U.S. patent application number 11/042161 was filed with the patent office on 2005-06-23 for dynamically-controlled cushioning system for an article of footwear.
This patent application is currently assigned to NIKE, Inc.. Invention is credited to Potter, Daniel R., Schrock, Allan M..
Application Number | 20050132617 11/042161 |
Document ID | / |
Family ID | 24204183 |
Filed Date | 2005-06-23 |
United States Patent
Application |
20050132617 |
Kind Code |
A1 |
Potter, Daniel R. ; et
al. |
June 23, 2005 |
Dynamically-controlled cushioning system for an article of
footwear
Abstract
An article of footwear with a dynamically-controlled cushioning
system is disclosed. The cushioning system includes a sealed,
fluid-filled bladder formed with a plurality of separate cushioning
chambers, and a control system. The control system, which includes
a CPU, pressure sensors and valves, controls fluid communication
between the chambers to dynamically adjust the pressure in the
cushioning chambers for various conditions such as the activity
that the footwear is used in, the weight of the individual and the
individual's running style. Certain adjustments can be made while
the footwear is in use.
Inventors: |
Potter, Daniel R.; (Forest
Grove, OR) ; Schrock, Allan M.; (Portland,
OR) |
Correspondence
Address: |
BANNER & WITCOFF, LTD.
1001 G STREET, N.W.
WASHINGTON
DC
20001-4597
US
|
Assignee: |
NIKE, Inc.
Beaverton
OR
|
Family ID: |
24204183 |
Appl. No.: |
11/042161 |
Filed: |
January 26, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11042161 |
Jan 26, 2005 |
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10202202 |
Jul 23, 2002 |
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10202202 |
Jul 23, 2002 |
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09552163 |
Apr 18, 2000 |
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6430843 |
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Current U.S.
Class: |
36/132 ;
36/29 |
Current CPC
Class: |
A43B 13/206 20130101;
A43B 3/0005 20130101; A43B 13/203 20130101 |
Class at
Publication: |
036/132 ;
036/029 |
International
Class: |
A43B 013/20 |
Claims
1. An article of footwear having a dynamically-controlled
cushioning system, the system comprising: a control system attached
to the article of footwear; a fluid-filled bladder received within
a sole of the article of footwear, said bladder being closed to
ambient air, and having a plurality of separate cushioning chambers
in fluid communication with each other, each said chamber having: a
pressure detector in communication with said control system for
detecting pressure in said chamber; and a regulator in
communication with, and actuated by, said control system for
regulating the level of fluid communication of the chamber with
other chambers; said control system modulating the level of fluid
communication between said chambers by actuating said regulators in
a predetermined sequence to maintain a predetermined pressure in
each chamber.
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. A method of dynamically controlling a pressure in a cushioning
system of an article of footwear, comprising: operating a regulator
to allow the entry of fluid from a fluid reservoir of a cushioning
system into a first chamber of the cushioning system or the exit of
fluid from the first chamber of the cushioning system to the fluid
reservoir; and operating an actuator to change a volume of the
fluid reservoir to expel fluid from the fluid reservoir into the
first chamber or draw fluid from the first chamber into the fluid
reservoir.
10. The method recited in claim 9, further comprising operating a
second regulator to allow the entry of fluid from a second chamber
of the cushioning system into the first chamber or the exit of
fluid from the first chamber to the second chamber.
11. The method recited in claim 9, further comprising: receiving
input from a user; and operating the regulator based upon the data
input.
12. The method recited in claim 11, wherein the data input
corresponds to one or more of an anticipated use of the article of
footwear, a weight of the user, and a pronation characteristic of a
user.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a cushioning system for an article
of footwear. In particular, the cushioning system includes a
fluid-filled bladder having separate reservoir chambers. The
chambers are in fluid communication with each other, and a control
device dynamically-distributes and regulates pressure within the
chambers based on sensed and user input criteria.
BACKGROUND OF THE INVENTION
[0002] Articles of footwear, such as the modern athletic shoes, are
highly refined combinations of many elements which have specific
functions, all of which work together for the support and
protection of the foot. Athletic shoes today are as varied in
design and purpose as are the rules for the sports in which the
shoes are worn. Tennis shoes, racquetball shoes, basketball shoes,
running shoes, baseball shoes, football shoes, walking shoes, etc.
are all designed to be used in very specific, and very different,
ways. They are also designed to provide a unique and specific
combination of traction, support and protection to enhance
performance.
[0003] Moreover, physical differences between wearers of a specific
shoe, such as differences in each user's weight, foot size, shape,
activity level, and walking and running style, make it difficult to
economically optimize a mass produced shoe's performance to a
particular individual.
