GB2184563A - Optical fibre units - Google Patents

Optical fibre units Download PDF

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Publication number
GB2184563A
GB2184563A GB08629919A GB8629919A GB2184563A GB 2184563 A GB2184563 A GB 2184563A GB 08629919 A GB08629919 A GB 08629919A GB 8629919 A GB8629919 A GB 8629919A GB 2184563 A GB2184563 A GB 2184563A
Authority
GB
United Kingdom
Prior art keywords
optical fibre
fibres
unit according
fibre unit
bonded together
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.)
Withdrawn
Application number
GB08629919A
Other versions
GB8629919D0 (en
Inventor
Raymond Sydney Ashpole
Norman Charles Fielder
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.)
Telephone Cables Ltd
Original Assignee
Telephone Cables Ltd
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 Telephone Cables Ltd filed Critical Telephone Cables Ltd
Publication of GB8629919D0 publication Critical patent/GB8629919D0/en
Publication of GB2184563A publication Critical patent/GB2184563A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401—Optical cables
    • G02B6/4429—Means specially adapted for strengthening or protecting the cables
    • G02B6/443—Protective covering
    • G02B6/4431—Protective covering with provision in the protective covering, e.g. weak line, for gaining access to one or more fibres, e.g. for branching or tapping
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401—Optical cables
    • G02B6/4403—Optical cables with ribbon structure
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401—Optical cables
    • G02B6/4407—Optical cables with internal fluted support member
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4401—Optical cables
    • G02B6/441—Optical cables built up from sub-bundles
    • G02B6/4413—Helical structure
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
    • G02B6/4479—Manufacturing methods of optical cables
    • G02B6/4482—Code or colour marking

Abstract

An optical fibre unit comprises a plurality of optical fibres 1, each with a protective coating 3, bonded together to form a flexible assembly for example by impregnating the interstices with wax or a thermoplastics material 2, or alternatively by lashings in the form of a filament or tape wound helically around the fibres. The element may further comprise a flexible strength element 4 or may be formed in a ribbon shape (Figure 4) or stack (Figure 5). Each unit may then be housed in a cable structure, Figures 7 and 8. <IMAGE>

