DE2212473A1 - Method and device for covering an elongated flexible body, in particular a telecommunication cable, with a water-impermeable medium and filling in the gap - Google Patents

Description

PAT EN TA N WA LT Τ _β Ιβτ? Η: Τθ2Λ) Τ24 &'^

DIPL-ING. ERICH SCHUBERT Telegram-Adr, Patschub, Si.gn

Postal check accounts: Cologne 100931, Essen 20362

Bank accounts: Abs .: Patent attorney Dipl.-Ing. SCHUBERT, 59 Siegen, Eiserner Strasse 227 Deutsche Bank AG., P.O. Box 462 branches Siegen and Oberhausen (RhId.)

72 016 Kü / Schm

14c March 1972

British Insulated Callender's Cables Limited, 21, Bloomsbury Street, London W.C.1., England

Priority is claimed for this application from British Patent Application No. 6999/71 of March 16, 1971.

Method and apparatus for coating and space-filling an elongate flexible body, in particular telecommunication cable, with a waterproof medium

The invention relates to a method and a Device for both covering and filling the spaces between elongated elements of an elongated one flexible body, which is formed by stranding, bundling or combining a plurality of elongated elements, with a water-impermeable medium (hereinafter referred to as "filler"), which is not readily available from the Body under normal temperature and pressure conditions drips or oozes and which is a relative sliding movement of the elongated Allow elements against each other during the bending of the flexible body.

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The invention relates particularly, but not exclusively, to the manufacture of the so-called "fully filled" telecommunications cable, This is made up of a large number of plastic-insulated conductors that form a core or two or more cable units or cores is subdivided, as well as from a waterproof sheath enclosing the core or cores, the spaces between the insulated conductors of the or each core - and where there is more than one core, in in some cases also between the years - essentially from one end to the other of a cable section are completely filled with the filler. Completely filled telecommunication cables of this type are

en subject of the associated German patent application / DT-AS 1 465 286, P 15 90 151.6, P 20 56 520.2 and P 21 28 952.1.

The filler of such cables is a material that is liquid at a temperature above ambient temperature and turns into a viscous or solid state at ambient temperature. Examples of the material are as follows:

(a) Mixtures of chalk and castor oil;

(b) microcrystalline petroleum oils;

(o) Mixtures of microcrystalline petroleum waxes and oils, for example Vaseline;

(d) semi-solid or grease type polyethylene of low molecular weight and high melt flow index;

(e) mixtures of petroleum jelly, microcrystalline petroleum waxes, polyisobutylene and aluminum stearate;

(f) mixtures of cumeron-indene resins;

(g) a mixture of two or more filler materials (a) to (f).

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In the method for covering and filling the interstices between elongated elements of an elongated flexible body with a filler, the body is guided according to the invention in the direction of its length into and out of a closed chamber, which is filled with filler in a liquid or semi-liquid state and at a pressure is filled above atmospheric pressure, through inlet and outlet dies maintained at such a temperature that there is essentially no leakage of the filler from the chamber through the dies while the body is continuously conveyed through the chamber, and filler in a liquid or semi-liquid state and at superatmospheric pressure is continuously flowed into and out of the chamber at the same time, the pressure of the filler in the chamber and the effective difference between the flow rate of the fill means and the speed of passage of the body with reference to the number and distribution of the elongate elements as well as to the diameter of the body are such that the interstices are substantially freed of air by the filler and substantially filled with it, the filler being cooled in a viscous or solid state makes the body essentially impermeable to the longitudinal flow of water.

By a "semi-liquid state" in relation to the filler is meant a condition in which the filler can be caused to flow below the above atmospheric pressure to which it is subjected.

Two or more separate elongated flexible bodies can be inserted into the closed chamber simultaneously, each in the direction of their length, through one of a corresponding number of inlets.

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letting dies through and out of the chamber through a single outlet die conveyed through and brought together by the latter to form a single composite body, this single outlet die also serves as a closing die or closing nipple. In this case the pressure of the Filler in the chamber and the effective difference between the flow rate of the filler and the rate of passage of the bodies in terms of number and distribution of the elongated elements and, with reference to the diameter of the larger or largest body, such that the spaces between each Body are essentially cleaned of air and essentially filled with filler, which bit into when cooled a viscous or solid state that formed in this way make the composite body substantially impermeable to the longitudinal flow of water.

It should be noted that when the or each body in the chamber is stationary for a length of time long enough in order for their temperature to rise to a level approximating that of the chamber, the relationship between the temperature of the part of the body in a die and the die temperature can be such that the filler in the die has a temperature above their solidification point and some filler leakage may occur. Licking out at this point can be reduced by draining the filler in the chamber manually or automatically when the or every body in the chamber is stationary.

