rotating crosshead 3 leaving a distance all around to the inside circumference 4 of the hollow roller 1 so that it can move within the hollow roller 1 without coming into contact with the inside circumference 4 the ends 3 39 of the crosshead 3 which project from the hollow roller 1 are mounted in bearings 5 with universal ball joints in a roller stand 6 which is only indicated in general the top roller 10 is stressed by external forces at the roller journals 7 these are applied by force exertion devices symbolized by arrows 8 the hollow roller 1 can move as a whole relative to the crosshead 3 in the plane of effect which lies in the plane of the drawing it is guided in guide rings 11 at its ends on roller bearings 9 these rings do not rotate but can move in the plane of effect on slide surfaces 12 which extend parallel to this plane on the top 3 34 of the crosshead 3 facing towards the roller gap 31 several hydraulic loading devices six in the embodiment shown are distributed over the length of the hollow roller 1 in the form of sealing members 14 which rest against the inside circumference 4 of the hollow roller 1 with their contact surface 24 which is adapted.