Patent Publication Number: US-8985862-B2

Title: High-density multi-fiber adapter housings

Description:
RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. §119 of U.S. Provisional Application Ser. No. 61/770,835 filed on Feb. 28, 2013, the content of which is relied upon and incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present specification generally relates to housings for optical fibers, and more particularly, high-density multi-fiber adapter housings. 
     BACKGROUND 
     Typical optical telecommunication systems and networks include one or more telecommunications data centers that provide large numbers of optical and electrical cable connections that join various types of network equipment. The typical system also includes a number of outlying stations that extend the system into a network. Examples of network equipment include electrically-powered (active) units such as optical line terminals (OLTs), optical network terminals (ONTs), network interface devices (NIDs), servers, splitters, combiners, multiplexers, switches and routers, fanout boxes and patch panels. This network equipment is often installed within cabinets in standard-sized equipment racks. Each piece of equipment typically provides one or more adapters where optical or electrical patch cables (“jumper cables”) can be physically connected to the equipment. These patch cables are generally routed to other network equipment located in the same cabinet or in another cabinet. 
     A common problem in telecommunications systems, and in particular with optical telecommunications equipment, is space management. Current practice in telecommunications is to utilize standard electronics racks or frames that support standards-sized stationary rack-mounted housings of various widths. Vertical spacing has been divided into rack units “U”, where 1 U=1.75 inches. The housings may be fixed, slide-out, or swing-out patch/splice panels or shelves. However, the configurations and sizes of present-day housings for optical telecommunications equipment have been defined largely by the properties of the fiber optic cables that connect to the devices supported by the housings. In particular, the configurations and sizes have been established based on the particular ability of the fiber optic cables and optical fibers therein to interface with the devices without exceeding the bending tolerance of the fiber optic cable and/or the optical fibers. This has resulted in telecommunications equipment that occupies relatively large amounts of space, and in particular a relatively large amount of floor space in a central office of a telecommunications network. It has also led to data center patch panels being increasingly overpopulated due to connector and cable volumes. 
     SUMMARY 
     In one embodiment, an adapter housing for receiving a plurality of multi-fiber connectors includes a rectangular, box-like housing structure having opposing side walls and a back wall or door that is adapted to mount in a 2-U space in an equipment rack, wherein the housing structure has a width of no greater than about 17.75 inches and a height of no greater than about 3.50 inches. A bank of adapters includes at least one grouping of a plurality of adapters. Each adapter is configured to receive two multi-fiber connectors, and is aligned side-by-side in the grouping with major side walls of adjacent adapters facing each other. The bank of adapters includes individual connector-adapter-connector locations of at least 200 multi-fiber adapters configured to receive up to 2400 connector pairs within the housing structure. 
     In another embodiment, an adapter housing for receiving a plurality of multi-fiber connectors includes a rectangular, box-like housing structure having opposing side walls and a back wall or a door that that mounts in a 2-U space in an equipment rack, wherein the housing structure has a width of no greater than about 17.75 inches and a height of no greater than about 3.50 inches. At least one shelf is located within the housing structure. An adapter row is supported by at least one shelf. The adapter row includes at least 40 individual connector-adapter-connector locations at least one connector-adapter-connector location having a multi-fiber adapter configured to receive two multi-fiber connectors 
     Additional features and advantages of the claimed subject matter will be set forth in the detailed description which follows, and in part, will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an adapter housing according to one or more embodiments shown and described herein; 
         FIG. 2  is an exploded view of an adapter and MTP-type connectors for use with the adapter housing of  FIG. 1 ; 
         FIG. 3  illustrates a grouping of adapters according to one or more embodiments shown and described herein; 
         FIG. 4  illustrates an extendable shelf of the adapter housing of  FIG. 1  according to one or more embodiments shown and described herein; and 
         FIG. 5  illustrates schematically a bank of adapters for use in the adapter housing of  FIG. 1  according to one or more embodiments shown and described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments described herein generally relate to high-density multi-fiber adapter housings that are used to receive and house a plurality of multi-fiber connectors (MTP based connectivity) to establish and maintain connections therewith. An array or set of tightly packed adapters provide individual connector-adapter-connector locations that provide a relatively high density of connector/adapter pairs in a housing structure adapted to be mounted in a 2 U space of an equipment rack, which will be described in greater detail below. 
