Conventional articles of athletic footwear include two primary elements, an upper and a sole structure. The upper provides a covering for the foot that comfortably receives and securely positions the foot with respect to the sole structure. The sole structure is secured to a lower portion of the upper and is generally positioned between the foot and the ground. In addition to attenuating ground reaction forces, the sole structure may provide traction, control foot motions (e.g., by resisting over pronation), and impart stability, for example. Accordingly, the upper and the sole structure operate cooperatively to provide a comfortable structure that is suited for a wide variety of athletic activities.
The sole structure generally incorporates multiple layers that are conventionally referred to as an insole, a midsole, and an outsole. The insole is a thin, compressible member located within the upper and adjacent to a plantar (i.e., lower) surface of the foot to enhance footwear comfort. The midsole, which may be secured to the upper along the length of the upper, forms a middle layer of the sole structure and is primarily responsible for attenuating ground reaction forces. The outsole forms the ground-contacting element of footwear and is usually fashioned from a durable, wear-resistant material that includes texturing to improve traction.
The conventional midsole is primarily formed from a resilient, polymer foam material, such as polyurethane or ethylvinylacetate, that extends throughout the length of the footwear. The properties of the polymer foam material in the midsole are primarily dependent upon factors that include the dimensional configuration of the midsole and the specific characteristics of the material selected for the polymer foam, including the density of the polymer foam material. By varying these factors throughout the midsole, the relative stiffness and degree of ground reaction force attenuation may be altered to meet the specific demands of the activity for which the footwear is intended to be used. In addition to polymer foam materials, conventional midsoles may include, for example, one or more fluid-filled bladders or moderators.
Another type of sole structure incorporates various polymer foam support elements, which may be positioned in a heel region of the footwear. Examples of footwear that incorporate support elements include U.S. Pat. Nos. 5,353,523 and 5,343,639 to Kilgore, et al.; U.S. Pat. No. 6,487,796 to Avar, et al.; and U.S. Pat. No. 6,898,870 to Rohde, each of which is incorporated by reference herein. The support elements may have a generally cylindrical configuration, and each of the support elements may extend between two semi-rigid plates and through a void in the sole structure.
Various embodiments of the invention involve an article of footwear having an upper and a sole structure secured to the upper. The sole structure includes a midsole, at least four support elements, and a plate. The midsole defines a void positioned in a heel region of the footwear and extending through a medial side of the footwear and a lateral side of the footwear, with the void having an upper surface and an opposite lower surface. The support elements are located within the void and extend between the upper surface and the lower surface. The plate extends under the support elements and defines a plurality of indentations extending inward from an edge of the plate. Each of the indentations extend between two of the support elements, and each of the indentations have a depth that is in a range of one-eighth to one-half of a width of the plate.
The indentations may include a first indentation and a second indentation. The first indentation may extend inward from the lateral side of the footwear, and the second indentation may extend inward from the medial side of the footwear. In this configuration, the depth of the first indentation may be greater than the depth of the second indentation. The indentations may also include a third indentation extending inward from a rearward portion of the footwear.
The support elements may be arranged in a variety of configurations. As an example, the support elements may be positioned such that a first pair of the support elements are located adjacent the lateral side and a second pair of the support elements are located adjacent the medial side. In this configuration, the first indentation may extend between the first pair and the second indentation may extend between the second pair.
The advantages and features of novelty characterizing various aspects of the invention are pointed out with particularity in the appended claims. To gain an improved understanding of the advantages and features of novelty, however, reference may be made to the following descriptive matter and accompanying drawings that describe and illustrate various embodiments and concepts related to the aspects of the invention.
The foregoing Summary, as well as the following Detailed Description, will be better understood when read in conjunction with the accompanying drawings.
Introduction
The following discussion and accompanying figures disclose an article of footwear having support elements in accordance with aspects of the present invention. Concepts related to the support elements are disclosed with reference to footwear having a configuration suitable for the sport of running. The support elements are not solely limited to footwear designed for running, however, and may be incorporated into a wide range of athletic footwear styles, including shoes that are suitable for baseball, basketball, football, rugby, soccer, tennis, volleyball, and walking, for example. In addition, the support elements may be incorporated into footwear that is generally considered to be non-athletic, including a variety of dress shoes, casual shoes, sandals, and boots. An individual skilled in the relevant art will appreciate, therefore, that the concepts disclosed herein with regard to the support elements apply to a wide variety of footwear styles, in addition to the specific style discussed in the following material and depicted in the accompanying figures.
