FOOTWEAR INCLUDING A SELF-ADJUSTING MIDSOLE

Abstract

An article of footwear including an outsole having a plurality of first traction members extending from the outsole and defining a plurality of openings. A plurality of second traction members extend through the openings in the outsole and are configured to move between an extended position, where the second traction members are fully extended in the openings, and a retracted position, where the second traction members are at least partially retracted within the openings. A compressible member is positioned adjacent to the plurality of second traction members and is configured to compress when the second traction members move to the retracted position.

Description

BACKGROUND OF THE INVENTION

Running and walking generate stress on a person's body, especially their feet, from the repeated impact of their feet with the ground. Off-road running, where the ground's softer and more forgiving than pavement, lessens the impact on the body. Trail running is gaining popularity for this and other reasons.

Different terrains require different footwear traction. For example, off-road runners often encounter loose gravel or mud. Trail shoes are, for the most part, quite similar in construction to road running shoes. However, off-road running shoes are made to be more durable than road shoes to endure the roughness of the terrain, i.e., rocks and uneven ground. Also, off-road running shoes typically have cleats or cleat-like surfaces that project downwardly from the bottom surface of the shoe to improve traction between the shoe and the ground. The longer the cleats, the better grip a shoe will have with the ground. Road shoes, on the other hand, have shorter cleats or no cleats to improve surface contact between the bottom of the shoe and the ground since road running is done on hard surfaces such as roads, sidewalks and other paved surfaces.

The structure and support of a shoe depends on the terrain or surface that the shoe will be used on. For example, shoes that are primarily used for running on trails will have different traction than shoes used for running on harder surfaces such as pavement. For this reason, runners that run on both off-road and on-road surfaces typically have at least one pair of shoes for road running and at least one other pair of shoes for off-road running. Having multiple pairs of shoes is expensive. Also if a runner plans to run on a coarse having both on-road and off-road surfaces, the runner must decide which of their pairs of shoes will work best for both surfaces, often sacrificing traction on one of the surfaces.

BRIEF SUMMARY

The present footwear includes a midsole that adjusts traction to different terrains. By providing self-adjusting traction, the same footwear can be used on different terrains without sacrificing support or traction.

Specifically, the present footwear includes an outsole having a plurality of first traction members extending from the outsole and defining a plurality of openings. A plurality of second traction members extend through the openings in the outsole and are configured to move between an extended position, where the second traction members are fully extended in the openings, and a retracted position, where the second traction members are at least partially retracted within the openings. A compressible member is positioned adjacent to the plurality of second traction members and is configured to compress when the second traction members move to the retracted position.

In another embodiment, the present footwear includes an outsole including traction components located on a perimeter of the outsole for providing traction on an underlying surface, and a plurality of openings on a central portion of the outsole. A plurality of adjustable lugs extend through and are movable within the openings. An adjustment member is operatively connected to the adjustable lugs for extending or retracting the lugs based on the hardness of the underlying surface.

In a further embodiment, the present footwear includes an outsole including a plurality of fixed lugs integrally formed on at least a portion of a perimeter of a first side of the outsole where the outsole defines a plurality of openings located at least partially within the plurality of lugs. A plurality of adjustable lugs extend through the openings where the adjustable lugs are movable between an extended position and a retracted position. A compressible member is positioned adjacent to the plurality of adjustable lugs on a second, opposing side of the outsole. The plurality of adjustable lugs are in the extended position when the compressible member is not compressed, and the adjustable lugs being in a retracted position when the compressible member is compressed.

DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a bottom perspective view of footwear including the self-adjusting midsole.

FIG. 2 is an exploded perspective view showing the self-adjusting midsole and the outsole.

FIG. 3 is a top view of the outsole.

FIG. 4 is a cross-section view of the self-adjusting midsole and the outsole taken substantially along the line 4-4 shown in FIG. 1 where the adjustable lugs are in the extended position.

FIG. 5 shows the cross-section view of FIG. 4 where the footwear is contacting a rough terrain and the adjustable lugs retract and compress the compressible member.

DETAILED DESCRIPTION

Referring now to FIGS. 1-3, an article of footwear including a midsole that adjusts to the hardness or softness of different terrains to provide better traction for users.

The article of footwear generally designated as reference number 10, includes a midsole 11 that is removably attached to an outsole 12 formed of a relatively durable material that is molded to have a particular design or shape such as the shape shown in FIG. 2. The outsole 12 includes a ground-contacting side or bottom surface 14 having a plurality of relatively rigid, fixed traction members or lugs 16 integrally formed with the bottom surface 14 of the outsole and extending about at least a portion of the outer perimeter 18 of the bottom surface. The bottom surface 14 of the outsole also includes a tread pattern 20 for enhancing the traction of the outsole. The tread pattern 20 may be any suitable tread pattern or combination of tread patterns. The outsole 12 also defines a plurality of openings or through holes 22 that are described in more detail below. The upper or top surface 24 of the outsole, which is opposite to the bottom surface 14, defines a recess or recessed area 26 in the toe-portion or front portion of the article of footwear.

