U.S. patent application number 12/162516 was filed with the patent office on 2009-02-19 for coverings for viscoelastic foam mattresses.
This patent application is currently assigned to MMI-IPCO, LLC. Invention is credited to Charles Haryslak, Douglas Lumb, Moshe Rock.
Application Number | 20090044338 12/162516 |
Document ID | / |
Family ID | 38345859 |
Filed Date | 2009-02-19 |
United States Patent
Application |
20090044338 |
Kind Code |
A1 |
Rock; Moshe ; et
al. |
February 19, 2009 |
Coverings for Viscoelastic Foam Mattresses
Abstract
Covers for mattresses having a reclining surface of viscoelastic
foam have a fabric body with a first surface disposed in engagement
with the reclining surface; an opposite, second surface disposed
for engagement by a person reclining upon the cover; and at least
one air flow region defined by the fabric body for enhanced
circulation of air between the reclining surface of viscoelastic
foam and an opposed skin surface of the person reclining upon the
cover.
Inventors: |
Rock; Moshe; (Brookline,
MA) ; Haryslak; Charles; (Marlborough, MA) ;
Lumb; Douglas; (Methuen, MA) |
Correspondence
Address: |
FISH & RICHARDSON PC
P.O. BOX 1022
MINNEAPOLIS
MN
55440-1022
US
|
Assignee: |
MMI-IPCO, LLC
Lawrence
MA
|
Family ID: |
38345859 |
Appl. No.: |
12/162516 |
Filed: |
January 24, 2007 |
PCT Filed: |
January 24, 2007 |
PCT NO: |
PCT/US2007/060974 |
371 Date: |
July 29, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60764612 |
Feb 2, 2006 |
|
|
|
Current U.S.
Class: |
5/500 |
Current CPC
Class: |
A47C 27/007 20130101;
A47C 31/001 20130101; D10B 2403/021 20130101; D04B 1/02 20130101;
D04B 1/04 20130101; C08L 2201/12 20130101; A47C 21/046 20130101;
D10B 2403/0111 20130101; A47C 31/006 20130101; D04B 21/02
20130101 |
Class at
Publication: |
5/500 |
International
Class: |
A47C 21/00 20060101
A47C021/00 |
Claims
1. A cover for a mattress having a reclining surface of
viscoelastic foam, the cover comprising: a circular knit fabric
body having four-way stretch and defining: a first pile surface
disposed in engagement with the reclining surface; an opposite,
second pile surface disposed for engagement by a person reclining
upon the cover with the first surface disposed in engagement with
the reclining surface; and at least one air flow region for
enhanced circulation of air between the reclining surface of
viscoelastic foam and an opposed skin surface of the person
reclining upon the cover.
2. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 1, wherein at least one of said first
pile surface and said second pile surface defines one or more
regions with relatively high pile disposed among one or more
regions of relatively low pile or no pile, with the one or more
regions of relatively low pile or no pile defining the at least one
air flow region for enhanced circulation of air between the
reclining surface of viscoelastic foam and an opposed skin surface
of the person reclining upon the cover.
3. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 2, wherein the one or more regions with
relatively high pile and the one or more regions of relatively low
pile or no pile are arranged upon at least one of said first pile
surface and said second pile surface by engineered body mapping
techniques in a manner to position the at least one air flow region
for enhanced circulation of air between the reclining surface of
viscoelastic foam and an opposed skin surface of the person
reclining upon the cover in accordance with requirements of
corresponding body regions of the person reclining upon the
cover.
4. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 2, wherein the one or more regions with
relatively high pile and the one or more regions of relatively low
pile or no pile are arranged upon at least one of said first pile
surface and said second pile surface by standard knitting design
techniques in a manner to position the at least one air flow region
for enhanced circulation of air generally between the reclining
surface of viscoelastic foam and an opposed skin surface of the
person reclining upon the cover in a regular pattern.
5. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 3 or claim 4, wherein contrasting height
among regions of relatively high pile and regions of relatively low
pile or no pile is established by contrasting height of sinker
loops.
6. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 5, wherein said circular knit fabric
body comprises stitch yarn with spandex.
7. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 5, wherein said circular knit fabric
body comprises stretch stitch yarn.
8. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 5, wherein said sinker loops of said at
least one of said first pile surface and said second pile surface
are in unnapped yarn form.
9. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 5, wherein said sinker loops of said at
least one of said first pile surface and said second pile surface
are in napped, velour form.
10. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 5, wherein said sinker loops of said at
least one of said first pile surface and said second pile surface
are in cut loop form without pre-napping.
11. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 5, wherein the circular knit fabric body
comprises hydrophilic fibers.
12. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 5, wherein the circular knit fabric body
comprises material selected from the group consisting of cotton and
wool.
13. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 5, wherein the circular knit fabric body
comprises fibers of synthetic material.
14. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 13, wherein the synthetic material is
selected from the group consisting of polyester; nylon; acrylic;
polyester, nylon or acrylic that has been rendered hydrophilic; and
blends thereof.
15. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 1 or claim 2, wherein the circular knit
fabric body has chemical treatment for one or more properties
selected from the group consisting of wicking enhancement, stain
release, water repellency, stain repellency, antimicrobial
properties, and oil repellency.
16. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 15, wherein said fabric body comprises
hydrophilic fibers.
17. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 1 or claim 2, wherein said fabric body
comprises a fabric laminate.
18. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 2, wherein said one or more regions of
relatively high pile comprises a plurality of spaced-apart pile
pillars and said one or more regions of relatively low pile or no
pile comprises intersecting channels extending among said pile
pillars and defining said at least one air flow region for enhanced
circulation of air between the reclining surface of viscoelastic
foam and an opposed skin surface of the person reclining upon the
cover.
19. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 18, wherein said fabric body comprises a
double bar raschel warp knit construction.
20. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 18, wherein said fabric body comprises a
knit with about 16 to about 28 wales per inch.
21. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 18, wherein said fabric body comprises a
knit structure with about 14 courses to about 36 courses per
inch.
22. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 18, wherein yarns of said fabric body
have fineness in a range of about 40 to about 600 denier.
23. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 18, wherein yarns of said fabric body
comprise individual fibers having fineness in a range of about 1
dpf to about 12 dpf.
24. A cover for a mattress having a reclining surface of
viscoelastic foam, said cover comprising: a fabric body defining: a
first surface disposed in engagement with the reclining surface; an
opposite, second surface disposed for engagement by a person
reclining upon the cover; and at least one air flow region for
enhanced circulation of air between the reclining surface of
viscoelastic foam and an opposed skin surface of the person
reclining upon the cover.
25. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 24, wherein said fabric body comprises a
first fabric layer defining said first surface and a second fabric
layer defining said opposite, second surface, with said at least
one air flow region defined therebetween; and said fabric body
further comprises a plurality of intermediate members extending
generally between the first fabric layer and the second fabric
layer and through said at least one air flow region for enhanced
circulation of air between the reclining surface of viscoelastic
foam and an opposed skin surface of the person reclining upon the
cover.
26. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 25, wherein said plurality of
intermediate members are disposed to resiliently urge apart said
first fabric layer and said second fabric layer.
27. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 25, wherein the first fabric layer is
permeable to water vapor and impermeable to liquid water.
28. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 25, wherein each of the first fabric
layer and the second fabric layer comprises stitch yarn.
29. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 28, wherein the stitch yarn of the first
fabric layer has fineness in a range of about 50 to about 600
denier
30. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 28, wherein the stitch yarn of the first
fabric layer has individual fiber fineness in the range of about
0.3 to about 6.0 dpf.
31. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 28, wherein the stitch yarn of the first
fabric layer comprises hydrophilic fibers.
32. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 28, wherein the stitch yarn of the first
fabric layer comprises fibers of synthetic material.
33. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 32, wherein the synthetic material is
selected from the group consisting of polyester; acrylic; nylon;
polyester, acrylic or nylon that has been rendered hydrophilic; and
blends thereof.
34. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 28, wherein the stitch yarn of the
second fabric layer comprises natural fibers.
35. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 34, wherein the stitch yarn of the
second fabric layer comprises material selected from the group
consisting of cotton and wool.
36. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 28, wherein the second fabric layer
further comprises lay-in yarn held by the stitch yarn.
37. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 36, wherein the lay-in yarn comprises an
elastomeric yarn.
38. The cover for a mattress having a reclining surface of
viscoelastic foam of claim 37, wherein the lay-in yarn comprises
total fineness in a range of about 70 to about 300 denier.
39. A method of forming a cover for a mattress having a reclining
surface of viscoelastic foam, the cover, said method comprising the
steps of: forming a circular knit fabric having four way stretch,
with a first pile surface and an opposite, second pile surface and
defining at least one air flow region for enhanced circulation of
air between the reclining surface of viscoelastic foam and an
opposed skin surface of the person reclining upon the cover; and
forming the circular knit fabric into a cover for a mattress having
a reclining surface of viscoelastic foam.
Description
TECHNICAL FIELD
[0001] This disclosure relates to viscoelastic foam mattresses and
fabric coverings for such mattresses.
BACKGROUND
[0002] A trend in the mattress market is the use of viscoelastic
foams, also referred to as "memory foams" or foams having
compressible memory to form a sleeper-supporting surface.
Viscoelastic foam conforms to the shape of an object resting upon
its surface, and regains its generally flat surface once the object
is removed. These foams, described, for example, in U.S. Pat. No.
6,734,220, the entire disclosure of which is incorporated by
reference herein, are generally formed of cured polyurethane-based
viscoelastic polymer. Viscoelastic mattresses are often covered
with a fabric cover, typically made of a fabric referred to as
"ticking."