[0004] Closed-celled foam is often used as a cushioning material in
shoe soles and ethylene-vinyl acetate copolymer (EVA) foam is a
common material. In many athletic shoes, the entire misdeal is
comprised of EVA. While EVA foam can be cut into desired shapes and
contours, its cushioning characteristics are limited. One of the
advantages of fluid, in particular gas, filled bladders is that gas
as a cushioning component is generally more energy efficient than
close-celled foam. Cushioning generally is improved when the
cushioning component, for a given impact force, spreads the impact
force over a longer period of time, resulting in a smaller impact
force being transmitted to the wearer's body. Thus, fluid-filled
bladders are routinely used as cushions in such shoes to increase
shoe comfort, enhance foot support, decrease wearer fatigue, and
reduce the risk of injury and other deleterious effects. In
general, such bladders are comprised of elastomeric materials which
are shaped to define at least one pressurized pocket or chamber,
and usually include multiple chambers arranged in a pattern
designed to achieve one or more of the above-stated
characteristics. The chambers may be pressurized with a variety of
different mediums, including air, various gases, water, or other
liquids.
[0005] Numerous attempts have been made to improve the desirable
characteristics associated with fluid-filled bladders by attempting
to optimize the orientation, configuration and design of the
chambers. In U.S. Pat. No. 2,080,469 to Gilbert, bladders have been
constructed with a single chamber that extends over the entire area
of the sole. Alternatively, bladders have included a number of
chambers fluidly interconnected with one another. Examples of these
types of bladders are disclosed in U.S. Pat. No. 4,183,156 to Rudy,
and U.S. Pat. No. 900,867 to Miller. However, these types of
bladder constructions have been known to flatten and "bottom out"
when they receive high impact pressures, such as experienced in
athletic activities. Such failures negate the intended benefits of
providing the bladder.
[0006] In an effort to overcome this problem, bladders have been
developed with the chambers fluidly connected to each other by
restricted openings. Examples of these bladders are illustrated in
U.S. Pat. No. 4,217,705 to Donzis, U.S. Pat. No. 4,129,951 to
Petrosky, and U.S. Pat. No. 1,304,915 to Spinney. However, these
bladders have tended to either be ineffective in overcoming the
deficiencies of the non-restricted bladders, or they have been too
expensive to manufacture.
[0007] Bladders are also disclosed in patents that include a number
of separate chambers that are not fluidly connected to each other.
Hence, the fluid contained in any one chamber is precluded from
passing into another chamber. One example of this construction is
disclosed in U.S. Pat. No. 2,677,906 to Reed. Although this design
obviates "bottoming out" of the bladder, it also requires each
chamber to be individually pressurized, thus, the cost of
production can be high.
[0008] Another problem with these known bladder designs is that
they do not offer a way for a user to individually adjust the
pressure in the chambers to optimize their shoes' performance for
their particular sport or use. Several inventors have attempted to
address this issue by adding devices that make the chamber pressure
adjustable. For example, U.S. Pat. No. 4,722,131 to Huang discloses
an open system type of air cushion. The air cushion has two
cavities, with each cavity having a separate air valve. Thus, each
cavity can be inflated to a different pressure by pumping in or
releasing air as desired.
[0009] However, in such systems, a separate pump is required to
increase the pressure in the cavities. Such a pump would have to be
carried by the user if it is desired to inflate the cavities away
from home, inconveniencing the user. Alternatively, the pump could
be built into the shoe, adding weight to the shoe and increasing
the cost and complexity. Additionally, open systems tend to lose
pressure rapidly due to diffusion through the bladder membrane or
leakage through the valve. Thus, the pressure must be adjusted
often.
[0010] A significant improvement over this type of design is found
in U.S. Pat. No. 5,406,719 to Potter ("Potter"), the disclosure of
which is hereby incorporated by reference. Potter controllably
links a plurality of chambers within a bladder with at least one
variable-volume fluid reservoir such that the pressure in each
chamber may be manually adjusted by a user modulating selected
control links and the volume of the reservoir. The chambers may be
oriented to allow chambers of different pressure in areas
corresponding with different areas of the foot. For example, to
correct over-pronation, pressure in chambers located on the medial
side of the shoe can be selectively increased by the user.
[0011] The system in Potter is also closed to the atmosphere.
Accordingly, pressure in the system may be higher than ambient
pressure. Moreover, dirt and other debris cannot enter the
system.
[0012] However, since Potter requires manual adjustment, the
pressure in the various chambers cannot be dynamically modulated or
adjusted during use of the shoe. Accordingly, considerable user
effort is required to "fine tune" the performance of the shoe for a
particular use and individual, and such adjustments must be re-done
by the user when the sport or activity changes.
[0013] In recent years, consumer electronics have become
increasingly more reliable, durable, light-weight, economical, and
compact. As a result, the basic elements of a miniaturized
fundamental control system, such as a central processing unit,
input/output device, data sensing devices, power supplies, and
micro actuators are now commercially available at reasonable
prices. Such systems are small, light-weight, and durable enough to
be attached to an article of footwear, such as a shoe, without
compromising the shoe's performance.