     Referring to  FIG. 1 , a multi-fiber adapter housing  10  includes a rectangular, box-like housing structure  12  having a top portion  14  and a bottom portion  16 . In the illustrated embodiment, the top portion  14  is removeable from the bottom portion  16  (e.g., using releasable fasteners) to provide access to an interior  18  of the housing structure  12 . One or both of the top portion  14  and bottom portion  16  may have one or more moveable panels, doors or other opening features for providing access to the interior  18  of the housing structure  12 . In the illustrated embodiment, the top portion  14  includes a ceiling or top wall  20  and a back wall  22  connected to the top wall  20 . The bottom portion  16  includes a floor or bottom wall  23  and opposing side walls  24  and  26  extending upwardly therefrom. When the top portion  14  and the bottom portion  16  are connected together, a 2-U sized housing structure  12  may be provided adapted to be mounted in a 2-U space of an equipment rack. A “U” space referred to herein may be defined as having a width W of no more than about 17.75 inches and a height H of no more than about 1.75 inches. The width W may be the available space between the inside dimensions of uprights of the equipment rack. Thus, a 2-U space, as used herein, refers to a space having a height H of no more than 3.50 inches for the given width W of 17.75 inches. 
     The multi-fiber adapter housing  10  includes a plurality of extendable shelves  30  that each carries at least one adapter row  32  of individual adapters  34  providing connector-adapter-connector locations. The adapters  34  may be single fiber or multi-fiber adapters. Multi-fiber adapters may be MTP-type adapters. As used herein, an “MTP-type adapter” refers to any type of multi-fiber adapter. As used herein, the term “connector-adapter-connector location” refers to a location in which a MTP-type adapter may be positioned, which is configured to accept two multi-fiber connectors such that the multi-fiber connectors may be connected together to transmit a fiber optic signal therebetween using the MTP-type adapter. In the illustrated embodiment, the adapter housing  10  includes five extendable shelves  30  and five adapter rows  32  in the interior of the 2-U housing structure  12 . The adapter rows  32  together provide a bank  36  of adapters  34  having adapters  34  each providing an individual connector-adapter-connector location in the interior  18  of the 2-U housing structure  12 . As can be seen, a single fiber optic cable  40  may enter the housing structure  12 , for example, through side wall  26 . The fiber optic cable  40  may separate into multiple, multi-fiber ribbon cables  42 , each having an MTP-type connector  46 . The MTP-type connectors  46  are received by the individual adapters  34  for connection with other MTP-type connectors  48 . The type of cables  40  entering and exiting the adapter housing  10  will depend on the ultimate end use; however, in the illustrated embodiment, there may be one cable  40  for each shelf  30  and associated adapter rows  32  (e.g., dividing into 40 multi-fiber ribbon cables  42 ). 
     Referring to  FIG. 2 , an individual adapter  34  is illustrated that provides a connector-adapter-connector location  50  for operably connecting the MTP-type connectors  46  and  48 . The adapter  34  includes an adapter body  52  having a first connector end  54  for receiving the connector  48  and a second connector end  56  for receiving the connector  46 . The adapter body  52  further includes a first minor sidewall  58 , a second minor side wall  60 , a first major side wall  62  and a second major side wall  64  that extend between the first and second connector ends  54  and  56 . A connector channel  66  extends between the first connector end  54  and the second connector end  56 . Guide slots  68  and  70  may be provided on the first minor side wall  58  and second minor side wall  60  of the adapter body  52  and may extend through channel  66  from the first connector end  54  and the second connector end  56 , respectively, which can be used to accept the MTP-type connectors  48  and  46  to connect the optical fibers (e.g.,  12 ,  24  or more optical fibers). In this regard, the cable  42  and cable  72  may be terminated with the MTP-type connectors  48  and  46  and the MTP-type connectors  48  and  46  may then be received by the adapter  34  within the connector channel  66  to connect the optical fibers in cable  42  to the optical fibers in cable  72 . In some embodiments, the guide slots  68  and  70  may be configured to receive the MTP-type connectors  48  and  46  in a particular orientation only to reliably achieve the connection. 
     Referring now to  FIG. 3 , a grouping  80  of the adapters  34  is illustrated. As can be seen, the adapters  34  can be oriented vertically with a long axis of the guide slots  68  and  70  ( FIG. 2 ) oriented in vertical direction. Such a vertical orientation can facilitate a higher density of the adapters  34  within a U space. In the illustrated embodiment, the adapters  34  are aligned side-by-side with first and second major walls  62  and  64  of adjacent adapters  34  facing each other. Therefore, the grouping  80  is oriented such that the first and second minor side walls  58 ,  60  of the adapters  34  are in a vertical position, for example, at the top or bottom of the grouping  80 . Orienting the adapters  34  in the grouping  80  in this manner, facilitates the alignment of the highest number of adapters  34  in a certain width in the interior  18  of housing structure  12 . In some embodiments, adjacent adapters  34  of the grouping  80  may be connected together, for example, by welding or adhesive. In other embodiments, the adapters  34  of the grouping  80  may be formed together as an integral group, for example, by a molding process. As can be seen, each of the adapters  34  of the grouping  80  provides a connector-adapter-connector location  50  where the connectors  46  and  48  are connected together. In the illustrated example, the grouping  80  includes ten adapters  34  and ten corresponding connector-adapter-connector locations  50 . The grouping  80 , in other embodiments, may include from about two adapters  34  to about 40 adapters  34 . More than 40 adapters  34  may be used in a grouping in some embodiments, for example, depending on the width of the housing structure  12  ( FIG. 1 ). 
