Patent Application
20190072736
The present invention generally relates to connection systems for telecommunication cables, and more particularly to a high density optical fiber distribution system used to cross-connect and interconnect optical fibers used in telecommunications, the system providing an on-frame splicing compartment with dedicated splice storage for a preterminated optical fiber termination block assembly.
In the field of telecommunications, conventional copper wires are being replaced by optical fiber transmission lines. Thus, it is necessary to provide a distribution and organizing facility for the fiber-optic cables at appropriate locations within exchanges inside telecommunication companies, office buildings or cabinets in the outside plant.
Typical distribution systems or optical distribution frames are used in the central office of telecommunication companies as manual patch panels for connecting outside plant optical cables with central office equipment. Conventional optical distribution frames are typically large and/or specialized frame structures to provide access points for the optical network to allow the inter connection to optical equipment, other optical network equipment and/or to customer lines. The connections are made in optical fiber termination blocks, which are structures containing optical connection modules and optical devices.
The optical connection modules connect optical fibers of a main cable (the so-called network cable) and/or of distribution cables (station cables) to cables running to the customer or to an optical device. Alternatively, the optical connection modules can be used for interconnecting optical fibers of two or more distribution cables. Often, the optical termination modules also contain storage space for spare length of optical fiber to facilitate removal/replacement of bad or underperforming connections with new, more stable connections. Optical devices, on the other hand, perform functions within the network such as splitting (passive optical device) or amplification (active optical device). The optical connection modules generally comprise a housing, a cassette supported by the housing for stowing optical fibers, optical fiber splices, and/or optical devices, and an optical connector patch panel.
Installation of this type of terminal block can be a complex process requiring splices to be made in each optical connection module in the termination block.
As telecommunication companies migrate from copper networks to optical fiber networks, they need to accommodate the infrastructure for both the existing copper network and the incoming newer fiber network. However, space within the central offices is usually limited. Thus, what is needed is an easy to install high density fiber distribution system that is both modular and expandable to allow for staged installation of the system and that can be accommodated on existing rack and frame structures rather than requiring the specialized frame systems.
The present invention is a high density optical fiber distribution system having preterminated optical fiber termination block. In particular, the exemplary fiber distribution frame includes a rack, a preterminated optical fiber termination block assembly mounted to the frame, wherein the preterminated optical fiber termination block assembly includes a plurality of termination modules configured to connect optical fiber connectors disposed on a first end of a multi-fiber stub cable with adapter mounted in a face of each termination module, and a splicing compartment mounted on the rack configured to interconnect a second end of the multi-fiber stub cable to a distribution cable, wherein the splicing compartment comprises a plurality of drawers containing optical splices and wherein each drawer of the splicing compartment can be correlated to one of the preterminated optical fiber termination block assembly. In one aspect, there is a one-to-one correlation between one of the plurality of drawers in the splicing compartment and the preterminated optical fiber termination block assembly mounted to the frame.
The present invention will be further described with reference to the accompanying drawings wherein like reference numerals refer to like parts in the several views, and wherein:
While the invention is amenable to various modifications and alternative forms, and specifics thereof have been shown by way of the drawings and will be described herein in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims.
In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “forward,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.
The present invention is directed to a high density fiber distribution system which utilizes a standard telecommunication rack commonly used in the industry today. The exemplary high density fiber distribution system, described herein, is modular and provides a higher density of connections than is currently available. In particular, system comprises the preterminated optical fiber termination blocks having a plurality of termination modules configured to connect optical fiber connectors disposed on a first end of a multi-fiber stub cable with adapter mounted in a face of each termination module and an on frame splicing compartment with dedicated splice storage for the preterminated optical fiber termination block.
The preterminated optical fiber termination block assembly 140 is an optical fiber termination block 141 that has been preterminated with a stub cable 160.
Stub cable 160 can be prepared from a high fiber count cable section. In one aspect, a section of indoor riser rated 144 fiber cable containing twelve 12 fiber ribbons in a loose tube can be used to make the stub cable, such a Ribbon Fiber Cable, Riser, 144 F, Single-mode (OS2), available from Corning, Inc. (Hickory, N.C.). In another aspect, a section of indoor riser rated 144 fiber cable containing twelve loose buffer tubes, each containing twelve 250 or 900 micron optical fibers tube, can be used to make the stub cable, such as ezDISTRIBUTION™ Indoor Tight Buffered Riser, 144 color-coded 900 μm tight buffered fibers into a single flame retardant cable, available from Prysmian Group (Lexington S.C.). Other high count optical fibers can be used to prepare stub cable 160. These high fiber count cables are generally stiff. The protection of the jacked cable can be utilized in areas where the fibers could be subject to damage from external forces and where there is sufficient space to accommodate the cable bend radius. However a more flexible stub cable is generally desired when considering slack storage and accessing the optical fiber termination block and the integrated splicing compartment.
