US20130025070A1

US20130025070A1 - Mattress assembly with high airflow

Info

Publication number: US20130025070A1
Application number: US13/560,386
Authority: US
Inventors: James Gerard Ruehlmann; Richard Ferrell Gladney
Original assignee: Dreamwell Ltd
Current assignee: Morgan Stanley Senior Funding Inc
Priority date: 2011-07-29
Filing date: 2012-07-27
Publication date: 2013-01-31
Also published as: CA2783982A1

Abstract

Mattress assemblies that provide user comfort and increased airflow generally include multilayered foams having open celled structures. Viscoelastic foams can be utilized having intact windows between adjacent cells of less than 50 percent.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/513,090, filed Jul. 29, 2011, incorporated herein by reference in its entirety.

BACKGROUND

The present disclosure generally relates to foam mattress assemblies exhibiting increased airflow.
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 include both open cell (interconnected cells) and closed cells.
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.
Unfortunately, the high density 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 a 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.
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.
Accordingly, it would be desirable to provide a mattress assembly, especially a mattress including one or more layers of aviscoelastic memory foam, with an improved airflow to effectively dissipate user heat.

BRIEF SUMMARY

Disclosed herein are mattress assemblies exhibiting increased airflow. In one embodiment, a mattress assembly comprises a non-viscoelastic first foam layer comprising planar top and bottom surfaces; a second foam layer overlaying top planar surface of the first foam layer, the second foam layer comprising a pre-stressed foam having planar top and bottom surfaces; and a viscoelastic third foam layer overlaying the top planar surface of the second foam layer, the second foam layer comprising planar top and bottom, wherein the viscoelastic third foam layer is the uppermost layer of the mattress assembly.
In another embodiment, a mattress assembly, comprises a non-viscoelastic first foam layer having top and bottom planar surfaces; a non-viscoelastic second foam layer overlaying the top planar surface of the non-viscoelastic first foam layer having planar top and bottom surfaces; a viscoelastic third foam layer overlaying the top planar surface of the second foam layer having planar top and bottom surfaces; and a viscoelastic fourth foam layer overlaying the top planar surface of the third foam layer, wherein the fourth foam layer is the uppermost layer of the mattress assembly.
In yet another embodiment, a mattress assembly comprises a non-viscoelastic first foam layer having planar top and bottom surfaces; a non-viscoelastic second foam layer overlaying the top planar surface of the first foam layer having planar top and bottom surfaces; a viscoelastic foam third layer overlaying the top planar surface of the second foam layer having planar top and bottom surfaces; and a gel infused viscoelastic fourth foam layer overlaying the top planar surface of the third foam layer having equal to or less than 50 percent by weight gel loading; and a viscoelastic fifth foam layer overlaying the top planar surface of the fourth foam layer, wherein the fifth foam layer is the uppermost layer of the mattress assembly.
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

Referring now to the figures wherein the like elements are numbered alike:

FIG. 1 illustrates a top down view of a mattress assembly;

FIG. 2 illustrates a cross sectional view of a mattress assembly taken along line 1-1 of FIG. 1 in accordance with an embodiment of the present disclosure;

FIG. 3 illustrates a cross sectional view of a mattress assembly taken along line 1-1 of FIG. 1 in accordance with an embodiment of the present disclosure;

FIG. 4 illustrates a cross sectional view of a mattress assembly taken along line 1-1 of FIG. 1 in accordance with an embodiment of the present disclosure; and

FIG. 5 illustrates a cross sectional view of a mattress assembly taken along line 1-1 of FIG. 1 in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

