U.S. patent application number 10/845470 was filed with the patent office on 2005-01-13 for elastic material for compression braces and the like.
This patent application is currently assigned to La Pointique International Ltd.. Invention is credited to Chiang, Jackson, Chuang, Jonathon.
Application Number | 20050010155 10/845470 |
Document ID | / |
Family ID | 34940733 |
Filed Date | 2005-01-13 |
United States Patent
Application |
20050010155 |
Kind Code |
A1 |
Chiang, Jackson ; et
al. |
January 13, 2005 |
Elastic material for compression braces and the like
Abstract
An elastic material is disclosed, including a breathable, closed
cell foam panel. The elastic panel (310) includes recessed portions
or channels (312) on at least one side, and apertures (314)
therethrough, the apertures disposed in the channels (312). The
channels may intersect to produce a network of flow paths for heat
and sweat transfer, or may comprise nonintersecting channels that
establish a directional flow path. In another embodiment, the
channels define a plurality of protrusions, such as circular
protrusions (332) or rectangular protrusions (342). The elastic
panel is preferably formed by compressing a sheet of closed cell
foam between a pair of oppositely disposed, heated plates (410,
420), wherein one of the plates includes a plurality of pins (422),
and the other of the plates includes apertures (414) adapted to
receive the pins. One or both of the plates includes protrusions
(412) for forming the recessed portions or channels.
Inventors: |
Chiang, Jackson; (Taipei,
TW) ; Chuang, Jonathon; (Brisbane, AU) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE
SUITE 2800
SEATTLE
WA
98101-2347
US
|
Assignee: |
La Pointique International
Ltd.
Tukwila
WA
|
Family ID: |
34940733 |
Appl. No.: |
10/845470 |
Filed: |
May 13, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10845470 |
May 13, 2004 |
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10355652 |
Jan 29, 2003 |
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10355652 |
Jan 29, 2003 |
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10004469 |
Oct 23, 2001 |
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6726641 |
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10004469 |
Oct 23, 2001 |
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09846332 |
May 2, 2001 |
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6508776 |
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Current U.S.
Class: |
602/60 |
Current CPC
Class: |
B32B 2266/0207 20130101;
B32B 2535/00 20130101; B29C 44/5663 20130101; B32B 5/18 20130101;
B32B 25/04 20130101; B32B 3/266 20130101; A61F 5/01 20130101; B32B
2305/18 20130101; B32B 5/245 20130101; B32B 2266/08 20130101; B32B
3/30 20130101; B32B 37/10 20130101; B32B 1/08 20130101; Y10T
428/24273 20150115; B32B 3/06 20130101; B32B 25/10 20130101; B32B
5/32 20130101; A61F 13/061 20130101; A61F 5/0104 20130101; B32B
5/04 20130101; B32B 38/004 20130101; A61F 5/0109 20130101 |
Class at
Publication: |
602/060 |
International
Class: |
A61F 013/00 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A method of manufacturing a material suitable for use in a
compression brace material, the method comprising the following
steps: providing a sheet of closed cell foam material between a
first plate having a plurality of spaced-apart pins extending from
a first surface, and a second plate having a plurality of
spaced-apart apertures, wherein the apertures are sized and spaced
to slidably engage the pins when the first plate and second plate
are suitably aligned, and further wherein at least one of the first
plate and the second plate further includes a plurality of
protrusions; heating at least one of the first plate and the second
plate to a selected temperature; urging the first plate and the
second plate together such that the pins on the first plate
penetrate the sheet of closed cell foam material and slidably
engage the apertures on the second plate; maintaining a pressure
between the first plate and the second plate for a period of time
such that the protrusions impress a plurality of depressions on the
sheet of closed cell foam material; and separating the first plate
from the second plate and removing the closed cell foam
material.
2. The method of claim 1, wherein the sheet of closed cell foam
material is neoprene, having a thickness between about 2.0 mm and
about 10.0 mm.
3. The method of claim 2, wherein at least one of the first plate
and the second plate is heated to a temperature between 145.degree.
C. and 160.degree. C.
4. The method of claim 3, wherein the pins have a diameter of
between 0.5 mm and 3.0 mm.
5. The method of claim 3, wherein the pressure maintained between
the first plate and the second plate is about 50 kg/cm.sup.2.
