FOLDING BACK DEVICE OF TUBE FOR ROLLER

PURPOSE:To fold back the excess length part of a tube for roller with good workability by a method wherein the excess length part of the tube for roller is diametrically expanded by the predetermined amount by diametrically expanding expanders with a pair of tube expanding mechanism and, after that, the expanders are moved with moving mechanism so as to fold back the excess length part to the outer peripheral surface of a mold. CONSTITUTION:Under the condition that the tips of respective expanders 39a are inserted in the excess length part 5a of a tube 5 for roller, the respective expanders 39a are diametrically expanded with a pair of tube expanding mechanism so as to diametrically expand the excess length part 5a to the dimension larger than the outer diameter of a mold 1. Next, the respective expanders 39a are moved to the outer peripheral surfaces at both ends of the mold 1 with their moving mechanism so as to fold back the expanded excess length part 5a to the outer peripheral surface of the mold 1. Thus, the excess length part 5a of the tube 5 for roller is automatically and diametrically expanded by the predetermined dimensions and can be folded back in a short period of time on the outer peripheral surface of the mold 1 without developing twisting and breaking.