Patent Publication Number: US-2011047708-A1

Title: Mattresses with heat dissipation

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application is a nonprovisional application and claims the benefit of U.S. Provisional Application No. 61/239,386, filed Sep. 2, 2009, the complete disclosure of which is hereby incorporated by reference 
     This application is also related to copending U.S. application Ser. No. 12/619,286, filed Nov. 16, 2009, the complete disclosure of which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of mattresses, and in particular with mattresses having various layers, including a fibrous air circulation layer disposed between separate cushion layers. 
     It is becoming more common to provide cushion layers on top of a mattress core. Examples of such cushion layers include foam materials, such as visco, latex and polyurethane. However, when laminating such layers together, the glue being placed between the layers may result in a “hard spot” where the two layers are joined by the glue. Moreover, the glue prevents the layers from adequately stretching. The mattresses of the invention address these and other issues. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides a wide variety of mattresses having various cushion layers with a fibrous air spacer layer positioned between at least one of the cushion layers. For example, in one embodiment a mattress is constructed of a core and cushion layer that is positioned above the core. A fibrous air spacer layer (also referred to as an air spacer layer or spacer fabric) is positioned above the cushion layer, and a layer of visco-elastic foam is positioned above the fibrous layer. In this way, the fibrous layer is sandwiched between the cushion layer and the layer of visco-elastic material. In some cases, cushion layer may comprise a polyurethane foam. Also, in certain embodiments, an air spacer layer could also be positioned between the core and the cushion layer, and the core in some cases could have a modified surface layer. 
     In certain embodiments, the fibrous air spacer layer may be positioned between various layers in a mattress. For instance, the fibrous air spacer layer may be positioned between layers of cushion layers, such as between two layers of viscoelastic foam. As another example, the fibrous air spacer layer may sit between two layers of latex foam, or between combinations of various foams, such a viscoelastic, latex, polyurethane and the like. As yet another example, the air spacer layer could sit atop essentially any type of firm core (spring, foam, latex or the like) and a topper layer (which may comprise any type of cushioning material configured to loosely rest on the core). In other embodiments, the layers between which the fibrous air spacer layer sits could have their surfaces modified (so that they are not planar). The surfaces of these layers could be altered using SMT (surface modified technology) or by profile cutting. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a perspective view of one embodiment of a fibrous air spacer layer according to the invention. 
         FIG. 2  is a side view of the fibrous air spacer layer of  FIG. 1   
         FIG. 3  is an exploded perspective view of one embodiment of a mattress having a fibrous air spacer layer according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS 
     The invention provides a wide variety of mattresses that may be constructed of a variety of materials. The mattresses may be constructed of a wide variety of cores, such as box spring cores, individually wrapped spring cores, spring steel cores, latex rubber cores, air cores, gel cores, and the like. However, it will be appreciated that the invention is not limited to the specific type of core that is used, but rather on the layers that are positioned above or beneath such a core. Also, it will be appreciated that in some cases a core may not be needed and the various cushion layers as described herein may provide adequate cushioning to function as a mattress or support layer for a user. In most applications, the mattress will be a typical bed mattress that is long and wide enough to support a user while sleeping. However, it will be appreciated that the principles of the invention may be used with other types of cushioning, such as seat cushions, couches, chairs, and the like. 
     Positioned above or beneath the core are one or more cushion layers which provide additional comfort to the user. Examples of such layers are visco-elastic foams, latex foams, polyurethane foams, gels, coils, air, and the like. Such foam layers may have a wide variety of densities, hardnesses, indentation deflection pressures, thicknesses and the like. However, for visco-elastic layers, the thickness will typically be in the range from about 0.5 inch to about 8 inches. For latex foams, the thicknesses will generally be in the range from about 0.5 inch to about 6 inches, and for polyurethane foams, the thickness will typically be in the range from about 0.25 inch to about 15 inches. 
     One important feature of the invention is that the fibrous air spacer layer is positioned between two of the cushion layers and/or between the cushion layer and the core. One example of a fibrous cushion layer  10  is illustrated in  FIGS. 1 and 2 . As shown, fibrous air spacer layer  10  is constructed of multiple strands of fibers  12  and which sit between a honey comb layer  14 . The fibers are loosely arranged so that air may circulate between the fibers. Also, honey comb layer  14  provides a convenient way to bond the fibrous air spacer layer  10  between other layers. In one specific embodiment, fibrous air spacer layer  10  may be constructed of a three-dimensional spacer or polyester fabric that is constructed of two warp-knitted layers which are connected by pile mono filaments in a single knitting process. In another embodiment, fibrous air spacer layer  10  may be constructed of two covering layers that are held apart from each other by a pile layer. In turn, the pile layer is made up of pile threads which provide a degree of elasticity to the layer. A textile construction process is used to make the layer, with its physical properties being determined by the material used to make the pile and the thread composition. One example of spacer fabrics that can be used include the Space Air®, Flex and Space Com textiles, available from Pressless GmbH. Another type of material that can be used for layer  22  is commercially available from Mueller Textile of Wiehl, Germany. Further, one specific type of fibrous air spacer layer is described in published U.S. Application No. 2007/021705, incorporated herein by reference. Typically, fibrous air spacer layer  10  will have a thickness in the range from about 1/16 inch to about 2 inches. In certain embodiments, other fibrous materials may be used. For example, fiberballs, such as those described in copending U.S. application Ser. No. 12/619,286, filed Nov. 16, 2009 and incorporated herein by reference could be used. Also, in some cases the air spacer layer  10  can be constructed to have different degrees of firmness. For example, some could be more firm while others are more plush. This helps with the overall posture of the mattress, affecting the degree how firm or how plush the mattress feels to the user. Further, different air spacer layers could be used in combination, with some being more firm while others are more plush. In some cases, air spacer layer  10  could include a gel material incorporated into part of the fibers, such as in a bottom portion of the layer Such a gel material serves to transfer heat away from the adjacent cushion layers while also permitting airflow through the fibers in the air layer that do not have the gel. This has the benefit of using two heat transfer mechanisms to remove heat from the adjacent cushion layers. 
