to the present invention or even combinations of various shapes of depressions on the same panel are also possible. For example, different shapes may be grouped with respect to each other to construct a formation. A plurality of formations may be at least partially distributed across the panel, whereby the distribution of different shapes may be repeatedly the same within the plurality of formations.

[0056] Further embodiments are described below to facilitate understanding of the present invention: 1. An inflatable ball (100, 200) having an outer shell including panels (140, 150, 240, 250, 340, 350, 600), in particular a soccer ball, wherein a. the panels (140, 150, 240, 250, 340, 350, 600) include at least one surface texture (120, 220), b. at least a subset of the panels (150, 250, 350, 600) includes indentations (110, 211, 310, 610) in addition to the surface texture (120, 220), c. the indentations (110, 211, 310, 610) have a shape different from the shape of the surface texture (120, 220), the inflatable ball. 2. The inflatable ball according to embodiment 1, wherein only a subset of the panels includes indentations in addition to the surface texture. 3. The inflatable ball according to embodiment 1, wherein all the panels include indentations in addition to the surface texture. 4. The inflatable ball according to any one of embodiments 1 to 3, wherein the indentations are polygonal, in particular substantially kite-shaped, and / or elliptical, in particular substantially circular. 5. The inflatable ball according to any one of embodiments 1 to 4, wherein the indentations do not contact the panel edges (130, 230, 330) and / or are disposed substantially within the central region of the panel. 6. The inflatable ball according to any one of embodiments 1 to 5, wherein the indentations are non-uniformly distributed on each panel having the indentations. 7. The inflatable ball according to any one of embodiments 1 to 5, wherein the indentations are uniformly distributed on each panel having the indentations. 8. The inflatable ball according to any one of embodiments 1 to 7, wherein each panel includes only one surface texture. 9. The inflatable ball according to embodiment 8, wherein the surface texture is substantially uniformly distributed on each of the panels. 10. The inflatable ball according to any one of embodiments 1 to 9, wherein the shape of the surface texture is the same on each panel. 11. An expandable ball according to any one of embodiments 1 to 7, wherein at least some of the panels include more than one surface texture. 12. An expandable ball according to any one of embodiments 1 to 11, wherein the maximum extent of at least one surface texture perpendicular to the surface of the expandable ball is smaller than the maximum depth of the indentation. 13. An expandable ball according to any one of embodiments 1 to 12, wherein each panel having an indentation has at least two, preferably at least three, and more preferably at least four distinct indentation depths, indentation lengths (612, 613), indentation widths (611, 614), or combinations thereof. 14. An expandable ball according to any one of embodiments 1 to 13, wherein on each panel having an indentation, the indentation depth, indentation length, indentation width, or combinations thereof decreases on average in a direction (675) from the inner region of the panel to the outer / edge region (170, 370, 570). 15. An expandable ball according to any one of embodiments 1 to 14, wherein the indentation length (612, 613) varies from 1.0 to 30.0 mm, preferably from 1.5 to 20.0 mm, and more preferably from 2.0 to 10.0 mm. 16. An expandable ball according to any one of embodiments 1 to 15, wherein the indentation depth varies from 0 to 10 mm, preferably from 0 to 8 mm, and more preferably from 0 to 6 mm. 17. An expandable ball according to any one of embodiments 1 to 16, wherein the indentation width (611, 614) varies from 0.1 to 15.0 mm, preferably from 0.2 to 7.5 mm, and more preferably from 0.4 to 2.5 mm. 18. An expandable ball according to any one of embodiments 1 to 17, wherein the flight behavior of the expandable ball, particularly the predictability of the flight behavior, depends on one of the position of the indentations on the panel, the shape of the indentations, the depth of the indentations, the distance between the indentations relative to each other, or combinations thereof. 19. The shortest distance (615) between two adjacent indentations on the same panel is 0.5 to 45.0 mm, preferably 1.0 to 30.0 mm, and most preferably 1.5 to 15.0 mm, for the expandable ball according to any one of Embodiments 1 to 18. 20. Each panel includes an outer layer containing polyurethane PU, for the expandable ball according to any one of Embodiments 1 to 19. 21. Each panel includes an inner layer containing a foamed material, preferably ethylene propylene diene monomer EPDM, for the expandable ball according to any one of Embodiments 1 to 20. 22. At least some of the indentations extend partially into the upper surface of the inner layer, for the expandable ball according to Embodiment 20 or 21. 23. At least one surface texture extends only within the outer layer, for the expandable ball according to any one of Embodiments 20 to 22. 