Patent Publication Number: US-11385414-B2

Title: Fiber optic connectors having an internal compliant member to compensate for tolerance stack-up of components

Description:
RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Ser. No. 62/928,421 filed on Oct. 31, 2019, the content of which is relied upon and incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     The disclosure is directed to fiber optic connectors that compensate for tolerance stack-up of components of the fiber optic connectors. More specifically, the disclosure is also directed to fiber optic connectors having an internal compliant member to compensate for the tolerance stack-up of components in an axial direction. 
     Optical fiber is increasingly being used for a variety of applications, including but not limited to broadband voice, video, and data transmission. As bandwidth demands increase optical fiber is migrating toward subscribers in outdoor communication networks such as in fiber to the premises applications such as FTTx and the like. To address this need for making optical connections in communication networks for the outside the plant environment hardened fiber optic connectors were developed. One of the most commercially successful hardened fiber optic connectors is the OptiTap® male plug connector sold by Corning Cable Systems, LLC of Hickory, N.C., such as disclosed in U.S. Pat. Nos. 7,090,406 and 7,113,679 (the &#39;406 and &#39;679 patents) and incorporated herein by reference. The Optitap® connector is a hardened male plug connector for terminating a cable that is configured for optical connection using a receptacle. As used herein, the term “hardened” describes a connector or receptacle port intended for making an environmentally sealed optical connection suitable for outdoor use, and the term “non-hardened” describes a connector or receptacle port that is not intended for making an environmentally sealed optical connection such as a SC connector. 
     The hardened connector such as the OptiTap may mated with another connector using a receptacle or adapter that receives a separate connector on each end for making an optical connection. Receptacles or adapters may be mounted on the wall of a box or bulkhead, and thus require three distinct assemblies for making an optical connection (e.g., a first connector, receptacle or adapter, and a second connector) as well-known in the art. 
       FIGS. 1A-1C  are prior art depictions showing various stages of mating of a preconnectorized cable  10  having a plug connector  5  such as an OptiTap® connector with a receptacle  30 . Receptacle  30  mates plug connector  5  with a standard SC connector (i.e., a non-hardened connector) at a second end (not visible in these views) using an adapter sleeve for aligning ferrules when mating plug connector  5  with the non-hardened connector. Protection of the non-hardened connector side of the receptacle is typically accomplished by mounting the receptacle  30  through a wall of an enclosure or the like so that the non-hardened end of the receptacle is disposed inside the enclosure for environmental protection of the non-hardened connector. As shown by  FIGS. 1A-1C , the other end of the receptacle  30  is accessible for receiving the plug connector  5  at the wall of the enclosure. Other applications may mount the receptacle  30  inside an enclosure on a bracket or the like. 
     Receptacle  30  allows an optical connection between the hardened connector such as the OptiTap® male plug connector with a non-hardened connector such as the SC connector at nodes in the optical network that typically transition from an outdoor space to an indoor space.  FIG. 2  depicts an exploded view of receptacle  30 , which is described in further detail in U.S. Pat. No. 6,579,014. As depicted, receptacle  30  includes a receptacle housing  12  and an adapter sleeve  18  disposed therein. The receptacle  30  receives a non-hardened connector at a second end  16  as represented by the arrow pointing to the left Adapter sleeve  18  is biased toward a first end  14  of the receptacle  30  that receives the connector  5  using springs  38 . This biasing of the adapter sleeve  18  toward the first end  14  that receives the plug connector  5  is used for maintaining physical ferrule-to-ferrule contact between the plug connector and the SC connector to increase the “float” between the mating ferrules. When mated, the ferrule of the plug connector  5  is not latched to the adapter sleeve and springs  38  of receptacle  30  are used for increasing the “float” between the mating ferrules of the plug connector and the non-hardened connector and is used because. 
     Network operators often desire to optically connect a first hardened connector to another hardened connector in a space that requires a rugged connection point, which receptacle  30  is incapable of accomplishing. Consequently, there exists an unresolved need for fiber optic connectors that can mate directly with to another hardened connector in a quick and reliable manner while providing a ruggedized solution that preserves optical performance. 
     SUMMARY 
     The disclosure is directed to ferrule-based fiber optic connectors comprising an internal compliant member disposed about a body that secures or holds a portion of the connector assembly directly. The internal compliant member is useful for compensating for the tolerance stack-up of components within the connector. The concepts disclosed are useful for female hardened fiber optic connectors that mate directly to hardened plug connectors. As an example, the concepts are useful with a female hardened connector that mates with an OptiTap® hardened male plug connector, but other applications for the concepts disclosed are possible and advantageous as well. Thus, the concepts also allow a compact footprint for fiber optic connectors since the spatial arrangement is more compact than the prior art. 
     One aspect of the disclosure is directed to a fiber optic connector comprising a connector assembly comprising a connector assembly body, a ferrule and a resilient member for biasing the ferrule forward, a body for securing a portion of the connector assembly, an internal compliant member, a connector sleeve assembly, a balancing resilient member and a housing comprising a threaded portion. The internal compliant member is disposed about a barrel portion of the body and abutting a shoulder of the body. The connector sleeve assembly comprises a housing with a passageway between a first end and a second end along with a ferrule sleeve. When assembled, the connector assembly is at least partially disposed in a passageway of the housing and the ferrule of the connector assembly is at least partially disposed in the ferrule sleeve. The balancing resilient member for biasing the housing to a forward position. 
     Another aspect of the disclosure is directed to a fiber optic connector comprising a connector assembly comprising a connector assembly body, a ferrule and a resilient member for biasing the ferrule forward, a body for securing a portion of the connector assembly, an internal compliant member, a connector sleeve assembly, a balancing resilient member, and a housing comprising a threaded portion with internal threads. The internal compliant member is disposed about a barrel portion of the body and abutting a shoulder of the body. The connector sleeve assembly comprises a housing with a passageway between a first end and a second end along with a ferrule sleeve. When assembled, the connector assembly is at least partially disposed in a passageway of the connector sleeve assembly and the ferrule of the connector assembly is at least partially disposed in the ferrule sleeve. 
