Abstract:
An over-molding tool is provided for over-molding an over-mold onto a fiber optic cable assembly. The over-molding tool includes first and second mold tool sets. The first mold tool set applies a first portion of the over-mold onto the fiber optic cable assembly. The second mold tool set then applies a second portion of the over-mold onto the fiber optic cable assembly. In preferred embodiments, the first and the second portions of the over-mold fuse to each other. By employing the first and the second mold tool sets, the fiber optic cable assembly can be supported at closer intervals along its length when being over-molded in comparison to a single, longer mold tool set. In addition, a lower capacity injection pump can be used when applying the over-mold in two portions. In other embodiments, additional mold tool sets can be added that sequentially apply additional portions of the over-mold.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/980,384, filed Oct. 16, 2007, which application is hereby incorporated by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The principles disclosed herein relate to molding systems. More particularly, the present disclosure relates to injection molding systems for applying over-molds to cables and to fiber optic cable systems. An example injection molding system is suitable for applying over-molds to fiber optic cable systems having main cables and branch cables. 
       BACKGROUND 
       [0003]    Optical networks are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities to customers.  FIG. 7  illustrates a fiber optic network  100  deploying passive fiber optic lines. As shown at  FIG. 7 , the network  100  can include a central office  110  that connects a number of end subscribers  115  (also called end users  115  herein) in a network. The central office  110  can additionally connect to a larger network such as the Internet (not shown) and a public switched telephone network (PSTN). The network  100  can also include fiber distribution hubs (FDHs)  130  having one or more optical splitters (e.g., 1-to-8 splitters, 1-to-16 splitters, or 1-to-32 splitters) that generate a number of individual fibers that can lead to the premises of an end user  115 . The various lines of the network can be aerial or housed within underground conduits (e.g., see conduit  105 ). 
         [0004]    The portion of network  100  that is closest to central office  110  is generally referred to as the F 1  region, where F 1  is the “feeder fiber” or “feeder distribution cable” from the central office. The F 1  portion of the network can include an F 1  distribution cable having on the order of 12 to 48 feeder fibers; however, alternative implementations can include fewer or more fibers. The portion of network  100  near the end users  115  may be referred to as an F 2  portion of network  100 . Splitters used in an FDH  130  can accept fibers from an F 1  distribution cable and can split those incoming fibers into, for example, 216 to 432 individual distribution fibers that can be associated with one or more F 2  distribution cables. The F 2  distribution cables are routed in fairly close proximity to the subscriber locations. Each fiber within the F 2  distribution cable is adapted to correspond to a separate end user location. 
         [0005]    Referring to  FIG. 7 , the network  100  includes a plurality of breakout locations  125  at which branch cables  144  (e.g., drop cables, stub cables, etc.) are separated out from main cables  120  (e.g., distribution cables). Breakout locations  125  can also be referred to as tap locations or branch locations and branch cables  144  can also be referred to as breakout cables  144 . At a breakout location  125 , fibers of the branch cables  144  are typically spliced to selected fibers of the main cable  120 . However, for certain applications, the interface between the fibers of the main cable  120  and the fibers of the branch cables  144  can be connectorized. 
         [0006]    Stub cables are typically branch cables  144  that are routed from breakout locations  125  to intermediate access locations  104  such as a pedestals, drop terminals or hubs. Intermediate access locations  104  can provide connector interfaces located between breakout locations  125  and subscriber locations  115 . A drop cable is a cable that typically forms the last leg to a subscriber location  115 . For example, drop cables are routed from intermediate access locations  104  to subscriber locations  115 . Drop cables can also be routed directly from breakout locations  125  to subscriber locations  115  hereby bypassing any intermediate access locations. 
         [0007]    Branch cables  144  can manually be separated out from a main cable  120  in the field using field splices. Field splices are typically housed within sealed splice enclosures. Manual splicing in the field is time consuming and expensive. 
         [0008]    As an alternative to manual splicing in the field, pre-terminated cable systems have been developed. Pre-terminated cable systems include factory integrated breakout locations manufactured at predetermined positions along the length of a main cable (e.g., see U.S. Pat. Nos. 4,961,623; 5,125,060; and 5,210,812). The factory integrated breakout locations need to be sealed to prevent environmental contamination and degradation of the cable system. In addition, certain components of the cable system at the integrated breakout location need to be permanently secured in their respective positions. The present disclosure satisfies these and other needs. 
       SUMMARY 
       [0009]    Aspects of the present disclosure relate to manufacturing mid-span breakout configurations for pre-terminated fiber optic distribution cables. A molding system is disclosed that is particularly well suited for over-molding features onto slender and/or flexible objects such as fiber optic cables. The molding system can employ a mold with intermediate supports to hold the slender and/or flexible object(s) while over-molding to prevent unacceptable movement of and stresses within the object(s). The mold can further employ multiple cavities filled by a sequence of multiple injection cycles. The mold can be reconfigured between the injection cycles. In addition, the molding system can allow components to be placed on the slender and/or flexible object(s) prior to molding thus resulting in the components being embedded within the over-mold. 