SUMMARY
[0003] In various aspects, the disclosure features covers for
mattresses having a reclining surface of viscoelastic foam.
[0004] In one aspect, the cover comprises a circular knit fabric
body having four-way stretch and defining: (a) a first pile surface
disposed in engagement with the reclining surface; (b) an opposite,
second pile surface disposed for engagement by a person reclining
upon the cover with the first surface disposed in engagement with
the reclining surface; and (c) at least one air flow region for
enhanced circulation of air between the reclining surface of
viscoelastic foam and an opposed skin surface of the person
reclining upon the cover.
[0005] In some implementations, at least one of the first pile
surface and the second pile surface defines one or more regions
with relatively high pile disposed among one or more regions of
relatively low pile or no pile, with the one or more regions of
relatively low pile or no pile defining the one or more air flow
regions for enhanced circulation of air between the reclining
surface of viscoelastic foam and an opposed skin surface of the
person reclining upon the cover. Some of these implementations
include one or more of the following features. The one or more
regions with relatively high pile and the one or more regions of
relatively low pile or no pile are arranged upon at least one of
the first pile surface and the second pile surface by engineered
body mapping techniques in a manner to position the one or more air
flow regions for enhanced circulation of air between the reclining
surface of viscoelastic foam and an opposed skin surface of the
person reclining upon the cover in accordance with requirements of
corresponding body regions of the person reclining upon the cover.
The one or more regions with relatively high pile and the one or
more regions of relatively low pile or no pile are arranged upon at
least one of the first pile surface and the second pile surface by
standard knitting design techniques in a manner to position the one
or more air flow regions for enhanced circulation of air generally
between the reclining surface of viscoelastic foam and an opposed
skin surface of the person reclining upon the cover in a regular
pattern. Contrasting height among regions of relatively high pile
and regions of relatively low pile or no pile is established by
contrasting height of sinker loops. The sinker loops are in
unnapped yarn form; in napped, velour form; or in cut loop form
without pre-napping. The fabric body comprises a fabric laminate.
The fabric body comprises stretch stitch yarns, e.g., stitch yarns
with spandex. The fabric body comprises hydrophilic fibers. The
fabric body comprises fibers of synthetic material, e.g., selected
from the group consisting of polyester, acrylic, nylon, these
fibers rendered hydrophilic, and blends thereof. The fabric body
comprises material selected from the group consisting of cotton and
wool. The fabric body has chemical treatment for one or more
properties selected from the group consisting of wicking
enhancement, stain release, water repellency, stain repellency,
antimicrobial properties, and oil repellency. In some
implementations, the fabric body comprises a double bar raschel
warp knit construction.
[0006] In some implementations, the one or more regions of
relatively high pile comprises a plurality of spaced-apart pile
pillars and the one or more regions of relatively low pile or no
pile comprises intersecting channels extending among the pile
pillars and defining the one or more air flow regions for enhanced
circulation of air between the reclining surface of viscoelastic
foam and an opposed skin surface of the person reclining upon the
cover. In some of these implementations, the fabric body comprises
a knit structure with about 16 to about 28 wales per inch and about
14 to about 36 courses per inch. The fabric body has fineness in a
range of about 40 to about 600 denier, with individual fibers
having fineness in a range of about 1 dpf to about 12 dpf.
[0007] In another aspect, the cover comprises a fabric body
defining (a) a first surface disposed in engagement with the
reclining surface; (b) an opposite, second surface disposed for
engagement by a person reclining upon the cover; and (c) at least
one air flow region for enhanced circulation of air between the
reclining surface of viscoelastic foam and an opposed skin surface
of the person reclining upon the cover.
[0008] In some implementations, the fabric body comprises a first
fabric layer defining the first surface and a second fabric layer
defining the opposite, second surface, with the one or more air
flow regions defined therebetween; and the fabric body further
comprises a plurality of intermediate members extending generally
between the first fabric layer and the second fabric layer and
through the one or more air flow regions for enhanced circulation
of air between the reclining surface of viscoelastic foam and an
opposed skin surface of the person reclining upon the cover. Some
of these implementations include one or more of the following
features. The plurality of intermediate members are disposed to
resiliently urge apart the first fabric layer and the second fabric
layer. The first fabric layer is permeable to water vapor and
impermeable to liquid water. Each of the first fabric layer and the
second fabric layer comprises stitch yarn. The stitch yarn of the
first fabric layer has fineness in a range of about 50 to about 600
denier. The stitch yarn of the first fabric layer has individual
fiber fineness in the range of about 0.3 to about 6.0 dpf. The
stitch yarn of the first fabric layer comprises hydrophilic fibers.
