A suction filter of this type is described in German Patent No. DE-PS 35 33 038. A cage is placed on the housing, through which the agitator shaft is led and on which the drive motor is placed. For the vertical adjustment of the agitator shaft two lateral piston rods are provided, which are connected to each other by means of a main cross beam. In turn, two hydraulic cylinders projecting vertically upward are arranged on the main cross beam itself. The piston rods of these hydraulic cylinders are connected to each other by means of a cross beam.
A disadvantage of this embodiment is, however, that such an agitator suction filter has a relatively large overall height.