Two-sided optical fiber management tray and method of use

An arrangement for a fiber optic distribution network includes a fiber management tray having a first major side and an opposite second major side. The arrangement also includes a fiber optic cable including optical fibers. The fiber optic cable has first and second jacketed sections and an unjacketed mid-span access location positioned between the first and second jacketed sections. The unjacketed mid-span access location can be managed by the fiber management tray with drop splicing being performed at the first major side of the tray and the remainder of the fiber management and splicing being performed at the second major side of the tray.

TECHNICAL FIELD

The present disclosure relates generally to components for managing optical fiber in a fiber optic communication network. More particularly, the present disclosure relates to optical fiber management trays used to manage optical fiber in a fiber optic communications network.

BACKGROUND

Fiber optic communication systems are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities (e.g., data and voice) to customers. Fiber optic communication systems employ a network of fiber optic cables to transmit large volumes of data and voice signals over relatively long distances. Fiber management is an important part of operating and maintaining an effective fiber optic communication system. Fiber management trays are commonly used to effectively manage and protect optical fiber in a fiber optic communication system. A typical fiber management tray provides splicing and fiber management functionality. Most fiber management trays are single-sided and fiber management trays are often arranged in a stack with the individual fiber management trays being pivotally mounted relative to one another. Example splice trays of this type are disclosed at U.S. Pat. Nos. 8,554,044 and 6,507,691.

SUMMARY

One aspect of the present disclosure relates to a two-sided fiber management tray that allows optical fibers to be stored and managed at opposite first and second major sides of the tray. In one example, the tray defines a fiber wraparound transition structure that allows optical fibers to be routed/transitioned between the first and second sides.

Another aspect of the present disclosure relates to a two-sided optical fiber management tray having opposite top/front and bottom/back sides. The optical fiber management tray is particularly well suited for managing optical fibers at a mid-span access location of a multi-fiber optical cable. At a mid-span access location, it is often desirable to access some of the optical fibers for splicing to drop cables while allowing the remainder of the optical fibers to pass through the mid-span access location without being accessed (e.g., cut and spliced to a drop cable or connected to an optical component such as a passive power splitter or a wavelength division multi-plexer).

When a tray in accordance with the principles of the present disclosure is used to manage a mid-span access location, pass-through fibers of the mid-span access location can be stored/managed on the back/bottom side of the tray and fibers of the mid-span access location desired to be accessed for splicing can be stored/managed at the top/front side of the tray. Buffer tubes containing optical fibers from the cable can be anchored to the bottom/back side of the tray and buffer tubes containing optical fibers corresponding to the drop cables can be anchored to the top/front side of the tray. A wraparound-style routing transition can be provided through the tray to permit the optical fibers intended to be spliced to drop cables to be routed from the bottom/back side of the tray to the top/front side of the tray. In this way, the optical fibers intended to be spliced are effectively separated/segregated from the pass-through fibers.

This type of arrangement is particularly well suited for a two stage deployment method where: a) an initial construction crew lays out the fiber distribution network and routes the splice fibers to the top/front of the tray and the pass-through fibers to the bottom/back of the tray; and b) a subsequent installation crew accesses the splice fibers for splicing to drop cables. The segregation of the splice fibers from the passthrough fibers ensures that the proper optical fibers are accessed for splicing during the installation stage.

In certain examples, the back side has sufficient area to hold passive optical components (e.g., passive optical power splitters, wavelength division multiplexers, etc.) that can be optically coupled to one or more of the optical fibers of the mid-span access location. The passive optical components can be either factory or field mounted. In certain example, splice holders can be provided at either the top/front or bottom/back side.

In certain examples, buffer tube fixation regions can be provided for fixing buffer tubes corresponding to pass-through cables and buffer tubes corresponding to drop cables to the tray. In certain examples, trays in accordance with the principles of the present disclosure can accommodate buffer tubes corresponding to up to twenty drop cables. In other examples, splice trays in accordance with the principles of the present disclosure can accommodate buffer tubes corresponding to more or less than twenty drop cables. In certain examples, trays in accordance with the principles of the present disclosure may eliminate the need for multiple trays thus reducing cost and simplifying installation practices.

In certain examples, splice trays in accordance with the principles of the present disclosure may simplify incorporating passive optical components into a splice terminal/splice enclosure.

In certain examples, the tray in accordance with the principles of the present disclosure can include a bottom side for supporting an optical component, such as an optical power splitter or wavelength division multiplexer, and a top side for facilitating drop cable splicing. In such an example, an optical fiber from a mid-span access location of a multi-fiber fiber optic cable can be spliced to the optical component at the bottom side of the tray. It will be appreciated that the optical component can provide splitting so as to have more outputs than inputs. Output fibers can be provided corresponding to the outputs. At least some of the output fibers from the optical component can be routed from the bottom side of the tray to the top side of the tray so as to be available for splicing to optical fibers corresponding to drop cables. Other output fibers from the optical component can be spliced to optical fibers corresponding to the multi-fiber cable such that signals can be fed in a downstream and/or upstream direction through the multi-fiber fiber optic cable.

