Patent Publication Number: US-2003223723-A1

Title: Reconfigurable fiber optic cable management enclosure

Description:
FIELD OF THE INVENTION  
       [0001] This invention relates to fiber optic cable management systems, and more particularly to enclosures for use in fiber optic cable management systems.  
       BACKGROUND OF THE INVENTION  
       [0002] Fiber optic management systems provide termination and service access points for fiber optic circuits. Where a large number of fiber optic cables are to be connected, connections are typically made in fiber distribution frames. The frames can be comprised of multiple equipment racks that form bays for containing fiber optic management components, such as splice boxes and connection modules.  
       [0003] Enclosures for use in fiber optic cable management systems have been the subject of several patents, including U.S. Pat. Nos. 6,362,422; 6,215,938; 6,181,862; 5,898,129; 5,825,962; 5,778,130; 5,530,954; 5,208,894; 5,093,885; 4,971,421; 4,900,123; 4,824,196; 4,708,430; and 4,630,886.  
       [0004] Fiber optic cable enclosures can contain various cable management devices such as splice trays, connection modules, adapters, etc. In some instances, it would be desirable to be able to route cables from the rear of an enclosure to the front, and/or to rearrange the interior portions of the enclosure to perform different cable management functions.  
       [0005] There is a need for a fiber optic cable enclosure that can be easily reconfigured to accommodate various cable connection and routing needs.  
       SUMMARY OF THE INVENTION  
       [0006] Enclosures for use in a cable management system constructed in accordance with this invention include an outer shell having a generally rectangular shape and defining an interior space, the outer shell includes a bottom panel, a top panel and first and second sidewalls. A first reversible mounting bracket is provided for connection to the bottom panel, and a second mounting bracket is provided for connection to the top panel. The first and second mounting brackets can include means for supporting cable management devices.  
       [0007] The mounting brackets can each include a generally L-shaped member having a first portion positioned adjacent to the top or bottom panel, and a second section positioned substantially perpendicular to the top or bottom panel.  
       [0008] The means for supporting cable management devices can include a master plate that can be mounted between the brackets. The master plate can define one or more openings for attachment of the cable management devices.  
       [0009] The enclosure can further include a door for covering a front opening of the enclosure, and a latch attached to the door, wherein the latch is positioned adjacent to the center of one edge of the door.  
       [0010] The enclosure can also include a mounting bracket attached to at least one of the sidewalls. The mounting bracket can define an opening for routing cables from the rear of the enclosure to the front of the enclosure. A cable shield can be provided for enclosing cables between the mounting bracket and an opening in the adjacent sidewall.  
       [0011] The cable shield can include a top portion having a flat section and a curved section, a front portion extending vertically downward for the top portion, a side portion conforming to the shape of the top portion and the front portion, and a tab attached to the top portion for connection to an adjacent mounting bracket. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0012]FIG. 1 is an isometric view of an enclosure constructed in accordance with the invention;  
     [0013]FIG. 2 is an isometric view of selected components of the enclosure of FIG. 1;  
     [0014]FIG. 3 is a perspective view of a portion of the enclosure of FIG. 1;  
     [0015]FIG. 4 is a perspective view of another portion of the enclosure of FIG. 1;  
     [0016]FIG. 5 is a perspective view of a splice tray that can be used in the enclosure of FIG. 1;  
     [0017]FIG. 6 is a perspective view of a slack cable tray that can be used in the enclosure of FIG. 1;  
     [0018]FIG. 7 is a plan view of a bottom portion of the enclosure of FIG. 1 with cable trays in place;  
     [0019]FIG. 8 is an alternative plan view of a bottom portion of the enclosure of FIG. 1 with cable trays in place;  
     [0020]FIG. 9 is an isometric view of a master plate that can be used in conjunction with the enclosure of FIG. 1; and  
     [0021]FIG. 10 is an isometric view of the cable shield of the enclosure of FIG. 1. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0022] Referring to the drawings, FIG. 1 is an isometric view of an enclosure  10  constructed in accordance with the invention. The enclosure includes a generally rectangular shell  12  including top  14 , a bottom  16 , and first and second sides  18  and  20 . The enclosure forms an interior space  22  that can accommodate a variety of well known fiber optic cable components, such as connectors, adapters, modules, etc.  
     [0023] Mounting brackets  24  and  26  are connected to the sidewalls and are provided for attaching the enclosure to an equipment rack. The brackets incorporate a pass through design in that holes are provided for cables to be passed from the rear of the enclosure to the front. Mounting bracket  24  is shown to provide a mounting location for the cable shield  28  which protects the cable from damage from falling debris. The cable shield covers the cables  30  and  32  from a point where they pass through mounting bracket  24  until they enter the enclosure through an opening similar to opening  34  in sidewall  18 .  
     [0024] A first tray  36  is positioned in the interior of the enclosure near the front, and can include cable management devices such as clamps  38  and  40  for restraining cables within the enclosure. A second tray  42  is positioned in the interior of the enclosure near the back, and can include additional cable management devices. A reversible bracket  44  is positioned between the trays. Bracket  44  separates front and back sections of the enclosure. By changing the position of bracket  44 , the relative sizes of the front and back sections change. Trays  36  and  42  can be mounted in either the front or the back of the enclosure, depending upon the position of bracket  44 .  