     Still another aspect of the disclosure is directed to a fiber optic connector comprising a connector assembly comprising a connector assembly body, a ferrule and a resilient member for biasing the ferrule forward, a body for securing a portion of the connector assembly, an internal compliant member, a connector sleeve assembly, a balancing resilient member, and a female coupling housing comprising an opening having a threaded portion. The internal compliant member is disposed about a barrel portion of the body and abutting a shoulder of the body. The connector sleeve assembly comprises a housing with a passageway between a first end and a second end along with a ferrule sleeve and a latch. When assembled, the connector assembly is at least partially disposed in a passageway of the connector sleeve assembly and the ferrule of the connector assembly is at least partially disposed in the ferrule sleeve. The balancing resilient member for biasing the housing to a forward position with the latch configured for engaging the connector assembly when assembly and the balancing resilient member comprising a predetermined resilient force that is greater than the friction force required for displacement of the ferrule within the ferrule sleeve. 
     Yet another aspect of the disclosure is directed to a fiber optic connector comprising a connector assembly comprising a housing, a ferrule and a resilient member for biasing the ferrule forward, a body for securing a portion of the connector assembly, an internal compliant member, a connector sleeve assembly, a balancing resilient member, and a female coupling housing. The internal compliant member is disposed about a barrel portion of the body and abutting a shoulder of the body. The connector sleeve assembly comprises a housing with a passageway between a first end and a second end along with a ferrule sleeve and a latch. When assembled, the connector assembly is at least partially disposed in a passageway of the connector sleeve assembly and the ferrule of the connector assembly is at least partially disposed in the ferrule sleeve. The balancing resilient member for biasing the housing to a forward position with the latch configured for engaging the connector assembly when assembled and the balancing resilient member comprising a predetermined resilient force that is greater than the friction force required for displacement of the ferrule within the ferrule sleeve. The female coupling housing comprises an opening for receiving a complimentary connector. 
     Also disclosed are methods of assembling a fiber optic connector assembly comprising providing a connector assembly comprising a connector assembly housing, a ferrule and a resilient member for biasing the ferrule forward; providing a body for securing a portion of the connector assembly, the body comprising a barrel portion and a shoulder; installing an internal compliant member about the barrel portion of the body and abutting the shoulder of the body; providing a connector sleeve assembly comprising a housing with a passageway between a first end and a second end, a ferrule and a latch; inserting the connector assembly at least partially into the passageway of the connector sleeve assembly and inserting the ferrule at least partially into the ferrule sleeve; installing a balancing resilient member for biasing the connector sleeve assembly to a forward position with the latch of the connector assembly engaging the connector assembly, wherein the biasing resilient member has a predetermined resilient force that is greater than the friction force required for displacing the ferrule within the ferrule sleeve; and assembling the connector sleeve assembly into a female coupling housing. 
     Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the same as described herein, including the detailed description that follows, the claims, as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description present embodiments that are intended to provide an overview or framework for understanding the nature and character of the claims. The accompanying drawings are included to provide a further understanding of the disclosure and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments and together with the description serve to explain the principles and operation. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIGS. 1A-1C  show portions of a conventional preconnectorized fiber drop cable having a hardened connector such as an OptiTap® male plug connector being inserted into and connected with a conventional receptacle for alignment and mating the hardened connector with a non-hardened connector; 
         FIG. 2  is a partially exploded view of a conventional receptacle such as depicted in  FIGS. 1A-1C  for mating a hardened connector with a non-hardened connector; 
         FIG. 3  is a partial-sectional view thru the outer housing of an explanatory fiber optic connector having a connector assembly, a connector sleeve assembly and a balancing resilient member according to the concepts disclosed herein; 
         FIG. 4  is an exploded view of the explanatory fiber optic connector of  FIG. 3 ; 
         FIG. 5  is a partially exploded view of the explanatory fiber optic connector of  FIG. 3 ; 
         FIG. 6  is a partially assembled view of a sub-assembly of the fiber optic connector of  FIG. 3 ; 
         FIG. 7  is a sectional view of a sub-assembly of  FIG. 6  showing further details; 
         FIGS. 8 and 9  depict further details of the housing and spring seat of the connector sleeve assembly of the sub-assembly of the fiber optic connector of  FIGS. 16 and 17 ; 
         FIGS. 10-12  depict further details of the outer housing of the fiber optic connector of  FIG. 3 ; 
         FIG. 13  is a partial-sectional view thru the outer housing of another explanatory fiber optic connector having a connector assembly, a connector sleeve assembly and a balancing resilient member according to the concepts disclosed herein, and which is mated to an OptiTap® male plug connector similar that shown in  FIGS. 1A-1C ; 
         FIG. 14  is a perspective view of cable assembly having another explanatory fiber optic connector according to the concepts disclosed; 
         FIG. 15  is an exploded view of cable assembly of  FIG. 14 ; 
         FIG. 16  is an exploded view of the fiber optic connector of  FIG. 14 ; 
         FIGS. 17-20  are partial assembly perspective views of the construction of the cable assembly of  FIG. 14 ; 
         FIGS. 21 and 22  are exploded perspective views of the connector sleeve assembly of the fiber optic connector of cable assembly of  FIGS. 14-16 ; 
         FIGS. 23 and 24  are front and rear perspective views of the assembled connector sleeve assembly of  FIG. 14 ; 
         FIG. 25  is a sectional view of the assembled connector sleeve depicted in  FIGS. 23 and 24 ; 
         FIG. 26  is a partial assembly perspective view of the cable assembly of  FIG. 14  depicting the connector sleeve assembly attached to the connector assembly; 
         FIG. 27  is an end perspective view of the cable assembly of  FIG. 14  with the dust cap removed; 
         FIG. 28  is a sectional view of the fiber optic connector of  FIG. 14 ; 
         FIG. 29  is a perspective view of the cable assembly of  FIG. 14  being aligned with a complimentary connector for mating; 
         FIGS. 30-33  depict another fiber optic connector having with a one-piece body that secures a portion of the fiber optic assembly; and 
         FIGS. 34-37  depict sectional views showing a representative female fiber optic connector as disclosed herein mating with complimentary male connector to illustrate movement of components and need for tolerance compensation using the internal resilient member. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Whenever possible, like reference numbers will be used to refer to like components or parts. The fiber optic connectors and cable assemblies described herein are suitable for making optical and/or optical-electrical connections (if electrical connections are included in the connectors) directly to a conventional male hardened plug connector. The fiber optic connectors disclosed comprise an internal compliant member disposed on an internal body of the female hardened fiber optic connector that secures or holds a portion of a connector assembly such as an SC connector assembly. The internal compliant member is used to compensate for the stack-up of parts that may comprise hard stops or movement in the axial direction during mating and can impact fiber optic connector performance. In addition to performance improvements, the use of the internal compliant member also improves manufacturing since it allows a larger tolerance range for the assemblies or parts that may be used in the fiber optic connector. 
