Patent ID: 6435088
Filing Date: 2002-08-20
Classification: B41F

Abstract:
A sheet guide unit provided for a sheet-fed press which prevents a sheet from flapping or fluttering, which is provided under an intermediate cylinder or a delivery cylinder, and separated from the cylinders by a small sheet guide space for guiding the sheet, comprising:a curved sheet guide surface with which the lower surface of the cylinder creates the small sheet guide space, the space through which the air stream is directed; an air supply chamber which is behind said sheet guide surface; a plurality of air vents which vent air from said air supply chambers into the small sheet guide space, said air vents facing away from each other toward the sides of the cylinder on either side of its center line which vent air along the surface of said curved sheet guide surface along the width of the cylinder, thereby the difference in the velocity of the air flow above and below the sheet being conveyed causes the sheet to be drawn toward said curved sheet guide surface and suspended slightly above said curved sheet guide surface as the sheet is conveyed; a pair of air aspiration chambers provided adjacent to said air supply chamber on the outer sides of the cylinder into which the air is aspirated; and an air guide fin which is an outer extended portion of said curved sheet guide surface into said air aspiration chamber, and serves for directing the air into said air aspiration chamber; wherein the volume of air drawn out from said air aspiration chambers on either side of the cylinder is larger than the volume of air aspirated into said air aspiration chambers, thereby a negative pressure in the vicinity of the both ends of the sheet guide surface is created for preventing the air streams exiting from both ends of the sheet guide surface from colliding with the frame and causing turbulence.