CA1276826C - Optical fiber cable - Google Patents
Optical fiber cableInfo
- Publication number
- CA1276826C CA1276826C CA000502893A CA502893A CA1276826C CA 1276826 C CA1276826 C CA 1276826C CA 000502893 A CA000502893 A CA 000502893A CA 502893 A CA502893 A CA 502893A CA 1276826 C CA1276826 C CA 1276826C
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- Canada
- Prior art keywords
- optical fiber
- fiber cable
- cable according
- tension
- elongated
- Prior art date
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Abstract
ABSTRACT OF THE DISCLOSURE
An optical fiber cable includes an elongated flexible body having at least two spiral grooves formed in a circumferential surface thereof and extending longitudinally of the body. An optical fiber is received in one of the spiral grooves while an elongated flexible tension member is received in the other spiral groove, the tension member being composed of at least one elongated element made of aramid fibers.
An optical fiber cable includes an elongated flexible body having at least two spiral grooves formed in a circumferential surface thereof and extending longitudinally of the body. An optical fiber is received in one of the spiral grooves while an elongated flexible tension member is received in the other spiral groove, the tension member being composed of at least one elongated element made of aramid fibers.
Description
1~ ,1t~26 OPTIC~L FIBER C~BLE
B~CKGROUND OF TIIE INVENTION
Field of the Invention 'l~his invention relates to an optical fiber cable which is lightweight and flexible and has a high strength.
Prior Art It has been desired that an optlcal ~iber cable has a smaller cliama~er and a ~igh strength and is lightweight and ~lexible. One exampl~ of the conventional optical fiber cable comprises an elongated tension member or core made of twisted steel wires, a plurality of optical fibers spirally wound around the tension member, a cushioning member wound around the spirally-wound optical fibers, a holder tape of a plastics material applied around the cushioning member, and a sheath wound around the holder tape. This conventional optical fiber cable is advantageous in that it can has a small diameter.
However, it has a relatively low mechanical strength, and besides it is relatively heavy in weight because of the use of the tension member of steel wires.
Another conventional optical fiber cable comprises an elongated body or spacer member made of polyethylene or the llke havlng a plurality o~ spiral grooves ~ormed ln a alrcum~ercn~lal sur~acq thqreo~ ~nd ex~ending lon~i~udinally thereoE, optlcal ib~rs receiv~d respectively in some o~ the splral groove~, tension wires o~ s~eel received re~pectivqly in the otller grooves, a cushioning member wound aroulld the body, a holder tape oE a plastics material applied around the cushioning member, and a sheath wound around the holder tape.
~,~...
. ~ .
' .
. ' ' . . . ' . .: ' :
: . . .
.
- . . ~ . :
: , . - ~ .
~2'7~Z6 ~lthouc3h this convention~l optical fiber cable has an increclsed strell~3th, it is relatively heavy in weight on account of the use of the steel tension wires and is inferior in flexibility.
SUMMARY OF THE INVENTIOW
It is thare~orc an object of this invention to provide an optlcal fibcr cable o the type having an elongated body or spacer member with spiral grooves which cable is lightweight, and possesses a high strength and a good flexibility, and is subjected to less transmission loss due to temperature variations.
According to the present invention, there is provided an optical fiber cable comprising:
(a) an elongated flexible body having at least two spiral grooves formed in a circumferential surface thereof and extending longitudinally of said boy;
(b) optical fiber means received in one of said spiral grooves; and (c) an elongated flexible tension member received in the o~hex spiral groove, said tension member comprisin~
at lea~t one qlongated el0ment ma~e o aramld f ibqrs .
BRIEF DESCRIP'rION OF trl~E ~RAWING~
Fig. 1 is a cross-sectional view of an optical fiber cable provided in accordance with the present invention;
.
7~1~2~
Fig. 2 is a view similar to Fig. 1 but showing a modified optical fiber cable;
F'ig. 3 is a view similar to Fig. 1 but showing another modified optical fiber cable;
Fig. ~ is a cross-sectional view of an optical fiber unit incorporated to be in the optical fiber cable;
Fig. 5 is a view similar to Fig. 4 but showing a modified optical fiber unit; and Fig~ 6 is a cro~s-~ectional view of al1ott1er modified op~ical f~hcr unit.
DESC~IPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
The invention will now be described with re~erence to the drawings in which like reference numerals denote corresponding parts in several views.
