U.S. patent application number 13/036931 was filed with the patent office on 2011-12-29 for laminated support.
This patent application is currently assigned to LANCASTRIA LIMITED. Invention is credited to Padraig Hackett, David Woolfson.
Application Number | 20110314607 13/036931 |
Document ID | / |
Family ID | 34113373 |
Filed Date | 2011-12-29 |
United States Patent
Application |
20110314607 |
Kind Code |
A1 |
Woolfson; David ; et
al. |
December 29, 2011 |
Laminated Support
Abstract
A mattress, cushion or the like has an outer cover enclosing a
resilient core. The resilient core is formed by a viscoelastic foam
layer with a vapour permeable reinforcing layer of stretchable
material laminated onto a top surface of the viscoelastic foam
layer. The reinforcing layer prevents cracking in the top surface
of the viscoelastic foam layer and provides improved heat and
moisture dissipation during use. The reinforcing layer is
preferably formed by a spaced knitted fabric.
Inventors: |
Woolfson; David; (Dublin,
IE) ; Hackett; Padraig; (Dublin, IE) |
Assignee: |
LANCASTRIA LIMITED
Dublin
IE
|
Family ID: |
34113373 |
Appl. No.: |
13/036931 |
Filed: |
February 28, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10579196 |
Apr 16, 2007 |
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PCT/IE04/00158 |
Nov 12, 2004 |
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13036931 |
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Current U.S.
Class: |
5/636 ; 5/655.9;
5/724 |
Current CPC
Class: |
B32B 2307/724 20130101;
B32B 5/245 20130101; B32B 5/08 20130101; B32B 5/18 20130101; B32B
2262/0253 20130101; Y10T 442/469 20150401; Y10T 442/45 20150401;
Y10T 428/233 20150115; A47C 31/006 20130101; Y10T 442/3325
20150401; A47C 27/001 20130101; A47C 27/22 20130101; B32B 5/026
20130101; Y10T 442/3179 20150401; A47C 27/006 20130101; B32B 27/12
20130101 |
Class at
Publication: |
5/636 ; 5/724;
5/655.9 |
International
Class: |
A47C 27/15 20060101
A47C027/15; A47C 16/00 20060101 A47C016/00; A47G 9/10 20060101
A47G009/10; A47C 17/00 20060101 A47C017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2003 |
IE |
S2003/0849 |
Claims
1. A laminated body contact support element (1), for a mattress,
cushion or the like including an inner layer (4) of viscoelastic
foam material and an air permeable outer layer (5) of stretchable
material laminated onto a top surface (6) of the viscoelastic foam
layer (4), characterised in that the outer layer (5) comprises a
highly breathable three dimensional fabric which forms an air layer
above the viscoelastic foam layer (4).
2-18. (canceled)
19. A laminated body contact support element, for a mattress,
cushion or the like including an inner layer of viscoelastic foam
material and an air permeable outer layer of stretchable material
laminated onto a top surface of the viscoelastic foam layer, the
outer layer comprising a highly breathable three dimensional fabric
which forms an air layer above the viscoelastic foam layer.
20. A laminated support as claimed in claim 19 wherein the outer
layer comprises a spacer fabric.
21. A laminated support as claimed in claim 19 wherein the outer
layer comprises a spaced knitted fabric having a pair of
spaced-apart knitted layers with spacer yarns extending between
said knitted layers, one of said knitted layers being laminated
onto the top surface of the viscoelastic foam layer.
22. A laminated support as claimed in claim 19 wherein the maximum
stretch of the outer layer material is less than the breaking
stretch of the underlying viscoelastic foam layer material.
23. A laminated support as claimed in claim 19 wherein the tensile
strength of the outer layer material is greater than the tensile
strength of the viscoelastic foam layer material.
24. A laminated support as claimed in claim 19 wherein the outer
layer is of knitted polyester material.
25. A laminated support as claimed in claim 19 wherein the outer
layer has a thickness in the range 0.5 mm to 30 mm.
26. A laminated support as claimed in claim 25 wherein the outer
layer has a thickness in the range 3 mm to 6 mm.
27. A laminated support as claimed in claim 19 wherein the outer
layer has a stretchability in the range 20% to 200%.
28. A laminated support as claimed in claim 27 wherein the outer
layer has a stretchability in the range 40% to 140%.
29. A laminated support as claimed in claim 19 wherein the outer
layer is adhesively bonded to the viscoelastic layer.
30. A laminated support as claimed in claim 19 wherein outer layers
are bonded to both the top surface and a bottom surface of the
viscoelastic layer.
