Note: Descriptions are shown in the official language in which they were submitted.
SOCK HAVING A SOLE OF DUAL FACE TERRY FABRIC
TECHNICAL FIELD
[0002]The innovation covers the field of legwear, more particularly the
technical sock
category used by athletes and people living active lifestyles.
BACKGROUND
[0003]A sock is a type of clothing used to cover a wearer's feet with the aim
of
providing comfort inside shoes. This comfort can be provided by way of a
softer
cushioned feel, by removal of sweat, and/or by providing warmth in colder
environments.
[0004]Sweat is a natural way to facilitate cooling of body temperature, since
evaporation of sweat is an endothermic (i.e., heat absorbing) process. During
exercise,
body temperature rises, and may result in excessive sweating. Sweat must be
evaporated to cause endothermic cooling of a body. Since this evaporation is
an
integral part of sweat cooling, it may be desirable for clothing articles to
have the ability
to transfer moisture through them in order to promote evaporation of sweat.
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[0005]As compared with other clothing articles, socks contend with more
difficult
conditions, since socks are tightly fitted against a wearer's skin and are
typically
covered with shoes having limited breathability. Such conditions result in
less
evaporation and prolonged wetness, which in turn result in increased friction
against the
wearer's skin ¨ giving rise to blisters as well as bacteria growth, bad odor,
and other
disorders.
[0006]There exist specialized synthetic fiber socks which quickly spread the
moisture
all across the sock fabric, working on the principle of increasing the surface
area of
moistened fabric to increase the evaporation. This principle of increasing
moistened
fabric area performs reasonably well in garments where the fabric is in direct
interaction
with the atmosphere, but the reduced atmospheric interaction specific to the
context of
socks tends to limit the effectiveness of conventional moisture-spreading
fabrics when
applied to socks. The special cross-section design of these synthetic fibers
enables the
fabric made with them to hold greater amounts of moisture, but this moisture
is evenly
spread throughout (i.e., along the inner side as well as outer side),
resulting in a
condition similar to that of a natural fiber fabric, wherein once sweating
begins, a
wearer's skin remain in contact with wet fabric until the fabric is completely
dried after
evaporation.
[0007]In view of the limited airflow inside a shoe, it would be desirable to
provide a sock
capable of keeping a wearer's skin isolated from wet fabric while exhibiting
good
wicking performance to expedite evaporation.
SUMMARY
[0008]With the constraint of low airflow in mind, socks according to various
embodiments of the present invention include at least a sole portion thereof
comprising
a specialized layered fabric including a dual face or dual layer material
(e.g., terry
material) with a hydrophobic inner face (or layer) and a hydrophilic outer
face (or layer).
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The sole portion of the sock corresponds to a sole portion of a wearer's foot
having a
maximum number of sweat glands and almost no airflow. The inner face (or
layer) of the
sock is arranged for placement in contact with skin of a wearer. With the
inner face (or
layer) being rich in hydrophobic fibers and the outer face (or layer) being
rich in
hydrophilic fibers, moisture is adsorbed from a wearer's skin by the
hydrophobic fibers
of the inner face (or layer) and is immediately absorbed by the absorbent
outer face (or
layer) where it is spread all over. This dual face or dual layer structure
promotes
transport of moisture to the side which is to interact with the atmosphere,
thereby
isolating skin from moist outer fabric. Skin covered with such a sock and
additionally
covered with a shoe may be maintained in a dry condition despite the
constraint of
reduced interaction of the sock with a surrounding atmosphere. No matter how
slow the
evaporation process, socks according to embodiments of the present invention
promote
separation of wetness from the wearer's skin, thereby avoiding problems of
excessive
friction, blisters and discomfort associated with use of conventional socks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]FIG. 1 is a perspective view of a sock according to one embodiment of
the
present invention, showing different constructions corresponding to different
foot and
ankle locations.
[00101FIG. 2 is a top plan view showing the inner side of a slit-open sock
according to
the embodiment shown in FIG. 1.
(0011] FIG. 3 is a bottom plan view showing the outer side of a slit-open sock
according
to the embodiment shown in FIGS. 1-2.
[0012]FIG. 4A is a perspective schematic view showing a dual face terry
material
proximate to skin of a wearer, with an (upward-facing) inner face including
loops (or
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pile) of hydrophobic yarn arranged to adsorb droplets of sweat for transport
away from
the skin.
[0013] FIG. 4B is a perspective view of the dual face terry material of FIG.
