Note: Descriptions are shown in the official language in which they were submitted.
CA 02588320 2009-10-26
MODULAR FOOTWEAR SYSTEM
BACKGROUND
This invention relates to a modular system for an item of footwear (e.g.,
shoes,
boots, sandals, slippers). In particular, the system provides removable
modular sole
components that allow customization of an item of footwear with respect to
traction,
cushioning, support, fit, performance and/or aesthetic functions and features.
Footwear having replaceable sole unit receivers are known in the prior art.
One such footwear item, which is particularly adapted for use by fishermen,
footwear
is disclosed in US Patent No. 6,813,847 and in pending US Publication No.
US2006/0042119. The footwear disclosed in that patent includes a cavity in its
sole
that removably receives a sole plate having a tread pattern on its lower
surface.
SUMMARY
In accordance with one aspect of the invention, the inventive subject matter
disclosed herein contemplates a sole unit and/or sole unit receiver, which
combine to
form a sole assembly, that have one or more of the following features alone or
in
combinations:
In accordance with one aspect of the invention there is provided a sole
assembly. The sole assembly includes a sole unit and a sole unit receiver, the
sole
unit receiver having a thin cavity defined by a top surface and a downwardly
extending sidewall that is disposed along a perimeter portion of the top
surface, and
the sole unit being sized to substantially fill the cavity. The sole unit has
one or more
engageable elements, the sole unit and engageable elements being adapted to be
received by the sole unit receiver for an item of footwear to form a sole unit
assembly.
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The one or more engageable elements each have a corresponding engageable
element
on the sole unit receiver to form a male-female pair of complementary parts
that
provide an interference fit that helps secure the sole unit to the sole unit
receiver
relative to forces that may act generally parallel to the ground facing
surface of the
sole unit. The interference fit is in the nature of a bidirectional stop that
helps secure
the sole unit against forces that act generally along at least a long axis of
the sole unit.
One of the pair of engageable elements of the sole assembly is a male part
having and
elongate portion that is generally oriented perpendicularly to the ground
facing
surface of the sole assembly, and the end of the male part that engages the
complementary female part terminates in a shape that has an outwardly
extending
horizontal component that resists vertical forces. The sole unit includes at
least one
portion of a surface with a plurality of teeth adapted to engage a set of
teeth on the
sole unit receiver. The set of teeth are disposed in a slot in a forefoot
section of the
sole unit receiver.
The sole unit may further include an engageable element that allows for
coupling of the sole unit to the sole unit receiver by a rotational action of
one of the
complementary elements.
The male engageable element may include a hand tool for engaging or
disengaging the elements.
The elongate element may include a threaded element.
The sole unit may include an engageable element in a midfoot portion
centrally spaced between lateral and medial sides of the sole unit.
The male part may be disposed in a midfoot portion of the sole unit, spaced
centrally between lateral and medial sides of the sole unit.
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The sole assembly may include a surface that is adapted to be received in the
sole unit receiver, the surface including a surface with a texture or pattern
adapted to
frictionally engage a surface on the sole unit receiver.
The sole unit may have a three dimensional conformation and the sole unit
receiver may have a complementary conformation for receiving the sole unit.
The sole assembly may include a cushioning element or a receiver for a
cushioning element discretely disposed on at least a portion of a forefoot or
a portion
of a rearfoot area of the sole unit.
The sole unit may be adapted to address pronation or supination.
The sole assembly may include a reinforcement material may include a fiber,
filament or fabric.
The sole unit may be adapted to be received in the sole unit receiver, the
sole
unit including at least one portion of a surface with a plurality of teeth
adapted to
engage a set of teeth on the sole unit receiver.
The sole unit may be operable to be received by the sole unit receiver, the
sole
unit receiver including a set of teeth, and the sole unit may include
provisions for
engaging the set of teeth on the sole unit receiver to secure the sole unit to
the sole
unit receiver.
The sole unit may have an intermediate waist portion and opposing portions
on either side of the intermediate portion that may be wider than the
intermediate
portion, the sole unit being receivable in sole unit receiver having
complementary
opposing portions and an intermediate waist portion so that the interference
of the
opposing portions in the sole unit against the complementary waist portion in
the sole
unit receiver results in a bidirectional stop.
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One opposing portion may include a forefoot portion and the other opposing
portion may include a rear foot portion, and the intermediate portion may
include a
midfoot portion.
The sole unit may include a felt or studded outsole portion.
The sole assembly may include a hand key configured with a portion for
gripping and an opposite portion with a size and shape that allows for
manipulation of
an engageable element in a sole assembly for assisting in flexing apart the
engageable
element so it may be more open to receive its complementary engageable
element.
The sole assembly may include an apparatus for manipulating an engageable
element in the sole assembly, the apparatus being provided in a kit including
the
apparatus and the sole assembly, the apparatus including a portion for
gripping, and
provisions for assisting in flexing apart the engageable element so it may be
more
open to receive its complementary engageable element.
The male part may have the shape of a hook.
The male part may have the shape of a mushroom.
The male part may have a tear-dropped shape.
The sole assembly may include an upper attached to the sole unit receiver to
form an item of footwear.
In accordance with another aspect of the invention there is provided a sole
assembly. The sole assembly includes a sole unit and a sole unit receiver, the
sole
unit receiver having a thin cavity defined by a top surface and a downwardly
extending sidewall that is disposed along a perimeter portion of the top
surface, and
the sole unit sized to substantially fill the cavity. The sole unit has one or
more
engageable elements, the sole unit and engageable elements being adapted to be
received by the sole unit receiver for an item of footwear to form a sole unit
assembly.
