MULTI-LAYER MULTI-MATERIAL FOAM MATTRESSES

Abstract

The multi-layer multi-material foam mattresses of the present disclosure and related inventions provide novel combinations of multiple layer, multiple material foam layers or stacks which provide unexpected and improved support characteristics and pressure relief and distribution. By combining multiple layers of visco-elastic or latex foam as the top structure of a mattress supported by underlying layers of a laminated urethane foam core, the conformance properties of visco-elastic or latex foam are achieved along with structural support from the underlying core. The multi-layer multi-material foam mattresses of the present disclosure and related inventions include in the various embodiments two or three layers of a first type of foam such as visco-elastic foam or latex foam, in combination with a multi-layer foam support core of a second type of foam such as urethane foam. The disclosed multi-layer/multi-material foam combinations provide superior comfort and conformance, pressure relief, orthopedic support and dampen motion transfer. The multiple layers of the first type of foam preferably have differing density and mass and/or thickness to provide relative gradation between layers and a aggregate performance of support and conformance to body contours and resulting pressure distribution, i.e., avoidance of pressure concentrations. The multiple layers of the second type of foam preferably have differing density and mass and/or thickness to provide relative gradation between layers and aggregate performance of softness and support for the overlying layers of the first type of foam.

Description

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 61/325,410, filed on Apr. 19, 2010, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention and related disclosure is related to bed mattresses, and more specifically to foam bed mattresses having layers of different types of materials.

BACKGROUND OF THE INVENTION

Sleep plays an important role in a person's overall health and enjoyment of life. The quality and quantity of sleep affects the body's ability to function normally and the ability to reach peak performance. Physiologically, sleep affects brain activity, heart rate, blood flow to the brain, sexual arousal, and body temperature. Sleep deprivation shows a strong correlation to obesity, diabetes, stroke, depression, and hypertension. Restful sleep is dependent upon the level of comfort while lying prone. Concentration of pressure on certain parts of the body and poor skeletal alignment are significant causes of restless sleep. Sleeping on a mattress or other support surface that does not properly support and conform to the shape of the body or to the spine's natural curves may significantly contribute to restlessness or inability to sleep.

Multi-layer foam mattresses of the prior art are designed to provide adequate support, without the use of wire springs, and pressure-relieving conformity particularly in the top layer. Typically, the first or top foam layer that is in contact with the user is made of visco-elastic foam, i.e., foam which is both viscous in order to conform under pressure, and elastic in order to return to its uncompressed state. Visco-elastic foam is sensitive to body heat such that the material conforms to the user's body, providing a more comfortable sleep surface. Multiple layer foam mattresses come in a variety of forms as the type of material, the thickness of each layer and the density of each layer can be varied to provide a mattress with different support characteristics.

Current foam technology can be categorized according to load bearing capacity by time and temperature variables. A standardized measure of Indentation Load Deflection (ILD) or Indentation Force Deflection (IFD) is a scaled range measurement of the load-bearing capacity and deformation properties of flexible foam, measured as force required to compress a sample, e.g. 50 sq. in., nominal 4 inch thickness, to 25 sq. in. or to a stated percentage of the sample initial height, pursuant to ASTM D3574. Rates of recovery and thermal response rates in the case of visco-elastic foams are also measured.

Although visco-elastic foams provide the advantages of shape conformity and thermal responsiveness, structural support is thereby sacrificed, particularly in areas of highest load concentrations. The support characteristics of visco-elastic type foam can be altered with density, although increased density produces a very hard and rigid surface without any thermal softening. The thickness of the layers in a multi-layer stack-up can also be determinative of certain support characteristics, although this may be a minimal factor if that is the only variable between layers. For this reason, in the prior art the number of adjacent layers of visco-elastic foam in a support pad or mattress has been kept to a very minimum, i.e., no more than two based upon the apparent belief that additional layers provide no particular advantage for the added cost.

SUMMARY OF THE INVENTION

The multi-layer multi-material foam mattresses of the present disclosure and related inventions provide novel combinations of multiple layer, multiple material foam layers or stacks which provide unexpected and improved support characteristics and pressure relief and distribution.

