Patent Publication Number: US-2023147367-A1

Title: Fiber optic connector with interlocking crimp sleeve

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is being filed on Apr. 7, 2021 as a PCT International Patent Application and claims the benefit of U.S. Patent Application Ser. No. 63/006,829, filed on Apr. 8, 2020, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Fiber optic communication systems are becoming prevalent in part because service providers want to deliver high bandwidth communication capabilities (e.g., data and voice) to customers. Fiber optic communication systems employ a network of fiber optic cables to transmit large volumes of data and voice signals over relatively long distances. Optical fiber connectors are an important part of most fiber optic communication systems. Fiber optic connectors allow two optical fibers to be quickly optically connected without requiring a splice. Fiber optic connectors can be used to optically interconnect two lengths of optical fiber. Fiber optic connectors can also be used to interconnect lengths of optical fiber to passive and active equipment. 
     A fiber optic connector is often secured to the end of a corresponding fiber optic cable by anchoring strength numbers of the cable to the connector housing of the connector. Anchoring is typically accomplished through the use of conventional techniques such as crimps or adhesive. Anchoring the strength numbers of the cable to the connector housing is advantageous because it allows tensile load applied to the cable to be transferred from the strength members of the cable directly to the connector housing. Improvements are desired. 
     SUMMARY 
     One aspect of the disclosure relates to a plug connector configured to terminate an end of a cable. The plug connector extends along a longitudinal axis between opposite first and second axial ends. The plug connector defines a plug region at the first axial end and an anchor region at the second axial end. One or more carrying members (e.g., optical fiber, conductive wire, etc.) of the cable pass through the plug connector from the anchor region to the plug region. A surrounding portion of the cable (e.g., a jacket, a buffer tube, and/or one or more strength members (e.g., aramid yarn, reinforcing rods, etc.) attaches to the plug connector at the anchor region. 
     In certain implementations, the anchor region of the connector includes a support portion and a series of first interlock members which protrude outwardly from the support portion. A crimp sleeve can be disposed over the anchor region of the plug connector so that the surrounding portion of the cable extends between the crimp sleeve and the first interlock members. When the plug connector is assembled, the crimp sleeve can include second interlock members extending radially into gaps between the first interlock members to sandwich the surrounding portion of the cable therebetween. 
     In certain examples, each of the second interlock members of the crimp sleeve extends along a majority of an axial length of respective one of the gaps. In certain examples, the crimp sleeve has an exterior surface in which each of the second interlock members define respective depressions each having a rectangular cross dimension. 
     In certain examples, each of the first interlock members of the plug includes an outer surface facing radially outwardly from the support portion, a first transition surface extending between the support portion and one axial end of the outer surface, and a second transition surface extending between the support portion and the other axial end of the outer surface. In an example, the first and second transition surfaces are perpendicular to the longitudinal axis. In an example, the outer surface of a first interlock member has a common transverse cross-dimension along the axial length of the outer surface. In an example, each of the outer surface, the first transition surface, and the second transition surface engages the surrounding portion of the cable to induce friction therebetween. 
     In accordance with certain aspects of the disclosure, a plug connector manufacturing system includes a die set configured to install the crimp sleeve on the plug connector to anchor the cable to the plug connector. The die set is configured to form the second interlock members of the crimp sleeve to enhance retention of the surrounding portion of the cable between the crimp sleeve and the anchor end of the plug connector. The die set includes one or more forming members that align with gaps between the first interlock members of the plug connector when the plug connector is loaded onto the die set. The forming members create the second interlock members of the crimp sleeve. 
     The die set includes first and second bodies that are selectively movable between actuated and non-actuated positions. The first and second bodies cooperate to define a crimp station when the first and second bodies are in the actuated position. The first body defines an alignment stop against which the anchor end of the connector body abuts when the connector body is mounted to the die set to align the plug connector within the die set. 
     The forming members are disposed within the crimp station. In certain examples, the forming members extend along a majority of an axial length of the respective gap. In certain examples, the forming members have flat surfaces facing towards the crimp sleeve. In some examples, the forming members are disposed at one of the first and second bodies. In other examples, the forming members are disposed at both of the first and second bodies. 
