Information
-
Patent Grant
-
6354020
-
Patent Number
6,354,020
-
Date Filed
Wednesday, October 20, 199924 years ago
-
Date Issued
Tuesday, March 12, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Yu; Mickey
- Mohandesi; Jila M.
Agents
- Sterne, Kessler, Goldstein & Fox P.L.L.C.
-
CPC
-
US Classifications
Field of Search
US
- 036 29
- 036 28
- 036 71
- 036 35 B
- 036 93
- 036 153
- 036 3 B
-
International Classifications
-
Abstract
A support and cushioning system for an article of footwear. The system includes a resilient insert disposed between a midsole and an outsole of a shoe. The resilient insert includes several chambers disposed in a heel portion of the resilient insert. These chambers are fluidly interconnected to each other via heel chamber interconnection passages. The resilient insert also includes several chambers disposed in a forefoot portion of the resilient insert. These chambers are also fluidly interconnected to each other. A connecting passage connects at least one of the chambers in the heel portion and at least one of the chambers in the forefoot portion of the resilient insert. A bladder having a fluidly interconnected heel chamber and forefoot chamber is also inserted above the midsole to provided added cushioning to the wearer. In one embodiment, the resilient insert contains air at ambient pressure and the bladder contains air at slightly above ambient pressure.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to footwear, and more particularly to an article of footwear having a system for providing cushioning and support for the comfort of the wearer.
2. Related Art
One of the problems associated with shoes has always been striking a balance between support and cushioning. Throughout the course of an average day, the feet and legs of an individual are subjected to substantial impact forces. Running, jumping, walking and even standing exert forces upon the feet and legs of an individual which can lead to soreness, fatigue, and injury.
The human foot is a complex and remarkable piece of machinery, capable of withstanding and dissipating many impact forces. The natural padding of fat at the heel and forefoot, as well as the flexibility of the arch, help to cushion the foot. An athlete's stride is partly the result of energy which is stored in the flexible tissues of the foot. For example, during a typical walking or running stride, the achilles tendon and the arch stretch and contract, storing energy in the tendons and ligaments. When the restrictive pressure on these elements is released, the stored energy is also released, thereby reducing the burden which must be assumed by the muscles.
Although the human foot possesses natural cushioning and rebounding characteristics, the foot alone is incapable of effectively overcoming many of the forces encountered during athletic activity. Unless an individual is wearing shoes which provide proper cushioning and support, the soreness and fatigue associated with athletic activity is more acute, and its onset accelerated. This results in discomfort for the wearer which diminishes the incentive for further athletic activity. Equally important, inadequately cushioned footwear can lead to injuries such as blisters, muscle, tendon and ligament damage, and bone stress fractures. Improper footwear can also lead to other ailments, including back pain.
Proper footwear should complement the natural functionality of the foot, in part by incorporating a sole (typically, an outsole, midsole and insole) which absorbs shocks. However, the sole should also possess enough resiliency to prevent the sole from being “mushy” or “collapsing,” thereby unduly draining the energy of the wearer.
In light of the above, numerous attempts have been made over the years to incorporate into a shoe means for providing improved cushioning and resiliency to the shoe. For example, attempts have been made to enhance the natural elasticity and energy return of the foot by providing shoes with soles which store energy during compression and return energy during expansion. These attempts have included using compounds such as ethylene vinyl acetate (EVA) or polyurethane (PU) to form midsoles. However, foams such as EVA tend to break down over time, thereby losing their resiliency.
Another concept practiced in the footwear industry to improve cushioning and energy return has been the use of fluid-filled devices within shoes. These devices attempt to enhance cushioning and energy return by utilizing cushions containing pressurized fluid that are disposed adjacent the heel and forefoot areas of a shoe. The overriding problem of these devices is that the cushioning means are inflated with a pressurized gas which is forced into the cushioning means, usually through a valve accessible from the exterior of the shoe.
There are several difficulties associated with using a pressurized fluid within a cushioning device. Most notably, it may be inconvenient and tedious to constantly adjust the pressure or introduce a fluid to the cushioning device. Moreover, it is difficult to provide a consistent pressure within the device thereby giving a consistent performance of the shoes. In addition, a cushioning device which is capable of holding pressurized gas is comparatively expensive to manufacture. Further, pressurized gas tends to escape from such a cushioning device, requiring the introduction of additional gas. Finally, a valve which is visible to the exterior of the shoe negatively affects the aesthetics of the shoe, and increases the probability of the valve being damaged when the shoe is worn.
A cushioning device which, when unloaded contains air at ambient pressure, provides several benefits over similar devices containing pressurized fluid. For example, generally a cushioning device which contains air at ambient pressure will not leak and lose air, because there is no pressure gradient in the resting state. The problem with many of these cushioning devices is that they are either too hard or too soft. A resilient member that is too hard may provide adequate support when exerting pressure on the member, such as when running. However, the resilient member will likely feel uncomfortable to the wearer when no force is exerted on the member, such as when standing. A resilient member that is too soft may feel comfortable to a wearer when no force is exerted on the member, such as when standing or during casual walking. However, the member will likely not provide the necessary support when force is exerted on the member, such as when running. Further, a resilient member that is too soft may actually drain energy from the wearer.
A shoe which incorporates a cushioning system including a means to provide resilient support to the wearer during fast walking and running, and to provide adequate cushioning to the wearer during standing and casual walking is disclosed in U.S. Pat. No. 5,771,606 to Litchfield et al., which is incorporated herein in its entirety by reference. U.S. Pat. No. 5,771,606 describes a resilient insert member including a plurality of heel chambers, a plurality of forefoot chambers and a central connecting passage fluidly interconnecting the chambers. The resilient insert is made from an elastomeric material and may contain air at ambient pressure. The resilient insert is placed between an outsole and a midsole of an article of footwear.
Although the resilient insert of U.S. Pat. No. 5,771,606 provides resilient support and adequate cushioning to the wearer during a wide range of activities, the arrangement and shape of the forefoot chambers results in a decrease in flexibility of the resilient insert about the metatarsal area of the foot. In addition, the shape, interconnection and placement of the heel chambers make the resilient insert somewhat rigid, such that substantial cushioning only occurs as to downward forces during heel strike.
Accordingly, what is needed is a shoe which incorporates a cushioning system including a means to provide resilient support and adequate cushioning to the wearer that anatomically compliments the wearer's foot so that flexibility is maintained and stability increased. In addition, the cushioning system must be more compliant during a wearer's gait thereby providing maximum support and cushioning benefit when downward and/or shear forces are applied.
SUMMARY OF THE INVENTION
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as embodied and broadly described herein, the article of footwear of the present invention comprises a sole and a resilient support and cushioning system. The system of the present invention includes a resilient insert member and a bladder disposed within an article of footwear.