An optical fiber cable 10 shown in Fig. 1 comprises an elongated flexible body or spacer member 12 made of a high-density plastics material such as a polyethylene resin, a polypropylene resin and a flame retardant polyethylene resin.
The body 12 of a circular cross-section has four or two pairs of grooves 14 and 16 formed in and spirally extending along a circumerential surface thereof, the four grooves being di~p~d in circum~erqntlally e~ually ~pac~d r~lation to each o~her as vi~w~d in cro~s-~ection. ~he groov~s 1~ and 16 are disposed ~l~ernately, and thq grooves 1~ have a greater cros~-S~CtiQn than tl1e grooves 16.
An elongated flexible tension member 18 is received in each of the pair of diametrically-opposed spiral grooves 14 ~ . ~ . . . . .
: . . . . . .
- ~ - . ., : . . :
.
~276826 along an entire length thereof. The tension member 18 comprises a plurality of ~five in the illustrated embodiment) elongated elements 20 or strands made of aramid fibers and twisted together. The tension member 18 serves to offer a resistance to tension or a pulling force so that the optical fiber cable 10 can have a high tensile strength. The size of the grooves 14, the number of the aramid fiber elements 20 received therein are determined in accordance with the tensile strength of the optical fiber cable 10 to be obtained. On the other hand, a pair of optical fibers 22 are received respectively in the diametrically opposed spiral grooves 16.
As the aramid fibers of which the element~ 20 are made, Kevlar manufactured by DuPont or HM-50 sold by Teijin, Japan, can be used.
A holder layer 24 comprises a tape of a plastics material, such as nylon, polyethylene and polyester, wound around the body 12 to hold the tension members 18 in place in the respective grooves 14. ~he tension member 18 of the aram~d fiber elements 20 is compressible and deformable, and lt has a size slightly larger than the cross-section of the groove 14 when sub~ected to no load. Therefore, for a~sembllng the optical fiber cable 10, each tension member 18 15 forced lnto a respective one of the grooves 14, so that its constituent elements 20 of aramid fibers are held in squeezed or compressed condition in the groove 14 by the holder layer 24. Thus, the flexible tension member 18 is filled in the groove 14.
A sheath 26 made of a polyethylene resin, a flame-retardant polyethylene resin or the like is wound around the . . : .
, . . . . . : -: : , .. -.' .,: . .
.. - . . . . .
.. . . . .
~ 1 ~7~ 6 hol~er layer 2~.
Since the tension member 1 a composed oE the aramid fiber elements 20 has a higher tensile strength and is less heavy than a steel tension member of the same size, the optical fiber cable 10 can be less heavy in weight and have a higher strength. Therefore, the optical fiber cable 10 can have a higher strength as compared with a conventional one of the same dlameker. And, the optical fiber cable 10 can be of a smallcr diameter a~ comparec1 with a conventLonal one having the same strength. In addltion, the tension memher 18 composed of the aramid fiber elements 20 is more flexible than a steel tension member o the same size, and therefore the flexibility of the optical fiber cable 10 is enhanced. Further, since the tension member 18 of the aramid fiber elements 20 is compressible, it can be quite intimately fitted in or fully filled in the groove 14, so that the cross-sectional area of the groove 14 can be fully used, thereby further increasing the strength of the optical fiber cable.
Further, since the aramid fiber has a negative coe~iclenk o~ thcr~nal e~pansion, the expansion and contraction v~ khe optical ~iber cable 10 duq to tomperakure varia~ions can be ~uitably kept to a minimum. As a re~ult, a transmis~ion loss oP th~ optical fiber cable 10 caused by such temp~rature variations is also kepk to a minimum.
Further, the optical fiber cable 10 is made entirqly o~
non-metallic materials and therefore has non-lnductive and electrically-lnsulating properties.
.
: ' ' .: ,' .,. '' . , ' ~' ` ' ' ~ - , .. .
, ~ 2'7~;~32`~i Fig. 2 shows a modified optical fiber cable 10a which dif~ers ~rom the optical ~iber cable 10 of Fig. 1 only in that an elongated central tension core 28 is embedded or molded in an elongated body 12 at its center and extending along the axis of the body 12. The central core 28 is flexible and is made of, say, two strands of aramid fiber-reinforced plastics material ~KERP), glass fiber-reinforced plastics material, carbon fiber~rcinforced plastics material or steel. The use o~ th~ aen~ral t~n~lon core 2n ~urther increases th~
resistance of the optical ~iber cable 1Oa to tension or a pulling force. Usually, the elongated body or spacer member 12 is molded of such plastics material by extrusion, and, advantageously, the use of the central core 28 greatly facilitates such an extrusion operation. The central core 28 has such a small diameter that it will not adversely affect the flexibility and lightweight of the optical fiber cable lOa.