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The one or more engageable elements each has a corresponding engageable
element
on the sole unit receiver to form a male-female pair of elements that provides
an
interference fit that helps secure the sole unit to the sole unit receiver
relative to forces
that may act generally parallel to the ground facing surface of the sole unit.
The
interference fit is in the nature of a bidirectional stop that helps secure
the sole unit
against forces that act generally along at least a long axis of the sole unit.
One of the
pair of engageable elements of the sole assembly is a male part having an
elongate
portion that is generally oriented perpendicularly to the long axis of the
sole assembly
and the male part extending transverse to the long axis of the sole assembly
into a
sidewall of the sole unit or sole unit receiver. The sole unit includes at
least one
portion of a surface with a plurality of teeth adapted to engage a set of
teeth on the
sole unit receiver. The set of teeth are disposed in a slot in a forefoot
section of the
sole unit receiver.
The sole unit further may include an engageable element that allows for
coupling of the sole unit to the sole unit receiver by a rotational action of
one of the
complementary elements.
The male engageable element may include a hand tool for engaging or
disengaging the elements.
The elongate element may include a threaded element.
In accordance with another aspect of the invention there is provided a method
of making an item of footwear. The method involves, providing a sole unit and
a sole
unit receiver, the sole unit receiver having a thin cavity defined by a top
surface and a
downwardly extending sidewall that is disposed along a perimeter portion of
the top
surface, and the sole unit sized to substantially fill the cavity. The method
also
involves providing the sole unit with one or more engageable elements, each
having
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corresponding engageable element on the sole unit receiver to form a male-
female
pair of complementary parts that provide an interference fit that helps secure
the sole
unit to the sole unit receiver relative to forces that may act generally
parallel to the
ground facing surface of the sole unit. The method further involves providing
the sole
unit receiver so that a sole unit assembly in engaged or disengaged form is
together.
The interference fit is in the nature of a bidirectional stop that helps
secure the sole
unit against forces that act generally along at least a long axis of the sole
unit. One of
the pair of engageable elements of the sole assembly is a male part having an
elongate
portion that is generally oriented perpendicularly to the ground facing
surface of the
sole assembly, and the end of the male part that engages the complementary
female
part terminates in a shape that has an outwardly extending horizontal
component that
resists vertical forces. The sole unit includes at least one portion of a
surface with a
plurality of teeth adapted to engage a set of teeth on the sole unit receiver.
The set of
teeth are disposed in a slot in a forefoot section of the sole unit receiver.
In accordance with another aspect of the invention there is provided a sole
unit
with at least two or more engageable elements spaced along a peripheral
portion of
the sole unit, the engageable elements each being adapted to engage a
complementary
engageable element associated with a sole unit receiver to form a male-female
pair of
elements that provides an interference fit that helps secure the sole unit to
the sole unit
receiver. The sole unit also includes at least one engageable element spaced
away
from and in between lateral and medial sides of the sole unit, which is
adapted to
engage an engageable element including a recess in the sole unit receiver and
limit
longitudinal movement of the sole unit relative to the sole unit receiver. The
sole unit
is adapted to be received in the sole unit receiver and the sole unit includes
at least
one portion of a surface with a plurality of teeth adapted to engage a set of
teeth on
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the sole unit receiver. The set of teeth are disposed in a slot in a forefoot
section of
the sole unit receiver.
The sole unit may include an engageable element in a midfoot portion
centrally spaced between lateral and medial sides of the sole unit.
The sole unit may include a pair of engageable elements including an indented
element and a projecting element spaced between lateral and medial sides of
the sole
unit, and the projecting element engaging the indented element in the sole
unit
receiver to limit longitudinal movement of the sole unit relative to the sole
unit
receiver.
The sole unit may include a sole unit receiver to form a sole assembly, the
sole
unit receiver having a thin cavity defined by a top surface and a downwardly
extending sidewall that is disposed along a perimeter portion of the top
surface, and
the sole unit sized to substantially fill the cavity.
In accordance with another aspect of the invention there is provided a method
of making a removable sole unit for a shoe. The method involves providing a
sole
unit and adapting a sole unit to have at least two or more engageable elements
spaced
along a peripheral portion of the sole unit, the engageable elements each
being
adapted to engage a complementary engageable element associated with a sole
unit
receiver to form a male-female pair of elements that provide an interference
fit that
helps secure the sole unit to the sole unit receiver, and at least one
engageable element
spaced away from and in between lateral and medial sides of the sole unit,
which is
adapted to engage an engageable element includes a recess in the sole unit
receiver
and limit longitudinal movement of the sole unit relative to the sole unit
receiver. The
sole unit is adapted to be received in the sole unit receiver and the sole
unit includes at
least one portion of a surface with a plurality of teeth adapted to engage a
set of teeth
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on the sole unit receiver. The set of teeth are disposed in a slot in a
forefoot section of
the sole unit receiver.
The method may involve providing a sole unit receiver having a thin cavity
defined by a top surface and a downwardly extending sidewall that may be
disposed
along a perimeter portion of the top surface, and the sole unit being sized to
substantially fill the cavity, the sole unit and sole unit receiver combining
to form a
sole assembly.