A variety of additional aspects will be set forth in the description that follows. The aspects relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are explanatory only and are not restrictive of the broad inventive concepts upon which the examples disclosed herein are based.

DETAILED DESCRIPTION

The present disclosure relates generally to fiber management trays designed to reduce cost and simplify installation practices. The present disclosure also relates to fiber management trays configured to accommodate passive optical components such as optical power splitters and wavelength division multiplexers. The present disclosure also relates to fiber management trays suited for effectively managing the optical fibers of a mid-span access location of a multi-fiber optical cable. The present disclosure also relates to two-sided trays that allow for optical fibers storage and routing on opposite first (e.g., top/front) and second (e.g., bottom/back) major sides of the trays.

In certain examples, fiber management trays in accordance with the principles of the present disclosure can include a routing transition structure that permits fibers to be routed between opposite major sides of the trays. In certain examples, such routing transition structures can have a wraparound configuration that allows fibers to be laterally inserted into the transition structures thereby eliminating the need to insert (i.e., thread) free ends of the optical fibers axially through the transition structures. Thus, mid-span portions of the optical fibers can be inserted into the routing transition structures. In certain examples, fiber management trays in accordance with the principles of the present disclosure can have buffer tube fixation (i.e., anchoring) locations and can also have pre-defined fiber routing paths (e.g., one or more fiber loops). In certain examples, the pre-defined fiber-routing paths can be provided at both the first and second sides of the tray. The fiber routing paths can be defined by guides, walls, dividers, separators, and/or fiber bend radius limiters for guiding optical fibers along pre-defined routing paths and for preventing the optical fibers from being bent beyond pre-defined bend radius limitations.

In certain examples, fiber management trays in accordance with the principles of the present disclosure can include structures for mounting optical fiber splices and/or passive optical components on either the first or second major sides of the trays. The fiber guide structures can also support other routing paths such as a figure eight pattern and a partial loop.

Optical fiber management trays in accordance with the principles of the present disclosure can be particularly well suited for managing optical fibers at a mid-span access location of a multi-fiber optical cable. At a mid-span access location, it is often desirable to access some of the optical fibers of the multi-fiber optical cable for splicing to drop cables (e.g., cut and spliced to a drop cable or connected to an optical component such as a passive power splitter or a wavelength division multi-plexer) while allowing the remainder of the optical fibers to pass through the mid-span access location without being accessed. When a tray in accordance with the principles of the present disclosure is used to manage a mid-span access location, fibers of the mid-span access location desired to be accessed for splicing can be stored/managed at a first major side of the tray and pass-through fibers of the mid-span access location can be stored/managed on a second major side of the tray. Ends of buffer tubes protecting the optical fibers can be anchored to the tray (e.g., at either side of the tray). In one example, buffer tubes corresponding to optical fibers of the multi-fiber optical cable can be anchored to the second major side of the tray while buffer tubes protecting optical fibers corresponding to the drop cables can be anchored to the first major side of the tray. A wraparound-style routing transition can be provided through the tray to permit the optical fibers intended to be spliced to drop cables to be routed between the first and second major sides of the tray. In this way, the optical fibers of the multi-fiber cable intended to be spliced to drop cables at the mid-span location are effectively separated/segregated from the remainder of the optical fibers of the multi-fiber cable.

This type of arrangement is particularly well suited for a two-stage deployment method where: a) an initial construction crew lays out the fiber distribution network and routes the fibers intended to be spliced to drop cable fibers at the mid-span location to the top/front of the tray and the remainder of the optical fibers to the bottom/back of the tray; and b) a subsequent installation crew accesses the fibers for splicing to drop cables, and anchors buffer tubes corresponding to the drop cables to the front/top of the tray. The segregation of the fibers intended to be spliced to drop cables from the other optical fibers ensures that the proper optical fibers are accessed for splicing during the installation stage.

FIGS. 1-4illustrate a fiber management tray20in accordance with the principles of the present disclosure. The fiber management tray20is shown having a generally rectangular configuration. In the depicted example, the fiber management tray20is elongated along an axis22and includes a length L and a width W. The length L extends along the axis22and is longer than the width W.

The fiber management tray20has a top side26(seeFIGS. 1 and 3) and a bottom side28(seeFIGS. 2 and 4). The top side26can also be referred to as a front side and the bottom side28can also be referred to as a back side. The top and bottom sides26,28may also be referred to as first and second sides.

The fiber management tray20includes first and second ends30,32separated by the length L of the fiber management tray20. In certain examples, the first and second ends30,32can each include pivot mounts34(FIG. 2) for allowing either of the ends30,32to be pivotally connected to another structure such as a fiber optic terminal (e.g., a fiber optic splice terminal or other type of housing/enclosure). Mounting tabs36can also be provided adjacent the opposite first and second ends30,32of the fiber management tray20. The mounting tabs36can define fastener openings38(FIGS. 3 and 4) for using fasteners used to secure the fiber management tray20to a structure such as a terminal.

