Note: Descriptions are shown in the official language in which they were submitted.
CA 02783753 2012-07-24
FOAM MATTRESS ASSEMBLY WITH INCREASED AIRFLOW AND
INDEPENDENT SUSPENSION
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U. S. Provisional Application No.
61/513,091, filed on July 29, 2011, incorporated herein by reference in its
entirety.
BACKGROUND
[0001] The present disclosure generally relates to foam mattress assemblies
exhibiting increased airflow and independent suspension.
[0002] Foam mattresses such as those formed of polyurethane foam, latex
foam, and the like, are generally known in the art. One of the ongoing
problems
associated with foam mattress assemblies is user comfort. To address user
comfort,
these mattresses are often fabricated with multiple foam layers having varying
properties such as density and hardness, among others, to suit the needs of
the
intended user. More recently, manufacturers have employed so called memory
foam,
also commonly referred to as viscoelastic foams, which are generally a
combination of
polyurethane and one or more additives that increase foam density and
viscosity,
thereby increasing its viscoelasticity. These foams are often open cell foam
structures
having both closed and open cells but in some instances may be reticulated
foam
structures. The term "reticulated" generally refers to a cellular foam
structure in
which the substantially all of the membrane windows are removed leaving a
skeletal
structure. In contrast, open cell structures typically include both open cell
(interconnected cells) and closed cells.
[0003] When used in a mattress, the memory foam conforms to the shape of a
user when the user exerts pressure onto the foam, thereby minimizing pressure
points
from the user's body. The memory foam then returns to its original shape when
the
user and associated pressure are removed. However, the return to the original
shape is
a relatively slow process because of the viscoelastic cellular structure of
these types of
foams.
1
CA 02783753 2012-07-24
[0004] Unfortunately, the high density of the various types of foams used in
current mattress assemblies, particularly those employing memory foam layers,
generally prevents proper ventilation. As a result, the foam material can
exhibit an
uncomfortable level of heat to the user after an extended period of time.
Additionally,
these foams can retain a high level of moisture, further causing discomfort to
the user
and potentially leading to foul odors.
[0005] Reticulated memory foams, i.e., foams in which the cellular walls are
substantially removed, are known to provide greater airflow. However, because
substantially all of the cellular walls have been removed leaving behind a
skeletal
structure, these foams are inherently weak, provide less load-bearing
capabilities
relative to other non-reticulated viscoelastic foams, and are subject to
fatigue at a rate
faster than partially or completely closed cell foam structures. Moreover,
reticulated
viscoelastic foams require special processing to remove the cellular walls to
form the
skeletal structure making these foams relatively expensive.
[0006] Still further, as noted above, prior mattress assemblies generally
include multiple stacked layers. The layers typically have planar top and
bottom
surfaces. In some instances, these mattresses may have convoluted surfaces.
These
surfaces are generally static in terms of motion response to a user.
[0007] Accordingly, it would be desirable to provide a mattress assembly, with
an improved airflow to effectively dissipate user heat. Still further, it
would be
desirable to provide foam mattress assemblies with motion separation so as to
independently respond to each specific body part for increased user comfort.
BRIEF SUMMARY
[0008] Disclosed herein are mattress assemblies exhibiting increased airflow
and independent suspension. In one embodiment, a mattress assembly comprises a
first foam layer; a second foam layer configured with an independent response
system
overlaying the first foam layer, wherein the second foam layer comprises a
floor and a
plurality of spaced apart support structures extending at about similar
lengths from the
floor; and a third foam layer overlaying the second foam layer having a planar
top
2
CA 02783753 2012-07-24
surface facing a user resting on the mattress assembly.
[0009] In another embodiment, a mattress assembly comprises a first foam
layer comprising top and bottom planar surfaces, the first foam layer further
comprising a plurality of channels extending from the top to the bottom planar
surfaces; a second foam layer configured with an independent response system
overlaying the first foam layer, wherein the second foam layer comprises a
floor and a
plurality of spaced apart support structures extending at about equal lengths
from the
floor; and a third foam layer overlaying the second foam layer having a planar
top
surface facing a user resting on the mattress assembly.
