PURPOSE: To enable easy adjustment of the thickness of parison in the axial and radial directions, by moving an inner core, whose external form has been varied in the radial and axial directions, in the axial direction relatively to an outer core by adjusting the same to an extrusion distance of parison.
CONSTITUTION: As for an inner core 1, an external form of the same is varied in the radial and axial directions by corresponding to a form of a hollow product. A part varying the form is a part X shown in a figure by a latticelike oblique line. A clearance with an outer core 2 is varied by moving the inner core 1 of this kind in the axial direction relatively to the outer core 2 by adjusting the inner core 1 to an extrusion distance of parison, which results in adjustment of a thickness of the parison both in the radial and axial directions.
SHIMIZU MASAHIRO
FUJIKAWA SANETOSHI
