US20130318828A1

US20130318828A1 - Two-part sole for footwear

Info

Publication number: US20130318828A1
Application number: US13/487,369
Authority: US
Inventors: Jeff Sink
Original assignee: Deckers Outdoor Corp
Current assignee: Deckers Outdoor Corp
Priority date: 2012-06-04
Filing date: 2012-06-04
Publication date: 2013-12-05

Abstract

A sole for an article of footwear including a first part having a bottom surface with a plurality of first protrusions increasing in thickness from a medial side to a lateral side, where each adjacent pair of the first protrusions define a first recess therebetween, and a second part having a top surface with a plurality of second protrusions increasing in thickness from a lateral side to a medial side, where each adjacent pair of the second protrusions define a second recess therebetween. When the first part and the second part are attached together, the plurality of first protrusions and recesses on the bottom surface of the first part matingly engage corresponding ones of the plurality of second protrusions and recesses on the top surface of the second part to form a midsole that deflects and absorbs impact forces resulting from multiple running conditions.

Description

BACKGROUND

Walking, jogging and running are forms of bipedal motion that cause varying levels of stress on a person's legs and feet. As a result, shoe manufacturers add cushions and supports to shoes to provide comfort and to absorb impact forces generated by the repeated contact of a person's feet with the ground when performing these activities.
Shoes have different supports and support structures depending on the type of activity. For example, walking shoes do not require as much support as running shoes due to the fact that running generates greater stress and impact on a person's legs and feet during running. Cushions and supports in shoes are configured to relieve the impact stress on a person's body resulting from different running conditions. Overpronation is a running condition where a foot rolls inwardly such that the inner or medial portion of the foot absorbs a majority of the impact stress. In contrast, underpronation occurs when the impact stress is mainly on the outer or lateral portion of the foot where the foot does not roll inwardly. Both of these types of running conditions are corrected by providing more cushioning and support to the shoes at the areas of the foot that absorb a majority of the impact stress. Adding cushioning and supports to shoes to account for different running conditions, increases the manufacturing cost of the shoes and ultimately increases the cost of shoes for consumers. Also, users must purchase different shoes for different bipedal motion activities and to overcome different running conditions, which significantly increases the costs associated with those activities.

SUMMARY

An article of footwear is provided that includes a two-part sole that divides and deflects impact forces due to bipedal motion and provides support at both the medial and lateral sides of the article of footwear to reduce the effects of multiple running conditions such as overpronation and underpronation.
In an embodiment, a sole for an article of footwear is provided that includes a first part having a bottom surface with a plurality of first protrusions increasing in thickness from a medial side to a lateral side, where each adjacent pair of the first protrusions define a first recess therebetween, and a second part having a top surface with a plurality of second protrusions increasing in thickness from a lateral side to a medial side, where each adjacent pair of the second protrusions defines a second recess therebetween. When the first part (firmer material) and the second part (softer material) are attached together, the plurality of first protrusions and recesses on the bottom surface of the first part matingly engage corresponding ones of the plurality of second protrusions and recesses on the top surface of the second part to form a sole that deflects and absorbs impact forces resulting from multiple running conditions.
In another embodiment, an article of footwear is provided that includes an upper and a midsole attached to the upper, where the midsole includes a first part and a second part. The first part includes a top surface and a bottom surface where the bottom surface includes a plurality of first protrusions increasing in thickness from a medial side to a lateral side and each adjacent pair of the first protrusions define a first recess therebetween. The second part includes a top surface and a bottom surface, where the top surface includes a plurality of second protrusions increasing in thickness from a lateral side to a medial side and each adjacent pair of the second protrusions define a second recess therebetween. When the first part and the second part are attached together, the plurality of first protrusions and recesses on the bottom surface of the first part matingly engage corresponding ones of the plurality of second protrusions and recesses on the top surface of the second part. The bottom surface of the second part includes a plurality of tread members or angled cleats, where a rear portion of each tread member is taller or thicker than a front portion of the tread member. Each of the tread members is positioned directly adjacent to the thickest portion of one of the second protrusions to allow the tread member to bend or push into the second protrusion upon impact with the ground to absorb the shock generated by the impact.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view an article of footwear including the present two-part sole.

