A MIDSOLE FOR A SHOE

Abstract

A midsole for a shoe, where the midsole is 3D printed from an elastic polymeric material, the midsole comprising: a sole facing surface, a foot facing surface, a plurality of walls that in a first position are substantially perpendicular to the sole facing surface that extend from the sole facing surface to the foot facing surface where each wall has a height, where the plurality walls define a plurality of cells having a central axis that is substantially parallel to the walls and having a radius from a wall to the central axis, where the walls in a second position are configured to elastically deform upon application of an external force so that the deformation provides a change in the radius and/or the height, and where the walls are adapted to return to their first position upon removal of the external force

Claims

1. A midsole for a shoe, where the midsole is 3D printed from an elastic polymeric material, the midsole comprising: a sole facing surface; a foot facing surface; a plurality of walls that in a first position are substantially perpendicular to the sole facing surface and extend from the sole facing surface to the foot facing surface where each wall has a height; wherein the plurality of walls define a plurality of cells having a central axis that is substantially parallel to the walls and having a radius from a wall to the central axis; wherein the walls in a second position are configured to elastically deform upon application of an external force so that the deformation provides a change in at least one of the radius and the height; and wherein the walls are configured to return to their first position upon removal of the external force.

2. The midsole for a shoe of claim 1, wherein a peripheral boundary of a cell comprises at least two walls.

3. The midsole for a shoe of claim 1, wherein the midsole comprises at least two layers of material that are bonded to each other.

4. The midsole for a shoe of claim 1, wherein each wall comprises at least two layers of material.

5. The midsole for a shoe of claim 1, wherein the radius of each cell is between 1.5 mm and 8 mm.

6. The midsole for a shoe of claim 1, wherein the plurality of cells have a first radius in a heel area and a second radius in a forefoot area, where the first radius is larger than the second radius.

7. The midsole for a shoe of claim 1, wherein the plurality of walls have a first height in the heel area, and a second height in the forefoot area, the first height being larger than the second height.

8. The midsole for a shoe of claim 1, wherein the plurality of walls have a third height in the arch area, a second height in the forefoot area, and a first height in the heel area, at least one of the first and the second height being larger than the third height.

9. The midsole for a shoe of claim 1, wherein the elastic polymeric material is selected from at least one of a silicone based material, a silicone composition, and a composition comprising a mixture of silicone.

10. The midsole for a shoe of claim 1, wherein the hardness of the polymer is between 30 and 90 Shore A upon curing.

11. The midsole for a shoe of claim 1, wherein the thickness of each wall is between 0.4 mm and 1.6 mm.

12. The midsole for a shoe of claim 1, wherein the structural stability is stronger in a direction of the thickness of the midsole, than in at least one of the longitudinal direction and transversal direction of the midsole.

13. The midsole for a shoe of claim 1, wherein the at least one cell is open from the sole facing surface to the foot facing surface.

14. The midsole for a shoe of claim 1, wherein at least one cell is void of any liquid, particulate, or solid material, allowing the walls in the second position to deform into the volume defined by the cell in the first position without substantial resistance.

15. The midsole for a shoe of claim 1, wherein each layer of material of the midsole is 3D printed on top of a prior layer.

16. The midsole for a shoe of claim 1, wherein the plurality of cells have a first radius in the heel area and a second radius in a forefoot area, the first radius is smaller than the second radius.

17. The midsole for a shoe of claim 1, wherein the plurality of walls have a first height in the heel area, and a second height in the forefoot area, the first height may be smaller than the second height.

18. The midsole for a shoe of claim 1, wherein the plurality of walls have a third height in the arch area, a second height in the forefoot area, and a first height in the heel area, where at least one of that the first height and the second height is smaller than the third height.

19. The midsole for a shoe of claim 1, wherein the hardness of the polymer is between 65 and 85 Shore A upon curing.

20. The midsole for a shoe of claim 1, wherein the thickness of each wall is between 0.5 and 1.2 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG. 1 shows a perspective view of a midsole in accordance with the invention,

[0043] FIG. 2 shows a top view of a heel area of a midsole in accordance with the invention,

[0044] FIG. 3 shows a sectional view of the present invention, and

[0045] FIG. 4 shows a sectional view of three walls of a cell of a midsole in accordance with the invention.

DETAILED DESCRIPTION

[0046] FIG. 1 shows a perspective view of a midsole 1, having a heel area 2, an arch area 3, and a forefoot area 4. The midsole comprises a lateral side 5 and medial side 6, as well as a toe end 7 and a heel end 8. The heel area 2 is configured to receive the heel of the foot, where the heel area is the area of the midsole which receives the first impact, during movement. As may be seen in this figure, the heel area has a greater height than the forefoot area 4, where the arch area 3 on the medial side 6, has a height that may be greater than the heel area and the forefoot area.

[0047] The midsole 1 comprises a plurality of cells 18, and a plurality of walls 9, where the walls are interconnected to each other, creating a number of open cells 18 in the midsole 1. In this exemplary embodiment, the walls create a cell 18 having a hexagonal shape, where each cell 18 has six walls, that are interconnected and each wall in the central area 10 of the midsole defines one wall of two cells.