In accordance with another aspect of the invention there is provided a sole
assembly. The sole assembly includes a sole unit and a sole unit receiver, the
sole
unit having a plurality of complementary engageable elements spaced along
lateral
and medial sides of the sole assembly, the sole unit and engageable elements
being
adapted to be received by the sole unit receiver for an item of footwear to
form a sole
unit assembly, and at least one engageable element disposed in a midfoot
portion of
the sole unit, centrally spaced between lateral and medial sides of the sole
unit, the
engageable elements each having a corresponding engageable element on the sole
unit
receiver to form a male-female pair of elements that provides an interference
fit that
helps secure the sole unit to the sole unit receiver relative to forces that
may act
generally parallel to the ground facing surface of the sole unit. The
interference fit is
in the nature of a bidirectional stop that helps secure the sole unit against
forces that
act generally along at least a long axis of the sole unit, one of the pair of
engageable
elements of the sole assembly is a male part having an elongate portion that
is
generally oriented perpendicularly to the ground facing surface of the sole
assembly,
and the end of the male part that engages the complementary female part
terminates a
shape that has an outwardly extending horizontal component that resists
vertical
forces. The sole unit includes at least one portion of a surface with a
plurality of teeth
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adapted to engage a set of teeth on the sole unit receiver. The set of teeth
are disposed
in a slot in a forefoot section of the sole unit receiver.
In accordance with another aspect of the invention there is provided a sole
unit
that is adapted to be received in a sole unit receiver, the sole unit sized
and shaped to
approximate at least a forefoot or rearfoot of a person, the sole unit having
at least one
surface portion with a plurality of rows of teeth running generally
perpendicular to the
longitudinal axis of the sole unit and adapted to engage a set of
complementary teeth
on a sole unit receiver. The teeth are disposed in a slot in a forefoot
portion of the
sole unit, and the sole unit receiver has a thin cavity defined by a top
surface and a
downwardly extending sidewall that is disposed along a perimeter portion of
the top
surface. The sole unit is sized to substantially fill the cavity.
The sole unit may include a sole unit receiver to form a sole assembly.
The set of complementary teeth may be disposed in a slot in the sole unit
receiver.
The teeth may be disposed on opposing surfaces of the sole unit and
complementary sets of teeth disposed on a slot in the sole unit receiver
having top and
bottom surfaces with complementary teeth.
The foregoing is not intended to be an exhaustive list of embodiments and
features of the present inventive concept. Persons skilled in the art are
capable of
appreciating other embodiments and features from the following detailed
description
in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a perspective view of an item of footwear with a removable sole unit
embodying the subject invention.
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Fig. 2 is an exploded view of the footwear of Fig. 1 showing the sole unit
removed from the remainder of the footwear.
Fig. 3 is a bottom view of the footwear of Fig. 1.
Fig. 4 is a sectional view, at an enlarged scale, taken on the line 4-4 in
Fig. 3.
Fig. 5 is a cross-sectional view, at an enlarged scale, taken on the line 5-5
of
Fig. 3.
Fig. 6 is an exploded side elevation, partially broken away, of the footwear
of
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Fig. 1.
Fig. 7 is a partial side elevation view, at an enlarged scale, of another
embodiment of the invention.
Fig. 8 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 9 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 10 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 11 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 12 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 13 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 14 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 15 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 16 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 17 shows a bottom and a side view of an alternative embodiment of a sole
assembly according to the inventive subject matter.
Fig. 18 shows an alternative embodiment of a sole unit and sole unit receiver
according to the inventive subject matter.
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Fig. 19 shows an alternative embodiment of a sole unit and sole unit receiver
according to the inventive subject matter.
Figs. 20-21 show a bottom and a side view of an alternative embodiment of a
sole assembly according to the inventive subject matter.
Fig. 22 shows an example of a hand key for helping in the disengagement of a
sole unit from a sole unit receiver, according to the inventive subject
matter.
DETAILED DESCRIPTION
In broad terms, the inventive subject matter herein relates to a sole unit
that is
engageable to a sole unit receiver by various novel engagement systems. The
combination of a sole unit and sole unit receiver (which hereinafter may be
referred to
as a "sole assembly") provides foot supporting and ground engaging functions,
as
well as other functionality, that sole systems are known to provide, such as
cushioning, support, fit, performance and/or aesthetic functions. While sole
assemblies generally extend the length and width of a foot, a sole assembly
could also
consist of an assembly that provides a smaller area of coverage such as
coverage just
under a forefoot (e.g. Fig. 21) or rearfoot portion of a foot, or just under a
lateral or
medial side of a foot.
The functions generally provided by a sole assembly may be distributed across
the assembly of sole unit and sole unit receiver in most any fashion. For
example, the
sole unit could be adapted to include just a traction surface, such as a
rubber outsole,
and the sole unit receiver could be adapted to provide the primary cushioning
functionality, for example by it being in the form of a foamed EVA material.
Alternatively, the sole unit could include cushioning materials or elements,
e.g., 101,
Fig. 19. Alternatively, both the sole unit and sole unit receiver could have
cushioning
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and/or outsole features. The sole assembly attaches to a shoe upper for
enclosing or
securing around a foot. The upper could be a complete enclosure that surrounds
a foot
or it could be a partial enclosure such as a set of sandal straps.
Referring to Figs. 1-21 footwear 10 comprises an upper 11 and a sole
assembly having a sole unit receiver 12 and sole unit 26. The sole assembly
includes a
forefoot section, midfoot section, and rearfoot (or heel) section. The sole
assembly
further includes a lateral half and a medial half.
As used herein, "footwear" refers to any item for supporting the foot and
engaging the ground and encompasses shoes, sandals, boots, slippers, over
shoes,
athletic shoes, and other footwear articles. "Cushioning elements" refers to
basic
shock absorbing, energy return, and/or protective underfoot materials or
structures
that are intended to react to the forces of foot strike by providing force
attenuation,
dissipation, dampening, or energy return (spring), which are typically
included on
sports and athletic shoes. Traditionally, a cushioning element comprised a
consistent
and uniform layer of shock absorbing and protective material, such as such as
EVA or
polyurethane, placed in a shoe between the foot and the ground. However, in
relatively recent years there has been trend towards customized placements of
varying
cushioning materials and structures under a foot. Nowadays, common cushioning
elements may be based on EVA or polyurethane foam, visco-elastomers of foam or
gels, fluid filled bladders, mechanical springs or resiliently collapsible
mechanical
structures, fluid (e.g., air) springs, or any combination of the foregoing.
