Note: Descriptions are shown in the official language in which they were submitted.
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TIMBER 054
SUSPENSION HEEL
[0001]
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The
present invention relates generally to footwear.
More particularly, the present invention relates to a
suspension system that supplies enhanced cushioning in high
heeled footwear.
2. Description of Related Art
[0003] High
heels are a very popular footwear choice due to
their elegant style and increase in virtual height of the
wearer. However,
certain challenges relating to high-heeled
footwear exist for both the consumer and manufacturer.
Despite their popularity, high-heeled shoes require a certain
set of skills to wear effectively without losing stability or
falling down. Moreover, there typically is a loss of comfort
as compared with flat-soled shoes. For instance, the foot is
positioned at an awkward angle for sustained periods of time
with the toes pointed in a plantarflexion position.
[0004] The
shock absorbing qualities of such high-heeled
footwear can be extremely poor. In the
construction of a
typical high-heeled shoe, the attachment of the heel component
to the sole of the shoe may require a very rigid connection in
order to keep the heel component from moving fore and aft or
side to side during a normal walking gait. The possibility
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elongated heel creates. With all of the forces focused on the
distal end of the heel, a large torque is placed on the point
where the heel component meets the shoe sole. A non-rigid
connection can quickly deteriorate. In this
case, the heel
would eventually detach from the shoe sole.
[0005] While a
rigid connection provides needed durability,
it negatively impacts the shoe's ability to cushion the user
from the ground. Given that
cushioning and protection from
the ground are primary functions of footwear, the inclusion of
a stiff, high-heeled shoe can detract from one of the
fundamental purposes of footwear.
[0006] The
benefits of style and the increase in virtual
height for the wearer are often desirable enough for the user
to overlook the discomfort often found in many high heel
shoes. However,
daily episodes of wearing high-heeled shoes
that provide sub-par cushioning can lead to long term
disabilities including back injuries, joint discomfort,
bunions, heel spurs, and other foot injuries.
SUMMARY OF THE INVENTION
[0007] The present
invention addresses the disadvantages of
conventional high-heeled footwear by providing compliance
where the heel meets the ground. This provides much needed
cushioning to the wearer.
Importantly, this is accomplished
while allowing the user to retain beneficial qualities of a
high-heeled shoe such as style, a rigid connection between the
heel and sole, and stability.
[0008] As will be
explained in more detail below, aspects
of the invention provide for this compliance through a
combination of features. Compliance
in the vertical
direction, in order to provide cushioning, absorbs the ground
reaction force by straining a compliant material. Compliance
is further created via a rolling action in the gait and
increased surface area contact between a compliant heel plug
and the ground. The rolling action as the wearer walks helps
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to distribute contact forces and keeps those forces from
transmitting up through the heel of the shoe and into the
wearer's body.
[0009] An article of footwear, comprising a sole, an upper
and a suspension heel member. The sole has a first surface
for supporting a wearer's foot and a second surface remote
from the first surface. The upper connected to the sole. And
the suspension heel member includes a heel shaft having a
first end connected to the second surface of the sole, and a
second distal end remote from the first end. The distal end
of the heel shaft has a heel cavity therein. The suspension
heel member also includes a compliant heel plug having a base
section for contacting the ground and a connecting section
attached to the base section and being adapted to fit within
the cavity of the distal end of the heel shaft. The compliant
heel plug and the distal end of the heel shaft form a relief
detail for providing force attenuation to the wearer.
[0010] In one example, the base section of the compliant
heel plug includes anterior and posterior regions, and the
posterior region includes a curved surface with a predefined
radius for providing a rolling action when contacting the
ground during use of the article of footwear.
[0011] Attenuating the amount of force transmitted through
an article of footwear by providing an article of footwear
with a sole, an upper connected to a first surface of the
sole, and a suspension heel, having a heel shaft and a
compliant heel plug rigidly affixed to interior sidewalls of a
cavity in the heel shaft, connected to a second surface of the
sole. Flexing a base section and a partially exposed
connecting section of the compliant heel plug upon application
of force to the upper or the compliant heel plug. Decreasing
the contact forces transmitted through the article of footwear
that are created when the compliant heel plug strikes a
surface, in comparison to a traditional heel, by providing a
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curved posterior section of the compliant heel plug to create
a greater contact surface area and a rolling action.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1A-C illustrates views of a high-heeled shoe
in accordance with aspects of the invention.
