Abstract:
A fiber optic connector assembly includes a connector and a carrier. The connector has a first and second ends and a terminated fiber. The fiber defines a first end adjacent the first end of the connector and a second end protruding out of the second end of the connector. A carrier having a connector end and an opposite cable end is engaged with the connector. An alignment structure on the carrier includes a first end, a second end and a throughhole and also a cutaway extending perpendicularly to and communicating with the throughhole. The fiber is positioned within at least a portion of the throughhole with the second end located within the cutaway. A window is within the cutaway over the second end of the fiber for visually inspecting the alignment of the second end of the fiber with an end of another fiber.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of application Ser. No. 12/500,188, filed Jul. 9, 2009, which application claims the benefit of provisional application Ser. No. 61/079,732, filed Jul. 10, 2008, which applications are incorporated herein by reference in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to a fiber optic connector assembly, and more particularly, to a field terminable fiber optic connector assembly. 
       BACKGROUND 
       [0003]    The use of fiber optic networks as a signal-carrying medium for communications is now widespread and continues to increase. Fiber optic networks frequently include a plurality of fiber optic cables having optical fibers. As fiber optic networks continue to grow, the need for optical fiber terminations for maintenance or expansion purposes is also growing. As such, there is a need for an optical fiber termination which can be performed in the field. 
       SUMMARY 
       [0004]    An aspect of the present disclosure relates to a fiber optic connector assembly comprising a fiber optic connector having a first mating end and a second end and an optical fiber terminated to the fiber optic connector, the optical fiber defining a first end adjacent the mating end for optical connection to a second fiber optic connector, the optical fiber defining a second end protruding out of the second end of the fiber optic connector. A carrier having a connector end and an oppositely disposed cable end is engaged with the fiber optic connector. An alignment structure is disposed on the carrier, the alignment structure including a first end and a second end and a throughhole extending from the first end to the second end, the alignment structure including a cutaway portion extending generally perpendicularly to and communicating with the throughhole, the optical fiber terminated to the fiber optic connector being positioned within at least a portion of the throughhole with the second end of the optical fiber located within the cutaway portion of the alignment structure. A window is disposed within the cutaway portion of the alignment structure over the second end of the optic fiber, the window configured for visually inspecting an alignment of the second end of the optical fiber with an end of a second optical fiber entering the cable end of the carrier. A heat activated element that is configured to melt when exposed to a predetermined amount of heat and resolidify when the heat is removed bonds the first optical fiber to the second optical fiber. 
         [0005]    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 
         [0006]    The accompanying drawings are included to provide a further understanding of the inventive aspects of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and together with the description serve to further explain the principles of the disclosure. Other aspects of the present disclosure and many of the advantages of the present disclosure will be readily appreciated as the present disclosure becomes better understood by reference to the following Detailed Description when considered in connection with the accompanying drawings, and wherein: 
           [0007]      FIG. 1  is a perspective view of a fiber optic connector assembly having features that are examples of inventive aspects in accordance with the principles of the present disclosure, the fiber optic connector assembly shown in a fully assembled configuration; 
           [0008]      FIG. 1A  illustrates the fiber optic connector assembly of  FIG. 1  with the alignment guide of the assembly removed; 
           [0009]      FIG. 2  is a fully exploded view of the fiber optic connector assembly of  FIG. 1 ; 
           [0010]      FIG. 2A  illustrates the exploded view of the fiber optic connector assembly of  FIG. 1A ; 