[0010] In another embodiment, a mattress assembly comprises a first foam
layer comprising top and bottom planar surfaces, the first foam layer further
comprising a plurality of channels extending from the top to the bottom planar
surfaces; a second foam layer configured with an independent response system
overlaying the first foam layer, wherein the second foam layer comprises a
floor and a
plurality of spaced apart support structures extending at about equal lengths
from the
floor; and a third foam layer overlaying the second foam layer having a planar
top
surface facing a user resting on the mattress assembly.
[0011 ] The disclosure may be understood more readily by reference to the
following detailed description of the various features of the disclosure and
the
examples included therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Referring now to the figures wherein the like elements are numbered
alike:
[0013] Figure 1 illustrates a top down view of a mattress assembly;
[0014] Figure 2 illustrates an exploded perspective view of a mattress
assembly
in accordance with an embodiment of the present disclosure;
3
CA 02783753 2012-07-24
[0015] FIG. 3 illustrates a perspective view of a foam layer configured to
provide a mattress assembly with motion separation; and
[0016] Figure 4 illustrates an exploded perspective view of a mattress
assembly
in accordance with an embodiment of the present disclosure;
DETAILED DESCRIPTION
[0017] Disclosed herein are mattress assemblies that provide user comfort
with improved airflow to effectively dissipate user heat during use and motion
separation to independently respond to each specific body part for increased
user
comfort. FIG. I illustrates a top down view representative of the mattress
assemblies,
which are generally designated by reference numeral 10. As will be discussed
herein,
the various embodiments of the mattress assemblies disclosed herein have in
common
the following components: multiple stacked foam layers, wherein the uppermost
foam layer 12 is shown, a side rail assembly 14 about at least a portion of
the
perimeter of the stacked mattress layers, and an optional fabric covering 16
about the
side rail assembly as shown, i.e., mattress border. The uppermost foam layer
12 is
generally referred to herein as the cover layer and has a planar top surface
adapted to
substantially face the user resting on the mattress assembly having a length
and width
dimensions sufficient to support a reclining body of the user. In some
embodiments,
the uppermost foam layer 12 may be dimensioned to overlay the side rails.
Likewise,
the optional foam layer may be configured to cover the side and top surfaces
of he
mattress assembly.
[0018] FIG. 2 shows an exploded perspective view of an exemplary foam
mattress assembly in accordance with one embodiment. The mattress assembly 100
includes a base foam core layer 102 configured with generally planar top and
bottom
surfaces. For this as well as the other embodiments disclosed herein, the foam
core
layer 102 is chosen to have a thickness less than or equal to the overall
thickness of
the mattress assembly. Generally, the thickness of the foam core layer 102 is
within a
range of 4 inches to 10 inches, with a range of about 6 inches to 8 inches
thickness in
other embodiments, and a range of about 6 to 6.5 inches in still other
embodiments.
4
CA 02783753 2012-07-24
The core foam layer can be formed of open or closed cell natural latex foam
although
other foams can be used, including without limitation, viscoelastic foams, non-
viscoelastic foams, polyurethane foams, and the like. In one embodiment, the
foam
core layer 102 is pre-stressed. That is, the foam core layer is subjected to a
pre-
stressing process such as disclosed in US Pat. No. 7,690,096 to Gladney et
al.,
incorporated herein by reference in its entirety. By way of example, a force
can
applied to at least a section of the foam core layer in an amount sufficient
to
temporarily compress its height so as to permanently alter a mechanical
property of
the foam layer to provide a pre-stressed foam layer having a firmness that is
different
from the firmness of a similar foam that was not pre-stressed.
