MATTRESS COMPRISING SUPPORT LAYER COMPRISING A CURVED CHANNEL

Abstract

A mattress comprising at least one support layer comprising at least one non-linear channel extending laterally from a first side to an opposite side, and a plurality of support members disposed in the channel. The mattress may comprise a comfort layer, such as a viscoelastic foam layer, above the support layer. A mattress assembly comprising the mattress and a mattress foundation.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

Generally, the present disclosure relates to bedding, and, more specifically, to a mattress comprising a support layer comprising a curved channel.

Description of the Related Art

Foam mattresses, such as viscoelastic or so-called “memory foam” mattresses, provide desirably high levels of firmness and support for many users. However, mattresses comprising only viscoelastic foam may lack sufficient support for some users. Also, mattresses comprising only viscoelastic foam may lack desired levels of support for certain regions of a user's body. Alternatively or in addition, mattress comprising solid foam, including but not necessarily limited to viscoelastic foam, may retain a user's heat and may thus “sleep hot.” Heat retention in a mattress is generally undesirable to a majority of users.

The present disclosure may address and/or at least reduce one or more of the problems identified above.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the disclosure in order to provide a basic understanding of some aspects of the disclosure. This summary is not an exhaustive overview of the disclosure. It is not intended to identify key or critical elements of the disclosure or to delineate the scope of the disclosure. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is discussed later.

In one embodiment, the present disclosure is directed to a mattress comprising at least one support layer comprising at least one non-linear channel extending laterally from a first side to an opposite side w, and a plurality of support members disposed in the channel.

In one embodiment, the present disclosure is directed to a mattress assembly comprising a mattress comprising at least one support layer comprising at least one non-linear channel extending laterally from a first side to an opposite side, and a plurality of support members disposed in the channel; and a mattress foundation disposed under the mattress.

In one embodiment, the present disclosure is directed to a mattress, comprising at least one support layer comprising at least one non-linear channel extending laterally from a first side to an opposite side, and a plurality of support members disposed in the channel; and a viscoelastic foam layer disposed above the support layer.

The present disclosure may provide for mattresses with improved comfort for users reclining thereon.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:

FIG. 1 illustrates a stylized top view of a mattress, in accordance with embodiments herein;

FIG. 2 illustrates a stylized side view of a mattress, in accordance with embodiments herein;

FIG. 3 illustrates a stylized top sectional view of the mattress of FIG. 2 along the line A-A′, in accordance with embodiments herein;

FIG. 4 illustrates a stylized side view of a mattress, in accordance with embodiments herein;

FIG. 5 illustrates a stylized side view of a mattress, in accordance with embodiments herein;

FIG. 6 illustrates a stylized top sectional view of the mattress of FIG. 5 along the line B-B′, in accordance with embodiments herein;

FIG. 7 illustrates a stylized side view of a mattress, in accordance with embodiments herein;

FIG. 8 illustrates a stylized top sectional view of the mattress of FIG. 7 along the line C-C′, in accordance with embodiments herein;

FIG. 9 illustrates a stylized side view of a mattress, in accordance with embodiments herein;

FIG. 10 illustrates a stylized side view of a mattress, in accordance with embodiments herein;

FIG. 11 illustrates a stylized side view of a mattress assembly, in accordance with embodiments herein; and

FIG. 12 illustrates a stylized side view depiction of the mattress foundation of FIG. 11, in accordance with embodiments herein.

While the subject matter disclosed herein is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims.

DETAILED DESCRIPTION

Various illustrative embodiments of the disclosure are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will, of course, be appreciated that, in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

The present subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and to not obscure the present disclosure with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the present disclosure. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.

Embodiments herein are directed to mattresses comprising support layers comprising a curved channel.

Turning to FIG. 1, a stylized top view of a mattress 100, in accordance with embodiments herein, is illustrated. The mattress 100 has a generally rectangular profile in top view, with opposed shorter sides 103, 105 each having a dimension 101, and opposed longer sides 104, 106 each having a dimension 102. Typically, the shorter sides 103, 105 provide the head and foot ends, respectively, of the mattress 100, and the longer sides 104, 106 provide the sides of the mattress 100.