An article of footwear 10 is depicted in
Upper 20 is secured to sole structure 30 and defines a cavity for receiving a foot. Access to the cavity is provided by an ankle opening 21 located in heel region 11. A lace 22 extends in a zigzag pattern through various apertures in upper 20. Lace 22 may be utilized in a conventional manner to selectively increase a size of ankle opening 21 and modify certain dimensions of upper 20, particularly girth, to accommodate feet with varying dimensions. Various materials are suitable for upper 20, including leather, synthetic leather, rubber, textiles, and polymer foams, for example, that are stitched or adhesively bonded together. The specific materials utilized for upper 20 may be selected to impart wear-resistance, flexibility, air-permeability, moisture control, and comfort. More particularly, different materials may be incorporated into different areas of upper 20 in order to impart specific properties to those areas. Furthermore, the materials may be layered in order to provide a combination of properties to specific areas. Although the configuration of upper 20 discussed above is suitable for footwear 10, upper 20 may exhibit the configuration of any conventional or non-conventional upper.
Sole structure 30 is secured to a lower surface of upper 20 and includes an outsole 31 and a midsole 32. Outsole 31 forms a ground-engaging surface of sole structure 30 and is formed of a durable, wear-resistant material, such as rubber, that is textured to enhance traction. In some embodiments, outsole 31 may be formed integral with midsole 32 or may be a lower surface of midsole 32. A conventional midsole is primarily formed of a polymer foam material, such as polyurethane or ethylvinylacetate, as discussed in the Background of the Invention section. In contrast with the structure of a conventional midsole, midsole 32 defines a void 33 in heel region 13 that includes four support elements 40a-40d. Void 33 extends through sole structure 30 from lateral side 14 to medial side 15 and has an upper surface 34 and an opposite lower surface 35. Although midsole 32 may be substantially formed from a polymer foam material, midsole 32 is depicted as having an upper plate 36 and a lower plate 37 that defines void 33. More particularly, upper plate 36 forms upper surface 34, and lower plate 37 forms lower surface 35. Each of support elements 40a-40d extend between surfaces 34 and 35, thereby extending between plates 36 and 37, to provide ground reaction force attenuation as footwear 10 impacts the ground during running, walking, or other ambulatory activities. In addition, support elements 40a-40d may impart stability or otherwise control foot motions, such as the degree of pronation. Sole structure 30 may also include an insole positioned within the cavity formed by upper 20 and located to contact a plantar (i.e., lower) surface of the foot, thereby enhancing the overall comfort of footwear 10.
Lower Plate Structure
Lower plate 37 is depicted individually in
Areas 38a-38d respectively correspond with the positions of support elements 40a-40d. Lower plate 37 extends under, therefore, each of support elements 40a-40d. In areas between support elements 40a-40d and forward of support elements 38b and 38d, lower plate 37 defines various indentations 39a-39e that extend inward from outer edges of lower plate 37. Indentation 39a extends inward between areas 38a and 38b, indentation 39b extends inward between areas 38a and 38c, and indentation 39c extends inward between areas 38c and 38d. In addition, indentation 39d protrudes inward in a portion of lower plate 37 that is forward of area 38b, and indentation 39e protrudes inward in a portion of lower plate 37 that is forward of area 38d.
Indentation 39a, which is positioned adjacent lateral side 14, protrudes inward to a greater degree than indentations 39b-39e. As depicted in
An advantage of indentations 39a-39e relates to the ability of support elements 40a-40d to deflect independently as footwear 10 impacts the ground. The motion of the foot during running proceeds as follows: Initially, the heel strikes the ground, followed by the ball of the foot. As the heel leaves the ground, the foot rolls forward so that the toes make contact, and finally the entire foot leaves the ground to begin another cycle. During the time that the foot is in contact with the ground and rolling forward, it also rolls from the outside or lateral side to the inside or medial side, a process called pronation. While the foot is air-borne and preparing for another cycle, the opposite process, called supination, occurs. Given this motion for the foot, the first portion of footwear 10 to contact the ground is the portion of outsole 31 located under area 38a and support element 40a. Indentations 39a and 39b permit support element 40a to deflect or otherwise compress independent of support elements 40b-40d. Another advantage is that indentations 39a-39e decrease the overall mass of footwear 10 by decreasing the amount of material utilized in footwear 10. In comparison with footwear having no indentations, footwear 10 will generally have a lesser mass, which contributes to the overall athletic performance of the wearer.
The degree to which support elements 40a-40d deflect or compress independently is at least partially related to the depth of indentations 39a-39e. With regard to support element 40a, for example, the depth of indentations 39a and 39b is directly related to the degree of independence of support element 40a. More particularly, as the depth of indentations 39a and 39b increases, the degree to which support element 40a deflects or compresses independently also increases. Similarly, as the depth of indentations 39a and 39b decreases, the degree to which support element 40a deflects or compresses independently also decreases. By varying the depth of indentations 39a-39e, therefore, the degree to which support elements 40a-40d deflect or compress independently may be modified to suit the needs of the wearer or the demands of a particular athletic activity, for example.
