Apparatus for continuously forcing an elongate and extrusile raw material into an extrusion pressure vessel

An apparatus for continuously forcing an elongate, rod-shaped, extrusile raw material into an extrusion pressure vessel of an extruder, the apparatus comprising:

• a first propeller, a second propeller and a guide passage with an axis extending within said propellers through which the raw material advances, said propellers being serially arranged along the axis for rotation around the axis, said propellers being fixed in their axial positions;
• each propeller having an inner periphery bordering the guide passage and a helical biting edge formed along said inner periphery and extending into the guide passage, said helical biting edge being formed at a predetermined lead angle to bite an outer periphery of the raw material;and
• a drive mechanism for rotating said first and second propellers in opposite directions from each other, said helical biting edges being inclined so that the raw material is forced toward the pressure vessel by said propellers notwithstanding the opposite directions of rotation of said propellers.