In a preferred embodiment, the multi-layer, multi-material foam mattress contains at least two layers of visco-elastic foam arranged in a stacked arrangement; at least one layer of polyurethane foam located beneath the at least two layers of visco-elastic foam and having a substantially planar top surface and a substantially planar bottom surface opposite the substantially planar top surface; and a support core, located beneath the at least two layers of visco-elastic foam and at least one layer of polyurethane foam, the support core comprising at least three foam layers that are not visco-elastic. The thickness of the first or top layer of the at least two layers of visco-elastic foam is less than the thickness of the second layer of the at least two layers of visco-elastic foam and the thickness of the at least one layer of polyurethane foam. The density of the second layer of the at least two layers of visco-elastic foam is greater than the density of the first or top layer of the at least two layers of visco-elastic foam and the density of the at least one layer of polyurethane foam. The three foam layers of the support core may include one generally planar foam layer sandwiched between two extracted foam layers, wherein each of the two extracted foam layers contains one generally planar surface and one convoluted surface opposite the generally planar surface and wherein the one convoluted surface of each of the two extracted foam layers is in contact with the one generally planar layer of the support core.

In another embodiment, the mattress contains a first layer of visco-elastic foam; a second layer of polyurethane foam located beneath the first layer; and a support core, located beneath the first and second layers, comprising at least three layers of foam. The first layer of visco-elastic foam may be hole-punched. A spacer fabric may also be inserted between the first and second layers of the mattress. The visco-elastic foam layer may alternatively contain three zones, a first zone proximate to the head of the mattress, a second zone proximate to the middle of the mattress and a third zone proximate to the foot of the mattress, wherein the first and third zones have a density that is less than the density of the second zone. The visco-elastic layer may additionally contain one planar surface and one non-planar surface, the non-planar surface being in contact with the second layer of polyurethane foam.

In still another embodiment, the mattress contains at least one layer of latex foam; and a support core comprising at least two layers of non-latex foam located beneath the at least one layer of latex foam. The at least one layer of latex foam has a density that is greater than the density of the support core. The mattress may include additional layers of latex foam in a stacked arrangement and the support core may contain additional layers of non-latex foam.

In yet another embodiment, the mattress includes at least two layers of visco-elastic foam in a stacked arrangement; and a support core, located beneath the at least two layers of visco-elastic foam, having at least two urethane foam layers.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment of the quick response multi-layer foam mattress of the present invention.

FIG. 2 is a cross-sectional view of the quick response multi-layer foam mattress of FIG. 1 viewed in the direction of arrows 2-2.

FIG. 3 is an exploded view of a two layer foam mattress of the present invention having an intermediate fiber layer.

FIG. 4 is an exploded view of an alternate two layer foam mattress of the present invention having an intermediate fiber layer.

FIG. 5 is an exploded view of an alternate two layer foam mattress of the present invention.

FIG. 6 is an exploded view of an alternate two layer foam mattress of the present invention.

FIG. 7 is an exploded view of an alternate two layer foam mattress of the present invention.

FIG. 8 is a perspective view of the support core.

FIG. 9 is a cross-sectional view of an alternate two layer foam mattress with pillowtop.

DETAILED DESCRIPTION OF PREFERRED AND ALTERNATE EMBODIMENTS

The multi-layer multi-material foam mattresses of the present disclosure and related inventions include in the various embodiments two or more layers of a first type of foam such as visco-elastic or latex, in combination with a foam support core having two or more layers of a second type of foam such as urethane foam.

Support Core

Each of the various two or three layer foam combinations described herein can be placed atop a support core (hereinafter referred to interchangeably as “support core” and “access core”), which is made of two or more layers of foam which is different from the foam material of the overlying layers, and which in preferred embodiments is urethane foam. The support core responds to the user's weight and evenly distributes it across the mattress. The support core also helps to reduce stress on pressure points, provides proper neck and spine alignment (correct orthopedic support) and reduces motion. The following table indicates the thickness, density and ILD characteristics of a preferred embodiment of the support core, which is shown in FIG. 8:

	THICKNESS	DENSITY	Indentation Load
FOAM LAYER	(in inches)	(in lb/ft3)	Deflection (ILD)
1st Layer	2.5	1.8	44
2nd Layer	0.75	1.8	65
3rd Layer	2.5	1.8	44