     In certain implementations, the anchor end of the plug connector defines a strength member retention section and a jacket retention section. The jacket retention section is disposed between the strength member retention section and an axial end of the plug connector. the support portion of the anchor end has a reduced transverse cross-section at the jacket retention section compared to the transverse cross-section at the strength member retention section. Strength members of the cable extend over the axial end of the plug connector, over the jacket retention section, and over the strength member retention section. The jacket of the cable extends over the axial end and over the jacket retention section. The jacket terminates without extending over the strength member retention section of the support portion. 
     In certain implementations, the plug connector includes a plug body and a rear body. The plug body defines the plug end of the plug connector and the rear body defines the anchor end of the plug connector. In certain examples, the rear body snap-fits to the plug body. In certain examples, a spring is disposed between the plug body and the rear body to bias the carrying member (e.g., to bias a ferrule holding an optical fiber) towards the plug end of the plug connector. 
     Another aspect of the present disclosure relates to a method of terminating a cable at a plug connector. The cable can include a carrying member surrounded by a jacket. In certain examples, the cable also can include strength members disposed within the jacket. In certain examples, the plug connector can include a plug body and a rear body. 
     One aspect of the method includes positioning the cable at an anchor region of the plug connector; positioning a crimp sleeve over the cable at the anchor region; positioning the plug connector, the cable, and the crimp sleeve at a die set so that the anchor region aligns with a crimp station of the die set; and installing the crimp sleeve at the anchor region using the die set. 
     In certain implementations, the die set includes one or more forming members at the crimp station. Accordingly, installing the crimp sleeve includes compressing the crimp sleeve with at least the forming members to form second interlock members of the crimp sleeve. 
     In certain implementations, positioning the cable at the anchor region includes routing a carrying member through a passage defined through the plug connector to a plug region and routing a surrounding portion of the cable over an exterior of the anchor region so that the surrounding portion extends across a series of first interlock members protruding radially outwardly from the exterior of the anchor region. In certain examples, the surrounding portion of the cable includes a jacket and strength members. In some such examples, routing the surrounding portion of the cable over the exterior of the anchor region includes routing the strength members over a majority of the anchor region and routing the jacket over less of the anchor region than the strength members. 
     In certain implementations, positioning the plug connector and the crimp sleeve at the die set includes aligning an edge of the crimp sleeve and the axial end of the plug connector at a stop surface defined by the die set to align the crimp sleeve and anchor section with the forming members of the die set. In certain implementations, the plug connector includes a plug body that connects to a rear body, which defines the anchor region. In some such implementations, the plug body and the rear body are connected together when the anchor region is positioned at the crimping station. In other such implementations, the rear body is separate from the plug body when the anchor station and crimp sleeve are disposed at the crimping station. 
     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 
       The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows: 
         FIG.  1    is a perspective view of an example cable assembly including an example cable anchored to an example plug connector using a crimp sleeve in accordance with the principles of the present disclosure. 
         FIG.  2    is a perspective view of the plug connector of  FIG.  1   , which extends along a longitudinal axis between an anchor region and a plug region. 
         FIG.  3    is a cross sectional view of the plug connector of  FIG.  1    taken along the longitudinal axis of the plug connector. 
         FIG.  4    is a top perspective view of an example die set with a first body of the die set shown exploded from a second body of the die set so that a portion of the crimping station is visible. 
         FIG.  5    is an enlarged view of the portion of the crimping station of  FIG.  4   . 
         FIG.  6    is a bottom perspective view of the die set of  FIG.  4    in which another portion of the crimping station is visible. 
         FIG.  7    is an enlarged view of the other portion of the crimping station of  FIG.  6   . 
         FIG.  8    is a perspective view of the cable assembly of  FIG.  2    disposed at a crimping station of a die set, with the crimp sleeve shown uncompressed, and with a portion of the die set being removed for ease in viewing. 
         FIG.  9    shows the plug connector and partial die set of  FIG.  8    with the cable removed for ease in viewing the second axial ends of the plug connector and crimp sleeves. 
