Abstract:
A futon mattress has a first support component formed from fabric batting, a second support component formed from convoluted foam and a separation layer interposed between the first support component and the second support component for preventing the migration of the fiber batting into the convoluted foam.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a mattress for use in connection with convertible furniture, such as futons. More specifically, the present invention pertains to a futon wherein mattress components are held spaced apart from one another to maintain the ability of the mattress to support weight and retain resiliency. 
     BACKGROUND OF THE INVENTION 
     In presently available convertible furniture, such as futons, the furniture includes a frame that is movable between an upright, seating position and a horizontal, sleeping position. The convertible furniture includes a mattress enclosed within a decorative covering that is placed on the furniture frame and acts as a cushion for the seat and back when the convertible furniture is in the upright position and functions as a mattress when the convertible furniture is in the horizontal, sleeping position. 
     Currently, the most common types of futon mattresses are formed from either cotton or wool batting or foam, or a combination thereof, to provide the required cushioning when the mattress is positioned in either the upright position or the sleeping position. Currently, futon mattresses having a foam core, such as fabricated from convoluted foam, are the most popular due to their light weight and superior cushioning capabilities. 
     When convoluted foam is used in current futon mattress designs, it is usually interposed between layers of fiber batting. The problem with this design is that as the futon mattress is used, the fiber batting migrates into the convolutions of the foam which effectively reduces the ability of the mattress to support weight and retain resiliency. It is the tendency of the fiber batting to migrate that makes futon mattresses with convoluted foam in their construction perform poorly for retained loft, retained resiliency, and body impression over time. 
     Accordingly, a need exists for a convertible furniture mattress that maintains separation between its fiber batting and convoluted foam layers in order to optimize the abilities of the foam to be supportive and resilient over time. There is also a need to select a material which will provide the desired separation between the fiber batting and convoluted foam layers as well as create different feels in the finished futon mattress. 
     SUMMARY OF THE INVENTION 
     It is a general object of the present invention to provide a futon mattress having cushioning which maintains a high degree of comfort and support over time. 
     It is also an object of the present invention to provide a futon mattress wherein fiber batting components are prevented from migrating into convolutions of foam components forming a core of the mattress. 
     It is a further object of the present invention to provide a futon mattress employing a separating layer or material interposed between cushioning components for optimizing the comfort factor of the mattress. 
     In one aspect of the invention, a futon mattress includes a first support component formed from fiber batting. A second support component is formed from convoluted foam. A separation layer is interposed between the first support component and the second support component for preventing the migration of the fiber batting into the convoluted foam. The fiber batting component includes a protective, decorative fabric material on an external surface thereof. The separation layer is comprised of a flexible, foraminous material, such as polypropylene netting. 
     In another aspect of the invention, a futon mattress includes an upper protective, decorative fabric material, and an upper fiber batting layer disposed adjacent to the upper protective, decorative fabric material. An upper flexible netting material is disposed adjacent to the upper fiber batting layer. An upper convoluted foam layer is disposed adjacent to the upper netting material. A lower convoluted foam layer is disposed adjacent to the upper convoluted foam layer. A lower fiber batting layer is disposed adjacent to the lower netting material. The lower protective, decorative fabric is disposed adjacent to the lower fiber batting layer. With this construction, the layers of netting material prevent the migration of the fiber batting layers into the convoluted foam layers thereby optimizing the ability of the convoluted foam layers to be supportive and resilient. The fiber batting layers, the netting layers and the convoluted foam layers are encased in a sleeve formed by the protective, decorative fabric materials. 
    
    
     Various other objects, features and advantages of the invention will be made apparent from the following description taken together with the drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate the best mode presently contemplated of carrying out the invention. 
     In the drawings: 
     FIG. 1 is a perspective view of a piece of convertible furniture having a mattress embodying the present invention; 
     FIG. 2 is a fragmentary, exploded view of the components of the mattress in a disassembled state, including separation layers for maintaining the spacing of the cushioning components; 
     FIG. 3 is a fragmentary, perspective view of the components of the mattress in an assembled state; 
     FIG. 4 is a sectional view taken on line  4 — 4  of FIG. 3; 
     FIG. 5 is a graphical representation of a mattress having a construction without the separation layers; and 
     FIG. 6 is a graphical representation of a mattress construction including the separation layers. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a piece of convertible furniture  10  having a frame consisting of a pair of side arms  12 , a back  14  and a seat support  16 . The back  14  and seat support  16  are movable from the upright, seating position shown in FIG. 1 to a horizontal, sleeping position in which the back  14  is horizontally aligned with the seat support  16 . 