         [0010]    One aspect of the present disclosure relates to manufacturing a mid-span breakout configuration including over-molding an enclosure which provides reinforcement and environmental sealing at the breakout configuration. 
         [0011]    Another aspect of the present disclosure relates to embedding an optical fiber breakout block, tensile reinforcement that resists stretching of the mid-span breakout configuration, and a tether retention block within the enclosure. 
         [0012]    A further aspect of the present disclosure relates to a mid-span breakout configuration including an optical fiber breakout block having structure that prevents over-mold material from entering the interior of the optical fiber breakout block. 
         [0013]    Still another aspect of the present disclosure relates to a molding system for applying over-molds to cables. A multiple piece mold allows insertion of a cable or cable system within a cavity of the mold prior to a first injection of molding material. The molding material is injected into the mold cavity along an inlet channel. The molding system includes provisions to apply the over-mold in multiple stages along the cable. The multiple piece mold further includes a reconfigurable molding cavity when applying the over-mold in multiple stages. Upon initiation of the over-molding process, the reconfigurable molding cavity is set to a first configuration with a first portion of the molding cavity open to the inlet channel and a second portion of the molding cavity closed from the inlet channel by walls within the cavity. The walls can also locate and stabilize certain components of the cable system and/or certain portions of the cable thus serving as intermediate supports. A first injection cycle delivers a first shot of molten molding material filling the first portion of the molding cavity. Upon sufficient solidification of the molding material within the first portion of the molding cavity, interchangeable mold pieces are reconfigured and set to a second configuration. The second configuration opens the second portion of the molding cavity to the inlet channel and removes the walls within the cavity. Upon removal of the walls, the previously injected molding material within the first portion of the molding cavity is open to the second portion of the molding cavity. A second injection cycle delivers a second shot of molten molding material filling the second portion of the molding cavity and fusing the first and second shots of molding material within the molding cavity. The molding system includes provisions to solidify and release the over-molded cable from the multiple piece mold. 
         [0014]    Certain cable systems have pressure sensitive components that would be crushed by pressures typically found within injection molding systems. The present disclosure includes provisions to limit the molding pressure within a limit safe for the components being over-molded. In particular, the mold cavity is heated to reduce the viscosity of the injected molding material thus reducing molding pressure. In addition, vents are properly sized and placed to allow the mold cavity to fill without excessive injection pressure. Furthermore, a control system can be provided to limit the injection pressure. 
         [0015]    A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIG. 1  is a cross-sectional view illustrating a cable with a first and a second component attached; 
           [0017]      FIG. 2  is a cross-sectional view illustrating the cable and components of  FIG. 1  installed in a mold set to a first configuration defining a first mold cavity; 
           [0018]      FIG. 3  is a cross-sectional view illustrating the cable and the first component of  FIG. 1  over-molded by filling the first mold cavity of  FIG. 2  with a molding material; 
           [0019]      FIG. 4  is a cross-sectional view illustrating the cable and the first and second components of  FIG. 1  and the over-mold of  FIG. 3  within the mold of  FIG. 2  set to a second configuration defining a second mold cavity; 
           [0020]      FIG. 5  is a cross-sectional view illustrating the cable and the first and second components of  FIG. 1  over-molded by filling the second mold cavity of  FIG. 4  with additional molding material; 
           [0021]      FIG. 6  is a cross-sectional view illustrating the cable and the first and second components of  FIG. 1  and the over-mold of  FIG. 5  removed from the mold of  FIG. 2  (set to the second configuration of  FIG. 4 ); 
           [0022]      FIG. 7  shows a prior art passive fiber optic network; 
           [0023]      FIG. 8  is a cross-sectional view of an example distribution cable; 
           [0024]      FIG. 9  is a left side view of a mid-span breakout location; 
           [0025]      FIG. 10  is an enlarged right side view of the mid-span breakout location of  FIG. 9  with an over-mold, wrapping tape, and a protective sleeve removed but represented by dashed outlines; 
           [0026]      FIG. 11  is an enlarged right side view of the mid-span breakout location of  FIG. 9  with the over-mold and tensile reinforcing member removed, the wrapping tape showing as transparent, and the protective sleeve removed but represented in dashed outline; 
           [0027]      FIG. 12  is a cross-sectional view of an example tether cable; 
           [0028]      FIG. 13  is a perspective view showing the front, top, and right side of an example breakout block; 
           [0029]      FIG. 14  is a perspective view showing the rear, top, and left side of the breakout block of  FIG. 13 ; 
           [0030]      FIG. 15  is a perspective view showing the rear, top, and right side of an example retention block; 
           [0031]      FIG. 16  is a perspective view showing the front, top, and left side of the retention block of  FIG. 15 ; 
           [0032]      FIG. 17  shows an initial preparation of the tether cable of  FIG. 12  used at the mid-span breakout location of  FIG. 9 ; 
           [0033]      FIG. 18  shows an initial preparation of the distribution cable of  FIG. 8  at the mid-span breakout location of  FIG. 9 ; 