FIG. 2 is an elevation view of a lateral side of the article of footwear of FIG. 1.

FIG. 3 is an elevation view of a medial side of the article of footwear of FIG. 1.

FIG. 4 is an exploded perspective view of the two-part sole of FIG. 1.

FIG. 5 is a top view of the lower portion of the two-part sole of FIGS. 2-4.

FIG. 6 is a bottom view of the top portion of the two-part sole of FIGS. 2-4.

FIG. 7 is a bottom perspective view of the article of footwear of FIG. 1.

FIG. 8 is a fragmentary, enlarged view of the article of footwear of FIG. 1 where the lower part of the two-part sole is not pressed into the upper part.

FIG. 9 is a fragmentary, enlarged view of the article of footwear of FIG. 1 where a portion of the lower part of the two-part sole is pressed into the upper part.

DETAILED DESCRIPTION

The present footwear sole includes two mating parts that combine to divide, absorb and deflect shock from impact forces resulting from bipedal motion activities, such as walking, jogging and running, to substantially reduce the effect of impact forces caused by multiple running conditions.
Referring now to FIGS. 1-9, an article of footwear or shoe generally designated 10, includes an upper 12 attached to a sole 14 by stitching, adhesive or any suitable attachment method. The sole 14 includes an upper part, first part or midsole 16 and a lower part, a second part or outsole 18, which is attached to the midsole by stitching, molding, adhesive or by any suitable attachment methods or combination of attachment methods. The combination of the midsole 16 and outsole 18 of the present two-part sole 14 provides enhanced cushioning, support and stability to a wearer's feet as described below.
The upper part or midsole 16 has a top surface 20 and an opposing side or bottom surface 22 where the first part is preferably made of ethylene vinyl acetate (EVA) and is formed to generally follow the shape of a person's foot. The top surface 20 is generally flat and is attached to the upper 12 by adhesive. It should be appreciated that any suitable attachment method may be used to attach the first part or midsole to the upper 12. The bottom surface 22 of the first part 20 includes a plurality of first triangular-shaped protrusions or supports 24 formed by angled surfaces 26 that increase in thickness from a medial side 28 to a lateral side 30. It should be appreciated that the angled surfaces 26 may be at any suitable angle relative to the bottom surface 22. In the illustrated embodiment, the first supports 24 are separated by corresponding first triangular-shaped grooves or recesses 32. As shown in FIG. 6, the toe portion 34 and the heel portion 36 of first part 20 are generally flat and do not include the first supports 28. Thus as shown in FIGS. 2 and 3, the thickness of the first supports 24, and thereby the first part 16, is greatest at the medial side 30 and gradually decreases in thickness to the lateral side 32 of the midsole. The EVA material of the first part 20 provides cushioning and support to a wearer's feet to lessen the impact stress absorbed by the wearer's body, and more particularly, their legs and feet, resulting from running conditions such as overpronation and underpronation.
Referring now to FIG. 6, the bottom surface 22 of the first part 16 also includes two longitudinal recesses 38 that are spaced from each other and extend generally longitudinally between the toe portion 34 and the heel portion 36 of the midsole 16. Each of the longitudinal recesses 38 extends through each of the first supports 24 and respectively follows the contour of the medial and lateral sides 28, 30 of the midsole 16.
Referring now to FIGS. 4 and 5, the second part or outsole 18 is made of a generally soft polyurethane (PU) which provides cushioning to a wearer's feet. In the illustrated embodiment, the second part 18 is made of a material having a density that is less than a density of the first part 16. It should be appreciated that the first and second parts may have the same density, different densities or any suitable densities. As shown in FIGS. 2 and 3, the top surface 40 of the second part 18 includes triangular-shaped second protrusions or supports 44 formed by angled surfaces 45 where the supports 44 are separated by corresponding triangular-shaped second grooves or recesses 46. The second supports 44 and the second grooves 46 align and mate with the corresponding first protrusions 24 and first recesses or grooves 32 on the bottom surface 22 of the first part 16. As shown in FIG. 5, the second supports 44 and the second grooves 46 on the second part 18 are narrowest in thickness at the medial side 28 and gradually increase in thickness to the lateral side 30. As a result, the second part 18 of the sole 14 provides more cushioning at the outer or lateral side 30 of the shoe to substantially reduce the impact forces on the wearer's feet at the lateral side of the shoe.
