Patent Publication Number: US-2011072684-A1

Title: Support structures in footwear

Description:
RELATED APPLICATION 
     This application claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/246,028, filed Sep. 25, 2009, the contents of which are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND 
     The present disclosure relates, in general, to support structures in footwear, which are located between the bottom of a wearer&#39;s foot and the floor or ground upon which the wearer treads. The footwear may be athletic type footwear, but not necessarily so. 
     More specifically, in an article of footwear having an upper and a sole structure, a support structure is included as part of the sole structure. The support structure may be comprised of any number of resilient materials such as natural rubber, artificial rubber, or any appropriate flexible resilient elastomeric material, which could be thermoplastic urethanes, polyester, polyether, polycaprolactone, polyoxypropylene and polycarbonate macroglycol based materials, and mixtures thereof. 
     The support structure elements may be a part of the midsole, if there is one, or they may be part of the outsole, or portions in both, depending on the manufacturing technique chosen. For example, if the components are molded, the external portions of the support structures will be part of the outsole, whereas the internal support elements of the support structure may be included in either the outsole mold or the midsole mold, or portions in both molds, so that the components properly marry when the outsole and midsole is joined. 
     The disclosed structure, in the embodiments shown and in other related embodiments as claimed, provides support for the foot while also, in some embodiments, creates a limited instability that assists in toning muscles in the lower leg. 
     In certain embodiments, air is transferred from the heel to the forefoot portion of the footwear as the foot impacts the walking, running or exercising surface (sometimes referred to herein as the “treading surface”) to absorb shocks and to assist the walking or running motion by optimizing the transfer of rebound forces to the bottom of the foot. The air then returns to the heel portion as the foot rolls forward, which again assists the forward motion by decreasing the volume under the forefoot. In other embodiments, no air transfer is used, with the support structures providing support and rebounding forces. The amount of support and rebounding will depend on the shapes of the internal support elements and the resiliency of the materials chosen. 
     Previously known structures do not accomplish these objectives in the straightforward manner shown in the present disclosure. The features discussed herein improve the comfort of an article of footwear by combining improved resiliency with improved compressibility, among other things. Furthermore, the present disclosure does not depend on an expensive, hermetically sealed structure or valves to maintain relatively high pressures as shown in prior attempts at achieving the objectives of the present disclosure. 
     SUMMARY 
     Disclosed are various embodiments of a structure to provide support for the foot while also, in some embodiments, to create a limited instability that assists in toning muscles in the lower leg. Three basic embodiments are shown below, although other embodiments may be used, which fall within the scope of the claims. 
     One embodiment comprises two support structures (sometimes referred to as pods) one structure in the heel portion of an article of footwear and another structure in the forefoot portion. One or both of the support structures may be hollow and may include internal support elements such as ridges or posts to support the foot. Additionally, air or another gas may be included in the structures with a passageway between the internal support elements permitting the transfer of gas back and forth as the wearer treads. Thus, energy is absorbed as the foot strikes the treading surface and is either stored to be returned as the foot rolls forward or, when air is included in the design, is transferred from the heel to forefoot portions and then back again as the foot pressure moves from the heel portion to the forefoot portion. 
     Another embodiment comprises three support structures in the heel portion and three in the forefoot portion. Any or all of the support structures may be hollow, and any or all of them may include internal support elements such as ridges, posts or other internal structure to support the foot. Air may be included in some or all of the structures with a passageway between some or all of the internal support elements permitting the transfer of air back and forth as the wearer treads. The number of support structures can be greater or fewer than three in both portions, and the number of support structures may be different in the heel and forefoot portions. All support structures could be entirely in the heel portion or entirely in the forefoot portion. 
     Another embodiment includes one support structure (pod) in the heel portion and one in the forefoot portion. Each pod includes ridges that cause the portion of the outsole that contacts the treading surface to bow outwardly toward the treading surface. No air or other fluid is transferred between the pods. 
     The disclosed construction, in the embodiments shown and in other related embodiments as claimed, provides support for the foot while also, in some embodiments, creates a limited instability that assists in toning muscles in the lower leg. The outer most surfaces of the support structures may be curved outward appearing convex when the outsole is viewed from the outside. In the preferred embodiments, internal support elements such as ridges, posts, columns or other formations of chosen resilience, elasticity and weight bearing properties are constructed within the support structures. In the two-pod configuration of the support structures where one pod is located in the heel portion and the other pod is in the forefoot portion of the outsole, each pod is made convex to a chosen height to provide a measure of instability as the pods impact the treading surface. This instability causes the wearer to make balancing adjustments as the wearer executes his or her stride. These adjustments are made with the muscles in the lower leg thereby promoting muscle toning. Air or another gas may be added to the support structures to work in combination with the solid internal resilient support elements to provide the level of support necessary to maintain the convex shape of a pod to a height sufficient to achieve the toning effect while at the same time not overly emphasizing the instability to the point of making the footwear uncomfortable. 