FIG. 2 illustrates a stylized side view of the mattress 100, in accordance with embodiments herein. The side view shows the longer side 104.

The mattress 100 includes an support layer 120 comprising at least one non-linear channel 122 extending laterally from a first side to an opposite side. By “non-linear” it is meant that the floor and the ceiling of the channel as seen in side view are generally not in a straight line, e.g., floor and the ceiling of the channel as seen in side view may be curved. In some embodiments, the curvature of the channel 122 may be a singular uniform curve, while in other embodiments, the curvature of the channel 122 may comprise a plurality of curves, which may or be uniform in some cases and non-uniform in other cases. In the exemplary embodiment of FIG. 2, the portion of the channel 122 near the middle of the mattress is higher than the portions of the channel 122 near the head and foot ends, respectively.

The channel 122 may permit airflow laterally through the mattress 100, which may provide a reduction in heating of the mattress 100 and/or cooling to the mattress 100. This may reduce the tendency of known foam mattresses to gather or retain increased temperatures, which may result in a “sleep hot” characteristic.

The support layer 120 also comprises a plurality of support members 124 disposed in the channel 122 (e.g., as shown in FIG. 2, tubular foam springs 124a-124h).

The support layer 120 may comprise a visco-elastic foam, a non-viscoelastic foam, or a polyurethane foam, among other materials. In one embodiment, the support layer 120 comprises a non-viscoelastic foam.

A variety of support members may be included in the channel 122 in the support layer 120. For example, the support members may be metal springs, plastic springs, air bladders, adjustable air bladders, or water bladders, among others known to the person of ordinary skill in the art. Particular support members included in the channel 122 in the support layer 120 will be described in more detail below.

The mattress 100 also comprises a comfort layer 130 disposed directly above the support layer 120. The comfort layer 130 may comprise any material and/or assemblage of sublayers suitable for providing comfort to a user reclining on the mattress 100. In one embodiment, the comfort layer 130 comprises a foam. In a particular embodiment, the comfort layer 130 comprises a viscoelastic foam. For example, the viscoelastic foam may have a density from about 25 kg/m³ to about 250 kg/m³, such as from about 50 kg/m³ to about 120 kg/m³. In an even more particular embodiment, the viscoelastic foam may have a density of about 80-85 kg/m³. Alternatively or in addition, the viscoelastic foam may have a hardness from about 5 N to about 20 N, such as a hardness of about 10 N. Alternatively or in addition, the comfort layer 130 may include a base sublayer and a pillow-top sublayer.

The support layer 120 and the comfort layer 130 may be bonded together by any suitable adhesive. The support layer 120 and the comfort layer 130 may be assembled using any process and/or equipment known in the art.

In other embodiments (not shown), the mattress 100 may include a polymeric material layer, such as a polyurethane layer, disposed under the support layer 120. If included, the polymeric material layer may comprise a foam (e.g., polyurethane foam) that may have any properties suitable for use in a base layer in a mattress. For example, the polymeric material layer may comprise a polyurethane foam having a density from about 10 kg/m³ to about 100 kg/m³. The polyurethane layer may be bonded to the support layer 120 by any suitable adhesive.

For the avoidance of doubt, and in accordance with practice before the United States Patent and Trademark Office, none of the present figures is to scale.

Embodiments of the support layer 120 will be described, in more detail, with reference to FIGS. 3-6. In one embodiment, each of the support members is selected from the group consisting of tubular foam springs 124a-124e, foam spheres 424 (described below with reference to FIG. 4), foam hemispheres (described below), and polygonal support members 624 (described below with reference to FIGS. 5-6.

Tubular foam springs 124a-124e generally having a tubular resilient body made of foam and forming an outer wall.

