GB1560960A - Impregnating cable - Google Patents

Impregnating cable Download PDF

Info

Publication number
GB1560960A
GB1560960A GB48443/77A GB4844377A GB1560960A GB 1560960 A GB1560960 A GB 1560960A GB 48443/77 A GB48443/77 A GB 48443/77A GB 4844377 A GB4844377 A GB 4844377A GB 1560960 A GB1560960 A GB 1560960A
Authority
GB
United Kingdom
Prior art keywords
cable
sealing material
duct
inlet
viscous
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB48443/77A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Publication of GB1560960A publication Critical patent/GB1560960A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01BCABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B7/00Insulated conductors or cables characterised by their form
    • H01B7/17Protection against damage caused by external factors, e.g. sheaths or armouring
    • H01B7/28Protection against damage caused by moisture, corrosion, chemical attack or weather
    • H01B7/282Preventing penetration of fluid, e.g. water or humidity, into conductor or cable
    • H01B7/285Preventing penetration of fluid, e.g. water or humidity, into conductor or cable by completely or partially filling interstices in the cable
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01BCABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00Apparatus or processes specially adapted for manufacturing conductors or cables
    • H01B13/32Filling or coating with impervious material
    • H01B13/322Filling or coating with impervious material the material being a liquid, jelly-like or viscous substance
    • H01B13/323Filling or coating with impervious material the material being a liquid, jelly-like or viscous substance using a filling or coating head
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A30/00Adapting or protecting infrastructure or their operation
    • Y02A30/14Extreme weather resilient electric power supply systems, e.g. strengthening power lines or underground power cables

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacturing Of Electric Cables (AREA)
  • Insulated Conductors (AREA)
  • Processing Of Terminals (AREA)

