Abstract: An insertion machine includes an insertion station (44) whereat groups of items are stuffed into an envelope held open at an envelope opening station (49). The insertion station comprises a cam (212)-driven carriage (202) which linearly reciprocates in a direction (480) toward and away from the envelope opening station (49). The carriage (202) carries a plurality of selectively mounted, selectively rotatable pusher fingers (204). The pusher fingers (204) have a profile suitable for shoving items along a partially inclined insertion plate surface 403 and into an opened envelope. The pusher fingers (204) are selectively rotatable to an operative orientation (720) and to an inoperative orientation (722) under the supervision of a controller (205). Jam detectors (550, 552) are provided proximate reciprocating entry fingers (500, 502) which move when a jam occurs in the inserting process. Should a jam occur, the pusher fingers (204) are controlled to rotate to their inoperative orientation (722).