In one embodiment, the resilient insert includes a plurality of heel chambers, a plurality of forefoot chambers and a central connecting passage fluidly interconnecting one of the heel chambers with one of the forefoot chambers. The forefoot chambers are staggered and fluidly interconnected in series along either side of forefoot chamber interconnection passages. Each forefoot chamber is arranged so that a line taken lengthwise through each chamber is essentially perpendicular to a longitudinal centerline of the resilient insert.
The single central connecting passage and arrangement of the forefoot chambers i.e., their length extending in a lateral rather than a longitudinal direction, allow for a relatively “free space” below the metatarsal area of the foot allowing for better flexibility. Further, the staggered arrangement of the forefoot chambers on either side of the centrally located forefoot chamber interconnection passages reduces the number of hard edges of the forefoot chamber under the metatarsal region of the foot thereby reducing the rigidity of the insert in that area while still maintaining its supportive function.
In one embodiment, the central connecting passage contains an impedance means to restrict the flow of air between the heel chambers and the forefoot chambers. During heel strike, the impedance means prevents air from rushing out of the heel chambers too quickly. Thus, the air in the heel chambers provides support and cushioning to the wearer's foot during heel strike.
The bladder of the present invention includes at least one heel chamber, at least one forefoot chamber and at least one connecting passage fluidly interconnecting the two chambers. In one embodiment, the bladder is disposed above the midsole of the article of footwear, and provides cushioning to the wearer's foot. In one embodiment, the bladder is vacuum formed from two sheets of resilient, non-permeable elastomeric material such that the bladder contains air at slightly above ambient pressure.
In use, the bladder provides cushioning to the wearer's foot while standing or during casual walking. The resilient insert provides added support and cushioning to the wearer's foot during fast walking and running. In an alternate embodiment, for example, for use as a high performance shoe, the article of footwear may contain only the resilient insert disposed in the sole. In another alternate embodiment, for example, for use as a casual shoe, the article of footwear may contain only the bladder disposed above the sole.
When stationary, the foot of a wearer is cushioned by the bladder. When the wearer begins a stride, the heel of the wearer's foot typically impacts the ground first. At this time, the weight of the wearer applies downward pressure on the heel portion of the resilient insert, causing the heel chambers to be forced downwardly. A large lateral heel chamber absorbs the main impact. In addition, the wearer's forward momentum at foot strike causes the heel of the foot to move forward briefly while a heel portion of the shoe sole is still in contact with the ground. This forward velocity creates a shear load which forces a decoupled portion of the large lateral heel chamber to flex forward with the weight of the wearer. As the foot of the wearer then rolls medially and forwardly, the forces on the heel chambers dissipate. With reference to the large lateral heel chamber, this results in the decoupled portion returning to its original unflexed position. The fore-aft flexing of the large lateral heel chamber acts as a shock absorber in the longitudinal direction of the insert due to the shearing action within the chamber that allows the foot to briefly “glide” forward and aft upon the resilient insert.
In this embodiment, the heel chambers are also fluidly interconnected in series in a U-shape along heel chamber interconnection passages. Each heel chamber has a functionally distinctive shape with the large lateral heel chamber having a decoupled portion capable of fore-aft flexing. The fore-aft flexing of the large lateral heel chamber creates a shearing action within that chamber which allows for cushioning of shear forces as well as cushioning of downward forces. The rearmost medial heel chamber also has a decoupled portion which acts to supply air to a forward triangular-shaped heel chamber on the medial side of the resilient insert. The triangular-shaped heel chamber traps air and acts as a medial post to help prevent over-pronation of the foot.
The heel chambers of the resilient insert are connected via heel chamber interconnection passages. A rearmost passage essentially divides the heel portion into a medial region and a lateral region so that the two regions act independently of each other. The medial region heel chambers are designed geometrically to help compensate for the problem of over-pronation, the natural tendency of the foot to roll inwardly after heel impact.
During a typical gait cycle, the main distribution of forces on the foot begins adjacent the lateral side of the heel during the “heel strike” phase of the gait, moves toward the center axis of the foot in the arch area at mid-stride, rolls medially and then moves to the medial side of the forefoot area during “toe-off.”
The configuration of the heel chamber interconnection passage between the rearmost medial heel chamber and the triangular-shaped medial heel chamber ensures that the air flow within the resilient insert complements such a gait cycle. Thus, the downward pressure resulting from heel strike causes air within the resilient insert to flow from the lateral region into the medial region, increasing air pressure therein. The medial region stiffens due to the increased air pressure, thereby providing support to the medial region of the wearer's foot and inhibiting over-pronation. Compression of the heel portion also causes the air in the lateral region to be forced forwardly, through the central connecting passage and into the forefoot portion of the resilient insert.
In addition, the forefoot and heel chambers of the resilient insert have substantially concave upper surfaces which extend beyond each side of the wearer's foot and act to cradle the foot upon impact thereby improving stability. The resilient insert is preferably blow molded from an elastomeric material, and may contain air at ambient pressure or slightly above ambient pressure. The resilient insert is disposed in the sole of an article of footwear.
The flow of air into the forefoot portion causes the forefoot chambers to expand, which slightly raises the forefoot or metatarsal area of the foot. When the forefoot of the wearer is placed upon the ground, the expanded forefoot chambers help cushion the corresponding impact forces. As the weight of the wearer is applied to the forefoot, the downward pressure caused by the impact forces causes portions of the forefoot chambers to compress while their concave upper surfaces inflate to cradle the foot and increase stability. Simultaneously, air is thrust rearwardly through the central connecting passage into the heel portion.
After “toe-off,” no downward pressure is being applied to the article of footwear, so the air within the resilient insert should return to its normal state. Upon the next heel strike, the process is repeated.
In light of the foregoing, it will be understood that the system of the present invention provides a variable, non-static cushioning, in that the flow of air within the bladder and the resilient insert complements the natural biodynamics of an individual's gait.
BRIEF DESCRIPTION OF THE FIGURES
The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings.
FIG. 1
is a top plan view of a resilient insert in accordance with the present invention.
FIG. 2
is a lateral side view of the resilient insert of FIG.
1
.
FIG. 3
is a medial side view of the resilient insert of FIG.
1
.
FIG. 4
is a cross-sectional view taken along line
4
—
4
of FIG.
1
.
FIG. 5
is a cross-sectional view taken along line
5
—
5
of FIG.
1
.
FIG. 6
is a cross-sectional view taken along line
6
—
6
of FIG.
6
.
FIG. 7
is a top plan view of a foremost lateral forefoot chamber of FIG.
1
.
FIG. 7A
is a cross-sectional view taken along line
7
A—
7
A of FIG.
7
.
FIG. 7B
is a cross-sectional view taken along line
7
B—
7
B of FIG.
7
.
FIG. 8
is a top plan view of a rearward lateral forefoot chamber of FIG.