6. The method of claim 3, wherein the pressure between the first
plate and the second plate is maintained for between about 4
minutes and about 6 minutes.
7. The method of claim 3, wherein the protrusions are between about
1.0 mm and 2.0 mm deep.
8. The method of claim 7, wherein the protrusions consist of a
plurality of elongate parallel protrusions having a spacing of
between about 10.0 mm and 15.0 mm.
9. The method of claim 7, wherein the protrusions are shaped to
form a plurality of circular protrusions in the sheet of closed
cell foam material.
10. An elastic panel formed from a sheet of closed cell foam, the
elastic panel having a first side defining a plurality or recessed
channels that are formed by compressing the sheet of foam with
oppositely-disposed heated plates, and a plurality of apertures
through the sheet of foam that are formed by penetrating the panel
with heated pins, such that the channels and apertures are formed
without cutting any material away from the sheet of closed cell
foam.
11. The elastic panel of claim 10, wherein the sheet of closed cell
foam is a neoprene sheet.
12. The elastic panel of claim 10, wherein the plurality of
recessed channels comprises two sets of intersecting, parallel,
elongate channels.
13. The elastic panel of claim 10, wherein the plurality of
recessed channels defines a plurality of rectangular protrusions on
the first side of the foam sheet.
14. The elastic panel of claim 10, wherein the plurality of
recessed channels comprises a single set of parallel elongate
channels.
15. The elastic panel of claim 11, wherein the neoprene sheet is
between about 2.0 mm and 10.0 mm in thickness.
16. The elastic panel of claim 10, wherein the apertures are
disposed in the plurality of recessed channels.
17. The elastic panel of claim 12, wherein the apertures are
circular, with a diameter of between about 0.5 mm and 3.0 mm.
18. The elastic panel of claim 17, wherein the apertures are
disposed in the elongate channels.
19. The elastic panel of claim 12, further comprising a porous
inner fabric layer affixed to the first side of the elastic
panel.
20. The elastic panel of claim 14, wherein the apertures are
disposed in the elongate channels.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This is a continuation-in-part of U.S. patent application
Ser. No. 10/355,652, filed Jan. 29, 2003, which is a
continuation-in-part of application Ser. No. 10/004,469, filed Oct.
23, 2001, which is a continuation-in-part of application Ser. No.
09/846,332, filed May 2, 2001, priority from the filing date of
which is hereby claimed under 35 U.S.C. .sctn. 120.
FIELD OF THE INVENTION
[0002] This invention generally relates to breathable, elastic
materials that are suitable for elastic compression braces, and to
methods for forming such materials.
BACKGROUND OF THE INVENTION
[0003] Elastic compression braces are available in many forms.
Commonly, such braces are composed of soft, elastic material so
that when worn, they provide a certain amount of support for an
injured joint. These types of braces, often purchased without a
prescription or the need for skilled professional fitting, have
been used for a number of years and have been commonly available as
braces for the knee, ankle, thigh, wrist, elbow, chest, shoulder,
or lower back. These resilient, pliable compression braces can be
worn for sprains and strains, arthritis, tendonitis, bursitis,
inflammation, to reduce discomfort during post-operative use, or to
treat post-trauma discomfort.
[0004] The elastic compression braces are often made from synthetic
rubber (e.g., polychloroprene). This particular material is
desirable because of its combination of favorable properties useful
in elastic compression braces. Polychloroprene rubber has good
elasticity and a relatively high density, thereby providing good
compression support and resistance to shear forces.
[0005] Polychloroprene rubber is a closed cell material and
therefore does not dissipate heat very well during use. Its closed
cell characteristics can be useful in retaining heat during use by
reflecting emitted heat back into the bones and joints of the
affected area. This localized concentration of heat can aid venous
flow, help reduce edema, and make the soft tissues less susceptible
to injury.
[0006] Although use of polychloroprene rubber in elastic
compression braces can concentrate heat, the natural tendency of
the closed cell material to prevent heat dissipation may cause
problems for the user. When worn, the polychloroprene material
braces are stretched to impart a compression load around the
affected body area. This compression fit, combined with the high
density of the material and the lack of air circulation and
dissipation through the material, can result in heat discomfort and
perspiration, and may lead to heat rashes. Prolonged use of such
braces can cause the user to perspire constantly, resulting in
discomfort, and often prompting the user to prematurely stop
wearing the brace. In effect, the material itself dictates the
length of time that the orthopedic brace can be worn. It is not
uncommon for users to stop wearing such braces after about one to
two hours. In an effort to provide better breathability, certain
prior polychloroprene rubber braces have been manufactured with
perforations or holes punched through the entire depth of the
material. However, these braces may not retain sufficient
structural integrity to serve as an effective compression brace for
the wearer because neoprene material is removed from these
braces.
