Patent ID: 6942008

Claim:
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 the compacting direction thereof, said apparatus comprising: a frame; a hydraulic drive unit which provides the movement of the first squeeze plate, said drive unit comprising a movable cylinder member connected to the first squeeze plate and an associated stationary piston member having (a) a piston rod including a distal end and a connection between said distal end and said frame which said connection is rigid and which inherently prevents movement between said distal end and said frame regardless of any other restraint of said piston rod, said piston rod also extending tightly through an inner end wall of the cylinder member and (b) a piston dividing the chamber of said cylinder member into an outer end chamber and an inner, annular compartment surrounding a piston rod, whereby said movable cylinder member is guided in a linear movement thereof by the piston and by the piston rod, both compartments being provided with inlet and outlet connections for supply and discharge of a pressure fluid, a supplementary means for guiding the movable cylinder member, and wear plates mounted at a bottom of the first squeeze plate.