1
.
FIG. 8A
is a cross-sectional view taken along line
8
A—
8
A of FIG.
8
.
FIG. 8B
is a cross-sectional view taken along line
8
B—
8
B of FIG.
8
.
FIG. 9
is a top plan view of the foremost medial forefoot chamber of FIG.
1
.
FIG. 9A
is a cross-sectional view taken along line
9
A—
9
A of FIG.
9
.
FIG. 9B
is a cross-sectional view taken along line
9
B—
9
B of FIG.
9
.
FIG. 10
is top plan view of a rearward medial forefoot chamber of FIG.
1
.
FIG. 10A
is a cross-sectional view taken along line
10
A—
10
A of FIG.
10
.
FIG. 10B
is a cross-sectional view taken along line
10
B—
10
B of FIG.
10
.
FIG. 11
is a top plan view of the foreward lateral heel chamber of FIG.
1
.
FIG. 11A
is a cross-sectional view taken along line
11
A—
11
A of FIG.
11
.
FIG. 11B
is a cross-sectional view taken along line
11
B—
11
B of FIG.
11
.
FIG. 12
is a top plan view of the rearmost lateral heel chamber of FIG.
1
.
FIG. 12A
is a cross-sectional view taken along line
12
A—
12
A of FIG.
12
.
FIG. 12B
is a cross-sectional view taken along line
12
B—
12
B of FIG.
12
.
FIG. 12C
is a cross-sectional view taken along line
12
C—
12
C of FIG.
12
.
FIG. 13
is a top plan view of the foreward medial heel chamber of FIG.
1
.
FIG. 13A
is a cross-sectional view taken along line
13
A—
13
A of FIG.
13
.
FIG. 13B
is a cross-sectional view taken along line
13
B—
13
B of FIG.
13
.
FIG. 14
is a top plan view of the rearmost medial heel chamber of FIG.
1
.
FIG. 14A
is a cross-sectional view taken along line
14
A—
14
A of FIG.
14
.
FIG. 14B
is a cross-sectional view taken along line
14
B—
14
B of FIG.
14
.
FIG. 15
is an exploded view of an exemplary configuration of an outsole, resilient insert and midsole in accordance with the present invention.
FIG. 16
is a top plan view of a bladder of the present invention.
FIG. 17
is a medial side view of the bladder of FIG.
16
.
FIG. 18
is a cross-sectional view taken along line
18
—
18
of FIG.
16
.
FIG. 19
is an exploded view of an exemplary configuration of the outsole, resilient insert, midsole and bladder in accordance with the present invention.
FIG. 20
is a cross-sectional view taken along line
20
—
20
of FIG.
19
.
FIG. 21
is a perspective view of a shoe of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention is now described with reference to the figures where like reference numbers indicate identical or functionally similar elements. Also in the figures, the left most digit of each reference number corresponds to the figure in which the reference number is first used. While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the relevant art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the invention. It will be apparent to a person skilled in the relevant art that this invention can also be employed in a variety of other devices and applications.
Referring now to
FIGS. 1-3
, a resilient insert
102
is shown. Resilient insert
102
provides an article of footwear with continuously modifying cushioning and cradling of a wearer's foot, such that a wearer's stride forces air within resilient insert
102
to move in a complementary manner with respect to the stride.
FIG. 1
is a top plan view of resilient insert
102
in accordance with the present invention.
FIG. 2
is a lateral side view of resilient insert
102
.
FIG. 3
is a medial side view of resilient insert
102
.
Resilient insert
102
is a three-dimensional structure formed of a suitably resilient material so as to allow resilient insert
102
to compress and expand while resisting breakdown. Preferably, resilient insert
102
may be formed from a thermoplastic elastomer or athermoplastic olefin. Suitable materials used to form resilient insert
102
may include various ranges of the following physical properties:
|
Preferred
Preferred
|
Lower Limit
Upper Limit
|
|
|
Density (Specific Gravity in g/cm <3>)
0.80
1.35
|
Modulus £ 300% Elongation (psi)
1,000
6,500
|
Permanent Set £ 200%% Strain (%)
0
55
|
Compression Set 22 hr/23° C.
0
45
|
Hardness
|
Shore A
70
—
|
Shore B
0
55
|
Tear Strength (KN/m)
60
600
|
Permanent Set at Break (%)
0
600
|
|
Many materials within the class of Thermoplastic Elastomers (TPEs) or Thermoplastic Olefins (TPOs) can be utilized to provide the above physical characteristics. Thermoplastic Vulcanates (such as SARLINK from PSM, SANTAPRENE from Monsanto and KRATON from Shell) are possible materials due to physical characteristics, processing and price. Further, Thermoplastic Urethanes (TPU's), including a TPU available from Dow Chemical Company under the tradename PELLETHANE (Stock No. 2355-95AE), a TPU available from B. F. Goodrich under the tradename ESTANE and a TPU available from BASF under the tradename ELASTOLLAN provide the physical characteristics described above. Additionally, resilient insert
102
can be formed from natural rubber compounds. However, these natural rubber compounds currently cannot be blow molded as described below.
The preferred method of manufacturing resilient insert
102
is via extrusion blow molding. It will be appreciated by those skilled in the art that the blow molding process is relatively simple and inexpensive. Further, each element of resilient insert
102
of the present invention is created during the same preferred molding process. This results in a unitary, “one-piece” resilient insert
102
, wherein all the unique elements of resilient insert
102
discussed herein are accomplished using the same mold. Resilient insert
102
can be extrusion blow molded to create a unitary, “one-piece” component, by any one of the following extrusion blow molding techniques: needle or pin blow molding with subsequent sealing, air entrapped blow molding, pillow blow molding or frame blow molding. These blow molding techniques are well known to those skilled in the relevant art.
Alternatively, other types of blow molding, such as injection blow molding and stretch blow molding may be used to form resilient insert
102
. Further, other manufacturing methods can be used to form resilient insert
102
, such as thermoforming and sealing, vacuum forming and sealing or rfwelding/hfwelding the resilient insert leaving an aperture so that the resilient insert may be inflated with air.
Resilient insert
102
is a hollow structure preferably filled with ambient air. In one embodiment, resilient insert
102
is impermeable to air; i.e., hermetically sealed, such that it is not possible for the ambient air disposed therein to escape upon application of force to resilient insert
102
. Naturally, diffusion may occur in and out of resilient insert
102
. The unloaded pressure within resilient insert
102
is preferably equal to ambient pressure. Accordingly, resilient insert
102
retains its cushioning properties throughout the life of the article of footwear in which it is incorporated. If resilient insert
102
is formed by air entrapment extrusion blow molding, the air inside resilient insert
102
may be slightly higher than ambient pressure (e.g., between 1-5 psi above ambient pressure).
