The device structure is in the form of 3-roller hydraulic symmetrical type. The up roller is in the central position over two bottom rollers, it vertical lifting up and down through hydraulic oil in cylinder acting on the piston. The two bottom rollers are main driven rollers, they do rotation movement, and to supply torque of the device through the output gear of gear box meshes with bottom rollers gear. The construction of the device is compact, easy to operate and maintain.