[0007] In particular, prior art methods of punching or cutting
holes into the braces can produce weaknesses in the material. The
material is designed to be wrapped and/or stretched about a portion
of the user, which results in elongation and deformation of the cut
holes. Holes that are simply cut or punched into the material will
cause local weakening of the material, and stretching may cause the
material to tear in such regions.
[0008] Thus, there is a need for an elastic compression brace
having sufficient structural strength and integrity to offer a
sufficient level of compression support, while also dissipating
heat during use to reduce or avoid undue perspiration and heat
discomfort, especially during prolonged use.
SUMMARY OF THE INVENTION
[0009] The present invention is directed to an elastic panel or
layer that may be used in a composite material-for example, for use
in an orthopedic compression brace-and a method for making the
elastic panel. The elastic panel includes aspects that improve the
breathability of the panel-for example, to facilitate the rejection
of heat and moisture in an orthopedic brace.
[0010] The elastic panel is formed from a sheet of closed cell
foam, such as a neoprene sheet having a thickness between about 2.0
and 10.0 mm. One side of the elastic panel defines a recessed
portion or channels that are formed by compressing the sheet of
foam with oppositely disposed heated plates. A plurality of
apertures is provided through the sheet of foam, the apertures
being formed by penetrating the panel with heated pins. The
apertures and channels are therefore formed without cutting any
material away from the sheet of closed cell foam.
[0011] In an embodiment of the invention, the apertures are
circular and have a diameter between about 0.5 and 3.0 mm. In
another embodiment of the invention, the apertures are disposed in
the channels.
[0012] A method of manufacturing a material suitable for use in a
compression brace material, includes the steps of providing a sheet
of closed cell foam material between an pair of heated plates,
wherein one plate includes a plurality of spaced-apart pins and the
other plate includes a plurality of spaced-apart apertures that are
sized and spaced to engage the pins, and further wherein at least
one of the plates includes a plurality of protrusions for forming
channels in the sheet, urging the plate together to form apertures
in the sheet, and maintaining a pressure between the first plate
and the second plate for a period of time such that the protrusions
impress a plurality of depressions on the sheet of closed cell foam
material.
[0013] In an embodiment of the invention, at least one of the
plates are heated to a temperature between about 145.degree. C. and
160.degree. C., and a pressure of about 50 kg/cm.sup.2 is
maintained for about 4-6 minutes to form the channels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
become better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein:
[0015] FIG. 1 is a side elevation view semi-schematically
illustrating a knee brace made from an orthopedic material,
according to principles of the present invention;
[0016] FIG. 2 is a semi-schematic perspective view of the knee
brace shown in FIG. 1;
[0017] FIG. 3 is a cross-sectional view schematically illustrating
components of a composite material of the present invention;
[0018] FIG. 4 is a frontal plan view illustrating a section of a
punctured center layer of the composite material of the present
invention;
[0019] FIG. 5 is a back plan view illustrating a section of the
punctured center layer shown in FIG. 4;
[0020] FIG. 6 is a perspective view illustrating an elbow brace
made from the composite material of the present invention;
[0021] FIG. 7 is a perspective view illustrating a wrist brace made
from the composite material of the present invention;
[0022] FIG. 8 is a side view illustrating an ankle brace made from
the composite material of the present invention;
[0023] FIG. 9 is a perspective view of another embodiment of an
elastic layer, having a plurality of intersecting channels and
apertures therethrough;
[0024] FIG. 10 is a cross-sectional side view of the elastic layer
shown in FIG. 9;
[0025] FIG. 11 is a perspective view of another embodiment of an
elastic layer, having a plurality of nonintersecting channels and
apertures therethrough;
[0026] FIG. 12 is a cross-sectional side view of the elastic layer
shown in FIG. 11;
[0027] FIGS. 13A, 13B, and 13C are perspective views of additional
embodiments of elastic layers having recessed areas, protruding
areas, and apertures, according to the present invention;
[0028] FIG. 14 is a perspective view illustrating a method for
making the elastic layers utilizing a set of opposed plates;
[0029] FIG. 15 is a cross-sectional side view of the opposed plates
shown in FIG. 14;
[0030] FIG. 16 is a perspective view illustrating another method
for making the elastic layers, with a different set of opposed
plates;
[0031] FIG. 17 is a cross-sectional side view of the opposed plates
shown in FIG. 16; and
[0032] FIG. 18 is a cross-sectional side view similar to FIG. 17,
wherein the elastic layer has an upper fabric layer and a lower
fabric layer attached thereto prior to forming the channels and
apertures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] FIGS. 1 and 2 illustrate a knee brace 20 made from an
orthopedic material according to principles of this invention. The
orthopedic material is illustrated in FIGS. 3, 4, and 5. The knee
brace is a soft orthopedic brace made from a flexible, resilient
composite 100 shown in FIGS. 3, 4, and 5. The flat form composite
material 100 is cut to shape and sewn or otherwise assembled to
form a tubular knee brace 20, illustrated in FIGS. 1 and 2.