31. A laminated support as claimed in claim 19 wherein the bottom
surface of the viscoelastic foam layer is laminated onto a support
substrate.
32. A laminated support as claimed in claim 31 wherein the support
substrate comprises a standard foam or a combustion modified
foam.
33. A laminated support as claimed in claim 19 further including a
vapour permeable outer cover.
34. A mattress incorporating a support element as claimed in claim
19.
35. A cushion incorporating a support element as claimed in claim
19.
36. A pillow incorporating a support element as claimed in claim
19.
37. A laminated body contact support element for a mattress,
cushion or the like including an inner layer of viscoelastic foam
material and an air permeable outer layer of stretchable material
adhesively bonded to a top surface of the viscoelastic foam layer,
said outer layer comprising a highly breathable three-dimensional
fabric which forms an air layer above the viscoelastic foam layer,
the maximum stretch of the outer layer material being less than the
breaking stretch of the underlying viscoelastic foam layer
material.
Description
TECHNICAL FIELD
[0001] This invention relates to laminated body contact supports
such as mattresses, cushions, pillows and the like products.
BACKGROUND ART
[0002] It is known to use viscoelastic foams in mattresses,
cushions and the like because of their desirable properties.
Examples of such products are to be found in our earlier filed
European Patent Application No. 01650114.0 (Publication No. EP
1192925). Such viscoelastic foams have a low rebound property, are
temperature sensitive and tend to mould themselves to the shape of
a persons body in contact with the mattress to provide a more
uniform pressure distribution for increased comfort. This is
particularly advantageous in hospital beds with a view to
minimising problems with bedsores and increasing a patients comfort
generally. These types of foam are now finding increasing
application in domestic furniture, particularly bedding.
[0003] These mattresses, in common with conventional mattresses,
allow the dissipation of perspiration from a persons body through
the mattress in the form of water vapour, that is they are vapour
permeable. However a problem arises in that when in use the
atmosphere within the mattress has a relatively high humidity due
to this transient water vapour. In such an atmosphere of relatively
high humidity and when subject to the stresses applied to the
mattress by the weight of the person being supported and due to
their movement on the mattress, the upper surface of the
viscoelastic foam may become cracked, particularly in those areas
subjected to the greatest stress. It is exacerbated by the
prolonged stresses caused by patients sitting in a semi reclined
position on the mattress and shifting their position. If the
visco-elastic foam is stretched beyond its yield then a stress
crack will result. Over a period of time multiple cracks may appear
in the foam in the seating position and the comfort and performance
of the mattress is adversely affected.
[0004] Further, while viscoelastic foams are permeable the
migration of water vapour through the layer of foam is relatively
slow. In use the portions of the mattress in contact with the user
tends to heat up due to this warm water vapour and this is
undesirable for the comfort of the user and may promote bed sores.
In patent specification U.S. Pat. No. 6,159,574 there is disclosed
a laminated visco-elastic support such as a cushion or mattress
which includes at least one visco-elastic foam layer. A thin layer
of reticulated filter polyurethane foam is bonded to an outer face
of the support to promote increased air circulation adjacent a
persons skin for increased comfort of the user. While this
construction may provide some improvement it does not effectively
salve the aforementioned problems. Migration of water vapour
through the polyurethane foam is also relatively slow.
[0005] The present invention is directed towards overcoming these
problems.
SUMMARY OF THE INVENTION
[0006] According to the invention there is provided a laminated
body contact support element for a mattress, cushion or the like
including an inner layer of viscoelastic foam material and an air
permeable outer layer of stretchable material laminated onto a top
surface of the viscoelastic foam layer, characterised in that the
outer layer comprises a highly breathable three dimensional fabric
which forms an air layer above the viscoelastic foam layer.
[0007] The outer layer material is very breathable so that it does
not trap moisture and maintains a comfortable microclimate for the
user. It also has two-way stretchability so as not to diminish or
at least only minimally effect the beneficial properties of the
viscoelastic foam layer. Further, the outer layer has a relatively
high strength so that it will not crack in use.
[0008] In a particularly preferred embodiment the outer layer
comprises a spacer fabric. The spacer fabric essentially comprises
a pair of spaced-apart outer layers interconnected by spaced-apart
internal cross members to provide a very open 3-dimensional
fabric.
[0009] In a particularly preferred embodiment the outer layer
comprises a spaced knitted fabric having a pair of spaced-apart
knitted layers with spacer yarns extending between said knitted
layers, one of said knitted layers being laminated onto the top
surface of the viscoelastic foam layer.
