Patent Publication Number: US-11019884-B2

Title: Sole structure having a midsole component with movable traction members

Description:
TECHNICAL FIELD 
     The present disclosure relates to a sole structure for an article of footwear. In particular, the present disclosure relates to a sole structure including a midsole component with movable traction members. 
     BACKGROUND 
     Footwear typically includes a sole configured to be located under a wearer&#39;s foot to space the foot away from the ground or floor surface. Soles can be designed to provide a desired level of cushioning. The ground contact surface of the article of footwear can be configured for durability. 
     SUMMARY 
     Sole structures should provide stability, support, and traction, while maintaining flexibility, during a golf swing. By minimizing foot slippage, while allowing foot flexion, the sole structure enables a golfer to enhance its distance, speed, and accuracy during a golf swing. The presently disclosed sole structure can be part of an article of footwear, such as a golf shoe, and maximizes foot traction while not encumbering foot flexibility. To do so, the presently disclosed sole structure includes a midsole component and traction members movably coupled to the midsole component. The midsole component includes a midsole body. The midsole body defines an outer midsole surface and an inner midsole surface opposite the outer midsole surface. The traction members are coupled to the midsole body. Each traction member includes a base and a traction body protruding from the base away from the inner midsole surface. The traction body extends through the midsole body, and the base abuts the inner midsole surface. As such, the traction members are movable relative to the midsole body. The securing layer is disposed over the base and is coupled to the inner midsole surface to hold the plurality of traction members in contact with the midsole component. 
     “A,” “an,” “the,” “at least one,” and “one or more” are used interchangeably to indicate that at least one of the item is present; a plurality of such items may be present unless the context clearly indicates otherwise. All numerical values of parameters (e.g., of quantities or conditions) in this specification, including the appended claims, are to be understood as being modified in all instances by the term “about” whether or not “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring and using such parameters. In addition, a disclosure of a range is to be understood as specifically disclosing all values and further divided ranges within the range. 
     The terms “comprising,” “including,” and “having” are inclusive and therefore specify the presence of stated features, steps, operations, elements, or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, or components. Orders of steps, processes, and operations may be altered when possible, and additional or alternative steps may be employed. As used in this specification, the term “or” includes any one and all combinations of the associated listed items. 
     Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” “top,” “bottom,” etc., are used descriptively for the figures, and do not represent limitations on the scope of the present teachings, as defined by the claims. 
     For consistency and convenience, directional adjectives are employed throughout this detailed description corresponding to the illustrated embodiments. The term “longitudinal” as used throughout this detailed description and in the claims refers to a direction extending a length of a component (e.g., an upper or sole component). In some cases, the longitudinal direction may extend from a forefoot portion to a heel portion of the component. Also, the term “lateral” as used throughout this detailed description and in the claims refers to a direction extending along a width of a component. In other words, the lateral direction may extend between a medial side and a lateral side of a component. Furthermore, the term “vertical” as used throughout this detailed description and in the claims refers to a direction generally perpendicular to a lateral and longitudinal direction. For example, in cases where an article is planted flat on a ground surface, the vertical direction may extend from the ground surface upward. Additionally, the term “inner” refers to a portion of an article disposed closer to an interior of an article, or closer to a foot when the article is worn. Likewise, the term “outer” refers to a portion of an article disposed further from the interior of the article or from the foot. Thus, for example, the inner surface of a component is disposed closer to an interior of the article than the outer surface of the component. This detailed description makes use of these directional adjectives in describing an article and various components of the article, including an upper, a midsole structure and/or an outer sole structure. 
     The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the best modes for carrying out the teachings when taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic, isometric view of an embodiment of an article of footwear. 
         FIG. 2  is a schematic, exploded isometric view of an embodiment of an article of footwear. 
         FIG. 3  is a schematic, bottom view of a sole structure of an embodiment of an article of footwear. 
         FIG. 4  is a schematic, top view of the sole structure shown in  FIG. 1 , without a securing layer. 