[0013] FIG. 2 is an exploded side view that illustrates the
elements of the high-heeled shoe of FIG. 1A.
[0014] FIG. 3 illustrates a perspective view of a compliant
heel plug of FIG. 2 separated from a high heel cavity.
[0015] FIGS. 4A-2 illustrate cutaway views of a compliant
heel plug in accordance with aspects of the invention.
[0016] FIG. 5 illustrates a top view of a compliant heel
plug in accordance with aspects of the invention.
[0017] FIG. 6 illustrates is a cutaway view of a suspension
heel in accordance with aspects of the invention.
[0018] FIGS. 7A-B illustrate a relief detail in unloaded
and loaded phases in accordance with aspects of the invention.
[0019] FIGS. 7C-D illustrate alternative relief detail
arrangements in accordance with aspects of the invention.
[0020] FIG. 8 illustrates aspects of a compliant heel plug
in accordance with aspects of the invention.
[0021] FIGS. 9A-2 illustrate compression of relief detail
spacing in accordance with aspects of the invention.
[0022] FIGS. 10A-E illustrate different views of one
embodiment of the suspension heel in accordance with aspects
of the invention.
[0023] FIGS. 11A-E illustrate different views of an
alternate embodiment of the suspension heel in accordance with
aspects of the invention.
[0024] The features shown in the figures are not drawn to
scale.
DETAILED DESCRIPTION
[0025] In describing preferred embodiments of the invention
illustrated in the appended drawings, specific terminology
will be used for the sake of clarity. However, the invention
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is not intended to be limited to the specific terms used, and
it is to be understood that each specific term includes all
technical equivalents that operate in a similar manner to
accomplish a similar purpose. While the
illustrated
embodiments present a suspension heel architecture that is
desirably used in a high-heeled shoe, one skilled in the art
would recognize that aspects of the invention may be employed
with other types of footwear including, but not limited to,
low-heeled shoes or boots.
[0026] FIGS. 1A-B
are side views illustrate an article of
footwear 10 that utilizes a suspension heel architecture
according to aspects of the invention. FIG. 10 is
a bottom
view of the article of footwear 10. The article of footwear
includes a sole 12, heel member 14 and upper 16. The upper
16 is omitted in the illustration of FIG. 1B. The upper 16 of
FIG. lA presents an open-toe configuration, although those
skilled in the art would recognize that other embodiments,
such as closed-toe or boot configurations, may also be
employed. Here, the upper 16 may include one or more forefoot
straps 18 that connect to the sole 12, and an ankle strap 20
that is secured to one of the forefoot straps 18.
[0027] Turning to
FIG. 1B, the sole 12 may comprise an
outsole 22 and an insole/midsole 24. Outsole 22
and the
insole/midsole 24 may comprise any types of conventional soles
suitable for use with a high-heeled shoe. The
outsole may
include a tread pattern in the forefoot region for traction
and stability, as illustrated in FIG. 1C. The heel member 14
that forms a suspension heel includes a heel shaft 26 and
compliant heel plug 28. Heel shaft 26 may be rigidly secured
to the heel portion of outsole 22. For example, the heel may
be fastened to the outsole 22 using adhesives, tacks, screws
or other fastening means. As will be explained in more detail
below, compliant heel plug 28 is firmly affixed to heel shaft
26 while providing cushioning and significantly attenuating
the ground reaction force.
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( 0 0 2 8) The heel
shaft 26 can be made from a variety of
materials. In one example, the heel shaft 26 is formed with
an injection molded ABS-type plastic. Other
materials
include, but are not limited to, wood (such as hard woods,
recycled wood), other rigid materials, and combinations
thereof.
