U.S. patent application number 12/407605 was filed with the patent office on 2009-07-09 for laminated visco-elastic support.
Invention is credited to Michael B. Allaway, Dag Landvik.
Application Number | 20090172887 12/407605 |
Document ID | / |
Family ID | 46303461 |
Filed Date | 2009-07-09 |
United States Patent
Application |
20090172887 |
Kind Code |
A1 |
Landvik; Dag ; et
al. |
July 9, 2009 |
LAMINATED VISCO-ELASTIC SUPPORT
Abstract
A laminated support for pressure-relief comprising multiple foam
layers. The combinations of layers can comprise one or more layers
of visco-elastic foam, highly resilient polyurethane foam,
reticulated filter polyurethane foam, and the like.
Inventors: |
Landvik; Dag;
(Saltsjo-Duvnas, SE) ; Allaway; Michael B.;
(Paris, FR) |
Correspondence
Address: |
MICHAEL BEST & FRIEDRICH LLP
100 E WISCONSIN AVENUE, Suite 3300
MILWAUKEE
WI
53202
US
|
Family ID: |
46303461 |
Appl. No.: |
12/407605 |
Filed: |
March 19, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11005803 |
Dec 7, 2004 |
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12407605 |
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|
10403255 |
Mar 31, 2003 |
7507468 |
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11005803 |
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|
09703893 |
Nov 1, 2000 |
6541094 |
|
|
10403255 |
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08458968 |
Jun 2, 1995 |
6159574 |
|
|
09703893 |
|
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|
10403255 |
Mar 31, 2003 |
7507468 |
|
|
08458968 |
|
|
|
|
09703893 |
Nov 1, 2000 |
6541094 |
|
|
10403255 |
|
|
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|
08458968 |
Jun 2, 1995 |
6159574 |
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09703893 |
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Current U.S.
Class: |
5/740 ;
5/690 |
Current CPC
Class: |
Y10T 428/249981
20150401; Y10T 428/24992 20150115; B32B 2479/00 20130101; Y10T
428/233 20150115; Y10T 428/249991 20150401; A47C 27/15 20130101;
Y10T 428/24983 20150115; B32B 2266/0278 20130101; B32B 5/18
20130101; Y10T 428/249992 20150401; B32B 7/02 20130101; Y10T
428/2495 20150115; Y10T 428/249953 20150401 |
Class at
Publication: |
5/740 ;
5/690 |
International
Class: |
A47C 27/15 20060101
A47C027/15; A47C 27/00 20060101 A47C027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 3, 1994 |
GB |
9411120.0 |
Jun 9, 1994 |
GB |
9411504.5 |
Claims
1. A layered bed mattress for pressure-relief of a user, the bed
mattress comprising: a first foam layer having a generally planar
first support surface adapted to substantially face the user
resting upon the bed mattress and having length and width
dimensions sufficient to support a reclining body of a person, and
a generally planar second surface opposite the first support
surface, the first and second surfaces defining therebetween a
substantially uniform undeflected thickness, the first foam layer
comprising visco-elastic foam; and a second foam layer having a
generally planar third surface adjacent and substantially facing
the second surface of the first foam layer, the second foam layer
having a substantially uniform undeflected thickness greater than
that of the first foam layer.
2. The layered bed mattress as claimed in claim 1, wherein the
visco-elastic foam of the first foam layer is responsive to body
heat from the user.
3. The layered bed mattress as claimed in claim 1, wherein the
first foam layer is adhered to the second foam layer.
4. The layered bed mattress as claimed in claim 2, wherein the
first foam layer is adhered to the second foam layer.
5. The layered bed mattress as claimed in claim 1, wherein the
second foam layer has a hardness greater than that of the first
foam layer.
6. The layered bed mattress as claimed in claim 2, wherein the
second foam layer has a hardness greater than that of the first
foam layer.
7. The layered bed mattress as claimed in claim 3, wherein the
second foam layer has a hardness greater than that of the first
foam layer.
8. The layered bed mattress as claimed in claim 4, wherein the
second foam layer has a hardness greater than that of the first
foam layer.
9. The layered bed mattress as claimed in claim 1, wherein the
second foam layer comprises visco-elastic foam.
10. The layered bed mattress as claimed in claim 2, wherein the
second foam layer comprises visco-elastic foam.
11. The layered bed mattress as claimed in claim 3, wherein the
second foam layer comprises visco-elastic foam.
