Tire building drum

A tire building drum, comprising in combination:

• a plurality of base segments circumferentially arranged to define as a whole a cylindrical drum body and adapted to be radially expansible;
• a pair of side flange means disposed oppositely at axially outer positions of said base segments to be movable along the axial direction of the drum body toward and away from said base segments;
• a synchronized drum width changing means axially moving said side flange means toward and away from each other in synchronism with radial retraction and expansion of said base segments;
• and a drum width arranging means operated independently of said synchronized drum width changing means for adjusting a drum width measured along the axial direction of the drum body between said side flange means:
• characterized in that
• each of said side flange means includes a slide base provided axially movably toward and away from each of said base segments and a side flange axially movably toward and away from said slide base;
• and that
• said drum width arranging means includes:
• a pair of screw shafts having oppositely threaded portions which are in threaded engagement with said slide base and said side flange, respectively, for connecting said slide base and side flange,
• a rotary shaft having axially outer end portions axially slidably received in said screw shafts and rotatable in unison with said screw shafts, and
• a rotary shaft rotating mechanism provided at the central portion of said rotary shaft to transform a radial rotational force into an axial rotational force for transmitting the same to said rotary shaft,
• whereby said rotary shaft is rotated by said rotary shaft rotating mechanism to cause said side flange to be axially moved toward and away from said slide bases.