The fiber management tray20can also include buffer tube fixation regions40(i.e., anchoring regions) located adjacent each of the first and second ends30,32. The buffer tube fixation regions40can be configured for securing or otherwise attaching buffer tubes corresponding to pass-through cables and/or drop cables to the fiber management tray20. In certain examples, the fixation regions40can include structures for allowing buffer tubes to be clamped, tied, bound or otherwise attached to the fiber management tray20. In certain examples, the fixation regions40can include structures for receiving ties. In the depicted example, the fixation regions40include sets of openings48defined through a tray main body24for receiving ties (seeFIG. 3). In other examples, separate structures (e.g., members, rods, flanges, braces, etc.) can be attached to the tray and used to provide attachment points for secure buffer tubes to the tray via ties. In this way, the number of holes through the tray can be reduced to increase the strength of the tray.

FIGS. 23-26show an alternative anchoring configuration200having anchoring bars202that connect to the front/top of the main body of a fiber management tray200. In one example, the anchoring bars202connect to the main body of the tray by a snap-fit connection. The anchoring bars202include main support members204(i.e., main beams) that extend across the width of the tray and tie-down location members206(i.e., cantilevers) that project outwardly from the main support members204. The tie-down location members have lengths that extend along the length of the tray. In use, ties are routed under the tie-down members and used to strap/affix buffer tubes corresponding to drop cables to the tie-down members206. Sets of openings208through the main body of the tray can receive ties used to secure buffer tubes receiving the optical fibers of through-cables to the bottom/back side of the tray. As used herein, a buffer tube is a tube that receives and protects at least one optical fiber.

Referring back toFIGS. 1-4, as previously described, the fiber management tray20includes a top side26and a bottom side28. The tray main body24having a top surface42at the top side26of the fiber management tray20and a bottom surface44at the bottom side28of the fiber management tray20.

The top side26of the fiber management tray20is configured for storing, protecting, and routing optical fiber. For example, the top side26can include structure that defines one or more fiber routing paths. In certain examples, the fiber routing paths can define one or more fiber loops. In certain examples, the fiber routing paths can include a fiber management loop27that is elongated along the length L of the fiber management tray20so as to have a racetrack-type configuration.

Referring toFIGS. 1 and 3, top side26includes various structures that project upwardly from the top surface42of the main tray body24and that cooperate to define a protected fiber management path (e.g., a fiber management loop) at the top side26of the fiber management tray20. For example, the top side26of the fiber management tray20includes side walls50that project upwardly from the top surface42of the main tray body24. The side walls50can be generally parallel to one another and are positioned at opposite sides of the fiber management tray20. In the depicted examples, the side walls50extend along the length L of the fiber management tray20and define portions of a perimeter of the fiber management tray20. The top side26also includes end walls52that are positioned near the first and second ends30,32of the fiber management tray20and that extend generally across the width W of the fiber management tray20. The end walls52are curved and project upwardly from the top surface42of the main tray body24. The end walls52function as fiber guides and have curvatures compatible with minimum bend radius requirements of the fibers intended to be managed on the fiber management tray20. The end walls52define curved ends of the fiber management loop27defined by the top side26of the fiber management tray20and the side walls50define opposite sides of the fiber management loop27.

The fiber management loop27is also defined by inner fiber guide walls54. The inner fiber guide walls54project upwardly from the top surface42of the main tray body24and include portions that oppose the side walls54and portions that oppose the end walls52. The end walls52and the inner fiber guide walls54cooperate to define curved end channels56located at opposite ends of the loop27. The top side26of the fiber management tray20can also include structure for assisting and retaining fibers in the loop27. For example, tabs58project from the end walls52and oppose the top surface42and tabs60project inwardly from the side walls50and oppose the top surface42. The tabs58,60extend over fibers routed along the fiber management loop27so as to retain the fibers in the tray. Splice holder mounting locations80(e.g., receptacles) are provided for receiving and retaining splice holders used to hold splice sleeves that protect fusion splices between drop cables and fibers of a through cable.

Referring toFIGS. 2 and 4, the bottom side28of the fiber management tray20also includes a fiber management configuration for routing and storing optical fiber thereon. For example, the bottom side28of the fiber management tray20can include one or more optical fiber routing paths defined by one or more fiber guides, fiber guide walls, fiber guide channels, or other structures. In the depicted embodiment, the bottom side28of the fiber management tray20defines a fiber management path in the form of a fiber management loop29similar to the fiber routing loop27provided at the top side26of the fiber mounting tray28. For example, the bottom side28includes opposing side walls62that project downwardly from the bottom surface44of the main tray body24and extend along the length L of the fiber management tray20. In the depicted example, the side walls62are generally parallel and form opposite elongated sides of the fiber management loop path29provided at the bottom side28of the fiber management tray20. The bottom side28of the fiber management tray20also includes end walls64that project downwardly from the bottom surface44of the main tray body24. The end walls64extend across the width W of the fiber management tray20and define opposite ends of the fiber management loop path29. Inner fiber guide walls66project downwardly from the bottom surface44of the main tray body24and include portions that oppose the end walls64and portions that oppose the side walls62. In this way, the inner fiber guide walls66and the end walls64define curved end channels that delineate curved end portions of the fiber management loop29. The inner fiber guide walls66and the side walls62also define channel portions that extend along the sides of the fiber management loop29. A central platform61is provided for mounting optical components such as passive optical components (e.g., passive optical power splitters and wavelength division multiplexers). Hooks63can be provided for managing partial fiber loops.

