US Patent 8011823 Clay kneader

A clay kneader has a drum having a pressure raising section on a supply opening side, an extrusion section having an inner diameter smaller than that of the pressure raising section on side of an extrusion opening for extruding clay as a columnar article, and a flow controlling section located between the pressure raising section and the extrusion section and being equipped with a supply opening for clay, a screw having a rotary shaft having a diameter which gradually decreases toward the extrusion opening in the flow controlling section and being ended around a boundary between the flow controlling section and the extrusion section, and a helical rotating blade provided along the rotary shaft for kneading the clay a rotary shaft.