Description

SPECIFICATION Optical fibre units This invention relates to optical fibre units and to optical fibre cables incorporating such units. Optical fibres at present produced are usually provided with a protective coating, for example of synthetic resin, commonly called a primary coating.
According to one aspect of the invention an optical fibre unit comprises a plurality of optical fibres each with a primary coating, and the coated fibres are bonded togetherto form a compactflexible assembly.
The fibres may be bonded together by impregnating the interstices between the fibres with a thermoplastics material,forexample an EVAtype plastic, or a wax, which adheres to the fibre coatings. The bonding material should, of course, have a melting point sufficiently high to be retained within the fibre interstices during any subsequent processing ofthe optical fibre assembly, for example on the application of an extruded thermoplastic sheath around the fibre unit during manufacture of an optical fibre cable incorporating the fibres. A microcrystalline wax having a melting point of the order of 80"C has been found particularly suitable for this purpose.The use of such a substance as the bonding material is especially advantageous as it enables the ends ofthe fibres to be readily separated when required, which may sometimes be necessary, for example,forconnection to other fibres.
The fibres may be bonded together in the form of a bundle, and in such a case they may be alternatively secured to each other by one or more lashings wound helicallyaround the fibre bundle. The or each lashing, which may be in the form of a filament or tape, is preferablysecured to thefibre bundle bya suitable adhesive. In this case a lubricating material may be provided between the fibres.
The fibres forming the bundle may extend parallel to the bundle axis or may be disposed in a helical or periodically reversing helical fashion aboutthe bundle axis.
In some cases they may be disposed, preferably uniformly,around a centralflexiblefilamentof larger diameter, for example of nylon. This gives a more stable arrangement, with improved flexibility and also reduces the likelihood ofthe fibres themselves being subjected totensile stress.
However the fibres may in some cases be bonded together in the form of a ribbon, preferably by means of a wax, and a plurality of such ribbons may be superposed on top of each otherto form a stack. The individual ribbons may also be bonded together by means of a wax if desired.
Several different embodiments of the invention will now be described by way of example with referenceto Figures 1 to 8 ofthe accompanying schematic drawings, in which Figures 1 to 5 represent cross sections through three different forms of optical fibre unit in accordance with the invention, Figure 6 illustrates a side view of an alternative form of optical fibre unit, and Figures 7and 8 represent two differentforms of optical fibre cable suitable for incorporating optical fibre units in accordance with the invention.
Thus, referring first to Figure 1, the optical fibre unit illustrated comprises seven optical fibres 1 hav ing a primary resin coating and arranged in a com pact bundle, the fibres being bonded together by means of a microcrysta I li ne wax 2 such as that sold by CERESE Ltd with a melting point of about 78"to 80"C, the wax being impregnated into the interstices between the fibres, and being sufficiently adhesive to secure the fibres together, but enabling the ends of the fibres to be readily separated when desired, for example forcoupling to otherfibres. The resin coat- ings 3 of the fibres are preferably differently coloured for identification purposes.In place of the wax 2, a thermoplastics material, such as an EVAtype plastics, could alternatively be impregnated into the interstices of the fibres so as to provide the bonding medium. Another bonding medium which could be used is a U.V. curable resin.
An alternative form of optical fibre unit, this time incorporating ten optical fibres 1 formed into a bundle is illustrated in Figure 2,thefibres being bon ded together by a suitable bonding medium as at2 which could be any ofthe materials utilised to secure the fibres ofthefirstunit.
Figure 3 represents a cross section ofthe third unit, also comprising ten opticalfibresl,thefibresinthis case being grouped around a central flexiblefilament 4, for example of nylon, of approximately twice the diameterofthefibres, thefibres again being bonded to each other, and additionally to the central fila mentasat2byasuitablebonding medium,forex- ample as previously mentioned.
Figure 4 represents a cross section of an alternativy form of optical fibre unit incorporating fourresin- coated optical fibres 1 disposed side by side and bonded together by means of a microcrystalline wax 2 to form a flat ribbon-like assembly.
Several such ribbons 15,forexamplefouras shown in Figure 5, may be stacked one on top ofthe other and lightly secured together, for example also by means of wax, to form a 4x4 array.
However different numbers of ribbons may be stacked together, and ribbons having asimilarcon- struction to that illustrated in Figure 5, may incorporate different numbers offibres.
The unit illustrated in Fig u re 6 comprises the requi- red number of resin-coated fibres 1, in this case seven, grouped togetherto form a compact bundle 5, and bonded together by means of a helically wound lashing 6 of Kevlar or othersuitable material. The lashing 6 is conveniently bonded to fibres 1 by an adhesive substance, and may be in the form of a selfadhesive tape. By bonding the lashing to the fibres unravelling ofthelashingwhenthefibresarecutis effectively prevented.
One cable accommodating a plurality of optical fibre units as described with reference to any one of Figures 1 to 6 is illustrated in Figure 7, the cable comprising an extrusion 7 ofthermoplastics material having a central core portion 8 surrounding a central strength member9,fourradiallyextendingfins 10 and an outer cover 11, the core, fins and cover being integral with each other and defining between them four longitudinally extending channels 12.Pre viouslyformed optical fibre units 5, which may be constructed as illustrated in any one of Figures 1 to 6, are introduced into the channels 12 during the extrusion process; where the bonding medium wax or thermoplastics material it will be appreciated that its melting point must be sufficiently high to ensure that it is retained within the interstices between the fibres 1 during the extrusion process. The fibre units 5 are conveniently fed into the channels 12 at a rate faster than the rate atwhich the extrusion 7 is formed so that they follow an undulating path and are loosely accommodated within their respective channels 12.
Each channel 12 may beformed, as shown at 13, with a region extending along the cablewhich isof thinner cross section than the remainder of the wall, enabling itto be more easily cut, broken or pulled away to provide access to a fibre unit 5 within the channel ifthis is required.
The cable illustrated in Figure 8 has a similarconstruction to that of Figure 5, except that thethinned portions 13 ofthe outer cover 11 are replaced by lon gitudinally extending slots 14. These slots permitthe fibre units 5 to be introduced after the extrusion process and also provide ready access to them. In a modification, not shown, each said slot may be covered byan openableflap.
Although in each of Figures 7 and 8 only onefibre unit5 is shown in each ofthe channels 12, in practice several units may be accommodated in the channels if desired. It will be appreciated thatthe extruded assembly with the fibre units contained within it may be surrounded by one or more outer sheaths, which may also be of extruded plastics material possibly incorporating a moisture barrier of plastics coated metal foil.
Awater-blocking and/or hydrogen trapping material, preferably in powder form may be included within each ofthe channels if desired.
Itwill also beappreciatedthatthefibre units in accho dance with the invention can be accommodated in other forms of cable structures.