     Referring now to  FIG. 3 , one specific embodiment of a mattress  20  will be described. Mattress  20  is constructed of a polyurethane layer  22  which may optionally have a surface modified top surface  24 . This may be accomplished using a SMT process, by profile cutting and the like. Also, it will be appreciated that any of the layers of mattress  20  could be surface modified or planar or combinations thereof. Polyurethane layer  22  may be positioned on top of a core or may alternatively function as the core itself. Examples of cores to which layer  22  may be attached include traditional spring coil cores, pocket spring cores, air cores, latex cores and the like. Typically, polyurethane layer  22  will have a thickness in the range from about 1 inch to about 12 inches. Laminated to polyurethane layer  22  is a visco layer  26  which may have a thickness in the range from about 0.5 inch to about 4 inches and may optionally have a surface modification. Laminated to visco layer  26  is a fibrous air spacer layer  28 . Optionally, or in addition to, an air spacer layer may be placed between layers  22  and  26 . Finally, laminated to air spacer layer  28  is another visco layer  30 . Air spacer layer  28  will typically have a thickness in the range from about 1/16 inch to about 2 inches, and visco layer  30  will have a thickness in the range from about 0.5 inch to about 3 inches. 
     While one specific embodiment has been described in connection with  FIG. 3 , it will be appreciated that fibrous air spacer layer  28  could be placed in other locations as well, such as between polyurethane layer  22  and visco layer  26 . Also, each of the cushion layers in  FIG. 3  could also be made of different materials. For example, polyurethane layer  22  could be constructed of latex, visco, a gel, an inflatable bladder, or the like. Similarly, visco layers  26  and/or  30  could be constructed on a polyurethane, latex, gel, an inflatable bladder, or the like. Hence, in one arrangement, layers  22  and  26  could both be made of latex, with air spacer layer  28  positioned between them. Further, some of these layers could be eliminated, such as layer  22 . As another example, layers  22  and  26  could be used, with layer  28  placed between them, and with layer  30  being eliminated. In other cases, air spacer layer  28  could be placed between the core and a topper layer. This topper layer is loosely held on top of a firm core and may comprise one or more layers of padding materials. In some cases, the air spacer layer  28  could also be included in the topper layer itself. 
     By using fibrous air spacer layer  28 , a number of significant advantages are achieved. First, by using fibrous air spacer layer  28 , improved air circulation is provided between the various layers. With the mattress of  FIG. 3 , air circulation is provided between the two visco layers  26  and  28 . However, as previously described, air circulation could be provided between other layers, such as between a visco layer, latex layer and/or polyurethane foam layers. This provides for a more hygienic and comfortable sleeping environment. 
     Another significant advantage is that air spacer layer  28  provides improved heat dissipation through and around the various cushion layers, including layers  22 ,  26  and  30 . This also provides for a more hygienic and comfortable sleeping environment. Fibrous air spacer layer is particularly useful when placed adjacent one of the visco layers as the visco foam material tends to trap the user&#39;s body heat. By providing air circulation beneath the other surface of the visco layer, heat is able to travel through the visco foam and to be dissipated from the other surface, thereby providing a cooler sleeping environment. 
     Another feature is that moisture transported and dissipated through the layers is increased, leading to a more sanitary and hygienic sleeping environment. 
     Further, because most laminating methods involve gluing multiple layers of foams, viscose and latex together in the cushion or support layers, “hard spots” result where the two layers are joined together. This is uncomfortable for the user and also prevents the layers from stretching. By gluing the various comfort or support layers to fibrous air spacer layer  28 , fibrous air spacer layer  28  functions as a stretchable spacer fabric and also eliminates the hard spot where the foams would normally be attached to each other. Because fibrous air spacer layer  28  is stretchable, it functions as a stretchable spacer fabric to allow the layers to be more pliable. 
     The invention has now been described in detail for purposes of clarity and understanding. However, it will be appreciated that certain changes and modifications may be practiced within the scope of the appended claims.