Tire building drum for the manufacture of tires

A building drum for building a tire, comprising;

• a support,
• a central shaft and an outer circumferential surface coaxial with the axis of rotation of the drum and comprising a principal cylindrical surface axially delimited on both sides by a shoulder extended by a lateral protuberance for receiving a bead of the tire,
• several segments extending between axial ends together defining the principal cylindrical surface,
• said segments being divided into first and second groups of adjacent segments mounted to move between an expanded position in which they are circumferentially juxtaposed and a retracted position in which adjacent segments are radially offset,
• wherein the building drum further comprises adjacent elbow levers,
• wherein each elbow lever includes a first arm that is pivotally attached to one of the axial ends of a segment in such a manner that, in the expanded position, said first arm extends substantially radially to form one of the shoulders and wherein said elbow lever further includes a second arm that extends axially outward from the first arm at a bend and that is pivotally attached to the support in such a manner that said second arm forms one of the protuberances so that in the expanded position, the second arm of the elbow lever extends axially outward beyond an adjacent one of the axial ends of the attached segment for engaging the bead of the tire.