           [0034]      FIG. 19  is an enlarged perspective view showing the rear, top, and left side of the mid-span breakout location of  FIG. 9 ; 
           [0035]      FIG. 20  is an enlarged perspective view showing the front, top, and right side of the mid-span breakout location of  FIG. 9 ; 
           [0036]      FIG. 21  is an enlarged perspective view showing the front, top, and right side of the mid-span breakout location of  FIG. 9  with a cross-sectional cut made near the front end; 
           [0037]      FIG. 22  is an enlarged perspective view showing the rearward, top, and left side of the mid-span breakout location of  FIG. 9  with a cross-sectional cut made near the center; 
           [0038]      FIG. 23  is an enlarged perspective view showing the rearward, top, and left side of the mid-span breakout location of  FIG. 9  with a cross-sectional cut made near the rear end; 
           [0039]      FIG. 24  is a perspective view showing the rear, top, and right side of an example assembled mold for over-molding the mid-span breakout location of  FIG. 9  including a bottom mold section, a top mold section, a rear mold section, a reconfigurable center mold section, and a front mold section; 
           [0040]      FIG. 25  is a perspective view showing the front, top, and left side of the assembled mold of  FIG. 24 ; 
           [0041]      FIG. 26  is a perspective view showing the rear, top, and right side of the mold of  FIG. 24  with the top mold section separated from the assembly and a first center mold section configured with an inlet connected by passages to a first mold cavity; 
           [0042]      FIG. 27  is a perspective view showing the rear, top, and right side of the mold of  FIG. 24  with the top mold section separated from the assembly and a second center mold section configured with the inlet connected by passages to a second mold cavity; 
           [0043]      FIG. 28  is a perspective view showing the front, top, and right side of the first center mold section of  FIG. 26  including the passages along a right half and a left half; 
           [0044]      FIG. 29  is a perspective view showing the front, top, and right side of the second center mold section of  FIG. 27  including the passages along a right half and a left half; 
           [0045]      FIG. 30  is a perspective view showing the rear, top, and right side of the mold of  FIG. 24  with the top mold section and the center mold section removed; 
           [0046]      FIG. 31  is a perspective view showing the rear, top, and right side of the mold of  FIG. 24  with the top mold section, a right half of the rear mold section, the right half (see  FIG. 28 ) of the first center mold section of  FIG. 26 , and a right half of the front mold section removed, thus partially revealing a vertical longitudinal cross-section of the first mold cavity of  FIG. 26 ; 
           [0047]      FIG. 32  is a perspective view showing the rear, top, and right side of the mold of  FIG. 24  with the top mold section, the right half of the rear mold section (of  FIG. 31 ), the right half (see  FIG. 29 ) of the second center mold section of  FIG. 27 , and the right half of the front mold section (of  FIG. 31 ) removed, thus partially revealing a vertical longitudinal cross-section of the second mold cavity of  FIG. 27 ; 
           [0048]      FIG. 33  is a perspective view showing the rear, top, and right side of the assembled mold of  FIG. 24  in the configuration of  FIG. 26  with a cross-sectional cut through the top mold section of  FIG. 26 , thus revealing the passages of  FIG. 28  connecting to a first set of passages of the top mold section; 
           [0049]      FIG. 34  is a perspective view showing the rear, top, and right side of the assembled mold of  FIG. 24  in the configuration of  FIG. 27  with a cross-sectional cut through the top mold section of  FIG. 26 , thus revealing the passages of  FIG. 29  connecting to a second set of passages of the top mold section; 
           [0050]      FIG. 35  is a perspective view showing the rear, top, and right side of the assembled mold of  FIG. 24  with a cross-sectional cut through the top mold section and with the center mold section removed, thus revealing the second set of passages of  FIG. 34  of the top mold section connecting to the second mold cavity of  FIG. 27  and to a second set of passages of the bottom mold section; 
           [0051]      FIG. 36  is a perspective view showing the rear, top, and left side of the bottom mold section of the mold of  FIG. 24 ; 
           [0052]      FIG. 37  is a perspective view showing the front, bottom, and right side of the top mold section of the mold of  FIG. 24  revealing the first set of passages of  FIG. 33  connecting to the first mold cavity of  FIG. 26 ; 
           [0053]      FIG. 38  is a cross-sectional perspective view showing the rearward, top, and left side of the bottom mold section of the mold of  FIG. 24  revealing a first set of passages of the bottom mold section connecting to the first mold cavity of  FIG. 26  and the second set of passages (see  FIG. 35 ) of the bottom mold section connecting to the second mold cavity of  FIG. 27 ; 
           [0054]      FIG. 39  is a cross-sectional perspective view showing the forward, bottom, and right side of the top mold section of the mold of  FIG. 24  revealing the first set of passages of  FIG. 33  of the top mold section connecting to the first mold cavity of  FIG. 26  and the second set of passages of  FIG. 34  of the top mold section connecting to the second mold cavity of  FIG. 27 ; 
           [0055]      FIG. 40  is a perspective view showing the rear, bottom, and right side on an inlet block for use with the inlets of  FIGS. 26 and 27 ; 
           [0056]      FIG. 41  is a perspective view showing the front, top, and left side of a press base for use in primarily holding the bottom mold section of the mold of  FIG. 24 ; and 
           [0057]      FIG. 42  is a perspective view showing the rear, bottom, and right side of a press top for use in primarily holding the top mold section of the mold of  FIG. 24  and the inlet block of  FIG. 40 . 
