BALL-CONTACTING PAD FOR SPORT SHOE

Abstract: A sport shoe having ball-contacting pads mounted thereon for increasing kicking performance without appreciably decreasing ball feel is disclosed. The pads include a top layer separated from a bottom layer by interconnecting elastic elements or webs. The top and bottom layers are substantially planar and elongate. The pad is arranged on the shoe so that when, for example, a soccer player kicks a ball, reaction forces from the impact will displace the top layer longitudinally, substantially parallel to the bottom layer, thus stretching the elastic interconnecting elements, storing potential energy. As the ball leaves the player's shoe, the reaction forces are diminished, and the potential energy in the interconnecting elements moves the top layer to again move longitudinally, but in an opposite direction. This return movement imparts a tangential force on a ball, thus enabling a player to kick the ball with substantial spin, a key tactic during many parts of a soccer game.

Description: BAL -CONTACTING PAD FOR SPORT SHOE BACKGROTTND OF THE INVENTTON Field of the Invention This invention pertains generally to the field of sports shoes used for kicking balls, and more particularly pertains to sport shoes for kicking balls in which it is desired to impart maximum velocity and spin on the ball . These parameters are most applicable to the games of soccer, American football, and rugby. Description of the Related Art Good soccer players can kick a soccer ball with enough spin to cause it to arc past defensive players on its way to an opposer' s goal. Such ball control is particularly critical during penalty shots, corner shots, free kicks, and long passes. Accordingly, soccer players look for shoes that will generate maximum angular velocity and hence, ball control. High-quality soccer shoes often provide a high- friction surface, such as rubber pads at strategic locations on the shoe upper. These rubber pads prevent the ball from slipping on the shoe when the soccer player kicks the ball. Some available pads are somewhat rigid which often detracts from the performance of the shoe when the player needs to feel the ball with his or her foot, such as during dribbling or trapping. Thus, a shoe that provides good kicking performance may have poor tactile response for dribbling or trapping, and conversely, a shoe with superior feel may provide unsatisfactory kicking performance. Accordingly, it will be beneficial to have a soccer shoe that provides feel for ball handling and improved properties for generating maximum ball velocity and spin during kicking. SUMMARY OF THE INVET-JTTΩN The present invention overcomes the deficiencies in the prior art by providing a ball-contacting pad that has superior properties for kicking a soccer ball to achieve improved ball control (i.e., velocity and spin) while providing a good "feel" of the ball on the player's foot. The advantages of the present invention are provided by a pad comprising two layers connected by elastic elements or webs. A bottom layer preferably includes a scrim for inelasticity. The top layer may also have a scrim and preferably includes a high- friction surface for contacting the soccer ball. The interconnecting elements are located between the top and bottom layers and are preferably biased from front to back so that as the top layer moves backward, the interconnecting elements stretch to store potential energy. The bias also allows the pad to compress easily to provide good tactile feel. The ball-contacting pads are attached to a shoe upper at strategic locations where players most often use their foot for handling and kicking the ball. A purpose of the ball-contacting pad of the present invention is to create a structure that permits parallel displacement of the top, ball-contacting surface relative to its bottom, shoe-attaching surface. As the top surface moves parallel to the bottom surface, potential energy is stored in the elastic, interconnecting elements. The potential energy is used to create a higher tangential force on a ball, thereby significantly increasing the ball's spin by pulling back on the top surface while it is in contact with the ball. The interconnecting, elastic elements are shaped and oriented for optimum potential energy storage. Additionally, a lubricating fluid is located between the layers to reduce friction as the top and bottom layers slide past one another. The relative motion of the layers during ball impact is most aptly described as parallel. However, it is to be understood that the layers deform during ball impact so that the relative motion is not purely parallel, but includes motion wherein the top layer moves toward the bottom layer. Various advantages and features of novelty which characterize the invention are particularized in the claims forming a part hereof. However, for a better understanding of the invention and its advantages, reference should be had to the drawings and to the accompanying description in which there is illustrated and described preferred embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a sport shoe having ball-contacting pads of the present invention attached to the shoe's upper. Fig. 2 is a perspective