Drum to build and form a belt tire

Abstract

A drum to build and form a belted tire, having a central support element, the central portion of which consists of radially slidable segments, and two bead retainers arranged at both sides of said support element, the spacing of said bead retainers being axially adjustable symmetrically with respect to the support element, the bead retainers having, at their circumference, radially expandable, integrally formed rings arranged to be brought into engagement with the tire in an air-tight manner, wherein the support element has an integrally formed rigid cases between the central portion and the bead retainers, the rigid cases being fixedly connected to the side of the bead retainers facing the central portion, the contact face of each rigid case facing the central portion being bevelled, the segments of the central portion which are arranged between the two cases engage the bevelled contact faces of the cases, are retained by springs and are similarly bevelled at the place of contact with the cases, whereby when the distance between the bead retainers and the distance between the cases is decreased, the segments automatically extend radially outwardly and the cases slide underneath the segments and wherein the side of the ring facing the tire bead is cylindrical.