Abstract: A tri-roll inverter for use in machines requiring copy sheet inversion for collated copy set output includes input and output nips. All sheets entering the input nip of the inverter are corrugated by a corrugation system as they enter a spring loaded inversion channel. The corrugation system includes an idler roll, a steel driver roll, and two plastic driver rolls on opposite sides of the steel driver roll. The spring and corrugation system urge the sheets back out of the inversion channel into engagement with the output nip for feeding back into a machine for further processing. The plastic rolls enable each sheet to reach zero velocity quickly and invert at a fast rate without stalling or jamming.

Abstract: An electrophotographic printing machine of the type having a duplex tray for collecting sheets having an image formed on one side thereof. Successive sheets collected in the duplex tray are advanced therefrom to the processing stations of the printing machine to have an image formed on the other side thereof. The duplex tray has at least one backstop member positioned thereon and adapted to engage an edge of the sheets being collected. The backstop member stops movement of the sheets and is adapted to deflect upon being contacted by the sheet edge. When the leading edge of the sheet engages the backstop member, the backstop member deflects and absorbs energy. This also increases the sheets contact area and minimizes denting and deletions of the image edge of the sheet edge contacting the backstop member.