The outsole 12 is preferably made of two components—a base 28 and an outer layer 30. The base 28 is preferably molded using a foam material or foam-based material, such as ethylene vinyl acetate (EVA), having a designated hardness that is determined based on the use of the footwear. In an embodiment, the hardness or hardness value of the base 28 is preferably 54 to 60 asker C but it is contemplated that the base may have any suitable hardness value. The ground-contacting portion of the base 28 is made of an abrasion resistant material. In another embodiment, an abrasion resistant material or coating is applied to the base 28. The outer layer 30 is preferably made of a solid rubber but can also be made with blown rubber, a combination of EVA and rubber blended compounds, rubber compounds or other suitable materials. The outer layer 30 is attached to the base 28 by molding, adhesive or any other suitable attachment method. The hardness of the outer layer 30 is 58 to 62 shore A but may be any suitable hardness value. It should be appreciated that the base 28 and the outer layer 30 may also be integrally formed to make the outsole 12.

An adjustment member 32 is positioned in the recess 26 defined by the upper surface 24 of the outsole 12 and includes a plurality of adjustable traction members or adjustable lugs 34 that are integrally formed with the adjustment member 32 and project downwardly from a bottom surface 36 of the adjustment member. The adjustable lugs 34 have a size, shape and pattern that allow the lugs to be inserted through the openings 22 defined by the outsole 12. When the adjustment member 32 is positioned in the recessed area or recess 26 of the outsole 12, the adjustable lugs 34 extend through the through holes 22 and are adjacent to the fixed lugs 16 on the outsole 12 to form part of the ground contacting side or bottom surface 14 of the outsole. As shown in FIG. 1, the adjustable lugs 34 of the adjustment member 32 are positioned within the fixed lugs 16 of the outsole 12 so that the fixed lugs enclose at least a portion of the adjustable lugs. It should be appreciated that the fixed lugs 16 and the adjustable lugs 34 may be on any portion of the outsole 12.

The adjustment member 32 is preferably made of rubber but also may be made with rubber compounds, a foam or foam-based material such as EVA, or any other suitable material or combination of materials. In an embodiment, the adjustment member 32 is made of a material having a hardness of 58 to 62 shore A. Preferably, the adjustment member 32 is made of a material having a hardness that is greater than the hardness of the material forming the base 28 to provide sufficient cushion and comfort to a user. As shown in FIGS. 3 and 4, the adjustable lugs 34 on the adjustment member 32 have a size and shape that provides sufficient clearance between the outside surface of each of the adjustable lugs and the inside surface of the through holes 22 to allow the adjustable lugs to move relative to the through holes.

An upper portion 38 of the adjustment member 32 has a thickness that corresponds to the depth of the recessed area 26 defined in the upper surface 24 of the outsole 12 to allow the upper surface 40 of the adjustment member 32 to be substantially flush with the upper surface 24 of the outsole 12 after the adjustment member 32 is positioned in the recessed area. This minimizes any bumps or unevenness on the upper surface of the midsole 10 that might cause discomfort to a user's foot while wearing the footwear.

A compressible member 42 is placed on the upper surfaces 24 and 40 of the outsole 12 and adjustment member 32. The compressible member 42 is preferably made of a resilient, foam or foam-based material such as EVA that is designed to absorb impact during use of the footwear. The compressible member 42 is manufactured to have a designated hardness to absorb such impact while also providing comfort to a user. The hardness of the compressible member 42 is less than the hardness of the outsole 12 to enhance the comfort of a user. In an embodiment, the compressible member 42 has a hardness of 48 to 52 asker C but may have any suitable hardness value. Also, the size and shape of the compressible member 42 preferably corresponds to the size and shape of the upper surface 24 of the outsole 12. During use of the footwear, the compressible member 42 compresses when one or more of the adjustable lugs 34 impact a hard surface thereby allowing the adjustable lugs 34 to at least partially retract within the openings 22. On softer surfaces, the resilient, compressible member 42 expands and causes the adjustable lugs 34 to move to an extended position thereby providing traction on those surfaces.

Referring now to FIGS. 4 and 5, the adjustable lugs 34 on the adjustment member 32 extend through the through holes 22 defined by the outsole 12 so that the bottom surfaces of the adjustable lugs 34 are generally parallel or in the same plane as the bottom surfaces of the fixed lugs 16 on the outsole 12. As shown in FIG. 4, the compressible member 42 is seated on the adjustment member 32 to absorb contact from the adjustment member when the adjustable lugs 34 contact relatively hard surfaces.