           [0011]      FIG. 3  is a front perspective view of a fiber optic connector of the fiber connector assembly of  FIG. 1 ; 
           [0012]      FIG. 4  is a rear perspective view of the fiber optic connector of  FIG. 3 ; 
           [0013]      FIG. 5  is a perspective view of the saddle assembly of the fiber optic connector assembly of  FIG. 1 ; 
           [0014]      FIG. 6  is an exploded view of the saddle assembly of  FIG. 5 ; 
           [0015]      FIG. 7  is an exploded view of the alignment guide of the fiber optic connector assembly of  FIG. 1 ; 
           [0016]      FIG. 8  is a cross-sectional view of the alignment guide taken along line  8 - 8  of  FIG. 7  with the window of the alignment guide inserted into the base of the alignment guide; 
           [0017]      FIG. 9  is a front view of the alignment guide of  FIG. 7 ; 
           [0018]      FIG. 10  is a cross-sectional view of the alignment guide taken along line  10 - 10  of  FIG. 7  with the window of the alignment guide inserted into the base of the alignment guide; 
           [0019]      FIG. 11  is a perspective view of the base of the alignment guide of  FIG. 7 ; 
           [0020]      FIG. 12  is a side view of the base of  FIG. 11 ; 
           [0021]      FIG. 13  is a top view of the base of  FIG. 11 ; 
           [0022]      FIG. 14  is a cross-sectional view of the base taken along line  14 - 14  of  FIG. 13 ; 
           [0023]      FIG. 15  is a rear view of the base of  FIG. 11 ; 
           [0024]      FIG. 16  is a cross-sectional view of the base taken along line  16 - 16  of  FIG. 12 ; 
           [0025]      FIG. 17  is a perspective view of the alignment window of the alignment guide of  FIG. 7 ; 
           [0026]      FIG. 18  is a front view of the alignment window of  FIG. 17 ; and 
           [0027]      FIG. 19  is a right side view of the alignment window of  FIG. 17 . 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    Reference will now be made in detail to the exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
         [0029]    Referring now to  FIGS. 1 and 2 , a fiber optic connector assembly  10  that can be used in terminating at least one optical fiber in the field is shown. In the embodiment shown, the fiber optic connector assembly  10  includes two simplex assemblies  10   a  joined together to form a duplex assembly  10   b.  Each simplex assembly  10   a  generally includes a carrier  12  and a fiber optic connector  14  that is coupled to the carrier  12 . The simplex assemblies  10   a  may be joined together with at least one removable joint pin  16  that is coupled to the connectors  14  of the assemblies  10   a.  Also, the each of the carriers  12  of the fiber optic connector assemblies  10   a  includes a hole  18  on a first side  20  and an integrally molded pin  22  on an opposing second side  24  so that two carriers  12  may be joined together. Since each carrier  12  includes a hole  18  and a molded pin  22  on opposite, alternating sides, a carrier  12  can be joined to another carrier at either side thereof. 
         [0030]    The separability of the fiber optic connector assemblies  10   a  provides the advantage of using one or two assemblies, as needed, or being able to swap the assemblies when the position of the two fiber optic connectors  14  have to be switched relative to one another. For example, the position of the two fiber optic connectors  14  may have to be switched when the fiber optic connector assembly  10  of the present disclosure is used as an insert within a housing such as the housing of a hybrid fiber/copper connector or a quad connector as described in U.S. Provisional Patent Application Ser. No. 61/044,370 and U.S. Provisional Patent Application Ser. No. 61/005,107, the entire disclosures of which are incorporated herein by reference. 
         [0031]    As discussed in the above-mentioned applications that have been incorporated herein by reference, if the gender of one of the hybrid connectors or quad connectors needs to be changed, the position of the two fiber optic connectors  14  within the housing may need to be switched. This can be accomplished by separating the two simplex fiber optic connector assemblies  10   a  of the present disclosure and swapping their positions. 
         [0032]    Although described in U.S. Provisional Patent Application Ser. No. 61/044,370 and U.S. Provisional Patent Application Ser. No. 61/005,107 as being usable in hybrid or quad connector housings, the fiber optic connector assembly  10  of the present disclosure can be used as an insert in any type of housing to protect the fiber optic connector assembly from damage. 
