U.S. patent application number 16/158484 was filed with the patent office on 2019-04-18 for optical fiber cable with dual layer buffer tube for microduct application.
The applicant listed for this patent is Sterlite Technologies Limited. Invention is credited to Kavya Chintada, Atul Mishra, Venkatesh Murthy, Kishore Sahoo.
Application Number | 20190113701 16/158484 |
Document ID | / |
Family ID | 63840715 |
Filed Date | 2019-04-18 |
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United States Patent
Application |
20190113701 |
Kind Code |
A1 |
Murthy; Venkatesh ; et
al. |
April 18, 2019 |
OPTICAL FIBER CABLE WITH DUAL LAYER BUFFER TUBE FOR MICRODUCT
APPLICATION
Abstract
The present disclosure provides an optical fiber cable. The
optical fiber cable includes a central strength member. The central
strength member lies substantially along a longitudinal axis of the
optical fiber cable. In addition, the optical fiber cable includes
a first layer. The first layer includes a plurality of water
swellable yarns. Further, the optical fiber cable includes a
plurality buffer tubes. Each of the plurality of buffer tubes
includes a plurality of optical fiber. Moreover, the optical fiber
cable includes a second layer of a pair of binder yarns. Further,
the optical fiber cable includes a third layer. The third layer is
formed of a plurality of water swellable yarns. The optical fiber
cable includes a fourth layer. The fourth layer is a sheath
layer.
Inventors: |
Murthy; Venkatesh;
(Aurangabad, IN) ; Sahoo; Kishore; (Aurangabad,
IN) ; Mishra; Atul; (Aurangabad, IN) ;
Chintada; Kavya; (Aurangabad, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sterlite Technologies Limited |
Aurangabad |
MH |
US |
|
|
Family ID: |
63840715 |
Appl. No.: |
16/158484 |
Filed: |
October 12, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 6/4494 20130101;
G02B 6/4434 20130101; G02B 6/4438 20130101; G02B 6/4482 20130101;
G02B 6/4495 20130101; G02B 6/4415 20130101; G02B 6/52 20130101;
G02B 6/4413 20130101; G02B 6/4464 20130101 |
International
Class: |
G02B 6/44 20060101
G02B006/44 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 13, 2017 |
IN |
201721036545 |
Claims
1. An optical fiber cable comprising: a central strength member
lying substantially along a longitudinal axis of the optical fiber
cable, wherein the central strength member is formed of fiber
reinforced plastic, wherein the central strength member has a
diameter of about 3.0 mm; a first layer wrapped helically around
the central strength member, wherein the first layer is formed of a
plurality of water swellable yarns; a plurality of buffer tubes
stranded helically around the first layer, wherein each of the
plurality of buffer tubes encloses a plurality of optical fibers,
wherein each of the plurality of buffer tubes is formed of a
combination of two sub layers having different material, wherein
each of the plurality of buffer tubes has a first sub layer and a
second sub layer; wherein the first sub layer is formed of
polycarbonate, wherein the second sub layer is formed of
polybutylene terephthalate; a second layer, wherein the second
layer cross helically surrounds a core of the optical fiber cable,
wherein the second layer is formed of a pair of binder yarns,
wherein the pair of binder yarn comprising: a first binder yarn,
wherein the first binder yarn is wrapped helically in clockwise
direction; and a second binder yarn, wherein the second binder yarn
is wrapped helically in anti-clockwise direction; a third layer,
wherein the third layer is wrapped helically around the core of the
optical fiber cable, wherein the third layer is formed of a
plurality of water swellable yarns; and a fourth layer surrounding
the third layer, wherein the fourth layer is formed of high density
polyethylene, wherein the optical fiber cable has a diameter of
about 7.7 mm.+-.0.2 mm.
2. The optical fiber cable as recited in claim 1, wherein each of
the plurality of buffer tubes has a first diameter of about 1.55
mm.+-.0.05 mm, wherein each of the plurality of buffer tubes has a
second diameter of about 1.85 mm.+-.0.05 mm.
3. The optical fiber cable as recited in claim 1, wherein the first
sub layer has a thickness of about 75 microns.+-.10 microns,
wherein the first sub layer has a density of about 1.2
gm/cm.sup.3.
4. The optical fiber cable as recited in claim 1, wherein the
second sub layer has a thickness of about 75 microns.+-.10 microns,
wherein the second sub layer has a density of about 1.31
gm/cm.sup.3.
5. The optical fiber cable as recited in claim 1, wherein the
plurality of buffer tubes is eight, wherein the plurality of
optical fibers in each of the plurality of buffer tubes is twenty
four, wherein each of the plurality of optical fibers has a
diameter of about 250 microns.
6. The optical fiber cable as recited in claim 1, wherein the
fourth layer has a thickness in a range of about 0.4 mm to 0.6 mm,
wherein the fourth layer has a density in a range of about 0.90
gm/cm.sup.3 to 0.96 gm/cm.sup.3.
7. The optical fiber cable as recited in claim 1, wherein the
central strength member is a solid pultrusion type fiber reinforced
plastic, wherein the central strength member is coated with a
polyethylene layer, wherein the central strength member is coated
to accommodate plurality of buffer tubes.
8. The optical fiber cable as recited in claim 1, wherein the first
binder yarn is aramid binder yarn, wherein the second binder yarn
is aramid binder yarn.
9. The optical fiber cable as recited in claim 1, further
comprising a plurality of ripcords, wherein the plurality of
ripcords are positioned below the fourth layer.
10. The optical fiber cable as recited in claim 1, wherein the
optical fiber cable is blown into a duct, wherein the duct is
having an inner diameter of about 10 mm and outer diameter of about
14 mm, wherein the optical fiber cable has a fill factor in a range
of about 54% to 64% in the duct.
11. The optical fiber cable as recited in claim 1, wherein each of
the plurality of buffer tubes has a packing factor in a range of
about 75% to 92%, wherein the packing factor is defined as ratio of
equivalent cross sectional area of fiber bunch to inner cross
sectional area of a buffer tube of the plurality of buffer tubes,
wherein the equivalent cross sectional area is area formed by
equivalent diameter of fiber bunch which is calculated by formula,
1.155*Square root of number fibers per tube*Diameter of the
fiber.
12. An optical fiber cable comprising: a central strength member
lying substantially along a longitudinal axis of the optical fiber
cable, wherein the central strength member is formed of fiber
reinforced plastic, wherein the central strength member has a
diameter of about 3.0 mm; a first layer wrapped helically around
the central strength member, wherein the first layer is formed of a
plurality of water swellable yarns; a plurality of buffer tubes
stranded helically around the first layer, wherein each of the
plurality of buffer tubes encloses a plurality of optical fibers,
wherein each of the plurality of buffer tubes has a first diameter
of about 1.55 mm.+-.0.05 mm, wherein each of the plurality of
buffer tubes has a second diameter of about 1.85 mm.+-.0.05 mm,
wherein each of the plurality of buffer tubes is formed of a
combination of two sub layers having different material, wherein
each of the plurality of buffer tubes has a first sub layer and a
second sub layer; wherein the first sub layer is formed of
polycarbonate, wherein the second sub layer is formed of
polybutylene terephthalate; a second layer, wherein the second
layer cross helically surrounds a core of the optical fiber cable,
wherein the second layer is formed of a pair of binder yarns,
wherein the pair of binder yarns comprising: a first binder yarn,
wherein the first binder yarn is wrapped helically in clockwise
direction; and a second binder yarn, wherein the second binder yarn
is wrapped helically in anti-clockwise direction; a third layer
wrapped helically around the core of the optical fiber cable,
wherein the third layer is formed of a plurality of water swellable
yarns; and a fourth layer surrounding the third layer, wherein the
fourth layer is formed of high density polyethylene, wherein the
fourth layer has a thickness in a range of about 0.4 mm to 0.6 mm,
wherein the fourth layer has a density in a range of about 0.90
gm/cm.sup.3 to 0.96 gm/cm.sup.3, wherein the optical fiber cable
has a diameter of about 7.7 mm.+-.0.2 mm.
13. The optical fiber cable as recited in claim 12, wherein the
first sub layer has a thickness of about 75 microns.+-.10 microns,
wherein the first sub layer has a density of about 1.2
gm/cm.sup.3.
14. The optical fiber cable as recited in claim 12, wherein the
second sub layer has a thickness of about 75 microns.+-.10 microns,
wherein the second sub layer has a density of about 1.31
gm/cm.sup.3.
15. The optical fiber cable as recited in claim 12, wherein the
plurality of buffer tubes is eight, wherein the plurality of
optical fibers in each of the plurality of buffer tubes is twenty
four, wherein each of the plurality of optical fibers has a
diameter of about 250 microns.
16. The optical fiber cable as recited in claim 12, wherein the
central strength member is a solid pultrusion type fiber reinforced
plastic, wherein the central strength member is coated with a
polyethylene layer, wherein the central strength member is coated
to accommodate the plurality of buffer tubes.
17. The optical fiber cable as recited in claim 12, wherein the
first binder yarn is aramid binder yarn, wherein the second binder
yarn is aramid binder yarn.
18. The optical fiber cable as recited in claim 12, further
comprises a plurality of ripcords, wherein the plurality of
ripcords is positioned below the fourth layer and along with the
third layer in a linear manner.
