US Patent 10357115 Foam mattress with symmetrical wavy foam layers

A symmetrical zoned foam mattress includes an upper foam layer with a wavy lower side and a lower foam layer with a wavy upper side. The lower layer has top, middle and bottom lateral valleys. The wavy lower side of the upper layer is glued to the wavy upper side of the lower layer. The top lateral valley has a minimum located within eighteen inches of the top head end of the lower layer. The bottom lateral valley has a minimum located within eighteen inches of the bottom foot end of the lower layer. A center plane intersects the lower foam layer at a minimum of the middle lateral valley. The minimum of each of the top and bottom lateral valleys is about fifteen inches from the end of the mattress regardless of whether the consumer chooses to use the top or bottom end as the head of the mattress.