[0029] The
compliant heel plug 28 may also be made from a
variety of materials, so long as they are compliant or
otherwise elastic-type materials that strain/compress when a
force is applied. For
instance, injected, compressed and
thermoplastic rubbers are all suitable for use as the
compliant heel plug 28. The compliant heel plug may also be
formed from a composite of materials such as a combination of
foam and rubber or foam and plastic.
[0030] FIG. 2
illustrates an exploded side view of the
high-heeled shoe 10 with heel member 14 detached from both
outsole 22 and compliant heel plug 28. As shown,
the
compliant heel plug 28 includes a base section 30 and a
connecting section 32. FIG. 3
illustrates an exploded
perspective view of the heel shaft 26 separated from the
compliant heel plug 28. As shown in this view, the distal end
of heel shaft 26 includes a heel cavity 34 for accepting the
connecting section 32 of the compliant heel plug 28.
Depending on the configuration of the heel shaft 26, the heel
cavity 34 may be formed as a molded cavity.
[0031] The heel
cavity 34 includes interior sidewalls 36
and end surface 38. As shown in
the side and top cutaway
views of FIGS. 4A and 4B, the heel shaft 26 may include one or
more holes or open regions 40. These open
regions 40
desirably extend along the shaft to the end surface 38. The
diameters of the open regions 40 may be on the order of 5-10
mm, by way of example.
[0032] As shown in
FIG. 5, the connecting section 32 of the
compliant heel plug 28 may include one or more open regions 42
therealong. The open regions 42 are separated by spacers 44,
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which desirably extend from an upper surface of the connecting
section 32 to the base section 30. The connecting section 32
also includes an exterior surface 46 sized to fit snugly
inside receptacle of the heel cavity 34.
[0033] The cutaway view of FIG. 6, taken along the anterior
section of the heel member 14, illustrates that, when
assembled, the exterior surface 46 of the connecting section
32 adjoins the interior sidewalls 36 of the heel cavity 34.
The exterior surface 46 is configured to snugly fit within the
interior sidewalls 36. As shown, the exterior surface 46 may
narrow or slope (taper) from the base section 30 toward the
end surface 38 of the heel cavity 34. This frustoconical or
pyramidal-type tapering may be on the order of 1-10 degrees.
There is generally a small draft angle of, e.g., 1-5 degrees,
to ensure that the part comes out of the mold correctly.
Other angles may be used for aesthetic purposes.
[0034] The compliant heel plug 28 is desirably affixed to
the heel cavity by adhering the exterior surface 46 to the
interior sidewalls 36. The upper portions of the spacers 44
may also be adhered to the end surface 38.
[0035] As shown in FIG. 6, a relief detail 48 is provided
between the base of the heel shaft 26 and the base section 30
of the compliant heel plug 28. The relief detail 48 provides
spacing between the base section 30 of the compliant heel plug
28 and heel member 14. The relief detail 48 desirably
circumscribes the entirety of the heel member 14. It may be
formed due to the tapering configuration of the exterior
surface 46 of the connecting section 32. The relief detail 48
allows the lower region of the compliant heel plug 28, such as
the base section 30 and the portion of the connecting section
exposed by the relief detail 48 to flex and deliver desired
force attenuation to the wearer.
[0036] The enlarged views of FIGS. 7A and 7B illustrate how
the compliant heel plug 28 provides vertical compliance to the
shoe 10. In the scenario of FIG. 7A, assume that the shoe is
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at rest on the ground without force being applied. In this
situation, the relief detail spacing is at its maximum value.
Here, the relief detail spacing on the anterior side (RDm) is
desirably equivalent to the relief detail spacing on the
posterior side (RD142), although this is not required.
Similarly, the relief detail spacing along the medial and
lateral sides may also be the same size.
[0037] In a
preferred embodiment, the relief detail spacing
in an unloaded or uncompressed state is substantially uniform
about the anterior, posterior, medial and lateral regions. In
one example, the spacing of the relief detail in an unloaded
or uncompressed state is on the order of 5.0 mm. In another
example, the spacing of the relief detail in the uncompressed
state may be between 3.0 - 7.0 mm. In a further example, the
spacing of the relief detail in the uncompressed state may be
at least 1.5 mm. In yet another example, the spacing of the
relief detail in the uncompressed state is no more than
10.0 mm.
