Patent ID: 6551089
Filing Date: 2003-04-22
Classification: B29C

Abstract:
Extrusion head for a blow molding machine for producing multi-layered hollow plastic bodies, including one or more extruders, attached to a housing (12) of an extrusion head, for feeding molten plastic melt into the extrusion head (10), a central torpedo (14), and two spiral-channel distributor elements for distribution of the plastic melt(s) across the circumference and feeding into an annular storage space (22) which terminates in an annular outlet nozzle (24) through which the plastic melts are expelled by means of an axially movable ejector piston disposed in concentric surrounding relationship to the torpedo (14), wherein the ejector piston is accommodated in the housing and includes an outer cylindrical sleeve (18) having an inner surface configured to form a first one of the spiral channel distributor elements, and an inner cylindrical sleeve (16) having an outer surface configured to form a second one of the spiral-channel distributor elements in confronting relationship to the first distributor element in a single annular gap, which is defined between the outer cylindrical sleeve (18) and the inner cylindrical sleeve (16) approximately centrally in the ejector piston, with the circumferentially distributed plastic melt of both distributor elements exiting at the lower end of the annular gap from the ejector piston.