Note: Descriptions are shown in the official language in which they were submitted.
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COMPOSITE SOLE ASSEMBLY
BACKGROUND OF INVENTION
The present invention relates to a shoe sole construction with improved
comfort and,
more particularly, to a composite sole assembly for use with sandal type
footwear designed to
stimulate and exercise the foot during a natural walking gait.
Sandals are an open type of outdoor footwear consisting of a sole held to the
wearer's
foot by straps or thongs passing over the instep and generally, but not
always, around the
ankle. Some traditional sandals, such as clogs, are made predominantly out of
wood and, as
such, are inflexible in that the entire sole construction is solid and does
not flex as the foot
normally does during a normal gait.
Many conventional clog type sandals made of hard wood have a reputation of
being
popular yet uncomfortable because of their inflexibility. Further, the
"exercise" associated
with this type of sandal is created by encouraging the "gripping action" of
the toes during toe-
off which requires plantar-flexing of the toes against the wooden base.
Although this
"gripping action" promotes exercise of the foot, this action against an
inflexible base also
forces a user's instep against the forefoot strap. These actions increase foot
pressure and
discomfort. In addition, due to such sandals being made of wood, they are much
heavier than
other shoes in the market. This is exaggerated by the gripping action of the
toes which causes
a mid-foot strike. Thus, it is known that many users of such sandals
experience foot pain
when wearing these shoes immediately, and the majority of users experience
such pain after
as little as several hours of use.
Additionally, when the shapes of the sole don't match the plantar surface of a
wearer's foot, such soles or shoe interiors have minimal arch and heel contact
with the foot.
Combining this with inflexible soles increases pressure during flex and toe
off.
While many improvements have been made, there is still a need for an improved
light
weight sole construction particularly useful in sandal-type footwear with
improved comfort.
It is therefore desirable to provide a superior cushioned foam pad arrangement
for a sandal
sole assembly. It is a further object of the present invention to provide an
improved
anatomical footbed design for a sandal which delivers more cushioning and arch
support and
improves toning.
In view of the foregoing, it is an important object of the present invention
to provide a
composite sole assembly for a sandal type shoe including a chassis, a forefoot
pad and a heel
pad wherein both pads are made of a foam material so as to deliver improved
cushioning and
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comfort. It is a further object of the present invention to provide an
exercise sandal so shaped
as to automatically cause an anatomically correct positioning of the toes and
foot when the
sandal is worn and used. Introducing anatomical shapes to support the heel and
arch areas is
needed to alleviate forefoot discomfort and improve the overall comfort of the
shoe.
Specific advantages and features of the present invention will be apparent
from the
attached drawings and the description of an illustrative embodiment of the
present invention.
SUMMARY OF INVENTION
A sole assembly of the present invention includes, in one embodiment, a
chassis made
of a somewhat rigid material that integrates with a heel pad of foam material
and a forefoot
pad of foam material. The chassis includes two opposite posts or flanges for
securing the
upper, in some cases and, the outsole to the sole assembly. A heel pad is
designed for the
heel area to deliver improved cushioning and comfort. The heel pad is
insertable into an
opening in the chassis and covers the entire heel area from the center of the
shank back and
continues through the middle of the heel from top to bottom. A forefoot pad is
positioned in
the forefoot area under the chassis but on top of the outsole and extends the
entire width of
the chassis with the exception of two posts or flanges needed to secure the
upper. The
forefoot pad creates a pivot point that enables natural flexing and enhances
forward roll and
toe off as well as reduces forefoot strap stress. An upper is attached to the
sole assembly via
the posts or flanges of the chassis on the medial and lateral sides. The
outsole is attached to
the bottom of the chassis and the forefoot pad.
The present invention is designed for incorporation into an article of
footwear.
Although the present invention will be described in connection with a
conventional clog type
sandal, it is likewise well-suited for use in essentially any sandal type
footwear construction
as well as other non-sandal type shoe constructions.