The preferred embodiment of the support core includes three foam layers—one generally planar foam layer 60 sandwiched between two extracted foam layers 50, 70. The top layer 50 of the support core 40 is designed to support and absorb pressure. The second or middle layer 60 is designed to distribute pressure evenly across the mattress and the third or bottom layer 70 of the support core is designed for additional support and absorption. The middle generally planar foam layer 60 may be made of polyurethane foam having a higher ILD than the two outer extracted foam layers 50, 70. However, the middle, generally planar foam layer 60 may also be made of latex, or any other suitable material. The two outer or extracted foam layers 50, 70 are made of polyurethane foam but can also be made of any other suitable material that is capable of having sections removed. The outer layers 50, 70 of the support core 40 may also be made of different materials, have different patterns, different ILDs and different densities. These outer layers 50, 70 are generally planar on one side and on the opposite side have patterned voids formed by removal of portions of an otherwise uniform or planar surface. The two outer support core layers 50, 70 have the same pattern, wherein a substantially different ILD exists on the edges of the foam layer than exists in the center of the foam layer. The edges of the foam layer extend inward around the perimeter of the layer for approximately 4.5 inches. This configuration adds support to one sitting or otherwise exerting pressure at the corners of the mattress. The first or top layer 50 of the support core 40 has a generally planar top surface and an extracted bottom surface. The third or bottom support core layer 70 has an extracted top surface and a generally planar bottom surface. The top extracted surface of the third or bottom layer 70 is in direct contact with the generally planar bottom surface of the second or middle layer 60 and the generally planar top surface of the second or middle layer 60 is in direct contact with the bottom extracted surface of the first or top layer 50.

The two or three-layer foam combinations of the various embodiments of the present invention (as described below) in combination with the three-layer support core 40 provides pressure relief by both distributing body weight more evenly and by dispersing pressure in areas where pressure is concentrated. Empirical design from human body pressure mapping was used to identify foam layer combinations that reduce the number of pressure points that exceed 32 mm Hg. Generally, blood flows through the capillaries at an approximate pressure of 32 millimeters of mercury (mm Hg). Once the external pressure on a capillary exceeds its internal blood pressure, occlusion occurs and restricts blood flow. Reducing pressure points on the human body that exceed 32 mm Hg reduces the autonomic to shift body position (less tossing and turning) while sleeping to maintain comfort.

Preferred Embodiment

A preferred embodiment of the quick response multi-layer foam mattress of the present invention, as shown in FIGS. 1 and 2, includes a multi-layer foam combination of a first type of foam supported by a multi-layer combination of a second type of foam or support core (as described above) 40 which serves as support for the overlying layers. The first two layers 10, 20, located closest to the user, are made of visco-elastic foam so that when the user is lying prone on the mattress 100, the mattress 100 will respond to the force and temperature change by conforming to the shape of the user's body. This response or change in the physical form of the mattress 100 will preferably occur in a relatively short time frame and more preferably in a short time frame such as several minutes or even one minute of less, which type of response is generally referred to herein as “quick response” as in “quick response multi-layer foam mattress”. When the weight is removed, the mattress 100 will slowly return to reassume its initial shape. The visco-elastic foam is reactive not only to the user's weight, but also with the user's body temperature, softening with heat and becoming more able to adjust to body contours. The third layer 30 is made of polyurethane. Describing the preferred embodiment in a more specific manner, the following chart indicates the approximate thickness and density of each of the three top layers:

FOAM	THICKNESS	DENSITY	Indentation Force
LAYER	(in inches)	(in lb/ft3)	Deflection (IFD)
Visco-Elastic	0.5	2.5	12 lbs. @ 25% indentation
Visco-Elastic	2.5	5.0	12 lbs. @ 25% indentation
Polyurethane	1.0	1.45	33 lbs. @ 25% indentation
Support Core
(as described
above)

Indentation Force Deflection (IFD) is a measure of the load bearing capacity of flexible polyurethane foam. IFD is generally measured as the force (in pounds) required to compress a 50 square inch circular indentor foot into a 4 inch thick sample, typically 15 inches square or larger, to a stated percentage of the sample's initial height. Common IFD values are generated at 25 and 65 percent of the initial height or thickness of the foam sample. (Reference Test Method ASTM D3574, also sometimes referred to as “ILD” (Indentation Load Deflection))

The top or first visco-elastic foam layer 10 has a thickness that is generally less than the thickness of the middle or second visco-elastic foam layer 20. This gives the user a greater feel for the memory foam without waiting as long for the visco to react to his/her weight and heat. The middle or second visco-elastic foam layer 20 generally has a density that is greater than the density of the top or first visco-elastic foam layer 20. The middle or second foam layer 20 delivers a depth of conformance that gradually cradles the user as it reacts to body weight and temperature. The relatively greater density of the second layer 20 is initially masked by the relatively lower density first layer 10. This produces an initial feel to a user of the mattress 100 which is not as hard or harsh as would be perceived if the first layer 10 had the greater density of the second layer 20. Each foam layer has a generally planar top surface and a generally planar bottom surface. The bottom surface of the first or top layer 10 is in direct contact with the top surface of the second or middle layer 20 and the bottom surface of the second or middle layer 20 is in direct contact with the top surface of the third or bottom layer 30. The bottom surface of the third or bottom layer 30 is in direct contact with the top surface of the support core 40.

