Bottle cap with tamper ring

Claim 1

A closure cap for a bottle or similar container having a threaded neck, said cap including a downwardly extending cylindrical skirt (3) comprising a body portion having internal screw threads (5) that mate with said threaded neck and a retaining band (7) having an inwardly directed projection (9) the lower face of which is angled inwardly to allow it to be forced over an annular collar on the neck of the bottle, said retaining band (7) including a vertical rupturable line (13,14) formed by a vertical cut (13) through said band (7) with vertical interruptions and being interconnected to said body portion by an interconnecting wall (8) of uniform thickness and of an external diameter smaller than that of said body portion; the interconnecting wall (8) including narrower frangible portions (12) and a wider portion (12') adjacent to said vertical rupturable line (13,14), whereby upon unscrewing of the closed cap the retaining band (7) becomes detached from said skirt (3) except at said wider portion (12') and becomes split apart along said vertical rupturable line (13,14), characterised in that said portions (12,12') of said interconnecting wall (8) are formed by interruptions between a plurality of cut segments (11') aligned and located inside said interconnecting wall in a circular fashion and axially spaced from said body portion such that the axial extent of the cut segments is substantially less than the axial extent of said interconnecting wall and the interruptions (12) are substantially smaller than the segments (11') apart from one interruption (12') which is at least twice the length of the adjacent segments (11'), that said retaining band (7) and said inwardly directed projection (9) are of uniform circular configuration, and that there is a single vertical rupturable line the upper end of which is interconnected with one of the ends of a cut segment (11').