Patent Publication Number: US-RE42258-E

Title: Outside plant fiber distribution apparatus and method

Description:
CROSS- REFERENCE TO RELATED APPLICATIONS    
     
       Notice: More than one reissue application has been filed for the reissue of U.S. Pat. No.  6 , 363 , 200 . The reissue patent applications include the present application; application Ser. No.  12 / 218 , 241 , filed Jul.  11 ,  2008 ; application Ser. No.  11 / 397 , 885 , filed Apr.  4 ,  2006 ; and application Ser. No.  10 / 810 , 547 , filed Mar.  26 ,  2004 , now U.S. Patent RE  40 , 358 . The present application and application Ser. No.  12 / 218 , 241  are continuation reissue applications of application Ser. No.  11 / 397 , 885 , which is a divisional reissue application of application Ser. No.  10 / 810 , 547 , which is a reissue application of U.S. Pat. No.  6 , 363 , 200 . 
     
     This application is a divisional of application Ser. No. 09/122,947, filed Jul. 27, 1998, now U.S. Pat. No. 6,160,946 which application is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to an apparatus for housing fiber optic telecommunications equipment in outside plant environments. More particularly, this invention relates to an enclosure and management apparatus for housing cross-connect and/or interconnect equipment for fiber optic telecommunications systems. This invention also relates to modules for housing optical couplers such as optical splitters, wavelength division multiplexers. 
     BACKGROUND OF THE INVENTION 
     With the increased use of fiber optic technology in telecommunications, there is a need for apparatus which permit access to cross-connect functions and interconnect functions, while protecting the components in the field. For example, it is desirable to have access to fiber optic cables in outdoor locations such as contained within an enclosure adjacent to buildings which are linked at the enclosure to a feeder line. 
     In order to protect fiber optic connections from the environment and from damage due to impact or vandalism, such equipment is housed in enclosures which may be securably locked from unauthorized access. An example enclosure is shown in U.S. Pat. No. 5,734,776. The enclosure has a circular base, and a cylindrical shape. Enclosures with a more square shape are also known. Reltec (Reliable Electric) of Cleveland, Ohio sells a generally square enclosure, or pedestal, typically made of green colored metal, identified as CAD12. The Reltec CAD12 enclosure is generally about 12 inches by 12 inches at the base and about three to four feet high. 
     Providing cross-connect and/or interconnect functions within the enclosure is desired. Ease of assembly of the system and ease of access for later maintenance of the system are also desired. There is a need for further apparatus and methods for enclosing and managing outside plant equipment with cross-connect and interconnect functions. There is also a need for enclosing and managing fiber optic splice locations and optical couplers. 
     SUMMARY OF THE INVENTION 
     An optical fiber distribution frame apparatus includes a frame member having upper and lower module mounting brackets and an interior. The upper and lower module mounting brackets are spaced apart to define a space for receipt of a plurality of fiber optic modules mounted to the frame member. Each module includes a front and two mounting flanges. Each mounting flange is mountable to one of the upper and lower module mounting brackets. 
     The modules are provided with one or more functions. One of the modules defines a connection module and further includes a rear spaced from the front, a spaced apart top and bottom positioned adjacent to the flanges, and spaced apart sides. The connection module is configured and arranged for housing a plurality of connection locations having exposed openings along the front arranged in one or more vertical arrays. The bottom, the rear, and the opposed sides of the connection module define a cable notch region, wherein the cable notch region includes an opening for a first cable to enter the module. The first cable is connectable to the connection locations within an interior of the connection module either directly or through optical couplers. A further module defines a storage module including first and second spools positioned on the front. 
     The connection locations preferably define adapters for connection to connectors of fiber optic cables. Preferably, the adapters are angled downwardly when the connection module is mounted to the frame member. 
     An enclosure is preferably provided to surround the frame member for use in an outside plant application. In the case of configuring the optical fiber distribution frame apparatus as an interconnect system, the storage module preferably includes a cable clamp positioned on the front for clamping a second cable, wherein the second cable is connectable to the connection locations on the connector module. The frame member preferably has a cable tray and an opening sized for receipt of the second cable. The interconnect system may also include a blank or filler module defining a generally planar front. 
     In the case of configuring the optical fiber distribution frame apparatus as a cross-connect system, two connection modules are provided, and the storage module is positioned between the two connection modules. One or more patch cords link the connection locations of the two connection modules. 
