Abstract:
A box spring ( 9 ) having a rigid perimeter wall ( 16 ) to provide a firm foundation to support an edge of a mattress ( 1 ) where individuals normally sit. A layer of coil springs ( 20 ) rests on a center portion ( 2 ) of the box spring and extends above the rigid perimeter wall to provide active support to a center portion of the mattress where individuals normally lie.

Description:
FIELD OF THE INVENTION 
     This invention relates to mattresses, more particularly, a framed box spring having a raised layer of coil springs surrounded by a frame that provides rigid support to the edges of a mattress while the raised coil springs provide an active support for the center portion of the mattress. 
     BACKGROUND OF THE INVENTION 
     A box spring is the part of a bed that provides a foundation for and supports the mattress. The box-spring is usually the same size as the mattress which is placed above the box-spring. Conventional box springs are typically made of a frame covered in cloth that provides a hard foundation. Alternatively, box springs may have a frame having an upper layer of springs attached thereto. The purpose of the box spring is to reduce wear on the mattress by absorbing shock and to create a flat and firm structure for the mattress to lie upon. However, with conventional box springs only one of these two objectives may be met depending on the structure of the box spring. For example, a conventional box spring made solely of a frame provides a flat firm structure but does not absorb shock. Alternatively, a box spring having a frame with an upper layer of springs absorbs shock but does not provide a firm foundation for the outer perimeter of the mattress. Having a firm outer perimeter is important to provide support to individuals sitting on the edge of the mattress. 
     Therefore, a need exists for a box spring that provides a firm foundation for supporting the perimeter of a mattress while also providing an active foundation to support the center portion of a mattress. 
     The relevant prior art includes the following references: 
     
       
         
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 Pat. No. 
                   
                   
               
               
                   
                 (U.S. Patent 
                   
                 Issue/Publication  
               
               
                   
                 References) 
                 Inventor 
                 Date 
               
               
                   
                   
               
             
             
               
                   
                 3,080,576  
                 Cervisi 
                 Mar. 12, 1963 
               
               
                   
                 3,945,627  
                 Simon 
                 Mar. 23, 1976 
               
               
                   
                 3,992,732  
                 Cervisi 
                 Nov. 23, 1976 
               
               
                   
                 4,083,069 
                 Glickman 
                 Apr. 11, 1978 
               
               
                   
                 4,236,262 
                 Spiller 
                 Dec. 02, 1980 
               
               
                   
                 4,519,107 
                 Dillon et al. 
                 May 28, 1985 
               
               
                   
                 4,685,162 
                 Higgins et al. 
                 Aug. 11, 1987 
               
               
                   
                 5,319,815 
                 Stumpf et al. 
                 Jun. 14, 1994 
               
               
                   
                 7,748,066 
                 Gladney 
                 Jul. 06, 2010 
               
               
                   
                   
               
             
          
         
       
     
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a box spring that provides a film foundation for supporting the perimeter of a mattress while also providing an active foundation to support the center portion of a mattress. 
     The present invention fulfills the above and other objects by providing a box spring having a framed edge to provide a firm foundation to support a perimeter edge of a mattress. The framed edge is rigid, thereby allowing firm support of a semi-rigid perimeter of a mattress. This support is needed to support the perimeter edge of the mattress which individuals sit on in an upright position and expect firmer support. A layer of coil springs rests on a base and extends a predetermined distance above the framed edge to provide active support and shock absorption to a center portion of the mattress on which individuals lay and expect to be softer than the outer edge of the mattress. 
     An alternative embodiment of the invention replaces the layer of coil springs with a one or more layers of foam that extends a predetermined distance above the framed edge of the box spring. 
     The above and other objects, features and advantages of the present invention should become even more readily apparent to those skilled in the art upon a reading of the following detailed description in conjunction with the drawings wherein there is shown and described illustrative embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following detailed description, reference will be made to the attached drawings in which: 
         FIG. 1  is a top perspective partial cutaway view of a conventional mattress; 
         FIG. 2  is a top perspective view of an uncovered conventional box spring having a conventional frame supporting an upper layer of springs; 
         FIG. 3  is a top perspective view of an uncovered conventional box spring having only a conventional frame and no springs; 
         FIG. 4  is a top perspective view of an uncovered box spring of the present invention; 
         FIG. 5  is a top perspective partial cutaway view of an uncovered box spring of the present invention; 
         FIG. 6  is a side view of an uncovered box spring of the present invention; and 
         FIG. 7  is a top perspective view of a covered box spring of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     For purposes of describing the preferred embodiment, the terminology used in reference to the numbered accessories in the drawings is as follows:
           1 . conventional mattress     2 . center portion of mattress     3 . perimeter encasement     4 . foam panels     5 . conventional box spring     6 . conventional frame     7 . upper layer of coil springs     8 . upper surface of conventional frame     9 . box spring of the present invention     10 . frame     11 . lower portion of frame     12 . upper portion of frame     13 . rectangular perimeter     14 . cross support     15 . vertical support     16 . perimeter wall     17 . upper edge of perimeter wall     18 . lower edge of perimeter wall     19 . panel     20 . spring     21 . upper protective layer     22 . raised center portion of box spring       