     The internal support elements that may be placed inside a support structure can be any number of possible configurations or geometries. For example, they may be concentric ridges generally conforming to the shape of the support structure, or pod. If the pod is generally oval, the internal ridges may be oval as well. The ridges closest to the outside of the oval would be the shortest height, with the ridges progressively closer to the central portion of the oval being progressively higher to assist the pod to bulge outward closer to the central portion. The width of the ridges can be varied, as well as the number of ridges. Each ridge could have different properties of resilience and weight bearing capability. Many alternatives are possible and can be deduced by one skilled in the art once the performance parameters are established. The performance parameters include the amount of weight that the structure must carry, the amount of resiliency required for the desired rebounding effect and the amount of convexity to be maintained during the wearer&#39;s stride. The recovery characteristics could be the same for each internal support element within a support structure, or the recovery characteristics could vary from one internal support element to another. 
     The internal support elements could be pillars or protrusions that extend for the entire height of the support structure, or they may extend only partially from one surface to the other. The internal support elements or protrusions could be wedge shaped, pyramidal, conical, plateau, ramp shaped, block shaped, rectangular or otherwise depending on the impact and recovery characteristics desired. 
     In addition to the physical internal support elements within the pods, air or another gas can be utilized within the support structures. In certain embodiments, air is transferred within channels from the heel to the forefoot portion of the footwear as the foot impacts the treading surface during walking, running or exercising to absorb shocks and to assist the striding motion by optimizing the transfer of rebound forces to the bottom of the foot. When the footwear impacts the treading surface, usually with the heel first, the air is forced from the heel pod or pods through one or more channels, and then the air is returned to the heel portion as the foot rolls forward, which again assists the forward motion by decreasing the volume under the forefoot. During certain foot movements, especially during exercising, the forefoot portion may strike the treading surface first, forcing the air or other gas through one or more channels to the heel portion. The gas would then return when the pod or pods in the heel portion strike the treading surface. If the heel portion did not strike the ground, the gas would return to the forefoot portion by virtue of known fluid dynamics principles, albeit more slowly. In the preferred embodiment, the gas pressure within the system is at atmospheric pressure, but could be a different pressure in other embodiments. The gas system could be hermetically sealed, but is not in the preferred embodiment. Gas may be permitted to exit the system in predetermined quantities during use as the pods are impacted and be replenished by the resiliency of the internal support elements and the memory characteristics of the outsole shape acting to return the pods to their initial volume. 
     In the preferred embodiment, the convex shape of the pods is flattened somewhat at the apex in order to minimize movement of the internal support elements and to moderate the instability caused by the domed effect of the convex shape. 
    
    
     
       DRAWINGS 
       The above-mentioned features and objects of the present disclosure will become more apparent with reference to the following description taken in conjunction with the accompanying drawings wherein like reference numerals denote like elements and in which: 
         FIG. 1  is a side view of the outsole of one embodiment of the footwear in accordance with the present disclosure. 
         FIG. 2  is a plan view of the outsole of one embodiment of the footwear in accordance with the present disclosure. 
         FIG. 3  is a plan view of the interior portion of outsole of one embodiment of the footwear in accordance with the present disclosure taken along line  3 - 3  in  FIG. 1 . 
         FIG. 4  is a cross section view of the outsole of one embodiment of the footwear in accordance with the present disclosure taken along line  4 - 4  in  FIG. 3 . 
         FIG. 5  is a cross section view of a portion of the outsole of one embodiment of the footwear in accordance with the present disclosure taken along line  5 - 5  in  FIG. 2 . 
         FIG. 6  is a cross section view of a portion of the outsole of one embodiment of the footwear in accordance with the present disclosure taken along line  6 - 6  in  FIG. 2 . 
         FIG. 7  is a plan view of the outsole of a second embodiment of the footwear in accordance with the present disclosure. 
         FIG. 8  is a plan view of the interior portion of the outsole of a second embodiment of the footwear in accordance with the present disclosure. 
