Abstract:
An apparatus and method to protect fiber ribbons. A router having a body and cap are disclosed. Fiber cable sheath is stripped from one end, and the fiber ribbons thus exposed are inserted through the body and through cap bores in the cap. The cap is frictionally pushed into the body, and transportation tubes are installed over the fiber ribbons. The cap bores are sized to frictionally admit one end of a transportation tube, which has the effect of holding the transportation tubes in place. An optional insert is disclosed which has the function of reducing the body minor barrel bore diameter through which the fiber cable enters the router.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to fiber cables, and in particular to an apparatus and method to protect fiber ribbons. 
   2. Background of the Invention 
   Fiber cable was invented in the early 1970s, and its use has grown to include telecommunications, medicine, military, automotive, and industrial. Telecommunications applications include global networks, local telephone exchanges, subscribers&#39; homes, and desktop computers, and carry voice, data, or video over distances of ranging from a few feet to hundreds of miles. 
   Optical fiber is frequently used for transmission of data signals in private networks, such as exist in manufacturing firms, banks, universities, financial firms, and more. These entities have a need for secure, reliable systems to transfer computer and monetary information between buildings to the desktop terminal or computer, and around the world. The security inherent in optical fiber systems is a major benefit. Cable television or community antenna television (CATV) companies find the high information-carrying capacity, or bandwidth, of fiber cable extremely useful in transmitting signals to subscribers. 
   Intelligent transportation systems also find great utility in fiber cable. Examples of these include smart highways with intelligent traffic lights, automated toll booths, and changeable message signs to give motorists information about delays and emergencies. 
   Fiber cables routinely carry hundreds of individual fibers. These fibers are grouped into discreet bundles called ribbons. For example, a single fiber cable may carry between 216 and 864 individual fibers. These individual fibers are typically grouped into a number of ribbons, for example, twelve ribbons. Strengthening members are also included in the fiber cable assembly, to provide the strength and stiffness necessary to protect the fibers from stretching and excessive bending. 
   A critical point in fiber cable systems is the location where a fiber cable containing a plurality of ribbons is split up into its component ribbons. Just as the strengthening members protect the individual fibers along the run of the fiber cable, a router is recommended to protect the individual ribbons once these emerge from the protection of the cable sheathing and strengthening members. 
   Thus, it would be desirable to provide an apparatus and method to protect fiber ribbons at the point where they emerge from the protection of the fiber cable. 
   Existing Designs 
   A number of designs have been proposed to support fiber ribbons exiting their fiber cable. These generally involve installing transportation tubes around the emergent ribbons, to support the ribbons. 
   U.S. Pat. Nos. 5,692,090 and 5,802,227 were granted Szegda and Dunn et al. respectively, for fiber optic cable end connectors. While these provided termination and support for the fiber cable, no provision was taught to support the individual fibers emerging from same, except one Szegda &#39;090 embodiment taught support for a single central fiber ribbon. 
   U.S. Pat. Nos. 5,535,298, 6,510,273, 6,623,173 and 6,880,980 were granted Fasnacht et al, Ali et al, Grois et al., and Kang et al. respectively While these disclosed means to support fiber ribbons using transportation tubes, they suffered from the disadvantage of complexity, and therefore higher cost. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to provide an apparatus and method to protect fiber ribbons which supports individual ribbons extending beyond a fiber cable sheath. Design features allowing this object to be accomplished include a router having a body minor barrel bore, a cap having cap bores, a fiber cable disposed within the body minor barrel bore, fiber ribbon disposed within at least one cap bore, and a transportation tube around each ribbon extending through the cap bores. Advantages associated with the accomplishment of this object include avoiding kinking, bending, and damage to the fiber ribbons, along with the consequent cost and maintenance savings. 
   It is another object of the present invention to provide an apparatus and method to protect fiber ribbons which provides a cover to each fiber ribbon. Design features allowing this object to be accomplished include a cable entering a router through a router minor barrel bore, fiber ribbons extending through router cap bores, and transportation tubes covering the fiber ribbons which extend through the cap bores. Benefits associated with the accomplishment of this object include avoidance of damage to the fiber ribbons, and the associated cost and maintenance savings. 