As can be seen with reference to
FIG. 1
, resilient insert
102
is preferably a unitary member comprising three distinct components: a forefoot portion
104
, a heel portion
106
, and a central connecting passage
124
. Heel portion
106
is generally shaped to conform to the outline of the bottom of an individual's heel, and is disposed beneath and about the heel of a wearer when resilient insert
102
is incorporated within a shoe. In one embodiment, as shown in
FIG. 1
, heel portion
106
includes a plurality of heel chambers
116
,
118
,
120
and
122
.
Disposed opposite heel portion
106
is forefoot portion
104
. Forefoot portion
104
is generally shaped to conform to the forefoot or metatarsal area of a foot, and is disposed beneath and about a portion of the forefoot of a wearer when incorporated within a shoe. In one embodiment, as shown in
FIG. 1
, forefoot portion
104
includes a plurality of forefoot chambers
108
,
110
,
112
and
114
. Preferably, the volume of air within the chambers of forefoot portion
104
is substantially less than the volume of air within the chambers of heel portion
106
.
For a men's sample size nine, the measurements of the forefoot and heel chambers is as follows:
|
Height
Height
|
(ins.)
(ins.)
|
Length
(outside
(inside
Width
|
Chamber Number & Location
(ins.)
edge)
edge)
(ins.)
|
|
|
Forefoot Chamber 108 (FIG. 7)
2.073
.630
.394
1.158
|
Forefoot Chamber 110 (FIG. 8)
2.222
.766
.452
1.209
|
Forefoot Chamber 112 (FIG. 9)
1.993
.630
.394
1.217
|
Forefoot Chamber 114 (FIG. 10)
2.042
.767
.452
1.068
|
Heel Chamber 116 (FIG. 11)
1.679
1.140
.906
1.467
|
Heel Chamber 118 (FIG. 12)
1.986
1.179
.900
2.359
|
measurements on line 12A—12A
|
Heel Chamber 118 (FIG. 12)
1.495
1.072
.768
2.359
|
measurements on line 12B—12B
|
Heel Chamber 120 (FIG. 13)
1.248
1.091
.906
1.629
|
Heel Chamber 122 (FIG. 14)
1.324
1.182
.904
2.178
|
|
The insert
102
measures 9.453 inches in total length and 4.521 inches in total width. The central connecting passage
124
varies in thickness from 0.197 inches in the forefoot to 0.236 inches in the heel. Further, forefoot chamber interconnection passages
129
are 0.197 inches thick whereas heel chamber interconnection passages
128
are 0.256 inches thick.
As shown in
FIG. 1
, impedance means
126
is disposed within central connecting passage
124
. Impedance means
126
provides a restriction in central connecting passage
124
to restrict the flow of air through central connecting passage
124
. In one embodiment, impedance means
126
comprises a convolution of connecting passage
124
formed by restriction walls
502
(shown in detail in
FIG. 5
) placed in central connecting passage
124
. In
FIG. 1
, impedance means
126
is shown as being substantially oval-shaped. However, impedance means
126
may comprise numerous shapes or structures. For example, in another embodiment, the impedance means could be provided by a pinch-off of the material or increased wall thickness of the material.
Impedance means
126
prevents air from rushing out of heel chambers
116
,
118
,
120
and
122
upon heel strike wherein pressure is increased in heel portion
106
. The shape or structure of impedance means
126
determines the amount of air that is permitted to pass through central connecting passage
124
at any given time.
The different structures of the impedance means of the present invention are accomplished during the preferred blow-molding manufacturing process described above. Accordingly, no complicated or expensive valve means need be attached to resilient insert
102
. Rather, the shape of impedance means
126
is determined by the same mold used to form the remainder of resilient insert
102
.
As noted above, the shape of impedance means
126
will affect the rate and character of air flow within resilient insert
102
, in particular between heel portion
106
and forefoot portion
104
thereof.
Central connecting passage
124
comprises an elongated passage which connects heel portion
106
to forefoot portion
104
. In the embodiment shown in
FIG. 1
, central connecting passage
124
connects a forefoot chamber
110
to a heel chamber
116
.
Heel chambers
116
,
118
,
120
and
122
are fluidly interconnected in series via heel chamber interconnection passages
128
. Heel chamber interconnection passages
128
allow air to transfer between heel chambers
116
,
118
,
120
and
122
.
FIG. 6
shows a cross-sectional view of resilient insert
102
taken along line
6
—
6
through one of the heel chamber interconnection passages
128
. The rearmost heel chamber interconnection passage
128
divides the heel portion into a medial region
130
and a lateral region
132
. Similarly, forefoot chambers
108
,
110
,
112
and
114
are fluidly interconnected in series via forefoot chamber interconnection passages
129
, as shown in FIG.
1
.
FIG. 4
shows a cross-sectional view of resilient insert
102
taken along a line
4
—
4
, through one of the forefoot chamber interconnection passages
129
. Forefoot chamber interconnection passages
129
allow air to transfer between staggered forefoot chambers
110
,
114
,
108
and
112
respectively in forefoot portion
104
.
As previously indicated, resilient insert
102
is formed of a suitably resilient material so as to enable heel and forefoot portions
106
,
104
to compress and expand. Central connecting passage
124
is preferably formed of the same resilient material as the heel and forefoot portions
106
,
104
.
As shown in
FIG. 2
, heel chambers
116
,
118
,
120
and
122
are larger in volume, than forefoot chambers
108
,
110
,
112
and
114
. This configuration provides heel chambers
116
,
118
,
120
and
122
with a larger volume of air for support and cushioning of the wearer's foot. Since typically during walking and running, the heel of the wearer receives a larger downward force during heel strike, than the forefoot receives during “toe-off”, the extra volume of air in heel chambers
116
,
118
,
120
and
122
provides the added support and cushioning necessary for the comfort of the wearer. In particular, the large lateral heel chamber
118
is shaped and sized to absorb the main impact of the heel strike. Moreover, heel chamber
118
is shaped so as to flex forward as a result of the shear load created by the forward velocity of a wearer's foot at heel strike.
As can be seen with reference to
FIG. 1
, forefoot chambers
108
,
110
,
112
and
114
are staggered on either side of forefoot chamber interconnection passages
129
. Further each forefoot chamber is arranged so that a line A—A, B—B, C—C and D—D taken lengthwise through respective forefoot chambers
108
,
110
,
112
and
114
is essentially perpendicular to a lateral centerline X—X of the resilient insert
102
. The substantially longitudinal arrangement of the forefoot chambers as well as their staggered arrangement on either side of the forefoot chamber interconnection passages results in fewer hard edges of the forefoot portion of the insert being disposed directly under the metatarsal area of the foot. Due to the substantially “free space” directly under the metatarsal area of the wearer's foot, the insert has increased flexibility during toe-off and is more compliant to a wearer's gait.