Another configuration for lower plate 37 is depicted in
A further configuration for lower plate 37 is depicted in
Yet another configuration for lower plate 37 is depicted in
Lower plate 37 may be formed from a variety of polymer materials, including polyurethane, thermoplastic polyurethane, nylon, polyether block amide, and polybutylene terephthalate, for example. In order to enhance bonding between lower plate 37 and support elements 40a-40d, lower plate 37 may be formed from materials that are utilized for one or more components of support elements 40a-40d. In addition to the materials noted above, therefore, lower plate 37 may be formed or partially formed from any of the materials discussed below for the various components of support elements 40a-40d. In some configurations, lower plate 37 may also be formed from two different polymer materials or different densities of polymer materials. With reference to
Outsole 31 may also include indentations that correspond with the various indentations 39a-39e in lower plate 37, as depicted in
Support Element Structure
The support elements used in accordance with the arrangements described may be formed of any suitable material. For instance, the support elements may be fluid filled, such as those described in U.S. patent application Ser. No. 10/242,607, entitled, “Article of Footwear with a Sole Structure Having Fluid Filled Support Elements,” filed Oct. 3, 2005 and incorporated herein by reference. In addition, the support elements may be formed of foam, rubber or a stiff plastic. Still further, the support elements may be mechanical elements that are adjustable.
Additional Support Element Configurations
With reference to
The barrier layers forming support component 150 extends between chambers 151a-151d to form a base 152 that connects chambers 151a-151d. When incorporated into footwear 100, base 152 is positioned adjacent outsole 131, but may be positioned adjacent plate 140. An x-shaped conduit 153 places each of chambers 151a-151d in fluid communication. Accordingly, an increase in pressure within one of chambers 151a-151d induces a corresponding increase in pressure in the other chambers 151a-151d. In some embodiments, conduit 153 may be absent such that chambers 151a-151d are not in fluid communication. Alternately, base 152 may be absent such that chambers 151a-151d are separate from each other, as depicted in
Inserts that may limit the degree to which the first surface and second surface protrude outward due to the pressure of the fluid within chamber may be utilized with chambers 151a-151d. As depicted in
Support component 150 or individual chambers 151a-151d may be utilized in place of support elements 110 and with lower plate 37. As described above, an advantage of indentations 39a-39e in lower plate 37 relates to the ability of support elements 110 to deflect independently as footwear 10 impacts the ground. When utilized with support component 150, for example, chambers 151a-151d may also deflect independently as footwear 10 impacts the ground. In addition, indentations 39a-39e decrease the overall mass of footwear 10 by decreasing the amount of material utilized in footwear 10.
Additional Footwear Configuration
Footwear 10 is disclosed above as incorporating various support elements 110 (or support component 150) that include may include fluid-filled chambers. As an alternative to fluid-filled structures, an article of footwear may include an alternate arrangement as including an upper and a sole structure. Upper is secured to sole structure and defines a cavity for receiving a foot. In general, upper may have the general configuration disclosed above for upper 20, or upper may have any other conventional or non-conventional structure. Sole structure is secured to a lower surface of upper and includes an outsole and a midsole. Outsole forms a ground-engaging surface of sole structure and may have the general configuration of outsole 31 discussed above. In addition to other elements, midsole includes a plate 240 and a support component 250, shown in
Plate 240 is positioned between support component 250 and outsole and includes various indentations, three of which are identified as indentations 241a-241c. Whereas indentation 241a is located on a lateral side of footwear, each of indentations 241b and 241c are located on a medial side of footwear. As with lower plate 37 described above, an advantage of indentations 241a-241c relates to the ability of support elements 251 to deflect independently as footwear impacts the ground. In addition, indentations 241a-241c decrease the overall mass of footwear.
Based upon the above discussion, a variety of plate configurations may be utilized to modify the degree to which portions of a footwear sole deflect. More particularly, indentations in a plate may be utilized to decouple the deflection of one support element, whether formed from a fluid-filled structure or foam, from other support elements.
The invention is disclosed above and in the accompanying drawings with reference to a variety of embodiments. The purpose served by the disclosure, however, is to provide an example of the various features and concepts related to aspects of the invention, not to limit the scope of aspects of the invention. One skilled in the relevant art will recognize that numerous variations and modifications may be made to the embodiments described above without departing from the scope of the invention, as defined by the appended claims.
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Number | Date | Country | |
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20090100709 A1 | Apr 2009 | US |