The fiber management tray20further includes routing transition structures for transitioning optical fibers between the top and bottom sides26,28. In certain examples, the structures can have a “wraparound” configuration. Such a configuration allows optical fibers to be laterally inserted therein without requiring free ends of the optical fibers to be axially threaded through the structure. Referring toFIGS. 1-4, routing transition structures in the form of routing transition openings70are defined through the tray main body24for routing optical fibers between the top and bottom sides26,28of the fiber management tray20. The routing transition openings70are located adjacent the first and second ends30,32of the fiber management tray20and each include laterally open portions72for allowing fibers to be laterally inserted into the openings70. As depicted, the laterally open portions72are shown at the outer perimeter of the fiber management tray20. As depicted, the routing transition opening70includes a main region74for receiving optical fibers transitioned between the top and bottom sides26,28of the fiber management tray20, and an access portion76that allows the fibers to be laterally inserted into the main portion74. The access portion76is depicted as a slot having an open end at the periphery of the fiber management tray20. The open end of the access portion76coincides with the laterally open portion72.

It will be appreciated that directional terms such as top, bottom, upwardly, downwardly and like terms are used for description purposes only. It will be appreciated that in use, trays in accordance with the principles of the present disclosure can be mounted in any orientation.

When mounted within a terminal, in certain examples, a first side of the fiber management tray (e.g., the top side26) is more accessible than a second side (e.g., the bottom side28) of the fiber management tray20. For example, the tray20can be pivotally mounted to the terminal with the first side facing outwardly from a wall (e.g., the bottom of the enclosure or a side wall of the enclosure) while the second side faces toward the wall of the enclosure. In certain examples, the fiber management tray20can be pivotally mounted to the terminal and can be configured such that the first side of the fiber management tray20is readily accessible in a first pivot position, while the second side can only be accessed by pivoting the fiber management tray20relative to the terminal from the first position to a second position where the second side can be accessed. Normally, the fiber management tray20is in the first position. In certain examples, the tray20can pivot at least 180 degrees between the first and second positions. In certain examples, positive stops can be provided for positively stopping pivotal movement of the tray20at the first pivot position and at the second pivot position.

In certain examples, management of optical fibers of a multi-fiber cable that are intended to be spliced to drop cables is performed at the more accessible side of the fiber management tray20(e.g., the top side26) and management of the remainder of the optical fibers of the multi-fiber cable is performed at the less accessible side (e.g., the bottom side28) of the fiber management tray20. In certain examples, passive optical components (e.g., optical power splitters, wavelength division multiplexers, and other structures) can be mounted at the less accessible side (e.g., the bottom side28) of the fiber management tray20. In certain examples, pass-through fibers are managed at the less accessible side of the tray20and fibers intended to be accessed and spliced to drop cables are managed at the more accessible side of the tray. In certain examples, an optical fiber from the main multi-fiber cable can be accessed at the mid-span access location and spliced at the bottom side of the tray to an optical component such as a passive optical power splitter or wave division multiplexer device. Outputs of the optical component can be routed to the top side of the tray for splicing to drop cables. Outputs of the optical component can also be spliced at the bottom side of the tray to optical fibers of the mid-span access cable for forward feeding and/or back feeding signals through the main fiber optic cable.

It will be appreciated that the fiber management tray20is particularly well suited for use in managing optical fibers for pass-through and splicing applications. A typical fiber pass-through configuration includes a fiber optic cable having a mid-span portion that is managed by the fiber management tray20. In such an example, the cable has a jacket containing a plurality of optical fibers (e.g., 12 optical fibers). Generally, the jacket is stripped away from the optical fibers at the mid-span location and the fiber management tray20is used to manage the optical fibers at the mid-span location. In this way, the fiber management tray20protects and manages the optical fibers that are not protected by a cable jacket. The jacketed ends of the cable on opposite ends of the mid-span location are preferably anchored to a housing that encloses the tray20and the optical fibers between the jacketed ends of the cables are managed on the fiber management tray20. Buffer tubes can be used to protect the optical fibers as the optical fibers extend from the jacketed ends of the multi-fiber cable to the tray20. The ends of the buffer tubes corresponding to the optical fibers of the multi-fiber optical cable are typically anchored at the bottom side28of the fiber management tray20.

