Note: Descriptions are shown in the official language in which they were submitted.
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FLEX SOLE
RELATED APPLICATIONS
The present application is a continuation-in-part (CIP) and claims the
priority of copending U.S. Application Serial No. 09/347,051 filed July 2,
1999, entitled
"FLEX SOLE", which is incorporated by reference herein. The invention is also
related
to copending U.S. Application Serial No. 09/373,122 filed August 12, 1999,
entitled
"FLEX SOLE", which is also incorporated by reference herein.
FIELD OF THE INVENTION
The invention relates to footwear or shoes, particularly walking or athletic
shoes.
BACKGROUND OF THE INVENTION
Footwear can be designed to provide a variety of stylistic and functional
benefits. A particular functional benefit is the comfort of the wearer of the
shoe.
Particularly when walking or running, the flexibility and shock absorption of
the shoe
determine the amount of comfortable support provided to the feet of the shoe
wearer.
Shoes normally worn for active use, e.g., extensive walking or fitness
sports, typically consist of an upper sole (of canvas, leather or other supple
fabric
material) joined to an outer sole (of rubber, leather or other durable
material) having a
bottom that contacts the ground. The inner surface of the outer sole, i.e.,
outsole, has
distinct regions that contact corresponding portions of the wearer's foot
sole. For
example, the outsole can have distinct heel, arch and plantar regions that
underlie the
respective portions of the foot. These regions of the outsole can be
specifically adapted
to provide functional benefits to the parts of the foot that are supported by
them. A
highly flexible inner sole, i.e., insole, is usually provided that directly
contacts the
wearer's foot and is positioned between the foot and the upper surface of the
outsole.
The insole has an upper surface of fabric or soft leather to give added
comfort and
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breathability to the sole of the foot. The outsole needs to embody both
flexible and
durable characteristics, to resist wear from pavement and torsional stresses,
also to
cushion shock from impact due to foot motion.
Others in the art have sought to provided added shock absorption to the
outsole by providing added layers or members in various regions of the
outsole. For
example, U. S. Patent No. 4, 783, 910 to Boys, 1l et al. , provides a midsole
with a discrete
heel capsule to cushion G-forces, in conjunction with an anti-torsion heel
member. U.S.
Patent Nos. 1, 994, 681 to Blumfeld, 4, 245, 406 to Landay, et al. , and 5,
839, 208 to Huang
disclose outsoles having inner cavities presenting patterns of ribbed
structures that are
joined to the sides of the outsole. Such structures are said to enhance the
shock-
absorbing support function of the outsole and its torsional stability.
U. S. Patent No. 4, 794, 707 to Franklin, et al., shows a midsole with an
internal dynamic rocker element disposed in the forefoot of the midsole, said
to enhance
walking comfort.
U. S. Patent No. 4, 663, 865 to Telecemian has a first set of ribs that extend
from within the heel cavity and a second set of ribs extending diagonally
through the arch
cavity, both sets dovetailing into the floor of the plantar cavity. A
resilient cushion is
located in the plantar cavity, being shaped and sized corresponding to that
cavity.
However, the separate cushion does not form an integral part of the inner
plantar cavity
of the outsole, but rather functions as an integral component of the midsole
than of the
outsole. Moreover, such a cushion requires additional steps to assemble
together with
the midsole during the manufacturing process.
Therefore it is desirable to provide a strategically positioned cushioning
support member in a strategic functional region of the outsole activity, which
member
2~ functions integrally with the outsole in cushioning shock to a given area
of the foot of the
shoe wearer.
It is further desirable to provide a cushioning member that is fabricated
as part of the inner cavity of the outsole, so that the member is joined
thereto and
functions integrally with the outsole, versus other components of the shoe
during wear.
It is still further desirable to provide an integral cushioning member that
functions together with other stabilizing members found within the inner
cavity of the
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outsole.
SUMMARY OF THE INVENTION
The invention advantageously provides enhanced support of the foot
wearing a shoe according to the invention, while eliminating unnecessary
manufacturing
steps. An upper sole, an insole, and an outsole are provided to manufacture a
shoe
according to the invention. The outsole comprises a heel, an arch, and a
plantar region.