For example polymer spring units have been placed in portions in the sole unit
receiver, particularly the heel portion, and in some cases the forefoot
portion.
Mechanical polymer springs may be formed from an injected thermoplastic, such
as
Hytrel polymer, PEBAX, and TPU, as well as other resilient polymers, thermo-
set
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plastics, and metallic materials known in the art, alone or in combination.
See, for
example, U.S. Patent Number 5,461,800, which discloses a foamless midsole
unit,
comprising upper and lower plates sandwiching transverse cylindrical units
formed of
resilient polymer See also, for example, U.S. Patent Numbers 4,910,884,
6,625,905,
and 5,337,492. Other forms of mechanical springs, such as leaf-spring
structures are
also contemplated.
A sole unit 26 or sole unit receiver 12 may include cushioning elements in
accordance with any of the foregoing cushioning elements. Contemplated
fabrication
methods for the sole assembly and any associated cushioning elements include
molding, injection molding, direct-injection molding, one-time molding,
composite
molding, insert molding, co-molding separate materials, or other techniques
known in
the art, alone or in combination. Contemplated fabrication or assembly methods
include adhesives, bonding agents, welding, mechanical bonding, die cutting of
molded or other materials, or interlocking shapes, alone or in combination.
Laminated
structures are within the scope of the present invention.
Dampening elements, which are a form of cushioning element (as defined
herein), may also be incorporated into the sole units and/or sole unit
receivers
disclosed herein. "Dampening" generally refers to the ability of certain
materials to
reduce the amplitude of oscillations, vibrations, or waves. In footwear, shock
from
impact may generate compression waves or other vibrations within the sole
system.
Contemplated dampening materials include visco-elastomers. In some instances,
plain
elastomer materials may be used as dampeners; however, they may not provide as
desirable dampening qualities on the spring unit as a visco-elastomer. Example
materials for a visco-elastic dampener include any number of polymers,
including
polyurethanes and polyethylenes in foam or gel form, fabricated by
conventional
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molding practices or by film. Other suitable visco-elastomers are known to
persons
skilled in the art. Contemplated fabrication methods for visco-elastomers
include
molding, injection molding, direct-injection molding, one-time molding,
composite
molding, insert molding, co-molding separate materials, or other techniques
known in
the art, alone or in combination. Contemplated fabrication or assembly methods
include adhesives, bonding agents, welding, mechanical bonding, or other
mechanical
or chemical fastening means know to persons in the art, alone or in
combination.
Laminated dampener structures are within the scope of the present invention.
The outsole or traction surface for a sole assembly may include rubber,
leather, cleats, spikes, studs, shanks of metal or other rigid material,
felts, EVA, foam,
and other cushioning technologies, and combinations of the foregoing.
The sole unit 26 and sole unit receiver 12 may be releasably engaged to each
other by various configurations of male-female interconnections and/or
interference-
fit arrangements (hereinafter such elements may be referred to as "engageable
elements"). Generally, the various pairs of engageable elements may be
distributed
across a sole assembly in any manner or number provided that they reasonably
securely engage the sole and sole unit receiver together for purposes of an
intended
use of an item of footwear. For example, all male parts could be disposed on
the sole
unit and all female parts could be disposed on the sole unit receiver, or vice
versa. Or
the sole unit or the sole unit receiver could each have a set of male-female
parts that
engage corresponding parts on the other of the sole unit or sole unit
receiver. The
following embodiments illustrate just some of many possible arrangements of
releasably interconnecting elements.
Figs. 1 and 2 show an item of footwear 10 that has a sole unit receiver 12. In
this example embodiment, the sole unit receiver may be a thin cavity 14
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CA 02588320 2007-05-11
defined by a foot supporting surface and a downwardly extending sidewall 16
that is
disposed along a perimeter portion of the foot supporting surface. The
sidewall may
have a thickness "a", which for some embodiments might be about one-quarter
inch.
This is just an example dimension and persons skilled in the art will
appreciate from
the teachings herein a range of other dimensions may apply. Located in the
sidewall
at the toe end of the cavity 14 is a thin slot 20, Fig. 5. The slot 20
preferably is at the
top of the cavity 14. Located around the periphery of the cavity 14 are a
plurality of
flaps 22. The bottoms of the flaps may be contiguous with the bottom surface
18 of
the sidewall and they have a thickness "b", Fig. 4, which may be less than the
thickness a. In the embodiment illustrated the flaps are located in pairs with
one flap
in each pair being on each side of the footwear. One pair of flaps 22 is
located around
where the ball of the user's foot would be, one pair is located around where
the arch of
the user's foot would be, and another pair is located around where the user's
heel
would be. The sidewall 18 includes a passageway 24 at its back edge which
extends
between the cavity 14 and the back of the footwear.
A sole unit 26 is generally sized to fit within and substantially fill the
cavity
14. The sole unit may have the same thickness as the thickness of the sidewall
so that
the sole unit and sole unit receiver have a flush surface for purpose of
ground contact.
The sole unit may also be designed in whole or part to vary in elevation from
the sole
unit receiver. For example, a heel portion may be raised to provide a boot
heel or a
central portion might be recessed to provide certain cushioning functionality
that is
based on the greater collapsibility of the relatively raised perimeter to the
recessed
central portion.