FIG. 5
is a cross-sectional view of resilient insert
102
taken along line
5
—
5
of
FIG. 1
, through the portion of central connecting passage
124
that contains impedance means
126
. As shown, restriction walls
502
of impedance means
126
form barriers in central connecting passage
124
. The sides of central connecting passage
124
and impedance means
126
combine to form narrow passages
504
and
506
on either side of impedance means
126
. Narrow passages
504
and
506
slow the flow of air between heel portion
106
and forefoot portion
104
so that upon heel strike, the air in heel portion
106
gradually flows into forefoot portion
104
to provide adequate support and cushioning to the wearer's foot.
As shown in
FIG. 1
, once the air passes impedance means
126
, it enters forefoot portion
104
via central connecting passage
124
by way of forefoot chamber
110
. The air is then distributed via chamber interconnection passages
128
to forefoot chambers
114
,
108
and
112
, respectively. The staggered relationship of forefoot chambers
110
,
114
,
108
and
112
on either side of forefoot chamber interconnection passages
129
, as well as their length being laterally arranged, results in fewer edges of the resilient insert being directly under the metatarsal region of the wearer's foot. This results in greater flexibility in this area of the resilient insert which anatomically compliments the wearer's foot during toe-off.
Individual heel and forefoot chambers will now be discussed with reference to
FIGS. 7-14
.
FIGS. 7
,
7
A and
7
B show forefoot chamber
108
. As shown in
FIG. 1
, lateral forefoot chamber
108
, is the foremost lateral chamber of resilient insert
102
. Toward the outer edge of forefoot chamber
108
, an upper surface
702
is concave and extends upwards beyond the outer edge of the wearer's foot, as shown in FIG.
7
A. The concave upper surface
702
of lateral forefoot chamber
108
is not compressed during toe-off but instead inflates with air to cradle the foot of the wearer. Similarly,
FIGS. 8
,
8
A and
8
B show lateral forefoot chamber
110
which is the rearward lateral chamber of resilient insert
102
, as shown in FIG.
1
. Lateral forefoot chamber
110
also has a concave upper surface
802
, as shown in
FIG. 8A
which extends upwards from the outer edge of forefoot chamber
110
and acts in the same manner during toe-off as lateral forefoot chamber
108
.
Lateral forefoot chamber
108
has rounded edges
704
,
706
and
708
, as shown in
FIGS. 7A and 7B
. Rounded edges
704
,
706
and
708
allow lateral forefoot chamber
108
to gradually collapse under pressure during toe-off so that air from forefoot portion
104
begins to flow toward central connecting passage
124
and heel portion
106
. Similarly, lateral forefoot chamber
110
also has rounded edges
804
,
806
and
808
, as shown in
FIGS. 8A and 8B
, to allow forefoot chamber
110
to gradually collapse under pressure during toe-off so that air from forefoot portion
104
begins to flow toward central connecting passage
124
and heel portion
106
.
FIGS. 9
,
9
A and
9
B show medial forefoot chamber
112
. As shown in
FIG. 1
, medial forefoot chamber
112
is the foremost medial forefoot chamber of resilient insert
102
. Toward the outer edge of medial forefoot chamber
112
, an upper surface
902
is concave and extends upwards beyond the inner edge of the wearer's foot, as shown in FIG.
9
A. The concave upper surface
902
of forefoot chamber
112
is not compressed during toe-off but instead inflates with air to cradle the foot of the wearer. Similarly,
FIGS. 10
,
10
A and
10
B show medial forefoot chamber
114
which is the rearward medial forefoot chamber of resilient insert
102
, as shown in FIG.
1
. Medial forefoot chamber
114
also has a concave upper surface
1002
, as shown in
FIG.10A
which extend upwards from the outer edge of medial forefoot chamber
114
and acts in the same manner during toe-off as medial forefoot chamber
112
.
Medial forefoot chamber
112
has rounded edges
904
,
906
and
908
, as shown in
FIGS. 9A and 9B
. Rounded edges
904
,
906
and
908
allow medial forefoot chamber
112
to gradually collapse under pressure during toe-off so that air from forefoot portion
104
begins to flow toward central connecting passage
124
and heel portion
106
. Similarly, medial forefoot chamber
114
also has rounded edges
1004
,
1006
and
1008
, as shown in
FIGS. 10A and 10B
, to allow medial forefoot chamber
114
to gradually collapse under pressure during toe-off so that air from forefoot portion
104
begins to flow toward central connecting passage
124
and heel portion
106
.
FIGS. 11
,
11
A and
11
B show lateral heel chamber
116
. As shown in
FIG.1
, lateral heel chamber
116
is the forward lateral heel chamber of resilient insert
102
. On the outer edge of lateral heel chamber
116
, an upper surface
1102
is concave, as shown in FIG.
11
A and extends upwards beyond the outer edge of the wearer's foot. The concave upper surface
1102
of lateral heel chamber
116
is not compressed during heel strike but instead inflates with air to cradle the foot of the wearer.
Similarly, lateral heel chamber
118
, as shown in
FIGS. 12
,
12
A,
12
B and
12
C, is the rearmost lateral heel chamber of resilient insert
102
. Lateral heel chamber
118
also has a concave upper surface
1202
, as shown in
FIG. 12A
, which extends upwards from the outermost edge of heel chamber
118
and acts in the same manner during heel strike as lateral heel chamber
116
. Heel chamber
118
also has a decoupled portion
1204
that extends rearward of heel chamber interconnection passage
128
, as shown in FIG.
1
. Decoupled portion
1204
absorbs the main impact of the heel strike thereby cushioning the wearer's heel from the downward force. The decoupled portion
1204
of heel chamber
118
also flexes forward due to the shear load created by the forward velocity of a wearer's foot at heel strike. As the foot of the wearer then rolls medially and forwardly, the forces on heel chambers
118
dissipate. This results in decoupled portion
1204
returning to its original “unflexed” position. The fore-aft flexing of decoupled portion
1204
of heel chamber
118
creates a shearing action within that chamber and acts as a shock absorber in the longitudinal direction X—X of insert
102
. Thus, the wearer's foot will essentially “glide” back and forth upon the resilient insert due to the fore-aft flexing of decoupled portion
1204
.
FIGS. 13
,
13
A and
13
B show medial heel chamber
120
. As shown in
FIG. 1
, medial heel chamber
120
is the forward medial heel chamber of resilient insert
102
. On the outer edge of medial heel chamber
120
, an upper surface
1302
is concave, as shown in FIG.
13
A and extends upwards beyond the medial edge of the wearer's foot. The concave upper surface
1302
of medial heel chamber
120
is not compressed during heel strike but instead inflates with air to cradle the foot of the wearer as well as to aid in preventing over-pronation of the wearer's foot.
