Green tire building process and apparatus

A green tire building apparatus, comprising in combination:

• a tire building drum collapsible and rotatable for toroidally deforming a cylindrical green case having at least a carcass ply and a pair of beads embedded in both axial end portions of said carcass ply;
• a tread band building mechanism for jointing both longitudinal ends of a belt-like tread rubber to produce an endless tread band which has a circumferential length substantially equal to its final circumferential length measured when said endless tread band is to be assembled with said cylindrical green case;
• a breaker band building mechanism for jointing both longitudinal ends of a belt-like breaker ply to produce an endless breaker band which has a circumferential length shorter than its final building circumferential length measured when said endless breaker ply is to be applied on an inner periphery of said endless tread band;
• an applying drum collapsible and rotatable for receiving said endless tread band from said tread band building mechanism and supporting said endless tread band with said final building circumferential length, and for bringing said endless breaker band into alignment with said endless tread band in their mid-circumferential planes and radially expanding said breaker band its final building circumferential length;
• and
• an annular carrier mechanism expansible and capable of coaxially surrounding said building drum and said applying drum to permit said endless tread band with said final building circumferential length to be applied thereon and retained thereby, then to permit said endless breaker band to be radially outwardly expanded to said final building circumferential length so that said endless breaker band is applied on the inner periphery of said endless tread band to build a tread breaker assembly, and finally to permit said cylindrical green case to be toroidally deformed and applied on the inner periphery of said tread breaker assembly for production of a green tire.