view of a portion of a preferred embodiment of a ball-contacting pad of the present invention. Fig. 3 is a cross-sectional view of the ball- contacting pad of Fig. 2 when the top and bottom layers are in static alignment. Fig. 4 is a cross-sectional view of the ball- contacting pad of Figs. 2 and 3 as it would appear during impact by a ball. Fig. 5 is a cross-sectional view of an alternative embodiment of a ball-contacting pad of the present invention. DETAILED DESCRIPTION OF THE INVENTION Fig. 1 shows a perspective view of a sport shoe 12 having ball-contacting pads 10 located thereon. A preferred embodiment of the ball-contacting pad 10 is shown in Figs. 2—4 and includes a textured surface 14 having transverse open channels 16. The textured surface 14 is located on a top layer 18, which is interconnected to a bottom layer 20 by elastic interconnecting elements, or webs, 22. The bottom layer 20 attaches to the shoe 12. As represented in Fig. 1, the sport shoe 12 includes the pads 10 at strategic locations on an upper 24 of the shoe. The shoe 12 also includes a toe region 26 and a heel region 28. Under most kicking conditions, the toe 26 is the leading edge of the foot as it impacts the ball. Accordingly, the ball-contacting pads 10 have margins that may be referred to as a leading edge 30 and a trailing edge 32. As explained below, the interconnecting elements 22 are biased to enhance the ball-kicking properties of the pads 10 and must be oriented properly relative to the shoe to provide the optimum performance. Fig. 2 represents a perspective view of the elongate ball-contacting pad 10 as it would appear immediately after extrusion or casting during the manufacturing process. At this stage, the pad 10 includes the layers 18, 20 and elements 22. Interstices 34 are between the layers 18, 20 and the elements 22. As stated, the pad 10 may be extruded or cast. Preferably, the element will be fabricated of an elastic material having a high coefficient of friction and a predictable spring rate, such as natural rubber, synthetic rubber, or other polymer. A suitable material is ROTON A28, available from ESN Elastomer GmbH, Robert- Koch-Straβe 6, 66119 Saarbrϋcken, Germany. The bottom layer 20 preferably includes a scrim 36, which can be seen in Figs. 3 and 4, to reduce the elasticity of the bottom layer 20. Preferably, the scrim is a nonelastic, material (woven or nonwoven) that is embedded in the bottom layer 20 during fabrication of the pad 10. Alternative embodiments may include a scrim embedded in the top layer 18. Further embodiments include a scrim attached to an outside surface of the top 18 or bottom 20 layer. The scrim improves the efficiency of transferring a force at the top layer 18 into elongation of the elements 22. Functionally, the scrim makes the layer substantially inelastic in the plane of the scrim, while permitting the layer to be flexible along all directions out of the plane of the scrim. Therefore, if the top layer 18 has a scrim, it will be able to deform as shown in Fig. 4 and described below, but it would not elongate substantially along its longitudinal direction. Also, because the scrim is flexible perpendicular to its plane, it does not interfere with tactile response of the ball on the foot during ball handling. As shown in Figs. 3 and 4, the interstices 34 include a lubricating fluid 38 to reduce friction between the top layer 18 and the bottom layer 20 during impact with a ball. The lubricating fluid may be a silicone oil, an elastomeric gel, a petroleum product, or other viscous fluid. Alternatively, a lubricating talc may be located in the interstices 34 to reduce friction. It is not necessary to fill the entire interstices 34 with the fluid 38, but it is generally considered desirable to coat the walls of the interstices 34 sufficiently to reduce the friction between the top and bottom layers during ball impact. The amount and type of fluid 38 that is located within the interstices 34 will be determined by empirical tests. Additionally, the type and amount of fluid 38 may be dependent upon particular performance parameters that are desired. Preferably, the fluid will be contained within the interstices by an edge wall 56 (Fig. 1) . Alternatively, the margins of the pad may be sewn together, but this may reduce the elastic response of the pad. Fig. 5 discloses a cross-sectional view of an alternative embodiment of a ball-contacting pad 40, which includes a top layer 42, a bottom layer 44, and interconnecting elements 46. The pad 40 also includes a textured top surface 48 that includes depressions and ridges for creating a friction surface for ball control. The embodiment of Fig. 5 may further include a viscous, lubricating fluid 38, or talc, in its interstices 54. The primary structural difference between the pad 40 and the pad 10 described above is the structure and arrangement of the interconnecting elements 46. Elements 46 are elastic elements having a somewhat triangular cross-section, including a perpendicular surface 50 that is perpendicular to the top layer 42 and the bottom layer 44, and a beveled surface 52 which is roughly analogous to the hypotenuse of the triangular cross-section. Because of the structure and shape of the