Patent · US Active

Method for producing a tube of glass

US10315947B2 · kind B2 · utility

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1References

2Claims

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Assignee

HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

Boris Gromann · Aschaffenburg, DE
Nigel Whippey · Seligenstadt, DE

Key dates

Filing date	Jul 12, 2017
Grant date	Jun 11, 2019
Priority date	—
Expiry date	Jul 12, 2037

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB23K2103/54
WIPO fieldMachine tools
WIPO sectorMechanical engineering

Abstract

A method for forming a hollow cylinder, in a single step, into a quartz glass tube with a large outer diameter and high dimensional stability is provided. To produce the tube, the cylinder, while rotating, is softened in portions in a heating zone which is moved at a relative feed rate Va and the softened portion is radially expanded by a centrifugal force and/or internal overpressure applied in the hollow cylinder bore so as to form a deformation zone. The radial expansion of the softened portion is carried out at a location-dependent radial expansion rate Vr, the profile of which along the deformation zone has a maximum value Vr,max which is smaller than 20 cm/min. The temperature in a rear heating portion of the heating zone, assigned to the end of the deformation zone, is lower than in a front heating portion assigned to the beginning of the deformation zone.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.