Pneumatic rollers and paper handling arrangements
AssigneeXerox Corporation
InventorsWarren B. Jackson, David K. Biegelsen, Lars-Erik Swartz
Life of this patent
Estimating the term…
Abstract
A roller assembly is provided with openings in its outer surface for selective communication with a source of vacuum or a positive pressure. The openings may be angled along the roller rotational axis to impart a component of velocity to the paper perpendicular to the tangential roller surface velocity. Additionally, by selectively connecting the openings with sources of pressure and vacuum, enhanced paper alignment is achieved, multiple paper feeds eliminated, transitions between different velocities of rollers completed, or paper reverted so that printing can be achieved on first and second sides thereof.
Claims12
A roller assembly for handling sheet material in a printing apparatus, the roller assembly comprising:
- an air source;
- a cylindrical roller having an external surface and a rotational axis about which the external surface rotates;
- a plenum in the roller communicating with the air source;
- and
- openings in the external surface of the roller communicating with the plenum for directing the sheet material in a desired direction relative to the rollers wherein at least one of the openings is oriented in a direction non-perpendicular to the rotational axis of the roller to impart a velocity component in a direction perpendicular to a tangential direction of rotation of the external surface.
A roller assembly for processing sheet material in a printing apparatus, the roller assembly comprising:
- a first roller having an external surface with a series of openings communicating with a plenum in the first roller, the plenum being in selective communication with a vacuum source and a pressure source for urging a sheet material toward and away from the external surface, respectively, as the first roller rotates, wherein the first roller is selectively connected to the vacuum source and the pressure source during predetermined rotational positions of the first roller as the sheet material traverses and leaves, respectively, the external surface thereof;
- and
- a second roller disposed downstream from the first roller for receiving the sheet material from the first roller, wherein the second roller is selectively connected to the pressure source and the vacuum source during predetermined rotational positions of the second roller as the sheet material approaches and traverses, respectively, the external surface thereof.
Dependencies are inferred from the claim text.