A sub-set of the total number of fibers of the cable are routed from the bottom side28of the fiber management tray20through one of the routing transition structures70to the top side26of the fiber management tray20. At the top side26of the fiber management tray20, the first sub-set of optical fibers is routed about the looped fiber management path27provided at the top side26of the fiber management tray20. The optical fibers not routed to the top side26of the fiber management tray20form a second sub-set of the optical fibers of the fiber optic cable. The second sub-set of optical fibers are managed at the bottom side28of the fiber management tray20. For example, the second sub-set of optical fibers are arranged in a loop around the fiber management loop path29provided at the bottom side28. As so configured, the fibers of the second sub-set of optical fibers are adapted to function as pass-through fibers that pass from the first section of optical cable, through the fiber management tray20, to the second section of fiber optic cable without splicing or any other type of interruption. The first sub-set of optical fibers provided at the top side26of the fiber management tray20are available for ready splicing to drop cables. For example, ends of buffer tubes corresponding to drop cables can be anchored to the top side26of the fiber management tray20at the fixation regions40. The first sub-set of optical fibers can be cut and spliced to the fibers of the drop cables at the top side26of the fiber management tray20. Splice holders for holding fusion splices (e.g., splice sleeves) between the fibers of the first sub-set of cable fibers and the drop cable fibers can be mounted at the top side26of the fiber management tray20. For example, the splice holders can be mounted at the splice holder mounting locations80positioned inside the boundary defined by the looped fiber storage path27.

Referring toFIGS. 3 and 4, a cable100having a jacket102and a plurality of optical fibers104is depicted. A portion of the jacket102has been removed to form a mid-span access location106of the cable100. The mid-span access location106is positioned between a first jacketed section100aof the cable100and a second jacketed section100bof the cable100. Ends of the first and second jacketed sections100a,100bcan be anchored to a housing that encloses the tray20. The ends of buffer tubes101that protect the optical fibers104as the optical fibers104extend from the jacketed sections100a,100bof the cable100to the tray20can be anchored to the fiber management tray20at the fixation region40adjacent the first end30of the fiber management tray20. In the depicted example, ties are used to anchor the ends of the buffer tubes101to the fiber management tray20. Unbuffered portions of the optical fibers104corresponding to the mid-span access location106can be managed by the fiber mounting tray20. For example, a first subset108of the optical fibers104(e.g., four optical fibers) are routed through the routing transition opening70to the top side26of the fiber management tray20. In certain examples, the first subset108of optical fibers can be managed at the bottom side28of the fiber management tray20(e.g., wrapped in a few loops about the looped cable management path29of the bottom side28) prior to routing the first subset of optical fibers108through one of the routing transition openings70to the top side26of the fiber management tray20. At the top side26of the fiber management tray20, the first subset108of the optical fibers104can be routed along the looped cable management path27provided at the top side26of the fiber management tray20. Thereafter, the first subset108of optical fibers104can be routed back from the top side26to the bottom side28through one of the transitional openings70. Thereafter, the first subset108of optical fibers104can be routed directly to the second jacketed section100bof the cable100or can be managed further at the bottom side28of the fiber management tray20before being routed to the second jacketed section100bof the cable100.

The remainder of the optical fibers104not routed to the top side26of the fiber management tray20form a second subset110of the optical fibers104and are managed at the bottom side28of the fiber management tray20. For example, the second subset110of optical fibers104can be routed along the looped fiber management path29defined by the bottom side28of the fiber management tray20. After looping about the fiber management path29of the bottom side28of the fiber management tray20, the second subset110of optical fibers104is routed to the second jacketed section100bof the cable100. In certain examples, the jacketed section100ais an upstream section of the cable100and the second jacketed section100bis a downstream section of the cable100. The second subset110of optical fibers104is not routed to the top side26of the tray20for any management.

In the configuration ofFIG. 3, the optical fibers104have been pre-installed on the fiber management tray20to facilitate the subsequent splicing of drop cables to the optical fibers. Specifically, the first subset108of optical fibers104have been pre-assigned as fibers suitable for being spliced to drop cables at the fiber management tray20. In contrast, the second subset110of optical fibers have been pre-assigned as pass-through fibers that merely pass through the mid-span access location106from the first jacketed section100aof the cable100to the second jacketed section100bof the cable100without being cut, spliced or otherwise accessed at the fiber management tray20.

When it is desired to add a drop cable, a technician can access one of the optical fibers104of the first sub-set108at the top side26of the fiber management tray20. Upon accessing the optical fiber104of the first sub-set108, optical fiber104is cut and spliced to a corresponding optical fiber120of a drop cable122(seeFIGS. 5 and 6). An end of a buffer tube103of the drop cable122can be anchored to the top side26of the fiber management tray20at one of the fixation regions40. The splice can be protected within a splice sleeve121that is held within a splice holder123. The splice holder can be mounted to the top side26of the fiber management tray20.

The buffer tubes101can each enclose twelve optical fibers and the cable100can include more than one buffer tube101. For example, the cable100can include two buffer tubes each containing twelve fibers with the ends of both buffer tubes101being anchored to the tray. Of course, cables having different numbers of fibers can be utilized and different counts of optical fibers can be managed by the top and bottom sides26,28of the fiber management tray20without departing from the principles of the present disclosure.