     Although the concepts disclosed herein are explained with respect to a female hardened fiber optic connector used for optical connection with the male hardened plug connector an OptiTap® connector, the concepts disclosed may be used with other fiber optic connectors hardened or not and are not limited to this particular optical connection. As used herein, female hardened fiber optic connector means the connector directly receives another rugged connector such as a plug connector for a two-assembly optical connection (e.g., male to female) without the use of a receptacle or adapter for a three-assembly optical connection (e.g., male to male using receptacle or adapter). 
     The concepts of the disclosure advantageously allow robust and reliable optical connections using ferrule-based fiber optic connectors with an internal compliant member to compensate for tolerance stack-up of components. The fiber optic connector such as by balancing the ferrule retraction and inhibiting the loading-up of the ferrule displacement in the fiber optic connector that can occur during assembly and/or during mating, thereby avoiding undue optical attenuation. 
       FIGS. 3 and 4  depict a fiber optic connector  100  that comprises a connector assembly  52  that is fixed (i.e., inhibited from freely traveling) to the fiber optic connector such as fixed to a connector housing  164  of fiber optic connector  100  and the connector sleeve assembly  136  floats relative to the connector housing  164 . In this case, the connector housing  164  comprises the internal threads for the female hardened connector as shown in  FIG. 3 . Having the connector assembly  52  “fixed” to the fiber optic connector means that the connector assembly is inhibited from traveling by a portion of the fiber optic connector such as an inner portion of the fiber optic connector like a retention body that may secure the connector assembly or the travel may be inhibited by an outer portion of the connector such as an outer housing depending on the construction of the connector. 
     Consequently, one concern with directly mating a male plug connection with a female fiber optic connector  100  is that the tolerance stack-up of components or of forces may cause issues with components of the connector arriving at undesired locations due to the tolerance stack-up of or forces on the components. Specifically, the stack-up of tolerances or of force may result in a condition that can displace ferrule sleeve to a hardstop in the connector sleeve assembly before being mated with the complimentary connector. Later when a mating connector is inserted into fiber optic connector  100  there can be optical performance issues that result since the connector sleeve, ferrule sleeve or other component is shifted beyond the desired location. For instance, since the ferrule sleeve is “loosely captive” within the housing of the connector sleeve assembly it may be “pushed” to the farthest point within the housing away from the inserted ferrule (i.e., to the far end where it awaits the complimentary mating ferrule). The ferrule sleeve will not move on its own from this position due to the static friction force between ferrule sleeve and ferrule of the connector assembly. 
     When the mating ferrules/ferrule sleeve are displaced from a generally centered position it may cause undue optical attenuation and/or other performance issues. For instance, the mating ferrule of the plug connector may be displaced by a distance than is greater than the design parameters of the plug connector being mated with the first fiber optic connector. Although the connectors may still be mated and operate; however, this uneven displacement of ferrules is undesirable and may cause elevated levels of optical attenuation, reduce reliability and/or cause other issues for the mated connectors. 
     It is noted that optical performance of a fiber optic connector may also depend on the fiber optic cable design being used. The hard stop between the mating connector housings (e.g., the female connector housing impacting or seating with the complementary male connector housing) and the connector sleeve assembly limits the amount of axial interference and determines the maximum extra optical fiber length generated in the connectors due to ferrule retraction. The ability to absorb extra optical fiber length in the connector may depend on many factors like the fiber optic cable construction, size of the cavity housing the optical fiber, but often is a relatively small value such as on the order of a few hundred microns and may impact optical performance. 
     The present application addresses these concerns by providing an internal compliant member disposed within the fiber optic connector to compensate for the tolerance stack-up of components and preserves optical performance. The internal compliant member may be compressed within the connector when needed to compensate for the tolerance stack-up of components such as when a connector assembly body bottoms-out (e.g., hits a hard stop) before a coupling nut is fully seated during mating of the connector with a plug connector, thereby allowing the continued tightening of the coupling nut while preserving optical performance. Further, it the internal compliant member is not needed it acts as a passive component during mating. Although, the internal compliant member may be a suitably sized O-ring other constructions or designs are possible for the internal compliant member such as a rubber or plastic washer or even felt material as desired. 
     The following female fiber optic connectors as shown for explanatory purposes and are suited for mating directly with a male connector such as an OptiTap plug connector similar that shown in  FIGS. 1A-1C , without the use of the adapter. However, the female fiber optic connectors disclosed may have many different designs using the concepts of an internal compliant member as disclosed herein. 
