FIELD OF THE INVENTION

[0001] The present invention relates to body supports, and more particularly to mattresses.

BACKGROUND OF THE INVENTION

[0002] Mattresses are typically utilized to support a user's body or a portion thereof while the user rests, relaxes, and the like. Mattresses including foam often provide desirable qualities such as softness and resiliency; however, such foam mattresses typically inhibit dissipation of water vapor away from the user supported on the mattress.

SUMMARY OF THE INVENTION

[0003] The invention provides, in one aspect, a body support including a surface for supporting a user, a core having a top layer, and a cover. The top layer of the core includes reticulated viscoelastic foam. The cover encloses the core and includes a porous material positioned adjacent the top layer of the core. The porous material and the reticulated viscoelastic foam facilitate dissipation of water vapor at the surface of the body support, thereby reducing a relative humidity at the surface of the body support.

[0004] Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a perspective cutaway view of a body support in accordance with one embodiment of the invention.

[0006] FIG. 1 A is a detailed view of a portion of the body support shown in FIG. 1.

[0007] FIG. 2 is an exploded, enlarged cross-sectional view of the body support of

FIG. 1.

[0008] FIG. 3 is a perspective cutaway view of a body support in accordance with another embodiment of the invention. [0009] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

[0010] FIG. 1 illustrates a body support 1 including a core 4 and a cover 8 enclosing or surrounding the core 4. In the illustrated embodiment, the body support 1 is configured as a mattress 12, though other configurations may be employed. The core 4 includes a top layer 16 made of reticulated viscoelastic foam. Reticulated viscoelastic foam has characteristics that are well suited for use in the mattress 12, including an enhanced ability to permit fluid movement through the reticulated viscoelastic foam top layer 16, thereby providing enhanced air or water vapor movement within, through, and away from a top surface 20 of the mattress 12.

[0011] Reticulated foam is a cellular foam structure in which the cells of the foam are essentially skeletal. In other words, the cells of the reticulated foam are each defined by multiple apertured windows surrounded by struts. The cell windows of the reticulated foam can be entirely gone (leaving only the cell struts) or substantially gone. For example, the foam may be considered "reticulated" if at least 50% of the windows of the cells are missing (i.e., windows having apertures therethrough, or windows that are completely missing and therefore leaving only the cell struts). Such structures can be created by destruction or other removal of cell window material, or preventing the complete formation of cell windows during the manufacturing process.

[0012] With continued reference to FIG. 1, the reticulated viscoelastic foam top layer

16 includes a thickness Ti of about 5 cm. In other embodiments, the reticulated viscoelastic foam top layer 16 may have a thickness Ti up to about 7 cm, by way of example. The reticulated viscoelastic foam top layer 16 of the illustrated embodiment has substantially planar top and bottom surfaces 24, 28 (see FIG. 2). In other embodiments, one or both of the top and bottom surfaces 24, 28 may have multiple protrusions extending from the reticulated viscoelastic foam top layer 16. The protrusions may, for example, be generally conical in shape, may be frusto-conical, or may have rounded tips. In still other embodiments, the protrusions may be, but are not limited to, pads, bumps, pillars, and other localized protrusions, ribs, waves (e.g., having a smooth, sawtooth, or other profile), and other elongated protrusions, and the like.

[0013] In addition, in some embodiments the reticulated viscoelastic foam top layer

16 can have a hardness of at least about 20 N and no greater than about 110 N. In other embodiments, the reticulated viscoelastic foam top layer 16 can have a hardness of at least about 30 N and no greater than about 90 N, or at least about 40 N and no greater than about 75 N. Unless otherwise specified, the hardness of a material referred to herein is measured by exerting pressure from a plate against a sample of the material to a compression of 40% of an original thickness of the material at approximately room temperature (e.g., 21 to 23 degrees Celsius). The 40% compression is held for a set period of time, following the International Organization of Standardization (ISO) 2439 hardness measuring standard.

[0014] In some embodiments, the reticulated viscoelastic foam top layer 16 can have a density of no less than about 60 kg/m ³ and no greater than about 1 10 kg/m ³ . In other embodiments, the reticulated viscoelastic foam top layer 16 can have a density of no less than about 70 kg/m ³ and no greater than about 100 kg/m ³ , or no less than about 80 kg/m ³ and no greater than about 90 kg/m ³ .

