WO1999035928A1

WO1999035928A1 - Shoe with force responsive sole

Info

Publication number: WO1999035928A1
Application number: PCT/US1999/001204
Authority: WO
Inventors: A. Ray Snow
Original assignee: Snow A Ray
Priority date: 1998-01-20
Filing date: 1999-01-20
Publication date: 1999-07-22
Also published as: AU2461899A

Abstract

According to the invention, the cushioning, shock absorbance, and energy return provided by a shoe is controlled by the surface area of cleats (30, 31 and 32) acting upon a resilient membrane (22 and 23) between the cleats (30-32) and receiving recesses or apertures (43-45) for the cleats (30-32). By providing cleats (30-32) of various lengths, the surface area of cleats (30-32) in contact with and stretching the resilient membrane (22 and 23) increases as more force is put on the sole of the shoe. This provides a desirable variation in support offered by the shoe so that more support is provided as more force is applied to the sole, and shock absorbance is maintained.

Description

SHOE WITH FORCE RESPONSIVE SOLE

SPECIFICATION Related Application

This application claims the benefit of U. S. Provisional Application No. 60/071,881, filed January 20, 1998.

Background of the Invention

Field; The invention is in the field of shoes which provide a cushioning and shock absorbing effect on the feet during walking, running, or jumping.

State of the Art: Most shoes today, particularly athletic shoes, have cushioning material in the sole to provide a cushioning and shock absorbing effect to the feet of the wearer and, also, to support the feet of the wearer. Further, some shoes are designed to provide some energy return so that as force is applied to the sole of a shoe by a wearer as in running or jumping, the sole will return some of that energy. Thus, it is desirable that as a wearer places weight on a foot during walking, running, or jumping and the sole of the shoe absorbs energy to cushion the foot, that at least some of that energy is returned to the wearer as a rebound to help the wearer move his foot off the ground for the next step or jump.

It is currently difficult to provide a range of cushioning, shock absorbance, and support in a shoe that varies with the force applied to the shoe, or that can be easily varied by a user of the shoe. A soft shoe that provides substantial cushioning for the foot in nonstrenuous activities such as walking, generally will bottom out, i.e., reach the limit of its cushioning, resulting in a somewhat sudden end to the cushioning and shock absorbance provided when greater force is applied as in running or jumping. Shoes which provide support for running and jumping generally do not provide the same degree of cushioning. The sole described in my U. S. Patent No. 5,595,003 provides cleats which stretch elastic or resilient members as the cleats extends into cleat-receiving recesses when force is applied to the sole of the shoe. The elasticity of the elastic members determines the cushioning and support given by the sole. Although the elastic members may be chosen to require more force for greater stretch, it is still necessary to provide elastic members with stretch characteristics chosen for the type of activity expected to be performed in the shoe. Thus, while elastic material which is relatively easy to stretch may provide good cushioning and sufficient support for walking, it will easily bottom out in more strenuous activities such as running and jumping. When bottoming out, most of the shock absorbance of the sole is lost. Elastic material that is more difficult to stretch will provide good support, energy return, and adequate cushioning and shock absorbance for running and jumping, but will not provide the cushioning of the more easily stretched material for walking or standing. The weight of the person using the shoe is also a factor for the cushioning provided.

With all shoes, it is currently necessary to select the cushioning used to provide support for the strenuous activities of a heavy person expected to use the shoe. It is not possible to provide cushioning which varies with the force applied to the shoe so that soft cushioning is provided for a light person performing light activity and more substantial cushioning with increased support is provided when used by a heavier person or for more strenuous activity.

Summary of the Invention

According to the invention, the cushioning, shock absorbance, and energy return provided by a shoe is controlled by the surface area of cleats acting upon resilient means between the cleats and receiving recesses or apertures for the cleats. By providing cleats of various lengths, the surface area of cleats in contact with and stretching the resilient means increases as more force is put on the sole of the shoe. This provides a desirable variation in support offered by the shoe so that more support is provided as more force is applied to the sole, and shock absorbance is maintained.

Further, a change in support can be selectively made by a user for various activities by changing various cleat patterns to change the surface area of cleats in contact with the resilient means to again offer the degree of support needed for a specific activity. Cleats can be added to increase the support and energy return of the sole for strenuous sports activities such as running and jumping, and removed for less strenuous activities such as standing and walking where only a soft support is needed but with increased cushioning of the foot. Cleats can be removed or added by sliding a cleat cassette into or out of selected areas of the sole of the shoe.