The stitch yarn of the first fabric layer comprises a synthetic
material, e.g., selected from the group consisting of polyester,
acrylic, nylon, these fibers rendered hydrophilic, and blends
thereof. The stitch yarn of the second fabric layer comprises
natural fibers. The stitch yarn of the second fabric layer
comprises material selected from the group consisting of cotton and
wool. The second fabric layer further comprises lay-in yarn held by
the stitch yarn, e.g., an elastomeric yarn. The lay-in yarn
comprises total fineness in a range of about 70 to about 300
denier.
[0009] The disclosure also features methods for forming a cover for
a mattress having a reclining surface of viscoelastic foam.
[0010] For example, in one aspect, the disclosure features a method
including (a) forming a circular knit fabric having four way
stretch, with a first pile surface and an opposite, second pile
surface and defining at least one air flow region for enhanced
circulation of air between the reclining surface of viscoelastic
foam and an opposed skin surface of the person reclining upon the
cover; and (b) forming the circular knit fabric into a cover for a
mattress having a reclining surface of viscoelastic foam.
[0011] In a further aspect, the disclosure features covers for a
mattress having a reclining surface of viscoelastic foam, the cover
formed by the above methods.
[0012] The term "pile," as used herein, includes pile surfaces
formed by any desired method, including but not limited to cut
loops, loops cut on the knitting machine, loops cut off the
knitting machine, and raised fibers.
[0013] Some implementations exhibit one or more of the following
advantages. The fabric cover conforms generally to the surface of
the viscoelastic foam mattress as the foam changes in configuration
from its original flat form to a conforming, compressed state and
back to the original flat form. The cover provides minimum
restriction to movement of the foam, so there is less tendency for
the foam to bulge and/or crease. The fabric cover is comfortable to
the user. Preferred mattress covers define one or more regions of
air circulation between the viscoelastic foam surface of the
mattress and the opposed skin surface of a person sleeping on the
mattress, so that even as the viscoelastic foam conforms closely to
the shape of the person sleeping on the mattress, the cover permits
circulation of air between the surface of the mattress and the
person's skin, to allow the person to sleep comfortably, including
during warmer conditions.
[0014] The details of one or more implementations are set forth in
the accompanying drawings and the description below. Other features
and advantages will be apparent from the description and drawings,
and from the claims.
DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a side view of a mattress cover on a mattress
having a viscoelastic foam surface layer, with a sleeping person
reclining upon the mattress surface.
[0016] FIG. 2 is a perspective view of a mattress cover according
to one implementation, in which a raised upper surface and/or a
raised lower surface of the cover defines one or more air flow
regions for enhanced circulation of air between a sleeping person
and the viscoelastic surface of the mattress. FIG. 2A is a highly
enlarged partial perspective view of area A-A in FIG. 2.
[0017] FIG. 3 is a sectional view of a mattress cover according to
another implementation, in which a raised upper surface and/or a
raised lower surface has one or more regions of relatively high
pile among one or more regions of relatively low or no pile, the
regions of relatively low or no pile defining one or more air flow
regions for enhanced circulation of air between a sleeping person
and the viscoelastic surface of the mattress. In this
implementation, the regions are arranged according to engineered
body mapping techniques to accommodate corresponding body regions
of a sleeping person.
[0018] FIG. 4 is a perspective view of a mattress cover according
to another implementation, similar to the implementation of FIG. 3,
in which a raised upper surface and/or a raised lower surface has
one or more regions of relatively high pile among regions of
relatively low or no pile, the regions of relatively low or no pile
defining air flow regions for enhanced circulation of air between a
sleeping person and the viscoelastic surface of the mattress, the
regions in this implementation being evenly spread in an overall
pattern according to standard knitting design techniques.
[0019] FIG. 5 is a sectional view of a mattress cover according to
another implementation of the disclosure, in which pile pillars
extending from upper and/or lower surfaces of the cover define air
flow regions for enhanced circulation of air between a sleeping
person and the viscoelastic surface of the mattress.
[0020] FIG. 6 is a sectional view of a mattress cover according to
a further implementation of the disclosure, in which intermediate
members span air flow regions defined between the upper surface and
the lower surface of the mattress cover for enhanced circulation of
air between a sleeping person and the viscoelastic surface of the
mattress.
[0021] FIG. 7 is a perspective view of a mattress cover in which
the smooth, technical face surface of two fabric layers are adhered
together face-to-face to form a two-layer laminate, with their
respective outer, technical back surfaces facing outward.
[0022] FIG. 8 is a perspective view of the mattress cover of FIG.
3.
[0023] FIG. 9 is a perspective view of the mattress cover of FIG.
5.
[0024] FIG. 10 is a perspective view of the mattress cover of FIG.
6.
[0025] FIG. 11 is a side elevational view showing loop structure of
a two-layer, three dimensional fabric suitable for use in the
mattress cover shown in FIGS. 6 and 10.
[0026] FIG. 12 is a side elevational view showing a larger area of
the fabric of FIG. 11.
[0027] FIG. 13 is a perspective view of the fabric of FIG. 12
viewed from its technical back and illustrating formation of sinker
loops.