[0015] With reference to FIGS. 1A and 2, the cover 8 includes a porous material to facilitate dissipation of water vapor from the surface 20 of the mattress 12 and into the reticulated viscoelastic foam top layer 16. In the illustrated embodiment, the cover 8 includes a top textile 36 quilted, sewn, or otherwise secured to a spacer fabric 40 positioned adjacent the reticulated viscoelastic foam top layer 16 of the core 4. In some embodiments by way of example, the top textile 36 is a double jersey textile commercially available from Sunds Textiles A/S of Sunds, Denmark and [iDC & HQ] DesleeClama Group of Geluveld (Zonnebeke), Belgium, while the spacer fabric 40 is commercially available from E. Cima, S.A.U of Barcelona, Spain. In other embodiments, the top textile 36 may be a pique textile or a polyester textile.

[0016] The spacer fabric 40 includes spaced substrates 44 with monofilaments 48 extending between the substrates 44 (FIG. 1A). In the illustrated embodiment of the cover 8, the spacer fabric 40 has a thickness T ₂ (FIG. 2) of at least about 4 mm and no greater than about 16 mm. In other embodiments, the thickness T ₂ may be at least about 7 mm and no greater than about 13 mm, or about 10 mm. The monofilaments 48 interconnect the substrates 44 of the spacer fabric 40, and are generally oriented orthogonally to the substrates 44 (FIG. 1A). The monofilaments 48 maintain a spacing or gap between the substrates 44, thereby permitting an airflow created by natural convection currents to occur between the substrates 44. Such an airflow promotes dispersion or dissipation of moisture or water vapor away from the top surface 20 of the mattress 12.

[0017] With reference to FIG. 1, the core 4 of the illustrated embodiment further includes an intermediate layer 52 supporting the reticulated viscoelastic foam top layer 16 and made of viscoelastic foam. In the illustrated embodiment, the intermediate layer 52 is made of non-reticulated viscoelastic foam, although the intermediate layer 52 can instead be made of reticulated viscoelastic foam in other embodiments. Viscoelastic foam (whether reticulated or otherwise) is sometimes referred to as "memory foam" or "low resilience foam." Coupled with the slow recovery characteristic of viscoelastic foam, the viscoelastic foam intermediate layer 52 can at least partially conform to the user's body or body portion (e.g., head, hips, feet, and the like, hereinafter referred to as "body"), thereby distributing the force applied by the user's body upon the mattress 12. The mattress 12 can provide a relatively soft and comfortable surface for the user's body.

[0018] With continued reference to FIG. 1 , the viscoelastic foam intermediate layer

52 includes a thickness T3 of about 6 cm, although other thicknesses can instead be used. The viscoelastic foam intermediate foam layer 52 has substantially planar top and bottom surfaces 56, 60 (FIG. 2). In other embodiments, one or both of the top and bottom surfaces 56, 60 may have multiple protrusions extending from the viscoelastic foam intermediate layer 52. The protrusions may, for example, be generally conical in shape, may be frusto-conical, or may have rounded tips. In still other embodiments, the protrusions may be, but are not limited to, pads, bumps, pillars, and other localized protrusions, ribs, waves (e.g., having a smooth, sawtooth, or other profile), and other elongated protrusions, and the like.

[0019] In some embodiments, the viscoelastic foam intermediate layer 52 has a hardness of at least about 20 N and no greater than about 100 N for desirable softness and body-conforming qualities. In other embodiments, the viscoelastic foam intermediate layer 52 can have a hardness of at least about 40 N and no greater than about 90 N. In still other embodiments, the viscoelastic foam intermediate layer 52 can have a hardness of at least about 60 N and no greater than about 80 N.