As noted above, the sole unit may be made from any single or combination of
materials used or usable in the construction of soles. These materials include
rubbers,
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foams, elastomers, visco-elastomers, plastics, natural and synthetic leathers,
textiles,
woods, fibers and metals. In a simple construction, the sole unit may have a
flexibility that is similar to that of the sole unit receiver 12. However, the
sole unit
may be replaced with another construction to provide greater or lesser
flexibility,
according to the demands of a particular user or intended use. The sole unit
may also
be replaced with another construction to provide customized support functions.
For
example, a sole unit may be provided with more support on a medial side to
help a
runner whose foot pronates. Likewise a sole unit may be provided with more
support
on a lateral side to compensate for a runner whose foot supinates.
Additionally, the
sole unit could be constructed with a material that provides resistance to
environmental conditions such as sharp objects or corrosive chemicals for
safety in
work places where such conditions may be present.
Turning now to one possible embodiment illustrating how a sole unit
releasably engages the sole unit receiver, a thin tab 28 may be located at any
portion
along the sole unit for engagement with a complementary slot in the sole unit
receiver. For example, as illustrated in Figures, tab 28 is disposed on the
toe end of
the sole unit 26 and fits into the slot 20 when the sole unit is inserted into
the cavity.
A sole unit may be a unitary structure (e.g., molded unit) or it may be
composed of two or more subcomponents combined together as a single unit (e.g.
by
adhesives or fasteners). For example, the tab 28 may be an extension of a thin
base
layer 30 which forms the upper portion of the sole unit and supports a midsole
and/or
outsole structure, for example.
The base layer generally will have sufficient flexibility to accommodate
normal foot flexion for a specific use. For example, dance shoes typically
allow more
flexion than hiking or work boots. In one possible embodiment where the sole
unit
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consists of the base layer and a flexible outsole material, the base layer is
substantially
less flexible than the remainder of the sole unit so as to have a sufficient
combination
of stiffness and resilience to facilitate the placement of the sole unit in
the sole unit
receiver, while allowing for desired flexion, as described in more detail
below. In one
possible embodiment the outsole material is glued to the base layer, but it
could be
joined by other means, such as fasteners or co-molding. Alternatively, there
could be
no specific base plate
The base layer or other sole unit construction may also support other
elements,
such as a cushioning element 101 on the same or an opposite surface. The base
layer,
as well as other sole assembly components may be made from various plastic or
rubber materials, such as ABS, Hytrel, Pebax, PVC, polyurethanes, Nylons,
including
Nylon 6 and Nylon 12, thermoplastic urethanes, EVA, carbon and glass fiber
composites, rubbers, spring metals, etc. The base layer as a distinct
component is
optional and a single unit may be formed or constructed that provides multiple
sole
unit functions in a monolithic struture. For example, this could be achieved
by known
co-molding or over-molding processes where materials of different material
properties or structures are joined together. In such constructions, the tab
28 could be
integral with the rest of the sole unit.
In one possible embodiment, the sole unit includes a base layer with
reinforcing glass fibers, filaments, or fabric molded into the layer. In one
possible
embodiment, the base layer is Nylon 6 and incorporates about 5% glass fiber.
In
certain embodiments, the base plate is constructed to flex with the sole unit
receiver
but is stiffer than the general receiver, and any midsole, for better
retention in the
receiver.
13
CA 02588320 2007-05-11
Sole units may also be provided that have flexural lines.that correspond to
the
lines of flex in a foot.
Looking at Fig. 2, located around the periphery of the bottom surface of the
sole unit are a set of female engageable elements in the form of a plurality
of
depressions 38 that are arranged to receive male engageable elements, in the
form of
flaps 22, when the sole unit is inserted into the cavity. In the embodiment
illustrated
the depressions 38 extend to the more rigid base layer 30.
The flaps 22 may be elastically deformable or flexible enough to be deflected
upwardly to allow the portions of the base layer located above the depressions
38 to
be snapped in place above the flaps when the sole unit is inserted into the
cavity.
However, the flaps are sufficiently stiff to hold the sole unit in place once
the base
layer is pushed past the flaps. In the embodiment illustrated, the bottom
edges 56 of
the flaps 22, and the top edges 58 of the portions of the base layer 30
located above
the depressions 38 are rounded to facilitate pushing the base layer past the
flaps. The
flaps are somewhat harder than the remainder of the sidewall. For example, the
flaps
may have a hardness of between 90 and 95 Shore A Durometer and the remainder
of
the sidewall may have a hardness of between 80 and 85 Shore A Durometer. These
numbers are intended to be example Durometers, and Durometers of varying
degree
may be appropriate, depending on the specific application to be pursued. The
engageable elements in a pair of complementary engageable elements may have
the
same or different Durometer. In some cases variations in Durometer could
facilitate
an interlocking fit of one element to another. For example, a male element may
have a
higher Durometer so as to achieve a compression fit with a female part of
lower
Durometer, or vice versa.
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CA 02588320 2007-05-11
In certain embodiments, as shown in Fig. 8, for example, the flaps 22 or other
engageable elements are segmented so as to provide more flexibility for easier
insertion or removability. The segmentation 221 may be achieved by placing one
or
more cuts, notches, or recessed flex lines that run from an outside edge of a
flap
wholly or partially to the base of the flap. A similar effect can be achieved
by closely
spacing together short sections of individual flaps, for example 2-6 mm
between flaps.
To increase the surface area of outsole against the ground, the perimeter of
the
sole assembly may include selectively placed male-female engageable elements.
Figs.
8, 17, and 20, for instance, show selectively placed engageable elements at
rear foot,
midfoot, and forefoot regions of the sole assembly. The parts also provide an
interference fit that is bidirectional (discussed in more detail below).