         FIG.  10    shows an example implementation of the anchor region suitable for use with the plug connector of  FIG.  1   . 
         FIG.  11    is an exploded view of an example implementation of the plug connector of  FIG.  1    including a plug body and a rear body. 
     
    
    
     DETAILED DESCRIPTION 
     Various examples will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Reference to various examples does not limit the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible examples for the appended claims. 
     The present disclosure relates to a connectorized cable assembly  100  including a plug connector  110  terminating a cable  150 . The plug connector  110  extends along a longitudinal axis  120  between opposite first and second axial ends  114 ,  116  of the plug connector  110 . The cable  150  includes at least one carrying member (e.g., an optical fiber, a conductive wire, etc.) disposed within a surrounding portion  154  (e.g., a jacket, strength members, a buffer tube, etc.). The cable  150  is routed to the second axial end  116  of the plug connector  110 . The carrying member extends through a passage  111  ( FIG.  3   ) defined by the plug connector  110  towards the first axial end  114  of the plug connector  110 . The surrounding portion  154  of the cable  150  is attached to the plug connector  110  at the second axial end  116 . 
     In certain implementations, the plug connector  110  includes a plug region  111  at the first axial end  114  and an anchor region  115  at the second axial end  116 . The plug region  111  is configured to be received within a receptacle (e.g., adapter port, electrical socket, etc.). The surrounding portion  154  of the cable  150  is disposed about the anchor region  115  of the plug connector  110 . A crimp sleeve  160  is disposed over the surrounding portion  154  of the cable  150  at the anchor region  115 . The surrounding portion  154  is sandwiched between first interlocking members  118  of the plug connector  110  and second interlocking members  168  of the crimp sleeve  160  to retain the surrounding portion  154  at the plug connector  110  (e.g., see  FIG.  3   ). 
     In certain implementations, the surrounding portion  154  of the cable  150  includes a jacket  158  surrounding the one or more carrying members. In certain implementations, the surrounding portion  154  includes one or more strength members  156  (e.g., aramid yarn, fiberglass rods, etc.) disposed within the jacket  158 . In some examples, the strength members  156  are disposed between the carrying member and the jacket  158 . In other examples, the strength members  156  are embedded within the jacket  158 . In certain implementations, the surrounding portion  154  includes a buffer tube or intermediate jacket. 
     In some implementations, the carrying member includes an optical fiber. In some such implementations, the optical fiber is held by an optical ferrule at the plug region  111  of the plug connector  110 . In other such implementations, the plug connector  110  is ferruleless. In other implementations, the carrying member includes a conductive wire. In some such implementations, the conductive wire extends to a termination contact (e.g., a spring contact, an insulation displacement contact, etc.) at the plug region  111  of the plug connector  110 . In certain implementations, the cable  150  includes a plurality of carrying members extending through the surrounding portion  154 . 
     To secure the surrounding portion  154  of the cable  150  to the plug connector  110 , the crimp sleeve  160  is radially compressed over the anchor region  115  of the plug connector  110  and the surrounding portion  154  of the cable  150  using a die set  200  (e.g., see  FIGS.  4  and  6   ). Once the crimp sleeve  160  is crimped using the die set  200 , the strength members  156  and cable jacket  158  are secured in place (e.g., through friction). 
     As shown, the die set  200  includes a crimping station having forming members  218 ,  228  that press into the crimp sleeve  160  to form the second interlock member  168 . In certain implementations, the forming members  218 ,  228  align with gaps  119  extending along the longitudinal axis  120  between the first interlock members  118  when the plug connector  110  and crimp sleeve  160  are mounted at the die set  200 . Accordingly, when pressure is applied to the die set  200 , the forming members  218 ,  228  deform the portions of the crimp sleeve  160  radially aligned with the gaps  119  towards the gaps  119  to form the second interlock members  168  (e.g., see  FIG.  3   ). In certain examples, the forming members  218 ,  228  leave a recesses  219  that face radially outwardly from the crimp sleeve  160 . 
