US3601967A - Manufacture of multiconductor cables - Google Patents

Manufacture of multiconductor cables Download PDF

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Publication number
US3601967A
US3601967A US810092A US3601967DA US3601967A US 3601967 A US3601967 A US 3601967A US 810092 A US810092 A US 810092A US 3601967D A US3601967D A US 3601967DA US 3601967 A US3601967 A US 3601967A
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United States
Prior art keywords
sealing material
cable
storage vessel
core
die
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 - Lifetime
Application number
US810092A
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English (en)
Inventor
Brian John Wardley
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Balfour Beatty PLC
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BICC PLC
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Filing date
Publication date
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • H01B13/32—Filling or coating with impervious material
    • H01B13/322—Filling or coating with impervious material the material being a liquid, jelly-like or viscous substance
    • H01B13/323—Filling or coating with impervious material the material being a liquid, jelly-like or viscous substance using a filling or coating head
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
    • H01B13/32—Filling or coating with impervious material
    • H01B13/322—Filling or coating with impervious material the material being a liquid, jelly-like or viscous substance
    • H01B13/323—Filling or coating with impervious material the material being a liquid, jelly-like or viscous substance using a filling or coating head
    • H01B13/326—Material preparing or feeding devices

Definitions

  • the material is cooled to effect crystallization by abstraction of heat by the insulated conductors constituting the core to cause sufficient scaling material to become solidified to form an effective moisture barrier.
  • the sealing material while at such a temperature is preferably continuously circulated around a ring main in which is located a plurality of cable feeding stations for transferring the material to a core curing a conventional stranding process.
  • This invention relates to telecommunication cables of the kind comprising a multiplicity of plastics insulated conductors enclosed within a waterproof sheath.
  • a waterproof impermeable material which will not drain under the influence of gravity or such hydrostatic pressure as may arise in the event of damage to the cable sheath or joint casing but which will permit relative sliding movement of the plastics insulated conductors or group of conductors over one another during such bending of the cable as occurs during manufacture and installation of the cable. Examples of such materials are:
  • Microcrystalline petroleum waxes b. Mixtures of microcrystalline petroleum waxes and oils, for instance petroleum jelly c. Low molecular weight, high Malt Flow lndex polyethylene or polypropylene of a semisolid or greaselike nature d. Mixtures of petroleum jelly, microcrystalline petroleum waxes, polyethylene, polysioutylene and aluminum stearate.
  • filling material is to some extent limited by the method of introducing the filling material into the cable core and by the nature of the dielectric of the conductors forming the core.
  • Degradation of the material occasioned by pumping is reduced if pumping takes place while the material is at a temperature just above the temperature at which crystallization begins and it has been proposed to provide a cable core with a barrier of sealing material by pumping the sealing material from a thermostatically controlled storage vessel to a cable feeding station while at a temperature just above that at which crystallization begins and cooling the material to effect crystallization while transferring it from said cable feeding station to the cable core.
  • the present invention consists of a method of providing a multiconductor cable core with a barrier of sealing material which comprises pumping the sealing material from a thermostatically controlled storage vessel to a cable feeding station while at a temperature just above that at which crystallization begins, transferring the sealing material from the cable feeding station to the cable core while still at such a temperature, and cooling the material to effect. Crystallization by abstraction of heat by the insulated conductors constituting the core to cause sufficient sealing material to become solidified to form an effective barrier to the passage of moisture along the core.
  • the rate of delivery of sealing material to the core may be adjusted in relation to the linear speed of travel of the core but preferably the rate of delivery of sealing material is such that, for any linear speed of travel at which the core is required to travel, sufficient material will be applied to the core to form an effective barrier when it becomes solidified.
  • a temperature just above that at which crystallization begins is meant a temperature at which the sealing material is in a sufficiently liquid state to permit pumping of the material -to be effected with substantially no degradation of the material occurring.
  • the sealing material is a mixture of microcrystalline petroleum waxes and oils, such as petroleum jelly, the temperature at which crystallization begins is approximately 70 C. and the temperature just above the crystallization temperature at which the material can be pumped without causing substantial degradation is approximately 76 C.
  • the invention also includes apparatus for carrying out the aforesaid method comprising a thermostatically controlled storage vessel for storing the sealing material while at a temperature just above that at which crystallization begins, the vessel being connected to one or more than one cable feeding station having means for applying sealing material to the cable core and, connected between the storage vessel and the applicator means of the or each cable feeding station, means for withdrawing sealing material from the storage vessel and for controlling the rate of delivery of the material to the applicator means.