       
    
    
     DETAILED DESCRIPTION 
       [0058]    The present disclosure relates to applying an over-mold on or around slender and/or flexible objects, such as an optical cable, by injecting a liquid molding material within a mold cavity of a mold. In a preferred embodiment, the liquid molding material is at an elevated temperature when injected and solidifies when cooled. In other embodiments, a chemical reaction, a photochemical reaction, and/or a thermochemical reaction can solidify the liquid molding material. 
         [0059]    One or more slender and/or flexible objects, hereinafter called core bodies (body), are placed within the mold cavity prior to injecting the molding material. The core body (bodies) extends outside the mold cavity at one or more port locations. The mold has an opening that seals around the core body at each port location. 
         [0060]    In a preferred embodiment, the mold includes multiple mold pieces that are reconfigurable to form multiple mold cavities. The multiple mold cavities are of successively larger volumes and filled in succession from the smallest volume mold configuration to the largest. An initial configuration of the mold forms an initial mold cavity with the smallest volume and is loaded with the core body (bodies). Additional components which are entirely within the mold cavity can also be loaded and preferably attached to one or more core bodies. Initial port locations are adequate to support the core bodies within the initial mold cavity and prevent unacceptable movement during an initial over-molding process. In a preferred embodiment, the initial configuration includes multiple mold pieces that define the initial mold cavity and can also include other mold pieces not used in defining the initial mold cavity. The core bodies and the additional components can also be loaded into the initially unused mold pieces. An initial injection cycle fills a portion of the initial mold cavity that is not occupied by the core bodies or the additional components with the liquid molding material forming an initial over-mold. 
         [0061]    After injecting the molding material within the initial mold cavity, the initial over-mold can be allowed to cool and/or solidify to a desired degree. The mold is then reconfigured into a second configuration forming a second mold cavity. Certain portions of the initial mold cavity can also define certain portions of the second mold cavity. In a preferred embodiment, the mold pieces that define a portion of the initial mold cavity and completely correspond to portions of the second mold cavity are reused. In a preferred embodiment, the initial over-mold is left undisturbed within the reused mold pieces shared by the initial configuration and the second configuration. New mold pieces are introduced to the mold to form the second configuration and can replace mold pieces used in the initial configuration. Typically, the new mold pieces define portions of the second mold cavity. Certain of the initially unused mold pieces in the initial configuration can define portions of the second mold cavity. Thus the second mold cavity is defined with reused mold pieces, new mold pieces, and initially unused mold pieces. The second mold cavity may already be loaded with the core bodies and additional components that were initially loaded into the mold. Other core bodies and additional components can be loaded within the second mold cavity. The solidified or partially solidified initial over-mold can provide support to portions of the core bodies not yet over-molded during a second over-molding process. Additional port locations can engage the core bodies. The combination of the port locations and the initial over-mold are adequate to support the core bodies within the second mold cavity and prevent unacceptable movement during the second over-molding process. A second injection cycle fills the portion of the second mold cavity that is not occupied by the core bodies, the additional components, or the initial over-mold with the liquid molding material forming a second over-mold. 
         [0062]    After injecting the molding material within the second mold cavity, the second over-mold can be allowed to cool and/or solidify to a desired degree. The above process may be continued with additional mold configurations and additional over-molds or the over-molded core body (bodies) may be removed from the mold. 
         [0063]    Turning now to the figures and in particular to  FIGS. 1 through 6  there is shown an example over-mold  30  being over-molded onto a cable  10 . Additional example components  20  have been previously applied to the cable  10  and are also over-molded by the over-mold  30 . Together, the over-mold  30 , the additional components  20 , and the cable  10  form an example cable system  40 . An example mold  45  with multiple configurations is used to over-mold the cable  10 . 
         [0064]    The mold  45  is initially set to an initial configuration  50 ′ as shown at  FIGS. 2 and 3  including a first mold section  52 , a second mold section  54 , and an initial center mold section  56 ′. The initial center mold section  56 ′ includes an inlet  70 ′ directed to a first mold cavity  62 ′ by a first passage  80 ′. The first mold cavity  62 ′ is formed by the first mold section  52  and the initial center mold section  56 ′. The initial center mold section  56 ′ includes a wall  64  which excludes the second mold section  54  from the first mold cavity  62 ′. The cable  10  and additional component  20  are placed within the first mold cavity  62 ′ and can also be placed within the second mold section  54 . Ports  66 ,  67  of the first mold section  52  and the initial center mold section  56 ′ support the cable  10  within the first mold cavity  62 ′ and form a seal around the cable  10 . A port  68  of the second mold section  54  can also support the cable  10  outside the first mold cavity  62 ′. The cable  10  supports the additional components  20 . A first vent  72  allows air to escape the first mold cavity  62 ′ and also prevents excess pressure from developing within the cavity  62 ′. 