Description

(54) IMPREGNATING CABLE (71) We, TELEFONAKTIEBOLAGET L M ERICSSON, a company organised under the laws of Sweden, of S-126 25 Stockholm, Sweden, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention related to impregnating cable.
A method and an apparatus for impregnating cable are described and claimed in our British Patent Specification No. 1,444,663.
According to one aspect of this invention there is provided a method of impregnating cable with water-impenetrable and waterrepellent sealing material, the cable comprising a plurality of insulated conductors, in which method such cable is passed through a portion of duct between which and the cable and along the length of the portion of duct is formed a gap around the cable, and, in a first impregnation process, sealing material is heated and is supplied in liquid form into a middle section of the portion of duct from an inlet at a distance from each of two ends of the portion of duct and in a second impregnation process, outside the portion of duct, sealing material in a more viscous state than the first-mentioned sealing material forces a replacement of the first-mentioned sealing material in peripheral interstices of the cable.
The second impregnation process could be carried out in a coating head through which the cable passes after leaving the portion of duct, the inlet and the outlet of the head each being provided with a die which has a tapered input portion where the diameter decreases in the direction in which the cable moves, the coating head being supplied with the more viscous sealing material under pressure to give the first-mentioned sealing material in peripheral layers of the cable a flow path opposite to the movement of the cable, causing such sealing material to be replaced by more viscous sealing material, this being pressed between outer conductors of the cable to form a sealing layer.
According to another aspect of this invention there is provided apparatus suitable for impregnating cable with water-impenetrable and water-repellent sealing material, such cable comprising a plurality of insulated conductors, the apparatus including a portion of duct having open ends, through which portion of duct such cable can be passed with a gap around the cable and between the cable and the portion of duct along the length of the portion of duct, the apparatus further including an inlet into a middle section of the portion of duct at a distance from each of the ends of the portion of duct, means for heating sealing material and supplying it in liquid form to the inlet for impregnating such cable in a first impregnation process as the cable passes through the portion of duct, and coating means outside the portion of duct through which such cable passes after leaving the portion of duct, for applying to the cable sealing material in a more viscous state than the first-mentioned sealing material in such a way that, in a second impregnation process, the more viscous sealing material forces a replacement of the first-mentioned sealing material in peripheal interstices of the cable.
The invention also comprises cable which has been impregnated using a method or an apparatus according to the invention.
The invention will now be described by way of example with reference to the single figure of the accompanying drawing which is a longitudinal section of apparatus suitable for impregnating cable.
The apparatus shown in the drawing comprises a pipe 10 with open ends and an inlet 11 for sealing material, for example Vaseline (Registered Trade Mark), situated between the ends. More exactly, the inlet 11 is situated half-way between the ends. The pipe 10 is in a box 12 provided with a lid 13, the box being provided with two holders 14 for the pipe 10 and being arranged for picking up and diverting surplus sealing material. The holders 14 also comprise holding means whereby drainage chambers 15 communicate with the ends of the pipe 10 and the holding means are arranged, together with splash shields 16 outside them and bushes 17, to draw-off and catch surplus sealing material. In the chambers 15, there are flap members to reduce the flow of sealing material out of the chambers along cable passing through the pipe.
In a first impregnation process using the apparatus, cable 18 comprising several insulated conductors is conveyed to pass through the pipe 10 between which and the cable 18 there is an annular gap along the length of the pipe 10, which gap is thin compared with the diameter of the cable. The sealing material is heated and supplied in a liquid state under pressure to the inlet 11 by means not shown.
The apparatus furthermore comprises a coating head 20 comprising an inlet die 21, a pressure chamber 22 and an outlet die 23. The two dies are relatively short and each is exchangeable for adaptation to cables of different dimensions.
