Abstract:
A fiber optic connector includes a boot receiving an optical fiber; a connector body for receiving the optical fiber and terminating the optical fiber; and a latch coupled to the connector body, the latch for engaging an adapter for receiving the fiber optic connector, the latch repositionable relative to the connector body to enable polarity change of the fiber optic connector without changing a relative position of the connector body and the optical fiber.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Fiber optic connectors are used to terminate fiber optic cable. One format for a fiber optic connector is the LC format. Existing LC connectors have a latch that must be depressed. In high-density applications it can be difficult for users to get their fingers into tight spaces to depress the latch. To address this issue, existing LC connectors utilize a “push-pull” mating mechanism to activate the LC latch. These push-pull designs use a traditional LC body/latch combination, which increases the overall connector height, and also typically require the user to grasp a duplex clip to release the latch, which is far forward near the congested mating area. 
         [0002]    With fiber optic cable termination, it is sometimes necessary to change polarity of the connection. Existing uniboot connectors either do not allow polarity changes or make it difficult for the user to make a change. Polarity changes on these connectors require disconnecting the connector from a clip, and rotating the connector. This rotation of the connector simultaneously rotates the fiber, placing strain on the fiber. This requires numerous steps to be performed by the user, and also exposes the sensitive fiber to damage, particularly in the field where conditions are variable. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is an exploded, perspective view of a connector in an exemplary embodiment. 
           [0004]      FIG. 2  is a perspective view of the connector of  FIG. 1  assembled. 
           [0005]      FIG. 3  is a perspective view of the connector of  FIG. 1  with the cover removed. 
           [0006]      FIG. 4  is a perspective view of a cover in an exemplary embodiment. 
           [0007]      FIG. 5  is a perspective view of a latch in an exemplary embodiment. 
           [0008]      FIG. 6  is a perspective view of the connector of  FIG. 1  with the boot and cover removed. 
           [0009]      FIGS. 7-10  illustrates changing connector polarity in an exemplary embodiment. 
           [0010]      FIG. 11  illustrates a connector body and fiber holder in an exemplary embodiment. 
           [0011]      FIG. 12  illustrates mounting the cover to the body in an exemplary embodiment. 
           [0012]      FIGS. 13-16  illustrate a polarity icon in an exemplary embodiment. 
           [0013]      FIGS. 17- 19  illustrate polarity indicia in an alternate exemplary embodiment. 
           [0014]      FIG. 20  is an exploded, perspective view of a connector in another exemplary embodiment. 
           [0015]      FIG. 21  is a cross-sectional view of a portion of the connector of  FIG. 21 . 
           [0016]      FIG. 22  is a perspective view of a cover in an exemplary embodiment. 
           [0017]      FIG. 23  is a cross-sectional view of a portion of the connector of  FIG. 21 . 
           [0018]      FIG. 24  is an exploded perspective view of a connector body and a latch in an exemplary embodiment. 
           [0019]      FIG. 25  illustrates interaction between a connector body and a fiber holder in an exemplary embodiment. 
           [0020]      FIGS. 26-28  illustrate changing connector polarity in an exemplary embodiment. 
           [0021]      FIGS. 29-30  illustrate fiber holder polarity indicia in an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Embodiments of the invention provide a push-pull LC duplex fiber connector that allows the connector to be more easily unlatched from its mating adapter when compared with a traditional LC connector. The connector includes a separate latch clip that enables the polarity to be changed without rotating the individual connectors, eliminating the need to twist the fibers, resulting in easier field polarity changes and a more reliable connection. 
         [0023]      FIG. 1  is an exploded, perspective view of a connector  100  including a boot  102 , cover  104 , latch  106 , fiber holder  108 , and connector bodies  110 . The connector bodies  110  are latchless, LC type connector bodies. It is understood that embodiments may use different connector bodies, and the invention is not limited to LC type connections. A cable  120  runs through boot  102  and includes two optical fibers. Heat shrink material  122  encases at least a portion of cable  120  and a crimp ring  124  is secured to cable  102 . Connector bodies  110  terminate the two optical fibers in cable  120 . The connector bodies  110  are latchless, as latch  106  is used to secure the connector  100  to an adapter. 
