Auxetic structures and footwear with soles having auxetic structures

Patent metadata

Field	Value
Publication number	US-10986894-B2
Application number	US-201816052986-A
Country	US
Kind code	B2
Filing date	Aug 2, 2018
Priority date	Sep 18, 2013
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

A material that includes at least one layer made of an auxetic structure and articles of footwear having soles comprising the materials. When the material is under tension, it expands in both the direction under tension and in the direction orthogonal to the direction under tension. The articles of footwear have soles that have at least one layer made of a material that has a pattern of apertures to provide the auxetic structure. The apertures are surrounded by sole portions that can rotate or pivot to change the size of the apertures. An outer covering can be mated with an outsole structure formed by the auxetic structure. The outer covering includes features that mate with the apertures in the outsole structure. The outer covering is elastic and can stretch to accommodate expansion of the auxetic structure.

First claim

What is claimed is:

1. A sole structure for an article of footwear, the sole structure comprising:
a midsole structure formed from an ethylene-vinyl acetate or polyurethane foam and an outsole structure at least partially formed from a rubber, the outsole structure including an outsole layer and an outer covering disposed over the outsole layer, the outer covering including a ground-contacting surface disposed on one side of the outer covering;
wherein the sole structure has a longitudinal direction extending along a length of the article of footwear and a lateral direction extending along a width of the article of footwear;
wherein the longitudinal direction is tangential to the ground-contacting surface of the outer covering and the lateral direction is orthogonal to the longitudinal direction, wherein the lateral direction is also tangential to the ground-contacting surface of the outer covering;
a plurality of apertures extending through a thickness of the midsole structure and outsole layer, the plurality of apertures being arranged in geometric patterns to form an auxetic structure;
wherein the auxetic structure is such that tensioning the sole structure in one of the longitudinal direction and the lateral direction causes the outsole structure to expand in both the longitudinal direction and the lateral direction; and
wherein the outer covering extends across and into each of the plurality of apertures in both of the midsole and the outsole to prevent water or debris from entering the apertures, and wherein the outer covering is in contact with a wall of each aperture.

2. The sole structure according to claim 1 , wherein the outer covering comprises a stretchable elastic material.

3. The sole structure according to claim 1 , wherein the outer covering includes a plurality of features that protrude from the ground-contacting surface and form protuberances on an opposite surface of the outer covering.

4. An article of footwear comprising an upper and a sole structure attached to the upper, wherein the sole structure has a longitudinal direction extending along a length of the article of footwear and a lateral direction extending along a width of the article of footwear, the longitudinal direction and the lateral direction defining a plane, and wherein the sole structure comprises a composite auxetic material, the composite auxetic material comprising:
a first layer formed from a rubber, the first layer material comprising a pattern of polygonal apertures surrounded by polygonal portions, wherein each polygonal portion is joined to an adjoining polygonal feature by a flexible joint such that the polygonal portions may rotate with respect to each other when the first layer is under tension;
a second layer formed from an ethylene-vinyl acetate or polyurethane foam and attached to the first layer, wherein the second layer has the same pattern of polygonal apertures as the first layer and wherein the pattern of polygonal apertures in the second layer is aligned with the pattern of polygonal apertures in the first layer;
an outer covering of flexible and elastic material attached to the first layer on a side of the first layer that is opposite to the second layer, wherein the outer covering extends across and into each of the polygonal apertures in both the first layer and the second layer, and wherein the outer layer is in contact with a wall of each aperture; and
wherein when the composite auxetic material is under tension in a first direction, it expands in both the first direction and in a second direction that is orthogonal to the first direction.

5. The article of footwear according to claim 4 , wherein the outer covering is configured to stretch to accommodate the expansion of the sole structure in the longitudinal direction and the lateral direction.

6. The article of footwear according to claim 4 , wherein the outer covering further comprises a triangular tread pattern disposed on a ground-contacting surface of the outer covering.

7. The article of footwear according to claim 4 , wherein the composite auxetic material further comprises a third layer of flexible and elastic material attached to the second layer on a side of the second layer that is opposite to the first layer, and wherein the third layer extends across each of the polygonal apertures in the second layer.

8. The article of footwear according to claim 4 , wherein the outer covering comprises a pattern of polygonal features that protrude from its surface and that mate with the polygonal apertures in the first layer.

Assignees

• Nike Inc

Inventors

• Cross Tory M
• Hoffer Kevin W
• Jones David P
• Kirschner Patrick B
• Langvin Elizabeth
• Meschter James C

Classifications

• A43B5/00

  Footwear for sporting purposes (non-skid devices, e.g. ice-spurs or studs for football shoes, A43C15/00) · CPC title

• A43B3/0073

  Y-shaped · CPC title

• B29C44/357

  Auxetic foams, i.e. material with negative Poisson ratio; anti rubber; dilatational; re-entrant · CPC title

• A43B1/0009 Primary

  made at least partially of alveolar or honeycomb material · CPC title

• A43B13/226 Primary

  the profile being made in the foot facing surface · CPC title