     By way of description the fiber optic connector  100  depicted in  FIGS. 3-5  is a first embodiment of an in-line female hardened connector, and  FIGS. 6-12  are views of sub-assemblies or components of connector  100 .  FIGS. 13-16  depict another fiber optic connector  100 ′ in a second embodiment of an in-line female hardened connector according to the concepts disclosed herein with a simplified connector sleeve assembly, and  FIGS. 17-26  are views of sub-assemblies or components of connector  100 ′. The simplified connector sleeve assembly uses fewer parts than the connector sleeve assembly of the first embodiment and results in fewer components that can contribute to the tolerance stack-up of components.  FIGS. 27-29  depict a representative connector with a dust cap and the direct mating with a plug connector such as an OptiTap for an optical connection.  FIGS. 30-33  depict yet another fiber optic connector using the disclosed concepts and having the simplified connector sleeve assembly with a one-piece body that has the internal compliant member thereon. Of course, other fiber optic connectors are possible using the concepts of the claims such as being use with other types of hardened connectors. 
       FIGS. 3 and 14  depict fiber optic connectors  100  and  200  being portions of respective cable assemblies further including a fiber optic cable  140  attached to the respective connectors. Fiber optic cable  140  may comprise one or more optical fibers, one or more tensile elements such as strength members or strength components, and a cable jacket, but other suitable components are possible. The tensile elements of fiber optic cable  140  are typically secured to a cable attachment region of fiber optic connector  100 . 
       FIG. 3  is a partial-sectional view thru a housing  164  of an explanatory fiber optic connector  100  having a connector assembly  52 , a body  155 , an internal compliant member  156 , a connector sleeve assembly  136  and one or more balancing resilient members  130  according to the concepts disclosed herein.  FIGS. 4 and 5  respectively depict exploded views of the fiber optic connector  100 .  FIGS. 6 and 7  respectively depict a partial exploded view and an assembled view of a sub-assembly of fiber optic connector  100  to show further details of this embodiment. 
       FIG. 3  depicts fiber optic connector  100  having a dust cap  168  attached thereto via female coupling housing  164 . The female coupling housing  164  is sized for receiving the male plug connector  5  within the front end opening for direct optical mating. Fiber optic connector  100  has a relatively small form factor and aligns the plug connector  5  in the proper orientation so it may only mates in one direction. Further, the optical coupling between the fiber optic connector  100  and the plug connector  5  is environmentally sealed. Additionally, fiber optic connector  100  may be optically coupled and uncoupled with plug connector  5  as desired. 
     Fiber optic connector  100  comprises connector assembly  52 , a body  155  having at least one shell  155   a  (as shown two shells  155   a  that form the body), an optional crimp band  157 , connector sleeve assembly  136 , and female coupling housing  164 . As best shown in  FIGS. 6 and 7 , the internal compliant member  156  is disposed about a barrel portion BP of the body and abutting a shoulder S of the body  155 . Thus, the internal compliant member  156  may be compressed when needed between the shoulder S of the body and a portion of the female coupling housing  164 . The barrel of the body may have any suitable shape as desired such as round, oval, rectangular, etc. 
     Fiber optic connector  100  may also comprise other optionally components such as a cable boot  166 , a heat shrink tube  167 , a second crimp band  153 , and/or one or more O-rings. For complexity reduction and simplification, the fiber optic connector  100  can use many of the same parts as the OptiTap® plug connector  5  or other standard parts as desired; however, certain components are specific to fiber optic connector  100 . By way of example, fiber optic connector  100  may comprise an industry standard SC type connector assembly  52  or the like having a connector assembly housing  52   a , a ferrule  52   b  in a ferrule holder (not visible), a spring  52   c  (not visible), and a spring push  52   d . However, any of the embodiments can use any suitable connector assembly such as a SC or a LC connector assembly having a ferrule and a connector housing along with other suitable components. 
     Although, the term body is shown with a crimp band the body does not require crimp or crimp band and may use other securing means such as adhesive or the like for securing the shells  155   a  together. For instance,  FIG. 19  shows a body that can snap together and/or be securing using an adhesive. Other embodiments of the body could also be a one-piece design. The crimp band  157  may also be used for securing the tensile elements of fiber optic cable  140  if desired. For instance, the tensile elements may be a plurality of tensile yarns attached between the outer barrel BP of body  155  and crimp band  157 . In other embodiments, one or more strength components such as GRP rods maybe secured to the cable attachment region of the fiber optic connector such as between the shells  155   a . The optional second crimp band  153  may be used for cables or constructions where it is desired to strain-relieve the fiber optic cable directly to the connector assembly  52 . By way of example, tensile elements such as aramid yarns may be secured to the connector assembly  52  using second crimp band  153  for providing strain-relief. Fiber optic connectors may also include a dust cap  168 , but other suitable configurations are possible using fewer or more components. For instance, fiber optic connector  100  may also include an optional lanyard (not numbered) for the dust cap  168  as desired so it is prevented from being lost or separated from the assembly. 
     Generally speaking, most of the components of fiber optic connector  100  are formed from a suitable polymer, but other materials such as metal are possible. In one example, the polymer is a UV stabilized polymer such as ULTEM 2210 available from GE Plastics if the component is exposed to the elements; however, other suitable polymer materials are possible. For instance, stainless steel or any other suitable metal may be used for various components as desired. 
     The housing  133  of connector sleeve assembly  136  may be formed as a single component or formed as an assembly of more than one component. In this embodiment, the housing of  133  connector sleeve assembly  136  is formed from several components as best depicted in  FIG. 7 , thereby making the features of the connector sleeve easier manufacture, but the use of more components may increase the tolerance stack-up of parts. Of course, the concepts disclosed herein may be used with any suitable connector sleeve assembly. The housing  133  also includes latches  133   a  for securing connector assembly  52 , but the latches  133   a  are not visible in the FIGS. 