[0014] A control system to permit dynamic adjustment to the
pressure in a single chamber cushioning bladder is disclosed in
U.S. Pat. No. 5,813,142 to Demon ("Demon"), the disclosure of which
is hereby incorporated by reference. In Demon, a plurality of
single-chamber independent bladders are secured within a shoe and
in fluid communication with ambient air through fluid ducts. A
control system monitors the pressure in each bladder. Each duct
includes a flow regulator, that can be actuated by the control
system to any desired position such that the fluid duct can be
modulated to any position between and including being fully open
and fully closed. The control system monitors the pressure in each
of the bladders, and opens the flow regulator as programmed based
on detected pressure in each bladder.
[0015] Despite the benefits of using an on-board control system to
dynamically modulate bladder pressure in each bladder of Demon, the
specific implementation of this concept taught by Demon adversely
affects performance of the bladder as a cushion, thereby
significantly limiting the commercial viability of the concept. For
example, the plurality of bladders in Demon each have their own
reservoir, which is preferably ambient air. Accordingly, the static
pressure in each bladder cannot exceed ambient pressure. In
practice, it is desirable for the static pressure in the bladder to
be higher than ambient pressure. Such higher pressure urges the
bladder to return to its neutral position following impact,
prevents bottoming out of the bladder, and improves the cushioning
ability, or feel, of the bladder.
[0016] Also, like other bladder configurations that exhaust to
ambient air, the bladders in Demon are prone to collect dirt and
other debris through their exit/inlet port, particularly when a
user wears the shoe outdoors, such as when running on wet pavement.
Moreover, Demon neither teaches nor suggests dynamically-modulating
pressure between at least two chambers within the same bladder
thereby allowing the control system to optimize performance within
all areas of the bladder without compromising the integrity of the
system, and without requiring multiple bladders within the same
shoe.
[0017] Accordingly, despite the known improvements to bladder
designs, there remains a need for a cost effective, closed-system,
multi-chamber bladder that allows pressure in each chamber to be
dynamically distributed, adjusted, and regulated between each
chamber based on real-time sensed and user input criteria to
optimize the desirable characteristics of the bladder while the
shoe is being worn by its user.
[0018] In addition to other benefits that will become apparent in
the following disclosure, the present invention fulfills this
need.
SUMMARY OF THE INVENTION
[0019] The present invention is a cushioning system for an article
of footwear that includes a fluid-filled bladder having a plurality
of separate sealed cushioning chambers. Separate reservoir chambers
can also be placed in fluid communication with the cushioning
chambers. The chambers are in fluid communication with each other,
and a control device dynamically-distributes and regulates pressure
within the chambers based on sensed and user input criteria by
modulating the level of fluid communication between each of the
chambers and, if installed, the reservoir chambers.
[0020] In a preferred embodiment, the control system includes a
central processing unit (CPU), pressure sensing devices, and
electronically-actuated, CPU-commanded valves that work in
conjunction to control fluid communication between the chambers,
and if desired, with a variable volume reservoir to optimize
performance of the cushioning system for a particular wearer and
activity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a cross-sectional view through a shoe of the
present invention, incorporating a bladder in accordance with a
preferred embodiment of the present invention.
[0022] FIG. 2A is a top plan view of a bladder of the present
invention;
[0023] FIG. 2B is a cross-sectional view taken along line 2B-2B of
FIG. 2A;
[0024] FIG. 3 is a cross-sectional view taken along line 3-3 of
FIG. 2A;
[0025] FIG. 4 is a top plan view of another embodiment of bladder
of the present invention;
[0026] FIG. 5 is a cross-sectional view taken along line 5-5 of
FIG. 4;
[0027] FIG. 6 is a cross-sectional view taken along line 6-6 of
FIG. 4;
[0028] FIG. 7 is a cross-sectional view taken along line 7-7 of
FIG. 4;
[0029] FIG. 8 is a schematic side view of a portion of a shoe,
illustrating control knobs; and,
[0030] FIG. 9 is a schematic view of a control system in accordance
with the present invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
[0031] A cushioning system 8 for use in an article of footwear 9 is
disclosed in FIGS. 1 to 9. The cushioning system 8 includes a
bladder 10 having a plurality of chambers 12a-j in fluid connection
with each other at plenum 20 with each chamber entrance having an
individually operable regulator, such as a modulating valve 29. A
control system monitors pressure in the chambers and dynamically
operates the regulators to change the level of fluid communication
between the chambers, thereby changing their respective pressures,
to optimize performance of the bladder while the article of
footwear is being worn.
[0032] A. Bladder Assembly
[0033] In a preferred embodiment of the invention (FIGS. 1-3), a
bladder 10 is a thin, elastomeric member defining a plurality of
chambers 12 or pockets. The chambers 12 are pressurized to provide
a resilient support. Bladder 10 is particularly adapted for use in
the midsole of the shoe, but could be included in other parts of
the sole or have applicability in other fields of endeavor. In a
midsole, bladder would preferably be encapsulated in an elastomeric
foam 11 (FIG. 1). As is well known in the art, the foam need not
fully encapsulate the bladder. Moreover, the bladder can be used to
form the entire midsole or sole member.