[0019] The foam core layer 102 has a density of 1 pound per cubic foot
(lb/ft3)
to 6 lb/ft3. In other embodiments, the density is 1 lb/ft3 to 5 lb/ft3 and in
still other
embodiments, from 1.5 lb/ft3 to 4 lb/ft3. By way of example, the density can
be
about 1.5 lb/ft3.
[0020] The hardness of the foam core layer, also referred to as the indention
load deflection (ILD) or indention force deflection (IFD), is within a range
of 20 to 40
pounds-force, wherein the hardness is measured in accordance with ASTM D-3574
and is generally defined as the amount of force in pounds required to indent a
50" disc
into a 15" x 15" x 4" foam sample and make a 1" indentation. In other
embodiments,
the hardness is about 20 to 30 pounds-force.
[0021] Foam layer 104 configured with an independent response system
overlays the base foam core layer 102. Advantageously, the independent
response
system as will be described in greater detail below provides motion separation
to an
end user of the mattress assembly as well as improved airflow. The foam layer
104
may be fabricated from a viscoelastic foam or non-viscoelastic foam depending
on the
intended application. The foam itself can be of any material including without
limitation, latex foams, natural latex foams, polyurethane foams, combinations
thereof, and the like. Foam layer 104 generally has a thickness equal to or
less than 6
inches in some embodiments, equal to or less than 4 inches in other
embodiments, and
equal to or less than 3 inches in still other embodiments. In other
embodiments, the
CA 02783753 2012-07-24
thickness is greater than or equal to 1 inch. The density is generally within
a range of
2 to 6 lb/ft3 in some embodiments, and 3 to 5 lb/ft3 in other embodiments.
Hardness is
generally within a range of 10 to 20 pounds-force.
[0022] As shown more clearly in FIG. 3, foam layer 104 includes a planar
bottom surface 106 and a generally planar top surface 108 configured with a
recessed
portion 110 defining a perimeter wall 112, and a plurality of upright spaced
apart
foam support structures 114 extending from a floor 116 of the recessed portion
110 to
a height substantially equal to that of the perimeter wall 112. The upright
foam
support structures 114 can be of any shape and dimension including, without
limitation, cylindrical shapes, truncated cones, cubic shapes, polygonal prism
shaped,
e.g., triangular prism, hexagonal prism, combinations thereof, and the like.
The
various shapes can be formed using known techniques by which a plane splitting
of a
foam block is carried out with opposing outer sides compressed in a
corresponding
pattern. Alternatively, the upright foam support structures may be
individually formed
and adhered to the floor, or the like. In these embodiments, it is generally
important
that the top surface of each upright foam support structure have a planar
surface. In
some embodiments, the pitch between adjacent upright support structures is
generally
equal to or less than a diameter of an individual support structure. The
individual
upright support structures 114 may be randomly disposed within the recess or
may be
configured as a linear arrangement of rows and columns, or may be configured
as
offset rows and/columns. Still further, the foam layer 104 may be configured
to
include segments of the upright support structures within the recessed portion
that are
of a greater density than in other segments of the recessed portions. In still
other
embodiments, the foam layer 104 may include more than one recessed portion 110
such that recessed portion is divided into multiple portions defined by a wall
(not
shown) similar to that of the perimeter wall except providing
compartmentalization of
the upright structures within the interior region defined by the perimeter
wall. For
example, in some embodiments, two or more sections may be defined by an
interior
foam wall extending from a selected perimeter wall to an opposing perimeter
wall. In
still other embodiments, the two or more sections may be defined by an
interior wall
within the confines of the perimeter wall 112. In these embodiments, the
support
6
CA 02783753 2012-07-24
structures as well as the interior foam walls have a height about equal to the
height of
the perimeter wall 122.
[0023] By way of example, which is not intended to be limiting, a foam layer
104 configured for use in queen sized mattress can have a thickness of 3
inches, a
width of 59.5 inches and a length of 79.5. The perimeter wall has a width of 3
inches
and the upright support structure has a truncated cone shape having a height
of 1.5
inches (i.e., the recess floor has a thickness of 1.5 inches) and a diameter
of 2 inches.
