NZ760034A - Optical cable for indoor installation - Google Patents
Optical cable for indoor installationInfo
- Publication number
- NZ760034A NZ760034A NZ760034A NZ76003419A NZ760034A NZ 760034 A NZ760034 A NZ 760034A NZ 760034 A NZ760034 A NZ 760034A NZ 76003419 A NZ76003419 A NZ 76003419A NZ 760034 A NZ760034 A NZ 760034A
- Authority
- NZ
- New Zealand
- Prior art keywords
- outer sheath
- cable
- optical
- glue
- optical cable
- Prior art date
Links
- 230000003287 optical Effects 0.000 title claims abstract description 59
- 238000009434 installation Methods 0.000 title description 13
- 239000003365 glass fiber Substances 0.000 claims abstract description 58
- 239000000463 material Substances 0.000 claims description 25
- 239000010410 layer Substances 0.000 claims description 14
- 239000002356 single layer Substances 0.000 claims description 4
- 239000003292 glue Substances 0.000 abstract description 25
- 230000000007 visual effect Effects 0.000 description 11
- 239000000835 fiber Substances 0.000 description 10
- 239000000945 filler Substances 0.000 description 9
- 238000005253 cladding Methods 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 6
- 238000000576 coating method Methods 0.000 description 6
- 229920000915 polyvinyl chloride Polymers 0.000 description 5
- 239000004800 polyvinyl chloride Substances 0.000 description 5
- 229920000299 Nylon 12 Polymers 0.000 description 4
- 229920001903 high density polyethylene Polymers 0.000 description 4
- 239000004700 high-density polyethylene Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 239000004417 polycarbonate Substances 0.000 description 4
- 239000003086 colorant Substances 0.000 description 3
- 241000220317 Rosa Species 0.000 description 2
- 238000004026 adhesive bonding Methods 0.000 description 2
- 230000003247 decreasing Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 229920000728 polyester Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000010454 slate Substances 0.000 description 2
- 238000001429 visible spectrum Methods 0.000 description 2
- 238000009736 wetting Methods 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 1
- 239000004698 Polyethylene (PE) Substances 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 230000003116 impacting Effects 0.000 description 1
- 238000002329 infrared spectrum Methods 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 239000011505 plaster Substances 0.000 description 1
- -1 polyethylene Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 239000002966 varnish Substances 0.000 description 1
Abstract
Disclosed is an optical cable comprising an outer sheath housing a number of optical fibers, wherein the outer sheath has an outer cross-section in the shape of a hexagon. The outer sheath then exhibits six flat surfaces longitudinally extending along the whole cable length. Anyone of such flat surfaces may be covered with a thin layer of glue and then be attached to the wall surface. As this surface is flat, a reliable and durable fixing of the cable may be achieved using an amount of glue which is far reduced in comparison to the amounts of glue typically required for fixing known cables having a round cross-section. aces may be covered with a thin layer of glue and then be attached to the wall surface. As this surface is flat, a reliable and durable fixing of the cable may be achieved using an amount of glue which is far reduced in comparison to the amounts of glue typically required for fixing known cables having a round cross-section.
Description
OPTICAL CABLE
FOR INDOOR INSTALLATION
BACKGROUND
The present disclosure relates to the field of optical fibers and optical
cables suitable for indoor installation. In particular, the present
disclosure relates to an optical cable for indoor installation.
STATE OF THE ART
As known, an optical cable typically comprises an optical core
including one or more optical fibers and an outer sheath enclosing the
optical core. The outer sheath is typically made of a polymeric material
and has the function of grouping the optical fibers and protecting the
optical core from the mechanical point of view.
Within the outer sheath, the optical fibers may be arranged in various
ways. In particular, in the so-called "loose tube cables", the optical
fibers are loosely arranged within the outer sheath. Optionally, the
optical fibers may be grouped in one or more bundles, each bundle
being enclosed by a respective buffer tube. Within each buffer tube, the
individual fibers are free to move relative to one another.
Loose tube cables are typically used for applications where the
optical fibers must be individually extracted from the cable and spliced,
for example in FTTH (Fiber-To-The-Home) and FTTP (Fiber-To-The-
Premise) applications. For instance, drop cables of FTTH or FTTP
networks are typically implemented as loose tube cables with a
particularly reduced diameter (less than 10 mm).
