Verfahren und Vorrichtung zum Herstellen eines Bauteils aus Glas durch Ziehen aus einem Rohling

In a known process for the production of a long extended component made of glass by drawing from a blank, the blank is fed to a heating zone, where it is softened in areas, and the component is drawn continuously and controlled from the softened area by forming a bulb. Thereby, dead-time-free estimates are forecast for at least the control parameter, moreover at least one geometric component parameter correlatable to the control parameter is continuously measured and the measured values thus determined are used for comparison with the forecast estimates, and based on the forecast estimates thus compared, the target/actual deviation of the control parameter is determined and converted into a change of a manipulated variable. To ensure the production of a component with particularly high dimensional stability starting from said situation, the invention proposes firstly that a measurement of the geometric parameter be included at the first measuring point in the area of the bulb in order to predict the estimate, and secondly, that the temperature of the bulb be measured and used as a control parameter. In the device suitable for performing said process, a measuring instrument is provided for measuring the geometric size of the component, said instrument being allocated to a measuring point in the softened area of the blank.