| 摘要 |
The end wall (1) of a screw cap (A) of rigid thermoplastics material is provided with a sealing ring (3) of heat-polymerised plastisol and the cylindrical skirt (2) of the cap has an internal multiple thread at its upper end, an intermediate opening tear-strip (5), and a lower part (7) with an internal annular engagement rib (8) which snap-engages under an annular rib (13) of triangular cross-section situated below the thread (12) of the threaded neck (B) of a rigid container. The annular rib (8) of the cap (A) is interrupted in a plurality of zones (9) and the neck (B) of the container has a corresponding plurality of projections (16) which extend downwards from the base of the triangular rib (13) and, upon completion of the first screwing on of the cap (A), are each positioned in one of the interrupted zones (19) of the rib (8) of the cap (A), so as to prevent both a limited accidental unscrewing of the cap and the overtightening of the cap, and thus prevent the seal of the closure from being compromised in both cases. |