[0034] Referring to FIGS. 1 through 3, a piece of composite
material 100 in flat sheet form is folded over on itself. The
overlapping long edges on the opposite side of the fold are
fastened by a long, upright seam 50. The material in the flat is
cut in a shape so that when stitched along seam 50, as shown in
FIGS. 1 and 2, an angular knee support of generally tubular form is
produced having an open top 60 and an open bottom 70. Peripheral
stitching 80 at the upper edge and similar peripheral stitching 90
at the bottom edge provide finished edges for the completed knee
support.
[0035] The components that comprise the composite 100 are best
understood by referring to FIGS. 3, 4, and 5. FIG. 3 shows a
cross-sectional view illustrating the components of the composite
100 of the present invention. The composite material includes a
flexible and foldable center elastic layer 110, an inner fabric
layer 130, and an outer fabric layer 120. The center elastic layer
110 is preferably from a closed cell foam material in sheet
configuration. One preferred elastic closed cell material is
polychloroprene rubber, commonly known as neoprene rubber.
Preferred neoprene materials are articles of commerce. Another
suitable material for center layer 110 is styrene butadiene rubber
(SBR). These materials are available in a wide density range, so it
is not difficult to find material of a desired density that
provides the desired level of support and provides good orthopedic
compression during use. Ideally, such material for the purposes of
the present invention is from 1.5 mm to 8.0 mm thick. However,
other thicknesses may be used. Also, other elastic closed cell
materials may be used to form layer 110.
[0036] The center elastic layer 110 has formed therein on one side
thereof a plurality of intersecting grooves or channels 140. In
non-limiting example, one embodiment of the present invention shows
the pattern of intersecting channels 140 is formed by placing
neoprene sheet material down on a metal mesh and then placing a
weighted heat source on top of the flat sheet material. The
pressure and heat cause the mesh to depress into the sheet material
to permanently take the shape of the metal mesh on the underside
where the grid pattern of the metal mesh is pressing into the sheet
material. In addition or alternatively, the mesh may be
preheated.
[0037] In another embodiment of the present invention, a pattern of
intersecting channels 140 is formed on both surfaces of the sheet
material. This can be accomplished in one manner by sandwiching the
center layer 110 between top and bottom metal grids and heat
pressing both grids against center layer 110, causing both grids to
depress into the surfaces of the sheet material. The grid pattern
may be identical on both sides of the center layer 110, or may be
of different configurations.
[0038] In the embodiment shown in FIGS. 3 and 4, the plurality of
intersecting channels 140 formed in center elastic layer 110 define
a generally rectangular or square-shaped pattern or grid. It is to
be appreciated that the pattern can be of any other shape, e.g.,
diamonds, triangles, ovals, circles, etc., as long as the channels
140 intersect each other so as to provide a continuous or
interconnected passageway across the sheet material and along the
length of the material.
[0039] The center elastic layer 110 may be punctured to form a
multiplicity of punctures or cuts 150 through the layer. Cuts 150
are not shown in FIG. 3 for simplicity but are shown in FIGS. 4 and
5. FIG. 4 is a frontal plan view showing a section of punctured
center layer 110. FIG. 5 is a back plan view showing a section of
the punctured center layer 110 shown in FIG. 4. The multiplicity of
cuts 150 are dispersed across the surface of center elastic layer
110 and extend through the entire depth of the layer so that
fluids, including perspiration and air, can pass through the cuts
150 from one side of the layer to the other, especially when the
layer is stretched.
