Foam mattress with progressive support characteristics and method for manufacturing the same

Abstract

A mattress includes top and bottom foam layers. A bottom surface of the top foam layer and a top surface of the bottom foam layer include protrusions and recessions. The protrusions of the top surface of the bottom foam layer protrude into the recessions of the bottom surface of the top foam layer, and the protrusions of the bottom surface of the top foam layer protrude into the recessions of the top surface of the bottom foam layer. The most protruded surfaces of the protrusions of the bottom surface of the top foam layer are separated from corresponding surfaces of the recessions of the top surface of the bottom foam layer by a channel, but there is no channel between most protruded surfaces of the protrusions of the top surface of the bottom foam layer and corresponding surfaces of the recessions of the bottom surface of the top foam layer.

What is claimed is:  
     
         1 . A mattress comprising:
 a top foam layer; and   a bottom foam layer,   wherein a bottom surface of the top foam layer comprises a series of protrusions and recessions,   wherein a top surface of the bottom foam layer comprises a series of protrusions and recessions,   wherein the protrusions of the top surface of the bottom foam layer protrude into the recessions of the bottom surface of the top foam layer,   wherein the protrusions of the bottom surface of the top foam layer protrude into the recessions of the top surface of the bottom foam layer,   wherein most protruded surfaces of the protrusions of the bottom surface of the top foam layer are separated from corresponding surfaces of the recessions of the top surface of the bottom foam layer by a channel,   and wherein there is no channel between most protruded surfaces of the protrusions of the top surface of the bottom foam layer and corresponding surfaces of the recessions of the bottom surface of the top foam layer.   
     
     
         2 . The mattress according to  claim 1 , wherein the most protruded surfaces of the protrusions of the top surface of the bottom foam layer are adhered to the corresponding surfaces of the recessions of the bottom surface of the top foam layer by an adhesive, and
 wherein no adhesive exists between the most protruded surfaces of the protrusions of the bottom surface of the top foam layer and the corresponding surfaces of the recessions of the top surface of the bottom foam layer.   
     
     
         3 . The mattress according to  claim 1 , further comprising first ventilation channels formed in the top surface of the bottom foam layer,
 wherein the first ventilation channels extend between opposing side end surfaces of the bottom foam layer in a width direction of the mattress, the width direction extending perpendicular to a head-to-foot length direction of the mattress.   
     
     
         4 . The mattress according to  claim 1 , further comprising second ventilation channels extending in a height direction of the mattress from a top surface of the top foam layer to the bottom surface of the top foam layer. 
     
     
         5 . The mattress according to  claim 1 , wherein a height of the channel in a direction perpendicular to the top surface of the bottom foam layer is at least 0.25 inches. 
     
     
         6 . The mattress according to  claim 5 , wherein the height of the channel in the direction perpendicular to the top surface of the bottom foam layer is less than 1.5 inches. 
     
     
         7 . The mattress according to  claim 1 , wherein the mattress is configured to provide progressively firmer support characteristics as force applied to a top surface of the mattress increases. 
     
     
         8 . A method for manufacturing a mattress, the method comprising:
 cutting a first foam member in half to form first and second top layers, a bottom surface of the first top layer comprising a series of protrusions and recessions and a top surface of the second top layer comprising a series of protrusions and recessions opposite to the series of protrusions and recessions of the first top layer;   cutting a second foam member in half to form first and second bottom layers, a bottom surface of the first bottom layer comprising a series of protrusions and recessions and a top surface of the second bottom layer comprising a series of protrusions and recessions opposite to the series of protrusions and recessions of the first bottom layer; and   positioning the first top layer on top of the second bottom layer such that the protrusions of the top surface of the second bottom layer protrude into the recessions of the bottom surface of the first top layer and the protrusions of the bottom surface of the first top layer protrude into the recessions of the top surface of the second bottom layer;   wherein the cutting the first foam member in half and the cutting the second foam member in half are performed such that, when the first top layer is positioned on top of the second bottom layer, most protruded surfaces of the protrusions of the bottom surface of the first top layer are separated from corresponding surfaces of the recessions of the top surface of the second bottom layer by a channel, and there is no channel between most protruded surfaces of the protrusions of the top surface of the second bottom layer and corresponding surfaces of the recessions of the bottom surface of the first top layer.   
     
     
         9 . The method according to  claim 8 , further comprising positioning the second top layer on top of the first bottom layer such that the protrusions of the bottom surface of the first bottom layer protrude into the recessions of the top surface of the second top layer, and the protrusions of the top surface of the second top layer protrude into the recessions of the bottom surface of the first bottom layer,
 wherein the cutting the first foam member in half and the cutting the second foam member in half are performed such that, when the second top layer is positioned on top of the first bottom layer, most protruded surfaces of the protrusions of the top surface of the second top layer are separated from corresponding surfaces of the recessions of the bottom surface of the first bottom layer by a channel, and there is no channel between most protruded surfaces of the protrusions of the bottom surface of the first bottom layer and corresponding surfaces of the recessions of the top surface of the second top layer.