Exemplary stub cable 160 includes a plurality of optical fibers 161 having optical fiber connectors 170 mounted on one end thereof. In an exemplary aspect, the optical fiber connectors can be standard format optical fiber connectors such as LC optical fiber connectors or SC optical fiber connectors. The stub cable can include several sections including a high fiber count semi-rigid protected portion 164, a high fiber count flexible routing portion 162, a furcation/fanout device 166, and a plurality of low fiber count protected portions 168.
To make an exemplary stub cable 160 from a section of indoor riser rated 144 fiber cable containing twelve 12 fiber ribbons inside a central tube (not shown), the outer cable jacket and central tube are removed from a first end for about 60-80% of the length of the cable section to expose the loose tubes. The fiber ribbons are then inserted through a piece of flexible expandable braided tubing (¼ in. ID) without damaging any of the optical fiber within the tubes. The expandable braided tubing is slid all the way up over the cable jacket and is secured in place with a piece of 3:1 heat shrink (for example, a 4″-6″ piece) creating the high fiber count flexible routing portion 162 of the cable stub 160. When two or more stub cables are used to feed a high density optical fiber termination block, different color flexible expandable braided tubing can be used to differentiate between the stub cables.
Next, about 4 ft. of the cable jacket and central tube surrounding the twelve 12 fiber ribbons is removed from the opposite end of the cable section to expose the twelve 12 fiber ribbon. Each of the 12 fiber ribbons can be separated into individual optical fibers, each of which is fed through a color coded 900 micron loose buffer tubing contained inside an overall protective flexible jacketing. A section of the flexible jacketing of desired length is removed to expose each of the 900 micron loose buffer tubing and each optical fiber can be terminated with a SC (or LC) optical fiber connector. After this has been done to each ribbon fiber, the 12 900 μm loose buffer tubes can be placed in a protective tube that is slid up against the unstripped section of the stub cable (i.e. the high fiber count semi-rigid protected portion 164 shown in
The configuration of high density fiber optic distribution system 100 enables the patch cords and jumper cables to be handled predominantly on one side of the frame (e.g. the front side of the frame), while the stub cables and the distribution cables are handled on the other side of the frame (e.g. the backside of the frame).
The distribution cables include a large number of optical fibers disposed within a cable jacket. The optical fibers can be in the form of individual 250 micron or 900 micron fibers disposed in loose tubes or as ribbon fibers disposed in loose tubes. For example, an 864 fiber distribution cable can include twelve 12 fiber ribbons disposed in six loose tubes. In addition, distribution cables can include one or more strength rods which stiffen the cable. To facilitate the routing of the optical fibers of the distribution cable, its terminal end is modified to increase its flexibility and handling. For example, when an indoor/outdoor, dry, loose tube ribbon cable construction, such as an ALTOS Ribbon all dielectric cable, 576 fiber or an ALTOS Ribbon all dielectric cable, 864 fiber available from Corning, INC. (Corning N.Y.), is used for the distribution cable, about 25 feet of cable jacket and the 6 loose tubes are removed. A piece of flexible protective furcation tubing 52 is installed over each of the 144 fiber ribbon stacks until it covers the retained loose buffer tube. The flexible furcation tube can be secured to the loose buffer tube of the distribution cable by a piece of tape. Next, a section of heatshrink tubing can be positioned over the transition region of the buffer tube and flexible furcation tubing distribution cable and shrunk in place to permanently secure the flexible furcation tubing in place creating a distribution cable furcation. This process is repeated for each buffer tube/144 fiber ribbon stack.
Referring to
Optical fiber termination block cable assembly 140 can be installed on a frame and the high fiber count semi-rigid protected portion 164 can be attached/clamped to the fiber termination block, for example optical fiber termination block 141a, with bracket 90 and to the frame using a bracket 92, as shown in
A manifold bracket 96 can be attached to frame 110 and a splice compartment manifold 98 can be disposed on the splicing compartment 120 near the back of the splicing compartment. Each of the manifolds has a number of openings equal to the number of drawers in the splicing compartment. A piece of plastic tubing 80 extends from an opening in the splicing compartment manifold to a corresponding opening in the frame manifold bracket. In an exemplary aspect, a piece of plastic corrugated flexible tubing can be used. One furcation tubing 52 from the distribution cable 50 and the high fiber count flexible routing portion 162 of the cable stub 160 from each optical fiber termination block 141 is routed through the corrugated tubing to the integrated splicing compartment. Once furcation tubing 52 and flexible routing portion 162 have been fed through the plastic tubing they can enter the splicing compartment as described below.