     The housing  133  of connector sleeve assembly  136  has a through passageway from a first end  131  to a second end  132  for receiving ferrule sleeve  135  in a loosely captive manner and aligning respective ferrules of the fiber optic connector  100  and the mating connector as discussed herein. Specifically, when assembled, connector sleeve assembly  136  fits within female coupling housing  164  and is used for aligning ferrule  52   b  of the fiber optic connector  100  with the corresponding ferrule of the plug connector  5 . Connector sleeve assembly  136  comprises housing  133 , ferrule sleeve  135 , and a spring seat  137 . 
     As depicted, ferrule sleeve  135  has a portion disposed within housing  133  and is secured therein by spring seat  137 . Specifically, a flange (not numbered) of ferrule sleeve  135  is aligned to housing  133  using a recess portion of housing  133  and spring seat  137  is attached to the housing  133  for capturing and securing the flange of the ferrule sleeve  135  between the housing  133  and spring seat  137 . In this embodiment, balancing resilient member  130  is a wave spring having one end seated on the spring seat  137  and the other end seated on the front portion of body  155  for biasing the housing  133  to a forward position. As best shown in  FIGS. 6 and 7 , a portion of the balancing resilient member  130  is disposed radially outward of the connector assembly  52  when the connector is assembled. However, other arrangements or configurations for the balancing resilient member are possible according to the concepts disclosed herein. 
     Fiber optic connectors  100  according to the concepts disclosed may also comprise a balancing resilient member  130  for biasing a housing  133  of a connector sleeve assembly  136  to a forward position. As used herein, “a forward position” is the direction pointing from a rear of the connector to the mating face of the fiber optic connector. 
     The biasing resilient member  130  has a predetermined resilient force that is greater than the friction force required for displacement of a ferrule  52   b  of the connector assembly  52  within the ferrule sleeve  135  of the connector sleeve assembly  136  to provide a ferrule retraction balancing construction The details of use of the biasing resilient member  130  having a predetermined resilient force that is greater than the friction force required for displacement of a ferrule  52   b  of the connector assembly  52  within the ferrule sleeve  135  is explained in more detail below. 
     Fiber optic connectors disclosed herein include a connector assembly  52  comprising a connector assembly housing  52   a , a ferrule  52   b  and a resilient member  52   c . By way of example, and not limitation, suitable connector assemblies may include LC, SC along with other connector assemblies having a ferrule and ferrule sleeve arrangement as desired. Fiber optical connectors disclosed herein are advantageous for efficiently and economically streamlining the deployment and installation of fiber optic networks since they provide a robust and reliable operation. 
     The fiber optic connectors disclosed may also comprise a ferrule retraction balancing construction. The ferrule retraction balancing construction for fiber optic connectors  100  use one or more balancing resilient members  130  allows the housing  133  of the connector sleeve assembly  136  to translate axially toward the fiber optic connector housing  164  for a predetermined distance. This translation has the effect of moving the housing  133  relative to the ferrule sleeve  133 , relieving a hard stop and allowing the ferrule  52   b  of the connector assembly  52  to “balance” with the mating ferrule by permitting the springs  52   c  of opposing connector assemblies  52  to react to one another essentially without the additional force vectors. 
     When the ferrule sleeve  135  is pushed to one side due to the ferrule sleeve overcoming the friction force, the one or more balancing resilient members  130  effectively acts as a stop formed inside the cavity and inhibits a worst-case scenario for ferrule displacement. The worst case ferrule displacement would occur if the force of the spring  52   c  of connector assembly  52  and the friction of the ferrule sleeve both oppose the spring  252   c  of the mating connector  200 , which force difference would delegate the ferrule retraction and extra fiber accumulation to the mating connector  200 . Thus, when the one or more balancing resilient members  130  having a predetermined resilient force that is greater than the friction force required for displacement of a ferrule  52   b  of the connector assembly  52  within the ferrule sleeve  135 , the worst-case scenario is inhibited and fiber optic connector performance is preserved. 
     Furthermore, the one or more balancing resilient members  130  may be selected to provide the predetermined resilient member force that is greater than the friction force required for displacement of the ferrule  52   b  within ferrule sleeve  135  of fiber optic connector  100  for inhibiting a worst-case design scenario. 
     Moreover, the one or more balancing resilient members may take any suitable form such as a wave spring, a coil spring, leaf springs, etc. to provide the predetermined resilient force. 
     Moreover, different connector designs according to the concepts disclosed may have different force requirements for the balancing resilient member since the friction forces required for displacement of a ferrule within a ferrule sleeve may vary by the connector type. In one embodiment, the balancing resilient member  130  has a resilient member force of 2.5 Newton or greater, but other values are possible according to the concepts disclosed such as 5 Newton or greater or even 8 Newton or greater. By way of explanation, and not limitation, the friction force for a SC connector may be greater than the friction forces for an LC connector since the SC connector has a ferrule with a larger surface area in contact with the respective ferrule sleeve. 
     By way of example, if a ferrule has a diameter of about 2.5 millimeters such as in a SC connector assembly, then the balancing resilient member may have a predetermined resilient force of 5 Newton or greater. If a ferrule has a smaller diameter such as about 1.25 millimeter like used in a LC connector assembly, then the balancing resilient member may have a predetermined resilient force of 2.5 Newton or greater. These are explanatory examples and other values for the predetermined resilient force are possible. 
     In addition to the connector sleeve assembly  136  having a passageway  136   a  between the first end  131  and the second end  132  it also includes one or more connector sleeve orientation features. Connector sleeve orientation features can have many different suitable constructions such as lugs, tabs, openings, etc. for cooperating with the one or more coupling housing orientation features on the female coupling housing. In the embodiment illustrated, connector sleeve assembly  136  includes a first lug  136   b  and a second lug  136   c  for fitting the connector sleeve assembly  136  into the female coupling housing  164 . Stated another way, connector sleeve assembly  136  fits into female coupling housing  164  in only one orientation using first tab  136   b  and second tab  136   c  having different shapes as discussed below. 