     [0025] A door  46  is shown to be mounted to the front of the enclosure by hinges  48  and  50 . The door is preferably made of a relatively thin and slightly flexible material, such as polycarbonate. A latch  52  is mounted adjacent to one edge of the door and substantially in the center of the edge. The latch couples to a clip  54  mounted on the enclosure. Since the latch is positioned near the center of one edge of the door, the edges of the door away from the latch can be deflected slightly in the event that a cable is pinned between the door and the front edge of the enclosure, thereby reducing the likelihood of excessive pinching of the cable.  
     [0026] The front door is provided with a single latch point for one hand operation. A second door can be provided on a rear opening of the enclosure and can similarly include a latch positioned near the center of one edge. Economic enclosure design incorporates rounded comers, for example  56  and  58 , to prevent pinch points for fiber optic cable fibers and to give the enclosure a modern look. Rounded edges on various parts of the enclosure reduce snagging points for fiber optic cable strands, and reduce the possibility of microbends in the cable when pulled in tension over the edges of the enclosure.  
     [0027] Holes  60 ,  62 ,  64  and  66 , are provided in top panel to accept a variety of hardware, such as a splice tray drawer mechanism, or a record rack type splice tray holding apparatus. Additional holes  68 ,  70 ,  72  and  74  facilitate joining two or more enclosures together if there should be a need to stack and join enclosures. The holes  68 ,  70 ,  72  and  74  are centered in outwardly facing dimples. Screws, or similar fastening means can be inserted in the holes and attached to an adjacent enclosure. The head of the fastening device can fit within the dimple so that it does not interfere with items being inserted in the enclosure. In addition, the outwardly facing dimples will maintain a small space between adjacent enclosures and provide clearance for any irregularities in the adjacent surfaces of the stacked enclosures.  
     [0028] The enclosure can include additional openings  76  and  78  for entrance and exit of cables in the rear portion of the enclosure. While a rack mounted enclosure is shown in FIG. 1, the enclosure can alternatively be wall-mounted, for example by placing screws in the rear door and then attaching the screws to the wall. The front and rear doors can be removed and replaced by a metal and/or lockable door to discourage tampering.  
     [0029] Cover  28  protects high fiber count cables when the cables are routed from the rear mounting position to the front of the enclosure. This prevents damage to the fibers from falling debris.  
     [0030]FIG. 2 is an isometric view of selected components of the enclosure of FIG. 1 with the top panel removed. This view shows an additional reversible bracket  80  mounted near the top of the interior of the enclosure. Brackets  44  and  80  are shown to include openings  82  and  84  for attachment of various fiber optic cable management devices. The brackets can also serve as means for mounting a master plate that can be used to support various known cable management devices, such as cable adapters. FIG. 2 also shows openings  86  and  88  in mounting bracket  80  for attaching the mounting bracket to the top of the enclosure and the cable entrance opening  90  in sidewall  20 . In this illustrated embodiment, the openings in the sidewalls are in the form of slots having an open end at the front of the enclosure. By using such slots, cables can be routed by sliding them into the slots. This avoids the process of threading the cables through openings in the enclosure walls and can reduce the amount of bending required during the cable installation process.  
     [0031]FIG. 3 is a perspective view of a portion of the bottom interior of the enclosure of FIG. 1 taken from the rear of the enclosure and showing bracket  44  mounted in a first position. Bracket  44  is shown to have a generally L-shaped cross-section. Bracket  44  includes a first portion  92  that can be fastened to the bottom of the enclosure by fastening means  94  such as screws, bolts or rivets. Bracket  44  further includes a second portion  96  that is positioned substantially perpendicular to the plane of the bottom panel. A tab  98  is attached to one end of the second portion  96 . Fastening means  100  such as screws, bolts or rivets can fasten the tab  98  to the side of the enclosure. With bracket  44  installed in the position shown in FIG. 3, the bottom of the enclosure is divided into front and rear sections  102  and  104 , with the front section being more narrow than the rear section.  
     [0032] As shown in FIG. 3, the first portion  92  of bracket  44  extends from the second portion  96  toward the rear of the enclosure. However, the mounting bracket can be reversed so that the first portion  92  of bracket  44  extends from the second portion  96  toward the front of the enclosure. When in the alternative position, additional holes may be needed to attach the tabs at the ends of the bracket to the adjacent sidewalls. By switching the orientation of the bracket, the position of the first portion changes relative to the interior of the enclosure as illustrated below in FIGS. 7 and 8.  
     [0033]FIG. 4 is a perspective view of a portion of the top interior of the enclosure of FIG. 1 taken from the rear of the enclosure and showing bracket  80  mounted in a first position. Bracket  80  is shown to have a generally L-shaped cross-section. Bracket  80  includes a first portion  106  that can be fastened to the top of the enclosure by fastening means  108  such as screws, bolts or rivets. Bracket  80  further includes a second portion  110  that is positioned substantially perpendicular to the plane of the top panel. With bracket  80  installed in the position shown in FIG. 4, the bottom of the enclosure is divided into front and rear sections, with the front section being narrower than the rear section.  