Fig. 3 shows another modified optica} fiber cable 1Ob which differs from the optical fiber cable 1Oa of Fig. 2 in that more than two spiral grooves 16 are provided in the elongated body 12 for receiving a corresponding number of optical ~ibers 2~. In the illustrated embodiment, three pair o~ spiral ~rooves 16 ara provided, each paix o~ ~roove~ 16 b~lng ~l~po~ed in diam~trically opposcd r~lation to each oth~r. Tha c~ntral t~n~lon cor~ 2~ may b~ omitt~d.
Tlle invention will now be illustrated by way o~ th~
~ollowing EX~MPLE.
EXAMPLE
, .
~2~7~i~26 In this EXAMPLE, an optical fiber cable 10a shown in Fig.
B~CKGROUND OF TIIE INVENTION
Field of the Invention 'l~his invention relates to an optical fiber cable which is lightweight and flexible and has a high strength.
Prior Art It has been desired that an optlcal ~iber cable has a smaller cliama~er and a ~igh strength and is lightweight and ~lexible. One exampl~ of the conventional optical fiber cable comprises an elongated tension member or core made of twisted steel wires, a plurality of optical fibers spirally wound around the tension member, a cushioning member wound around the spirally-wound optical fibers, a holder tape of a plastics material applied around the cushioning member, and a sheath wound around the holder tape. This conventional optical fiber cable is advantageous in that it can has a small diameter.
However, it has a relatively low mechanical strength, and besides it is relatively heavy in weight because of the use of the tension member of steel wires.
Another conventional optical fiber cable comprises an elongated body or spacer member made of polyethylene or the llke havlng a plurality o~ spiral grooves ~ormed ln a alrcum~ercn~lal sur~acq thqreo~ ~nd ex~ending lon~i~udinally thereoE, optlcal ib~rs receiv~d respectively in some o~ the splral groove~, tension wires o~ s~eel received re~pectivqly in the otller grooves, a cushioning member wound aroulld the body, a holder tape oE a plastics material applied around the cushioning member, and a sheath wound around the holder tape.
~,~...
. ~ .
' .
. ' ' . . . ' . .: ' :
: . . .
.
- . . ~ . :
: , . - ~ .
~2'7~Z6 ~lthouc3h this convention~l optical fiber cable has an increclsed strell~3th, it is relatively heavy in weight on account of the use of the steel tension wires and is inferior in flexibility.
SUMMARY OF THE INVENTIOW
It is thare~orc an object of this invention to provide an optlcal fibcr cable o the type having an elongated body or spacer member with spiral grooves which cable is lightweight, and possesses a high strength and a good flexibility, and is subjected to less transmission loss due to temperature variations.
According to the present invention, there is provided an optical fiber cable comprising:
(a) an elongated flexible body having at least two spiral grooves formed in a circumferential surface thereof and extending longitudinally of said boy;
(b) optical fiber means received in one of said spiral grooves; and (c) an elongated flexible tension member received in the o~hex spiral groove, said tension member comprisin~
at lea~t one qlongated el0ment ma~e o aramld f ibqrs .
BRIEF DESCRIP'rION OF trl~E ~RAWING~
Fig. 1 is a cross-sectional view of an optical fiber cable provided in accordance with the present invention;
.
7~1~2~
Fig. 2 is a view similar to Fig. 1 but showing a modified optical fiber cable;
F'ig. 3 is a view similar to Fig. 1 but showing another modified optical fiber cable;
Fig. ~ is a cross-sectional view of an optical fiber unit incorporated to be in the optical fiber cable;
Fig. 5 is a view similar to Fig. 4 but showing a modified optical fiber unit; and Fig~ 6 is a cro~s-~ectional view of al1ott1er modified op~ical f~hcr unit.
DESC~IPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
The invention will now be described with re~erence to the drawings in which like reference numerals denote corresponding parts in several views.