[0034] Preferably, bladder 10 is composed of a resilient, plastic
material including polyester polyurethane, polyether polyurethane,
such as a cast or extruded ester base polyurethane film having a
shore "A" harness of 80 to 95 (e.g., Tetra Plastics TPW-250) which
is inflated with hexafluorethane (e.g., Dupont F-116) or sulfer
hexafluoride. Other suitable materials and fluids having the
requisite characteristics can be used, such as those disclosed in
U.S. Pat. No. 4,183,156, to Rudy, which is incorporated by
reference. Among the numerous thermoplastic urethanes which are
particularly useful in forming the film layers are urethanes such
as Pellethane, (a trademarked product of the Dow Chemical Company
of Midland, Mich.), Elastollan (a registered trademark of the BASF
Corporation) and ESTANE (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 could
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 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.
Further, the bladders 10 can also be fabricated by blow molding or
vacuum forming techniques.
[0035] As a bladder midsole, bladder 10 defines a forefoot support
14, a heel support 16, a medial segment 18 interconnecting the two
supports. Chambers 12 each define a support portion 13 and a
channel portion 15. The support portions 13 are raised to provide a
resilient resistance force for an individual's foot. The channel
portions 15 are relatively narrow in comparison to the support
portions 13, and are provided to facilitate the unique
manufacturing process described below. Forefoot and heel supports
14, 16 are comprised primarily of support portions so that a
cushioned support is provided under the plantar areas receiving the
greatest impact pressure during use of the shoe. Channel portions
15, while extending partially into the forefoot and heel supports
14, 16, are concentrated in medial segment 18.
[0036] In forefoot support 14, the support portions 13 are arranged
parallel to one another in a lateral direction across the sole to
provide a suitable flexibility in the forefront sole portion and to
apportion the cushioned resistance as desired. Nonetheless,
different chamber arrangements could be used.
[0037] In the illustrated athletic shoe, forefoot portion 14
includes chambers 12a-g. Chambers 12a-g are of varying sizes, with
the chambers nearer to the front (e.g., chamber 12a) defining a
larger volume than those closer to medial segment 18 (e.g., chamber
12g). As will be described more fully below, all of the chambers
12a-g are initially pressurized to the same level. However, due to
the different volumes of chambers, they will each possess a unique
resistance. In other words, the chambers with smaller volumes will
provide a firmer support than the chambers with larger volumes,
because the movement of a side wall defining a smaller chamber will
involve a greater percentage of the volume of air being displaced
than the same movement in a larger chamber. Hence, for example,
chamber 12g will provide a firmer support than chamber 12a.
[0038] Channel portions 15a-g of chamber 12a-g, in general extend
rearwardly from support portions 13a-g to plenum 20 located
transversely across medial segment 18. Channel potions 15 are
essential to the unique manufacturing process described in U.S.
Pat. No. 5,406,719 to Potter, the disclosure of which is hereby
incorporated by reference. Preferably, channel portion 15 are
provided along the sides of forefoot portion 14, so that the needed
cushioned support is not taken from the central portions of the
sole where it is most needed. In the illustrated embodiment,
channel portions 15 for adjacent chambers 12 are placed on opposite
sides of the sole. Of course, other arrangements could be used.
[0039] Additionally, in forefoot portion 14, void chambers 22 are
defined adjacent the more rearward chambers 12e-g. A void chamber
22 is a chamber that has not been pressurized. Void chambers 22
exist because of the need to limit the volume of the chambers 12e-g
to provide a certain firmness in these portions of the bladder.
Nevertheless, void spaces are not essential to the present
invention and could be eliminated. In a midsole usage (FIG. 1), the
resilient foam 11 would fill in the void space and provide ample
support to the user's foot.
[0040] In a manner similar to forefoot support 14, heel support 16
includes a row of chambers 12h-j. In the illustrated bladder, three
chamber 12h-j are provided. The support portions 13h-j of these
chambers are arranged parallel to one another in a generally
longitudinal direction across the sole to ensure that all three
chambers provide cushioned support for all impacts to the user's
heel. Nonetheless, as with the forefoot portion, different chamber
arrangements could be used. Additionally, each chamber 12h-j
includes a channel portion 15 which extends from the support potion
13 to plenum 20. In the same manner as in forefoot support 14,
chambers 12h-j provide different resistance forces in the support
of the heel. For example, the smaller chamber 12h will provide a
firmer resistance than the larger chambers 12i or 12j. The firmer
chamber 12h would act as a medial post in reducing pronation.
[0041] Chambers 12h-j are initially pressurized in the same
internal pressure as chambers 12a-g. One preferred example of
internal pressure for athletic footwear is 30 psi. Of course, a
wide variety of other pressures could be used. Alternatively,
chambers 12a-j can be pressurized to different internal pressures.