19. An optical fiber cable comprising: a central strength member
lying substantially along a longitudinal axis of the optical fiber
cable, wherein the central strength member is formed of fiber
reinforced plastic, wherein the central strength member has a
diameter of about 3.0 mm; a first layer wrapped helically around
the central strength member, wherein the first layer is formed of a
plurality of water swellable yarns; a plurality of buffer tubes
stranded helically around the first layer, wherein each of the
plurality of buffer tubes has a first diameter of about 1.55
mm.+-.0.05 mm, wherein each of the plurality of buffer tubes has a
second diameter of about 1.85 mm.+-.0.05 mm, wherein each of the
plurality of buffer tubes is formed of a combination of two sub
layers having different material, wherein each of the plurality of
buffer tubes has a first sub layer and a second sub layer; wherein
the first sub layer is formed of polycarbonate, wherein the first
sub layer has a thickness of about 75 microns.+-.10 microns,
wherein the first sub layer has a density of about 1.2 gm/cm.sup.3,
wherein the second sub layer is formed of polybutylene
terephthalate, wherein the second sub layer has a thickness of
about 75 microns.+-.10 microns, wherein the second sub layer has a
density of about 1.31 gm/cm.sup.3, wherein each of the plurality of
buffer tubes encloses a plurality of optical fibers, wherein the
plurality of buffer tubes is eight, wherein the plurality of
optical fibers in each of the plurality of buffer tubes is twenty
four, wherein each of the plurality of optical fibers has a
diameter of about 250 microns; a second layer, wherein the second
layer cross helically surrounds a core of the optical fiber cable,
wherein the second layer is formed of a pair of binder yarns,
wherein the pair of binder yarn comprising: a first binder yarn,
wherein the first binder yarn is wrapped helically in clockwise
direction; and a second binder yarn, wherein the second binder yarn
is wrapped helically in anti-clockwise direction; a third layer
wrapped helically around the core of the optical fiber cable,
wherein the third layer is formed of a plurality of water swellable
yarns; and a fourth layer surrounding the third layer, wherein the
fourth layer is formed of high density polyethylene, wherein the
fourth layer has a thickness in a range of about 0.4 mm to 0.6 mm,
wherein the fourth layer has a density in a range of about 0.90
gm/cm.sup.3 to 0.96 gm/cm.sup.3, wherein the optical fiber cable
has a diameter of about 7.7 mm.+-.0.2 mm.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to the field of optical fiber
cable and, in particular, relates to a micro optical fiber cable
for installation in ducts. The present application is based on, and
claims priority from an Indian Application Number 201721036545,
filed on 13 Oct. 2017 the disclosure of which is hereby
incorporated by reference herein.
BACKGROUND
[0002] Over the last few years, there has been a rapid growth in
the use of optical fiber cables. One such type of optical fiber
cables are air blown optical fiber cables. These air blown optical
fiber cables are used for various indoor-outdoor applications. The
air blown optical fiber cables are installed inducts/microduct.
Traditionally, the air blown optical fiber cables are installed by
blowing the optical fiber cable into a duct/microduct while
simultaneously pushing the optical cable into the duct in starting
length of cable to support the initial blowing of the optical fiber
cable. The blowing is done by injecting a high volume of compressed
air into the duct which flows inside the duct at high speed.
Accordingly, the high speed air propels the optical fiber cable
further inside the duct. The optical fiber cable is blown with a
cable blowing machine. Typically, the structure of these air blown
optical fiber cables includes a number of buffer tubes. The buffer
tubes are stranded around a central strength member in an S-Z
fashion. In addition, the buffer tubes are enclosed by a sheathing
layer for providing protection to the air blown optical fiber
cable. Typically, the buffer tubes are formed using polybutylene
terephthalate, PA-12 or polypropylene. Further, the buffer tubes
are single layer buffer tubes.
[0003] The currently available air blown optical fiber cables have
certain drawbacks. The existing air blown optical fiber cables
limits blowing distance and speed for installation in smaller ducts
due to the large diameter. In addition, the single layer design of
the buffer tubes leads to a higher thickness of the buffer tubes.
The higher thickness of the buffer tubes results in a large
diameter of the buffer tubes. Accordingly, the large diameter of
the buffer tubes leads to large diameter of the air blown optical
fiber cables. Further, the conventionally available air blown
optical fiber cables with large optical fiber diameter with single
layer buffer tubes is large diameter optical fiber cable. This
affects the blowing performance of the air blown optical fiber
cables into a duct of predefined size. These air blown optical
fiber cables with large diameter are difficult to blow for large
distances in the predefined duct size. Therefore, the
conventionally available optical fiber cables of this kind are
blown into duct of higher size. Furthermore, the existing optical
fiber cables use optical fiber having a diameter of about 200
microns to reduce the overall diameter of the optical fiber cable
to serve the purpose of duct size.
[0004] In light of the foregoing discussion, there exists a need
for an optical fiber cable which overcomes the above cited
drawbacks of conventionally known optical fiber cables.
SUMMARY
[0005] In an aspect, the present disclosure provides an optical
fiber cable. The optical fiber cable includes a central strength
member lying substantially along a longitudinal axis of the optical
fiber cable. The optical fiber cable includes a first layer wrapped
helically around the central strength member. The optical fiber
cable includes a plurality of buffer tubes stranded helically
around the first layer. Each of the plurality of buffer tubes
encloses a plurality of optical fibers. The optical fiber cable
includes a second layer cross helically positioned around a core of
the optical fiber cable. The optical fiber cable includes a third
layer wrapped helically around the core of the optical fiber cable.
The optical fiber cable includes a fourth layer surrounding the
third layer. The central strength member is formed of fibre
reinforced plastic. The central strength member has a diameter of
about 3 mm. The first layer is a plurality of water swellable
yarns. Each of the plurality of buffer tubes is formed of a
combination of two sub layers having different material. Each of
the plurality of buffer tubes has a first sub layer and a second
sub layer. The first sub layer is formed of polycarbonate. The
first sub layer is the inner sub layer of the buffer tube. The
second sub layer is formed of polybutylene terephthalate. The
second sub layer is the outer sub layer of the buffer tube. The
second layer is formed of a pair of binder yarns. The pair of
binder yarn includes a first binder yarn wrapped helically in
clockwise direction and a second binder yarn wrapped helically in
anti-clockwise direction. The third layer is formed of a plurality
of water swellable yarns. The fourth layer is formed of high
density polyethylene. The optical fiber cable has a diameter of
about 7.7 mm.+-.0.2 mm.
[0006] In an embodiment of the present disclosure, each of the
plurality of buffer tubes has a first diameter of about 1.55
mm.+-.0.05 mm. Each of the plurality of buffer tubes has a second
diameter of about 1.85 mm.+-.0.05 mm.
[0007] In an embodiment of the present disclosure, the first sub
layer has a thickness of about 75 microns.+-.10 microns. The first
sub layer has a density of about 1.2 gm/cm.sup.3.
[0008] In an embodiment of the present disclosure, the second sub
layer has a thickness of about 75 microns.+-.10 microns. The second
sub layer has a density of about 1.31 gm/cm.sup.3.
[0009] In an embodiment of the present disclosure, the plurality of
buffer tubes being eight. The plurality of optical fibers in each
of the plurality of buffer tubes is twenty four. Each of the
plurality of optical fibers has a diameter of about 250
microns.
[0010] In an embodiment of the present disclosure, the optical
fiber cable includes a plurality of ripcords. Each of the plurality
of ripcords is high strength water blocking type yarns.
[0011] In an embodiment of the present disclosure, the fourth layer
has a thickness in the range of about 0.4 mm to 0.6 mm, wherein the
fourth layer has a density in the range of about 0.90 gm/cm.sup.3
to 0.96 gm/cm.sup.3.
[0012] In an embodiment of the present disclosure, the central
strength member is a solid pultrusion type fiber reinforced
plastic. The central strength member is coated with a polyethylene
layer. The central strength member is coated to accommodate
plurality of buffer tubes.
[0013] In an embodiment of the present disclosure, the first binder
yarn is aramid binder yarn and the second binder yarn is aramid
binder yarn.
[0014] In an embodiment of the present disclosure, the binder yarn
is water blocking type aramid yarn.
[0015] In an embodiment of the present disclosure, further include
a plurality of ripcord. The plurality of ripcords is positioned
below the fourth layer and along with the third layer in linear
manner.
[0016] In an embodiment of the present disclosure, the optical
fiber cable is blown into a duct having an inner diameter of about
10 mm and outer diameter of about 14 mm. The optical fiber cable
when blown into duct having an inner diameter of 10 mm and outer
diameter of 14 mm has a fill factor in a range of about 54% to
64%.
[0017] In an embodiment of the present disclosure, the buffer tube
has a packing factor in a range of about 75% to 92%. The buffer
tube has packing factor which is defined as ratio of equivalent
cross sectional area of fiber bunch to inner cross sectional area
of the buffer tube. The equivalent cross sectional area is the area
formed by equivalent diameter of fiber bunch which is calculated by
formula, 1.155*Square root of number fibers per tube*Diameter of
the fiber.