In the exemplary embodiment, high density fiber optic distribution system 100 has one splicing compartment 120 and six optical fiber termination block cable assemblies 140, shown as optical fiber termination blocks 141a-141f in
Referring to
The preterminated optical fiber termination block assembly 140 is an optical fiber termination block 141 that has been preterminated with a stub cable 160. The pre-terminated optical fiber termination block according to the present invention can be attached to one of the vertical support members 118b (e.g. vertical support member 118b) of rack 110 by a mounting structure 142 and a frame-like structure 144 attached to the mounting structure that can receive a plurality of optical termination modules 150. The mounting structure can be attached to the bracket by mechanical fasteners such as by bolts 109 (
A plurality of routing plates 145 can be pivotally attached to the frame-like structure 144 of the optical fiber termination block in order to enable individual access to the individual routing plates and the optical termination modules 150 attached thereto by rotating them from their closed position (shown in
The pivot axis 147 of the routing plate can be preferably arranged at an extremity of the routing plate 145 at a front portion of frame-like structure 144, so that the routing plate, when pivoted into an open position, gives easy access to the fibers within the optical termination module and/or on routing plate. The pivot axis of each routing plate can have any acceptable hinge structure that allows the routing plate to pivot in a direction perpendicular to the surface of the routing plate. In the figures, the pivot axis of optical fiber termination block is disposed on the left side of the optical fiber termination block 141. In an alternative embodiment, a mirror image of optical fiber termination block 141 is contemplated which has its pivot axis on the right side of the optical fiber termination block.
Each routing plate 145 can be preferably be adapted to guide optical fibers or optical fiber ribbons from the stub cable into the optical termination module 150 as well as storing slack of the low fiber count protected portion(s) 168 of the stub cable 150 containing the optical fibers and ribbons to be connected in the attached optical termination module. In an exemplary aspect, each routing plate can also include a jumper strain relief device 146, shown in
Jumper strain relief device 146 includes a base plate 146a and a strain relief arm 146b that is rotationally attached to the base plate. The arm moves from a closed or strain relief position (
Advantageously, the shape of the strain relief arm 146b prevents the kinking or pinching to of the jumper cables 190 during the opening and closing of the strain relief arm or the rotating of routing plate 145 to access optical termination 150. Retention tabs 146g, 146h on the strain relief arm and the baseplate, respectively, ensure that all the jumper cables are retained in the jumper strain relief device 146 so that they do not interfere with the ability to access other optical termination modules 150 and routing plates 145. In an exemplary aspect the pathway through the jumper strain relief device is sized to accommodate the number of patch cables needed to fully connect the optical termination module. For example, the pathway through jumper strain relief device 146 shown in
This jumper strain relief device allows the rotation of the routing plates from a closed position to an open position while minimizing the tensile stress on the jumper cables to stress due to the swinging of the optical termination module out of the frame-like structure of optical fiber termination block 141, while also controlling bending radius of the jumper cables within a desired range.
Advantageously, high density fiber optic distribution system 100 also separates the many smaller, more fragile jumper cables 190 from the stub cables 160 (see
Tray side walls 152b, 152c extend from the ends of the front tray wall 152a toward the back of the tray where they curve toward the interior of the optical termination module and end before contacting the back tray wall 152d. The back portion of the optical termination module is somewhat wider than the front portion of the optical termination module and the back tray wall 152d extend across the back portion of the tray and part way down the sides of the tray creating the fiber access ways 153 on both sides of the optical termination module for the optical fibers to enter the optical termination module.
Optical termination module 152 can include connection means such as receptacles slots 154, hooks, slotted protrusions, latches, catches etc. that are configured to mate with corresponding features on the edge of the routing plate 145 to allow attachment of the optical termination module to the routing plate. As mentioned, the optical termination module can be removably attached to the routing plate in which case the routing plate can accommodate excess sufficient slack of the low fiber count protected portions 168 of stub cable 160 as shown in
The low fiber count protected portions enters the optical termination module through the fiber access way 153 adjacent to routing plate 145. The low fiber count protected portion can be secured in the fiber access way by placing a cable tie 95 around the protective tubing of the low fiber count protected portion, as shown in
In one exemplary aspect, splicing compartment 120 can allow twelve fiber ribbon splice capacity (Fusion and/or mechanical splicing) for up to 1728 fibers without requiring a separate off-frame splice cabinet providing significant space and monetary savings to the datacenter/central office owner. Because the splicing compartment is disposed on the same frame as the optical fiber termination blocks, much shorter stub cables are needed which also eliminates the need for storing excess lengths of the stub cables.