The second part 18 also includes two spaced, elongated longitudinal protrusions or supports 48 that each extend generally longitudinally between the toe and heel portions 34, 36 as shown in FIG. 5. The elongated supports 48 correspond in size and shape to the longitudinal recesses 38 on the first part 16 of the sole 14 so that the longitudinal recesses 38 and the longitudinal supports 48 matingly engage each other when the first and second parts 16, 18 are attached together to form the sole 14. The combination of the longitudinal recesses 38 and longitudinal supports 48 thereby provide additional structure and stability to the shoe.
To enhance traction with the ground, the second part 18 includes a plurality of tread members 50 that extend from the bottom surface 42 of the second part 18. Each of the tread members 50 has a generally triangular shape with an angled front portion 52 and a generally straight, rear portion 54. The angled front portion 52 of each tread member 50 includes a plurality of steps or stepped surfaces 56. As shown FIGS. 1-3, the tread members 50 are positioned adjacent to the second protrusions 44 so that the rear portion 54 of each tread member 50 generally aligns with the thickest or tallest portion of the second protrusions. It should be appreciated that the tread members 50 may be positioned at any suitable location relative to the second protrusions 44. In the heel portion 36 of the shoe 10, smaller tread members 58 are positioned between the tread members 50 to enhance the traction of the bottom surface 42 of the outsole 18 with the ground. It should be appreciated that any suitable number of smaller tread members 58 may be positioned between the tread members 50 and the tread members 50 and 58 may have any suitable size and shape.
Referring now to FIGS. 2, 3, 8 and 9, as discussed above, the rear portions 54 of the tread members 50 on the bottom surface 42 of the second part or outsole 18 are positioned to be generally aligned with the thickest or tallest portions of the second protrusions 44 on the lateral side 30 of the shoe (FIG. 2) and the thinnest or shortest portions of the second protrusions 44 on the medial side 28 of the shoe (FIG. 3). Accordingly, when one or more of the tread members 50 contacts the ground, each impacted tread member is moved, pushed or forced upwardly due to the impact with the ground. As shown in FIG. 9, the upward movement of each tread member 50 on the lateral side 30 of the shoe 10 causes the rear portion 54 of the tread member 50 to move into the thickest or tallest portion of a corresponding second protrusion. In contrast, the thinnest or shortest portions of second protrusions 44 are located on the medial side 28 of the shoe. As a result, there is less of the softer material forming the second protrusions 44 between the tread members 50 and the first part or midsole 16 on the medial side 28 of the shoe. The firmer first part or midsole 16 inhibits the upward movement of the tread members 50 on the medial side 28 of the shoe, which provides additional support and stability to the medial side of the shoe with less cushioning. It should be appreciated that the first part 16 and the second part 18 may be made of any suitable materials or combination of materials. It should also be appreciated that the first and second parts may be made of materials having any suitable densities.
The first and second parts 16, 18 of the present sole 10 fit together such that the first protrusions 24 of the first part 16 matingly engage the corresponding second grooves 26 of the second part 18 and the second protrusions 44 of the second part 18 matingly engage the corresponding first recesses 32 of the first part 16. The combination of the first and second parts 16, 18 of the sole 14 provide firm support at the inner or medial side 28 of a shoe to reduce the impact stresses from overpronation, and cushioning at the outer or lateral side 30 of the shoe for absorbing impact stresses due to underpronation. Further, the present sole 14 divides and deflects the shock generated by the impact forces so that less of the shock is transferred to a wearer's feet and legs. Thus, the present two-part sole 14 allows for great traction and stability on soft surfaces while transitioning to substantial cushioning and support on firm surfaces. The present two-part sole 14 also requires less parts, such as cushioning layers, than conventional shoes, which reduces the complexity and the weight of the shoe while providing support and stability to wearers.
While a particular embodiment of the present article of footwear has been described herein, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects.

