Ricoh D131 Service Manual page 1515

Details
Operation sequence for folding three sheets:
At power on (initialization) the FM6 junction gate [A] moves to home position.
The three sheets are pre-stacked then the first two folds are done
The FM6 stop pawl moves to the operation position [B].
[A] After the 2nd fold the sheet(s) are sent to the 3rd stopper for the last fold.
The leading edge of the sheets(s) hit stopper 3 and the upstream rollers continue
[B]
rotate (equivalent to 18 mm of feed) to flex paper toward the fold rollers.
The edge of the FM6 pawl is raised to flatten the leading edge so it cannot bend
[C]
back on itself as the paper enters the nip of the fold rollers.
[D] When the 3rd fold starts the FM6 pawl returns to its home position.
D454/D615 122 SM