Patent ID: 8181802

Claim:
A closure device comprising: a base ( 1 ) having an aperture ( 13 ) arranged within a surface of predetermined configuration; a top ( 23 ) having an aperture ( 27 ) arranged within a surface of complementary configuration to the surface of the base, the surface of the top being positioned adjacent to the surface of the base so as to inhibit the passage of material between the two surfaces; the arrangement being such that the top ( 23 ) is adapted to be movable substantially laterally relative to the base ( 1 ) between a first position in which the aperture ( 13 ) of the base and the aperture ( 27 ) of the top are not in alignment and a second position in which the apertures are in alignment, and biasing means ( 22 , 43 ) provided within the top so as to extend substantially laterally between the base and the top with a free end of the biasing means urging the top towards the first position in which the apertures ( 13 , 27 ) are not in alignment, the biasing means ( 22 ) including a resilient member extending substantially radially outwardly from the base ( 1 ) towards the top ( 23 ), the top ( 23 ) being provided with inwardly extending webs ( 42 ) to restrict lateral movement of the biasing means ( 22 ).