U.S. patent application number 10/640678 was filed with the patent office on 2004-02-19 for mattress.
This patent application is currently assigned to Lancastria Limited. Invention is credited to Woolfson, David.
Application Number | 20040031102 10/640678 |
Document ID | / |
Family ID | 11042674 |
Filed Date | 2004-02-19 |
United States Patent
Application |
20040031102 |
Kind Code |
A1 |
Woolfson, David |
February 19, 2004 |
Mattress
Abstract
A mattress comprises a sealed outer casing within which is
mounted a resilient support formed by a composite foam core. At
least an upper portion of the resilient support is formed by a
visco-elastic foam. A vent is provided in a side wall of the casing
and is covered by a filter which prevents ingress of bacteria into
the cover. A flap is mounted on the cover and in use extends down
over the vent to prevent the filter being damaged by fluids.
Inventors: |
Woolfson, David; (Dublin,
IE) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
Lancastria Limited
Dublin
IE
|
Family ID: |
11042674 |
Appl. No.: |
10/640678 |
Filed: |
August 14, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10640678 |
Aug 14, 2003 |
|
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09966053 |
Oct 1, 2001 |
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Current U.S.
Class: |
5/690 |
Current CPC
Class: |
A47C 27/15 20130101;
A47C 27/006 20130101; A61G 7/05784 20161101; A47C 27/144 20130101;
A47C 21/046 20130101; A47C 31/007 20130101; A47C 27/148
20130101 |
Class at
Publication: |
5/690 |
International
Class: |
A47C 017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 29, 2000 |
IE |
S2000/0783 |
Claims
1. A mattress comprising an outer casing within which is mounted a
resilient support, characterised in that the support is sealed
within the casing and said casing has an air vent in a side wall of
the casing.
2. A mattress as claimed in claim 1 wherein at least an upper
portion of the resilient support is formed by a layer of
visco-elastic foam.
3. A mattress as claimed in claim 1, wherein a filter is mounted
across the air vent to prevent the ingress of bacteria to an
interior of the casing.
4. A mattress as claimed in claim 3, wherein the filter has pores
for through-passage of air, said pores being sized to trap any
particle greater than 1 micron in size.
5. A mattress as claimed in claim 1, wherein a flap is mounted on
the casing, the flap being fixed to an exterior of the casing above
the vent and extending downwardly over the vent, a free edge of the
flap defining with the casing an opening for through passage of air
to and from the vent.
6. A mattress as claimed in claim 1, wherein at least portion of
the resilient support has a profiled area comprising projections
and hollows at an upper surface of the resilient support.
7. A mattress as claimed in claim 6 wherein said projections have a
flat-topped pyramid shape.
8. A mattress as claimed in claim 6, wherein said profiled area is
at a lower end of the resilient support forming a heel support
region of the resilient support.
9. A mattress as claimed in claim 2, wherein the visco-elastic foam
has a density in the range 60-95 kg/m.sup.3.
10. A mattress as claimed in claim 9 wherein the density of the
visco-elastic foam is about 85 kg/m.sup.3.
11. A mattress as claimed in claim 1 wherein the resilient support
includes a bottom layer of a combustion modified high resilient
foam and a top layer of visco-elastic foam.
12. A mattress as claimed in claim 11 wherein the resilient support
further includes an outer frame mounted about a side of said layers
forming an endless side margin about said layers, said outer frame
being formed of a high index foam.
13. A mattress as claimed in claim 1 including a composite
resilient support having a laminated core with a rectangular bottom
layer and an associated rectangular top layer superimposed on said
bottom layer, a top face of the bottom layer engaging and
adheisively secured to a complementary bottom face of the top
layer, said bottom layer being formed of a combustion modified high
resilience foam and said top layer being formed of a visco-elastic
foam, said layers being of equal depth, said core being encircled
by an outer frame formed of a high index foam which extends about
the side faces and end faces of the core and being adhesively
secured thereto, a sealed casing mounted about said core, said
casing being formed of an elastic material stretched about the core
with overlapping seams of the cover being welded together to form a
sealed enclosure about the core, an opening in said casing forming
a vent to allow air passage between an interior and an exterior of
the casing, a filter mounted across the vent, and a flap mounted on
the casing covering the vent and being fixed to said casing about a
periphery of the flap above and at each side of the vent leaving a
downwardly facing opening between a lower end of the flap and the
casing for air passage to and from the air vent.