         FIG. 9  is a cross section view of a portion the outsole of a second embodiment of the footwear in accordance with the present disclosure taken along line  9 - 9  in  FIG. 8 . 
         FIG. 10  is a perspective view of the outsole of a third embodiment of the footwear in accordance with the present disclosure. 
         FIG. 11  is a plan view of the outsole depicted in  FIG. 10 . 
         FIG. 12  is a cross section view of a portion of the outsole taken along line  12 - 12  in  FIG. 11 . 
         FIG. 13  is a cross section view of a portion of the outsole taken along line  13 - 13  in  FIG. 11 . 
         FIG. 14  is a cross section view of a portion of the outsole taken along line  14 - 14  in  FIG. 11 . 
         FIG. 15  is a cross section view of a portion of the outsole taken along line  15 - 15  in  FIG. 11 . 
     
    
    
     DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The preferred and alternative embodiments are shown in the figures. However, other embodiments may be used, which fall within the scope of the claims. 
     One embodiment comprises two support structures or pods, which can be seen in  FIGS. 1 ,  2 ,  3 ,  4 ,  5  and  6 . The forefoot support structure or forefoot pod is shown by numeral  2  and the heel support structure or heel pod is shown by numeral  3 . In this embodiment, both of the support structures  2  and  3  are somewhat hollow and are adapted to enclose a volume of gas. The support structures need not be hermetically sealed if they contain air, and may permit some air to move to the atmosphere and vice versa. The support structures  2  and  3  include internal support elements to support the foot. In the embodiment shown, these take the form of concentric, generally elliptical ridges. In pod  2 , there are three ridges; namely, outermost ridge  2   a , middle ridge  2   b  and innermost ridge  2   c . Pod  3  has two ridges, outermost ridge  3   a  and innermost ridge  3   b . In this embodiment, the ridges all have gaps (discussed further below) to allow passage of a gas, which in the preferred embodiment would be air. A passageway or channel  4  connects pods  2  and  3  permitting the transfer of gas back and forth as the wearer walks or runs. Thus, energy is absorbed as the foot strikes the treading surface, such as a floor, and is transferred from the heel to forefoot portions and then back again as the foot pressure moves from the heel portion to the forefoot portion. 
     As can be seen in the figures, the forefoot and heel support structures, numerals  2  and  3  respectively, are curved outward appearing convex when the outsole is viewed from the outside. As discussed above, this creates a limited instability that assists in toning muscles in the lower leg. The amount of the curvature may be altered depending on such factors as the size of the shoe, the weight expected to be carried, the expected age of the wearer and the amount of instability desired. The curvature could be reduced to a very small amount, resulting in only a slight curvature. The external shape and appearance of the pods could also be altered without affecting the utilitarian aspects of the features. For example, the pods could be made more circular or more elliptical, they could have squared or flattened portions, or the appearance of the edges of the pods could be given many different looks depending on aesthetic considerations. Also, designs may be added to the exterior portions of the support structures for the sake of appearance or to serve a functional purpose such as increasing traction. Additionally, the size of the support structures is not limited to what is shown in the drawings. For example, in  FIG. 2 , one or both of the pods could extend to the outer edge of the outsole. 
     The internal support elements that may be placed inside a support structure can be any number of possible configurations or geometries. In the embodiment of  FIG. 3 , they are generally concentric ridges  2   a ,  2   b ,  2   c ,  3   a  and  3   b  that generally conform to the shape of the support structure, or pod. In this embodiment, the pod is generally oval and the internal ridges are generally oval as well. As is shown in  FIG. 5 , the ridge  2   a  closest to the outside of the forefoot pod  2  is shorter than the ridge  2   b  next to it. Ridge  2   c  is the tallest of the three. As is shown in  FIG. 6 , in the heel pod  3  ridge  3   a  is shorter than ridge  3   b . The number of ridges in each pod could be greater or fewer than depicted in the drawings. This progression assists the pods to maintain a bulge outward closer to the central portion as the wearer strides. However, the width of the ridges can be varied, as well as the number of ridges. Additionally, each ridge could have different properties of resilience and weight bearing capability. Many alternatives are possible and can be deduced by one skilled in the art once the performance parameters of a particular shoe are established. The performance parameters include the amount of weight that the structure must carry, the amount of resiliency required for the desired rebounding effect and the amount of convexity to be maintained during the wearer&#39;s stride. The recovery characteristics could be the same for each support element within a support structure, or the recovery characteristics could vary from one support element to another. 