     In some implementations, the forming members  218 ,  228  include one or more raised ribs that extend laterally across the crimping station (e.g., see  FIGS.  5  and  7   ). In such implementations, the second interlock members  168  include circumferential protrusions extending radially inwardly towards the anchor region  115  of the plug connector  110 . In some examples, the circumferential protrusions are ring shaped (e.g., have a circular transverse cross-sectional profile). In other examples, the circumferential protrusions have a series of flat surfaces to form a polygonal shape (e.g., having a hexagonal transverse cross-sectional profile, a pentagonal transverse cross-sectional profile, or an octagonal transverse cross-sectional profile). In other implementations, the forming members  218 ,  228  include a series of shorter ribs arranged in one or more rows that extend laterally across the crimping station. In such implementations, the shorter ribs dimple the crimp sleeve  160  in circumferential rows to form the second interlock members  168 . 
     As shown in  FIGS.  4 - 7   , an example die set  200  includes separate first and second pieces  202 ,  206  that are movable between a loading configuration and a pressing configuration. Each of the pieces  202 ,  206  defines a respective cable station  206 ,  208 . When in the loading configuration, the cable stations  204 ,  208  are accessible to a user. When in the pressing configuration, the cable stations  204 ,  208  are aligned opposite each other. Each cable station  204 ,  208  is recessed into a surface  210 ,  220  of the respective die piece  202 ,  204  that faces the other die piece  204 ,  202 . Each cable station  204 ,  208  includes a crimp region  212 ,  222  at which the forming members  218 ,  228  are disposed. Each cable station  204 ,  208  also includes a cable channel  214 ,  224  through which the cable  150  extends away from the crimp sleeve  160  and connector  110 . In certain implementations, forming members  218 ,  228  are not disposed in the cable channel  214 ,  224 . 
     In certain implementations, the forming members  218 ,  228  include ribs having outer surfaces facing towards the anchor region  115  when the plug connector  110  is mounted at the cable station  204 ,  208 . In certain examples, the outer surfaces extend parallel to the longitudinal axis  120 . In certain examples, the ribs  218 ,  228  form continuous half rings laterally across the crimp regions  212 ,  222 . In certain examples, the ribs  218 ,  228  include multiple sections having flat outer surfaces (e.g., see  FIGS.  5  and  7   ). 
     In certain implementations, the edges  218   a ,  2228   a  of the ribs  218 ,  228  are recessed into the cable channel  214 ,  224  from the surface  210 ,  220  of the respective die set piece  202 ,  204 . Recessing the edges  218   a ,  228   a  may inhibit pinching or crimping of the sleeve  160  between the ribs  218 ,  228 . In certain examples, edges  218   a ,  228   a  of the ribs  218 ,  228 , whether recessed or not, are contoured or angled so that the ribs  218 ,  228  do not pinch the crimp sleeve  160  therebetween when the die set pieces  202 ,  204  are pressed together. For example, the edges  218   a ,  228   a  of each rib  218 ,  228  extend away from the surface  210 ,  220  of the respective die set piece  202 ,  204 . 
     In certain implementations, the cable station  204 ,  208  of at least one of the die pieces  202 ,  206  includes an alignment stop  216  configured to longitudinally align the anchor region  115  and crimp sleeve  160  at the crimp region  212 ,  222 . In certain examples, the alignment stop  216  includes a surface against which the second axial end  116  of the plug connector  110  abuts when properly loaded within the recessed cable station  204  (e.g., see  FIG.  9   ). When the second axial end  116  of the plug connector  110  abuts the alignment stop  216 , the forming members  218 ,  228  properly align with the gaps  119  between the first interlock members  118 . In certain examples, an axial end  166  of the crimp sleeve  160  also abuts the surface  216  (e.g., see  FIGS.  8  and  9   ). 