[0048] The peripheral area 11 of the midsole 1, may be provided with a peripheral wall 12, which extends around the periphery of the midsole, in order to provide a peripheral wall that can contact a respective surface of an outsole and/or an upper, when the midsole 1 is inserted into a shoe.

[0049] FIG. 2 shows a top view of a midsole 1 in accordance with the invention, where the midsole is provided with at least one reinforcement part 13, where the reinforcement part may be adapted to extend from one wall 9 of a cell 18 to an opposing wall of the same cell 18, in order to provide additional structural stability to the walls 9 surrounding the cell 18. The reinforcement part 13, may be utilized to provide a directional stability to the midsole 1, so that the reinforcement part 13 may reinforce certain areas of the midsole, in order to differentiate certain parts of the midsole. A similar reinforcement may be done by provided the reinforcement part as an increased thickness of material in predefined walls, where the thickness may be higher than the thickness of other walls of the midsole 1.

[0050] FIG. 3 shows a sectional view of a midsole 1 in accordance with the invention, where the sectional view is taken along axis III-Ill seen in FIG. 2. FIG. 3 shows the construction of each wall, taken from the side, where it may be seen that each wall 9, is constructed of a plurality of layers 14 which are stacked on top of each other when the layers are 3D printed during the manufacturing of the midsole. The layers, a sectional view of the layers may be seen, where each layer comprises a strand 15 of material, that is substantially circular in its cross sectional shape. Each strand 15 of material creates a layer and each layer may be distributed throughout the entire area of the shoe, especially when speaking of the bottom most layer 16, which creates a substantially planar bottom surface of the midsole, where the subsequent layers 17, 19, may be distributed along only parts of the midsole, especially when one part of the midsole comprises fewer layers in a certain area than it does in another area. E.g. when the heel area comprises 6-10 layers of material, the arch area may comprise 10-14 layers of material, to raise the arch part, and/or the forefoot area may comprise even fewer areas, or e.g. 4-6 layers. This magnitude of layers is only exemplary, and is not representative of all embodiments of the midsole 1.

[0051] FIG. 4 shows a sectional schematic view of three walls 20, 21, 22 of a cell 23. The cell has a foot facing surface 24 and a sole facing surface 25, where the foot facing surface faces the foot of the user, and the sole facing surface faces the sole of the shoe, when the midsole 1 is positioned in the shoe. Each wall 20,21,22 extends substantially along a longitudinal axis A, where the longitudinal axis is substantially vertical (when the midsole is arranged in a shoe) or a normal to the sole facing surface of the midsole 1.

[0052] A first layer 26 of a 3D printed material is positioned on top of a second layer 27 of 3D printed material, which in turn is positioned on top of a third layer 28 of 3D printed material, where each layer fuses and/or bonds to the previous layer, so that one wall 20, 21, 22, is capable of deforming away from the longitudinal axis A, when a force is applied in the direction of the longitudinal axis A. Thus, each wall provides a resistance to the force, but when the force applied to a single wall exceeds the bending force of the wall, at least a part wall will deflect away from the longitudinal axis. When the force is removed from the wall, the wall will return to its original position due to the shape memory of the elastic material of the 3D printed wall.

[0053] When a force applied in the direction A is applied to the foot facing surface 24 and the sole facing surface is stationary (in the direction of axis A) and the force exceeds the bending force of one or more of the walls, the foot facing surface 24 will move closer to the sole facing surface 25, and a part of the wall will begin to move away from the longitudinal axis, to give room for the movement of the surfaces 24, 25 to move closer to each other. The open space in the cell 23 or an adjacent cell (not shown) will allow the wall to deform away from the longitudinal axis, and thereby changing the form of the cell, so that the volume and/or the radius of at least part of the cell 23 decreases or increases due to the deformation of the wall. Furthermore, the force applied in the direction A may cause the wall to reduce in height, from the sole facing surface 25 to the foot facing surface 24 of the wall and/or cell.

[0054] The force applied to the midsole may be applied to the cell 23 and/or the wall in a direction that is in more than one direction, e.g. during walking or running, where the force is not only in the direction A, but may also be in a direction at an angle to the axis A. This force may cause a wall to bend away from the direction A, without buckling, causing the radius of a cell to change.

[0055] Thus, by providing a midsole having a number of walls 20,21,22 and cells 23 of an elastic material, it may be possible to provide a midsole that is capable of storing energy during deformation and therefore be a shock absorber in a shoe, as the midsole of the shoe.

[0056] The use of the terms first, second, third and fourth, primary, secondary, tertiary etc. does not imply any particular order, but are included to identify individual elements.

[0057] Moreover, the use of the terms first, second, third and fourth, primary, secondary, tertiary etc. does not denote any order or importance, but rather the terms first, second, third and fourth, primary, secondary, tertiary etc. are used to distinguish one element from another. Note that the words first, second, third and fourth, primary, secondary, tertiary etc. are used here and elsewhere for labelling purposes only and are not intended to denote any specific spatial or temporal ordering.

[0058] Furthermore, the labelling of a first element does not imply the presence of a second element and vice versa.

[0059] Although features have been shown and described, it will be understood that they are not intended to limit the claimed invention, and it will be made obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the claimed invention. The specification and drawings are, accordingly to be regarded in an illustrative rather than restrictive sense. The claimed invention is intended to cover all alternatives, modifications, and equivalents.