Abstract: An overlay mattress includes a foil mattress of plastic material in a surrounding envelope of textile material. The foil mattress has channels and a preferably self-closing valve for filling air into the channels that are also at least partly filled with fibers of so-called ball fiber and/or with foam plastics, at least in such an amount that the plastic material of the foil mattress is mutually separated. The channels extend transversely to the longitudinal direction of the mattress, and the channels are interconnected via air passages. Methods of manufacturing such an overlay mattress are also disclosed.

Abstract: The present invention relates to a non-return valve (100) intended to be joined to a container (11) for air or liquids. The non-return valve is formed of non-rigid plastic or rubber material (1, 15), which forms reliable, tight non-return valve function in an opening channel (2) of the non-return valve. The invention is primarily characterized in that a resilient device (5) is arranged in a channel (50) arranged on the side of the opening channel (2) of the non-return valve and that said resilient device (5) extends from one side (52) of the channel (50) to the opposite side (52) of said channel (50). The invention also relates to a method for producing in a common stage the non-return valve together with a container (11) or for joining said non-return valve to a container (11) after the production of the non-return valve.