An apparatus and a method are provided for adjusting the stroke length of a reciprocating member such that the stroke length can be infinitely varied between a minimum and a maximum stroke length. A pair of crankshafts are each connected to an eccentric and configured to operate with a phase offset such that the stroke length can be varied by adjusting the phase offset.

A clamshell die cutting press (10) that can transition between an opening of three inches and 0.937 and anywhere in between without the requirement of filler plates. This is accomplished by attaching the connecting rod or arm (20) that extends between the fixed platen (14) and the movable platen (16) to the fixed platen through an eccentric bevel gear (26). The bevel gear (26) is driven by an electric motor (28) which allows the adjustment to be made with a push of a button, and by moving the bridge rocker plates (34 and 36) and bridge cam stands using linear slides and servo motors.

The invention preferably relates to a compression roller station for rotary tableting machines with a guide profile which can be locked to the rotary tableting machine and comprises two side surfaces on which a pair of upper and lower shaft mountings for compression roller shafts are arranged externally in each case, so that two pairs of compression rollers can be attached to the same guide profile. In preferred embodiments, the shaft mountings have a laterally outwardly open shape, particularly preferably a u-shape, and are arranged for a swivelable mounting of compression roller shafts. In a further aspect, the invention relates to a rotary tableting machine comprising such a preferred compression roller station.