[0028] FIG. 14 is a front elevational view of the fabric of FIG. 12
viewed from its technical face.
[0029] FIG. 15 is a side view showing terry loops of the fabric
construction of FIG. 12 prior to (a) napping on the technical face
and (b) shearing on the technical back.
[0030] FIG. 16 is a side view of terry loops on the technical face
of the fabric construction of FIG. 15 after napping.
[0031] FIG. 17 is a side view of terry loops on the technical back
of the fabric construction of FIG. 16 after shearing.
[0032] Like reference symbols in the various drawings indicate like
elements.
DETAILED DESCRIPTION
[0033] A mattress 100 having a viscoelastic foam surface layer 101
with a cover 102 is shown diagrammatically in FIG. 1. The mattress
cover 102 is formed of a knitted fabric having at least two-way
stretch with good recovery, e.g., a circular knit or warp knit
fabric. The fabric typically includes spandex yarn, to allow the
knitted fabric to conform to deformation of the compressed
viscoelastic foam in multiple directions under load, and to avoid
restricting recovery of the viscoelastic foam when the load is
removed or reduced. Preferably the fabric has four-way balanced
stretch, i.e., the elongation when the fabric is subjected to a
load is substantially the same along the length and width of the
fabric. The mattress cover is constructed to define one or more air
flow regions for enhanced circulation of air between the reclining
surface of viscoelastic foam and skin surfaces of a person
reclining upon the cover. The regions for enhanced circulation of
air may be provided in various forms.
[0034] Referring to FIG. 2, in one implementation the fabric 211
forming mattress cover 102 includes raised surfaces 105, 107 on its
technical face and technical back. As indicated by the arrow in
FIG. 2A, these raised surfaces, formed of pile or loops, allow air
flow between the pile fibers or loops. Thus, the raised surfaces
provide enhanced circulation of air. Preferably, the fabric 211 is
a circular knit fabric having four way stretch.
[0035] In another implementation, for example, as shown in FIGS. 3
and 8, the fabric 211' forming mattress cover 102''' has a raised
surface with a three-dimensional geometry in which one or both
surfaces define a predetermined pattern of regions of no loops or
low loops or pile and regions of relatively higher loops or pile.
The regions of relatively higher pile 110 are positioned and
constructed to support the person reclining upon the cover and
spaced from the reclining surface of viscoelastic foam, with
regions of low pile and no pile 112 defining air flow regions for
enhanced circulation of air through the air flow regions, between
the reclining surface, F, of viscoelastic foam and the skin
surface, S, of the person reclining upon the cover 102'''. In some
cases, the fabric 211' is an engineered thermal fabric with regions
of contrasting cushioning and air-flow capacity and performance,
arranged by body mapping concepts, tailored to the different
requirements of different regions of the sleeper's body. Greater
cushioning will be provided by the regions 110 of relatively higher
loops, reducing pressure on regions of the body that tend to
compress the mattress more, e.g., hips and shoulders. Moreover, air
ventilation will occur in the no loop or low loop regions 112
disposed among the regions 110 of relatively higher loops, thereby
increasing the comfort level by reducing perspiration and heat
build-up. Thus, such fabrics 211' will tend to optimize the comfort
level of the person while sleeping. The distribution of the low and
high pile areas can be selected to suit particular conditions and
user preferences, and different products can be provided having
different distributions.
[0036] The high and low pile areas may be distributed in a regular
pattern, for example in bands, to simplify manufacture. For
example, as shown in FIG. 4, a lower band region 220 having
relatively higher pile height and/or relatively higher fiber
density may be positioned to extend generally across the person's
hips and an upper band region 222, also of relatively higher pile
height and/or relatively higher fiber density, may be positioned to
extend generally across the person's shoulders. At the upper and
lower extremities, respectively, of the mattress cover, a top
region 224 of relatively low pile or no pile is positioned to
extend generally beneath the person's head and along the side wall
at the head of the mattress and a bottom band region 226 of
relatively low pile or no pile is positioned to extend along the
side wall at the foot of the mattress. An intermediate region 228,
also of relatively low pile or no pile, is positioned to extend
generally across the person's upper torso.
[0037] In another implementation, for example, as shown in FIGS. 5
and 9, a fabric 111 forming a mattress cover 102'' has a raised
surface on the technical back and a velour or terry sinker loop
surface on the technical face. The raised surface on the technical
back, disposed to face the viscoelastic foam surface layer 101,
defines gaps or channels 104 allowing movement of air along the
surface of the fabric, e.g., between the surface, F, of the
mattress and the skin surface of the person reclining on the
mattress. The velour or terry loop on the technical face of the
fabric disposed to face the skin, S, of the reclining person,
similarly defines gaps or channels to allow air circulation between
the skin surface of the person's body and the viscoelastic surface
of the mattress. The surface of raised pile fabric 111 defines
spaced-apart pile pillars 103 among intersecting channels 104
defined therebetween. The pile pillars may be found at one surface
of the fabric, or at both surfaces (technical face and technical
back) of the fabric, e.g., as shown in FIGS. 5 and 9. The pile
pillars define air flow regions, allowing enhanced circulation of
air between the reclining surface, F, of the viscoelastic foam and
the skin surface, S, of a person reclining upon the cover 102''.