24. Further comprising a carcass, for the expandable ball according to any one of Embodiments 1 to 23. 25. The panel and the carcass are at least partially spray-coated with an adhesive, preferably containing latex, for the expandable ball according to Embodiment 24. 26. The panel edges of adjacent panels are connected to each other via thermally activated bonding, for the expandable ball according to any one of Embodiments 1 to 25. 27. The indentations are applied after the panel forming process, for the expandable ball according to any one of Embodiments 1 to 26. 28. The indentations are created by pressing at least one plate (500) having protrusions (510) onto one panel, for the expandable ball according to any one of Embodiments 1 to 27. 29. The subset includes less than 32 panels, preferably less than 24 panels, and most preferably 12 panels, for the expandable ball according to any one of Embodiments 1 to 28. 30. The number of panels not within the subset is less than 24 panels, preferably less than 16 panels, and most preferably 8 panels, for the expandable ball according to any one of Embodiments 1 to 29. 31. The maximum extent of at least one surface texture perpendicular to the surface of the expandable ball is less than 1.5 mm, preferably less than 1.0 mm, and more preferably less than 0.5 mm, for the expandable ball according to any one of Embodiments 1 to 30. 32. The shape of at least one surface texture is polygonal, preferably quadrilateral, for the expandable ball according to any one of Embodiments 1 to 31. 33. The maximum length of the sides of the polygonal surface texture is less than 20 mm, preferably less than 15 mm, and more preferably less than 10 mm, for the expandable ball according to Embodiment 32. It should be noted that the present invention may include the following aspects. [Aspect 1] An inflatable ball having an outer shell including panels, a. the panel includes at least one surface texture, b. at least a subset of the panel includes indentations in addition to the surface texture, c. the indentations have a shape different from the shape of the surface texture, an inflatable ball. [Aspect 2] Only a subset of the panels includes indentations in addition to the surface texture, or all the panels include indentations in addition to the surface texture, the inflatable ball according to Aspect 1. [Aspect 3] The indentations are polygonal and / or elliptical, the inflatable ball according to Aspect 1 or 2. [Aspect 4] The indentations do not contact the panel edges and / or are disposed essentially within the central region of the panel, the inflatable ball according to any one of Aspects 1 to 3. [Aspect 5] The indentations are non-uniformly distributed on each panel having an indentation, or the indentations are uniformly distributed on each panel having an indentation, the inflatable ball according to any one of Aspects 1 to 4. [Aspect 6] Each panel includes only one surface texture, and / or the shape of the surface texture is the same on each panel, the inflatable ball according to any one of Aspects 1 to 5. [Aspect 7] At least some of the panels include more than one surface texture, the inflatable ball according to any one of Aspects 1 to 6. [Aspect 8] The surface textures include a plurality of different shapes grouped with respect to each other to construct a formation, and a plurality of formations are distributed at least partially over the one or more panels, whereby the distribution of the different shapes is repeatedly the same within the plurality of formations, the inflatable ball according to any one of Aspects 1 to 7. [Aspect 9] The maximum extent of the at least one surface texture perpendicular to the surface of the inflatable ball is smaller than the maximum depth of the indentation, the inflatable ball according to any one of Aspects 1 to 8. [Aspect 10] Each panel having an indentation has at least two distinct indentation depths, indentation lengths, indentation widths, or combinations thereof, and / or On each panel having a recess, the recess depth, recess length, recess width, or a combination thereof decreases on average in a direction from the inner region to the outer / edge region of the panel, the expandable ball according to any one of Aspects 1 to 9. [Aspect 11] The recess length varies from 1.0 to 30.0 mm, and / or The recess depth varies from 0 to 10 mm, and / or The recess width varies from 0.1 to 15.0 mm, the expandable ball according to any one of Aspects 1 to 10. [Aspect 12] Each panel includes an outer layer containing polyurethane (PU), and / or Each panel includes an inner layer containing a foamed material, the expandable ball according to any one of Aspects 1 to 11. [Aspect 13] The subset includes less than 32 panels, and / or The number of panels not in the subset is less than 24 panels, the expandable ball according to any one of Aspects 1 to 12. [Aspect 14] The maximum extent of the at least one surface texture perpendicular to the surface of the expandable ball is less than 1.5 mm, and / or The shape of the at least one surface texture is polygonal, the expandable ball according to any one of Aspects 1 to 13. [Aspect 15] The total roughness volume of the surface of the expandable ball ranges from 7000 to 30000 mm 3 and can be achieved, the expandable ball according to any one of Aspects 1 to 14.

