Plastic screw closure

A plastic screw closure intended for sealing a bottle with a threaded bottle neck (10) having an outside diameter (D), an inside diameter (d), a thickness (1/2|D−d|) defined therebetween, an upper outer edge, and an inner surface, said screw closure, before being secured on the bottle neck to which said closure is to be applied, comprising:

• a top plate portion (2) which is substantially in the form of a circular disc;
• a substantially cylindrical peripheral portion (1) extending from said top plate portion, said peripheral portion having a screwthread (8) adapted to cooperate with the threaded bottle neck and a substantially cylindrical bead (5) adjacent said top plate portion;
• a substantially cylindrical deformable sealing strip (4) extending axially from said top plate portion (2) inward of said bead and having an inside diameter (2r2) which is smaller than the outside diameter (D) of the thread bottle neck;
• and
• a substantially cylindrical sealing olive (3) extending axially from said top plate portion (2) inward of said deformable sealing strip (4) and having, at least at a portion substantially opposite said deformable sealing strip, an outside diameter (2R1) greater than the inside diameter (d) of the threaded bottle neck (10),
• wherein when said closure is fitted onto the threaded bottle neck:
• said sealing olive is adapted to radially deform inwardly and seal at least substantially along the inner surface of the threaded bottle neck,
• said deformable sealing strip is adapted to radially deform outwardly at least as large as or greater than the radial inward deformation of said sealing olive and seal at least substantially along the upper outer edge of the threaded bottle neck, and
• said cylindrical bead is adapted to press said sealing strip against the threaded bottle neck.