As one preferred example, the pressure in the forefoot portion
could be set at 35 psi, while the heel portion could be pressurized
to 30 psi. The particular pressure in each section though will
depend on the intended activity and size of the chambers, and could
vary widely from the given examples. Finally, by individually
controlling the control valves during inflation, individual
chambers can be inflated to different pressures.
[0042] In the fabrication of the bladder 10, two elastomeric sheets
24, 26 are preferably secured together to define the particular
weld pattern illustrated in FIGS. 2-3; that is, that the two
opposed sheets 24, 26 are sealed together to define wall segments
28 arranged in a specific pattern (FIG. 2A). The welding is
preferably performed through the use of radio frequency welding,
the process of which is well known. Of course, other methods of
sealing the sheets could be used. Alternatively, the bladder could
also be made by blow molding, vacuum forming, or injection molding,
the processes of which are also well known.
[0043] When the bladder is initially welded (or otherwise formed),
the plenum 20 is fluidly coupled with all of the channel portions
of the chambers 12a-j, so that all of the chambers are in fluid
communication with one another. Each channel portion includes a
modulating valve 29a-k that is preferably electronically actuated
and can be commanded open, closed, or to an infinite position
between these two points, thereby regulating change in pressure
into and out of its respective chamber 12a-j.
[0044] An injection pocket 32 is provided to supply bladder 10 with
a quantity of fluid. Injection pocket 32 is in fluid communication
with a pressurizing channel 34, which in turn is fluidly coupled to
plenum 20 (FIGS. 2A and 2B). Chambers 12a-j, therefore, are
initially pressurized by inserting a needle (not shown) through one
of the walls defining an injection pocket 32, and injecting a
pressurized fluid therein. The pressurized fluid flows from pocket
32, through channel 34, into plenum 20, through channel portions
15a-j and into the supporting portion 13a-j of all of the chambers
12a-j. Once the predetermined quantity of fluid has been inserted
into the bladder, or alternatively when the desired pressure has
been reached, channel 34 is temporarily clamped. Preferred fluids
include, for example, hexafluorethane, sulfur hexafluoroide,
nitrogen, air, or other gases such as disclosed in the
aforementioned '156, '945, '029, or '176 patents to Rudy, or the
'065 patent to Mitchell et al.
[0045] Walls 24, 26 are welded, or otherwise heat sealed, forming a
seal around plenum 20 (FIG. 1) to completely seal the chambers in
fluid communication with each other at plenum 20. Once the seal has
been made, the needle is removed and channel 34 remains on
uninflated void area. Hence, as can be readily appreciated, this
unique independent chamber design can be fabricated by the novel
process in a easy, quick, and economical manner.
[0046] B. Control System Assembly
[0047] Referring specifically to FIG. 9, the control system 200 is
shown and includes a central processing unit ("CPU") 202, power
source 204, a plurality of pressure sensing devices 206a-k, and the
modulating valves 29a-k. Preferably, the system also includes an
input device 208, but it is not required.
[0048] One pressure sensing device 206a-k is positioned adjacent to
each modulating valve 29a-k such that the pressure in adjacent
chamber 12a-k is detected. The pressure sensing devices 206a-j
transmit sensed information to the CPU 202, where it is processed
according to preset programming to modulate the respective
modulating valves in response to the detected pressures in each
chamber. Such control systems and programming logic are known. For
example, in U.S. Pat. No. 5,813,142, the pressure sensing devices
206a-k include pressure sensing circuitry, which converts the
change in pressure detected by variable capacitor into digital
data. Each variable capacitor forms part of a conventional
frequency-to-voltage converter (FVC) which outputs a voltage
proportional to the capacitance of the variable capacitor. An
oscillator is electrically connected to each FVC and provides an
adjustable reference oscillator. The voltage produced by each
pressure sensing device is provided as an input to multiplexer
which cycles through the channels sequentially connecting the
voltage from each FVC to analog-to-digital (A/D) converter which
coverts the analog voltage into digital date for transmission to
the CPU via data lines. These components and this circuitry is well
known to those skilled in the art and any suitable component or
circuitry might be used to perform the same function.
[0049] The control system 200 also includes a programmable
microcomputer having conventional RAM and ROM, and received
information from pressure sensing device 206a-j indicative of the
relative pressure sensed by each pressure sensing device 206a-j.
The CPU 202 receives digital data from pressure sensing circuitry
proportional to the relative pressure sensed by pressure sensing
devices. The control system 200 is also in communication with
modulating valves 29a-j to vary the opening of each such valves and
thus the level of fluid communication of each chamber with the
other chambers. As the modulating valves are preferably solenoids
(and thus electrically controlled), the control system is in
electrical communication with modulating valves.
[0050] In a preferable embodiment, the control system also includes
a user input devices 208, which allows the user to control the
level of cushioning of the shoe. Such devices are known in the art.