A cavity is formed in one or more of the heel, arch and plantar regions of the
outsole. A
cushioning pad is permanently affixed in the cavity. The upper sole, insole
and outsole
are then assembled to make the shoe according to the invention. The pad
functions
integrally with the outsole in cushioning shock to a given area of the foot
wearing the
shoe. A midsole and the manufacturing process for making the same are no
longer
needed as a result.
In a preferred embodiment of the invention, the outsole is made of a
flexible polymeric material having a given density and the pad is molded in
place within
the plantar region, the pad being formed of a different polymeric material
than the
outsole, such that the plantar and heel regions are of differing densities,
respectively.
In other embodiments of the invention, inj ection molding is used to mold
the insole and the outsole (with the cushioning pad attached) into a bonded
insole/outsole
in a single molding step. Alternatively, inj ection molding is used to mold
the upper sole,
the insole, and the outsole in a single molding step, depending on
manufacturing
requirements. A further advantage of the invention is the flexibility of
selecting a
molding process suitable for the particular manufacturing situation.
In a further embodiment of the invention, the cavity is defined by a
plurality of ribs (made of, e.g., thermal plastic rubber or TPR) integrally
formed on the
peripheral wall of the outsole. The cushioning pad (made of, e.g., ethyl vinyl
acetate or
EVA) is placed in the cavity as defined by the ribs. The peripheral wall and
bottom of
the outsole are molded in a first stage. The cushioning pad is made
separately. The ribs
are then molded in a second stage. The cushioning pad is permanently affixed
by
adhesion to the top surface of the bottom of the outsole in the cavity and to
the
surrounding ribs after the ribs are molded. In an alternative embodiment of
the invention,
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the ribs are molded while the cushioning pad is in place in the cavity of the
outsole.
In yet another preferred embodiment of the invention, a plurality of ribs
form a structure defining a series of combs that articulate with the
peripheral wall of the
outsole, the arrangement further delimiting an inner periphery of the cavity,
wherein the
pad is joined to that inner periphery. In a further preferred embodiment, the
cavity and
pad are shaped to correspond to the contours of the peripheral walls of the
outsole.
In an additional embodiment of the invention, a plurality of ribs form a
structure defining a series of open combs that extends transversely across the
outsole and
articulates with the peripheral wall of the outsole within one or more of the
heel, arch and
plantar regions. It is further preferred that the pad be molded in place
within the combs
of the plantar region.
An advantage of the invention is that a strategically positioned cushioning
support pad can function in a strategic region of the outsole, as an integral
part of the
outsole, in cushioning shock to a given area of the foot wearing a shoe
according to the
invention.
Another advantage of the invention is that the cushioning pad can be
fabricated as part of the cavity of the outsole, so that the pad is joined
thereto and
functions integrally with the outsole, versus other components of the shoe
during wear.
Yet another advantage of the invention is an integral cushioning pad that
functions together with other stabilizing members (e.g., ribs) found within
the cavity of
the outsole.
A further advantage of the invention is enhanced support and shock
absorption by providing an outsole with selected cushioning capacity where
needed,
without the necessity of a separately engineered midsole.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the invention will
become readily apparent with reference to the following detailed description
of a
presently preferred, but nonetheless illustrative embodiment when read in
conjunction
with the accompanying drawings, in which like reference designations represent
like
features throughout the enumerated Figures. The drawings referred to herein
will be
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understood as not being drawn to scale except if specifically noted, the
emphasis instead
being placed upon illustrating the principles of the invention. In the
accompanying
drawings:
Fig. 1 is an exploded perspective view of the invention in a preferred
5 sports shoe, including an upper, a fabric insole and an outsole with a
plantar pad, shown
prior to assembly;
Fig. 2 is a partial perspective view of the internal plantar region of the
outsole of Fig. l, showing the cushioning pad formed on to the floor of the
plantar cavity;
Fig. 3 is a cross section taken at lines 3-3 of Fig. 2;
Fig. 4 is a flow diagram illustrating the general methodology of the
invention;
Figs. 5 and 8 are flow diagrams illustrating different embodiments of the
method for making a shoe according to the invention;
Figs. 6-7 are diagrams illustrating embodiments of the bonded
insole/outsole with a cushioning pad according to the invention;
Figs. 9-10 are flow diagrams illustrating different embodiments of the
molding process in making a shoe according to the invention;
Fig. l l is a perspective view of a shoe showing an alternative construction
of the pad of the invention located in the plantar region of the outsole;
Fig.12 is a cross sectional view taken substantially along lines 5-5 of Fig.
