U.S. patent application number 09/766704 was filed with the patent office on 2002-07-25 for cable repeater connecting joint.
Invention is credited to Girzone, William, Kordahi, Maurice.
Application Number | 20020097965 09/766704 |
Document ID | / |
Family ID | 25077253 |
Filed Date | 2002-07-25 |
United States Patent
Application |
20020097965 |
Kind Code |
A1 |
Kordahi, Maurice ; et
al. |
July 25, 2002 |
CABLE REPEATER CONNECTING JOINT
Abstract
A connector for a cable repeater includes a repeater including a
joint having two mutually perpendicular and intersecting axes of
rotation at one end thereof. A coupling includes a joint having two
mutually perpendicular and intersecting axes of rotation. A first
connecting link is pivotally connected at a first end thereof to
the repeater joint and secured at a second end thereof to the
coupling. A second connecting link is pivotally connected at a
first end thereof to the coupling joint and secured at a second end
thereof to a length of optical fiber cable. In preferred
embodiments, a bend limiting device is provided at the end of the
length of cable, with the second connecting link being secured at
its second end to the bend limiting device.
Inventors: |
Kordahi, Maurice; (Highland,
NJ) ; Girzone, William; (Bradley Beach, NJ) |
Correspondence
Address: |
John P. Maldjian
TyCom (US) Inc.
Rm 2B-106
250 Industrial Way West
Eatontown
NJ
07724
US
|
Family ID: |
25077253 |
Appl. No.: |
09/766704 |
Filed: |
January 22, 2001 |
Current U.S.
Class: |
385/100 ;
385/53 |
Current CPC
Class: |
G02B 6/3829 20130101;
G02B 6/4461 20130101; G02B 6/38875 20210501; G02B 6/3887
20130101 |
Class at
Publication: |
385/100 ;
385/53 |
International
Class: |
G02B 006/44; G02B
006/36 |
Claims
1. A connector for connecting an optical fiber repeater to a length
of optical fiber cable, comprising: a first joint, said first joint
attached to an end of the repeater; a coupling, said coupling
having a second joint; a first connecting link, said first
connecting link attached at a first end thereof to the first joint
and attached to the second end thereof to the coupling; a second
connecting link, said second connecting link attached at a first
end thereof to the second joint, and attached at a second end
thereof to a portion of the cable segment; wherein one of said
first joint and said second joint includes first and second axes of
rotation that are perpendicular to one another, and the other of
said first joint and said second joint includes at least one axis
of rotation being substantially parallel to the first axis of
rotation of said one of said first joint and said second joint.
2. The connector according to claim 1, wherein said first joint
includes: a first ring secured to the repeater; a second ring
pivotally connected to the first ring by a first pivot axis
structure; and a second pivot axis structure secured to the second
ring, the second pivot axis structure pivotally connecting the
first connecting link to the second ring.
3. The connector according to claim 2, wherein the first pivot axis
structure of the first joint comprises a pair of spaced-apart
coaxial pins opposite one another on the first and second rings,
and the second pivot axis structure of the first joint comprises a
pair of coaxial pins opposite one another on the second ring.
4. The connector according to claim 1, wherein the second joint
comprises a coupling ring pivotally secured to the coupling by a
first coupling pivot axis structure, the second connecting link
pivotally connected to the coupling ring by a second coupling pivot
axis structure.
5. The connector according to claim 4, wherein the first pivot axis
structure of the second joint comprises a pair of coaxial pins
opposite one another on the coupling.
6. The connector according to claim 5, wherein the second pivot
axis structure of the second joint comprises a pair of coaxial pins
opposite one another on the coupling ring.
7. The connector according to claim 1, wherein said first and
second connecting links are hollow permitting fibers to extend
therethrough.
8. A connector for connecting a cable repeater to an end portion of
an optical fiber cable segment, comprising: a first gimbal, said
first gimbal being coupled to said repeater; a second gimbal, said
second gimbal being spaced from said first gimbal; a first
connecting link coupled at a first end thereof to the first gimbal
and coupled at a second end thereof to the second gimbal; and a
second connecting link coupled at a first end thereof to the second
gimbal and coupled at a second end thereof to a portion of the
optical fiber cable segment; wherein said first gimbal permits
relative pivotal movement between the first connecting link and the
repeater about two axes and said second gimbal permits relative
pivotal movement between the first connecting link and the second
connecting link about two axes.