4A with an
(upward-facing) outer face including hydrophilic yarn, and showing absorption
of sweat
by the outer face following transport of sweat to the outer face by the
hydrophobic inner
layer.
[0014]FIG. 5 is a table providing results of tests for vertical wicking and
absorbency of a
dual face terry material that may be used to fabricate at least a portion of a
sock
according to embodiments to the present invention.
[0015] FIG. 6 is a schematic stitch diagram for a dual face terry material of
at least a
portion of a sock according to embodiments of the present invention.
DETAILED DESCRIPTION
[0016]As noted previously, a sock according to the present invention may
include a
dual face or dual layer material (e.g., terry material) at at least a sole
portion thereof,
with the inner face or layer including a hydrophobic yarn, the outer face or
layer
including a hydrophilic yarn, and the inner face or layer being arranged for
placement in
contact with skin of a wearer. This construction essentially provides low
absorbency
fibers along the inner face (or layer) and high absorbency fibers along the
outer face (or
layer). Such construction is designed to transport moisture away from skin of
a wearer
via absorption using the hydrophobic yarn of the inner face or layer, and to
spread
moisture within the outer face via absorption using the hydrophilic yarn of
the outer face
or layer, to permit evaporation of sweat from the outer face or layer to a
surrounding
environment.
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[0017] Examples of hydrophobic yarns that may be used in constructing portions
of a
sock as described herein include, but are not limited to, polypropylene,
polyester,
acrylic, and blends of the foregoing materials. As will be recognized by one
skilled in
the art, other hydrophobic materials or combinations of materials may be used.
Examples of hydrophilic yarns that may be used in constructing portions of a
sock as
described herein include, but are not limited to, wool, cotton, viscose, and
blends of the
foregoing materials. As will be recognized by one skilled in the art, other
hydrophilic
materials or combinations of materials may be used.
[0018] In certain embodiments, a sock as described herein includes plaiting of
stretch
hydrophobic yarn. Such plaiting may be provided in the dual face or dual layer
material
arranged in at least the sole portion of the sock. Such plaiting may be
tailored to
specific zones of a sock provide desired level of stretch characteristics.
[0019] In certain embodiments, an inner face or inner layer of the dual face
or dual layer
material consists of 100% hydrophobic yarn. Such yarn may keep a wearer's skin
dry
and isolated while providing cushioning.
[0020] In certain embodiments, an outer face or outer layer of the dual face
or dual layer
material (or an outer face or outer layer of the entire sock) comprises
hydrophilic yarn to
transport sweat from the inner face or inner layer to the outer face or outer
layer. Sweat
is absorbed by the outer face or outer layer and spread around such face or
layer by
absorption to promote evaporation. In certain embodiments, the outer layer or
outer
face of the entire sock (not just the sole portion) comprises hydrophilic
material to
maximize evaporation of sweat to an ambient environment.
[0021] In certain embodiments, an inner side or inner layer of the dual face
or dual layer
material has minimal to no affinity for moisture or sweat. Such inner side or
inner layer
may have an absorbency test value of at least 30 seconds according to AATCC
Test
Method 79. Such test method measures a propensity of fabric to take up water,
CA 02844442 2014-03-04
whereby a fabric sample is placed in an embroidery hoop with all creases
removed, a
burette dispenses a drop of water onto the surface of the fabric from a
distance of 9.5
mm below the burette, and time is recorded until the water drop is complete
absorbed
into the fabric.
[0022] In certain embodiments, an outer face or outer layer of the dual face
or dual layer
material has great affinity for moisture or sweat. Such outer side or outer
layer may
have any absorbency test value of 5 seconds or less.
[0023] In certain embodiments, an outer face or outer layer of the dual face
or dual layer
material (which covers the entirety of the sole portion, and in certain
embodiments
preferably covers the entire outer perimeter of a sock) exhibits excellent
spread of
moisture, with the outer face or outer layer being arranged to interact with
an ambient
atmosphere. Such outer face or outer layer may exhibit vertical wicking of at
least 10
centimeters in 30 minutes. Vertical wicking tests (e.g., AATCC Test Method 197
or
Consumer Testing Lab method CTL-FW-106) generally involve placement of
suspension of vertically aligned fabric specimen with a cut edge in a
container of liquid,
(e.g., distilled water) and recordation of height of liquid the is absorbed
for a specified
time. Such tests are used to evaluate the ability of fabric to transport
liquid along and/or
through the fabric.
