Abstract:
A fiber access terminal includes a drop cable side and a distribution cable side. The sides are separated by a frame to which a variety of cable management and cable connections components may be mounted. Optical fibers are routed from drop and distribution cables through a plurality of routing paths to splice trays for connection to other optical fibers. The terminal includes a base and a dome cover mounted to the base defining an enclosed interior. Passageways between the base and the dome cover are closed by removable covers to limit moisture and animals from accessing an interior of the dome cover. A tether connects the removable covers to the frame.

Description:
RELATED APPLICATION  
       [0001]     This application claims benefit of provisional application attorney docket No. 2316.2323USP1, entitled FIBER ACCESS TERMINAL INCLUDING MOISTURE BARRIER PLATE, filed Jan. 4, 2006, the disclosure of which is incorporated by reference.  
       TECHNICAL FIELD  
       [0002]     The present invention relates generally to provision of optical fiber telecommunications service. More specifically, the present invention relates to a fiber access terminal and a method of using a fiber access terminal.  
       BACKGROUND  
       [0003]     As demand for telecommunications increases, optical fiber services are being extended in more and more areas. To more efficiently extend the fiber optic service into areas where current and future customers are located, often distribution cables with more then one optical fiber are utilized. To provide service to a particular premises in the area, the distribution cables may be received within a fiber access terminal. Such terminals provide a location in the field where one or more optical fibers of the distribution cable may be split out from the distribution cable. The remainder of the fibers within the distribution cable may then be expressed through the fiber access terminal to extend to another location where service is desired.  
         [0004]     Within the fiber access terminal, a variety of fiber terminations and equipment is located. Typically, a base of the fiber access terminal is buried in the ground, and an upper portion of the fiber access terminal is positioned above the ground. There is a need to protect the fiber terminations and equipment within the fiber access terminal from contaminants, such as weather, water, debris, and animals.  
       SUMMARY  
       [0005]     The present invention relates to a fiber access terminal including a base defining an interior and mountable to the ground. A dome cover defines an enclosed interior and is mounted to the base. A frame holds telecommunications equipment and is mounted to the base and extends into the interior defined by the dome cover. The frame and the base cooperate to define one or more passageways between an interior defined by the base and the interior defined by the dome cover. A removable cover is provided to close the one or more passageways. In such a manner, contamination of the interior of the dome cover and the telecommunications equipment contained within is lessened. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate several aspects of the present invention and together with the description, serve to explain the principles of the invention. A brief descriptions of the drawings is as follows:  
         [0007]      FIG. 1  is a first perspective view of a fiber access terminal according to the present invention.  
         [0008]      FIG. 2  is a further perspective view of the fiber access terminal of  FIG. 1 .  
         [0009]      FIG. 3  is a side view of the fiber access terminal of  FIG. 1 , showing the base mounted in the ground and cable leading to and exiting from the base.  
         [0010]      FIG. 4  is a perspective view like  FIG. 1 , without the dome cover.  
         [0011]      FIG. 5  is a perspective view like  FIG. 2 , without the dome cover.  
         [0012]      FIG. 6  is an exploded perspective view of  FIG. 5 .  
         [0013]      FIG. 7  is a first perspective view of the removable covers.  
         [0014]      FIG. 8  is a second perspective view of the removable covers.  
         [0015]      FIG. 9  is a top view of the removable covers.  
         [0016]      FIG. 10  is first side view of the removable covers.  
         [0017]      FIG. 11  is a second side view of the removable covers.  
         [0018]      FIG. 12  is a first perspective view of an alternative embodiment for the frame.  
         [0019]      FIG. 13  is an enlarged perspective view of the alternative frame of  FIG. 12  with adapters.  
         [0020]      FIG. 14  is a second perspective view of the alternative frame of  FIG. 12 .  
         [0021]      FIG. 15  shows a distribution cable and clamp, along with a strength member clamp.  
         [0022]      FIG. 16  shows a side view of the strength member clamp.  
         [0023]      FIG. 17  shows the strength member clamp of  FIG. 16  in exploded form.  
         [0024]      FIG. 18  shows the alternative frame of  FIG. 12  mounted to the base to form a fiber access terminal, and including a tether to hold the removable covers; the removable covers shown slightly raised relative to the base.  
         [0025]      FIG. 19  is a perspective view of the fiber access terminal including the base, removable covers, and frame of  FIG. 18 , with the dome cover partially removed.  
         [0026]      FIG. 20  is an exploded perspective view of the fiber access terminal of  FIG. 18 .  
         [0027]      FIG. 21  is a further exploded perspective view of the fiber access terminal of  FIG. 18 .  