11;
Fig. 13 is a perspective view of a shoe showing another, alternative
construction of the pad of the invention located in the plantar region of the
outsole; and
Fig.14 is a cross sectional view taken substantially along lines 7-7 of Fig.
13.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the invention, elements of a preferred form of footwear are
generally shown by shoe 10, in Figs. 1-3 and 11-14. More specifically and for
purposes
of illustration, Figs. 1-3 and 11-14 generally show one or more elements of
only a
representative shoe 10, while a corresponding shoe of the pair of footwear is
not shown.
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Shoe 10 comprises of an upper sole 12, an insole 14, an outsole 16 and a pad
18 having
a structure and function that shall be detailed below. Those skilled in the
art will further
appreciate that the invention could take the form of the sports shoe 10
depicted or,
alternatively, the footwear could be a walking shoe, hiking boot or other
footwear for
active use. Similarly, the materials used for the various elements could be
leather or
other synthetic materials.
Further according to the invention, the outsole 16 of the shoe 10 has a
peripheral wall 20 delimiting a plantar 22, a heel 24 and an arch 26 region of
the outsole.
As shown in Figs. 1-3, an inner cavity 28 is preferably formed in at least one
of the
plantar 22, heel 24 and arch 26 regions, the cavity having a floor 30. In the
embodiment
of the invention shown in Figs. 1-3, cavity 28 is located in the plantar
region 22. Pad 18
is a separate cushioning element preferably located within the plantar cavity
28 and
bonded to floor 30, where the pad 18 is formed as an integral functional part
of the
outsole 26.
Fig. 4 is a flow diagram illustrating the general methodology in
manufacturing a shoe according to the invention. Figs. l-3 are also referred
to herein in
describing the general method of the invention. Referring to Fig. 4, an upper
sole 12, an
insole 14, and an outsole 16 are provided in step 111. The outsole 16
comprises a heel
24, an arch 26, and a plantar region 22. A cavity 28 is formed in the outsole
16 in step
113. A cushioning pad 18 is permanently affixed in the cavity 28 in step 115,
thereafter
serving as an integral, functional part of the outsole 26. The cavity 28 can
be located
anywhere in the outsole 16 where cushioning support is needed, e.g., the heel
24, the arch
26, or the plantar region 22. This provides an advantage and particular
flexibility for
selecting cushioning capacity where needed, without requiring a separately
engineered
midsole. The upper sole 12, the insole 14, and the outsole 16 (with the
affixed pad 18)
are then assembled to form a shoe according to the invention (step 117).
For optimal manufacturing efficiency, the upper sole 12, the insole 14, and
the outsole 16 are made separately and assembled later to form the shoe 10.
Fig. 5 is a
flow diagram that illustrates such an embodiment of the method of the
invention.
Elements of a shoe according to the invention (as shown in Figs. 1-3) are also
referred
to herein in describing this embodiment of the method of the invention.
Referring to Fig.
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5, the upper sole 12, the insole 14, and the outsole 16 are made on an
individual basis
(steps 121, 123 and 125, respectively). The cavity 28 is formed in the outsole
16 in step
127. The cushioning pad 18 is permanently affixed in the cavity 28, serving as
an
integral, functional part of the outsole 16 in step 129. After the cushioning
pad 18 is
affixed in the cavity 28 of the outsole 16, it is bonded with the insole 14
(step 128). The
bonded insole 14 and outsole 16 (with affixed pad 18) are then assembled with
the upper
sole 12 to form the shoe 10 according to the invention (step 126). The bonded
insole 14
and outsole 16 with pad 18 are shown in Figs. 6-7 (bottom view and side view
thereof,
respectively), collectively known as bonded insole/outsole 10A. The base of
bonded
insole/outsole 10A has molded-in grip formations 16a, which is known in the
art. One
advantage of this embodiment of the method of making the shoe 10 according to
the
invention is that a component, e.g., upper sole 12, of the shoe 10 can be made
separately
without waiting for other components (e.g., insole 14, the outsole 16 or
bonded
insole/outsole 10A) to be manufactured. In particular, components of the shoe
10 can be
efficiently made without waiting for the completion of the affixing of the pad
18 to the
cavity 28 of the outsole 16. This embodiment of the method of manufacturing
the shoe
10 according to the invention is particularly suitable when the upper sole 12
is pre-
fabricated or separately made by an outside manufacturer, e.g., an original
equipment
manufacturer (OEM).
