CA2038787A1 - Overhead electric and optical conductor manufacture - Google Patents
Overhead electric and optical conductor manufactureInfo
- Publication number
- CA2038787A1 CA2038787A1 CA 2038787 CA2038787A CA2038787A1 CA 2038787 A1 CA2038787 A1 CA 2038787A1 CA 2038787 CA2038787 CA 2038787 CA 2038787 A CA2038787 A CA 2038787A CA 2038787 A1 CA2038787 A1 CA 2038787A1
- Authority
- CA
- Canada
- Prior art keywords
- conductor
- flexible
- length
- passage
- optical
- 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.)
- Abandoned
Links
Landscapes
- Communication Cables (AREA)
Abstract
ABSTRACT
In a simple and inexpensive method of manufacturing a composite flexible overhead electric and optical conductor having a flexible optical waveguide loosely housed in a bore extending throughout the length of the conductor, the flexible electric conductor, without a flexible optical guide loosely housed in the bore, is wound around the hub of a cable drum in such a way that each end of the wound conductor is exposed and accessible. The flexible optical guide is then accommodated in the bore of the wound conductor by introducing a leading end of the optical guide into the end of the bore at one exposed end 11 of the wound conductor and by propelling the optical guide along the bore of the wound conductor by fluid drag of a gaseous medium which is passed through the bore in the desired direction of advance at such a pressure that the optical guide is carried along the bore until the optical guide is loosely housed in and throughout the length of the bore of the wound conductor.
In a simple and inexpensive method of manufacturing a composite flexible overhead electric and optical conductor having a flexible optical waveguide loosely housed in a bore extending throughout the length of the conductor, the flexible electric conductor, without a flexible optical guide loosely housed in the bore, is wound around the hub of a cable drum in such a way that each end of the wound conductor is exposed and accessible. The flexible optical guide is then accommodated in the bore of the wound conductor by introducing a leading end of the optical guide into the end of the bore at one exposed end 11 of the wound conductor and by propelling the optical guide along the bore of the wound conductor by fluid drag of a gaseous medium which is passed through the bore in the desired direction of advance at such a pressure that the optical guide is carried along the bore until the optical guide is loosely housed in and throughout the length of the bore of the wound conductor.
Description
2038~87 OVERHEAD ELECTRIC & OPTICAL CONDUCTOR MANUFACTURE
This invention relates to composite flexible overhead electric and optical conductors suitable for incorporation in an overhead electric and optical transmission system in which at least one such composite conductor is suspended freely in long lengths between towers or other upstanding supports mutually spaced along the route of the system.
In the Complete Specification of our British Patent No: 1598438 there is described and claimed a composite flexible overhead electric and optical conductor which is now widely used in overhead electric and optical transmission systems both in the United Kingdom and elsewhere and which comprises at least one layer of helically wound bare elongate elements of metal or metal alloy, at least one elongate compartment within and extending throughout the length of the conductor and, loosely housed in the elongate compartment or at least one of the elongate compartments, at least one separate optlcal fibre and/or at least one optlcal bundle.
In one preferred embodlment of the composite flexlble overhead electric and optical conductor in accordance wlth our aforesaid patent, the or each elongate compartment ls disposed withln a substantially circumferentlally rlgid central core around which the bare elongate elements of metal or metal alloy of the or each layer are helically wound.
, ~ ",, ,.~ .,.
.: ., . ~ .
... .
.
. . . ; . .
: ; , ., ,, ~ ; .; ; .
~:038787 2.
It is an object of the present invention to provide an improved method of manufacturing a composite flexible overhead electric and optical conductor in accordance with our aforesaid patent, which method of manufacture is simple and substantially less expensive than methods of manufacture hitherto proposed and used.
According to the invention, the improved method comprises causing a flexible central core to travel in the direction of its length; helically winding around the advancing core at least one layer of bare elongate elements of metal or metal alloy to form a flexible electric conductor having within and extending throughout the length of the conductor at least one bore or other passage; winding the flexible electric conductox around the hub of a cable drum in such a way that each end of the wound conductor is exposed and accessible; and accommodating at least one length of flexible optical guide comprising at least one optical fibre throughout the length of the bore or other passage or of at least one of the bores or other passages wlthin the wound conductor by introducing a leading end of the length of optical guide into the end of said bore or pas~age at one exposed end of the wound conductor and by propelllng the optical guide along said bore or passage of the wound conductor by fluid drag of a gaseous medium which will have no deleterious effect on the optical guide or on the conductor and which is passed through . . ~ .
