Mattress and supporting structure therefor

Claim 1

A sleeping unit, comprising, a flexible deck for supporting a mattress, said deck having a perimeter comprising two sides, a head and a foot, said deck having an upper mattress supporting surface which in transverse planes is convex and in longitudinal planes is concave, said longitudinal concavity being greatest at the sides of the mattress supporting surface and decreasing progressively toward the center of the mattress supporting surface, said transverse convexity being greatest in a midportion of the deck and decreasing progressively toward the head and foot of the deck, said mattress supporting surface having a longitudinal centerline which is concave, a foldable frame which surrounds the perimeter of said deck, said frame having a horizontal head rail, a horizontal foot rail and two side rails; connecting means of the frame for subjecting the flexible deck to substantially horizontal tensile forces in longitudinal and transverse directions to give the mattress supporting surface its said concavity and convexity when there is no vertical load on the deck, said substantially horizontal tensile forces in transverse directions being disposed along lines which are concave and lie in vertical longitudinal planes on opposite sides of the deck, a mattress having a perimeter comprising a pair of longitudinal edges and a pair of transverse edges, said mattress having an upper surface which is generally smooth in the respect that it has no localized depressions and no localized protrusions for accommodating the anatomy of a person sleeping thereon, said mattress having an area of maximum thickness at a location which is spaced inwardly from said transverse edges and is positioned over said longitudinal centerline to provide an enhanced cushioning effect, said perimeter including an area of minimum thickness of the mattress, said mattress having a taper which extends from said area of maximum thickness to said area of minimum thickness, said mattress having a lower surface which is supported on and conforms to the mattress supporting surface of the deck.