GB1593965A - Creation of Inventions and Patents with Artificial Intelligence

GB1593965A – Manufacture of submarine cable
– Google Patents

GB1593965A – Manufacture of submarine cable
– Google Patents
Manufacture of submarine cable

Download PDF
Info

Publication number
GB1593965A

GB1593965A
GB5810/78A
GB581078A
GB1593965A
GB 1593965 A
GB1593965 A
GB 1593965A
GB 5810/78 A
GB5810/78 A
GB 5810/78A
GB 581078 A
GB581078 A
GB 581078A
GB 1593965 A
GB1593965 A
GB 1593965A
Authority
GB
United Kingdom
Prior art keywords
dielectric
cooling
cable
sizing
coaxial cable
Prior art date
1977-02-17
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
GB5810/78A
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.)

International Standard Electric Corp

Original Assignee
International Standard Electric Corp
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.)
1977-02-17
Filing date
1978-02-14
Publication date
1981-07-22

1978-02-14
Application filed by International Standard Electric Corp
filed
Critical
International Standard Electric Corp

1981-07-22
Publication of GB1593965A
publication
Critical
patent/GB1593965A/en

Status
Expired
legal-status
Critical
Current

Links

Espacenet

Global Dossier

Discuss

Classifications

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

H01B13/06—Insulating conductors or cables

H01B13/14—Insulating conductors or cables by extrusion

B—PERFORMING OPERATIONS; TRANSPORTING

B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL

B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING

B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor

B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion

B29C48/05—Filamentary, e.g. strands

B—PERFORMING OPERATIONS; TRANSPORTING

B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL

B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING

B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor

B29C48/06—Rod-shaped

B—PERFORMING OPERATIONS; TRANSPORTING

B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL

B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING

B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor

B29C48/15—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor incorporating preformed parts or layers, e.g. extrusion moulding around inserts

B—PERFORMING OPERATIONS; TRANSPORTING

B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL

B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING

B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor

B29C48/25—Component parts, details or accessories; Auxiliary operations

B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling

B29C48/911—Cooling

B—PERFORMING OPERATIONS; TRANSPORTING

B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL

B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING

B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor

B29C48/25—Component parts, details or accessories; Auxiliary operations

B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling

B29C48/919—Thermal treatment of the stream of extruded material, e.g. cooling using a bath, e.g. extruding into an open bath to coagulate or cool the material