interconnecting elements 46, it is unlikely that the top layer 42 will contact the bottom layer 44 during ball contact. Accordingly, a friction-reducing fluid may not be necessary or desirable in this embodiment. It may be desirable to have a scrim in the bottom layer 44 and top layer 42 to reduce deformation along the plane of the respective layers. As noted above, the ball-contacting pad 10, as shown in Fig. 2, represents the element immediately after it has been extruded or cast. Preferably, the ball-contacting pad is prepared as a sheet having the configuration of Fig. 2 and is thereafter cut or trimmed into desired shapes for mounting on the shoe upper 24, as shown in Fig. 1. The profile of the ball-contacting pads 10 can be configured and located on the shoe in an almost infinite array of possibilities. After forming the ball-contacting pad as shown in Fig. 2, it is preferably provided with the lubricating fluid 38 in the interstices 34. Thereafter, the edges of the ball-contacting pad 10 are sealed with the edging layer 56 that is preferably a thin strip of the material used to fabricate the ball-contacting pad 10. The preferred method comprises fabricating the pad with an oversize top layer 18 that extends beyond the elastic elements 22. The overhanging portion of the top layer 18 is then folded down to cover the interstices 34 and adhered in place. Alternatively, it is possible to seal the open ends of the interstices 34 by pinching the ball- contacting pad 10 at its margins and sewing or cementing the margins to contain the viscous fluid 38 within the interstices between the margins. After the interstices 34 have been closed off by the edging 56 or other methods as described, the pad 10 is located on, and affixed to, the shoe upper 24. The sport shoe 12 is then ready for use. The following description shall assume the shoe 12 is being used for soccer, but it shall be understood that the description can apply equally well to other games, such as American football and rugby. In the most common kicking situation, a player kicks a soccer ball 58 by extending forward a leg so that the toe 26 of the shoe is the leading edge of the shoe during ball impact; that is, the foot is moving forward, toe first. If the player desires maximum velocity, and thus maximum distance for the soccer ball, he or she will kick the ball so that the force of the kick is directed through the ball's center of mass and the ball will move forward linearly. Often, however, the player will want to put spin on the ball so that it moves in an arc to make it more difficult for opposing players to intercept. To cause ball spin, the player will kick the ball "off center" so as to create a force vector that does not pass through the center of mass of the ball. Using conventional vector physics techniques, the force vector on the ball can be resolved into a radial component and a tangential component. The radial component will give the ball a linear forward velocity, while the tangential component will cause the ball to spin. The greater the tangential component, the greater the amount of spin on the ball. The tangential force will not be purely tangential due to the deformation of the ball during impact, but for descriptive purposes it shall be called tangential herein. The following description shall assume a situation in which the ball is stationary and the player approaches the ball and kicks it in a manner to cause forward velocity and spin. Once the present invention is understood in terms of this simple model, Newtonian physics may be employed to extrapolate the performance of the elements 10, 40 in more complex situations, such as when the ball is rolling toward, or away from, the player when it is kicked. Although the analysis of the pads and ball motion in these more complex situations involves more variables, the dynamics of the ball- contacting pads 10, 40 is substantially the same as described in the following description. Accordingly, assume a stationary ball that has no forward or rotational velocity. A player approaches the ball and kicks it by extending forward the shoe 12. When the shoe contacts the ball, it creates an impulse force having direction and magnitude. If the force is directed through the center of mass of the ball, the ball will move forward (i.e., translate) in the direction of the impulse force and will have no appreciable rotational velocity. If the impulse force is "off center," i.e., not through the center of mass, then the force will have two components, a radial component through the center of mass and a tangential component. The forces will cause equal and opposite reaction forces on the ball- contacting pad 10, as shown in Fig. 4. The radial component will compress the pad, causing the top layer to move toward the bottom layer. The tangential component will cause the top layer 18 to move longitudinally toward the heel 28. Recall that the bottom layer is affixed to the shoe. As the top layer moves, potential energy is stored in the elastic interconnecting elements 22, which can be modeled as springs having a spring constant k. The tangential force can be resolved into a tension force in each elastic element 22. The amount of elongation in each element 22 will be