         FIG. 5  is a schematic, sectional, fragmentary view of the sole structure shown in  FIG. 1 , taken along section line  5 - 5  of  FIG. 3 . 
         FIG. 6  is a schematic, fragmentary top view of traction members of the sole structure shown in  FIG. 1 . 
         FIG. 7  is a schematic, fragmentary top view of traction members of a sole structure in accordance with another embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings, wherein like reference numbers correspond to like or similar components throughout the several figures, and  FIG. 1  schematically illustrates an embodiment of an article of footwear  100 . In the exemplary embodiment, article of footwear  100  has the form of a golf shoe. However, in other embodiments, the provisions discussed herein for the article of footwear  100  could be incorporated into various other kinds of footwear including, but not limited to: basketball shoes, hiking boots, soccer shoes, football shoes, sneakers, running shoes, cross-training shoes, rugby shoes, baseball shoes as well as other kinds of shoes. Moreover, in some embodiments, the provisions discussed herein for article of footwear  100  could be incorporated into various other kinds of non-sports related footwear, including, but not limited to: slippers, sandals, high heeled footwear, and loafers. 
     For purposes of clarity, the following detailed description discusses the features of the article of footwear  100 , also referred to simply as the article of footwear  100 . However, it will be understood that other embodiments may incorporate a corresponding article of footwear (e.g., a right article of footwear when article of footwear  100  is a left article of footwear) that may share some, and possibly all, of the features of article of footwear  100  described herein and shown in the figures. 
     The embodiments may be characterized by various directional adjectives and reference portions. These directions and reference portions may facilitate in describing the portions of an article of footwear. Moreover, these directions and reference portions may also be used in describing sub-components of an article of footwear (e.g., directions and/or portions of an inner sole component, a midsole component, an outer sole component, an upper or any other components). 
     For consistency and convenience, directional adjectives are employed throughout this detailed description corresponding to the illustrated embodiments. The term “longitudinal” as used throughout this detailed description and in the claims refers to a direction extending a length of a component (e.g., an upper or sole component). In some cases, the longitudinal direction may extend from a forefoot portion to a heel portion of the component. Also, the term “lateral” as used throughout this detailed description and in the claims refers to a direction extending along a width of a component. In other words, the lateral direction may extend between a medial side and a lateral side of a component. Furthermore, the term “vertical” as used throughout this detailed description and in the claims refers to a direction generally perpendicular to a lateral and longitudinal direction. For example, in cases where an article is planted flat on a ground surface, the vertical direction may extend from the ground surface upward. Additionally, the term “inner” refers to a portion of an article disposed closer to an interior of an article, or closer to a foot when the article is worn. Likewise, the term “outer” refers to a portion of an article disposed farther from the interior of the article or from the foot. Thus, for example, the inner surface of a component is disposed closer to an interior of the article than the outer surface of the component. This detailed description makes use of these directional adjectives in describing an article and various components of the article, including an upper, a midsole structure and/or an outer sole structure. 
     The article of footwear  100  may be characterized by a number of different regions or portions. For example, the article of footwear  100  could include a forefoot portion, a midfoot portion, a heel portion and an ankle portion. Moreover, components of the article of footwear  100  could likewise comprise corresponding portions. Referring to  FIG. 1 , the article of footwear  100  may be divided into the article forefoot portion  10 , the article midfoot portion  12 , and the article heel portion  14 . The article forefoot portion  10  may be generally associated with the toes and joints connecting the metatarsals with the phalanges. The article midfoot portion  12  may be generally associated with the arch of a foot. Likewise, the article heel portion  14  may be generally associated with the heel of a foot, including the calcaneus bone. The article of footwear  100  may also include an ankle portion  15  (which may also be referred to as a cuff portion). In addition, the article of footwear  100  may include an article lateral side  16  and an article medial side  18 . In particular, the article lateral side  16  and the article medial side  18  may be opposing sides of the article of footwear  100 . Furthermore, both the article lateral side  16  and the article medial side  18  may extend through article forefoot portion  10 , the article midfoot portion  12 , the article heel portion  14  and the ankle portion  15 . 