In other examples, the fiber management tray20can be used to manage optical components (e.g., optical splitters, wavelength division multiplexers, or other components) and can also be configured to facilitate drop cable splicing. In one example, an optical component having splitting capabilities is mounted to the bottom side28of the tray20. An optical fiber from a multi-fiber optical cable can be accessed at a mid-span access location of the multi-fiber cable and spliced to an input side of the optical component. The optical component can include a plurality of output fibers that receive split or otherwise separated signals from the input fiber. The split or otherwise separated signals can be split by optical power splitting or can be split based on wavelength. In one example, the optical component can provide a 1:8 split ratio, a 1:16 split ratio, or a 1:32 split ratio. At least some of the output fibers from the optical component can be routed from the bottom side28of the tray20to the top side26of the tray20so as to be readily accessible for splicing to drop cables at the top side of the tray. In certain examples, other fibers of the multi-fiber fiber optic cable can be used to distribute signals split at the optical component. For example, optical fibers of the multi-fiber fiber optic cable can be accessed (e.g., cut) at the mid-span access location106and spliced to the output fibers from the optical component at the bottom side28of the tray. In this way, it is possible to feed signals from the optical component from the tray20in a downstream direction through the downstream section of the multi-fiber fiber optic cable or in an upstream direction from the tray20through the upstream section of the multi-fiber fiber optic cable.

FIGS. 7-10illustrate another fiber management tray20ain accordance with the principles of the present disclosure. The fiber management tray20ahas the same basic configuration as the fiber management tray20except fixation regions40ahave been modified to include a staggered arrangement of tie openings configured for enhancing the density of buffer tubes supported by the fiber management tray20a.

FIGS. 11-14illustrate a further fiber management tray20bin accordance with the principles of the present disclosure. Fiber management tray20bhas the same basic configuration as the fiber management tray20. However, the fiber management tray20has fixation regions40bthat accommodate a fewer number of buffer tubes. Also, a loop path at a bottom side28bof the fiber management tray20bis elongated to occupy space previously occupied by anchoring locations in the earlier examples. Further, a fiber management arrangement at a top side26bof the fiber management tray20bincludes an elongated fiber management loop path that extends substantially along the entire length of the fiber management tray20b, and smaller, intermediate circular loop paths provided adjacent each end of the fiber management tray20b.

Also, the fiber management tray20bhas an alternative routing transition structure70bfor transitioning optical fibers between the top and bottom sides26b,28bof the fiber management tray20b. For example, the alternative transition structure70bis defined through the side walls of the fiber management tray20. For example, the transition structures include main portions74bdefined through the main tray bodies and access portions76bthat extend through the side walls. The access portions76bare open-ended and have open ends at the periphery of the tray.

FIGS. 15-18show another fiber management tray20cin accordance with the principles of the present disclosure. The fiber management tray20cis similar to previously described trays except the fiber management tray20cincludes one pair of routing transition structures70bthrough the side walls of the fiber management tray20and one pair of routing transition structures70located at the end of the fiber management tray20c.

FIGS. 19-22illustrate still another fiber management tray20din accordance with the principles of the present disclosure. The fiber management tray20dis similar to previously described embodiments except the fiber management tray20dincludes sets of routing transitioning structures70at both ends of the fiber management tray20dand two pairs of fiber transitioning structures70bdefined through the side walls at intermediate locations between the end fiber transition structures.

FIGS. 27 and 28illustrate a closure300that houses another fiber management tray20ein accordance with the principles of the present disclosure. It will be appreciated that the closure300can be used to house any of the fiber management trays20,20a,20b,20c,20d,20edisclosed herein and can be used for accommodating various fiber routing configurations at the mid-span location of a multi-fiber fiber optic cable. The closure300includes a bottom portion302(e.g., a bottom half-portion) and a top portion304(e.g., a top half-portion). The bottom and top portions302,304meet at a sealed interface that can be sealed by a perimeter gasket or other structure. The bottom and top portions302,304can be clamped together via side clamps306(e.g., perimeter latches) that compress the bottom and top portions302,304together to compress the gasket therein between for sealing. It will be appreciated that the side clamps306can be unlatched to provide access to the interior of the closure300. Thus, the closure300is readily re-enterable.

Referring toFIGS. 27-30, the closure300includes four end ports308for allowing fiber optic cables to be routed in and out of the closure300. The end ports308can be sealed by sealing components such as grommets310. It will be appreciated that the sealing elements can have different configurations to accommodate different cable types and shapes. For example, the sealing elements can include larger holes for accommodating multi-fiber fiber optic cables and smaller holes for accommodating drop cables. Depending on the type of cable used, the sealing element can be various shapes such as round or elongated. When the holes are not being occupied by a cable, plugs can be used to seal the holes. As depicted atFIG. 30, the grommets310are configured for receiving a plurality of drop cables312having an elongated transverse cross-sectional profile.