In a preferred shoe of the invention, the shoe has a first sole portion having at least one cleat extending therefrom, a second sole portion having at least one aperture corresponding to and for receiving the at least one cleat, and force responsive, resilient means held between the first and second sole portion and at least partially covering the at least one aperture. The resilient means normally maintains the first and second sole portions spaced apart and provides resistance to relative movement of the first and second sole portions toward one another because as the first and second sole portions move toward one another, the resilient means stretches as the at least one cleat moves into the at least one receiving recess. By increasing the surface area of cleats in contact with the resilient means, the resistance to movement of the first sole portion toward the second sole portion increases. Thus, if the surface area of the cleats in contact with and stretching the resilient means increases as the two sole portions come together, the force resisting the force applied between the sole portions increases so that the soles will maintain their support of the wearer and maintain their shock absorption capabilities and will not bottom out even though a wide range of force is applied to the shoe. At low force application, the shoe can remain very soft and comfortable.

The surface area of the cleats in contact with the resilient means can change on a substantially continuous basis or on a step-wise basis. With a plurality of cleats of different lengths, the longer cleats will be in contact with the resilient means and provide the initial surface area to resist movement. As shorter cleats come into contact with and start stretching the resilient means the resistance to movement increases. A single cleat can have a sloped surface so that more of the surface contacts and stretches the resilient means as more force is applied.

In addition, if a portion of the sole is removable and replaceable by the user, the user can adjust the cushioning and support of the shoe by adding more or less cleats or more or less cleat surface area in contact with the resilient means at various locations during relative sole portion movement.

The Drawings The best mode presently contemplated for carrying out the invention is illustrated in the accompanying drawings, in which:

Fig. 1 is a vertical section taken lengthwise through a shoe of the invention;

Fig. 2, a top plan view of the upper sole portion of the sole of the invention;

Fig. 3, a vertical section taken on the line 3-3 of Fig. i;

Fig. 4, a vertical section taken on the line 4-4 of Fig. i; Fig. 5, a vertical section taken on the line 5-5 of Fig. i;

Fig. 6, a vertical section similar to that of Fig. 3, but showing the relative positions of sole portions with more weight or force applied;

Fig. 7, a vertical section similar to that of Figs. 3 and 6, but showing still more weight or force applied;

Fig. 8, a fragmentary vertical section showing an alternative form of cleat in elevation; Fig. 9, a top plan view of an alternate arrangement of apertures in a bottom sole portion;

Fig. 10, a top plan view of an upper sole portion showing a cleat arrangement for use with the bottom sole portion of Fig. 9; Fig. 11, a fragmentary vertical section through the arrangement shown in Figs. 9 and 10;

Fig. 12, a top plan view of an alternate bottom sole portion of a shoe showing a different resilient membrane location; Fig. 13, a vertical section of a shoe using the arrangement of Fig. 12;

Fig. 14, a fragmentary side elevation with covering removed showing the cleats, apertures, and resilient membranes with the shoe under full load for the arrangement of Figs. 12 and 13;

Fig. 15, a top plan view of an upper sole portion showing a removable section with cleats withdrawn from the heel portion thereof;

Fig. 16, a top plan view similar to that of Fig. 15, but showing the removable section inserted into the upper sole portion; Fig. 17, a side elevation of the removable section of Figs. 15 and 16;

Fig. 18, a vertical section taken on the line 18 - 18 of Fig. 16; Fig. 19, a top plan view of an upper sole portion similar to that of Fig. 2 showing additional alignment tabs;

Fig. 20, a fragmentary vertical section through a side of a shoe of the invention showing a side skirt embodiment;

Fig. 21, a fragmentary vertical section similar to that of Fig. 20 showing a different embodiment of side skirt; and

Fig. 22, a fragmentary vertical section similar to those of Figs. 20 and 21 showing a still different embodiment of side skirt.

