Patent ID: 7448864

Claim:
An extruder head for extrusion blow-molding plastic containers, with a ring gap nozzle having a mandrel ( 1 ) and a ring-shaped nozzle body ( 2 ); an elastically deformable sleeve ( 3 ); and setting devices ( 4 ) for radially deforming the elastic sleeve ( 3 ); whereby the sleeve ( 3 ) arranged at the end on the nozzle outlet side defines a nozzle gap whose width is variable by axial setting movements of the mandrel ( 1 ) and/or the nozzle body ( 2 ), and whose geometry can be influenced by deforming the sleeve ( 3 ) while a hose-shaped preformed blank is being extruded, and whereby the sleeve ( 3 ) is radially movably guided on sliding surfaces ( 7 , 8 ) supporting the sleeve ( 3 ) in the upward and downward directions; characterized in that the sleeve ( 3 ) is realized from the upper end on the inlet side to the outlet of the nozzle in the form of a cylinder having an inner surface of constant diameter, whereby the lower edge ( 15 ) of the sleeve ( 3 ) on the inside of the cylinder shapes the exiting cross-section of the stream of melt exiting from the ring-gap nozzle.