As best shown atFIGS. 28-31, a fiber management and cable anchoring assembly314is housed within the closure300. In the depicted example, the fiber management and cable anchoring assembly314is secured to the bottom portion302of the closure300and is readily accessible when the top portion304is removed from the bottom portion302of the closure300. The fiber management and cable anchoring assembly314includes a cable anchoring plate316, a tray mounting tower318, a pivot arm320and the fiber management tray20e. The cable anchoring plate316preferably has a robust construction (e.g., a metal construction) and can be fastened or otherwise secured to the bottom portion302of the closure300. The tray mounting tower318attaches to the cable anchoring plate316such that the components can function as a unit. As depicted, a middle portion322of the tray mounting tower318mounts beneath the cable anchoring plate316. The middle portion322can include attaching structures324for securing the cable anchoring plate316to the tray mounting tower318. In certain examples, the attaching structures324can have a snap-fit configuration or can have a keyed configuration or other type of interconnect structure. In the depicted embodiment, the attaching structures324are cross-shaped and fit through corresponding openings326defined through the cable anchoring plate316. Once the attaching structures324have been inserted through the openings326, the tower318can be slid relative to the cable anchoring plate316to move the attaching structures324to a retaining position.

The cable anchoring plate316is configured for anchoring fiber optic cables to the closure300. In certain examples, strength members of fiber optic cables routed through the end ports308can be fastened (e.g., with fasteners such as bolts or screws) otherwise secured to the cable anchoring plate316. In certain examples, the closure300manages both drop cables and mid-span access cables and all of the cables strength members that are anchored to the closure300through the cable anchoring plate316.

The tray mounting tower318functions to mount the fiber management tray20eto the closure300and to elevate the fiber management tray20eabove the cable anchoring plate316. The tray mounting tower318includes a latching post328located at one end of the middle portion322and a pivot mount post330positioned at the opposite end of the middle portion322. The latching post328and the pivot mount post330both extend well above the top side of the cable anchoring plate316. The pivot arm320functions to pivotally connect the fiber management tray20eto the pivot mount post330. When the closure300is closed, the fiber management tray20eis latched in a stowed position by the latch post328(seeFIG. 29). In the stowed position, the fiber management tray20eis generally parallel to the major top and bottom sides of the closure300with a gap being provided between the bottom side of the fiber management tray20eand the top side of the cable anchoring plate316. The spacing between the bottom side of the fiber management tray20eand the cable anchoring plate316provides space for routing and managing buffer tubes used to protect optical fibers as the optical fibers are routed from their corresponding fiber optic cables to the tray20e. With the fiber management tray20ein the stowed position and the top portion304of the closure300removed from the bottom portion302, the top side of the fiber management tray20eis accessible while the bottom side of the fiber management tray20eis inaccessible.

As described in previous embodiments, optical fibers can be routed on the fiber management tray20esuch that optical fibers suitable for splicing to drop cables are provided at the top side of the fiber management tray20ewhile pass-through fibers, optical components such as splitters or wavelength division multiplexers, and other structures can be provided at the bottom side of the fiber management tray20e. To access the bottom side of the fiber management tray20e, one end of the fiber management tray20eis released from the latching post320by allowing the fiber management tray20eto be pivoted relative to the pivot mount post330from the stowed position to an open position. In certain examples, the fiber management tray20epivots about a pivot axis332(FIG. 30) defined at the pivot mount post330and the fiber management tray20ecan pivot at least 180 degrees about the pivot axis332between the stowed position and the open position. In this manner, the bottom side of the tray20ecan be readily accessed when the tray20eis in the open position. In certain examples, the latching post328can include a resilient latch for latching the fiber management tray20ein the stowed position.

Referring toFIGS. 33-36, the fiber management tray20eis similar to previously described embodiments and includes fiber management structures on both sides of the tray, excess fiber storage structures and looping structures at both sides of the tray, routing transition structures for routing optic fibers between the top and bottom sides of the tray, buffer tube anchoring structures for anchoring buffer tubes to the top and bottom sides of the tray, and structures for attaching splice holders and optical components to the tray.

As shown atFIG. 31, an optical component such as a passive optical splitter334is attached to the bottom side of the fiber management tray20e. Also, a plurality of splice holders336are attached to the bottom side of the tray. Further, as shown atFIG. 30, plurality of splice holders338are attached to the top side of the tray. In an example configuration, the closure300can be used to provide fiber management, fiber protection, and optical splitting at a mid-span location of a multi-fiber cable.