[0020] The viscoelastic foam intermediate layer 52 can also have a density providing a relatively high degree of material durability. The density of the viscoelastic foam intermediate layer 52 can impact other characteristics of the mattress 12, such as the manner in which the mattress 12 responds to pressure, and the feel of the mattress 12. In some embodiments, the viscoelastic foam intermediate layer 52 has a density of no less than about 30 kg/m ³ and no greater than about 150 kg/m ³ . In other embodiments, the viscoelastic foam intermediate layer 52 can have a density of at least about 40 kg/m ³ and no greater than about 135 kg/m ³ . In still other embodiments, the viscoelastic foam intermediate layer 52 can have a density of at least about 50 kg/m ³ and no greater than about 120 kg/m ³ .

[0021] In other embodiments, the intermediate layer 52 may be made of a high mobility foam. Such a high mobility foam intermediate layer may have a hardness of at least about 50 N and no greater than about 1 10 N. In still other alternative embodiments, the high mobility foam intermediate layer may have a hardness of at least about 60 N and no greater than about 100 N, or at least about 70 N and no greater than about 90 N. In some embodiments, the high mobility foam intermediate layer may have a density of no less than about 15 kg/m ³ and no greater than about 65 kg/m ³ . Alternatively, the high mobility foam intermediate layer may have a density of no less than about 25 kg/m ³ and no greater than about 55 kg/m ³ , or no less than about 35 kg/m ³ and no greater than about 45 kg/m ³ . In some embodiments, the high mobility foam intermediate layer may have a ball rebound of greater than about 40%. In other embodiments, the high mobility foam intermediate layer may have a ball rebound of greater than about 50%, or greater than about 60%.

[0022] In still other embodiments, the intermediate layer 52 may be made of an extra soft foam. The extra soft foam intermediate layer may have a hardness of at least about 20 N and no greater than about 75 N. In still other alternative embodiments, the extra soft foam intermediate layer may have a hardness of at least about 30 N and no greater than about 65 N, or at least about 40 N and no greater than about 55 N. In some embodiments, the extra soft foam intermediate layer may have a density of no less than about 35 kg/m ³ and no greater than about 85 kg/m ³ . In other embodiments, the extra soft foam intermediate layer may have a density of no less than about 45 kg/m ³ and no greater than about 75 kg/m ³ , or no less than about 55 kg/m ³ and no greater than about 65 kg/m ³ . [0023] With reference to FIG. 1 , the core 4 further includes a bottom layer 64 supporting the top and intermediate layers 16, 52 and made of high resiliency foam. In this regard, it should be noted that the core 4 need not necessarily include an intermediate layer 52, in which case the core 4 can comprise a top layer 16 and an underlying bottom layer 64 with the properties and qualities described herein.

[0024] In some embodiments, the high resiliency foam bottom layer 64 has a thickness T4 of about 11 cm. Alternatively, the high resiliency foam bottom layer 64 may have a thickness T ₄ of about 14 cm, by way of example. The high resiliency foam bottom layer 64 of the illustrated embodiment has a substantially planar bottom surface 68 and a top surface 72 having multiple protrusions 74 extending from the high resiliency foam bottom layer 64 (see FIG. 2). The protrusions 74 can be generally conical in shape, can be frusto- conical, or can have rounded tips as shown in FIG. 2. In other embodiments, the protrusions 74 can be, but are not limited to, pads, bumps, pillars, and other localized protrusions, ribs, waves (e.g., having a smooth, sawtooth, or other profile), and other elongated protrusions, and the like. Alternatively, the high resiliency foam bottom layer 64 may have a substantially planer top surface 72.

[0025] In some embodiments, the high resiliency foam bottom layer 64 can have a hardness of at least about 80 N and no greater than about 250 N. In other embodiments, the high resiliency foam bottom layer 64 can have a hardness of at least about 100 N and no greater than about 230 N, or at least about 130 N and no greater than about 210 N. The high resiliency foam bottom layer 64 can have a density of no less than about 10 kg/m ³ and no greater than about 80 kg/m ³ . In other embodiments, the high resiliency foam bottom layer 64 can have a density of no less than about 20 kg/m ³ and no greater than about 65 kg/m ³ , or no less than about 30 kg/m ³ and no greater than about 55 kg/m ³ . In some embodiments, the high resiliency foam bottom layer 64 can have a ball rebound of greater than about 40%. In still other embodiments, the high resiliency foam bottom layer 64 can have a ball rebound of greater than about 45%, or greater than about 50%. As used herein, "ball rebound" refers to the rebound of a steel ball in a test according to ASTM D 3574 "Standard Test Methods for Flexible Cellular Materials".