, . . - , ~ .
:" , . ` .,. -..
.: , .; . " f " ' 3.
said bore or passage in the deslred direction of advance at such a pressure that the length of optical guide is carried along said bore or passage until the length of optical guide is loosely housed in and throughout the length of said bore or passage of the wound conductor.
Preferably, the length of optical guide loosely housed in the bore or other passage of the wound conductor wlll substantially exceed the length of the bore or passage so that there is an excess length of optical guide within the bore or passage.
At least one said bore or other passage may be within the flexible central core - in which case the flexible central core will be substantially clrcumf~erentlally rigid - or said bore or other passage ;
may be within a bare metal elongate element, or between ad~acent bare metal elongate elements, of the layer or at least one of the layers of hellcally wound bare metal elongate elements. ~ ~
Where the or each bore or other passage i8 wlthin a bare metal elongate element, or between ad~acent bare metol elongate elements, of the layer or at least one of the layers of hellcally wound bare metal elongate elements, the flexlble central core may be a single bare wlre or other elongate element of metal or metal alloy or a plurallty Or such bare wlres or other elongate elements assembled together.~
~:0~8787 .
This invention relates to composite flexible overhead electric and optical conductors suitable for incorporation in an overhead electric and optical transmission system in which at least one such composite conductor is suspended freely in long lengths between towers or other upstanding supports mutually spaced along the route of the system.
In the Complete Specification of our British Patent No: 1598438 there is described and claimed a composite flexible overhead electric and optical conductor which is now widely used in overhead electric and optical transmission systems both in the United Kingdom and elsewhere and which comprises at least one layer of helically wound bare elongate elements of metal or metal alloy, at least one elongate compartment within and extending throughout the length of the conductor and, loosely housed in the elongate compartment or at least one of the elongate compartments, at least one separate optlcal fibre and/or at least one optlcal bundle.
In one preferred embodlment of the composite flexlble overhead electric and optical conductor in accordance wlth our aforesaid patent, the or each elongate compartment ls disposed withln a substantially circumferentlally rlgid central core around which the bare elongate elements of metal or metal alloy of the or each layer are helically wound.
, ~ ",, ,.~ .,.
.: ., . ~ .
... .
.
. . . ; . .
: ; , ., ,, ~ ; .; ; .
~:038787 2.
It is an object of the present invention to provide an improved method of manufacturing a composite flexible overhead electric and optical conductor in accordance with our aforesaid patent, which method of manufacture is simple and substantially less expensive than methods of manufacture hitherto proposed and used.
According to the invention, the improved method comprises causing a flexible central core to travel in the direction of its length; helically winding around the advancing core at least one layer of bare elongate elements of metal or metal alloy to form a flexible electric conductor having within and extending throughout the length of the conductor at least one bore or other passage; winding the flexible electric conductox around the hub of a cable drum in such a way that each end of the wound conductor is exposed and accessible; and accommodating at least one length of flexible optical guide comprising at least one optical fibre throughout the length of the bore or other passage or of at least one of the bores or other passages wlthin the wound conductor by introducing a leading end of the length of optical guide into the end of said bore or pas~age at one exposed end of the wound conductor and by propelllng the optical guide along said bore or passage of the wound conductor by fluid drag of a gaseous medium which will have no deleterious effect on the optical guide or on the conductor and which is passed through . . ~ .
, . . - , ~ .
:" , . ` .,. -..
.: , .; . " f " ' 3.
said bore or passage in the deslred direction of advance at such a pressure that the length of optical guide is carried along said bore or passage until the length of optical guide is loosely housed in and throughout the length of said bore or passage of the wound conductor.
Preferably, the length of optical guide loosely housed in the bore or other passage of the wound conductor wlll substantially exceed the length of the bore or passage so that there is an excess length of optical guide within the bore or passage.