influenced by its proximity to the center of impact and to the shape and configuration of the pad 10 or 40; thus, each element n will be elongated an amount Xj,. Hooke's law dictates that the amount of elongation is proportional to the amount of tension force or, F = -kx,,. The impact ' s radial force component will cause the ball 58 to move in the direction of the radial force, and the force will subside as the ball begins to move away from the foot. As this occurs, the potential energy stored in the elements 22 will begin moving the top layer 18 toward its static alignment . This movement will result in a nearly pure tangential force on the ball 58, causing an angular velocity that is proportional to the tangential force. This dynamic effect enables a soccer player to put significantly more spin on the ball than with prior art shoes. Additionally, because the ball-contacting pad 10 is pliable along an axis perpendicular to the plane of the top layer 18, it provides greater feel of the ball - li ¬ on the player's foot so as not to interfere with low- impact ball handling such as dribbling and trapping. Ball-handling feel is also facilitated by the structure and orientation of the elements 22, which are designed to offer low resistance to forces perpendicular to the plane of the top layer 18. As can be seen in Fig. 4, the ball-contacting pad 10 compresses during impact with the ball 58 so that the top layer 18 is closer to the bottom layer 20 near the center of impact than it is in its static state, as represented in Fig. 3. This compression can cause the walls of the interstices 24 to come into contact, thus creating friction within the interstices that would prevent the top layer 18 from shifting transversely relative to the bottom layer 20. The lubricating fluid 38 within the interstices 34 reduces this friction allowing greater movement of the top layer in the direction of the tangential reaction force. The ball-contacting pad 40 in the embodiment of Fig. 5 will perform substantially the same as the ball- contacting pad 10 of Figs. 2—4. However, the different configuration of the interconnecting elements 46 will reduce contact between the walls of interstices 54, thus reducing the need for a lubricating fluid. Additionally, the pad 40 will not compress as much as the pad 10 described above because of the perpendicular wall 50, which will not "lay over," as do the elements 22. During ball impact, the portion of the interconnecting element 46 that is closest to the perpendicular wall will be compressed. Conversely, the portion near the beveled surface 52 will be put into tension as the top layer 42 is moved by the tangential reaction force. Thus, the portion of the element 46 that is near the beveled surface 52 will act as a spring and store potential energy so that the ball-contacting pad 40 will perform substantially as described in connection with the ball-contacting pad 10 of Figs. 2— . Other alternative embodiments of the interconnecting elements and the top and bottom layers of a ball-contacting pad may be constructed using the principles and teachings as described above. Furthermore, it may be possible to achieve many of the advantages and benefits of the present invention by providing a top layer that is separated from the bottom layer by an elastic foam, or other structural material, that would replace the interconnecting elements 22, 46 but provide many of the advantages and benefits described herein. Additionally, although embodiments described herein include particular textured surfaces 14, 48, it is to be understood that many other surfaces are available and would be suitable for the present invention. The primary purpose of the top layer and surfaces 14, 18 is to provide a ball-contacting surface such that the ball will not slip or slide along the top layer during ball impact. The current, preferred-embodiment pads 10 are made of ROTON A28 from ESN Elastomer having a 2 mm thick top layer 18 with 1 mm deep channels 16 and a 1.5 mm thick bottom layer 20. The elements 22 are 1.2 mm thick and spaced approximately 12 mm apart and forming an angle of 30° with the bottom layer 20. The bottom layer includes a linen textile layer adhered to its bottom surface as a scrim 36. The scrim was attached "off bias," that is, neither warp nor weft are aligned to a longitudinal axis of the pad 10. The interstices 34 were coated with a silicone oil, and the ends of the interstices were left open. The spring constant of the elements 22 has a theoretical design goal of approximately 14,000 N/m. Current pads have achieved a relative motion of the top layer 18 to the bottom layer 20 of up to 20 mm under standard ball-kicking forces. It is believed that additional performance benefits may be realized if the tangential motion of the top layer can be as much as 35 mm. Numerous characteristics and advantages of the invention have been set forth in the foregoing description, together with details of the structure and function of the invention. The novel features hereof are pointed out in the appended claims. The disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principle of the invention to the full extent indicated by the broad general meaning of the terms in the claims.