9. The connector according to claim 8, further comprising a bend
limiting device secured to and encompassing a portion of the
optical fiber cable segment, the second connecting link being
secured at its second end to the bend limiting device.
10. The cable system according to claim 9, further comprising a
boot surrounding the bend limiting device and extending along the
length of optical fiber cable segment.
11. The connector according to claim 8, wherein said first and
second connecting links comprise hollow members configured to carry
fibers from the end portion of the optical fiber cable segment to
the repeater.
12. The connector according to claim 11, wherein each of the first
and second gimbals includes first and second pairs of spaced apart
pivot pins providing an opening therebetween enabling optical
fibers to extend through said openings.
13. The connector according to claim 8, wherein said first and
second gimbals providing relative motion between a longitudinal
axis of the repeater and a longitudinal axis of the optical fiber
cable in excess of 55.degree..
14. The connector according to claim 13, wherein the bend angle of
the first gimbal as measured between a longitudinal axis of the
repeater and a longitudinal axis of the first connecting link is
limited to approximately 50.degree. or less and the bend angle of
the second gimbal as measured between a longitudinal axis of the
first connecting link and a longitudinal axis of the optical fiber
cable is limited to approximately 50.degree. or less.
15. The connector according to claim 13, wherein second gimbal
provides relative motion between a longitudinal axis of the first
connecting link and a longitudinal axis of the optical fiber cable
in excess of 20.degree..
16. The connector according to claim 8, wherein the first and
second gimbals provide for a bend angle of up to approximately
75.degree. between a longitudinal axis of the repeater and a
longitudinal axis of the cable.
17. A fiber optical cable network system comprising: a plurality of
repeaters, each repeater having a repeater gimbal at each end
thereof; a plurality of couplings, each coupling having a coupling
gimbal therein; a plurality of fiber optic cable segments; a
plurality of first connecting links, each first connecting link
pivotally connected at a first end thereof to a respective repeater
gimbal and secured at a second end thereof to a respective
coupling; a plurality of bend limiting boot assemblies, each bend
limiting boot assembly enclosing a portion of an end of a
respective fiber optic cable segment; and a plurality of second
connecting links, each second connecting link pivotally connected
at a first end thereof to a respective coupling gimbal and secured
at a second end thereof to a respective bend boot assembly.
18. The cable system according to claim 17, wherein said first and
second connecting links each comprises a hollow member configured
to carry optical fibers from a respective repeater to a respective
fiber optic cable segment.
19. The connector according to claim 17, wherein each of a
corresponding repeater gimbal and coupling gimbal together provide
for a bend angle in excess of 55.degree. between a longitudinal
axis of the repeater and a longitudinal axis of a corresponding
bend limiting boot assemblies.
20. The connector according to claim 19, wherein the bend angle of
each repeater gimbal as measured between a longitudinal axis of its
respective repeater and a longitudinal axis of its respective first
connecting link is limited to approximately 50.degree. or less and
the bend angle of each couple gimbal as measured between a
longitudinal axis of its respective first connecting link and a
longitudinal axis of its respective optical fiber cable segment is
limited to approximately 50.degree. or less.
21. The connector according to claim 17, wherein coupling gimbal
provides relative motion between a longitudinal axis of its
respective first connecting link and a longitudinal axis of its
respective optical fiber cable segment in excess of 20.degree..
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is related to U.S. patent application Ser.
No. 09/669,638, filed Sep. 26, 2000, and entitled "Multi-Body
Modular Repeater System and Articulated Housing for Use Therein",
and which is hereby incorporated by reference herein.
FIELD OF INVENTION
[0002] The present invention is directed to joints connecting cable
repeaters to lengths of fiber optic cable, and, more particularly,
to a connecting joint for a cable repeater having improved bending
capability.
BACKGROUND
[0003] Fiber optic cable laid undersea is typically required to
traverse great distances. Cable repeaters are well known to be
placed in-line at desired intervals along the cable to receive,
amplify, and retransmit the signal being carried by the cable. A
bend limiting device, having a rubber boot, is typically secured to
the end of the cable. The repeater is connected to the bend
limiting device, with connecting optical fibers extending through
the bend limiting device. To deploy the fiber optic cable, it is
coiled onto large drums on a ship. Consequently, the repeaters
become wrapped about the drums along with the cable. Due to the
nature of the signals, and the ever increasing amount of
information being transmitted in the optical fibers, repeaters are
getting larger, and their increased length creates problems as they
are coiled around a drum. Although the drums may be up to 9-12 feet
in diameter, current repeaters may approach 51/2 feet in length,
and, therefore, are not able to lie flat, or even substantially
flat, along a drum. Tremendous stresses due to forces on the order
of up to 100,000 pounds are encountered at the connection point
between the repeater and the fiber optic cable to which it is
attached, especially during paying out and reeling in of the
cable.
