U.S. patent application number 14/215932 was filed with the patent office on 2014-10-23 for performance dress sock.
The applicant listed for this patent is MINISTRY OF SUPPLY. Invention is credited to Aman Advani, Gihan S. Amarasiriwardena, Caitlin Hickey, Claudia Richardson.
Application Number | 20140311187 14/215932 |
Document ID | / |
Family ID | 51727963 |
Filed Date | 2014-10-23 |
United States Patent
Application |
20140311187 |
Kind Code |
A1 |
Amarasiriwardena; Gihan S. ;
et al. |
October 23, 2014 |
PERFORMANCE DRESS SOCK
Abstract
A sock having a low pressure area made of a first knit density
and at least one high pressure area made of a variable knit density
portion. The variable knit density has portions that are made of a
second knit density greater than the first knit density. The at
least one variable knit density portion is arranged transverse to
an orientation of major strain. A sock may also have hydrophobic
fibers located substantially across a surface of the sock adapted
to be adjacent to skin when worn and hydrophilic fibers located
substantially across the hydrophobic fibers and extending therefrom
to form loop structures adapted for wicking moisture away from the
hydrophobic fibers.
Inventors: |
Amarasiriwardena; Gihan S.;
(Boston, MA) ; Advani; Aman; (Boston, MA) ;
Richardson; Claudia; (Somerville, MA) ; Hickey;
Caitlin; (Cambridge, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MINISTRY OF SUPPLY |
BOSTON |
MA |
US |
|
|
Family ID: |
51727963 |
Appl. No.: |
14/215932 |
Filed: |
March 17, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61791208 |
Mar 15, 2013 |
|
|
|
Current U.S.
Class: |
66/178R |
Current CPC
Class: |
A41B 11/02 20130101;
D10B 2401/022 20130101; D10B 2403/0114 20130101; A41B 11/00
20130101; D04B 1/26 20130101; D10B 2401/021 20130101 |
Class at
Publication: |
66/178.R |
International
Class: |
A41B 11/00 20060101
A41B011/00 |
Claims
1. A sock comprising: a low pressure area comprising a first knit
density; and at least one high pressure area comprising a variable
knit density portion, the variable knit density comprising portions
having a second knit density greater than the first knit density,
wherein the at least one variable knit density portion is arranged
transverse to an orientation of major strain.
2. The sock of claim 1, wherein the at least one variable density
portion is disposed in a portion corresponding to a metatarsal
region of a foot when worn.
3. The sock of claim 2, wherein the variable density portion is
arranged transverse to a line connecting a first
metatarsophalangeal joint region to a fifth metatarsophalangeal
joint region.
4. The sock of claim 1, wherein the variable density portion
comprises a pattern.
5. The sock of claim 4, wherein the pattern comprises a plurality
of polygons.
6. The sock of claim 1 further comprising a frictional surface
adapted to be aligned along an orientation of minor strain.
7. The sock of claim 6, wherein the frictional surface is disposed
in a rear portion of the sock.
8. The sock of claim 6, wherein the frictional surface comprises a
plurality of strips.
9. The sock of claim 6, wherein the frictional surface comprises at
least one of urethane and silicone.
10. The sock of claim 1 further comprising a third knit density
portion disposed proximate an area corresponding to an arch of a
foot when worn, wherein the third knit density is greater than the
first knit density.
11. The sock of claim 10, wherein the third knit density portion
extends around the sock and is configured to surround the arch area
when the sock is worn.
12. The sock of claim 1, wherein the sock comprises a dress
sock.
13. The sock of claim 1 further comprising synthetic polyester
comprising activated charcoal.
14. The sock of claim 13, wherein the activated charcoal comprises
coffee grounds.
15. A sock comprising: hydrophobic fibers disposed substantially
across a surface of the sock adapted to be adjacent to skin when
worn; and hydrophilic fibers disposed substantially across the
hydrophobic fibers and extending therefrom to form loop structures
adapted for wicking moisture away from the hydrophobic fibers.
16. The sock of claim 15, wherein the sock comprises a greater
amount of hydrophilic fibers than hydrophobic fibers.
17. The sock of claim 16, wherein the sock comprises about a 75/25
ratio of hydrophilic fibers to hydrophobic fibers.