[0018] In another aspect, the present disclosure provides an
optical fiber cable. The optical fiber cable includes a central
strength member lying substantially along a longitudinal axis of
the optical fiber cable. The optical fiber cable includes a first
layer wrapped helically around the central strength member. The
optical fiber cable includes a plurality of buffer tubes stranded
helically around the first layer. Each of the plurality of buffer
tubes encloses a plurality of optical fibers. The optical fiber
cable includes a second layer cross helically positioned around the
core of the optical fiber cable. The optical fiber cable includes a
third layer wrapped helically around the core of the optical fiber
cable. The optical fiber cable includes a fourth layer surrounding
the third layer. The central strength member is formed of fibre
reinforced plastic. The central strength member has a diameter of
about 3 mm. The first layer is a plurality of water swellable
yarns. Each of the plurality of buffer tubes has a first diameter
of about 1.55 mm.+-.0.05 mm. Each of the plurality of buffer tubes
has a second diameter of about 1.85 mm.+-.0.05 mm. Each of the
plurality of buffer tubes is formed of a combination of two sub
layers having different material. Each of the plurality of buffer
tubes has a first sub layer and a second sub layer. The first sub
layer is formed of polycarbonate. The first sub layer is the inner
sub layer of the buffer tube. The second sub layer is formed of
polybutylene terephthalate. The second sub layer is the outer sub
layer of the buffer tube. The second layer is formed of a pair of
binder yarns. The pair of binder yarn includes a first binder yarn
wrapped helically in clockwise direction and a second binder yarn
wrapped helically in anti-clockwise direction. The third layer is
formed of a plurality of water swellable yarns. The fourth layer is
formed of high density polyethylene. The fourth layer has a
thickness in the range of about 0.4 mm to 0.6 mm. The fourth layer
has a density in the range of about 0.90 gm/cm3 to 0.96 gm/cm3. The
optical fiber cable has a diameter of about 7.7 mm.+-.0.2 mm.
[0019] In yet another aspect, the present disclosure provides an
optical fiber cable. The optical fiber cable includes a central
strength member lying substantially along a longitudinal axis of
the optical fiber cable. The optical fiber cable includes a first
layer wrapped helically around the central strength member. The
optical fiber cable includes a plurality of buffer tubes stranded
helically around the first layer. Each of the plurality of buffer
tubes encloses a plurality of optical fibers. The optical fiber
cable includes a second layer cross helically positioned around the
core of the optical fiber cable. The optical fiber cable includes a
third layer wrapped helically around the core of the optical fiber
cable. The optical fiber cable includes a fourth layer surrounding
the third layer. The central strength member is formed of fibre
reinforced plastic. The central strength member has a diameter of
about 3 mm. The first layer is a plurality of water swellable
yarns. Each of the plurality of buffer tubes has a first diameter
of about 1.55 mm.+-.0.05 mm. Each of the plurality of buffer tubes
has a second diameter of about 1.85 mm.+-.0.05 mm. Each of the
plurality of buffer tubes is formed of a combination of two sub
layers having different material. Each of the plurality of buffer
tubes has a first sub layer and a second sub layer. The first sub
layer is formed of polycarbonate. The first sub layer is the inner
sub layer of the buffer tube. The first sub layer has a thickness
of about 75 microns.+-.10 microns. The first sub layer has a
density of about 122 gm/cm.sup.3. The second sub layer is formed of
polybutylene terephthalate. The second sub layer is the outer sub
layer of the buffer tube. The second sub layer has a thickness of
about 75 microns.+-.10 microns, wherein the second sub layer has a
density of about 1.31 gm/cm.sup.3. Each of the plurality of buffer
tubes encloses a plurality of optical fibers. The plurality of
buffer tubes being eight. The plurality of optical fibers in each
of the plurality of buffer tubes is twenty four. Each of the
plurality of optical fibers has a diameter of about 250 microns.
The second layer is formed of a pair of binder yarns. The pair of
binder yarn includes a first binder yarn wrapped helically in
clockwise direction and a second binder yarn wrapped helically in
anti-clockwise direction. The third layer is formed of a plurality
of water swellable yarns. The fourth layer is formed of high
density polyethylene. The fourth layer has a thickness in the range
of about 0.4 mm to 0.6 mm. The fourth layer has a density in the
range of about 0.90 gm/cm3 to 0.96 gm/cm.sup.3. The optical fiber
cable has a diameter of about 7.7 mm.+-.0.2 mm.
BRIEF DESCRIPTION OF FIGURES
[0020] Having thus described the disclosure in general terms,
reference will now be formed to the accompanying figures,
wherein:
[0021] FIG. 1 illustrates a cross sectional view of an optical
fiber cable, in accordance with an embodiment of the present
disclosure; and
[0022] FIG. 2 illustrates a cross sectional view of an optical
fiber cable, in accordance with another embodiment of the present
disclosure.
[0023] It should be noted that the accompanying figures are
intended to present illustrations of exemplary embodiments of the
present disclosure. These figures are not intended to limit the
scope of the present disclosure. It should also be noted that
accompanying figures are not necessarily drawn to scale.
DETAILED DESCRIPTION
[0024] Reference will now be formed in detail to selected
embodiments of the present disclosure in conjunction with
accompanying figures. The embodiments described herein are not
intended to limit the scope of the disclosure, and the present
disclosure should not be construed as limited to the embodiments
described. This disclosure may be embodied in different forms
without departing from the scope and spirit of the disclosure. It
should be understood that the accompanying figures are intended and
provided to illustrate embodiments of the disclosure described
below and are not necessarily drawn to scale. In the drawings, like
numbers refer to like elements throughout, and thicknesses and
dimensions of some components may be exaggerated for providing
better clarity and ease of understanding.
[0025] It should be noted that the terms "first", "second", and the
like, herein do not denote any order, ranking, quantity, or
importance, but rather are used to distinguish one element from
another. Further, the terms "a" and "an" herein do not denote a
limitation of quantity, but rather denote the presence of at least
one of the referenced item.
[0026] FIG. 1 illustrates a cross sectional view of an optical
fiber cable 100, in accordance with various embodiments of the
present disclosure. The optical fiber cable 100 is a micro optical
fiber cable. The optical fiber cable 100 is used for installation
in micro ducts. In addition, the optical fiber cable 100 is used
for underground installations. Also, the optical fiber cable 100 is
used for communication, and the like. In an embodiment of the
present disclosure, the optical fiber cable 100 is a 192F micro
optical fiber cable. In addition, 192F corresponds to 192 optical
fibers. Further, the optical fiber cable 100 has a small diameter
which makes the optical fiber cable 100 suitable for installation
in the smaller micro ducts.
[0027] The optical fiber cable 100 is formed of a plurality of
layers (mentioned below in the patent application). The optical
fiber cable encloses plurality of buffer tubes each formed of two
sub layers having different material and thickness. Each of the
plurality of buffer tubes encloses a plurality of optical fibers.
In an embodiment of the present disclosure, the plurality of
optical fibers is loosely held inside the each of the plurality of
buffer tubes. In an embodiment of the present disclosure, each of
the plurality of buffer tubes has a small diameter (mentioned below
in the patent application). Further, the optical fiber cable 100
has a reduced cable diameter (provided below in the patent
application).
[0028] The optical fiber cable 100 includes a central strength
member 132, a first layer 134, a plurality of buffer tubes 136 and
a plurality of optical fibers 138. In addition, the optical fiber
cable 100 includes a second layer 140, a third layer 142 and a
fourth layer 144. Further, the optical fiber cable 100 includes a
plurality of ripcords 146a-146b.
[0029] The optical fiber cable 100 includes the central strength
member 132. The central strength member 132 lies substantially
along a longitudinal axis of the optical fiber cable 100. In an
embodiment of the present disclosure, the central strength member
132 is formed of fiber reinforced plastic. The central strength
member 132 is a solid pultrusion type fiber reinforced plastic. The
fiber reinforced plastic is a composite material having a polymer
matrix reinforced with glass fibers. In an example, the fiber
reinforced plastics includes but may not be limited to glass
fibers, carbon fibers, aramid fibers, basalt fibers and the like.
In another embodiment of the present disclosure, the central
strength member 132 is formed of any other suitable material. In an
embodiment of the present disclosure, the central strength member
132 may be coated with a layer of polyethylene. The central
strength member 132 is coated to accommodate the plurality of
buffer tubes around it. In another embodiment of the present
disclosure, the central strength member may be coated with any
other suitable material. In yet another embodiment of the present
disclosure, the central strength member 132 may not be coated. In
an embodiment of the present disclosure, the central strength
member 132 has a circular cross-section.
[0030] The central strength member 132 provides physical strength
to the optical fiber cable 100 and resists over bending of the
optical fiber cable 100. In addition, the central strength member
132 provides tensile strength to the optical fiber cable 100. The
tensile strength corresponds to a resistance shown by the optical
fiber cable 100 against longitudinal loads. The central strength
member 132 is characterized by a diameter measured along the cross
section. In an embodiment of the present disclosure, the diameter
of the central strength member 132 is about 3 millimeters. In
another embodiment of the present disclosure, the diameter of the
central strength member 132 may vary.
[0031] The optical fiber cable 100 includes the first layer 134.
The first layer 134 surrounds the central strength member 132. The
first layer 134 is formed of a plurality of water swellable yarns
134a-134c helically disposed around the central strength member 132
and the plurality of buffer tubes 136. The plurality of water
swellable yarns 134a-134c prevents ingression of water inside a
core of the optical fiber cable 100. In an embodiment of the
present disclosure, the number of water swellable yarns present in
the first layer 134 is 3. In another embodiment of the present
disclosure, the number of water swellable yarns present in the
first layer 134 may vary.
