Tire building apparatus with improved drum shoulder

An expandable tire building drum having drum segments that have radially outwardly facing tire support surfaces and are each movable radially with respect to the hub of said drum between a retracted position and an expanded position, said drum segments also having shoulder portions adjacent to which are to be formed the bead filler portions of tires to be built on said building drum, wherein the improvement comprises:

• a shoulder segment hinged by a pivot connection to each of the shoulder portions of said drum segments, said shoulder segment being rotatable about said pivot connection between a raised position and a lowered position, said shoulder segment having a radially outwardly facing surface that in the raised position of said shoulder segment is level with the radially outwardly facing tire support surface of the drum segment to which the shoulder segment is hinged, said shoulder segment also having first and second abutments that face generally radially inwardly toward said hub of said drum,
• said drum having for each said shoulder segment a first shoulder segment fixed with respect to said hub, said first shoulder segment support engaging said first abutment on said shoulder segment when said drum segment is in said retracted position so as to maintain said shoulder segment in said raised position,
• said shoulder portion of said drum segment having a second shoulder segment support that engages said second abutment on said shoulder segment when said drum segment is in said expanded position so as to maintain said shoulder segment in said lowered position wherein said outwardly facing surface forms a bevelled corner on said drum segment for supporting the bead filler portion of a tire to the built on said building drum.