Abstract: A method for compressing powder or granular material by a rotary tabletting machine (1), includes an initial step in which an opening (2) is filled with material to be compressed, a compacting step (C), in which a load is gradually applied to the material until a maximum value (F1) is reached, a first releasing step (R1) in which the load is removed, a precompression step (P), in which a second load (F2) is applied to the material, a precompression step (MP), in which the second load (F2) is maintained, and a second releasing step (R2), in which the second load is released, a main compression step (CP), in which a third load (F3), that is not smaller than the previous loads (F1,F2), is applied to the material, and a final ejecting step in which the tablet is discharged from the opening (2).

Abstract: A stamping device for a tablet making machine includes a pair of coaxial stamping heads (1) which enter, on opposing faces, a matrix carried by a matrix plate (2) formed around a rotary turret (3), a pair of punches (4) which are guided by respective holes made in the turret (3) and which are adapted to be coupled with the stamping heads (1) in axial alignment therewith, and a coupling (13) for joining the stamping head (1) and the respective punches (4). The device includes also a locking mechanism (6), which comprise a screw member (7) passing through a transverse hole (8) made close to the end of the respective punch (4). The screw member (7) has a head (9) having a concentric semi-spherical section (10) that matches a complementary recess connected to the outer surface of the respective punch (4).