   It is still another object of this invention to provide an apparatus and method to protect fiber ribbons which supports individual ribbons extending beyond a fiber cable sheath. Design features allowing this object to be accomplished include a router having a body minor barrel bore, a cap having cap bores, a fiber cable disposed within the body minor barrel bore, fiber ribbon disposed within at least one cap bore, and a transportation tube around each ribbon extending through the cap bores. Advantages associated with the accomplishment of this object include the reduction of repair costs, and the increase of reliability. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention, together with the other objects, features, aspects and advantages thereof will be more clearly understood from the following in conjunction with the accompanying drawings. 
     Six sheets of drawings are provided. Sheet one contains  FIGS. 1 and 2 . Sheet two contains  FIGS. 3 and 4 . Sheet three contains  FIGS. 5 and 6 . Sheet four contains  FIGS. 7-9 . Sheet five contains  FIGS. 10-12 . Sheet six contains  FIGS. 13 and 14 . 
       FIG. 1  is a front quarter elevated isometric view of a router. 
       FIG. 2  is a front quarter elevated isometric view the component parts of a router. 
       FIG. 3  is a side cross-sectional view of the component parts of a router. 
       FIG. 4  is a side cross-sectional view of a router. 
       FIG. 5  is a side view of a fiber cable with part of its sheath stripped off. 
       FIG. 6  is a side cross-sectional view of a router body with a router insert installed in its router body minor barrel bore. 
       FIG. 7  is a side cross-sectional view of a fiber cable inserted through a router. 
       FIG. 8  is a side cross-sectional view of a fiber cable inserted through a router with its fiber ribbons extending beyond the router major barrel, and a router cap ready to be installed. 
       FIG. 9  is a side cross-sectional view of a fiber cable inserted through a router with its fiber ribbons extending beyond the router major barrel, and a router cap installed on the router body with the fiber ribbons extending through router cap bores. 
       FIG. 10  is a side cross-sectional view of a router installed on a cable end, with the fiber ribbons extending through router cap bores, and a transportation tube poised, ready to be installed over a fiber cable. 
       FIG. 11  is a side cross-sectional view of a router installed on a cable end, with the fiber ribbons extending through router cap bores, and a transportation tube installed over a fiber cable, with one end of the transportation tube frictionally pushed into a router cap bore. 
       FIG. 12  is a close-up side cross-sectional view of fiber ribbon extending through a router cap bores, and a transportation tube installed over the fiber ribbon, with one end of the transportation tube frictionally pushed into the router cap bore. 
       FIG. 13  is a front quarter elevated view of a router being installed through a fiber closure base aperture. 
       FIG. 14  is a front quarter elevated view of a router installed through a fiber closure base aperture. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  is a front quarter elevated isometric view of router  2 .  FIG. 2  is a front quarter elevated isometric view the component parts of router  2 .  FIG. 3  is a side cross-sectional view of the component parts router  2 .  FIG. 4  is a side cross-sectional view of router  2 . 
   Router  2  comprises cap  4 , and optionally insert  8 , frictionally inserted into body  6 . Body  6  comprises body major barrel  16  rigidly attached to one end of body funnel  18 , and body minor barrel  20  rigidly attached to an opposite end of body funnel  18 . In the preferred embodiment, body major barrel  16  and body minor barrel  20  were substantially cylindrical, body funnel  18  was substantially a cone section, and body major barrel  16 , body minor barrel  20 , and body funnel  18  were substantially co-axial. 
   Body  6  comprises body minor barrel bore  40  in body minor barrel  20 , body funnel bore  42  in body funnel  18 , and body major barrel bore  44  in body major barrel  16 . Body minor barrel bore  40 , body funnel bore  42 , and body major barrel bore  44  mutually communicate. 
   Cap  4  comprises cap barrel  12  and cap lip  14  disposed around one end of cap barrel  12 . In the preferred embodiment, cap barrel  12  was a solid cylinder, and cap lip  14  was circular in cross-section, with an outside diameter greater than cap barrel  12 . 
   Body major barrel bore  44  is sized to frictionally admit cap barrel  12 . Cap lip  14  serves as a stop when cap barrel  12  is inserted into body major barrel bore  44 , as may be observed in  FIG. 4 . 
   Cap  4  further comprises a plurality of cap bores  10  extending axially through cap lip barrel  12 . Cap bores  10  are sized to slidably admit fiber cable ribbons  34 , and to frictionally admit an end of transportation tube  46 , as is illustrated in  FIGS. 11 and 12 . 