For example, as shown in FIG. 8, a knob 210a-c on the article of
footwear 9 is adjusted by the user to indicate a particular sport
or activity to be engaged in by the user, the user's weight, and or
the type of pronation desired to be corrected. The CPU 202 detects
the commanded signal from the input device 208, and adjusts the
pressure in the various chambers 12a-j accordingly.
[0051] The CPU programming may be pre set during manufacturing, or
include a communications interface 212 for receiving updated
programming information remotely. Such communications ports and
related systems are known in the industry. For example, the
interface 212 may be a radio frequency transceiver for transmitting
updated programming to the CPU. An associated receiver would be
installed on the shoe and in electrical communication with the CPU.
The interface may alternately, or additionally, have a serial or
parallel data port, infrared transceiver, or the like.
[0052] C. Variable Volume Reservoir
[0053] If desired, one or more variable volume reservoirs 516 as
disclosed more fully in U.S. Pat. No. 5,406,719 can be inserted
into the bladder and placed in fluid communication with the plenum
20. Such reservoirs 516 preferably include a pressure sensing
device 206l-o and a modulating valve 29l-o, within a channel
connecting the reservoir with the plenum 20. The volume of the
reservoir can be modulated electronically through solenoid 517a-d,
which causes flat screw 526 to actuate. The control system 200
detects the sensed pressure in the reservoir, and can command the
solenoid 517a-d and modulating valve 29l-o as needed to increase
the pressure in any of the chambers 512a-d.
[0054] In particular, and as best shown in FIGS. 4-7, the
pressurizing of the various chambers 512a-d may be selectively
varied in a known manner in a closed cushioning system. Referring
specifically to FIG. 4, an alternative preferred cushioning
element, or bladder, is shown. Bladder 510 preferably includes four
separate gas-filled post support storage chambers 512a-d. Chambers
512 compress and stiffen when a load is applied in order to provide
cushioning but do not collapse upon themselves. Forward medial
support chamber 512b and rearward medial support chamber 512c are
disposed on the medial side in the heel region, and extend
approximately 1/2 of the width of the bladder. Lateral chamber 512d
also is disposed in the heel region, and extends from the medial
side for approximately 2/3 of the width of the bladder. Chambers
512b-d are spaced from each other.
[0055] Chambers 512b and 512c are linked by interconnecting tube or
port 514g which may be selectively opened or closed by pinch-off
valve 518g, the operation of which is discussed in greater detail
below. Chambers 512c and 512d also may be linked by port 515 to
facilitate initial pressurization of the chambers. However, as
shown in FIG. 4, if desired, port 515 may be permanently sealed to
prevent fluid communication between chamber 512c and chamber 512d.
Chamber 512a forms the forward portion of cushioning element 510,
and extends generally across the width of the sole. Chamber 512a is
formed as a separate element from chambers 512b-d, with foam
element 513 disposed therebetween, and if desired can be linked
directly in fluid communication with any chambers 512b-d.
[0056] Foam element 513 forms the arch portion of the cushioning
element and includes cylindrical opening 520a-d formed partially or
fully therethrough. Variable volume reservoir chambers 516a-d are
disposed within openings 520a-d, respectively. Chambers 516a-d have
a bellows shape which allows the chambers to collapse upon
themselves to reduce the volume. Front medial reservoir chamber
516a is linked in fluid communication with front support chamber
512 by interconnecting tube or port 514a, and with rear medial
compressible reservoir 516c by interconnecting tube 514c. Rear
medial reservoir chamber 516 is linked in fluid communication with
forward medial post chamber 512b by interconnecting tube 514c.
Front lateral reservoir chamber 516b is linked in fluid
communication with front support chamber 512a by interconnecting
tube 514b, and with rear lateral reservoir chamber 516d by
inter-connecting tube 514d. Rear lateral reservoir chamber 516d is
further linked in fluid communication with lateral support chamber
512d by interconnecting tube 514f. The opening and closing of each
of interconnecting tubes 514a-g is controlled by a corresponding
valve 518a-g, described further below.
[0057] Cushioning is provided by the confined gas in chambers
512a-d, and any load on any part of a given chambers will
instantaneously increase the pressure equally throughout the whole
chamber. The chamber will compress to provide cushioning,
stiffening but not collapsing, due to the increase in pressure of
the contained gas. When open, interconnecting tubes 514 do not
restrict the fluid communication between support chambers 5132 and
reservoirs 516, and two support chambers and/or reservoirs
connected by an open tube function dynamically as a single chamber.
Thus, when all of tubes 514 are open, cushioning element 510
functions as a substantially unitary bladder providing cushioning
throughout the misdeal.
[0058] Valves 518a-g may comprise any suitable valve known in the
art, for example, a pinch-off valve including a screw as shown in
FIGS. 5 and 6. With reference to FIG. 4, valves 518a-g, for
example, valve 518c, includes hollow rivet 522 disposed in a hole
extending partially throughout foam element 513 from one end
thereof, and includes an actuator 519a-g in electrical
communication with and commanded by the CPU 202. Rivet 522 disposed
in a hole extending partially through foam element 513 from one end
522a extending radially therethrough at the inner end. The inner
wall of rivet 522 is screw-threaded, and adjusting screw 524 is
disposed therein and includes actuator 525 in electrical
communication with and commanded by the CPU. Screws 524 preferably
are made of light weight plastic.