Claims (20)

1. An opticalfibre unit comprising a plurality of optical fibres each with a primary coating, wherein the coated fibres are bonded together to form a compact flexible assembly.
2. An optical fibre unitaccordingto Claim 1 wherein the fibres are bonded together by a thermoplastics material which adheres to the fibre coatings.
3. An optical fibre unitaccordingto Claim 1 wherein the fibres are bonded together by a wax which adheres to the fibre coatings.
4. An optical fibre unit according to Claim 2 wherein the thermoplastics material is an EVAtype plastic.
5. An optical fibre unit according to Claim 3 wherein the bonding material is a microcrystalline wax having a melting point ofthe order of 80 C.
6. An optical fibre unit according to Claim 1 wherein the fibres are bonded together by one or more lashings wound helically around the assembled fibres.
7. An optical fibre unit according to Claim 6 wherein the or each lashing is secured to thefibre assembly byan adhesive.
8. An optical fibre unit according to Claim 6 or7 wherein the or each lashing is intheform ofafilamentor tape.
9. An optical fibre unit according to any of Claims 6 to 8 wherein a lubricating material is provided between the fibres.
10. An optical fibre unit according to anyof Claims 1 to 9 wherein the fibres extend parallel to the axis ofthe unit.
11. An optical fibre unit according to any of Claims 1 to 9 wherein the fibres are disposed in a helical or periodically reversing helical fashion about the axis of the unit.
12. An optical fibre unit according to Claim 11 wherein the fibres are disposed around a central flexible filament of larger diameter.
13. An optical fibre unit according to Claim 12 wherein the fibres are disposed uniformly around the central filament.
14. An optical fibre unit according to Claim 12 or 13 wherein the central filament is composed of nylon.
15. An optical fibre unit according to Claim 1, 3Or 5 in which the fibres are bonded together side by side in the form of a ribbon.
16. An optical fibre unit according to Claim 15 wherein a plurality of said ribbons are superposed on each other to form a stack.
17. An optical fibre unit according to Claim 16 wherein the ribbons are bonded together.
18. An optical fibre unit substantially as hereinbefore described with reference to any one of Figures 1 to 6 ofthe accompanying drawings.
19. An optical cable incorporating oneor more optical fibre units according to any preceding Claim.
20. An optical cable according to Claim 19 constructed substantially as shown in and as here it before described with reference to Figure 7 or 8 of the accompanying drawings.
GB08629919A 1985-12-23 1986-12-15 Optical fibre units Withdrawn GB2184563A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB858531673A GB8531673D0 (en) 1985-12-23 1985-12-23 Optical fibre units

Publications (2)

Publication Number Publication Date
GB8629919D0 GB8629919D0 (en) 1987-01-28
GB2184563A true GB2184563A (en) 1987-06-24

Family

ID=10590214

Family Applications (2)

Application Number Title Priority Date Filing Date
GB858531673A Pending GB8531673D0 (en) 1985-12-23 1985-12-23 Optical fibre units
GB08629919A Withdrawn GB2184563A (en) 1985-12-23 1986-12-15 Optical fibre units

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GB858531673A Pending GB8531673D0 (en) 1985-12-23 1985-12-23 Optical fibre units

Country Status (1)