         [0065]    As shown at  FIG. 3 , the first mold cavity  62 ′ is injected with a molten molding material creating an initial over-mold  30 ′. Excess molding material can exit through the first vent  72 . The initial over-mold  30 ′ is allowed to cool until it is sufficiently solid. The initial center mold section  56 ′ is removed from the mold  45  and replaced with a final center mold section  56  as shown at  FIG. 4 , setting the mold  45  to a final configuration  50 . The cable  10 , additional components  20 , and the initial over-mold  30 ′ are left undisturbed in the first and second mold sections  52 ,  54  while the center mold sections  56 ′,  56  are switched. The final center mold section  56  includes an inlet  70  directed to a second mold cavity  62  by a second passage  80 . The second mold cavity  62  is formed by the first mold section  52 , the final center mold section  56 , and the second mold section  54 . The port  68  of the second mold section  54  supports the cable  10  within the second mold cavity  62  and forms a seal around the cable  10 . Additional support is provided to the cable  10  by the initial over-mold  30 ′. A second vent  74  allows air to escape the second mold cavity  62  and also prevents excess pressure from developing within the cavity  62 . 
         [0066]    As shown at  FIG. 5 , the second mold cavity  62  is injected with additional molten molding material combining with the initial over-mold  30 ′ to create a final over-mold  30 . Excess molding material can exit through the second vent  74 . The additional molten molding material can fuse with the initial over-mold  30 ′. The final over-mold  30  is allowed to cool until it is sufficiently solid. The mold is then removed from the cable system  40  as shown at  FIG. 6 . 
         [0067]    Aspects of the present disclosure relate to manufacturing mid-span breakout configurations for pre-terminated fiber optic distribution cables. In particular, a molding system is disclosed that is particularly well suited for over-molding features onto slender and flexible objects such as fiber optic cables. The molding system can employ a mold with intermediate supports to hold the fiber optic distribution cable, at least one fiber optic tether cable, and other components of the mid-span breakout configuration while over-molding to prevent unacceptable movement of and stresses within the cables and components. The mold may further employ multiple cavities filled by a sequence of multiple injection cycles. The mold can be reconfigured between the injection cycles. In addition, the molding system allows the fiber optic distribution cable, the at least one fiber optic tether cable, and the other components of the mid-span breakout configuration to be assembled and placed within the multiple mold cavities of the mold prior to over-molding thus resulting in the components being embedded within the over-mold. 
         [0068]    Turning now to  FIGS. 8 through 23  there is shown an example fiber optic cable breakout configuration. A fiber optic cable assembly  240  including the breakout configuration is more fully described at U.S. patent application Ser. No. 11/787,218, filed Apr. 12, 2007, and U.S. Patent Application Publication Number 2008/0253729, published Oct. 16, 2008, both entitled FIBER OPTIC CABLE BREAKOUT CONFIGURATION WITH TENSILE REINFORCEMENT, which are hereby incorporated by reference in their entirety. 
         [0069]      FIG. 8  shows an example distribution cable  220  including six separate buffer tubes  222  each containing twelve optical fibers  224 . The fibers can include either ribbon fibers or loose fibers. The buffer tubes  222  can be gel filled. The distribution cable  220  also includes a central strength member  226  for reinforcing the cable  220 . The distribution cable  220  further includes an outer jacket  230  that encloses the buffer tubes  222 . In certain embodiments, ripcords  232  can be provided for facilitating tearing away portions of the jacket  230  to access the optical fibers  224  within the jacket  230 . The distribution cable  220  can also include a strength layer  228  for providing further tensile reinforcement to the distribution cable  220 . In one embodiment, the strength layer includes a plurality of strength members such as aramid yarn (i.e., KEVLAR®) for further reinforcing the cable. 
         [0070]    The distribution cable  220  of  FIG. 8  is merely one example of a type of cable to which the various aspects of the present disclosure apply. Other distribution cable configurations can also be used. For example, the distribution cable  220  can include an outer jacket enclosing a single buffer tube and at least two strength members extending on opposite sides of the single buffer tube. An outer strength member such as aramid yarn can surround the single buffer tube within the jacket. The single buffer tube can enclose loose fibers or ribbon fibers. 
