Patent Publication Number: US-2011047816-A1

Title: Article Of Footwear With Performance Characteristic Tuning System

Description:
FIELD OF THE INVENTION 
     This invention relates generally to articles of footwear. In particular, the invention relates to articles of footwear having adjustable tuning members that store and release energy. 
     BACKGROUND 
     In the world of sports, athletes are often looking for any advantage to improve performance. The ability to store and release energy in an article of footwear may provide this desired performance improvement. During the stance phase of gait, it is thought that the plantar fascia has the ability to store energy which is released during the propulsive phase of the gait cycle. As the foot flexes at the metatarsophalangeal (MTP) joint, the fascia tightens to assist in locking the midfoot for an efficient take off. This foot structure may also aid in transmitting forces from the Achilles tendon to the forefoot during the propulsive phase of the gate cycle. During the late stages of ground contact, the energy stored in the plantar fascia is released. 
     Providing an article of footwear that compliments and/or enhances this natural energy storage and release may provide a variety of performance enhancing advantages. 
     SUMMARY 
     The following presents a general summary of aspects of the invention in order to provide a basic understanding of the invention and various features of it. This summary is not intended to limit the scope of the invention in any way, but it simply provides a general overview and context for the more detailed description that follows. 
     Aspects of this invention relate to articles of footwear, such as those generally used in athletic activities. In some arrangements, the article of footwear may include a stiffening plate configured to add stiffness to the article of footwear. In addition, the article of footwear includes one or more tuning members connected to the stiffening plate and configured to adjust the stiffness of the article of footwear. The stiffening plate and tuning members may be connected to a midsole of the article of footwear or an outsole. 
     In some arrangements, the article of footwear also includes an outsole member. The outsole member may be a plurality of outsole units arranged along various portions of the article of footwear and configured to provide traction and/or impact attenuation to the wearer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present invention and certain advantages thereof may be acquired by referring to the following detailed description in consideration with the accompanying drawings, in which: 
         FIG. 1  is an article of footwear that may be used in conjunction with aspects of a performance characteristic tuning system according to illustrative aspects of the invention. 
         FIG. 2  is an example performance characteristic tuning system according to illustrative aspects of the invention. 
         FIGS. 3A and 3B  illustrate example foot positions in which energy is stored and released by the performance characteristic tuning system according to illustrative aspects of the invention. 
         FIG. 4  is an example article of footwear having a plurality of outsole members used in conjunction with the performance characteristic tuning system according to illustrative aspects of the invention. 
         FIG. 5  illustrates example outsole support members that may be used in conjunction with the outsole members of  FIG. 4  according to illustrative aspects of the invention. 
         FIGS. 6A and 6B  illustrate one example article of footwear with tuning members extending upward along a sidewall according to illustrative aspects of the invention. 
     
    
    
     The reader is advised that the attached drawings are not necessarily drawn to scale. 
     DETAILED DESCRIPTION 
     In the following description of various example structures in accordance with the invention, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example articles, including one or more articles of footwear. Additionally, it is to be understood that other specific arrangements of parts and structures may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. Also, while the terms “top,” “bottom,” “front,” “back,” “rear,” “side,” “underside,” “overhead,” and the like may be used in this specification to describe various example features and elements of the invention, these terms are used herein as a matter of convenience, e.g., based on the example orientations shown in the figures and/or the orientations in typical use. Nothing in this specification should be construed as requiring a specific three dimensional or spatial orientation of structures in order to fall within the scope of this invention. Aspects of the invention may be used with any of several types of articles of footwear including athletic footwear, such as footwear designed for sports such as basketball, running, football, soccer, track and field events such as jumping, and the like. Nothing in the specification or figures should be construed to limit the invention to use with any single, particular article of footwear or type of article of footwear described. 
     A. General Description of an Illustrative Article of Footwear Having a Performance Characteristic Tuning System 
     In general, as described above, aspects of this invention relate to an article of footwear. More detailed descriptions of aspects of this invention follow. 
