US Patent 7444706 Bed construction with reduced sagging

A bed construction having a one-sided mattress assembly supported on a rigid foundation. The one-sided mattress assembly includes a core of pocketed coil springs having a layer of resiliently compressible material covering the upper surface thereof and having a bottom surface constructed of a substantially rigid material without a compressible layer. The core of coil springs is attached to the bottom surface around its periphery. The foundation has a rigid inner construction and a noncompressible top layer. The bed construction reduces the amount of compressible padding in the mattress by one-half and consequently the mattress is capable of exhibiting a substantial reduction in the amount of permanent deflection in use.