Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is a divisional of application Ser. No. 10/980,981, filed Nov. 3, 2004, now U.S. Pat. No. 7,171,100, issued Jan. 30, 2007, which application is incorporated herein by reference. 

   TECHNICAL FIELD 
   The present invention relates to apparatus and methods for termination and storage of optical fiber cables, such as distribution cables. 
   BACKGROUND 
   With respect to termination and storage of optical-fibers including distribution fibers, various concerns exist. One concern is providing high density to minimize needed space. In the case of outside plant enclosures, a reduced size for the enclosures and the internal structures is preferred. 
   A further concern related to termination and storage of optical fiber cables is the ease of access to the cables and the terminations. Such ease of use is desired during assembly, during installation in the field, and later when changes or modifications to the system are desired requiring adding or removing terminations, or when cleaning and checking the terminations. 
   A further concern in the area of termination and storage of optical fiber cables includes protecting the optical fiber from damage from excess bending below the minimum bend radius of the cable. Such protection of the fibers is desired during assembly and installation, and later when individual terminations and cables are accessed for cleaning or modification. 
   Further improvements in these areas are desired. 
   SUMMARY 
   One aspect of the present invention relates to a cable storage tray including a base and a hinged cover. The base receives a loop of optical fiber cables between inner and outer walls. The optical fiber cables further communicate with a cable pathway on the cover with the optical fiber cables positioned between inner and outer walls of the cable pathway. The cable storage tray protects a slack length of cable. Cable retention tabs are preferably provided to retain the cables in the cable pathways. 
   A further aspect of the present invention relates to an apparatus and method including providing a plurality of slack storage trays mounted to a fixture. Each slack storage tray includes inner and outer walls extending from a bottom wall for holding multiple loops of optical fiber cables. The cables are wound around the inner wall about an axis perpendicular to the bottom wall. The fixture further includes a plurality of cable terminations in a cable termination area. The cable termination area is preferably defined by a plurality of rows of adapters. The rows are preferably slidable relative to the slack storage trays. Cables are terminated in the cable termination area. Slack associated with the cables is stored in the slack storage trays. 
   A method is provided wherein loops of cable slack are stored in a storage tray that allows the cable slack to be pulled from the storage tray at a selected time, and then later received by the storage tray when the slack is no longer needed. One preferred method includes providing a two level storage tray where a first portion of the slack is looped around a cable radius limiter on a first level of the tray, and a second portion of the slack is positioned around a cable radius limiter on a second level of the tray. The preferred method also includes providing a moveable cover to close access to the first level, and wherein the cover defines the cable radius limiter of the second level. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a front, top, right side perspective view of a fiber distribution cabinet in accordance with the present invention, including two front doors pivoted to the open position. 
       FIG. 2  is a front, top, left side perspective view of the distribution cabinet of  FIG. 1 . 
       FIG. 3  is a front, top, right side perspective view of some of the interior components of the distribution cabinet of  FIG. 1 . 
       FIG. 4  is a rear, top, right side perspective view of the components shown in  FIG. 3 . 
       FIG. 5  is a top perspective view of one of the cable storage trays. 
       FIG. 6  is a further perspective view of the cable storage tray of  FIG. 5 , with the cover in the pivoted open position. 
       FIG. 7  is a further perspective view of the cable storage tray shown in  FIG. 6 . 
       FIG. 8  is a perspective view of the cover of the cable storage tray of  FIG. 5 . 
       FIG. 9  is a perspective view of the base of the cable storage tray of  FIG. 5 . 
       FIG. 10  is a further perspective view of the base of  FIG. 9 . 
       FIG. 11  is an enlarged view of a top portion of the cable storage and termination areas of the components shown in  FIG. 3 , including some cables, and further including one row of adapters moved into an access position. 
       FIG. 12  is a top view of a modified base including cable splicing features. 
   

   DETAILED DESCRIPTION 
   Referring now to  FIGS. 1-4 , one embodiment of an optical fiber distribution cabinet  10  is shown. Cabinet  10  may also be referred to as an enclosure  10 , such as an outside plant enclosure. Enclosure  10  receives feeder cables and provides connection points for connecting to distribution cables to connect the feeder cables to equipment connected to the distribution cables. Enclosure  10  provides a secure and weather-resistant structure around the internal components. 
   Enclosure  10  includes a housing  12  defining an interior  14  for receiving the cabling and the terminations. Cables enter enclosure  10  at opening  30 , and cables exit at opening  31 . Pivoting doors  16  provide front access to housing  12  and are pivoted about hinges  18 . Disposed within interior  14  is an enclosure subunit or fixture  20  including various cable management structures. Interior  14  also includes splitters  24  for splitting the feeder cable into individual cables. Vertical cable guides  26  and cable radius limiters  28  help manage the cabling. 