According to the present invention, there is provided a sandal-type shoe
having a sole
assembly on the underside of which is attached an outsole of suitable
material. In one
embodiment, the sole assembly includes a chassis, a forefoot pad and a heel
pad that is
mounted in an opening formed in the chassis. The opening in the chassis
includes a rim
extending around the periphery thereof and functions to create a space for the
insertion of the
heel pad. The chassis further includes two peripheral posts or flanges, each
post or flange
extending toward the outsole below the bottom surface of the chassis. The
chassis and the
peripheral posts or flanges are molded in one piece and designed to provide
secure
attachment with the shoe upper. The forefoot pad includes a pair of notches or
cut-outs
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adapted to receive the flanges of the chassis and is shaped to conform to at
least a portion of
the bottom of the chassis.
The chassis, combined with heel pad and forefoot pad, form the present
composite
sole assembly. The heel pad includes a generally concaved top surface, a
curved side wall
extending downwardly from the top surface and a tapered front wall. The heel
pad fits into
an opening in the chassis and mates with the interior front wall of such
opening. A
cushioning forefoot pad is positioned between the chassis and the outsole.
Thus, when a
person's foot steps-down onto the sole assembly of the present invention, the
forefoot and
heel pads which are constructed of a low density material provide cushioning
and shock
absorption to the wearer's foot and the chassis which is constructed of a more
rigid material
supports the wearer's foot.
The top surface of the chassis combined with the top surface of the heel pad
defines a
raised area in the midfoot region and a recessed area located in the hind foot
or heel region.
The raised area is positioned to underlie the medial arch of the wearer's foot
and the recessed
area is positioned to underlie the heel of the wearer's foot. The recessed
area is defined by
the peripheral edges formed around the top surface of the heel pad from the
medial side to the
lateral side of the heel. The peripheral edge associated with the heel pad
forms a raised
portion where it wraps around the heel of a wearer's foot.
When a foot is inserted into a sandal that houses the top surface of the
present sole
assembly, the recessed area serves to receive and locate the heel in a
substantially concaved
heel area, and the raised area portion supports the medial arch of a wearer's
foot so that the
top surface of the sole assembly contacts substantially the entire bottom
surface of a wearer's
foot. The raised area portion may be associated with one or both of the
chassis and heel pad.
The combination of a raised area under the medial arch and a recessed area
immediately
under the heel improves the distribution of pressure and comfort of shoes made
in accordance
with the teachings of the present invention.
While wearing the composite sandal of the present invention, a micro imbalance
is
created during toe-of that increases the range of motion during a person's
stride or normal
walking gait which enhances muscle activity and increases a wearer's focus on
a natural gait.
The forefoot pad also creates a pivot point that promotes forward roll and
natural gait.
These and other objects and advantages of the present invention will become
more
apparent to those skilled in the art after considering the following detailed
specification taken
in conjunction with the accompanying drawings.
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BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a side elevational view of a sandal type footwear showing the
present sole
assembly constructed in accordance with the teachings of the present
invention.
FIG. 2 is an exploded perspective view of the present sole assembly combined
with an
outsole showing the various components of the present sole assembly
constructed in
accordance with the teachings of the present invention.
FIG. 3 is an exploded side elevational view of the present sole assembly
constructed
in accordance with the teachings of the present invention.
FIG. 4 is a bottom plan view of the present sole assembly of FIG. 3.
FIG. 5A is a perspective view of a chassis of the present sole assembly
constructed in
accordance with the teachings of the present invention.
FIG. 5B is a bottom plan view of the chassis of FIG. 5A.
FIG. 5C is a top plan view of the chassis of FIG. 5A.
FIG. 6A is a perspective view of a forefoot pad of the present sole assembly
constructed in accordance with the teachings of the present invention.
FIG. 6B is a side elevational view of the forefoot pad of FIG. 6A.
FIG. 7A is a perspective view of a heel pad of the present sole assembly
constructed
in accordance with the teachings of the present invention.
FIG. 7B is a bottom plan view of the heel pad of FIG. 7A.