Similarly, medial heel chamber
122
, as shown in
FIGS. 14
,
14
A and
14
B, is the rearmost medial heel chamber of resilient insert
102
. Medial heel chamber
122
also has a concave upper surface
1402
, as shown in
FIG. 14A
, which extends upwards from the outer edge of heel chamber
122
and acts in the same manner during heel strike as medial heel chamber
120
. Medial heel chamber
122
also has a decoupled portion
1404
that extends rearward from heel chamber interconnection passage
128
, as shown in FIG.
1
. Medial heel chamber
122
acts independently of lateral heel chamber
118
by providing air to medial heel chamber
120
during and just after heel strike.
Medial heel chambers
120
and
122
act together after heel strike to provide added support to the wearer's foot in medial region
130
to address the problem of over-pronation, the natural tendency of the foot to roll inwardly after heel impact. During a typical gait cycle, the main distribution of forces on the foot begins adjacent the lateral side of the heel during the “theel strike” phase of the gait, then moves toward the center axis of the foot in the arch area, and then moves to the medial side of the forefoot area during “toe-off.” Heel chambers
120
and
122
on medial region
130
address the problem of over-pronation by preventing the wearer's foot from rolling to the medial side during toe-off by trapping air within the triangular shaped medial heel chamber
120
. The outer medial edge of heel chamber
120
has a squared outer edge that provides extra stiffness so that the heel chamber is more rigid, and harder to compress along the outer edge thereof.
In order to appreciate the manner in which resilient insert
102
may be incorporated within an article of footwear,
FIG. 15
discloses an exemplary configuration of incorporation.
FIG. 15
is an exploded view showing resilient insert
102
disposed within a sole
1502
. Sole
1502
includes an outsole
1506
and a midsole
1504
. Thus, in the embodiment shown in
FIG. 15
, resilient insert
102
is shown disposed between outsole
1506
and midsole
1504
. Outsole
1506
and midsole
1504
are described below with reference to FIG.
15
.
Outsole
1506
has an upper surface
1508
and a lower surface
1510
. Upper surface
1508
has concave indentations
1512
(not visible in
FIG. 15
) formed therein having upturned side edges
1514
. Indentations
1512
are formed to receive resilient insert
102
. Upturned side edges
1514
do not entirely cover the edges of resilient member
102
so that the exterior of resilient insert
102
is visible when it is disposed in sole
1502
. Further, the rearmost chambers of resilient insert
102
are also visible. In one embodiment, outsole
1506
is made from a clear crystalline rubber material so that resilient insert
102
is visible to the wearer through outsole
1506
. Outsole
1506
has tread members
1516
on lower surface
1510
. Further, the bottom surface of concave indentations
1512
on lower surface
1510
of outsole
1506
contact the ground during use.
Midsole
1504
has an upper surface
1518
and a lower surface
1520
. As shown in
FIG. 15
lower surface
1520
of midsole
1504
has concave indentations
1522
formed therein. Concave indentations
1522
are formed to receive resilient insert
102
. In one embodiment, midsole
1504
does not have side edges, and is made from EVA foam, as is conventional in the art.
FIGS. 16-18
show a bladder
1602
of the present invention. Bladder
1602
has a rear air chamber
1604
and a front air chamber
1606
. In one embodiment, bladder
1602
is manufactured by thermoforming two sheets of plastic film. Each sheet of film used in the thermoforming process is between approximately 6-25 mils (0.15-0.60 mm). In the preferred embodiment, sheets of film between 10-15 mils (0.25-0.40 mm) are preferred.
FIG. 16
shows weld lines
1612
created by the thermoforming manufacturing process. Bladder
1602
is made from a relatively soft material, such as urethane film having a hardness of Shore A 80-90, so that bladder
1602
provides added cushioning to the wearer.
During the thermoforming process, weld lines
1612
form connecting passages
1608
and
1610
which fluidly connect rear and front chambers
1604
and
1606
. Connecting passages
1608
and
1610
are preferably narrow, approximately 0.030 inch (0.8 mm)-0.050 inch (1.3 mm) in width and 0.030 inch (0.8 mm)-0.050 inch (1.3 mm) in height, to control the rate of air flow between rear air chamber
1604
and front air chamber
1606
during use. In another embodiment, bladder
1602
may be formed by RF welding, heat welding or ultrasonic welding of the urethane film material, instead of thermoforming.
Bladder
1602
is a hollow structure preferably filled with air at slightly above ambient pressure (e.g., at 1-5 psi above ambient pressure). In one embodiment, bladder
1602
is impermeable to air; i.e., hermetically sealed, such that it is not possible for the air disposed therein to escape upon application of force to bladder
1602
. Naturally, diffusion may occur in and out of bladder
1602
. However, because bladder
1602
contains air at only slightly above ambient pressure, it retains its cushioning properties throughout the life of the article of footwear in which it is incorporated.
FIG. 17
shows a medial side view of bladder
1602
.
FIG. 18
shows a cross-sectional view of bladder
1602
taken along line
18
—
18
of FIG.
16
. In particular,
FIG. 18
shows connecting passages
1608
and
1610
formed by weld lines
1612
. As shown in
FIGS. 17 and 18
, the portion of bladder
1602
disposed between connecting passages
1608
and
1610
, is relatively flat. Thus, bladder
1602
provides cushioning for the heel and forefoot portions of the wearer's feet.
In order to appreciate the manner in which resilient insert
102
and bladder
1602
may cooperate to provide both support and cushioning within a shoe,
FIG. 19
discloses an exemplary configuration of incorporation of these members within an article of footwear.
FIG. 19
is an exploded view showing sockliner
1902
, lasting board
1914
, bladder
1602
, midsole
1504
, resilient insert
102
and outsole
1506
as disposed within an article of footwear.
FIG. 20
is a cross-sectional view taken along line
20
—
20
of FIG.
19
. Thus, in the embodiment shown in
FIG. 19
, resilient insert
102
is shown disposed between outsole
1506
and midsole
1504
.
FIG. 20
shows the indentations
1512
,
1522
formed in outsole
1506
and midsole
1504
, respectively to accommodate resilient insert
102
, as described above.
Bladder
1602
is shown disposed above midsole
1504
and below a lasting board
1914
and a sockliner
1902
. Lasting board
1914
may be made from a thick paper material, fibers or textiles, and is disposed between sockliner
1902
and bladder
1602
. Sockliner
1902
includes a foot supporting surface
1904
having a forefoot region
1906
, an arch support region
1908
and a heel region
1910
. A peripheral wall
1912
extends upwardly from and surrounds a portion of foot supporting surface
1904
.
An article of footwear incorporating the present invention is now described with reference to FIG.
21
. Resilient insert
102
and bladder
1602
are disposed within an article of footwear
2100
, shown in FIG.
21
. Article of footwear
2100
includes a sole
1502
including outsole
1506
and midsole
1504
. Resilient insert
102
is disposed between outsole
1506
and midsole
1504
. Resilient insert
102
is visible in FIG.