Disclosed herein are mattress assemblies that provide user comfort with improved airflow to effectively dissipate user heat during use. FIG. 1 illustrates a top down view representative of the various 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 at least the side rail assembly as shown, e.g., a mattress border. In some embodiments, the optional fabric covering may overlay the uppermost foam layer 12 and extend about the perimeter. 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 and having a length and width dimensions sufficient to support a reclining body of the user.
FIG. 2 shows a cross sectional view of a mattress assembly in accordance with one embodiment. The mattress assembly 100 includes a base core foam layer 102 configured with generally planar top and bottom surfaces. For this as well as the other embodiments disclosed herein, the core foam layer 102 is chosen to have a thickness greater than or equal to the overall thickness of the mattress assembly. Generally, the thickness of the foam core layer 102 is 4 inches to 10 inches, with about 6 inches to 8 inches thickness in other embodiments, and about 6.5 inches in still other embodiments. The core foam layer can be formed of standard polyurethane foam although other foams can be used, including without limitation, viscoelastic foams. In one embodiment, the core foam layer is open cell polyurethane foam. In other embodiments, the core foam layer is closed cell polyurethane foam. The core foam layer 102 has a density of 1 pound per cubic foot (lb/ft³) to 5 lb/ft³. In other embodiments, the density is 1 lb/ft³to 3 lb/ft³and in still other embodiments, from 1 lb/ft³to 2 lb/ft³. By way of example, the density can be 1.65 lb/ft³. The hardness of the core foam 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″×15″×4″ foam sample and make a 1″ indentation. In one embodiment, the hardness is about 32 to 35 pounds-force.
A relatively thin pre-stressed polyurethane foam layer 104 including planar top and bottom surfaces is disposed on the base core foam layer 102. Suitable pre-stressed polyurethane foams are generally formed in the manner disclosed in U.S. 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 a standard polyurethane foam 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 polyurethane foam that was not pre-stressed. The pre-stressed polyurethane foam layer is a standard polyurethane foam as noted above (i.e., not viscoelastic) and generally has a pre-stressed thickness of less than 1 inch to 0.5 inches. The density is generally less than 2.5 lb/ft³to 0.5 lb/ft³in some embodiments, and less than 2 lb/ft³to 1 lb/ft³in still other embodiments. The hardness is generally less than 30 pounds-force to 10 pounds-force in some embodiments, and less than 25 pounds-force to 15 pounds-force in still other embodiments. In one embodiment, the thickness is 0.5 inches, the hardness is 22 pounds-force, and the density is 1.5 lb/ft³.
A cover panel 106 is formed of a viscoelastic foam and disposed on the polystyrene foam layer 104. The viscoelastic polyurethane foam in this embodiment as well as in the other embodiments disclosed herein where a viscoelastic foam is utilized in the mattress assembly has an open cell structure, wherein the percentage of intact windows (i.e., cell walls) between adjacent cells is less than 50 percent in one embodiment, and less than 40 percent in other embodiments, and less than 30 percent in still other embodiments. The cover panel 106 in this embodiment has planar top and bottom surfaces. The thickness is generally less than 3 inches to 0.5 inches in some embodiments, and less than 2 inches to 1 inch in other embodiments. The density is less than 3 lb/ft³to 1 lb/ft³in some embodiments, and less than 2.5 lb/ft³to 2 lb/ft³in other embodiments. In one embodiment, the hardness is generally less than 15 pounds-force to 5 pounds-force. In one embodiment, the cover panel is at a thickness of 1.5″, a density of 2.5 lb/ft³, and a hardness is 12 pounds-force.
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.
The mattress assembly further includes a foam side rail assembly 120 about all or a portion of the perimeter of the mattress layers 102, 104, 106. The side rails that define the assembly may be attached or placed adjacent to at least a portion of the perimeter of the mattress layers 102, 104, 106, and may include metal springs, spring coils, encased spring coils, foam, latex, gel, viscoelastic gel, or a combination, in one or more layers. Side rails may be placed on opposing sides of the stacked mattress layers, on all four sides of the stacked mattress layers, or only on one side of the stacked mattress layers. In certain embodiments, the side rails may comprise edge supports with 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.
