Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4439—Auxiliary devices
  • G02B6/4471—Terminating devices ; Cable clamps
  • G02B6/4472—Manifolds
  • G02B6/4473—Three-way systems
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4401—Optical cables
  • G02B6/4415—Cables for special applications
  • G02B6/4427—Pressure resistant cables, e.g. undersea cables
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4439—Auxiliary devices
  • G02B6/4471—Terminating devices ; Cable clamps
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
  • G02B6/4401—Optical cables
  • G02B6/4415—Cables for special applications
  • G02B6/4427—Pressure resistant cables, e.g. undersea cables
  • G02B6/4428—Penetrator systems in pressure-resistant devices

Definitions

• the present invention relates to the field of submarine fiber-optic communications systems and, in particular, to a passive branching joint assembly for connecting three or more fiber-optic cables together.
• submarine fiber-optic cable communications systems are but one type of telecommunication system
• submarine fiber-optic cables are capable of carrying a greater number of data and voice transmissions than traditional submarine cable systems or modern satellite communication systems.
• submarine fiber-optic cables lie on the ocean's floor, thousands of feet below sea level. Because no one cable could be made that extended thousands of miles in length, submarine fiber-optic cable communication systems are comprised of a series of submarine fiber-optic cables that are spliced together at cable joints. In this manner, many individual cables can be connected to form a single cable of the required length.
• each cable is comprised of a series of optic fibers clustered around a steel "king" wire. Together, these wires form the fiber-optic "core" of the cable.
• the fiber-optic core itself is surrounded by steel strength members and two watertight, insulating jackets (an inner copper jacket and an outer polyethylene jacket) encase the entire assembly.
• the function of the optic fibers is to carry the data and voice transmissions sent over the fiber-optic cable; the steel wires in conjunction with the insulating jackets, carry any loads placed upon the cable and give the cable its rigidity.
• a cable joint is used to connect two or more cables together.
• two-cable joints were formed by "terminating" the two cables in separate terminating sockets and connecting the two terminating sockets with a load-bearing fiber storage tray or cylinder.
• the individual optic fibers of the cables were then spliced together and secured in the storage tray and the entire subassembly was then covered with a steel jacket and "insulated” to keep it waterproof.
• Cable terminating technology is well-known in the prior art.
• the idea behind cable terminating is to secure the load-bearing steel members of the fiber optic cable, including both the steel strength members and the steel king wire, to a terminating socket so that any load placed upon the steel members would be transferred to the terminating socket.
• the fragile optic fibers of the cable would completely pass through the terminating socket.
• the steel strength members are terminated by stripping off the cable's protective insulation, separating the strength members from the fiber-optic core, and slipping the steel members and the core through the center of the terminating socket.
• a copper jacket and a steel plug are then placed over the fiber-optic core and the steel plug is firmly wedged into the terminating socket. In this way, the steel strength members are secured against the interior surface of the terminating socket, while the fiber-optic core passes freely through the socket.
• the individual optic fibers are separated from the king wire and the king wire is attached to a king wire clamp.
• the king wire clamp is also connected to the terminating socket, or is connected to a load-bearing fiber storage tray that is attached to the terminating socket, the end result of these two processes is that all load-bearing steel members of the fiber-optic cable are secured to the terminating socket.
• branch joint assembly Such an arrangement will have at least one trunk cable and at least two branch cables.
• branch cable joints are assembled using a modified branching repeater body.
• Branch repeater bodies are designed for used in powered systems, but the associated electronics are unnecessary in unpowered systems.
• branching repeater bodies are typically modified for use in unpowered systems by removing the internal electronics. This practice is expensive and time- consuming.
• a branch assembly specifically designed for use with branching fiber optic cable joints.
• the present invention is a passive joint assembly which includes a cylindrical housing attached at each end to an end plate. Each end plate has at least one opening to accommodate one or more terminating sockets. Disposed within the housing is a fiber storage device which may either be attached to the housing or "floating" within the housing (i.e., non-load- bearing).
• a fiber optic cable extends through and is attached to a corresponding terminating socket.
• a fiber optic cable is terminated; the cable passes through the end plate, enters the terminating socket, and the steel strength wires of the fiber optic cable are secured to the terminating socket.
• the king wire of each cable is attached to a corresponding king wire clamp attached to each terminating socket or to the fiber storage device.
• the individual optic fibers of the cables are then spliced together and secured in the fiber storage device. Thus, all loads placed on the individual cables are carried through the end plates and the cylindrical housing rather than through the fiber storage device.
• FIG. 1 is a cross section of a passive joint assembly according to the preferred embodiment of the invention.
• FIG. 2 is a cross section of the passive joint assembly illustrated in
• FIG. 3 is a radial cross section of the passive joint assembly of FIG. 1.
• the present invention is a passive joint assembly for use with fiber- optic cables.
