IMPROVEMENTS IN CLOSURES FOR SCREW-THREADED CONTAINERS

摘要

A closure cap for a bottle or other container having an externally screw threaded neck is moulded in a tough thermoplastics material and has an internally threaded skirt (22) and a top panel (21). An inwardly directed lip (26) is provided on the skirt (22) between the top panel and the thread. The internal diameter of the lip is less than the nominal diameter of a co-operating sealing surface on the container neck and serves to retain an essentially annular lining (25) of more compressible material within the shell. The shell is also provided with an annular rib (27) on the underside of the top panel (21) and is dimensioned to fit within the mouth of the container. The axial extent of the rib (27) is preferably less than the space between the lip (26) and the top of the shell (21). The undersurface (28) of the lip (26) preferably slopes downwardly and inwardly. The lip (26) may have an intermediate portion of reduced thickness to promote flexing of the rib in the upward direction.