[0032] The optical fiber cable 100 includes the plurality buffer
tubes 136. The plurality of buffer tubes 136 is stranded around the
first layer 134 in a helical fashion.
[0033] The cross section of each of the plurality of buffer tubes
136 is circular in shape. In an embodiment of the present
disclosure, the cross section of each of the plurality of buffer
tubes 136 may be of any suitable shape. In an embodiment of the
present disclosure, each of the plurality of buffer tubes 136 has a
uniform structure and dimensions. In an embodiment of the present
disclosure, the plurality of buffer tubes 136 includes 8 buffer
tubes. Each of the plurality of buffer tubes 136 is having two sub
layers. Two sub layers include a first sub layer and a second sub
layer. The first sub layer is the inner sub layer and the second
sub layer is the outer sub layer. Each sub layer is formed of a
different material. Each sub layer has a different thickness. Each
sub layer has a different density. The inner sub layer is formed of
polycarbonate having a density of about 1.2 gm/cm.sup.3. In
general, polycarbonates are a group of thermoplastic containing
carbonate groups in chemical structure. The inner sub layer has a
thickness of about of about 75 microns.+-.10 microns. The outer sub
layer is formed of polybutylene terephthalate. The second sub layer
has a density of about 1.31 gm/cm.sup.3. The second sub layer has a
thickness of about 75 microns.+-.10 microns. In another embodiment
of the present disclosure the thickness and density of the inner
sub layer and the outer sub layer may vary.
[0034] Furthermore, each of the plurality of buffer tubes 136 has a
first diameter and a second diameter. In an embodiment of the
present disclosure, the first diameter and the second diameter of
each of the plurality of buffer tubes 136 is fixed. In an
embodiment of the present disclosure, the first diameter of each of
the plurality buffer tubes 136 is about 1.55 mm.+-.0.05 mm. In
another embodiment of the present disclosure, the first diameter of
each of the plurality of buffer tubes 136 may vary. In an
embodiment of the present disclosure, the second diameter of each
of the plurality of buffer tubes 136 about 1.85 mm.+-.0.05 mm. In
another embodiment of the present disclosure, the second diameter
of each of the plurality of buffer tubes 136 may vary.
[0035] Going further, each of the plurality of buffer tubes 136
encloses the plurality of optical fibers 138. In an embodiment of
the present disclosure, each of the plurality of buffer tubes 136
encloses 24 optical fibers. In another embodiment of the present
disclosure, each of the plurality of buffer tubes 136 encloses 12
optical fibers (as shown in FIG. 2). Each of the plurality of
buffer tubes 136 is a tube for encapsulating the plurality of
optical fibers 138. The plurality of buffer tubes 136 provides
support and protection to each of the plurality of optical fibers
138 against crush, bend and stretch. In addition, the plurality of
buffer tubes 136 protects the plurality of optical fibers 138 and
prevents ingression of water inside the stranded core of the
optical fiber cable 100. Further, each of the plurality of buffer
tubes 136 provides mechanical isolation, physical damage protection
and identification of each of the plurality of optical fibers 138.
Each of the plurality of buffer tubes 136 is colored. In an
embodiment of the present disclosure, the color of plurality of
buffer tubes 136 includes red, green, yellow, brown, blue, purple,
grey (slate) and orange. In another embodiment of the present
disclosure, the color of each of the plurality of buffer tubes 136
may vary. The coloring is done for identification of each of the
plurality of buffer tubes 136. In an embodiment of the present
disclosure, each of the plurality of buffer tubes 136 is filled
with a gel. In an embodiment of the present disclosure, the gel is
a thixotropic gel. In an embodiment of the present disclosure, the
thixotropic gel prevents ingression of water inside each of the
plurality of buffer tubes 136.
[0036] Further, each of the plurality of optical fibers 138 is a
fiber used for transmitting information as light pulses from one
end to another. In addition, each of the plurality of optical
fibers 138 is a thin strand of glass capable of transmitting
optical signals. Also, each of the plurality of optical fibers 138
is configured to transmit large amounts of information over long
distances with relatively low attenuation. Further, each of the
plurality of optical fibers 138 includes a core region and a
cladding region. The core region is an inner part of an optical
fiber and the cladding section is an outer part of the optical
fiber. Moreover, the core region is defined by a central
longitudinal axis of each of the plurality of optical fibers 138.
In addition, the cladding region surrounds the core region.
[0037] Each of the plurality of optical fibers 138 has a diameter
of about 250 microns. In another embodiment of the present
disclosure, the diameter of each of the plurality of optical fibers
138 may vary. In an embodiment of the present disclosure, each of
the plurality of optical fibers 138 is a colored optical fiber. In
an embodiment of the present disclosure, each of the plurality of
optical fibers 138 has a different color. The color of each of the
plurality of optical fibers 138 is selected from the group. The
group include blue, orange, green, brown, slate, yellow, red,
violet, white, black, aqua and pink. The group further includes the
above color along with a single ring marking. The group further
includes the above color along with the double ring marking. The
coloring is done for identification of each of the plurality of
optical fibers 138. In another embodiment of the present
disclosure, each of the plurality of optical fibers 138 may be of
any different color.
[0038] In an embodiment of the present disclosure, a number of the
plurality of optical fibers 138 in each of the plurality of buffer
tubes 136 is 24. In an embodiment of the present disclosure, a
total number of the plurality of optical fibers 138 in the
plurality of buffer tubes 136 is 192 (8*24=192), when the number of
buffer tubes is 8. In another embodiment of the present disclosure,
a total number of the plurality of optical fibers 138 in the
plurality of buffer tubes 136 is 288 (24*12=288), when the number
of buffer tubes is 24 (as shown in FIG. 2). In yet another
embodiment of the present disclosure, the number of optical fibers
and the number of buffer tubes in the plurality of buffer tubes 136
may vary.
[0039] In an embodiment of the present disclosure, each of the
plurality of optical fibers 138 has a fiber attenuation of about
0.35 dB/km at a wavelength of about 1310 nanometers. In another
embodiment of the present disclosure, each of the plurality of
optical fibers 138 has a fiber attenuation of about 0.25 dB/km at a
wavelength of 1550 nanometers. In yet another embodiment of the
present disclosure, each of the plurality of optical fibers 138 has
a fiber attenuation of about 0.4 dB/km at a wavelength of 1625
nanometers. The fiber attenuation corresponds to a loss in optical
power as the light travels through each of the plurality of optical
fibers 138. Each of the plurality of optical fibers 138 has a
dispersion of less than 0.2 ps/ km. The dispersion corresponds to a
spreading of the optical signals over time.
[0040] The optical fiber cable 100 includes the second layer 140.
The second layer 140 is formed of a pair binder yarns. The pair of
binder yarn is used for binding of the core of the optical fiber
cable 100. The second layer 140 cross helically surrounds the core
of the optical fiber cable 100. The pair of binder yarns includes a
first binder yarn and a second binder yarn. The first binder yarn
is wrapped helically in clockwise direction. The second binder yarn
is wrapped helically in anti-clockwise direction. The first binder
yarn is aramid binder yarn. The second binder yarn is aramid binder
yarn. In an embodiment of the present disclosure, the binder yarn
is a normal binder yarn. In another embodiment of the present
disclosure, the binder yarn is a zero shrinkage binder yarn. In yet
another embodiment of the present disclosure, the binder yarn is a
low shrinkage binder yarn. In an embodiment of the present
disclosure, the binder yarn is an aramid yarn. In another
embodiment of the present disclosure, the binder yarn is formed of
any other suitable material.
[0041] The optical fiber cable 100 includes the third layer 142.
The third layer 142 includes a plurality of water swellable yarns.
The plurality of water swellable yarns prevents ingression of water
and moisture inside the core of the optical fiber cable 100. In
addition, the plurality of water swellable yarns prevents water
penetration along the length of the optical fiber cable 100.
[0042] In an embodiment of the present disclosure, the third layer
142 of the optical fiber cable 100 is replaced with water blocking
aramid binder yarns. In another embodiment of the present
disclosure, the third layer 142 of the optical fiber cable 100 is
replaced with water blocking rip cords. The use of water blocking
aramid binder yarns and water blocking rip cord prevents ingression
of water and moisture inside the core of the optical fiber cable
100.
[0043] The optical fiber cable 100 includes the fourth layer 144.
The fourth layer 144 is a sheathing layer. In an embodiment of the
present disclosure, the fourth layer 144 is a sheath formed of at
least one of UV proof black medium density polyethylene material
and UV proof black high density polyethylene material. In general,
medium density polyethylene is a thermoplastic material produced by
chromium/silica catalysts, Ziegler-Natta catalysts or metal locene
catalysts. In another embodiment of the present disclosure, the
fourth layer 144 is formed of any other suitable material. The
fourth layer 144 protects the optical fiber cable 100 from harsh
environment and harmful UV rays. In addition, the fourth layer 144
has the inherent ability to resist crushes, kinks and tensile
stress. In an embodiment of the present disclosure, the fourth
layer 144 has a thickness of about 0.5 millimeter. In another
embodiment of the present disclosure, the fourth layer 144 may have
any suitable thickness.