  • a feeding station at each stranding point and to transfer sealing material in a liquid state to the core at, or shortly in advance of, the closing die of the stranding head, in which case the number of feeding stations in operation will be the same as the number of layers of conductors, pairs or quads laid up around the center conductor, pair or quad, but where the first layer is laid up around a group of two or more conductors, pairs or quads it may be advantageous to have a feeding station at the point where these two or more conductors, pairs or quads are brought together to form a core center.
  • a further feeding station may be located at the outlet end of the final closing die but we have found that this is not generally necessary.
  • the sealing material is applied to the core through an applicator die constituting or forming a separable part of the closing die associated with a stranding head and in this case the sealing material is applied! to the surface of the last-formed layer of conductors, pairs or quads, to the surface of each conductor of the layer of conductors, pairs or quads being brought down by the closing die onto said last-formed layer, and to the surface of the layer of conductors, pairs or quads formed at said closing die, thereby ensuring that the cable interstices are completed filled with sealing material.
  • Each feeding station may have its own individual source of supply and surplus material (i.e. material that is not carried forward through the stranding head) in a liquid or semisolid state may either be returned to the storage vessel to be brought back to the requisite temperature in or on its way to such vessel or it may be collected for reprocessing by the supplier.
  • sealing material is maintained in a thermostatically controlled storage vessel at a temperature just above that at which crystallization begins and is continuously circulated through a ring main which is thermally insulated and may be trace heated to maintain the circulating material at the appropriate temperature. From this ring main sealing material while still at such a temperature is bled off at intervals and fed to the feeding stations. Transfer of the sealing material to the cable core is preferable controlled by a valve at each feeding station but it may be controlled by a metering pump.
  • the sealing material is circulated in the ring main at a much higher rate than the aggregate rate at which it is withdrawn for transfer to the cable core, for example at a rate to times as great.
  • Such circulation is preferably effected by a pump having an intake in a part of the storage vessel remote from the part to which the circulating material'is returned.
  • FIG. 1 is a diagrammatic illustration of apparatus suitable for use in providing a multiconductor cable core with a barrier of sealing material which extends throughout the length of the cable core, while the cable core is being manufactured by a conventional stranding machine,
  • FIG. 2 is an end view of an applicator die of the apparatus diagrammatically illustrated in FIG. 1,
  • FIG. 3 is a section on the line llllll in FIG. 2, and
  • FIG. 4 is a diagrammatic illustration of an alternative form of apparatus for providing a continuous barrier of sealing material in a multiconductor cable core.
  • the apparatus comprises a storage vessell for the sealing material thermostatically controlled in any convenient manner and, connected to the lower part of the vessel, aring main 2 comprising an outward pipe 3, in which is connected a pump 5, and a return pipe 4.
  • a cable feeding station 11 At each end of a plurality of locations spaced at intervals along the length of the return pipe 4, of which three only are shown, is a cable feeding station 11 at which sealing material at a temperature just above that at which crystallization begins and hence in a liquid state "is continuously bled off from the ring main 2 and transferred to the cable core.
  • Each cable feeding station 11 has a' valve 12 for controlling the rated of flow of sealing material being bled off from the system 2 and a die 15 for applying the material to the cable core.
  • the die 15 is detachably secured to the entry end of the closing die of a stranding head.
  • the storage vessel 1 and all piping of the ring main 2 are lagged and the piping is provided with steam trace heating.
  • the piping is provided with steam trace heating.
  • stainless steel steam heating coils 7 for use when the sealing material in the vessel has been allowed to go solid, as for instance when commencing circulation of the sealing material in preparation for applying sealing material to a cable core.
  • the sealing material in the thermostatically controlled storage vessel 1 is maintained in a liquid state by any suitable method.
  • sealing material which is being pumped around the ring main 2 in a liquid state, is continuously bled off and transferred in a liquid state into the applicator die 15.
  • the rate of delivery of the sealing material in a liquid state to the cable core via each applicator die 15 is controlled by its associated valve 12.
  • the sealing material is cooled to effect crystallization by abstraction of heat by the insulated conductors constituting the core to cause sufficient sealing material to become solidified to form an effective barrier to the passage of moisture along the core. Circulation of the sealing material through the ring main 2 will generally be maintained at a'rate 5 to 10 times as great as the aggregate rate at which it is withdrawn from the ring main at the cable feeding stations 1 l.
  • Surplus material spewing from each applicator die 15 is returned to a collecting tank 16 where any loss of temperature may be compensated by trace heating the tank. From the collecting tank 16 the surplus material is pumped by a scavenge pump 18 back through a filter 17 into the upper part of the storage tank 1 from where, after it has been brought back to the temperature of the circulating material, it can be recirculated through the ring main 2.
  • a pipe 19 is provided for feeding sealing material directly from the ring main 2 into the collecting tank 16 when required, as for instance preparatory to starting up the sealing operation.