     As can be seen in FIG. 1, when the frame of the convertible furniture  10  is in the upright, seating position, the mattress  18  acts as both the seat and back cushion. Likewise, when the frame of the convertible furniture  10  is moved to the horizontal, sleeping position, the mattress  18  lies flat and acts as a cushion for a person to sleep upon. 
     As discussed previously, conventional convertible furniture mattresses are typically formed from layers of fiber batting and a convoluted foam core. A problem arises that, over time, the fiber batting migrates or is forced into the spaces between peaks of the convoluted foam due to the weight of the mattress user. 
     In accordance with the present invention, the mattress includes a flexible, foraminous separation layer interposed or sandwiched between each fiber batting layer and each convoluted foam layer. Use of the separation layer serves to prevent the intrusion of the batting into the convoluted foam core so that the mattress maintains its optimal cushioning qualities. 
     Referring now to FIG. 2, the mattress  18  is comprised of an upper protective, decorative fabric material  20 , an upper fiber batting layer  22 , an upper separation layer  24 , an upper convoluted foam layer  26 , a lower convoluted foam layer  28 , a lower separation layer  30 , a lower fiber batting layer  32  and a lower protective, decorative fabric material  34 . 
     FIG. 3 shows the aforelisted components of the mattress  18  disposed one on top each other, the fiber batting layers  22 ,  32 , the separation layers  24 ,  30 , and the convoluted foam layers  26 ,  28  being encased in a sleeve like “tick” formed by the decorative fabric materials  20 ,  34  which are tufted together. Mattress  18  has a convoluted foam core defined by the upper and lower convoluted foam layers  26 ,  28 , respectively. Each layer  26 ,  28  is identical and includes one side  36  formed with a series of spaced apart foam peaks  38  and an opposite side  40  which has a continuous flat surface. The flat surfaces  40  of the convoluted foam layers  26 ,  28  are interfaced together. The fiber batting layers  22 ,  32  are typically fabricated from cotton or wool material. 
     A distinctive feature of the mattress  18  is the separation layer  24  or  30  which lies between the layers of fiber batting  22 ,  32  and the convoluted foam layers  26 ,  28 . Each separation layer  24  or  30  is preferably formed of a flexible, foraminous material, such as polypropylene mesh or netting, which effectively maintains the integrity of the convoluted foam layers  26 ,  28  so that they can continue to support various weights of users and retain resiliency. The invention contemplates that the size of the holes  42  in the netting  24  or  30  can be adjusted to create different feels in the mattress  18 . 
     Testing was performed on a mattress construction as shown in FIGS. 3 and 4 without the netting  24 ,  30  and with the netting. In each case, a six-sided 36 inch wide roller weighing 230 pounds was rolled over the upper protective, decorative fabric material 20 for 100,000 cycles, wherein each cycle includes moving the roller over the longitudinal center line of the mattress (36 inches total rolled area). This type of testing is meant to simulate real-life usage of the mattress. Height readings of the mattress  18  were taken before and after the roller test. The visual set data obtained from the testing resulted in a pre-test mattress height, a post-test mattress height, a set measurement defined by the difference in pre-test and post-test heights and a percentage set calculated by dividing the set measurement by the pre-test mattress height. 
     FIG. 5 shows a visual set profile for a layered mattress construction similar to FIGS. 3 and 4 but without the netting  24 ,  30 . The lighter line in the profile indicates the pre-test mattress height, and the darker line indicates the post-test mattress height. Without the netting  24 ,  30 , the batting layers  22 ,  32  migrate into the convoluted foam layers  26 ,  28  causing appreciable sag measured by a 17.9 percent set. 
     FIG. 6 shows a visual set profile for a layered mattress construction similar to FIGS. 3 and 4 with the netting  24 ,  30 . As can be seen from the profile, the degree of sag is markedly reduced relative to the mattress construction without the netting  24 ,  30 . With the netting,  24 ,  30  maintaining separation of the batting layers  22 ,  32  from the convoluted foam layers  26 ,  28 , the sag is calculated at a 10.7 percent set; that is, there is an approximate improvement of 40 percent in performance over the mattress  18  without the netting  24 ,  30 . The mattress  18  with the netting  24 ,  30  thus has a greater retained loft, greater retained resiliency and resists body impression over a greater period of time. 
     While the invention has been described with reference to a preferred embodiment, those skilled in the art will appreciate that certain substitutions, alterations and omissions may be made without departing from the spirit thereof. Accordingly, the foregoing description is meant to be exemplary only, and it should not be deemed limitative on the scope of the invention as set forth with the following claims.