The upright support structures are equally spaced apart at a distance of about
1 inch as
measured from the base and linearly arranged by columns and rows.
[0024] Referring back to FIG. 2, a cover panel 106 is shown disposed on the
foam layer 104. The cover panel layer can be formed from viscoelastic foam or
non-
viscoelastic foam depending on the intended application. The foam itself can
be of
any open or closed cell foam material including without limitation, latex
foams,
natural latex foams, polyurethane foams, combinations thereof, and the like.
The
cover panel 106 has planar top and bottom surfaces. The thickness of the cover
panel
is generally within a range of about 0.5 to 2 inches in some embodiments, and
less
than 1" in other embodiments so as to provide the benefits of motion
separation and
increased airflow from the underlying foam layer 104. The density of the cover
panel
layer 106 is within a range of I to 5 lb/ft3 in some embodiments, and 2 to 4
lb/ft3 in
other embodiments. The hardness is within a range of about 10 to 20 pounds-
force in
some embodiments, and less than 15 pounds-force in other embodiments. In one
embodiment, the cover panel is at a thickness of 0.5", a density of 3.4
lb/ft3, and a
hardness of 14 pounds-force. In some embodiments, multiple foam layers (not
shown)
can overlay foam layer 104.
[0025] The various multiple stacked mattress layers 102, 104, and 106 may be
adjoined to one another using an adhesive or may be thermally bonded to one
another
or may be mechanically fastened to one another as may be desired for different
applications.
7
CA 02783753 2012-07-24
[0026] The mattress assembly 100 further includes a side rail assembly 120
about all or a portion of the perimeter of the mattress assembly defined by
foam
layers 102, 104, 106. The side rails that define the assembly may be attached
to or
placed adjacent to at least a portion of the perimeter of the stacked mattress
layers 102, 104, 106, and may include metal springs, spring coils, encased
spring
coils, foam, latex, natural latex, latex w/ gel, gel, viscoelastic gel, or a
combination, in
one or more layers. The side rails may be placed on one or more of the sides
of the
stacked mattress layers, e.g., on all four sides of the stacked mattress
layers, on
opposing sides, on three adjacent sides, or only on one side of the stacked
mattress
layers. In certain embodiments, the side rails may comprise edge supports with
a
firmness greater than that provided by the stacked mattress layers. The side
rails may
be fastened to the stacked mattress layers via adhesives, thermal bonding, or
mechanical fasteners.
[0027] In one embodiment, the side rail assembly is formed of a natural latex
foam having a density generally less than 3 lb/ft3 to 0.5 lb/ft3 and a
hardness greater
than 30 pounds-force to 80 pounds-force. In one embodiment, the side rails are
formed of natural latex foam having a density of 1.65 lb/ft3 and a hardness of
45
pounds-force.
[0028] In some embodiments, the side rail assembly 120 may be formed of
multiple layers as is generally shown in FIG. 2. For example, the side rail
assembly
may include a core layer 122 having a higher hardness than an overlaying
relatively
thinner edge layer 124 having a lower hardness for improved user comfort. By
way of
example, the core side rail can have a thickness of 5.5 inches, a hardness of
45
pounds-force, and a density of 1.65 lb/ft3. The edge side rail layer 124,
disposed on
core side rail layer 122, can have a thickness of 1 inch, a hardness of 24
pounds-force,
and a density of 1.65 lb/ft3. Optionally, one or more of the side rail
assembly layers
may be pre-stressed in the manner described above.
