and is engageable with an adjustable stop 20 ad of the adjusting linkage 20 aa connected to the press plunger 18 is a mold opening linkage 22 which has engagement means 22 ae and 24 ae for engagement with respective engaging stops 20 ae and 20be of the mold crosspieces 20 a and 20b it can be seen from fig3 that a sliding track 26 i 26 ii an 26 iii is assigned respectively to each of the press molds i ii and iii the sliding tracks are connected to conveyor belts 28 i 28 ii and 28 iii in fig1 the apparatus is shown in the filling position the mold parts of each of the press molds are at their maximum distance d from one another the mold cavity of the press mold i is connected to the intermediate hopper i 5 via the filling orifice i 4 a vacuum is built up in the mold cavity of the press mold i through the vacuum connection orifice i 7 and by means of this vacuum the molding material is sucked into the mold cavity at the same time fluidizing air is introduced in the intermediate hopper or at the entrance of the mold cavity the molding material is poured into the mold cavity and compressed with a uniform density subsequently the press plunger 18 is moved to the right until it reaches the positiion according to fig2 the mold parts of the individual press molds are.