         [0033]    While the connectors  14  shown and described as being used with the fiber optic connector assembly  10  of the present disclosure are either LX.5 or BX5 connectors as manufactured by ADC Telecommunications, Inc., which have been described in detail in U.S. Pat. Nos. 5,883,995 and 6,142,676 and U.S. Provisional Patent Application Ser. No. 61/044,370 and U.S. Provisional Patent Application Ser. No. 61/005,107, hereby incorporated by reference in their entirety, it will be understood by those skilled in the art that the scope of the present disclosure is not limited to the use of a LX.5 or BX5-type connector within the assembly. Also, while the fiber optic connector assembly  10  of the present disclosure is depicted and described as being formed from two simplex connector assemblies  10   a  joined together to form a duplex assembly  10   b,  in other embodiments, the fiber optic connector assembly  10  can be configured to include any number of connectors  14  and able to terminate any number of optical fibers. Also, while the fiber optic connector assembly  10  of the present disclosure includes simplex assemblies  10   a  that are removably joined together, in other embodiments, the fiber optic connector assembly  10  may include any number of assemblies that are integrally formed. 
         [0034]    For sake of simplicity, the fiber optic connector assembly  10  of the present disclosure will be described with respect to one of the simplex assemblies  10   a,  with the understanding that the description thereof will be applicable to the other of the simplex assemblies  10   a.    
         [0035]    Still referring to  FIGS. 1 and 2 , the fiber optic connector assembly  10 , in addition to the carrier  12  and the fiber optic connector  14 , also includes a saddle assembly  26  and an alignment guide  28  that are coupled to the carrier  12 . As will be described in further detail below, the alignment guide  28  is used to align a factory terminated optical fiber  30  with a field optical fiber  32  and the saddle assembly  26  is used to mechanically splice the factory fiber  30  to the field fiber  32 . 
         [0036]    The carrier  12  includes a connector end  34  and a cable end  36 , which is oppositely disposed from the connector end  34 . In the present embodiment, the connector end  34  defines a slot  38  for slidably mounting the connector  14 . The connector  14 , further details of which are described in U.S. Pat. Nos. 5,883,995 and 6,142,676 and U.S. patent application Ser. No. 11/735,267, incorporated herein by reference in their entirety, defines a tube  40  adjacent the rear end  42  of the connector  14 . The tube  40  defines an annular groove  44  (see  FIG. 4 ) disposed on the outer surface of the tube  40 . The connector  14  is placed on the carrier  12  with the annular groove  44  slidably fitting in the slot  38  of the carrier  12 . Once slidably inserted, the connector  14  may be epoxied to the carrier  12 . It will be understood by those skilled in the art that the scope of the present disclosure is not limited to the carrier defining a slot for mounting the connector and that the connector can be mounted to the carrier in any other suitable manner. 
         [0037]    Still referring to  FIGS. 1 and 2 , disposed between the connector end  34  and the cable end  36  of the carrier  12  is a fiber support  48 . In the embodiment shown, the fiber support  48  defines a V-shaped guide way  50  that narrow as the depth of the guide way  50  increases. 
         [0038]    A termination region, generally designated by  52 , is disposed between the cable end  36  of the carrier  12  and the fiber support  48 . The termination region  52  is the portion of the carrier  12  wherein a factory terminated fiber  30  that extends from the connector  14  is mechanically spliced to a field fiber  32  that is aligned with the factory fiber  30 . 
         [0039]    The termination region  52  of the carrier  12  defines a groove  54  for supporting the alignment guide  28 . The groove  54  is contoured to fit the outer surface of the alignment guide  28 . The termination region  52  also defines a guide path  56  that extends from the rear end of the alignment guide  28  (when the alignment guide is in place) to the connector end  34  of the carrier  12 . The guide path  56  is configured to generally align with a crimp tube hole  60  defined at the cable end  36  of the carrier  12  and also align with the guide way  50  of the fiber support  48  of the carrier  12 . As will be described in further detail below, when the alignment guide  28  is positioned within the carrier  12 , the guide path  56  also aligns with the throughhole  104  of the alignment guide  28  so that a factory terminated fiber  30  can be matched up to the field fiber  32 . 
