Process and device for covering a lens preform with a protective sheet

US4564408A · kind A · utility

Assignee

• Saint-Gobain Vitrage · FR

Inventors

• Richard Crumbach · Aachen, DE
• Heinz Schilde · Würselen, DE
• Helmut Tiedemann · Baesweiler, DE

Key dates

• Filing date: May 25, 1984
• Grant date: Jan 14, 1986
• Expiry date: May 25, 2004

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T156/1028
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

To cover the concave face of a lens preform with a protective sheet of transparent plastic by an elastic pressing element, the invention proposes inserting an elastic membrane between the pressing element and the protective sheet. Before or during pressing, the membrane is lowered over the preform which has been provided with the protective sheet. As a result of its presence, the entire peripheral area of the protective sheet can be applied homogeneously against the edge of the preform.