       FIG. 2  illustrates an exploded isometric view of an embodiment of the article of footwear  100 .  FIGS. 1 and 2  illustrate various components of article of footwear  100 , including an upper  102  and a sole structure  103 . 
     Generally, the upper  102  may be any type of upper. In particular, the upper  102  may have any design, shape, size and/or color. For example, in embodiments where the article of footwear  100  is a basketball shoe, the upper  102  could be a high top upper that is shaped to provide high support on an ankle. In embodiments where article of footwear  100  is a golf shoe  111 , the upper  102  could be a low top upper. 
     In some embodiments, the upper  102  includes an upper opening  115  that provides entry for the foot into an interior cavity of upper  102 . In some embodiments, the upper  102  may also include a tongue (not shown) that provides cushioning and support across the instep of the foot. Some embodiments may include fastening provisions, including, but not limited to: laces, cables, straps, buttons, zippers as well as any other provisions known in the art for fastening articles. In some embodiments, a lace  125  may be applied at a fastening region of the upper  102 . 
     Some embodiments may include uppers that extend beneath the foot, thereby providing 360 degree coverage at some regions of the foot. However, other embodiments need not include uppers that extend beneath the foot. In other embodiments, for example, the upper  102  could have a lower periphery joined with a sole structure and/or sock liner. 
     The upper  102  could be formed from a variety of different manufacturing techniques resulting in various kinds of upper structures. For example, in some embodiments, an upper could have a braided construction, a knitted (e.g., warp-knitted) construction or some other woven construction. In an exemplary embodiment, the upper  102  may be a knitted upper. 
     The article of footwear  100  includes a sole structure  103  configured to provide traction. In addition to providing traction, the sole structure  103  may attenuate ground reaction forces when compressed between the foot and the ground during walking, running or other ambulatory activities. The configuration of the sole structure  103  may vary significantly in different embodiments to include a variety of conventional or non-conventional structures. In some cases, the configuration of the sole structure  103  can be configured according to one or more types of ground surfaces on which the sole structure  103  may be used. Examples of ground surfaces include, but are not limited to: natural turf, synthetic turf, dirt, hardwood flooring, as well as other surfaces. 
     The sole structure  103  is secured to the upper  102  and extends between the foot and the ground when the article of footwear  100  is worn. In different embodiments, the sole structure  103  may include different components. In the exemplary embodiment shown in  FIGS. 1 and 2 , the sole structure  103  may include an inner sole component  120 , a midsole component  122 , and one or more outer sole members  124 . In some cases, one or more of these components may be optional. 
     Referring now to  FIG. 2 , in some embodiments, the inner sole component  120  may be configured as an inner layer for a midsole and may be referred to as the insole. For example, as discussed in further detail below, inner sole component  120  may be integrated, or received, into a portion of the midsole component  122 . However, in other embodiments, inner sole component  120  could function as an insole layer and/or as a strobel layer. Thus, in at least some embodiments, the inner sole component  120  could be joined (e.g., stitched or glued) to the lower portion  104  of the upper  102  for purposes of securing the sole structure  103  to the upper  102 . 
     The inner sole component  120  may have an inner insole surface  132  and an outer insole surface  134 . The inner insole surface  132  may generally be oriented towards the upper  102 . The outer insole surface  134  may be generally oriented towards the midsole component  122 . Furthermore, a peripheral sidewall insole surface  136  may extend between inner insole surface  132  and outer insole surface  134 . 