12. A layered bed mattress for pressure-relief of a user, the bed
mattress comprising: a first foam layer having a generally planar
first support surface adapted to substantially face the user
resting upon the bed mattress and having length and width
dimensions sufficient to support a reclining body of a person, and
a generally planar second surface opposite the first support
surface, the first and second surfaces defining therebetween a
substantially uniform undeflected thickness, the first foam layer
comprising visco-elastic foam; and a second foam layer having a
generally planar third surface adjacent and substantially facing
the second surface of the first foam layer, the second foam layer
comprising visco-elastic foam.
13. The layered bed mattress as claimed in claim 12, wherein the
visco-elastic foam of the first foam layer is responsive to body
heat from the user.
14. The layered bed mattress as claimed in claim 12, wherein the
first foam layer is adhered to the second foam layer.
15. The layered bed mattress as claimed in claim 13, wherein the
first foam layer is adhered to the second foam layer.
16. The layered bed mattress as claimed in claim 12, wherein the
second foam layer has a hardness greater than that of the first
foam layer.
17. The layered bed mattress as claimed in claim 13, wherein the
second foam layer has a hardness greater than that of the first
foam layer.
18. The layered bed mattress as claimed in claim 14, wherein the
second foam layer has a hardness greater than that of the first
foam layer.
19. The layered bed mattress as claimed in claim 15, wherein the
second foam layer has a hardness greater than that of the first
foam layer.
20. A layered bed mattress for pressure-relief of a user, the bed
mattress comprising: a first foam layer having a generally planar
first support surface adapted to substantially face the user
resting upon the bed mattress and having length and width
dimensions sufficient to support a reclining body of a person, and
a generally planar second surface opposite the first support
surface, the first and second surfaces defining therebetween a
substantially uniform undeflected thickness, the first foam layer
comprising visco-elastic foam; and a second foam layer having a
generally planar third surface adjacent and substantially facing
the second surface of the first foam layer, the second foam layer
having a density less than that of the first foam layer and a
hardness greater than that of the first foam layer.
21. The layered bed mattress as claimed in claim 20, wherein the
second foam layer is thicker than the first foam layer.
22. The layered bed mattress as claimed in claim 20, wherein the
visco-elastic foam of the first foam layer is responsive to body
heat from the user.
23. The layered bed mattress as claimed in claim 21, wherein the
visco-elastic foam of the first foam layer is responsive to body
heat from the user.
24. The layered bed mattress as claimed in claim 20, wherein the
first foam layer is adhered to the second foam layer.
25. The layered bed mattress as claimed in claim 21, wherein the
first foam layer is adhered to the second foam layer.
26. The layered bed mattress as claimed in claim 20, wherein the
second foam layer comprises visco-elastic foam.
27. The layered bed mattress as claimed in claim 21, wherein the
second foam layer comprises visco-elastic foam.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 11/005,803 filed Dec. 7, 2004, which is a
continuation of U.S. patent application Ser. No. 10/403,255, filed
on Mar. 31, 2003, now issued as U.S. Pat. No. 7,507,468, which is a
continuation of U.S. patent application Ser. No. 09/703,893, filed
on Nov. 1, 2000, now issued as U.S. Pat. No. 6,541,094, which is a
continuation of U.S. patent application Ser. No. 08/458,968, filed
on Jun. 2, 1995, now issued as U.S. Pat. No. 6,159,574, which
claims priority to United Kingdom Patent Application Number
9411120.0 filed on Jun. 3, 1994, and to United Kingdom Patent
Application Number 9411504.5 filed on Jun. 9, 1994, the entire
contents of all of which are incorporated herein by reference. This
application is also a continuation of co-pending U.S. patent
application Ser. No. 10/403,255, filed on Mar. 31, 2003, now issued
as U.S. Pat. No. 7,507,468, which is a continuation of U.S. patent
application Ser. No. 09/703,893, filed on Nov. 1, 2000, now issued
as U.S. Pat. No. 6,541,094, which is a continuation of U.S. patent
application Ser. No. 08/458,968, filed on Jun. 2, 1995, now issued
as U.S. Pat. No. 6,159,574, which claims priority to United Kingdom
Patent Application Number 9411120.0 filed on Jun. 3, 1994, and to
United Kingdom Patent Application Number 9411504.5 filed on Jun. 9,
1994, the entire contents of all of which are incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The invention relates to mattresses and cushions, and more
particularly to supports made of visco-elastic material.