[0024] In certain embodiments, a sock as disclosed herein may have separate
colors on
inner and outer sides (or faces) thereof. In certain embodiments, an inner
face (or
layer) may include a first color, an outer face (or layer) may include a
second color, and
the first color differs from the second color. In certain embodiments, the
provision of
separate colors along inner and outer sides (or faces) of a sock may exclude
heel and
toe areas of the sock.
[0025] In certain embodiments, a sock may include a mesh or mesh channeled
material
portion arranged to be positioned along a top portion of a wearer's foot where
conditions
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of less sweat and greater airflow may be experienced. Such mesh or mesh
channeled
material portion may include hydrophilic main yarn and stretch hydrophobic
plaiting
yarn.
[0026]In certain embodiments, a sock may include a plain knit fabric portion
arranged to
be positioned along a wearer's ankle. Such plain knit fabric portion may
include
hydrophilic main yarn and stretch hydrophobic plaiting yarn.
[0027]In certain embodiments, a sock may include reverse plaited terry fabric
portions
arranged to be positioned along a wearer's heel and along a wearer's toes, and
intended to provide increased (e.g. maximum) cushioning. Such reverse plaited
terry
fabric portions may include hydrophilic and/or hydrophobic main yarn and
stretch
hydrophobic plaiting yarn.
[0028] In certain embodiments, a sock may include simulated rib fabric portion
arranged
to be positioned at a top portion of the sock (e.g., above an ankle portion)
for maximum
grip along a wearer's leg. The simulated rib fabric portion may include
hydrophilic main
yarn, stretch hydrophobic plaiting, and laid-in elastic yarn.
[0029]In certain embodiments, at least a sole portion of a sock may include
two thread
terry fabric construction with dual faces or layers, having a hydrophobic
inner pile,
stretch hydrophobic plaiting, and hydrophilic main yarn in the outer layer or
face.
[0030]In certain embodiments, at least a sole portion of a sock may include an
inner
pile (e.g., embodying an inner face or layer) comprising hydrophobic yarn,
with stretch
plaiting in the middle, and with an outer face or outer layer comprising
hydrophobic
yarn.
[0031]In certain embodiments, a hydrophobic inner face or inner layer portion
is
arranged to press against and contact a hydrophilic outer face or outer layer
portion
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under application of elastic pressure and/or body weight of a wearer. Such
contact
causes adsorbed moisture on the hydrophobic inner face or inner layer portion
to be
absorbed by the hydrophilic outer face or outer layer, into which the moisture
is rapidly
spread to promote evaporation.
[0032]While the present invention will be described with reference to a few
specific
embodiments, the description is illustrative of the invention and is not to be
construed as
limiting the invention.
[0033]FIG. 1 is a perspective view of a sock according to one embodiment of
the
present invention, showing different constructions corresponding to different
foot and
ankle locations depending on functional requirements at those places. Mesh
channels 5
are arranged to be positioned at a top portion of a wearer's foot where there
is lesser
sweat and greater airflow. The mesh channels 5 include hydrophilic main yarn
and
stretch hydrophobic plaiting yarn. A plain knit fabric portion 2 arranged to
be positioned
along a wearer's ankle includes standard plain knit fabric with hydrophilic
main yarn and
stretch hydrophobic plaiting yarn. Reverse plaited terry fabric is provided at
heel and toe
portions 3 for maximum cushioning, with hydrophilic main yarn and stretch
hydrophobic
plaiting. A simulated rib fabric portion 1 arranged to be positioned at a top
portion of the
sock (e.g., above an ankle portion) to receive a wearer's leg and provide
maximum grip,
with such portion 1 including hydrophilic main yarn, stretch hydrophobic
plaiting, and
laid-in elastic yarn. A sole portion 4 includes two thread terry fabric
construction with
dual faces, having a hydrophobic inner pile, stretch hydrophobic plaiting, and
hydrophilic
main yarn.
[0034] FIG. 2 is a top plan view showing the inner side of a slit-open sock
according to
the embodiment shown in FIG. 1. Provided at the top of the sock and arranged
to be
positioned around a wearer's leg is an inner surface 6 of false rib fabric for
maximum
grip, with hydrophilic main yarn, stretch hydrophobic plaiting, and laid-in
hydrophobic
elastic yarn. Arranged to be positioned around a wearer's ankle and/or leg is
an inner
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surface 7 of standard plain knit fabric including stretch hydrophobic plaiting
yarn with
hydrophilic main yarn on an outer side thereof. Reverse plaiting terry fabric
is provided
along inner heel surface 8 and inner toe surface 9, with thick terry pile for
maximum
cushioning including hydrophilic and or hydrophobic main yarn with stretch
hydrophobic
plaiting. Arranged to be positioned at a top portion of a wearer's foot is an
inner surface
of mesh fabric 10 at a location having lesser sweat and greater airflow, with
such fabric
including stretch hydrophobic plaiting yarn with hydrophilic main yarn on an
outer side.