     The midsole component  122  may be configured to provide cushioning, shock absorption, energy return, support, as well as possibly other provisions. To this end, the midsole component  122  may have a geometry that provides structure and support for article of footwear  100 , and the material for the midsole component  122  may be selected to provide a desirable combination of durability and flexibility. For instance, the midsole component  122  may be wholly or partly made of a thermoplastic or other suitably durable material. As a non-limiting example, the midsole component  122  is wholly or partly made of ethylene vinyl acetate (EVA). As a non-limiting example, the midsole component  100  may be made of sixty percent EVA and forty percent rubber to minimize the weight of the midsole component  122 . Carbon rubber may be added to in high wear areas of the midsole component  122 . Carbon rubber is synthetic rubber with carbon added. Specifically, the midsole component  122  may be seen to have a lower portion  140  and a sidewall portion  142 . The sidewall portion  142  may extend around the entire periphery  144  of the midsole component  122 . As seen in  FIG. 1 , the sidewall portion  142  may partially wrap up the sides of article of footwear  100  to provide increased support along the base of the foot. The midsole component  122  can be a single-piece or unitary structure and can be manufactured using an insert molding process, such as injection molding and compression molding. 
     The midsole component  122  includes a midsole body  121  defining an inner midsole surface  150  and an outer midsole surface  152  opposite the inner midsole surface  150 . The midsole body  121  may be a one-piece structure to enhance the structural integrity of the midsole component  122 . The outer midsole surface  152  may also be referred as the ground-facing surface. The inner midsole surface  150  may be generally oriented towards the upper  102 , while the outer midsole surface  152  may be oriented outwardly. Furthermore, in the exemplary embodiment, the midsole component  122  includes a central recess  148  disposed the inner midsole surface  150 . The central recess  148  may generally be sized and configured to receive the inner sole component  120 . The midsole component  122  may be divided into the midsole forefoot portion  123 , the midsole portion  129 , and the midsole heel portion  131 . The midsole component  122  also has a midsole lateral edge  133  and a midsole medial edge  135  opposite the midsole lateral edge  133 . The midsole lateral edge  133  and the midsole medial edge  135  both extend around the periphery of the midsole component  122  from a foremost edge  137  to the rearmost edge  139  of the midsole component  122 . 
     In some embodiments, the midsole component  122  may include a plurality of openings  200 , at least some of which may extend through the entire thickness of the midsole component  122 . In the exemplary embodiment shown in  FIG. 2 , some of the openings  200  are visible within central recess  148 . 
     In different embodiments, the midsole component  122  may generally incorporate various provisions associated with midsoles. For example, in one embodiment, the midsole component  122  may be formed from a polymer foam material that attenuates ground reaction forces (i.e., provides cushioning) during walking, running, and other ambulatory activities. In various embodiments, the midsole component  122  may also include fluid-filled chambers, plates, moderators, or other elements that further attenuate forces, enhance stability, or influence the motions of the foot, for example. 
       FIG. 3  illustrates a bottom view of the sole structure  103 . The sole structure  103  may be divided into the sole forefoot portion  110 , the sole midfoot portion  112 , and the sole heel portion  114 . The sole structure  103  also has a sole lateral side  116  and a sole medial side  118  opposite the sole lateral side  116 . Further, the sole structure  103  is elongated along a longitudinal axis X. 
     To increase the resiliency of the sole structure  103 , one or more toughened portions may be comolded or adhered with the midsole component  122 . These toughened portions (e.g., outer sole members  124 ) may be formed from a material that has comparatively higher rubber content and/or other additives to increase the durometer and wear resistance of these portions. In different embodiments, the locations of one or more outer sole members  124  could vary. In some embodiments, one or more outer sole members  124  could be disposed in the sole forefoot portion  110  of the sole structure  103 . In other embodiments, one or more outer sole members  124  could be disposed in the sole midfoot portion  112  of the sole structure  103 . In still other embodiments, one or more outer sole members  124  could be disposed in the sole heel portion  114  of the sole structure  103 . In the embodiment shown in  FIG. 2 , two outer sole members  124  are disposed in the article sole forefoot portion  110  of the sole structure  103 , while another two outer sole members  124  are disposed in the sole heel portion  114 . 
