Abstract: A pressing machine includes a roller and a pressing shoe which can be moved towards and away from the roller to exert pressure on the roller or on a material in a gap between the shoe and the roller. The shoe is mounted in a pressure chamber to which hydraulic pressure medium can be supplied to move the shoe. Upon movement towards the roller, the shoe applies pressure over a zone extending for a part of the circumference of the roller. Means is mounted on the pressing shoe for altering the length of this zone in the circumferential direction of the roller. To this end, the shoe may have two movable jaws which establish said zone, the jaws being movable by adjusting means over a cylindrical surface of said shoe which has substantially the same centre of curvature as the roller. The pressing shoe is particularly advantageous in a paper machine for dewatering a web of paper or for supporting the rollers of a rolling apparatus.