18. A method of manufacturing a performance dress sock, the method
comprising the steps of: robotically knitting a low pressure area
of the sock at a first knit density; and robotically knitting a
high pressure area of the sock at a variable knit density, wherein
the variable knit density comprises portions having a second knit
density greater the first knit density, and wherein the at least
one variable knit density portion is arranged transverse to an
orientation of major strain.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent
Application No. 61/791,208, filed on Mar. 15, 2013, which is
incorporated herein by reference as if set forth in its
entirety.
FIELD OF THE INVENTION
[0002] This invention relates generally to performance apparel and,
particularly, to performance dress socks.
BACKGROUND
[0003] Socks pose a particularly difficult problem with respect to
performance as they experience significant strain during walking
due to movement of the foot throughout a gait cycle. Further,
stresses in socks are amplified as a significant portion of a
wearer's weight is placed on each foot while walking Often,
compromises are made to provide either a sock that is durable but
inappropriate for office wear (e.g., athletic socks) or a sock that
is designed for appearance and wear with office attire (e.g., dress
socks) that tends not to be as durable. Also, many socks are
manufactured with a substantially constant knit density, which
tends to provide either cushioning (in the case of a higher knit
density) or dynamic stretch properties (in the case of a lower knit
density). Therefore, there is a need for durable, comfortable socks
that are considered appropriate for wear in professional
environments, and that also provide a combination of cushioning and
dynamic stretch abilities.
SUMMARY OF THE INVENTION
[0004] Embodiments of a performance dress sock incorporate select
materials and construction to improve wearer comfort and durability
of the wares while maintaining a professional appearance (e.g., in
an office setting). The performance dress sock can have a half-calf
or mid-calf arrangement with the upper part of the sock largely
driven by aesthetic considerations, as opposed to typical socks
which maintain a relatively
[0005] In one aspect, the invention relates to a sock having a low
pressure area made of a first knit density and at least one high
pressure area made of a variable knit density portion. The variable
knit density has portions that are made of a second knit density
greater than the first knit density. The at least one variable knit
density portion is arranged transverse to an orientation of major
strain.
[0006] In one embodiment of the above aspect, the variable density
portion is located in a portion corresponding to a metatarsal
region of a foot when the sock is worn. The variable density
portion may be arranged transverse to a line connecting a first
metatarsophalangeal joint region to a fifth metatarsophalangeal
joint region. The variable density portion may be a pattern. The
pattern may be a plurality of polygons, and the pattern may be a
grid. In some embodiments, the sock has a frictional surface
adapted to be aligned along an orientation of minor strain. The
frictional surface may be located in a rear portion of the sock,
and the frictional surface may be one or more strips. In certain
embodiments, the frictional surface is made of at least one of
urethane and silicone.
[0007] In some embodiments, the sock has a third knit density
portion (with a knit density greater than the first knit density)
near an area corresponding to an arch of a foot when the sock is
worn. The third knit density portion may extend around the sock to
surround the arch area when the sock is worn. In certain
embodiments, the sock is a dress sock. The sock may be made of
synthetic polyester comprising activated charcoal, such as coffee
grounds.
[0008] In another aspect, the invention relates to a sock having
hydrophobic fibers located substantially across a surface of the
sock adapted to be adjacent to skin when the sock is worn. The sock
also has hydrophilic fibers located substantially across the
hydrophobic fibers and extending therefrom to form loop structures
adapted for wicking moisture away from the hydrophobic fibers.
[0009] In one embodiment, the sock has a greater amount of
hydrophilic fibers than hydrophobic fibers. The sock may have about
a 75/25 ratio of hydrophilic fibers to hydrophobic fibers.
[0010] In another aspect, the invention relates to a method of
manufacturing a performance dress sock. The method includes the
steps of robotically knitting a low pressure area of the sock at a
first knit density and robotically knitting a high pressure area of
the sock at a variable knit density. The variable knit density has
portions having a second knit density greater the first knit
density. The at least one variable knit density portion is arranged
transverse to an orientation of major strain.