The pressure chamber 22 is fed at constant pressure with sealing material (for example, Vaseline or a Vaseline-based sealing material) which has such a temperature that it is in a more viscous state than the sealing material supplied to the inlet 11 and, after coating, is solid. The two dies 21 and 23 each has a partconically shaped input portion but have cylindrical output portions. Experience has shown that the cylindrical portions can each have an inner diameter which is smaller than the diameter of the cable and a length which is about the diameter of the cable, without the insulation of the outer conductors of the cable being damaged on passage through the dies-the insulated conductors impregnated and surrounded by sealing material can be somewhat compressed without being damaged and the sealing material reduces friction between the cable and the dies.This condition is advantageous as the more viscous sealing material, as a result of the dies, is prevented from penetrating into the box 12 for surplus liquid sealing material and by the outlet die 23 being pressed between the outer conductors of the cable where a change from a liquid to a more viscous sealing material is effected and thus a stable layer having a good adherence to the cable is formed. This layer prevents drainage from the cable during its movement away from the apparatus to a station for screw-line or longitudinal coating of one or more heat protecting bands. Thus, the coating head and the not-shown means for supplying under pressure the more viscous sealing material comprises coating means for carrying out a second impregnation process on the cable 18.
The cable which is to be impregnated can be coiled or banded and if so in such a way and with such a material that the more viscous sealing material easily reaches and penetrates between outer conductors. As an example of such a material, polyester-band banded in an open screw-line can be mentioned.
The cable can also be provided with a layer yarn or narrow bands which are preferably crossed over the cable, that is one layer with a right-hand pitch and one with a left-hand pitch so that a checked pattern of band or yarn is formed.
The length of each of the part-conical portions of the dies 21 and 23 is preferably 1-2 x D where D is the diameter of the cable and preferably half of the cone angle of each of the conical portions is in the range from 1-5 to 3 degrees. The length of the cylindrical portion of each of the dies is preferably O S- 1-5 x D, its inner diameter being preferably 0-9$0-98 x D.
If petroleum jelly is used as the sealing material, the pressure and temperature in the first impregnation process are preferably in the range from 0 5 to 1-5 bars and in the range from 5 to 15 centrigrade degrees above the drop point (90 centigrade); and the pressure and temperature in the second impregnation process are preferably in the range from 01 to 0 3 bars in and the range from 20 to 400 centigrade.
WHAT WE CLAIM IS: 1. A method of impregnating cable with water-impenetrable and water-repellent sealing material, the cable comprising a plurality of insulated conductors, in which method such cable is passed through a portion of duct between which and the cable and along the length of the portion of duct is formed a gap around the cable, and, in a first impregnation process, sealing material is heated and is supplied in liquid form into a middle section of the portion of duct from an inlet at a distance from each of the two ends of the portion of duct and, in a second impregnation process, outside the portion of duct, sealing material in a more viscous state than the first-mentioned sealing material forces a replacement of the first-mentioned sealing material in peripheral interstices of the cable.
2. A method according to claim 1, wherein the second impregnation process is carried out in a coating head through which the cable passes after leaving the portion of duct, the inlet and the outlet of the head each being provided with a die which has a tapered input portion where the diameter decreases in the direction in which the cable moves, the coating head being supplied with the more viscous sealing material under pressure to give the first-mentioned sealing material in peripheral layers of the cable a flow path opposite to the movement of the cable, causing such sealing material to be replaced by more viscous sealing material, this being pressed between outer conductors of the cable to form a sealing layer around the cable.
3. A method according to claim 2, wherein the outlet die of the coating head has a cylindrical portion extending from the tapered portion in the direction in which the cabie moves and having an inner diameter
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

