Note: Descriptions are shown in the official language in which they were submitted.
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FOOTWEAR CONSTRUCTION
BACKGROUND OF THE INVENTION
The present invention relates to footwear and, more particularly, to a
footwear
construction and a method for making the same.
In the footwear industry, there is an ongoing effort to produce footwear that
provides a high level of stability and support, while maintaining exceptional
comfort. This effort
is heightened in the design of high performance footwear, such as watersport,
hiking,
mountaineering, multisport and rugged outdoor walking footwear. To minimize
the effects of
travel over jagged, rugged or uneven surfaces high performance footwear is
frequently provided
with components that provide torsional stability (e.g. resistance to twisting
forces) and
longitudinal stability (e.g. resistance to linear forces).
Conventionally, stability and comfort have been competing characteristics.
Efforts to improve stability and support typically result in a reduction in
flexibility in the shoe,
and subsequently comfort. A common technique for improving stability in
watersport footwear,
such as high performance sandals, is to provide a sole assembly including a
single continuous
midsole, which extends from toe to heel of the footwear and a single,
continuous, high-grip
outsole, which likewise extends from toe to heel of the footwear. The midsole
is rigid enough to
provide the above mentioned torsional and longitudinal stability. To the
midsole, a leather or
synthetic upper is joined by stitching. The upper extends upward from the
midsole and over the
top of the wearer's forefoot. There, the opposing sides of the upper are
joined with a lace system
which secures the footwear to the wearer's foot.
While this construction-particularly its sole assembly-increases stability, it
commonly reduces the comfort and wearability of the footwear. For example, the
rigid midsole
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typically provides very limited cushioning and therefore results in reduced
comfort. Further, the
rigid midsole generally is unable to flex along the longitudinal axis of the
footwear which
extends from toe to heel generally along the center of the footwear.
Accordingly, with each step,
the wearer must exert sufficient force to bend the midsole. This can increase
fatigue in the
wearer's foot muscles. As a result, there remains a long felt and unmet need
for a footwear
construction that provides the desired level of stability and support, as well
as comfort and
flexibility.
SUMMARY OF THE INVENTION
The aforementioned problems are overcome by a footwear construction including
a midsole frame having a forefoot base, a heel base and an intermediate frame
section that
connects the forefoot base and the heel base. In one embodiment, the forefoot
base and heel base
also are separated from one another by a frame void.
In another embodiment, the forefoot base can include at least one forefoot
base
void extending across the width of the footwear to improve flexibility of the
footwear.
In a further embodiment, the construction can include a midsole including an
upper surface and a lower surface. The midsole is housed at least partially
within and/or joined
with the midsole frame, with the midsole frame forefoot base and a heel base
separated from one
another below the midsole lower surface by the frame void, and connected to
one another above
the lower surface by the intermediate frame section.
In yet another embodiment, the construction can include an outsole secured to
the
midsole frame. The forefoot portion of the outsole can define at least one
outsole forefoot void,
which can be aligned with the forefoot base void. Optionally, the outsole can
be separated into
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an outsole forefoot portion and an outsole heel portion separated from one
another by an outsole
void.
In yet a further embodiment, the footwear construction can include an upper
and a
closure, with the closure secured to a portion of the midsole frame,
optionally to the intermediate
frame section, to further secure the footwear to a wearer's foot.
The construction described herein provides a novel footwear having a high
degree
of support, as well as improved flexibility and comfort. The midsole frame and
its components
add structural stability and firmness to the footwear. These characteristics
are particularly
advantageous in high performance and other footwear. With the one or more
voids included in
the midsole frame and/or the outsole, an added level of flexibility can be
provided without
compromising the structural stability of the footwear.
These and other objects, advantages and features of the invention will be more
readily understood and appreciated by reference to the detailed description of
the preferred
embodiments and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of footwear of a first embodiment;
Fig. 2 is a bottom exploded perspective view of the footwear;
Fig. 3 is a bottom perspective view of the footwear;
Fig. 4 is a side view of the footwear;
Fig. 5 is a sectional view taken along line 5-5 of Fig. 4; and
Fig. 6 is a sectional view taken along line 6-6 of Fig. 4.
