Abstract: A sheet stacker in which sheets are compiled in a tray (71) against registration (74) and a completed set is ejected, the registration members (74) being retracted, by an eject mechanism comprising a continuously rotating drive roller (80) projecting through the base (72) of the tray and a coacting idler roller (81) mounted on a spring arm (82) which is retracted during stacking and then pressed against the top of the completed set to effect ejection. Preferably the roller (80) is a deformable roller having a low coefficient of friction surface.

Abstract: A sheet registration apparatus and device for registering a sheet on a surface 72 against a registration stop 75 or 74, 75 includes a wiper device 100 having a plurality of resilient blades 101 rotatable about an axis 103 which is generally normal to the surface 72. The blades lie in radial planes through the axis and extend in the direction of the axis towards sheet-engaging tips 106 which are arranged to wipe across the sheet surface over a limited arc of rotation so as to urge the sheets towards the registration stop. To this end the blades are held out of contact with the sheets during part of each revolution by a swash plate 102 having an arcuate opening 114.