Arranged to be positioned along a sole portion of a wearer's foot is an inner
surface of a
two thread terry fabric 11 with dual face construction, having an inner pile
(or inner
face) made with hydrophobic yarns, with stretch hydrophobic plaiting in the
middle, and
with hydrophilic main yarn on an outer side or outer face.
[0035] FIG. 3 is a bottom plan view showing the outer side of a slit-open sock
according
to the embodiment shown in FIGS. 1-2. Provided at the top of the sock and
arranged to
be positioned around a wearer's leg is an outer surface 12 of simulated rib
fabric for
maximum grip, with hydrophilic main yarn, stretch hydrophobic plaiting, and
laid-in
hydrophobic elastic yarn. Arranged to be positioned around a wearer's ankle
and/or leg
is an inner surface 13 of standard plain knit fabric including hydrophilic
main yarn with
stretch hydrophobic plaiting yarn. Reverse plaiting terry fabric is provided
along inner
heel surface 14 and inner toe surface 15, exhibiting plain stitch, with
hydrophilic main
yarn and stretch hydrophobic plaiting. Arranged to be positioned at a top
portion of a
wearer's foot is an outer surface of mesh fabric 16 at a location having
lesser sweat and
greater airflow, with such fabric including hydrophilic main yarn with stretch
hydrophobic
plaiting yarn on an inner side. Arranged to be positioned along a sole portion
of a
wearer's foot is an inner surface of a two thread terry fabric 17 including
dual face
construction , exhibiting plain stitch with hydrophilic main yarn on an outer
side, with
stretch hydrophobic plaiting in the middle, and with hydrophobic yarn pile on
an inner
side.
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[0036] FIGS. 4A-4B illustrate the functioning of the dual face or dual layer
terry fabric as
described herein, Sweat vapor 24 is exuded by a wearer's skin 18 and
momentarily
adsorbs to inner terry pile 19 made of hydrophobic yarns. Under elastic
pressure and
body weight the two layers of fabric (i.e., the hydrophobic inner layer 19 and
the
hydrophilic outer layer 20), are pressed against each other. Adsorbed moisture
on the
inner side 19 of the terry fabric is absorbed up by the outer hydrophilic
layer 20 the
moisture it is spread rapidly for evaporation.
[0037] FIG. 5 is a table providing results of tests for vertical wicking and
absorbency of a
dual face terry material (fabric) that may be used to fabricate at least a
portion of a sock
according to embodiments to the present invention. . An inner face portion of
the
material exhibited an absorbency test value of greater than 30 seconds upon
testing
according to AATCC Test Method 79. An outer face portion exhibited an
absorbency
test value of 1.8 seconds upon testing according to AATCC Test Method 79. The
results clearly show that this fabric has no affinity for moisture on the
inner side, while
the outer layer is highly absorbent. With respect to vertical wicking, the
vertical wicking
of the outer layer is also excellent, showing that moisture is rapidly spread
for quick
evaporation. The foregoing results are also indicative of the fact that the
layer next to a
wearer's skin remains dry.
[0038] FIG. 6 is a schematic stitch diagram for a dual face terry material
(fabric) of at
least a portion of a sock according to embodiments of the present invention.
Such
figure illustrates knit stich hydrophilic main yarn 21, knit stitch, plaited
stretch
hydrophobic yarn 22, and float stitch terry hydrophobic yarn 23 arranged in an
exemplary construction.
[0039] While the invention has been has been described herein in reference to
specific
aspects, features and illustrative embodiments of the invention, it will be
appreciated
that the utility of the invention is not thus limited, but rather extends to
and
encompasses numerous other variations, modifications and alternative
embodiments,
CA 2844442 2018-04-03
as will suggest themselves to those of ordinary skill in the field of the
present invention,
based on the disclosure herein. Various combinations and sub-combinations of
the
structures described herein are contemplated and will be apparent to a skilled
person
having knowledge of this disclosure. Any of the various features and elements
as
disclosed herein may be combined with one or more other disclosed features and
elements unless indicated to the contrary herein. Correspondingly, the
invention as
hereinafter described is intended to be broadly construed and interpreted, as
including
all such variations, modifications and alternative embodiments.
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