[0029] In another embodiment, the side rail assembly 120 is formed of open
cell polyurethane foam having a non-random large cell structure or a random
cellular
structure with many large cells. The large cell structure can be defined by
the number
8
CA 02783753 2012-07-24
of cells per linear inch. In one embodiment, the large cell structure is about
10 to 40
cells per inch, with about 15 to 30 cells per inch in other embodiments, and
with
about 20 cells per inch in still other embodiments. The open cell foam
structure
includes a plurality of interconnected cells, wherein the windows between the
adjacent
cells are broken and/or removed. In contrast, in closed cell foam there are
substantially no interconnected cells and the windows between the adjacent
cells are
substantially intact. In reticulated foams, substantially all of the windows
are
removed. By using an open cell structure with a large open cellular structure,
movement of moisture and air through a side rail can occur. Also, if the side
rail is
adhesively or thermally attached to the mattress layers, e.g., 102, 104, and
106, the
skeletal struts of the open cell foam will bond to the mattress layers,
thereby
facilitating air and moisture transfer from the mattress layers through the
side layers to
the environment. In one embodiment, the side rail assembly includes a natural
latex
foam, which may be viscoelastic or non-viscoelastic depending on the intended
application.
[0030] For ease in manufacturing the mattress assembly, the side rail assembly
may be assembled in linear sections that are joined to one another to form the
perimeter about the mattress layers. Alternatively, the ends may be mitered or
have
some other shape, e.g., lock and key type shape.
[0031 ] An optional fabric layer (e.g., 16 in FIG. 1) can be disposed about
the
perimeter of the side rail, i.e., serves as a mattress border. In one
embodiment, the
fabric border layer is attached at one end to the top planar surface of the
uppermost
mattress layer 106 and at the other end to the bottom planar surface of the
bottom
most layer 102. In one embodiment, at least a portion of the fabric layer can
formed
of a spacer fabric to provide a further increase in airflow. As used herein,
spacer
fabrics are generally defined as pile fabrics that have not been cut including
at least
two layers of fabric knitted independently that are interconnected by a
separate spacer
yarn. The spacer fabrics generally provide increased breathability, crush
resistance,
and a three dimensional appearance relative to other fabrics. The at least two
fabric
layers may be the same or different, i.e., the same or different density,
mesh,
9
CA 02783753 2012-07-24
materials, and like depending on the intended application. When employing the
spacer
fabric, a lightweight flame retardant barrier layer may be disposed
intermediate to the
mattress foam layers and the spacer fabric about the perimeter of the side
rail
assembly.
[0032] By way of example, an exemplary mattress assembly illustrative of the
embodiment shown in FIG. 2 has a 6.5" pre-stressed foam core layer of natural
latex
foam having a density of 1.65 lb/ft3 and a hardness of 24 pounds-force; a
natural latex
foam layer having a density of 3.9 lb/ft3 and configured with the independent
response
system as described above is disposed on the foam core layer. The independent
response system layer includes a perimeter wall having a width of 3 inches and
a
truncated cone shaped upright support structure having a height of 1.5 inches
(i.e., the
recess floor has a thickness of 1.5 inches) and a diameter of 2 inches. The
upright
support structures are equally spaced apart at a distance of about 1 inch as
measured
from the base and linearly arranged by columns and rows. A natural latex foam
cover
layer having top and bottom planar surfaces is disposed onto the foam layer
configured with the independent response system and is at a thickness of 0.5",
a
density of 3.4 lb/ft3, and a hardness of 14 pounds-force. The side rail
assembly is of a
two layer construction of natural latex foam and circumscribes a perimeter of
the
mattress layers 102, 104, and 106. The side rail assembly has a width of 3", a
height
of 6.5 inches and is formed of a core layer having a height of 5.5 inches, a
density
of 1.65 lb/ft3 and a hardness of 45 pounds-force. An edge layer having a
height of I
inch is disposed onto the core layer and has a density of 1.65 lb/ft3 and a
density of 24
pounds-force. A mattress border and panel of a spacer fabric is utilized as a
mattress
border.