Claims

What is claimed is:

1. A sole for an article of footwear comprising:

a first part including a bottom surface having a plurality of first protrusions increasing in thickness from a medial side to a lateral side, each adjacent pair of said first protrusions defining a first recess therebetween; and

a second part including a top surface having a plurality of second protrusions increasing in thickness from a lateral side to a medial side, each adjacent pair of said second protrusions defining a second recess therebetween,

wherein when said first part and said second part are attached together, said plurality of first protrusions and recesses on said bottom surface of said first part matingly engage corresponding ones of said plurality of second protrusions and recesses on said top surface of said second part.

2. The sole of claim 1, wherein said first protrusions have a triangular shape.

3. The sole of claim 2, wherein said second protrusions have a triangular shape.

4. The sole of claim 1, wherein said second protrusions have a triangular shape.

5. The sole of claim 4, wherein said first protrusions have a triangular shape.

6. The sole of claim 1, wherein each said first recess of said first part have a triangular shape and decrease in width from the medial side to lateral side.

7. The sole of claim 1, wherein each said recess of said second part have a triangular shape and decrease in width from the lateral side to medial side.

8. The sole of claim 1, wherein said first part further comprises two longitudinal recesses extending between the toe and heel portions of the first part.

9. The sole of claim 8, wherein said second part further comprises two longitudinal supports extending between the toe and heel portions of the second part, said longitudinal supports being configured to matingly engage said two longitudinal protruding recesses of said first part when said first and second parts are attached together.

10. The sole of claim 1, wherein said second part includes a plurality of tread members, each of said tread members being positioned adjacent to a different one of said second protrusions.

11. An article of footwear comprising:

an upper; and

a sole attached to said upper, said sole including a first part and a second part,

said first part including a top surface and a bottom surface, said bottom surface including a plurality of first protrusions increasing in thickness from a medial side to a lateral side, each adjacent pair of said first protrusions defining a first recess therebetween,

said second part including a top surface and a bottom surface, said top surface including a plurality of second protrusions increasing in thickness from a lateral side to a medial side, each adjacent pair of said second protrusions defining a second recess therebetween, wherein when said first part and said second part are attached together, said plurality of first protrusions and recesses on said bottom surface of said first part matingly engage corresponding ones of said plurality of second protrusions and recesses on said top surface of said second part.

12. The article of footwear of claim 11, wherein said first protrusions have a triangular shape.

13. The article of footwear of claim 12, wherein said second protrusions have a triangular shape.

14. The article of footwear of claim 11, wherein said second protrusions have a triangular shape.

15. The article of footwear of claim 14, wherein said first protrusions have a triangular shape.

16. The article of footwear of claim 11, wherein said recesses of said first part have a triangular shape and decrease in width from the medial side to lateral side.

17. The article of footwear of claim 11, wherein said recesses of said second part have a triangular shape and decrease in width from the lateral side to medial side.

18. The article of footwear of claim 11, wherein said first part further comprises two longitudinal recesses extending between the toe and heel portions of the first part.

19. The article of footwear of claim 11, wherein said second part further comprises two longitudinal supports extending between the toe and heel portions of the second part, said longitudinal supports being configured to matingly engage said two longitudinal recesses of said first part when said first and second parts are attached together.

20. The sole of claim 11, wherein said second part includes a plurality of tread members, each of said tread members being positioned adjacent to a different one of said second protrusions.