Ricoh D131 Service Manual page 1513

Details
FM5 Double Parallel Fold
In Fold Method 5 (FM5):
The leading edge of the paper is stopped by Fold Stopper 1.
The paper flexes toward the nip of fold rollers
Fold Stopper 2 stops the paper and flexes it into the nip of fold rollers
Fold rollers and
Fold Stopper 3 is not used.
FM3, FM4, and FM5 follow the same sequence but the resultant fold is different:
In FM5 Fold Stopper 1 is positioned so the paper will fold into halves when it enters the
first nip.
This critical positioning of Fold Stopper 1 accounts for the difference in folding at the
next nip.
D454/D615
perform the second crease and feed the folded paper in exit path.
120
and which performs the first fold.
and .
SM