| 摘要 |
<p>A building up drum for tyre prodn. has expanding bellows and two circumferential edges for laying the seam of the carcass to form the beads. The o.d. of the drum, including the contracted bellows, approaches the i.d. of the bands of carcass material in the initial unstretched state. The circumferential edges lie on radially expanding bearers with an approx. cylindrical surface. Each bearer axially joins the bellows, and when expanded the o.d. of the bearers is the i.d. of the unstretched bands. The machine has a device to expand and contract them. Provides simple system to operate, eliminates expanding, necking or folding the seam area, and is of simple construction.</p> |