Country Link
GB (2) GB8531673D0 (en)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2215081A (en) * 1988-02-11 1989-09-13 Stc Plc Optical fibre cable
EP0349206A2 (en) * 1988-06-30 1990-01-03 AT&T Corp. Bonded array of transmission media
EP0385682A2 (en) * 1989-02-28 1990-09-05 AT&T Corp. Stable package of elongated strand material and methods of and apparatus for providing same
EP0417384A2 (en) * 1989-08-11 1991-03-20 KABEL RHEYDT Aktiengesellschaft Optical cable
EP0429238A2 (en) * 1989-11-13 1991-05-29 Minnesota Mining And Manufacturing Company Self-supporting coil of optical fiber and method of forming the coil
EP0495400A2 (en) * 1991-01-17 1992-07-22 Siemens Aktiengesellschaft Optical cable and method of its production
FR2698181A1 (en) * 1992-10-21 1994-05-20 Northern Telecom Ltd Optical fiber cable and its manufacturing process
FR2706046A1 (en) * 1993-06-02 1994-12-09 Siemens Ag Optical cable, method for its manufacture and device for implementing the method.
US5908873A (en) * 1995-12-20 1999-06-01 Borden Chemicals, Inc. Peelable bonded ribbon matrix material; optical fiber bonded ribbon arrays containing same; and process for preparing said optical fiber bonded ribbon arrays
EP1018662A2 (en) * 1999-01-07 2000-07-12 Alcatel Optical cable
EP1235087A2 (en) * 2000-12-27 2002-08-28 CCS Technology, Inc. Fiber optic cable assembly and method of making same
EP1237027A2 (en) * 2001-02-28 2002-09-04 Asahi Glass Company, Limited Optical fiber cable with central support member having lobe structure
US7136556B2 (en) 2002-08-10 2006-11-14 Emtelle Uk Limited Signal transmitting cable

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1423590A (en) * 1973-01-19 1976-02-04 Siemens Ag Communications cables
US4011007A (en) * 1971-06-28 1977-03-08 American Optical Corporation Optical fiber bundle image conduit
GB1570624A (en) * 1975-12-11 1980-07-02 Western Electric Co Optical fibre transmission arrangements
EP0015425A2 (en) * 1979-02-28 1980-09-17 Siemens Aktiengesellschaft Stranding element for optical cables
GB1578680A (en) * 1977-05-31 1980-11-05 Siemens Ag Ribbon-type cables
GB2069746A (en) * 1980-02-19 1981-08-26 Standard Telephones Cables Ltd Communications cables
DE3232413A1 (en) * 1982-08-27 1984-03-01 Siemens AG, 1000 Berlin und 8000 München Filling compound for a longitudinally watertight optical telecommunications cable
GB2144556A (en) * 1983-06-07 1985-03-06 Int Standard Electric Corp Optical fibre cable
EP0165632A2 (en) * 1984-05-23 1985-12-27 Koninklijke Philips Electronics N.V. Optical flat type cable, method of manufacturing same, and an optical cable composed of several flat type cables
GB2161618A (en) * 1984-07-13 1986-01-15 Telephone Cables Ltd Optical fibre cables
GB2164198A (en) * 1984-09-05 1986-03-12 Telephone Cables Ltd Cables

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4011007A (en) * 1971-06-28 1977-03-08 American Optical Corporation Optical fiber bundle image conduit
GB1423590A (en) * 1973-01-19 1976-02-04 Siemens Ag Communications cables
GB1570624A (en) * 1975-12-11 1980-07-02 Western Electric Co Optical fibre transmission arrangements
GB1578680A (en) * 1977-05-31 1980-11-05 Siemens Ag Ribbon-type cables
EP0015425A2 (en) * 1979-02-28 1980-09-17 Siemens Aktiengesellschaft Stranding element for optical cables
GB2069746A (en) * 1980-02-19 1981-08-26 Standard Telephones Cables Ltd Communications cables
DE3232413A1 (en) * 1982-08-27 1984-03-01 Siemens AG, 1000 Berlin und 8000 München Filling compound for a longitudinally watertight optical telecommunications cable
GB2144556A (en) * 1983-06-07 1985-03-06 Int Standard Electric Corp Optical fibre cable
EP0165632A2 (en) * 1984-05-23 1985-12-27 Koninklijke Philips Electronics N.V. Optical flat type cable, method of manufacturing same, and an optical cable composed of several flat type cables
GB2161618A (en) * 1984-07-13 1986-01-15 Telephone Cables Ltd Optical fibre cables
GB2164198A (en) * 1984-09-05 1986-03-12 Telephone Cables Ltd Cables