     1. Example Articles of Footwear Having a Performance Characteristic Tuning System 
     In some arrangements, an article of footwear may include portions that alter the stiffness or flexibility of the article of footwear. For instance, an article of footwear may include a stiffening plate that is connected to the article of footwear. In some arrangements, the stiffening plate may be part of a sole structure of the article of footwear and may be connected to a bottom surface of a midsole of the article of footwear or may be arranged between layers of a midsole of the article of footwear. In other arrangements, the stiffening plate may be connected to a bottom surface of an upper of the article of footwear. The stiffening plate may extend from a toe region of the article of footwear to a heel region of the article of footwear. In some arrangements, the stiffening plate or a portion thereof may wrap upward along a sidewall or sole of the article of footwear. In some examples, tuning members associated with the stiffening plate may also wrap or extend vertically upward along the sidewall, as well as horizontally along a bottom surface. 
     In some examples, the article of footwear may include one or more tuning members connected to the stiffening plate. The tuning members may extend from the toe region of the article of footwear to the heel region and may be connected at the toe region and the heel region. In some arrangements, the tuning members might be connected to the plate only at the toe region and the heel region and might not be connected to the stiffening plate at locations between the toe region and the heel region. 
     In some examples, the article of footwear may further include an outsole. For instance, the outsole may include a plurality of outsole members configured to cover at least a portion of the stiffening plate and expose at least a portion of the stiffening plate. The outsole members may include an outer traction surface configured to contact the ground and provide traction for the wearer. In addition, the outsole members may include an outsole support member arranged between the outer traction surface and the remainder of the article of footwear. In some arrangements, the outsole support member may be arranged between the outer traction surface and the stiffening plate. The outsole support members may be configured to provide impact attenuation for the wearer and may include recesses configured to correspond to features of the stiffening plate and/or tuning members. 
     Additional aspects and specific examples of the articles described above will be described in detail more fully below. The reader should understand that these specific examples are set forth merely to illustrate examples of the invention, and they should not be construed as limiting the invention. 
     B. Specific Examples of the Invention 
     Referring to the figures and the following discussion, articles of footwear in accordance with the present invention are described. Footwear is depicted and discussed as running shoes, however, the concepts disclosed with respect to footwear may be applied to a wide range of other athletic footwear styles, including walking shoes, tennis shoes, soccer shoes, basketball shoes, football shoes, and cross-training shoes, for example. In addition, the concepts of the present invention may be applied to a wide range of non-athletic footwear, including work boots, sandals, loafers, and dress shoes. Accordingly, the present invention is not limited to the precise embodiments disclosed herein, but applies to footwear generally. 
       FIG. 1  illustrates one example article of footwear  100  that may generally be used with aspects of the invention described herein. Footwear  100  includes an upper  120  that is connected to a sole structure  130 . Upper  120  may be a conventional or non-conventional upper that includes, for example, layers of foam materials, synthetic textiles, and leather that are stitched or adhesively bonded to each other to form a comfortable structure for receiving a foot. Sole structure  130  may include an insole or sock liner which is a thin impact attenuating member generally located within upper  120  and at a position that corresponds with the sole of the foot, thereby enhancing the comfort of footwear  100 . Sole structure  130  also may include a midsole  132  that forms the primary impact attenuating layer of footwear  100  and serves, therefore, to attenuate ground reaction forces and absorb energy when footwear  100  is compressed against the ground. In addition, sole structure  130  includes an outsole  134 . Outsole  134  forms the primary ground-contacting surface of footwear  100  and may be fashioned from a wear-resistant material, such as carbon black rubber compound, and may include texturing to enhance traction. Various example outsole configurations will be described more fully below. 
