| 摘要 |
A plastic screw cap comprising a cylindrical cup provided with an internal thread and with a pilferproof ring which is connected to the rim of the cup by means of a plurality of bridges which form a circular fracture line, the ring having a plurality of internal flaps which are inclined towards the bottom of the cup; the pilferproof ring comprising a cylindrical wall, whose thickness is such that it is substantially flexible in a radial expansion direction, a rim which is connected to the rim of the cup by the bridges, and an opposite rim which is connected to an internal annular bead whose inside diameter is smaller than the inside diameter of the wall and whose thickness is significantly greater than the thickness of the wall, a plurality of flaps protruding from the region connecting the flexible wall and the internal annular bead and having such a thickness as to acquire substantial rigidity with respect to radial stresses. |