         [0024]    Boot  102  includes boot polarity indicia  130 , which includes two letters, but may include any type of symbol, color coding etc. Similarly, fiber holder  108  includes fiber holder polarity indicia  132 , which may match the boot polarity indicia  130 . Fiber holder  108  may include fiber holder polarity indicia  132  on both the top and bottom surfaces of the fiber holder  108 . The boot polarity indicia  130  and the fiber holder polarity indicia  132  indicate the polarity of the connector, depending upon whether the boot polarity indicia  130  and the fiber holder polarity indicia  132  are aligned or not (e.g., whether letters A and B are matched or not).  FIG. 2  is a perspective view of the assembled connector  100 .  FIG. 3  is a perspective view of the assembled connector  100 , with cover  104  removed. 
         [0025]      FIG. 4  is a perspective view of the cover  104 . Cover  104  includes a generally rectangular cover body  140 . Extending from a rear of cover body  140  is a resilient latch  142 . Latch  142  secures the cover  104  to body  102 . A front edge of body  140  includes fingers  144  that extend away from cover body  140 . As shown in  FIG. 1 , cover  104  is received in a cutout  103  in boot  102 . Fingers  144  are positioned under one edge of the cutout and latch  142  engages another edge of the cutout. To remove the cover, latch  142  is defeated using a finger or a tool. Tabs  143  extend below cover body  140  and travel in slots  155  ( FIG. 5 ) of latch  106  to limit travel of the boot  102  relative to the fiber holder  108 . 
         [0026]    Cover  104  also includes a nub  146  extending downwards from an underside of cover body  140 . Nub  146  coacts with a ridge  150  on latch  106  ( FIG. 5 ). Latch  106  includes resilient arms  152  that engage mating structure on an LC adapter. Arms  152  extend forward, away from boot  102 , along the axis of insertion of the connector  100  with an adapter. As such, connector  100  has a lower profile than existing connectors having latches that extend up and rearward. Arms  152  are integral with ridge  150 , and deflect when ridge  150  is deflected as described herein. Latch  106  also includes mounting tabs  154  that secure the latch  106  to fiber holder  108 . 
         [0027]    Latch  106  is secured to fiber holder  108  and boot  102  slides relative to fiber holder  108  to provide the push-pull activation of latch  106 . When mating the connector  100  to an adpater, boot  102  is pushed forward moving nub  146  forward of ridge  150 . This allows the latch arms  152  to engage mounting structure on an LC adapter. To disconnect connector  100  from an adapter, the boot  102  is pulled back, opposite the axis of insertion, causing nub  146  to ride on ridge  150 . This deflects arms  152  downwards and releases latch  106  from the LC adapter.  FIG. 6  is a perspective view of connector  100  with boot  102  and cover  104  removed. 
         [0028]    One aspect of embodiments of the invention is the ability to change polarity of the connector without applying undue stress on the optical fibers in cable  120 .  FIG. 7  illustrates a first step in changing the connector polarity, which involves removing the cover  104  from boot  102 .  FIG. 8  illustrates a second step in changing the connector polarity. In this second step, the boot  102  is pulled back along the cable  120  to expose the fiber holder  108 . Latch  106  is removed from the fiber holder  108 . 
         [0029]      FIG. 9  illustrates a third step in changing the connector polarity. As shown, the boot  102  is rotated  180  degrees and the latch  106  is moved from a first side of the fiber holder  108  to a second side of the fiber holder  108 . The fiber holder  108  is not rotated or repositioned. This reduces strain on the optical fibers terminated to the connector bodies  110 . Rotating the connector bodies  110 , which occurs with prior art designs, can cause torsional stress on the optical fibers. Embodiments of the invention avoid such stresses by maintaining the position of the fiber holder  108  and the connector bodies  110 . Further, the terminated connector bodies  110  need not be removed from the fiber holder  108  when changing polarity. This prevents damage to the optical fiber. In traditional designs, when changing the polarity, damage could result from just pulling the connectors out of the holder before rotation. 
         [0030]      FIG. 10  illustrates a fourth step in changing the connector polarity. As shown in  FIG. 10 , the fiber holder  108  is repositioned in boot  102  and cover  104  snapped back into position. 
