Abstract:
Apparatus for routing cables in a distribution frame. The apparatus includes a planar panel having takeup spools mounted thereon for the storage of excess lengths of cable. A hollow cylindrical member is mounted for pivoting movement about a pivot axis, where the longitudinal axis of the cylindrical member is parallel to the pivot axis. The cylindrical member has a longitudinally extending gap in its wall. Cables are routed to the panel, are selectively wound on selected ones of the spools to provide slack management, are routed into the cylindrical member, and are routed out of the cylindrical member through the gap.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to distribution frames and, more particularly, to apparatus for routing cables in a distribution frame. 
     Modern high speed telecommunications equipment increasingly relies on the use of optical fiber as a transmission medium, since it provides the bandwidth needed by customers. However, the optical fiber cables must be handled with care to prevent optical losses. When an optical fiber is bent, micro-cracking may occur and damage the expensive fiber cables. It is therefore important to control the bend radius of the fiber. As a general rule, fiber handling and packaging is much more restrictive than wire handling and packaging. 
     As customers demand higher bandwidth, the communications service providers are interested in purchasing the most compact system that takes up the least amount of floor space. Accordingly, increasingly higher fiber counts are packaged into a limited space. To complicate matters, optical fiber organization always involves slack management for two reasons: 
     1) Fiber termination can yield length variation that dictates its manufacturing tolerance; and 
     2) It is desirable to have equal length fiber cables used for multiple equipment module locations. 
     To satisfy these constraints, it is known to use valuable space within the same bay frame or adding additional half width or full width bay frames to provide room for slack management. This is disadvantageous in that equipment space is always at a premium and adding additional bays takes up floor space. Further, using space in the same equipment bay is not always feasible since the same space is sought after for packaging active equipment. It would therefore be desirable to provide a cable management system which, in a limited amount of space, efficiently routes optical fiber cables, provides slack management, and routes the cables in a manner to minimize bending. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided apparatus for routing cables in a distribution frame which comprises a planar panel having a plurality of takeup spools with their axes aligned perpendicular to the plane of the panel for the storage of excess lengths of cable, and a hollow cylindrical member mounted for pivoting movement about a pivot axis. The longitudinal axis of the cylindrical member is parallel to the pivot axis and the cylindrical member has a longitudinally extending gap in its wall. Cables are routed to the panel, are selectively wound on selected ones of the spools to provide slack management, are routed into the cylindrical member, and are routed out of the cylindrical member through the gap. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing will be more readily apparent upon reading the following description in conjunction with the drawings in which like elements in different figures thereof are identified by the same reference numeral and wherein: 
     FIG. 1 is a schematic front view of a distribution frame incorporating the present invention; 
     FIG. 2 is a schematic side view of the frame of FIG. 1; 
     FIG. 3 is a side view illustrating a takeup spool panel according to the present invention in its storage position; 
     FIG. 4 is a view of the panel shown in FIG. 3 which has been slid out of its storage position and pivoted to provide full access thereto; 
     FIG. 5 is a perspective view showing the mounting of a plurality of the panels shown in FIGS. 3 and 4; 
     FIG. 6 is an exploded perspective view of the cable routing cylindrical member and its pivoting mounting bracket; 
     FIG. 7 is an enlarged front view showing the cables routed in and out of the cylindrical member; 
     FIG. 8 is a top view with the cylindrical member in its use position; and 
     FIG. 9 is a top view showing the cylindrical member pivoted to provide access to a connector panel of the distribution frame. 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, FIGS. 1 and 2 schematically depict a distribution frame, designated generally by the reference numeral  10 , in which optical fibers  12  are routed from near the top of the frame to panels  14  holding takeup spools  16  for slack management of the optical fibers  12 . The fibers  12  are then routed to the cylindrical members  18  or  19 , and finally to the connector panels  20 . 
     As shown in FIGS. 3,  4 , and  5 , each of the panels  14  is pivotably mounted to a tray  22 . A group of four trays  22 , each holding a respective pivotably mounted panel  14 , is mounted inside an enclosure  24 . The enclosure  24  is formed, in its top and bottom, with four parallel slots  26 . A pair of posts  28  extends through each of the slots  26  and is secured to the top of a respective tray  22 . The posts  28  and the slots  26  cooperate to guide the tray for sliding movement in and out of the enclosure  24 , and to limit the travel of the tray  22  relative to the enclosure  24 . To secure each tray  22  and its panel  14  within the enclosure  24 , screws  30  are provided which extend through suitable openings in the front plate  32  of the panel  14  and are threaded into openings  34  of the upturned flange  36  at the front of the enclosure  24 . This arrangement allows a panel  14  to be fully exposed by removing the screw  30 , sliding the tray  22  out of the enclosure  24  as far as it will go, and then pivoting the panel  14  about its pivot  38 , as best shown in FIG.  4 . 
     As is clearly shown in FIGS. 3 and 4, the fibers  12  enter a tray  22  through a flexible conduit  40  which is secured to the panel  14  by a clip  42 . The fibers  12  exit the conduit  40  and are routed to appropriate takeup spools  16  for slack management, and are then routed out of the tray  22  through either of the two exit conduits  44 . Preferably, the conduits  40 ,  44  are of the type having a longitudinal slit so that the fibers  12  can be placed therein in a direction transverse to the longitudinal axis of the fibers. 