         [0040]    Adjacent the cable end  36  of the carrier  12 , each of the right and left sidewalls  64 ,  66  of the carrier  12  defines a vertical recess  68 . The vertical recesses  68  are configured to accommodate the legs  70  of the saddle  72  when the saddle  72  is placed on the carrier  12 , as will be discussed in further detail below. Although in the present disclosure, each carrier  12  is shown to include its own individual saddle  72 , in other embodiments, a single, larger saddle may be used to expand the width of two or more simplex carriers  12 . 
         [0041]    The carrier  12  further include a crimp tube  74 , which is engaged with the cable end  36  of the carrier  12 . In the present embodiment, the crimp tube  74  is in a press-fit engagement with the crimp tube hole  60  in the cable end  36  of the carrier  12 . In other embodiments, the crimp tube  74  may be molded integrally with the carrier  12 . The crimp tube  74  defines a passageway through which the cleaved field optical fiber  32  is inserted. Strength members/layers (e.g., Kevlar) of a fiber optic cable can be crimped on the outer surface of the crimp tube  74  for securing the fiber optic cable to the carrier  12 . 
         [0042]    Referring now to  FIGS. 5 and 6 , the saddle assembly  26  is shown in closer detail. The saddle assembly  26  includes the saddle  72  and a resistor  80  with a heat responsive adhesive element  82  configured to be positioned between the saddle  72  and the carrier  12 . In the embodiment shown, the heat responsive element  82  is a glue pellet  83 . Although in the depicted embodiment, glue pellet  83  is shown as being generally rectangular, it will be understood by those skilled in the art that other shapes for the glue pellet  83  may be used. The glue pellet  83  includes a first surface  84  and an oppositely disposed second surface  86 . In the depicted embodiment, at least one pathway  88  is pre-formed in the glue pellet  83 . In the depicted embodiment, the at least one pathway  88  is a channel  89  that is pre-formed in the second surface  86  of the glue pellet  83 . The channel  89  is adapted to receive a portion of the cleaved field optical fiber  32  and a portion of the field buffer, which surrounds the cleaved field optical fiber  32 . In the present embodiment, the channel  89  is arcuately shaped so as to conform to the outer surface of the buffer. It should be noted that the shape of the glue pellet  83  may be varied in other embodiments and may or may not include a preformed channel, depending upon the application. 
         [0043]    As shown in  FIG. 5 , the glue pellet  83  is in thermally conductive contact with the saddle  72 , which is in thermally conductive contact with the resistor  80 . Thus, the saddle  72  is preferably made out of thermally conductive materials. In the present embodiment, the first surface  84  of the glue pellet  83  is in contact with a bottom surface  90  of the saddle  72 , thereby establishing the thermally conductive contact between the glue pellet  83  and the saddle  72 . The resistor  80  is in contact with a top surface  92  of the saddle  72 , thereby establishing the thermally conductive contact between the resistor  80  and the saddle  72 . Similar saddle assemblies including shaped adhesive pre-forms are described in U.S. patent application Ser. Nos. 11/735,267 and 11/735,260, the disclosures of which are incorporated herein by reference in their entirety. 
         [0044]    When the field optical fiber  32  is ready for termination, a portion of the outer surface of the buffer of the field fiber optic cable is disposed in the channel  89  of the glue pellet  83 . In the present embodiment, the glue pellet  83  is shaped such that nearly half of the outer circumference of the outer surface of the buffer is disposed in the channel  89 . 
         [0045]    Still referring to  FIGS. 5 and 6 , the saddle  72  is generally U-shaped with two legs  70  extending vertically downwardly. The glue pellet  83  is received between the legs  70 . The legs  70  are configured to slide within the recesses  68  defined on the sidewalls  64 ,  66  of the carrier  12 . As will be described in further detail below, when the glue pellet  83  melts, the saddle  72  moves vertically downwardly with respect to the carrier  12  with the legs  70  riding along the recesses  68 . 
         [0046]    Referring now to  FIGS. 7-19 , the alignment guide  28  in the fiber optic connector assembly  10  serves as the location for the termination of the optical fibers. The alignment guide  28  includes a base  100  and an alignment window  102  that is separately mounted on the base  100 . 