The optical cables for FTTH or FTTP networks are typically installed
in indoor environments such as offices, apartments or houses. Different
ways are known for installing optical cables in indoor environments. For
example, the optical cables may be laid in ducts which run within the
walls or which are attached to the wall surfaces. Alternatively, the
optical cables may be directly attached to the wall surfaces, for example
by means of glue. This latter arrangement, though easier to be
deployed, makes the optical cables visible at naked-eye on the wall
surface. In this situation, it is desirable that the optical cables have a
reduced visual impact and match with the surrounding environment as
much as possible, so as not to create unpleasant visual effects.
US 2018/0188461 discloses an optical cable invisibly formed so as to
be substantially transparent. The optical cable comprises a plurality of
optical fibers, each fiber comprising a core, a clad and optionally a
coating layer made of a transparent resin (e.g. PVC, polyester
elastomer, polyester, polyethylene or nylon, either alone or in
combination). The cable also comprises a transparent sheath (made
e.g. of PVC) surrounding the fibers. A transparent filler fills the space
between the optical fibers and the sheath, for example yarns such as
aramid fiber or glass fiber.
SUMMARY
The Applicant has noticed that the optical cable of US 2018/0188461
exhibits some drawbacks.
In particular, while it might have a reduced visual impact as required
in indoor environments, the installation of the optical cable of US
2018/0188461 by direct gluing to a wall surface may be difficult.
Providing a reliable and durable fixing of the optical cable to the surface
of a wall may be indeed problematic, for a number of reasons. For
example, the wall surface may exhibit poor adhesion properties, e.g.
due to the presence of roughness or relief textures or to treatment with
varnish, polished plaster, etc. In order to increase reliability and
durability of the fixing, a large amount of glue and/or a particularly
strong glue is required. In any case, the installation complexity and cost
are both increased, and this is particularly undesirable for FTTH and
FTTP applications.
The Applicant has then faced the problem of providing an optical
cable for indoor installation which overcomes the aforesaid drawbacks.
In particular, the Applicant has tackled the problem of providing an
optical cable for indoor installation which may be reliably and durably
fixed to a wall surface by a reduced amount of glue and without
requiring use of particularly strong and costly glues.
According to embodiments of the present disclosure, the above
problem is solved by an optical cable comprising an outer sheath
housing a number of optical fibers, wherein the outer sheath has an
outer cross-section in the shape of a hexagon.
In the present description and in the claims, the expression
"hexagon" will designate a plane figure with six sides and six internal
angles of about 120° (where "about" means that a tolerance of ± 5° is
allowed), whose corners may be either sharp or blunted.
Since the outer sheath of the optical cable has an outer cross-section
in the shape of a hexagon, it exhibits at least one flat surface (in
particular, six flat surfaces) longitudinally extending along the whole
cable length. Anyone of such flat surfaces may be covered with a thin
layer of glue and then be attached to the wall surface. As this surface is
flat (or substantially flat, short of imperfections due to the manufacturing
process), a reliable and durable fixing of the cable may be achieved
using an amount of glue which is far reduced in comparison to the
amounts of glue typically required for fixing known cables having a
round cross-section.
For example, the Applicant has estimated that for fixing a known
cable with round cross-section having an outer diameter of 2 mm, a
layer of glue with a thickness of 0.5-1 mm is typically required. This is
due to the fact that, in order to ensure a stable fixing, the glue layer
shall be thick enough to partially embrace the round cable and provide
a contact surface of a certain width between optical cable and wall
surface.
With the outer cross-section section in the shape of a hexagon,
instead, an optical cable with an outer diameter of about 2 mm (wherein
the outer diameter is defined as the diameter of the circumscribed circle
of the hexagon) may be reliably and durably fixed with a layer of glue
with a thickness of 10-50 microns applied to anyone of the flat surfaces
of the outer sheath. Further, no particularly strong and/or costly glues
are needed. Hence, the installation complexity and cost are both
advantageously decreased, which is particularly desirable for FTTH and
FTTP applications.
According to an embodiment of the present disclosure, the outer
sheath of the cable is an uncolored, non opaque outer sheath.
