| 摘要 |
<p>A paper roll braking device for rotary presses, in which a paper web (W) is drawn from a supply roll (WR) in a printing unit, comprising rotors (25) provided on supporting members for supporting the supply roll, braking sections provided at a plurality of locations along the rotors and having friction discs (21, 22, 23, 24) that can engage with, or disengage from, the rotors at their respective locations. Changeover sections for controlling the engagement of the friction discs with the rotors, and a mechanism (41) senses changes in the running tension of the web (W). The contact pressure between the friction discs and the rotors is adjusted via the changeover section in accordance with the changes in running tension detected by the tension sensing mechanism. A diameter section monitors the outside diameter of the supply roll, and a control section switches the changeover sections as the supply roll outside diameter reaches a predetermined diameter.</p> |
