U.S. patent application number 11/354667 was filed with the patent office on 2006-11-09 for variable support footwear using electrorheological or magnetorheological fluids.
This patent application is currently assigned to Outland Research, LLC. Invention is credited to Louis B. Rosenberg.
Application Number | 20060248750 11/354667 |
Document ID | / |
Family ID | 37392781 |
Filed Date | 2006-11-09 |
United States Patent
Application |
20060248750 |
Kind Code |
A1 |
Rosenberg; Louis B. |
November 9, 2006 |
Variable support footwear using electrorheological or
magnetorheological fluids
Abstract
A variable footwear support system includes at least one
rheological body within a sole of an article of footwear, control
electronics within the article of footwear, and at least one E/M
field generator coupled to the control electronics and arranged
operably proximate to at least one rheological body. The sole is
formed of a resilient material and the rheological body contains a
Theological fluid having a viscosity that is variable in the
presence of an energy field. The control electronics is adapted to
generate at least one control signal. The at least one E/M field
generator is adapted to generate an energy field corresponding to a
control signal generated by the control electronics upon the
rheological body.
Inventors: |
Rosenberg; Louis B.; (Pismo
Beach, CA) |
Correspondence
Address: |
SINSHEIMER JUHNKE LEBENS & MCIVOR, LLP
1010 PEACH STREET
P.O. BOX 31
SAN LUIS OBISPO
CA
93406
US
|
Assignee: |
Outland Research, LLC
Pismo Beach
CA
|
Family ID: |
37392781 |
Appl. No.: |
11/354667 |
Filed: |
February 14, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60678548 |
May 6, 2005 |
|
|
|
Current U.S.
Class: |
36/29 |
Current CPC
Class: |
A43B 1/0054 20130101;
A43B 3/0005 20130101; A43B 13/189 20130101 |
Class at
Publication: |
036/029 |
International
Class: |
A43B 13/20 20060101
A43B013/20 |
Claims
1. A variable footwear support system, comprising: at least one
rheological body within a sole of an article of footwear, wherein
the sole is formed of a resilient material and wherein the
rheological body contains a rheological fluid having a viscosity
that is variable in the presence of an energy field; control
electronics adapted to generate at least one control signal; and at
least one E/M field generator coupled to the control electronics
and arranged operably proximate to at least one rheological body,
wherein the at least one E/M field generator is adapted to generate
an energy field corresponding to a control signal generated by the
control electronics upon the rheological body.
2. The variable footwear support system of claim 1, wherein at
least one rheological body is within at least one of a heel region,
a forefoot region, a medial region, and a lateral region of the
sole of the article of footwear.
3. The variable footwear support system of claim 1, wherein at
least one rheological body comprises a bladder chamber defining a
cavity adapted to contain the rheological fluid.
4. The variable footwear support system of claim 1, wherein at
least one rheological body comprises: a plurality of bladder
chambers each defining a cavity adapted to contain the rheological
fluid; and at least one conduit coupled to at least two of the
plurality of bladder chambers such that a cavity of one of the
plurality of bladder chambers is in fluid communication with a
cavity of at least one other of the plurality of bladder chambers,
wherein at least one E/M field generator is operably proximate to
at least one conduit.
5. The variable footwear support system of claim 1, wherein at
least one rheological body includes a foam matrix impregnated with
the rheological fluid.
6. The variable footwear support system of claim 1, wherein the
rheological fluid comprises electrorheological fluid and the E/M
field generator comprises at least one electrode adapted to
generate an electric field upon the electrorheological fluid
contained within the rheological body.
7. The variable footwear support system of claim 1, wherein the
rheological fluid comprises magnetorheological fluid and the E/M
field generator comprises at least one electromagnet adapted to
generate a magnetic field upon magnetorheological fluid contained
within the rheological body.
8. The variable footwear support system of claim 1, further
comprising at least one sensor adapted to detect at least one of an
intensity and a frequency of foot-falls of the wearer of the
article of footwear and generate sensor data based upon the
detecting, wherein the control electronics is adapted to receive
the generated sensor data and generate at least one control signal
corresponding to the received sensor data.
9. The variable footwear support system of claim 8, wherein the at
least one sensor and the control electronics are within the same
article of footwear.
10. The variable footwear support system of claim 8, wherein the at
least one sensor and the control electronics are within different
articles of footwear.
11. The variable footwear support system of claim 8, wherein the at
least one sensor includes at least one of a pressure sensor, an
accelerometer, and a contact switch.
12. The variable footwear support system of claim 8, wherein the
control electronics is further adapted to store the received sensor
data.
13. The variable footwear support system of claim 8, wherein the
control electronics is further adapted to output the received
sensor data to a host computer.
14. The variable footwear support system of claim 1, further
comprising a user interface coupled to the control electronics,
wherein the user interface is adapted to be engaged by a wearer of
the article of footwear to receive user input; and the control
electronics is adapted to receive the user input and generate at
least one control signal corresponding to the received user
input.
15. The variable footwear support system of claim 14, wherein the
user interface is integrated within the article of footwear.
16. The variable footwear support system of claim 14, further
comprising a handheld computing device, wherein the user interface
is integrated within the handheld computing device.
17. The variable footwear support system of claim 14, wherein the
handheld computing device is coupled to the control electronics via
at least one of a wired connection and a wireless connection.
18. The variable footwear support system of claim 1, wherein the
control electronics is adapted to generate at least one control
signal corresponding to one or more of a plurality of different
physical activities of a wearer of the article of footwear, the
plurality of different physical activities including at least two
of walking, jogging, running, hiking, climbing stairs, playing
basketball, and playing tennis.
19. The variable footwear support system of claim 1, wherein the at
least one control signal is generated at least in part upon a
detected physical characteristic of the gait of a wearer of the
article of footwear.
20. The variable footwear support system of claim 19, wherein the
detected physical characteristic includes at least one of a rate, a
magnitude of the gait of the wearer of the article of footwear.
21. A variable footwear support method, comprising: receiving
sensor data from at least one sensor, the sensor data describing at
least one of an intensity and a frequency of footfalls of a wearer
of an article of footwear; generating at least one control signal
based on the received sensor data; and energizing at least one E/M
field generator based on the at least one generated control signal,
wherein each energized E/M field generator generates an energy
field upon at least one rheological body arranged within a sole of
an article of footwear, wherein the sole is formed of a resilient
material and wherein the at least one rheological body contains a
rheological fluid having a viscosity that is variable in the
presence of the generated energy field.
22. The variable footwear support method of claim 21, wherein the
at least one sensor and the at least one rheological body are
within the same article of footwear.
23. The variable footwear support method of claim 21, wherein the
at least one sensor and the at least one rheological body are
within different articles of footwear.
24. A variable footwear support method, comprising: receiving user
input from a user interface; generating at least one control signal
based on the received user input; and energizing at least one E/M
field generator based on the at least one generated control signal,
wherein each energized E/M field generator generates an energy
field upon at least one rheological body arranged within a sole of
an article of footwear, wherein the sole is formed of a resilient
material and wherein the at least one rheological body contains a
rheological fluid having a viscosity that is variable in the
presence of the generated energy field.
Description
[0001] This application also claims the benefit of U.S. Provisional
Application No. 60/678,548 filed May 6, 2005, which is incorporated
in its entirety herein by reference.
BACKGROUND
[0002] 1. Field of Invention
[0003] Embodiments disclosed herein generally relate to articles of
footwear having electronically controllable cushioning systems that
are low power, low cost, and fast responding.