14. A mattress comprising an outer casing within which is mounted a
resilient support, at least an upper portion of the support being
formed by a layer of visco-elastic foam, the support having a lower
end forming a heel support region of the support, an upper surface
of said heel support region being a profiled area of projections
and hollows.
15. A mattress as claimed in claim 14 wherein the projections have
a flat-topped pyramid shape.
16. A mattress as claimed in claim 14 wherein the support is sealed
within the casing and said casing has an air vent in a side wall of
the casing.
17. A mattress as claimed in claim 16 wherein a filter is mounted
across the air vent to prevent ingress of bacteria to an interior
of the casing.
18. A mattress as claimed in claim 16 wherein a flap is mounted on
the casing, the flap being fixed to an exterior of the casing above
the vent and extending downwardly over the vent, a free edge of the
flap defining with the casing an opening for through passage of air
to and from the vent.
19. A mattress comprising an outer elastic casing within which is
mounted a resilient support, at least an upper portion of the
support being formed by a layer of visco-elastic foam having a
density of about 85 kg/m.sup.3.
20. A mattress as claimed in claim 19 wherein the resilient support
has a laminated construction including a rectangular bottom layer
and an associated rectangular top layer superimposed on said bottom
layer, a top face of the bottom layer engaging and being adhesively
secured to a complementary bottom face of the top layer, said
bottom layer being formed by a combustion modified high resilience
foam and said top layer being formed by the layer of visco-elastic
foam.
Description
BACKGROUND OF THE INVENTION
[0001] The invention is particularly related to a mattress which is
suitable for use in medical applications for the improved comfort
of patients who are confined to bed for long periods of brne. Such
patients often suffer from bedsores due to the concentration of
pressure in regions where the patient's body touches the mattress,
particularly in the regions of the shoulders, hips and heels.
Another problem arising in medical environments is the possibility
of infection of the mattress with bacteria which could subsequently
infect a patient.
[0002] The present invention is directed towards overcoming these
problems.
SUMMARY OF THE INVENTION
[0003] According to the invention there is provided a mattress,
comprising an outer casing within which is mounted a resilient
support, wherein the support is sealed within the casing and said
casing has an air vent in a side wall of the casing. Thus,
conveniently the casing can be formed with welded seams without
ballooning of the casing. Further, the vent allows the mattress to
breathe.
[0004] In a particularly preferred embodiment at least an upper
portion of the resilient support is formed by a visco-elastic foam.
Advantageously the visco-elastic slow foam or memory foam has a
tendency to mould itself into the shape of the body lying on the
foam layer, thus providing an even distribution of pressure over
the body of the patient and thus minimising localised high pressure
points.
[0005] In a preferred embodiment, a filter is mounted across the
air vent to prevent the ingress of bacteria to an interior of the
casing.
[0006] In another embodiment the filter has pores for
through-passage of air, said pores being sized to trap any particle
greater than 1 micron in size. As bacteria typically attaches to
particles over 6 microns in size and the filter blocks the passage
of any particle greater than 1 micron in size, the filter
effectively prevents ingress of bacteria into the cover.
[0007] In a further embodiment a flap is mounted on the cover, the
flap being fixed to an exterior of the cover above the vent and
extending downwardly over the vent. This advantageously protects
the vent and filter being damaged by fluid such as when cleaning
the mattress for example.
[0008] The cover is preferably of an elastic material which is
stretched over the foam core. Additional anti-bacterial,
fungistatic protection may be provided for the foam core and for
the cover if desired.
[0009] In a preferred embodiment of the invention at least portion
of the foam layer has a profiled area comprising projections and
hollows at an upper support surface of the foam layer.