Alternative Visco-Elastic Foam/Support Core Embodiments

An alternate embodiment of the present invention includes a two-layer foam combination and support core, as shown in FIG. 3. A spacer fabric or fiber inlay 85 is positioned between the two foam layers 80, 90. The first or top layer 80 is made of hole-punched visco-elastic foam so that it, in combination with the spacer fabric inlay 85, operates to provide ventilation and provide for improved air circulation.

	THICKNESS	DENSITY
FOAM LAYER	(in inches)	(in lb/ft3)
Visco-Elastic (hole punched)	3.0	5.0
Spacer Fabric	⅛	—
Polyurethane	1.0	1.45
Support Core (as described above)

The spacer fabric or fiber inlay 85 is approximately ⅛-inch thick and has a length that is equal to that of the first and second foam layers 80, 90. The first or top layer 80 has a top surface that is opposite a bottom surface. The first or top layer 80 includes a plurality of ⅜-inch holes positioned in a 2×2 inch pattern through the foam layer 80 from the top surface to the bottom surface. The second or bottom foam layer 90 has a generally planar top surface and a generally planar bottom surface, which is opposite the top surface. The bottom surface of the first or top layer 80 is in direct contact with the top surface of the spacer fabric or fiber inlay 85 and the top surface of the second or bottom layer 90 is in direct contact with the bottom surface of the spacer fabric or fiber inlay 85. The bottom surface of the second or bottom layer 90 is in direct contact with the top surface of the support core 40.

Another embodiment of the present invention, similar to the previously described embodiment, includes a two-layer foam combination atop a support core 40. A spacer fabric or fiber inlay 115 is placed between the top and bottom foam layers 110, 120. The 44-inch spacer fabric 115 is centered length-wise atop the second or bottom foam layer 120, as shown in FIG. 4. The first or top layer 110 is made of hole-punched visco-elastic foam. Thickness and density characteristics of each layer are as follows:

	THICKNESS	DENSITY
FOAM LAYER	(in inches)	(in lb/ft3)
Visco-Elastic (hole punched)	3.0	5.0
Spacer Fabric	⅛	—
Polyurethane	1.0	1.45
Support Core (as described above)

The spacer fabric or fiber inlay 105 is approximately ⅛-inch thick and has a length of approximately 44 inches. The first or top layer 110 has a top surface that is opposite a bottom surface. The first or top layer 110 includes a plurality of ⅜-inch holes positioned in a 2×2 inch pattern through the foam layer 110 from the top surface to the bottom surface. The second or bottom foam layer 120 has a generally planar top surface and a generally planar bottom surface, which is opposite the top surface. The bottom surface of the first or top layer 110 is in direct contact with the top surface of the spacer fabric 105 and portions of the top surface of the second or bottom foam layer 120. The top surface of the bottom layer 120 is in direct contact with the bottom surface of the spacer fabric 105 and portions of the bottom surface of the first or top foam layer 110. The bottom surface of the second or bottom layer 120 is in direct contact with the top surface of the support core 40.

Still another embodiment of the present invention includes two-layers of foam 130, 135 in combination with the support core 40. The first or top layer 130 is made of hole-punched visco-elastic foam having a convoluted 44-inch center base 132 to accept an optional spacer fabric, as shown in FIG. 5. The foam layers 130, 135 have the following characteristics:

	THICKNESS	DENSITY
FOAM LAYER	(in inches)	(in lb/ft3)
Optional Spacer Fabric	⅛	—
Visco-Elastic (hole punched	3.0	5.0
with convoluted center base)
Polyurethane	1.0	1.45
Support Core (as described above)

Still another embodiment of the present invention, shown in FIG. 6, includes a two-layer foam combination and access core 40. The first or top layer 140 is made of visco-elastic foam and the second or bottom layer 145 is made of polyurethane foam, each layer having the following characteristics:

	THICKNESS	DENSITY
FOAM LAYER	(in inches)	(in lb/ft3)
Visco-Elastic (w/three	3.0	First 35% of length = 2.5
lengthwise zones)		Second 30% of length = 5.0
		Last 35% of length = 2.5
Polyurethane	1.0	1.45
Support Core (as
described above)