The channels will also enhance moisture evaporation. The channels
104 may have any desired configuration; for example the channels
may be in discrete regions of the fabric which may be
interconnected or not interconnected, or may be continuous from one
edge of the fabric to the opposite edge.
[0038] In another implementation, shown in FIGS. 6 and 10, a fabric
body 11 forming a mattress cover 102' has the form of a two-layer,
spacer fabric having an air circulation space defined between
layers. For example, the fabric 11 may be a three-dimensional
double knit fabric consisting of a first layer 13 and a second
layer 15 that are spaced apart resiliently by interconnecting yarns
21. Such fabrics will be discussed in detail below. The resilient
interconnecting yarns 21 urge the first layer 13 and second layer
15 apart, including under the weight of the reclining person, to
permit air flow passageways 22 between the two layers, and thus
between the surface, F, of the viscoelastic foam mattress and the
surface, S, of a reclining person's skin. Air circulating through
these air flow passageways 22 assists in cooling, and in removal of
perspiration or other moisture, by evaporation.
[0039] In the implementations shown in FIGS. 2, 3 and 5, the fabric
may be a two-layer laminate, with the smooth, technical face
surface of the respective fabric layers being adhered together
face-to-face and the respective outer, technical back surfaces
(carrying the raised surfaces of FIG. 2, the regions of high pile
and low pile of FIG. 3, or the pile pillars of FIG. 5) facing
outward at both surfaces. For example, referring to FIG. 7,
laminate 300 includes two fabrics 302, 304, the smooth surfaces of
which are adhered together at an interface 306. Each fabric carries
a raised pile area 308, 310 on its technical back surface 312,
314.
[0040] The fabrics discussed above with reference to FIGS. 3-6 will
now be discussed in further detail.
Fabrics Having a Pattern of High and Low/No Pile Regions
[0041] In the engineered knit fabrics 211' discussed above with
reference to FIGS. 3 and 8, the various regions can have pile of
predetermined fiber density and predetermined pile height. The
contrast of cushioning and airflow may be achieved, for example, by
forming regions of different pile heights (e.g., using different
sinker heights), different pile densities (e.g., using full face
velour and velour with pattern of pile and no pile), and/or
different types of yarns (e.g., using flat yarns with low shrinkage
and texture yarns with high shrinkage). Regions of selected shape
and size can be arranged in predetermined desired pattern,
tailored, as discussed above, for use by persons of different ages
and different genders, etc. and for other factors, such as
seasonality, etc.
[0042] The surfaces of regions of relatively high pile height may
be, for example, plain velour. Typically, the yarn and the pile
density is maintained constant for all regions, again for
simplicity of manufacture. The three dimensional pattern may exist
on one or both sides of the fabric. For example, if the fabric is
formed by a reverse plaiting process, the three dimensional pattern
will exist on both sides of the fabric, typically, in register.
[0043] The engineered thermal fabric articles can be produced by
any procedure suitable for creating regions of contrasting pile
heights and/or regions with no pile, in predetermined designs.
Examples of suitable procedures include electronic needle and/or
sinker selection; tubular circular or terry loop knit construction,
e.g. by reverse plaiting, to form double face fleece or to form
pseudo single face fabric, or by regular plaiting, to form single
face fleece; warp knit construction; woven construction; and fully
fashion knit construction.
[0044] To simplify manufacturing, in some implementations, e.g., as
shown in FIG. 4 and discussed above, the regions of contrasting
performance are arranged in band form, extending across the
mattress cover.
[0045] Any suitable yarn or fibers may be employed in forming the
engineered thermal fabrics. Examples of suitable yarn or fibers
include synthetic yarn or fibers formed, e.g., of polyester, nylon
or acrylic; natural yarn or fibers formed, e.g., of cotton or wool;
regenerate yarn or fibers, such as rayon; and specialty yarn or
fibers, such as aramid yarn or fibers, as sold by E.I. duPont de
Nemours and Company, Inc. under the trademarks NOMEX.RTM. and
KEVLAR.RTM..
Fabrics Having Pile Pillars
[0046] Referring to FIGS. 5 and 14, the raised surface fabric 111
discussed above includes a plurality of courses of loop yarn 113
integrated with stitch or backing yarn 115. The manner in which
pile pillars are formed in this fabric will be discussed in detail
below.
[0047] First, loop yarn 113 is plaited around stitch yarn 115 in
order to define a plurality of fabric loops 114 (FIG. 15). Fabric
111 has a circular knit reverse plaited construction suitable for
generating a two-face-surface fabric, as described below.