In the particular embodiment shown in FIG. 2, the channel 122 comprises a plurality of tubular foam springs 124, of which only one of the tubular foam springs 124a-124h are visible in the side view depicted in FIG. 2.

Turning to FIG. 3, a sectional view taken along the line A-A′ in FIG. 2 is shown. This sectional view looks down across the middle of the support layer 120. As shown, the channel 122 comprises sets of tubular foam springs 124a-124h, appearing as rounded features, configured within channel 122. The channel 122 may be formed from multiple support layer portions or by other techniques known to the person of ordinary skill in the art.

In another embodiment, FIG. 4 illustrates a stylized side view of a mattress 400. As shown in FIG. 4, the mattress 100 includes an support layer 420 comprising a channel 122 comprising a plurality of foam spheres 424a-424j. The foam spheres 424 may be arranged in sets laterally across the mattress 400, similarly to the sets of tubular foam springs 124a-124h depicted in FIG. 3. In the side view of FIG. 4, only a subset of the sets of foam spheres 424a-424j is visible in the channel 122. In some embodiments, the spacing between the foam spheres 424 may vary across the mattress 100. For example, a greater concentration of foam spheres 424 may be positioned in locations where a greater amount of support is desired, e.g., near shoulder regions, back regions, lower leg regions, and/or the like.

Each foam sphere 424 may comprise any known foam material. The foam spheres 424a-424j may provide relief to pressure points of a user reclining on the comfort layer 130 of the mattress 400.

Although FIG. 4 depicts foam spheres 424a-424j, in another embodiment, the support members may be a plurality of foam hemispheres (not shown), substantially the same as the foam spheres 424a-424j, differing in that the foam hemispheres are each disposed with a flat surface against the bottom of the channel 122. In alternative embodiments, the elements 424-a-424j may be a combination of spheres and hemispheres.

Even though FIGS. 2-5 depict mattresses 100, 400 comprising only tubular foam springs 124 or foam spheres 424, in embodiments, a mattress according to the present disclosure may comprise both tubular foam springs and foam spheres and/or hemispheres. Tubular foam spring and foam spheres/hemispheres may be mixed within one or more channels of an support layer 120 or 420, one or more channels may contain only one of tubular foam springs, foam spheres, or foam hemispheres, or both.

Although FIGS. 2-5 depict particular numbers of channels 122 or 422 and particular numbers of tubular foam springs 124 or foam spheres 424, the person of ordinary skill in the art having the benefit of the present disclosure will understand that variations in the number and sizes of channels and support members will be within the scope of the present disclosure.

Turning now to FIGS. 5-6, another embodiment of a mattress 500 in accordance with embodiments herein is shown.

Many of the elements of the mattress 500 are identical to elements of the mattresses 100 and 400. Such identical elements will be given the same reference numeral and will not be described further.

As shown in FIGS. 5-6, the support layer 120 of the mattress 500 may be considered to comprise at least a first zone and a second zone. The different zones may differ in ways that are differentially impactful on the perceived support of the mattress 500 to a user reclining thereon.

As shown in FIG. 5, each zone contains a portion of the channel 122 disposed laterally therein. Each of the first zone and the second zone have a density of support member rows, by which is meant one or both of: (a) the length of each zone divided by the number of rows of support members 624 per zone, or (b) a distance between neighboring support members 624 in the zone. In the embodiment depicted in FIG. 5, the mattress 500 is a standard North American queen or king mattress with a length of 80″ (203 cm). A first zone (e.g., near the head end 103 of the mattress 500) has a length of 30″ (76 cm) and a second zone (e.g., near the foot end 106 of the mattress 500) has a length of 50″ (127 cm). In the embodiment depicted in FIG. 5, the first zone comprises three rows of support members 624a-624c, and the second zone comprises five rows of support members 624d-624h. In both zones, the distance between neighboring channels is 4″ (10 cm). In this embodiment, accordingly, the first zone and the second zone have the same density of support member rows under either definition, (a) about 10″/row or (b) about 4″ between neighboring rows.