The major part of the flow path of the filler through the chamber is preferably approximately parallel to the Axis of the or each body. To increase the flow rate of the filler relative to the or each body, the direction of flow of the filler is preferably against the direction of passage of the body, but the passage of the

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"~ 5 -

The body and the flow of the filler can, if desired, also be in the same direction, If two or more bodies are conveyed through the chamber at the same time, then the filler in the chamber can also be made to move into more than to flow in one direction.

The pressure of the filler inside the chamber is always above atmospheric pressure and is sufficient to ensure that that the filler penetrates into the interstices of the or each body. When two or more separate elongated Bodies are conveyed into the chamber at the same time and are put together at the outlet die, then needs the Pressure of the filler in the chamber to be only that which is sufficient to fill the gaps of the larger or largest of the separate elongated body to fill, and does not need to be sufficient to fill the spaces of the individual made from it compound body to fill because the action of the closing nipple when bundling the separate body the filler brings to substantially fill the spaces between the bundled or collapsed bodies. In any case, are the pressure at the inlet opening for the filler and the size of the outlet opening for the filler preferably such that the Volume of filler in a liquid or semi-liquid state which passes through the chamber in a given Time is a multiple of the volume of the body, or the Suiune is the volume of the body which is at the same time Time to run through the chamber.

Even if the method according to the invention is used for this can be, the gaps between the insulated conductors of a telecommunication cable layer by layer during the manufacture of the To cover and fill cables on a conventional stranding or bundling machine, the process is in particular but not exclusively, suitable for enrobing and filling

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of a cable or cable core in a single operation, i.e. dadur.ch that the stranded core, the bundled cable core or two or more cable units that form a cable core are to be bundled, be promoted through a single closed chamber.

The inlet and outlet matrices can be kept at the desired temperature by natural cooling by Dies or die holders of such a shape are used that the heat loss at the dies is sufficiently high is to vttcosen the filler near the matrices in «inen or solid state, but preferably the temperature of the matrices is at the desired low value artificial means held, e.g. by forced cooling with a medium, e.g. water.

The invention also comprises an apparatus for carrying out the method described above, wherein the The device is composed of a closed chamber, at least an inlet die through which an elongated flexible body can pass into the chamber, from an outlet die through which an elongated flexible body can pass out of the chamber, from a device associated with the matrices which maintains them at a temperature such that no substantial leakage of! filler from the chamber takes place through the matrices while the body is continuous through the chamber is conveyed, as well as from inlet and outlet openings in the chamber through which openings the filler in a "liquid or semi-liquid state into the chamber and can flow out of this chamber at a pressure above atmospheric.

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The chamber preferably has an elongated shape and a substantially cylindrical cross-section. If a single one elongated body is to be conveyed through the chamber, then an inlet die and an outlet die arranged coaxially with the chamber at the opposite ends thereof.

When two or more separate elongated bodies at the same time are to be conveyed into the chamber and are to be brought together at the outlet die, then a corresponding Number of inlet matrices arranged at one end of the chamber to achieve the desired final shape of the formed therefrom collapsed elongated body, and the outlet die is at the opposite end of the chamber and arranged coaxially to this.

The inlet and outlet openings for filler are preferably at opposite ends of the peripheral wall of the chamber near the inlet and outlet matrices but spaced apart arranged by these. If the chamber is of such a size that it permits two or more bodies to to be conveyed through them simultaneously, then two or more inlet openings for introducing the filler and two or more outlet openings are provided for discharging the filler. The chamber is preferably heated and thermostatically controlled to keep the filler at the required temperature while it is in the chamber, and it is preferably enclosed by a suitable heat insulating material.

In order to limit heat loss from the chamber in the vicinity of each die, each die is preferably opposed the chamber is thermally insulated, for example by a preformed one

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annular body of thermal insulation material, which is between one end of the closed chamber and the die or the Matrices is arranged. The dies are each normally round in cross-section and can run through a length of pipe be formed, for example from metal or Kermjaik material, which through an annular chamber for a forced flow of a Coolant, e.g. water. Alternatively, each die or a holder for the die with radially extending Ribs can be equipped to increase the heat loss on the pipe. The or each inlet die can be a closure die or a closing nipple through which a bundle or stranded strand of elements or an outer layer of elements is formed, but it is preferably one of a closing nipple separate die. If a single elongated body is to be conveyed through the chamber, the The bore of the outlet die must be the same as that of the inlet die or slightly larger. When two or more separate to demand elongated bodies through the chamber at the same time then the bore of the outlet die may be the same as that of the overall diameter of the bundled composite body or slightly larger.

