Abstract: A stalled roll registration device that minimizes or prevents creasing of a sheet as it is fed through the device. The rolls that register the sheet are not perfectly cylindrical and have a larger radius toward the outside edges of the sheetpath. After the sheet is stalled and then started through the registration pair, the velocity difference caused by the noncylindrical rolls causes the edges of the sheet to be urged toward the edges of the sheetpath thereby minimizing the risk of wrinkling the sheet.

Abstract: A sheet aligning and registration device for a printing machine. In a stalled roll registration device there is provided a drive mechanism preceding the stalled roll which allows a sheet to move while within the drive nip. The drive mechanism uses a drive roll and an eccentric idler roll in contact therewith. The idler is biased against the drive roll by a compression spring such that as the eccentric idler roll rotates, the spring is alternately compressed and relaxed. When a sheet is driven through the drive mechanism and into the stalled nip, a buckle is formed which causes a force to be exerted on the drive nip which causes the eccentric roll to stall in the horizontal position in which little normal force is exerted on the sheet. The sheet is then free to deskew and align in the stalled nip. Once the sheet is aligned and deskewed, the stalled nip is actuated and the sheet is forwarded to a process station.

Abstract: A simple, low cost corrugation device for removing curl from sheets includes a compliant corrugator roll that is effective with light weight, low beam strength papers needing corrugation and passive with heavy weight, high beam stiffness papers not needing/not wanting corrugation. One type of corrugation roll is a cylindrical elastomeric roll made of a foam or sponge-like material. An alternative corrugator roll configuration is a hollow frustrum of a cone.