[0040] In one embodiment of the present invention, cuts 150 are
located only in registry with the channel portions 140. In another
embodiment, cuts 150 are located not only within the channels 140,
but also in the ungrooved/channeled portion of elastic layer 110.
The cuts 150 may be located only at the intersections of the
channels 140, or a multiplicity of cuts 150 may be of uniform
pattern and spaced apart uniformly about the center elastic layer
110. Ideally, the multiplicity of cuts 150 should not be so large
or the cuts spaced so close together that the overall structural
integrity of the neoprene material is reduced beyond the ability of
the material to provide sufficient orthopedic compression support
during use.
[0041] The multiplicity of cuts 150 may define a cut pattern. FIGS.
4 and 5 show a cut pattern having three "legs" that radiate from a
common point. It is to be appreciated, however, that the cut
pattern may be any shape, such as a straight line, a curved line, a
cross, or a five-legged pattern, without departing from the scope
of the present invention. It is to be further appreciated that
preferably the puncture does not actually remove any significant
material, if any, from center elastic layer 110 or channels 140;
rather, the puncture simply extends through the channels. Thus, the
puncture does not form a hole or passage through the neoprene
material unless the material is stretched.
[0042] The pattern for the multiplicity of cuts 150 may be formed
in center elastic layer 110 by a number of methods. One such method
of forming a cut pattern in the neoprene material is by a roller
having a cylindrical outer surface with projecting punches in the
desired cut pattern so that rolling the roller over the flat
surface of the neoprene material punches out cuts in the desired
pattern.
[0043] Referring back to FIG. 3, composite material 100 also
includes a soft, flexible, resilient, porous inner fabric layer
130. Inner layer 130 may be a knitted flexible and foldable,
stretchable cloth fabric material that is porous to air and water
because of the pores inherently formed by the knitted fabric.
Composite material 100 also includes a flexible and elastic, porous
outer fabric layer 120, which also may be made from a stretchable
knitted fabric of the same or different type from layer 130. The
inner and outer fabric layers 130 and 120, respectively, may also
be made from other stretchable knitted fabrics including nylon,
Dacron.RTM. or other synthetic fibers.
[0044] After the center elastic layer 110 is altered with a
plurality of intersecting channels 140 on one side thereof and
punctured with a cut pattern 150, inner fabric layer 130 is bonded
to the grooved face of center layer 110, while outer fabric layer
120 is bonded to the non-grooved face of center layer 110. Inner
fabric layer 130 may be adhered to the center layer 110 using an
adhesive technique that prevents the glue or other adhesive from
being placed in channels 140. As such, the adhesive does not close
or obstruct channels 140. Outer fabric layer 120 is also glued or
otherwise adhered or bonded to center layer 110. The adhesive bonds
the entire contacting surface areas of the center layer 110 and the
adjoining inner and outer fabric layers 130 and 120, respectively.
It is to be noted that the adhesive does not disrupt the porosity
of the center layer 110 and the inner or outer layers 130 and
120.
[0045] Returning to FIGS. 1 and 2, knee brace 20 is intended to be
worn with the grooved/channeled side facing the body of the wearer.
This provides the advantageous result of retaining heat against the
body while allowing knee brace 20 to be breathable. Furthermore,
because knee brace 20 is made from the composite material, it has
sufficient porosity that internal heat build-up during use is
essentially avoided. Knee brace 20 also provides good compression
around a body part supported by knee brace 20 in its stretched
condition. The elastic center layer retains substantially all of
its ability to apply a compression load on the body portion being
braced because material is not actually removed from the neoprene
center layer, as in some conventional braces. Additionally, knee
brace 20 is of sufficient density due to the neoprene, SBR, or
other selected material to provide the compression necessary to
serve as a useful knee brace. The inner and outer layers 130 and
120 also provide additional compressive strength to knee brace
20.
[0046] Knee brace 20 also provides good breathability. When knee
brace 20 is in use, it stretches in a bidirectional manner, thereby
creating a pumping action to allow air to flow through the channels
140 of knee brace 20. This carries body sweat through channels 140
and out the ends of knee brace 20. Knee brace 20 also allows fresh,
cool air to pass inwardly through knee brace 20 to reach the body.
