Abstract: The sheet jogging mechanism is comprised of a pivotally movable articulated arm including pivotally interconnected forward and rear arm sections. As the rear arm section is swung toward the side of a loosely formed stack of sheets, the forward arm section is moved progressively from a parallel to a convergent orientation relative to the side of the sheet stack until a jogging rod mounted on the front end thereof engages one side of the sheet stack. As the rear arm section is swung further toward the sheet stack, the forward arm section pivots relative thereto and toward the side of the sheet stack until again assuming a parallel orientation relative to the sheet stock so as to bring a second jogging rod mounted on the rear end thereof into engagement with the one side of the sheet stack.