Abstract: A positioning mechanism for calender machines is disclosed. The mechanism employs an interconnected piston and cylinder arrangement whereby the rolls may be separated quickly and subsequently automatically repositioned. When a paper break occurs or when it is otherwise desired to separate the rolls quickly, the cylinders, by means of a lost motion connection, quickly separate the rolls by a specified amount to prevent damage to the apparatus. A hydraulic circuit maintains the spacing required for the lost motion connection and allows for interchanging of rolls of different diameters.