     During running or other activities that compress sole structure  130  between the foot and the ground, footwear  100  provides impact force attenuation. That is, footwear  100  attenuates ground reaction forces and absorbs energy that would otherwise be transferred to the leg and foot of the individual. The degree of impact attenuation provided by footwear  100  is generally related to the overall stiffness of sole structure  130 . In general, a greater stiffness corresponds with lesser impact attenuation, whereas lesser stiffness corresponds with greater impact attenuation. Accordingly, stiffness and impact force attenuation are generally correlated through an inverse relationship. 
     In addition, a natural gait of a human includes flexing of the foot in various regions, as well as flexing of the ankle. For instance, a wearer may begin his or her gait by placing the heel of a foot on the ground. As the wearer moves his or her body in a forward direction, the foot will flex until the foot is in contact with the ground, i.e., the heel, ball of foot, and toe region are contacting the ground. The wearer will then lift the other foot and place the heel of that foot in contact with the ground. As the wearer moves his or her body in a forward motion, the second foot will contact the ground and the first foot will pivot at the ankle as the shin of the wearer moves forward. In addition, the first foot will flex as the heel leaves the ground, then as the ball of the foot leaves the ground. Finally, as the toes of the first foot leave the ground, the foot will return to an unflexed position in order to contact the ground with the heel again. Throughout this process, the foot flexes as well as pivots with respect to the shin, at the ankle. As will be discussed more fully below, this natural motion of walking may be enhanced by footwear that aids in returning the shoe and foot to the flat or unflexed position when the foot leaves the ground. 
     The various elements of sole structure  130  will now be discussed in detail. To aid in the following discussion, footwear  100  may be divided into three general regions: a forefoot or toe region  111  that generally corresponds with a front portion of the foot, including the toes; a midfoot region  112  that generally corresponds with a middle portion of the foot that includes the arch; and a heel region  113  that generally corresponds with the heel. Regions  111 - 113  are not intended to demarcate precise areas of footwear  100 . Instead, regions  111 - 113  are intended to define general areas that aid in the following discussion. 
     Midsole layer  132  may be attached directly to upper  120  throughout the length of footwear  100  and supplies a portion of the impact attenuation characteristics provided by sole structure  130 . In toe region  111 , midsole layer  132  generally extends between upper  120  and outsole  134 . An upper surface of the midsole layer  132  may be contoured to conform to the shape of the foot. Accordingly, midsole layer  132  may include a raised arch on the medial side of midfoot region  112 , raised peripheral areas extending around sides of the foot, and a depression for receiving the heel, for example. The thickness of midsole layer  132  may vary along the length of footwear  100 . For example, midsole layer  132  may have a relatively constant thickness in heel region  113  and midfoot region  112 . In toe region  111 , however, the thickness of midsole layer  132  may decrease to a point at the front of footwear  100 . Suitable materials for midsole layer  132  include foam materials, such as ethylvinylacetate and polyurethane foam, which are commonly incorporated into the midsoles of conventional footwear. If desired, the midsole  132  may include one or more fluid-filled bladders, e.g., embedded within the foam of the midsole material, and/or one or more discrete columnar elements, e.g., made of foam or other impact-attenuating materials, akin to the columnar elements present in articles of footwear commercially available from NIKE, Inc. of Beaverton, Oreg. 
       FIG. 2  is a bottom view of an article of footwear having a performance characteristic tuning system  200  according to aspects described herein. The article of footwear and performance characteristic tuning system  200  generally includes a stiffening plate  220  extending from the toe region  211  of the article of footwear to the heel region  213 . The stiffening plate  220  may be configured to alter the stiffness or flexibility of the article of footwear. In some arrangements, the plate  220  may be configured to store energy when stretched and release energy when the plate is released, as will be discussed more fully below. The stiffening plate  220  may be formed as a separate piece and connected to the article of footwear using known methods of attachment, such as adhesives, stitching, mechanical fasteners, and the like. In some arrangements, the plate  220  may be integrally formed with a sole structure (such as sole structure  130  in  FIG. 1 ) to provide additional impact attenuation. In other arrangements, the stiffening plate  220  may be formed separately and may be connected to a conventional midsole or a layer of a conventional midsole (such as midsole  132  in  FIG. 1 ). For instance, the plate  220  may be arranged between midsole layers or the plate may be arranged on a bottom surface of the midsole such that it is visible and, in some instances, accessible from the bottom of the article of footwear. In still other arrangements, the plate  220  may be connected to the upper (such as upper  120  in  FIG. 1 ) of the article of footwear and may be configured to provide impact attenuation, as well as energy storage and release, as will be discussed more fully below. 
