Patent ID: 6234227
Filing Date: 2001-05-22
Classification: B29D

Abstract:
A shaping drum for accommodating bead rotation in the manufacture of a tire on the drum, the drum including two bead holding systems mounted opposite each other on a central shaft, each bead holding system comprising:a support movable axially relative to the shaft,a plurality of rigid segments distributed in a circular array around the shaft, an articulation for mounting an axially outer end of each segment on the support for swinging motion of an axially inner end about the articulation from a retracted position to a bead clamping position, an elastic membrane at least partially covering the rigid segments, a bead seat formed in the segments axially inside the articulations, an axially outer fastening and an axially inner fastening fixing the membrane on the support, the membrane defining a stretchable span between the two fastenings which stretchable span extends above the bead seats and around the swinging inner ends of the segments, the distance of the span of the membrane from the axially outer fastening to the axially inner swinging ends of the segments in retracted positions being greater than three times the width of the bead seat and the span of the membrane between the axially inner fastening and the inner ends of the segments in retracted positions being greater than the width of the bead seat,the said drum further comprising means for introducing a pressurizing fluid into the space about the central shaft for shaping the tire.