In one embodiment, the side rail assembly is formed of a polyurethane foam having a density generally less than 3 lb/ft³and a hardness greater than 30 pounds-force. In one embodiment, the side rails are formed of having a density of 1.65 lb/ft³and a hardness of 45 pounds-force.
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 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 a 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 reticulated viscoelastic polyurethane foam.
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. The ends may be square as shown in the top down view FIG. 1 or may be mitered.
An optional fabric layer 122 is disposed about the perimeter of the side rail, i.e., serves as a mattress border. 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 is 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 relative to other fabrics, crush resistance, and a three dimensional appearance. The at least two fabric layers may be the same or different, i.e., the same or different density, mesh, 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.
In the embodiment shown, the mattress assembly 100 is generally less than 12 inches in height. By way of example, an exemplary mattress assembly illustrative of the embodiment shown in FIG. 2 has a 6.5″ foam core layer of standard polyurethane foam having a density of 1.65 lb/ft³and a hardness of about 32-35 pounds-force ILD; a 0.5″ pre-stressed polyurethane foam intermediate layer; and 1.5″ top cover layer of viscoelastic polyurethane foam having a density of 2.5 lb/ft³and a hardness of about 12 pounds-force. The side rail assembly may have a thickness of 2″ and is formed of an open cell foam having about 20 cells per linear inch as described above. A mattress border and panel of a spacer fabric is utilized as a mattress border.
FIG. 3 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 4 inches to 10 inches, with about 6 inches to 8 inches thickness in other embodiments, and about 6.5 inches in still other embodiments. The core foam layer can be formed of standard polyurethane foam although other foams can be used, including without limitation, viscoelastic foams. In one embodiment, the core foam layer is an open cell polyurethane foam. In other embodiments, the core foam layer is closed cell polyurethane foam. The core foam layer 202 has a density of 1 lb/ft³to 5 lb/ft³. In other embodiments, the density is 1 lb/ft³to 3 lb/ft³and in still other embodiments, from 1 lb/ft³to 2 lb/ft³. By way of example, the density can be 1.65 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 24 pounds-force.
A transition support layer 203 having planar top and bottom surfaces and formed of standard polyurethane foam is disposed on the base core foam layer 202. The transition support layer 203 generally has a thickness less than 1 inch to 0.5 inch, a density of less than 4 to 1 lb/ft³, and a hardness less than 15 to 10 pounds-force. In one embodiment, the transition layer 203 has a thickness of 0.5″, a density of 3 lb/ft³, and a hardness of 12 pounds-force.
Viscoelastic polyurethane foam layer 205 having planar top and bottom surfaces overlays on the transition support layer 203. The viscoelastic foam layer 205 is generally characterized as having a thickness less than 1 inch, a density of less than 3 to 1 lb/ft³, and a hardness less than 15 to 10 pounds-force. In one embodiment, the viscoelastic foam layer 205 has a thickness of 1″, a density of about 2.5 lb/ft³, and a hardness of 12 pounds-force.
A cover panel 206 formed of a viscoelastic foam is disposed on the viscoelastic foam layer 205. The cover panel 206 has planar top and bottom surfaces, a density of 1 to 3.5 lb/ft³, a hardness of 10 to 15 pounds-force, and a thickness of 1 to 2 inches. In one embodiment, the cover panel has a thickness of 1.5″, a density of about 2.5 lb/ft³, and a hardness of about 12 pounds-force.
The mattress assembly may further include the side rail assembly 220 and the optional fabric border 222 as described above.
By way of example, an exemplary mattress assembly illustrative of the embodiment shown in FIG. 3 has a 6.5″ foam core layer of standard polyurethane foam having a density of 1.65 lb/ft³and a hardness of about 24 pounds-force ILD; a 0.5″ transition support having a density of 3 lb/ft³and a hardness of 12 pounds-force; a 1″ viscoelastic polyurethane foam layer having a density of 2.5 lb/ft³and a hardness of about 12 pounds-force; and a cover panel layer has a thickness of 1.5″, a density of about 2.5 lb/ft³, and a hardness of about 12 pounds-force. The side rail assembly may have a thickness of 2″ and is formed of an open cell foam having about 20 cells per linear inch as previously described. A mattress border and panel of a spacer fabric is utilized as a mattress border.