The first or top layer 140 includes three lengthwise zones (not shown) having three distinct density measurements. This zoned configuration allows for higher density foam at the middle portion of the mattress with a slightly lower density at the head and foot regions of the mattress, to provide additional support the user's spine or mid-section. Each foam layer 140, 145 have a generally planar top surface and a generally planar bottom surface, which is opposite the top surface. The bottom surface of the first or top layer 140 is in direct contact with the top surface of the second or bottom layer 145 and the bottom surface of the second or bottom layer 145 is in direct contact with the support core 40.

Still another embodiment of the present invention includes a two-layer foam combination and support core. The two foam layers 150, 155 have the following characteristics:

	THICKNESS	DENSITY
FOAM LAYER	(in inches)	(in lb/ft3)
Visco-Elastic	3.0	5.0
Polyurethane	1.0	1.45
Support Core (as described above)

As shown in FIG. 7, the first or top layer 150 has a generally planar top surface and a generally non-planar bottom surface, which is opposite the top surface. The generally non-planar bottom surface of the first or top layer 150 is convoluted with a 3×2 inch pattern. The second or bottom layer 155 has a generally planar top surface with a generally planar bottom surface which is opposite the top surface. The generally non-planar bottom surface of the first or top layer 150 is in direct contact with the top generally planar surface of the second or bottom layer 155. The generally planar bottom surface of the second or bottom layer 155 is in direct contact with the top surface of the support core 40.

Yet another embodiment of the present invention includes two layers of foam in combination with an underlying support core, the two layers having the following characteristics:

	THICKNESS	DENSITY
FOAM LAYER	(in inches)	(in lb/ft3)
Visco-Elastic	3.0	5.0
Polyurethane	1.0	1.45
Support Core (as described above)

Each foam layer has a generally planar top surface and a generally planar bottom surface which is opposite the generally planar top surface. The generally planar bottom surface of the first or top layer is in direct contact with the generally planar top surface of the second or bottom layer and the generally planar bottom layer of the second or bottom layer is in direct contact with the top surface of the support core.

Latex Foam/Alternative, Support Core Embodiments

Additional alternate embodiments of the multi-layer/multi-material foam mattresses of the present disclosure and related inventions include mattresses wherein the upper layer or layers are made of latex foam.

In one particular embodiment of multi-layer/multi-material foam mattress in which the upper layer or layers of made of latex foam material, the foam layers have the following characteristics:

		THICKNESS	DENSITY
	FOAM LAYER	(in inches)	(in lb/ft3)
	Latex	3.0	3.5
	Support Core Layer #1	2.0	1.5
	Support Core Layer #2	5.0	1.45

The foam mattress has an upper layer of latex foam which has a density of approximately 3.50 pounds per cubic foot and a thickness of approximately 3 inches. The upper layer of latex foam is placed over a laminated lower support core made of at least two layers of a different type of (non-latex) foam material such as urethane foam, the first and second layers of the lower support core being preferably laminated together.

In another alternate embodiment of a multi-layer/multi-material foam mattress having an upper layer or layers made of latex foam, the foam layers have the following characteristics:

		THICKNESS	DENSITY
	FOAM LAYER	(in inches)	(in lb/ft3)
	Latex	2.0	3.4
	Latex	1.0	3.5
	Latex	1.0	4.5
	Support Core Layer #1	2.0	1.5
	Support Core Layer #2	5.0	1.45

This combination of three latex layers of differing densities and thicknesses is supported by an underlying laminate of foam material layers of a different (non-latex) foam material such as urethane foam, the first and second layers of the lower support core being preferably laminated together.

In another alternate embodiment of a multi-layer/multi-material foam mattress wherein the upper layer or layers are made of latex foam, the foam layers have the following characteristics:

		THICKNESS	DENSITY
	FOAM LAYER	(in inches)	(in lb/ft3)
	Latex	1.5	3.25
	Latex	3.0	3.5
	Latex	1.0	3.75
	Support Core Layer #1	2.5	1.8
	Support Core Layer #2	0.75	1.5
	Support Core Layer #3	2.5	1.8

This combination of three latex layers of differing densities and thicknesses is supported by an underlying laminate of a foam material layers of a different (non-latex) foam material such as urethane foam, with a first or uppermost layer having downward oriented convolutions, a second substantially planar layer, and a third layer having upward oriented convolutions. The first, second and third layers of the lower support core are preferably laminated together.

