Abstract: To improve a known method for making a quartz glass tube as a semifinished product for the manufacture of optical fibers, the tube comprising an inner fluorine-doped quartz glass layer and an outer quartz glass layer, so as to achieve inexpensive manufacture and improved dimensional stability of the quartz glass tube, it is suggested according to the invention that the quartz glass of the inner layer should be produced in a first plasma deposition process with formation of an inner layer having a wall thickness of at least 1.5 mm, with a fluorine content of at least 1.5% by wt. being set in the quartz glass, and that the quartz glass of the outer layer should be produced in a second plasma deposition process and deposited directly or indirectly on the inner layer with formation of a composite tube, and that the composite tube should be elongated into the quartz glass tube.

Abstract: To improve a generally known method for producing a tubular semifinished product from fluorine-doped quartz glass such that it is possible to produce a tubular semifinished product of fluorine-doped quartz glass with an inner bore of high quality while the efforts for making or treating the same are as small as possible, the present invention suggests a method comprising the following steps: (a) providing a substrate tube consisting of fluorine-doped quartz glass; (b) forming, in a deposition process, SiO2 particles by means of plasma burners and in the presence of fluorine, and depositing said particles in layers on the cylindrical outer surface of the substrate tube rotating about its longitudinal axis with formation of a mother tube consisting of fluorine-doped quartz glass; and (c) elongating the mother tube in an elongation process to obtain the tubular semifinished product.

Abstract: A method and a device are for detecting the initiation of the driving off process by a driver of a vehicle. The time derivatives of the engine torque and of the engine speed are determined, and the initiation of the driving off process is then inferred from an evaluation of these time derivative values. The detection of the driving off process can be used for releasing a brake while avoiding unintentional rolling of the vehicle when making a hill start.

Abstract: The invention relates to a method and a device for detecting the initiation of the driving off process by a driver of a vehicle. In this context, at least one variable (M, N) is determined and the initiation of the driving off process is then inferred from said variable (M, N). The engine torque (M) and/or the engine speed (N) and/or a variable ({dot over (M)}, {dot over (N)}) which is correlated with the at least one variable (M, N) to be evaluated is used as at least one measured variable. The detection of the driving off process can be used, for example, in methods and devices for avoiding unintentional rolling of the vehicle, in particular when making a hill start.

Abstract: The invention relates to a method and a device for actuating at least one wheel brake device of a vehicle for preventing inadvertent rolling. A driving off assistance mode with a predefined brake pressure reduction is activated in the at least one wheel brake device if the stationary state of the vehicle has been detected (50) and the vehicle is located (51) on an incline, when viewed in the longitudinal direction of the vehicle, and an uphill direction was detected (52) as the designated driving off direction of the vehicle. The brake pressure reduction can take place with a delay after the brake pedal has been released in such a way that the vehicle rolls back at a crawling speed.

Abstract: According to a prior art method for producing a cylindrical component comprised of silica glass, a cylinder comprised of a softened silica glass mass is drawn in a predetermined drawing direction along a drawing axis by means of a drawing device which acts upon said cylinder. The aim of the invention is to provide a method which prevents, to the greatest possible extent, warping of the drawn cylinder and other deviations from the ideal cylinder dimensions and to prevent, to the greatest possible extent, the outer surface of the drawn cylinder from being touched. To these ends, the invention provides that the drawing device comprises a plurality of guide elements which are arranged one behind the other along the drawing axis, and which can be displaced independently of one another in a drawing direction and in a direction opposite thereto.

Abstract: A glass composition to be softened is fed to a heating zone and is shaped continuously into a cylindrical component in a deformation zone, and the cross-sectional geometry of the component is determined. A feed device, a heating device, and a take-off device are provided, and a glass composition is supplied continuously by the feed device to the heating device, where it is softened, the component being formed from the softened glass composition by means of the take-off device under formation of a deformation zone. To produce a component with only slight deviations from the desired cross-sectional geometry and to provide a flexible apparatus suitable for this purpose, the glass composition is locally heated or cooled in at least one deformation area, which extends over only a part of the circumference of the deformation zone, as a function of a determined deviation of the cross-sectional geometry from a nominal geometry.