Method and apparatus for cutting through a flat workpiece made of brittle material, especially glass

US5984159A · kind A · utility

Assignee

• Schott Glas · DE

Inventors

• Heinrich Ostendarp · Eschershausen, DE
• Christoph Hermanns · Mainz, DE
• Dirk Hauer · Nordenham, DE
• Juergen Stein · Mühlacker, DE
• Georg Geissler · Haigerloch, DE
• Ralf Steinfartz · Mainz, DE
• Bernd Hoetzel · Wörrstadt, DE
• Andrew Blunck · Eschershausen, DE

Key dates

• Filing date: Apr 14, 1998
• Grant date: Nov 16, 1999
• Expiry date: Apr 14, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T225/304
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

The method and apparatus for cutting through flat workpieces made of glass can cut through workpieces with greater thickness, e.g. glass panes with a thickness greater than 0.2 mm, than possible up to now with a comparable known method, without micro-fractures, glass fragments or splitter. In the method of the invention a heat radiation spot symmetric to the cutting line is produced on the workpiece. This heat radiation spot has edge portions with elevated radiation intensity and is moved along the cutting line and/or the workpiece and the heated section of the cutting line is subsequently cooled. A scanner motion produces the heat radiation spot so that edge portions of elevated radiation intensity coincide with a V- or U-shaped curve, which is open at the leading end of the heat radiation spot. The peak portion of the V- or U-shaped curve on the cutting line is at a temperature maximum that is under the melting point of the workpiece material. A controller of the scanning motion controls the scanner in circular cutting and freeform cutting so that a curved V- or U-shaped intensity distribution which fits the curved cutting path arises.