     The present invention also relates to a method of assembling an optical fiber distribution frame including the steps of providing a frame member, and selecting a plurality of fiber optic modules for mounting to the frame. The fiber optic modules are selected so as to fill the frame member with desired functions. Connection modules, storage modules, and blank or filler modules can be selected as desired. In the case of a cross-connect system, two connection modules are mounted to the frame member, with a storage module positioned between the two connection modules and mounted to the frame member in one embodiment. In the case of an interconnect system, a connection module is mounted to the frame member, as well as a storage module in another embodiment. 
     The present invention also relates to individual components comprising an optical fiber distribution frame apparatus. A frame member defines an interior, and includes an open front bounded by upper and lower module mounting brackets. The lower module mounting brackets further include a plurality of openings configured and arranged for receiving cable. 
     A connection module in accordance with the present invention includes a front and two mounting flanges. A rear of the module is spaced from the front. A top and bottom are positioned adjacent to the flanges, and opposed spaced apart sides define an enclosed interior for the connection module. The connection module interior houses a plurality of connection locations having exposed openings along the front. The bottom, the rear, and the opposed sides define a cable notch region wherein the cable notch region defines an opening for receiving a first cable. 
     A storage module in accordance with the present invention includes a front and two mounting flanges, and first and second spools in alignment extending between the two mounting flanges. Side edges of the front further include projecting cable guides. In the case of a storage module for use in an interconnect system, a cable clamp is also positioned on the front for clamping a cable. 
     Blank or filler modules are also provided in accordance with the invention to fill unused space of the frame member. Each blank module includes a generally planar front, and two mounting flanges. Side flanges extend in an opposite direction to the direction faced by the front. 
     The connection module may house within its interior a splice between the first cable entering the module through the cable notch region, and the individual cables leading to the connection locations on the front of the module or to one or more optical couplers housed within the interior of the module. Example couplers include optical splitters and wavelength division multiplexers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a fiber distribution apparatus in a cross-connect configuration, with portions of the enclosure and the cover removed. 
         FIG. 2  is a front view of a fiber distribution apparatus in an interconnect configuration, With portions of the enclosure and the cover removed. 
         FIG. 3  shows the cross-connect fiber distribution apparatus of  FIG. 1  including exemplary fibers in place. 
         FIG. 4  shows the interconnect fiber distribution apparatus of  FIG. 1  including exemplary fibers in place. 
         FIG. 5  is an exploded perspective view of the frame and the cover. 
         FIG. 6  is a side view showing the cover mounted to the frame. 
         FIG. 7  is a front view of the frame. 
         FIG. 8  is a front view of a connection module, showing two exposed adapters for connecting to two connectors. 
       FIG  9  is a side view of the connection module of  FIG. 8 , showing a first cable mounted to the rear in the cable notch and held by a cable clamp. Example individual fibers within the module are also shown schematically. 
         FIG. 10  shows the bottom of connection module in greater detail. 
         FIG. 11  is a perspective view of one of the front adapters held by a clip and connected to two connectors. 
         FIG. 12  shows in greater detail a portion of the front of the connection module with the adapters and clips. 
         FIG. 13  is a side view of a connection module like that shown in  FIG. 9 , and showing an exemplary fiber from the first cable linked to a splice, an optical splitter, and two front adapters, one from each vertical row. 
         FIG. 14  is a front view of the connection module of FIG.  13 . 
         FIG. 15  is a side view of a connection module like that shown in  FIG. 9 , and showing an exemplary fiber from the first cable linked to a splice, a WDM, and two front adapters, one from each vertical row. 
         FIG. 16  is a front view of the connection module of FIG.  15 . 
         FIG. 17  a side view of a connection module like that shown in  FIG. 9 , and showing an exemplary fiber from the first cable linked to a splice, and a front adapter. 
         FIG. 18  shows an alternative connection module to the module of  FIG. 8  with one vertical row of adapters. 
         FIG. 19  shows a second alternative connection module with three vertical rows of adapters. 
         FIG. 20  is a perspective view of a cross-connect storage module. 
         FIG. 21  is a perspective view of an interconnect storage module. 
         FIG. 22  is a perspective view of a two-position blank module. 
         FIG. 23  is a one-position blank module. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to  FIGS. 1 and 3 , a fiber distribution apparatus  10  is shown for use in cross-connect applications.  FIGS. 2 and 4  show a similar fiber distribution apparatus  10 ′ configured for interconnect applications. Both apparatus  10 ,  10 ′ include an outer enclosure  20 , and an inner frame  22  including a plurality of optical modules  23  mounted thereto. As will be described below in greater detail, modules  23  have particular functions, and apparatus  10 ,  10 ′ is preferably provided with different modules  23  selected to have the desired functions for the particular application. 