If a completely filled cable is made on a conventional stranding or bundling machine, then the device according to the invention on the outlet side of the end stranding or bundling head or on the outlet side any of some or all of the stranding or bundling heads of When the production of a completely filled Kate.3 is carried out on a conventional planter and it is necessary to fill the cable in a single operation, then the device according to the invention can instead the conventional laying plate / matrix device. In any case, the device according to the invention

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arranged in flow direction upstream of a conventional extrusion machine for applying a plastic sheath to the cable core will.

The closed chamber of the or each device can be filled with filler in a liquid or semi-liquid state supplied directly from a separate feed tank associated with the device, that from the outlet port The filler coming from the chamber is immediately returned to the tank. The separate feed tank can be placed directly below the chamber of the device with which it is associated and can therefore be used as a collecting tank for any Serve filler that can leak out of the matrices when the or each body in the chamber is stationary o The Walls of the tank may extend upward near, but spaced from, the inlet and outlet matrices of the chamber and may carry or matrices to stabilize the or each body as it travels to and from the chamber keep. Alternatively, the chamber can also be fed with filler from a circulation system, which the closed chambers some devices, the filler from the outlet opening of each closed chamber in the latter case after a collection tank, from where it is returned to a feed tank which is switched into the circulation system is and this served

The invention will now be described with reference to the drawing which shows it by way of example and which shows two embodiments of a device according to the invention, namely shows

Fig. 1 is a sectional side view of a device

for covering and filling the spaces between plastic-insulated conductors with Vaseline, whereby the conductors form the core of a telecommunications cable,

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- ίο -

Fig. 2 in a similar view of a device for Coating and filling the spaces between plastic-insulated conductors of each of five units with petroleum jelly, whereby the units are to be put together to form the composite core of a Telecommunication cable,

Fig. 3 is an end view of the device of Fig. 2, while

4 shows a schematic representation of the device according to FIG. 1 or according to FIGS. 2 and 3 in association with a separate feed tank for liquid petroleum jelly.

The device shown in Fig. 1 has a tubular Chamber 1, which is surrounded by a heating device 2 and an inlet opening 3 and an outlet opening 4 for exhibits the flow of petroleum jelly in the liquid state into and out of the chamber. At one end of the chamber 1 is located an inlet die 5 through which a core of stranded plastic-insulated conductors can get into the chamber, and is located at the opposite end of the chamber an outlet die 6 through which the core can exit the chamber. The outlet die 6 has a bore, which is slightly larger than that of the inlet die 5. The inlet and outlet matrices 5 and 6 are each annular Associated cooling chambers 7 and 8, through which water or another coolant is circulated to cool the die. Annular bodies 9 and 10 made of heat insulating material are each arranged between the chamber 1 and the dies and 6 and the cooling chambers 7 and 8 to prevent heat loss limit out of the chamber near each die.

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A pressure gauge is provided to enable a continuous reading of the pressure of petroleum jelly within the chamber 1.

In use, the core is fed through the chamber 1 and petroleum jelly becomes continuous in the liquid state conveyed into and out of the chamber at a pressure above atmospheric pressure, wherein the general direction of flow of the petroleum jelly within the chamber is approximately parallel, but in the opposite direction Direction to the running direction of the core. On the dies 5 and 6, the cooling chambers 7 and 8 hold the dies on one such a temperature that there is no substantial leakage of petroleum jelly from the chamber through the dies. Of the Pressure of the vaseline in the chamber 1 and the effective difference between the flow rate of the vaseline and the Throughput speed of the core are in relation to the number and distribution of the plastic-insulated conductors and on the diameter of the core so that the spaces in the core through the petroleum jelly can be purged of air and essentially filled with petroleum jelly. When cooling in a viscous or solid Condition, the petroleum jelly makes the core essentially impermeable to the longitudinal flow of water.

In the device according to FIGS. 2 and 3, a tubular ' shaped chamber 11 surrounded by a heating device 12 and has an inlet opening 13 and an outlet opening 14 for the Flow of petroleum jelly in a liquid state into and out of the chamber. Located at one end of the chamber five inlet matrices 15 ', through each of which one of five cable units is conveyed into the chamber can, with each unit a variety of plastic-insulated Has ladders. An outlet die 16 is arranged at the opposite end of the chamber and serves as a closing nipple for

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Bringing the five units together to form a composite To form the core, the outlet die having a bore that is slightly larger than the total diameter of the composite Core is. As with the device described with reference to Figure 1, the inlet and outlet matrices 15 and 16 are respectively surrounded by annular cooling chambers 17 and 18, and annular bodies 19 and 20 made of heat insulating material are arranged between the chamber 1 and the dies and the cooling chambers.