[0026] FIG. 3 illustrates a second embodiment of the mattress 12 in which like features to those of the embodiments described in connection with FIGS. 1-2 are identified with like reference numerals with the letter "a." The mattress 12a includes top, intermediate, and bottom layers 16a, 52a, 64a having thicknesses Ti, T ₃ , and T ₄ of about 7 cm, about 7 cm, and about 6.5 cm, respectively, by way of example. The core 4a also includes an additional intermediate layer 76 made of high resiliency foam and supporting the top and intermediate layers 16a, 52a. The additional intermediate layer 76 has a thickness T ₅ of about 6.5 cm (again, by way of example only), and has a substantially planar bottom surface 80 and a top surface 84 having multiple protrusions 88 extending from the additional intermediate layer 76. The protrusions 88 can be generally conical in shape, can be frusto-conical, or can have rounded tips as shown in FIG. 3. In other embodiments, the protrusions 88 can be, but are not limited to, pads, bumps, pillars, and other localized protrusions, ribs, waves (e.g., having a smooth, sawtooth, or other profile), and other elongated protrusions, and the like. Alternatively, the additional intermediate layer 76 may have a substantially planer top surface 84.

[0027] When supported upon either of the mattresses 12, 12a, the user is in contact with the top surface 20, 20a of the mattress 12, 12a. The user produces vapor (e.g., water vapor) by transpiration, which includes evaporation from the user' s skin, evaporation of sweat produced by the user, and respiratory evaporation. Such transpiration alters or increases the relative humidity at the top surface 20, 20a of the mattress 12, 12a. High relative humidity (e.g., above 60%) can feel uncomfortably wet to the user, while low relative humidity (e.g., below 25%) can feel uncomfortably dry to the user. The relative humidity at the top surface 20, 20a of the mattress 12, 12a is maintained at a comfortable level as a result of an airflow created by natural convection currents throughout the cover 8, 8a and the reticulated viscoelastic foam top layer 16, 16a. Such an airflow facilitates and/or promotes dissipation of the water vapor away from the top surface 20, 20a of the mattress 12, 12a to prevent the relative humidity at the top surface 20, 20a from rising to an uncomfortable level for the user.

[0028] A "microclimate" surrounding the user on the mattress 12, 12a can be tested by placing the mattress 12, 12a in a climate-controlled room, positioning a test dummy on the top surface 20, 20a of the mattress 12, 12a, and covering the test dummy with a duvet. Within the test dummy is a humidification device and fans for uniformly distributing and circulating moisture generated by the humidification device outside the test dummy. Sensors are placed between the test dummy and the top surface 20, 20a of the mattress 12, 12a upon which the test dummy is supported. The sensors measure the relative humidity in this microclimate, thereby providing insight into the ability of the mattress 12, 12a to facilitate dissipation of water vapor away from the top surface 20, 20a of the mattress 12, 12a.

[0029] Such testing was performed to confirm that both of the reticulated viscoelastic foam top layer 16, 16a of the core 4, 4a and the porous material of the cover 8, 8a individually contributed to an overall reduction in relative humidity at the top surface 20, 20a of the mattress 12, 12a compared to the relative humidity measured at the top surface of a conventional foam mattress including a non- reticulated viscoelastic foam top layer. Specifically, the testing indicated that the reticulated viscoelastic foam top layer 16, 16a provided a reduction in relative humidity at the top surface 20, 20a of the mattress 12, 12a of about 8.3%, while the porous material of the cover 8, 8a provided an additional reduction in relative humidity at the top surface 20, 20a of the mattress 12, 12a of about 2.9% to about 5.3%. It is expected that different configurations of the cover 8, 8a can provide larger or smaller reductions in relative humidity at the top surface 20, 20a of the mattress 12, 12a, for example, about 2.0% to about 8.0%, or about 2.5% to about 6.5%. Also, the cover 8, 8a and the reticulated viscoelastic foam top layer 16, 16a cooperate to provide a surprising level of humidity control for the user that may otherwise not have been possible in existing mattresses.

[0030] Various features of the invention are set forth in the following claims.