         [0071]    The typical mid-span breakout location is provided at an intermediate point along the length of a distribution cable. Commonly one or more tethers (e.g., drop cables or stub cables) branch out from the distribution cable at the breakout location.  FIGS. 9-11  illustrate the fiber optic cable assembly  240  which may be over-molded by an over-mold  260  to protect the internal components of the assembly  240  from the environment. The fiber optic cable assembly includes a distribution cable  220  and tethers  244  that branch from the distribution cable  220  at a mid-span breakout location  246 . Multi-fiber optic connectors  243  are mounted at free ends of the tethers  244 . As shown at  FIG. 10 , the breakout location  246  includes splice locations  245  where selected optical fibers  224   dc  of the main distribution cable  220  are spliced to corresponding optical fibers  224   t  of the tethers  244 . Splice sleeves  248  are provided over the splices at the splice locations  245 . The splice sleeves  248  are within a protective sleeve  250  (e.g., a plastic tube) that extends along a length of the breakout location  246  and has a first end supported by a breakout block  254  and an opposite second end supported by a retention block  258 . 
         [0072]    The breakout location  246  has a front end  292  and a rear end  294  that correspond to a common field installation process of pulling the front end  292  through a conduit  105  first with the rear end  294  and the tethers  244  trailing. Other installation processes are also possible. 
         [0073]      FIG. 12  is a cross-sectional view representative of an example configuration for the tethers  244  joined to the distribution cable  220  at the breakout location  246 . The depicted configuration has a flat profile and includes a central buffer tube  262  containing a plurality of optical fibers  224   t  (e.g., typically one to twelve loose or ribbonized fibers). Strength members  264  (e.g., flexible rods formed by glass fiber reinforced epoxy) are positioned on opposite sides of the central buffer tube  262 . An outer jacket  266  surrounds the strength members  264  and the buffer tube  262 . The outer jacket  266  includes an outer perimeter having an elongated transverse cross-sectional shape. An additional strength layer  265  (e.g., aramid yarn) can be positioned between the buffer tube  262  and the outer jacket  266 . 
         [0074]    To maintain a desired amount of slack within the optical fibers  224   dc ,  224   t  located within the protective sleeve  250 , it is desired to maintain a set spacing S between the breakout block  254  and the retention block  258 . To ensure that the spacing S is maintained, the mid-span breakout location  246  includes a tensile reinforcing arrangement that mechanically ties or links the breakout block  254  to the retention block  258 . The tensile reinforcing structure assists in maintaining the spacing S by resisting stretching of the over-mold  260  at the mid-span breakout location  246 . In the embodiment of  FIG. 10 , the tensile reinforcing arrangement includes a tensile reinforcing member  270  that extends between the breakout block  254  and the retention block  258 , and is anchored to the breakout block  254  and the retention block  258 . In one embodiment, the tensile reinforcing member  270  is a flexible member such as a rope, string, strand, or wire. In a preferred embodiment, the tensile reinforcing member  270  is constructed of aramid yarn (i.e., KEVLAR®). 
         [0075]    In the embodiment of  FIG. 10 , the tensile reinforcing member  270  includes a first segment  270   1  and a second segment  270   2 . The first segment  270   1  extends from the breakout block  254  to the retention block  258  at a location on a first side (e.g., a bottom side) of the distribution cable  220 . The second segment  270   2  extends from the breakout block  254  to the retention block  258  at an opposite second side (e.g., a top side) of the distribution cable  220 . 
         [0076]    Referring to  FIGS. 13 and 14 , the breakout block  254  provided at the mid-span breakout location  246  includes a first piece  300   1  that forms a right side of the breakout block  254  and a second piece  300   2  that forms a left side of the breakout block  254 . The first and second pieces  300   1 ,  300   2  are connected at an upper seam and a lower seam. In one embodiment, a bonding material (e.g., epoxy) is used at the upper and lower seams to connect the first and second pieces  300   1 ,  300   2  together. 
         [0077]    Referring still to  FIGS. 13 and 14 , the breakout block  254  defines a straight-through channel  306  and a breakout channel  308 . The straight-through channel  306  has an inner diameter that generally matches the outer diameter of the outer jacket  230  of the distribution cable  220 . The breakout channel  308  is configured to separate the accessed optical fibers  224   dc  from the distribution cable  220  by routing the optical fibers  224   dc  outwardly from the distribution cable  220  to the protective sleeve  250 . The breakout channel  308  includes an opening for routing the optical fibers  224   dc  radially outwardly from the distribution cable  220  into the breakout channel  308 . The breakout channel  308  also includes a second opening for routing the optical fibers  224   dc  outwardly from the breakout channel  308  and into the protective sleeve  250 . As best shown at  FIG. 14 , the second opening is defined by a cylindrical stem  315  sized to fit within the first end of the protective sleeve  250 . 
         [0078]    The upper and lower seams of the breakout block  254  are preferably configured to prevent over-mold material from seeping into the interior of the breakout block  254  during the over-molding process. 
         [0079]    Referring to  FIGS. 15 and 16 , the retention block  258  used at the mid-span breakout location  246  includes a first piece  400   1  that forms a left side of the retention block  258  and a second piece  400   2  that forms a right side of the retention block  258 . The first and second pieces  400   1 ,  400   2  of the retention block  258  are joined together at upper and lower seams. A bonding material such as epoxy can be used to secure the first and second pieces  400   1 ,  400   2  together at the upper and lower seams. 