Explanation of Symbols

[0057] 100, 200 Inflatable Ball 110, 211, 310, 610 Depression 120, 220 Surface Texture 130, 230, 330 Panel Edge 140, 150, 240, 250, 340, 350, 600 Panel 160, 260 Sealable Opening 170, 270, 370 Edge Region 300 Panel Configuration 400 Goal 480 Bar 481, 511 Height 482 Post 490, 491, 492, 493, 494, 495 Collision Zone 500 Press Plate 510 Protrusion 570 Press Plate Edge 612, 613 Depression Length 611, 614 Depression Width 615 Shortest Distance 675 direction

Claims

1. 1. An inflatable ball having an outer shell including a plurality of panels, a. the plurality of panels includes at least one surface texture; b. only a portion of said plurality of panels includes indentations in addition to said surface texture; c. the depressions have a shape that is different from the shape of the surface texture; d. the dimples are kite-shaped, diamond-shaped, square-shaped, or elliptical when viewed perpendicular to the surface of the inflatable ball; e. An inflatable ball, wherein the length of said cavity varies from 1.0 mm to 30.0 mm and the width of said cavity varies from 0.1 mm to 15.0 mm.

2. 10. The inflatable ball of claim 1, wherein the depression does not contact a panel edge and / or is located within a central region of the panel.

3. the depressions are non-uniformly distributed on each panel having the depressions; or 3. The inflatable ball of claim 1, wherein the depressions are uniformly distributed on each panel having a depression.

4. Each panel contains only one surface texture, 4. An inflatable ball according to claim 1, wherein the shape of the surface texture is the same on each panel.

5. 4. The inflatable ball of claim 1, wherein at least some of the panels include more than one surface texture.

6. 6. The inflatable ball of claim 1, wherein a maximum extent of the at least one surface texture perpendicular to a surface of the inflatable ball is less than a maximum depth of the depression.

7. each panel having a recess has at least two distinct recess depths, recess lengths, recess widths, or combinations thereof; and / or 7. The inflatable ball of claim 1, wherein on each panel having a depression, the depression depth, depression length, depression width, or a combination thereof, decreases on average in a direction from an interior region to an exterior / edge region of the panel.

8. An inflatable ball as claimed in any one of claims 1 to 7, wherein the recess depth varies from 0 to 10 mm.

9. each panel comprises an outer layer comprising polyurethane; and / or 9. The inflatable ball of claim 1, wherein each panel includes an inner layer comprising a foam material.

10. the portion of the plurality of panels includes less than 32 panels; and / or 10. The inflatable ball of claim 1, wherein the number of panels that are not part of the plurality of panels is less than 24 panels.

11. the maximum extent of the at least one surface texture perpendicular to the surface of the inflatable ball is less than 1.5 mm; and / or 11. The inflatable ball of claim 1, wherein at least one of the surface textures has a polygonal shape.

12. The total roughness volume of the surface of the inflatable ball is 7000 to 30000 mm ３ is in the range the total roughness volume being the absolute value of the volumetric difference between a base sphere and the volume of the inflatable ball defined by the surface of the ball; 12. The inflatable ball of claim 1, wherein the base sphere is the smallest possible sphere that surrounds the inflatable ball and that does not have the surface texture and dimples on its surface.

Images