[0010] In another embodiment the maximum stretch of the outer layer
material is less than the breaking stretch of the underlying
viscoelastic foam layer material.
[0011] In a further embodiment the tensile strength of the outer
layer material is greater than the tensile strength of the
viscoelastic foam layer material.
[0012] In one embodiment the outer layer has a thickness in the
range 0.5 mm to 30 mm. In another embodiment the thickness is in
the range 3 mm to 6 mm.
[0013] In another embodiment the outer layer has a stretchability
in the range 20% to 200% and most preferably in the range 40% to
140%.
[0014] The outer layer may be laminated or bonded to the
viscoelastic foam layer in any suitable fashion. For example, a
solvent based adhesive or water based adhesive could be used. Other
possible bonding methods include the use of hot melt adhesive or
flame lamination. Further, the outer reinforcing layer can be
bonded in a continuous or semi-continuous fashion to the
viscoelastic foam layer.
[0015] In a preferred embodiment the outer layer comprises a highly
breathable fabric. This conveniently allows good airflow through
the reinforcing layer which will be closest to the person in use,
minimising heat and humidity between the mattress and the person in
use for added comfort.
[0016] The outer layer may be of any suitable material such as
knitted polyester or polyurethane coated synthetic material
(polyester, nylon and the like) suitable for medical mattresses or
other fabric material.
[0017] In another embodiment outer layers are bonded to both the
top surface and a bottom surface of the viscoelastic layer. This
provides a reversible laminated support element.
[0018] In another embodiment the bottom surface of the viscoelastic
foam layer is laminated onto a support substrate. Various types of
support substrate are possible, for example foam material, springs,
airbed bladder or baffles, water bladder or baffles, latex and the
like.
[0019] In another embodiment the support substrate comprises a foam
layer. Conveniently a standard foam or a combustion modified foam
layer may be provided.
[0020] In a further embodiment the laminated support further
includes a vapour permeable outer cover.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention will be more clearly understood by the
following description of some embodiments thereof, given by way of
example only, with reference to the accompanying drawings, in
which:
[0022] FIG. 1 is a perspective, partially cut-away, view of a
mattress according to the invention;
[0023] FIG. 2 is a detail sectional elevational view showing
portion of the mattress;
[0024] FIG. 3 is a view similar to FIG. 2 of portion of another
mattress according to the invention;
[0025] FIG. 4 is a perspective view similar to FIG. 1 showing
another mattress;
[0026] FIG. 5 is a perspective, partially cut-away, view of a
cushion according to the invention; and
[0027] FIG. 6 is a view similar to FIG. 5 of another cushion.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Referring to the drawings, and initially to FIGS. 1 and 2
thereof, there is illustrated a mattress, mattress overlay or
trolley pad according to the invention indicated generally by the
reference numeral 1. The mattress 1 comprises an outer cover 2
extending about a resilient core 3. In accordance with the
invention the core 3 is formed from a block or inner layer 4 of
viscoelastic foam with a vapour permeable reinforcing outer layer 5
of stretchable material laminated onto a top surface 6 of the
viscoelastic foam layer 4.
[0029] The reinforcing layer 5 comprises a spaced knitted fabric
having a pair of spaced-apart knitted layers, namely an inner layer
7 and an outer layer 8 with spacer yarns 9 between said knitted
layers 7, 8. A suitable material for forming the reinforcing layer
5 is 3 mesh (Registered Trade Mark) material produced by Mueller
Textil of Wiehl, Germany, which is a three-dimensional spacer
polyester fabric comprising two warp-knitted layers which are
connected by pile monofilaments in a single knitting process. This
reinforcing layer 5 may typically be either 3 mm or 6 mm thick. It
is bonded to the top surface 6 of the viscoelastic foam layer 4 in
any suitable fashion such as by adhesive. The viscoelastic foam
layer may be any suitable thickness, and in many applications will
be about 60 mm thick.
[0030] In use, the mattress 1 is used in conventional fashion with
the reinforcing layer 3 uppermost. During use the reinforcing layer
5 will resiliently deform following the contour of the viscoelastic
foam layer 4 at the same time reinforcing the top surface 6 of the
viscoelastic foam layer 4 to prevent cracking in the viscoelastic
foam layer 4. The reinforcing layer 5 also provides an air layer
which aids in dissipating heat and moisture away from the body of a
person, lying on the mattress 1 in use for their increased
comfort.
[0031] Referring now to FIG. 3 an alternative construction for the
core is shown and indicated generally by the reference numeral 20.