In a fourth alternate embodiment of a multi-layer/multi-material foam mattress wherein the upper layer or layers are made of latex foam, the various layers have the following characteristics:

		THICKNESS	DENSITY
	FOAM LAYER	(in inches)	(in lb/ft3)
	Latex	2.0	3.5
	Latex	4.5	4.5
	Support Core Layer #1	2.5	1.8
	Support Core Layer #2	0.75	1.5
	Support Core Layer #3	2.5	1.8

This combination of two latex layers of differing densities and thicknesses is supported by an underlying laminate of a foam material layers of a different (non-latex) foam material such as urethane foam, with a first or uppermost layer having downward oriented convolutions, a second substantially planar layer, and a third layer having upward oriented convolutions, the first, second and third layers of the lower support core being preferably laminated together.

Visco-Elastic Foam/Alternative Support Core Embodiments

The invention further includes multiple alternate embodiments of multi-layer/multi-material foam mattresses with multiple layers visco-elastic foam as the upper layers, and multiple layers of urethane foam as the lower layers.

In one embodiment of this type, the various foam layers have the following characteristics:

		THICKNESS	DENSITY
	FOAM LAYER	(in inches)	(in lb/ft3)
	Visco-Elastic	0.5	2.5
	Visco-Elastic	2.5	5.0
	Urethane Support Core Layer #1	2.0	1.5
	Urethane Support Core Layer #2	5.0	1.45

The two upper layers of visco-elastic foam are supported by two laminated lower layers of urethane foam, also referred to as a “laminated foam core”.

In another embodiment of multi-layer/multi-material foam mattresses with multiple layers visco-elastic foam as the upper layers, and multiple layers of urethane foam as the lower layers, the various layers have the following characteristics:

		THICKNESS	DENSITY
	FOAM LAYER	(in inches)	(in lb/ft3)
	Visco-Elastic	0.5	2.5
	Visco-Elastic	3.5	5.0
	Urethane Support Core Layer #1	2.0	1.5
	Urethane Support Core Layer #2	5.0	1.45

The two upper layers are supported by two laminated lower layers of urethane foam, also referred to as a “laminated foam core”.

In another embodiment of multi-layer/multi-material foam mattresses with multiple layers visco-elastic foam as the upper layers, and multiple layers of urethane foam as the lower layers, the various foam layers have the following characteristics:

		THICKNESS	DENSITY
	FOAM LAYER	(in inches)	(in lb/ft3)
	Visco-Elastic	0.5	2.5
	Visco-Elastic (Convoluted)	2.0	4.0
	Visco-Elastic	2.0	5.0
	Visco-Elastic	1.0	7.5
	Urethane Support Core Layer #1	2.5	1.8
	Urethane Support Core Layer #2	0.75	1.5
	Urethane Support Core Layer #3	2.5	1.8

There are four upper layers of visco-elastic foam, including a first or uppermost layer of visco-elastic foam being substantially planar and having nominal thickness, a convoluted second layer of visco-elastic foam with a an uncompressed thickness of approximately 2 inches (including approximate 1 inch convolutes, preferably extending downward), and third and fourth substantially planar layers of visco-elastic foam. The four upper layers are supported by a combination of three laminated lower layers of urethane foam, also referred to as a “laminated foam core”. The first or uppermost of the lower layers contains downward oriented (away from the overlying visco-elastic foam layers) convolutes, a substantially planar intermediate layer and a lowermost layer having upward oriented (toward the overlying visco-elastic layers) convolutes. The convolutes on the urethane layers do not have to extend all the way to the edges of the foam layers.

In another embodiment of multi-layer/multi-material foam mattresses with multiple layers visco-elastic foam as the upper layers, the various foam layers have the following properties:

		THICKNESS	DENSITY
	FOAM LAYER	(in inches)	(in lb/ft3)
	Visco-Elastic	0.5	2.5
	Visco-Elastic	2.0	7.5
	Visco-Elastic	4.0	5.0
	Urethane Support Core Layer #1	2.5	1.8
	Urethane Support Core Layer #2	0.75	1.5
	Urethane Support Core Layer #3	2.5	1.8

The three upper layers of visco-elastic foam are supported by a combination of three laminated lower layers of urethane foam, also referred to as a “laminated foam core”. The first or uppermost layer of the urethane support core contains downward oriented (away from the overlying visco-elastic foam layers) convolutes, the intermediate layer of the urethane support core is substantially planar, and a lowermost layer of the urethane support core contains upward oriented (toward the overlying visco-elastic layers) convolutes. The convolutes contained on the urethane layers do not have to extend all the way to the edges of the foam layers.