Detailed Description of the Illustrated Embodiments As illustrated in Figs. 1-5, one embodiment of the athletic shoe of the invention comprises an upper sole portion 20, a bottom sole portion 21 molded to include a bottom contact surface thereon, front and rear resilient membranes 22 and 23, respectively, and a standard shoe upper 24. Heel support material 25 is secured on top of the heel portion of upper sole portion 20 and an inner sole 26 extends over upper sole portion 20 and heel support material 25. The top sole portion 20 is preferably made of a hard rubber or plastic material and includes a plurality of downwardly extending cleats. In the embodiment illustrated, these cleats are elongate and generally arranged in a U- pattern with a set of cleats 30, 31, and 32 extending downwardly from the forward or toe portion of the upper sole portion 20 and a set of cleats 33, 34, and 35 extending downwardly from the rearward or heel portion of upper sole portion 20. Cleat 33 is elongate but not in U-pattern as shown in Fig. 2. As shown in Fig. 3, rearward or heel cleat 33 is shorter than heel cleat 34 which is shorter than heel cleat 35. Without weight on upper sole portion 20, longer cleat 35 rests on resilient membrane 23, while cleats 33 and 34 are above and do not contact membrane 23.

Similarly, forward or toe cleat 30 is shorter than cleat 31, which is shorter than cleat 32. Without weight on upper sole portion 20, longer cleat 32 rests on resilient membrane 22, while cleats 30 and 31 are above and do not contact membrane 22.

Bottom sole portion 21 is molded of an elastomer material such as an EVA plastic which is light and provides a good wearing, ground contacting lower surface. Various other materials could be used and the lower sole portion 21 could have a separate ground contacting material bonded to the lower surface thereof, if desired. Bottom sole portion 21 includes apertures in number and configuration equal to the cleats of the upper sole portion 20, so as to be capable of receiving such cleats therein. Thus, apertures 40, 41, and 42, Fig. 5, in the forward or toe portion of bottom sole portion 21 are sized and configured similarly to and are positioned to receive cleats 30, 31, and 32. Similarly, apertures 43, 44, and 45, Fig. 3, in the rearward or heel portion of bottom sole portion 21 are sized and configured similarly to and are positioned to receive cleats 33, 34, and 35.

Resilient membranes 22 and 23 may be gum rubber, surgical rubber, or other suitable resilient material and are preferably secured to the top of bottom sole portion 21 as by gluing so as to cover the cleat-receiving apertures. The membranes may have a support plate such as described in my Patent No. 5,595,003 secured to the bottom thereof, top thereof, or the membranes may be sandwiched between support plates. Such support plates have apertures therethrough corresponding to the apertures in the bottom sole portion and will be formed of material which is substantially rigid in the plane of the material such as one-sixteenth inch thick plastic sheet material. The support plates, when secured to the membranes over the area of contact with the membranes, limit the portion of the membranes which stretch in response to movement of the cleats to provide better control of the characteristics of the shoe. In order to maintain the relative lateral position of the upper sole portion 20 and bottom sole portion 21 substantially the same and prevent relative lateral movement between the two which would move the cleats and receiving apertures out of alignment, front and rear alignment tabs 50 and 51, respectively, Fig. 1, extend from upper sole portion 20 and are received by front and rear alignment apertures 52 and 53, respectively. The aligned tabs 50 and 51 are longer than the longest cleats 32 and 35 so are always received within alignment apertures 52 and 53. Additional alignment tabs and receiving apertures can be added if desired or as needed for additional stability, such as along the sides of the sole portions. Fig. 19 show possible locations 100 for additional alignment tabs although various other locations could be selected.

To help maintain the flexibility of upper sole portion 20 in the general area of the ball of the foot so that the shoe will easily bend under the ball of the foot as forward steps are taken as most shoes do, a groove 55 extends across upper sole portion 20 and cleats 30, 31, and 32 are separated under groove 55. This provides a thinner, more flexible line across upper sole portion 20 to allow such bending.

When the shoe is in the condition in which no force is applied, such as when the shoe is off the foot of the wearer or the wearer is sitting with no weight on the shoe, the shoe is in the condition shown in Figs. 1 and 3-5. As shown in Fig. 5, the longer cleats 35 rest on membrane 23, but do not stretch it. When force is applied to the shoe, or when the wearer stands in the shoe, or walks, runs, or jumps, the cleats cause the membrane to stretch as the cleats extend into the receiving recesses. The current invention provides an increased resistance to the relative movement of the upper and bottom sole portions as the two are forced closer together. This is accomplished by increasing the surface area or contact area of the cleats with the membrane as the sole portions move toward one another.