**WARNING** start of CLMS field may overlap end of DESC **. flow of sealing material out of the chambers along cable passing through the pipe. In a first impregnation process using the apparatus, cable 18 comprising several insulated conductors is conveyed to pass through the pipe 10 between which and the cable 18 there is an annular gap along the length of the pipe 10, which gap is thin compared with the diameter of the cable. The sealing material is heated and supplied in a liquid state under pressure to the inlet 11 by means not shown. The apparatus furthermore comprises a coating head 20 comprising an inlet die 21, a pressure chamber 22 and an outlet die 23. The two dies are relatively short and each is exchangeable for adaptation to cables of different dimensions. The pressure chamber 22 is fed at constant pressure with sealing material (for example, Vaseline or a Vaseline-based sealing material) which has such a temperature that it is in a more viscous state than the sealing material supplied to the inlet 11 and, after coating, is solid. The two dies 21 and 23 each has a partconically shaped input portion but have cylindrical output portions. Experience has shown that the cylindrical portions can each have an inner diameter which is smaller than the diameter of the cable and a length which is about the diameter of the cable, without the insulation of the outer conductors of the cable being damaged on passage through the dies-the insulated conductors impregnated and surrounded by sealing material can be somewhat compressed without being damaged and the sealing material reduces friction between the cable and the dies.This condition is advantageous as the more viscous sealing material, as a result of the dies, is prevented from penetrating into the box 12 for surplus liquid sealing material and by the outlet die 23 being pressed between the outer conductors of the cable where a change from a liquid to a more viscous sealing material is effected and thus a stable layer having a good adherence to the cable is formed. This layer prevents drainage from the cable during its movement away from the apparatus to a station for screw-line or longitudinal coating of one or more heat protecting bands. Thus, the coating head and the not-shown means for supplying under pressure the more viscous sealing material comprises coating means for carrying out a second impregnation process on the cable 18. The cable which is to be impregnated can be coiled or banded and if so in such a way and with such a material that the more viscous sealing material easily reaches and penetrates between outer conductors. As an example of such a material, polyester-band banded in an open screw-line can be mentioned. The cable can also be provided with a layer yarn or narrow bands which are preferably crossed over the cable, that is one layer with a right-hand pitch and one with a left-hand pitch so that a checked pattern of band or yarn is formed. The length of each of the part-conical portions of the dies 21 and 23 is preferably 1-2 x D where D is the diameter of the cable and preferably half of the cone angle of each of the conical portions is in the range from 1-5 to 3 degrees. The length of the cylindrical portion of each of the dies is preferably O S- 1-5 x D, its inner diameter being preferably 0-9$0-98 x D. If petroleum jelly is used as the sealing material, the pressure and temperature in the first impregnation process are preferably in the range from 0 5 to 1-5 bars and in the range from 5 to 15 centrigrade degrees above the drop point (90 centigrade); and the pressure and temperature in the second impregnation process are preferably in the range from 01 to 0 3 bars in and the range from 20 to 400 centigrade. WHAT WE CLAIM IS:
1. A method of impregnating cable with water-impenetrable and water-repellent sealing material, the cable comprising a plurality of insulated conductors, in which method such cable is passed through a portion of duct between which and the cable and along the length of the portion of duct is formed a gap around the cable, and, in a first impregnation process, sealing material is heated and is supplied in liquid form into a middle section of the portion of duct from an inlet at a distance from each of the two ends of the portion of duct and, in a second impregnation process, outside the portion of duct, sealing material in a more viscous state than the first-mentioned sealing material forces a replacement of the first-mentioned sealing material in peripheral interstices of the cable.
2. A method according to claim 1, wherein the second impregnation process is carried out in a coating head through which the cable passes after leaving the portion of duct, the inlet and the outlet of the head each being provided with a die which has a tapered input portion where the diameter decreases in the direction in which the cable moves, the coating head being supplied with the more viscous sealing material under pressure to give the first-mentioned sealing material in peripheral layers of the cable a flow path opposite to the movement of the cable, causing such sealing material to be replaced by more viscous sealing material, this being pressed between outer conductors of the cable to form a sealing layer around the cable.
3. A method according to claim 2, wherein the outlet die of the coating head has a cylindrical portion extending from the tapered portion in the direction in which the cabie moves and having an inner diameter
equal to the smallest inner diameter of the die, the length of the cylindrical portion being in the range from 0-8 to 1-5 times the diameter of the cable.
4. Apparatus according to claim 3, wherein the smallest inner diameter of the outlet die of the coating head is smaller than the diameter of the cable.
5. Apparatus according to claim 4, wherein the smallest inner diameter of the outlet die of the coating head is in the range from 0-94 to 0-98 times the diameter of the cable.
6. A method of impregnating cable, substantially as herein described with reference to the single figure of the accompanying drawing.
7. Apparatus suitable for impregnating cable with water-impenetrable and waterrepellent sealing material, such cable comprising a plurality of insulated conductors, the apparatus including a portion of duct having open ends, through which portion of duct such cable can be passed with a gap around the cable and between the cable and the portion of duct along the length of the portion of duct, the apparatus further including an inlet into a middle section of the portion of duct at a distance from each of the ends of the portion of duct, means for heating sealing material and supplying it in liquid form to the inlet for impregnating such cable in a first impregnation process as the cable passes through the portion of duct, and coating means outside the portion of duct through which such cable passes after leaving the portion of duct, for applying to the cable sealing material in a more viscous state than the first-mentioned sealing material in such a way that, in a second impregnation process, the more viscous sealing material forces a replacement of the first-mentioned sealing material in peripheral interstices of the cable.
8. Apparatus according to claim 7, wherein the coating means includes a coating head with an inlet and an outlet centered with the portion of duct, the inlet and outlet of the head each being provided with a die having a tapered input portion where the diameter decreases in the direction in which cable moves in use of the apparatus, the coating head further including a pressure chamber between the dies and provided with an inlet for receiving the more viscous sealing material.
9. Apparatus suitable for impregnating cable, substantially as herein described with reference to the single sigure of the accompanying drawing.
10. Cable which has been impregnated using a method according to any of claims 1 to 6 or apparatus according to any of claims 7 to 9.
GB48443/77A 1976-11-26 1977-11-21 Impregnating cable Expired GB1560960A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE7613303A SE7613303L (en) 1976-11-26 1976-11-26 KIT TO IMPREGNATE A CABLE BODY AND DEVICE FOR PERFORMING THE KIT.