  • each of the dies 15 by which the sealing material in a liquid state is applied to the cable core during its manufacture comprises a body 21 having a smoothly tapering bore 22 which is bellmouthed at its entry end and which, at its exit end, corresponds to or is somewhat greater than the circumscribing circle of the cable core passing through the die.
  • the outer surface of the wall of the body 21 is stepped at three locations along its length to form three cylindrical portions, 23, 24 and 25. Portion 23 at the exit end of the die is externally screw threaded.
  • a sleeve 27 which has an internal diameter corresponding to the external diameter of the cylindrical portion 25 and which has at one end an inwardly directed internally screwthreaded flange 28, is screwed on to the end portion 23 of the body 21 until the sleeve fits tightly over the cylindrical portion 25 and abuts the step thereof.
  • a hole 29 in the wall of the sleeve 27 is bounded by an upstanding continuous wall 31 and provides access for flow of sealing material in a liquid state to an annular chamber 30 lying between the internal surface of the sleeve 27 and the cylindrical portion 24.
  • the wall 31 bounding the hole 29 is internally screw threaded for connection to a pipe carrying sealing material from the feeding station 11. Sealing material in a liquid state is fed from the annular chamber 30 to the cable core passing through the die via the ports 26.
  • the die 15 is detachably secured to the entry end of the closing die of a stranding head.
  • the rate of flow of sealing material into each die 15 is at least sufficient to maintain a pool of material in aliquid state in the annular chamber 30 and in the bell-mouth of the die. Surplus material from each die 15, if any, is allowed to fall into its associated V collecting tank 16 to be reheated and pumped back into the storage tank as previously described.
  • the ring main may serve two or more adjacently sited cable-making machines.
  • each stranding head of a conventional stranding machine has at its inlet end an applicator die 45 which is of a form similar to that shown in FIGS. 2 and 3 and at which sealing material in a liquid state is fed to a cable core from an individual thermostatically controlled tank 41 in which the sealing material is maintained in a liquid state in any suitable manner, for instance by heating coils 47.
  • the sealing material in a liquid state is fed to the applicator die 45 through a pipe 42 constituting the cable feeding station, and filter 43 by a metering pump 44.
  • Surplus material spewing from the applicator die 45 falls back into the tank 41 where it is reheated and pumped back to the applicator die.
  • a pipe 46 is provided for feeding sealing material being pumped through the pipe 42 directly back into the tank 41 when required, as for instance preparatory to starting up the sealing operation.
  • sufficient sealing material is caused to become solidified by abstraction of heat by the insulated conductors constituting the core to form in effective barrier to the passage of moisture along the core.
  • the process of fully filling a multiconductor cable in accordance with the present invention has the advantage that it eliminates substantially all mechanical working of the sealing medium--generally petroleum jelly-and so eliminates the separating out of oil from the wax which occurs under the action of shear brought about by pumping such material when in its solid state.
  • sealing material in the storage vessel is maintained at a temperature just above that at which crystallization begins and is continuously pumped from the storage vessel and circulated around a ring main to one or more cable feeding stations located in the ring main:
  • sealing material is pumped around the ring main at a rate substantially exceeding the aggregate rate of flow of material from the cable feeding stations to the cable core.
  • each of a plurality of cable feeding stations is fed with sealing material from a separate source of supply.
  • Apparatus for use in providing a cable core comprising a multiplicity of insulated conductors witha barrier of sealing material which will not drain under the influence of gravity or such hydrostatic pressure as may arise in the event of damage to the sheath of the cable but which will permit relative sliding movement of the insulated conductors over one another during such bending of the cable as occurs during manufacture and installation of the cable, which apparatus comprises:
  • a thermostatically controlled storage vessel for storing the sealing material
  • thermostatically controlled storage vessel is connected to a ring main for the sealing material in which is connected means for continuously withdrawing sealing material from the storage vessel, driving it around the ring main and back into the vessel, and a cable feeding station is provided at at least one location in the ring main.
  • each of a plurality of applicator means has associated with it a heated tank for collecting surplus material spewing from the applicator means, a pipe extends from the collecting tank to the storage vessel, and a scavenge pump is provided for pumping the surplus material from the collecting tank back into the storage vessel.
  • each means for withdrawing sealing material from the storage vessel and controlling its rate of delivery to the applicator means is a metering pump.
  • each storage vessel is so located with respect to the applicator means of its associated cable feeding station as to collect surplus material spewing from the applicator means.
  • the applicator means comprises a die which forms at least a part of the closing die of a stranding head of a stranding machine and which has a number of ports for entry of sealing material, which ports are distributed uniformly around the axis of the die and are inclined to it so as to impart to sealing material entering the die a component of movement in the same axial direction as the direction of travel of the cable core.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Manufacturing Of Electric Cables (AREA)
  • Insulated Conductors (AREA)
US810092A 1968-04-05 1969-03-25 Manufacture of multiconductor cables Expired - Lifetime US3601967A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB06462/68A GB1203138A (en) 1968-04-05 1968-04-05 Improvements in or relating to the manufacture of multi-conductor cables