Correspondingly, a certain amount of heat is able to pass from
inside knee brace 20 to the outside through the plurality of cuts
150, which open up as the brace is stretched during use.
[0047] In accordance with a further aspect of the present
invention, silicone 152, in the form of a gel or beads, may be
applied along the inside of knee brace 20 lengthwise of the brace,
perhaps on opposite sides of the brace. Additionally or
alternatively, the silicone beads 154 may be placed
circumferentially around the inside of the brace, perhaps near the
ends of the brace. The silicone may be applied in a stripe of some
width, in a narrow line or band, or in other patterns. Moreover,
the stripe or line of silicone may be straight or curved. This
silicone material causes the brace to stay in place on the body due
to the friction between the silicone and the body. The silicone
does not, however, cause discomfort or undue rubbing against the
body.
[0048] In one embodiment, the silicone may be applied to the
interior of knee brace 20 after the brace has been fully
constructed. In another embodiment, the silicone is applied to the
inside of inner fabric layer 130 of knee brace 20 and then the
inner layer 130 is applied to the inside surface of center layer
110. As those skilled in the art will appreciate, other materials,
in addition to silicone, may be employed to cause the brace to stay
in place on the body, without departing from the scope of the
present invention.
[0049] FIGS. 6-8 illustrate further uses of the composite material
100 in compression braces. FIG. 6 shows an elbow brace 160 in which
composite material 100 is folded and seamed along its length. The
brace may have an intermediate seam 170 to form a generally
L-shaped tubular elastomeric brace. The top and bottom edges of the
tubular brace have stitched peripheral seams 180 for edge
reinforcement. FIG. 7 illustrates a wrist brace 190 made from the
composite material 100, in which the material is folded and seamed
lengthwise to form a generally straight tubular brace having
peripheral stitching 200 at its opposite ends for edge
reinforcement. FIG. 8 illustrates an ankle brace 210 made from
composite material 100. The ankle brace 210 is formed as a
generally L-shaped tubular brace with peripheral stitching 220 at
its opposite ends, peripheral stitching 230 around an edge portion
of the brace that fits around the heel of the user. The brace may
include intermediate stitching 240 fastening adjoining intermediate
edges of the L-shaped ankle support.
[0050] These compression braces can be used to provide required
levels of anatomical compression support while improving
ventilation to the supported area to reduce the discomfort caused
by perspiration and over-heating. The improved composite material
of this invention thus improves the anatomical support provided by
compression braces, because the user is able to wear the brace for
extended periods rather than having to remove the brace prematurely
because of heat discomfort.
[0051] An alternative embodiment of an elastic layer 310 is shown
in FIGS. 9 and 10, wherein FIG. 9 shows a perspective view of the
elastic layer 310 and FIG. 10 shows a cross-sectional view of the
elastic layer 310 through section 10-10. The elastic layer 310
includes a plurality of channels 312 arranged in an intersecting
pattern and a number of small, generally circular apertures 314
through the elastic layer 310. The apertures 314 of this preferred
embodiment are positioned at intersections of the channels 312,
although it is contemplated that not every intersection need have
an aperture 314, and/or additional apertures may be provided in the
channels 312 at intermediate locations.
[0052] The combination of intersecting channels 312 and open
apertures 314 provides a network for air and moisture to flow from
one side of the elastic layer 310 to the other, while still
retaining sufficient elasticity in the elastic layer 310 to produce
the desired compressive force. As discussed in more detail below,
the open apertures 314 may be formed using heated pins that
penetrate the material to form the apertures 314, such that the
material is partially softened or melted, resulting in a
reinforcement of the material about the apertures 314. The center
elastic layer 310 is preferably made from a sheet of a closed cell
polymeric foam material such as neoprene, as discussed in more
detail below.
[0053] It will be appreciated that the elastic layer 310 may be
combined with outer and inner fabric layers such as are identified
as 120 and 130, respectively, in FIG. 3. It will be appreciated
that the circular apertures 314 differ from the cuts 150 of the
embodiment shown in FIG. 4, in that the apertures 314 are "open,"
even when the elastic layer 310 is not stretched. It is also
contemplated that the apertures 314 may be other than circular in
shape, while retaining the aspect of being always open.