BRIEF DESCRIPTION OF THE FIGURES
[0011] Other features and advantages of the present invention, as
well as the invention itself, can be more fully understood from the
following description of the various embodiments, when read
together with the accompanying drawings, in which:
[0012] FIG. 1A is a depiction of a strain profile obtained through
experimentation with orientations of strain and an outline of a
foot superimposed thereon;
[0013] FIG. 1B is a schematic bottom view of a sock designed taking
into consideration the strain profile of FIG. 1A and the pressure
profile of FIG. 2, in accordance with one embodiment of the
invention;
[0014] FIG. 2 is a depiction of a pressure profile obtained through
experimentation with an outline of a foot superimposed thereon;
[0015] FIG. 3 is a schematic, side, cross-sectional view of the
sock of FIG. 1 with arrows indicating thermal escape paths, in
accordance with one embodiment of the invention;
[0016] FIG. 4 is a schematic depiction of one arrangement of
hydrophobic and hydrophilic fibers in relation to a skin surface,
in accordance with one embodiment of the invention;
[0017] FIG. 5A is a schematic depiction of polyester fiber infused
with coffee charcoal and a structure of the coffee charcoal, in
accordance with one embodiment of the invention;
[0018] FIG. 5B is a magnified view of the polyester fiber infused
with coffee charcoal of FIG. 5A;
[0019] FIG. 5C is a magnified view of the structure of the coffee
charcoal of FIG. 5A;
[0020] FIG. 6A is an isometric view of loafer socks, in accordance
with one embodiment of the invention;
[0021] FIG. 6B is a schematic, isometric view of the loafers socks
of FIG. 6A with a frictional surface;
[0022] FIG. 7A is an isometric view of a performance dress sock, in
accordance with one embodiment of the invention; and
[0023] FIG. 7B is a partial bottom view of the sock of FIG. 7A.
DETAILED DESCRIPTION
[0024] A performance dress sock may have several features that
contribute to its performance and functioning as a second skin,
beginning with an understanding of how the strain, pressure, and
temperature of the foot affect various regions of the sock, as
determined through body mapping. These analyses are described in
detail below with respect to creating a dress sock that provides
cushioning venting, and dynamic stretch properties in desired
locations.
[0025] To understand skin strain dynamics on the medial, posterior,
and plantar surfaces of the foot, such as where soft tissue needs
support (e.g., through tension) and where skin is stretching the
most, the GOM ARAMIS Optical measurement system (Braunschweig,
Germany) with stereo high-speed video cameras was used to create a
digital image correlation of a stochastic pattern. Six subjects
with varying foot types were monitored for deformation of the foot
during the walking gait cycle, with the subjects both bare foot and
wearing a shoe sawn in half to understand dynamics within the shoe.
Plantar strain was monitored via an optical arrangement through a
transparent force plate. An exemplary result 100 (including
superimposed lines 102 depicting the direction of major strain and
a foot outline 104) is depicted in FIG. 1A. Based on this testing,
it was determined that during midstance the arch of the foot
collapses, causing major strain in a transverse direction across
the arch, as depicted with the transverse arch line 106. In the
metatarsal region, the orientation of major strain is angled from
the first metatarsophalangeal joint (MPJ) to the fifth MPJ, as
depicted with the metatarsal strain line 108. In the Achilles heel
region, major strain is oriented in a substantially vertical
direction.
[0026] The performance dress sock is configured to address certain
issues identified in the strain analysis, and to repeatably
withstand wear and support a wearer throughout various movements.
For example, as depicted in an embodiment of a performance sock 110
in FIG. 1B, a compression band 112a (e.g., an area of higher knit
density) may be used in an area of the sock 110 corresponding with
the arch of the foot to provide additional support. The compression
band 112a (e.g., the area of higher knit density) can apply greater
tension along the direction of major strain than lower knit density
areas, and can extend all the way around the foot in the arch
region. The compression band 112a may also have a higher elastane
content (e.g., between about 20 and 40% by mass of the knit in the
compression band 112a) than other portions to support the arch. To
reduce friction on the plantar surface (i.e., the sole of the
foot), and to reduce potential for blistering, the sock 110 may
allow for stretching along the direction/orientation of major
strain in high pressure areas, as described in greater detail
below. One way to achieve this selective stretchability is through
a varied pattern (e.g., of stripes or polygons) in relatively
higher 114a and lower knit density 114b (a variable density portion
116), which provides preference of stretch in a certain direction
(e.g., along a direction of major strain as determined by the
strain analysis) while still providing cushioning. The variable
knit density portion 116 covered by the pattern and/or the pattern
itself may be arranged substantially transverse to the
direction/orientation of major strain to better maintain its
characteristics even while being stretched. By allowing the sock
110 to stretch with and in the same manner as a wearer's skin, the
user experiences less blistering and more comfort, while avoiding
many of the problems associated with traditional socks, such as
bunching and sagging.