In still another embodiment, shown in FIG. 9, the mattress contains a two-layer foam pillowtop that sits above the foam mattress. The first layer 163 of the pillowtop is hole punched visco-elastic foam. The holes, positioned in a 4×4 inch pattern, provide ventilation and improved air circulation. The second layer 163 of the pillowtop is also visco-elastic foam that is generally thicker than the first pillowtop layer 163, having a higher density than the first pillowtop layer 163. Beneath the two layer foam pillowtop are two additional layers 160, 161 of visco-elastic foam which sit atop a three-layer support core 40. The two-layer pillowtop and multi-layer foam mattress may each be enclosed by separate cover layers with an attachment device securing the cover layer of the multi-layer mattress to the cover layer of the pillowtop. The thickness and density characteristics of the layers of this embodiment are as follows:

	THICKNESS	DENSITY
FOAM LAYER	(in inches)	(in lb/ft3)
Visco-Elastic Pillowtop Layer #1	0.5	2.5
(hole punched)
Visco-Elastic Pillowtop Layer #2	2.0	5.0
Visco-Elastic	2.0	7.5
Visco-Elastic	2.0	5.0
Urethane Support Core Layer #1	2.5	1.8
Urethane Support Core Layer #2	0.75	1.5
Urethane Support Core Layer #3	2.5	1.8

Any of the described foam mattresses can be made in any desired shape or size, including for example conventional bed sizes such as single, twin, double, queen and king. The foam mattresses of the disclosure can be covered with any suitable covering or sheet material or materials, padding or contour materials or layers, and may also incorporate fire resistant materials.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Other features and aspects of this invention will be appreciated by those skilled in the art upon reading and comprehending this disclosure. Such features, aspects, and expected variations and modifications of the reported results and examples are clearly within the scope of the invention where the invention is limited solely by the scope of the following claims.

Claims

1. A quick-response multi-layer foam mattress comprising:

at least two layers of visco-elastic foam arranged in a stacked arrangement;

at least one layer of polyurethane foam located beneath the at least two layers of visco-elastic foam and having a substantially planar top surface and a substantially planar bottom surface opposite the substantially planar top surface;

a support core located beneath the at least two layers of visco-elastic foam and at least one layer of polyurethane foam, the support core comprising at least three foam layers that are not visco-elastic;

wherein the thickness of the first or top layer of the at least two layers of visco-elastic foam is less than the thickness of the second layer of the at least two layers of visco-elastic foam and the thickness of the at least one layer of polyurethane foam;

wherein the density of the second layer of the at least two layers of visco-elastic foam is greater than the density of the first or top layer of the at least two layers of visco-elastic foam and the density of the at least one layer of polyurethane foam.

2. The mattress of claim 1, wherein the at least three foam layers of the support core include one generally planar foam layer sandwiched between two extracted foam layers.

3. The mattress of claim 2, wherein each of the two extracted foam layers contains one generally planar surface and one convoluted surface opposite the generally planar surface.

4. The mattress of claim 3, wherein the one convoluted surface of each of the two extracted foam layers is in contact with the one generally planar layer of the support core.

5. The mattress of claim 1, wherein an Indentation Force Deflection (IFD) of each of the at least two layers of visco elastic foam is approximately 12 lbs.@25% indentation.

6. The mattress of claim 1, wherein one of the at least two layers of visco elastic foam has a thickness of approximately 0.5 inches and a density of approximately 2.5 lb/ft3 and is positioned closest to a user lying prone on the mattress.

7. The mattress of claim 1, wherein an Indentation Force Deflection (IFD) of the at least one polyurethane layer is approximately 33 lbs.@25% indentation.

8. The mattress of claim 1, wherein an Indentation Load Deflection (ILD) of the top and bottom layers of the at least three foam layers of the support core is less than an ILD of the middle layer of the at least three foam layers of the support core.

9. The mattress of claim 1, wherein the density of each the at least three foam layers of the support core is approximately 1.8 lb/ft3.

10. A quick-response multi-layer foam mattress comprising:

a first layer of visco-elastic foam;

a second layer of polyurethane foam located beneath the first layer;

a support core, located beneath the first and second layers, comprising at least three layers of foam.