     In some implementations, the cable stations  204 ,  208  of the die set pieces  202 ,  206  are mirror images of each other. In other implementations, the cable station  204  of the first piece  202  is configured to receive the plug connector  110 , crimp sleeve  160 , and cable  150  before the second piece  204  is moved to the pressing configuration. Accordingly, the crimp region  212  of the cable station  204  is deeper (i.e., has a larger transverse cross-section) than the cable channel  214  to better accommodate the anchor region  115  and crimp sleeve  160  (see  FIGS.  5  and  9   ). In certain implementations, the crimp region  222  of the cable station  208  has a similar or the same transverse cross-section to the cable channel  224 . 
     In certain implementations, at least the crimp regions  212 ,  222  of the cable stations  204 ,  208  have polygonal transverse cross-sectional shapes that cooperate to define a hexagonally-shaped transverse cross-sectional profile of the crimp station. In certain examples, the forming members  218 ,  228  of the die set pieces  202 ,  204  also cooperate to define hexagon transverse cross-sectional shapes. In certain examples, the cable channel  224  of at least one of the die pieces  202 ,  204  has a polygonal transverse cross-sectional shape that matches the polygonal transverse cross-sectional shape of the crimp region  222  (see  FIG.  7   ). In some examples, both of the cable channels  214 ,  224  have a common transverse cross-sectional shape. In other examples, the cable channel  214  of the first die piece  202  is curved (see  FIG.  5   ). 
     Referring to  FIGS.  2  and  10   , an example plug connector  110  includes a support portion  112  at the anchor region  115 . The first interlock members  118  protrude outwardly from the support portion  112 . In certain examples, the support portion  112  forms the innermost surface of the gaps  119  between the interlock members  118 . The support portion  112  is sufficiently strong to enable the crimp sleeve  160  to deformed thereon without crushing the carrying member of the cable  150  that extends therethrough. In certain examples, the support portion  112  has a circular transverse cross-sectional shape prior to installation of the crimp sleeve  160 . 
     In certain implementations, the support portion  112  defines a strength member retention region  113  and a cable jacket retention region  117 . The cable jacket retention region  117  is disposed between the strength member retention region  113  and the second axial end  116  of the plug connector  110 . In certain examples, the strength member retention region  113  and the cable jacket retention region  117  cooperate to extend along an axial length of the anchor region  115  of the plug connector  110 . In certain implementations, the support portion  112  has a first transverse cross-dimension CD 1  (e.g., diameter) at the strength member retention region  113  and a second transverse cross-dimension CD 2  at the cable jacket retention region  117 . The first transverse cross-dimension CD 1  is larger than the second transverse cross-dimension CD 2  (see  FIG.  10   ). 
     As shown in  FIG.  3   , the strength members  156  of the cable  150  extend along both the strength member retention region  113  and the cable jacket retention region  117 . In certain examples, the jacket  158  of the cable  150  extends along only the cable jacket retention region  117 . The smaller transverse cross-dimension CD 2  of the jacket retention region  117  accommodates the presence of the jacket  158  between the support portion  112  and the crimp sleeve  160 . The larger transverse cross-dimension CD 1  of the strength member retention region  113  provides for a tight fit of the crimp sleeve  160  around the support portion  112  at the strength member retention region  113 . 
     As shown in  FIG.  10   , each of the first interlock members  118  has an outwardly-facing surface  118   a  extending along the longitudinal axis  120  between opposite first and second ends. In certain examples, the outwardly-facing surface extends parallel to the longitudinal axis  120 . A first transition surface  118   b  extends between the support portion  120  and the first end of the outer surface  118   a . A second transition surface  118   c  extends between the support portion  120  and the second end of the outer surface  118   a . In certain examples, the transition surfaces  118   b ,  118   c  extend transverse to the longitudinal axis  120 . 
     As shown in  FIG.  3   , each of the second interlock members  168  has an inwardly-facing surface  168   a  extending along the longitudinal axis  120  between opposite first and second ends. In certain examples, the inwardly-facing surface  168   a  extends parallel to the longitudinal axis  120 . A first transition surface  168   b  extends to the first end of the inner surface  168   a . A second transition surface  168   c  extends to the second end of the outer surface  168   a . In certain examples, the transition surfaces  168   b ,  168   c  extend transverse to the longitudinal axis  120 . In certain examples, portions of the transition surfaces  168   b ,  168   c  of the second interlock members  168  extend along portions of the transition surfaces  118   b ,  188   c  of adjacent ones of the first interlock members  118 . 
     As shown in  FIG.  3   , the outer surfaces  118   a  and transition surfaces  118   b ,  118   c  of the first interlock members  118  each form friction surfaces for retaining the surrounding portion  154  of the cable  150 . The inner surfaces  168   a  and transition surfaces  168   b ,  168   c  of the second interlock members  168  each form friction surfaces for retaining the surrounding portion  154  of the cable  150 . Accordingly, the surrounding portion  154  of the cable  150  is frictionally retained not only along the first interlock members  118 , but also along the second interlock members  119 . Further, in certain examples, the surrounding portion  154  of the cable  150  is frictionally retained not only along the outer-or inner-most surfaces  118   a ,  168   a  of interlock members  118 ,  168 , but also along at least parts of the transition surfaces  118   b ,  118   c ,  168   b ,  168   c  of the interlock members  118 ,  168 . 
     The first interlock members  118  each have respective axial lengths (e.g., axial lengths AL 1 , AL 3 ) extending along the longitudinal axis  120 . In some examples, the first interlock members  118  have a common axial length. In other examples, the axial length varies amongst the first interlock members  118 . The gaps  119  extending between the first interlock members  118  each have respective axial lengths (e.g., axial lengths AL 2 , AL 4 ). In some examples, the gaps  119  have a common axial length. In other examples, first interlock members  118  are spaced at different distances apart. The axial length AL 2 , AL 4  of the gap  119  between two interlock members  118  is larger than the axial length AL 1 , AL 3  of either of the two interlock members  118 . In certain implementations, the axial length AL 1  of each of the first interlock members  118  disposed along the strength member retention region  113  is larger than the axial length AL 3  of each of the first interlock members  118  disposed along the cable jacket retention region  117 . 
     In certain implementations, the ribs  218 ,  228  of the die pieces  202 ,  204  are sized to fit within the gaps  119  while accommodating the thickness of the crimp sleeve  160  disposed between the ribs  218 ,  228  and the bounding first interlock members  118 . In certain examples, each rib  218 ,  228  has a width that is no more than 0.75 times the axial length AL 2 , AL 4  of the respective gap  119 . In certain examples, each rib  218 ,  228  has a width that is no more than 0.5 times the axial length AL 2 , AL 4  of the respective gap  119 . 
     In accordance with certain aspects of the disclosure, the plug connector  110  is made from multiple separate pieces. For example,  FIG.  11    shows an exploded view of an example plug connector  110  including a plug body  170  and a rear body  173  that couple together to form the plug connector  110 . The plug body  170  defines the plug region  113  of the plug connector  110 . The rear body  173  defines the anchor region  115  of the plug connector  110 . In certain examples, a spring may be captured between the plug body  170  and the rear body  173  (e.g., to bias the carrying member towards a plug end face). In certain implementations, the rear body  173  is assembled to the plug body  170  before the cable  150  is anchored to the plug connector  110 . 
     The plug body  170  extends between a first end  171  and an opposite second end  172 . The rear body  173  extends between opposite first and second ends  174 ,  175 , respectively. The first end  174  of the rear body  173  couples to the second end  172  of the plug body  170 . In certain implementations, the rear body  173  includes an insertion portion  176  at the first end  174  of the rear body  173 . The insertion portion  176  may be inserted inside the plug body  170  through an opening at the second end  172 . In certain implementations, the first end  174  of the rear body  173  snap-fits (e.g., latches) within the plug body  170 . For example, barbs  177  at the insertion portion  176  may engage catch surfaces within the plug body  170 . 
     From the forgoing detailed description, it will be evident that modifications and variations can be made in the aspects of the disclosure without departing from the spirit or scope of the aspects. While the best modes for carrying out the many aspects of the present teachings have been described in detail, those familiar with the art to which these teachings relate will recognize various alternative aspects for practicing the present teachings that are within the scope of the appended claims.