Looking at Figs. 1-7, a ledge 40 extends from the sidewall 18 into the cavity
14 below the slot 20. The sole unit 26 includes a recess 42 which is located
below the
tab 28 and is configured to receive the ledge 40 when the sole unit is placed
in the
cavity. Thus the tip 44 of the sole unit, which is below the recess 42
overlaps the
ledge 40 and prevents, for example, sand from working its way into the slot 20
and
forcing the tab outwardly causing a discontinuity between the outer surface of
the sole
unit and the outer surface of the sidewall at the toe end of the footwear.
Figs. 6-21 illustrate other mechanisms for helping secure a sole unit to a
sole
unit receiver. Looking first to Figs. 6-7 as representative, the mechanisms
are
generally based on an engagement of a set of non-planar surfaces having a
three-
dimensional conformation. The conformation therefore not only provides greater
surface area over which force is distributed relative to planar surfaces, but
it also
provides conformations having axial components that are perpendicular to an
axis of
force (projecting downwardly from the bottom of the shoe) and therefore are
capable
CA 02588320 2007-05-11
of bidirectionally resisting the forces acting generally parallel to the
bottom of the
sole unit.
The sole assembly may be configured three-dimensionally to conform to a
heel, a forefoot, and/or side foot portions. For example, while the use of the
interlocking tab 28 and slot 20 at the toe end, the strap 32 and hook 36 at
the heel end
and the flaps 22 in between all prevent the sole unit from being pulled out of
the
footwear perpendicular to the sole unit, if the sole unit is strongly urged
rearwardly it
might pull free. To help prevent this, the top surface 46 of the cavity has an
indented
portion and the sole unit 26 has a projecting portion which interacts with the
indented
portion to prevent movement of the sole unit relative to the sole unit
receiver
longitudinally along the footwear without first lifting the sole unit
perpendicularly out
of the cavity. In the embodiment shown in Figs. 1-6, the indented portion is
an
inwardly facing curved surface 48 located in the arch portion of the bottom
surface 46
of the cavity, as can best be seen in Fig. 6. The sole unit 26 has an upwardly
facing
curved surface 50 which interacts with the curved surface 48 in the top of the
cavity
when the sole unit is placed in the cavity. The three-dimensional
conformations may
be provided not only in a shank or midfoot region, but also in the forefoot or
heel.
Similarly, there may be multiple locations in any given shoe.
Figs. 8-21 show additional embodiments of footwear with bidirectional stops
according to the inventive subject matter disclosed herein. As noted above, in
existing
designs the sole unit may slide forward or backward generally along an axis of
force
applied to an item of footwear that is generally parallel to the bottom
surface of the
sole unit. Typically, therefore, there will be an axis of force that coincides
with the
long axis of a shoe. In some activities, such as tennis and other court
sports, there will
be substantial forces in a direction generally perpendicular to the long axis
of the
16
CA 02588320 2007-05-11
show. The forces result from the foot strike or push off, and may include
shear forces
that seek to dislodge the sole unit from the sole unit receiver. The inventive
subject
matter addresses the problem arising from such forces by providing a set of
engageable elements in the sole assembly that are in the nature of a
bidirectional stop
that helps prevent the movement of a surface of the sole unit relative to the
sole unit
receiver. As used herein, a "bidirectional stop" generally means stop that
limits
movement along at least one axis from either direction on the axis. For
example, a
bidirectional stop may be a set of elements that are disposed on portions of a
sole unit
and sole unit receiver that are intermediate the end portions of the sole unit
and sole
unit receiver and that engage each other so that forward and rearward travel
of the
sole unit relative to the sole unit receiver is limited. The bidirectional
stops may also
limit relative movement of each sideways.
In the embodiments of Figs. 7-15, the sole unit 26 has opposing portions on
either side of an intermediate portion of the sole assembly. The intermediate
portion
of the sole unit receiver has an opening, such as opening 52, that mates with
a
generally complementary protrusion (e.g., protrusion 54) on the sole unit. The
opening and protrusion therefore provide an interference fit that limits fore-
aft
motion, and side-to-side motion, as well. Looking closer at Fig. 7, the
indented
portion is a rectangular recess 52 which is located in the bottom surface 46
of the sole
unit receiver. In this embodiment the projecting portion is a raised block 54
which fits
into the recess 52 when the sole unit is placed in the cavity. The recess and
block can
have any shape, and can be multiple elements, such as a sawtooth pattern.
In this and other embodiments, there may be a reversal of the male-female
parts. In other words, the sole unit 26 may have the opening that mates with a
protrusion in the sole unit receiver 14. As used herein, complementary means
17
CA 02588320 2007-05-11
geometrically shaped and sized for snug interconnection, or a male or female
part that
is not so shaped and sized but has material properties such that it will
conform to a
male or female part to which it is being interconnected.
Fig. 9 shows another embodiment wherein the sole unit receiver 12 includes a
slot 120 for receiving a complementary element of a sole unit 26. The bottom
surface
of the slot includes an opening 121. A forefoot portion of a sole unit has
male part
123 on its bottom surface that fits through the opening and helps create a
mechanical
lock. The sole unit may also include a mechanical lock in the shank region
with
vertically oriented male parts 154a & 154b that interface with complementary
female
parts 152a and 152b formed in the sole unit receiver. The vertical orientation
helps
prevent the sole unit from shifting forward and backward, as well as from side-
to-
side.
Fig. 8 shows a variation wherein the male-female parts 252/254 have a hook-
like shape so that the sole unit resists being pulled-out by vertical forces,
such as
suction from walking or running in mud. Similarly, Fig. 10 shows a male part
354 on
a sole unit having a mushroom-like shape that engages a female part 352 in the
sole
unit receiver. The mushroom head has horizontal components that help resist
vertical
forces and the vertical post portion helps resist fore/aft movement. As
another
example, the male/female parts could have a tear-drop shape, with a narrow
waist
area, with a male end that is other than a mushroom shape that squeezes past
the
narrow area and locks in. In these embodiments, the expanded head has
horizontal
and or vertical components that resist vertical forces, and the vertical post
portion
helps to resist fore/aft movement.
