An apparatus is provided for processing a document traveling along a document
path within a document validator. The such apparatus includes a disk where a periphery
of the disk extends into the document path of the document validator, a support
shaft that passes through a center hole of the disk, the shaft loosely supporting
the disk and allowing the disk to rotate around the shaft in a predominant plane
of the disk and to freely move in the predominant plane of the disk in a direction
that is perpendicular to a longitudinal axis of the shaft and a resilient member
that biases the disk into the document path to engage a side edge of the document
when the document is misaligned with the document path as it travels along the
document path thereby retarding forward movement of the side edge and rotation
of the document into alignment with the document path.