Apparatus for and method of manufacturing of preforms having a longitudinal wall with a variable cross section

US5330342A · kind A · utility

Assignee

• Ossberger Turbinenfabrik GmbH & Co. · DE

Inventors

• Gerhard Linss · Weißenburg, DE
• Karl-Friedrich Ossberger · Weißenburg, DE

Key dates

• Filing date: Nov 20, 1992
• Grant date: Jul 19, 1994
• Expiry date: Nov 20, 2012

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29L2031/703
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

An apparatus for manufacturing a tube-like preform having a longitudinal wall with a variable cross-section for blow molding of a hollow body from a thermoplastic material, includes a tubular die having a variable exit opening, and a collar die having a recess and movable into engagement with and away from the tubular die, the preform being produced by ejecting of the thermoplastic material from the exit opening of the tubular die into the recess of the collar die while moving tubular die, with controlling a speed of movement of the collar die and a cross-section of the exit opening of the tubular die in such a manner that larger and smaller cross-section of the exit opening correspond to speed rate of the collar die, so that a thickness of the wall of the producible preform changes from peaks to valleys in a wave-like manner to form the variable cross-section of the wall.