FIG. 6, a top sectional view of the mattress 500 taken along line B-B′ in FIG. 5, shows support members 624. The support members 624 may be polygon-shaped, i.e., of a pentagon shape, a hexagon shape, a heptagon shape, etc. These support members 624 may be capable of providing support while providing sufficient flexibility such that comfort is also provided.

FIG. 6 also shows that the first zone and the second zone may differ in the number of support members 624 per row 624a-624h. The number of support members 624 per row in each zone may be termed the “density of support members” of the zone. For example, as depicted in FIG. 6, the rows 624a-624c of the first zone may each contain five support members 624, whereas the rows 624d-624h of the second zone may each contain nine support members 624, i.e., the second zone has a greater density of support members than the first zone. Consequently, the second zone may be perceived by a user reclining on the mattress 500 as providing greater support than the first zone. If the second zone is located proximal to the foot 106 of the mattress 500, the second zone may hence provide greater support to the legs and/or lower back of the user than the first zone provides to the upper back and head of the user.

The embodiment shown in FIGS. 5-6 is of course exemplary in the number of rows 624a-j in the support layer 120, the number of zones of the support layer 120, the number of support members 624 in the rows of the first zone, and the number of support members 624 in the second zone. These figures are also exemplary regarding any dimension of the channel 122 and the support members 624. The person of ordinary skill in the art may vary these and other parameters of the mattress 500 as a routine matter.

Turning now to FIGS. 7-8, an alternative embodiment of a mattress 700 comprising a first zone and a second zone having differential impacts on perceived user support is depicted. The mattress 700 has many elements identical to elements of the mattresses 100, 400, and 500. Such identical elements will be given the same reference numeral and will not be described further.

As shown in FIG. 7, the support layer 120 of mattress 700 may be considered to comprise at least a first zone and a second zone. The exemplary mattress dimensions are the same as shown in FIG. 5. However, in contrast to the mattress 500 shown in FIG. 5, the first zone of the mattress 700 has a density of support member rows of (a) about 10″/row or (b) about 4″ between rows, whereas the second zone of the mattress 700 has a channel density of (a) 50″ divided by six rows, or about 8.33″/row or (b) about 3″ between rows. In other words, the mattress 700 of FIG. 7 has a first zone having a first density of support member rows and a second zone having a second density of support member rows, wherein the first density of support member rows differs from the second density of support member rows.

FIG. 8 shows a top sectional view of the mattress 700 taken along line C-C′ in FIG. 7. In FIG. 8, the first zone and the second zone have the same number of tubular foam springs 124 per row 124a-124j.

The embodiment shown in FIGS. 7-8 is of course exemplary in the number of rows 124a-124i in the support layer 120, the number of rows in each zone, the number of zones of the support layer 120, the number of tubular foam springs 824 in the channels 122 of the first zone, and the number of tubular foam springs 824 in the channels 122 of the second zone. For example, the channel 122 may comprise three zones, with a head zone and a foot zone each having more support members than a median zone therebetween. These figures are also exemplary regarding any dimension of the channels 122 and the tubular foam springs 124. The person of ordinary skill in the art may vary these and other parameters of the mattress 700 as a routine matter. Additionally, the tubular foam springs 124 may be substituted by foam spheres 424 and/or springs 624, as depicted and described in FIGS. 4-6, and vice versa.

In another embodiment, not shown, a mattress in accordance with embodiments herein may comprise a support layer 120 comprising a first zone and a second zone, wherein the first zone has one or more rows of support members at a first density of support member rows, and a first density of support members in each row, and the second zone has one or more rows of support members at a second density of support member rows, and a second density of support members in each row; wherein either the first density of support member rows differs from the second density of support member rows; the first density of support members in each row differs from the second density of support members in each row, or both.

FIGS. 2-8 have shown support layers 120 comprising a single channel 122. The depicted channel 122 has a single upward curve. FIGS. 9-10 depict exemplary embodiments of mattress 900 and 1000 that differ in number and/or curvature of channels.

