Apparatus for injecting air or gas into a tubular film bubble

US4462779A · kind A · utility

Assignee

• Windmöller & Hölscher KG · DE

Inventors

• Friedhelm Brinkmeier · Lengerich, DE
• Heinrich Frommeyer · Georgsmarienhütte, DE

Key dates

• Filing date: May 11, 1982
• Grant date: Jul 31, 1984
• Expiry date: May 11, 2002

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B31B70/266
• WIPO field: Textile and paper machines
• WIPO sector: Mechanical engineering

Abstract

To maintain an air or gas bubble forming in a moving tube of plastics material between pairs of squeeze rollers, an air or gas injecting needle is mounted to pivot substantially in a plane containing the centerline of the tube. The needle pierces the tube wall of the bubble when in one rotary position, moves with the tube while pivoting through an arc depending on the depth of needle penetration and is withdrawn from the bubble in a second rotary position.