At least one said bore or other passage may be within the flexible central core - in which case the flexible central core will be substantially clrcumf~erentlally rigid - or said bore or other passage ;
may be within a bare metal elongate element, or between ad~acent bare metal elongate elements, of the layer or at least one of the layers of hellcally wound bare metal elongate elements. ~ ~
Where the or each bore or other passage i8 wlthin a bare metal elongate element, or between ad~acent bare metol elongate elements, of the layer or at least one of the layers of hellcally wound bare metal elongate elements, the flexlble central core may be a single bare wlre or other elongate element of metal or metal alloy or a plurallty Or such bare wlres or other elongate elements assembled together.~
~:0~8787 .
4.
The leading end of the length of optical guide may be introduced into the end of said bore or passage at either exposed end of the wound conductor but, preferably, it is introduced into the end of said bore or passage at the exposed leading end of the wound conductor, that is to say the end of the wound conductor nearer the hub of the cable drum, and, for this purpose, preferably the leading end of the wound conductor protrudes through a hole in a flange of the cable drum.
10By virtue of the fact that both ends of the wound conductor are exposed and accessible, after a flexible ;
optical guide has been accommodated in the or a bore or other passage in the wound conductor, the flexible optical guide can be readily tested.
15The or each flexible optlcal guide may be propelled along the bore or other passage of the wound conductor by fluid drag of the gaseous medium using the method and apDaratus as described ln our Britlsh Patent Specification No: 2179471B but lt ls to be clearly ; ~ 20 understood that any suitable method hltherto proposed and used of propelling a flexlble optical guide along a ~ bore or other passage by fluid drag of a gaseous medium ;~ can be employed.
Where the advanclng flexible central core is substantiallY circumferentially rigid and has at least one bore or other passage within and extendlng .. .... . .. . . . . ..
The leading end of the length of optical guide may be introduced into the end of said bore or passage at either exposed end of the wound conductor but, preferably, it is introduced into the end of said bore or passage at the exposed leading end of the wound conductor, that is to say the end of the wound conductor nearer the hub of the cable drum, and, for this purpose, preferably the leading end of the wound conductor protrudes through a hole in a flange of the cable drum.
10By virtue of the fact that both ends of the wound conductor are exposed and accessible, after a flexible ;
optical guide has been accommodated in the or a bore or other passage in the wound conductor, the flexible optical guide can be readily tested.
15The or each flexible optlcal guide may be propelled along the bore or other passage of the wound conductor by fluid drag of the gaseous medium using the method and apDaratus as described ln our Britlsh Patent Specification No: 2179471B but lt ls to be clearly ; ~ 20 understood that any suitable method hltherto proposed and used of propelling a flexlble optical guide along a ~ bore or other passage by fluid drag of a gaseous medium ;~ can be employed.
Where the advanclng flexible central core is substantiallY circumferentially rigid and has at least one bore or other passage within and extendlng .. .... . .. . . . . ..
5.
throughout its length, preferably the central core comprises a seamless tube of aluminium or of other metal or metal alloy having a single central bore - in which :
case the seamless tube may be made by the Conform process - but, where lt ls deslred that the central core includes two or more passages extendlng wlthin and throughout the length of the core, the:central core preferably is of composite form and comprises a central elongate member of metal or metal alloy having in its 10 outer surface a plurality of circumferentlally spaced -~
grooves extending helically around the member and, surrounding the helically grooved central member, a separately formed circumferentially continuous wall of metal or metal alloy, which wall may conslst of a longitudinally extending, transversely folded strip of metal or metal alloy.
The bare metal elongate elements of the or each ~: layer may each be of circular or non-circular transverse cross-section. Where two or more layeræ of bare metal elongate elements are hellcally wound around the advanclng central core, preferably the elongate elements of ad~acent layers are helically wound in opposlte ~- dlrections. ~:
. The or each flexible optical guide may be a separate optical fibre or it may be an optical fibre element comprlsing two or more optical fibres assembled ;~ together such as, for example, a flexible plastlcs tube ~' 6. Z0~3787 having two or more optical fibres loosely housed in the bore of the tube or, for example, an optical fibre ribbon comprising a plurality of optical fibres extending side by side with their axes lying in a substantially common plane. One optical fibre ribbon structure which is especially suitable for use in the improved method of the present invention is described and claimed in the specification of;our British Patent No: 2141558B.