     The stiffening plate  220  may be formed of any suitable material, such as a variety of plastics, including polyethylene, PEAK, nylon, ZYTEL, as well as carbon fiber, and the like. The plate  220  material may be selected based on desired performance characteristics of the article of footwear. For instance, a stiffer or harder material may be selected for an article of footwear requiring greater stability, less flexibility, etc. On the other hand, a softer or more flexible material may be selected for articles of footwear in which flexibility is a highly desirable characteristic. 
     As shown throughout the figures, the plate  220  may be a single piece formed using known methods of manufacture, such as various molding operations (e.g., injection molding, compression molding, etc.), rapid manufacturing additive fabrication techniques, such as laser sintering, and the like. The single piece plate  220  may be flexible along the entire length of the plate  220 . In some arrangements, the plate  220  may be formed to permit additional flexibility in certain areas of the plate  220  or, alternatively, to restrict flexibility in certain areas of the plate  200 . For instance, the plate may be formed having varying thickness which may alter the stiffness of the plate in thicker areas. 
     The arrangement of  FIG. 2  also includes a plurality of tuning members  230 . The tuning members  230  provide an adjustable means of adding or restricting flexibility to the plate  220  and thus, the article of footwear. For instance, the plate  220  may have a first flexibility based on the material selected for manufacture, etc. The tuning members  230  may then be used to further adjust the flexibility of the plate  220 . That is, the tuning members  230  may be of a material to add stiffness to the plate  220 , and may be tightened or loosened to provide the desired flexibility for a chosen wearer, activity, etc. 
     As shown in the figures, the stiffening plate  220  may include five tuning members  230 . However, this is merely one example. In fact, any number of tuning members  230  may be used. The number of tuning members  230  might only be limited by the size of the plate  220  (e.g., the width). The tuning members  230  may extend from a toe region  211  through the midfoot region to the heel region  213  of the shoe. In some arrangements, such as shown in  FIG. 2 , the tuning members  230  may not extend to the top most portion of the toe region  211  but rather may extend to a point below that region. This may allow more even spacing of the tuning members  230 , ease of attachment, etc. 
     The plate  220  may include a plurality of recesses in which the tuning members  230  may rest. Alternatively, the plate  220  may provide a generally smooth surface on which the tuning members  230  are arranged. In addition, the plate  220  may include one or more guide regions  240   a - 240   d  that aid in aligning and maintaining alignment of each tuning member  230 . For instance, the plate  220  in  FIG. 2  includes several guide regions, one at the heel region  240   a,  one or more at the midfoot region  240   b,    240   c  and one at the toe region  240   d.  These guides  240   a - 240   d  may be formed into the plate  220  during manufacture of the plate  220 , i.e., the guides  240   a - 240   d  may be molded into the plate  220 . In some arrangements, the guides may be formed separately from the plate and connected to the plate via known methods of attachment such as adhesives, stitching, mechanical fasteners and the like. The guides  240   a - 240   d  may include a plurality of channels or recesses into which the tuning members  230  are received. The guides  240   a - 240   d  generally aid in alignment of the tuning members  230  and aid in maintaining the position of the tuning members  230 . Although the arrangements shown depict the tuning members  230  extending generally parallel to each other, in some arrangements, the tuning members may be arranged at an angle and/or one or more tuning members  230  may overlap one or more other tuning members. 