         [0028]      FIG. 22  is a side view of the removable covers of  FIG. 18 , including the tether.  
         [0029]      FIG. 23  is a side view of a first side of the frame of  FIG. 12 , showing example cabling.  
         [0030]      FIG. 24  is a second side view of the frame of  FIG. 12 , showing example cabling. 
     
    
     DETAILED DESCRIPTION  
       [0031]     Reference will now be made in detail to the exemplary aspects of the present invention that are illustrated in the accompanying drawings. Whatever possible, the same reference numbers will be used through out the drawings to refer to the same or like parts. Referring now to  FIGS. 1-11 , a fiber access terminal  10  is shown including a base  12 , and a dome cover  14  which define a protected interior  16 . A frame  18  is mounted to base  12  and holds telecommunication equipment  19 , such as terminations, splices, and breakouts. The frame  18  is mounted to the base and extends into an interior  20  of dome cover  14 . A first end  24  of base  12  is mounted below ground level  21 . A second end  26  of base  12  projects above ground level and mounts to a bottom end  28  of dome cover  14 . Latches  30 ,  31  mount dome cover  14  to base  12 .  
         [0032]     Frame  18  includes a first side  32  and an opposite second side  34 . One or both of sides  32 ,  34  can hold the telecommunications equipment. First and second sides  32 ,  34  of frame  18  cooperate with second end  26  of base  12  to define first and second passageways  42 ,  44  extending between an interior  36  of base  12  and interior  20  of dome cover  14  from base  12 . First and second passageways  42 ,  44  can allow for undesirable elements to enter interior  20  of dome cover  14 , such as moisture and animals. Moisture in the air can pass from the ground into dome cover  14  and condense on dome cover  14  or on frame  18  and the telecommunications equipment. Animals, such as mice, can enter interior  20  of dome cover  14  from base  12  and disrupt the cable connections. Hand access to the passageways  42 ,  44  is needed during system set up to allow the cables passing through the ground to pass through into dome cover interior  20 .  
         [0033]     Terminal  10  includes a cover system  50  for selectively covering the first and second passageways  42 ,  44 . In the preferred embodiment, cover system  50  includes a first removable cover  52  for closing first passageway  42 , and a separate, second removable cover  54  for closing second passageway  44 .  
         [0034]     First removable cover  52  includes a top member  62  and a compressible base member  64  mounted to the top member  62 . The compressible base member preferably engages the frame  18  and the base  12  to close the first passageway  42 . The compressible base member  64  is preferably made from a material such as foam. Foam base member  64  and the other polymeric materials preferably meet the anti-fungus growth tests as specified in the GR-13-Core requirements for Telcordia Requirements for Outside Plant Enclosures, specifically the ASTM G-21 test. One example foam that is usable is SCE-41 neoprene, closed cell foam.  
         [0035]     Preferably top member  62  of first removable cover  56  is planar in shape and is made from plastic, such as ABS. Foam base member  64  can be joined to planar top member  62  with adhesive. Preferably, top member  62  has a first outer edge portion  66  which extends beyond the outer edge portion of foam base member  64  such that a rim is defined to engage the top edge of base  12  when first removable cover  52  is in position to close first passageway  42 . In addition, an inner edge region  72  of first removable cover  52  includes the foam base member  64  extending beyond an edge of planar top member  62  in areas  73  in order to better close air passageways around cables entering interior  20  of dome cover  14 .  
         [0036]     Second removable cover  54  is constructed in a similar manner and like parts are designated with an apostrophe (′). In cover  52 , areas  73  are used to seal around the distribution cables which bring service to and from terminal  10 . In cover  54 , area  73 ′is used to seal around the drop cables which lead to customers&#39; premises. Variations are possible in the perimeter shapes of first and second removable covers  52 ,  54  in order to fit the first and second passageways  42 ,  44  of differently shaped terminals. While  FIGS. 7-11  show covers  52 ,  54  together, covers  52 ,  54  are separate units. Covers  52 ,  54  can be operated separately to selectively close or open passageways  42 , 44 .  
         [0037]     A latch  82  is provided to hold first removable cover  52  in position so that first removable cover  52  does not inadvertently dislodge from its closed position. Latch  82  includes a pivoting member  84  which selectively blocks removal of first removable cover  52  from its position closing first passageway  42 . Similar latches  82  are provided to hold second removable cover  54  in position. Latches  82  are movable to allow later access to passageways  42 ,  44 .  
