Abstract: An air operated double diaphragm pump comprising an air valve mechanism. The air valve mechanism may comprise a single valve system that replaces the two valve system found in conventional air operated double diaphragm pumps. The position of the valve may be determined by the diaphragm motion of the pump up to a stall position. A spring-loaded mechanical actuation may complete the valve action from the stall position to the final or end of stroke position of the pump.

Abstract: A print media alignment apparatus is disclosed. An embodiment includes a first member configured to apply a varying force to at least one print media sheet of a print media stack. This force varies from a minimum below a first print media stack height to a maximum at a second print media stack height. The alignment apparatus also includes a second member configured to apply a constant force to the print media stack irrespective of the stack height. Another embodiment includes a print media width adjuster configured to be moveable adjacent a print media stack having at least one sheet of print media, the print media stack defining a plane. The alignment apparatus also includes a wall on the width adjuster. The wall includes a wall first print media contact surface configured to slope at an angle with respect to the plane. The alignment apparatus further includes a member attached to the width adjuster, the member including a member print media contact surface configured to be perpendicular to the plane.