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DETAILED DESCRIPTION OF THE INVENTION
1. Overview
Footwear constructed in accordance with a preferred embodiment is shown in
Figs. 1-6 and generally designated 10. The footwear 10 includes an upper 20
joined with a
midsole 30, which is further joined with a midsole frame 50, which is joined
with an outsole 90.
A closure 40 can be joined with the midsole frame 50 and/or upper 20 to
further secure the
footwear on the foot of a wearer. The midsole frame 50 can include a forefoot
frame base 52 and
a heel frame base 54, which are joined by an intermediate frame section 60.
Optionally, a plate
70 can be included in the footwear between the midsole 30 and the midsole
frame 50. The
midsole frame 50 and outsole 90 can each include voids 80, 82, 84 and 91, 92,
94, which are
generally aligned with one another, respectively. When included, these voids
can provide
improved flexion of the footwear along the longitudinal axis A of the footwear
to reduce fatigue
on the wearer's foot.
For purposes of disclosure, the present invention will be described in
connection
with a watersport sandal. As will be appreciated, the present invention is
well suited for use with
any other type of soled footwear, including other multi-sport footwear,
outdoor footwear,
walking footwear, athletic footwear and work footwear.
II. Structure
The components of the sandal 10 will now be described in more detail. The
upper
20 is generally conventional and includes quarters 22 and a vamp 24, which can
be separate or
integral components. As shown in Fig. 1, the upper can be constructed to wrap
from one side of
the wearer's foot, over the top of the forefoot, and back down the other side
of the foot. The
peripheral edge portions 26 can be secured to the upright flanges 34 and 36
extending from the
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midsole 30 by any conventional means, such as adhesives, stitching, staples,
fusion and the like.
Optionally, the upper can also include a heel portion 28 that extends from the
quarters 22,
wrapping around the rear of the wearer's heel or Achilles tendon to provide
additional
securement of the footwear to a wearer's foot. Further optionally, the upper
can extend over an
cover the wearer's toes to provide a closed toe footwear (not shown). Finally,
the upper 20 can
be absent from the footwear altogether as desired. The upper can be
constructed from any
suitable material such as neoprene, EVA, plastic, mesh fabric, canvas, leather
or any other
suitable material.
The midsole 30 to which the upper 20 is secured is generally formed in the
shape
of a wearer's foot. The midsole can include forward and rearward upstanding
flanges 34 and 36,
respectively, which serve to provide a point of attachment of the upper to the
midsole. These
flanges can be absent from the construction as desired, with the upper secured
directly to the
base portion 38 of the midsole by any conventional fastening construction.
Opposite the upper
surface 35 of the midsole is a lower surface 37, which extends from one side
of the footwear
corresponding to the outside of a wearer's foot, to another side of the
footwear, corresponding to
the inside of a wearer's foot, across a width of the bottom of the midsole.
The midsole also can
extend from the forward most portion of the footwear to the rearward most
portion of the
footwear.
The midsole 30 and other components of the footwear 10 can be constructed from
a resilient and semi-rigid synthetic material, for example, polyurethane.
Polyurethane is
generally well known in footwear industry; therefore, it will not be described
in detail here. The
rigidity and flexibility of polyurethane can be varied from application to
application as desired
using a variety of well-known techniques, such as by adjusting the type,
proportion and amount
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of the reactant to make-up the material. In addition, the rigidity and
flexibility of the
polyurethane can be varied by adjusting the volume of polyurethane used.
Although
polyurethane is a preferred midsole material, the density and precise chemical
make-up of the
midsole material will vary depending on a variety of factors, including the
size of the midsole
and the desired cushioning and flexibility characteristics of the footwear.
As shown in Fig. 2, the lower surface 37 of the midsole optionally can include
a
recess 38. This recess can be configured to accept a plate 70. The recess can
be configured to be
of a depth sufficient to position the plate 70 in a desired location, or as
deep as the plate itself.
The optional plate 70 can be constructed to extend from the forefoot 100 of
the
footwear to the arch portion 110, and to the heel portion 120 if desired. As
shown, however, the
plate extends from the forefoot portion toward the heel portion, but
terminates within the heel
portion. Thus, as shown, the plate extends only part of the distance from the
toe to heel of the
footwear. In addition, the plate can include one or more projecting regions 72
that project from
the generally planar structure of the plate 70. These projecting regions can
be configured to
register with the voids defined by the midsole frame and/or outsole as
described below. The plate
can be constructed from any semi-rigid and/or rigid but flexible material.