11. The mattress of claim 10, wherein the first layer of visco-elastic foam is hole punched.

12. The mattress of claim 11 further including a spacer fabric located between the first and second layers.

13. The mattress of claim 12, wherein the spacer fabric has a length that is less than a length of the first and second layers and wherein the spacer fabric is centered lengthwise between the first and second layers.

14. The mattress of claim 10, wherein the first layer of visco-elastic foam has a first zone proximate to a head region of the mattress, a second zone proximate to a middle region of the mattress, and a third zone proximate to a foot region of the mattress, the first and third zones having a density that is less than the density of the second zone.

15. The mattress of claim 10 wherein the first layer of visco-elastic foam contains a generally planar top surface and a non-planar bottom surface opposite the generally planar top surface, the non-planar bottom surface being in contact with the second layer of polyurethane foam.

16. The mattress of claim 10, wherein the first layer of visco-elastic foam and the second layer of polyurethane foam each have a substantially planar top surface and a substantially planar bottom surface opposite the substantially planar top surface.

17. The mattress of claim 10, wherein the first layer of visco elastic foam has a thickness of approximately 3 inches and a density of approximately 5 lb/ft3.

18. The mattress of claim 10, wherein the second layer of polyurethane foam has a thickness of approximately 1 inch and a density of approximately 1.45 lb/ft3.

19. A quick response multi-layer foam mattress comprising:

at least one layer of latex foam; and

a support core comprising at least two layers of non-latex foam located beneath the at least one layer of latex foam;

the at least one layer of latex foam having a density that is greater than the density of the support core.

20. The mattress of claim 19, wherein the at least one layer of latex foam is approximately 3 inches thick with a density of approximately 3.5 lb/ft3.

21. The mattress of claim 19 further including two additional layers of latex foam in a stacked arrangement with the at least one layer of latex foam and located above the support core.

22. The mattress of claim 21, wherein the support core comprises three layers of non-latex foam.

23. The mattress of claim 19, wherein the mattress comprises two layers of latex foam and the support core comprises three layers of non-latex foam.

24. A quick response multi-layer foam mattress comprising:

at least two layers of visco-elastic foam in a stacked arrangement; and

a support core, located beneath the at least two layers of visco-elastic foam, having at least two urethane foam layers.

25. The mattress of claim 24, wherein one of the at least two layers of visco elastic foam has a thickness of 0.5 inches and the other layer of visco elastic foam has a thickness of approximately 2.5 inches.

26. The mattress of claim 24, wherein one of the at least two layers of visco elastic foam has a density of 2.5 lb/ft3 and the other layer of visco elastic foam has a density of 5.0 lb/ft3.

27. The mattress of claim 24, wherein one of the at least two urethane foam layers has a thickness of approximately 2.0 inches and the other urethane foam layer has a thickness of approximately 5.0 inches.

28. The mattress of claim 24, wherein one of the at least two urethane foam layers has a density of 1.5 lb/ft3 and the other urethane foam layer has a density of approximately 1.45 lb/ft3.

29. The mattress of claim 24, having four layers of visco-elastic foam and the support core having three layers of urethane foam.

30. A quick response multi-layer foam mattress comprising:

a pillowtop having at least two layers of visco elastic foam;

at least two layers of visco-elastic foam in a stacked arrangement beneath the pillowtop;

a support core, located beneath the at least two layers of visco elastic foam comprising at least three layers of urethane foam.

31. The mattress of claim 30, wherein one of the at least two layers of visco elastic foam in the pillowtop is hole punched.

32. The mattress of claim 31, wherein the hole-punched layer of visco elastic foam is the top layer.

33. The mattress of claim 30, wherein one of the at least two layers of visco elastic foam of the pillowtop has a thickness of approximately 0.5 inches and the other layer of visco elastic foam of the pillowtop has a thickness of approximately 2.0 inches.

34. The mattress of claim 30, wherein one of the at least two layers of visco elastic foam of the pillowtop has a density of approximately 2.5 lb/ft3 and the other layer of visco elastic foam of the pillowtop has a density of approximately 5.0 lb/ft3.

35. The mattress of claim 30, wherein both of the at least two layers of visco elastic foam beneath the pillowtop have a thickness of approximately 2.0 inches.

36. The mattress of claim 30, wherein one of the at least two layers of visco elastic foam beneath the pillowtop has a density of approximately 7.5 lb/ft3 and the other layer of visco elastic foam beneath the pillowtop has a density of approximately 5.0 lb/ft2.