1. Field of the Invention
This invention relates to shoes designed to minimize impact shock and to increase stability and support.
2. Description of the Related Art
The athletic shoe is a combination of elements, which cooperatively interact in an effort to minimize weight and maximize comfort, cushioning, stability and durability. When running and walking, generally the foot makes initial contact with the ground at a force of 2.5 times their body weight, which may be repeated many times per minute per foot. The cushioning in most athletic shoes is supplied through the foam midsole that can be made from ethylene vinyl acetate (EVA) or polyurethane.
Shoes in the related art have included thicker midsoles to provide more cushioning ability. However, added thickness of foam in the midsole can cause the midsole to have increased stiffness in bending. Under these conditions, the lateral corner of the sole can tend to operate as a fulcrum upon heel strike and create an extended lever arm and greater moment, which can cause the foot to rotate medially and pronate with greater velocity than desired. This can lead to over-pronation of the foot and possible injury. Further, this condition can present a potentially unstable condition for the foot and result in the transmission of higher than desired levels of impact stress due to the relatively small surface area of contact.
It is an object of the present invention to provide a sole for an article of footwear that reduces or overcomes some or all of the deficiencies inherent in prior known footwear. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of certain preferred embodiments.
According to an aspect of the invention, it has been recognized that prior shoe designs suffer from one or more disadvantages. The present invention relates to improved shoes that address the competing concerns of cushioning and stability with the ground support phase of running and walking in both the heel strike area and the forefoot area. More specifically, an example pertains to athletic shoe constructions designed to attenuate applied force and shock, and to provide support and stability during running and walking.
A shoe according to an example of the invention provides improved shock absorption upon heel strike without relying on soft midsoles to obtain the needed shock absorption during both the initial heel impact and the forefoot impact during running and walking.
According to an improvement, the sole of a shoe includes one or more protrusions or blades, extending transverse to the longitudinal axis of the shoe. In an example, one or more blades can extend substantially perpendicular to a longitudinal axis of the shoe. In a further example, one or more blades can extend at an angle with respect to the longitudinal axis of the shoe.
In an embodiment of the invention, one or more blades are located in a forward forefoot region of the shoe and/or in a rearward heel region of the shoe.
In a further example of the invention, the one or more blades located in the forefoot region are separated from the blades located in the rearward heel region by middle region that includes blade like protrusions that intersect each other at an angle.
In an example of the invention, the one or more blades extend at least substantially between a lateral side of the shoe to a medial side of the shoe. In an exemplary embodiment, one or more blades extend at least substantially across the shoe while other blades extend a distance less than the complete distance.
In one or more examples of the invention, a first plurality of transversely extending blades project downwardly and rearwardly and are positioned in a forward portion of the sole forward of the arch area. A second plurality of blades project downwardly and forwardly and are positioned rearwardly of the arch area of the shoe.
As an example of the invention, one or more blades can have a different wall thicknesses than one or more of the other blades. In an example, the wall thickness of the blades in the rear lateral portion is thicker than the center of the rear portion or medial side to allow more flex or bending of the blade after initial contact. As a further example, one or more blades can vary in thickness along the length of the blade in a direction transverse to the longitudinal axis of the shoe.
In a further example, one or more blades can vary in thickness in the longitudinal direction of the shoe either individually or vary in thickness with respect to an adjacent blade in the forward and/or rearward direction.
In a further example of the invention, an arch area of the sole includes blades that intersect each other. For example, blades located in the forefoot region and angled toward the back of the shoe intersect with blades located in the heel region that are angled toward the front of the shoe to form a crosshatch like pattern.
In a further example of the invention, the sole having blades facing rearwardly and forwardly is made in a single mold.
The downwardly protruding blades increase the surface area of the sole, thereby increasing traction. When used on hard surfaces, the blades collapse and moderate impact forces incurred by the wearer. Consequently, the blades allow the wearer to operate their foot with less effort and more comfort.
As should be apparent, the invention can provide a number of advantageous features and benefits. It is to be understood that in practicing the invention, an embodiment can be constructed to include one or more features or benefits of embodiments disclosed herein, but not others. Accordingly, it is to be understood that the preferred embodiments discussed herein are provided as examples and are not be construed as limiting, particularly since embodiments can be formed to practice the invention that do not include each of the features of the disclosed examples.
The invention will be better understood from reading the description which follows and from examining the accompanying figures. These are provided solely as non-limiting examples of the invention. In the drawings:
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference characters will be used throughout the drawings to refer to the same or like parts.
The present invention may be embodied in various forms. A preferred embodiment of an article of footwear, such as a shoe 10 is shown in
In an embodiment of the invention, an instep 15 of upper 11 includes a securing device 16 to secure a wearer's foot within upper 11. The securing device 16 may be a hook and loop fastener as shown, however, laces, buckles, latches or any other suitable securing device to keep the wearers foot within upper is within the spirit and scope of the present invention.