FIG. 4. shows a cross sectional view of a mattress assembly in accordance with one embodiment. The mattress assembly 300 includes a base core foam layer 302 configured with planar top and bottom surfaces. Generally, the thickness of the foam core layer 302 is 4 inches to 10 inches, with about 6 inches to 8 inches thickness in other embodiments, and about 6.5 inches in still other embodiments. The core foam layer 302 can be formed of standard polyurethane foam although other foams can be used, including without limitation, viscoelastic foams. In one embodiment, the core foam layer is an open cell polyurethane foam. In other embodiments, the core foam layer is closed cell polyurethane foam. The core foam layer 302 has a density of 1 pound per square foot (lb/ft³) to 5 lb/ft³. In other embodiments, the density is 1 lb/ft³to 3 lb/ft³and in still other embodiments, from 1 lb/ft³to 2 lb/ft³. By way of example, the density can be 1.65 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 24 pounds-force.
A transition support layer 303 having planar top and bottom surfaces and formed of standard polyurethane foam is disposed on the base core foam layer 302. The transition support layer 303 generally has a thickness of 0.5 to 1 inch, a density of 1 to 4 lb/ft³, and a hardness of 10 to 15 pounds-force. In one embodiment, the transition layer 303 has a thickness of 0.5″, a density of 3 lb/ft³, and a hardness of 12 pounds-force.
Viscoelastic polyurethane foam layer 305 having planar top and bottom surfaces is disposed on the transition support layer 303. The viscoelastic foam layer 305 is generally characterized as having a thickness of 1 to 3 inches, a density of 1 to 4 lb/ft³, and a hardness of 10 to 15 pounds-force. In one embodiment, the viscoelastic polyurethane foam layer 305 has a thickness of 1.5″, a density of about 2.5 lb/ft³, and a hardness of 12 pounds-force.
A gel infused viscoelastic foam layer 307 having planar top and bottom surfaces is disposed on the viscoelastic foam layer 305. Suitable gel infused viscoelastic layers are generally disclosed in US Pat. No. 2010/0005595 to Gladney et al., which is incorporated by reference in its entirety. In one embodiment, the gel infused viscoelastic foam layer is infused with gel at less than about 50 percent by weight in some embodiments, with less than 40 percent by weight in other embodiments, and with less than 35 percent in still other embodiments. Optionally, the gel infused viscoelastic layer may be loaded with activated carbon for odor control. In one embodiment, the gel infused visco elastic foam layer 307 is formed of a non-random open cell polyurethane viscoelastic foam having a thickness of 0.5 to 2 inches, a density of 3 to 6 lb/ft³and a hardness of 10 to 15 pounds-force. In one embodiment, the gel infused viscoelastic foam layer 307 has a 36 percent by weight gel loading, a density of 4.5 lb/.ft³, and a hardness of 11 pounds-force.
A cover panel 306 formed of a viscoelastic foam is disposed on the gel infused viscoelastic foam layer 307. The cover panel 306 has planar top and bottom surfaces, a density of 1 to 3.5 lb/ft³, a hardness of 10 to 15 pounds-force, and a thickness of 0.5 to 2 inches. In one embodiment, the cover panel has a thickness of 1.5″, a density of about 2.5 lb/ft³, and a hardness of about 11 pounds-force.
The mattress assembly may further include the side rail assembly 320 and the optional fabric border 322 as described above.
By way of example, an exemplary mattress assembly illustrative of the embodiment shown in FIG. 3 has a 6.5″ foam core layer of standard polyurethane foam having a density of 1.65 lb/ft³and a hardness of about 24 pounds-force ILD; a 0.5″ transition support having a density of 3 lb/ft³and a hardness of 12 pounds-force; a 1.5″ viscoelastic polyurethane foam layer having a density of 2.5 lb/ft³and a hardness of about 12 pounds-force; a 1″ gel infused viscoelastic foam layer having a 36 percent by weight gel loading, a density of 4.5 lb/.ft³, and a hardness of 11 pounds-force; and a cover panel layer having a thickness of 1.5″, a density of about 2.5 lb/ft³, and a hardness of about 11 pounds-force. The side rail assembly may have a thickness of 2″ and is formed of an open cell foam having about 20 cells per linear inch as previously described. A mattress border and panel of a spacer fabric is utilized as a mattress border.