[0054] In use, the elastic layer 310, which may be combined in a
composite material as discussed above, would normally be oriented
with the open portion of the channels 312 facing inwardly, toward
the user, thereby promoting lateral air and moisture flow towards
the apertures 314 next to the user's skin, and thereby promoting
the expulsion of moisture and heat away from the user.
[0055] FIGS. 11 and 12 show a perspective view and a
cross-sectional view, respectively, of another alternative
embodiment of a elastic layer 320, wherein the elongate channels
322 do not intersect with each other, but rather are oriented
longitudinally along the elastic layer 320. A plurality of
apertures 324 extends through the elastic layer 320, the apertures
324 being disposed generally within the elongate channels 322. The
use of parallel, longitudinal channels 322 produce an anisotropic
flexibility in the elastic layer 320 that results in less
elasticity (greater stiffness) in the longitudinal direction,
relative to the elasticity in the transverse direction. The
parallel channels 322 also will permit a more directional flow of
heat and moisture, whereby the material may be optimized for a
particular application. Using this material, the designer may
orient the elastic layer 320 such that the channels 322 are
directed along a preferred direction--for example, to take
advantage of the geometry or natural circulatory pattern for the
particular body part that the elastic layer 320 is intended to
envelop.
[0056] FIGS. 13A, 13B, and 13C show several exemplary alternative
embodiments of elastic layers 330, 340, 350 that are contemplated
by the present invention. In particular, FIG. 13A shows an elastic
layer 330 having a plurality of circular protrusions 332 arranged
in a regular pattern on the elastic layer. The recessed portion 333
of the elastic layer 330 between the protrusions 332 includes a
plurality of apertures 334 that extend through the elastic layer
330. Similarly, FIG. 13B shows an elastic layer 340 having a
plurality of square or rectangular protrusions 342 arranged in a
regular pattern on the elastic layer. The recessed portion 343 of
the elastic layer 340 between the protrusions 342 includes a
plurality of apertures 344 that extend through the elastic layer
340. FIG. 13C shows an elastic layer 350 having a plurality of wavy
channels 353 that extend longitudinally along the elastic layer
350, wherein a plurality of apertures 354 is disposed in the wavy
channels 353. It will be readily apparent that other patterns for
the channels (or protrusions) are possible.
[0057] Referring now to FIGS. 14 and 15, an exemplary method for
producing the elastic material will be described. Although the
disclosed method is shown for the elastic layer 310 shown in FIGS.
10 and 11, it will be appreciated that the method may be used to
produce any of the elastic layers shown in FIGS. 9-13C.
[0058] As shown in FIG. 14 and the cross-sectional side view of
FIG. 15, the elastic layer 310 may be formed utilizing an upper
plate 410 and a lower plate 420. In a preferred embodiment, a sheet
400 of a closed cell polymeric material, such as neoprene, is
disposed between the upper plate 410 and the lower plate 420. The
sheet 400 is preferably between about 2.0 mm and 10.0 mm in
thickness. The upper plate 410 includes a plurality of apertures
414 that extend at least partially through the upper plate 410 from
the lower surface 416. The lower plate 420 includes a corresponding
plurality of upwardly extending pins 422 that are sized and
positioned to slidably engage the plurality of apertures 414 when
the upper and lower plates 410, 420 are urged together. The pins
422 preferably have a diameter of between about 0.5 mm and 3.0 mm,
and the apertures corresponding apertures 414 are slightly larger
in diameter than the pins 422.
[0059] The upper plate 410 also includes a pattern of elongate
protrusions 412 on its lower surface 416 that are adapted to form
the desired pattern of indentations or channels 312 on the
polymeric sheet 400. In a preferred embodiment, the pins 422 (and
apertures 414) are spaced about 10.0 mm-15.0 mm apart, and the
elongate protrusions 412 are two sets of intersecting, parallel
linear protrusions, each set of linear protrusions having a line
spacing of 10.0 mm-15.0 mm. The elongate protrusions 412 are
preferably about 1.0 mm-2.0 mm high.