         [0080]    Referring still to  FIGS. 15 and 16 , the retention block  258  defines a generally cylindrical straight-through passage  410 . The straight-through passage  410  defines an inner diameter sized to correspond with the outer diameter of the outer jacket  230  of the distribution cable  220 . When the retention block  258  is mounted on the distribution cable  220 , the distribution cable  220  extends through the straight-through passage  410  and may be bonded to the straight-through passage  410 . The retention block  258  also defines a tether passage arrangement  412  that passes through the retention block  258 . The tether passage arrangement  412  is adapted for receiving ends of the tethers  244 . 
         [0081]    Adjacent the front end of the retention block  258 , the tether passage arrangement  412  is defined by a generally cylindrical stem  414  that fits within the second end of the protective sleeve  250 . At the rear end of the retention block  258 , the tether passage arrangement defines two tether receptacles  416 . 
         [0082]    To prepare the mid-span breakout location on the distribution cable  220 , a portion of the outer jacket  230  is first ring cut and stripped away (see  FIG. 18 ) to provide a stripped region  500  having an upstream end  502  and a downstream end  504 . The outer strength member  228  can also be displaced (e.g., bunched at the bottom side of the cable) adjacent the ends  502 ,  504  to facilitate accessing the buffer tubes  222 . One of the buffer tubes  222  is then selected and a first window  508  is cut into the buffer tube adjacent the upstream end  502  of the stripped region  500  and a second window  510  is cut into the buffer tube  222  adjacent the downstream end  504  of the stripped region  500 . The optical fibers  224   dc  desired to be broken out are then accessed and severed at the second window  510 . After the optical fibers  224   dc  have been severed, the optical fibers  224   dc  are pulled from the buffer tube  222  through the first window  508 . With the distribution cable  220  prepared as shown at  FIG. 18 , the optical fibers  224   dc  are ready to be terminated to the prepared tether  244  of  FIG. 17 . 
         [0083]    To connect the tethers  244  to the distribution cable  220  at the mid-span breakout location  246 , the protective sleeve  250  is first slid over the exterior of the pre-prepared tethers  244 . The splice sleeves  248  can also be slid over the optical fibers  224   t  of each of the tethers  244 . A polymeric binder or resin is then applied to the ends of the exposed optical fibers  224   dc ,  224   t  to encase and ribbonize the ends of the optical fibers  224   dc ,  224   t . The ribbonized ends of the optical fibers  224   dc ,  224   t  are then fusion spliced together. After the fusion splice has been completed, the splice sleeves  248  are slid over the fusion splices to protect the splice locations  245 . 
         [0084]    Once the optical fibers  224   dc ,  224   t  have been fused together, the breakout block  254  is mounted to the distribution cable  220 . The first and second pieces  300   1 ,  300   2  of the breakout block  254  are then mounted over the distribution cable  220  adjacent the upstream end  502  of the stripped region  500 . As the first and second pieces  300   1 ,  300   2  of the breakout block  254  are mounted over the distribution cable  220 , the optical fibers  224   dc  are positioned to extend through the breakout channel  308 . Thereafter, the protective sleeve  250  is slid over the optical fibers  224   dc ,  224   t  such that the first end fits over the cylindrical stem  315  provided at the rear end of the breakout block  254 . 
         [0085]    Next, the retention block  258  is mounted at the downstream end  504  of the stripped region  500 . The first and second pieces  400   1 ,  400   2  of the retention block  258  are then mounted around the distribution cable  220  with the tether optical fibers  224   t  extending through the tether passage arrangement  412  and the stripped region  500  of the distribution cable  220  extending through the straight through-channel  410 . The cylindrical stem  414  of the retention block  258  is inserted into the second end of the protective sleeve  250 . 
         [0086]    Once the breakout block  254 , the retention block  258  and the protective sleeve  250  have been secured to the distribution cable  220 , the tensile reinforcing member  270  can be secured to the assembly in the manner previously described. Thereafter, tape  263  can be wrapped about the mid-span breakout location  246 . 
         [0087]    The fiber optic cable assembly  240 , prepared above, is over-molded with the over-mold layer  260  about the mid-span breakout location  246  to complete the manufacturing process. 
         [0088]    An exemplary mold  645  is illustrated at  FIGS. 24 through 39 . An initial configuration  650 ′ (shown at  FIG. 26 ) forms a first mold cavity  662 ′ and a final configuration  650  (shown at  FIG. 27 ) forms a second mold cavity  662  within the mold  645 . Similarities exist between the example mold  45  of  FIGS. 2 through 5  and the example mold  645  of  FIGS. 24 through 27  in that an appropriate and corresponding cable assembly is placed within the mold  45 ,  645  in the initial configuration  50 ′,  650 ′. The first mold cavity  62 ′,  662 ′ is then injected with a molding material that fills the first mold cavity  62 ′,  662 ′ and forms an initial over-mold. The mold  45 ,  645  is then reconfigured to the final configuration  50 ,  650  forming the second mold cavity  62 ,  662 . The second mold cavity  62 ,  662  is then injected with additional molding material that fills the second mold cavity  62 ,  662  and forms a final over-mold  30 ,  260 . 