         [0031]      FIG. 11  illustrates interaction between the connector body  110  and fiber holder  108 . Fiber holder  108  includes at least one tab  160  extending adjacent to a surface of each connector body  110 . The design in  FIG. 11  uses two tabs  160  adjacent to each connector body  110 . The interference between the tabs  160  and the surface of the connector bodies  110  prevents the connector bodies  110  from rotating. This keeps the connector bodies  110  aligned with the adapter to which connector  100  is mated. 
         [0032]      FIG. 12  illustrates toolless mounting of cover  104  to body  102 . 
         [0033]      FIG. 13  is a perspective view of connector  100  with an alternate cover  204  and a polarity icon  206 . Cover  204  is made from a clear material (i.e., transparent) and allows viewing of polarity icon  206  through cover  204 . Polarity icon  206  includes polarity icon indicia  208  which includes two letters, but may include any type of symbol, color coding etc. The polarity icon indicia  208  appears on both sides of polarity icon  206 , with the symbols reversed. The orientation of the polarity icon indicia  208  indicates the polarity of the connector  100 . Also shown in  FIG. 13  is a flared end  103  of boot  102 . The flared end  103  helps with strain/bend relief and also provides a lip for the user to pull against when unmating the connector from an adapter.  FIG. 14  is a top, perspective view of cover  204  fitted with polarity icon  206 .  FIG. 15  is a bottom, perspective view of cover  204  and polarity icon  206 . 
         [0034]      FIG. 16  is a perspective view of connector  100  with cover  204  and a polarity icon  206  after switching polarity relative to  FIG. 13 . To change polarity of the connector  100 , the steps of  FIGS. 7-10  discussed above are followed. Further, the polarity icon  206  is flipped by the installer and reinstalled in cover  204 . As shown in  FIG. 16 , the polarity icon indicia  208  is opposite that of  FIG. 13 , indicating that a change in polarity has occurred from a first polarity configuration to a second polarity configuration. The orientation of the polarity icon indicia  208  indicates the polarity of the connector. 
         [0035]      FIG. 17  shows a boot  302  in an alternate embodiment. Boot  302  is similar to boot  102  in  FIG. 13 , and includes a window  304  formed on an opposite side of cutout  103 . Window  304  is generally rectangular and allows viewing of the fiber holder polarity indicia  132  on the top and bottom surfaces of fiber holder  108 .  FIG. 18  shows the window  304  of boot  302  and the fiber holder polarity indicia  132  visible through window  304 . If polarity of the connector is changed (i.e., by rotating the boot  302  relative to the fiber adapter  108  as discussed above), the orientation of the fiber holder polarity indicia  132  changes.  FIG. 19  shows the window  304  after the polarity of the connector has been changed relative to  FIG. 18 . As is shown, the orientation of the fiber holder polarity indicia  132  is now reversed relative to  FIG. 18 . This allows easy determination of the polarity of the connector. 
         [0036]      FIG. 20  is an exploded, perspective view of a connector  400  in an alternate embodiment. The connector  400  allows for polarity change of the connector, without rotating the connector bodies as described above. Connector  400  includes individual latches on each connector body and a uni-boot design. Connector  400  includes a boot  402 , cover  104 , latches  406 , fiber holder  408 , and connector bodies  410 . The connector bodies  410  are LC type connector bodies. It is understood that embodiments may use different connector bodies, and the invention is not limited to LC type connections. A cable  420  runs through boot  402  and includes two optical fibers. Heat shrink material  422 , which may be optional, encases at least a portion of cable  420  and a crimp ring  424  secures cable  420  to fiber holder  408 . Connector bodies  410  terminate the two optical fibers in cable  420 . As described in further detail herein, connector bodies  410  each receive a latch  406 , which are used to secure the connector  400  to a duplex adapter. 
         [0037]      FIG. 21  is a cross-sectional showing the interaction between latch  406  and boot  402 . Each latch  406  includes a latch arm  430  that extends in a direction from a front, mating end of connector body  410  towards boot  402 . A latch collar  432  ( FIG. 20 ) is used to secure the latch  406  to connector body  410 , and is described in further detail herein. Boot  402  includes hooks  434 , each of which is received in an opening  436  in a distal free end of latch arm  430 . A cam surface  438  is formed on an interior surface of opening  436 , near the free, distal end of latch arm  430 . 