     The convex shape of the pods may be flattened somewhat at the apex in order to minimize movement of the internal support elements and to moderate the instability caused by the domed effect of the convex shape. 
     In addition to the physical internal support elements within the pods, air or another gas can be utilized within the support structures. In the embodiment depicted in  FIG. 3 , air is transferred from the heel to the forefoot portion and then back again via channel  4  that connects pods  2  and  3 . The external channel structure  5  is seen in  FIGS. 2 and 3 . Looking at the outsole from the perspective of  FIG. 2 , the outermost surface of the structure  5  may be raised above the arch area  6  of the outsole  8 , but it may also be flush with the arch area  6 , or below the surface of the arch area  6 . In fact, there may be no evidence of a channel  4  when looking at the outsole from the perspective of  FIG. 2 . 
     In  FIG. 3 , in between the edges of the pods  2  and  3  and the respective support structures  2   a ,  2   b  and  2   c , and  3   a  and  3   b , are channels that permit the gas to flow within the pods. Also, the support structures themselves have gaps. Forefoot pod gaps are shown as numerals  10   a ,  10   b  and  10   c  and heel pod gaps are shown as numerals  12   a  and  12   b . These gaps facilitate the movement of the gas within the pods. The channels could also be cut into the midsole, which in the usual construction of this type of shoe would lie on top of the outsole and the support structures. 
     Another embodiment shown in  FIGS. 7-9  comprises three support structures or pods in the heel portion and three in the forefoot portion. The three forefoot pods are shown at numerals  14   a ,  14   b  and  14   c , and the three heel pods are shown at numerals  16   a ,  16   b  and  16   c . An alternative to the internal ridges  2   a ,  2   b  and  2   c  are shown as posts  18   a ,  18   b  and  18   c . Post  18   b  is shown in  FIG. 9  as being taller than posts  18   a  and  18   c . In such a construction, the center posts of an array in each pod depicted in  FIG. 8  would be taller than the posts at each side to assist the pods to maintain a convex shape in order to have the same effect as the convex shapes in the first embodiment discussed above. In this embodiment, the areas in between the posts allow for the movement of gas within each pod. A channel  20  connects the forefoot pods  14   a ,  14   b  and  14   c  with each other and also with heel pods  16   a ,  16   b  and  16   c . Air or another gas is thereby permitted to transfer between the pods as the wearer treads. The number of support structures can be greater or fewer than three in both portions, and the number of support structures may be different in the heel and forefoot portions. Additionally, all of the support structures could be entirely in the heel portion or entirely in the forefoot portion without gas traveling between the forefoot and heel portions. 
     The internal support elements need not be limited to ridges or posts as described above. The internal support elements could be pillars or protrusions that extend for the entire height of the support structure, or they may extend only partially from one surface to the other. The internal support elements or protrusions could be wedge shaped, pyramidal, conical, plateau, ramp shaped, block shaped, rectangular or otherwise, depending on the impact and recovery characteristics desired. A combination of shapes can be used. 
     Another example of an alternative design is shown in  FIGS. 10-15 , wherein a combination of rectangular and other elements are shown in a relatively intricate structure. In the perspective view of  FIG. 10  and the cross section view of  FIG. 11 , one can see a continuous ramp like configuration generally in the central portions of the forefoot and heel portions of the outsole, on the side of the outsole closest to the foot, at numerals  22  and  24  respectively. The continuous ramps  22  and  24  are highest at their centers so that the external portions of the outsole at both the forefoot portion  48  and heel portion  50  extend outward in a convex shape. Partial ramps are included in both the heel portion ( 26 ,  28 ,  30  and  32 ) and the forefoot portion ( 34 ,  36 ,  38  and  40 ). Also shown in this embodiment are wedges in the heel portion ( 42  and  44 ) and wedges in the forefoot portion ( 46 ,  48 ,  50  and  52 ). All of these features assist in the basic function of this disclosure, which is to provide convex shaped structures on the surface contacting portion of the outsole. The shapes of the internal structures and the materials used in the construction of the outsole can vary depending on the loads to be carried by the footwear. 
     While the apparatus and method have been described in terms of what are presently considered to be the most practical and preferred embodiments, it is to be understood that the disclosure need not be limited to the disclosed embodiments. It is intended to cover various modifications and similar arrangements included within the spirit and scope of the claims, the scope of which should be accorded the broadest interpretation so as to encompass all such modifications and similar structures. The present disclosure includes any and all embodiments of the following claims.