Abstract:
Track-and-field athletic shoes and sole structures for such track shoes are provided. The sole structures may include one or more spike assemblies with movable spikes that enhance the grip of the track shoe over an entire course, including when banking on a turn, and that positions a runners foot in a more natural position relative to the runner&#39;s center or mass while banking.

Description:
BACKGROUND 
     Field 
     The present disclosure relates generally to track-and-field athletic shoes, and more particularly to a sole structure for track-and-field athletic shoes having movable spikes to increase traction when banking. 
     Description of the Related Art 
     Generally, track-and-field athletic shoes (“track shoes”) used for track events are fitted with spikes on the forefoot portion of the sole to provide traction for accelerating and stopping, and to resist twisting of the shoe when running. Track shoe spikes are provided in various shapes and arrangements depending on the running surface and the particular track-and-field event taking place. Track shoes are typically fitted with a large number of spikes arrayed on the entire forefoot portion of the sole. Some track shoes attach as many spikes as possible, within permitted limits, with the belief that such an arrangement provides greater overall traction. However, when the margin for winning an event may come down to hundredths of a second, minimizing the weight of track shoes is another primary importance, such that runners are forced to balance the weight added to the track shoe by a large number of spikes and the desire for additional traction along the entire course of the track-and-field event. Runners looking to reduce time tend to sacrifice traction in order to reduce the weight of the track shoe. Reduced traction is most notable when banking on a turn, where a runner&#39;s body weight shifts to compensate for the bank and all of the spikes may no longer engage the running surface. Thus, a need exists for an improved spike for track shoes that provides improved traction and stability over the entire course of the track-and-field event, including while banking on a turn, and that positions a runners foot in a more natural position relative to the runners center or mass while banking. 
     BRIEF SUMMARY 
     The present disclosure discloses track-and-field athletic shoes and sole structures for such track shoes. In the embodiments of the present disclosure, the sole structures may include one or more spike assemblies with movable spikes that enhance the grip of the track shoe over an entire course, including when banking on a turn, and that positions a runners foot in a more natural position relative to the runners center or mass while banking. 
     One exemplary embodiment of a track shoe according to the present disclosure includes an upper and a sole secured to the upper is provided. The sole has at least one track spike assembly positioned at a forefront region of the sole. Preferably, the track shoe according to this embodiment has a plurality of track spike assemblies, and each track spike assembly has a plurality of spikes movable between a flat position and banking position. Preferably, each track spike assembly includes a spike support member having a channel, and a spike plate positioned at least partially within the channel. The spike plate is movable between the flat position and the banking position, and includes a spike positioned at each end of the spike plate configured to engage a running surface. The spike plate may also include at least one spike positioned between the spikes at each end of the spike plate. 
     One exemplary embodiment of a sole for a track shoe according to the present disclosure includes, a plate having a forefront region and a rearward region, and at least one track spike assembly positioned at the forefront region of the plate. Preferably, the at least one track spike assembly includes a plurality of track spike assemblies, and each track spike assembly has a plurality of spikes movable between a flat position and banking position. The at least one track spike assembly includes, a spike support member having a channel, a spike plate secured at least partially within the channel and movable between the flat position and the banking position, and a spike configured to engage a running surface is positioned at each end of the spike plate. Preferably, at least one spike is also positioned on the spike plate between the spikes at each end of the spike plate. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The figures depict embodiments for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein, wherein: 
         FIG. 1  is an perspective view of an exemplary embodiment of a track shoe according to the present disclosure; 
         FIG. 2  is a perspective view of a forefront portion of a sole of the track shoe of  FIG. 1 , illustrating an exemplary embodiment of track spikes according to the present disclosure; 
         FIG. 3  is an perspective view of another exemplary embodiment of a track shoe according to the present disclosure; 
         FIG. 4  is a perspective view of a forefront portion of a sole of the track shoe of  FIG. 3 , illustrating another exemplary embodiment of track spikes according to the present disclosure; 
         FIG. 5  is an exploded view of an exemplary embodiment of a track spike assembly according to the present disclosure; 
         FIG. 6  is an exploded view of another exemplary embodiment of a track spike assembly according to the present disclosure; 
         FIG. 7  is an exploded view of another exemplary embodiment of a track spike assembly according to the present disclosure; 
         FIG. 8  is an elevation view taken from arrow  8  of  FIG. 1 , illustrating one end spike in a banking position; 
         FIG. 9  is an elevation view taken from arrow  9  of  FIG. 1 , illustrating the other end spike in the banking position; 
         FIG. 10  is a perspective view of an athlete running along the bank of a track; 
         FIG. 11  is an a front elevation view of the track shoe shown at arrow  11  of  FIG. 10 , illustrating a position of the shoe while running on a flat surface of a track and a related position of the spikes; and 
         FIG. 12  is a front elevation view similar to  FIG. 11 , illustrating a position of the shoe while banking on a track and a related position of the spikes. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure describes track-and-field athletic shoes (“track shoes”) and sole structures for such track shoes. In the embodiments of the present disclosure, the sole structures may include one or more spike assemblies with movable spikes that enhance the grip of the track shoe over an entire course of a track, including when banking on a turn. 