[0004] Consequently, a gimbal may be provided at each longitudinal
end of the repeater, to which the bend limiting devices are
attached. A gimbal, as used herein, refers to a device having two
mutually perpendicular and intersecting axes of rotation. A gimbal
provides free angular movement in two directions. The bend angle
allowed by the gimbal between the repeater and bend limiting device
is limited to approximately 50.degree. or less as exceeding this
angle at a pivot point can damage the optical fibers.
[0005] A repeater for attachment to a fiber optic cable and its end
connecting structure as known in the prior art are shown in FIG. 1.
Repeater 2 has a cone 5 enclosing each end thereof (only one end is
shown for simplicity), and a gimbal 4 contained within cone 5.
Gimbal 4 is formed of a first ring 6 secured to the cone 5 of the
repeater 2. A second ring 8 sits within and is pivotally connected
to first ring 6 by a pair of coaxial pins 10, only one of which is
visible in the drawing. The axes of pins 10 are perpendicular to a
longitudinal axis L of repeater 2. A connecting link 12 is
pivotally connected at a first end thereof to the second ring 8 by
a pair of coaxial pins 14, only one of which is visible. The common
axis of pins 14 extend perpendicular to the common axis of pins 10,
and pins 14 move in a plane which is perpendicular to the common
axis of pins 10 as ring 8 pivots about pins 10. Connecting link 12
is connected at its second end to a bend limiting device 16. A bend
limiting device 16 is located at the end of a boot 19 proximate the
repeater 2. The end of a segment of a fiber optic cable 17,
excluding the optical fibers thereof, is attached to and housed
within the boot 19, as seen in FIG. 3. Optical fibers 46, as seen
in FIG. 4, extend through the connecting link 12 to carry signals
to the repeater 2. The bend limiting device 16 prevents the
relative rotation between the repeater 2 and the boot 19 from
exceeding a predetermined maximum bend angle a by abutting with the
first ring 6 or another part of the gimbal 4 when the predetermined
maximum bend angle a is reached. This in turn prevents the fibers
46 from becoming damaged. A commonly used maximum bend angle a
between the longitudinal axis L of repeater 2 and the longitudinal
axis B of bend limiting device 16 allowed by gimbal 4 is
approximately 50.degree., thereby limiting the ability to wrap
repeater 2, and fiber optic cable 17 to which it is attached,
around a drum for effective deployment.
[0006] It is an object of the present invention to provide a cable
repeater connecting joint which reduces or wholly overcomes some or
all of the aforesaid difficulties inherent in prior known devices.
Particular objects and advantages of the invention will be apparent
to those skilled in the art, that is, those who are knowledgeable
or experienced in this field of technology, in view of the
following disclosure of the invention and detailed description of
preferred embodiments.
SUMMARY
[0007] The principles of the invention may be used to advantage to
provide a cable repeater connecting joint having improved bending
capability for fiber optic cable systems. A repeater is connected
by a pair of joints and a coupling to a bend limiting boot
assembly. In a preferred arrangement, each of the joints have two
mutually perpendicular and intersecting axes of rotation. The bend
limiting boot assembly encloses an end of a length of cable. Such a
connecting system increases the ability to wrap the cable with its
attached in-line repeater and associated structure around a drum by
reducing the critical bend without sacrificing strength or
exceeding any predetermined optical fiber bend limits.
[0008] In accordance with a first aspect, a connector for
connecting a cable repeater to a length of cable includes a cable
repeater having a joint. The cable repeater joint has two mutually
perpendicular and intersecting axes of rotation. A coupling has a
joint having two mutually perpendicular and intersecting axes of
rotation. A first connecting link is pivotally connected at a first
end thereof to the cable repeater joint and secured at a second end
thereof to the coupling. A second connecting link is pivotally
connected at a first end thereof to the coupling joint and secured
at a second end thereof to a length of cable.
[0009] In accordance with another aspect, a connector for
connecting a cable repeater to a length of cable includes a cable
repeater having a first gimbal. A coupling has a second gimbal. A
first connecting link is pivotally connected at a first end thereof
to the first gimbal and secured at a second end thereof to the
coupling. A second connecting link is pivotally connected at a
first end thereof to the second gimbal and secured at a second end
thereof to a length of cable.