FIG. 5 shows a cross sectional view of a mattress assembly in accordance with one embodiment. The mattress assembly 400 includes a base core foam layer 402 configured with planar top and bottom surfaces. Generally, the thickness of the foam core layer 402 is 4 inches to 10 inches, with about 6 inches to 8 inches thickness in other embodiments, and about 6.5 inches in still other embodiments. The core foam layer 402 can be formed of standard polyurethane foam although other foams can be used, including without limitation, viscoelastic foams. In one embodiment, the core foam layer is an open cell polyurethane foam. In other embodiments, the core foam layer is closed cell polyurethane foam. The core foam layer 302 has a density of 1 pound per square foot (lb/ft³) to 5 lb/ft³. In other embodiments, the density is 1 lb/ft³to 3 lb/ft³and in still other embodiments, from 1 lb/ft³to 2 lb/ft³. The hardness is within a range of 20 to 40 pounds-force. By way of example, the core layer 402 can have a thickness of 8″, a density of 1.65 lb/ft³and a hardness of 24 pounds-force.
A transition support layer 403 having planar top and bottom surfaces and formed of standard polyurethane foam is provided on the base core foam layer 402. The transition support layer 403 generally has a thickness less than 1″, a density of less than 4 lb/ft³, and a hardness less than 15 pounds-force. In one embodiment, the transition layer 403 has a thickness of 0.5″, a density of 3 lb/ft³, and a hardness of 12 pounds-force.
Viscoelastic polyurethane foam layer 405 having planar top and bottom surfaces is disposed on the transition support layer 403. The viscoelastic foam layer 405 is generally characterized as having a thickness less than 3 inches, a density of less than 4.5 lb/ft³, and a hardness less than 15 pounds-force. In one embodiment, the viscoelastic polyurethane foam layer 405 has a thickness of 1.5″, a density of about 3.5 lb/ft³, and a hardness of 11 pounds-force.
A gel infused viscoelastic foam layer 407 having planar top and bottom surfaces is disposed on the viscoelastic foam layer 405. In one embodiment, the gel infused viscoelastic foam layer is infused with gel at less than about 50 percent by weight in some embodiments, with less than 40 percent by weight in other embodiments, and with less than 35 percent in still other embodiments. Optionally, the gel infused viscoelastic layer may be loaded with activated carbon for odor control. In one embodiment, the gel infused visco elastic foam layer 407 is formed of a non-random open cell polyurethane viscoelastic foam having a thickness less than 2 inches, a density generally less than 6 lb/ft³and a hardness greater than 15 pounds-force. In one embodiment, the gel infused viscoelastic foam layer 407 has a 36 percent by weight gel loading, a density of 4.5 lb/.ft³, and a hardness of 11 pounds-force.
A cover panel 406 formed of a viscoelastic foam is disposed on the gel infused viscoelastic foam layer 407. The cover panel 406 has planar top surface and a convoluted bottom surface, a density less than 4.5 lb/ft³, a hardness less than 15 pounds-force, and a thickness less than 2″. The convoluted bottom surface is in contact with the top planar surface of the gel infused viscoelastic layer 307. An exemplary convoluted foam has an egg crate structure such as the one disclosed in US Pat. Pub. No. 2007/0226911 to Gladney et al., incorporated herein by reference in its entirety. In one embodiment, the cover panel has a thickness of 1.5″, a density of about 3.5 lb/ft³, and a hardness of about 11 pounds-force.
The mattress assembly may further include the side rail assembly 420 and the optional fabric border 422 as described above.
By way of example, an exemplary mattress assembly illustrative of the embodiment shown in FIG. 4 has a 8″ foam core layer of standard polyurethane foam having a density of 1.65 lb/ft³and a hardness of about 24 pounds-force ILD; a 0.5″ transition support having a density of 3 lb/ft³and a hardness of 12 pounds-force; a 1.5″ viscoelastic polyurethane foam layer having a density of 3.5 lb/ft³and a hardness of about 11 pounds-force; a 1.5″ gel infused viscoelastic foam layer having a 36 percent by weight gel loading, a density of 4.5 lb/.ft³, and a hardness of 11 pounds-force; and a cover panel layer having a convoluted bottom surface, a thickness of 1.5″, a density of about 3.5 lb/ft³, and a hardness of about 11 pounds-force. The side rail assembly may have a thickness of 2″ and is formed of an open cell foam having about 20 cells per linear inch as previously described. A mattress border and panel of a spacer fabric is utilized as a mattress border.
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.
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.

