Method and device for producing a cylindrical glass body

US7600399B2 · kind B2 · utility

Assignee

• HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

• Thomas Bogdahn · Karlstein, DE
• Oliver Ganz · Könnern, DE

Key dates

• Filing date: Jan 23, 2002
• Grant date: Oct 13, 2009
• Expiry date: Jun 20, 2023

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03B37/0124
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

In a known method for producing a cylindrical glass body in a vertical drawing process, a glass blank is softened in a heating zone and drawn off as a glass strand by means of a draw-off device at a controlled drawing speed, the draw-off device comprising a first draw-off unit with rolling bodies rolling on the glass strand and being distributed around the circumference thereof, the rolling bodies being formed by a reference rolling body and at least one auxiliary rolling body, the drawing speed being controlled via the speed of the reference rolling body. Starting therefrom, in order to reduce damage to the surface of the glass strand caused by the draw-off device and to avoid deformations caused by existing bends of the glass strand, it is suggested according to the invention that a value for the torque of the reference rolling body (3) should be determined in dependence upon the weight of the drawn-off glass strand (5), and that the determined value should be used as a setpoint torque for setting the torque in the at least one auxiliary rolling body (4; 7; 8).