Turning to FIG. 9, a mattress 900 is depicted comprising a wave-like channel 922. Disposed in the wave-like channel 922 is a plurality of rows of support members, such as tubular foam springs 124a-124h as described above.

In some embodiments, the wave-like channel 922 may resemble a sinusoidal wave, wherein the mattress may comprise a portion of a period, a full period, or a plurality of periods of the sinusoidal wave. Moreover, the frequency of the sinusoidal wave may vary across the mattress 900. For example, an increase in the frequency of the sinusoidal wave of the wave-like channel 922 may be positioned in locations where a greater amount of support is desired, e.g., near shoulder regions, back regions, lower leg regions, and/or the like.

FIG. 10 depicts a mattress 1000 comprising a curved channel 122 and two additional partial channels 1022a and 1022b. Each of the curved channel 122, the partial channel 1022a, and the partial channel 1022b comprise at least one row of support members, such as tubular foam springs 124a-124j as described above. For example, an increased number of partial channels 1022 may be positioned in locations where a greater amount of support is desired, e.g., near shoulder regions, back regions, lower leg regions, and/or the like.

The embodiments depicted in FIGS. 9-10 are exemplary. In embodiments wherein a support layer 120 comprises a wave-like channel 922, the wave may comprise a different number of wavelengths (herein referring to peak-to-peak distances) than the two wavelengths depicted in FIG. 9. Alternatively or in addition, if the wave comprises two or more wavelengths, the peak-to-peak distance may vary between wavelengths, i.e., some peaks may be closer to or further from one or more neighboring peaks than is true for other peaks. Other routine variations will be apparent to the person of ordinary skill in the art having the benefit of the present disclosure.

In embodiments wherein the support layer 120 comprises one or more partial channels 1022, the number of partial channels 1022, their locations, and/or the number of rows of support members in each partial channel 1022 may vary. Partial channels 1022 as depicted in FIG. 10 may be combined in a support layer 120 with a wave-like channel 922 as depicted in FIG. 9. In other embodiments, not shown, a support layer 120 may comprise only partial channels 1022.

In addition, though FIGS. 2-10 depict channels 122, 922, and 1022 as having a constant height, any channel 122, 922, or 1022 may include variations in height across either horizontal dimension (not shown). Alternatively or in addition, any support member(s) described herein may be used in any channel 122, 922, or 1022.

A variety of support layers 120 have been depicted in FIGS. 2-10. In embodiments wherein a mattress comprises one support layer, the support layer may be any one of the support layers 120, along with others not depicted but described herein. In such embodiments, a single support layer is simultaneously the bottom-most support layer and the uppermost support layer.

In embodiments wherein a mattress comprises two, three, or more support layers, each support layer may comprise any one of the support layers 120, along with others not depicted but described herein. Any one of the support layers 120, along with others not depicted but described herein may be duplicated in a mattress comprising two or more support layers. Alternatively or in addition, in any mattress comprising two or more support layers, any one of the support layers 120, along with others not depicted but described herein. may be arranged in any order, i.e., any support layer 120, or any other not depicted but described herein, may be the bottom-most support layer, the uppermost support layer, or at any position between the bottom-most and uppermost support layers.

In another embodiment, as depicted in stylized side view in FIG. 11, the present disclosure relates to a mattress assembly 1100, in accordance with embodiments herein. The mattress assembly 1100 comprises a mattress as described above, such as a mattress 100 comprising a channel 122 comprising at least one support member, e.g., rows of tubular foam springs 124a-124h. The depicted mattress 100 may further comprise a polyurethane layer 110 below the support layer 120.

The mattress assembly 1100 also comprises a mattress foundation 1140 disposed under the mattress 100. The mattress foundation 1140 may comprise any structure known to the person of ordinary skill in the art for the support of mattresses. Exemplary mattress foundations 1140 include, but are not limited to, box springs; metal frames; and adjustable supports, including electromechanically adjustable supports, among others.