     In some arrangements, the tuning members  230  may be connected at the toe region  211  and at the heel region  213 . In some arrangements, the tuning members  230  may be connected using snap fits, mechanical fasteners, and the like. In some arrangements, the tuning members  230  may only be connected to the stiffening plate  220  at the toe region  211  and the heel region  213  and are not connected to the plate  220  at any location between the toe region  211  and the heel region  213 . This two-point connection allows the tuning members  230 , as well as the stiffening plate  220 , to store energy during portions of the gait in which a user&#39;s foot is in contact with the ground at both the toe  211  and heel region  213 . For instance,  FIGS. 3A and 3B  illustrate one example of the energy storage and release of the system described herein.  FIG. 3A  illustrates a foot positioned with both the toe region  311  and heel region  313  in contact with the ground surface. In this arrangement, the tuning members and/or the plate (shown collectively as  325 ) are stretched to a tension. Additional tension is added to the tuning members and/or plate  325  as the heel of the foot leaves the ground and the toe remains in contact with the ground, further stretching the tuning members and/or plate  325  as shown in  FIG. 3B . In stretching, the tuning members and/or stiffening plate  325  store energy. This stored energy is then released as the toe of the wearer leaves the ground, thereby aiding in propelling the article of footwear back to an unflexed position and propelling the user forward. 
     In some arrangements, the plate may be formed of two or more pieces, rather than as a single piece. For instance, the plate may include a heel counter and/or a toe cap element. In these arrangements, the plates may be formed such that they are “pulled together” by the tuning members during the propulsion phase of the gait, similar to the plantar fascia being loaded. In some examples, the tuning members  230  may wrap upward, along a sidewall, such as a sidewall of a midsole. Some examples of this arrangement are shown in  FIGS. 6A and 6B . 
     With further reference to  FIG. 2 , the tuning members  230  may be formed of any suitable material, such steel, nylon, rubber, various elastic materials, elastic and inelastic materials in combination, and the like. The gauge of the material used in forming the tuning members  230  may vary to provide varying characteristics and may alter the energy storage and release properties of the tuning members  230 . For instance, a certain gauge tuning member  230  may be selected because it may store more energy due to greater tension created when the tuning member  230  is stretched. Thus, greater energy may be released. 
     In some arrangements, the tuning members  230  may be evenly spaced along the width of the article of footwear. In still other arrangements, such as shown in  FIG. 2 , the spacing of the tuning members  230  may vary along the length of the article of footwear. In still other arrangements, tuning members  230  might be grouped such that some tuning members  230  are evenly spaced while others are not. 
     In some arrangements, the tuning members  230  may be configured to permit different regions of the article of footwear to have varying stiffness or flexibility characteristics. For instance, the type or size of the tuning member  230  for the medial side of the foot may be different from the type or size of the tuning member  230  for the lateral side of the foot to provide a different stiffness on the medial side than the lateral side. This may allow for customization for a particular wearer or for additional performance enhancement for a particular sport or activity. 
     One advantage of using tuning members  230  in conjunction with the stiffening plate  220  is that the tuning members  230  may allow for the stiffness of the system to be adjusted, either at the manufacturing level or, in some arrangements, at the user level. For instance, the material selected for the tuning members  230 , and/or the configuration of the tuning members  230 , may provide varying degrees of stiffness depending on the desire of the wearer, the activity for which the shoe will be used, etc. Additionally or alternatively, the user may be able to adjust the stiffness of the system as desired. For instance, the plate  220  and tuning members  230  may be removable and interchangeable with tuning members  230  having different performance characteristics. In other arrangements, the tuning members  230  may be configured to be tightened or loosened in order to adjust the stiffness associated with the system  200 . For instance, in some arrangements, the tuning members  230  may be tightened or loosened in a manner similar to a guitar string. That is, the article of footwear may include one or more pegs or dials around which the tuning members  230  may be wound. As the dials are rotated, the tuning members  230  may tighten or loosen depending on the direction of movement of the dial. In some examples, the dials may be arranged in a heel region or an arch region of the article of footwear. 
