Sole construction for energy and rebound
A sole construction for supporting at least a portion of a human foot and for providing energy storage and return is provided. The sole construction includes a generally horizontal layer of stretchable material, at least one chamber positioned adjacent a first side of the layer, and at least one actuator positioned adjacent a second side of the layer vertically aligned with a corresponding chamber. Each actuator has a footprint size smaller than that of the corresponding chamber, and is sized and arranged to provide individual support to the bones of the human foot. The support structure when compressed causes the actuator to push against the layer and move the layer at least partially into the corresponding chamber. In one embodiment, dual action energy storage and rebound is provided by using a plurality of actuators that move both upwardly and downwardly into corresponding chambers. In another embodiment, lateral stability is improved by using tapered actuators having a convex shape to accommodate the natural rolling movement of the foot.
1. A structure for supporting at least a portion of a foot, the structure comprising:
an elastic membrane having a first side, and a second side opposite the first side;
a plurality of plungers positioned on the first side of the elastic membrane and configured to underlie a metatarsal region of a foot, at least one of the plurality of plungers being elongate in a direction generally from a front to a rear of the structure;
a plurality of walls positioned on the second side of the elastic membrane, the plurality of walls defining at least one chamber and corresponding to at least a portion of one of the plurality of plungers such that when a compressive force is applied to the structure, the portion of one of the plurality of plungers and the at least one chamber move toward one another thereby stretching the elastic membrane into the chamber; and
wherein the plurality of walls defines at least one upstanding member positioned on the second side of the elastic membrane extending longitudinally along the chamber in a direction generally from the front to the rear of the structure;
wherein the plurality of plungers define at least one region corresponding to the at least one upstanding member such that when a compressive force is applied to the structure, the upstanding member and the at least one region move toward one another thereby stretching the elastic membrane into the at least one region.
2. The structure of claim 1 , wherein at least one of the plurality of plungers have portions for contact with the ground that substantially underlie only the plunger.
3. The structure of claim 2 , wherein each of the plurality of plungers have portions for contact with the ground that substantially underlie only the plungers.
4. The structure of claim 3 , wherein the portions for contact with the ground comprise at least one layer bonded to the plunger.
5. The structure of claim 2 , wherein the portions for contact with the ground are sized and shaped to conform substantially to the size and shape of the plunger.
6. The structure of claim 2 , wherein the portions for contact with the ground are chemically bonded to the plunger.
7. The structure of claim 1 , further comprising at least one layer of stiff material on the second side of the elastic membrane overlying the at least one chamber.
8. The structure of claim 7 , wherein the layer of stiff material overlies substantially the entirety of the plurality of plungers and the at least one chamber.
9. The structure of claim 8 , wherein the layer of stiff material comprises graphite.
10. The structure of claim 1 , wherein the plurality of plungers are sized, shaped, and positioned relative to each other to underlie the metatarsal region.
11. The structure of claim 10 , wherein the elastic membrane is sized and shaped to substantially underlie only the metatarsal region of the foot.
12. The structure of claim 1 , wherein the plurality of plungers and the elastic membrane are integrally formed.
13. The structure of claim 12 , wherein the elastic membrane is configured to underlie the metatarsal region.
14. The structure of claim 1 , wherein the at least one region is defined by at least two of the plurality of plungers and extends from a top to a bottom of the plungers.
15. The structure of claim 1 , wherein at least one of the plurality of plungers is positioned to at least partially cradle one of the metatarsal bones of a foot.
16. The structure of claim 1 , wherein the plurality of walls comprises a side wall and a top wall that at least partially enclose the at least one chamber.
17. The structure of claim 1 , wherein the at least one upstanding member is positioned within the at least one chamber.
18. The structure of claim 1 , wherein the at least one upstanding member extends longitudinally along less than the entire length of the at least one chamber in a direction generally from the front to the rear of the structure.
19. The structure of claim 1 , wherein the elastic membrane is configured to underlie the metatarsal region and a toe region.