     In the embodiment depicted in  FIG. 2 , the sole structure  103  includes four outer sole members  124 , while, in the embodiment depicted in  FIG. 3 , the sole structure  103  includes two outer sole members  124 . Although the exemplary embodiment includes a specific number of outer sole members  124 , other embodiments could include any other number of outer sole members  124 . For instance, only a single outer sole member  124  may be present. Regardless of the quantity, each outer sole member  124  is configured as a ground contacting member. In some embodiments, the outer sole member  124  could include properties associated with outsoles, such as durability, wear-resistance and increased traction. In other embodiments, the outer sole member  124  could include properties associated with a midsole, including cushioning, strength and support. In the exemplary embodiment, plurality of outer sole members  124  may be configured as outsole-like members that enhance traction with a ground surface while maintaining wear resistance. The sizes of various outer sole members  124  could vary. 
     With continued reference to  FIGS. 2 and 3 , each outer sole member  124  defines an inner outsole surface  170  and an outer outsole surface  172 . The inner outsole surface  170  may generally be disposed against midsole component  122 . The outer outsole surface  172  may face outwardly and may be a ground contacting surface. The midsole component  122  and the outer sole members  124  may be a one-piece structure in order to enhance the structural integrity of the sole structure  103 . Alternatively, the outer sole members  124  may be discrete components coupled to the midsole component  122 , thereby enhancing the flexibility of the sole structure  103 . The outer sole members  124  may be bonded or otherwise attached to the midsole component  122 . Such bonding or attachment could be accomplished using any known methods for bonding components of articles of footwear, including, but not limited to: adhesives, films, tapes, stitching, or other methods. 
     In the exemplary embodiment, the inner sole component  120  may be disposed within central recess  148  of the midsole component  122 . More specifically, outer insole surface  134  of the inner sole component  120  may be oriented towards, the inner midsole surface  150  of the midsole component  122 . Furthermore, in some cases, the peripheral sidewall insole surface  136  of the inner sole component  120  may be in contact with the midsole component  122  along an inner recess sidewall  149 . In addition, plurality of outer sole members  124  may be disposed against outer midsole surface  152  of the midsole component  122 . For example, the inner outsole surface  170  of the outer sole members  124  may face towards, and be in contact with, the outer midsole surface  152  of the midsole component  122 . In some embodiments, when assembled, the midsole component  122  and the inner sole component  120  could comprise a composite midsole assembly, or dual layered midsole assembly. 
     In different embodiments, the upper  102  and sole structure  103  could be joined in various ways. In some embodiments, upper  102  could be joined to inner sole component  120 , e.g., using an adhesive or by stitching. In other embodiments, the upper  102  could be joined to the midsole component  122 , for example, along sidewall portion  142 . In still other embodiments, the upper  102  could be joined with both inner sole component  120  and the midsole component  122 . Moreover, these components may be joined using any methods known in the art for joining sole components with uppers, including various lasting techniques and provisions (e.g., board lasting, slip lasting, etc.). 
     The midsole component  122  can include provisions to facilitate expansion and/or adaptability of a sole structure during dynamic motions. In some embodiments, a sole structure may be configured with auxetic provisions. In particular, one or more components of the sole structure may be capable of undergoing auxetic motions (e.g., expansion and/or contraction). As a consequence, the sole structure  103  has an auxetic structure or configuration. Auxetic structures have a negative Poisson&#39;s ratio, such that when they are under tension in a first direction, their dimensions increase both in the first direction and in a second direction orthogonal or perpendicular to the first direction. 
     As seen in  FIGS. 2-4 , the sole structure  103  may include a plurality of openings  200 . As used herein, the term “opening” refers to any hollowed area or recessed area in a component. In some cases, an opening may be a through hole, in which the opening extends between two opposing surfaces of a component. In other cases, an opening may be a blind-hole, in which the hole may not extend through the entire thickness of the component and may therefore only be open on one side. A component, such as the midsole component  122 , may utilize a combination of through holes and blind-holes. 
