Abstract: A press frame has a floored portion that defines a pressing area and a floorless portion that defines a discharge area. The frame carries first and second squeezing elements that are moveable between the pressing area and discharge area. Only the first squeezing element is powered, and it can be driven selectively toward or away from the second squeezing element to press and discharge screenings. A linking device limits the maximum separation of the first and second squeezing elements so that the first element pulls the second, together with processed screenings, to the discharge area in a discharge cycle. An interposer limits the minimum separation of the first and second squeezing elements so that the powered element pushes the nonpowered element back to the pressing area after the discharge cycle.