An optical fiber cable 10 shown in Fig. 1 comprises an elongated flexible body or spacer member 12 made of a high-density plastics material such as a polyethylene resin, a polypropylene resin and a flame retardant polyethylene resin.
The body 12 of a circular cross-section has four or two pairs of grooves 14 and 16 formed in and spirally extending along a circumerential surface thereof, the four grooves being di~p~d in circum~erqntlally e~ually ~pac~d r~lation to each o~her as vi~w~d in cro~s-~ection. ~he groov~s 1~ and 16 are disposed ~l~ernately, and thq grooves 1~ have a greater cros~-S~CtiQn than tl1e grooves 16.
An elongated flexible tension member 18 is received in each of the pair of diametrically-opposed spiral grooves 14 ~ . ~ . . . . .
: . . . . . .
- ~ - . ., : . . :
.
~276826 along an entire length thereof. The tension member 18 comprises a plurality of ~five in the illustrated embodiment) elongated elements 20 or strands made of aramid fibers and twisted together. The tension member 18 serves to offer a resistance to tension or a pulling force so that the optical fiber cable 10 can have a high tensile strength. The size of the grooves 14, the number of the aramid fiber elements 20 received therein are determined in accordance with the tensile strength of the optical fiber cable 10 to be obtained. On the other hand, a pair of optical fibers 22 are received respectively in the diametrically opposed spiral grooves 16.
As the aramid fibers of which the element~ 20 are made, Kevlar manufactured by DuPont or HM-50 sold by Teijin, Japan, can be used.
A holder layer 24 comprises a tape of a plastics material, such as nylon, polyethylene and polyester, wound around the body 12 to hold the tension members 18 in place in the respective grooves 14. ~he tension member 18 of the aram~d fiber elements 20 is compressible and deformable, and lt has a size slightly larger than the cross-section of the groove 14 when sub~ected to no load. Therefore, for a~sembllng the optical fiber cable 10, each tension member 18 15 forced lnto a respective one of the grooves 14, so that its constituent elements 20 of aramid fibers are held in squeezed or compressed condition in the groove 14 by the holder layer 24. Thus, the flexible tension member 18 is filled in the groove 14.
A sheath 26 made of a polyethylene resin, a flame-retardant polyethylene resin or the like is wound around the . . : .
, . . . . . : -: : , .. -.' .,: . .
.. - . . . . .
.. . . . .
~ 1 ~7~ 6 hol~er layer 2~.
Since the tension member 1 a composed oE the aramid fiber elements 20 has a higher tensile strength and is less heavy than a steel tension member of the same size, the optical fiber cable 10 can be less heavy in weight and have a higher strength. Therefore, the optical fiber cable 10 can have a higher strength as compared with a conventional one of the same dlameker. And, the optical fiber cable 10 can be of a smallcr diameter a~ comparec1 with a conventLonal one having the same strength. In addltion, the tension memher 18 composed of the aramid fiber elements 20 is more flexible than a steel tension member o the same size, and therefore the flexibility of the optical fiber cable 10 is enhanced. Further, since the tension member 18 of the aramid fiber elements 20 is compressible, it can be quite intimately fitted in or fully filled in the groove 14, so that the cross-sectional area of the groove 14 can be fully used, thereby further increasing the strength of the optical fiber cable.
Further, since the aramid fiber has a negative coe~iclenk o~ thcr~nal e~pansion, the expansion and contraction v~ khe optical ~iber cable 10 duq to tomperakure varia~ions can be ~uitably kept to a minimum. As a re~ult, a transmis~ion loss oP th~ optical fiber cable 10 caused by such temp~rature variations is also kepk to a minimum.
Further, the optical fiber cable 10 is made entirqly o~
non-metallic materials and therefore has non-lnductive and electrically-lnsulating properties.
.
: ' ' .: ,' .,. '' . , ' ~' ` ' ' ~ - , .. .
, ~ 2'7~;~32`~i Fig. 2 shows a modified optical fiber cable 10a which dif~ers ~rom the optical ~iber cable 10 of Fig. 1 only in that an elongated central tension core 28 is embedded or molded in an elongated body 12 at its center and extending along the axis of the body 12. The central core 28 is flexible and is made of, say, two strands of aramid fiber-reinforced plastics material ~KERP), glass fiber-reinforced plastics material, carbon fiber~rcinforced plastics material or steel. The use o~ th~ aen~ral t~n~lon core 2n ~urther increases th~
resistance of the optical ~iber cable 1Oa to tension or a pulling force. Usually, the elongated body or spacer member 12 is molded of such plastics material by extrusion, and, advantageously, the use of the central core 28 greatly facilitates such an extrusion operation. The central core 28 has such a small diameter that it will not adversely affect the flexibility and lightweight of the optical fiber cable lOa.