18
CA 02588320 2007-05-11
In the foregoing and other embodiments disclosed herein, the male and female
parts may be on any one of or both of the sole unit and sole unit receiver.
They may
be formed with any of the materials used to make a sole unit or sole unit
receiver.
Some strengthening of the materials might be desirable to provide for durable
engageable elements. For example, if the female part is formed in midsole EVA
of a
sole unit receiver, a relatively higher durometer might be used for this part.
Figs. 17 and 20 show another embodiment with a plurality of bidirectional
stops in the assembly 1722/1724 and 2022/2024 along the periphery of the sole
assembly. The female engageable elements 1724, 2024 are carried on the sole
unit 26
and male engageable elements 1722, 2022 on the sole unit receiver 12. Some are
oriented generally parallel to the long axis of the shoe and others are
oriented
generally perpendicular to it. In these embodiments, the engageable elements
1722 or
2022 on the sole unit receiver may also serve as outsole for the shoe in
supplementation to or replacement of any outsole on the sole unit 26.
Figs. 8-10 illustrate another possible embodiment of a bidirectional stop that
may be used with, or independent from the protrusion/opening type of
bidirectional
stop discussed above. Looking particularly at Fig. 10, the sole unit 26 has
opposing
portions 56, 58, and an intermediate waist portion 60 that is narrower than
the
opposing portions 56, 58. The recess in the sole unit receiver 12 that
receives the sole
unit has a complementary shape. For example, an hour-glass or figure-eight
shape
has such a waist portion and opposing ends. In the embodiment shown,
peripheral
surfaces 62a and 63a on sole unit 26 respectively engage peripheral surfaces
62b and
63b on the sole unit receiver 12. There is a similar engagement on the other
side of
the sole assembly. The waist therefore creates a bidirectional, interference
fit that
prevents the sole unit from moving forward or rearward. In contrast to some of
the
19
CA 02588320 2007-05-11
other embodiments, this bidirectional interference fit can be achieved without
any
vertical extensions from a surface plane, such as the mushroom head
arrangement
discussed above.
While the embodiments show the waist in the midfoot and the opposing
sections in the forefoot and rearfoot, the concept may be applied in any
region of the
sole unit receiver. For example, as illustrated in Fig. 21, the opposing
sections 156,
158 and intermediate waist 160 may reside entirely within the forefoot or
rearfoot or
across any region of the forefoot, midfoot or rearfoot.
To facilitate the releasability or attachability of the sole unit to the sole
unit
receiver, one or more hand tools may be provided in the sole assembly. The
hand tool
generally is a structure or structures that are disposed on the sole assembly
and can be
pulled, pushed, turned or otherwise manipulated to cause the sole unit and
sole unit
receiver to engage or disengage. The hand tool may be located any place on the
sole
unit, but normally it would be placed in a manner that is not subject to wear
and tear
and does not interfere the performance or comfort of a shoe. Accordingly it
may be
placed on a side, heel or front of a shoe, and it interfaces where a sole unit
and sole
unit receiver join together. It may also be recessed in the bottom of a sole
assembly.
An example of a hand tool is shown in Figs. 1-2. In this example, an elongate
member, such as a strap or flexible lever element 32, is located at a heel
portion of the
sole unit. The elongate member may extend through a passageway 24 and up the
back
of the footwear. The passageway helps to tuck the elongate strap below the
surface
profile of the outsole so that it is less vulnerable to wear and tear and less
likely to
interfere with foot strike or push-off movements during walking or running.
The
elongate member may be made from an inelastic or an elastically deformable
material. It may have one half of a set of interconnectable elements on one
portion
CA 02588320 2007-05-11
that engages the other half of the set disposed on the shoe upper or the sole
assembly.
In the embodiment shown, the elongate member is a strap and has an opening 34
located near its end. A hook or button 36 located on the back of the footwear
is
configured to receive the opening.
In addition to hand tools on or in the sole assembly, the inventive subject
matter also contemplates a separate hand key that may be used to assist in
engaging or
disengaging the sole unit and sole unit receiver from one another. For
example, Fig.
22 shows a flat, hand key 2200 that may be used to assist in flexing apart
engageable
elements so that they may be more open to receive their complementary
engageable
elements. There are end portions 2210 that are about the width of and can
engage a
male engageable element 1722 (Fig. 17) to lift it and allow the sole unit to
be slid in
place with engagement of its complementary female parts to the male part
1722..
There is also an optional clip 2220 for a user to attach the hand key to
clothing, a key
chain, etc.
In one possible embodiment, after the sole unit is placed in the cavity, the
strap's opening 34 is placed over the hook 36. If the strap 32 has elasticity,
the
elasticity may help hold the rear end of the sole unit on the footwear. In
another
possible embodiment, the hand tool may connect to the sole unit receiver
between the
sole unit and the sole unit receiver so that pulling the strap pops out the
sole unit in a
manner similar to which batteries can be popped out of a battery compartment
by a
strap in some consumer electronic devices. In other embodiments the hand tool
may
be a rigid lever or a pull ring on an elongate member, for example.
A hand tool that extends from the sole assembly to a side portion of a shoe is
not the only contemplated arrangement. The hand tool could also be tucked into
a
cavity, recess, hole, notch, slot, etc. and have an end exposed for hand
manipulation.
