Today the loading of heavy rolls at rotogravure presses is fully automated. The use of this pre-centering has proved indispensable in achieving this.
The paper roll with prepared splice arrives on the transfer stage by means of the MecaRoll system. For the loading action the transfer stage travels to the axis of the centering device and raises the roll until the photocells detect the roll centre. Now the actual centering action commences. The 2 centering arms with the centering cones are inserted into the roll core. Lateral deviations of the roll are equalised by means of the easily moved slewing rail; height deviations are detected by the linear transducer and independently corrected left and right by the hydraulics of the fine height adjustment. In the course of this action the roll is accurately centered and the roll width is compared with the preset nominal value. After this action the roll position is secured by means of pneumatic clamps, the centering arm is retracted and the roll is run-in for the loading process on to the reelstand. The attainable accuracy with this pre-centering is of the order of +/- 0.5 mm with reference to chucks of the reelstand.