FIG. 12 illustrates a stylized depiction of the mattress foundation of FIG. 11, in accordance with embodiments herein. In some embodiments, the mattress foundation may be comprised of two or more sections. For example, the mattress foundation 1140 may comprise a 1^st section 1240a, a 2^nd second section 1240b, a 3^rd section 1240c, and a 4^th section 1240d. Some or all of the sections 1240a-1240d may be configured to move independently, as indicated by the dotted lines over the 1^st section 1240a, the 3^rd section 1240c, and the 4^th section 1240d.

Each of the 1^st through 4^th section 1240a-1240d may be connected to pivot points to allow for independent movements. For example, the 1^st section 1240a and the 2^nd section 1240b may be movably coupled to a 1^st pivot point 1210a. In one embodiment, the 1^st section may move up and down about the 1^st pivot point 1210a. The 1^st section 1240a may be at the head of a bed.

The 2^nd section 1240b and the 3^rd section may be movably coupled to a 2^nd pivot point 1210b. In one embodiment, the 3^rd section may move up and down about the 2^nd pivot point 1210b.

The 3^rd section 1240c and the 4^th section 1240d may be movably coupled to a 3rd pivot point 1210c. In one embodiment, the 4^th section may move up and down about the 3^rd pivot point 1210c. In one embodiment, the 4^th section may be at the foot of a bed. Those skilled in the art would appreciate that additional sections and/or pivot points may be implemented onto the mattress foundation 1140 and remain with the spirit and scope of embodiments herein.

The particular embodiments disclosed above are illustrative only, as the disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the process steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is, therefore, evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the disclosure. Accordingly, the protection sought herein is as set forth in the claims below.

Claims

1. A mattress, comprising:

at least one support layer comprising at least one non-linear channel extending laterally from a first side to an opposite side, and a plurality of support members disposed in the channel.

2. The mattress of claim 1, further comprising a comfort layer disposed above the support layer.

3. The mattress of claim 2, wherein the comfort layer comprises a foam.

4. The mattress of claim 3, wherein the foam is a viscoelastic foam.

5. The mattress of claim 1, wherein each of the support members is selected from the group consisting of tubular foam springs, foam spheres, or foam hemispheres.

6. The mattress of claim 1, wherein the support layer comprises a non-viscoelastic foam.

7. The mattress of claim 1, further comprising a polyurethane layer disposed below the support layer.

8. A mattress assembly, comprising:

a mattress, comprising: at least one support layer comprising at least one non-linear channel extending laterally from a first side to an opposite side, and a plurality of support members disposed in the channel; and

a mattress foundation disposed under the mattress.

9. The mattress assembly of claim 8, further comprising a comfort layer disposed above the support layer.

10. The mattress assembly of claim 9, wherein the comfort layer comprises a foam.

11. The mattress assembly of claim 10, wherein the foam is a viscoelastic foam.

12. The mattress assembly of claim 8, wherein each of the support members is selected from the group consisting of tubular foam springs, foam spheres, or foam hemispheres.

13. The mattress assembly of claim 8, wherein the support layer comprises a non-viscoelastic foam.

14. The mattress assembly of claim 8, further comprising a polyurethane layer disposed below the support layer.

15. A mattress, comprising:

at least one support layer comprising at least one non-linear channel extending laterally from a first side to an opposite side, and a plurality of support members disposed in the channel; and

a viscoelastic foam layer disposed above the support layer.

16. The mattress of claim 15, wherein each of the support members is selected from the group consisting of tubular foam springs, foam spheres, or foam hemispheres.

17. The mattress of claim 16, wherein each of the support members is a tubular foam spring.

18. The mattress of claim 16, wherein each of the support members is a foam sphere or a foam hemisphere.

19. The mattress of claim 15, wherein the support layer comprises a non-viscoelastic foam.

20. The mattress of claim 15, further comprising a polyurethane layer disposed below the support layer.