     [0034] As shown in FIG. 4, the first portion  106  of bracket  80  extends from the second portion  110  toward the rear of the enclosure. However, the mounting bracket can be reversed so that the first portion  106  of bracket  80  extends from the second portion  110  toward the front of the enclosure. When in the alternative position, additional holes may be needed to attach the tabs at the ends of the bracket to the adjacent sidewalls. Brackets  44  and  80  are mounted such that the first portions of each of the brackets are aligned vertically so that additional cable management devices can be connected to the holes in the brackets, or a master plate can be connected to the brackets.  
     [0035]FIG. 5 is a perspective view of the first tray  36  that can be used in the enclosure of FIG. 1. Tray  36  is shown to include openings  112  that can be used to attach cable clamps as shown in FIG. 1. A pair of spring-loaded fasteners  114  and  116  are used to connect the tray to the bottom of the enclosure.  
     [0036]FIG. 6 is a perspective view of the second tray  42  that can be used in the enclosure of FIG. 1. Tray  42  is shown to include openings  118  that can be used to attached various known cable management devices. A pair of spring-loaded fasteners  120  and  122  are used to connect the tray to the bottom of the enclosure.  
     [0037]FIG. 7 is a plan view of the bottom of the enclosure showing the bracket mounted in a first position such that the enclosure is divided into two sections  124  and  126 , with the front section  124  being narrower than the rear section  126 .  
     [0038]FIG. 8 is a plan view of the bottom of the enclosure showing the bracket mounted in a second position such that the enclosure is divided into two sections  124 ′ and  126 ′, with the front section  124 ′ being wider than the rear section  126 ′.  
     [0039] The spring-loaded fasteners in trays  36  and  42  are positioned such that the trays can be mounted in the front or rear section of the enclosure when the bracket  44  is mounted in either the first or second position. The trays are removable and reversible in that the front tray can be used in the rear and the rear tray can be used in the front. Thus the enclosure can be reconfigured when the cable is routed from the rear mounting position to the front.  
     [0040]FIG. 9 is an isometric view of the master plate  128  the can be used in combination with the enclosure of FIG. 1. The plate  128  can be mounted vertically within the interior of the enclosure using, for example, spring-loaded clips  130  and  132 . The plate defines a substantially rectangular opening  134 . Openings  136  and  138  are provided near the opening  134  for attachment of modular cable management devices, such as module  140 .  
     [0041]FIG. 10 is an isometric view of the cover  28  of FIG. 1. The cover includes a top portion  142  having a flat section  144  and a curved section  146 . A front portion  148  extends vertically downward for the top portion. A side  150  portion conforms to the shape of the top and front portions. A tab  152  is attached to the top portion for connection to the adjacent mounting bracket. The curved section of the top portion provides a bend radius control feature for the enclosed cable. The cover is mounted such that it covers an opening in one of the mounting brackets and the opening  90  in the sidewall  20  that permits the cable to enter the enclosure.  
     [0042] In typical prior art enclosures, the fiber optic cables are attached to the rear of the enclosure. Cables are typically routed into the rear of the enclosure through openings in the sides. In the front of the enclosure, fiber optic jumpers are generally routed to other equipment or are provided as a cross connect between equipment made by different manufacturers. The enclosure of this invention allows for fiber optic cable to be attached in its originally intended and designed location in the rear of the housing and to be routed through the rack mounting bracket to the front of the enclosure without fear of damage to the cable caused by falling tools or debris. The cable shield  28  protects the cable as it is routed from the rack mounting bracket to the front of the enclosure. The shield is mountable after the enclosure has been installed in the rack, making it removable as well at the end user&#39;s option. The shield also enhances the normal bend radius of the cable in that it restricts the cable in three mutually perpendicular axes. The shape of the shield forces the cable to bend in predetermined directions with a large bend radius. This assists in preventing a violation of the minimum bend radius.  
     [0043] The master plate can support fiber optic modules or adapter plates within the enclosure. The master plate  128  can be removed for making the enclosure a splice enclosure with the addition of a splice tray holder or slide tray mechanism. The master plate is removable and reversible in order to have the cable routed from the rear mounting position to the front of the enclosure and to allow cable management in the front of the housing. The use of an interchangeable master plate allows for taller adapter plates or modules to be inserted simply by changing one piece of hardware. The holes in the master plate can be positioned to accept single and doublewide adapters and modules.  
     [0044] The enclosures of this invention provide for cross connects and general fiber optic cable handling. By being able to route cables to the front of the enclosure, normal fiber optic cable jumpers can be provisioned out the back side of the enclosure to cross connect modules located in other enclosures. Holes provided in the top panel accept a variety of hardware, such as splice tray drawer mechanisms, or record rack types of splice tray holding apparatus.  
     [0045] While the enclosures of this invention have been described in terms of particular embodiments, it will be apparent to those skilled in the art that various changes can be made to the disclosed embodiments without departing from the invention as defined by the following claims.