[0004] 2. Related Prior Art
[0005] Mattresses and cushions used every day in homes and
hospitals are not well-suited for people requiring pressure-relief.
In hospitals, for example, long-term patients often suffer from
pressure sores.
SUMMARY OF THE INVENTION
[0006] Known supports made of standard polyurethane foam do not
provide even or well-distributed support of a body reclining
thereon because of the polyurethane material. Such known standard
supports have a spring-like characteristic that tends to return an
increased reactive force in response to increasingly large forces
on the support. Moreover, the greater the deflection of the
polyurethane support, the greater the reactive force provided by
the standard support. This spring-like characteristic is
undesirable in the case of long-term patient care because the
points at which the greatest pressure occurs are the points at
which pressure sores can be formed.
[0007] Changing the density of the standard polyurethane foam used
in such known supports does not improve the performance of such
known supports. For example, use of a lower density foam requires a
thicker, bulkier cushion or mattress, which can easily become
unwieldy or unstable, and can still result in pressure points
because of the inherent spring-like nature of the polyurethane
foams. Also, if a sufficiently large force is applied to a support
made of low density polyurethane foam, it is possible that the
force will "bottom out" or act through the support and onto
whatever structure lies below or behind the support.
[0008] The present invention therefore seeks to provide improved
supports, such as mattresses and cushions, for pressure-relief.
[0009] According to the present invention there is provided a
laminated support for pressure-relief comprising at least two
layers of foam adhered together, wherein at least one layer is a
visco-elastic foam.
[0010] In one embodiment, the laminated support comprises two
layers of visco-elastic foam adhered together, wherein one layer of
visco-elastic foam has a greater hardness than the other layer. The
laminated support may further comprise a layer of polyurethane foam
adhered to the layers of visco-elastic foam.
[0011] In another embodiment, the laminated support comprises a
single layer of visco-elastic foam and a single layer of
polyurethane foam adhered together.
[0012] The visco-elastic properties of the laminated support
respond to a combination of body weight and body temperature. In
particular, visco-elastic foam supports tend to soften when heated,
and therefore tend to soften in response to body heat. As a result,
relatively hard visco-elastic material will initially firmly
support a body lying thereon and will soften at the pressure
points. Thus, the support subsequently gently molds to the form of
the body, allowing pressure to be absorbed uniformly and
distributed evenly across the support. This property is of
particular benefit in the prevention and healing of pressure
sores.
[0013] Other features and advantages of the invention will become
apparent to those skilled in the art upon review of the following
detailed description, claims and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows a side view of a support embodying the present
invention.
[0015] FIG. 2 shows a side view of a support that is an alternative
embodiment of the present invention.
[0016] FIG. 3 shows a side view of a support that is a second
alternative embodiment of the present invention.
[0017] FIG. 4 shows a side view of a support that is a third
alternative embodiment of the invention.
[0018] FIG. 5 is a perspective view in partial cross section of the
support shown in FIG. 1.
[0019] FIG. 6 is a perspective view in partial cross section of the
support shown in FIG. 2.
[0020] FIG. 7 is a perspective view in partial cross section of the
support shown in FIG. 3.
[0021] Before one embodiment of the invention is explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangements
of the components set forth in the following description or
illustrated in the drawings. The invention is capable of other
embodiments and of being practiced or being carried out in various
ways. Also, it is understood that the phraseology and terminology
used herein are for the purpose of description and should not be
regarded as limiting.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The support or cushion A shown in FIGS. 1 and 5 includes a
bottom layer 1 of 40 mm thick visco-elastic foam having a density
of 110 kg/m.sup.3 and a hardness of 30N, and a top layer 2 of 10 mm
thick visco-elastic foam having a density of 85 kg/m3 and a
hardness of 10N.
[0023] The support B shown in FIGS. 2 and 6 is well-suited for use
as an overlay which can be placed on top of an existing mattress to
provide extra comfort and pressure-relief. The overlay B includes a
bottom layer 3 of 60 mm thick visco-elastic foam having a density
of 83 kg/m.sup.3 and a hardness of 13N, and a top layer 4 of 10 mm
thick visco-elastic foam having a density of 83 kg/m.sup.3 and a
hardness of 10N. A support similar to the construction of support B
could also be manufactured to include a bottom layer of 80 mm thick
highly resilient polyurethane foam having a density of 35
kg/m.sup.3 and a hardness of 12N, and a top layer of 70 mm thick
visco-elastic foam having a density of 82 kg/m.sup.3 and a hardness
of 13N.