The upper 11 may or may not include a midsole portion that is secured within upper 11 and can be made from for example, a foam or soft rubber type material. An embodiment of the invention includes a midsole that could be formed as an element of shoe 10, distinct from sole 12. A further embodiment of the invention includes a sole 12 that can provide the functions of a midsole, which include controlling over pronation, shielding the foot from excessive ground reaction forces, as well as advantageously utilizing the ground reaction forces.
Sole 12 is typically the ground contacting element of shoe 10, and is usually made from a durable, wear resistant material that can include texturing to improve traction. Sole 12 is preferably formed of a compressible material, which helps to absorb at least some of the impact forces encountered by sole 12 in use, and allows portions of sole 12 to flex and revert at least substantially back to a pre-impact position. As such, sole 12 can be made from foams, such as ethyl vinyl acetate (EVA), rubber, polyurethane, foamed rubber and non-foamed polymers. The sole 12 can be made from any desirable material suited to perform the functions of the sole and may be manufactured by injection molding, pouring, compression molding, or any other suitable manufacturing method.
As shown in the figures with respect to one or more exemplary embodiments of the invention, the plurality of blades or protrusions 20 project downwardly from sole 12 and define grooves 19 between adjacent blades 20. When the sole 12 comes into contact with a firm surface such as the ground surface while running or walking, the one or more protrusions or blades 20 formed as part of the sole 12 will bend or compress upon impact. In this way, the blades 20 help absorb the impact and shock to help lessen the forces acting on the body of the user.
In a preferred embodiment shown in
The different angled surfaces of the blades 20 are designed to be oriented in a direction that can increase cushioning and comfort as well as enhance performance for the user. As such, embodiments of the invention including the rearwardly and forwardly facing blades 20, address the issues of cushioning and stability in both the heel strike area and the forefoot area with respect to applied force and shock during running and walking. In this way, a more comfortable and desirable running/walking experience is realized by the user due at least in part to the effects of the plurality of blades 20 formed with the sole 12.
As discussed in more detail below, other features can be adjusted at the time of manufacturing to obtain a desirable amount of deflection and/or compression, such as locating blades in one area of the sole 12 but not in other areas, using a particular type of material for the blades, varying a distance between each blade 20, and/or varying the width, thickness, and/or length of the blade 20.
It is within the spirit and scope of the present invention to have the blades 20 in the heel region 26 facing rearwardly and the blades 20 in the forefoot region 25 facing forwardly. In a further example of the invention, blades 20 in the heel region 26 and/or forefoot region 25 can have one or more blades 20 facing in both the forward and rearward directions. For example, a blade 20 in the forefoot region 25 can face rearwardly while an adjacent blade 20 located in the direction of the heel can be facing forwardly. In this way, the adjacent blades 20 can form a pyramid like formation that could compress upon impact and provide cushioning to the user.
It should be appreciated that the blades 20 of one or more examples of the invention can be any desirable shape. As best shown for example in
Due to the positioning of the blades 20, the blades 20 provide a cushioning and a supportive feel to the user as well as enhancing performance of the shoe. As an example with respect to the blades 20 located in the forefoot region 25 shown in
As can be appreciated, the blades 20 will flex more or less depending on the weight of the user and whether the user is running or walking. In order to further affect the cushioning, stability and performance of the shoe, the blades 20 are spaced apart to allow enough compression and bending for cushioning but not too much to lessen support and performance provided by the shoe. In an example, the blades 20 can be spaced apart such that upon compression, a blade 20 will compress and bend and contact at least a portion of an adjacent blade 20. Additionally, in an example, at least a portion of a compressed blade 20 will contact an adjacent blade 20 and at least a portion of the compressed blade 20 will contact the bottom surface 33 of sole 12. With a portion of the compressed blade 20 contacting the bottom surface 33 as well as an adjacent blade 20, the blades 20 work in conjunction with each other and in conjunction with the remaining portions of the sole 12 to support and cushion the impact.
As can be appreciated, the blades 20 can be spaced apart at any desirable spacing in order to obtain desirable cushioning, support and performance while also reducing damage and wear on the blades 20. For example, one or more of the blades 20 can be spaced close together in order to reduce or prevent the blade 20 from contacting the bottom surface 33 of sole 12. In an alternate embodiment, the blades 20 can be spaced apart such that a bending of blade 20 will cause at least a substantial portion of the blade 20 to contact the bottom surface 33.
In an example of the invention, the spacing or width between adjacent blades 20 can be approximately the same size as the width of the blades 20. One or more embodiments of the invention provides for the spacing to be any desirable spacing to vary the performance of the shoe. In a further example, the spacing between two adjacent blades 20 can be a different spacing than between two adjacent blades 20 at a different location of the sole 12. In an even further embodiment, a height of one or more blades 20 can vary from a position near the upper to a ground contacting end 30 as desired. That is, one or more blades 20 can extend different distances away from surface 33.
