Patent ID: 6641766
Filing Date: 2003-11-04
Classification: B29C,F04B

Abstract:
A positive displacement extruder for a viscous material, comprising:a main body having a chamber therein and an inlet and an outlet for the viscous material, said inlet and outlet being in communication with the chamber; a feed member rotatably arranged in the chamber of the main body and adapted to be driven for rotation so that the viscous material charged into the chamber through the inlet is extruded from the outlet; a mouthpiece having an inlet that is spaced in a circumferential direction from the outlet of the main body, and an extrusion nozzle in communication with the inlet of the mouthpiece; at least one cylinder device comprising a cylinder having an opening and a piston that can be reciprocated in the cylinder, said cylinder device rotatable about a center axis of the extruder so that the cylinder opening is alternately brought into communication with the outlet of the main body and the inlet of the mouthpiece; a cylinder device holder carrying the at least one cylinder device; a drive mechanism connecting the feed member to the cylinder device holder, wherein said drive mechanism provides a common drive for the feed member and the cylinder device holder; and a stationary cam device for causing a reciprocating movement of the piston in the cylinder.