Abstract: The method for filling a soft, flexible, thin-walled inflatable bladder with a fluid medium to a predetermined extent that comprises; folding a portion of the soft, flexible, thin-wall of the bladder and engaging the fold in predetermined pressure engagement between opposing clamping surfaces of a clamping device and thereafter introducing fluid medium into the bladder to fill it. The fold slides from engagement between the surfaces when the tensile forces directed onto and through the wall by the fluid medium delivered into the bladder exceed the holding force exerted by the clamping device.

Abstract: A water mattress includes an outer bladder for retaining water and an inner chamber assembly for inhibiting wave motion within the bladder. The chamber assembly includes multiple chambers each having a bottom sheet and a closure sheet, and the bottom sheet being deformed to provide the bottom and sides of the chamber. Adjacent chambers are joined along a single seam to form the chamber assembly. In a preferred method, the bottom sheet is heated and drawn into a vacuum form where it is cooled to permanently deform the sheet into an integral, multiple chamber, seamless configuration.

Abstract: A water mattress includes an outer bladder for retaining water and an inner chamber assembly for inhibiting wave motion within the bladder. The chamber assembly includes multiple chambers each having a bottom sheet and a closure sheet, and the bottom sheet being deformed to provide the bottom and sides of the chamber. Adjacent chambers are joined along a single seam to form the chamber assembly. In a preferred method, the bottom sheet is heated and drawn into a vacuum form where it is cooled to permanently deform the sheet into integral, multiple chamber, seamless configuration.