DRUECKMASCHINE

The machine is intended for drawing in particular cylindrical hollow parts (2) the walls of which having varying thicknesses. The blanks are threaded on a mandrel (8). In order to even out the thickness variations, either the mandrel (8) may axially slide, or the rollers (28, 29, 30) may be radially moved as a whole, the distance between them being kept constant. In order to move radially the mandrel, parallel flat surfaces (22, 23, 24, 25) are arranged in a plane at right angles with the rotation axis (19) of the spindle (4). The mandrel moves between these surfaces. The external surface of the blank may thereby be centered by means of the followers with respect to the rotation axis (19, 21) of the spindle (4) and of the tailstock (5). The radial displacement of the roller holders is effected hydraulically. The chambers of the cylinders facing the rods and the chambers of the cylinders facing the bottoms of the cylinders are short-circuited. The mandrel is rigid and concentric with the rotation axis and the center of the tailstock.