Abstract: Sheet units to be tipped onto a carrier web of indefinite length are brought into the relationship to one another that they are to have on the web while riding on an upper stretch of an endless carrier. Abutment elements on the endless carrier, at regular intervals along it, define rearwardly facing surfaces that project above said upper stretch and move forward at a predetermined velocity. An endless driver having an upper stretch paralleling that of said carrier and driven faster, frictionally urges sheet units into engagement of their front edges against said surfaces. An air permeable belt, driven at said velocity, has a bottom stretch that is under a suction shoe and the rear portion of which is upwardly adjacent to the front portion of said endless carrier, so that sheet units are sucked off of the carrier and onto said belt to be carried forward by it without change in their edgewise speed.