DE8437106U1 - Device for producing longitudinally watertight telecommunication cables - Google Patents

Description

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cablemetal electro
Limited liability company

84-61/F

17 December 1984

Device for the production of watertight telecommunication cables

The invention relates to a device for producing longitudinally watertight telecommunications cables with plastic-insulated cores, in which the cavities of the cable core are filled with a sealing material, consisting of a chamber in which the sealing material is pressed under pressure into and around the cable core to be filled and which is equipped with ring-shaped sealing elements enclosing the core at the entry point and exit point, as well as a device with which a jacket is applied to the filled core.

Filling the cavities in the core and between the core and the sheath of telecommunications cables with sealing material serves to prevent, in the event of damage to the cable sheath, a leak at one point in

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Water that has penetrated the core can penetrate along the plastic-insulated wires in the lengthwise direction of the cable. If the penetration of water is not prevented, short circuits can occur in connecting sleeves between the individual transmission circuits and the electrical values of the cable as a whole are significantly impaired. Devices have therefore been developed to seal the cores of plastic-insulated telecommunications cables. A Vaseline-like mass, referred to below as "filler", is used as a sealing material, for example, which is highly viscous at room temperature and can be liquefied by applying heat. Because of the temperature-dependent consistency of the filler, it is necessary to liquefy it before it is introduced into the cable core. Suitable processes and devices are known for this purpose.

In the chamber provided for the filling process, the filling compound is introduced into the core of the cable to be filled by applying pressure. The entry and exit points of the core, which is continuously moved through the chamber, must be so tight that, on the one hand, the required pressure can be generated and maintained in the chamber and , on the other hand, that no filling compound escapes from the chamber. This requirement must be met regardless of the viscosity and regardless of the number of stranding elements present in the core.

A device as described above is known from DE-PS 25 23 843. In this known device, which is intended in particular for cables with larger diameters, ring-shaped sealing elements are provided in the form of ring disks made of elastic material, the inside diameter of which can be changed. The sealing elements are thus adjustable so that they always lie tightly against the core to be filled. With this known device , it is only possible to fill higher-pair and therefore correspondingly thicker cores of telecommunication cables at low production speeds and with filling materials that have to be kept at low temperatures. Despite the tight fit of the sealing elements on the core, there is also a build-up of air on both sides of the chamber.

(3LF343)

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Filling mass is released, which must be collected and returned to the filling device. Due to the tight fit of the sealing elements on the core and the resulting increased friction, relatively high extraction forces are also required*

The invention is based on the object of specifying a device with which the cores of telecommunications cables of any diameter can be filled with a filling compound of any viscosity and with which the core can be pulled through the chamber at increased speed with the usual pulling force.

This object is achieved in a device of the type described above according to the invention in that each annular sealing element consists of at least one tube through which a coolant flows, which is formed by bending into an annular component, the inside width of which corresponds to the diameter of the core and in which the The individual sections of the pipe lie loosely but tightly against one another when the device is in the rest position.

The ring-shaped components bent from the tube can be dimensioned so that their inside diameter corresponds to the nominal diameter of a core of a telecommunications cable to be filled. The core is thus tightly surrounded by a sealing element that does not rest particularly firmly on the core, so that no increased pulling force has to be applied to it. Since the pipe is constantly flowing with a coolant during the filling process, the warm filling compound is cooled down within the sealing elements and thus solidified. The The filling compound seals the gap between the core and the tubular component itself. It becomes so solid towards the end of the component that it can no longer escape or can only escape in small quantities as a "lubricant". Pressure or leakage losses due to excess filling compound therefore no longer occur.

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Since the individual sections of the pipe in the component that represents the sealing element fit loosely against one another, the component can give way when the diameter changes, so that the core is not damaged by a sealing element that is too tight, for example when the diameter increases.

In a preferred embodiment, the tube is bent in a helical shape to produce the sealing element, with the individual turns lying close to one another. This results in the further advantage that the inside diameter of the component thus created can be changed by rotating at least one of the two tube ends around the axis of the component. The component can then be used as a sealing element for cores with different diameters without further changes.

Embodiments of the subject matter of the invention are shown in the drawings.

Show it:

Fig. 1 shows a schematic representation of the entire device according to the invention.

Fig. 2 shows a detail of the device in an enlarged view.

Fig. 3 and 4 two different designs for the sealing element in a further enlarged view.