[0044] The optical fiber cable 100 includes the plurality of
ripcords 146a-146b. The plurality of ripcord 146a-146b is disposed
below the fourth layer 144 and along with the third layer 142 in
linear manner. In an embodiment of the present disclosure, the
plurality of ripcords 146a-146b lies substantially along the
longitudinal axis of the optical fiber cable 100. The plurality of
ripcords 146a-146b facilitates access to the plurality of optical
fibers 138. In an embodiment of the present disclosure, the
plurality of ripcords 146a-146b is formed of a polyester material.
In another embodiment of the present disclosure, the plurality of
ripcords 146a-146b is formed of any other suitable material. In an
embodiment of the present disclosure, the plurality of ripcords
146a-146b is twisted yarns. In an embodiment of the present
disclosure, the number of ripcords in the optical fiber cable 100
is 2. In another embodiment of the present disclosure, the number
of ripcords in the optical fiber cable 100 may vary.
[0045] In an embodiment of the present disclosure, the plurality of
rip cords 146a-146b in the optical fiber cable 100 are replaced by
yarns having high strength and water blocking characteristics. The
yarns facilitate access to the plurality of optical fibers 108 and
prevent ingression of water and moisture inside the core of the
optical fiber cable 100.
[0046] In an embodiment of the present disclosure, the optical
fiber cable 100 may have a suitable diameter. In an embodiment of
the present disclosure, the diameter of the optical fiber cable 100
is in a range of about 7.7 mm.+-.0.2 mm. In another embodiment of
the present disclosure, the diameter of the optical fiber cable 100
may vary. In an embodiment of the present disclosure, the weight of
the optical fiber cable 100 is in a range of about 53.+-.10
kilogram per kilometre. In another embodiment of the present
disclosure, the weight of the optical fiber cable 100 may vary.
[0047] In an embodiment of the present disclosure, each of the
plurality of buffer tubes 136 has a packing factor in a range of
about 75% to 92%. In general, the packing factor of buffer tube is
defined as the ratio of equivalent cross-sectional area of optical
fiber bunch to the cross-sectional area formed by inner diameter of
the buffer tube. Equivalent cross-sectional area is the area formed
by equivalent diameter of the optical fiber bunch. Equivalent
diameter is calculated by using the expression as follows:
1.155*Square Root of number of optical fibers per tube*Diameter of
optical fiber.
[0048] In an embodiment of the present disclosure, the optical
fiber cable 100 is blown into a duct having a fill factor in a
range of about 54% to 64%. The duct is characterized by an inner
diameter and an outer diameter. The inner diameter of the duct is
about 10 mm. The outer diameter of the duct is about 14 mm. In
general, fill factor is a measure of the acceptability of a cable
to be installed in a duct. The fill factor is sometimes defined as
the ratio of the cross-sectional area of the cable to the
cross-sectional area of the bore of the duct and in the case of a
cable and a bore diameter, is sometimes defined as the ratio of the
square of cable diameter to square of the bore diameter.
[0049] In an embodiment of the present disclosure, the optical
fiber cable 100 has a maximum operation tensile strength of about
1000 Newton. In an embodiment of the present disclosure, the
minimum bending radius of the optical fiber cable 100 during
installation is 20 D and after installation is 10 D. In an
embodiment of the present disclosure, the crush resistance of the
optical fiber cable 100 is about 500 Newton per 100 millimetre. In
an embodiment of the present disclosure, the impact strength of the
optical fiber cable 100 is 1 Newton meter. In an embodiment of the
present disclosure, the torsion of the optical fiber cable 100 is
.+-.180 degree. In an embodiment of the present disclosure, the
temperature performance of the optical fiber cable 100 during
installation is in the range of -10 degree Celsius to 50 degree
Celsius. In an embodiment of the present disclosure, the
temperature performance of the optical fiber cable 100 during
operation is in the range of -30 degree Celsius to 70 degree
Celsius. In an embodiment of the present disclosure, the
temperature performance of the optical fiber cable 100 during
storage is in the range of -30 degree Celsius to 70 degree Celsius.
In another embodiment of the present disclosure, the optical fiber
cable 100 has any suitable value or range of crush resistance,
impact strength, torsion, tensile strength, minimum bending radius
and temperature performance.
[0050] FIG. 2 illustrates a cross sectional view of an optical
fiber cable 200, in accordance with another embodiment of the
present disclosure. The optical fiber cable 200 is a 288F micro
optical fiber cable. In addition, 288F corresponds to 288 optical
fibers. Further, the optical fiber cable 200 has a small diameter
which makes the optical fiber cable 200 suitable for installation
in the micro ducts.
[0051] The optical fiber cable 200 includes a central strength
member 232, a first layer 234, a first layer of plurality of buffer
tubes 236 and a plurality of optical fibers 238. In addition, the
optical fiber cable 200 includes a second layer 240, a second layer
of plurality of buffer tubes 242 and a plurality of optical fibers
244. Further, the optical fiber cable 200 includes a third layer
246, a fourth layer 248, a fifth layer 250 and a plurality of
ripcords 252a-252b.
[0052] The optical fiber cable 200 includes the central strength
member 232. The central strength member 232 lies substantially
along a longitudinal axis of the optical fiber cable 200. In an
embodiment of the present disclosure, the central strength member
232 is formed of fiber reinforced plastic. In an embodiment of the
present disclosure, the central strength member 232 may be coated
with a layer of polyethylene. The central strength member 232 is
characterized by a diameter measured along the cross section. In an
embodiment of the present disclosure, the diameter of the central
strength member 232 along with the polyethylene coating is about
2.8 millimeters. In another embodiment of the present disclosure,
the diameter of the central strength member 232 may vary.
[0053] The optical fiber cable 200 includes the first layer 234.
The first layer 234 surrounds the central strength member 232. The
first layer 234 includes a plurality of water swellable yarns
234a-234c helically disposed around the central strength member 232
and the first layer of buffer tubes 236. The plurality of water
swellable yarns 234a-234c prevents ingression of water inside the
core of the optical fiber cable 200. In an embodiment of the
present disclosure, the number of water swellable yarns present in
the first layer 234 is 3. In another embodiment of the present
disclosure, the number of water swellable yarns present in the
first layer 234 is 5. In yet another embodiment of the present
disclosure, the number of water swellable yarns present in the
first layer 234 may vary.
[0054] The optical fiber cable 200 includes the first layer of
plurality of buffer tubes 236. The first layer of plurality of
buffer tubes 236 are stranded around the first layer 234 in a
helical fashion. In an embodiment of the present disclosure, the
lay length of the first layer of buffer tubes 236 is in a range of
about 80 millimeters-100 millimeters. In general, the lay length is
a longitudinal distance along the length of the central strength
member 232 required for the plurality of buffer tubes to go all the
way around the central strength member 232.
[0055] Each of the plurality of buffer tubes 236 is same in
construction, structure, dimension, color and design as each of the
plurality of buffer tubes 136 (as mentioned in detailed above in
the patent application).
[0056] Going further, each of the plurality of buffer tubes 236
encloses the plurality of optical fibers 238. In an embodiment of
the present disclosure, each of the plurality of buffer tubes 236
encloses 12 optical fibers. Each of the plurality of buffer tubes
236 is a tube for encapsulating the plurality of optical fibers
238. Each of the plurality of optical fibers 238 has a diameter of
about 250 microns.
[0057] In an embodiment of the present disclosure, a number of the
plurality of optical fibers 238 in each of the plurality of buffer
tubes 236 is 12. In an embodiment of the present disclosure, a
total number of the plurality of optical fibers 238 in the first
layer of the plurality of buffer tubes 236 is 108 (9*12=108), when
the number of buffer tubes is 9. Each of the plurality of optical
fibers 238 has the same color, properties and dimensions as each of
the plurality of optical fibers 138 (as explained in detailed above
in the patent application).
[0058] The optical fiber cable 200 includes the second layer 240.
The second layer 240 includes a plurality of water swellable yarns.
The plurality of water swellable yarns prevents ingression of water
inside the core of the optical fiber cable 200. In addition, the
water swellable yarns prevent water penetration along the length of
the optical fiber cable 200.
[0059] The optical fiber cable 200 includes the second layer of
plurality of buffer tubes 242. The second layer of plurality of
buffer tubes 242 is stranded around the second layer 240 in a
helical fashion. In an embodiment of the present disclosure, the
lay length of the second layer of plurality of buffer tubes 242 is
in a range of about 100 millimetres-140 millimetres. In an
embodiment of the present disclosure, the second layer of plurality
of buffer tubes 242 includes 15 buffer tubes.
[0060] Each buffer tube of the second layer of plurality of buffer
tubes 242 is same in construction, structure, dimension, color and
design as each of the plurality of buffer tubes 136 (as mentioned
in detailed above in the patent application).
[0061] Going further, each of the buffer tubes in the second layer
of plurality of buffer tubes 242 encloses the plurality of optical
fibers 244. In addition, each of the buffer tubes in the second
layer of plurality of buffer tubes 242 encloses 12 optical
fibers.
[0062] In an embodiment of the present disclosure, a number of the
plurality of optical fibers 244 in each of the plurality of buffer
tubes in the second layer of plurality of buffer tubes 242 is 12.
In an embodiment of the present disclosure, a total number of the
plurality of optical fibers 244 in the second layer of plurality of
buffer tubes 242 is 180 (15*12=180) when the number of buffer tubes
is 15. Each of the plurality of optical fibers 244 has the same
color, properties and dimensions as the plurality of optical fibers
138 (as explained in detailed above in the patent application).