     One or more openings  200  may extend through the entire thickness of the midsole component  122 . It is envisioned that all the openings  200  may be through-holes extending through the entire thickness of the midsole component  122 . In some embodiments, the openings  200  may spread along the sole forefoot portion  110 , the sole midfoot portion  112 , and the sole heel portion  114 . In other embodiments, the openings  200  may not extend through each of these portions. The openings  200  may also extend through the plurality of outer sole members  124 . However, in other embodiments, one or more outer sole members  124  may not include any openings. 
     In different embodiments, the geometry of one or more openings  200  could vary. Moreover, embodiments could also utilize any other geometries, such as utilizing sole portions with parallelogram geometries or other polygonal geometries that are arranged in a pattern to provide the sole with an auxetic structure. In the exemplary embodiment, each opening  200  has a tri-star geometry, including three arms or points extending from a common center. Various embodiments of the sole structure  103  may define any of the auxetic opening, including both the size, shape and arrangement, that are disclosed in U.S. Patent Publication Number 2015/0237958, titled “Midsole Component and Outer Sole Members with Auxetic Structure,” the entire disclosure of which is herein incorporated by reference as well as any openings disclosed in U.S. Patent Publication Number 2015/0237957, titled “Multi-Component Sole Structure Having an Auxetic Configuration,” the entire disclosure of which is also herein incorporated by reference. In addition, embodiments can make use of any of the auxetic openings, including both the size, shape and arrangement, that are disclosed in U.S. Patent Publication Number 2015/0245686, titled “Sole Structure with Holes Arranged in Auxetic Configuration”, the entire disclosure of which is herein incorporated by reference. 
     With continuing reference to  FIGS. 2-4 , as a non-limiting example, each of the openings  200  is star-shaped in order to provide the midsole component  122  with auxetic properties. In the depicted embodiment, for example, each opening  200  is shaped as an isotoxal star polygon. In the present disclosure, the term “isotoxal” refers to geometry of a polytope (e.g., a polygon, a polyhedron or tiling), which symmetries act transitively on its edges. The isotoxal star polygonal shape of the openings  200  provides the midsole component  122  with auxetic properties. Each opening  200  has a first triangular void  236 , a second triangular void  238 , and a third triangular void  240  directly interconnected with one another at a common point. The first triangular void  236  is obliquely angled relative to the second triangular void  238  and the third triangular void  240 . The second triangular void  238  is obliquely angled relative to the third triangular void  240 . The angular orientations of the first triangular void  236 , the second triangular void  238 , and the third triangular void  240  relative to one another provide the midsole component  122  with auxetic properties. 
     The openings  200  may be arranged on sole structure  103  in an auxetic pattern, or auxetic configuration. In other words, plurality of openings  200  (e.g., thru-holes) may be arranged on midsole component  122  and/or outer sole members  124  in a manner that allows those components to undergo auxetic motions, such as expansion or contraction. An example of auxetic expansion, which occurs as the result of the auxetic configuration of plurality of openings  200 . In a non-tensioned state, the openings  200  have an un-tensioned area. As tension is applied across sole structure  103  along an exemplary linear direction  410  (e.g., a longitudinal direction), as shown in  FIG. 3 , the sole structure  103  undergoes auxetic expansion. That is, the sole structure  103  expands along direction  410 , as well as in a second direction  412 , which is perpendicular to direction  410 . 