(0038] In another
embodiment, the relief detail need not
fully circumscribe the heel. For instance, one could have the
anterior portion flush to or connected with the heel and the
other three sides with a relief detail. This would
provide
cushioning upon heel strike and enhanced stability when the
weight of the wearer is evenly distributed across the shoe.
This is shown in FIG. 7C, where the heel member 14 includes
anterior portion 50 without the relief detail. The anterior
portion 50 may be part of compliant heel plug 28, heel
shaft 26, or may be part of both components. And FIG. 7D
shows a variation that includes multiple anterior portions 52,
which also provide the aforementioned benefits.
(0039] The
particular spacing may vary depending upon the
amount of shock attenuation and/or style desired. Larger
relief detail spacing would allow for greater vertical
compliance than smaller relief detail spacing. In one
scenario, the relief detail spacing may vary depending on the
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type/style of high heeled shoe. For instance, a shoe marketed
as the most comfortable high heeled shoe might have a larger
relief detail spacing than a shoe that is driven by
aesthetics, while still maintaining a threshold level of
compliance and shock attenuation at heel strike.
[0040] Once a
force is applied to the heel member 14, as
will occur when the shoe is being worn and the wearer is
walking, the heel of the shoe will contact the ground. The
compliant heel plug 28 will flex or otherwise partly compress
under such a force. Compliance
is provided by the relief
detail spacing. As the force is applied, the relief detail
spacing decreases due to the complaint heel plug 16 flexing.
Thus, at least a portion of the ground reaction force is
absorbed and the wearer is provided with a degree of
cushioning. This can be seen in the example of FIG. 73, where
the relief detail spacing on the anterior side (RDE13) is
smaller than the relief detail spacing on the anterior side as
shown in FIG. 7A (RD141). Similarly, the posterior side relief
detail spacing (RD144) in FIG. 7B is smaller than the posterior
side relief detail spacing as shown in FIG. 7A (RDI12). It
should be understood that the medial and lateral relief detail
spacing will also be smaller in the case when the heel member
is under force than when a force is not applied.
[0041] In one
example, where the posterior relief detail
spacing (RDm) is on the order of 5 mm at its maximum value
without force applied in FIG. 7A, the relief detail spacing
(RDH4) as shown in FIG. 713 may decrease between about 1-2 mm
(or 20-40%) to 4-5 mm (or 80-100%) due to force applied.
Testing has shown compression on the order of about 1 mm with
50 pounds of force, 3 about mm with 150 pounds of force, and
substantially full compression at 200 pounds of force.
[0042] The amount
of relief detail compression will vary
due to the wearer's weight as well as the particular motion of
her gait and the material(s) used in the compliant heel plug
28. For example, a greater weight being applied to the shoe
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may result in higher ranges of compression, while smaller
weights may result in smaller ranges of compression for a
given embodiment of the invention. Similarly, gaits that
produce harder or faster striking of the compliant heel plug
28 against the ground may result in higher ranges of
compression, while walking gaits that produce softer or slower
striking of the compliant heel plug 28 against the ground may
result in lower ranges of compression. The
hardness of the
walking surface itself may also affect the compression of the
relief detail spacing.
[0043]
Furthermore, depending on the point(s) of impact,
the force applied to the base section 30 of the compliant heel
plug 28 may not be evenly displaced. FIG. 8
illustrates
posterior section 30a of the compliant heel plug 28 coming
into initial contact with the ground during exemplary motion
as the wearer is walking in the shoe. In one
example, the
posterior section 30a has a radius R, on the order of 10 mm.
In other examples, the radius Rp may be between 5-15 mm or at
least 3 mm. In some alternatives, the radius Rp may be chosen
based on aesthetics. In one
scenario, the maximum radius Rp
ranges from 5 - 40 mm.