[0063] The total number of optical fibers present in the optical
fiber cable 200 is 288 (108+180=288). In another embodiment of the
present disclosure, the total number of optical fibers present in
the optical fiber cable 200 may vary.
[0064] The optical fiber cable 200 includes the third layer 246.
The third layer 246 is formed of a plurality of binder yarns. The
binder yarn is used for binding of the core of the optical fiber
cable 200. In an embodiment of the present disclosure, the binder
yarn is a normal binder yarn. In another embodiment of the present
disclosure, the binder yarn is a low shrinkage binder yarn.
[0065] The optical fiber cable 200 includes the fourth layer 248.
The fourth layer 248 includes a plurality of water swellable yarns.
The plurality of water swellable yarns prevents ingression of water
and moisture inside the core of the optical fiber cable 200. In
addition, the plurality of water swellable yarns prevents water
penetration along the length of the optical fiber cable 200.
[0066] The optical fiber cable 200 includes the fifth layer 250.
The fifth layer 250 is a sheathing layer. In an embodiment of the
present disclosure, the fifth layer 250 is a sheath formed of at
least one of UV proof black medium density polyethylene material
and UV proof black high density polyethylene material. The fifth
layer 250 protects the optical fiber cable 200 from harsh
environment and harmful UV rays. In an embodiment of the present
disclosure, the fifth layer 250 has a thickness of about 0.5
millimetres. In addition, the fifth layer 250 has the inherent
ability to resist crushes, kinks and tensile stress.
[0067] The optical fiber cable 200 includes the plurality of
ripcords 252a-252b. The plurality of ripcords 252a-252b is disposed
between the fifth layer 250 and the fourth layer 248. In an
embodiment of the present disclosure, the plurality of ripcords
252a-252b lies substantially along the longitudinal axis of the
optical fiber cable 200. Each of the plurality of ripcords 252
facilitates access to the plurality of optical fibers.
[0068] In an embodiment of the present disclosure, the optical
fiber cable 200 may have a suitable diameter. In an embodiment of
the present disclosure, the diameter of the optical fiber cable 200
is in a range of about 9.2 millimeters.+-.0.2 millimeters. In
another embodiment of the present disclosure, the diameter of the
optical fiber cable 200 may vary. In an embodiment of the present
disclosure, the weight of the optical fiber cable 200 is in a range
of about 72.+-.10 kilogram per kilometer. In another embodiment of
the present disclosure, the weight of the optical fiber cable 200
may vary.
[0069] In an embodiment of the present disclosure, the optical
fiber cable 200 has a maximum operation tensile strength of about
350 Newton. In an embodiment of the present disclosure, the optical
fiber cable 200 has a maximum installation tensile strength of
about 1250 Newton. In an embodiment of the present disclosure, the
minimum bending radius of the optical fiber cable 200 during
installation is 20 D and after installation is 10 D. In an
embodiment of the present disclosure, the crush resistance of the
optical fiber cable 200 is about 700 Newton per 100 millimeter. In
an embodiment of the present disclosure, the impact strength of the
optical fiber cable 200 is 1 Newton meter. In an embodiment of the
present disclosure, the torsion of the optical fiber cable 200 is
.+-.180 degree. In an embodiment of the present disclosure, the
temperature performance of the optical fiber cable 200 during
installation is in the range of -30 degree Celsius to 70 degree
Celsius. In an embodiment of the present disclosure, the
temperature performance of the optical fiber cable 200 during
installation is in the range of -10 degree Celsius to 70 degree
Celsius. In an embodiment of the present disclosure, the
temperature performance of the optical fiber cable 200 during
service is in the range of -10 degree Celsius to 70 degree Celsius.
In an embodiment of the present disclosure, the temperature
performance of the optical fiber cable 200 during storage is in the
range of -30 degree Celsius to 70 degree Celsius. In another
embodiment of the present disclosure, the optical fiber cable 200
has any suitable value or range of crush resistance, impact
strength, torsion, tensile strength, minimum bending radius and
temperature performance.
[0070] In an embodiment of the present disclosure, the optical
fiber cable 200 with 288 fibers and average diameter of 9.3
millimeter went through one or more tests to check the blowing
performance of the optical fiber cable 200. In another embodiment
of the present disclosure, a mini optical fiber cable with 288
fibers and average diameter of 10.2 millimeter went through the one
or more tests to check the blowing performance of the mini optical
fiber cable. In yet another embodiment of the present disclosure,
the mini optical fiber cable with 24 fibers and average diameter of
4.3 millimetres went through the one or more tests to check the
blowing performance of the mini optical fiber cable.
[0071] In an embodiment of the present disclosure, each of the
three cables has to pass one or more pre-defined criteria of the
test. A first pre-defined criterion of the one or more pre-defined
criteria is that the cables should blow all the way in the 2000
meter route. A second pre-defined criterion of the one or more
pre-defined criteria is that the route must be completed under 60
minutes. A third pre-defined criterion of the one or more
pre-defined criteria is to stop the trial when the speed of blowing
is below 20 meter per minute. A fourth pre-defined criterion of the
one or more pre-defined criteria is that the cables should be blown
out under 60 minutes. A fifth pre-defined criterion of the one or
more pre-defined criteria is that no lubricant for the mini cables
having less than 144 fibers should be used.
[0072] In an embodiment of the present disclosure, the track used
for the testing of the one or more optical fiber cables includes 2
loops. Each loop of the two loops is used to measure 1000 meter in
length providing a total track distance of 2000 meter. Further, the
track includes three end loops and each end loop is equally spaced
at 500 meter. In addition to the end loop, the track includes 14
chambers, 4 chambers of which stimulate two road crossings.
[0073] In an embodiment of the present disclosure, the standard
equipment used for the test includes a compressor, a blowing
machine, and an air flow meter. The compressor is Kaersar Mobil air
M17 fitted with an inline air intercooler. The blowing machine is a
CBS air stream C1700. The air flow meter is a suitable in-line air
flow meter. Further, a new unused micro duct is used for each of
the one or more cable for the consistency with the test
results.
[0074] In an embodiment of the present disclosure, one or more
blowing equipment was used for the trials. The one or more
equipment include a Minijet and a M17 compressor. In an embodiment
of the present disclosure, the one or more cables were tested at
some predefined distance interval to check the blowing performance
of the one or more cables.
[0075] Test Cable 1: 288f mini cable with an average diameter of
9.3 mm.
[0076] The first cable for the test includes the optical fiber
cable 200. The type of tube used for the optical fiber cable 200 is
18/14 mm. The route used for the optical fiber cable 200 includes a
distance of 1900 meter. The number of fiber in the optical fiber
cable 200 is 288. The data corresponding to the test results of the
optical fiber cable 200 includes distance, time, speed and air flow
of the blowing operation.