     In some arrangements, the tuning members  230  may be used without a stiffening plate  220 . For instance, the tuning members  230  may be directly connected to an upper, sole, midsole, heel counter, toe counter, etc. of the article of footwear and may not include any stiffening plate. In still other arrangements, the tuning members  230  may wrap upward and extend vertically along a portion of a sidewall, as shown in  FIGS. 6A and 6B . 
       FIG. 4  is a bottom view of an article of footwear having a performance characteristic tuning system including outsole members  300 . The system  300  includes a stiffening plate  320  and tuning members  330  similar to those described above. In addition, the system  300  includes an outsole and, in this arrangement, a plurality of outsole members  350   a - 350   c.  The outsole members  350   a - 350   c  are configured to contact the ground and to provide traction for the wearer. In the arrangement shown, three outsole members  350   a - 350   c  are included in the system. The outsole members  350   a - 350   c  shown generally cover at least a portion of the plate  320  and tuning members  330  and expose at least a portion of the plate  320  and tuning members  330 . However, in some arrangements, a conventional outsole may be used that would extend from the toe region to the heel region to cover the plate  320  and tuning members  330 . As shown in  FIG. 4 , the outsole members  350   a - 350   c  are arranged in areas that contact the ground during a user&#39;s gait. For instance, the heel region includes a substantially u-shaped outsole member  350   a  that surrounds an outer perimeter of the heel region. This arrangement may add stability to the article of footwear. Another outsole member  350   b  is arranged at the ball of the foot and yet another outsole member  350   c  is arranged around at least a portion of a perimeter of the toe region. This will aid in providing balance and stability to the wearer as the toe region of the foot pushes off to leave the ground. Although a three-piece outsole member configuration is shown, additional arrangements may be used in which more or fewer outsole members are provided. For example, the outsole members  350   b,    350   c  arranged in the toe and midfoot region may be formed as a single member to add additional stability for the wearer. 
     The outsole members  350   a - 350   c  generally include an outer surface  360  configured to provide traction to the wearer. The outer surface  360  may include a pattern or texture including recesses, protrusions, etc. that aid in providing traction. In addition, the arrangement includes outsole support members ( 370   a - 370   c  in  FIG. 5 ) to which the outsole is connected and which may provide additional impact attenuation for the wearer.  FIG. 5  illustrates example outsole support members  370   a - 370   c  which may be used in conjunction with the arrangement shown in  FIG. 4 . The outsole support members  370   a - 370   c  may be formed of any suitable material, such as various plastics, etc. that may be lightweight and supportive. The outsole support members  370   a - 370   c  may be generally hollow or solid, as desired. In addition, the outsole support members  370   a - 370   c  include a plurality of recesses  380  that correspond to the position of the tuning members and/or the tuning member guides. In some arrangements, the outsole support members  370   a - 370   c  may be configured to mate with the stiffening plate or tuning member guides to provide impact attenuation. Connection of the outsole to the outsole support members may provide a ground contacting surface for the article of footwear. This arrangement aids in maintaining the position of the outsole support members  370   a - 370   c  around the various features of the plate and the tuning members. 
     The outsole support members  370   a - 370   c  may be connected to the plate using various known methods of connection, such as adhesives, stitching, mechanical fasteners, and the like. 
     Although the outsole members may be connected to the stiffening plate, the tuning members may be free floating with the outsole support members in order to permit the tuning members to stretch and release to provide the energy storage and release associated with the performance characteristic tuning system described herein. 
     CONCLUSION 
     While the invention has been described in detail in terms of specific examples including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and methods. Thus, the spirit and scope of the invention should be construed broadly as set forth in the appended claims.