Fig. 5 is a partial side view of Fig. 4. 1 is a coil from which a fully stranded Core 2 of a telecommunication cable is removed. The core 2 is then placed in

a chamber 3 with a pressure head 4, to which pipe sections 5 and 6 After exiting the outlet pipe,

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piece 5, the core 2 is guided through an extruder 7, in which a protective sheath is applied to the filled core 2, so that a finished telecommunications cable 8 emerges from the extruder 7. The telecommunications cable 8 is then wound onto a spool 9, which can simultaneously serve as a take-off for the telecommunications cable 8.

For the sake of simplicity, all devices known from conventional technology, such as melting devices for the filling compound, monitoring devices for the required pressure and the correct viscosity of the filling compound, have been omitted from the drawing in Figs. 1 to 4.

According to the illustration in Fig. 2, the pipe section 6, in which a sealing element 10 indicated by a small box is located, is attached to the pressure head 4 of the chamber 3, in which the filling compound is pressed into and around the core 2, on the inlet side. An identical sealing element 11 is attached to the pipe section 5, which is attached to the pressure head 4 on the outlet side.

The sealing elements 10 and 11 consist of tubes through which a coolant, for example water, flows. To produce a sealing element, a tube 12 can be used as shown in Fig. 3 for example, be bent in a helical manner, so that a ring-shaped component 13 is produced in which the turns of the tube 12 lie flush against one another. The inside diameter of the component 13 corresponds to the diameter of a core of a telecommunications cable to be filled. It can be changed by, for example, bending the end 14 of the tube 12 is rotated around the axis of the component 13, while at the same time the other end 15 of the pipe 12 is held. However, it is also possible to rotate both pipe ends 14 and 15 to change the diameter, in which case they must be rotated in opposite directions.

The tube 12 preferably has a square cross-section with rounded corners. This results in a very large surface for cooling the filling compound without any gaps into which the filling compound could escape. The component 13 can have a length that corresponds at least to the diameter of a core to be filled. The component 15 is preferably three times as long as the diameter of the core to be filled.

Because the component 13 consists of a helically wound tube 12, there are slanted edges at the entry and exit points of the core to be filled. In order to create edges at these points that are at right angles to the direction of movement of the core, V-shaped filler pieces 19 and 20 can be attached to the ends of the component 13.

In the embodiment of the sealing element shown in Fig. 4, a tube 16 is bent in a meandering manner to form an annular component 17.

XS The main direction of the meandering loops extends in the axial direction of the component 17. This embodiment of the component representing the sealing element has the advantage that it can automatically adapt to fluctuating diameters of a core to be filled, because its loops are formed by a thicker core can be easily pressed apart. To ensure that component 17 always returns to its smallest diameter, at least one spring ring 18 can be attached around the outside of it. The same statements apply to the cross-sectional shape and dimensions of pipe Iv" and component 17 as for the same parts in Fig. 2.

The components 13 and 17 are arranged as sealing elements 10 and 11 in the pipe sections 5 and 6, respectively, and are secured against displacement therein. Of course, more than one component 13 or 17 can be used for each sealing element 10 or 11. It is also possible to combine both variants shown in Figs. 3 and 4 in one sealing element.

(3LF343)

Claims (6)

totetrfflispruche 1. Device for producing longitudinally watertight telecommunications cables with plastic-insulated cores, in which the hollow spaces of the cable core are filled with a sealing material, consisting of a chamber in which the sealing material is pressed under pressure into and around the cable core to be filled and which is equipped with ring-shaped sealing elements enclosing the core at the inlet and outlet points of the core, as well as a device with which a jacket is applied to the filled core, characterized in that each ring-shaped sealing element (10, 11) consists of at least one tube (12, 16) through which a coolant flows, which is formed by bending into an annular component (13, 17) whose inside diameter corresponds to the diameter of the lit* &bull; The ' · » &igr;&igr;&eegr; · · · I 4 · II Λ C t · · core (2) and in which the individual sections of the tube (12, 16) lie loosely but tightly against one another in the rest position of the device. 2. Device according to claim 1, characterized in that the tube (12) is bent in a helical shape and that its ends (14, 15) project radially outward from the annular component (13). 3. Device according to claim 1, characterized in that the tube (16) is bent in a meandering manner such that its main direction extends in the axial direction of the annular component (17). 4. Device according to claim 1 or 3, characterized in that at least one annular spring (18) is arranged around the annular component (17). 5. Device according to one of claims 1 to 4, characterized in that the tube (12, 16) has a square cross-section. 6. Device according to one of claims 1 to 5, characterized in that the tube (12, 16) consists of copper.