Description

PATENT SPECIFICA Ti ON
( 21) Application No 5810/78 ( 22) Filed 14 Feb 1978 ( 31) Convention Application No 769569 ( 32) Filed 17 Feb 1977 in ( 33) United States of America (US) ( 44) ( 51) ( 1) 1 593 965 ( 1
Complete Specification published 22 July 1981
INT CL 3 HOIB 13/06//7/14 ( 52) Index at acceptance HIA IC 2 E 3 D 2 5 6 L ( 72) Inventors CHARALAMBOS GEORGIOU THEODOSSI and DAVID ARTHUR HIBBS ( 54) MANUFACTURE OF SUBMARINE CABLE ( 71) We, INTERNATIONAL STANDARD ELECTRIC CORPORATION, a Corporation organised and existing under the laws of the State of Delaware, United States of America, of 320 Park Avenue, New York 22, State of New York, United States of America, 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:-
The present invention relates to the manufacture of submarine coaxial cable and, more particularly, to an improved method and apparatus for manufacturing submarine coaxial cable so as to reduce the total water content of the dielectric of the cable.
It is normal practice in the manufacture of submarine coaxial cable to extrude a dielectric, typically polyethylene, around the center conductor or core of the cable and cool the dielectric by passing the dielectric covered core through troughs of water in one operation and subsequently store the cable in a temperature-controlled room until the dielectric temperature and size is stabilized Due to the precise transmission characteristics demanded from submarine coaxial cables, it is the practice to extrude the dielectric diameter oversize and subsequently size the dielectric by a separate operation to close diameter tolerances The sizing operation is executed as a separate process which takes place after the temporaty storage of the dielectric covered core in a temperature-controlled room It will be appreciated that this process requires the use of additional facilities and labor to store the long lengths of cable being fed into and out of the extrusion and sizing equipment.
The dielectric sizing is achieved by a multiplicity of cutters rotated around the dielectric at high speed while the cable dielectric is pulled axially through the cutter assembly.
This method achieves precise diameter control and results in a layer of dielectric of approximately 0 020 inch average thickness being removed from around the dielectric surface Alternatively, the cable sizing can be achieved by a multiplicity of fixed or rotating cutting dies placed in a tandem manner along the cable The cutting orifices of the dies are arranged to produce sequentially reducing diameters so that the thickness of material removed at each cutting stage is controlled.
Special low-loss grades of polyethylene have been developed for use in submarine cable These have a dielectric loss in the order of 47 microradians at the designed top transmission frequency of the cable which is M Hz Even lower loss materials are in the course of development for cables planned to operate at transmission frequencies up to 200 M Hz.
Problems have been experienced in the use of these materials where the fabricated cable has exhibited excessive attenuation due to an increase in the dielectric loss of the polyethylene This excess loss has been found to be due to the permeation of water into the polyethylene during the cooling process which takes place immediately after the extrusion of the polyethylene.
According to one aspect of the present invention, there is provided a method of manufacturing a submarine coaxial cable, comprising: extruding a dielectric around an inner conductor for the cable; cooling in a liquid the dielectric covering on the inner conductor to a stabilized profile; immediately thereafter sizing the dielectric covering whereby to remove at least a portion of the outer region of the dielectric prior to appreciable permeation of cooling liquid from the outer region of the dielectric into the inner region thereof, applying an outer conductor to the dielectric and forming a sheath over the outer conductor.
According to another aspect of the present invention there is provided, in a method of manufacturing a submarine 1,593,965 coaxial cable, the steps comprising:
extruding a dielectric around the center conductor for the cable; passing the dielectric covered center conductor through a cooling liquid; sizing the dielectric immediately after and in tandem with the extrusion and cooling steps, applying an outer conductor to the dielectric and forming a sheath around the outer conductor.
According to a further aspect of the present invention there is provided an apparatus for manufacturing submarine coaxial cable comprising: means for extruding a dielectric around the center conductor for the cable; means for cooling the dielectric covered center conductor as it emerges from said extrusion means, said cooling means including a receptacle for containing a cooling liquid; dielectric sizing means in tandem with said extrusion means and said cooling means; and means for drawing the center conductor through said extrusion means, said cooling means and said sizing means in sequence.
By reducing the total water content of the dielectric by this means, the adverse effect of water absorption on the dielectric loss of the dielectric will be minimized Also, by the use of a tandem dielectric sizing process, the labor costs associated with the temporary storage of the cable prior to a separate sizing process, as presently used, will be saved, thus resulting in a more efficient overall manufacturing procedure.
Further, by dispensing with the intermediate storage space required to store extruded cable before the sizing operation in the presently used process, more storage space may be made available for the conditioning of the core in the sized condition when more efficient dissipation of absorbed water can take place.
The drawing illustrates schematically an apparatus for extruding and sizing submarine coaxial cable in accordance with an embodiment of the present invention.
The highest concentration of absorbed water during the cooling process is found to be in the outer most 0 10 inch layer of the dielectric, decreasing amounts being present in the underlying areas of the dielectric toward the cable center conductor or core Expressed in other terms, approximately 25 % of the water content of the dielectric material is contained within the top 5 % O of the material thickness.
Subsequent to the extrusion and sizing processes, water in the polyethylene dielectric travels both toward the cable center conductor and to the atmosphere from the sized cable surface The result of the water movement is that the concentration of water content tends to become more evenly dispersed over the cross-section of the dielectric with time while the total quantity of absorbed water decreases Also, as a consequence of the extrusion processing speed which is within the range of 10 to 20 feet per minute and the reverse order sizing operation which is processed within the range of 25 to 35 feed per minute, it can be appreciated that the residence time in storage over a 10 nautical mile length cable resulted in the fact that one end of the cable length experienced between 3 to 6 days difference in storage time over which the dispersion of absorbed water in the polyethylene took place A minimum period of 14 days was therefore required to produce an acceptable uniformity of water content and, therefore, electrical characteristics of the cable over the cable length.
Obviously, there is a practical limit to the time the cable dielectric core could be left in storage after sizing to dissipate water prior to application of the impermeable outer conductor and the outer jacket of the.
cable This is due to the excessive storage space that would be required to hold the cable in storage for a period in excess of 14 days It is, therefore, highly advantageous to avoid the lengthy storage previously required of the cable dielectric core which was necessitated by the permeation of water into the dielectric.
Rather than temporarily storing the extruded and cooled dielectric core and thereafter sizing the core in a separate operation, the dielectric sizing equipment is now incorporated into the extrusion process line immediately after the cooling troughs so that a large percentage of the water-rich dielectric surface can be removed before the water permeates into the interior of the dielectric As a consequence, the total water content of the core will be reduced after storage Since approximately 25 % O of the water content of the dielectric material is contained within the top 5 % of the material thickness, preferably the sizing equipment is set to remove approximately 5 % of the dielectric thickness As a minimum, the sizing operation should remove at least 3 % of the dielectric thickness to avoid appreciable permeation of water from the outer region of the dielectric into the inner region thereof It will be appreciated that removal of greater amounts of the outer layer of the dielectric will result in wasted material and higher costs, although total water content of the core would be reduced.
Reference is made to the drawing which illustrated the apparatus of the present invention, generally designated 10 The center conductor or core 12 of the cable to be insulated is paid off from a rotating payoff drum 14 and through a constant speed 3 I 593965 metering device 16 From there, the conductor is led through the die head of an extruder 18 wherein the conductor receives a thick layer of dielectric, preferably polyethylene, heated to a molten formable state The insulated conductor 20 is then led through a multiplicity of cooling troughs 22 filled wvith water or any other suitable cooling liquid The water is maintained at a series of predetermined temperatures consistent with stress-free cooling of the dielectric The cooling liquid may or may not be held at pressures above ambient atmospheric pressure in order to suppress the formation of voids in the dielectric.
After a predetermined length of cooling trough, the cable is passed through a pulling device 24 which applies a constant tension over the cable back to the metering device 16 to keep the insulated core 20 at a predetermined catenary profile within the extruder die and cooling troughs.
The cooling dielectric is then passed through a series of final cooling troughs 26 filled with liquid at ambient temperatures and then into sizing equipment 28 The sizing equipment may incorporate a multiplicity of cutters (not shown) rotated around the dielectric at high speed while the cable is pulled axially through the cutter assembly Alternatively, the sizing equipment may comprise a multiplicity of fixed or rotating dies placed in a tandem manner along the cable.
The sized cable passes through a further pulling device 30 arranged to pull the cable at constant tension The cable is then fed along a multiplicity of rollers 32 to a storage area 34 where the completed cable dielectric is stored at a controlled temperature Thus, it is seen that the sizing equipment 28 immediately follows the extrusion and cooling equipment, and is in tandem therewith, so that it may remove the outer layer of the dielectric immediately following the drawing of the dielectric core from the cooling troughs 26 Since the dielectric sizing process takes place immediately after and in tandem with the extrusion and cooling processes, the waterrich surface layer of the dielectric is removed before the water has time to permeate into the inner regions of the dielectric As a consequence, the total water content of the dielectric, and the adverse effect of water absorption on the dielectric loss of the dielectric, is minimized Further, by the tandem dielectric sizing technique the labor costs associated with storage of the cable during the operation of a separate sizing process as presently used is saved, thus resulting in a more efficient overall manufacture of cable.
Furthermore, by dispensing with the intermediate storage space required to store extruded cable before the sizing operation, more storage space will be made available for the conditioning of the core in the sized condition when more efficient dissipation of absorbed water can take place In addition, because the intermediate storage operation between the extrusion and sizing processes is eliminated, the direction of the cable processing flow is not reversed and, therefore, dissipation of absorbed water takes place uniformly throughout the cable.
Therefore, the electrical characteristics of the cable are generally uniform throughout its length.