The invention also includes a composite flexible overhead electric and optical conductor when manufactured by the improved method herelnbefore described.
The invention is further illustrated by a lS description, by way of example, of the preferred method ~ of manufacturing a composite flexib}e overhead electric ;- and optlcal conductor with reference to the accompanying ~ `
drawings, in which:-Figure 1 1s a transverse cross-sectional vlew of the composite overhead flexlble electric and optical conductor to be manufactured by said preferred method:
~ , .
-~ Figure 2 is a diagrammatic sectional side view of preferred apparatus used for introducing a flexible optical guide into the central bore of the wound electrlc conductor, and.
~- Figure 3 ls a diagrammatic pictorial view of the ap~aratus employed in effecting the final step ln said preferred method.
throughout its length, preferably the central core comprises a seamless tube of aluminium or of other metal or metal alloy having a single central bore - in which :
case the seamless tube may be made by the Conform process - but, where lt ls deslred that the central core includes two or more passages extendlng wlthin and throughout the length of the core, the:central core preferably is of composite form and comprises a central elongate member of metal or metal alloy having in its 10 outer surface a plurality of circumferentlally spaced -~
grooves extending helically around the member and, surrounding the helically grooved central member, a separately formed circumferentially continuous wall of metal or metal alloy, which wall may conslst of a longitudinally extending, transversely folded strip of metal or metal alloy.
The bare metal elongate elements of the or each ~: layer may each be of circular or non-circular transverse cross-section. Where two or more layeræ of bare metal elongate elements are hellcally wound around the advanclng central core, preferably the elongate elements of ad~acent layers are helically wound in opposlte ~- dlrections. ~:
. The or each flexible optical guide may be a separate optical fibre or it may be an optical fibre element comprlsing two or more optical fibres assembled ;~ together such as, for example, a flexible plastlcs tube ~' 6. Z0~3787 having two or more optical fibres loosely housed in the bore of the tube or, for example, an optical fibre ribbon comprising a plurality of optical fibres extending side by side with their axes lying in a substantially common plane. One optical fibre ribbon structure which is especially suitable for use in the improved method of the present invention is described and claimed in the specification of;our British Patent No: 2141558B.
The invention also includes a composite flexible overhead electric and optical conductor when manufactured by the improved method herelnbefore described.
The invention is further illustrated by a lS description, by way of example, of the preferred method ~ of manufacturing a composite flexib}e overhead electric ;- and optlcal conductor with reference to the accompanying ~ `
drawings, in which:-Figure 1 1s a transverse cross-sectional vlew of the composite overhead flexlble electric and optical conductor to be manufactured by said preferred method:
~ , .
-~ Figure 2 is a diagrammatic sectional side view of preferred apparatus used for introducing a flexible optical guide into the central bore of the wound electrlc conductor, and.
~- Figure 3 ls a diagrammatic pictorial view of the ap~aratus employed in effecting the final step ln said preferred method.
7.
Referring to Figure 1, the composite flexible overhead electrlc and optical conductor 1 to be manufactured by the preferred method of the invention comprises a central seamless circumferentially rigid aluminium tube 3 in the bore 4 of which throughout the length of the conductor is looæely housed a flexible optlcal guide 2, the length of the optical guide exceeding the length of the tube. The seamless aluminium tube 3 ls surrounded by three layers 6 of helically wound bare aluminium wires 7 each of circular cross-section, the helical lay of the wires of each layer being of opposlte hand to that of the helical lay of the wires of the or each ad~acent layer.
The flexlble optical guide 2 may be of any one of a number of forms includinq a separate optical fibre and an optlcal fibre element comprising two or more optical f1bres, e.g. an optical fibre ribbon.
In the preferred method of manufacturlng the composite flexlble overhead electrlc and optlcal conductor 1 shown ln Flgure 1, the steps ln the manuracture of the electrlc conductor that are effected prlor to introductlon of the flexible optlcal guide 2 are conventlonal and well known in the art. The central seamless clrcumferentially rlgid aluminium tube 3 -whlch may be formed by the Conform extrusion process orby any other suitable extrusion process - is caused to travel ln the dlrection of its length towards and ':
, , . . . .