[0077] The optical fiber cable 200 is blown to a distance of 50
meter in 1.06 minutes with a speed of 60 meter per minute. The
optical fiber cable 200 is blown to the next distance from 50 meter
to 100 meter in 1.58 minutes with the speed of 59 meter per
minutes. The optical fiber cable 200 is blown to the next distance
from 100 meter to 150 meter in 2.54 minutes with the speed of 52
meter per minutes. The optical fiber cable 200 is blown to the next
distance from 150 meter to 200 meter in 3.58 minutes with the speed
of 48 meter per minutes with an air flow of 2 bar. The optical
fiber cable 200 is blown to the next distance from 200 meter to 250
meter in 5.05 minutes with the speed of 50 meter per minutes with
an air flow of 4 bar. The optical fiber cable 200 is blown to the
next distance from 250 meter to 300 meter in 6.04 minutes with the
speed of 58 meter per minutes with an air flow of 6 bar. The
optical fiber cable 200 is blown to the next distance from 300
meter to 350 meter in 6.58 minutes with the speed of 58 meter per
minutes with an air flow of 6 bar. The optical fiber cable 200 is
blown to the next distance from 350 meter to 400 meter in 7.54
minutes with the speed of 57 meter per minutes with an air flow of
6 bar. The optical fiber cable 200 is blown to the next distance
from 400 meter to 450 meter in 8.53 minutes with the speed of 55
meter per minutes with an air flow of 6 bar. The optical fiber
cable 200 is blown to the next distance from 450 meter to 500 meter
in 9.53 minutes with the speed of 53 meter per minutes with an air
flow of 6 bar. The optical fiber cable 200 is blown to the next
distance from 500 meter to 550 meter in 10.55 minutes with the
speed of 55 meter per minutes with an air flow of 7 bar. The
optical fiber cable 200 is blown to the next distance from 550
meter to 600 meter in 11.55 minutes with the speed of 52 meter per
minutes with an air flow of 7 bar. The optical fiber cable 200 is
blown to the next distance from 600 meter to 650 meter in 12.48
minutes with the speed of 58 meter per minutes with an air flow of
7 bar. The optical fiber cable 200 is blown to the next distance
from 650 meter to 700 meter in 13.49 minutes with the speed of 58
meter per minutes with an air flow of 7 bar. The optical fiber
cable 200 is blown to the next distance from 700 meter to 750 meter
in 14.47 minutes with the speed of 58 meter per minutes with an air
flow of 7 bar. The optical fiber cable 200 is blown to the next
distance from 750 meter to 800 meter in 15.47 minutes with the
speed of 58 meter per minutes with an air flow of 7 bar. The
optical fiber cable 200 is blown to the next distance from 800
meter to 850 meter in 16.47 minutes with the speed of 58 meter per
minutes with an air flow of 8 bar. The optical fiber cable 200 is
blown to the next distance from 850 meter to 900 meter in 17.46
minutes with the speed of 58 meter per minutes with an air flow of
8 bar. The optical fiber cable 200 is blown to the next distance
from 900 meter to 950 meter in 18.47 minutes with the speed of 57
meter per minutes with an air flow of 8 bar. The optical fiber
cable 200 is blown to the next distance from 950 meter to 1000
meter in 19.44 minutes with the speed of 56 meter per minutes with
an air flow of 8 bar. The optical fiber cable 200 is blown to the
next distance from 1000 meter to 1050 meter in 20.44 minutes with
the speed of 53 meter per minutes with an air flow of 8 bar. The
optical fiber cable 200 is blown to the next distance from 1050
meter to 1100 meter in 21.46 minutes with the speed of 52 meter per
minutes with an air flow of 8 bar. The optical fiber cable 200 is
blown to the next distance from 1100 meter to 1150 meter in 22.42
minutes with the speed of 58 meter per minutes with an air flow of
9 bar. The optical fiber cable 200 is blown to the next distance
from 1150 meter to 1200 meter in 23.36 minutes with the speed of 60
meter per minutes with an air flow of 9 bar. The optical fiber
cable 200 is blown to the next distance from 1200 meter to 1250
meter in 24.36 minutes with the speed of 58 meter per minutes with
an air flow of 9 bar. The optical fiber cable 200 is blown to the
next distance from 1250 meter to 1300 meter in 25.35 minutes with
the speed of 55 meter per minutes with an air flow of 9 bar. The
optical fiber cable 200 is blown to the next distance from 1300
meter to 1350 meter in 26.40 minutes with the speed of 55 meter per
minutes with an air flow of 9 bar. The optical fiber cable 200 is
blown to the next distance from 1350 meter to 1400 meter in 27.39
minutes with the speed of 55 meter per minutes with an air flow of
10 bar. The optical fiber cable 200 is blown to the next distance
from 1400 meter to 1450 meter in 28.40 minutes with the speed of 53
meter per minutes with an air flow of 10 bar. The optical fiber
cable 200 is blown to the next distance from 1450 meter to 1500
meter in 29.47 minutes with the speed of 53 meter per minutes with
an air flow of 10 bar. The optical fiber cable 200 is blown to the
next distance from 1500 meter to 1550 meter in 30.50 minutes with
the speed of 52 meter per minutes with an air flow of 11 bar. The
optical fiber cable 200 is blown to the next distance from 1550
meter to 1600 meter in 31.55 minutes with the speed of 50 meter per
minutes with an air flow of 11 bar. The optical fiber cable 200 is
blown to the next distance from 1600 meter to 1650 meter in 33.03
minutes with the speed of 45 meter per minutes with an air flow of
11 bar. The optical fiber cable 200 is blown to the next distance
from 1650 meter to 1700 meter in 34.17 minutes with the speed of 45
meter per minutes with an air flow of 12 bar. The optical fiber
cable 200 is blown to the next distance from 1700 meter to 1750
meter in 35.22 minutes with the speed of 50 meter per minutes with
an air flow of 12 bar. The optical fiber cable 200 is blown to the
next distance from 1750 meter to 1800 meter in 36.28 minutes with
the speed of 46 meter per minutes with an air flow of 12 bar. The
optical fiber cable 200 is blown to the next distance from 1800
meter to 1827 meter in 37.05 minutes with the speed of 50 meter per
minutes with an air flow of 13 bar.
[0078] The optical fiber cable 200 passed the test. The average
speed calculated for blowing the optical fiber cable 200 was 50.97
meter per minute.
[0079] Test Cable 2: 288f mini cable with an average diameter of
10.2 mm.
[0080] The second cable for the test includes the mini optical
fiber cable. The type of tube used for the mini optical fiber cable
is 18/14 mm. The route used for the mini optical fiber cable
includes a distance of 1900 meter. The number of fiber in the mini
optical fiber cable is 288. The data corresponding to the test
results of the mini optical fiber cable includes distance, time,
speed and air flow of the blowing operation.
[0081] The mini optical fiber cable is blown to a distance of 50
meter in 1.03 minutes with a speed of 50 meter per minute. The mini
optical fiber cable is blown to the next distance from 50 meter to
100 meter in 2.11 minutes with the speed of 44 meter per minutes.
The mini optical fiber cable is blown to the next distance from 100
meter to 150 meter in 3.28 minutes with the speed of 38 meter per
minutes. The mini optical fiber cable is blown to the next distance
from 150 meter to 200 meter in 4.56 minutes with the speed of 37
meter per minutes with an air flow of 5 bar. The mini optical fiber
cable is blown to the next distance from 200 meter to 250 meter in
6.21 minutes with the speed of 33 meter per minutes with an air
flow of 7 bar. The mini optical fiber cable is blown to the next
distance from 250 meter to 300 meter in 7.34 minutes with the speed
of 50 meter per minutes with an air flow of 8 bar. The mini optical
fiber cable is blown to the next distance from 300 meter to 350
meter in 8.41 minutes with the speed of 44 meter per minutes with
an air flow of 8 bar. The mini optical fiber cable is blown to the
next distance from 350 meter to 400 meter in 9.58 minutes with the
speed of 38 meter per minutes with an air flow of 8 bar. The mini
optical fiber cable is blown to the next distance from 400 meter to
450 meter in 11.08 minutes with the speed of 44 meter per minutes
with an air flow of 9 bar. The mini optical fiber cable is blown to
the next distance from 450 meter to 500 meter in 12.23 minutes with
the speed of 38 meter per minutes with an air flow of 9 bar. The
mini optical fiber cable is blown to the next distance from 500
meter to 550 meter in 13.47 minutes with the speed of 35 meter per
minutes with an air flow of 9 bar. The mini optical fiber cable is
blown to the next distance from 550 meter to 600 meter in 14.58
minutes with the speed of 43 meter per minutes with an air flow of
10 bar. The mini optical fiber cable is blown to the next distance
from 600 meter to 650 meter in 16.12 minutes with the speed of 40
meter per minutes with an air flow of 10 bar. The mini optical
fiber cable is blown to the next distance from 650 meter to 700
meter in 17.26 minutes with the speed of 40 meter per minutes with
an air flow of 10 bar. The mini optical fiber cable is blown to the
next distance from 700 meter to 750 meter in 18.34 minutes with the
speed of 42 meter per minutes with an air flow of 11 bar. The mini
optical fiber cable is blown to the next distance from 750 meter to
800 meter in 19.46 minutes with the speed of 42 meter per minutes
with an air flow of 11 bar. The mini optical fiber cable is blown
to the next distance from 800 meter to 850 meter in 21.02 minutes
with the speed of 40 meter per minutes with an air flow of 11 bar.
The mini optical fiber cable is blown to the next distance from 850
meter to 900 meter in 22.21 minutes with the speed of 40 meter per
minutes. with an air flow of 11 bar. The mini optical fiber cable
is blown to the next distance from 900 meter to 950 meter in 23.36
minutes with the speed of 45 meter per minutes with an air flow of
13 bar. The mini optical fiber cable is blown to the next distance
from 950 meter to 1000 meter in 24.52 minutes with the speed of 38
meter per minutes with an air flow of 13 bar. The mini optical
fiber cable is blown to the next distance from 1000 meter to 1050
meter in 26.12 minutes with the speed of 37 meter per minutes with
an air flow of 13 bar. The mini optical fiber cable is blown to the
next distance from 1050 meter to 1100 meter in 27.36 minutes with
the speed of 38 meter per minutes with an air flow of 13 bar. The
mini optical fiber cable is blown to the next distance from 1100
meter to 1150 meter in 29.00 minutes with the speed of 35 meter per
minutes with an air flow of 13 bar. The mini optical fiber cable is
blown to the next distance from 1150 meter to 1200 meter in 30.27
minutes with the speed of 35 meter per minutes with an air flow of
13 bar. The mini optical fiber cable is blown to the next distance
from 1200 meter to 1250 meter in 32.00 minutes with the speed of 33
meter per minutes with an air flow of 13 bar. The mini optical
fiber cable is blown to the next distance from 1250 meter to 1300
meter in 33.35 minutes with the speed of 31 meter per minutes with
an air flow of 13 bar. The mini optical fiber cable is blown to the
next distance from 1300 meter to 1350 meter in 35.12 minutes with
the speed of 31 meter per minutes with an air flow of 13 bar. The
mini optical fiber cable is blown to the next distance from 1350
meter to 1400 meter in 36.53 minutes with the speed of 30 meter per
minutes with an air flow of 13 bar. The mini optical fiber cable is
blown to the next distance from 1400 meter to 1450 meter in 38.34
minutes with the speed of 29 meter per minutes with an air flow of
13 bar. The mini optical fiber cable is blown to the next distance
from 1450 meter to 1500 meter in 40.22 minutes with the speed of 29
meter per minutes with an air flow of 13 bar. The mini optical
fiber cable is blown to the next distance from 1500 meter to 1550
meter in 42.12 minutes with the speed of 29 meter per minutes with
an air flow of 13 bar. The mini optical fiber cable is blown to the
next distance from 1550 meter to 1600 meter in 44.03 minutes with
the speed of 28 meter per minutes with an air flow of 13 bar. The
mini optical fiber cable is blown to the next distance from 1600
meter to 1650 meter in 45.57 minutes with the speed of 28 meter per
minutes with an air flow of 13 bar. The mini optical fiber cable is
blown to the next distance from 1650 meter to 1700 meter in 48.03
minutes with the speed of 25 meter per minutes with an air flow of
13 bar. The mini optical fiber cable is blown to the next distance
from 1700 meter to 1750 meter in 50.24 minutes with the speed of 22
meter per minutes with an air flow of 13 bar. The mini optical
fiber cable is blown to the next distance from 1750 meter to 1800
meter in 53.00 minutes with the speed of 19 meter per minutes with
an air flow of 13 bar. The mini optical fiber cable is blown to the
next distance from 1800 meter to 1824 meter in 54.31 minutes with
the speed of 19 meter per minutes with an air flow of 13 bar.