[0059] Interconnecting tubes 514 are disposed within indented
portion 522a. The fluid communication may be controlled by
adjusting the extent to which screws 524 extend within region 522b.
When screws 524 are disposed out of contact with tubes 514, there
is substantially free fluid communication between reservoirs 516
and/or support chambers 512. When screws 524 are in the innermost
position, they fully contact and pinch-off tubes 514, preventing
fluid communication substantially completely.
[0060] As discussed, reservoirs 516a-d are disposed within
cylindrical holes 520a-d formed in foam element 513. The interior
of holes 520 are screw-threaded and form containing chambers for
reservoirs 516. Flat screws 526 are disposed in respective holes
520a-d. Downward rotation of screws 526 brings the screws into
contact with and compresses reservoir chambers 516. Accordingly,
each reservoir 516 can be adjusted to and maintained at a desired
volume by simple rotation of the corresponding flat screw 526 which
causes the reservoir to collapse. When reservoirs 516 are at their
maximum volume, the top of screws 526 are level with the top of
holes 520. Screws 526 are made of a light weight material, such as
plastic, and are manipulated by actuators 527, that are in
electrical communication with and commanded by the CPU 202.
Pressure sensing devices 206k-n are disposed in each reservoir and
transmit pressure information to the CPU 202.
[0061] Due to the light-weight nature of both screws 526, chambers
518 and foam element 513, only a minimal downward force is needed
to collapse reservoirs 516 and retain reservoirs 516 at the desired
volume. Thus, only a minimal torque is needed to rotate screws 526
to the desired level. If a sock liner is provided, corresponding
hooks could be provided therethrough as well to provide ease of
access.
[0062] By making use of reservoirs 516a-d and tubes 514, the degree
of pressurization and thus the stiffness of each support chamber
512a-d can be adjusted to provide customized cushioning at
different locations of the shoe, without requiring gas to be added
to or leaked from the bladder. For example, if it is desired to
increase the resistance to compression in the medial rear portion
of the shoe, the pressure in one or both of support chambers 512b
and 512c may be increased by the CPU 202 commanding the appropriate
actuators until desired pressure is obtained in the appropriate
chambers in the following manner. Screw 524 of valve 518a would be
commanded by the CPU to rotate into contact with connecting tube
514a, fully compressing the tube and preventing the fluid
communication therethrough so as to isolate medial front reservoir
516a from support chamber 512a. Reservoir 516a would be collapsed
by the CPU 202 commanding the rotation of the corresponding flat
screw 526, forcing gas therefrom and into reservoir 516c and medial
support chambers 512b and 512c. Therefore, reservoir 516c also
would be collapsed forcing gas therefrom and into medial support
chambers 512b and 512c. Screw 524 of pinch-off valve 518e would be
commanded by the CPU to rotate so as to compress the connecting
tube, isolating reservoirs 516a and 516c from support chambers 512b
and 512c.
[0063] The mass of the gas in chambers 512b and 512c has been
increased, and since chambers 512b and 512c are now isolated from
the other support chambers of the bladder, their effective volume
is reduced. Thus, the pressure in chambers 512b and 512c is
increased. As a result, when chambers 512b and 512c are loaded,
element 510 has an increased resistance to compression and is
stiffer at the location of support chambers 512b and 512c. If
desired, the resistance to compression of chambers 512b and 512c
can be further increased by the CPU 202 commanding the closing of
tube 514c, making the chambers independent of each other and
decreasing their effective volumes further. Thus, when a load is
localized at one or the other of chambers 512b or 512c, the
stiffness of the loaded chamber is increased since fluid
communication to the other chamber is prevented. For most people,
during walking or running the foot rolls forwardly from the heel.
Thus, chamber 512c experiences maximum loading separately from
chamber 512b. As the foot rolls forwardly, the stiffness of each
chamber is increased as it receives the maximum load beyond the
maximum stiffness when the chambers are in communication.
Accordingly, the overall stiffness experienced by the wearer is
increased.
[0064] The pressure in both of chambers 512b and 512c could be
further increased by the CPU 202 commanding the reopening of
interconnecting tube 514a and rotation of flat screws 526 into
their uppermost position to allow fluid communication from support
chamber 512a into collapsible reservoirs 516a and 516c. The process
described above is then repeated to force the gas from reservoirs
516a and 516c into chambers 512b and 512c to further increase their
stiffness. The CPU 202 can dynamically modify the process, while
the shoes are being worn by their user, until any desired stiffness
is obtained. In a similar manner, the effective volumes of chambers
512a and/or 512d can be adjusted by the CPU 202 commanding and
performing similar manipulations on reservoirs 516b and 516d. In
fact, by making use of all four reservoirs 516., gas may be
transferred from any one of chambers 512 to any of the other
chambers to increase or decrease the stiffness of the bladder at a
desired location, to thereby tune the overall cushioning
characteristics of the midsole for a particular activity or for a
specific gait characteristic of the wearer.