         [0089]    In particular, the mold  645  is initially set to the initial configuration  650 ′ as shown at  FIGS. 26 ,  31 , and  33  including a first mold section  652 , a second mold section  654 , an initial center mold section  656 ′, a top mold section  658 , and a bottom mold section  660 . The initial center mold section  656 ′ includes an inlet  670  directed to the first mold cavity  662 ′ by a passage  680 . The first mold cavity  662 ′ is formed by the first mold section  652 , the initial center mold section  656 ′, and portions of the top mold section  658  and the bottom mold section  660 . The initial center mold section  656 ′ includes a wall  664  which excludes the second mold section  654  and remaining portions of the top mold section  658  and the bottom mold section  660  from the first mold cavity  662 ′. The fiber optic cable assembly  240  is placed within the first mold cavity  662 ′ and can also be placed within the second mold section  654 . Ports  666 ,  667  of the first mold section  652  and a port  663  of the initial center mold section  656 ′ support the cable assembly  240  within the first mold cavity  662 ′ and form a seal around the cable assembly  240 . A port  668  of the second mold section  654  can also support the cable assembly  240  outside the first mold cavity  662 ′. In particular, the ports  666  and  668  hold and seal the distribution cable  220  and the ports  667  hold and seal one or more tether cable  244 . In certain configurations of the fiber optic cable assembly  240 , certain tether cables  244  and/or distribution cables  220  may not be present and/or may not extend through one or more of their respective ports  666 ,  667 ,  668 . In this case, the unused ports  666 ,  667 ,  668  can be plugged. A first vent  672  allows air to escape the first mold cavity  662 ′ and also prevents excess pressure from developing within the cavity  662 ′. 
         [0090]    The first mold cavity  662 ′ is injected with a molten molding material creating an initial over-mold. Excess molding material can exit through the first vent  672 . The initial over-mold is allowed to cool until it is sufficiently solid. The initial center mold section  656 ′ is removed from the mold  645  and replaced with a final center mold section  656  as shown at  FIGS. 27 ,  32 , and  34 . The fiber optic cable assembly  240  is left undisturbed in the first and second mold sections  652 ,  654  while the center mold sections  656 ′,  656  are switched. The top mold section  658  can be raised to facilitate the switch. The final center mold section  656  includes another inlet  670  directed to the second mold cavity  662  by a passage  680 . The second mold cavity  662  is formed by the first mold section  652 , the final center mold section  656 , the second mold section  654 , the top mold section  658 , and the bottom mold section  660 . The port  668  of the second mold section  654  supports the fiber optic cable assembly  240  within the second mold cavity  662  and also forms a seal around the cable assembly  240 . Additional support is provided to the cable assembly  240  by the initial over-mold. A second vent  674  allows air to escape the second mold cavity  662  and also prevents excess pressure from developing within the cavity  662 . 
         [0091]    The second mold cavity  662  is injected with additional molten molding material combining with the initial over-mold to create a final over-mold  260 . Excess molding material can exit through the second vent  674 . The additional molten molding material can fuse with the initial over-mold. The final over-mold  260  is allowed to cool until it is sufficiently solid. The mold  645  is then removed from the cable system  240  as shown at  FIGS. 19 and 20 . 
         [0092]    To facilitate installation of the fiber optic cable assembly  240 , the various mold sections are separable. For example, the top mold section  658  and bottom mold section  660  are mating halves. The first mold section  652  is formed from a first half  652   a  and a second half  652   b.  Likewise, the second mold section  654  is formed from a first half  654   a  and a second half  654   b.  As illustrated at  FIG. 28 , the initial center mold section  656 ′ is formed from a first half  656   a ′ and a second half  656   b ′ split vertically. Likewise, the final center mold section  656  is formed from a first half  656   a  and a second half  656   b,  as illustrated at  FIG. 29 . 
         [0093]    Additional example tools such as an inlet block  710 , illustrated at  FIG. 40 , a mold press base  720 , illustrated at  FIG. 41 , and a mold press top  730 , illustrated at  FIG. 42 , facilitate installing the mold  645  in an injection molding machine. The mold press base  720  includes a pocket  722  for holding the bottom of the mold  645 . Similarly, the mold press top  730  includes a channel  734  for holding the top of the mold  645 . The mold press top  730  further includes an inlet block channel  732  for receiving the inlet block  710 . 
         [0094]    In addition to the cable and cable assemblies disclosed above, the concepts of the present disclosure may be applied to other cable systems, both optical and non-optical. An example of another cable assembly is given at U.S. Provisional Patent Application Ser. No. 60/976,054, filed Sep. 28, 2007, and U.S. patent application Ser. No. 12/180,670, filed Jul. 28, 2008, both entitled FACTORY SPLICED CABLE ASSEMBLY, which are hereby incorporated by reference in their entirety. 
         [0095]    From the forgoing detailed description, it will be evident that modifications and variations can be made without departing from the spirit or scope of the invention.