     Enclosure  20  typically extends from the ground over underground cables  300 ,  302  ( FIG. 3 ) and  400 ,  402  ( FIG. 4 ) which extend upwardly from the ground and contain multiple individual optical fibers or bundles of fibers. Cables  300 ,  302 ,  400 ,  402  may be single cables or multiple cables. Enclosure  20  protects the inner components, in this case fiber optic telecommunications equipment. Enclosure  20  can be any convenient structure sized to protect frame  22  and modules  23 . In the drawings, enclosure  20  includes a main vertical portion  40  extending from the ground and a top cap  42 . Typically, a movable front door is provided, and a lock provides secure access. 
     Referring now to  FIGS. 1-7 , frame  22  is secured to main portion  40  of enclosure  20  along a rear side  41  of main portion  40 . Frame  22  includes a base or bottom  50 , and an opposed top  52 . Frame  22  further includes a front  54 , and an opposed rear  56 , and spaced apart sides  58 . Rear  56  of frame  22  can be screwed, riveted, or otherwise fastened to rear side  41  of main portion  40  of enclosure  20  through holes  62 . 
     Frame  22  further includes an upper module mounting bracket  66 , and a lower module mounting bracket  68  extending between sides  58 . Each module mounting bracket  66 ,  68  receives a plurality of modules  23  connected via fasteners  70 , such as screws, or other fasteners. Preferably, the fasteners are releasable to enable removal of modules  23 , as desired, such as for repair, or replacement. Each of the module mounting brackets  66 ,  68  includes a plurality of holes  67 ,  69  for receipt of fasteners  70 . 
     Lower module mounting bracket  68  defines a cable tray  60  ( FIG. 5 ) including a plurality of lower holes  72 , each sized for receipt of one or more cables, as will be described in greater detail below. 
     A cover  76  ( FIGS. 5 and 6 ) mounts to frame  22  so as to close front  74 . Side flanges  78  of cover  76  include a plurality of downwardly angled slots  80  for receipt of pins  82  extending from sides  58 ,  60  of frame  22 . Nuts, such as wing nuts, can be mounted to pins  82  with threads to help secure cover  76  to frame  22 . 
     Referring now to  FIGS. 1-4 , and  8 - 12 , a connection module  24  is shown. Connection module  24  comprises one of modules  23 . Connection module  24  includes a front  90  defining a plurality of connection locations  91 . Front  90  also includes opposed mounting flanges  92 ,  94  extending along front  90  for mounting to module mounting brackets  66 ,  68  of frame  22 . Each of flanges  92 ,  94  includes a plurality of holes  96 ,  98  for receiving fasteners  70 . A spaced apart rear  100  of connection module  24 , and a spaced apart top  102  and bottom  104 , and opposed, spaced apart sides  106 ,  108  define an interior region. A cable notch  110  formed by portion of rear  100 , bottom  104 , and sides  106 ,  108  receives a cable  300  for connection to the connection locations  91  within the interior of module  24 . Notch  110  further includes an opening  112  for cable  300 . Opening  112  is large enough to receive one or more additional cables. 
     Each of the connection locations,  91  preferably includes an adapter  200  for mounting to a fiber optic connector, such as an SC (shown), an ST, an FC, or other connector. Cable  300  entering connector module  24  at opening  112  includes its individual fibers connected to the individual connection locations  91 , as desired. Two illustrated example fibers  300 a,  300 b of cable  300  connect to two connection locations  91 . A connector  208  ( FIG. 11 ) is preferably on an end of fibers  300 a,  300 b. Adapter  200  preferably has two ends  202  and  204 . End  202  is disposed within module  24  for connection to connector  208 . Opposite end  204  defines the exposed opening of the connection location  91  along the front of module  24  for connection to a second connector  218 . A clip  210 , such as the clip disclosed in U.S. Pat. No. 5,214,735 may be used to releasably attach each adapter to module  24 . Clip  210  also angles connection locations  91  downwardly when module  24  is installed in frame  22  as in the drawings. Each clip  210  holds each adapter  200  in one of the openings  93  of front  90  of module  24  to define each connection location in the preferred embodiment. In the illustrated embodiment of module  24 , only two connection locations  91  are shown, but a fully loaded module  24  would define a connection location  91  at each opening  93 . Clip  210  is preferably a snap mounted clip to enable easy assembly. A removable clip  210  is preferred to allow cleaning of connector  208  and end  202  if desired. 
     A similarly configured second connection module  24 a is mounted to frame  22  to permit cross-connection through the use of patch cords  114 a,  114 b ( FIG. 3 ) to cross-connect between the fibers of each cable connected to the respective connection modules  24 ,  24 a. Cable  302  is connected to the rear of module  24 a as cable  300  is for module  24 . Patch cords  114 a,  114 b, and fibers  300 a,  300 b are shown schematically in  FIGS. 3 and 9 , but each fiber has a connector like connectors  208 ,  218  to mate with adapter  200 . Alternatively, other connector systems as noted above can be used, as desired. 
     Each connection module  24 ,  24 a can be made of sheet metal sections, held together with fasteners, such as screws, so as to allow access as desired to the interior of each module. 
     To facilitate cable management, and cable protection, a cross-connect storage module  26  as one of modules  23  is provided having three spools  116  along a front  120  ( FIGS. 1 ,  3  and  20 ). Along a front  120  of an interconnect storage module  26 a as one of modules  23  is provided two spools  116  ( FIGS. 2 ,  4  and  21 ). Flanges  124 ,  126  permit mounting of each storage module  26 ,  26 a to frame  22  in a similar manner as modules  24 ,  24 a. Holes  128 ,  130  receive fasteners  70  to mount storage modules  26 ,  26 a to frame  22 . Front projections  118  along vertical side edges  117  further enable cable management and cable protection during use. A cable clamp  134  ( FIG. 4 ) is provided for front mounting of one or more cables to storage module  26 a for the interconnect system. Posts  135  ( FIG. 21 ) hold the clamp pieces. 
     Cable notch  110  is useful to avoid excess cable bending during manipulation and positioning of connection modules  24 . The use of notch  110  provides a greater distance between the cables extending upward from the ground to the clamp mounting locations on modules  24 . The extra distance is advantageous when manipulating module  24  as it is installed into or removed from frame  22 . 
     In the example cross-connect system of  FIG. 3 , two fibers  300 a,  300 b ( FIG. 9 ) of cable  300  are shown as optically linked to two fibers of cable  302  through patch cords  114 a,  114 b in a cross-connect application between modules  24 ,  24 a. In the example interconnect system of  FIG. 4 , two fibers  402 a,  402 b of cable  400  are shown as optically linked to two fibers of cable  400 . 
     Referring now to  FIGS. 18 and 19 , alternative connection modules  224 ,  226  include different numbers of vertical rows of connector locations  91 . Modules  24 ,  24 a included two vertical rows. Connection module  224  includes a single row of connection locations  91 , and connection module  226  includes three. Four or more rows are also possible. 
     Referring now to  FIGS. 13-17 , module  24  is shown as including optical components such as splices and/or optical couplers within the module between cable  300 , and connection locations  91 . In  FIGS. 13 and 14 , a splice  350  to a one-by-two optical splitter  351  allows for module  24  to have line and monitor functions associated with connection locations  91 . Row  352  of connection locations  91  could serve as the line function, and row  354  could serve as the monitor function. Each pair of connection locations  91  (one from each row) would be linked to one of the fibers of cable  300  in FIG.  13 . Other splitters, such as one-by-fours, etc. may be used, as desired. 
     In  FIGS. 15 and 16 , a splice  360  to a wave division multiplexer (WDM)  361  allows for module  24  to have wavelength division multiplexing functions associated with connection locations  91 . A “dense” wave division multiplexer may be used, if desired (DWDM). For the multiplexing function, row  362  of connection locations  91  could serve as the first wavelength ports, and row  364  could serve as the different wavelength ports. Each pair of connection locations  91  (one from each row) would be linked to one of the fibers of cable  300  in FIG.  15 . 
       FIG. 17  shows just a splicing component  370  so that each fiber of cable  300  could be spliced to a fiber leading to one connection location  91 . Other passive optical components can be selected as desired to provide module  24  with the desired function or functions. 
     Referring now to  FIGS. 22 and 23 , blank panels  150 ,  170  comprising modules  23  are shown. Each blank panel  150 ,  170  includes a generally planar front  152 , and flanges  154  including holes  158 ,  160  to enable mounting of the blank modules  150 ,  170  to frame  22 . Blank modules  150 ,  170  are utilized to fill open spaces of frame  22 . Blank module  170  is a single width, and blank module  150  is a double width. Additional widths can be supplied as desired. 
     During assembly of a system for a particular outside plant application, the desired function (cross-connect, interconnect, other) is selected. The types of modules  23  (connection, storage, blank) and widths of modules  23  are also selected. Further the types of connections and whether any optical splices or optical couplers are to be utilized are selected. The appropriate modules are selected and then mounted to frame  22  within an enclosure  20 . Over time, the modules  23  can be removed for repair, replacement, or to change functions. Also, the front connections can be changed as the need arises. 
     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.