[0060] The plates 410, 420 are heated and the polymeric sheet 400
is disposed therebetween. The upper and lower plates 410, 420 are
then moved or urged together, such that the heated pins 422 on the
lower plate 420 puncture the sheet 400 to produce apertures 314
therein, and slidably engage the apertures 414 on the upper plate
410. The heated plates 410, 420 are held together for a period of
time to form the pattern of channels 312 in the sheet 400. In a
preferred mode the upper and lower plates 410, 420 are heated to a
temperature of between about 145.degree. C. and 160.degree. C., and
the plates 410, 420 are held together for about 4-6 minutes, with a
biasing pressure of approximately 50 kg/cm.sup.2.
[0061] As indicated by the arrows in FIG. 14, the upper and lower
plates 410, 420 are pushed together to generate the pattern of
apertures channels 312 and apertures 314 in the sheet 400. After
the desired time, the plates 410, 420 are separated, to permit the
sheet 400 to be removed and replaced, or shifted longitudinally to
repeat the process on another portion of the sheet 400. It will be
readily apparent the particular orientation of the upper and lower
plates 410, 420 is not important, and that the method may
alternatively be accomplished with the plates switched or the
entire assembly rotated an arbitrary amount.
[0062] The present method provides several advantages. The
plurality of apertures 314 and the pattern of channels 312 are
formed simultaneously, in a single step, simplifying the
manufacturing process. Also, utilizing heated plates 410, 420 and
pins 422 to form the apertures 314 and channels 312 result in a
relatively thick and/or strengthened region about the perimeter of
the apertures 314 and channels 312, reducing the likelihood of
tears in the material and helping to maintain the overall strength
of the material. It will be readily appreciated that the method
does not require cutting away any material from the sheet 400.
[0063] FIGS. 16 and 17 show a slightly different configuration of
plates 430, 440, similar to the plates of the preceding embodiment,
wherein an upper plate 430 includes a plurality of pins 432 that
extends downwardly from a lower surface 436 of the upper plate 430.
A plurality of elongate protrusions 434 also extends from the lower
surface 436. A lower plate 440 includes a plurality of apertures
442 that are sized and shaped to slidably receive the pins 432 in
the upper plate 430 when the upper and lower plates are properly
aligned. Other than the location of the pins 432 on the upper plate
430 rather than the lower plate 440, this second embodiment is
substantially the same as the embodiment disclosed in FIGS. 14 and
15. In particular, the preferred dimensions and operating
parameters are the same as those disclosed above.
[0064] It is contemplated that any of the elastic layers 310, 320,
330, 340, 350 may have porous outer fabric layers affixed thereto,
as discussed above (see FIG. 3), wherein one or both of the outer
fabric layers may be applied before, or after, the material is
impressed with apertures and channels. For example, as shown in
FIG. 18, the sheet 400 may include an upper porous fabric layer 323
attached to an upper surface and a lower porous fabric layer 321
attached to a lower surface of the inner layer. The fabric layers
321, 323 are preferably a knitted, flexible, and stretchable cloth
fabric material that is porous to air and water because of the
pores inherently formed by the knitted fabric.
[0065] In one method, as shown in FIG. 18, both the upper fabric
layer 323 and the lower fabric layer 321 are attached to the
elastic layer 310 prior to forming the apertures 314 and channels
312. If the upper fabric layer 323 has sufficient flexibility, it
may conform to the channels 312 that are formed in the elastic
layer 310, such that the impressed pattern of channels 312 will be
apparent in the upper fabric layer 323. It will be appreciated that
the resulting material will retain the advantages of having
apertures 314 and channels 312 that enhance the heat and vapor
transport through the material.
[0066] In an alternative method, only the lower fabric layer 321 is
applied to the sheet 400 prior to forming the apertures 314 and
channels 312, so that when the upper fabric layer 323 is affixed,
the channels 312 are already formed in the elastic layer 310 such
that the upper fabric layer 323 generally hides the pattern of
channels 312. Again, the beneficial aspects of apertures 314 and
channels 312 for enhancing heat and vapor transport are
retained.
[0067] Although the elastic layers disclosed above are suitable for
use in a compression brace material, it is contemplated that the
materials may also alternatively find many other useful
applications--for example, as breathable, insulating layer in
sporting outerwear and/or as a component of other clothing such as
jackets, gloves, vests, boots and the like.
[0068] While the preferred embodiment of the invention has been
illustrated and described, it will be appreciated that various
changes can be made therein without departing from the spirit and
scope of the invention.
* * * * *