Optionally, such
material can be plastic, high density EVA, polyurethane, hard rubber and the
like.
The optional plate can also be configured to form around an optional heel
button
recess 39 also defined in the midsole 30 on its lower surface 37. Within the
heel button recess, a
heel button 76 can be located. This heel button can be of any size or shape,
for example,
circular, square, elliptical, triangular, etc. and constructed from any
suitable heel cushioning
material, for example low density EVA.
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The midsole frame 50 can include a forefoot frame base 52 and a heel frame
base
54, which are joined by an intermediate frame section 60. The forefoot frame
base 52 and heel
frame base 54 are optionally joined substantially only by the intermediate
frame section 60.
Indeed, the forefoot base 52 and heel base 54 can be separated by a frame void
80 when the
bases are in a common plane or in different planes. The forefoot frame base 52
includes a
forefoot wall 53, which extends upward from the upper surface 57. The forefoot
frame base 52
can also define frame voids. These forefoot frame voids 82 and 84 can be
defined by the bottom
51 of the forefoot base 54, as well as the forefoot wall 53. In the forefoot
wall 53, the voids 82
and 84 can widen as desired.
The heel frame base 54, shown in Fig. 2 and 3 can include a heel wall 55 that
extends upward from the upper surface 59 of the heel frame base 54. As shown,
this heel wall
55 can extend upward from the base 54 in select regions. Accordingly, portions
of the side wall
33 of the midsole 30 remain exposed to viewers of the footwear between the
base and the
intermediate frame section 60. If desired, the heel wall 55 can extend upward
from the heel base
54 around the entire periphery of the base, and optionally can conceal the
midsole side wall 33.
With reference to Figs. I and 2, the intermediate frame section 60 connects
the
forefoot frame base 52 and the heel frame base 54. The section 60 can be
joined with any
portion of these bases as desired, for example, the forefoot wall 53 and the
heel wall 55. Fig. 2
shows that the section 60 is connected to a rearward portion of the heel wall
55 and a rearward
portion of the forefoot wall 53. Further, it is illustrated that the heel base
to the forefoot base can
be connected by substantially only the section 60 (on both sides of the
footwear), and that all of
these components can be formed from one, integral piece as desired.
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The intermediate frame section 60 is shown as an arch-shaped component;
however, it can be of any other geometric configuration as desired, for
example, a portion of a
quadrilateral or a triangle. As shown, a portion of the intermediate frame
section 60 extends a
distance above both the forefoot frame base 52 and the heel frame base 54.
This section 60 can
also extend above the plate 70 and upper surface 35 of the midsole 30 a
selected distance. In one
embodiment, the section 60 is adjacent the quarters 22 of the upper 20.
The intermediate frame section 60 illustrated in Fig. 1, 4, and 5 can further
include apertures 67 that receive the portions of the closure 40, which as
shown, are straps that
are part of a lacing system. The apertures 67 can vary in size and shape from
that shown
depending on the desired attributes of the closure 40. In addition, the
intermediate frame section
60 can define one or more heel strap apertures 69 through which a heel strap
75 can be
positioned to further secure the footwear to the wearer's heel.
Optionally, the lower surfaces of the forefoot frame base 52 and the heel
frame
base 54 can include alignment ridges 59. As shown in Figs. 2 and 3, these
alignment ridges are
immediately adjacent the voids 82 and 84. The ridges 59 can be used to align
the outsole with
the midsole frame, and in particular, to align the outsole voids 92 and 94
with the midsole frame
voids 82 and 84.
The intermediate frame section 60 can be constructed from polyurethane, EVA,
plastic, synthetic materials, rubber, combinations of the foregoing, or any
other material as
desired. In addition, the frame can be constructed using injection molding
techniques, or any
other technique as desired.