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2215081B (en) * 1988-02-11 1992-05-20 Stc Plc Optical fibre communications cable
GB2215081A (en) * 1988-02-11 1989-09-13 Stc Plc Optical fibre cable
EP0349206A2 (en) * 1988-06-30 1990-01-03 AT&T Corp. Bonded array of transmission media
US4900126A (en) * 1988-06-30 1990-02-13 American Telephone & Telegraph Co. Bonded array of transmission media
EP0349206B1 (en) * 1988-06-30 1999-09-15 AT&T Corp. Bonded array of transmission media
EP0385682A2 (en) * 1989-02-28 1990-09-05 AT&T Corp. Stable package of elongated strand material and methods of and apparatus for providing same
EP0385682A3 (en) * 1989-02-28 1991-01-30 AT&T Corp. Stable package of elongated strand material and methods of and apparatus for providing same
EP0417384A3 (en) * 1989-08-11 1992-01-02 Aeg Kabel Aktiengesellschaft Optical cable
EP0417384A2 (en) * 1989-08-11 1991-03-20 KABEL RHEYDT Aktiengesellschaft Optical cable
EP0429238A2 (en) * 1989-11-13 1991-05-29 Minnesota Mining And Manufacturing Company Self-supporting coil of optical fiber and method of forming the coil
EP0429238A3 (en) * 1989-11-13 1991-07-24 Minnesota Mining And Manufacturing Company Self-supporting coil of optical fiber and method of forming the coil
US5179613A (en) * 1989-11-13 1993-01-12 Minnesota Mining And Manufacturing Company Self-supporting coil of optical fiber and method of forming the coil
EP0495400A2 (en) * 1991-01-17 1992-07-22 Siemens Aktiengesellschaft Optical cable and method of its production
EP0495400A3 (en) * 1991-01-17 1993-01-13 Siemens Aktiengesellschaft Optical cable and method of its production
US5210813A (en) * 1991-01-17 1993-05-11 Siemens Aktiengesellschaft Optical cable and method for manufacturing the optical cable
FR2698181A1 (en) * 1992-10-21 1994-05-20 Northern Telecom Ltd Optical fiber cable and its manufacturing process
FR2706046A1 (en) * 1993-06-02 1994-12-09 Siemens Ag Optical cable, method for its manufacture and device for implementing the method.
US5908873A (en) * 1995-12-20 1999-06-01 Borden Chemicals, Inc. Peelable bonded ribbon matrix material; optical fiber bonded ribbon arrays containing same; and process for preparing said optical fiber bonded ribbon arrays
US6455607B1 (en) 1995-12-20 2002-09-24 Borden Chemical, Inc. Peelable bonded ribbon matrix material; optical fiber bonded ribbon arrays containing same; and process for preparing said optical fiber bonded ribbon arrays
EP1018662A2 (en) * 1999-01-07 2000-07-12 Alcatel Optical cable
EP1018662B1 (en) * 1999-01-07 2006-03-22 Draka Comteq B.V. Optical cable
EP1235087A2 (en) * 2000-12-27 2002-08-28 CCS Technology, Inc. Fiber optic cable assembly and method of making same
EP1235087A3 (en) * 2000-12-27 2004-02-04 CCS Technology, Inc. Fiber optic cable assembly and method of making same
EP1237027A2 (en) * 2001-02-28 2002-09-04 Asahi Glass Company, Limited Optical fiber cable with central support member having lobe structure
EP1237027A3 (en) * 2001-02-28 2004-05-06 Asahi Glass Company, Limited Optical fiber cable with central support member having lobe structure
US6826338B2 (en) 2001-02-28 2004-11-30 Asahi Glass Company, Limited Optical fiber cable having a partitioning spacer
US7136556B2 (en) 2002-08-10 2006-11-14 Emtelle Uk Limited Signal transmitting cable
USRE41388E1 (en) 2002-08-10 2010-06-22 Emtelle Uk Limited Signal transmitting cable

Also Published As

Publication number Publication date
GB8629919D0 (en) 1987-01-28
GB8531673D0 (en) 1986-02-05

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