Claims (8)

WHAT WE CLAIM IS:-

1 A method of manufacturing a submarine coaxial cable, comprising:
extruding a dielectric around an inner conductor for the cable; cooling in a liquid the dielectric covering on the inner conductor to a stabilized profile; immediately thereafter sizing the dielectric covering whereby to remove at least a portion of the outer region of the dielectric prior to appreciable permeation of cooling liquid from the outer region of the dielectric into the inner region thereof, applying an outer conductor to the dielectric and forming a sheath over the outer conductor.

2 A method of manufacturing a submarine coaxial cable as set forth in claim 1 wherein: said sizing comprises removing at least 3 % of the dielectric thickness.

3 A method of manufacturing a submarine coaxial cable as set forth in claim 2 wherein: said sizing removed about 500 of the dielectric thickness.

4 In a method of manufacturing a submarine coaxial cable, the steps comprising: extruding a dielectric around the center conductor for the cable; passing the dielectric covered center conductor through a cooling liquid; sizing the dielectric immediately after and in tandem with the extrusion and cooling steps, applying an outer conductor to the dielectric and forming a sheath around the outer conductor.

An apparatus for manufacturing submarine coaxial cable comprising: means for extruding a dielectric around the center conductor for the cable; means for cooling the dielectric covered center conductor as it emerges from said extrusion means, said cooling means including a receptable for containing a cooling liquid; dielectric sizing means in tandem with said extrusion means and said cooling means; and means for drawing the center conductor through said extrusion means, said cooling means and said sizing means in sequence.