Claims: CLAIMS 1. A pad for attaching to a sport shoe, comprising: (a) a first surface for contacting a ball during kicking; (b) a second surface adapted to be attached to the shoe; and (c) at least one interconnecting element located between and interconnecting the first surface and the second surface; (d) wherein nonperpendicular contact of the first surface with an object causes the element to store potential energy therein. 2. The pad of claim 1 wherein the first surface, second surface, and element are integrally formed of an elastomer. 3. The pad of claim 1 further comprising at least two interconnecting elements and wherein the elements and surfaces define at least one interstice. 4. The pad of claim 3 further comprising a lubricant located within the at least one interstice. 5. The pad of claim 1 wherein the interconnecting element is substantially rectangular in cross-section and the deformation is substantially elongation. 6. The pad of claim 1 wherein the interconnecting element is substantially rectangular in cross-section and the deformation is compression and elongation. 7. The pad of claim 1 further including a scrim attached to the first surface. 8. A shoe comprising a sole and an upper wherein the upper includes at least one ball-contacting pad having a first layer, a second spaced-apart layer, and an elastic element interconnecting the first and second layers. 9. The shoe of claim 8 wherein nonperpendicular contact of the pad and a mass displaces the second layer substantially parallel to the first layer, causing the elastic elements to elongate in tension. 10. The shoe of claim 8 wherein the first layer includes a substantially inelastic scrim embedded therein. 11. The shoe of claim 8 wherein the first layer includes a substantially inelastic scrim attached thereto. 12. The shoe of claim 8 wherein the first and second layers are substantially planar and the elastic elements are angled relative to the layers. 13. The shoe of claim 8 wherein the elastic element and the layers define at least one interstice. 14. The shoe of claim 13 wherein the at least one interstice contains a viscous fluid. 15. The shoe of claim 13 wherein the at least one interstice contains a lubricant. 16. A ball-contacting pad for use in kicking a sports ball, comprising a bottom layer and a top layer and intermediate cross-members that store potential energy when the ball-contacting pad dynamically contacts a ball, which potential energy is transferred to the ball as a substantially tangential force causing the ball to rotate. 17. The pad of claim 16 further comprising a scrim embedded in the bottom layer. 18. The pad of claim 16 further comprising a scrim attached to the bottom layer. 19. The pad of claim 16 further comprising a scrim embedded in the top layer. 20. The pad of claim 16 wherein the cross- members are slanted relative to the top layer and bottom layer. 21. The pad of claim 20 wherein the pad includes a leading edge and the cross-member is attached to the bottom layer at a location closer to the leading edge than a location at which the cross-member is attached to the top layer.

Inventors: BRIANT ANTOINE, TIEFENBACHER KONRAD, BRIANT, ANTOINE, TIEFENBACHER, KONRAD
Applicants: ADIDAS AG
Application year: 1996
Main classification: A43B5
IPC codes: A43B5, A43B23