Expandable bead molding ring of the tire mold for

摘要

PROBLEM TO BE SOLVED: To simplify the structure of a mold using a radially expandable bead molding ring for molding an undercut bead.;SOLUTION: The hub 209, clamp ring 208b and lock ring 266 of a molding press 220 fall and the expandable bead molding ring 252 is expanded outwardly in its radial direction by the contact of cam surfaces 258 and 267 (first stage operation). After the outer periphery of the bead molding ring 252 comes into contact with a side wall molding plate 202b and the expansion of the bead molding ring 252 is stopped, the bead molding ring 252 and an upper spring plate 260 move outwardly (downwardly) in an axial line direction (second stage operation. By this constitution, the bead molding pocket 240b corresponding to a desired undercut bead shape is formed.;COPYRIGHT: (C)2003,JPO