FIG. 7C is a side elevational view of the heel pad of FIG. 7A.
FIG. 8 is a perspective view of another embodiment of the present chassis.
It should be understood that the present drawings are not necessarily to scale
and that
the present embodiments are sometimes illustrated by graphic symbols, phantom
lines,
diagrammatic representations and fragmentary views. In certain instances,
details which are
not necessary for an understanding of the present invention or which render
other details
difficult to perceive may have been omitted. It should also be understood that
the present
invention is not necessarily limited to the particular embodiments illustrated
herein. Like
numbers utilized throughout the various Figures designate like or similar
parts or structure.
DETAILED DESCRIPTION
In the present invention, a composite sole assembly is provided to improve
comfort
and can be installed in any sandal type shoe. Although the present sole
assembly will be
disclosed in connection with a clog type sandal, those skilled in the art will
recognize that the
present sole assembly can be used with any sandal type shoe and with any
footwear in
general without departing from the spirit and scope of the present invention.
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The reference numeral 1 designates generally a sandal type shoe construction
as
illustrated in FIG 1. The shoe 1 includes an outsole 2, a sole assembly 10
mounted onto the
outsole 2 and an upper 4 attached to the sole assembly 10. The upper 4
includes overlapping
inner and outer flaps or straps 6 and 8 which are each respectively secured to
the sole
assembly 10 by any suitable fastening means 7 including, but not limited to,
screws, buttons,
snaps, laces, glue, cement or other adhesives, a hook and loop fastening
means, or other
suitable means. Strap 8 closes and fastens to strap 6 over the forefoot to
hold the shoe in
place on a person's foot. The shoe upper 4 is constructed of an outer covering
material such
as leather, canvas, nylon mesh or other suitable material with an inner lining
of fabric or soft
foam material.
In the first illustrated embodiment of the present invention as best
illustrated in FIGS.
2 and 3, there is shown a sole portion of a sandal-type shoe 1 which includes
a sole assembly
10 on the underside of which is attached an outsole 2 of a suitable material.
The sole
assembly 10 is relatively thick in comparison with the outsole 2. The overall
shape of the
sole assembly 10 and outsole 2 is generally that of a human foot, a sole
structure or sandal for
a right foot being illustrated in the drawings. It will be understood, of
course, that a
corresponding structure would be used for the left foot. The present invention
is comprised
of a three-part sole assembly 10. In one embodiment, the sole assembly 10
includes a chassis
12, a forefoot pad 14 and a heel pad 16 that is mounted in an opening 18 in
the chassis 12.
Any other suitable layer may be provided and may be positioned between the
present sole
assembly 10 and the outsole 2 such as a midsole (not shown). The sole assembly
10 and the
outsole 2 are secured to the upper 4 and to each other using any suitable
attachment means 7
including cement, adhesives, glue, welt and direct attachment constructions.
Chassis 12 has a top surface 20 and a bottom surface 22 as best illustrated in
FIGS.
5A, 5B and 5C. The top surface 20 is positioned and oriented for engagement
with a foot.
Since the chassis 12 is designed to support the foot and to be incorporated
into conventional
footwear, the chassis 12 is generally foot-shaped. The chassis 12 may,
however, take on
other shapes, as desired, to accommodate various alternative sole and shoe
designs. The
chassis 12 includes a generally smooth top surface designed to support the
wearer's foot. The
top surface 20 of the chassis 12, combined with the top surface 24 of the heel
pad 16, is
shaped to match the natural shape or silhouette of a wearer's foot, for
example, by providing
the top surface with a concaved area 44 and a raised arch area 42 as will be
hereinafter further
explained.
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The chassis 12 of the illustrated embodiment further includes an opening 18 in
the
interior of the chassis 12, with a rim 26 extending around the periphery
thereof. The opening
18 is positioned in the heel area and extends completely through the chassis
12. In another
embodiment, the opening 18 may be just a recessed portion with a closed bottom
portion, the
recessed portion being sized and shaped to receive the heel pad 16. The
opening 18 creates
space for the insertion of the heel pad 16 and is bounded on one side by a
sloped front wall 28
having a downwardly and rearwardly tapered surface that causes the top of the
opening 18 to
be wider than the bottom as best illustrated in FIGS. 5A and 5C.