[0010] In accordance with yet another aspect, a cable system
includes a plurality of repeaters. Each repeater has a repeater
gimbal at each end thereof. Each of a plurality of couplings has a
coupling gimbal therein. The cable system also includes a plurality
of first connecting links. Each first connecting link is pivotally
connected at a first end thereof to a repeater gimbal and secured
at a second end thereof to a coupling. A plurality of bend limiting
devices is also provided. Each bend limiting device encloses an end
of a length of cable. Each of a plurality of second connecting
links is pivotally connected at a first end thereof to a coupling
gimbal and secured at a second end thereof to a bend limiting
device.
[0011] From the foregoing disclosure, it will be readily apparent
to those skilled in the art, that is, those who are knowledgeable
or experienced in this area of technology, that the present
invention provides a significant advance. Preferred embodiments of
the cable repeater connecting joint of the present invention can
provide improved bending capability and, consequently, reduce the
stress encountered as a repeater and cable to which it is attached
are wrapped around a drum. These and additional features and
advantages of the invention disclosed here will be further
understood from the following detailed disclosure of preferred
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Preferred embodiments are described in detail below with
reference to the appended drawings wherein:
[0013] FIG. 1 is a diagrammatic perspective view of a cable
repeater of the prior art connected to a bend limiting device with
a gimbal;
[0014] FIG. 2 is a diagrammatic perspective view of a connecting
joint of the present invention shown connecting a cable repeater to
a bend limiting device;
[0015] FIG. 3 is a diagrammatic elevation view of the connecting
joint of FIG. 2, showing the cable repeater, connecting joint and
length of cable wrapped around a drum; and
[0016] The figures referred to above are not drawn necessarily to
scale and should be understood to present a representation of the
invention, illustrative of the principles involved. Some features
of the cable repeater connecting joint depicted in the drawings
have been enlarged or distorted relative to others to facilitate
explanation and understanding. The same reference numbers are used
in the drawings for similar or identical components and features
shown in various alternative embodiments. Cable repeater connecting
joints as disclosed herein, will have configurations and components
determined, in part, by the intended application and environment in
which they are used.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0017] As shown in FIG. 2, a connecting joint 3 in accordance with
the invention comprises a repeater 2 having a longitudinal axis L.
A cone 5 encompasses each end of repeater 2, only one end of
repeater 2 being shown here. In a preferred embodiment, connecting
joint 3 includes a gimbal 4. A gimbal, as used herein, refers to a
device having two mutually perpendicular and intersecting axes of
rotation. A gimbal provides free angular movement within limits in
two directions. Gimbal 4 is of conventional construction and is
secured within cone 5 of repeater 2. It is to be appreciated that
another gimbal 4 (not shown here) is located within the cone 5 at
the other end of repeater 2. Gimbal 4 includes a first ring 6
secured within cone 5. A second ring 8 is pivotally connected to
first ring 6 by a pivot axis structure, preferably a pair of pins
10, only one of which is visible in the drawing. Pins 10 are
axially aligned with one another, each pin 10 extending through
first and second rings 6, 8 on opposite sides of first and second
rings 6, 8. A first connecting link 12 is pivotally connected at a
first end thereof to second ring 8 by a pivot axis structure,
preferably a pair of pins 14 coaxially positioned on opposite sides
of second ring 8 and extending into first connecting link 12. The
common axes of pins 14 extend perpendicular to the common axes of
pins 10, and pins 14 move in a plane perpendicular to the axes of
pins 10 as second ring 8 rotates about pins 10. The second end of
first connecting link 12 is secured to a coupling 18 having a
longitudinal axis C.
