Suction extraction assembly for an extension on a sheet fed printing press

摘要

The suction unit has air passages in a base wall (6) lying level with a sheet supply path. The base wall is engaged at least in some sections by an engagement wall (5) in the area of the base surface which points downwards. The base wall and the engagement wall define a suction gap (S) which is open towards the upper cross edge (Q) of the sheet stack (BS) to pick up the air stream (V1) which flows over the sheet stack and is forced forwards underneath the base wall. Independent claim describes base wall for an apron section of a sheet delivery unit which has a grid structure with several adjoining air passages. An engagement wall engages under the grid structure in a longitudinal zone adjoining the lower cross edge to define an air pick up nozzle facing the sheet stack.