[0048] Once fabric 111 is formed, technical face 117 is napped or
otherwise raised (FIG. 16). The napping process is carried out in a
manner to maintain full loop coverage with minimal distortion of
technical back 119. In particular, during the napping process, the
integrity of loop yarn 113 on technical back 119 may, to some
extent, be compromised, as it is pulled shorter, due to the napping
process. Accordingly, loop yarn 113 generally must be knit longer,
e.g. utilizing sinker loops of at least 2.0 mm or greater, in order
to be able to shear loops 114 along technical back 119 at the
conclusion of the napping process.
[0049] Once the napping or raising process is completed, loops 114
along technical back 119 are sheared, as shown in FIG. 17.
Generally, the shearing step takes place after the napping step. If
shearing takes place as the first fabric finishing step, as is
usual for standard single face cut loop fabrics, the cut loops 114
can be pulled through the back to the face during any subsequent
napping process.
[0050] The channels between pile pillars may be formed using, for
example, the techniques described in U.S. Pat. No. 6,927,182, the
complete disclosure of which is incorporated herein by reference.
In such techniques, vertical channels are constructed with the use
of tipped and tipless sinkers, high and low sinkers, or some
combination of both (e.g., 4 tipped sinkers, 2 tipless, 3 tipped
sinkers, 2 tipless, repeat; 3 high sinkers, 1 low sinker, 2 high
sinkers, 2 low sinkers, repeat; etc.). Horizontal channels may be
created by removing the loop yarn from one or more feeds in some
arrangement, or with the use of a shrinkable loop yarn which
creates a channel after processing with wet (e.g., hot water,
steam) or dry (air) heat (e.g., 4 loop in, 2 loop out, 3 loop in, 2
loop out, repeat; 3 low shrinkage loop, 3 high shrinkage loop, 3
low shrinkage loop, 3 high shrinkage loop, repeat; etc.).
[0051] Loop yarn 113 generally has bulk greater than that of the
stitch yarn 115. For example, loop yarn 113 may have a denier of
between about 70 and 600, while stitch yarn 115 has a denier of
between about 30 and 150. Loop yarn 113 is preferably formed of
100% polyester or nylon. Loop yarn 113 may also be formed of other
materials such as acrylic. Stitch yarn 115 may be formed, e.g., of
polyester or nylon.
[0052] The fabric 111 may be knit on a standard terry sinker loop
knitting machine or on a jacquard machine, the latter enabling the
production of different height fabric loops along the technical
back of the fabric.
Two-Layer Fabrics
[0053] The two-layer fabrics 11 described above with reference to
FIGS. 6 and 10 may be prepared by knitting a three-dimensional knit
fabric on a double-needle bar warp knitting machine or circular
knitting machine, both of which are well known in the art. As shown
in FIGS. 11 and 12, the three-dimensional knit spacer fabric is
generally indicated at 11 and includes a first fabric layer 13
formed of stitch yarn 17, a second fabric layer 15 formed of stitch
yarn 19, and pile yarn 21 interconnecting the two layers. In
addition, knit fabric 11 includes backing or lay-in yarns 25 and 26
(FIG. 11), held by stitch yarns 17 and 19 respectively.
[0054] Pile yarns 21 have sufficient resilience and stiffness to
space the two fabric layers apart, e.g., including when pressure is
applied upon a fabric layer outer surface. The pile yarns 21 extend
generally between the first fabric layer 13 and the second fabric
layer 15 and through the air flow region therebetween. As discussed
above, the resilient separation provided by pile yarns 21 enhances
circulation of air between the reclining surface of viscoelastic
foam and an opposed skin surface of the person reclining upon the
cover. The pile yarns are spaced and positioned to resiliently urge
apart the two fabric layers, thereby maintaining the air flow
region to optimize user comfort. Moreover, the pile yarns 21 are
sufficiently spaced from one another to allow circulating air flow
through the intermediate region of the fabric 11. This enhanced air
flow helps to prevent bed sores, which can occur due to constant
body pressure and limited air circulation.
[0055] Pile yarn 21 may be knit with between 16 and 28 wales per
inch and 14 to 36 courses per inch. This density enhances the
ability of the fabric to maintain the spacing of the two layers
under pressure. Pile yarn 21 may be made of the same material as
the two fabric layers, or may be made of a different material. In
order to render the interconnecting pile yarn resilient, the yarn
may be made of a resilient material such as monofilament or
multifilament polyester, nylon, etc. Pile yarn 21 may have a
fineness of between 40 and 600 denier, e.g., between 40 and 300
denier, with an individual fiber fineness of 1 to 12 dpf.