Fig. 3 shows another modified optica} fiber cable 1Ob which differs from the optical fiber cable 1Oa of Fig. 2 in that more than two spiral grooves 16 are provided in the elongated body 12 for receiving a corresponding number of optical ~ibers 2~. In the illustrated embodiment, three pair o~ spiral ~rooves 16 ara provided, each paix o~ ~roove~ 16 b~lng ~l~po~ed in diam~trically opposcd r~lation to each oth~r. Tha c~ntral t~n~lon cor~ 2~ may b~ omitt~d.
Tlle invention will now be illustrated by way o~ th~
~ollowing EX~MPLE.
EXAMPLE
, .
~2~7~i~26 In this EXAMPLE, an optical fiber cable 10a shown in Fig.
2 was prepared to determine its characteristics. Tlle elongated body 12 was l,1ade oE flame-retardant polyethylene resin and had an outer diameter of 3.3 mm. The pair of spiral grooves 14 for receiving the respective tension members 18 had a width of 1.6 mm while the pair of spiral grooves 16 for receiving the respective optical fibers 22 had a width of 1.0 mm. The central core 28 was composed of two strand each havlng a size of 1~20 deni~r and made o aramid fiber-r~lnorc~d plastics mat~ri~l containlng 40 ~ hy volume of aramid Eiber. Each ten~ion member 1~ was composed of five elongated elements 20 twisted together and each having a size of 1420 denier. Each of the pair of optical fibers 22 had a diameter of 0.8 mm. The holder layer 24 comprised a nylon tape and had a thickness of 0.05 mm. The sheath was made of a flame-retardant polyethylene resin and had a thickness of 0.5 mm. The resultant optical fiber cable 1Oa had a diameter of 4.3 mm and a weight of 14.1 kg/km. The optical fiber cable 1Oa was tested to determine its mechanical characteristics and temperature characteristics. The results obtained are shown in TABLE below.
.
- ' ' ~ 2 ~ 6 TABLE
~ _ _ Test Test conditions Results __ __ I_ Mec~l~nical Stretching Stretching O.S ~ elongation character- rate: 10 mm/min. at 65 kg istics Distance between Breakage at 250 test two gage marks: 2 m kg Bending Mandrel of 20 mm Transmission loss diameter did not increase ~end angle: 360 after 30 recipro-Bending frequency: cations. Maximum 30 reciprocations loss increase was 0.07 dB~
.... _. .. . ,. . ~
Wiplng Die dlameter: ~Omm Load: 30, ~0, 50~ No breakage after 60 and 80 kg. 5 reciporcations Wiping frequency: at 80 kg.
5 reciprocations Length wiped: 2 m Temperature Cable length: 100 m Transmission ~oss characteristics Temperature: - 60 increase: not test to + 80 more than 0.02 dB
The bending test was carried out by winding the optical fiber cable around the mandrel and pulling the fiber cable back and forth. The transmission loss was measured by a wavelength of 0.85 ~m. The tested fiber cable had the optical fiber ~olded longitudinally intermediate opposite ends thereof and received in the grooves 16 to provide a loop.
As can be seqn ~rom T~B~, the tast~d optic~l ~iber aabla exhibited ~ higll tensile strength and excell~nt temperature characteri~tLcs, and was not damaged even when ~ubjected to repeated bending and wiping. Thus, the optical ~lber cable i~
lightweight and has a high strength, a good ~lexibility and excellent temperature characteristics, and is relatlvely small ~ 8 . .
.
.
.
, -, : . -.
1.276~
in diameter. Therefore, ~or example, the optical fiber cable according to the present invention can be best suited as a portable type which is to be used outdoors where severe conditions may be encountered.
~ s described above, the optical fiber cables according to the present invention have the tension members 18 made of aramid fiber elements having a high tensile strength and a low specific gravity, and therefore the optica:L fiber cable is lightwelgllt and ~u~iciently flexible and has excellent temperature charactorl~tlcs. ~nd, the optical ~iber cable can have a sufficient strength even if it has a smaller diameter than the conventional optical fiber cables having tension members of steel.