21
. In another embodiment, outsole
1506
is made so that portions of the outer edges of the heel and forefoot chambers of resilient insert
102
are visible. Further, bladder
1602
(not visible in
FIG. 21
) is disposed between midsole
1504
and lasting board
1902
(not visible in FIG.
21
). An upper
2102
is attached to sole
1502
. Upper
2102
has an interior portion
2104
. The insole is disposed in interior portion
2104
.
In order to fully appreciate the cushioning effect of the present invention, the operation of the present invention will now be described in detail. When stationary, the foot of a wearer is cushioned by bladder
1602
. Although the maximum thickness of bladder
1602
, is approximately 0.2 inch (5 mm) above the top surface of midsole
1504
, the bladder produces an unexpectedly high cushioning effect. In one embodiment, bladder
1602
, made by RF welding, is between 0.08-0.12 inch (2-3 mm). If bladder
1602
is blow molded, it may be as thick as 0.28-0.31 inch (7-8 mm) when manufactured, and can be partially recessed in midsole
1504
.
When the wearer begins a stride, the heel of the wearer's foot typically impacts the ground first. At this time, the weight of the wearer applies downward pressure on heel portion
106
of resilient insert
102
, causing heel chambers
116
,
118
,
120
and
122
of heel portion
106
to be forced downwardly while their concave upper surfaces are simultaneously inflated about the wearer's heel. Further, large lateral heel chamber
118
absorbs the main impact of the heel strike due to its size and location within the insert. After heel strike and before toe-off, the heel of the wearer also experiences a shear force that occurs when the heel of the wearer briefly moves forwardly while the heel portion of the shoe sole remains in contact with the surface. The decoupled portion
1204
of heel chamber
118
is shaped so that it flexes forward when the wearer's heel briefly moves forwardly while the heel portion of the shoe sole remains in contact with the surface and then flexes back when the heel portion of the shoe sole is lifted off the surface during toe-off.
The configuration of heel chamber interconnection passages
128
between heel chambers
116
,
118
,
120
and
122
can help compensate for the problem of over-pronation, the natural tendency of the foot to roll inwardly after heel impact. During a typical gait cycle, the main distribution of forces on the foot begins adjacent the lateral side of the heel during the “heel strike” phase of the gait, then moves toward the center axis of the foot in the arch area, at which point the wearer's heel experiences the shear force due to the forward momentum of the heel while in contact with the surface, and finally moves to the medial side of the forefoot area during “toe-off.” The configuration of heel chambers
116
,
118
,
120
and
122
is incorporated within resilient insert
102
to ensure that the air flow within resilient insert
102
complements such a gait cycle.
Referring to
FIG. 1
, it has been previously noted that the rearmost heel chamber interconnection passage
128
within heel portion
106
essentially divides heel portion
106
into two regions: medial region
130
and lateral region
132
. The downward pressure resulting from heel strike causes air within resilient insert
102
to flow from medial region
130
, including heel chambers
120
and
122
, into lateral region
132
, including heel chambers
116
, and
118
. Thus, medial region
130
, is cushioned first to prevent the wearer's foot from rolling inwardly. Further compression of heel portion
106
causes the air in lateral region
132
to be forced forwardly, through central connecting passage
124
, into forefoot portion
104
.
The velocity at which the air flows between heel chambers
116
,
118
,
120
and
122
and forefoot chambers
108
,
110
,
112
and
114
depends on the structure of central connecting passage
124
and, in particular, the structure of impedance means
126
.
The flow of air into forefoot portion
104
causes forefoot chambers
108
,
110
,
112
and
114
to expand, which slightly raises the forefoot or metatarsal area of the foot. It should be noted that when forefoot chambers
108
,
110
,
112
and
114
expand, they assume a somewhat convex shape inflating about the foot of the wearer. When the forefoot of the wearer is placed upon the ground, the expanded forefoot chambers
108
,
110
,
112
and
114
help cushion the corresponding impact forces. The longitudinal arrangement of forefoot chambers
108
,
110
,
112
and
114
is such that lines A—A, B—B, C—C and D—D which extend respectively therethrough are essentially perpendicular to the longitudinal center axis X—X of insert
102
. This arrangement of the forefoot chambers allows for greater flexibility about the metatarsal region of the insert during toe-off. As the weight of the wearer is applied to the forefoot during toe-off, the downward pressure due to the impact forces a portion of forefoot chambers
108
,
110
,
112
and
114
about axis X—X of the insert to compress, forcing air within the chambers to inflate concave portions
702
,
802
,
902
and
1002
to cradle the foot and to provide increased stability. In addition, air is simultaneously forced rearwardly through connecting passage
124
into heel portion
106
. Once again, the velocity at which the air flows from forefoot chambers
108
,
110
,
112
and
114
to heel chambers
116
,
118
,
120
and
122
will be determined by the structure of impedance means
126
.
After “toe-off,” no downward pressure is being applied to the article of footwear, so the air within resilient insert
102
should return to its normal state. Upon the next heel strike, the process is repeated.
In light of the foregoing, it will be understood that resilient insert
102
of the present invention provides a variable, non-static cushioning, in that the flow of air within resilient insert
102
complements the natural biodynamics of an individual's gait.
Because the “heel strike” phase of a stride or gait usually causes greater impact forces than the “toe-off” phase thereof, it is anticipated that the air will flow more quickly from heel portion
106
to forefoot portion
104
than from forefoot portion
104
to heel portion
106
. Similarly, impact forces are usually greater during running than walking. Therefore, it is anticipated that the air flow will be more rapid between the chambers during running than during walking.
The foregoing description of the preferred embodiment has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teachings.
Similarly, it is not necessary that bladder
1602
be shaped as shown in FIG.
16
. For example, FIGS. 16-18 of U.S. Pat. No. 5,771,606 to Litchfield et al., incorporated herein by reference, shows alternate embodiments of the bladder of the present invention which are equally acceptable.
Although an oval-shaped impedance means is shown in the accompanying drawings, other shapes will also serve to provide support and cushioning to resilient insert
102
of the present invention. The shape of impedance means
126
will directly affect the velocity of the air as it travels within resilient insert
102
.
The mass flowrate of air within the resilient insert of the present invention is dependent upon the velocity of the heel strike (in the case of air traveling from the heel chamber to the forefoot chamber). Further, the size and structure of the impedance means of the present invention directly affects the impulse forces exerted by the air moving within the chambers of the resilient insert. With a given flowrate, the size and structure of the impedance means will dramatically affect the velocity of the air as it travels through the impedance means. Specifically, as the cross-sectional area of the impedance means becomes smaller, the velocity of the air flow becomes greater, as do the impulse forces felt in the forefoot and heel chambers.