   The individual cables from splitters  24  are terminated in termination area  38 , which includes a plurality of adapters  40 . Cable manager  34  manages the individual cables (not shown) extending to a front side  38   a  of termination area  38 . On a back side  38 b of termination area  38  are a plurality of cables  78  defining the distribution cables (see  FIG. 11 ). The distribution cables are managed by a fiber storage area  42  including a plurality of fiber storage trays  44 . 
   Referring now specifically to  FIGS. 3 ,  4 , and  11 , cable manager  34 , termination area  38 , and fiber storage area  42  are shown in greater detail. In the illustrated embodiment, cable manager  34  and termination area  38  are mounted to a side wall  50  of fixture  20 . Fiber storage trays  44  are mounted to a back wall  52  of fixture  20 , behind termination area  38 . 
   Cable manager  34  includes a plurality of curved cable guides  56  for directing the cables in a downward direction from termination area  38 . At an end of cable guide  56 , one of cable retention fingers  58 ,  59  are provided. Cable manager  34  includes sections  60 ,  61 ,  62  with staggered guides  56 . In section  60 , guides  56  project outward the furthest from back wall  52 . In section  62 , guides  56  project the least. In section  61 , guides  56  project an intermediate amount. Such a construction helps avoid too many cables in any vertical space. Outer bars  63  of cable manager  34  further help retain the cables extending to termination area  38 . 
   Adapters  40  in termination area  38  are mounted on movable slides  64 , which slide relative to mounting members  66 . Mounting members  66  extend from side wall  50 . Slides  64  are selectively movable along a longitudinal axis  70  so as to move a selected row  72  of adapters  40 . In the moved position, each adapter  40  and the associated connecters are more easily accessible to a technician needing to connect or disconnect the cable and an adapter, or to clean one of the connecters. In the moved position, both the front and the back of each adapter  40  are more accessible. In  FIG. 11 , top slide  64  is moved to the access position. Lever  74  helps control movement of each slide  64 . Slides  64  and mounting members  66  are described in greater detail in U.S. Pat. No. 6,591,051, the disclosure of which is incorporated herein by reference. In  FIGS. 1-4 , only one adapter  40  is shown in each slide  64 . Five more adapters  40  fit into each slide  64  shown. Also, it is noted that axis  70  is disposed at angle not at 90 degrees relative to side wall  50 . Slides  64  pull slightly toward a front of enclosure  10 . 
   In the illustrated embodiment, slides  64  move horizontally along each longitudinal axis  70 . Feeder cables (not shown), also referred to as splitter output cables, extend from splitters  24 , through cable guides  26  and/or slack storage  28 , to cable manger  34 . From cable manager  34 , the cables with end connectors mate with one of adapters  40  on front side  38   a . Adapters  40  in the illustrated embodiment are shown with removable dust protector plugs  76  in each adapter. 
   Still referring to  FIGS. 3 and 11 , the distribution cables  78  extending from adapters  40  on slides  64  are managed by fiber storage trays  44 . Each fiber storage tray  44  allows for management of slack associated with each cable  78 . Such slack includes slack for manufacturing tolerances for cables  78 . Fiber storage tray  44  also allows for management of additional slack, such as the slack needed to avoid excessive pulling on the cable when cable  78  and its terminating connector are removed from adapter  40  and cleaned by the technician. Further, slack may also be desirable to allow for ease of movement of slides  64 . Fiber storage tray  44  manages the slack in an organized manner to avoid excessive pulling on cables  78  to prevent damage. 
   Now referring to  FIGS. 5 through 10 , fiber storage tray  44  includes a base  120  and a cover  164  hinged to base  120  along hinge axis  152 . Cover  164  hinges for movement to an open position to allow access to a first side  121  of base  120 . Cover  164  hinges closed to limit access to side  121 , and help protect cables stored on base  120 . 
   Base  120  includes a bottom wall  122 , generally planar, with an upstanding outside wall  124 . Upstanding outside wall  124  defines a cable entry location  126  for cables entering tray  44 . Cable entry location  126  is located adjacent a side  46  of tray  44 . 
   In the illustrated embodiment, adjacent cable entry location  126  is a fan out holder  128  for holding one or more cable fan outs  130 . Fan outs  130  are held between end tabs  132  and  134  of base  120 . 
   Base  120  further includes an inner radius  138  limiter defined by an inner wall  144  extending from bottom wall  122 . Inner wall  144  defines a surface for looping the cables generally about an axis  148  perpendicular to bottom wall  122 . Various cable retention tabs  140  project from upstanding outside wall  124  and inner wall  144  to further define a cable path  142 . Cabling within tray  44  can be wound or looped one or more times around inner radius limiter  138 . The cabling generally stays in position around inner radius limiter  138  within cable path  142  by retention tabs  140 . 