While the optical fiber cables according to the present invention have bQen specifically shown and described herein, the invention itself is not to be restricted by the exact showing of the drawings or the description thereof. For example, as shown in Fig. 4, each of the pair of optical fibers 22 received in the respective spiral grooves 16 may be replaced by a tape-like optical fiber unit 30 comprising a flat base 32 of a synthetic resin and a plurality of optical iibers 22a embedded or molded in the base 32 in parallel juxta~osed relation. ~lso, each opti~al ~iber 22 may be replaced by a plurality o~ ~three in the illu~tratqd ~mbodim~nt) tape~ op~ical ~ibar unit 30 (Flg~ 5).
Further, a~ ~hown in Fig. 6, each optical fiber 22 may be replaced by an optical ~iber unit 36 comprising an elongated core 38, a plurality of optical fibers 22a spirally wound around the core 38 and a sheath 40 covering the optical fibers j .. . : . ~ . . .
... . : . .
: . : . : - - - . - . . . .
, ~ ,, . . , .
- , ...
. . . ~ . ., . : . . .. : .
.
32~
22a. Further, although in the illustrated embodiment, the teIlsion meInber 18 is composed of five elongated eleInellts 20 and filled in the groove 1~, it may be composed of at leas one elongated element 20.
, ~ .
. ... ' ~- - , . . : :
. - - . .: : ., , - . , :
; . ., - . , - : ,: . ~ , ,
.
- ' ' ~ 2 ~ 6 TABLE
~ _ _ Test Test conditions Results __ __ I_ Mec~l~nical Stretching Stretching O.S ~ elongation character- rate: 10 mm/min. at 65 kg istics Distance between Breakage at 250 test two gage marks: 2 m kg Bending Mandrel of 20 mm Transmission loss diameter did not increase ~end angle: 360 after 30 recipro-Bending frequency: cations. Maximum 30 reciprocations loss increase was 0.07 dB~
.... _. .. . ,. . ~
Wiplng Die dlameter: ~Omm Load: 30, ~0, 50~ No breakage after 60 and 80 kg. 5 reciporcations Wiping frequency: at 80 kg.
5 reciprocations Length wiped: 2 m Temperature Cable length: 100 m Transmission ~oss characteristics Temperature: - 60 increase: not test to + 80 more than 0.02 dB
The bending test was carried out by winding the optical fiber cable around the mandrel and pulling the fiber cable back and forth. The transmission loss was measured by a wavelength of 0.85 ~m. The tested fiber cable had the optical fiber ~olded longitudinally intermediate opposite ends thereof and received in the grooves 16 to provide a loop.
As can be seqn ~rom T~B~, the tast~d optic~l ~iber aabla exhibited ~ higll tensile strength and excell~nt temperature characteri~tLcs, and was not damaged even when ~ubjected to repeated bending and wiping. Thus, the optical ~lber cable i~
lightweight and has a high strength, a good ~lexibility and excellent temperature characteristics, and is relatlvely small ~ 8 . .
.
.
.
, -, : . -.
1.276~
in diameter. Therefore, ~or example, the optical fiber cable according to the present invention can be best suited as a portable type which is to be used outdoors where severe conditions may be encountered.
~ s described above, the optical fiber cables according to the present invention have the tension members 18 made of aramid fiber elements having a high tensile strength and a low specific gravity, and therefore the optica:L fiber cable is lightwelgllt and ~u~iciently flexible and has excellent temperature charactorl~tlcs. ~nd, the optical ~iber cable can have a sufficient strength even if it has a smaller diameter than the conventional optical fiber cables having tension members of steel.
While the optical fiber cables according to the present invention have bQen specifically shown and described herein, the invention itself is not to be restricted by the exact showing of the drawings or the description thereof. For example, as shown in Fig. 4, each of the pair of optical fibers 22 received in the respective spiral grooves 16 may be replaced by a tape-like optical fiber unit 30 comprising a flat base 32 of a synthetic resin and a plurality of optical iibers 22a embedded or molded in the base 32 in parallel juxta~osed relation. ~lso, each opti~al ~iber 22 may be replaced by a plurality o~ ~three in the illu~tratqd ~mbodim~nt) tape~ op~ical ~ibar unit 30 (Flg~ 5).