Publications (1)

Publication Number Publication Date
US3601967A true US3601967A (en) 1971-08-31

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ID=10077779

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Application Number Title Priority Date Filing Date
US810092A Expired - Lifetime US3601967A (en) 1968-04-05 1969-03-25 Manufacture of multiconductor cables

Country Status (10)

Country Link
US (1) US3601967A (de)
JP (1) JPS4922112B1 (de)
CH (1) CH515588A (de)
DE (1) DE1917267A1 (de)
FI (1) FI50376C (de)
FR (1) FR2005637A6 (de)
GB (1) GB1203138A (de)
IL (1) IL31880A0 (de)
MY (1) MY7100113A (de)
SE (1) SE343977B (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3789099A (en) * 1971-11-09 1974-01-29 Western Electric Co Methods of manufacturing waterproof cable
US3850139A (en) * 1971-06-21 1974-11-26 Western Electric Co Apparatus for manufacturing waterproof cable
US3854444A (en) * 1971-06-21 1974-12-17 Western Electric Co Apparatus for manufacturing waterproof cable
US3876487A (en) * 1971-11-09 1975-04-08 Western Electric Co Apparatus for manufacturing waterproof cable
US3889455A (en) * 1972-08-02 1975-06-17 Pirelli Method and apparatus for impregnating stranded wires during stranding thereof
DE2507471A1 (de) * 1974-02-26 1975-08-28 Western Electric Co Verfahren und vorrichtung zum fuellen der zwischenraeume eines verseilten, langgestreckten gegenstandes
US4197695A (en) * 1977-11-08 1980-04-15 Bethlehem Steel Corporation Method of making sealed wire rope
US4899266A (en) * 1984-10-24 1990-02-06 Ahroni Joseph M Miniature light sets and lampholders and method for making them
US20170145601A1 (en) * 2015-11-25 2017-05-25 Maschinenfabrik Rieter Ag Air Spinning Machine along with a Method for Operating the Same

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4104480A (en) * 1976-11-05 1978-08-01 General Cable Corporation Semiconductive filling compound for power cable with improved properties
US4246435A (en) * 1979-07-20 1981-01-20 General Cable Corporation Filled communication cable employing a paraffinic oil-base filling compound
DE3207083A1 (de) * 1982-02-26 1983-09-08 Siemens AG, 1000 Berlin und 8000 München Einrichtung zur herstellung eines elektrischen und/oder optischen kabels

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1886447A (en) * 1925-06-17 1932-11-08 Slade Edward Apparatus for making strands and covered wires
US1966575A (en) * 1931-04-23 1934-07-17 E M F Electric Company Proprie Automatic weld rod manufacturing apparatus
US2093206A (en) * 1935-06-27 1937-09-14 Us Rubber Prod Inc Cord covered tube and apparatus for applying cords to tubes, cores, and the like
US2155403A (en) * 1936-06-13 1939-04-25 William E Cook Method of making insulated wire
US2202575A (en) * 1936-04-30 1940-05-28 Deroche Andre Electrical cable and conductor and process for manufacturing the same
US2427507A (en) * 1944-04-11 1947-09-16 Carbide & Carbon Chem Corp Method of producing sealed cables
US2792441A (en) * 1952-08-15 1957-05-14 Bell Telephone Labor Inc Sealing electrical apparatus
US3121038A (en) * 1960-06-01 1964-02-11 Gen Electric Method of providing a high resistance insulation coating for a conductor in a sheath

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1886447A (en) * 1925-06-17 1932-11-08 Slade Edward Apparatus for making strands and covered wires
US1966575A (en) * 1931-04-23 1934-07-17 E M F Electric Company Proprie Automatic weld rod manufacturing apparatus
US2093206A (en) * 1935-06-27 1937-09-14 Us Rubber Prod Inc Cord covered tube and apparatus for applying cords to tubes, cores, and the like
US2202575A (en) * 1936-04-30 1940-05-28 Deroche Andre Electrical cable and conductor and process for manufacturing the same
US2155403A (en) * 1936-06-13 1939-04-25 William E Cook Method of making insulated wire
US2427507A (en) * 1944-04-11 1947-09-16 Carbide & Carbon Chem Corp Method of producing sealed cables
US2792441A (en) * 1952-08-15 1957-05-14 Bell Telephone Labor Inc Sealing electrical apparatus
US3121038A (en) * 1960-06-01 1964-02-11 Gen Electric Method of providing a high resistance insulation coating for a conductor in a sheath

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3850139A (en) * 1971-06-21 1974-11-26 Western Electric Co Apparatus for manufacturing waterproof cable
US3854444A (en) * 1971-06-21 1974-12-17 Western Electric Co Apparatus for manufacturing waterproof cable
US3789099A (en) * 1971-11-09 1974-01-29 Western Electric Co Methods of manufacturing waterproof cable
US3876487A (en) * 1971-11-09 1975-04-08 Western Electric Co Apparatus for manufacturing waterproof cable
US3889455A (en) * 1972-08-02 1975-06-17 Pirelli Method and apparatus for impregnating stranded wires during stranding thereof
DE2507471A1 (de) * 1974-02-26 1975-08-28 Western Electric Co Verfahren und vorrichtung zum fuellen der zwischenraeume eines verseilten, langgestreckten gegenstandes
US4197695A (en) * 1977-11-08 1980-04-15 Bethlehem Steel Corporation Method of making sealed wire rope
US4899266A (en) * 1984-10-24 1990-02-06 Ahroni Joseph M Miniature light sets and lampholders and method for making them
US20170145601A1 (en) * 2015-11-25 2017-05-25 Maschinenfabrik Rieter Ag Air Spinning Machine along with a Method for Operating the Same
US10370779B2 (en) * 2015-11-25 2019-08-06 Maschinenfabrik Rieter Ag Air spinning machine along with a method for operating the same

Also Published As

Publication number Publication date
IL31880A0 (en) 1969-05-28
GB1203138A (en) 1970-08-26
DE1917267A1 (de) 1970-09-17
FI50376B (de) 1975-10-31
FI50376C (fi) 1976-02-10
JPS4922112B1 (de) 1974-06-06
FR2005637A6 (de) 1969-12-12
CH515588A (de) 1971-11-15
MY7100113A (en) 1971-12-31
SE343977B (de) 1972-03-20

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