The typical pressure of petroleum jelly in the liquid state and typical dwell sides of a cable core or cable cores within the chamber of the devices shown in the drawings for coating and impregnating cores of different Dimensions in a single operation before applying one or more layers of electrical tape to the filled core are given below, for example:

diameter Number of pairs Number of Print of the Core residence time d. isolated in the separate core Locations in Vaselines in the chamber Conductor (mm) separate core in the (in sec.) Chamber in KN / m ² 0.9 30th 3 110 1.0 1.25 50 4th HO ¹ t ° 0.8 100 6th 210 1.0

As can be seen from Fig. 4, the chamber of the Fig. 1 · or in FIGS. 2 and 3 shown device with Vaseline in the liquid state directly from a separate supply

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or · feed tank 30, which is directly below the chamber is arranged. Vaseline is supplied by a pump 31 through the inlet port is pumped into the chamber and is taken in directly from the chamber returned the tank. The tank is also used to collect any Petroleum jelly that leaks out of the matrices when the core or cores are stationary in the chamber. Such a leak can be reduced by allowing a little petroleum jelly to drip off normally or automatically when the core or the Cores in the chamber are stationary. The end walls of tank 30 extend upwardly near the inlet and outlet matrices and carry holders 32 which hold dies for stabilizing the core or cores entering the device and be promoted out of this.

The invention also relates to modifications of the enclosed Claim 1 outlined embodiment and relates above all to all features of the invention, which in detail - or in combination - are disclosed throughout the description and drawing.

Claims

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Claims (1)