Further, a~ ~hown in Fig. 6, each optical fiber 22 may be replaced by an optical ~iber unit 36 comprising an elongated core 38, a plurality of optical fibers 22a spirally wound around the core 38 and a sheath 40 covering the optical fibers j .. . : . ~ . . .
... . : . .
: . : . : - - - . - . . . .
, ~ ,, . . , .
- , ...
. . . ~ . ., . : . . .. : .
.
32~
22a. Further, although in the illustrated embodiment, the teIlsion meInber 18 is composed of five elongated eleInellts 20 and filled in the groove 1~, it may be composed of at leas one elongated element 20.
, ~ .
. ... ' ~- - , . . : :
. - - . .: : ., , - . , :
; . ., - . , - : ,: . ~ , ,
Claims (12)
1. An optical fiber cable comprising:
(a) an elongated flexible body having at least two spiral grooves formed in a circumferential surface thereof and extending longitudinally of said boy;
(b) optical fiber means received in one of said spiral grooves; and (c) an elongated flexible tension member received in the other spiral groove, said tension member comprising at least one elongated element made of aramid fibers.
(a) an elongated flexible body having at least two spiral grooves formed in a circumferential surface thereof and extending longitudinally of said boy;
(b) optical fiber means received in one of said spiral grooves; and (c) an elongated flexible tension member received in the other spiral groove, said tension member comprising at least one elongated element made of aramid fibers.
2. An optical fiber cable according to claim 1, in which said tension member comprises a plurality of elongated elements made of aramid fibers and twisted together.
3. An optical fiber cable according to claim 1, in which said tension member is filled in said other spiral groove in a compressed fashion.
4. An optical fiber cable according to claim 1, in which said elongated body has more than two spiral grooves, a plurality of said optical fiber means and a plurality of said tension members being alternately received in said plurality of spiral grooves.
5. An optical fiber cable according to claim 1, in which said optical fiber means comprises at least one tape-like optical fiber unit comprising a flat base of a synthetic resin and a plurality of optical fibers embedded in the base in juxtaposed relation.
6. An optical fiber cable according to claim 1, in which said optical fiber means comprises an elongated core, a plurality of optical fibers spirally wound around said core.
7. An optical fiber cable according to claim 1, in which said body has an elongated central tension core provided therein and extending along an axis thereof.
8. An optical fiber cable according to claim 7, in which said tension core is made of aramid fiber-reinforced plastics material.
9. An optical fiber cable according to claim 7, in which said tension core is made of glass fiber-reinforced plastics material.
10. An optical fiber cable according to claim 7, in which said tension core is made of steel.
11. An optical fiber cable according to claim 7, in which said tension core is made of carbon fiber-reinforced plastics material.
12
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60-30534 | 1985-03-04 | ||
| JP3053385U JPH0128961Y2 (en) | 1985-03-04 | 1985-03-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1276826C true CA1276826C (en) | 1990-11-27 |
Family
ID=12306431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000502893A Expired - Fee Related CA1276826C (en) | 1985-03-04 | 1986-02-27 | Optical fiber cable |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPH0128961Y2 (en) |
| CA (1) | CA1276826C (en) |
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|---|---|---|---|---|
| WO2008111252A1 (en) * | 2007-03-12 | 2008-09-18 | Mitsubishi Materials Corporation | Insert for thread cutting |
| JP5783025B2 (en) * | 2011-12-12 | 2015-09-24 | 三菱マテリアル株式会社 | Cutting insert and cutting edge exchangeable end mill |
| WO2016080486A1 (en) * | 2014-11-21 | 2016-05-26 | 三菱日立ツール株式会社 | Cutting insert and cutting edge-replaceable rotary cutting tool |
| DE112019004901T5 (en) * | 2018-09-27 | 2021-06-10 | Kyocera Corporation | CUTTING INSERT, CUTTING TOOL, AND METHOD FOR MANUFACTURING A CUTTING ITEM |
| EP3865232A4 (en) * | 2018-10-11 | 2022-07-27 | Sumitomo Electric Hardmetal Corp. | Cutting insert and inner diameter cutting tool |
-
1985
- 1985-03-04 JP JP3053385U patent/JPH0128961Y2/ja not_active Expired
-
1986
- 1986-02-27 CA CA000502893A patent/CA1276826C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0128961Y2 (en) | 1989-09-04 |
| JPS61148506U (en) | 1986-09-12 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |