Apparatus for producing casting mould parts

The present invention provides an apparatus for producing casting mould parts by compacting mould material between a first squeeze plate and a second squeeze plate forming movable end walls of a moulding chamber, which subsequent to the compacting can be opened by moving the second squeeze plate out of the way, after which the mould part can be pushed out of the moulding chamber by a further movement of the first squeeze plate in its compacting direction, the movement of the first squeeze plate being provided by a hydraulic drive unit comprising a movable cylinder member connected to the first squeeze plate and an associated stationary piston member having a piston rod extending tightly through an inner wall of the cylinder member and a piston. The movable cylinder member is guided in its linear movement by the piston and by the piston rod. By further providing supplementary means for guiding the movable cylinder member, it is possible to reduce the sag of the piston rod and cylinder member, when the cylinder member is advanced to the full extent to push out the produced mould part and improve the rigidity of the first squeeze plate against tilting movement during compacting.