Publications (1)

Publication Number Publication Date
GB1560960A true GB1560960A (en) 1980-02-13

Family

ID=20329573

Family Applications (1)

Application Number Title Priority Date Filing Date
GB48443/77A Expired GB1560960A (en) 1976-11-26 1977-11-21 Impregnating cable

Country Status (8)

Country Link
AR (1) AR212137A1 (en)
AU (1) AU514507B2 (en)
BR (1) BR7707628A (en)
CA (1) CA1113215A (en)
FR (1) FR2372497A1 (en)
GB (1) GB1560960A (en)
MX (1) MX144730A (en)
SE (1) SE7613303L (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5709752A (en) * 1991-09-18 1998-01-20 Siemens Aktiengesellschaft Apparatus for filling interspaces between leads and a sheath of a cable

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1074469A (en) * 1952-04-12 1954-10-06 Pirelli Manufacturing process of submarine cables for laying in deep water, insulated with guttapercha or a thermoplastic synthetic material
SE384095B (en) * 1973-09-14 1976-04-12 Ericsson Telefon Ab L M KIT TO IMPREGNATE A CABLE BODY AND DEVICE FOR IMPLEMENTING THE KIT
CA1059847A (en) * 1974-02-26 1979-08-07 Robert W. Rake Method of and apparatus for sealing a cable core with waterproofing compound

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5709752A (en) * 1991-09-18 1998-01-20 Siemens Aktiengesellschaft Apparatus for filling interspaces between leads and a sheath of a cable

Also Published As

Publication number Publication date
MX144730A (en) 1981-11-18
CA1113215A (en) 1981-12-01
BR7707628A (en) 1978-08-01
AU514507B2 (en) 1981-02-12
SE7613303L (en) 1978-05-27
FR2372497A1 (en) 1978-06-23
AR212137A1 (en) 1978-05-15
AU3076877A (en) 1979-05-24

Similar Documents

Publication Publication Date Title
US4232935A (en) Communications cable with optical waveguides
DE60036956T2 (en) FLOW CABLE
FI58410C (en) FOERFARANDE FOER FRAMSTAELLNING AV EN DRAGFOERSTAERKT ELEKTRISK KABEL
GB1364856A (en) Method of waterproofing cables
US3649434A (en) Encapsulating process and products of wire coated with poly(tetrafluoroethylene)
EP0253981A1 (en) Device for conveying webs
US4129466A (en) Method for impregnating stranded wires during stranding thereof
GB1560960A (en) Impregnating cable
EP0182420B1 (en) Apparatus for and method of making the cable core of a telecommunication cable water-tight in the longitudinal direction
US2732592A (en) Extrusion of thermoplastic material
US4568400A (en) Circular cable coating nozzle for applying waterproof covering to cables
EP0709610B1 (en) Pipe connection
EP0812257B1 (en) Process and device for heating a moving web, in particular a corrugated cardboard web
EP0132218A2 (en) Apparatus for coating steel tubes
US2880698A (en) Apparatus for applying axially extending stripes to the surface of an insulated wireor cord
US4374870A (en) Method of impregnating a cable
US3104277A (en) Fluid-tight lead-out device for an electric conductor
DE3003155C2 (en)
DE3045941A1 (en) Cable filling unit - having filling chamber to carry cable strands round central filament passing through coating chamber
NZ193716A (en) Powder filled cable manufacture
DE10016518A1 (en) Method and device for producing an insulated cable
US297175A (en) shelbourne
DE2233884A1 (en) Extruding cable sheath - and vulcanising using hot medium in contraflow around advancing sheath and cable
NZ197696A (en) Longitudinal foil wrapping on cable:adjustable die
EP0063698B1 (en) Apparatus for applying a layer of wires to a filamentary material

Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee
PE20 Patent expired after termination of 20 years

Effective date: 19971120