For example, splicing compartment 120 can have six splice drawers 125A-125F that correspond to the six optical fiber termination blocks 141a-141f, wherein each splice drawer corresponds to one of the six optical fiber termination blocks. In one aspect, each drawer 125 of the splicing compartment has a splice capacity which corresponds to the connection capacity of one of the optical fiber termination block. In addition, each splice drawer can accommodate storage of excess lengths of the high fiber count flexible routing portion 162 of the stub cable from the optical fiber termination block assembly as well as excess lengths of the flexible to furcation tubing 52 containing fiber ribbons 59 from the distribution cable as shown in
Splicing compartment 120 can also include a plurality of reticulated arms 128 wherein each reticulated arm corresponds to one of the splice drawers 125 and wherein each reticulated arm serves as a fiber management channel for optical fibers and optical fiber ribbons or optical fiber cables entering the corresponding splice drawer of the splicing compartment. In an exemplary aspect, each drawer in the splicing compartment has a corresponding reticulated arm extending between the backside of the drawer to one of the side walls of the splicing compartment such as side wall 121c shown in
Referring to
In one exemplary aspect, at least one of the plurality of low fiber count protected portions enter each splice drawer along a reticulated arm disposed at the backside of each of the plurality of drawers.
Referring to
Once the flexible portions from the distribution cable and the stub cable have been fed through the corrugated tubing they can be secured to the reticulated arm with cable ties or hook and loop bundling tape and fed into the appropriate splice drawer in the splicing compartment through an inlet device.
To splice the stub cable and distribution cable fibers, first remove a section of the flexible braided tubing off of each set of ribbon fibers. The exposed fiber ribbons are placed in the splice tray in the drawer and each ribbon in the cable stub is spliced to a corresponding ribbon in the distribution cable with a multi-fiber splice device.
In an exemplary aspect, the top wall 121a of the splicing compartment 120 can be composed of two wall segments 123. A permanent wall segment 123a that create an enclosed space for the drawers and a removable wall segment 123b that covers reticulated arms 128. The removable wall segment is removed during installation of the exemplary fiber distribution system described herein and can be secured in place after installation is complete to protect the optical fibers disposed in the reticulated arms from external forces that may cause signal degradation or signal loss. In addition, the reticulated arm design allows storage of a sufficient amount optical fiber to ensure that the proper fiber bend radius is maintained during opening and closing of the splice drawer without causing any signal loss due to kinking, jamming or snagging of the optical fibers/ribbons entering the drawer.
Each splice drawer in the splicing compartment 120 can include a one or more splice trays to connect optical fibers in the stub cable to the optical fibers in a distribution cable. For example,
Alternatively, a plurality of optical fiber termination blocks can be correlated to a single splice drawer in the splicing compartment making a one to many correlation between each splice drawer in the splicing compartment and the optical fiber distribution blocks mounted on the frame. Alternatively in extreme high density cases or cases where the stub cable comprises a large number of discrete optical fibers, either a plurality of splice trays in a single drawer and/or a plurality of drawers may be used to splice fibers from a single optical fiber termination block.
The exemplary fiber distribution system describe herein has many advantages. The exemplary system can be used with a standard 19 in. rack/frame instead of requiring a specialized frame structure. The system can have a high connection density in a smaller footprint than many conventional systems. The system includes an integrated/built-in splicing compartment with modular drawers for each optical fiber termination block. All fiber splicing occurs in the integrated splicing compartment eliminating the need for off-frame splicing. Because all of the splicing is done in the integrated splicing compartment, shorter stub cables are needed and there is no inter-frame routing of the stub cables to be managed. This reduces the load and congestion in above rack cable raceways. The optical fiber termination block includes independent on-board jumper/patch cable strain relief for each optical termination module in the block. The system provides a modular system that allows optical fiber termination blocks to be added to the system as capacity needs increase. New optical fiber termination blocks can be added without disturbing existing service connections. Alternatively, the modularity of the exemplar system enables the use of other telecommunication on the frame/rack. The system also provides simplified integrated cable management for the distribution and stub cables on frame in separate cable management compartment on rear side of the jumper spool bay.
The built-in on rack splicing compartment of the present disclosure can save premium space in a telecommunication room rather than having to find floor space for a separate splicing cabinet. The exemplary system described herein can also reduce complexity of maintenance operations due to the very organized cabling system used and the fact that all of the interconnections between the distribution cable and the stub cable are done on the same frame where the optical termination blocks are mounted.
Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2017/050705 | 2/9/2017 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62308534 | Mar 2016 | US |
