부산대학교 도서관

This invention provides a system and method for rotating sheets (a sheet rotator) receiving cut sheets from a source and providing them to a utilization device. The rotator continually engages sheets with at least one drive or rotation component throughout the transport and rotation process. The rotator includes a transport mechanism having a plurality of nip roller pairs along the length of a feed table. The nip rollers (nips) can be selectively engaged with, and disengaged from, the driven rollers using discrete actuators. This allows for feed velocity differentials when entering and exiting the rotator feed table, and also for clearance during sheet rotation. A rotator disk assembly is centered on the table between, and comprises a driven rotator disk and an overriding, freely rotating pressure disk. When sheets enter or pass through the rotator section, the pressure disk is raised to provide a clearance for sheets to pass. Sheets are rotated by lowering the pressure disk and raising surrounding nips to provide clearance for the disk to turn at least 90 degrees. Nips can then be lowered to drive the rotated sheet downstream to the outfeed end of the feed table.