[0024] The support C shown in FIGS. 3 and 7 is well-suited for use
as a mattress and includes a bottom layer 5 of 75 mm thick
polyurethane foam having a density of 35 kg/m.sup.3, a middle layer
6 of 60 mm thick visco-elastic foam having a density of 83
kg/m.sup.3 and a hardness of 13N, and a top layer 7 of 10 mm deep
visco-elastic foam having a density of 83 kg/m.sup.3 and a hardness
of 10N.
[0025] Suitable polyurethane foams are manufactured by A/S
Dan-Foam, 5560 Arup, Denmark. One example of a polyurethane foam
has the manufacturer's code HE35S.
[0026] Similarly, suitable visco-elastic foams are made by A/S
Dan-Foam, 5560 Arup, Denmark and sold under the trade mark TEMPUR.
One such visco-elastic foam has the manufacturer's code T-85. A
preferred range of density of the visco-elastic foam is 50 to 120
kg/m.sup.3.
[0027] For each of the above embodiments A, B, and C, the layers
comprising the cushion, overlay or mattress, are adhered together
using an enviromentally-friendly water-based adhesive such as SABA
AQUABOND RSD.TM., a two-component water-based adhesive produced by
SABA DINXPERLO BV, B-7090 AA DINXPERLO, Belgium. Hardness is to be
measured 65% compression at 20.degree. C.
[0028] For each of the above embodiments A, B, and C, the layers
comprising the cushion, overlay or mattress, once the appropriate
layers of foam have been adhered together, a 2 mm thick sheet 8 of
a reticulated filter polyurethane foam is adhered to each outer
face of the laminated support. This layer 8 is air permeable.
[0029] The support D illustrated by FIG. 4 includes a single layer
of visco-elastic foam sandwiched between two layers of reticulated
filter polyurethane foam. In particular, the support D includes a
sheet of visco-elastic foam 9, which is sandwiched between two
sheets of reticulated polyurethane foam 8. The sheet of
visco-elastic foam 9 preferably has a thickness ranging from 50 mm
to 150 mm, a density ranging from 50 kg/m.sup.3 to 120 kg/m.sup.3,
and a hardness ranging from 10N to 30N measured at 65% compression
at 20.degree. C.
[0030] Any of the supports A, B, C, and D may be provided with an
outer covering (not shown). Two examples of outer coverings are
described below.
[0031] One example is a textile net cover followed by a removable
outer fabric cover. The textile net cover eases the taking on and
off of the fabric cover and is made from a specially treated
textile which allows the foam layers to `breathe` whilst preventing
contamination of the foam layers by fluids. An example of such
netting is the 100% cotton netting manufactured by BIDET &
HORST GmbH & Co KG, D-4460Horstel, Germany.
[0032] A second example of an outer covering is a waterproof,
vapor-permeable cover made of base nylon fabric coated with
polyurethane film. Preferably, this cover material is 0.25 mm
thick, weighs 245 g/m.sup.2, and is constructed having a single
sheet top surface, no joins, welded seams and a sealed zip flap. In
addition, this cover may be pretreated with an anti-bacterial
agent.
[0033] The laminated support of the present invention, when covered
with the polyurethane coat nylon material ensures good hygiene for
patients with incontinence. The elasticity of the cover allows the
pressure-relieving properties of the visco-elastic foam to be
unimpaired.
[0034] Laminated supports manufactured in accordance with the
present invention allow air to circulate around a patient's skin
and thus avoid the discomfort of perspiration and skin
irritation.
[0035] The visco-elastic foam layers provide the laminated support
with its special pressure-relieving properties. The support is thus
able to mould according to the weight and temperature of a body in
contact therewith. When the body is moved from a particular point
of contact, the support quickly regains its initial shape, ready to
be re-molded.
[0036] This property of the support is different from normally
polyurethane foams which bulk up when compressed, thereby exerting
pressure rather than relieving it. As a result, the quality of
sleep of a person reclining on a support constructed of layers of
foam having visco-elastic properties is different from normal
polyurethane foams which bulk up when compressed, thereby exerting
pressure rather than relieving it.
[0037] In use, it is the side of the support which has the
visco-elastic foam layer, or the softest visco-elastic foam layer,
foremost which is arranged for contact with a person's body. As a
result, the support does not need to be turned, as is customary
with hospital mattresses, for example.
[0038] Various features of the invention are set forth in the
following claims.
* * * * *