Press for pulverulent materials

In a press for compressing pulverulent materials into concave-shaped or convex-shaped articles, the combination comprising a press frame;

• an upper punch holder unit fastened to the press frame for supporting concentrical upper punches and including control means for controlling the displacement of said upper punches;
• a table fastened to said frame;
• a plurality of vertical stationary rods upwardly projecting from said table;
• a matrix plate having a central aperture for a matrix and slidably arranged on said vertical rods, said rods each having a upper stop and a lower stop for determining the displacement range of said matrix plate;
• piston-cylinder means fastened to said frame for supporting said matrix plate, lever means having one end portion pivoted to said frame above said matrix plate and an opposite other end portion;
• slider means slidably arranged on said lever means at said opposite end portion and abutting on said matrix plate, piston-cylinder means acting on said other end portion to displace said matrix plate through said slider means;
• a first lower punch holder plate slidably arranged on said vertical rods beneath said matrix plate and having a central aperture;
• a first lower punch adapted to be fastened at its one end within said aperture of said lower punch plate and projecting into the central aperture of said matrix plate;
• control means for controlling the movement of said first lower punch holder plate;
• a second lower punch holder plate arranged within a central aperture of said table;
• a second lower punch supported by said second plate and arranged within said control means for controlling the movement of said first lower punch plate;
• a core passing through said lower and upper punches;
• a core rod carrying said core at the lower end thereof;
• support means for holding said core rod;
• extracting lever means operatively connected to one of said lower punches for removing an article formed by said punches and core;
• piston-cylinder means for controlling the displacement of said core rod support means, and stop elements operative for limiting the displacement of all said support means of said punches and core rod, respectively.