In the present description and in the claims, the expression "non
opaque" will designate a material allowing light in the visible spectrum
to pass through, wherein "visible spectrum" designates a wavelength
range from 390 nm to 700 nm. A non opaque material may be either a
translucent material or a transparent material. In a translucent material,
photons are scattered at either of the two surfaces of the translucent
material (where there is a change of the refraction index) or within the
thickness of the material. In a transparent material (e.g. a glass-like
material), instead, light passes through without being scattered, photons
being refracted according to the known Snell's law.
An uncolored, non opaque outer sheath with outer cross-section in
the shape of a hexagon provides a cable with a particularly reduced
visual impact, as discussed below.
On the one hand, the uncolored, non opaque outer sheath as such
has a more reduced visual impact in comparison to a colored, opaque
outer sheath.
On the other hand, non-opaqueness of the outer sheath makes its
content (typically, optical fibers) visible to the naked eye. This in
principle could make the cable visually impacting. However, when light
rays impinge on the surface of an optical cable with an uncolored, non
opaque outer sheath, they are reflected and refracted at the interface
between air and outer sheath, the refraction being governed by the
known Snell's law. Then, the light rays are reflected within the cable (or
on the wall surface behind it) and finally they are refracted again at the
interface between outer sheath and air according to the Snell's law.
As it will be better explained with reference to Figure 2, in case of an
optical cable with an uncolored, non opaque round outer sheath (as the
cable of US 2018/0188461), parallel impinging light rays are reflected
and refracted by the cable in different directions due to the round profile
of the interfaces between air and outer sheath. In case of an optical
cable with uncolored, non opaque hexagonal outer sheath, instead, the
impinging light rays encounter on their path two parallel flat surfaces of
the hexagonal outer sheath. Hence, the light rays continue being
parallel in spite of reflection and refraction by the cable, thanks to the
flat profile of the interfaces between air and outer sheath. As a result,
the outer sheath with hexagonal outer cross-section makes its content
(typically, optical fibers) less visible to the naked eye than the outer
sheath with round cross-section.
This is particularly advantageous, especially when the optical fibers
arranged within the outer sheath are opaque and colored, for example
according to the known standard TIAC (2005) Optical Fiber Cable
Color Coding defining an identification scheme for optical fibers or
buffered fibers, based on twelve standards colours (blue, orange,
green, brown, slate, white, red, black, yellow, violet, rose, aqua). In this
case, the uncolored, non opaque outer sheath with hexagonal outer
cross-section of the cable of the present disclosure makes the colored
optical fibers less visible at the naked eye, thereby decreasing the
visual impact of the cable and minimizing the risk to create unpleasant
visual effects in the indoor environment where the cable is installed.
Therefore, according to a first aspect, the present disclosure provides
for an optical cable comprising an outer sheath housing a number of
optical fibers, and having an outer cross-section in the shape of a
hexagon.
The outer sheath may comprise a single layer or two or more layers
made of different materials.
According to an embodiment, the outer sheath has a round inner
cross-section.
In an embodiment, the outer sheath has an outer diameter lower than
mm.
In an embodiment, the outer sheath has an inner diameter lower than
9 mm.
In an embodiment, the optical cable of the present description has an
outer sheath which is an uncolored, non opaque outer sheath.
For the purpose of the present description and of the appended
claims, except where otherwise indicated, all numbers expressing
amounts, quantities, percentages, and so forth, are to be understood as
being modified in all instances by the term "about". Also, all ranges
include any combination of the maximum and minimum points disclosed
and include any intermediate ranges therein, which may or may not be
specifically enumerated herein.
The present disclosure, in at least one of the aforementioned
aspects, can be implemented according to one or more of the following
embodiments, optionally combined together.
For the purpose of the present description and of the appended
claims, the words "a" or "an" should be read to include one or at least
one and the singular also includes the plural unless it is obvious that it
is meant otherwise. This is done merely for convenience and to give a
general sense of the disclosure.
