Prepress apparatus for an assembly of stacked sheets

摘要

An apparatus for prepressing an assembly of stacked, superimposed glass and plastic sheets for subsequent autoclave lamination to provide a glazing includes a frame positioned between a delivery conveyor and a discharge conveyor and carrying prepress and support rollers. The prepress rollers are rotatably mounted in pairs and attached to air cylinders which retract the rollers during entry of an assembly in order to clear a vacuum ring which extends about a peripheral edge of the assembly and then extend the rollers into contact with an upper surface of the assembly to apply pressure thereto. The assembly is supported from its bottom side by the support rollers which are rotatably attached to the frame and are located on either side of a plurality of drive rollers which are rotatably attached to the frame in pairs. The drive rollers are of different diameters and are adjustably mounted on an axis of rotation which is tilted from the horizontal path of the assembly. The drive rollers are driven to move the assembly through the frame while the prepress rollers apply pressure to the asssembly. The different diameters and the tilted axis of rotation compensate for different lengths of the paths of travel of the drive rollers along the surface of the assemblies of curved or bent sheets.