     Connector sleeve assembly  136  optionally includes an orientation rail  139  ( FIG. 8 ) for allowing connector assembly  52  of female hardened plug connector  150  to be assembled into the connector sleeve assembly  136  in only a single orientation. Orientation rail  139  has a profile that only allows a narrow end of connector body  52   a  to abut the orientation rail  139  during assembly. 
     Housing  164  may have any suitable construction for the fiber optic connector using the concepts disclosed herein. As best shown in  FIGS. 10-12 , female coupling housing  164  has an elongate structure with a passageway  163  extending from the opening at a front end  161  to a rear end  162  and sized so that the shroud of the plug connector  5  fits into the front end  161  of passageway  163  when properly aligned. Consequently, plug connector  5  may be directly mated with the fiber optic connector  100  for making an optical connection therebetween. As shown, female coupling housing  164  includes a first portion at the front end that includes the internal attachment feature such as internal threads  165  that cooperate directly with the complimentary external threads of plug connector  5 . Once the plug connector  5  is attached to the fiber optic connector  100  the assembly is suitable for making an optical connection therebetween. 
     Female coupling housing  164  includes features for aligning and securing connector sleeve assembly  136  along with alignment features for correctly orientating plug connector  5 . In one embodiment, female coupling housing  164  includes a stop ledge  164   a  integrally formed in a side wall (i.e., disposed on the side wall) that is disposed rearward of internal threads  165 . Stop ledge  164   a  is configured so that it only allows the shroud of plug connector  5  to fully seat within the female coupling housing  164  in one orientation for keying the optical coupling. In other words, the shroud of the plug connector  5  has alignment fingers having different shapes and the stop ledge  164   a  only allows the plug connector  5  to fully seat for optical coupling in one orientation by preventing insertion of the larger alignment finger into the female coupling housing  164  past the stop ledge  164   a . Female coupling housing  164  also includes a shelf (not visible) within the passageway and disposed rearward of the stop ledge  164   a . Shelf  164   d  has a complementary shape for receiving connector sleeve assembly  136  and includes a first retention feature  164   b  and a second retention feature  164   c . Shelf  164   d  has a generally rectangular shape that cooperates with the generally rectangular shape of connector sleeve assembly  136  so that it fits within the passageway of female coupling housing  164 . First retention feature  164   b  and second retention feature  164   c  have different sizes that cooperate with tabs  136   b , 136   c  disposed on connector sleeve assembly  136  so that it may only fully seat into shelf  164   d  in one orientation. Further, the stop ledge  164   a  has a specific orientation relative to first retention feature  164   b  and second retention feature  164   c.    
     When fully assembled the body  155  fits into female coupling housing  164  and is keyed to direct the insertion of the same into the coupling housing  164  in the correct orientation. In this case, shells  155   a  include planar surfaces on opposite sides of body  155  to inhibit relative rotation between body  155  and female coupling housing  164 . In other embodiments, the body  155  may be keyed to the female coupling housing  164  using other configurations such as a complementary protrusion/groove or the like. 
     Rear end  162  of housing  164  includes second portion (not numbered) having a reduced cross-section. The second portion is used for securing heat shrink tubing  167  for providing environmental protection between the housing  164  and the fiber optic cable  140  and weatherproofing the cable assembly. The other end of heat shrink tubing  167  is disposed about a portion of the cable jacket, thereby inhibiting water from entering fiber optic connector  100 . Further, the second portion allows for the attachment of boot  166  to the rear end  162  of coupling housing  164 . After the heat shrink tubing  167  is attached, boot  166  may be slid over heat shrink tubing  167 . Specifically, boot  166  may be positioned over the shrink tubing  167  at rear end  162  of female coupling housing  164  for providing further bending strain relief for the cable assembly. 
     Boot  166  may be formed from a flexible material such as KRAYTON or the like. Heat shrink tubing  167  and boot  166  generally inhibit kinking and provide bending strain relief to the cable  140  near fiber optic connector  100 . Boot  166  has a longitudinal passageway (not visible) and may have a stepped profile therethrough. The first end of the boot passageway is sized to fit over the heat shrink tubing  167 . The first end of the boot passageway has a stepped down portion sized for cable  140  or other suitable cable that may be used and the heat shrink tubing  167  and acts as stop for indicating that the boot is fully seated. Dust cap  168  has external threads for engaging the internal threads of female coupling housing  164  for attachment and thereby inhibit dirt and debris from entering the fiber optic connector  100  via the front end  161  of female coupling housing  164 . Moreover, the dust cap  168  may include an O-ring for providing a weatherproof seal between fiber optic connector  100  and dust cap  168  when installed. 
       FIG. 13  is a partial-sectional view thru the outer housing of another explanatory fiber optic connector  100 ′. Fiber optic connector  100 ′ is similar to connector  100  and comprises a connector assembly  52 , a connector sleeve assembly  136  and a balancing resilient member  130  according to the concepts disclosed herein, but fiber optic connector  100 ′ has a construction that is different from fiber optic connector  100 . 
     Specifically, fiber optic connector  100 ′ using a different body  155 ′ with a different fiber optic cable  140 . Instead of the shells  155   a  used in fiber optic connector  100 , fiber optic connector  100 ′ has a monolithic body  155 ′ that has the fiber optic cable inserted into and secured using an adhesive. Additionally, the balancing resilient member  130  of fiber optic connector  100 ′ is configured as a coil spring that is seated on a portion of the fiber optic connect and housing  133  of connector sleeve assembly  136 . 
