Method for expanding and contracting a drum of a one-hole type tire building drum apparatus and a tire building drum apparatus

摘要

The present invention comprises a plurality of segments (5) that operate together with a moving body moving along the main axis (1) to enlarge or reduce the diameter of the drum, an operating air chamber and a returning air chamber, The moving body is moved in a direction to enlarge the diameter of the drum, and when the air is discharged, the moving body is moved in a direction to reduce the diameter of the drum by the pressure of the storage air in the return air chamber.;According to the present invention, since the segment 5 is enlarged and reduced by using the transfer device, unstable elements such as the bladder 7, the return spring S and the like resulting from enlarging and reducing the drum portion D can be eliminated Stability and promptness can be ensured. In addition, since the consumable parts are small, the time and effort during replacement can be reduced and continuous operation is possible, which can improve the productivity.