Each blade 20 can be of uniform or variable thickness throughout its height. In an example, sides 31, 32 of the blades 20 can be parallel to each other and both be disposed at an angle, for example between 15 degrees and 90 degrees, with respect to the bottom surface 33. In an embodiment of the invention, the one or more blades are oriented at an angle from 25 to 75 degrees with respect to the bottom surface 33. In a further preferred embodiment the blades 20 are oriented approximately 45 degrees with respect to the bottom surface 33. It is within the spirit and scope of the present invention to provide any desirable angle for the blades 20. In a further example of the invention, one or more of the blades 20 can be provided at a first angle and one or more of the remaining blades 20 can be provided at one or more different angles.
As discussed above, blades 20 located in the forefoot region 25 of the shoe 10 can be angled rearwardly towards a heel region of the shoe 10. In an example of the invention, a blade 20 located at an end of the shoe 10 in the forefoot region 25 forms an angle with respect to the bottom surface 33 that is greater than or less than an angle formed by a blade 20 located closer to the heel region 26. In a further example, a blade 20 located at an end of the shoe 10 in the heel region 26 can form an angle with respect to the bottom surface that is greater than or less than an angle for a blade 20 located closer to the forefoot region 25. In an example, the angles formed by blades 20 are reduced for each blade 20 starting at the toe end and heading in the direction of the heel. Similarly, the angles formed by blades 20 are reduced for each blade 20 starting at a heel end and heading in the direction of the toe. In a further example, the angles can be increased heading from an end of the shoe 10 towards the middle of the shoe 10.
In an embodiment of the invention shown in
As further shown in
When the blades 20 extend across the width of sole 12 and reach a lateral and/or medial side of the sole 12, the side surface 27 of the blades 20 form the side surface of the sole 12. That is, the transition from the bottom surface 30 of the blades 20 to the side surface 27 is at least substantially continuous. Further, in an example of the invention, the grooves 19 extend from a bottom surface of the sole 12 to a side surface of the sole 12. As such, the grooves 19 are maintained in a position between adjacent blades 20 along the entire length of the blades 20. It should be appreciated that one or more of the grooves 19 can extend less than a complete length of the one or more blades 20. In an example of the invention with respect to a groove 19 extending only a part of the length of the blade 20, the adjacent blades 20 in the area without the groove 19 would be formed as a unitary piece. It should be appreciated that the unitary piece could be located at any position along the length of the blade 20, for example in the region of the side surface 27 or in a location approximately at the middle of the sole 12.
Further, as shown in
It is also to be appreciated that although the embodiments illustrated and described herein show blades 20 located in the forward and rearward areas of the sole that extend substantially perpendicular to longitudinal axis, other orientations of blades 20 that project downwardly from sole 12 are considered to be within the scope of the invention. For example, sole 12 could include blades 20 oriented at an angle generally along the longitudinal axis of the shoe to an angle perpendicular to the longitudinal axis. The actual orientation of the one or more blades 20 depends at least in part on the type of performance desired for the shoe. A further example of the invention includes blades 20 such that the longitudinal axis of the blade 20 is non-planar. That is, an example provides for at least a portion of the blade 20 to be curved as the blade 20 extends between the medial and lateral sides of the shoe 10.
In a further example of the invention best shown in
As discussed above, the amount of shock absorption each individual blade member 20 provides can be determined for example by either the firmness of the material or the thickness of each blade 20. In an example of the invention, one or more of the blades 20 can have a variable wall thickness in the lengthwise direction and/or the widthwise direction. In one embodiment, one or more blades 20 can have a greater thickness at the ends or sides which will reduce in thickness towards the top or middle of the blade 20. For example, one or more blades 20 can have a thicker wall thickness formed along the edges, which is tapered to a thinner wall thickness towards a middle. Providing the variable thickness according to this example allows for desirable deflection or compression upon initial contact with a firm surface.
Further, in one preferred embodiment, the lateral side of one or more blades 20 has thinner walls than the medial side so that upon contact with a ground surface during use, different shock absorption is provided from one side with respect to another side. For example, as the foot starts the rolling motion during running or walking, the sole will tend to firm up as it rotates towards the medial side to prevent over pronation.
Accordingly, one or more embodiments of the present invention do not need to rely on softer or thicker midsole foams to provide adequate shock absorption and support. The mechanical compressing, bending and flexing of the blades 20 provides increased shock absorption that in turn provides enhanced support, stability and performance.
In a further example of the invention, the sole, which includes blades facing rearwardly and forwardly, is made in a single mold in a single processing method step. In a preferred embodiment, the portion of the mold for making the blades 20 has smaller dimensions than the dimensions of the blades 20 after they are finally produced. In one example of the invention, the mold is approximately one third the size of the finally produced blade 20. In other examples of the invention, the mold is a size smaller or larger than one third of the finally produced blade 20. In an example of the invention, the material for making the blades is injected into the mold at high pressure.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
This application claims priority under 35 U.S.C. §119(e) that claims the benefit of U.S. Provisional Application No. 61/289,134, filed Dec. 22, 2009, the entire contents of which are herein incorporated by reference.
Number | Date | Country | |
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61289134 | Dec 2009 | US |