BRIEF DESCRIPTION OF THE FIGURES
The present disclosure will become fully clear after reading the
following detailed description, given by way of example and not of
limitation, with reference to the attached drawings wherein:
- Figure 1 schematically shows an optical cable according to
embodiments of the present disclosure and a known optical cable;
- Figure 2 schematically shows the light rays effect on an optical cable
according to embodiments of the present disclosure and a known
optical cable;
- Figure 3 schematically shows an optical cable for indoor installation
according to a first embodiment of the present disclosure; and
- Figure 4 schematically shows an optical cable for indoor installation
according to a second embodiment of the present disclosure.
DETAILED DESCRIPTION
Figure 1 shows the contour of a known optical cable 100 with round
cross-section and the contour of an optical cable 200 with hexagonal
outer cross-section according to embodiments of the present
disclosure. The two cables substantially have the same outer diameter
D (the outer diameter of cable 200 being defined as the diameter of the
circumscribed circle of the hexagon).
Both the cables 100 and 200 are fixed to a wall surface 300 by
means of respective layers of glue 400 having a same central
thickness. It may be appreciated that, in the optical cable 200 with
hexagonal outer cross-section, the width X of the contact surface
between cable outer sheath and wall surface 300 is larger than the
width Y of the contact surface between the outer sheath of the known,
round optical cable 100 and wall surface 300. Since the width X is
larger than the width Y, the fixing is more stable and more reliable.
Hence, with the optical cable 200 with hexagonal outer cross-section, a
same thickness of glue advantageously guarantees a more reliable and
stable fixing of the cable to the wall surface.
In Figure 2, the light rays effects on a known optical cable 100 having
with round outer sheath and on an optical cable 200 with hexagonal
outer sheath according to an embodiment of the present disclosure are
depicted.
In case of an optical cable 100, parallel impinging light rays R are
reflected and refracted by the cable round surfaces in different
directions due to the round profile of the interfaces between air and
outer sheath. In case of an optical cable 200, instead, the impinging
light rays R encounter on their path two parallel flat surfaces of the
hexagonal outer sheath, namely the flat surface in contact with the wall
surface 300 and the opposite one. Hence, the light rays R continue
being parallel in spite of reflection and refraction by the cable, thanks to
the flat profile of the interfaces between air and outer sheath. As a
result, the outer sheath with hexagonal outer cross-section of cable 200
advantageously makes its content (typically, optical fibers) less visible
to the naked eye than the outer sheath with round cross-section of
cable 100.
In Figure 3, an optical cable for indoor installation according to a first
embodiment of the present disclosure is indicated by reference number
1.
The optical cable 1 comprises an outer sheath 2 and a plurality of
optical fibers 3.
The outer sheath 2 is made of a polymeric material. According to a
first embodiment, the polymeric material is an opaque polymeric
material, for example HDPE (high density polyethylene)
polyvinylchloride or low smoke zero halogen polymers like those
disclosed, for example, in EP1940932.
The outer sheath 2 may comprise a single layer (as shown in Figure
3) or two or more layers made of different materials.
The outer sheath 2 has an outer cross-section in the shape of a
hexagon, namely a plane figure with six internal angles of about 120°
each, wherein the term "about" indicates a tolerance of ± 5°. Though in
Figure 3 the outer sheath 2 is schematically depicted with six sharp
corners, it has to be understood that the outer sheath 2 may exhibit
instead blunted or smooth corners, due to the extrusion process by
which the outer sheath 2 is manufactured. Also, the sides of the
hexagon may exhibit imperfections due to the manufacturing process,
namely deviations from the perfectly straight profile.
In the present embodiment, the inner cross-section of the outer
sheath 2 is round.
The outer diameter of the outer sheath 2 – which is defined as the
diameter of the circumscribed circle of the hexagon, as depicted in
Figure 1 with reference to the cable 200 – can be lower than 10 mm, for
example it is comprised between 1 mm and 10 mm, or between 2 mm
and 5 mm. In an embodiment, the outer diameter of the outer sheath 2
may be of 2.5 mm.
The inner diameter of the outer sheath 2 – which is defined as the
diameter round inner cross section – can be lower than 9 mm, for
example it is comprised between 1.6 mm and 1.9 mm.
The thickness of the outer sheath 2 can be comprised between 0.1
mm and 0.5 mm, for example from 0.2 mm and 0.3 mm.
