Vacuum system for combination fold-off control.

摘要

A signature folder is disclosed in which a vacuum system is provided to prevent tail whipping of the signature when the direction of movement thereof is reversed. The folder provides two counter-rotating cylinders. A portion of the signature moves along the periphery of one cylinder and then reverses direction to move onto the periphery of the other cylinder. A vacuum system is provided adjacent to the signature when it reverses direction. The vacuum system includes a pair of guides and a central, freely rotatable vacuum roll. The vacuum causes the reversing portion of the signature to move into engagement with the guides and roll and eliminates tail whipping. Further, it guides the signature so that it smoothly moves onto the periphery of the subsequent roll.