: 8-through stranding apparatus (not shown) at which three layers 6 of aluminium wires 7 are helically wound around the advancing tube, the wires of each of the outer two layers being helically wound in~the opposite direction to that of the hellcally wound wlres of the underlying layer. Downstream of the stranding apparatus, the leading end 11 of the flexible electric conductor 10 so formed i8 threaded through a hole 16 ln a flange lS of a cable drum 14 (Pigure 3) so that it is exposed and accesslble and the flexible conductor is then wound : around the hub of the drum leaving the tralllng end 12 of the wound conductor exposed and accesslble.
Referring to Figures 2 and 3, the preferred apparatus used for introduclng a flexible optical guide into the central bore of the wound electric conductor 10 . comprises a substantially fluid-tight housing 21 of ~-.
elongate shape having, at one end of the housing, an end -wall 22 and, at the other end of the housing, an end wall 23 of hemi-spherical shape. Mounted in the housing ~ 20 21 is a pay-off stand 24 on whlch ls freely plvotally -~ mounted a reel 25 on which ls wound a flexlble optlcal guide 18.
In the end wall 22 of the housing 21 is an inlet port 27 throu~h which pressurised air from a source (not ; 25 shown) can be introducod into the housing, the rate of . lntroductlon o~ the air belng controllable by a~valve ~8. A v1nual lndlcatlon of the pres~uee of the a1r 2~387~37 within the housing 21 is given by a pressure meter 29.
Connected to an outlet 31 in the end wall 22 of the housing 21 is a pipe 32 of transparent plastics material for connection to the central bore of the wound electric conductor 10 at its leading end 11.
Posltioned within the housing 21 between the reel 25 and the outlet 31 is a pair of rubber-coated pinch wheels 34, one of which is rotatably driven through a gear box (not shown) by a 12 v.d.c. motor 35, the leads from the motor passing through a fluid-tight seal in an aperture 36 in the end wall 22 via an electro mechan,cal relay (not shown), controlled by a programmable controller, to a power supply (not shown).
The housing 21 may have at least one window in its wall and may incorporate an internal lighting system to enable the behaviour of the flexible optical guide 18 and the reel 25 to be continuously monitored, thereby giving an indication of any obstruction in the central bore of the wound electric conductor 10.
In employing the apparatus shown ln Figure 2 to lntroduce the flexlble optical gulde 18 ~rom the reel 25 into the bore of the flexible electric conductor 10 wound on the hub of the cable drum 14, the flexible optical guide ls passed from the reel through a guide tube (not shown) between and in contact with the pair of wheels 34, through another guide tube (not shown) and through the pipe 32. A flexible lightweight body,(not !,, '' .', ' : ' . .
'. `' . . , , ' ,. , , i .. , .. , , ~ ~ . , Z03~3787 10 .
shown) similar in shape to a parachute or umbrella and having a transverse cross-sectional area substantially greater than that of the optical guide 18 may be attached to the leading end of the flexible guide and be S lntroduced into the central bore of the wound conductor 10 at its leading end 11. The pipe 32 is then connected to the central bore of the flexible conductor 10 at its leading end 11 to effect a fluid-tight seal.
Air under pressure is then introduced into the housing 21 through the inlet port 27 so that the housing is substantially filled with air at a predetermined pressure, the hemi-spherical end wall 23 of the housing belng so shaped as to deflect the air smoothly so that it flows towards and out of the outlet 31 through the lS pipe 32 and into the central bore of the wound conductor ~-10. As the pressure of the air withln the housing 21 approaches the required level, the pair of wheels 34 is rotatably driven by the motor 35 at continuously varying ~: speeds between upper and lower iimits to prodùce a ~;: 20 pulsing effect serving to provide an intermlttent release of flexible optlcal guide 18 from the reel 25.
The rate at whlch the flexlble optical guide 18 is unwound intermittently from the reel 25 by the palr of wheels 34 and the pressure and rate at which air is continuously lntroduced into the fluid-tlght housing 21 are such that regular pulsed progression of the flexible optical gulde along the pipe 32 and lnto the central , ~ ., , , . ~, ........... . ..... .....
2~38787 11 .
bore of the wound conductor 10 is produced by combination of the continuous varied drive and fluid drag of the air; where a flexible lightweight body is attached to the leading end of the flexible optical guide, the in~ected air will bear against the flexible body which assists in effecting advance of the flexible optical guide along the central bore.~ The process is continued until the desired length of flexible optical guide 18 is loosely housed in and throughout the length of the central bore of the wound conductor 10.