As indicated, when no weight is applied to the shoe, the upper and bottom sole portions are held in spaced apart condition by the membranes and, as shown in Figs. 3 and 5, only the longest cleats contact the membranes. With reference to the heel portion of the shoe, the unweighted position is shown in Fig. 3. As weight is put on the shoe, the upper sole portion moves toward the bottom sole portion and the longer cleat 35 moves into receiving aperture 45 as shown in Fig. 6. The resistance to movement will increase with the increased stretching of membrane 23 as cleat 35 extends farther into aperture 45, however, if the membrane is chosen to provide soft cushioning, the resistance to movement does not increase fast enough to prevent the shoe from bottoming out, i.e., the upper and bottom sole portions coming together, and loosing its shock absorbing ability for strenuous activity. With the invention, as the upper and bottom sole portions move together a distance to allow the shorter cleat 34 to contact resilient membrane 23, cleat 34 starts to move into receiving aperture 44 and stretching membrane 23 as shown in Fig. 6. This substantially increases the resistance to movement of the upper sole portion toward the bottom sole portion. This increase in resistance to movement, while providing less cushioning, gives more support and maintains the shoe's ability to absorb shock with much more strenuous activity. As movement of the upper sole portion toward the bottom sole portion continues, short cleat 33 will contact membrane 23 as shown in Fig. 6 and will begin to move into aperture 43 as shown in Fig. 7 adding another step of resistance to movement of the upper sole portion toward the lower sole portion. While the increase in resistance again adds greater support and less cushion, it maintains the shock absorbing ability of the shoe and prevents bottoming out. Thus, the shoe can be made to provide substantial cushioning initially for small forces applied, such as an average weight person standing or walking slowly, yet still provide the necessary support for that person, or a heavier person, during strenuous running or jumping. Since the upper sole portion 20 moves up and down in relation to the bottom sole portion 21, and this generates an air flow in and out of the area between the sole portions, holes 48, Fig. 2, may be provided as desired through upper sole portion 20 to allow air to flow around the foot in the shoe for ventilation and cooling purposes.

Rather than providing cleats of varying lengths which provide step increases of resistance (the steps have not been found to be noticeable or a problem) cleats may be provided with sloping surfaces as shown in Fig. 8 to provide a continuous increase in surface area of the cleat in contact with the membrane. As shown in Fig. 8, a sloping cleat 55 extends downwardly from upper sole portion 56. The longer portion of cleat 55 stretches membrane 57 as that portion of the cleat extends into receiving aperture 58 in bottom sole portion 59. As more force is applied between the sole portions, more of sloped cleat 55 extends into aperture 58 and more of membrane 57 is contacted and stretched. Various configuration of cleats can be used and cleats can be used over the entire sole or just in portions of the sole such as in the heel and toe portions as shown in Figs. 1 to 6. If desired, the cleats could be used in just the heel portion or just the toe portion.

An alternate cleat arrangement is shown in Figs. 9-11. The arrangement of receiving apertures 60 and guide aperture 61 in the heel portion of a bottom sole portion 62 are shown in Fig. 9-11 with the arrangement of cleats 63 and alignment tab 64 extending from an upper sole portion 65 being shown in Fig. 10. Fig. 11 shows the membrane 66 between upper sole portion 65 and bottom sole portion 62. Various cleats can be made various lengths or may be made with sloping formation as described. This arrangement has been found advantageous for the heel portion of a shoe.

The cleat and aperture arrangements described and shown so far show the cleats and aperture arranged directly under the foot of the wearer. Figs. 12-14 show an arrangement with the cleats and aperture arranged about the perimeter of the heel portion of the shoe. Figs. 12-14 also show a bottom sole portion 70 with a separate ground contacting wearing surface 71 which is molded around the bottom sole portion 70 and extends upwardly around the side of the shoe to join the shoe upper 72 as at 73. The shoe upper 72 includes an outer leather layer 74 and inner liner 75. The inner sole 76 rests on upper sole portion 77. Cleats 78 extend downwardly from upper sole portion 77 around the periphery thereof and rest on a resilient membrane 79 which extends over the receiving apertures 80 spaced under membrane 79. Membrane 79 is held in place by tabs 81. Cleats 78 may be made different lengths as shown in Fig. 14 as desired to operate as previously described. As seen in Figs. 13 and 14, with the cleats, receiving apertures, and resilient membrane about the periphery of the heel portion, and such could be similarly located about the periphery of the toe portion where both the heel and toe portions are so supported, the shoe can have a lower profile than when the cleats, membrane, and receiving aperture are located directly under the foot. This is because, as shown in Fig. 13, the foot will rest on the inner sole 76 at about the same level as the bottom of the cleats 78.