The chassis 12 further includes a pair of peripheral posts or flanges 30 and
32, each
flange extending downwardly towards the outsole 2 and below the bottom surface
of the
chassis 12. The chassis 12 and the peripheral flanges 30 and 32 are molded in
one piece and
the flanges 30 and 32 are designed to provide a structure for attaching the
shoe upper 4 to the
sole assembly 10 as illustrated in FIG. 1. In the present invention, the
chassis 12 could be
made from a variety of materials including, but not limited to, wood, a rigid
polymer such as
BPU, TPR, ABS, PCU and PU, or a foam material such as ethyl vinyl acetate
(EVA),
polyurethane (PU), blended co-polymers and blown rubber. The chassis 12 is
preferably
made from a material having a durometer hardness in the range of about 30-100
on the Shore
A scale.
In one embodiment, the chassis 12 is disposed along the entire length of the
sole
assembly 10. The chassis 12 may be tapered in thickness toward the forefoot
area as best
illustrated in FIGS. 3 and 5A, the depth or thickness varying from front to
rear due to the
anatomical shape. It will be apparent to one of ordinary skill in the art that
chassis 12 may be
altered in length, depth and shape without impairing the teachings and
practice of the present
invention.
Heel pad 16 includes a generally concaved top surface 24, a curved side wall
34
extending downwardly from the top surface 24 to a bottom surface 35, and a
tapered front
wall 36 as best illustrated in FIGS. 3 and 7A ¨ 7C. As shown in FIGS. 2-4, the
heel pad 16
mates with and is receivable into the opening 18 in the chassis 12, the heel
pad 16 having a
downwardly and rearwardly tapering front wall 36 (FIG. 3) that mates and
cooperates with
the interior front wall 28 of the opening 18 (FIGS. 5A and 5C). Heel pad 18
may fully
extend into and fill opening 18 of chassis 12 when received therein, or heel
pad 18 may
extend less than fully into opening 18 thereby leaving a gap or space
underneath the bottom
surface 35 of heel pad 16 when the heel pad 16 is received within opening 18.
The heel pad
16 can be deformed or bent sufficiently if necessary so that the pad 16 fits
inside the tapered
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opening 18. In another embodiment, the heel pad 16 includes a flange 38
extending around
the periphery of its top surface 24 for engaging the rim 26 of the chassis 12.
This
engagement further prevents the heel pad 16 from slipping out of the opening
18.
Heel pad 16 is generally constructed of a material that is less dense than
that used for
the outsole 2 such as a soft cushioned foam material. Examples of materials
appropriate for
the heel pad 16 include ethyl vinyl acetate (EVA), polyurethane (PU),
thermoplastic
elastomer (TPE), latex and other specialty elastomers. The heel pad 16 is
preferably made
from material having a durometer hardness in the range of about 15-60 on the
Asker C scale.
In the shoe construction 1 of FIGS. 1 and 2, a cushioning forefoot pad 14 made
of a
foam material is positioned between the chassis 12 and the outsole 2. The
forefoot pad 14
provides structure to the sole assembly 10 as well as additional padding
between a wearer's
foot and the ground. The forefoot pad 14 generally lies on the top of the
outsole 2 and
preferably terminates adjacent the front end portion 39 of the heel area of
the chassis 12 as
best seen in FIG. 3. The depth or thickness of the forefoot pad 14 varies from
the rear to the
front edge portion 40 and the front edge portion 40 may likewise be tapered as
illustrated in
FIGS. 3, 6A and 6B. The rear edge portion 41 may also be tapered as
illustrated. In another
embodiment, the forefoot pad 14 may extend from the heel to the toe area (not
shown).