In the alternative, the upper sole 12, the insole 14, and the outsole 16 can
be molded in a single step if simultaneous or pseudo-simultaneous
manufacturing is
desired, depending on manufacturing considerations or factory conditions. Fig.
8 is a
flow diagram that illustrates another embodiment of the method for making the
shoe 10
according to the invention. Elements of a shoe according to the invention (as
shown in
Figs. l-3) are also referred to herein in describing this embodiment of the
method of the
invention. Referring to Fig. 8, the upper sole 12, the insole 14, and the
outsole 16 are
separately provided in steps 131,133, and 135, respectively. The cavity 28 is
formed in
the outsole 16 in step 137. The cushioning pad 18 is permanently affixed in
the cavity
28 in step 139. After the pad 18 is affixed in the cavity 28, the upper sole
12, the insole
14, and the outside 16 (with the affixed pad 18) are bonded together, in a
simultaneous
or pseudo-simultaneous fashion, to form the shoe 10 according to the invention
using,
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e.g., injection molding which is commonly known in the art (step 138). This
particular
embodiment of the method of the invention is useful when, e.g., it is more
cost-efficient
to manufacture the upper sole 12, the insole 14, and the outsole 16 at a
single factory
location.
Fig. 9 is a flow diagram illustrating an embodiment of the molding
process in making a shoe according to the invention. The embodied molding
process of
Fig. 9 is suitable for making a bonded insole/outsole 10A (as shown in Figs. 6-
7) in an
OEM production arrangement. Elements of a shoe according to the invention (as
shown
in Figs. 1-3) are also referred to herein in describing this embodiment of the
molding
process of the invention. Referring to Fig. 9, a mold suitable for molding an
insole 14
and outsole 16 into a bonded insole/outsole 10A is provided in step 141. A
cushioning
pad 18 is attached (by adhesion, stitching or other means) to the insole 14 in
step 143.
The pad 18 (with attached insole 14) are placed in the mold for injection
molding (step
145). After closing the mold, the molding internal for the outsole 16 is
heated and then
injected into the mold to form the outsole 16 and bond it with the insole 14
with the
cushioning pad attached (step 147). That is, the insole 14 and the outsole 16
are molded
in a single step. The mold is allowed to cool and the bonded insole/outsole
10A is
removed in step 149, which is assembled with a pre-fabricated sole (e.g.,
provided by an
OEM) to make the sole according to the invention.
Fig. 10 is a flow diagram illustrating another embodiment of the molding
process in making a shoe according to the invention. The embodied molding
process of
Fig. 10 is suitable for molding the upper sole 12, the insole 14, and the
outsole 16 in a
single step. Elements of a shoe according to the invention (as shown in Figs.
1-3) are
also referred to herein in describing this embodiment of the molding process
of the
invention. Referring to Fig.10, a mold suitable for molding the insole 14, the
upper sole
12, and the outsole 16 is provided in step 151. The insole 14 is attached with
the
material for the upper sole 12 by, e.g., adhesion or stitching, etc. (step
153). The
cushioning pad 18, the material for the upper sole 12 (with the insole 14
attached) are
placed in the mold for injection molding (step 155). After closing the mold,
the molding
material for the outsole 16 is heated and then injected into the mold, so that
the outsole
16 is formed encapsulating the pad 18 and securely bonded with the insole 14
and the
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upper sole 12 (step 157). The mold is allowed to cool and the finished shoe is
removed
in step 159. The outsole 16 is formed, molded and bonded to the insole 14 and
the upper
sole 12, as described herein, in a single molding step.