In some instances, it may be desirable to allow a wearer to adjust or customize the cushioning and support of the shoe. In such instances, means is provided so that the wearer can either add or subtract cleats or change the shape or configuration of cleats. While this could be done in various ways, Figs. 15 - 18 show an embodiment of the invention wherein a removable cassette or insert 90 can be positioned along the bottom of the upper sole portion 91 or in a receiving slot 92 in the upper sole portion. Cleats 93 extend from the upper sole portion 91 and cleats 94 extend from insert 90. While slot 92 could have sides angled inwardly to mate with and hold similarly outwardly angled sides of insert 90 to hold it in position, or other securing means could be provided, if cleats 94 are long enough to contact membrane 95 on bottom sole portion 96, the cleats will hold the insert in slot 92 without other securing means. Without insert 90 in upper sole portion 91, only cleats

93 are in the heel portion of the shoe. These cleats 93 may be of various desired lengths with one leg of cleat 93 shown as long and contacting resilient member 95 with no weight on the shoe and the other leg of cleat 93 being shown as a shorter cleat. These cleats 93 alone will provide a soft cushion for the shoe. When a shoe with more support is desired, insert 90 is placed by the wearer in receiving slot 92 and a shoe with much greater support is provided for strenuous activity. Insert 90 is preferably slidable in and out of the upper sole portion with great ease by the shoe wearer and can be locked in place. The insert provides the wearer a choice in shoe comfort and shoe performance. With the insert locked in the sole portion of the shoe, the wearer is afforded sufficient resilience for running, cross-training, aerobics, and other types of movement generating heavy weight loading on the shoe. With the cassette removed from the sole portion of the shoe, the wearer receives the ultimate in modulated shock absorption while walking. A wide variety of cleat configurations can be provided on the inserts so the wearer, by changing and inserting an appropriate insert, can customize the shoe for any desired condition and activity. Inserts can be provided in the forward or toe portion of the shoe as well as or instead of the heel portion, or can be inserted at other locations, as desired. With the inserts of the invention, the cleats provided on the upper sole portion and on the insert can all be of the same length. The change in surface area of the cleats in the shoe is provided by the user adding, removing, or changing the insert to provide more or less cleats, or different cleat configurations, for the shoe. By providing more cleats, the wearer is increasing the surface area of the cleats in contact with and stretching the membrane. By removing cleats, the wearer is decreasing the surface area of the cleats in contact with and stretching the membrane.

The soles of the invention may be used with various types of shoes and may utilize various materials.

Since the upper and lower sole portions move toward and away from one another during use of the shoe, the sides or skirts covering the space between the sole portions must accommodate this motion as indicated in my U. S. Patent No. 5,595,003. This can be done in many ways as described in my cited patent. The sides may flex or one of the sole portions may move up and down in the sides as attached to the other sole portion. Either arrangement could be used in the shoes of Figs. 1-18.

Fig. 20 shows flexible material 101 such as leather, rubber, or plastic extending upwardly from securement to bottom sole portion 102 to a reverse loop 103 and securement to shoe upper 104. Upper sole portion 105 is secured to the bottom of shoe upper 104. As the upper sole portion 105 with shoe upper 104 attached thereto moves toward and away from bottom sole portion 102, side material 101 will flex and reverse loop 103 will move along the material. Fig. 21 shows a firm side skirt 110 of EVA plastic or other firm material secured to shoe upper 111 and free to move up and down in relation to bottom sole portion 112. A flexible membrane 113 is bonded to the top of bottom sole portion 112 and to the top of upper sole portion 114 to keep moisture and debris (skirt 110 keeps out most debris) from entering between upper sole portion 114 and membrane 115.

Fig. 22 shows a firm side skirt 120 of EVA plastic or other firm material secured to shoe upper 121 and forming a channel 122. The upper edge 123 of bottom sole portion 124 is received in channel 122 and is free to slide up and down therein. The bottom sole portion, or at least the upper edge 123 thereof, is also made of a firm EVA plastic or other firm material. While various cleat and recess configurations have been shown, it should be realized that various other configurations can be used and that a basic configuration of cylindrical cleats and cylindrical receiving recesses as shown in my Patent No. 5,595,003 will work well. In such instance, in accordance with the present invention, the cleats will be of at least two, and as currently preferred, three, different lengths.

While the embodiments shown in the drawings show the cleats extending from the upper sole portion with apertures in the bottom sole portion, these could be reversed so the cleats extend from the bottom sole portion into apertures in the upper sole portion.