The process of manufacturing cables having a hexagonal outer
cross-section is similar to that of customary (round shaped) fiber optic
cables, except for the use of a suitably special shaped die for extruding
a hexagonal shaped outer sheath.
In the present embodiment, each optical fiber 3 is an optical fiber for
communication applications, comprising a core 3a, a cladding 3b and a
coating 3c.
The core 3a and the cladding 3b are made of uncolored, transparent
materials, typically silica-based materials. The refractive index of the
transparent material used for the core 3a is higher than the transparent
material used for the cladding 3b, both refractive indexes being
measured at the infrared wavelength of the light which is intended to be
guided by the optical fiber 3. Such wavelength is typically comprised
between 750 nm and 1400 nm (near-infrared spectrum), for example
550 nm. This way, an infrared light coupled at one end of the optical
fiber 3 is confined within the core 3a by total internal reflection at the
interface between core 3a and cladding 3b and then longitudinally
propagates along the optical fiber 3.
The optical fibers 3 can be single-mode fibers, namely they support a
single propagation path of the infrared light through the core 3a. In
single-mode fibers, the diameter of the core 3a is typically comprised
between 8 and 10 microns and the diameter of the cladding 3b can be
of about 125 microns.
The coating 3c advantageously protects the optical fiber 3 from the
mechanical point of view and may also improve its tensile strength. The
diameter of the coating 3c can be comprised between 180 microns and
400 microns.
According to the first embodiment, the coating 3c of each optical fiber
is made of a resin. The coatings 3c of the optical fibers 3 can be colored
by different colors, so as to enable a field operator to distinguish them,
once they have been exposed by removing a length of the outer sheath
2. For example, the coatings 3c of the optical fibers 3 may be colored
according to the known standard TIAC (2005) Optical Fiber Cable
Color Coding defining an identification scheme for optical fibers or
buffered fibers, based on twelve standards colours (blue, orange,
green, brown, slate, white, red, black, yellow, violet, rose, aqua).
In an embodiment, the optical cable 1 may comprise a filler 4 filling
the space between the optical fibers 3 and the inner surface of the outer
sheath 2 and/or the interstitial spaces between the optical fibers 3. The
filler 4 can be a gel. Alternatively, no filler is provided for filling the
space between the optical fibers 3, thus making the cable a dry cable.
The filler 4 in the interstitial spaces between the optical fibers 3 may
be provided by pre-wetting the outer surface of each optical fiber 3 with
a small quantity of gel when the outer sheath 2 is extruded.
In an embodiment, the optical fibers 3 are loosely arranged within the
outer sheath 2. For example, the optical fibers 3 may be arranged
longitudinally and substantially parallel to the cable axis.
In a non-illustrated embodiment, the optical fibers 3 are grouped in
one or more bundles, each bundle being enclosed by a respective
buffer tube made of a polymeric material.
As discussed above, since the outer sheath 2 of the optical cable 1
according to the first embodiment has an outer cross-section in the
shape of a hexagon, it exhibits at least one flat surfaces (in particular,
six flat surfaces) longitudinally extending along the whole cable length.
Anyone of such flat surfaces may be covered with a thin layer of glue
and then be attached to the wall surface. Since this surface is flat (or
substantially flat, short of imperfections due to the manufacturing
process), a reliable and durable fixing of the cable 1 may be achieved
using an amount of glue which is far reduced in comparison to the
amounts of glue typically required for fixing known cables having a
round cross-section. Besides, as described above with reference to
Figure 1, a same amount of glue advantageously provides a much more
reliable and durable fixing in comparison to known cables having a
round cross-section, because a same amount of glue results in a wider
contact surface between outer sheath of the cable and wall surface.
In Figure 4, an optical cable for indoor installation according to a
second embodiment of the present disclosure is indicated by reference
number 1'.
Also the cable 1' according to the second embodiment comprises an
outer sheath 2' and a plurality of optical fibers 3'.
The shape of the outer sheath 2' according to the second
embodiment is the same as the outer sheath 2 according to the first
embodiment, in particular the hexagonal shape of its outer cross-
section. Hence, a detailed description will not be repeated.