[0065] For example, a wearer who tends to strike the ground at the
midfoot or the forefoot may prefer that forefoot chamber 512a be
more compliant. In this case, the fluid pressure could be
transferred to the three rearward chambers. Similarly, a wearer who
strikes the ground at the lateral rear may prefer that chamber 512d
be less resistant and that forefoot chamber 512a be more resistant,
in which case the fluid pressure could be transferred to chamber
512a from chamber 512d.
[0066] Furthermore, the overall pressure in chambers 512a-d and
thus element 510 as a whole, can be reduced by increasing the
available volume to include reservoirs 516a-d. For example,
connectors 514a, 514b, 514e, and 514f could be closed to isolate
reservoirs 516a-d from support chambers 512a-d. Reservoirs 516a-c
could be compressed to force fluid into reservoir 516d. Thereafter,
connector 514d could be closed to isolate reservoir 516d. Reopening
connectors 514a, 514b, and 514e and allowing reservoirs 516a-c to
expand by rotating flat screws 526 into their uppermost positions
would lower the pressure in support chambers 512a-c. The process
could then be repeated for reservoir 516c to further lower the
overall pressure in bladder 510.
[0067] Although as shown in FIG. 4, cushioning element 510 includes
two separate bladder elements, that is, chamber 512a is formed as a
separate element from chambers 512c-d, cushioning element 510 could
be a single integral element in which chamber 512a could extend
rearwardly to the forward boundary of chambers 512b and 512d, with
foam element 513 eliminated. However, the portion of chamber 512a
which would be disposed in the arch area of the shoe would be
thinner than the remainder of chamber 512a, so as to allow
pinch-off valves 518 to be disposed either above or below chamber
512a, and would include cylindrical holes formed therethrough for
placement of reservoir chambers 516. Separate wall elements having
internal threading could be disposed in the holes to allow for the
use of flat screws 526. In this construction, chamber 512a would
still be isolated by an internal wall from fluid communication with
chambers 512b and 512d. Of course, bladder 510 could be formed as a
single-element, including reservoirs 516.
[0068] D. Operation of the Cushioning System
[0069] A user wears the shoes containing the dynamically controlled
cushioning system much like a regular pair of shoes. However, he or
she can quickly adjust the cushioning of the shoes by manipulating
one or more of the control knobs 210a-c.
[0070] For example, in a running shoe application, as a person
increases speed, the impact force will increase. The chambers
receiving the increased impact force will increased in stiffness by
increasing pressure from the variable reservoir 516 or by closing
the valves for those chambers, or both. Similarly, in a basketball
shoe, when landing on the heel chambers after a jump, the pressure
on those chambers in increased by using the variable reservoirs or
by closing the valves leading to those chamber, or both.
[0071] To decrease stiffness of the chambers, for example, in both
the forefoot and heel chambers, such as in a walking shoe
application, the forefoot and heel chambers can be made to be
fluidly linked, thus increasing the total volume which results in a
less stiff feel. A user can dynamically control the softness level
by adjusting one or more of the control knobs.
[0072] Similarly, the side-to-side stiffness can be easily adjusted
to correct a wearer's over or under-pronation. For example, if a
wearer walks or runs in an over-pronated manner, pressure in the
chambers on the medial side may be increased, either automatically
by the CPU 202, or by a user selecting an appropriate setting on a
control knob 210c (FIG. 8), to make that side of the cushioning
support more stiff, and thereby reducing the wearer's tendency to
over-pronate. To correct under-pronation, pressure in the chambers
on the lateral side of the shoe may be increased in a similar
manner.
[0073] The present invention provides for an infinite number of
variations of pressure and thus stiffness at various locations in
the midsole, without requiring that gas be supplied to or released
from the bladder. That is, the variations in pressure are achieved
in a closed system. Thus, the attendant drawbacks of open air
systems such as leakage or the requirement for an external pump are
avoided. It is preferred that reservoir chambers 516 be placed in
the arch of midfoot area as shown. This area receives relatively
low loads and a closed reservoir in this location which would yield
limited cushioning would not pose a problem, especially where foam
element 513 is used. However it is possible to locate the
reservoirs and control system components at any convenient
location, even outside of the midsole such as on the upper.
Although one particular configuration of the various support
chambers, reservoirs and control system is shown, other
configurations could be used. For example, chamber 512a or 512d
could be broken into several smaller chambers linked in fluid
communication by interconnecting tubes.
[0074] In view of the wide variety of embodiments to which the
principles of the invention can be applied, it should be apparent
that the detailed embodiments are illustrative only and should not
be taken as limiting the scope of the invention. Rather, the
claimed invention includes all such modifications as may come
within the scope of the following claims and equivalents
thereto.
* * * * *