Whereas this invention is here illustrated and described with reference to embodiments thereof presently contemplated as the best mode of carrying out such invention in actual practice, it is to be understood that various changes may be made in adapting the invention to different embodiments without departing from the broader inventive concepts disclosed herein and comprehended by the claims that follow.

Claims

Claims 1. A shoe having a force responsive sole, comprising a first sole portion having at least one cleat extending therefrom; a second sole portion having at least one aperture corresponding to and for receiving said at least one cleat; force responsive, resilient means held between said first and second sole portions at least partially covering said at least one aperture and cooperable with said at least one cleat for normally maintaining said first and second sole portions spaced apart with the at least one cleat of the first sole portion aligned with the at least one receiving aperture of the second sole portion so as force is applied to the sole of the shoe, the resilient means is stretched as the at least one cleat extends into the at least one corresponding aperture, the surface area of the at least one cleat stretching the resilient means being changeable to change the resistance to movement offered by the resilient means; means interconnecting said first sole portion and said second sole portion; and a shoe upper for receiving a wearer's foot.

2. A shoe having a force responsive sole according to

Claim 1, wherein the surface area of the at least one cleat stretching the resilient means changes as the at least one cleat moves into the at least one corresponding aperture.

3. A shoe having a force responsive sole according to Claim 2, wherein the at least one cleat is a plurality of cleats and the at least one corresponding aperture is a corresponding plurality of apertures, and wherein some of the cleats of the plurality of cleats are shorter than other cleats of the plurality of cleats so that the shorter cleats of the plurality of cleats do not extend into their corresponding apertures and begin to stretch the resilient means until after other cleats have begun to stretch the resilient means to thereby increase the resistance to relative movement between the first and second sole portions as the first and second sole portions move toward one another.

4. A shoe having a force responsive sole according to Claim 3, wherein the cleats are of three different lengths.

5. A shoe having a force responsive sole according to Claim 3, wherein the shoe has a heel portion and a forward portion, and wherein cleats and corresponding apertures are located in the heel portion of the shoe.

6. A shoe having a force responsive sole according to Claim 5, wherein cleats and corresponding apertures are also located in the forward portion of the shoe.

7. A shoe having a force responsive sole according to

Claim 2, wherein the at least one cleat has a sloping surface toward the resilient means so that more of the at least one cleat extends into the at least one corresponding aperture and comes into contact with and stretches the resilient means as the first and second sole portions move together to thereby increase the resistance to relative movement between the first and second sole portions as the first and second sole portions move toward one another.

8. A shoe having a force responsive sole according to Claim 2, wherein the shoe has a heel receiving portion to receive the heel of a user, and wherein the cleats and corresponding apertures are located about a perimeter portion of the heel receiving portion of the shoe.

9. A shoe having a force responsive sole according to Claim 1, wherein the surface area of the at least one cleat stretching the resilient means is changeable by a wearer of the shoe.

10. A shoe having a force responsive sole according to Claim 9, wherein a portion of the first sole portion is removable and replaceable by the wearer to change the characteristics of the at least one cleat.

11. A shoe having a force responsive sole according to Claim 10, wherein the portion of the first sole portion that is removable and replaceable by the wearer is a portion that slides in and out of the first sole portion of the shoe.

12. A shoe having a force responsive sole according to Claim 10, wherein the shoe has a heel portion, and wherein the portion of the first sole portion that is removable and replaceable by the user is in the heel portion of the shoe.

13. A shoe having a force responsive sole according to

Claim 1, wherein the second sole portion includes ground contacting means and is adapted to contact the ground, additionally including a flexible side skirt secured between the second sole portion and the shoe upper to close an area between the first sole portion and the second sole portion.

14. A shoe having a force responsive sole according to Claim 1, additionally including a flexible material secured between the first sole portion and the second sole portion to close an area between the first sole portion and the second sole portion.

15. A shoe having a force responsive sole according to Claim 14, wherein the second sole portion includes ground contacting means and is adapted to contact the ground, additionally including a firm side skirt secured to the shoe upper which extends downwardly to be adjacent sides of the second sole portion to cover an area between the first sole portion and the second sole portion.

16. A shoe having a force responsive sole according to Claim 1, wherein the second sole portion includes ground contacting means and is adapted to contact the ground and includes a firm perimetral upstanding edge, and additionally including a firm side skirt secured to the shoe upper which extends downwardly with a receiving slot therein for slidably receiving the upstanding edge of the second sole portion to cover an area between the first sole portion and second sole portion.