   Insert  8  comprises insert barrel  22  and insert lip  24  disposed around one end of insert barrel  22 . In the preferred embodiment, insert barrel  12  was a hollow cylinder having insert bore  9 , and insert lip  24  circular in cross-section, with an outside diameter greater than insert barrel  22 . 
   Body minor barrel bore  40  is sized to frictionally admit insert barrel  22 . Insert lip  24  serves as a stop when insert barrel  22  is inserted into body minor barrel bore  40 , as may be observed in  FIG. 4 . 
     FIGS. 5-14  illustrate the instant method to protect fiber ribbons.  FIG. 5  is a side view of fiber cable  30  with part of its sheath  32  stripped off.  FIG. 6  is a side cross-sectional view of router body  6  with router insert  8  installed in router body minor barrel bore  40 .  FIG. 7  is a side cross-sectional view of fiber cable  30  with bared fiber ribbons  34  inserted through insert  8  and body  6  as indicated by arrow  36 . 
     FIG. 8  is a side cross-sectional view of fiber cable  30  inserted through insert  8  and body  6  with fiber ribbons  34  extending beyond router body major barrel  16 , and router cap  4  ready to be installed.  FIG. 9  is a side cross-sectional view of fiber cable  30  inserted through router  2  with fiber ribbons  34  extending beyond router body major barrel  16 , and router cap  10  installed on router body  6  as indicated by arrow  37 , with fiber ribbons  34  extending through router cap bores  10 . 
     FIG. 10  is a side cross-sectional view of router  2  installed on an end of cable  30 , with fiber cables  34  extending through router cap bores  10 , and a transportation tube  46  poised, ready to be installed over a fiber cable  34  as indicated by arrow  48 .  FIG. 11  is a side cross-sectional view of router  2  installed on an end of cable  30 , with fiber ribbons  34  extending through router cap bores  10 , and a transportation tube  46  installed over a fiber cable  34 , with one end of transportation tube  46  frictionally pushed into a router cap bore  10 .  FIG. 12  is a close-up side cross-sectional view of router  2  installed on an end of cable  30 , with fiber ribbons  34  extending through router cap bores  10 , and a transportation tube  46  installed over a fiber ribbon  34 , with one end of transportation tube  46  frictionally pushed into a router cap bore  10 . 
   As depicted in  FIGS. 5-12 , the instant method to protect fiber ribbons starts with stripping sheath  32  from fiber cable  30  in conventional fashion.  FIG. 6  illustrates the optional step of installing insert  8  into body  6  by pushing insert barrel  22  frictionally into body minor barrel bore until insert lip  24  butts up against the end of body minor barrel  20 . Insert  8  is used as necessary to reduce the entrance diameter into router  2  to accommodate smaller diameter fiber cables  30 . Where the diameter of fiber cable  30  is too large to fit into insert bore  9 , insert  8  is simply omitted from router  2 , and the step of installing insert  8  in body  6  is omitted from the instant method. 
     FIGS. 4-12  depict the optional case where insert  8  is used. If the diameter of fiber cable  30  is too great to slidably fit through insert bore  9 , then insert  8  is omitted, and cable  30  is slid directly through body minor barrel bore  40 . In this case, where insert  8  is omitted, references to insert bore  9  should be changed to body minor barrel bore  40 . 
     FIG. 7  shows the step of inserting cable  30  through body minor barrel bore  40  (or insert bore  9 , if insert  9  is used), body funnel bore  42 , and body major barrel bore  44 , until ribbons  34  emerge from body major barrel bore  44 , and part of cable  30  covered by sheath  32  rests within body minor barrel bore  9 , as indicated by arrow  36 . 
   Next, cap  4  is installed on body  6  as depicted in  FIGS. 8 and 9 : each ribbon  34  is slid through a respective cap bore  10 , and cap barrel  12  is frictionally pushed into body major barrel bore  44  as indicated by arrow  37  until cap lip  14  butts up against body major barrel  16 , as depicted in  FIG. 8 . 
