Abstract: An improved apparatus is operable to stack signatures having one edge portion which is thicker than other edge portions of the signatures. The apparatus compensates for the thickness of the one edge portion by flattening the one edge portion and offsetting successive layers in a stack of signatures. The apparatus includes a platform which receives the signatures in an initial orientation. This platform is rotated about a vertical axis to offset a first group of signatures from their initial orientation. The signatures subsequently received on the platform have a relatively thick edge portion offset from the first group of signatures. After a retractable apparatus has been extended over the top of a group of signatures, the platform is raised to press the signatures against the retractable apparatus and thereby flatten the signatures.

Abstract: There is provided an improved compensating stacker for stitched, folded, stapled, or the like signatures which is characterized by a temporary platform including a pair of counter-rotatable shafts having tines extending therefrom and toward the opposite shaft. The shafts rotate through 360.degree. moving the oppositely extending tines away from beneath a stack portion to drop the stack portion onto a turntable rotatable through 180.degree. after receipt of each stack portion from the temporary platform until a stack of a desired number is built up whereupon the stack is ejected from the turntable.

Abstract: There is provided a turning mechanism for article orientation, as in a compensating stacker of printed signatures, which is characterized by a three link system including a stationary mounting block having mounted therein for rotation a turnable shaft, a rotating lever arm attached to the turnable shaft, and means for selectively moving the lever arm through 180 degrees of rotation.