     A cylindrical member  18  or  19  is mounted adjacent each enclosure  24 . As shown in FIG. 1, illustratively there is an enclosure  24  mounted along each side of each connector panel  20 . The cylindrical members  18  or  19  mounted to opposite enclosures  24  are preferably mirror images of each other, and a detailed description of only the cylindrical member  18  follows. The mounting of each cylindrical member  18  is pivotable, as clearly shown in FIGS. 5 and 6. Thus, the cylindrical member  18  is preferably formed from sheet metal which is rolled and bent to form a hollow cylindrical portion  46  with a longitudinally extending gap  48  in its wall. Along one side of the gap  48 , the cylindrical member  46  is formed with a relatively small plate portion  50  having spaced openings  52  whose purpose will be described hereinafter. Along the other edge of the gap  48 , the cylindrical member  18  is formed with a plate  54  extending substantially radially outward from that edge of the gap  48 . Mounted to the plate  48  is an array of guide members  56  each for holding a respective one of the exit conduits  44 , as shown in FIG. 8. A further bent plate  58  is secured to the end of the plate  54 , as by screws  60  or welding. The distal end of the bent plate  58  is formed with openings  62  (FIG. 6) for receiving therein “dummy” fiber connectors, as will be described. 
     To mount the cylindrical member  18 , a bracket  64  is provided. The bracket  64  includes a pair of spaced circular rings  66 ,  68 , with the ring  68  illustratively being formed with a gap  70 . Connecting the rings  66 ,  68  is an elongated member  72 . The rings  66 ,  68  and the elongated member  72  are preferably formed from sheet stock as a unitary structure. An extension  74  joining the ring  66  to the elongated member  72  and an extension  76  joining the ring  68  to the elongated member  72  are used to pivotably mount the bracket  64  to tabs  78  (FIG. 8) mounted to the enclosure  24 . 
     To assemble the cylindrical member  18  along with the conduits  44 , the bracket  64  is first mounted to the enclosure  24 . The top of the cylindrical portion  46  of the cylindrical member  18  is then moved at an angle upwardly into the interior of the circular ring  66  until the tops of the plate portion  50  and the plate  54  abut against the ring  66 . The bottom of the cylindrical portion  46  is then moved over the cylindrical ring  68  and dropped into the interior of the ring  68 . The bottoms of the plate portion  50  and the plate  54  abut against the ring  68  and keep the cylindrical member  18  from falling therethrough. The conduits  44  are then placed transversely through the gap  48  into the interior of the cylindrical portion  46  and placed into the guide members  56 . At this time it is noted that there are four trays  22  within each enclosure  24 , each tray  22  having two conduits  44  exiting therefrom, for a total of eight conduits  44 . 
     To hold the cylindrical member  18  in the bracket  64 , a pair of retaining clips  80 ,  82  are provided, illustratively of identical construction. Preferably, the lower clip  80  is installed before the upper clip  82 . The lower clip  80  is installed by sliding its ends into slots provided therefor at the lower end of the cylindrical portion  46  and installing the screws  84  through openings in the tabs  86  formed as part of the clip  80 . The screws  84  are threaded into the openings  88  provided in the ring  68 . Similarly, the clip  82  has its ends slid into the slots  90  at the upper end of the cylindrical portion  46  and screws  92  are used to secure the clip  82  to the ring  66 . Thus, the cylindrical member  18  is prevented from moving longitudinally and rotatively. 
     A cover  94  is also provided. The cover  94  has a main planar portion  96 , a pair of legs  98  perpendicular to the planar portion  96 , and a bent plate portion  100  also perpendicular to the planar portion  96  and extending in the same direction as the legs  98 . Each of the legs  98  is formed with an opening  102  near its distal end and the plate portion  100  is formed with spaced openings corresponding to the spacing of the openings  52  in the plate portion  50  of the cylindrical member  18 . The spacing of the openings  102  and the legs  98  is the same as the spacing between the openings  60  in the bent plate  58  of the cylindrical member  18 . Accordingly, screws (not shown) may be utilized to secure the cover  94  to the cylindrical member  18  so as to cover the gap  48  while still providing room for the conduits  44  to exit the guide members  56 . 
     Before being installed in the conduits  44 , the fibers  12  had been terminated by connectors  104 . As is clear from FIGS. 7 and 8, after the conduits  44  are installed in the cylindrical member  18 , the fibers  12  contained therein are routed to appropriate connectors in the connector panel  20 . Spare fibers have their connectors  104  secured to the “dummy” connectors  106  installed in the openings  62  of the bent plate  58 . 
     A feature of the present invention is that when it is desired to gain access to the connector panel  20  for maintenance or removal thereof, each cylindrical member  18 ,  19  is pivoted to the position shown in FIG. 9 after all of the connectors  104  are disconnected so that the connector panel  20  can be removed from the distribution frame. 
     Accordingly, there has been disclosed improved apparatus for routing cables in a distribution frame. While an illustrative embodiment of the present invention has been disclosed herein, it is understood that various adaptations and modifications to the disclosed embodiment are possible and it is intended that this invention be limited only by the scope of the appended claims.