6 An apparatus for manufacturing 1,593,965 A 1,593,965 submarine coaxial cable as set forth in claim wherein said center conductor drawing means includes a haul-off device between said extrusion means and said cooling means.

7 An apparatus for manufacturing submarine coaxial cable as set forth in claim wherein: said center conductor drawing means includes a haul-off device between said cooling means and said sizing means.

8 Coaxial cable made by a method or apparatus according to any preceding claim.
M C DENNIS, Chartered Patent Agent, For the Applicants.
Printed for Her Majesty’s Stationery Office, by the Courier Press, Leamington Spa, 1981 Published by The Patent Office, 25 Southampton Buildings, London, WC 2 A IAY, from which copies may be obtained.

GB5810/78A
1977-02-17
1978-02-14
Manufacture of submarine cable

Expired

GB1593965A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

US05/769,569

US4089923A
(en)

1977-02-17
1977-02-17
Manufacture of submarine cable

Publications (1)

Publication Number
Publication Date

GB1593965A
true

GB1593965A
(en)

1981-07-22

Family
ID=25085845
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB5810/78A
Expired

GB1593965A
(en)

1977-02-17
1978-02-14
Manufacture of submarine cable

Country Status (3)

Country
Link

US
(1)

US4089923A
(en)

FR
(1)

FR2381381A1
(en)

GB
(1)

GB1593965A
(en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

US4720368A
(en)

1983-06-28
1988-01-19
Ube-Nitto Kasei Co., Ltd.
Method for forming a rod-like molding

JPS60154029A
(en)

1984-01-24
1985-08-13
Ube Nitto Kasei Kk
Method and apparatus for rectifying continuously extruded bar-like molding

CA1208863A
(en)

1984-04-24
1986-08-05
Wire Rope Industries Ltd. – Industries De Cables D’acier Ltee D’acier Ltee
Plastic filled wire rope

CH660801A5
(en)

1984-12-14
1987-06-15
Maillefer Sa

METHOD FOR MANUFACTURING AN OPTICAL FIBER WIRING ELEMENT, INSTALLATION FOR IMPLEMENTING THE METHOD AND WIRING ELEMENT OBTAINED BY THIS PROCESS.

US4781434A
(en)

1986-07-24
1988-11-01
Ube-Nitto Kasei Co., Ltd.
Spacer of optical fiber cable and method for forming the same

US4814133A
(en)

1986-07-24
1989-03-21
Ube-Nitto Kasei Co., Ltd.
Method of forming the spacer of an optical fiber cable

AT410610B
(en)

1999-03-18
2003-06-25
Uniline Kabelmaschb Und Handel

METHOD FOR THE CONTINUOUS PRODUCTION OF COATED CABLES AND DEVICE FOR IMPLEMENTING THE METHOD

US20220281151A1
(en)

2021-03-05
2022-09-08
Felix Sorkin
U-shaped extrusion line

Family Cites Families (7)

* Cited by examiner, † Cited by third party

Publication number
Priority date
Publication date
Assignee
Title

GB570139A
(en)

1941-11-03
1945-06-25
Edmond George Williams
Improvements in or relating to the extrusion of thermoplastic materials

US2731069A
(en)

1952-06-07
1956-01-17
Felten & Guilleaume Carlswerk
Device for compounding stranded conductors

US2820987A
(en)

1955-06-07
1958-01-28
Western Electric Co
Methods of and apparatus for controlling the application of plastic materials upon filamentary articles

US2904846A
(en)

1956-12-31
1959-09-22
Phillips Petroleum Co
Method for coating filamentous articles

GB1107253A
(en)

1963-12-10
1968-03-27
Submarine Cables Ltd
Method and apparatus for producing plastic insulated electrical conductors

US3356790A
(en)

1966-02-18
1967-12-05
Gen Cable Corp
Coaxial cable

US3849192A
(en)

1972-05-12
1974-11-19
Gen Cable Corp Inc
Method of applying and cooling low density polyethylene cable insulation

1977

1977-02-17
US
US05/769,569
patent/US4089923A/en
not_active
Expired – Lifetime

1978

1978-02-14
GB
GB5810/78A
patent/GB1593965A/en
not_active
Expired

1978-02-15
FR
FR7804238A
patent/FR2381381A1/en
not_active
Withdrawn

Also Published As

Publication number
Publication date

FR2381381A1
(en)

1978-09-15

US4089923A
(en)

1978-05-16

Contact information