   A transportation tube  46  is then slid over each fiber ribbon as indicated by arrow  48  in  FIG. 10 . Each cap bore  10  is sized to frictionally admit an end of a transportation tube  46 . Thus, when a transportation tube  46  is slid over a fiber ribbon  34  and into a cap bore  10 , the frictional fit between the cap bore  10  and the transportation tube  46  serves to hold the transportation tube  46  in position covering the fiber ribbon  34 , as shown in  FIGS. 11 and 12 . 
   After the above steps, the end of each fiber ribbon  34  opposite router  2  may be connected to further fiber components, for example in a splice tray. Although  FIGS. 3-12  depict four fiber ribbons  34  in four cap bores  10 , it is intended to fall within the scope of this disclosure that cap  4  incorporate any desired number of cape bores  10 , each capable of accommodating a fiber ribbon  34 . 
     FIG. 13  is a front quarter view of router  2  being installed through a fiber closure base aperture  52  in fiber closure base  50 , a common routing of cable  30 .  FIG. 14  is a front quarter view of a router  2  installed through a fiber closure base aperture  52 . These figures depict the optional step of inserting router  2  through a fiber closure base aperture  52  in fiber closure base  50 . In the interest of clarity, fiber ribbons  23  and transportation tubes  46  are not shown in these figures. 
   Thus, the instant method comprises the steps of: 
   A. Providing a router  2  comprising a body  6  and a cap  4 , the body comprising a body minor barrel  20  rigidly attached to one end of a body funnel  18  and a body major barrel  16  attached to an opposite end of the body funnel  18 , a body minor barrel bore  40  in the body minor barrel  20 , a body funnel bore  42  in the body funnel  18 , and a body major barrel bore  44  in the body major barrel  16 , the body minor barrel bore  40 , body funnel bore  42 , and body major barrel bore  44  mutually communicating, the cap  4  comprising a cap barrel  12 , a cap lip  14  disposed around one end of the cap barrel  12 , and at least one cap bore  10  extending through the cap barrel  12 , the body major barrel bore  44  being sized to frictionally admit the cap barrel  12 ;
 
B. Stripping sheath  32  off an end of a fiber cable  30 ;
 
C. Inserting the end of the fiber cable  30  through the body minor barrel bore  40 , body funnel bore  42 , and body major barrel bore  44 ;
 
D. Slidably inserting at least one fiber ribbon  34  into a corresponding cap bore  10 ; and
 
E. Frictionally inserting the cap barrel  12  into the body major barrel bore  44 .
 
   The above method may comprise the additional steps of providing at least one transportation tube  46  sized to slidably admit a fiber ribbon  34  and having at least one end which frictionally fits into a cap bore  10 , sliding the transportation tube  46  over a fiber ribbon  34 , and frictionally sliding one end of the transportation tube  46  into a cap bore  10 . 
   The above method may comprise the additional steps of providing an insert  8  comprising an insert barrel  22  having an insert barrel bore  9 , and an insert lip  24  disposed around one end of the insert barrel  22 , the body minor barrel bore  40  being sized to frictionally admit the insert barrel  22 , frictionally pushing the insert barrel  22  into the body minor barrel bore  40 , and slidably inserting the fiber cable  30  through the insert bore  9 . 
   The above method may comprise the additional steps of providing a fiber closure base  50  having a fiber closure base aperture  52  sized to admit the router  2 , and sliding the router  2  through the fiber closure base aperture  52 . 
   In the preferred embodiment, insert  8 , body  6  and cap  4  were made of nylon, plastic, or other appropriate material. Fiber cable, fiber ribbons  34 , and transportation tubes  46  were standard, off-the-shelf items. 
   While a preferred embodiment of the invention has been illustrated herein, it is to be understood that changes and variations may be made by those skilled in the art without departing from the spirit of the appending claims. 
   DRAWING ITEM INDEX 
   
       
         2  router 
         4  cap 
         6  body 
         8  insert 
         9  insert bore 
         10  cap bore 
         12  cap barrel 
         14  cap lip 
         16  body major barrel 
         18  body funnel 
         20  body minor barrel 
         22  insert barrel 
         24  insert lip 
         30  fiber cable 
         32  sheath 
         34  ribbon 
         36  arrow 
         37  arrow 
         40  body minor barrel bore 
         42  body funnel bore 
         44  body major barrel bore 
         46  transportation tube 
         48  arrow 
         49  arrow 
         50  fiber closure base 
         52  fiber closure base aperture