Ricoh C231 Service Manual page 454

PAPER FEED
6.7.5 PRINTING PRESSURE MECHANISM
[H]
[I]
When not in the printing cycle, the two solenoids [A] stay off and the stoppers [B]
lock the brackets [C] to keep the press roller [D] away from the drum.
When the 1st sheet of paper is fed, the solenoid is energized but the brackets
are still locked by the stoppers due to strong tension from the springs [E]. When
the high points of the cams [G] on the front and rear drum flanges reach the cam
followers [F] on both sides of the press roller shaft, a small clearance is made
between the stoppers and the brackets.
The two solenoid plungers are pulled down at the same time, releasing the
stoppers from the brackets. Printing pressure is applied by tension from the
springs [E] when the cam followers [F] come off the high points of the cams [G].
During the printing cycle, the solenoids stay on. However, if paper does not
reach the registration sensor [H] at the proper time (when the cam follower is on
the high point of the cam), the solenoids are de-energized to lock the brackets.
The printing pressure is released when the cams push down the cam followers
so that the press roller does not contact the master clamper [I].
After printing is finished, the solenoids de-energize and the springs push the
stoppers back. Before the drum returns to the home position, the stoppers lock
the brackets again when the cams push down the cam followers.
6.7.6 RE-FEEDING MECHANISM
If the registration sensor detects a non-feed, the machine tries again. However, if
the machine detects a non-feed the second time, the jam indicator lights.
C231/C237/C238
[D]
C238D038.WMF
6-32
[B]
[C]
[E]
[A]
[G]
[F]
SM