The improved method of the invention has the very important advantage that the cost of manufacture of the composite flexible overhead electric and optical conductor is substantially reduced because the or each lS flexible optical guide is not accommodated in the electrlc conductor during manufacture of the conductor.
Thus, conventional and long proved successful methods of manufacturing~the electric conductor can be used.
Furthermore, a flexible optlcal gulde of any desired form can subsequently be accommodated ln a bore or other passage ln a wound electrlc conductor at any tlme as and when a partlcular composite flexlble overhead electric and optical conductor is required by a customer. Thus, a manufacturer need only keep in store standard forms of ; 25 the flexible overhead electric conductor havlng throughout its length at least one bore or other passage.
Referring to Figure 1, the composite flexible overhead electrlc and optical conductor 1 to be manufactured by the preferred method of the invention comprises a central seamless circumferentially rigid aluminium tube 3 in the bore 4 of which throughout the length of the conductor is looæely housed a flexible optlcal guide 2, the length of the optical guide exceeding the length of the tube. The seamless aluminium tube 3 ls surrounded by three layers 6 of helically wound bare aluminium wires 7 each of circular cross-section, the helical lay of the wires of each layer being of opposlte hand to that of the helical lay of the wires of the or each ad~acent layer.
The flexlble optical guide 2 may be of any one of a number of forms includinq a separate optical fibre and an optlcal fibre element comprising two or more optical f1bres, e.g. an optical fibre ribbon.
In the preferred method of manufacturlng the composite flexlble overhead electrlc and optlcal conductor 1 shown ln Flgure 1, the steps ln the manuracture of the electrlc conductor that are effected prlor to introductlon of the flexible optlcal guide 2 are conventlonal and well known in the art. The central seamless clrcumferentially rlgid aluminium tube 3 -whlch may be formed by the Conform extrusion process orby any other suitable extrusion process - is caused to travel ln the dlrection of its length towards and ':
, , . . . .
: 8-through stranding apparatus (not shown) at which three layers 6 of aluminium wires 7 are helically wound around the advancing tube, the wires of each of the outer two layers being helically wound in~the opposite direction to that of the hellcally wound wlres of the underlying layer. Downstream of the stranding apparatus, the leading end 11 of the flexible electric conductor 10 so formed i8 threaded through a hole 16 ln a flange lS of a cable drum 14 (Pigure 3) so that it is exposed and accesslble and the flexible conductor is then wound : around the hub of the drum leaving the tralllng end 12 of the wound conductor exposed and accesslble.
Referring to Figures 2 and 3, the preferred apparatus used for introduclng a flexible optical guide into the central bore of the wound electric conductor 10 . comprises a substantially fluid-tight housing 21 of ~-.
elongate shape having, at one end of the housing, an end -wall 22 and, at the other end of the housing, an end wall 23 of hemi-spherical shape. Mounted in the housing ~ 20 21 is a pay-off stand 24 on whlch ls freely plvotally -~ mounted a reel 25 on which ls wound a flexlble optlcal guide 18.
In the end wall 22 of the housing 21 is an inlet port 27 throu~h which pressurised air from a source (not ; 25 shown) can be introducod into the housing, the rate of . lntroductlon o~ the air belng controllable by a~valve ~8. A v1nual lndlcatlon of the pres~uee of the a1r 2~387~37 within the housing 21 is given by a pressure meter 29.
Connected to an outlet 31 in the end wall 22 of the housing 21 is a pipe 32 of transparent plastics material for connection to the central bore of the wound electric conductor 10 at its leading end 11.
Posltioned within the housing 21 between the reel 25 and the outlet 31 is a pair of rubber-coated pinch wheels 34, one of which is rotatably driven through a gear box (not shown) by a 12 v.d.c. motor 35, the leads from the motor passing through a fluid-tight seal in an aperture 36 in the end wall 22 via an electro mechan,cal relay (not shown), controlled by a programmable controller, to a power supply (not shown).
The housing 21 may have at least one window in its wall and may incorporate an internal lighting system to enable the behaviour of the flexible optical guide 18 and the reel 25 to be continuously monitored, thereby giving an indication of any obstruction in the central bore of the wound electric conductor 10.