Forefoot pad 14 is generally constructed of a material that is less dense than
that used
for the outsole 2 such as a soft cushioned foam material so that the thickness
of sole assembly
may be increased to provide a cushioning effect while keeping the overall
weight down.
Examples of materials appropriate for the forefoot pad 14 include ethyl vinyl
acetate (EVA),
polyurethane (PU), thermoplastic elastomer (TPE), latex and other specialty
elastomers. The
pad 14 is preferably made from material having a durometer hardness in the
range of about
15-60 on the Asker C scale. The forefoot pad 14 is positioned under the
chassis 12 and on
top of the outsole 2 along the entire width of the chassis 12 except for the
flanges 30 and 32.
In this regard, the forefoot pad 14 includes a pair of notches or cut-outs 46
and 48 for
receiving the flanges 30 and 32 on the medical and lateral sides of the
chassis 12 as best
illustrated in FIGS. 2-4. The length of the forefoot pad 14 will depend upon
the desired
location of cushioning. The forefoot pad 14 is generally shaped to conform to
the shape of
the bottom surface of the chasses 12.
Thus, when a person's foot steps-down onto the sole assembly 10 of the present
invention, the forefoot and heel pads 14 and 16 containing the low density
material provides
cushioning and shock absorption to the foot during a person's normal walking
gait. The
forefoot pad 14 helps to relieve pressure between a person's toes and the
straps 6 and 8 and it
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also provides a gripping action during toe-off. It likewise provides
flexibility to the overall
forefoot assembly which likewise promotes a more comfortable gripping action
during toe-
off.
It is noted that the forefoot and heel pads 14 and 16 can be affixed to the
chassis 12 in
a wide variety of different ways. In one embodiment, the pads 14 and 16 made
of a low
density material and the chassis 12 made of a high density material can be
affixed to each
other by cementing, insert molding, or heat sealing.
An outsole 2 is provided and positioned on the underside of the sole assembly
10 and
includes a bottom surface for engagement with a walking surface such as the
ground. The
outsole 2 may be constructed of any suitable material such as rubber,
polyurethane, a foam
material such as EVA, or TPR having the preferred resiliency and abrasion
resistance,
depending upon the type of shoe desired. The outsole 2 is intended to provide
traction as the
ground-engaging surface of shoe 1 and it is preferably made from a material
having a
durometer hardness in the range of about 30-100 on the Shore A scale. The
outsole 2 can be
of conventional thickness. In the embodiment shown in FIGS. 1 and 2, the
outsole 2 covers
the entire lower-most surface of sole assembly 10. It will be apparent to one
skilled in the art
that outsole 2 may cover only portions of sole assembly 10.
The top surface 20 of chassis 12 combined with the top surface 24 of the heel
pad 16
define a raised area 42 in the midfoot region and a recessed area 44 located
in the hind foot or
heel region of the sole assembly 10 as best illustrated in FIGS. 2, 3, 5A, 5C,
7A and 7C. The
raised area 42 is positioned to underlie the medial arch of a wearer's foot
and the recessed
area 44 is positioned to underlie the heel of wearer's foot. The raised area
42 gradually rises
to an apex 50 (FIGS. 3, 5A and 5C) positioned to underlie the medial arch of a
wearer's foot.
A foot of the user rests directly upon the top surface of the sole assembly
10. In alternative
embodiments, the raised area 42 may be associated solely with the chassis 12.
It is also recognized and anticipated that the chassis 12 can also be formed
as a
plurality of attachable members which is then integrated with the forefoot pad
14 and heel
pad 16 as previously explained. In this regard, FIG. 8 illustrates one
embodiment of the
present chassis 12' wherein the chassis 12' is comprised of two members,
namely, a forefoot
portion 52 and heel portion 54. The heel portion 54 includes two tapered
flanges 56 and 58
extending horizontally from the heel portion 54 toward the forefoot portion
52. Each distal
end 60 and 62 of the flanges 56 and 58 are attached to the top surface 20' of
the forefoot
portion 52. The bottom surface of the flanges 56 and 58 are attached to the
forefoot portion
52 adjacent the side edges of the sloped front wall 28' as illustrated in FIG.
