Valve for closing cavities which are to be foam-filled

A valve for use in introducing a foamable reactive mixture into a cavity, with the valve capable of being positioned within the cavity and when so-positioned is in contact with at least one of the walls of the cavity, with the valve comprising:

• a) two essentially rotationally symmetrical coaxial cages, comprising an outer cage and an inner cage, said outer cage surrounding said inner cage, with the inner cage
• i) having an axial opening for the introduction of the reactive mixture and at least two radial openings for the passage of the reactive mixture into the annular space formed between the inner and the outer cage;
• ii) having a ball, capable of moving freely within said inner cage and capable of closing the inlet opening following completion of the introduction of the reactive mixture by falling downwards through gravity;
• iii) having a convex surface opposite said inlet opening, with said convex surface being directed inward, so that during the introduction of the reactive mixture the ball is positioned outside the inner cage axis and between said inlet opening and said convex surface;
• and
• b) with said outer cage having at least one radial opening for the passage of the reactive mixture from said annular space to said cavity, with the sizes of said axial opening and said radial openings being such that
• 1) the total cross-sectional area defined by all of the radial openings in said inner cage is at least twice the cross-sectional area defined by said axial opening and
• 2) the total cross-sectional area defined by all of the radial openings in said outer cage is at least twice the total cross-sectional area defined by all of the radial openings in said inner cage.