     Referring to  FIG. 4 , one of the extendable shelves  30  ( FIG. 1 ) is illustrated in isolation. In this embodiment, the shelf  30  includes a single adapter row  32  of the grouping  80  of the individual adapters  34 . The number of groupings  80  the shelf  30  may accommodate depends, for example, on the number of adapters  34  per grouping  80  and the width of the housing structure  12 . In the illustrated embodiment, for a housing adapted to be mounted in a 2-U space of 17.75 inches wide, the shelf  30  may accommodate four groupings  80 , each grouping  80  including ten individual adapters  34 . As described above, each adapter  34  provides a connector-adapter-connector location  50 . Thus, the shelf  30  supports 40 or more, such as 40 connector-adapter-connector locations  50  that can connect the connectors  46  and  48 . 
     The extendable shelf  30  may include any variety of connectors and routers for connecting the groupings  80  and routing the cables  42  and  72 . For example, the extendable shelf  30  may include extension members  90  that include routing guides  92  disposed on the extension members  90  to provide for routing for the cables  72  connected to the adapters  34  and the cables  42 . Referring also to  FIG. 1 , the extendable shelf  30  may also contain shelf rails  94 . The shelf rails  94  can be configured to be received in shelf guides  96  disposed in the housing structure  12  to retain and allow the extendable shelves  30  and the adapters  34  disposed thereon to move in and out of the housing structure  12 . The extendible shelves  30  can be moved in and out of the housing structure  12  by their shelf rails  94  moving within the shelf guides  96 . In this manner, the extendable shelves  30  can be independently movable within the shelf guides  96  in the housing structure  12 . The shelf guides  96  may be disposed on both a left side end  100  and a right side end  102  of the extendable shelf  30 . The shelf guides  96  may be installed opposite and facing each other in the housing structure  12  to provide complementary shelf guides  96  for the shelf rails  94  of the extendable shelves  30  received therein. If it is desired to access a particular extendable shelf  30  and/or a particular adapter  34 , a pull tab  106  of the desired extendable shelf  30  can be pulled forward to cause the extendable shelf  30  to extend forward out from the housing structure  12 . When access is completed, the extendable shelf  30  can be pushed back into the housing structure  12  wherein the shelf rails  94  move within the shelf guides  96  disposed in the housing structure  12 . 
     Referring now to  FIG. 5 , a schematic representation of a bank  120  of adapters  122  is illustrated. The bank  120  of adapters  122 , as described above, provides connector-adapter-connector locations  124  for connecting MTP connectors. The bank  120  of adapters has a width W (e.g., of about 15 inches) and a height H (of about 3 inches) that is sized to fit within a 2-U space. The bank  120  of adapters  122  is formed of multiple rows  126 ,  128 ,  130 ,  132  and  134  of the individual adapters  122 . In this embodiment, each row  126 ,  128 ,  130 ,  132  and  134  includes the same number of individual adapters  122 , such as 40 or more. In other embodiments, certain ones of the rows  126 ,  128 ,  130 ,  132  and  134  may include different numbers of adapters  122 . In the bank  120  of  FIG. 5 , there are five rows  126 ,  128 ,  130 ,  132  and  134  adapted to have 40 adapters per row for a total of 200 adapters in a 2-U space. For an MTP-type connector that includes 12 optical fibers, there may be 2400 optical fiber pairs or 4800 optical fibers coming into or leaving from the adapter housing  10  ( FIG. 1 ). 
     As used herein, the terms “fiber optic cables” and/or “optical fibers” include all types of single mode and multi-mode light waveguides, including one or more optical fibers that may be upcoated, colored, buffered, ribbonized and/or have other organizing or protective structure in a cable such as one or more tubes, strength members, jackets and the like. Likewise, other types of suitable optical fibers include bend insensitive optical fibers, or any other expedient of a medium for transmitting light signals. An example of a bend insensitive optical fiber is ClearCurve® Multimode fiber, commercially available from Corning Incorporated. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein, provided such modification and variations come within the scope of the appended claims and their equivalents.