     Referring to  FIGS. 1 and 3 , the track shoe  10  has an upper  12  and a sole  14 . The upper  12  can be formed as any conventional upper configured to support the foot of a runner, in particular an upper adapted for use in a track shoe. The upper  12  includes lace holes or eyelets along the throat of the upper to accommodate laces  16 . Typically, the upper has several layers, including a weather-resistant and wear-resistant outer layer of leather or synthetic material, such as nylon, and a soft, padded inner liner for foot comfort. Current uppers typically have an intermediate layer of a synthetic foam material. The layers of the upper  12  may be fastened together by stitching, gluing, or a combination thereof. 
     The sole  14  is formed of a plate  18  which extends along substantially the entire length of the track shoe  10 . The sole  14  and plate  18  can be broadly divided into a forefront region  18   a  and a rearward region  18   b . Generally, the forefront region  18   a  includes the area of track shoe  10  beneath the toe and the ball of the foot of a wearer, and the rearward region  18   b  includes the portion of the track shoe below the arch and heel of a wearer. The plate  18  is preferably formed of a relatively hard, light weight material, such as polyamide or a polyurethane plastic. An example of a suitable polyamide is nylon 12, and an example of a suitable polyurethane plastic is thermoplastic polyurethane (TPU). The rearward region  18   b  of the plate  18  is preferably thinner than the forefront region  18   a . For example, the rearward region  18   b  of plate  18  can have a thickness of approximately 2 mm, and the forefront region  18   a  of plate  18  can have a thickness of approximately 2.5 mm. The plate  18  may be fastened to the bottom of the upper  12  by stitching, gluing, or a combination thereof. The bottom of the rearward region  18   b  of the plate  18  may include a rubber layer (not shown) for added traction, as is known in the art. A midsole formed of a resilient shock absorbing material may be included in sole  14  along the heel and arch area of the track shoe. A midsole, if included, would be relatively thin to minimize weight. 
     Continuing to refer to  FIGS. 1 and 3 , the forefront region  18   a  of the plate  18  includes one or more spike assemblies  20 . The spike assemblies may be molded into the plate  18  or secured to the plate  18  using, for example, glue, epoxy or rivets. When more than one spike assembly are used, it is preferred that the spike assemblies are spaced far enough apart to allow the track shoe  10  to flex while running. For example, in the embodiments shown, the spike assemblies are spaced apart a distance of about 35 mm. 