[0010] In a particularly preferred embodiment said profiled area is
at a lower end of the foam layer forming a heel support region of
the foam layer. This advantageously provides extra pressure
reduction in the heel area of a patient when the mattress is in
use.
[0011] In another embodiment the projections are of generally
flat-topped pyramid shape arranged in a chequered formation with
hollows formed therebetween.
[0012] In another embodiment the visco-elastic foam has a density
in the range 60-95 kg/m.sup.3. Most preferably the density of the
visco-elastic foam is 85 kg/m.sup.3.
[0013] In a particularly preferred embodiment, the support is
provided by a multi-layered support core comprising the
visco-elastic foam top layer mounted on at least one bottom layer
of foam having a greater resilience than the visco-elastic foam.
This provides added rigidity and support to the core.
[0014] In a particularly preferred embodiment, the bottom layer
comprises a combustion modified high resilient foam.
[0015] Preferably the casing is of a stretchable elastic
material.
[0016] In another embodiment the resilient support further includes
an outer frame mounted about a side of said layers forming an
endless side margin about said layers, said outer frame being
formed of a high index foam.
[0017] In a particularly preferred embodiment the mattress includes
a composite resilient support having a laminated core with a
rectangular bottom layer and an associated rectangular top layer
superimposed on said bottom layer, a top face of the bottom layer
engaging and adhesively secured to a complementary bottom face of
the top layer, said bottom layer being formed of a combustion
modified high resilience foam and said top layer being formed of a
visco-elastic foam, said layers being of equal depth, said core
being encircled by an outer frame formed of a high index foam which
extends about the side faces and end faces of the core and being
adhesively secured thereto, a sealed casing mounted about said
core, said casing being formed of an elastic material stretched
about the core with overlapping seams of the core being welded
together to form a sealed enclosure about the core, an opening in
said casing forming a vent to allow air passage between an interior
and an exterior of the casing, a filter mounted across the vent and
a flap mounted on the casing covering the vent and being fixed to
said casing about a periphery of the flap above and at each side of
the vent leaving a downwardly facing opening between a lower end of
the flap and the casing for air passage to and from the air
vent.
[0018] In another aspect the invention provides a mattress
comprising an outer casing within which is mounted a resilient
support, at least an upper portion of the support being formed by a
layer of visco-elastic foam, the support having lower end forming a
heel support region of the support, an upper surface of said heel
support region being a profiled area of projections and hollows.
Preferably the projections have a flat-topped pyramid shape.
[0019] In another embodiment the support is sealed within the
casing and said casing has an air vent in a side wall of the
casing. Ideally a filter is mounted across the air vent to prevent
ingress of bacteria to an interior of the casing. Preferably a flap
is mounted onto the casing, the flap being fixed to an exterior of
the casing above the vent and extending downwardly over the vent, a
free edge of the flap defining with the casing an opening for
through passage of air to and from the vent.
[0020] In a further aspect the invention provides a mattress
comprising an elastic outer casing 5 within which is mounted a
resilient support, at least an upper portion of the support being
formed by a layer of visco-elastic foam having a density of about
85 kg/m.sup.3.
[0021] In another embodiment the resilient support has a laminated
construction including a rectangular bottom layer and an associated
rectangular top layer superimposed on said bottom layer, a top face
of the bottom layer engaging and being adhesively secured to a
complementary bottom face of the top layer, said bottom layer being
formed of a combustion modified high resilience foam and said top
layer being formed by the layer of visco-elastic foam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention will be more clearly understood from the
following description of some embodiments thereof, given by way of
example only, with reference to the accompanying drawings, in
which:
[0023] FIG. 1 is a perspective view of a mattress according to the
invention;
[0024] FIG. 2 is a plan view of a composite foam core of the
mattress;
[0025] FIG. 3 is a sectional view taken along the line III-III of
FIG. 2;
[0026] FIG. 4 is a perspective, partially cut-away view
illustrating the mattress;
[0027] FIG. 5 is a detail perspective view illustrating a profiled
pressure reducing portion of the core;
[0028] FIG. 6 is a perspective view of another mattress;
[0029] FIG. 7 is a perspective view of a cushion according to
another embodiment of the invention; and
[0030] FIG. 8 is a perspective view of a foam core of the cushion
of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] Referring to the drawings, and initially to FIGS. 1 to 5
thereof, there is illustrated a mattress according to the invention
indicated generally by the reference numeral 1. The mattress 1
comprises a sealed outer casing 2 within which is mounted a
resilient support formed by a composite foam core 3. A vent 4 is
provided in a side wall 7 of the casing 2 and is covered by a
filter 5, which prevents ingress of bacteria into the cover 2. A
flap 6 is mounted on the cover 2 and in use extends down over the
vent 4 to prevent the filter 5 being damaged by fluids. The flap 6
is attached to the cover 2 along top and side edges leaving at
least portion of the bottom edge open to allow air passage.