     The sole structure  103  further includes a plurality of traction members  322 , such as cleats or spikes, indirectly coupled to the midsole body  121 . The traction members  322  provide traction to the wearer of the article of footwear  100 . At least some or all of the openings  200  partly receive one of the traction members  322 . The sole structure  103  also includes a securing layer  428  directly coupled to the inner midsole surface  150  to hold the traction members  322  in direct contact with the midsole component  122 . The securing layer  428  may be made of a waterproof material and is wholly or partly made of a flexible material, such as a fabric, in order to provide flexibility to the sole structure  103 . As discussed below, the securing layer  428  is disposed over the traction members  322  and the midsole body  121 , such that the traction members  322  are disposed between the securing layer  428  and the inner midsole surface  150  of the midsole component  122 . As a consequence, the securing layer  428  holds the traction members  322  in direct contact with the midsole component  122 , while still permitting localized, relative movement between the traction members  322  and the inner midsole surface  150  of the midsole body  121 . The securing layer  428  defines an inner layer surface  430  and an outer layer surface  432 . The inner layer surface  430  may generally be oriented towards the inner sole component  120 , and the outer layer surface  432  may be generally oriented towards the midsole component  122 . 
     The traction members  322  collectively form a traction assembly  320 . In one embodiment, the traction assembly  320  is a single-piece or unitary structure including directly interconnected traction members  322  as shown in  FIGS. 2 and 6 , in order to enhance the structural integrity of the sole structure  103 . Alternatively, the traction assembly  320  includes a plurality of traction members  322  that are not directly connected to each other, as shown in  FIG. 7 , in order to maximize the degrees of freedom of the traction assembly  320 . 
     Each traction member  322  includes a base  332  and traction body  334  protruding from the base  332 . Each base  332  has substantially planar cross-section, thereby allowing the traction member  322  to be firmly (but movably) supported by the inner midsole surface  150  of the midsole body  121 . Further, the securing layer  428  can easily hold the traction members  322  in direct contact with the midsole body  121  because of the substantially planar cross-section of the base  332 . It is desirable to maintain the traction members  322  in direct contact with the inner midsole surface  150  of the midsole body  121  to ensure that the traction members  322  fully protrude beyond the outer midsole surface  152  of the midsole component  122 , which maximizes the traction capabilities of the traction members  322  while stilling enabling the traction members  322  to move relative to the midsole component  122 . To facilitate movement of the traction members  322  relative to the midsole body  121 , the traction members  322  are not directly bonded to the midsole component  122 . Rather, the securing layer  428  is directly bonded (or otherwise directly attached) to the inner midsole surface  150  of the midsole body  121  and is disposed over the bases  332  of the traction members  322  in order to hold the traction members  322  in direct contact with the midsole component  122 . Such bonding or attachment could be accomplished using any known methods for bonding components of articles of footwear, including, but not limited to: adhesives, films, tapes, stitching, or other methods. As a non-limiting example, an adhesive can be used to bond the securing layer  428  to the midsole body  121  at bonding locations B that are spaced apart from the bases  332  of the traction members  322 . As a consequence, the securing layer  428  is not directly bonded to the traction members  322 , thereby facilitating movement of the traction members  322 . In other words, the traction members  322  are “free-floating” between the securing layer  428  and the midsole component  122 . It is desirable to allow movement of the traction members  322  relative to the midsole component  122  during a golf swing, for example, in order to minimize foot slippage, while allowing foot flexion. As such, the sole structure  103  enables a golfer to enhance its distance, speed, and accuracy during a golf swing. The lack of bonding between the securing layer  428  and the traction members  322  further enables a natural motion of the sole structure  103  during a golf swing. The auxetic properties of the sole structure  103 , which is enabled by the geometry and/or arrangement of the openings  200 , also enables a natural motion of the sole structure  103  during a golf swing. In other words, the geometry of the openings  200  allows the sole structure  103  to mimic how the body and foot react to force and accounts for massive changes in foot size that occur throughout a golf swing. As a result, the auxetic properties of the sole structure  103  along with the lack of bonding between the securing layer  428  and the traction members  322  enhance the dynamism of the sole structure  103 . By not directly adhering the traction members  322  to the midsole component  122  (i.e., permitting local relative translation), the traction assembly  320  does not constrain the auxetic nature of the midsole component  122 , and permits a more natural movement of the sole structure  103 . 