[0018] Coupling 18 includes a substantially cylindrical housing 20
having a longitudinal axis C and a gimbal 22 secured therein. As
can be seen in FIGS. 3 and 4, longitudinal axis C of coupling 18 is
also the longitudinal axis C of first connecting link 12. Gimbal 22
includes a ring 24 pivotally connected to housing 20 by a pivot
axis structure, preferably a pair of coaxial pins 26, only one of
which is visible, positioned on opposite sides of housing 20 and
ring 24. The common axes of pins 26 extend perpendicular
longitudinal axis C. A second connecting link 28 is pivotally
connected at a first end thereof to ring 24 by a pivot axis
structure, preferably a pair of coaxial pins 30, only one of which
is visible. Each pin 30 extends through ring 24 into second
connecting link 28, the two pins 30 being on opposite sides of ring
24. The common axes of pins 30 extend perpendicular to the common
axes of pins 26, and pins 30 move in a plane perpendicular to the
axes of pins 30 as ring 24 rotates about pins 26. Second connecting
link 28 is secured at a second end thereof to bend limiting device
16. Bend limiting device 16 encloses an end of a length of cable
17, with the optical fibers 46 of the cable 17 extending therefrom
and to the repeater 2. As seen in FIGS. 3 and 4, the bend limiting
device 16, the housing 20 of the gimbal 22, and an external load
bearing surface on the repeater 2, such as on ring 6, are designed
to effectively absorb and transfer tensile forces and to limit the
bending of the optical fibers 46. A boot 19, preferably formed of
rubber and seen more clearly in FIG. 3, extends from bend limiting
device 16 partially along the length of cable 17. A bend limiting
boot assembly refers to the boot 19 and any bend limiting devices
16 or surfaces associated with the boot.
[0019] The improved bending capability of connecting joint 3 is
seen more clearly in FIG. 3, where repeater 2, connecting joint 3,
bend limiting device 16 and cable 17 are shown wrapped around a
drum 21. Gimbal 4 provides a maximum bend angle .beta. between
longitudinal axis L of repeater 2 and longitudinal axis C of
coupling 18 of up to approximately 50.degree.. Gimbal 22 provides a
maximum bend angle .DELTA. between longitudinal axis C of coupling
18 and longitudinal axis B of bend limiting device 16 of up to
approximately 25.degree.. Thus, the total maximum bend angle
.theta. for connecting joint 3, that is, the maximum bend angle
between the longitudinal axis L of repeater 2 and the longitudinal
axis B of bend limiting device 16 is up to approximately
75.degree.. This provides a much greater amount of flexibility for
wrapping lengths of cable with in-line repeaters around the drum
than prior art devices, reducing stress and possible breakage and
degradation of the optical cable.
[0020] In a preferred embodiment, connecting links 12, 28 are
preferably formed any suitable corrosion resistant, high-strength
material such as coated steel or beryllium-copper to provide
protection for the fibers carried therein and to transfer and
absorb high tensile forces. Further, this connecting joint 3
reduces the concentration of maximum stress as compared to the
prior art connection joint of FIG. 1 as the stress forces between
the repeater 2 and the boot 19 are distributed over two points as
opposed to being concentrated solely at a single point.
Additionally, by providing connecting joint 3 with two gimbals 4
and 22, the joint advantageously prevents twisting of joint 3 and
connecting fibers 46 while still allowing angular movement in two
mutually perpendicular directions. It is also recognized that the
two gimbal joints 4 and 22 need not be used and a single axis
pivoting joint may be used instead of either of the gimbals 4 and
22. Such would still maintain a dual, spaced, pivot axis
arrangement.
[0021] In a preferred embodiment, the ends of repeater 2 and bend
limiting device 16 are provided with grooves 40, 42, respectively.
A flexible bellows (not shown) may be used to cover connecting
joint 3, with grooves 40, 42 receiving respective flanges or
shoulders of the flexible bellows. Suitable fasteners, such as
clamps, may then be used to secure the bellows to repeater 2 and
bend limiting device 16.
[0022] While the maximum bend angle values of .beta., .DELTA., and
.theta. listed above correspond to one preferred embodiment,
advantages of the present invention can be achieved with other
contemplated bend angle values. For example, it is contemplated
that the total maximum bend angle .theta. can be any one of
numerous angles, including all angles between
50.degree.-100.degree., such as 55.degree., 60.degree., 65.degree.,
70.degree., 75.degree., and 80.degree., and still obtain
significant advantages over the prior art. Further, it is also
contemplated that the maximum bend angle .DELTA. between the
longitudinal axis B of the boot 19 and the longitudinal axis C of
the gimbal 22 need not be less than that of the maximum bend angle
.beta. between the longitudinal axis L of the repeater 2 and the
longitudinal axis C the gimbal 22, and the values of each of the
maximum bend angle .DELTA. and .beta. may be any positive
angle.
[0023] In light of the foregoing disclosure of the invention and
description of the preferred embodiments, those skilled in this
area of technology will readily understand that various
modifications and adaptations can be made without departing from
the scope and spirit of the invention. All such modifications and
adaptations are intended to be covered by the following claims.
* * * * *