   Base  120  includes hinge pins  146  for cooperating with hinge plates  180  of cover  164 . When cover  164  is in the hinged open position as shown in  FIGS. 6 and 7 , the cabling can be positioned in cable path  142 , or removed, if necessary. When cover  164  is placed in the closed position as shown in  FIG. 5 , the cabling is further secured within cable path  142  by cover  164 . The cabling exits base  120  and communicates with features on a first side  165  of cover  164  by passing through a cable entry location  166 . When cover  164  is closed, fan outs  130  are retained in base  120 . 
   Cover  164  includes a bottom wall  168 , generally planar. An upstanding outside wall  170  extends upward from bottom wall  168 . An inner radius limiter  172  includes an upstanding inner wall  173 . A cable path  176  is defined between upstanding outside wall  170  and inner wall  173 . Cable retention tabs  174  extend from outside wall  170  and inner wall  173 . Inner wall  173  defines a surface for wrapping the cables generally about an axis  178  perpendicular to bottom wall  168 . Cable retention tabs  174  further help retain cabling extending from cable entry location  166  through cable path  176  to an exit location  188 . Exit location  188  is generally at a front  190  of tray  44 . From cable exit location  188 , the cabling including the end connectors mate with adapters  40  on back side  38 b of termination area  38 . 
   Base  120  includes a latch groove  160  for receipt of a latch tab  184  of cover  164  to maintain the cover and base in the closed positions. 
   Base  120  includes projections  154  along a back  150  of tray  44  for mating with slots  86  in back wall  52  of fixture  20 . Slots  86  narrow to fit into the necked regions  156  of projections  154  as trays  44  are slid to the left side of fixture  20 . Spring arm  158  is biased against back wall and is also received in slot  86 . To remove a tray  44 , a gripping tab  162  is provided along a side of tray  44 . Tray  44  is slid to the right in order to remove spring arm  158  from the received slot  86  and to position projections  154  in the wide portion in each of slots  86  in order to remove the tray from back wall  52 . 
   During use of tray  44 , cable  78  from fan out  130  is loosely wound around inner radius limiter  138  of base  120  (see dashed lines in  FIG. 7 ) and passed through cable entry location  166 . Cover  164  is closed retaining the cable and any fan outs  130  in a first compartment of tray  44 . The cable is then positioned around inner radius limiter  172  of cover  164  around to exit  188 . The cables  78  extend to adapters  40  at back side  38 b of termination area  38 . When the slack in cable  78  is pulled relative to storage tray  44 , the inner radius limiters  138 ,  172  prevent cable  78  from going below the minimum bend radius. When the cable is pushed back into storage tray  44 , the slack is contained by tray  44  including the outside walls  124 ,  170 , cable retention tabs  140 ,  174  and cover  164  positioned over base  120 . The other end of the cabling managed by tray  44  passes out through cable entry location  126 , and can be tied at tie off locations  90  of fixture  20 . Fan outs  130  allow for multiple individual fibers to be combined into a single jacketed cable. These jacketed cables can exit enclosure  10  at exit  31 . 
   The adapters  40  are arranged in horizontal rows, with the connector axes  46  extending in a horizontal plane, generally coplanar with trays  44 . In this manner, the loops of slack for each connector on back side  38   b  are managed and protected. 
   Referring now to  FIG. 11 , a modified tray base  192  includes a splicing area  194  including a splice holder  196 . Inner radius limiter  138  includes gaps  198  for allowing cables to enter and have access to splice area  194 . 
   The splitters  24  can be of conventional designs. The splitters  24  shown in the preferred embodiment are described in further detail in copending application Ser. No. 10/980,978, filed Nov. 3, 2004, entitled FIBER OPTIC MODULE AND SYSTEM INCLUDING REAR CONNECTORS, the disclosure of which is hereby incorporated by reference. Other equipment besides splitters  24  can be used in cabinet  10 , if desired. Cable clamps  25  on fixture  20  are used for clamping of the feeder cables extending toward splitters  24 . 
   In  FIGS. 1 and 2 , a connector storage area  200 , or connector parking lot, is provided. The connector parking lot can be used to store the connectors and cables extending from splitters  24  until connection at front side  38   a  of termination area  38  is desired. 
   Various connector and adapter styles can be used. In the illustrated embodiment, SC type are shown. Other styles such as ST, FC, LX.5 (by ADC Telecommunications, Inc., such as in U.S. Pat. No. 6,142,676) and LC can be used. 
   The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.

Technology Category: 3