     The bases  332  of the traction members  322  are disposed outside the openings  200 , thereby allowing the midsole body  121  to support the traction members  322 . Specifically, the bases  332  of the traction members  322  abut the inner midsole surface  150 , while the traction bodies  334  of the traction members  322  extend through the openings  200  past the outer midsole surface  152  in order to engage the ground. Each traction body  334  has a tapered cross-section to facilitate purchase with the ground. 
     Each traction body  334  includes a plurality of protrusions  342  and an apex  344  interconnecting all the protrusions  342  to one another. As a non-limiting example, each traction body  334  includes only three protrusions  342  converging into the apex  344  to maximize the grip of the traction member  322  to the ground. Each of the protrusions  342  extend from the base  332 , and each is directly joined to one another at the apex  344  to maximize the grip of the traction member  322  to the ground. It is contemplated, however, that the traction body  334  may include more or fewer protrusions  342 . The protrusions  342  are obliquely angled to one another in order to maximize the grip of the traction member  322  to the ground. Further, the maximize the grip of the traction member  322  to the ground while maintaining the flexibility of the midsole component  122 , the hardness of the traction members  322  is greater than the hardness of the midsole body  121 . For instance, the indentation hardness of the material (measured, for example, in the Shore C Hardness Scale) forming the midsole body  121  (i.e., the first hardness) is less than the indentation hardness of the material forming the traction members  322 . As a non-limiting example, the hardness of the material forming the traction body  334  can be between twenty (20%) and thirty (30%) percent greater than the hardness of the material forming the midsole body  121  in order to minimize spin of at least one foot during the backswing and downswing stages of a golf swing. To this end, for example, the midsole body  121  may be wholly or partly made of EVA, and the traction bodies  334  may be wholly or partly made of TPU. Alternatively, the midsole body  121  and the traction bodies  334  can be made of the same or similar materials, but with different densities, in order to achieve the different hardnesses. 
     With reference to  FIG. 5 , the securing layer  428  is flexible to allow the traction members  322  to move relative to the midsole component  122 . The securing layer  428  has an outermost edge  446 , which surrounds the bases  332  of the traction members  322 . In an embodiment, only the outermost edge  446  of the securing layer  428  is directly bonded to the inner midsole surface  150  of the midsole component  122  (at for example bonding locations B) to facilitate movement of the traction members  322  relative to the midsole component  122 . In the depicted embodiment, the securing layer  428  is disposed over all the bases  332  of the traction members  322  to hold the traction members  322  in direct contact with the midsole component  122 . In another embodiment, the outer layer surface  432  of the securing layer  428  is directly bonded to the bases  332  and midsole component  122  (at, for example, bonding locations C) to enhance the structural integrity of the sole structure  103 . 
     Referring to  FIGS. 6 and 7 , as discussed above, each traction member  322  includes a base  332 . Each base  332  includes a base hub  348  and a plurality of base legs  350  extending from the base hub  348 . The base legs  350  are obliquely angled relative to one another to enhance the structural stability of the base  332 . At least some of the bases  332  are directly connected to another base  332  to enhance the structural stability of the traction members  322 . For example, in the embodiment depicted in  FIG. 6 , at least one of the base legs  350  of one traction member  322  is directly connected to the base hub  348  of another traction member  322 , thereby creating a structurally stable web of traction members  322  (i.e., the traction assembly  320  of interconnected traction members  322 ). Alternatively, as shown in  FIG. 7 , the traction members  322 , are not directly connected to one another to facilitate movement of each traction members  322  relative to the midsole component  122 . 
     While the best modes for carrying out the teachings have been described in detail, those familiar with the art to which this disclosure relates will recognize various alternative designs and embodiments for practicing the teachings within the scope of the appended claims. The sole structure illustratively disclosed herein may be suitably practiced in the absence of any element which is not specifically disclosed herein. Furthermore, the embodiments shown in the drawings or the characteristics of various embodiments mentioned in the present description are not necessarily to be understood as embodiments independent of each other. Rather, it is possible that each of the characteristics described in one of the examples of an embodiment can be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments not described in words or by reference to the drawings.