Patent ID: 8266927

Claim:
A method for producing a cylinder of quartz glass, said method comprising: performing a soot depositing process, wherein SiO 2 particles are deposited on an elongate carrier rotating about an axis of rotation so as to form a porous, hollow-cylindrical soot body; performing a sintering process wherein the soot body is held suspended in a vertical orientation in a furnace and the soot body has an inner wall defining an inner bore, a longitudinal axis, an upper end and a lower end; a holding element holding the soot body, wherein the holding element projects from the upper end into the inner bore of the soot body, and engages a bearing in the inner bore, wherein the bearing comprises an expanding bearing having at least one quartz glass spreading element that is movable against the inner wall of the inner bore, the at least one quartz glass spreading element co-acting with the holding element so that the at least one quartz glass spreading element moves generally outward with a movement component in a direction perpendicular to the longitudinal axis of the soot body and is pressed against the inner wall responsive to weight of the soot body.