In employing the apparatus shown ln Figure 2 to lntroduce the flexlble optical gulde 18 ~rom the reel 25 into the bore of the flexible electric conductor 10 wound on the hub of the cable drum 14, the flexible optical guide ls passed from the reel through a guide tube (not shown) between and in contact with the pair of wheels 34, through another guide tube (not shown) and through the pipe 32. A flexible lightweight body,(not !,, '' .', ' : ' . .
'. `' . . , , ' ,. , , i .. , .. , , ~ ~ . , Z03~3787 10 .
shown) similar in shape to a parachute or umbrella and having a transverse cross-sectional area substantially greater than that of the optical guide 18 may be attached to the leading end of the flexible guide and be S lntroduced into the central bore of the wound conductor 10 at its leading end 11. The pipe 32 is then connected to the central bore of the flexible conductor 10 at its leading end 11 to effect a fluid-tight seal.
Air under pressure is then introduced into the housing 21 through the inlet port 27 so that the housing is substantially filled with air at a predetermined pressure, the hemi-spherical end wall 23 of the housing belng so shaped as to deflect the air smoothly so that it flows towards and out of the outlet 31 through the lS pipe 32 and into the central bore of the wound conductor ~-10. As the pressure of the air withln the housing 21 approaches the required level, the pair of wheels 34 is rotatably driven by the motor 35 at continuously varying ~: speeds between upper and lower iimits to prodùce a ~;: 20 pulsing effect serving to provide an intermlttent release of flexible optlcal guide 18 from the reel 25.
The rate at whlch the flexlble optical guide 18 is unwound intermittently from the reel 25 by the palr of wheels 34 and the pressure and rate at which air is continuously lntroduced into the fluid-tlght housing 21 are such that regular pulsed progression of the flexible optical gulde along the pipe 32 and lnto the central , ~ ., , , . ~, ........... . ..... .....
2~38787 11 .
bore of the wound conductor 10 is produced by combination of the continuous varied drive and fluid drag of the air; where a flexible lightweight body is attached to the leading end of the flexible optical guide, the in~ected air will bear against the flexible body which assists in effecting advance of the flexible optical guide along the central bore.~ The process is continued until the desired length of flexible optical guide 18 is loosely housed in and throughout the length of the central bore of the wound conductor 10.
The improved method of the invention has the very important advantage that the cost of manufacture of the composite flexible overhead electric and optical conductor is substantially reduced because the or each lS flexible optical guide is not accommodated in the electrlc conductor during manufacture of the conductor.
Thus, conventional and long proved successful methods of manufacturing~the electric conductor can be used.
Furthermore, a flexible optlcal gulde of any desired form can subsequently be accommodated ln a bore or other passage ln a wound electrlc conductor at any tlme as and when a partlcular composite flexlble overhead electric and optical conductor is required by a customer. Thus, a manufacturer need only keep in store standard forms of ; 25 the flexible overhead electric conductor havlng throughout its length at least one bore or other passage.
Claims (13)
1. A method of manufacturing a composite flexible overhead electric and optical conductor which comprises causing a flexible central core to travel in the direction of its length; helically winding around the advancing core at least one layer of bare elongate elements of metal or metal alloy to form a flexible electric conductor having within and extending throughout the length of the conductor at least one passage; winding the flexible electric conductor around the hub of a cable drum in such a way that each end of the wound conductor is exposed and accessible; and accommodating at least one length of flexible optical guide comprising at least one optical fibre throughout the length of the passage within the wound conductor by introducing a leading end of the length of optical guide into the end of said passage at one exposed end of the wound conductor and by propelling the optical guide along said passage of the wound conductor by fluid drag of a gaseous medium which will have no deleterious effect on the optical guide or on the conductor and which is passed through said passage in the desired direction of advance at such a pressure that the length of optical guide is carried along said passage until the length of optical guide is loosely housed in and .
13.
throughout the length of said passage of the wound conductor.
13.
throughout the length of said passage of the wound conductor.
2. A method as claimed in Claim 1, wherein the length of optical guide loosely housed in and throughout the length of the passage of the wound conductor will substantially exceed the length of the passage so that there is an excess length of optical guide within the passage.