     In the exemplary embodiment of  FIGS. 1 and 2 , the track shoe includes two spike assemblies  20  spaced apart in the forefront region  18   a  of the plate  18 , as shown. In the exemplary embodiment of  FIGS. 3 and 4 , the track shoe includes three spike assemblies  20  spaced apart in the forefront region  18   a  of the plate  18 , as shown. The spike assemblies  20  are configured to move the spike plate and spikes between a flat position where the surface engaging area of the spikes, represented by Axis “B”, are substantially parallel to Axis “A” of the track shoe  10  (as seen in  FIG. 11 ), and a banking position where the surface engaging area of the spikes, represented by Axis “B”, are at an angle relative to Axis “A” of the track shoe  10  (as seen in  FIG. 12 ). The angle relative to Axis “A” is in the range of between about 5 degrees and about 15 degrees, and preferably the angle is 10 degrees. It should be noted that the spike assemblies according to the present disclosure are preferably constructed similar to a four-bar linkage system, except the links are replaced with cams. In the four-bar linkage system employed in the spike assemblies of the present disclosure, the spikes move in parallel planes relative to a running surface and the sole of the track shoe so that the spikes are positioned for peak traction while running on a flat surface or when banking. 
     Referring to  FIGS. 5-7 , exemplary embodiments of spike assemblies are shown. The spike assembly  20  includes a spike support member  22  that can either be molded into or secured to the sole  14 . The spike support member  22  is preferably formed of a relatively hard, light weight material, such as polyamide or a polyurethane plastic. An example of a suitable polyamide is nylon 12, and an example of a suitable rigid polyurethane plastic is thermoplastic polyurethane (TPU). Alternatively, the spike support member can be made of metal or metal alloy, preferably a lightweight metal or metal alloy, such as titanium or aluminum, or the spike support member can be made of any other suitable material sufficient to support the movable spikes and weight of a person wearing the track shoe  10 . Preferably, the spike support member  22  has a base  24  and side walls  26  and  28  extending from the base such that the base and side walls form a channel  30 . The base  24  and walls  26  and  28  are preferably formed of a relatively hard, light weight material, such as polyamide or a rigid polyurethane plastic. An example of a suitable polyamide is nylon 12, and an example of a suitable rigid polyurethane plastic is thermoplastic polyurethane (TPU). Alternatively, the base  24 , and walls  26  and  28  can be made of metal or metal alloy, preferably a lightweight metal or metal alloy, such as titanium or aluminum, or the base  24 , and walls  26  and  28  can be made of any other suitable material sufficient to support the movable spikes and weight of a person wearing the track shoe  10 . 
     If the spike support member  22  is molded into the plate  18 , the base  24  will follow the contours of the plate  18  based upon the molding process implemented. If the spike support member  22  is secured to the plate  18 , the base  24  would preferably be configured to conform to the contours of the plate  18  so that there is an even seem between the plate  18  and the spike support member  22 . 
     The walls  26  and  28  are preferably reinforced with gussets  32  positioned along each side wall, as shown. The gussets  32  can be molded into, or secured to the side walls  26  or  28  and the plate  18 . The gussets  32  are preferably formed of a relatively hard, light weight material, such as polyamide or a polyurethane plastic. An example of a suitable polyamide is nylon 12, and an example of a suitable rigid polyurethane plastic is thermoplastic polyurethane (TPU). Alternatively, the gussets  32  can be made of metal or metal alloy, preferably a lightweight metal or metal alloy, such as titanium or aluminum, or the gussets  32  can be made of any other suitable material sufficient to reinforce and support the walls  26  and  28 . The number of gussets  32  positioned along each side wall depends upon the length of the side wall and the number of spikes on the spike plate. In the embodiment of  FIGS. 1 and 2 , the long spike assemblies  20  have four gussets positioned along each side wall  26  and  28 . In the embodiment of  FIGS. 3 and 4 , the short spike assembly  20  closest to the toe has three gussets  32  positioned along each side wall  26  and  28 , and the long spike assemblies  20  have four gussets  32  positioned along each side wall  26  and  28 . The gussets  32  may be positioned along the wall in close proximity to where a spike would be to provide reinforcement in the area where the spikes are located. 
