CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims benefit of Pakistani Patent Application No.
519/2013 filed on July 31, 2013 entitled "SOCKS", and of
U.S. Patent Application No. 14/134,975 entitled "SOCKS." Priority of the foregoing applications is hereby claimed, and the
contents of such applications are hereby incorporated by reference herein, for all
purposes.
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.
[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).
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.
FIG. 2 is a top plan view showing the inner side of a slit-open sock according to
the embodiment shown in FIG. 1.
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.
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 pile)
of hydrophobic yarn arranged to adsorb droplets of sweat for transport away from the
skin.
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.
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.
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
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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,
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.
[0016] 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.
[0017] 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-1 06) 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.
[0018] 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.
[0019] 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
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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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 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.
[0026] 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.
[0027] 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.
[0028] 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
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.
[0029] 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.
[0030] FIGS. 4A-4B illustrate the functioning of the dual face or dual layer terry fabric
as described herein, Sweat vapor'17 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.
[0031] 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.
[0032] 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.
[0033] 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, as will suggest
themselves to those of ordinary skill in the field of the present invention, based
on the disclosure herein. Various combinations and subcombinations 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 claimed
is intended to be broadly construed and interpreted, as including all such variations,
modifications and alternative embodiments, within its scope and including equivalents
of the claims.
1. A sock comprising a sole of dual face terry material including an inner face and an
outer face, wherein the inner face comprises hydrophobic yarn, the outer face comprises
hydrophilic yarn, and the inner face is arranged for placement in contact with skin
of a wearer.
2. The sock according to claim 1, further comprising plaiting of stretch hydrophobic
yarn.
3. The sock according to any one of claims 1 or 2, wherein the inner face consists of
100% hydrophobic yarn.
4. The sock according to any one of claims 1 to 3, wherein the outer face consists of
100% hydrophilic yarn.
5. The sock according to any one of claims 1 to 4, wherein the inner face comprises an
absorbency test value of at least 30 seconds according to AATCC Test Method 79.
6. The sock according to any one of claims 1 to 5, wherein the outer face comprises an
absorbency test value of no more than 5 seconds according to AATCC Test Method 79.
7. The sock according to any one of claims 1 to 6, wherein the outer face comprises a
vertical wicking test value of at least 10 cm in 30 minutes.
8. The sock according to any one of claims 1 to 7, wherein the inner face comprises a
first color, the outer face comprises a second color, and the first color differs
from the second color.
9. The sock according to any one of claims 1 to 8, wherein the sole comprises a dual
layer material, wherein the dual layer material includes an inner layer comprising
the inner face, and wherein the dual layer material includes an outer layer comprising
the outer face.
10. The sock according to claim 9, wherein the dual layer material comprises terry material.