3. A method as claimed in Claim 1, wherein the flexible central core is substantially circumferentially rigid and said at least one passage is within the flexible central core.
4. A method as claimed in Claim 3, wherein the central core comprises a seamless tube of metal or metal alloy having a single central bore.
5. A method as claimed in Claim 4, wherein the seamless tube is formed by the Conform extrusion process.
6. A method as claimed in Claim 3, wherein the central core is of composite form and comprises a central elongate member of metal or metal alloy having within its outer surface a plurality of circumferentially spaced grooves extending helically around the member and, surrounding the helically grooved central member, a separately formed circumferentially continuous wall of metal or metal alloy.
14.
14.
7. A method as claimed in Claim 1, wherein said at least one passage is within a bare metal elongate element of said layer of helically wound bare metal elongate elements.
8. A method as claimed in Claim 1, wherein the leading end of the length of optical guide is introduced into the end of said passage at the exposed leading end of the wound conductor.
9. A method as claimed in Claim 8, wherein the leading end of the wound conductor protrudes through a hole in a flange of the cable drum.
10. A method as claimed in Claim 1, 4 or 6, wherein the flexible optical guide is a separate optical fibre.
11. A method as claimed in Claim 1, 4 or 6, wherein the flexible optical guide comprises an optical fibre element comprising at least two more optical fibres assembled together.
12. A method as claimed in Claim 1, 4 or 6, wherein the flexible optical guide is an optical fibre ribbon comprising a plurality of optical fibres extending side by side with their axes lying in a substantially common plane.
13. A composite flexible overhead electric and optical conductor when manufactured by the method claimed in Claim 1, 4 or 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2038787 CA2038787A1 (en) | 1991-03-21 | 1991-03-21 | Overhead electric and optical conductor manufacture |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2038787 CA2038787A1 (en) | 1991-03-21 | 1991-03-21 | Overhead electric and optical conductor manufacture |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2038787A1 true CA2038787A1 (en) | 1992-09-22 |
Family
ID=4147240
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2038787 Abandoned CA2038787A1 (en) | 1991-03-21 | 1991-03-21 | Overhead electric and optical conductor manufacture |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2038787A1 (en) |
-
1991
- 1991-03-21 CA CA 2038787 patent/CA2038787A1/en not_active Abandoned
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5123075A (en) | Overhead electric and optical transmission systems | |
| US4248035A (en) | Apparatus and method used in the assembly of fibre optic cables | |
| KR860000050B1 (en) | Manufacture of a flexible stranded optical fiber body | |
| US4372792A (en) | Manufacture of a flexible stranded optical fiber body | |
| US4199224A (en) | Communication cable utilizing optical transmission elements | |
| US4039248A (en) | Sheathed fiber light conductor | |
| JPH02217804A (en) | Optical fiber cable and insertion of optical fiber | |
| JPH02265109A (en) | Insertion methods for compound cable and optical fiber | |
| GB2233779A (en) | Optical fibre ribbon cable. | |
| US5267338A (en) | Low profile cable having component breakouts and processes for their manufacture | |
| FI92959C (en) | A method of making an optical fiber cable | |
| US5121901A (en) | Sheathed optical fibres and method of installing such fibres | |
| AU629964B2 (en) | Electric cable installation | |
| JPS6380210A (en) | Optical fiber cable and method and apparatus for manufacturing the same | |
| JPH0416887B2 (en) | ||
| EP0336738B1 (en) | Manufacture of a circumferentially rigid flexible tube or an optical cable | |
| EP3512694B1 (en) | Process and apparatus for the manufacturing of a figure-of-eight cable | |
| CA2038787A1 (en) | Overhead electric and optical conductor manufacture | |
| CA2039924C (en) | Composite electric and optical cable manufacture | |
| EP0448371A1 (en) | Overhead electric and optical conductor manufacture | |
| US4151704A (en) | Method and apparatus for laying up elongate members | |
| GB2110414A (en) | An optical cable | |
| US4218202A (en) | Apparatus for making remote control cable | |
| EP0528083B1 (en) | Manufacture of a reversed lay stranded assembly | |
| CA1109241A (en) | Apparatus and method used in the assembly of fibre optic cables |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Dead |