• the present invention may be used with both armored and unarmored cables, the preferred embodiment of the invention is for use with unarmored submarine fiber-optic cables.
• the passive joint assembly 10 includes a cylindrical housing 20 which accommodates a fiber storage device 30 within the housing.
• the housing 20 has a branch end 40 and a trunk end 50.
• the trunk end 50 of the housing 20 has a radially inward extending flange 60.
• the housing 20 is designed to withstand external hydrostatic pressures when the joint assembly 10 is placed on the ocean floor.
• the housing 20 is designed to withstand tensile and torsional loading when the cables are being deployed.
• the fiber storage device 30 can be a cylinder or a tray and has at least three king wire clamps 70 attached to corresponding terminating sockets 100.
• a branch end endplate 80 having two openings 90 to accommodate two terminating sockets 100 is securely attached with pins 137 to the branch end of the housing 40, as shown in FIG. 3.
• the branch end endplate 80 has a shoulder 110 which rests on the branch end of the housing 40.
• a trunk end endplate 120 having a single opening 90 to accommodate a terminating socket 100 is attached to the trunk end of the housing 50.
• the trunk end endplate 120 is threaded on its outer edge 125 and has a shoulder 130 that rests against the inner surface of the flange 60 of the trunk end of the housing.
• a threaded ring 135 is threaded over the trunk end endplate 120 and tightened to secure the trunk end endplate 120 against the flange 60 of the housing 20.
• the fiber storage device 30 is attached to the endlates 80, 120 in an axially slidable manner by set screws (not shown).
• An o-ring 127 is disposed between the trunk end endplate 120 and the fiber storage device 30 to limit and cushion the motion of the fiber storage device 30 and to compensate for axial tolerance build-up.
• Each endplate 80, 120 is covered by a cover plate 140 which acts to make a more uniform surface for the joint assembly 10 to facilitate application of an insulating jacket 150.
• the insulating jacket 150 is applied to make the joint water-tight and to electrically isolate the joint from the surrounding water.
• Each terminating socket 100 has a radially outward flange 160 at one end which prevents the socket 100 from being pulled out of the housing 20 through the end plates 80, 120.
• the terminating sockets 100 have a cylindrical passageway 170 that extends longitudinally through the socket 100 to a flared region 180.
• a fiber optic cable 190 is inserted through cylindrical passageway 170 of the terminating socket 100 and is attached to the terminating socket 100 by splaying the steel wires 200 surrounding the fiber optic core (not shown) and inserting a tapered copper jacket 220 and steel plug 230 over the core.
• the copper jacket 220 and steel plug 230 are then pushed into the flared region 180 of the terminating socket 100 so the steel wires 200 of the cable are secured between the surfaces of the flared region 180 of the terminating socket 100 and the jacket/plug 220/230.
• the king wire of the fiber optic cable 240 is then connected to a corresponding king wire clamp 70 which is attached to a terminating socket 100 and extends into the fiber storage device 30.
• the individual optic fibers of each cable (not shown) are connected in the desired manner.
• the spliced optic fibers are then stored in a fiber storage device 30.
• the passive joint assembly 10 is encased in a premolded, heat shrinkable insulating jacket 150 made of a material such as a polyolefin.
• the insulating jacket includes a branch end portion 252 and a trunk end portion 254.
• Each portion 252, 254 is premolded to generally complement a corresponding outer configuration of the passive joint assembly 10 and a portion of the attached cables 190.
• the portions 252, 254 form an overlapped area 255 which is adhesively bonded together.
• each jacket portion 252, 254 may have a radial lip 260 which fits into a corresponding radial groove 262, 264 on the outer surface of the endplate 80 and threaded ring 135, respectively.
• the radial grooves 262, 264 and radial lip 260 can be positioned such that the radial grooves 262, 264 are located along the outer surface of the endplates 80, 120, housing 20 or threaded ring 135.
• the passive joint assembly 10 may additionally include an external cylinder 270 surrounding the joint assembly 10, to which are attached a pair of bend limiting boots 280, 282, wherein the bend limiting boot 280 at the branch end is configured to accommodate at least two cables 190.
• the terminating sockets, the pins, and the casing are all made out of high-strength steel.
• any suitable high strength material may be used.
• the fiber storage device can be constructed from inexpensive, lower strength materials such as aluminum or plastic.
• the fiber storage device can be made of a material which can withstand the processing temperatures for application of the insulating jacket.
• the present invention permits various interconnections between the three or more cables.
• a trunk cable can be joined to the branch end cables, or the branch end cables can be interconnected.
• connections can be made between any two or more cables.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Cable Accessories (AREA)
• Light Guides In General And Applications Therefor (AREA)
• Mechanical Coupling Of Light Guides (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=24975807

Family Applications (1)

Country Status (5)

Families Citing this family (2)

Family Cites Families (3)

• 1997
  • 1997-10-08 AU AU48970/97A patent/AU4897097A/en not_active Abandoned
  • 1997-10-08 WO PCT/US1997/018210 patent/WO1998019190A1/en not_active Application Discontinuation
  • 1997-10-08 JP JP52049398A patent/JP2002500778A/ja active Pending
  • 1997-10-08 EP EP97911654A patent/EP0941493A1/de not_active Withdrawn
  • 1997-12-01 TW TW086115786A patent/TW357275B/zh active

Non-Patent Citations (1)

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