Claims

1. A mattress assembly, comprising:

a non-viscoelastic first foam layer comprising planar top and bottom surfaces;

a second foam layer overlaying top planar surface of the first foam layer, the second foam layer comprising a pre-stressed foam having planar top and bottom surfaces; and

a viscoelastic third foam layer overlaying the top planar surface of the second foam layer, the second foam layer comprising planar top and bottom, wherein the viscoelastic third foam layer is the uppermost layer of the mattress assembly.

2. The mattress assembly of claim 1, wherein the viscoelastic third foam layer has intact windows between adjacent cells of less than 50 percent.

3. The mattress assembly of claim 1, wherein the non-viscoelastic first foam layer is an open celled polyurethane foam.

4. The mattress assembly of claim 1, wherein the non-viscoelastic first foam layer has a thickness of 4 to 10 inches, a hardness of 20 to 40 pounds-force, and a density of 1 to 5 lb/ft³; the second pre-stressed foam layer has a thickness of 0.5 to 1 inch, a hardness of 10 to 30 pounds-force, and a density of 0.5 to 2.5 lb/ft³; and the viscoelastic third foam layer has a thickness of 0.5 to 3 inches, a hardness of 5 to 15 pounds-force, and a density of 1 to 3 lb/ft³.

5. The mattress assembly of claim 1, wherein the non-viscoelastic first foam layer has a thickness of 6.5 inches, a hardness of 32-35 pounds-force, and a density of 1.65 lb/ft³; the second pre-stressed foam layer has a thickness of 1.5 inches, a hardness of 22 pounds-force, and a density of 1.5 lb/ft³; and the viscoelastic third foam layer has a thickness of 1 to 2 inches, a hardness of 12 pounds-force, and a density of 2.5 lb/ft³.

6. The mattress assembly of claim 1, further comprising a side rail assembly formed of open cell polyurethane foam.

7. The mattress assembly of claim 1, further comprising a fabric layer about a perimeter to the mattress assembly, wherein at least a portion of the fabric layer is formed of a spacer fabric.

8. A mattress assembly, comprising:

a non-viscoelastic first foam layer having top and bottom planar surfaces;

a non-viscoelastic second foam layer overlaying the top planar surface of the non-viscoelastic first foam layer having planar top and bottom surfaces;

a viscoelastic third foam layer overlaying the top planar surface of the second foam layer having planar top and bottom surfaces; and

a viscoelastic fourth foam layer overlaying the top planar surface of the third foam layer, wherein the fourth foam layer is the uppermost layer of the mattress assembly.

9. The mattress assembly of claim 8, wherein the viscoelastic third and fourth foam layer have intact windows between adjacent cells of less than 50 percent.

10. The mattress assembly of claim 8, wherein the non-viscoelastic first and second foam layers are an open celled polyurethane foam.

11. The mattress assembly of claim 8, wherein the non-viscoelastic first foam layer has a thickness of 4 to 10 inches, a hardness of 20 to 40 pounds-force, and a density of 1 to 5 lb/ft³; the non-viscoelastic second foam layer has a thickness of 0.5 to 1 inch, a hardness of 10 to 15 pounds-force, and a density of 1 to 4 lb/ft³; the viscoelastic third foam layer has a thickness of 0.5 to 1 inches, a hardness of 10 to 15 pounds-force, and a density of 1 to 3 lb/ft³; and the viscoelastic fourth layer has a thickness of 0.5 to 2 inches, a hardness of 10 to 15 pounds-force, and a density of 1 to 3.5 lb/ft³.

12. The mattress assembly of claim 8, wherein the non-viscoelastic first foam layer has a thickness of 6.5 inches, a hardness of 24 pounds-force, and a density of 1.65 lb/ft³; the non-viscoelastic second foam layer has a thickness of 1 inch, a hardness of 12 pounds-force, and a density of 3 lb/ft³; the viscoelastic third foam layer has a thickness of 1 inch, a hardness of 12 pounds-force, and a density of 2.5 lb/ft³; and the viscoelastic fourth layer has a thickness of 1.5 inches, a hardness of 12 pounds-force, and a density of 2.5 lb/ft³.