8. However,
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those skilled in the art will recognize that the present chassis 12' can be
divided and attached
at any suitable location along the length thereof without departing from the
spirit and scope
of the present invention. The forefoot portion 52 and the heel portion 54 are
secured to each
other using any suitable attachment means including, but not limited to,
cement, adhesives,
glue, welt and direct attachment constructions. It is noted that the forefoot
portion 52 and
heel portion 54 can be made of different materials to enhance comfort. The
multi-piece
construction of the chassis 12' likewise is easy and inexpensive to
manufacture and is more
readily adaptable to fit different types of shoe constructions.
The components of the sole assembly 10 are preferably secured together via
conventional means such as by cementing or adhesives and are provided as an
integral unit
during assembly of the shoe 1. Joining the components 12 or 12', 14 and 16
together prevents
relative movement therebetween during assembly and use of the shoe 1. In a
further
embodiment, a lining (not shown) may be provided and may overlay the top
surface of the
sole assembly. The lining may be a fabric, coated fabric, leather or other
suitable material.
The lining may be secured to the sole assembly 10 with a suitable cement.
It should be understood, however, that the boundaries between the forefoot,
midfoot
and heal regions or areas described above are not precise and that these terms
should be
interpreted loosely and with a great deal of flexibility.
Further, the overall dimensions of the present sole assembly 10 as well as the
specific
shape and configuration of the various components thereof are also subject to
wide variations
and may be sized and shaped into a wide variety of different sizes and
configurations so as to
be compatible with the size and shape of the particular footwear onto which
the present
structures may be mounted, or to conform with any space limitations associated
therewith
without impairing the teachings and practice of the present invention. It is
also understood
that various modifications may be made to all of the various embodiments
without departing
from the spirit and scope of the present invention.
In use, the sole assembly 10 is associated with or located within a shoe 1
with its heel
end at the back of the shoe so that the recessed area 44 underlies
substantially the heel of a
wearer such that the recessed area 44 receives and the heel pad 16 supports
and wraps around
a substantial portion of the heel of a wearer. From there, the sole assembly
10 extends
forwardly to the toe area with the raised area 42 or 42' lying under
substantially the medial
arch area of a wearer's foot. The raised area 42 or 42' tapers toward the toe
end of the chassis
12 or 12'. Thus, when a wearer's foot is inserted into a shoe 1, the recessed
area 44 serves to
locate the heel on a substantially concave surface. The raised area 42 or 42'
positions and
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supports the medial arch of the foot so that the top surface of the sole
assembly 10 contacts
substantially the entire bottom surface of the foot. The combination of a
raised area 42 or 42'
under the medial arch and recessed area 44 immediately under the heel along
with the
positioning and location of the forefoot and heel pads 14 and 16 improves the
comfort of
shoes made in accordance with the present invention, and such a construction
introduces a
more natural anatomical shape to support the heel and arch areas of a person's
foot. This
construction further provides a better distribution of foot pressure and
reflects a more natural
shape of the foot. It also provides an improved foundation to support the foot
and to alleviate
forefoot discomfort.
Thus, there has been shown and described several embodiments of a composite
sole
assembly. As is evident from the foregoing description, certain aspects of the
present
invention are not limited by the particular details of the examples
illustrated herein, and it is
therefore contemplated that other modifications and applications, or
equivalents thereof, will
occur to those skilled in the art. The terms "having" and "including" and
similar terms as
used in the foregoing specification are used in the sense of "optional" or
"may include" and
not as "required". Many changes, modifications, variations and other uses and
applications
of the present invention will, however, become apparent to those skilled in
the art after
considering the specification and the accompanying drawings. All such changes,
modifications, variations and other uses and applications which do not depart
from the spirit
and scope of the invention are deemed to be covered by the invention which is
limited only
by the claims which follow.
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