According to the second embodiment, the outer sheath 2' is made of
an uncolored, non opaque material, for example an uncolored, non
opaque polymeric material, allowing the optical fibers 3 enclosed
therein to be seen at naked eye. For example, the outer sheath 2' may
comprise PC (polycarbonate), PA 12 (polyamide 12), HDPE (high
density polyethylene) or PVC (polyvinyl chloride) .
The outer sheath 2' may comprise a single layer (as shown in Figure
4) or two or more layers made of different uncolored, non opaque
materials. For example, the outer sheath 2' may comprises an
innermost layer and an outermost layer, the innermost layer being
made of uncolored transparent PC (polycarbonate) and the outermost
layer being a coating of uncolored transparent PA 12 (polyamide 12)
having a thickness of 0.05 mm.
In the present embodiment, each optical fiber 3' is an optical fiber for
communication applications, comprising a core 3a', a cladding 3b' and a
coating 3c'.
According to the second embodiment, the optical fibers 3' are single-
mode fibers with coloured opaque coatings, as described above in
connection with the first embodiment. Hence, a detailed description of
the optical fibers 3' will not be repeated.
In an embodiment, the optical cable 1' according to the second
embodiment may also comprise a filler 4' filling the space between the
optical fibers 3' and the inner surface of the outer sheath 2' and/or the
interstitial spaces between the optical fibers 3'. The filler 4' can be a gel,
for example an uncolored, non opaque gel. Alternatively, no filler is
provided for filling the space between the optical fibers 3, thus making
the cable a dry cable.
The filler 4' in the interstitial spaces between the optical fibers 3' may
be provided by pre-wetting the outer surface of each optical fiber 3' with
a small quantity of gel when the outer sheath 2' is extruded.
In an embodiment, the optical fibers 3' are loosely arranged within
the outer sheath 2'. For example, the optical fibers 3' may be arranged
longitudinally and substantially parallel to the cable axis.
In a non-illustrated embodiment, the optical fibers 3' are grouped in
one or more bundles, each bundle being enclosed by a respective
buffer tube made of a polymeric material.
Since the outer sheath 2' of the optical cable 1' according to the
second embodiment has an outer cross-section in the shape of a
hexagon, it exhibits the same advantages discussed above in
connection with the first embodiment, namely it may be fixed to a wall
surface by gluing in a very reliable and stable way.
In addition, advantageously, the uncolored, non opaque outer sheath
2' according to the second embodiment, having an outer cross-section
in the shape of a hexagon, provides a cable with a particularly reduced
visual impact.
First, the uncolored, non opaque outer sheath 2' as such has a more
reduced visual impact in comparison to the colored opaque outer
sheath 2 according to the first embodiment.
Further, as discussed above with reference to Figure 2, the outer
cross-section in the shape of a hexagon of the outer sheath 2' is such
that parallel impinging light rays continue being parallel in spite of
reflection and refraction at the interfaces between air and outer sheath
2'. As a result, the outer sheath 2' with hexagonal outer cross-section of
cable 1' according to the second embodiment makes its content
(namely, the colored optical fibers 3') less visible at the naked eye than
the outer sheath with round cross-section of a known cable.
In spite of the presence of colored optical fibers 3', the visual impact
of the cable 1' and the risk to create unpleasant visual effects in the
indoor environment where the cable 1' is installed are substantially
minimized.
Claims (6)
1. An optical cable (1, 1') comprising an outer sheath (2, 2') housing a number of optical fibers (3, 3'), wherein the outer sheath (2, 2') 5 has an outer cross-section in the shape of a hexagon.
2. The optical cable (1, 1') according to claim 1, wherein the outer sheath (2, 2') comprise a single layer or two or more layers made of different materials.
3. The optical cable (1, 1') according to claim 1, wherein the outer 10 sheath (2, 2') has a round inner cross-section.
4. The optical cable (1, 1') according to claim 1, wherein the outer sheath (2, 2') has an outer diameter lower than 10 mm.
5. The optical cable (1, 1') according to claim 1, wherein the outer sheath (2, 2') has an inner diameter lower than 9 mm. 15
6. The optical cable (1') according to claim 1, wherein the outer sheath (2') is an uncolored, non opaque outer sheath (2').
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IT102018000010988 | 2018-12-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
NZ760034A true NZ760034A (en) |
Family
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