[0004] 2. Discussion of the Related Art
[0005] Modern running and walking footwear are a combination of
many elements each having a specific function which aids in the
overall ability of the footwear to withstand many miles of running
or walking, while providing cushioning and support for the foot and
leg. Articles of athletic footwear are divided into two general
parts, an upper and a sole. The upper is designed to snugly and
comfortably enclose the foot, while the sole must provide traction,
protection and a durable wear surface. It is often desirable to
provide the footwear with a midsole having a layer of resilient,
cushioning materials for enhanced protection and shock absorption
when the heel strikes the ground during the stride of the wearer.
This is particularly true for training or jogging footwear designed
to be used over long distances or over a long period of time. These
cushioning materials must be soft enough to absorb the shock
created by the foot strike and firm enough not to "bottom out"
before the impact of the heel strike is totally absorbed.
[0006] The typical running stride involves the runner landing on
the lateral, posterior edge of the footwear in the heel region
followed by pronation toward the medial side as the foot continues
through its stride. As footstrike continues, the foot stops
pronating and begins to supinate as the foot rocks forward so that
the foot reaches a neutral position at midstance. From midstance,
the foot rocks forward to the forefoot region where toe-off occurs
at the ball and front of the foot. Toe-off typically involves the
toes on the medial side of the foot pushing off the running surface
as the foot leaves the ground to begin a new cycle.
[0007] Pronation involves the rolling of the foot from its lateral,
posterior side to its inner, medial side. Although pronation is
normal and necessary to achieve proper foot positioning, it can be
a source of foot and leg injuries for runners who over-pronate. The
typical runner who over-pronates lands on the outer lateral side of
the heel in a supinated position and then rolls medially across the
heel toward the inner side of the footwear beyond a point which may
be considered normal. While some amount of pronation is helpful in
decreasing pressure and stress experienced by the leg, excessive
pronation can cause stress on various joints, bones and soft
tissue. Supinating, which involves rolling of the foot from the
medial to the lateral side, while not as common as over pronating,
can also cause foot and leg injuries if it is excessive.
[0008] Conventional running and walking footwear are designed to
provide the user with the maximum amount of available cushioning
tend to sacrifice footwear stability by using a midsole cushioning
system that is too soft and has too much lateral flexibility for a
person who over-pronates or requires some form of motion control.
The lateral flexibility and deformation of traditional cushioning
materials contribute to the instability of the subtalar joint of
the ankle and increase the runner's tendency to over pronate. This
instability has been cited as one of the causes of "runner's knee"
and other such athletic injuries. As a result, over-pronators
generally do not use contemporary shoes specifically designed for
maximum cushioning, but instead use heavier, firmer footwear, or
footwear having motion control devices specifically designed to
correct physical problems such as excessive pronation. Motion
control devices limit the amount and/or rate of subtalar joint
pronation immediately following foot strike.
[0009] Various ways of resisting excessive pronation or instability
of the subtalar joint have been proposed and incorporated into
running footwear as motion control devices. In general, these
devices have been fashioned by modifying conventional footwear
components, such as the heel counter, and/or the midsole cushioning
materials. Conventional solutions provide a constant stiffness and
fixed level of support that presses against the medial side of the
foot, limiting internal rotation of the ankle. Examples of such
devices include: U.S. Pat. No. 5,046,267, to Kilgore et al.; U.S.
Pat. No. 5,155,927, to Bates et al.; and U.S. Pat. No. 5,367,791,
to Gross et al.
[0010] Footwear systems have been designed that employ fluid
bladder systems for providing desirable resilience characteristics.
For example, U.S. Pat. App. Pub. No. 2002/0053146, entitled
"Article of footwear with a motion control device," which is hereby
incorporated by reference, discloses a bladder system for footwear
in which fluid flow from one chamber to another chamber within the
shoe is used to define the stiffness characteristic of the shoe.
This system is superior to typical shoes in that it provides
stiffness that varies based upon how pressure is applied by the
user. On the other hand, this system has the significant drawback
of being fixed by its physical design, not allowing variation in
how the stiffness varies based upon differences in the physical
activity being performed by the user. Users of athletic shoes often
engage in a number of physical activities including walking,
running, jumping, and landing. Due to its physical design, however,
the aforementioned fluid bladder system accommodates all of these
diverse physical activities with the same physical response. In
this way it provides a fixed stiffness characteristic for the
wearer in much the same way that a typical shoe does.
[0011] Other attempts have been made to provide support and comfort
in an article footwear by incorporating bladders in fluid
communication with each other within a sole. Examples of such
devices are found in U.S. Pat. App. Pub. No. 2002/0053146 as well
as in U.S. Pat. No. 4,183,156 to Rudy, which is incorporated herein
by reference; U.S. Pat. No. 4,446,634 to Johnson et al.; U.S. Pat.
No. 4,999,932 to Grim; Austrian Patent No. 200,963 to Schutz et
al.; and HYDROFLOW, by BROOKS Sports, Inc. As with U.S. Pat. App.
No. 2002/0053146, these prior art systems do not allow for
variation in how the stiffness varies based upon differences in the
physical activity being performed by the user. In this way these
devices provide a fixed stiffness characteristic for the wearer in
much the same way that a typical shoe does. Moreover, while such
prior art systems, act to moderate the amount of motion control,
they do so using heavy, bulky footwear, which is weighted down by
support features, and designed for the severe over-pronator.
SUMMARY
[0012] Several embodiments disclosed herein address the needs above
as well as other needs by providing a variable support footwear
using electrorheological (ER) or magnetorheological (MR)
fluids.
[0013] One embodiment exemplarily disclosed herein provides a
variable footwear support system that includes at least one
rheological body within a sole of an article of footwear, control
electronics within the article of footwear, and at least one E/M
field generator coupled to the control electronics and arranged
operably proximate to at least one rheological body. The sole is
formed of a resilient material and the rheological body contains a
rheological fluid having a viscosity that is variable in the
presence of an energy field. The control electronics is adapted to
generate at least one control signal. The at least one E/M field
generator is adapted to generate an energy field corresponding to a
control signal generated by the control electronics upon the
rheological body.
[0014] Another embodiment exemplarily disclosed herein provides a
variable footwear support method that includes steps of receiving
sensor data from at least one sensor, generating at least one
control signal based on the received sensor data, and energizing at
least one E/M field generator based on the at least one generated
control signal. The sensor data describes at least one of an
intensity and a frequency of foot-falls of a wearer of an article
of footwear. Each energized E/M field generator is adapted to
generate an energy field upon at least one rheological body
arranged within a sole of an article of footwear. The sole is
formed of a resilient material and wherein the at least one
rheological body contains a rheological fluid having a viscosity
that is variable in the presence of the generated energy field.
[0015] Yet another embodiment exemplarily disclosed herein provides
a variable footwear support method that includes steps of receiving
user input from a user interface, generating at least one control
signal based on the received user input, and energizing at least
one E/M field generator based on the at least one generated control
signal. Each energized E/M field generator is adapted to generate
an energy field upon at least one rheological body arranged within
a sole of an article of footwear. The sole is formed of a resilient
material and wherein the at least one rheological body contains a
rheological fluid having a viscosity that is variable in the
presence of the generated energy field.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and other aspects, features and advantages of
several embodiments disclosed herein will be more apparent from the
following more particular description thereof, presented in
conjunction with the following drawings.
[0017] FIG. 1 illustrates an exploded view of an article of
footwear incorporating a bladder system according to one
embodiment;
[0018] FIG. 2 illustrates a top view of one embodiment of a bladder
system; and
[0019] FIG. 3 illustrates a top view of one embodiment of a
cushioning system.
[0020] Corresponding reference characters indicate corresponding
components throughout the several views of the drawings. Skilled
artisans will appreciate that elements in the figures are
illustrated for simplicity and clarity and have not necessarily
been drawn to scale. For example, the dimensions of some of the
elements in the figures may be exaggerated relative to other
elements to help to improve understanding of various embodiments
exemplarily disclosed herein. Also, common but well-understood
elements that are useful or necessary in a commercially feasible
embodiment are often not depicted in order to facilitate a less
obstructed view of these various embodiments exemplarily disclosed
herein.
DETAILED DESCRIPTION
[0021] The following description is not to be taken in a limiting
sense, but is made merely for the purpose of describing the general
principles of exemplary embodiments. The scope of the invention
should be determined with reference to the claims.
[0022] FIG. 1 illustrates an exploded view of an article of
footwear incorporating a bladder system filled with MR or ER fluid,
according to one embodiment. FIG. 2 illustrates a top view of the
bladder system shown in FIG. 1, in accordance with one
embodiment.
[0023] Referring to FIG. 1, an article of athletic footwear 80 is
comprised of an upper 75 for covering a wearer's foot and a sole
assembly 85. The upper 75 can include a sock liner 70 can be placed
therein. The sole assembly 85 includes the bladder system 10, a
midsole layer 60, and an outsole layer 65.
[0024] The outsole layer 65 is adapted to engage the ground and is
secured to at least a portion of midsole layer 60. Depending upon
the material forming the midsole layer 60 and upon the performance
demands of the shoe 80, midsole layer 60 can also form part or all
of the ground engaging surface so that part or all of outsole layer
65 can be omitted. The bladder system 10 is located in the heel
region 81 of footwear 80 and is incorporated into the midsole layer
60 by any conventional technique such as foam encapsulation or
placement in a cut-out portion of a foam midsole. A suitable foam
encapsulation technique is disclosed in U.S. Pat. No. 4,219,945 to
Rudy, hereby incorporated by reference.
[0025] As illustrated in FIGS. 1 and 2, the bladder system 10
includes a lateral bladder chamber 12, a medial bladder chamber 14,
and a central bladder chamber 16. The central bladder chamber 16 is
positioned between, and is in fluid communication with lateral and
medial bladder chambers 12, 14, respectively, via conduits 27.
According to various embodiments, a rheological fluid (e.g., an
electrorheological (ER) fluid that exhibits a change in its ability
to flow or shear in the presence of an electric field or a
magnetorheological (MR) fluid that exhibits a change in its ability
to flow or shear in the presence of a magnetic field, respectively)
is contained within the bladder chambers and conduits of the
bladder system 10. Accordingly, a bladder chamber containing
rheological fluid, or a conduit through which the rheological fluid
flows, may be referred to as a "rheological body."
[0026] As disclosed in U.S. Pat. No. 6,852,251, which is
incorporated in its entirety herein by reference, ER fluids are
colloidal suspensions whose rheological properties can be varied
through the application of an external electric field, enabling
variable viscosity under electronic control. Under the application
of a field of the order of 1-2 kV/mm, an ER fluid can exhibit a
solid-like behavior, such as the ability to transmit sheer stress.
This transformation from liquid-like to solid-like behavior can be
very fast, on the order of 1 to 10 ms, and is reversible when the
electric field is removed. U.S. Pat. No. 5,271,858 relates to an ER
fluid that includes esters and amides of an acid of phosphorus and
is also incorporated in its entirety herein by reference.
[0027] As disclosed in U.S. Pat. No. 5,906,767, which is
incorporated in its entirety herein by reference, MR fluids undergo
a change in viscosity in the presence of a magnetic field. MR
fluids typically include magnetic-responsive particles dispersed or
suspended in a carrier fluid. In the presence of a magnetic field,
the magnetic-responsive particles become polarized and are thereby
organized into chains of particles or particle fibrils within the
carrier fluid. The chains of particles act to increase the apparent
viscosity or flow resistance of the overall materials resulting in
the development of a solid mass having a yield stress that must be
exceeded to induce onset of flow of the MR fluid. The force
required to exceed the yield stress is referred to as the "yield
strength". In the absence of a magnetic field, the particles return
to an unorganized or free state and the apparent viscosity or flow
resistance of the overall materials is correspondingly reduced.
Such absence of a magnetic field is referred to herein as the
"off-state". MR fluids are also described in U.S. Pat. Nos.
5,382,373, 5,578,238, 5,599,474 and 5,645,752, each of which are
incorporated in their entirety herein by reference. These patents
mention that phosphate esters, in general, can be used as
surfactants in MR fluids. U.S. Pat. No. 5,645,752 describes an
exemplary MR fluid that includes a polyoxyalkylated alkylaryl
phosphate ester.
[0028] Referring next to FIG. 2, the bladder system 10 includes one
or more electro/magnetic (E/M) field generators disposed operably
proximate to respective ones of the conduits 27 that, when
energized, generate electronically controllable electric or
magnetic fields upon fluid flowing within respective conduits 27.
Exemplary regions in which E/M field generators can be disposed
operably proximate to conduits 27 are identified at cross-hatched
areas 28. When ER fluid is contained within the bladder system 10,
each E/M field generator may be provided as a single electrode or
multiple electrodes (e.g., disposed in a ring arrangement around a
corresponding conduit 27 or in any other physical arrangement). In
one embodiment, an electrode-based E/M field generator may be
provided as described in U.S. Pat. No. 6,378,558, which is
incorporated in its entirety herein by reference, wherein an E/M
field generator includes a coaxial cylinder of electrodes or
arrangement of parallel plates between which ER fluid flows. Due to
an electric voltage applied to the electrodes, the viscosity of the
ER fluid located between the electrodes and therewith the
through-flow resistance through the valve gap is controllable,
thereby modulating the rate of fluid flow. Similarly, when MR fluid
is contained within the bladder system 10, each E/M field generator
may be provided as a single electromagnet or multiple
electromagnets (e.g., disposed in a ring arrangement around a
corresponding conduit 27 or in any other physical arrangement). In
one embodiment, the flow of MR fluid can be controlled as described
in U.S. Pat. No. 5,452,745, which is incorporated in its entirety
herein by reference, wherein the flow of MR fluid is controlled by
energizing electromagnets located near or around a valve or orifice
such that a magnetic field is applied to the MR fluid as it flows
past. The interaction between ferromagnetic particles in the MR
fluid increases the effective viscosity of the MR fluid. This
change in viscosity causes the resistance to the fluid flowing
through the valve or orifice to increase, and causes a proportional
change in the inlet pressure to the valve, thereby slowing or
stopping the fluid flow.
[0029] As used herein, an "ER valve" or an "MR valve" (generically
referred to as an "E/M valve") refers to the combination of a
conduit 27 filled with ER fluid or MR fluid, respectively, and a
corresponding E/M field generator operably proximate to the conduit
27 (e.g., within a respective cross-hatched area 28). Accordingly,
depending on the degree to which an E/M field generator is
energized, an E/M valve can be fully "opened" (e.g., as when an E/M
field generator is not energized), fully "closed" (e.g., as when an
E/M field generator is fully energized), or partially opened/closed
(i.e., modulated).
[0030] Bladder chambers 12, 14, 16 and conduits 27 may be formed of
a thermoplastic elastomeric barrier film such as polyester
polyurethane, polyether polyurethane, a cast or extruded ester
based polyurethane film having a shore "A" hardness of 80-95, e.g.,
Tetra Plastics TPW-250. Other suitable materials can be used such
as those disclosed in the '156 patent to Rudy. Specific examples of
thermoplastic urethanes that may be used to form the bladder
chambers 12, 14, 16 and conduits 27 include urethanes such as
Pellethane.TM., (a trademarked product of the Dow Chemical Company
of Midland, Mich.), Elastollani.RTM. (a registered trademark of the
BASF Corporation) and ESTANE.RTM. (a registered trademark of the
B.F. Goodrich Co.), all of which are either ester or ether based
and have proven to be particularly useful. Thermoplastic urethanes
based on polyesters, polyethers, polycaprolactone and polycarbonate
macrogels can also be employed. Further suitable materials also
include thermoplastic films containing crystalline material, such
as disclosed in U.S. Pat. Nos. 4,936,029 and 5,042,176 to Rudy,
which are incorporated by reference; polyurethane including a
polyester polyol, such as disclosed in U.S. Pat. No. 6,013,340 to
Bonk et al., which is incorporated by reference; or a multi-layer
film formed of at least one elastomeric thermoplastic material
layer and a barrier material layer formed of a copolymer of
ethylene and vinyl alcohol, such as disclosed in U.S. Pat. No.
5,952,065 to Mitchell et al., which is incorporated by reference.
In one embodiment, bladder chambers 12, 14, 16 and conduits 27 are
integrally formed of first and second sheets of elastomeric barrier
film. In another embodiment, bladders 12, 14, 16 are formed from
generally transparent or translucent elastomeric film to enable
visibility through the bladders of the ER or MR fluid within.
[0031] U.S. Pat. No. 4,183,156 ('156) and U.S. Pat. No. 4,219,945
('945) to Marion F. Rudy, the contents of which are hereby
expressly incorporated by reference, describe conventional welding
techniques which can be used to form the shapes of the bladder
chambers 12, 14, 16 and conduits. As disclosed in the '156 and '945
patents, sheet 40 and 45 can be welded to one another to define the
side walls of bladder chambers 12, 14, 16 and conduits, as well as
interior welds (not shown in the drawings) within the bladder
chambers to maintain the bladder chambers in a generally flat
configuration. In another embodiment, bladder chambers 12, 14, 16
and conduits are formed using conventional blow-molding
techniques.
[0032] Bladder chambers 12, 14, 16 can be sealed to hold MR or ER
fluid. The fluid can be placed in the bladder through an inflation
tube (not shown) in a conventional manner by means of a needle or
hollow welding tool. After being filled with fluid, the bladder can
be sealed at the juncture of the bladder and inflation tube, or by
the hollow welding tool around the inflation point on the inflation
tube.
[0033] In one embodiment, one or more additional conduits (i.e.,
valves) with fixed flow characteristics can be used in combination
with the aforementioned E/M valves. For example, a one-way valve
with fixed flow characteristics may be used in serial combination
with an E/M valve to prevent backflow through any passages that are
intended to only allow flow in one direction. These one-way valves
may be set to open when the differential pressure between two
bladders reaches a predetermined level.
[0034] In one embodiment, pressure sensors (not shown) may be
provided within one or more bladder chambers to detect pressure
levels, pressure changes within and/or pressure differentials
between bladder chambers of the bladder system 10 and generate
corresponding sensor data. In one embodiment, the pressure sensors
may be electronically connected to control electronics (not shown)
on board the shoe 80 (e.g., incorporated within the midsole layer
60. In one embodiment, the control electronics of each shoe may
include a local microprocessor that is electrically connected to
each pressure sensor and is adapted to receive the sensor data.
Software running upon the microprocessor can process the received
sensor data to perform conditional logic based upon the magnitudes
of and/or changes in magnitude of the sensor data. In one
embodiment, each E/M field generator is energized to generate an
electric or magnetic field based upon electric current output by
power electronics. In one embodiment, the power electronics is
connected to the control electronics, wherein the control
electronics controls the level of electric current output by the
power electronics. In one embodiment, the control electronics
controls the power electronics in accordance with the received
sensor data. Having generally described an active suspension shoe
in accordance with numerous embodiments of the present invention
above, an exemplary process by which E/M field generators are
selectively energized will now be described.
[0035] Prior to the heel of a user touching down, a nominal
pressure in the bladder chambers is detected by one or more
pressure sensors provided within central bladder chamber 16.
Information within the sensor data generated by such a pressure
sensor is transmitted to the microprocessor and saved by software
running on the microprocessor as a nominal pressure variable (e.g.,
P_NOMINAL). Initial striking of the heel increases the pressure
within the central bladder chamber 16. The increase in pressure is
detected by one or more pressure sensors within one or more bladder
chambers in the heel as a result of chamber deformation. In one
embodiment, the total amount of information within the sensor data
generated by each pressure sensor is transmitted to the
microprocessor and saved by software running on the microprocessor
as a single pressure variable (e.g., P_STRIKE), regardless of how
many pressure sensors generate the pressure data. In another
embodiment, information within the sensor data generated by each
pressure sensor is transmitted to the microprocessor and is saved
by software running on the microprocessor as multiple pressure
variables, one for each bladder chamber within which a pressure
sensor is provided (e.g., P_STRIKE_LEFT, P_STRIKE_CENTER, and
P_STRIKE_RIGHT). Based upon the absolute and/or relative pressure
levels within the one or more chambers as detected by the one or
more pressure sensors, the microprocessor controls the power
electronics to modify the level of current output to one or more of
the E/M field generators. The magnitude of current output to each
E/M field generator affects the magnitude of the electric or
magnetic field that is generated within the conduit 27. The
magnitude of the electric or magnetic field that is generated
within the conduit 27 affects the flow rate of ER or MR fluid
through the conduit 27 between bladder chambers. Accordingly, by
controlling the level of current that is output by the power
electronics, the flow rate of ER or MR fluid through the conduit 27
between bladder chambers can be controllably adjusted.
[0036] By controllably adjusting the flow rate of ER or MR fluid
into and/or out of certain bladder chambers, varying degrees of
cushioning and support within the sole assembly 85 can be achieved.
For example, by allowing faster fluid flow from the central bladder
chamber 16 to the medial bladder chamber 14 than is allowed from
the central bladder chamber 16 to the lateral bladder chamber 12,
greater support is provided to the wearer on the medial side of the
shoe 80 and greater cushioning is provided to the wearer on the
lateral side of the shoe 80. Alternately, by allowing faster fluid
flow from the central bladder chamber 16 to the lateral bladder
chamber 12 than is allowed from the central bladder chamber 16 to
the medial bladder chamber 14, greater support is provided to the
wearer on the lateral side of the shoe 80 and greater cushioning is
provided to the wearer on the medial side of the shoe 80. Similar
control methods can be provided between chambers in the heel and
chambers in the forefoot of the shoe. For example, allowing faster
fluid flow from a medial bladder chamber in the heel of the shoe 80
to a medial bladder chamber in the forefoot of the shoe 80 than
fluid flow from a lateral bladder chamber in the heel of the shoe
80 to a lateral bladder chamber in the forefoot of the shoe 80 will
result in greater cushioning at the medial heel and greater support
at the lateral heel. Alternately, allowing faster fluid flow from a
lateral bladder chamber in the heel of the shoe 80 to a lateral
bladder chamber in the forefoot of the shoe 80 than fluid flow from
a medial bladder chamber in the heel of the shoe 80 to a medial
bladder chamber in the forefoot of the shoe 80 will result in
greater cushioning at the lateral heel and greater support at the
medial heel.
[0037] In addition to varying the ratio of flow rates among the
chambers on the lateral side with flow rates among chambers on the
medial side, the total rate between flow from multiple heel
chambers to multiple forefoot chambers may be controlled to control
the overall cushioning on the heel of the wearer. Thus, both the
total cushioning level as well as the relative cushioning ratio
between lateral and medial sides can be varied by the
microprocessor controlling the current to the E/M field
generators.
[0038] In one embodiment, a user may engage a user interface to
manually enter user input, the user input adapted to adjust
stiffness/cushioning characteristics of the sole assembly 85 and/or
modify the function by which the control electronics opens, closes,
or otherwise modulates the E/M valves. In one embodiment, the user
interface may be incorporated within the shoe 80 and be
electrically connected to the control electronics. In another
embodiment, the user interface may be incorporated within a
handheld computing device (e.g., a personal digital assistant
(PDA), a handheld wireless telephone, a handheld portable gaming
system, a handheld portable music player, or the like) adapted to
communicate with the control electronics (e.g., via a wireless
connection between the shoe 80 and the handheld computing device).
In one embodiment, each shoe 80 includes wireless transceiver
connected to the control electronics, wherein the wireless
transceiver is adapted to enable bidirectional communication with a
remote processor aboard the handheld computing device. Accordingly,
each wireless transceiver may be enabled using a Bluetooth protocol
and support interaction with any Bluetooth-enabled remote
processor. Moreover, the remote processor can be provided with
Bluetooth support and local software configured to interface with,
control, and configure the control electronics of each shoe 80.
[0039] In one embodiment, the control electronics of each shoe
opens, closes, or otherwise modulates each E/M valve in accordance
with one or more control algorithms. Accordingly, the user
interface may be engaged by the user and receive user input that
identifies one or more control algorithms, selected by the user, to
be implemented by the control electronics. For example, if the user
is going jogging, the user can engage the user interface (e.g., via
a menu system supported by the user interface) to select one or
more control algorithms optimized for jogging. The control
electronics of each shoe may then open, close, or otherwise
modulate one or more E/M valves of a respective shoe in accordance
with the one or more selected control algorithms optimized for
jogging. In the example above, if the user wanted to walk after
jogging, the user can engage with the user interface to select one
or more different control algorithms (e.g., algorithms optimized
for walking as opposed to jogging). The control electronics of each
shoe may then open, close, or otherwise modulate one or more E/M
valves of a respective shoe in accordance with the one or more
selected control algorithms optimized for walking.
[0040] In one embodiment, the handheld computing device includes
local memory for storing a plurality of selectable control
algorithms. Once selected by the user via the user interface, the
control algorithms can be uploaded to the control electronics of
each shoe (e.g., via the wireless transceiver). In such an
embodiment, the control electronics of each shoe may include a
local microprocessor that is adapted to receive the one or more
uploaded control algorithms, store the one or more received control
algorithms in a local memory, and output control signals to the
power electronics, wherein the output control signals are adapted
to open, close, or otherwise modulate the predetermined E/M valves
based on the one or more selected control algorithms.
[0041] In another embodiment, the control electronics of each shoe
includes a local memory adapted to store a plurality of selectable
control algorithms. Accordingly, once user input is received from a
user engaging the user interface, the handheld computing device
outputs a corresponding control command to the control electronics
of each shoe (e.g., via the wireless transceiver), wherein the
control command identifies one or more control algorithms stored
within the local memory. In such an embodiment, the control
electronics of each shoe may include a local microprocessor that is
adapted to receive the control command and output control signals
to the power electronics, wherein the output control signals are
adapted to open, close, or otherwise modulate the predetermined E/M
valves based on the one or more control algorithms identified by
the control command.
[0042] In yet another embodiment, the control electronics of each
shoe may include a local microprocessor that is adapted to receive
sensor data and/or timing data and output control signals to the
power electronics, wherein the output control signals are adapted
to open, close, or otherwise modulate the predetermined E/M valves
based on physical activities the user is currently engaged in
and/or based on particular gait characteristics of the user.
[0043] A plurality of different control algorithms can be stored
either within the handheld computing device or within the local
memory of the control electronics aboard the shoe itself. In one
embodiment, control algorithms can be optimized with respect to
different activities such as walking, jogging, running, basketball,
tennis, hiking, climbing stairs, and the like, and combinations
thereof. In addition, control algorithms can be optimized with
respect to certain aspects of a physical activity (e.g., optimized
with respect to running for speed, running for distance, jumping
for height, pivoting dexterity, and the like). Moreover, control
algorithms can be optimized with respect to certain ground surfaces
(e.g., optimized with respect to jogging on asphalt, running on
grass, walking on sidewalks, hiking on trails, and the like).
Further, control algorithms can be optimized with respect to the
gait styles of individual users. For example, a particular user
might have one control algorithm optimized with respect to hiking
on trails, a different control algorithm optimized with respect to
running on asphalt, a different control algorithm optimized with
respect to playing tennis, and a different control algorithm
optimized with respect to walking on city sidewalks.
[0044] A user who does not over-pronate generally will put less
initial pressure on the lateral side of the footwear and will force
less fluid, if any, into bladder chambers 16 and 14 during a
typical stride as compared to an over-pronator having the same
striking force. For such a user, a control algorithm implemented
within a shoe may, for example, send less current to the valve on
the lateral side of the footwear than to the valves on the medial
side of the footwear, allowing more fluid flow from the chamber on
the lateral side because extra support is not needed to counter
over pronation. For such a user, more support is thereby provided
on the medial side. After the landing phase of running is over,
equilibrium or initial pressure between the bladders is
re-established before the next heel strike, either by opening the
valves fully (by dropping and/or eliminating the current to the
electrodes or electromagnets) or through the use of passive one-way
valves that allows fluid to pass back into the central and lateral
bladder chambers. In one embodiment, the recovery time may be
approximately 1 second. The recovery time can be controlled by the
control electronics based upon how much current is sent to the E/M
valves during the recovery period.
[0045] A user who does over-pronate generally will put more initial
pressure on the lateral side of the footwear and will force more
fluid into bladder chambers 16 and 14 during a typical stride as
compared to a non-over-pronator having the same striking force. For
such a user, the control algorithm implemented within the shoe may,
for example, send more current to the valve on the lateral side of
the footwear than to the valves on the medial side of the footwear,
allowing less fluid flow from the chamber on the lateral side
because extra support is needed to counter over-pronation. For such
a user, more support is thereby provided on the lateral side. After
the landing phase of running is over, equilibrium or initial
pressure between the bladders is re-established before the next
heel strike, either by opening the valves fully (by dropping and/or
eliminating the current to the electrodes or electromagnets) or
through the use of passive one-way valves that allows fluid to pass
back into the central and lateral bladder chambers. The recovery
time can be controlled by the control electronics based upon how
much current is sent to the E/M valves during the recovery
period.
[0046] FIG. 3 illustrates a top view of one embodiment of a
cushioning system.
[0047] Referring to FIG.3, a cushioning system 100 can extend along
the length of footwear 80 (e.g., with one or more bladder chambers
in the heel region and one or more bladder chambers in the forefoot
region). Cushioning system 100 includes a bladder system 110.
Bladder system 110 is constructed the same as bladder system 10,
with similar components labeled with like numbers as bladder system
10, but in the 100 series of numbers. Accordingly, bladder chambers
112, 114 and 116 function in the same way as bladder chambers 12,
14 and 16, respectively.
[0048] Cushioning system 100 also includes chambers 152 and 156 in
the forefoot region 150 to provide lateral stability and increased
performance when running or jumping. Bladder chambers 152 and 156
extend along the forefoot region of footwear 80 and are formed of
the same material as bladder chambers 12, 14 and 16. In one
embodiment, bladder chambers 152 and 156 may be in fluid
communication with each other by one or more conduits 127 with one
or more E/M field generators operably proximate to one or more
respective conduits 127 (e.g., disposed within cross-hatched areas
158) to selectively stiffen one side of the forefoot of footwear 80
during a foot stride. Bladder chambers 152 and 156 may also be in
fluid communication with one or more heel chambers by one or more
conduits 127 with one or more E/M field generators operably
proximate to one or more respective conduits 127 (e.g., disposed
within cross-hatched areas 158) to selectively stiffen one of the
forefoot or heel region of the shoe.
[0049] In one embodiment, the E/M valves can be effectively
controlled when the one or more control algorithms are implemented
in conjunction with sensed pressure differentials between chambers
in the determination of when and how strongly to energize the
valves. Based upon the pressure differential between lateral and
medial chambers and/or the pressure differential between a forefoot
and heel chambers, fluid flow rates can be controlled using the E/M
field generators to selectively stiffen various regions of the shoe
including the lateral heel, the medial heel, the lateral forefoot,
and/or the medial forefoot.
[0050] It will be appreciated that a bladder system can be
constructed with more or less chambers than shown in FIGS. 2 and 3
depending upon the degree of control desired. For example, a
bladder system may include a single heel chamber and a single
forefoot chamber, both filled with MR or ER fluid, a single conduit
in fluid communication with the single heel and forefoot chambers
to allow fluid to flow between the chambers when pressure is
applied, one or more E/M field generators arranged operably
proximate to the conduit to influence the viscosity of the MR or ER
fluid that flows past.
[0051] In such a two-bladder chamber embodiment, when pressure is
applied to the sole such that the heel chamber experiences greater
pressure than that forefoot chamber, fluid will flow from the heel
to the forefoot and the rate of the flow can be electronically
controlled by energizing the one or more E/M field generators. If
the rate is slow as a result of a high viscosity being induced in
the MR or ER fluid, the heel will be stiff. If the rate is fast as
a result of low viscosity being induced in the MR or ER fluid, the
heel will be compliant. If the rate is controlled to be somewhere
between slow and fast, the heel will have an intermediate level of
compliance. The E/M field generators can be energized at varying
levels during a single stride based upon sensor readings for highly
controllable stiffness profiles. For example, a pressure sensor
within the heel can sense pressure levels within the heel chamber
and generate sensor data. The output sensor data is used by a local
microprocessor of the control electronics to output a control
signal, wherein the control signal is adapted to modulate power
applied to the one or more E/M magnets based upon the sensed
pressure levels. In this way, the stiffness of the heel can be
varied independently of the stiffness of the forefoot during a
single stride based upon one or more pressure sensor readings
during the execution of the stride.
[0052] In the two-bladder chamber embodiment described above, when
pressure is applied to the sole such that the forefoot chamber
experiences greater pressure than that heel chamber, fluid will
flow from the forefoot to the heel, the rate of the flow being
electronically controllable by energizing the electrodes or
electromagnets. If the rate is slow as a result of a high viscosity
being induced in the MR or ER fluid, the forefoot will be stiff. If
the rate is fast as a result of low viscosity being induced in the
MR or ER fluid, the forefoot will be compliant. If the rate is
controlled to be somewhere between slow and fast, the forefoot will
have an intermediate level of compliance. The E/M field generators
can be energized at varying levels during a single stride based
upon sensor readings for highly controllable stiffness profiles.
For example, a pressure sensor within the forefoot can sense
pressure levels within the forefoot chamber and generate sensor
data. The output sensor data is used by the local microprocessor to
output a control signal, wherein the control signal is adapted to
modulate power applied to the one or more E/M magnets based upon
the sensed pressure levels. In this way, the stiffness of the
forefoot can be varied independently of the stiffness of the heel
during a single stride based upon one or more pressure sensor
readings during the execution of the stride.
[0053] In an exemplary implementation, a control algorithm
optimized for a walking activity can be set such that one or more
E/M field generators are energized at a high level when the
pressure in the heel is greater than the pressure in the forefoot,
thereby providing a stiff heel. Further, the control algorithm
optimized for the walking activity can be set such that one or more
E/M field generators are energized at a low level when the pressure
in the forefoot is greater than the pressure in the heel, thereby
providing a compliant forefoot. In another exemplary
implementation, a control algorithm optimized for a jumping
activity can be set such that one or more E/M field generators are
energized at a low level when the pressure in the heel is greater
than the pressure in the forefoot, thereby providing a compliant
heel for soft landings. Further, the control algorithm optimized
for the jumping activity can be set such that one or more E/M field
generators are energized at a high level when the pressure in the
forefoot is greater than the pressure in the heel, thereby
providing a stiff forefoot for firm takeoffs.
[0054] In one embodiment, the user can engage a user interface
(e.g., by accessing a button or dial) to alter the current flowing
to one or more E/M field generators during some portion of a
stride. For example, when the user is out for a slow walk, he or
she may desire a firm heel and thus adjust the control algorithms
to provide a stiff heel. Later, that same user may decide to jog
and may want additional cushioning in the heel and thus press a
button or turn a knob to alter the control algorithm to provide a
more compliant heel. As described above, the user interface may be
mounted on the shoe itself or may be incorporated within a handheld
computing device that wirelessly communications with the shoes. In
one embodiment, the user interface can be engaged to adjust both
shoes (i.e., left and right) simultaneously because, in most
instances, the user will want both shoes to be provided with the
same cushioning characteristics. In another embodiment, the user
interface can be engaged to each shoe individually.
[0055] In one embodiment, the current flowing to one or more E/M
field generators may be altered automatically, without the need for
user to engage a user interface. In such an embodiment, each shoe
includes one or more sensors adapted to detect the intensity and
frequency of foot-falls and generate corresponding sensor data and
a local microprocessor adapted to receive usage data from the one
or more sensors, to determine a present usage mode based on the
received sensor data, and to adjust the stiffness/cushioning
characteristics in real time to optimize performance with respect
to the determined present usage mode.
[0056] In one embodiment, one or more sensors may be provided as an
accelerometer (e.g., a solid state accelerometer from Analog
Devices). In another embodiment, one or more sensors may be
provided as a pressure sensor (e.g., provided within the midsole
layer 60 of a shoe). In another embodiment, one or more sensors may
be provided as a contact switch or pressure switch that can be
closed with each footfall (note, contract/pressure switches would
give frequency, but not strength, of each footfall).
[0057] Using the sensor data from sensors incorporated within each
shoe, the local microprocessor controls current applied to the E/M
field generators to adjust the stiffness of the resilient underside
to achieve improved performance and/or comfort in the present
athletic task. To achieve this, the local microprocessor performs
real-time analysis on the usage data to determine the present usage
mode of the user (e.g., to determine whether the user is walking,
jogging, running, etc.). In one embodiment, the local
microprocessor performs real-time analysis on the usage data to
determine particular stages of a determined usage mode (e.g., to
determine whether the user is about to jump, whether the user is
currently jumping and is in the air, etc.). The local
microprocessor can then adjust the stiffness/cushioning
characteristics in real time to optimize performance with respect
to the identified present usage mode. For example, upon determining
that a user is about to jump (based upon usage data), the local
processor can stiffen the shoe's resilient underside. Then, when
the shoe is airborne, the local microprocessor can predict that a
landing is imminent and un-stiffen the shoes resilient
underside.
[0058] The local microprocessor can differentiate between usage
modes such as walking, jogging, and running based on sensor data
indicating, for example, a time delay between foot falls and/or the
strength of foot falls, as generated by the sensors such as those
described above. The more rapid the sequence of foot falls, the
faster the user is moving. The stronger the pressure (or
acceleration) signals at each foot fall, the more intense the
physical activity. Based upon the sensor data, the local
microprocessor can adjust the stiffness of the resilient underside.
The shoe can have a number of pre-programmed mappings (as described
previously) that the user can select between so that the modulation
for a given physical activity is what the particular user
desires.
[0059] In many sports (e.g., basketball, volleyball, etc.) players
are continually jumping and landing. They may want to achieve
maximum height and be optimally cushioned upon return. When an
athlete jumps, the muscles in his leg, ankle, and foot stiffen to
provide maximum thrust. When an athlete lands from a jump, the
muscles in his leg, ankle, and foot relax to provide optimized
cushioning. Similarly, the bladder system described above can be
actively controlled to adjust the stiffness of the resilient
underside by energizing one or more E/M field generators at the
moment of jumping, to stiffen the resilient underside when the
user's muscles stiffen, and then relax the resilient underside when
the user lands, to provide a highly cushioned landing. An exemplary
process by which such stiffening and cushioning can be achieved
will now be described in greater detail below. The local
microprocessor may continually poll the sensors in a given shoe.
When the microprocessor detects a sensor reading that has exceeded
a particular threshold value of downward pressure on the shoe, the
microprocessor can infer that a jump is in progress and can
energize one or more appropriate E/M field generators (e.g., in one
or more portions of the shoe) to a high level of current to provide
for maximum thrust during the launching stage of the jump. When the
microprocessor detects a sensor reading that indicates the pressure
has suddenly dropped to near-zero, the microprocessor can infer
that the shoe is now airborne and that the next impact seen by the
shoe will be a landing. The microprocessor can then drop the
current applied to one or more E/M field generators (e.g., in one
or more portions of the shoe) to optimally cushion the impending
landing. In this way, the user can have real-time modification of
the stiffness of the resilient underside of his/her shoe,
accommodating differently for the liftoff and landing phases of a
jump.
[0060] Each stride of a running athlete can be treated as a jump
(e.g., liftoff, airborne, then landing) by the local
microprocessor. In this way, the jumping method described in the
paragraph above could be used not just for vigorous jumps in a
basketball game but also during every stride of general running. In
such a mode the degree of change in stiffness is likely varied at a
lesser level than in vigorous jumping, but the basic method is the
same.
[0061] In one embodiment, each shoe has its own local
microprocessor and can be independently adjusted. In another
embodiment, the two microprocessors have a wireless link between
them, to allowing the shoes to coordinate in real time. For
example, sensor data and/or timing data and/or status data of one
shoe can be exchanged with the other shoe to coordinate jumping,
landing, and other stride-based changes to the resilience of the
other shoe.
[0062] As discussed above, each shoe may include one or more
sensors and a microprocessor. In another embodiment, each shoe may
include a wireless link enabling wireless communication of data
between shoes and/or wireless communication of data with a user
interface incorporated within a handheld computing device. In
another embodiment, usage mode algorithms may be implemented in
conjunction with the local microprocessor to determine current
usage modes of the user.
[0063] In one embodiment, the local microprocessor, using the
sensors as described above, can log data describing the physical
activity of the user. The logged data may include information
describing the number of foot falls, the time between foot falls,
the rate of foot falls, the intensity at the launch point of a
stride or jump, the intensity upon landing from a launch or jump,
and/or the airtime between launching and landing a jump. The logged
data can then be used by a user to better understand his
performance and possibly work to improve. For example, an athlete
may use logged data to work to minimize the intensity of force upon
landing from jumps by better cushioning with his/her knees. In
another example, an athlete may use the logged data to work to
lengthen his or her stride for more efficient running. In another
example, an athlete may use the logged data (e.g., describing
pressure differentials between lateral and medial sides of a foot)
to determine and document over-pronating or under-pronating events.
In one embodiment, data logged by the local microprocessor of a
shoe can be output to a host computer (e.g., a personal computer, a
handheld computer such as a PDA, etc.) by a temporary wire
connection or wireless link.
[0064] In one embodiment, the logged data can be output to a
computer at the end of a session (e.g., after a user has finished
walking, jogging, running, jumping, etc.). In another embodiment,
the logged data can be output to a computer in real time as the
sensors generate the sensor data. For example, and in one exemplary
implementation, a user may be doing an aerobics workout and sensor
data describing their footfall can be output to a host computer
running an aerobics workout software package. The aerobics workout
software package may be adapted to moderate the workout of the user
in real-time based upon the generated sensor data. Accordingly,
aerobics workout software package may quantify the user's
performance and ask the user to increase their rate, increase their
force, or make any other modifications to tune the aerobic workout.
The aerobics workout software package might also identify poor gate
posture (e.g., over-pronation) by displaying a warning graphic or
emitting a warning sound through user interface of the host
computer. In another exemplary implementation, a user may be
engaged with an entertainment software package (e.g., a video game)
and sensor data describing their footfall can be output to a host
computer running an entertainment software package. Accordingly,
the sensor data may be used as an interfacing means of controlling
characters (i.e., Avatars) within an environment supported by the
entertainment software package.
[0065] According to numerous embodiments exemplarily described
above, the stiffness/cushioning characteristics of the resilient
underside portion of a shoe can be electrically modified based upon
the physical activity of the wearer so as to further enhance user
performance. In one embodiment, an athletic shoe can be designed in
which the stiffness of the sole assembly can be adjusted, under
electronic control, based upon the type and intensity of the
physical activity being performed by the wearer. In another
embodiment, the stiffness of the sole assembly can be adjusted
using one or more low-power E/M field generators having a fast
response period enabling a wide range of stiffness values to be
commanded with rapid response using low power electronics. In
another embodiment, each shoe may include one or more sensors and
control electronics coupled to the one or more sensors, the control
electronics adapted to automatically adjust the stiffness of the
sole assembly appropriately during periods of activity and thereby
enhance comfort and/or performance of the wearer during the period
of activity.
[0066] In one embodiment, the fluid is present within hollow
chambers within the resilient material, flowing through specified
orifices when pressure is applied by the user to the heel or
forefoot. For example, pressure applied on the heel will force the
fluid to flow forward in the shoe, towards the forefoot. Pressure
on the forefoot will force the fluid to flow backwards in the shoe,
towards the heel. The same method could be employed for side to
side motion, fluid flowing left and right accordingly. One, more,
or all, of these flow directions can be incorporated together.
Accordingly, the viscosity of the fluid can be altered under
electronic control. This allows the rate of fluid flow between
chambers to be modulated by an electric current or magnetic field
selectively applied to the fluid. The degree of the electric and/or
magnetic field will impact the degree of viscosity and thus the
stiffness level in the shoe. This provides electronic control of
the compliance felt by the wearer of the shoe during physical
activity. The current and/or magnetic field can be applied to the
entire mass of fluid, or in preferred embodiments, only to the area
of an orifice (or orifices) through which the fluid must flow. In
such embodiments, the resilience of the shoe undersurface would be
controllable as follows: When the viscosity is high, the fluid
flowing from a chamber to which pressure has been applied will be
slowed, and the material will therefore be less resilient (more
stiff). When the viscosity is low, the fluid will flow more freely
from a chamber to which pressure has been applied and the material
will be more resilient (less stiff). A plurality of individually
controllable E/M field generators can be used for independent
control of various portions of the shoe underside. For example the
heel stiffness and forefoot stiffness could be independently
controlled. The control of the viscosity of electro-rheological and
magneto-rheological fluids may be accomplished while consuming a
low amount of power relative to the amount of stiffness modulation
achieved, therefore consuming very little energy during normal
operation. In another embodiment, the aforementioned bladder system
10 (or 110) can be replaced by, or supplemented with, ER or MR
fluid impregnated in a foam matrix (e.g., using technology obtained
from Lord Corporation). Accordingly, a foam matrix impregnated with
a rheological fluid may be collectively referred to as a
"rheological body." Therefore, the stiffness of the impregnated
foam matrix can be modulated using one or more of the
aforementioned E/M field generators operably proximate to the
impregnated foam matrix.