Parts similar to those described previously are assigned the same
reference numerals. In this case a bottom surface 21 of the
viscoelastic foam layer 4 is laminated onto a substrate formed by a
bottom foam layer 22 of a standard or a combustion modified
foam.
[0032] The viscoelastic foam layer 4 is typically in the order of
70-150 mm thick but may be any suitable thickness. The foam
substrate may also be in the range 70-150 mm thick or any other
suitable thickness. Both layers 4, 22 may be the same or different
thicknesses. The substrate foam layer 22 material has a density in
the order of 35-50 kg/m.sup.3. Other densities are also
possible.
[0033] Where a mattress or cushion simply comprising the
viscoelastic foam is required this may be sandwiched between two
other layers of the reinforcing material so it can be used either
side up. Such a mattress arrangement is shown in FIG. 4 and
indicated generally by the reference numeral 30. Parts similar to
those described previously are assigned the same reference
numerals. In this case a central viscoelastic foam layer 4 is
sandwiched between a pair of outer reinforcing layers 5.
[0034] Referring now to FIG. 5 there is shown a cushion according
to another embodiment of the invention indicated generally by the
reference numeral 40. Parts similar to those described previously
are assigned the same reference numerals. The cushion 40 has an
outer cover 2 extending about a resilient core 3 comprising an
inner layer 4 of viscoelastic foam on top of which is laminated an
outer reinforcing layer 5 of the spaced knitted fabric. The cushion
40 could be used for example in medical applications for
wheelchairs or could be used as a seat cushion for furniture
generally.
[0035] Referring now to FIG. 6 there is shown another cushion
indicated generally by the reference numeral 50. Parts similar to
those described previously are assigned the same reference
numerals. In this case a resilient core 53 of the cushion 50
comprises a layer 4 of viscoelastic foam on a top surface 6 of
which is laminated a reinforcing layer 5 of the spacer fabric. The
bottom surface 21 of the viscoelastic foam layer 4 is laminated
onto a substrate formed by a bottom foam layer 54 of a standard or
a combustion modified foam material.
[0036] While the invention has been described in the embodiments in
relation to mattresses and cushions it will be appreciated that it
can be applied to body contact supports generally. These also
include overlays--which can be placed on top of conventional
mattresses to provide more even pressure distribution and increase
comfort--trolley pads, wheelchair cushions, seat cushions,
headrests, pillows and the like which incorporate viscoelastic
foam, or indeed any applications in which viscoelastic foam panels
are subjected to relatively high humidity and stress in order to
prevent cracking of the viscoelastic foam and/or provide improved
heat and moisture dissipation. The term mattress as used in this
patent specification includes such body contact supports.
[0037] If will be appreciated that the invention provides a
laminated support with an air layer formed on top of a viscoelastic
foam layer. This modified viscoelastic foam layer may be mounted on
top of any suitable substrate such as foam, springs, airbed bladder
or baffles, water bladder or baffles, latex and so on for the
purposes of providing a support surface which will typically be in
the form of a mattress, cushion or pillow or the like. The air
layer forms a breathable skin on the surface of the viscoelastic
foam layer. This facilitates the provision of a comfortable
microclimate adjacent the skin of the user when lying or seated on
the support element. Ideally the outer layer has two-way stretch to
allow it to expand in sympathy with the viscoelastic foam whilst at
the same time the extent of stretch in the outer layer should be
less than the extension at break figure for the underlying
viscoelastic foam. Preferably also the tensile strength of the
outer air layer material should exceed that of the viscoelastic
foam and be such that the normal use of the mattress will not cause
it to rupture. Also, this outer air layer material is breathable
and water permeable to maintain a comfortable microclimate for the
user.
[0038] It will be appreciated that the viscoelastic foam layer may
be of any suitable thickness, and this will largely depend on the
application for which the support element is being used. Generally
speaking it is envisaged that the thickness of the viscoelastic
material will usually fall within the range 50 mm-150 mm. Various
different densities of viscoelastic foam material are also
possible. Densities in the range 50-110 kg per m.sup.3 have been
found suitable in many mattress and seating applications for
example.
[0039] Regarding the cover which will normally be provided about
the support element, various different covers are possible which
are vapour permeable. Suitable covers include a polyurethane or
nylon coating on a polyester backing fabric to provide a vapour
permeable cover which is waterproof and may be treated so that it
is anti-bacterial and fungostatic.
[0040] The invention is not limited to the embodiments hereinbefore
described which may be varied in both construction and detail
within the scope of the appended claims.
* * * * *