Patent ID: 7704344
Filing Date: 2010-04-27
Classification: B29D

Abstract:
1. A tire building drum comprising: a pair of bead lock means adapted to be displaced toward and away from each other and expanded or contracted radially; carcass band folding-back means positioned adjacent to the bead lock means, respectively; a center shaft for supporting these means; a core body at an axial inside of said bead lock means, said core body comprising a plurality of rigid support members toroidally disposed and adapted to be radially displaced to thereby expand or contract the core body; and a center bladder, deformable for expansion or contraction, which extends at a radial outside of said core body, and which has both axial side portions adapted to be displaced toward and away from each other integrally with said bead lock means, respectively; wherein the center bladder is expandable or contractible independently of the movement of the rigid support members, both in axial and radial directions, and thereby fully expands a carcass band to a toroidal shape independent of the core body, and wherein the core body is constructed such that, in a partially radially expanded state to a height where axially opposite side surfaces of each of the rigid support members correspond to radial positions of bead cores, the axially opposite side surfaces of each of the rigid support members provide support from an axial inside for axially opposite side surfaces of the carcass band expanded to toroidal shape by the center bladder at a position corresponding to a radial position of bead cores when the carcass band folding-back means is actuated, and the core body being radially expandable to a maximum diameter to provide support for the toroidal carcass band over a full width to provide a solid bonding surface for assembling additional tire component members including belt members and a tread rubber.