| 摘要 |
PURPOSE:To make deep tread grooves easily in dropping and moving a peripheral segment inwardly by a method wherein a cam, whose inside inclines in the reverse direction against the inside of a fan-wise taperring, is projected on the upper surface of the outer periphery of the drag of a mold. CONSTITUTION:When a green tire B is mounted on the drag 1 and the cope 2 is dropped, a peripheral segment 5 falls with the cope 2 but after a cam groove 5d is fitted to the cam 9, the peripheral segment 5 is guided by the inner slide 9a of the cam 9 and falls in the direction of the arrow P. At the same time that the taper ring 2a touches the drag 1 the peripheral segment 5 arrives at the innermost end of the stroke and stops moving. Thus, as soon as the peripheral segment 5 moves inside, the peripheral segment 6 falls at the same speed as that of the tread part Ab of the green tire B to provide a tread groove of uniform depth. |