[0056] The pile yarn may be made from fibers that have been
rendered hydrophilic in order to facilitate the transport of
moisture from top layer 13 to layer 15. Stitch yarn 17 of top layer
13 is also preferably made of fibers that have been rendered
hydrophilic. This construction facilitates moisture transport away
from the body, maintaining a comfortable top layer and air
circulation next to the skin. The top layer 13 may be chemically
treated or it may be formed of modified fibers that render the
fabric layer hydrophilic, as described in U.S. Pat. No. 5,312,667,
the complete disclosure of which is incorporated herein by
reference. The transport of water from the surface is substantially
enhanced by the hydrophilic nature of the top layer because liquid
moisture is readily transportable along the surface of the yarn
fibers of the layer.
[0057] Top layer 13 may be formed of stitch yarn having a fineness
of between 50 and 600 denier with an individual fiber fineness in
the range of between 0.3 and 2.5 dpf, if multifilament. Backing or
lay-in yarns 25 and 26 of top layer 13 may be multifilament and may
have a fineness of between 70 and 300 denier, with an individual
fiber fineness of 0.5 to 5.0 dpf.
[0058] The stitch yarns may be formed of synthetic material such as
polyester, acrylic or nylon, or in some cases a natural material
such as cotton. The yarns may be filament or spun, textured or
fully oriented. Preferably, stitch yarns 17 and 19 and backing
yarns 25 and 26 are formed of polyester or nylon that has been
rendered hydrophilic in order to enhance transport of perspiration
or water.
[0059] Second fabric layer 15 may be the same as top layer 13 or
may have different characteristics. Layer 15 may in some cases
consist of hygroscopic fibers in order to absorb and hold a
considerable volume of moisture. Particularly, backing yarn 26 of
second fabric layer 15 may be formed of moisture absorbent material
such as cotton (which absorbs 2 to 3 times its weight of water),
rayon, wool or a super absorbent fiber such as a hydrolyzed
copolymer of acrylic acid (which absorbs between two and eight
times its weight). In accordance with the disclosure, any suitable
moisture absorbent material may be used, e.g., natural fibers or
synthetics, so long as the yarn or fiber material chosen for layer
15 has relatively greater moisture absorbency than the fiber or
yarn of layer 13.
[0060] The use of a super absorbent fiber is quite desirable in
that the fibers will absorb many times their own weight, even when
under pressure, and will retain the absorbed liquid when subjected
to pressure. Examples of suitable types of super absorbent fibers
are described in U.S. Pat. No. 5,344,698, the complete disclosure
of which is incorporated herein by reference.
[0061] If cotton or rayon fibers are used for the second fabric
layer, they may be chemically modified after knitting the composite
fabric by treatment with alkyl chlorides and cross-linking of the
resultant ethers to form carboxymethylated cellulosic fibers, as
known to one of skill in the art, in order to render the second
layer super absorbent.
[0062] The surface of top fabric layer 13 may be sanded, brushed or
napped, forming a pile or velour surface. The yarn which is more
coarse, i.e. either the stitch yarn or the interconnecting pile
yarn, is napped. Generally the yarn napped is a multifilament
yarn.
[0063] Optionally, as discussed above, the fabric may incorporate
elastomeric yarn, such as LYCRA or SPANDEX, in one or both of
lay-in yarns 25 and 26 of layers 13 and 15, respectively, and/or
the stitch yarns 17, 19. Such yarn will have a total fineness
between about 70 and 300 denier. This will enhance softness and
flexibility of the layer, and thus its conformability to the
viscoelastic foam. The elastomeric yarn may also be added to the
stitch yarn of one or both layers.
[0064] Top layer 13 may be coated with a breathable barrier layer,
i.e., a barrier layer that is impermeable to liquid water but
permeable to water vapor. The barrier layer deposited on the fabric
layer is preferably a film with good moisture vapor transmission
characteristics. Suitable films include polyurethane, polysiloxane
and polysulfane.
[0065] The barrier layer may be applied to the fabric layer by
methods well known in the art. These include transfer coating, in
which the barrier layer is first placed or laid on a carrier.
Thereafter, the film is placed on the fabric layer, and the carrier
is then discarded. Alternative methods for applying the film
include direct lamination of an extruded film, as well as direct
roller coating of a solution onto the fabric layers from which the
solvent is then evaporated. A further method for applying the
barrier layer is first applying an adhesive on the fabric layer by
spraying or gravure printing and then placing a self-supporting
film on top of the adhesive in the manner of lamination.
[0066] A portion of the pile yarns 21 interconnecting the two
layers may be perpendicular to each of the first and second fabric
layers, while the remaining pile yarns 21 are disposed at varying
angles between the two layers, with the result that the former will
be of lesser and the latter of greater bulk. Such constructions are
described in U.S. Pat. No. 6,156,406, the complete disclosure of
which is incorporated herein by reference.
[0067] A number of implementations have been described.
Nevertheless, it will be understood that various modifications may
be made without departing from the spirit and scope of this
disclosure. Accordingly, other implementations are within the scope
of the following claims.
* * * * *