Abstract: A belt tensioning system for a belt transport particularly adapted for use in a document handling system of a reproducing machine. A belt is arranged for movement about first and second pulleys which are adjustably supported within a frame. The frame includes a tensioning system for adjusting the tension of the belt by changing the relative distance between the pulleys. The tensioning system includes a vernier for providing fine adjustment of the belt tension. The vernier system allows the belt tension to be adjusted while maintaining the parallelness of the belt pulleys.

Abstract: A document handling apparatus and a reproducing machine employing it, include a system for pre-registering a document prior to its advancement to a viewing station. A stop member is selectively positionable in and out of a path of the document. A guide chute defines a desired throat for guiding the document into engagement with the stop member. A system is provided for transporting the document to the viewing station. The guide chute is supported for movement in a direction away from the stop member in response to the movement of the stop member between its respective positions in and out of the document path.

Abstract: Apparatus for counterbalancing the movement of a platen cover or document handler between a first closed position and a second open position. The counterbalancing apparatus comprises a gas spring and a tension spring. The tension spring is arranged to increasingly counter the force exerted by the gas spring as the platen cover is moved from the first to the second position. This compensates for the reduced force exerted by the platen cover as it is opened. The platen cover in the second position preferably has moved past vertical and the tension spring is effective to counter the force exerted by the cover between vertical and the second position.