[0027] These variable knit density portions 116 and the associated
pattern may be manufactured through various techniques, including
robotic knitting. The higher knit density portions 114a (or
"cushions") may be formed on an elastic base, allowing them to move
independently and with the skin. For example, the sock 110 may be
made substantially of a base layer having a lower knit density
(e.g., a mass ratio of approximately 80% elastane to approximately
20% hydrophobic fibers) throughout, creating a sock with good
ventilation and stretching properties. To increase support,
tension, and cushioning in certain areas (such as those areas
determined by body mapping), additional fibers (particularly
hydrophilic and/or hydrophobic fibers) may be added to increase the
density and create a ratio of approximately 20% elastane, 40%
hydrophobic fibers, and 40% hydrophilic materials. These are only
exemplary ratios, and others are contemplated, including for lower
density vented areas to be made with 100% elastane and for higher
density areas to be made of approximately 80% hydrophilic material
(e.g., cotton) and 20% elastane. Additionally, instead of forming a
base layer and adding to it to create higher density areas, higher
density and lower density areas may be formed separately through
the manufacturing process (e.g., through robotic knitting). The use
and arrangement of hydrophobic and hydrophilic materials is
described in greater detail below.
[0028] The performance dress sock is also designed to address
issues associated with the pressure profiles developed during
pressure mapping, which also impacts the comfort and wear of the
sock during walking To understand the pressure profiles and the
correlation between stress and strain, and where feet need the most
cushioning, six subjects were monitored using a Tekscan mat (South
Boston, Mass.). An exemplary pressure profile 200 is depicted in
FIG. 2. The pressure profile 200 illustrates that pressure is
highest in the metatarsal region 202 and the calcaneal region 204,
with some pressure beneath the hallux 206. The areas with high
stress (or pressure) and strain are expected to experience higher
friction while walking, which could very likely develop into
blisters on the feet of the wearer. However, by designing a
performance dress sock to allow stretching in these high pressure
regions as described above (e.g., with variable knit density areas
116 and/or high knit density areas 112b, 112c), the risk of
blisters can be greatly reduced. To preserve some of the
breathability that may be lost in the high pressure regions when
using high density knit cushions 114a (which may provide cushioning
and increase comfort and overall durability), areas with minimal
pressure can have a lower knit density, such as on the upper side
of the sock 110.
[0029] While stress and strain are important considerations in the
design of the sock 110 to make it feel like a second skin, it is
also important to consider the thermal effects on the wearer of
such a sock. Thermal imaging may be used to identify the areas of
the foot that experience the highest temperature during wear
(called "hot spots"), and thus the areas that need the most
ventilation. Temperature buildup may be alleviated at these hot
spots by providing a path for the heat to escape outside of the
sock 110, as depicted in FIG. 3. When the cushions 114a and the
lower density portions 114b are arranged in a pattern, excess heat
may more easily escape a foot through the lower density portions
114b, even when the sock 110 is under compression. Because of the
difference in thickness between the cushions 114a and the lower
density portions 114b, channels are formed between the cushions
114a to allow this escape. Balancing these temperature
considerations with the strain and pressure considerations can lead
to a much better performing and more comfortable dress sock for a
wearer.
[0030] In addition to allowing for the removal of heat, the sock
110 may also be designed to remove moisture from a wearer's foot.
When moisture builds up and remains against a wearer's foot, the
wearer can experience an uncomfortable, clammy feeling. This
feeling may remain even immediately after the moisture is removed,
so it is desirable to provide a mechanism for removing moisture on
an ongoing basis. Blends of hydrophobic and hydrophilic yarns
(e.g., the hydrophobic synthetic polyester and the hydrophilic
cotton described above) can provide higher moisture transport rates
from a skin surface than a layer made of 100% hydrophobic fibers.
