Abstract: In a method of laying a cable, or a pipe for the subsequent introduction of a cable, in a fresh-water conduit, the surface of the cable or pipe is cleaned during the laying process immediately before entering the fresh-water conduit.

Abstract: The invention relates to a method of installing cables, in particular glass-fiber cables, in drinking water pipes and also to a cable suitable for drinking water pipe installation. In order to avoid contamination of the cable and to exclude contamination of the drinking water, provision is made that the cable is covered with a protective sheathing that is stripped off prior to contact with the drinking water. A cable suitable for this purpose can be covered already during its production process with the strippable protective sheathing.

Abstract: In a method of laying a cable, or a pipe for the subsequent introduction of a cable, in a fresh-water conduit, the surface of the cable or pipe is cleaned during the laying process immediately before entering the fresh-water conduit.

Abstract: The invention relates to a cable holding means within a pipe (1) having at least one holding element, which is secured on the inside wall (2) of the pipe (1), and at least one clamping element (4), which is secured on the holding element for the purpose of receiving the cable (5) or the cable bundle. In order for the cable or cable bundle to be held simply and reliably even when the course of the cable is highly curved, it is provided for the clamping element (4) to be secured on the holding element such that it is rotatable about a radial axis of the pipe (1).

Abstract: An optical fiber (1) has an outer coating (4) enclosing the cladding (3) and the fiber core (2). The coating has one or more plastic layers and a color coding in the form of an annular marking on or in the outermost plastic layer. The annular marking is open colored rings.

Abstract: A method for coating an optical fiber (1) has the optical fiber (1) exiting the longitudinal direction through a coating nozzle (10) from a volume (11) which is filled with a liquid hardenable coating material (6). The surface of the fiber is spaced from the wall (12) of the coating nozzle (10). The viscosity of the coating material (6) at room temperature is greater than 2500 mPa.multidot.s and the temperature of the coating material (6) is adjusted high enough for the coating material (6) to have a viscosity of less than 2000 mPa.multidot.s.

Abstract: An apparatus is proposed for controlling the coating thickness of an optical fiber (2) passing sequentially, in that order, from a unit (1) for fabricating the fiber (2) through a cooling unit (3), a coating unit (4) and along a device (5) which determines the diameter of the fiber. The apparatus includes a control element (14) for controlling a control device (15, 16) as a function of the measured diameter in such a way that the thickness of the coating corresponds to a target value, wherein the control device (15, 16) is placed before the coating unit (4) when viewed in the transport direction of the fiber (2), and the control device (15,16) adjusts the temperature of the fiber (2). Also described is a method for controlling the coating thickness.

Abstract: To draw an optical fiber (10) from one end of a glass preform (9) which is heated to above the glass softening temperature at least in that area, a gas (21) flows around the preform (9) into a furnace space (16) during the drawing process and subsequent feeding of the preform. During the feeding, the areas that are adjacent to the drawing end of the preform (9) pass through gas zones in which the helium content of the furnace gas increases in the drawing direction.

Abstract: During the fire-polishing of a lengthwise extended glass body (3), for example a preform for drawing optical fibers, the glass body (3) is held by a holding device (5, 7), and is heated by a burner (23) moving at a variable advancing speed parallel to the lengthwise axis (19). The surface temperature of the glass body (3) is determined with a temperature measuring device (25). The mechanical stress condition of the glass body (3) is detected with an optical device (29) and can be controlled by varying the burner temperature and/or the advancing speed of the burner. The invention makes it possible to counteract the occurrence of high mechanical stresses in the glass body (3).

Abstract: In an optical fiber (1) with a coating (8) for the cladding of one or more plastic layers containing the fiber core and a color marking (3) on or in the outer plastic layer, the color marking (3) is covered by a further transparent or translucent layer (4).

Abstract: An apparatus for heating an elongated glass body, which, for example, may be used as a pre-form for the drawing of glass fibers, includes a rotatable first chuck wherein the first end of the elongated glass body may be rotatably secured. In addition the apparatus includes a second rotatable chuck whereat the second end of the elongated glass body is introduced into a quartz tube and this quartz tube is clamped into the rotatable second chuck. A burner, which is adapted to slide parallel to the longitudinal axis of the elongated glass tube, heats the elongated glass body in such a manner, that a so called fire polish of the elongated glass body for the improvement of its surface quality occurs. A method for heating the elongated glass body is also disclosed.

Abstract: A device for coating an optical fiber, for example a glass fiber drawn from a glass preform, comprises a housing (3) with a lengthwise bore (11), into which a nozzle holder (13) containing a receiving aperture (25) is press-fit. An inlet nozzle (33) and an outlet nozzle (43), through which the optical fiber (1) can pass, are press-fit into the receiving hole (25) of nozzle holder (13) at a distance from each other. A coating space for applying a coating material to the optical fiber (1) is located between the inlet nozzle (33) and the outlet nozzle (43). The press-fitting of the nozzles (33, 43) into the nozzle holder (13), and press-fitting the nozzle holder (13) into the housing, achieves better reproducibility of the nozzle (33, 43) positioning when the device is being assembled.

Abstract: To increase the identification characteristics of optical fibers (9) with one or more protective covers (10, 11) and an external color coating (12) of UV-hardened varnish, additional different color identification markings (13) are integrated into the external color coating (12).