Abstract: A paper stacker for use with a printer which prints connected sheets that are to be stacked in a folded relationship having a surface for receiving the paper with a frame surrounding the paper that is raised in relationship to the paper in order to maintain paper within the confines of the frame as the frame moves upwardly. The frame is balanced by a constant force spring, and is indexed by optical sensors. The frame includes two adjustable fences for variously sized paper which adjustably moves with paddles to press the paper edges downwardly in the stack. Pinch rollers for driving the paper include low inertia drive rollers formed of a relatively low density plastic material with a pair of idler rollers. To improve stacking, ironing tractor idler rollers iron the tractor perforations, and chains orient the catenary stacking movement.

Abstract: A transfer printing station is provided which has two pairs of tractor drives movably arranged side-by-side on two drive shafts. During operation with only a single paper web, the unused tractor drives can be moved to a lateral parking position. The two pairs of tractor drives can be easily moved to match two different webs of paper of different widths. The structure enables a user to adapt the paper conveyor of a transfer printing station to operate with only a single paper web or two parallel webs.