[0067] A cushioning system disclosed herein provides varying
amounts cushioning to the wearer as well as varying amounts of
resistance to front-back motion and side-to-side motion depending
on the severity of such motion while walking, running, or
participating in other athletic activities. Accordingly, the
present invention introduces electronically controllable cushioning
and electronically controllable side-to-side and front-to-back
resilience using electrorheological or magnetorheological fluids
within the sole of the shoe, the fluids changing their viscosity
under the control of an electronic circuit based upon the changing
activities and/or desires or the user. This system can therefore be
controlled to provide optimum cushioning for a given activity,
while simultaneously providing the needed amount of side-to-side or
front-to-back motion control by stiffening a portion of the
footwear in response to the individual behavior. In one embodiment,
a bladder system filled with ER or MR fluid is used, the bladder
system being constructed with narrow passageways surrounded by
embedded electrodes and/or electromagnets. The narrow passageways
act as electronically controllable flow valves under the control of
an electronic circuit, the flow valves regulating the flow of the
fluid from one chamber of the bladder system to another. By
modulating the current flowing to the electrodes and/or
electromagnets, the cushioning and/or side-to-side motion control
of the shoe can be adjusted in real time to meet the changing needs
of the wearer. The system provides electronically controllable
comfort and control in a light weight, low power, fast responding,
and very compact construction that has no moving electromechanical
components such as motors that can wear out, make noise, draw too
much power, and/or respond too slowly. One embodiment of the
present invention utilizes lightweight bladders filled with ER or
MR fluid for the dual purposes of cushioning and motion
control.
[0068] An article of footwear designed accordance with one
embodiment of the present invention comprises a bladder system
positioned within the sole of the footwear, the bladder system
housing ER fluid or MR fluid. The system includes at least first
and second bladder chambers in fluid communication with each other.
A first valve is positioned between the first bladder chamber and
the second bladder chamber, the valve being comprised of a fluid
passageway with one or more electrodes or electromagnets positioned
operably proximate to (e.g., near or around) the passageway such
that when the electrodes or electromagnets are energized by control
electronics they impart an electric field or magnetic field
respectively upon the fluid flowing through the passageway. When
the fluid used in the footwear design is an ER fluid, the valve is
designed using one or more electrodes that impart an electric field
on the fluid moving through the passageway. When the fluid used in
the footwear design is an MR fluid the valve is designed using one
or more electromagnets that impart a magnetic field upon the fluid
moving through the passageway. In this way the valve under
electronic control of control electronics can vary the flow rate of
the ER or MR fluid flowing through the passageway between the first
and second bladder chamber and thereby modulate the shock
cushioning and/or side-to-side support provided by footwear. In one
embodiment, the control electronics include a microprocessor that
runs firmware code, the firmware code controlling the current
flowing to the valve to modulate the shock cushioning and/or
side-to-side support provided by the sole of the shoe. In another
embodiment, the footwear also includes one or more sensors
connected to the microprocessor such that the activity of the
wearer can be monitored during use and the cushioning and/or
side-to-side support provided by the ER or MR fluid can be
modulated based upon the monitored activity. In another embodiment,
the microprocessor collects data from the one or more sensors and
then adjusts the current to the valves in accordance with the data
collected from the sensors. In another embodiment, the
microprocessor is also connected to a timer or clock and uses data
from the timer or clock to adjust the current to the valves. Based
upon the level at which the first valve is energized, fluid will
flow at a certain rate from the first bladder chamber to the second
bladder chamber when pressure is applied by the wearer. This flow
rate will define the effective cushioning of the sole and/or the
effective side-to-side support provided by the sole to the wearer.
In some embodiments, the same first valve can be used to control
flow in both directions (in a first direction from the first
bladder chamber to the second bladder chamber and in a second
direction from the second bladder chamber to the first bladder
chamber). In other embodiments a second valve can be used to
control the flow in the second direction. The second valve can be a
passive valve that is not electronically controlled or the second
valve can be an active valve that is electronically controlled. In
some embodiments, the valves are one-way valves that only allow
flow in one direction. In some embodiments, more than two valves
can be used, a plurality of the valves with electronic control of
electrodes or electromagnets, the plurality of valves increasing
the controllability of the cushioning and/or side-to-side support
provided by the footwear.
[0069] In one embodiment, the bladder system housing MR or ER fluid
is positioned is within a heel region of the sole and the first
bladder chamber is disposed adjacent one side of the heel region, a
third bladder chamber is disposed adjacent the other side of the
heel region and the second bladder chamber is disposed between the
first and third bladder chambers in fluid communication therewith.
A first valve under electronic control is placed between the first
bladder chamber and the second bladder chamber and a second valve
under electronic control is positioned between the third bladder
chamber and the second bladder chamber. The valves are modulated by
control electronics such that fluid flows more easily from the
second chamber to one of the first chamber or the third chamber.
When fluid flows more easily to the first chamber, more support is
shifted to that side of the heel. When fluid flows more easily to
the third chamber, more support is shifted to that side of the
heel. The rate of fluid flow, which can be modulated independently
of the ratio between the fluid flows, controls the affects overall
cushioning feel of the central heel region.
[0070] Embodiments disclosed herein also describe one or more
bladder chambers in the heel region of the sole as well as one or
more bladder chambers within the forefoot regions of the sole, the
sole and forefoot chambers being in fluid communication with each
other through electronically controllable valves as described
previously. When pressure is applied to the heel region that is
greater than the pressure applied to the forefoot region, fluid is
forced from one or more chambers in the heel into one or more
chambers in the forefoot, the rate of the flow being modulated by
one or more electronically controlled valves between the heel
region and the forefoot region. In this way, the stiffness of the
heel can be modulated by the electronics that control the valves
and thereby affect that cushioning and support on the heel of the
wearer. When pressure is applied to the forefoot region that is
greater than the pressure applied to the heel region, fluid is
forced from one or more chambers in the forefoot into one or more
chambers in the heel, the rate of the flow being modulated by one
or more electronically controlled valves between the forefoot
region and the heel region. In this way the stiffness of the
forefoot region can be modulated by the electronics that control
the valves and thereby affect the cushioning and support on the
forefoot of the wearer.
[0071] In some embodiments, multiple chambers are used in the
forefoot and/or heel, the multiple regions including, for example,
a left region, central region, and right region, multiple
electronically controllable valves used to independently vary the
flow into and out of the regions thereby allowing independent
control of the cushioning and support and in the regions. In this
way the left, central, or right side of the heel can be made more
or less stiff independently of the other regions. Similarly the
left, central, or right side of the forefoot can be made more or
less stiff independently of the other regions. In one embodiment,
the electronic valves and chambers are positioned such that a first
valve modulates flow between a left heel chamber and a left
forefoot chamber, a second valve modulates flow between a central
forefoot chamber and a central heel chamber, and a third valve
modulates flow between a right heel chamber and a right forefoot
chamber. In this embodiment, control electronics regulate the
relative flow rates within all three valves to vary the
forward-back and left-right cushioning and support on the foot
based upon the activity of the wearer.
[0072] While embodiments have been disclosed herein by means of
specific examples and applications thereof, numerous modifications
and variations could be made thereto by those skilled in the art
without departing from the scope of the invention set forth in the
claims.
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