21
CA 02588320 2009-04-14
Figs. 11-15 illustrate various possibilities. For example, it could be a
rotational
engagement means, such as a male threaded element, such as 1150 or 1250, that
engages a complementary female threaded element. The male elements include a
head
1151 or 1251 that can be turned by hand. The hand tool could also be a cam
mechanism with a cam element located between the sole unit and the sole unit
receiver that when engaged by, for example, turning an element at a side or
bottom of
the sole assembly cams out the sole unit.
Notably, it can be seen that in these embodiments the hand tools are also
bidirectional stops that limit movement of the sole unit relative to the sole
unit
receiver. In the threaded versions, the sole unit not only limited from moving
parallel
to the bottom surface of the shoe, but also perpendicularly from the bottom.
Figs. 13-15 show other mechanisms for securing the sole unit to the sole unit
receiver. Engageable male and female parts are provided with a male portion 76
extending to a sidewall. In the example sole unit assemblies of Figs. 13 and
14, the
male portion is disposed on the sole unit 26. The male part is an elongated
element
that extends through a channel 78 in the side wall of the sole unit receiver
12 and into
a center portion of the sole unit, locking the sole unite and sole unit
receiver to each
other. The elongate element 76 is rotatable within a channel in the sole unit
26. In the
example, the channel is formed in a base layer of the sole unit. At the side
wall end,
the elongate element 76 has a lever 80, knob 180, or other structure that may
be
manipulated by hand. The lever or other structure may lockably engage a catch
or
receiver 82 in the sole unit receiver to secure the sole unit within the
assembly.
Alternatively, the inserted end of the elongate element 76 may have a fixture
84 that
on an appropriate degree of rotation engages a catch in the sole unit
receiver, thereby
locking the sole unit and sole unit receiver together. In a variation shown in
Fig. 15,
22
CA 02588320 2007-05-11
a threaded elongate element 180 mates with complementary threads on a threaded
receptacle formed or inserted in the side of sole unit receiver 181. Figs. 11-
12 show
that the locking mechanisms of the foregoing embodiments need not be oriented
only
from a sidewall and transverse to the long axis of an item of footwear but
also can be
located in the bottom of a sole assembly and extend upward toward the foot
supporting surface of the sole assembly. For example, a direct screw system
into the
bottom of a shoe could be used. Multiple locking systems in various
orientations may
also be used in a single sole assembly.
Figs. 13-14, and 16 show embodiments where sole assemblies include is one
or more sets of releasably engageable or interlocking elements, such as
interlocking
teeth. As shown in Figs. 13 and 14 a first set of teeth are disposed on a
surface of the
sole unit and a second set is disposed on a surface of the sole unit receiver.
In the
example shown in Fig. 16, the teeth 70a, 70b, 70c and 71a, 71b, 71c, are
disposed on
a forefoot portion of the sole unit 26 and engage complementary teeth 72a,
72b, 72c,
and 73a, 73b, and 73c, in a slot in a forefoot section of the sole unit
receiver. To
make the teeth engageable and releasable from a complementary set within the
slot,
they may be formed of a flexible material.
As shown in Fig.16, both surfaces of the sole unit may have the teeth, and
there are complementary sets of teeth on both surfaces of the slot in the sole
unit
receiver. For example, the teeth in the upper surface of the slot in the sole
unit
receiver may be formed in a layer of EVA midsole material and the teeth on the
upper
and/or lower surface of the sole unit may be formed in a thermoplastic that
serves as a
base layer for supporting a rubber out sole. By using upper and lower sets of
teeth, a
more secure interlock is achieved no matter which way the sole unit may flex
within
the sole unit receiver. Sets of complementary teeth may be disposed not only
at the
23
CA 02588320 2007-05-11
forefoot of the sole assembly but virtually at any other location in the
assembly. For
example, there could be sets running along lateral and medial sides of the
sole
assembly, or in the rearfoot portion.
Fig. 16 shows another possible mechanism for helping to secure the sole unit
and sole unit receiver together, which may be used alone or in conjunction
with other
mechanisms described herein. A surface of one or both the sole unit or sole
unit
receiver is provided with a texture or pattern 74 that engages the surface 75
of the
other item. The surfaces are better secured by the frictional resistance
between
surfaces (or at a micro-mechanical level). For example, the opposing surfaces
may be
provided with roughening or ridged patterns, such as herring bone patterns, or
textures
formed on or adhered to the surfaces, or any other texture or pattern that can
cause
frictional resistance. In one possible embodiment that texture or pattern is
directly
molded into the sole unit and/or sole unit receiver. Other means for causing
frictional
engagement include embedding a sand or sand-like material, fibers, or other
small,
discrete elements into one or both surfaces. As with other embodiments, the
engaging
surfaces can represent some or all the area of sole assembly.
Fig. 18 shows another embodiment wherein the sole unit 26 engages a sole
unit receiver 12 via a male engageable element 222 that is a vertical side
extension
from the main plane of the sole unit. The male part 222 engages female part
223 on
the sole unit receiver 12. Of course, there may be multiple engageable
elements. The
side extension may also provide cushioning or traction functions, as discussed
above.
The terms and expressions which have been employed in the foregoing
specification are used therein as terms of description and not of limitation,
and there is
no intention, in the use of such terms and expressions, of excluding
equivalents of the
features shown and described or portions thereof, it being recognized that the
scope of
24
CA 02588320 2007-05-11
the invention is defined and limited only by the claims which follow. Persons
skilled
in the art will recognize that many modifications and variations are possible
in the
details, materials, and arrangements of the parts and actions which have been
described and illustrated in order to explain the nature of this inventive
concept and
that such modifications and variations do not depart from the spirit and scope
of the
teachings and claims contained therein.