       FIG. 13  depicts fiber optic connector  100 ′ mated directly to a plug connector  5  similar that shown in  FIGS. 1A-1C  without the use of adapter  30 . As shown, the shroud of the male plug connector  5  has alignment fingers having different shapes and when mated the stop ledge only allows the plug connector  5  to fully seat for optical coupling in one orientation by preventing insertion of the larger alignment finger into the female coupling housing  164  past the stop ledge. In one embodiment, the correct mating orientation is marked on the female coupling housing  164  such as an alignment indicia so that the craftsman can quickly and easily mate fiber optic connector  100  with the plug connector  5 . For instance, the alignment indicia may be an arrow or dot molded into the female coupling housing  164 , however, other suitable indicia may be used. Thereafter, the craftsman engages the internal attachment feature  165  such as internal threads of female coupling housing  164  with the complimentary external threads of plug connector  5  for making the optical connection shown in  FIG. 6 . 
     Additionally, the optical connection is easily connected or disconnected by merely mating or unmating the plug connector  5  with the fiber optic connector  100  by threadly engaging or disengaging the coupling nut on the plug connector  5  with the attachment features  165  such as internal threads of the female coupling housing  164  of the fiber optic connector  100 . 
     Other connector designs are possible according to the concepts disclosed for solving the issues of ferrule displacement by using a ferrule retraction balancing construction for fiber optic connectors by balancing out the forces related to the ferrule sleeve friction during assembly and mating. By way of example,  FIG. 14  is a perspective view of a cable assembly  300  having another explanatory fiber optic connector  200  according to the concepts disclosed. Fiber optic connector  200  may use the same principals and concepts for the ferrule displacement balancing construction for inhibiting the loading-up of ferrule displacement within the fiber optic connector as discussed herein with respect to the other fiber optic connectors. 
       FIG. 15  is a partially exploded view of the cable assembly  300  having fiber optic connector  200  that is similar to fiber optic connector  100  and  FIG. 16  is a partially exploded view of connector  200 . Fiber optic connector  200  uses a different and simplified connector sleeve assembly  236  compared with connector  100 . Fiber optic connector  200  also has other features or modified components that improve or simplify the manufacturing or assembly for fiber optic connector  200 . For instance, a first shell  255   a  and a second shell  255   b  are designed so they can snap together and the crimp band  240  strain-relieves the fiber optic cable  140  to the spring push  52   d  of connector assembly  52 ; instead of strain-relieving the fiber optic cable to the body  155 . In other embodiments, portions of the cable may be strain-relieved to both the connector assembly  52  and the body if desired. Additionally, the female coupling housing  264  is different than female coupling housing  164  of fiber optic connector  100 . 
     Fiber optic connector  200  comprises connector assembly  52 , a connector sleeve assembly  236 , a body  255 , an internal compliant member disposed about a barrel portion of the body and abutting a shoulder, and a balancing resilient member  230  for biasing the housing of connector sleeve assembly  236  to a forward position along with a housing comprising a threaded portion. The balancing resilient member  230  may comprises a predetermined resilient force that is greater than the friction force required for the displacement of the ferrule  52   b  within the ferrule sleeve  135  as discussed herein. Connector assembly  52  comprises a connector assembly housing  52   a , a ferrule  52   b  and a resilient member (not visible) that is disposed within the connector assembly as known in the art. 
       FIGS. 17 and 18  are partial assembly perspective views showing a portion the construction of cable assembly  300 .  FIG. 17  is a perspective view depicting fiber optic cable  140  attached to connector assembly  52  and positioned in one shell  255   b . In this embodiment, cable  140  is secured to connector assembly  52  using a crimp band  240  that is attached to a portion of spring push  52   d .  FIG. 18  depicts the second shell  255   a  attached to the shell  255   b  with the internal compliant member  256  disposed about the barrel portion BP of the body  255  and abutting the shoulder of the body  255 .  FIGS. 19 and 20  respectively are a partially exploded perspective view and assembled view of a portion of the construction of the fiber optic connector  200  with the internal compliant member  256  and biasing resilient member cable  230 . 
     Cable assemblies may use any suitable fiber optic cables for the connector. However, different fiber optic cables  140  may require different structures for attaching and strain-relieving the cable. As discussed, fiber optic cable  140  may comprise one or more optical fibers, one or more tensile elements such as strength members or strength components, and a cable jacket, but other suitable components are possible. The tensile elements of fiber optic cable  140  (not shown) are typically secured to a cable attachment region of connector  200  or connector assembly  52 . In this embodiment, the strength members of cable  140  such as aramid yarns, fiberglass yarns or the like are positioned about a rear portion of spring push  52   d  and secured thereto using crimp band  240 . However, cable  140  may be strain-relieved to connector  200  in other suitable manners depending on the cable design and connector components used. For instance, strength members or strength components may be secured to the body  255  such as by using a crimp band or an adhesive. 
     As shown in  FIG. 18 , connector  200  comprises a body  255  for securing the connector assembly  52  at a front end of one or more shells. In this embodiment, body  255  comprises a first shell  255   a  and a second shell  255   b  that cooperate to form the body  255 . Shells  255   a  and  255   b  may be the same part or not depending on the desired construction for the connector. In this embodiment, shells  255   a , 255   b  each comprise a latch  255 L and a catch  255 C ( FIG. 19 ) for securing the first and second shells together in a snap-fit construction for ease of assembly. Simply stated, the latch  255 L of one shell cooperates with the catch  255 C of the other shell and vice versa for securing the two shells together. Other configurations for shells  255   a , 255   b  are also possible such as securing the shells with a crimp band or adhesive as desired or required. Connector  200  may also comprise other optional components such as a cable boot  266 , a heat shrink tube  267 , a second crimp band, and/or one or more O-rings for sealing. For complexity reduction and simplification, the connector  200  can use many of the same parts as the OptiTap® plug connector  5  or other standard parts as desired; however, certain components may be specific to connector  200 . 