[0033] FIG. 4 shows a cross sectional view of a mattress assembly in
accordance with one embodiment. The mattress assembly 200 includes a base core
foam layer 202 configured with planar top and bottom surfaces. Generally, the
thickness of the foam core layer 202 is within a range of 4 inches to 10
inches, with a
range of about 6 inches to 8 inches thickness in other embodiments, and a
range of
about 6 inches in still other embodiments. The core foam layer can be formed
of
CA 02783753 2012-07-24
standard polyurethane foam although other foams can be used, including without
limitation, viscoelastic foams. In one embodiment, the core foam layer is
ventilated.
Ventilation can be provided by providing open channels 203 extending from the
top
planar surface to the bottom planar surface. The channels are generally
circularly
shaped although other shapes can be utilized and have a diameter of less than
2 inches
in some embodiments, less than 1 inch in other embodiments, and less than 0.5
inches
in still other embodiments. The density of the open channels is generally
about 100 to
about 800 open channels per square foot in some embodiments, about 300 to
about
600 open channels per square foot in other embodiments, and about 400 to about
500
in still other embodiments. The core foam layer 202 has a density of 1 lb/ft3
to 5 lb/ft3.
In other embodiments, the density is 1 lb/ft3 to 3 lb/ft3 and in still other
embodiments,
from 1 lb/ft3 to 2 lb/ft3. By way of example, the density can be 4 lb/ft3. The
hardness
of the core foam layer is within a range of 20 to 40 pounds-force. In one
embodiment,
the hardness is about 29 pounds-force.
[0034] Foam layer 204 configured with the independent response system as
described above is disposed on the base core foam layer 202.
[0035] A cover foam layer 206 as described above is disposed on foam
layer 204.
[0036] The mattress assembly may further include the side rail assembly and
the optional fabric border as described above.
[0037] By way of example, an exemplary mattress assembly illustrative of the
embodiment shown in FIG. 4 has a 6" ventilated foam core layer of natural
latex foam
having top and bottom planar surfaces, a density of 4 lb/ft3 and a hardness of
29
pounds-force; a natural latex foam layer having a density of 3.9 lb/ft3 and
configured
with the independent response system as described above is disposed on the
foam core
layer; and a 1" foam cover layer of natural latex foam having top and bottom
planar
surfaces, a density of 3.4 lb/ft3 and a hardness of 14 pounds-force. The
ventilated
foam core has a plurality of equally spaced open channels extending from the
top
planar surface to the bottom planar surface of the core foam layer at a
diameter less
11
CA 02783753 2012-07-24
than 1 inch and a density of about 400 to 500 channels per square foot. The
independent response system foam layer includes a perimeter wall having a
width of 3
inches and a truncated cone shaped upright support structure having a height
of 1.5
inches (i.e., the recess floor has a thickness of 1.5 inches) and a diameter
of 2 inches.
The upright support structures are equally spaced apart at a distance of about
1 inch as
measured from the base and linearly arranged by columns and rows. The side
rail
assembly is of a two layer construction of natural latex foam and
circumscribes a
perimeter of the mattress layers 102, 104, and 106. The side rail assembly has
a width
of 3", a height of 6.5 inches and is formed of a core layer having a height of
5.5
inches, a density of 1.65 lb/ft3 and a hardness of 45 pounds-force. An edge
layer
having a height of 1 inch is disposed onto the core layer and has a density of
1.65
lb/ft3 and a density of 24 pounds-force. A mattress border and panel of a
spacer fabric
is utilized as a mattress border.
[0038] The various mattress layers in the mattress assemblies described above
may be adjoined to one another using an adhesive or may be thermally bonded to
one
another or may be mechanically fastened to one another. The mattress
assemblies may
further include one or more upholstery layers to cover mattress assemblies,
which may
include an outermost ticking layer.
[0039] This written description uses examples to disclose the invention,
including the best mode, and also to enable any person skilled in the art to
make and
use the invention. The patentable scope of the invention is defined by the
claims, and
may include other examples that occur to those skilled in the art. Such other
examples
are intended to be within the scope of the claims if they have structural
elements that
do not differ from the literal language of the claims, or if they include
equivalent
structural elements with insubstantial differences from the literal languages
of the
claims.
12