-H- 72 016 k / h. U. March 1972 Claims • [Procedure for covering and filling the spaces between, elongated elements of an elongated flexible Body with a filler, characterized in that the body in the direction of its length in a closed chamber (1) and is conveyed out of this, which with filler in liquid or semi-liquid state and with a Druok is filled above atmospheric pressure, is also conveyed through inlet and outlet matrices (5,6), which on a The temperature must be maintained so that there is no substantial leakage of filler material from the chamber through the dies takes place while the body is continuously moving through the chamber, and that at the same time the filler in a liquid or semi-liquid state and with superatmospheric pressure is caused to flow continuously into and out of the chamber, the Druok des Filler in the chamber and the effective difference between the flow rate of the filler and the thermoset flow rate of the body with reference to the number and distribution of the elongated elements and with reference to the durometer of the body are chosen so that the interstices are essentially cleaned of air by the filler Ib and are essentially filled with this, with the coolant in a viscous or solid state when cooled Makes the body substantially impermeable to the longitudinal flow of water. 2. The method naoh claim 1, characterized in that two or more elongated flexible bodies, each of which has a plurality of elongated elements, is caused, 209840/1038 at the same time in the direction of their length into the closed chamber through one of a corresponding number of inlet matrices (15) to pass through and out of the chamber through the outlet die (16) and collapsed by this to be to form a single composite flexible body, with the number and distribution of elongated elements and the diameter of the larger or largest body, the pressure of the filler in the chamber and the effective difference between the flow rate of the filler and the flow rate of the body, which are necessary to determine the To clear the gaps of each body of air and to fill them with filler, which turns into a viscous one when it cools down or solid state, the single composite flexible body is substantially impermeable to the longitudinal flow of water power. 3 · Method according to claim 1 or 2, characterized in that the pressure of the filler at an inlet opening (13) for the filler and the dimension of an outlet opening (H) for the filler are chosen so that the volume of the filler in a liquid or semi-liquid state which is conveyed through the chamber in a given time becomes, a teaching subject a dee volume of the body or the sum is the volume of the bodies which are conveyed through the chamber at the same time. 4-. Method according to one or more of the claims 1 to 3, characterized in that the majority of the flow path of the filler through the chamber approximately runs parallel to the axis of the or each body 209840/1038 • - 16 - 5. The method according to claim 4 »characterized in that Hindu the direction of flow of the filler through the chamber runs counter to the direction of passage of the or each body. 6. The method according to one or more of claims 1 to 5, characterized in that the inlet and outlet matrices be kept at the desired temperature by forced cooling with a medium. 7. The method according to one or more of claims 1 to 5, characterized in that the inlet and outlet matrices be kept at the desired temperature by natural cooling, with dies or holders for dies of be used in such a way that the heat loss at the dies is sufficiently high to keep the coolant in the lhe to convert the matrices into a viscous or solid state. 8. The method according to one or more of the claims 1 to 7, characterized in that the chamber is heated to bring the filler in the chamber to the required temperature to keep. 9. Process for the production of a multi-conductor cable core by the conventional stranding, bundling or lying process, characterized in that the spaces between insulated conductors of a stranded or bundled core, a collapsed Cable core or of two or more cable units which are to be put together to form a cable core a filler by the method according to one or more of claims 1 to 8 and filled. 209840/1038 1Oe device for covering and filling the spaces between elongate elements of an elongate body with a filler by the method of claim T, characterized in that the device is composed of a closed chamber (1), of at least an inlet die (5, 15) through which an elongated flexible body can pass into the chamber from an outlet die (6,16) through which an elongated flexible body can get out of the chamber, from a device (17 * 18), which is assigned to the matrices in order to keep them at such a temperature that essentially no Leakage of filler from the chamber through the dies takes place while the body is continuous is conveyed through the chamber, as well as from inlet and outlet openings (13,14) in the chamber through which the Filler in a liquid or semi-liquid state in and out of the chamber at superatmospheric Pressure can be made to flow. 11 ο device according to claim 10, characterized in that that the closed chamber has an elongated shape and is of substantially cylindrical cross-section, and that the inlet and outlet matrices are coaxial with the chamber at opposite ends thereof. 12. Apparatus according to claim 10 for coating and filling the spaces between elongated elements of two or more elongated flexible bodies with a filler, while the bodies are collapsed to form a single composite flexible body, characterized by 209840/1038 draws that the closed chamber has an elongated shape has and has a substantially cylindrical cross-section, and that two or more inlet matrices (15) at one end of the Are arranged chamber, through which two or more elongated flexible body in the Kammerjinin in the desired Can get final shape of the single composite flexible body, and that the outlet die (16) coaxial to Chamber is located at the opposite end of the chamber and is of such a size that it collapses the bodies, to form the only composite flexible body. 15 · NaOH apparatus of claim 11 or 12, daduroh in that the inlet and Auslaßöffungen (13,14) are arranged for dae filler on opposite ends of the peripheral wall of the chamber near the inlet and Auslaßmatrizen, but at a distance from these, . 14. Device according to one or more of the claims 10 to 13, characterized in that a heating device (2) the chamber is assigned to the filler on the required Maintain temperature while 6 * is in the chamber. 15. Device according to one of claims 10 to 14, daduroh characterized in that the chamber is surrounded by a heat insulating material. 16. The device according to one or more of claims 10 to 15, characterized in that each die opposite the chamber is thermally insulated. 209840/1038 17 «Device according to one or more of the claims 10 to 16, characterized in that each die is formed by a piece of pipe. 18. The device according to claim 17, characterized in that that the tube which forms each die is surrounded by an annular chamber (17, 18) for a forced flow of a coolant. 19. Device according to claim 17, characterized in that that the tube or die holder forming each die has radially extending ribs to increase heat loss is formed from the tube. 20. Device according to one or more of the claims 10 to 19, characterized in that the closed chamber the device is assigned a supply tank (50) for filler, that a pump (31) for pumping coolant from the tank is provided naoh the inlet opening of the chamber and that the tank is arranged so that filler from the Outlet opening can return directly to the tank. 21. The device according to claim 20, characterized in that the supply tank is immediately below the chamber and the matrices of the device. 22 device according to claim 21, characterized in that that the walls of the tank extend upwardly near, but spaced from, the inlet and outlet matrices and matrices (32) for stabilizing the or each body 209840/1038 carry or hold as it runs to or from the chamber. 23 · Device according to one or more of the claims 10 to 19 »characterized in that the chamber of the device has a circulation system for filler for the supply of filler naoh the closed chamber of at least one device is assigned that a collecting tank of the outlet opening of the chamber is assigned and that a pump for pumping filler from the collection tank back into the circulation system or into a supply tank is provided, which is switched into the supply system and serves this. 24. Apparatus for producing a conductor cable core including a conventional stranding or bundling machine, characterized in that the device according to one or more of claims 10 to 23 for covering and filling the spaces between the isolated Directing the core with a filler on the outlet side of the end stranding or bundling head or on the outlet side of any of some or all of the stranding or bundling heads of the machine. 25. Apparatus for producing a composite multi-conductor cable core including a conventional laying machine, characterized in that the device according to claim 11 for covering and filling the interstices " between the insulated conductors of each unit of the composite core to be formed with a filler instead of the conventional one Laying plate ^ / faatrizen device is arranged. 26. The device according to claim 24 or 25, characterized in that in the flow direction after the covering and filling device an extrusion machine is provided for applying a plastic sheath to the cable core. 209840/1038 Blank page