     Positioned within channel  30  of spike support member  22  is a spike plate  40 . The spike plate  40  is preferably formed of a relatively hard, light weight material, such as polyamide or a polyurethane plastic. An example of a suitable polyamide is glass filled nylon 12, and an example of a suitable polyurethane plastic is glass filled thermoplastic polyurethane (TPU). Alternatively, the spike plate can be made of metal or metal alloy, preferably a lightweight metal or metal alloy, such as titanium or aluminum, or the spike plate can be made of any other suitable material sufficient to support the movable spikes and weight of a person wearing the track shoe  10 . Spike plate  40  includes one or more spikes  44  positioned on the spike plate and extending away from the sole  14 . The spikes  44  are configured to engage a running surface, such as a track, and can be flat, rectangular structures as shown, or the spikes may be conical structures, or the spikes may be any other conventional spike structure. Preferably, each end of the spike plate  40  has a spike  44 , and one or more spikes  44  may be positioned on the spike plate  40  between the end spikes. The number and positioning of spikes  44  between the end spikes is a matter design choice.  FIG. 4  shows spike plates  40  having two, three and four spikes  44 . The spikes  44  are preferably formed of a relatively hard, light weight material, such as polyamide or a polyurethane plastic. An example of a suitable polyamide is nylon 12, and an example of a suitable polyurethane plastic is thermoplastic polyurethane (TPU). Alternatively, the spikes can be made of metal or metal alloy, preferably a lightweight metal or metal alloy, such as titanium or aluminum, or the spikes can be made of any other suitable material sufficient to grip the running surface and support the weight of a person wearing the track shoe  10 . 
     Cam members  46  and  48  are secured to each end of the spike plate  40  using known fastening techniques. For example, the cam members  48  may be secured to each spike plate  40  by passing screw  50  through one cam member  48  and the spike plate  40  into threaded cam member  48 , as shown. Alternatively, nuts and bolts, rivets, glues, epoxies, or other fasteners may be used to secure the cam members  46  and  48  to the spike plate  40 . Alternatively, the cam members may be molded directly into the spike plate  40  or otherwise formed as part of the spike plate. The cam members  46  and  48  are preferably formed of a relatively hard, light weight material, such as polyamide or a polyurethane plastic. An example of a suitable polyamide is nylon 12, and an example of a suitable polyurethane plastic is thermoplastic polyurethane (TPU). Alternatively, the cam members can be made of metal or metal alloy, preferably a lightweight metal or metal alloy, such as titanium or aluminum, or the cam members can be made of any other suitable material sufficient to support the movable spikes and weight of a person wearing the track shoe  10 . As seen in  FIGS. 8 and 9 , cam members  46  are configured to ride along cam surfaces  26   a  and  28   a  of walls  26  and  28 , respectively, when the spike plate  40  and spikes  44  are moved between the flat position and the banking position. Cam members  48  are configured to ride along cam surfaces  26   b  and  28   b  of walls  26  and  28 , respectively, when the spike plate  40  and spikes  44  are moved between the flat position and the banking position. 
     As noted, the spike plate  40  is movably secured to the spike support member  22  within the channel  30 . A linkage assembly is used to facilitate movement of the spike plate  40  and the spikes  44 . In one embodiment shown in  FIG. 5 , the linkage assembly includes guide opening or j-shaped slot  60  in spike plate  40 , mounting aperture  62  in each side wall  26  and  28 , and guide member  64 , such as a nut and bolt, or pin, that can pass through the side walls and rest within the guide opening  60 . In this linkage assembly, the guide member  64  performs a number of functions. First, the guide member  64  acts as a fastener to movably secure the spike plate  40  to the spike support member  22 . Second, the guide member  64  acts as a guide link controlling movement of the spike plate  40  (and thus the spikes  44 ) between the flat position and the banking position. Third, the guide member  64 , working with guide opening  60 , acts as a stop to limit the movement of the spike plate  40 . The guide member  64  acts as a focal point for movement of the spike plate  40  between the flat position and the banking position. 