With reference to Figs. 2 and 3, the outsole 90 is constructed from a
relatively
hard, but gripping rubber or other sufficiently durable and wear-resistant
material. The outsole
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90 includes bottom 99 which forms a wearing surface of the outsole 90 and may
be contoured to
define a desired tread pattern. Moreover, the bottom may be textured to
improve the traction and
aesthetic appeal of the shoe. The outsole 90 is substantially flat, however,
it may also include
one or more peripheral walls 93, 95 extending upwardly along the medial and/or
lateral sides
and/or in the heel or forefoot of the shoe. As shown, these outsole walls
extend upwardly along
the side walls of the midsole frame in the forefoot and heel regions of the
footwear. Specifically,
the outsole wall 93 extends upward along the forefoot wall 53 in the forefoot
frame base 52, and
the outsole wall 95 extends upward along the heel wa1155 in the heel frame
base 54.
As illustrated in Fig. 3, the outsole 90 optionally can be divided into two
separate
portions: a heel portion 96 and a forefoot portion 97. These portions can be
separated by an
outsole void 91. The forefoot and heel portions can include additional voids.
For example, as
shown, forefoot portion 97 defines forefoot voids 92 and 94. These voids are
defined by the
bottom 99 of the forefoot portion 97, as well as the outsole wall 93. In the
outsole wall 93, the
voids 92 and 94 can widen as desired.
With reference to Figs. 2, 3 and 6, the forefoot voids 92 and 94 of the
outsole are
aligned with the forefoot frame voids 82 and 84 of the midsole frame 50. In
addition, where
included, the projecting region 72 can project slightly into at least one of
the voids defined by the
midsole frame and the outsole. Optionally, the outsole 90 can be an integral
component of the
midsole frame 50, in which case, the voids extend through the midsole frame to
the lowermost
portion of the frame, which also forms the ground contacting surface of the
footwear 10.
Referring to Figs. 1 and 4, the footwear 10 can optionally include a closure
40.
As shown, the closure is a lacing system including a lace 42 and lace straps
44, which are
secured to the intermediate frame section 60 through the apertures 67. The
closure 40 optionally
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can include a pressure pad 49 to distribute the pressure on the wearer's
forefoot when the closure
is tightened. In addition, a lace lock 46 can be included in the system as
desired to ensure that
the system remains tightened. Although the closure 40 is shown as a lacing
system, it can be
substituted entirely or in part by hook and loop closure systems, ratcheting
closure systems,
straps, strapping systems and snap closure systems.
III. Manufacture
Manufacture of the footwear 10 will now be described with reference to Figs. 1-
3.
In general, each of the components, that is, the midsole 30, the midsole frame
50, the plate 70,
and outsole 90 can be formed using conventional techniques such as injection
molding. The
components are allowed to cure, and then trimmed and cleaned with a well known
cleaning
agent. In addition, the upper 20 is formed using conventional cutting and
stitching techniques.
With the components thus made, they are assembled.
Specifically, the upper 20 is secured to the rearward upstanding flanges 34
and 36
of the midsole 30 using any conventional fastening apparatus, such as cement,
adhesive, and/or
stitching. The flex plate 70 and heel button 76 can be further secured to the
midsole 30 with
cement or other adhesives as desired.
In addition, the outsole parts, that is, the heel portion 96 and a forefoot
portion 97,
can be secured to the respective heel frame base 54 and forefoot frame base 52
with cement
and/or adhesives or other molding techniques. The midsole 30 with the
assembled upper 20 can
be secured to the midsole frame 50 with the attached outsole. In one
embodiment, the midsole
is secured so that the intermediate frame section 60 projects upward and is
adjacent the upper
20. Excess cement and/or adhesives used to join the components can be cleaned
and removed
from the footwear 10.
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With the components assembled, the closure 40 and heel strap 75 can be secured
to the midsole frame 50 to complete the footwear. Thereafter, the article of
footwear is readied
for subsequent processing, packaging and shipping.
The above descriptions are those of the preferred embodiments of the
invention.
Various alterations and changes can be made without departing from the spirit
and broader
aspects of the invention as defined in the appended claims, which are to be
interpreted in
accordance with the principles of patent law including the doctrine of
equivalents. Any
references to claim elements in the singular, for example, using the articles
"a," "an," "the," or
"said," is not to be construed as limiting the element to the singular.
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