In such an example, an upstream end section of the multi-fiber cable can be routed through one of the end ports308and a downstream end section of the multi-fiber cable can be routed through another one of the end ports308. A mid-span access location of the multi-fiber fiber optic cable can be managed within the closure300. Strength members corresponding to the upstream and downstream end portions of the multi-fiber fiber optic cable can be anchored to the cable anchoring plate316with fasteners. Buffer tubes corresponding to the fibers of the multi-fiber fiber optic cable can be managed in the region beneath the fiber management tray20eand can be routed to the fiber management tray20e. Ends of the buffer tubes can be secured (e.g., strapped) to the end of the fiber management tray20ethat is closest to the pivot access332. Optical fibers from the multi-fiber fiber optic cable can be managed at the bottom side of the fiber management tray20e. For example, at least one of the optical fibers can be cut and spliced to an input side of the passive optical splitter334. Output fibers from the passive optical splitter334can be routed through the routing transition structures from the bottom side of the fiber management tray20eto the top side of the fiber management tray20ewhere such output fibers are ready for easy splicing to drop cables. Other optical fibers from the multi-fiber fiber optic cable can be cut and spliced to the output fibers of the passive optical splitter334at the bottom side of the fiber management tray20e. Such splices can be held within the splice holder336. Such a configuration allows signals from the passive optical splitter334to be directed through either the upstream end section or downstream end section of the multi-fiber fiber optic cable.

It will be appreciated that drop cables312(FIG. 30) can also be routed through the end ports308. Strength members corresponding to the drop cables312can be attached to the cable anchoring plate316. Buffer tubes corresponding to the drop cables312can be managed in the region directly above the cable anchoring plate316. Ends of the buffer tubes corresponding to the drop cables312can be attached to the buffer tube anchoring locations at the top side of the fiber management tray20e. Buffer tubes of the multi-fiber fiber optic cable are preferably attached to the buffer tube anchoring locations at the bottom side of the fiber management tray20e. The optical fibers corresponding to the drop cables312can be spliced to the output fibers from the passive optical splitter334at the top side of the fiber management tray20e. The splices can be held within the splice holder338mounted at the top side of the fiber management tray20e.

FIGS. 39-43show an alternative enclosure300′ in accordance with the principles of the present disclosure. The enclosure300′ has the same bottom portion302as the enclosure300and can house any of the fiber trays disclosed herein. The trays can include optical splitters and can also include splice holders. The enclosure300′ includes a top portion304′ that clamps and seals to the bottom portion302in the same matter as the top portion304. The top portion304′ supports a plurality of ruggedized fiber optic adapters344mounted at a main face346of the top portion304′. The adapters344have exterior sealed ports adapted to receive ruggedized connectors from outside the enclosure300′. The ruggedized connectors can be secured with a threaded connection, a bayonet connection or other robust mechanical connection. The ruggedized connectors are sealed relative to the enclosure300′ when secured within the exterior ports. The ruggedized adapters344also include interior ports for receiving connectorized ends354of a factory manufactured stub assembly including a plurality of connectorized pigtails. The non-connectorized ends of the pigtails/stub assembly can be spliced to fibers from a main cable at the splice tray. A protective cover355can be mounted inside the top portion304′ so as to cover the inner ports of the ruggedized adapters344and also to cover the portions of the pigtails routed to the adapter ports. The cover355can be transparent. The connectorized ends354of the pigtails are shown visible through the transparent cover355. The connectorized ends354can be inserted in the interior ports of the ruggedized adapters344. The portions of the pigtails extending outside of the cover355can be protected within a transport tube340(e.g., a furcation tube) which can also be contained within a corrugated protective tube342. The top portion304′ can be connected to the bottom portion302by a floating hinge structure352(e.g., a replaceable, disconnectable, non-rigid hinge) such as loops made of tie-wrap. Such a floating hinge allows translational as well as pivotal movement between the top and bottom portions thereby allowing more uniform compression of the housing seals as the top and bottom portions are secured together (e.g., clamped together). The transport tube340can be routed in an “S”-shaped pattern from an anchoring location356on the top portion304′ (e.g., adjacent to the cover) to an anchoring location358on the bottom portion302. The exterior ports or the ruggedized adapters344are oriented at an angled configuration so as to face at least partially toward one end of the enclosure300′. The bottom and top portions are symmetrical about a central axis so that the top portion304′ can be mounted in one of two different mounting configurations that are offset 180 degrees from one another. In one configuration, the exterior ports face toward one end348of the enclosure and in the other configuration the adapter ports face toward the other end350of the enclosure. The hinges352can be disconnected and then re-attached to allow the configurations to be reversed. The anchoring location358of the transfer tube is moved to the opposite side of the enclosure300′ to accommodate reversing of the top portion304′. In certain examples, the top portion304′ can be used to replace the cover304of an existing one of the splice closures300in the field. In this way, the enclosure300′ can be upgraded to include a connectorized configuration. The ability to mount the top portion304′ in different configurations allows the ports to face in the proper direction (e.g., upwardly on a pole for aerial applications and downwardly on a pole for under underground applications) without having to adjust the orientation of the bottom portion302and without having to disturb any existing cabling or splices. Example ruggedized fiber optic connectors and adapters are disclosed at U.S. Pat. No. 7,744,288, which is hereby incorporated by reference in its entirety.

From the forgoing detailed description, it will be evident that modifications and variations can be made without departing from the spirit and scope of the disclosure.