         [0047]    The base  100  is generally cylindrical in shape. In other embodiments, other shapes may be used for the base  100 . The base  100  defines a throughhole  104  extending from a first end  106  to the second end  108 . As shown in the Figures, at each end, the base defines a conical portion  110 . The conical portions  110  taper from a larger diameter portion adjacent the ends toward a small diameter portion toward the center of the base  100 . The conical portions  110  are configured to facilitate insertion of the optical fibers into the base  100 . 
         [0048]    The alignment guide  28  includes a cutout portion  112  about halfway along the length of the base  100 . As will be discussed in further detail below, the cutout  112  accommodates the window  102  that is placed on the base  100 . The cutout  112  is configured to expose and communicate with the throughhole  104  extending from the first end  106  to the second end  108  of the base  100 . 
         [0049]    The base  100  also includes a cutaway region  114  adjacent the second end  108 . The cutaway region  114  is configured to accommodate a portion of the saddle  72  when the glue pellet  83  melts and the saddle  72  moves vertically downwardly. When the saddle  72  comes to rest, the bottom surface  90  of the saddle  72  may rest on the cutaway region  114  of the base  100 . 
         [0050]    When the base  100  is initially provided on the fiber optic connector assembly  10 , a factory fiber  30  that is terminated to the connector  14  extends through the throughhole  104  in the base  100  about halfway through the length of the base  100 . The conical portion  110  at the first end  106  of the base  100  facilitates initial insertion of the factory fiber  30  into the base  100  of the alignment guide  28 . The end of the factory fiber  30  is exposed to the cutout portion  112  of the base  100 . 
         [0051]    The fiber that is factory terminated to the connector  14  and extending halfway through the length of the base  100  is supported by the fiber support  48  of the carrier  12  when the connector  14  and the base  100  are placed on the carrier  12 . 
         [0052]    Referring to  FIGS. 17-19 , the window  102  of the alignment guide  28  is shown in closer detail. The window  102  is placed within the cutout portion  112  of the base  100  and may be epoxied to the base  100 . The window  102  is preferably made out of a transparent material such as pyrex. Other materials are possible. The window  102  is configured to allow visual confirmation of the alignment between the factory fiber  30  that extends about halfway into the base  100  (exposed to the cutout  112 ) and the field fiber  32  that will be inserted from the opposite end of the carrier  12  into the base  100 . 
         [0053]    The window  102  defines a box-like configuration with a cutout portion  120  at the bottom  122 . As shown in  FIG. 10 , when the window  102  is placed within the cutout  112  of the base  100 , the cutout portion  120  of the window  102  is exposed toward one side of the base  100  with a portion of the cutout  120  also lying over the factory fiber/field fiber alignment location. The cutout portion  120  of the window  102  is configured to allow any excess index matching gel to flow thereinto. 
         [0054]    Once the factory fiber side of the fiber optic termination assembly is correctly positioned, the connector  14 , the factory fiber stub  30  and the alignment guide  28  may be epoxied in place on the carrier  12 . 
         [0055]    In use, with the connector  14  engaged to the carrier  12 , the optical fiber  30  affixed in the guide way  50  of the fiber support  48 , and the factory fiber end inserted into the throughhole  104  of the base  100  of the alignment guide  28 , an end of the cleaved field optical fiber  32  is inserted into the passageway of the crimp tube  74  defined at the rear of the carrier  12 . The end of the cleaved field optical fiber  32  is inserted through the channel  89  of the glue pellet  83  and into the throughhole  104  of the base  100  of the alignment guide  28 . In the present embodiment, an index matching gel is disposed between the cleaved end of the cleaved field optical fiber  32  and the end of the factory optical fiber  30 . The index matching gel has an index of refraction that matches the index of refraction of the glass of the factory optical fiber  30  and the cleaved field optical fiber  32 . According to one embodiment, the index matching gel may be hydroscopic. When the fiber ends are pushed together, the index matching gel flows into the cutout portion  120  of the window  102  filling at least a portion of the cutout  120 . 
