Modern rotogravure presses with rolls weighing up to 7 t require extremely accurate and stable transfer stage with integrated lifting device.
Automatic Reel Loading
The new, fully prepared roll arrives at the wait position directly in front of the reelstand. The automatic cycle for the loading is initiated by the splicing action. In a first step the core or past-used roll is taken directly from the reelstand arm by means of a Monorail core clamp. The new roll is positioned in the middle of the transfer stage. Then the platform travels to the pre-centering axis and lifts the roll. A photocell in the pre-centering device stops the lifting. Now the centering arm function commences. The centering cones are synchronously inserted into the core. Height deviations are corrected by the fine height adjustment. The fine height adjustment also permits the equalising of height differences left and right. The integrated slewing rail permits accurate lateral alignment of the roll. Once the roll is aligned, the position is blocked, the transfer stage runs to the load position and transfers the roll to the reelstand.
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 the chucks of the reelstand.
Core bin in use with an automatic unroller.
Core bin the unroller arm, ready to take up the cores.
Cores and part-used rolls weighing from 30 kg to 500 kg occur on rotogravure presses. As a result of the automatic roll loading, the cores also have to be automatically removed. This takes place either directly from the reel stand arm or from the core supports on the transfer stage.
Part-Used Rolls Remover with Monorail Gripper
For the removal of the cores, the core gripper either runs from the side by means of a monorail, directly in the axis of the reelstand arms or to the core supports of the transfer stage and automatically grips the core. This is lifted, removed from the reelstand zone and placed in a core basket. As an option a weighing scale can be incorporated in order to check the core and part-used roll weight. The entire range of movement is protected by a mesh barrier.