13. The mattress assembly of claim 8, further comprising a side rail assembly formed of open cell polyurethane foam.

14. The mattress assembly of claim 8, further comprising a fabric layer about a perimeter to the mattress assembly, wherein at least a portion of the fabric layer is formed of a spacer fabric.

15. A mattress assembly, comprising:

a non-viscoelastic first foam layer having planar top and bottom surfaces;

a non-viscoelastic second foam layer overlaying the top planar surface of the first foam layer having planar top and bottom surfaces;

a viscoelastic foam third layer overlaying the top planar surface of the second foam layer having planar top and bottom surfaces; and

a gel infused viscoelastic fourth foam layer overlaying the top planar surface of the third foam layer having equal to or less than 50 percent by weight gel loading; and

a viscoelastic fifth foam layer overlaying the top planar surface of the fourth foam layer, wherein the fifth foam layer is the uppermost layer of the mattress assembly.

16. The mattress assembly of claim 15, wherein the viscoelastic third, fourth and fifth foam layers have intact windows between adjacent cells of less than 50 percent.

17. The mattress assembly of claim 15, wherein the non-viscoelastic first and second foam layers are an open celled polyurethane foam.

18. The mattress assembly of claim 15, wherein the non-viscoelastic first foam layer has a thickness of 4 to 10 inches, a hardness of 20 to 40 pounds-force, and a density of 1 to 5 lb/ft³; the non-viscoelastic second foam layer has a thickness of 0.5 to 1 inch, a hardness of 10 to 15 pounds-force, and a density of 1 to 4 lb/ft³; the viscoelastic third foam layer has a thickness of 1 to 3 inches, a hardness of 10 to 15 pounds-force, and a density of 1 to 4 lb/ft³; the gel infused viscoelastic fourth foam layer has a thickness of 1 to 2 inches, a hardness of 10 to 15 pounds-force, and a density of 3 to 6 lb/ft³; and the viscoelastic fifth layer has a thickness of 0.5 to 2 inches, a hardness of 10 to 15 pounds-force, and a density of 1 to 3.5 lb/ft³.

19. The mattress assembly of claim 15, wherein the non-viscoelastic first foam layer has a thickness of 6.5 inches, a hardness of 24 pounds-force, and a density of 1.65 lb/ft³; the non-viscoelastic second foam layer has a thickness of 0.5 inch, a hardness of 12 pounds-force, and a density of 3 lb/ft³; the viscoelastic third foam layer has a thickness of 1.5 inches, a hardness of 12 pounds-force, and a density of 2.5 lb/ft³; the gel infused viscoelastic fourth foam layer has a thickness of 1 inch, a hardness of 11 pounds-force, and a density of 4.5 lb/ft³; and the viscoelastic fifth layer has a thickness of 1.5 inches, a hardness of 11 pounds-force, and a density of 2.5 lb/ft³.

20. The mattress assembly of claim 15, further comprising a side rail assembly formed of open cell polyurethane foam.

21. The mattress assembly of claim 15, further comprising a fabric layer about a perimeter to the mattress assembly, wherein at least a portion of the fabric layer is formed of a spacer fabric.

22. The mattress assembly of claim 15, wherein the gel infused viscoelastic fourth foam layer further comprises activated carbon.

23. The mattress assembly of claim 15, wherein the non-viscoelastic first foam layer has a thickness of 8 inches, a hardness of 24 pounds-force, and a density of 1.65 lb/ft³; the non-viscoelastic second foam layer has a thickness of 0.5 inch, a hardness of 12 pounds-force, and a density of 3 lb/ft³; the viscoelastic third foam layer has a thickness of 1.5 inches, a hardness of 12 pounds-force, and a density of 3.5 lb/ft³; the gel infused viscoelastic fourth foam layer has a thickness of 1.5 inches, a hardness of 11 pounds-force, and a density of 4.5 lb/ft³; and the viscoelastic fifth layer has a thickness of 1.5 inches, a hardness of 11 pounds-force, and a density of 3.5 lb/ft³.