         [0038]    As with the embodiment in  FIG. 1 , boot  402  moves relative to fiber holder  408 . When boot  402  is forward, hooks  434  do not interfere with travel of latch arm  430 . Latch arm  430  is resilient and snaps into an adapter for mating with connector bodies  410 . A shoulder  431  is formed on latch arm  430  that engages a wall in an adapter, as is conventional for LC type connectors. 
         [0039]    To unplug the connector  400 , boot  402  is moved backwards, away from the mating end of connector body  410 , hooks  434  ride over cam surfaces  438  to deflect latch arm  430  downwards towards connector body  410 . This causes the latch arm  430  to become disengaged from an adapter to free the connector  400  from the adapter. 
         [0040]    The downward hook design of  FIG. 21  provides snag-prevention. When fiber connectors are used as part of cable assemblies in the field, they are snaked and routed through areas that are typically congested with high volumes of cables or other obstacles. When connectors have exposed edges or protrusions, they can become snagged during installation, potentially damaging the connector or other materials in the area. This snagging could occur when another object is swept over the connector in any direction, but is most typically seen when impacted from the back or the front. The downward hook  434  of  FIG. 21  allows a smoother surface on the connector  400  and boot  402  to eliminate many possible snag points. The design of hook  434  allows latch arm  430  to have a lower profile and be contained within a region defined by the outside surface of boot  402 . As latch arm  430  does not extend beyond an outside surface of boot  402 , snag prevention is enhanced. 
         [0041]      FIG. 22  is a perspective view of the cover  404 . Cover  404  includes a generally rectangular cover body  440 . Extending from a rear of cover body  440  is a resilient latch  442 . Latch  442  secures the cover  404  to boot  402 . A front edge of body  440  includes a finger  444  that extends away from cover body  440 . As shown in  FIG. 1 , cover  404  is received in a cutout  403  in boot  402 . Finger  444  is positioned under one edge of the cutout and latch  442  engages another edge of the cutout. To remove the cover, latch  442  is defeated using a finger or a tool. Tab  443  extends below cover body  440  and travels in slot  445  ( FIG. 20 ) of fiber holder  408  to limit travel of the boot  402  relative to the fiber holder  408  in both the forward and rearward directions. 
         [0042]    Latch  406  is secured to connector body  410 . Boot  402  slides relative to fiber holder  408  to provide the push-pull activation of latch  406 . When mating the connector  400  to an adapter, boot  402  is pushed forward so that hook  434  does not contact cam surface  438 . This allows the latch arms  430  to engage mounting structure on an LC adapter. To disconnect connector  400  from an adapter, the boot  402  is pulled back, opposite the axis of insertion, causing hooks  434  to ride over cam surfaces  438 . This deflects arms  430  downwards and releases latch  406  from the LC adapter. 
         [0043]      FIG. 23  is a cross-section view showing tab  443  positioned in slot  445 . Slot  445  is sized to limit travel of the cover  404 , and thus boot  402 , relative to the fiber holder  408 . This controls position of the hooks  434  relative to latch arms  430  to achieve the desired interaction between the hooks  434  and cam surfaces  438 . 
         [0044]    The embodiment of  FIG. 20  also provides the ability to change polarity of the connector without applying undue stress on the optical fibers in cable  420 .  FIG. 24  is an exploded, perspective view of a connector body  410  and latch  406 . Connector body  410  includes a main section  450 , which is generally rectangular (e.g., square). A front section  452  includes a cylindrical portion  454  which receives collar  432  of latch  406 . Front section  452  mates with main section  450  to enclose a spring-loaded ferrule. 
         [0045]    Collar  432  has a generally rectangular outside surface, with an internal, cylindrical opening  456 . Collar  432  is positioned over cylindrical portion  454  so that latch  406  can rotate relative to connector body  410 . Two nubs  458  on cylindrical portion  454  engage openings  460  in collar  432  to fix the orientation of collar  432  relative to connector body  410 . Nubs  458  secure the collar  432  in two positions corresponding to opposite connector polarities (e.g., 0 and 180 degrees), as described in further detail herein. The interference between nubs  458  and openings  460  can be defeated by rotating the collar  432  to disengage the nubs  458  from openings  460 . 