     In another embodiment shown in  FIG. 6 , the linkage assembly includes mounting aperture  66  in spike plate  40 , guide openings or slots  68  in side walls  26  and  28 , and guide member  70 , such as a nut and bolt, or pin, that can pass through the guide openings  68  in the side walls and rests within the mounting aperture  66  in the spike plate  40 . Similar to the embodiment of  FIG. 5 , in this configuration, the guide member  70  performs a number of functions. First, the guide member  70  acts as a fastener to movably secure the spike plate  40  to the spike support member  22 . Second, the guide member  70  acts as a guide link guiding the spike plate between the flat position and the banking position. Third, the guide member  70 , working with the guide openings  68 , acts as a stop to limit the movement of the spike plate  40 . The guide member  70  acts as a focal point for movement of the spike plate  40  between the flat position and the banking position. 
     In another embodiment shown in  FIG. 7 , the linkage assembly includes mounting aperture  74  in spike plate  40 , j-shaped slots  76  and  78  in side walls  26  and  28 , respectively, and guide member  80 , such as a pin, that can pass through the j-shaped slot  76  in side wall  26 , through the mounting hole  74  in the spike plate  40 , and through j-shaped slot  78  in side wall  28 . Preferably, each end of j-shaped slot  78  has a detent  78   a  configured to receive the guide member  80 . In this embodiment, the mounting aperture  74  is smaller than the diameter of the guide member  80  so that guide member can be pressed into position within the mounting aperture  74  and the friction between the aperture  74  and the guide member  80  maintains the pin in position. The j-shaped slot  76  is about the size of the diameter of the guide member  80  so that the guide member can freely glide within the j-shaped slot  76 . The j-shaped slot  78  is preferably smaller than the size of the diameter of the guide member  80  so that the guide member cannot freely glide within the j-shaped slot  78 . As such, a force would be needed to move the guide member  80  within the j-shaped slot  78 , as will be described in more detail below. The j-shaped slot  78  has a pair of channels  82  extending along the wall  28 , as shown. The channels  82  provide flexibility to an area  28   c  of wall  28  to allow the guide member to move within the j-shaped slot  78 , as will be described in more detail below. 
     In the embodiments of  FIGS. 5 and 6 , the cam surfaces  26   a  and  26   b , the cam surfaces  28   a  and  28   b , and the cam members  46  and  48  are configured such that when a force is applied to the linkage assembly, the spike plate  40  and spikes  44  can move from one position, e.g., the flat position, to the other position, e.g., the banking position, and the spike plate  40  is releasably locked into each position. In the embodiment of  FIG. 7 , the linkage assembly along with the cam surfaces, and cam members releasably lock the spike plate  40  and spikes  44  in either the flat position or the banking position. 
     Turing to  FIGS. 10-12 , when a runner is banking on a turn of a track, seen in  FIG. 10 , the weight and angle of the runner relative to the running surface, here a track, applies lateral force to the linkage assembly. When the lateral force applied exceeds a predetermined number, the linkage assembly activates so that the spike plate  40  automatically moves from the flat position (shown in  FIG. 11 ) to the banking position (shown in  FIG. 12 ). When the runner returns to a non-banking part of the running surface, the position of the runner again shifts so that the weight and angle of the runner applies a vertical force to the linkage assembly. When the vertical force applied exceeds a predetermined number, the linkage assembly again activates so that the spike plate  40  automatically moves from the banking position to the flat position. The force needed to activate the linkage assembly and move the spike plate is in the range of about 3 lbs and about 8 lbs. As an example and referring to the spike assembly embodiment of  FIG. 7 , when a lateral force caused by a runner is applied to the spike assembly  20 , that force would be applied to the linkage assembly. When the lateral force applied exceeds for example, 3 lbs, there is sufficient force to cause the area  28   c  in wall  28  to flex allowing the guide member  80  to move from one position, e.g., the flat position, to the other position, e.g., the banking position. 
     While the present disclosure describes various embodiments of a track shoe and various embodiments of sole structures and spike assemblies for track shoes, it will be understood that various modifications can be made to the embodiments of the present disclosure herein without departing from the spirit and scope thereof. Therefore, the above description should not be construed as limiting the disclosure, but merely as embodiments thereof. Those skilled in the art will envision other modifications within the scope and spirit of the invention as defined by the claims appended hereto.