It is anticipated that the preferred embodiment of resilient insert
102
of the present invention will find its greatest utility in athletic shoes (i.e., those designed for walking, hiking, running, and other athletic activities).
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.
Claims
- 1. An article of footwear comprising:a sole; and a resilient insert disposed within said sole, said resilient insert including a first portion with a plurality of first compressible chambers fluidly interconnected to each other, wherein at least one chamber of said plurality of first chambers has a medial side, a lateral side and a substantially concave upper surface extending from said medial side to said lateral side in both an uncompressed state and a compressed state.
- 2. The article of footwear of claim 1, wherein said resilient insert contains air at ambient pressure in an uncompressed state.
- 3. The article of footwear of claim 1, wherein said resilient insert contains air at slightly above ambient pressure in an uncompressed state.
- 4. The article of footwear of claim 1, wherein said resilient insert further comprises:a second portion with a plurality of second compressible chambers fluidly interconnected to each other; a connecting passage fluidly interconnecting only one chamber of said first portion with only one chamber of said second portion; and impedance means, disposed within said connecting passage, for restricting a flow of air between said first portion and said second portion, wherein a cross-sectional area of said connecting passage, taken at a point at which said impedance means is disposed, has an average cross-sectional area less than the remainder of said connecting passage.
- 5. The article of footwear of claim 4, wherein said sole further comprises an outsole and a midsole, and wherein said resilient insert is disposed between said outsole and said midsole.
- 6. The article of footwear of claim 5, wherein said outsole further comprises an upper surface and a lower surface, said upper surface of said outsole having a plurality of corresponding indentations therein for receiving said plurality of first and second chambers of said resilient insert.
- 7. The article of footwear of claim 5, wherein said midsole further comprises an upper surface and a lower surface, said lower surface of said midsole having a plurality of corresponding indentations therein for receiving said plurality of first and second chambers of said resilient insert.
- 8. The article of footwear of claim 1, wherein said resilient insert is formed of a blow-molded elastomeric material.
- 9. The article of footwear in claim 1, wherein said resilient insert is vacuum formed.
- 10. The article of footwear in claim 1, wherein said resilient insert is thermoformed.
- 11. The article of footwear of claim 1, wherein at least one chamber of said plurality of first chambers is substantially larger than other of said plurality of first chambers.
- 12. The article of footwear of claim 1, wherein said plurality of first chambers are arranged so that a line taken lengthwise through each of said first chambers is essentially perpendicular to a longitudinal centerline of the resilient insert.
- 13. The article of footwear of claim 1, wherein at least one chamber of said plurality of first chambers is a decoupled portion of said resilient insert.
- 14. A resilient insert for an article of footwear comprising:a plurality of compressible chambers containing air at ambient pressure, said plurality of chambers fluidly interconnected to each other, wherein at least one chamber of said plurality of chambers has a substantially concave upper surface that extends to an uppermost point at a lateral edge of said at least one chamber in both an uncompressed state and a compressed state.
- 15. The resilient insert of claim 14, further comprising impedance means disposed within said connecting passage, wherein said impedance means restricts a flow of air between said plurality of heel chambers and said plurality of forefoot chambers and provides enhanced support and cushioning to the article of footwear by controlling the velocity at which the air moves between said plurality of heel chambers and said plurality of forefoot chambers.
- 16. The resilient insert of claim 14, wherein said resilient insert is formed of a unitary piece of blow-molded elastomeric material.
- 17. The resilient insert of claim 14, wherein at least one chamber of said plurality of heel chambers is substantially larger than other of said plurality of heel chambers.
- 18. The resilient insert of claim 14, wherein said plurality of forefoot chambers are arranged so that a line taken lengthwise through each of said forefoot chambers is essentially perpendicular to a longitudinal centerline of the resilient insert.
- 19. The resilient insert of claim 14, wherein at least one chamber of said plurality of heel chambers has a decoupled portion.
- 20. An article of footwear comprising:a sole; a resilient insert disposed within said sole, said resilient insert including a plurality of compressible chambers fluidly interconnected to each other, wherein at least one chamber of said plurality of chambers includes an upper surface having a medial side and a lateral side, said upper surface being substantially flat on said medial side of said upper surface, and said upper surface being substantially concave on said lateral side of said upper surface in both an uncompressed state and a compressed state.
- 21. The article of footwear of claim 20, said sole including a heel portion and a forefoot portion, wherein said plurality of chambers are disposed in said heel portion of said sole.
- 22. The article of footwear of claim 20, wherein said plurality of chambers includes at least one lateral heel chamber.
- 23. The article of footwear of claim 22, wherein said at least one lateral heel chamber includes an upper surface having a medial side and a lateral side, said upper surface being substantially flat on said medial side of said upper surface, and said upper surface being substantially concave on said lateral side of said upper surface in both an uncompressed state and a compressed state.
- 24. The article of footwear of claim 22, wherein said at least one lateral heel chamber is a decoupled portion of said resilient insert.
- 25. The article of footwear of claim 23, wherein said plurality of chambers includes at least one medial heel chamber.
- 26. The article of footwear of claim 25, wherein said at least one medial heel chamber has a substantially concave upper surface extending upwards from an outer edge of said medial heel chamber in both an uncompressed state and a compressed state, whereby said at least one medial heel chamber and said at least one lateral heel chamber form a substantially concave cushioning area for a wearer's heel.
- 27. The article of footwear of claim 25, wherein said at least one medial heel chamber includes an upper surface having a medial side and a lateral side, said upper surface being substantially flat on said lateral side of said upper surface, and said upper surface being substantially concave on said medial side of said upper surface in both an uncompressed state and a compressed state, whereby said at least one medial heel chamber and said at least one lateral heel chamber form a substantially concave cushioning area for a wearer's heel.
- 28. The article of footwear of claim 20, wherein said resilient insert contains air at ambient pressure in an uncompressed state.
- 29. The article of footwear of claim 20, wherein said plurality of chambers are connected in series.
- 30. The article of footwear of claim 20, wherein said resilient insert contains air at slightly above ambient pressure in an uncompressed state.
- 31. The article of footwear of claim 20, wherein said sole further comprises an outsole and a midsole, and wherein said resilient insert is disposed between said outsole and said midsole.
- 32. The article of footwear of claim 31, wherein said outsole further comprises an upper surface and a lower surface, said upper surface of said outsole having a plurality of corresponding indentations therein for receiving said plurality of chambers of said resilient insert.
- 33. The article of footwear of claim 31, wherein said midsole further comprises an upper surface and a lower surface, said lower surface of said midsole having a plurality of corresponding indentations therein for receiving said plurality of chambers of said resilient insert.
- 34. The article of footwear of claim 20, wherein at least one chamber of said plurality of chambers is substantially larger than another of said plurality of chambers.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/US99/20951 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO01/19211 |
3/22/2001 |
WO |
A |
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