Abstract: An extrusion nozzle for making tubular preforms has a mandrel extending along a vertical axis, an annular and stationary nozzle body spacedly radially surrounding the mandrel, and a holding ring having an upper end axially slidable in the nozzle body, braced axially downwardly against the nozzle body, and having a lower end spaced radially inward from shiftable limitedly radially relative to the nozzle body. A nozzle ring has an upper end axially slidable in the holding ring, is braced axially downwardly against the nozzle body, and has a radially deflectable lower end forming an annular extrusion gap with the mandrel. A first positioner engages the lower end of nozzle ring and is operable to radially deflect this lower end. A second positioner engages radially with the lower end of the holding ring or with the nozzle ring for radially deflecting same.

Abstract: An extrusion nozzle for making tubular preforms has a mandrel extending along a vertical axis, an annular and stationary nozzle body spacedly radially surrounding the mandrel, and a holding ring having an upper end axially slidable in the nozzle body, braced axially downwardly against the nozzle body, and having a lower end spaced radially inward from shiftable limitedly radially relative to the nozzle body. A nozzle ring has an upper end axially slidable in the holding ring, is braced axially downwardly against the nozzle body, and has a radially deflectable lower end forming an annular extrusion gap with the mandrel. A first positioner engages the lower end of nozzle ring and is operable to radially deflect this lower end. A second positioner engages radially with the lower end of the holding ring or with the nozzle ring for radially deflecting same.

Abstract: An extruder head for extrusion blow-molding plastic containers includes a ring gap nozzle with a mandrel and a ring-shaped nozzle body. An elastically deformable sleeve is arranged on an end of the nozzle outlet side and defines a gap width which can be varied by axial setting movements of the mandrel and/or the nozzle body. The geometry of the nozzle gap can be influenced by radially deforming the sleeve with setting devices during the extrusion of a hose-shaped preformed blank. The sleeve may be moved in a radial direction and is guided on sliding surfaces which support it in upward and downward directions. The sleeve may be in the form of a cylinder or tube. A lower edge of the sleeve shapes a cross-section of a melt stream exiting from the ring gap nozzle.