         [0046]      FIG. 25  illustrates interaction between the connector body  410  and fiber holder  408 . Main section  450  includes a rectangular (e.g., square) anti-rotation block  460  that is received in a similarly shaped channel  462  of fiber holder  408 . It is understood that geometries other than square may be used to prevent rotation. A cylindrical neck  461  adjacent to anti-rotation block  460  allows for easy insertion of the connector body  410  into the fiber holder  408 . Geometries other than cylindrical may be used for the connector body neck  461  that is inserted into the fiber holder  408 . Fiber holder  408  also includes at least one tab  464  extending adjacent to a surface of each connector body  410 . The design in  FIG. 25  uses two tabs  464  adjacent to each connector body  410 . The interference between the tabs  464  and the surface of the connector bodies  410  prevents the connector bodies  410  from rotating when mounted in fiber holder  408 . This keeps the connector bodies  410  aligned with the adapter to which connector  400  is mated. 
         [0047]      FIG. 26  illustrates a first step in changing the connector polarity, which involves removing the cover  404  from boot  402 . Boot  402  is pulled backwards from fiber holder  408  and connector bodies  410 . Hooks  434  ride over cam surfaces  438  and exit the latch arm. 
         [0048]      FIG. 27  illustrates a second step in changing the connector polarity. In this second step, latches  406  are rotated  180  degrees. Initial force applied to latch  406  disengages nubs  458  from openings  460  as collar  432  rotates about cylindrical portion  454 . As the collar  432  reaches  180  degrees from its initial position, nubs  458  re-engage openings  460  to secure latch  406  in the reversed polarity position. 
         [0049]      FIG. 28  illustrates a third step in changing the connector polarity. As shown, the boot  402  is rotated  180  degrees. The fiber holder  408  is not rotated or repositioned. This reduces strain on the optical fibers terminated to the connector bodies  410 . Rotating the connector bodies  410 , which occurs with prior art designs, can cause torsional stress on the optical fibers. Embodiments of the invention avoid such stresses by maintaining the position of the fiber holder  408  and the connector bodies  410 . Further, the terminated connector bodies  410  need not be removed from the fiber holder  408  when changing polarity. This prevents damage to the optical fiber. In traditional designs, when changing the polarity, damage could result from just pulling the connectors out of the holder before rotation. 
         [0050]    The final steps involve placing the fiber holder  408  back into boot  402  and reinstalling cover  404 . 
         [0051]      FIG. 29  is a perspective view of the fiber holder  408 . Fiber holder  408  includes a fiber holder polarity indicia  470  on one side of the fiber holder. As shown in  FIG. 30 , boot  402  includes a window  472  for viewing the fiber holder polarity indicia  470 . As the fiber holder polarity indicia  470  is formed on only one side of the fiber holder  408 , the polarity of connector  400  can be determined based on the presence or absence of the fiber holder polarity indicia  470  in window  472 . In alternate embodiments, a different fiber holder polarity indicia  470  is formed on each side of the fiber holder  408  (e.g., A on one side, B on the opposite side) so that one of the fiber holder polarity indicia  470  is presented in window  472  in either polarity orientation. 
         [0052]    Embodiments of the invention provide a high-density fiber connector to more easily access and unlatch a fiber LC connector without disturbing nearby connections. Embodiments enable higher density placement of mating adapters. Embodiments allow the user to grasp the connector boot far behind the mating area, where there is less interference from nearby connectors, and pull the boot to disengage the latch. Embodiments also provide damage-free polarity change and indicia to reflect the polarity change. 
         [0053]    Embodiments also provide a rotating latch allowing the polarity to be changed without rotating the individual connectors, eliminating the need to twist the fibers, resulting in easier field polarity changes and a more reliable connection. This establishes an easier and more reliable way for users in the field to change polarity of duplex fiber connectors. Although the rotating latch is most beneficial with uniboot-style connectors, it may also be applied to traditional connectors that use duplexing clips. 
         [0054]    The rotating latch  406  may be used with LC type connectors, such as the LC products from the Siemon Company. It is understood that the rotating latch may also be used with other types of connectors to provide polarity change. Also, the rotating latch may be used with other types of connectors (e.g., copper) to provide for reorienting latch position without disturbing the signal connections. The rotating latch  406  keeps the connector body positioned within the fiber holder and does not put stresses on the fiber, providing easy, damage-free polarity change. 
         [0055]    While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed for carrying out the invention, but that the invention will include all embodiments falling within the scope of this disclosure.