         [0038]     Frame  18  includes distribution cable clamps  102 ,  104  on first side  32  of frame  18 . Distribution cable clamps  102 ,  104  clamp to distribution cables extending to and from terminal  10 . In use, one or more of the fiber optic cables within a distribution cable is broken out into drop cables within terminal  10 . A remainder of the cables in distribution cable are expressed through terminal  10 .  
         [0039]     Frame  18  includes a splice holder  110 . Frame  18  can also include fiber optic adapters  114  (see  FIGS. 13 and 23 ) for holding two fiber optic connectors  115  in axial alignment. One fiber optic connector connected at one of adapters  114  is spliced to one of the broken out fibers from the distribution cable entering terminal  10 . A second fiber optic connector connected to the first fiber optic connector at the selected adapter  114  is a drop cable, extending to a customer&#39;s premises. A drop cable clamp  118  on frame  18  holds the drop cable in a secure manner.  
         [0040]      FIGS. 12-14  show an alternative frame  18 ′. Both of frames  18 ,  18 ′ include various structures to manage the cables, splices and terminations in an organized manner. For example, radius limiters  170 ,  172 , tie-offs  174 , and clips  176  can be used.  
         [0041]     To further hold the distribution cables to frame  18 , a strength member clamp  122  is provided to clamp to the strength member of a distribution cable. See also  FIGS. 15-17 . Clamp  122  includes a fastener mount  124  for mounting to frame  18 . Clamp  122  further includes a fastener clamp  126  for connecting to the strength member  109 . Screw  127  cooperates with housing  125  and tab  129  to securely hold the strength member  109 . Electrical grounds  128  for grounding the distribution cables can be used if desired.  
         [0042]     Referring now to  FIGS. 18-24 , an alternative terminal  10 ′ is shown with a base  12 , dome cover  14 , and removable covers  52 ,  54 . To keep removable covers  52 ,  54  from becoming separated from terminal  10 ′, a tether  140  is used. Tether  140  includes a first portion  142  which connects first removable cover  52  to frame  18 ′. A second portion  144  connects second removable cover  54  to frame  18 ′. In one preferred embodiment, tether  140  is a single strap or other elongated member extending through a hole  150  in frame  18 ′ with removable covers  52 ,  54  connected at each end.  
         [0043]     In one possible embodiment, tether  140  is made from an o-ring compressible material which is cut to define two ends. Each end  152 ,  154  is passed through a hole  162 ,  164  in each of removable covers  52 ,  54 , respectively. Each end  152 ,  154  is crimped with crimps  182 ,  184  to prevent removable covers  52 ,  54  from separating from tether  140 .  
         [0044]     During use, tether  140  keeps removable covers  52 ,  54  adjacent to frame  18 ′. Should access to an interior of base  12  be desired, dome cover  14  is removed, exposing frame  18 ′ and removable covers  52 ,  54 . One or both of removable covers  52 ,  54  is removed from their positions closing the passageways into base  12 . Tether  140  allows one or both of removable covers  52 ,  54  to hang along side an exterior of base  12 . Tether  140  would prevent the user from reinstalling dome cover  14  onto base  12 , unless the removable covers  52 ,  54  were back in the correct closed positions.  
         [0045]     Frame  18 ′ includes protrusions  135  to help prevent cover  54  from tipping, and possibly allowing access between base  12 , and dome cover  14  after cover  54  is placed in the closed position. Protrusions  135  are located below cover  54  in use. Cover  52  is prevented from tipping by latch  30  positioned above cover  52  during use.  
         [0046]     In the field, distribution cable  106  enters terminal  10 ,  10 ′ from the ground (see  FIG. 1 ). One or more of the inner cables  132  of distribution cable  106  is broken out into one or more drop cables  116  (see  FIGS. 1, 23  and  24 ), which lead to the customers&#39; premises. A remainder of the cables  132  are expressed through terminal  10 ,  10 ′ at cables  133  and exit terminal  10 ,  10 ′ at distribution cable  108  back into the ground (see  FIGS. 1 and 24 ). Cable  108  passes to another remote terminal  10 ,  10 ′, or other location where service is desired. Within terminal  10 ,  10 ′, the cable or cables  132  to be broken out are connected through splices at splice holder  110 , and possibly a fiber optic adapters  114  to the drop cables  116 . Cables  117  link the splices at splice holder  110  to the fiber optic adapters  114  connected to the drop cables  116  (see  FIGS. 23 and 24 ). Strength members  109  associated with distribution cables  106 ,  108  are clamped with strength clamping members  122  to frame  18 ,  18 ′. Ground wires  111  can be linked to frames  18 ,  18 ′ with electrical grounds  128 .  
         [0047]     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.