[0032] The cover 2 is formed of an elastic stretchable material
with seams of the cover 2 being welded to provide a sealed
enclosure for the core 3.
[0033] The foam core 3 comprises an upper layer 8 of a
visco-elastic material mounted on and adhesively secured to a lower
layer 9 which comprises a combustion modified high resilience foam.
The upper layer 8 has a top surface 10 upon which a patient is
supported in use.
[0034] A lower end of the upper layer has an anatomic profiling
region 12 in which material has been removed from the layer 8 to
provide a serious of projections 14 and associated hollows 15
arranged in a chequered configuration. The projections 14 have a
generally pyramidal shape having a square flat top 16 which is
substantially flush with the continuous portion of top surface 10
at an upper end of the upper layers. Side walls 17 slope downwardly
and outwardly of each side of the top 16 defining hollows 15 or
voids between the projections 14. In this case the hollows 15
extend roughly one half of the depth of the upper layer 8. The
depth of both layers 8, 9 is typically about 7 cm. The upper
visco-elastic foam layer 8 has a density of 85 kg/m.sup.3.
[0035] For added support to the core 3 an outer frame 20 is
provided comprising side pieces 21 glued to each side of the layers
8, 9 and end pieces 22 glued across the ends of the layers 8, 9.
The frame 20 is formed from a high index foam material.
[0036] In use, the mattress 1 is mounted on a bed with the upper
layer 8 of visco-elastic foam uppermost. When a patient lies on the
mattress 1 the upper layer 8 tends to deform to closely conform to
the contour of the patient's body to gently support and evenly
distribute the weight of the patient over a wide area. Further, the
profiled region 12 on which the patient's heels rest provides extra
pressure reduction in the heel area to reduce the risk of pressure
sore development in this area of the body.
[0037] The flap which covers the filter and vent does not have to
extend fully across the side of the casing and may simply extend
over the vent and filter.
[0038] It will be noted that the cover can be easily cleaned.
Further, as the cover 2 is sealed bacteria cannot impregnate the
mattress. The vent and filter allows the mattress to breathe when a
person lies on or gets up from the mattress and prevents ballooning
of the sealed casing.
[0039] It will be appreciated that all the foams used are treated
so that they are flame retardant to British Standard SI 1324.
[0040] Referring now to FIG. 6, there is shown another mattress 30
comprising an outer cover 31 surrounding a foam support core 32
formed by three layers of foam material comprising an upper layer
33 of visco-elastic foam, an intermediate layer 34 and a lower
layer 35 of foams of greater resilience than the visco-elastic
foam.
[0041] The term "mattress" as used in this patent specification can
also be taken to include cushions of similar construction. For
example, referring to FIGS. 7 and 8, there is shown a cushion 40
according to another embodiment of the invention. The cushion 40
comprises an outer cover 41 having an opening closed by a concealed
zip 42 along one edge, within which is mounted a foam support core
43. The foam core 43 comprises an upper layer 44 of visco-elastic
foam and a lower layer 45 of a combustion modified high resilience
foam.
[0042] The invention is not limited to the embodiments hereinbefore
described, but may be varied in both construction and detail within
the scope of the appended claims.
* * * * *