[0082] The mini optical fiber cable with 288 fibers failed the
test. The mini optical fiber cable failed in the test due to the
slow speed. The average speed calculated for blowing the mini
optical fiber cable was 34.90 meter per minute.
[0083] Test Cable 3: 24f mini cable with an average diameter of 4.3
mm.
[0084] The third cable for the test includes the mini optical fiber
cable. The type of tube used for the mini optical fiber cable is
10/7 mm. The route used for the mini optical fiber cable includes a
distance of 1900 meter. The number of fiber in the mini optical
fiber cable is 24. The data corresponding to the test results of
the mini optical fiber cable includes distance, time, speed and air
flow of the blowing operation.
[0085] The mini optical fiber cable is blown to a distance of 50
meter in 0.56 minutes with a speed of 65 meter per minute. The mini
optical fiber cable is blown to the next distance from 50 meter to
100 meter in 1.42 minutes with the speed of 65 meter per minutes.
The mini optical fiber cable is blown to the next distance from 100
meter to 150 meter in 2.34 minutes with the speed of 65 meter per
minutes. The mini optical fiber cable is blown to the next distance
from 150 meter to 200 meter in 3.27 minutes with the speed of 50
meter per minutes with an air flow of 0 bar. The mini optical fiber
cable is blown to the next distance from 200 meter to 250 meter in
4.32 minutes with the speed of 60 meter per minutes with an air
flow of 1 bar. The mini optical fiber cable is blown to the next
distance from 250 meter to 300 meter in 5.27 minutes with the speed
of 60 meter per minutes with an air flow of 1 bar. The mini optical
fiber cable is blown to the next distance from 300 meter to 350
meter in 6.23 minutes with the speed of 50 meter per minutes with
an air flow of 2 bar. The mini optical fiber cable is blown to the
next distance from 350 meter to 400 meter in 7.23 minutes with the
speed of 60 meter per minutes with an air flow of 3 bar. The mini
optical fiber cable is blown to the next distance from 400 meter to
450 meter in 8.27 minutes with the speed of 50 meter per minutes
with an air flow of 3 bar. The mini optical fiber cable is blown to
the next distance from 450 meter to 500 meter in 9.26 minutes with
the speed of 50 meter per minutes with an air flow of 4 bar. The
mini optical fiber cable is blown to the next distance from 500
meter to 550 meter in 10.31 minutes with the speed of 50 meter per
minutes with an air flow of 5 bar. The mini optical fiber cable is
blown to the next distance from 550 meter to 600 meter in 11.36
minutes with the speed of 50 meter per minutes with an air flow of
5 bar. The mini optical fiber cable is blown to the next distance
from 600 meter to 650 meter in 12.36 minutes with the speed of 50
meter per minutes with an air flow of 6 bar. The mini optical fiber
cable is blown to the next distance from 650 meter to 700 meter in
13.47 minutes with the speed of 50 meter per minutes with an air
flow of 7 bar. The mini optical fiber cable is blown to the next
distance from 700 meter to 750 meter in 14.52 minutes with the
speed of 45 meter per minutes with an air flow of 7 bar. The mini
optical fiber cable is blown to the next distance from 750 meter to
800 meter in 16.02 minutes with the speed of 40 meter per minutes
with an air flow of 7 bar. The mini optical fiber cable is blown to
the next distance from 800 meter to 850 meter in 17.02 minutes with
the speed of 55 meter per minutes. with an air flow of 8 bar. The
mini optical fiber cable is blown to the next distance from 850
meter to 900 meter in 18.05 minutes with the speed of 50 meter per
minutes. with an air flow of 8 bar. The mini optical fiber cable is
blown to the next distance from 900 meter to 950 meter in 19.06
minutes with the speed of 50 meter per minutes with an air flow of
9 bar. The mini optical fiber cable is blown to the next distance
from 950 meter to 1000 meter in 20.12 minutes with the speed of 60
meter per minutes with an air flow of 10 bar. The mini optical
fiber cable is blown to the next distance from 1000 meter to 1050
meter in 21.13 minutes with the speed of 45 meter per minutes with
an air flow of 10 bar. The mini optical fiber cable is blown to the
next distance from 1050 meter to 1100 meter in 22.15 minutes with
the speed of 60 meter per minutes with an air flow of 11 bar. The
mini optical fiber cable is blown to the next distance from 1100
meter to 1150 meter in 23.07 minutes with the speed of 52 meter per
minutes with an air flow of 11 bar. The mini optical fiber cable is
blown to the next distance from 1150 meter to 1200 meter in 24.14
minutes with the speed of 45 meter per minutes with an air flow of
11 bar. The mini optical fiber cable is blown to the next distance
from 1200 meter to 1250 meter in 25.21 minutes with the speed of 50
meter per minutes with an air flow of 12 bar. The mini optical
fiber cable is blown to the next distance from 1250 meter to 1300
meter in 26.32 minutes with the speed of 53 meter per minutes with
an air flow of 13 bar. The mini optical fiber cable is blown to the
next distance from 1300 meter to 1350 meter in 27.13 minutes with
the speed of 50 meter per minutes with an air flow of 13 bar. The
mini optical fiber cable is blown to the next distance from 1350
meter to 1400 meter in 28.47 minutes with the speed of 42 meter per
minutes with an air flow of 13 bar. The mini optical fiber cable is
blown to the next distance from 1400 meter to 1450 meter in 30.07
minutes with the speed of 28 meter per minutes with an air flow of
13 bar. The mini optical fiber cable is blown to the next distance
from 1450 meter to 1500 meter in 31.40 minutes with the speed of 33
meter per minutes with an air flow of 13 bar. The mini optical
fiber cable is blown to the next distance from 1500 meter to 1550
meter in 33.20 minutes with the speed of 28 meter per minutes with
an air flow of 13 bar. The mini optical fiber cable is blown to the
next distance from 1550 meter to 1600 meter in 35.19 minutes with
the speed of 25 meter per minutes with an air flow of 13 bar. The
mini optical fiber cable is blown to the next distance from 1600
meter to 1632 meter in 36.48 minutes with the speed of 25 meter per
minutes with an air flow of 13 bar.
[0086] The mini optical fiber cable with 24 fibers passed the test.
The average speed calculated for blowing the mini optical fiber
cable was 51.16 meter per minute.
[0087] It may be noted in reference with the above mentioned
embodiments, performance and test results of 288 fiber optical
fiber cable 200 (FIG. 2) (included above as part of table-1,
table-2 and table-3 embodiments) that the 192 fiber optical fiber
cable 100 (FIG. 1) shows similar blowing performance results as 288
fiber optical fiber cable 200. The blowing performance of 192 fiber
optical fiber cable 100 is similarly optimized as 288 fiber optical
fiber cable 200. Further, those skilled in the art would appreciate
that the 192 fiber optical fiber cable 100 (FIG. 1) is similarly
optimized as 288 fiber optical fiber cable 200 (FIG. 2) as both the
optical fiber cable (100, 200) use similar dual layer buffer
tubes.
[0088] Further, it may be noted that in FIG. 1, the optical fiber
cable 100 includes eight buffer tubes; and in other embodiment, the
optical fiber cable 200 includes twenty four buffer tubes; however,
those skilled in the art would appreciate that more or less number
of buffer tubes are included in the optical fiber cable 100.
[0089] The micro optical fiber cable has numerous advantages over
the prior art. The micro optical fiber cable is easy to installer
in small ducts. The optical fiber cable includes a dual layer of
buffer tubes with low thickness of polycarbonate and polybutylene
terephthalate. The dual layer buffer tubes can be used for other
configurations with 250 micron optical fibers and 200 micron
optical fibers to reduce cable diameter which in turn improves the
blowing performance. The small diameter of optical fiber cable
enables easier installation of the micro optical fiber cable in the
small ducts. Further, the small diameter increases the blowing
performance of the micro optical fiber cable.
[0090] The foregoing descriptions of pre-defined embodiments of the
present technology have been presented for purposes of illustration
and description. They are not intended to be exhaustive or to limit
the present technology to the precise forms disclosed, and
obviously many modifications and variations are possible in light
of the above teaching. The embodiments were chosen and described in
order to best explain the principles of the present technology and
its practical application, to thereby enable others skilled in the
art to best utilize the present technology and various embodiments
with various modifications as are suited to the particular use
contemplated. It is understood that various omissions and
substitutions of equivalents are contemplated as circumstance may
suggest or render expedient, but such are intended to cover the
application or implementation without departing from the spirit or
scope of the claims of the present technology.
* * * * *