When a user walks or runs on generally soft terrain, such as a dirt trail, a gravel trail or grass, the adjustable lugs 34 generally remain fully extended in an extended position shown in FIG. 4. When the ground contacting surface 18 of the outsole 12 contacts a relatively hard surface, e.g., pavement, or rough terrain (e.g., rocky, uneven ground) as shown in FIG. 5, the adjustable lugs 34 move to a retracted position (i.e., move at least partially within the through holes and away from the extended position). As the adjustable lugs 34 move upwardly within the through holes 22, the upper surface 40 of the adjustment member 32 pushes upwardly against the compressible member 42 to compress the compressible member as shown in FIG. 5. The compressible member 42 serves as a shock absorber and provides resistance to the adjustment member 32 so that the adjustable lugs 34 only retract as needed based on the terrain.

When a user returns to relatively soft terrain such as a trail or grass, the compressible member 42 expands and pushes against the upper surface 40 of the adjustment member 32 to cause the adjustable lugs 34 to move outwardly through the through holes 22. The self-adjusting, adjustable lugs 34 of the adjustment member 32 thereby allow the footwear to adjust to different terrains, such as soft or hard surfaces, or rocky and uneven terrains. This enables the footwear to provide maximum traction for a runner or walker in any terrain to enhance the user's performance as well as their safety so that they avoid injury due to a slip or fall.

Although the midsole 11 is shown being used with walking or running footwear, it should be appreciated that the midsole may be used with any type of footwear including, but not limited to, shoes, sandals, slippers and boots.

While a particular embodiment of the present 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

1. An article of footwear comprising:

an outsole including a plurality of first traction members extending from said outsole, said outsole defining a plurality of openings;

a plurality of second traction members extending through said openings in said outsole, said second traction members configured to move between an extended position, wherein said second traction members are fully extended in said openings, and a retracted position, wherein said second traction members are at least partially retracted within said openings; and

a compressible member positioned adjacent to said plurality of second traction members and configured to compress when said second traction members move to said retracted position.

2. The article of footwear of claim 1, further comprising an adjustment member including said plurality of second traction members, said plurality of second traction members extending from said adjustment member.

3. The article of footwear of claim 2, wherein said plurality of second traction members are integrally formed with said adjustment member.

4. The article of footwear of claim 2, wherein an upper surface of said outsole defines a recess for receiving said adjustment member so that an upper surface of said adjustment member and said upper surface of said outsole are substantially flush when said adjustment member is inserted in said recess.

5. The article of footwear of claim 1, wherein said plurality of first traction members and said plurality of said second traction members are adjacent to each other.

6. The article of footwear of claim 1, wherein said plurality of first traction members are positioned on an outer portion of said outsole and said openings are located at an inner portion of said outsole so that said plurality of second traction members are at least partially surrounded by said plurality of first traction members when said plurality of second traction members extend through said openings.

7. The article of footwear of claim 1, wherein said plurality of first traction members are integrally formed with said outsole.

8. The article of footwear of claim 1, wherein said outsole is made of an abrasion resistant material.

9. The article of footwear of claim 1, wherein said compressible member is made of a material having a first hardness value and said outsole is made of a material having a second hardness value, wherein said second hardness value is greater than said first hardness value.

10. The article of footwear of claim 1, wherein at least one of said compressible member and said outsole is made of a foam material.

11. A article of footwear comprising:

an outsole including traction means located on a perimeter of said outsole for providing traction on an underlying surface, and a plurality of openings on a central portion of said outsole;

a plurality of adjustable lugs extending through and movable within said openings; and

adjustment means operatively connected to said adjustable lugs for extending or retracting said lugs based on the hardness of the underlying surface.

12. The article of footwear of claim 11, wherein said adjustment means is made of a material having a first hardness value and said outsole is made of a material having a second hardness value, wherein said second hardness value is greater than said first hardness value.

13. The article of footwear of claim 11, wherein at least one of said adjustment means and said outsole is made of a foam material.

14. The article of footwear of claim 11, wherein said outsole is made of an abrasion resistant material.

15. An article of footwear comprising:

an outsole including a plurality of fixed lugs integrally formed on at least a portion of a perimeter of a first side of said outsole, said outsole defining a plurality of openings located at least partially within said plurality of lugs;

a plurality of adjustable lugs extending through said openings, said adjustable lugs being movable between an extended position and a retracted position; and

a compressible member positioned adjacent to said plurality of adjustable lugs on a second, opposing side of said outsole,

said plurality of adjustable lugs being in said extended position when said compressible member is not compressed, and said adjustable lugs being in a retracted position when said compressible member is compressed.

16. The article of footwear of claim 15, wherein said outsole is made of an abrasion resistant material.

17. The article of footwear of claim 15, wherein said compressible member is made of a material having a first hardness value and said outsole is made of a material having a second hardness value, wherein said second hardness value is greater than said first hardness value.

18. The article of footwear of claim 15, wherein at least one of said compressible member and said outsole is made of a foam material.

19. The article of footwear of claim 15, wherein said fixed lugs and said adjustable lugs are made of different materials.