Various ratios between the amounts of hydrophobic and the
hydrophilic materials may be used, including a 60/40, a 75/25, an
80/20, and other mass ratios between and beyond these values. As
arranged in FIG. 3, hydrophilic fibers 320a can work to pull
moisture away from the skin surface 322, while hydrophobic fibers
320b spread moisture horizontally across a surface, thereby
increasing surface area and accelerating evaporation of the
moisture. The hydrophilic fibers 320a and/or the hydrophobic fibers
320b may be untreated, relying on intrinsic known material
properties to provide the desired wicking and evaporation. One
embodiment of a joint hydrophilic/hydrophobic arrangement is
depicted in FIG. 4. Such a construction may be found in a higher
knit density area 114a, for which FIG. 4 would provide a
representative schematic cross-sectional view. The hydrophobic
fibers 320b are close to the skin, distributing moisture from
certain areas across a much larger surface area of the foot. The
hydrophilic fibers 320a extend away from the hydrophobic fibers
320b, forming "reservoirs" (or loops) in which moisture may
accumulate following wicking from the skin 322 and the hydrophobic
fibers 320b. The loops may be formed individually, allowing each to
act as a separate reservoir, and a length of fiber forming each
loop may be exposed to the environment (as opposed to trapping
moisture within a layer of fabric and relying on pores for moisture
to escape). The hydrophilic fibers 320a may be woven through a base
layer closest to the skin (e.g., a layer made of elastane and/or
particular hydrophobic fibers) in a variety of densities,
including, for example, 100 loops per square inch. In certain
embodiments, additional hydrophobic fibers 320b may be included
with the hydrophilic fibers 320a and woven together. The
arrangement of hydrophilic fibers 320a looping away from the
hydrophobic fibers 320b removes moisture from the skin 322 and
provides a preferential wicking direction toward the exterior of
the sock 110, allowing the wearer to feel dry even while moisture
cannot be immediately removed from the environment (e.g., when
wearing shoes). In this manner, the performance dress sock can
provide high performance characteristics through moisture
management and comfort not experienced with other dress socks.
[0031] A wearer's experience may further be improved based on the
materials used, as fabric composition is a factor in both comfort
and durability. The performance dress sock can include a
combination of synthetic and natural products, such as a
combination of synthetic polyester and long-staple cotton. Various
compositions are contemplated, including an approximately 60%
synthetic polyester and an approximately 40% long-staple cotton
composition. The synthetic polyester can contain activated
charcoal, such as that may be created through the partial
combustion of used coffee grounds, as depicted in FIG. 5A. The
carbon matter (coffee charcoal) 530 may be blended into the
polyester 532 prior to extrusion or otherwise infused into strands
of polyester 532. FIG. 5A also depicts schematically how the
activated coffee charcoal 530 attracts and absorbs aromatic organic
compounds and phenols 534 that commonly cause odor. FIGS. 5B
depicts a greatly magnified view of the coffee charcoal 530 blended
with the polyester 532, illustrating how the coffee 530 may be
embedded within the polyester 532 but still exposed to the
environment. FIG. 5C depicts a greatly magnified view of the coffee
charcoal 530 with sponge-like pores 536 for absorbing the odor
causing particles 534. Such a composition has proven to be up to
three times more effective at absorbing odor as compared to regular
cotton, and up over twice as effective as polyester, based on test
results using ASTM Standard D 5742. While the coffee charcoal 530
absorbs odor particles 534 during wear, the odor particles 534 may
be released when the socks 110 are laundered, allowing for further
odor capture when worn again. The materials used in the blend may
come from many sources, including recycled sources for polyester
and coffee previously ground at coffee roasters and similar shops.
The coffee 530 may be pharmaceutically processed prior to use in
the blend to remove coffee oils to substantially remove its own
scent.