         [0056]    With the cleaved end of the cleaved field optical fiber  32  inserted into the alignment guide  28 , optical radiation is passed through the optical fibers to assess proper alignment of the fiber end of the factory fiber  30  and the cleaved end of the field fiber  32 . As viewed from the window  102 , if optical radiation is detectable at the junction, then the alignment/abutment is not correct. The cleaved end may have to be polished or cleaned and reinserted into the alignment guide  28 . If little to no radiation is detectable at the junction of the factory fiber end and the cleaved field fiber end, then the cleaved field optical fiber  32  and the buffer can be secured to the fiber optic connector assembly  10  using the saddle assembly  26 . 
         [0057]    To secure the cleaved optical fiber  32  and the buffer to the fiber optic connector assembly  10 , an electrical power source is connected to the resistor  80 . Electrical current is passed through the resistor  80  which heats up the glue pellet  83  by way of the thermally conducting saddle  72 . As the glue pellet  83  heats up, the glue pellet  83  becomes tacky and adheres to the buffer and the cleaved optical fiber  32  and closes the passageway of the crimp tube  74 . When the current is interrupted, the glue pellet  83  resets to secure the buffer and the cleaved optical fiber  32  in its correct position in alignment with the factory optical fiber  30 . 
         [0058]    When the glue pellet  83  first starts to melt, the legs  70  of the saddle  72  slide vertically downwardly along the recesses  68  defined on the sidewalls  64 ,  66  of the carrier  12 . As discussed previously, the cutaway region  114  of the base  100  is configured to accommodate at least a portion of the saddle  72  as the saddle  72  moves downwardly relative to the carrier  12 . When the glue pellet  83  resets, the buffer of the field fiber  32  is sealed to the guide path  56  of the carrier termination region  52 , the rear end of the base  100  of the alignment guide  28  is sealed to the groove  54  in the carrier  12 , and the field fiber  32  is sealed to the base  100  of the alignment guide  28 , securing the entire rear side of the fiber optic termination assembly  10  in correct alignment. 
         [0059]    A field termination kit as described in further detail in U.S. Provisional Patent Application Ser. No. 60/911,792, the entire disclosure of which is incorporated herein by reference, can be used in terminating the field fiber to the factory fiber as discussed herein. 
         [0060]    In one embodiment, the glue pellet  83  may be remeltable such that if the performed seal is not satisfactory, the glue pellet  83  can be remelted by the application of electric current and reset. 
         [0061]    In one embodiment, the carrier  12  may be manufactured out of a dielectric or polymeric material such that substantially all of the heat energy from the resistor  80  is transferred to the conductive saddle  72  rather than the carrier itself. In other embodiments, the carrier  12  may be made out of metallic materials. 
         [0062]    In other embodiments of the carrier  12  and the saddle  72  of the fiber optic connector assembly, the legs  70  of the saddle  72  may include inwardly extending tab portions at the ends of the legs  70  for securing the saddle  72  to the carrier  12  and to limit separation during upward movement of the saddle  72  relative to the carrier  12 . In such an embodiment, the saddle  72  would snap fit onto the carrier  12  with the legs  70  extending along the recesses  68  and the inwardly extending tab portions extending into inwardly extending slots formed at the ends of the recesses  68 . In this manner, the saddle  72  may remain attached to the carrier  12  even if the saddle  72  moves upwardly relative to the carrier  12 , with the tabs of the legs  70  catching the inwardly extending slots at the bottom ends of the recesses  68  of the carrier  12 . 
         [0063]    As discussed above, with the field optical fiber  32  secured, the fiber optic connector assembly  10  can also be provided as an insert for a housing to protect the fiber optic connector assembly  10  from damage. A number of housings into which the fiber optic connector assembly  10  can be inserted are described in U.S. Provisional Patent Application Ser. No. 61/044,370 and U.S. Provisional Patent Application Ser. No. 61/005,107, hereby incorporated by reference in their entirety. 
         [0064]    Various modifications and alterations of this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure, and it should be understood that the inventive features are not to be unduly limited to the illustrative embodiments set forth herein.