A method and apparatus are provided for producing a tube of glass by zonewise heating and softening of a hollow cylinder by a movable heating zone while rotating about its rotation axis. The glass tube is continuously formed by radial expansion of the softened region under action of centrifugal force and/or internal overpressure applied in the hollow-cylinder bore. The method and apparatus make it possible to deform the hollow cylinder in a single or a small number of forming steps into a glass tube having a larger outer diameter and high dimensional accuracy by determining a circumferential position at which the wall thickness is comparatively small, and during heating and softening of the rotating hollow cylinder a coolant is dispensed from a coolant source onto the deformation zone only when or predominantly when the circumferential position having the comparatively small wall thickness passes the coolant source.

A method and apparatus are provided for producing a tube of glass by zonewise heating and softening of a hollow cylinder by a movable heating zone while rotating about its rotation axis. The glass tube is continuously formed by radial expansion of the softened region under action of centrifugal force and/or internal overpressure applied in the hollow-cylinder bore. The method and apparatus make it possible to deform the hollow cylinder in a single or a small number of forming steps into a glass tube having a larger outer diameter and high dimensional accuracy by determining a circumferential position at which the wall thickness is comparatively small, and during heating and softening of the rotating hollow cylinder a coolant is dispensed from a coolant source onto the deformation zone only when or predominantly when the circumferential position having the comparatively small wall thickness passes the coolant source.

In a method of manufacturing a tube of quartz glass by molding a hollow cylinder having a wall thickness of at least 20 mm, the cylinder is continuously fed under rotation about a rotational axis into a heating zone at a relative feed rate V.sub.C, softened and radially expanded under the effect of a gas pressure. A tube strand is continuously formed and is withdrawn at a withdrawal rate V.sub.T. In order to mold thick-walled initial hollow cylinders of quartz glass into tubes with larger diameter, the gas pressure is used as an actuating variable of a diameter regulation for the tube outer diameter or for a geometrical correlated parameter thereof, and in a pressure build-up phase the gas pressure is gradually increased from a lower initial value to a higher final value, and that the following applies to the ratio of V.sub.C and V.sub.T:V.sub.T=V.sub.C0.2.Math.V.sub.C.

In a method of manufacturing a tube of quartz glass by molding a hollow cylinder having a wall thickness of at least 20 mm, the cylinder is continuously fed under rotation about a rotational axis into a heating zone at a relative feed rate V.sub.C, softened and radially expanded under the effect of a gas pressure. A tube strand is continuously formed and is withdrawn at a withdrawal rate V.sub.T. In order to mold thick-walled initial hollow cylinders of quartz glass into tubes with larger diameter, the gas pressure is used as an actuating variable of a diameter regulation for the tube outer diameter or for a geometrical correlated parameter thereof, and in a pressure build-up phase the gas pressure is gradually increased from a lower initial value to a higher final value, and that the following applies to the ratio of V.sub.C and V.sub.T:V.sub.T=V.sub.C0.2.Math.V.sub.C.

An apparatus for the automated production of glass assemblies includes: a turning machine with at least two spindles, which are rotatable about a common axis of rotation and which each have a workpiece holder, wherein the workpiece holders are arranged opposite one another; one or more gas burners or lasers fixed on a first tool carriage which is movable in parallel and/or perpendicularly to the axis of rotation; one or more drives for driving a rotational movement of the spindles and a movement of the first tool carriage; a pressure module including a pump device at least one working cylinder for applying a pressure to an inner tube and/or to a space between the inner tube and an outer tube; and a control unit configured to control the burners or lasers, one or more drives, the first tool carriage and the pressure module.

An apparatus for the automated production of glass assemblies includes: a turning machine with at least two spindles, which are rotatable about a common axis of rotation and which each have a workpiece holder, wherein the workpiece holders are arranged opposite one another; one or more gas burners or lasers fixed on a first tool carriage which is movable in parallel and/or perpendicularly to the axis of rotation; one or more drives for driving a rotational movement of the spindles and a movement of the first tool carriage; a pressure module including a pump device at least one working cylinder for applying a pressure to an inner tube and/or to a space between the inner tube and an outer tube; and a control unit configured to control the burners or lasers, one or more drives, the first tool carriage and the pressure module.

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.

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.

A container and a method of manufacturing a container having a base portion and a sidewall which together form a partially enclosed space for holding a fluid; and a cooling element fixedly connected to the base portion, the cooling element comprising a cavity and a cooling material sealed within the cavity.

A container and a method of manufacturing a container having a base portion and a sidewall which together form a partially enclosed space for holding a fluid; and a cooling element fixedly connected to the base portion, the cooling element comprising a cavity and a cooling material sealed within the cavity.