The final drive is given to all the 4-sets of rollers of the drive unit in special models, providing better traction to the job. However, in that case a de-clutching arrangement is provided to the top rollers, in order to protect the gear boxes, as when the job hits the top rollers first while loading, forcing it to rotate via. the self locking gear box. The roller housings of this type of machine are hinged to the beds and open up automatically when a larger diameter job is introduced. For step less speed variation, AC Variable Frequency Drive is used. Dual Drive arrangement synchronizes with Single Variable Drive with interlocking. Manual anti-drift mechanism for idler unit.