     With reference to  FIG. 1 , a top perspective partial cutaway view of a conventional mattress is illustrated as an example of the prior art. The conventional mattress  1  comprises a core center portion  2  made up of various layers of foam to create the main body of the mattress  1 . The mattress may also have a center portion  2  comprising coil springs or a combination of springs and foam. The core  2  is surrounded and framed by a foam perimeter encasement  3  around the perimeter edge that is constructed out of foam panels  4  having a height equal to that of the center portion  2 . By using a foam encasement  3 , the center portion  2  is prevented from spreading outward when an individual is lying on the mattress  1 . In addition, the encasement  3  provides a more rigid support for individuals sitting on the edge of the mattress. 
     With reference to  FIG. 2 , a top perspective view of an uncovered conventional box spring  5  having a conventional frame  6  supporting an upper layer of springs  7  is illustrated as an example of the prior art. The upper layer of springs  7  extends across the entire upper surface  8  of the conventional frame  6 , thereby providing no rigid support to the perimeter encasement  3  of the mattress (as illustrated in  FIG. 1 ). As illustrated, the upper layer of springs  7  are substantially U-shaped springs but may also be coil springs. 
     With reference to  FIG. 3 , a top perspective view of an uncovered conventional box spring  5  having only a conventional frame  6  and no springs  7  is illustrated as an example of the prior art. The conventional frame  6  only provides only rigid support, thereby failing to provide and active support or shock absorption to center portion  2  the mattress  1  (as illustrated in  FIG. 1 ). 
     With reference to  FIGS. 4 ,  5  and  6 , a top perspective view of an uncovered box spring  9  of the present invention and a top perspective partial cutaway view of an uncovered box spring  9  of the present invention and a side view of an uncovered box  9  spring of the present invention, respectively, are illustrated. The box spring  9  comprises a frame  10  having a lower portion  11  and an upper portion  12 . The lower portion  11  comprises an outer rectangular perimeter  13  having torsion bars or cross supports  14  located between the rectangular perimeter  13 . Vertical supports  15  extend upward from the rectangular perimeter  13  to support the upper portion  12  of the wood frame  10 . The upper portion  12  comprises a rectangular shaped perimeter wall  16  having an upper edge  17  and a lower edge  18 . Cross supports  14  extend between the perimeter wall  16  proximal to the lower edge  18  to create a support for a panel  19 , which may be a rigid material or a fabric material, that provides further support for springs  20  located within the perimeter wall  16  above the panel  19 . The coil springs  20  preferably have a height that is greater than the perimeter wall  16  so the coil springs  20  extend above the upper edge  17  of the perimeter wall  16 . Although not illustrated here, a foam core comprising one or more layers of foam may be located within the perimeter wall  16  and have a height that is greater than the height of the perimeter wall. The foam core may be separate or in addition to one or more layers of coil springs  20 . As illustrated in  FIG. 6 , the coil springs  20  extend above the upper edge  17  of the perimeter wall  16  and are covered by one or more upper protective layers  21  to provide additional active support for the mattress  1 . The one or more upper protective layers  21  may be foam, fiber, cloth and so forth. 
     With reference to  FIG. 7 , a top perspective view of a covered box spring  9  of the present invention is illustrated. The box spring  9  has been covered in fabric  22 . The coil springs  20  that extend above the perimeter wall  16 , as illustrated in previous figures, create a raised center portion  22  on the box spring  9  that provides an active support to the center portion  2  of a mattress  1  while the perimeter wall  16  of the frame  10  provides a rigid foundation to support the perimeter encasement  3  of the mattress. 
     It is to be understood that while a preferred embodiment of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and drawings.