[0044] Benefits
of radius Rp may be found during heel
strike, allowing a more gradual heel strike as compared to a
traditional high heel with a straight geometry at the
posterior of the heel. The radius Rp provides for a rolling
action and increased surface area contact between the base
section 30 of the compliant heel plug 28 and the ground,
helping to distribute the contact forces and keeping those
forces from transmitting up through the heel of the shoe and
into the wearer's body. The radius Rp also increases stability
and traction due to enhanced ground contact. In one scenario,
the medial and lateral portions of the posterior section 30a
may also be rounded in combination with the radius Rp, although
it is not required.
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[ 0 04 5 ] As also
shown in FIG. 8, anterior region 30b of the
base section 30 of compliant heel plug 28 may also be rounded,
having a radius Ra. In one example, the radius Ra may be on
the order of 3 mm. In other
examples, the radius Ra may be
between 1-5 mm, or no greater than 7 mm. As above, there is
no requirement for the anterior region to have any radius Ra.
While not shown in the side view of FIG. 8, any or all of the
posterior region 30a, anterior region 30b and central region
30c may include a tread pattern for enhancing contact with the
ground.
[0046] As
indicated above, it can be seen in FIG. 8 that
the posterior region 30a typically contacts the ground before
the anterior region 30b. The impact forces are thus initially
applied primarily to the posterior region 30a. Thus, in one
scenario, the compression of posterior relief detail spacing
RDH4 may be greater than the anterior relief detail spacing
[0047] FIGS. 9A
and 9B illustrate exemplary compression of
relief detail spacing as a person is walking. For instance,
as shown in FIG. 9A, the posterior region 30a (see FIG. 8)
contacts the ground first, thereby causing compression of the
relief detail spacing in that region. Then, as shown in FIG.
9B, as the forefoot section of the article of footwear comes
into contract with the ground, the anterior region 30b (see
FIG. 8) also contacts the ground, resulting in compression of
the anterior relief detail spacing as well. Due to
gait,
weight and other factors, the compression may or may not be
uniform around the heel member 14.
[0048] According
to a further aspect of the invention, the
relief detail RD may be positioned as close to the ground as
possible. By locating
the relief detail RD in this manner,
there is a minimal effect on the shoe's aesthetics as compared
to a traditional high-heeled shoe. Further, when walking, the
initial application of force is normally introduced at the
distal end of the heel. Attenuating this force at the point
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of contact reduces the length of the moment arm. Applying
forces to a mechanism higher up the heel would lengthen the
moment arm and magnify the force applied to the heel member.
The increased lever action would induce more torque on the
heel causing the heel to become unstable under the foot.
The increased moment arm would act on the heel member-to-sole
connection and is the reason that heel members are secured so
tightly to the sole with the added requirement of a very stiff
heel member made, e.g., from wood or plastic.
[0049] In one
example, the relief detail RDH1 (FIG. 7A) may
be positioned on the order of 4-6 mm from the ground
contacting base of the anterior region 30b. In other
examples, the relief detail RDH1 may be at least 2 mm or no
more than 10 mm from the ground contacting base of the
anterior region 30b. In contrast, the relief detail Rn
may
be positioned on the order of 10-20 mm from the ground
contacting base of the posterior region 30a. In other
examples, the relief detail RDH2 may be at least 7 mm or no
more than 30 mm from the ground contacting base of the
anterior region 30b. As shown in FIG. 7A, the position of the
relief detail relative to the ground contacting surface may
gradually increase from the anterior region 30b to the
posterior region 30a.
[0050] FIGS. 10A-E illustrate different views of an
exemplary embodiment of the suspension heel in accordance with
aspects of the invention. FIGS.
11A-E illustrate different
views of an alternative exemplary embodiment of the suspension
heel in accordance with aspects of the invention. Broken
lines in FIGS. 10A-E and 11A-E indicate an upper portion of
the suspension heel that is affixable to the sole of a shoe.
[0051] The
scope of the claims should not be limited by the
preferred embodiments set forth in the examples, but should be
given the broadest interpretation consistent with the
description as a whole.
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INDUSTRIAL APPLICABILITY
[0052] The present invention enjoys wide industrial
applicability including, but not limited to, footwear having a
suspension system that supplies enhanced cushioning to the
wearer, which can be used in all manner of shoes and in a wide
variety of activities and conditions.
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