The molding apparatus suitable for the molding used in the various
embodiments of the invention may be of any suitable type. Particularly
preferred is
injection molding which utilizes any suitably known injection molding
apparatus, the
construction and operation thereof are well known in the art. Alternative
molding
techniques may also be employed, depending on the nature of the molding
material used.
In another embodiment of the invention, the cavity 28 is defined by a
plurality of ribs 32 integrally formed on the peripheral wall 20 of the
outsole. The
cushioning pad 18 is placed in the cavity 28 which is defined by the ribs 32.
The
peripheral wall 20 and bottom of the outsole are molded in a first stage. The
pad 18 is
made separately. The ribs 32 are molded in a second stage. The pad 18 is
permanently
affixed by adhesion to the floor 30 in the cavity 28 and to the surrounding
ribs after the
ribs 32 are molded. The outsole 16 (with the affixed pad 18) are then bonded
with the
upper sole 12 and insole 14 to form the shoe 10 according to the invention.
In an alternative embodiment of the invention, the ribs 32 are molded
when the pad 18 is in place in the cavity 28. The pad 18 is molded in the
cavity 28 and
the ribs 32 molded to the peripheral wall 20 and in the cavity in a single
step, using, e.g.,
injection molding which is known in the art.
The plurality of ribs 32 form a structure defining a series of combs that
articulate with the peripheral wall 20 of the outsole, the arrangement further
delimiting
an inner periphery 34 of the cavity 28, wherein the pad 18 is joined to that
inner
periphery. The ribs 32 are normally present in at least the heel 24 but also
may exist in
plantar region 22 where they provide added support and integrity to the
outsole. Ribs 32
preferably extend diagonally, versus the ribs which are present in the heel
that extend
longitudinally and transversely along outsole 16. Ribs 32 are preferably
injection
molded in one piece, together with the outsole 16, from a polymeric material,
e.g.,
Thermal Plastic Rubber (TPR). Pad 18 is preferably injection molded-in-place
from a
similar or different polymeric material relative as outsole 16. Suitable
materials for the
pad 18 are preferably selected from the group consisting Ethyl Vinyl Acetate
(EVA) and
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Thermal Plastic Urethane (TPU).
The inner periphery of cavity 28 and pad 18 are sized and shaped to
correspond to one another, and to the contours of the peripheral wall 20 of
outsole 16.
Pad 18 is typically made of EVA, although other resilient, flexible materials
are possible
5 as noted above. Pad 18 has an upper surface 36 that is juxtaposed with the
insole 14 and
an edge 38 that is positioned adjacent the periphery 34 of cavity 28 during
assembly of
shoe 10. Heel 40 and toe 42 caps are provided to receive a corresponding heel
44 and toe
46 of the upper 12, respectively, for facilitating the adhesive bonding of
these structures
together. Prior to assembly of the upper 12 and outsole 16, as mentioned
above, the pad
10 18 can be molded in place onto the floor 30 as follows. A preformed pad 18
is placed in
cavity 28 then a layer 48 is applied of a conventional TPR material or one of
the preferred
materials mentioned above that adhesively bonds to the top 36 and edge 38
surfaces of
the pad, acting further to mold these surfaces to the floor 30 and ribs 32
that comprise
inner periphery 34 or cavity 28. The pad 18 can also be molded by conventional
injection
molding, in a relatively simultaneous step along with the outsole 16.
Referring to Figs.12-13, pad 18 extends between peripheral walls 20 and
fills cavity 28, whereas Figs. 13-14 alternatively show ribs 32 being present
in plantar
region 22 such that the polymeric material of inj ection molded pad 18 is
found within the
comb structure between ribs 32. Because the polymeric material of ribs 32 and
outsole
16 can be the same or different than pad 18, it is possible to have different
regions of
outsole 16 with differing densities.
Although the invention has been particularly shown and described in detail
with reference to the preferred embodiments thereof, the embodiments are not
intended
to be exhaustive or to limit the invention to the precise forms disclosed
herein. It will be
understood by those skilled in the art that many modifications in form and
detail may be
made therein without departing form the spirit and scope of the invention.
Similarly, any
process steps described herein may be interchangeable with other steps in
order to
achieve the same result. All such modifications are intended to be encompassed
within
the scope of the invention, which is defined by the following claims and their
equivalents.