[0032] FIG. 6A depicts an embodiment of the invention directed to a
sock 610 in a loafer configuration. The sock 610 is largely similar
to the sock 110, including a higher knit density in a metatarsal
region 612b and a sole region 612c, a variable knit density portion
616, and a lesser knit density on a top portion 630. One difference
between the sock 610 and the sock 110 is the absence of a
compression band in the mid-section of the foot, though this may be
included. Additionally, frictional surfaces 632 may be applied to
help prevent slipping of the sock 610 on the foot, as depicted in
FIG. 6B. For example, the rear portion of loafer socks 610 tend to
slip below the foot when the sock 610 is stretched. By providing
frictional surfaces 632 (e.g., printed strips of urethane or
silicone) along the transverse lines of non-extension or minor
strain along an interior heel region of the sock 610, friction can
be increased in contact areas while the fabric can stretch with the
skin. Typically, in traditional construction, if a frictional
surface is on the rear of a sock (which often is not the case), it
is applied over a relatively large, continuous surface area. This
traditional frictional surface area tends to suffer from some of
the same stretching issues as other areas of traditional socks,
particularly down the foot in the direction of major strain at the
Achilles heel. Over time, the singular large surface area tends to
migrate down the foot. Using separate spaced strips 632, as
depicted in FIG. 6B, allows for the sock 610 to stretch in between
the strips 632 and does not substantially stretch the strips 632
themselves, such that the strips 632 remain connected to the same
area of skin for the duration of wearing. This provides a
consistent wear experience without the need for constant
adjustments, which is particularly useful for loafers socks 610
that are cut very low so as to be non-visible when worn with loafer
shoes. A low friction fabric may be used at or near the top of the
loafer sock to reduce irritation.
[0033] FIGS. 7A and 7B depict a performance dress sock 710
incorporating many of the elements described above. For example,
the sock 710 has areas of relatively low knit density (e.g.,
approximately 100 GSM) on top (dorsal) portions 730, separated by a
compression band 712a of higher knit density (e.g., approximately
200 GSM +/-15 GSM) to provide arch support. The top portions 730
are not expected to experience significant changes in pressure, so
use of the light vented knit may be appropriate. Other areas that
are not expected to experience changes in pressure may have the
same or a similar light vented knit. In contrast, areas
experiencing the greatest pressure changes, (e.g., the metatarsal
and sole regions 712b, 712c) may have higher knit densities to
increase durability. An upper part 732 of the sock 710 (i.e., the
part that surrounds the calf) may have a substantially uniform
medium knit density (e.g., approximately 150 GSM) to give a
professional appearance, and may include a flat seam at the top to
reduce irritation. An interior of the upper part 732 of the sock
may also have friction surfaces (e.g., urethane strips or dots) to
help prevent the socks from falling down the leg during wear. The
plantar surface of the sock 710 depicted in FIG. 7B may have a
padded surface 716 to provide cushioning in high pressure regions.
In some embodiments, the padded surface 716 may be a grid,
featuring an alternating pattern of thicker, higher knit density
portions 714a (e.g., terry knitting), and lower density knit
portions 714b. The small channels formed in such an arrangement
facilitate vapor transfer even when the sock 710 is compressed
against a sole of a shoe, as the variance in thickness between the
higher knit density portions 714a and the lower knit density
portions 714b is adapted to create an offset in thickness.
[0034] While the principles laid out above have been described with
respect to a performance dress sock, it is easily understood that
such a design process is easily applicable to other apparel,
particularly apparel that touches a wearer's skin. For example, it
is contemplated that shirts and underwear may be developed in the
same manner as the socks described herein, e.g., by understanding
the strain and pressure profiles in the areas of the body
associated with the skin contacting garment and creating a design
that allows for stretching with the skin of the wearer to provide
comfort. This may be achieved by varying knit density across
different portions of the garment, as described herein with respect
to socks.
[0035] Various embodiments and features of the present invention
have been described in detail with particularity. The utilities
thereof can be appreciated by those skilled in the art. It should
be emphasized that the above-described embodiments of the present
invention merely describe certain examples implementing the
invention, including the best mode, in order to set forth a clear
understanding of the principles of the invention. Numerous changes,
variations, and modifications can be made to the embodiments
described herein and the underlying concepts, without departing
from the spirit and scope of the principles of the invention. All
such variations and modifications are intended to be included
within the scope of the present invention, as set forth herein. The
scope of the present invention is to be defined by the claims and
all equivalents, rather than limited by the forgoing description of
various preferred and alternative embodiments.
* * * * *