Riso V8000 Series, Technical Manual

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CHAPTER 6. PAPER DRUM SECTION
Mechanism
1. Paper Drum Mechanism
For normal rotation, the paper drum is driven by the main motor; for master loading and super low speed
rotation, it is driven by the main pulse motor.
The position of the paper drum is determined by the position T sensor. The precise position of the paper
drum is confirmed by the main motor limit sensor using the position from position T sensor as a datum
position.
In standby mode after printing is complete, the stop position for the paper drum is 150° from position T.
2. Gripper Open/Close Mechanism
The gripper is normally open, closing only when paper is fed from the second paper feed section. It
opens when transferring paper to the ejection section.
The gripper open/close mechanism consists of the following three actions:
(1) The leading edge of the paper is gripped by the opening and closing action of the grippers.
(2) The gripper cover opens and closes to prevent the grippers from protruding and damaging the
master on the print drum.
(3) The paper lifter moves up and down when transferring the paper to the paper ejection section to
ensure positive separation of the paper from the paper drum and to prevent paper jams.
All of these actions are performed by cam followers.
The grippers are opened and closed by gripper cam (paper drum side) at the rear of the machine.
The gripper cover is opened and closed by the gripper cover cam at the front of the machine.
The paper lifter is moved up and down by the rear gripper cam at the rear of the machine.