     By way of explanation, other embodiments of body  255  may have the shells secured with a crimp band that is deformed about an outer barrel portion of the body  255 . Further, the crimp band may also be used for securing the tensile elements of cable  140  to the outer barrel of the body  255 . For instance, the tensile elements may be a plurality of tensile yarns attached between an outer barrel of body  255  and the crimp band. In other embodiments, one or more strength components such as GRP rods maybe secured to the cable attachment region of the fiber optic connector such as between the shells  255   a , 255   b . Alternatively, two crimp bands may be used for cables or constructions where it is desired to strain-relieve the fiber optic cable directly to the connector assembly  52  and to body  255 . By way of example, tensile elements such as aramid yarns may be secured to the connector assembly  52  as discussed herein and the second crimp band is used for strain-relieving tensile elements to the body  255 . Connectors may also include a dust cap, but other suitable configurations are possible using fewer or more components. For instance, connector  200  may also include an optional lanyard (not numbered) for the dust cap as desired so it is prevented from being lost or separated from the assembly. Generally speaking, most of the components of fiber optic connector  200  are formed from a suitable polymer, but other materials such as metal are possible such as discussed herein. 
       FIGS. 21 and 22  are exploded perspective views of the connector sleeve assembly  236  of the fiber optic connector  200  and  FIGS. 23 and 24  are front and rear perspective views of the assembled connector sleeve assembly  236 .  FIG. 25  is a sectional view of the connector sleeve assembly  236 . Connector sleeve assembly  236  comprises housing  133  and the ferrule sleeve  135 . In this embodiment, housing  133  is a simplified design that comprises a first portion  233  and a second portion  237 . First portion  233  and second portion  237  cooperate to capture ferrule sleeve  135  therein. Housing  133  of connector  200  comprises a passageway between a first end and a second end and the ferrule sleeve  135  is disposed within the passageway. As discussed herein, ferrule sleeve  135  is “loosely captive” within the passageway of housing  133 . 
     First portion  233  of housing  133  comprises one or more first protrusions  233 P on a first side that extend from its flange (not numbered) toward the second portion  237  of the housing. First portion  233  of housing  133  also include one or more second protrusions  233 P 2  on a second side that extend from the flange of first portion  233 . Protrusions  233 P and  233 P 2  are used for rotationally aligning the connector assembly  52  of fiber optic connector  200  (using second protrusions) with the mating connector assembly (using first protrusions). Moreover, locating the first and second protrusions on the same component (e.g., first portion  233 ) allows for improved rotational registration between mating connector assemblies since the protrusions are dimensioned from the same component and there will not be relative rotation between the protrusions on the same component. 
     Second portion  237  of housing  133  comprises one or more windows or slots  237 W formed in its flange (not numbered) that cooperate with the one or more protrusions  233 P of the first portion  233 . Specifically, the one or more first protrusions  233 P of the first portion  233  align with the one or more windows or slots  237 W of the second portion  237  for orienting the first portion  233  with the second portion  237 . More specifically, the protrusions  233 P and windows  237 W have different shapes as shown that orient the connector assembly  52  with the connector sleeve assembly so the connector sleeve assembly may only attach to the connector assembly in one orientation. In other words, one of the protrusions  233 P has an angular shape acting as an orientation rail  139  for cooperating and aligning with the asymmetric housing of connector assembly  52 , thereby rotationally aligning the connector assembly  52  with the connector sleeve assembly  236  in only one orientation. Consequently, when the connector sleeve assembly  236  is attached to the connector assembly  52  the first lug  236   b  and second lug  236   c  of housing  133  have a specific arrangement with respect to the connector assembly  52  with the asymmetric housing. As depicted and discussed herein, the first lug and the second lugs have different shapes for orienting the connector sleeve assembly  236  with the female coupling housing  264 . 
     As depicted, second portion  237  of housing  133  comprises attachment features for securing the second portion  237  with the first portion  233  of the housing and may be and suitable structure, fastener, adhesive or the like for securing the two portions together in a suitable fashion. Additionally, second portion  237  comprises one or more features for attaching the housing to the connector assembly  52 . In this embodiment, the housing  133  of connector sleeve assembly  236  comprises one or more latch arms  237 L that engage the connector ledge  52 L. Latch arms  237 L are configured for attaching the connector sleeve assembly  236  with the housing of connector assembly  52 . Of course, other variations of the connector sleeve assembly are possible using the concepts disclosed herein. 
     As best shown in  FIG. 25 , the simplified connector sleeve assembly  236  reduces the tolerance stack-up since only two parts are used for housing. In other words, connector sleeve assembly  236  provides a width W plus its tolerance ±T that is accounted for in the tolerance stack-up for fiber optic connector  200  during mating. Consequently, the tolerance attributed to a width W of the housing in the direction of the mating is easier to control during design and manufacture of the connector compared with a stack-up of tolerance for connector sleeve assemblies having more than two components. 
       FIG. 26  shows a partial assembly of fiber optic connector  200  before the housing  264  is installed. Specifically,  FIG. 26  depicts the connector sleeve assembly  236  attached to the connector assembly  52  during the construction of the connector  200 . As shown, the connector sleeve assembly  236  comprises a latch, and the balancing resilient member  230  biases the connector sleeve assembly  236  forward with the latch engaging the connector assembly  52  when assembled. Before attaching, the connector sleeve assembly  236  to the connector assembly  52 , the balancing resilient member  230  is disposed radially outward of the connector assembly and then the parts are attached together by snap-fitting or the like. The balancing resilient member  230  contacts a portion of the connector sleeve assembly  236  as shown. Balancing resilient member may have any suitable predetermined resilient force as discussed herein. 
     In other embodiments, the housing  133  of connector sleeve assembly  136  may be formed as a single component as shown or formed as an assembly of more than one component. However, the concepts disclosed herein may be used with any suitable connector sleeve assembly such as having a housing comprising several components if desired. 
       FIG. 27  is an end perspective view of the cable assembly  300  with the dust cap  168  removed from fiber optic connector  200 . Female coupling housing  264  of connector  200  may have any suitable construction for the fiber optic connector using the concepts disclosed herein. The female coupling housing  264  is sized for receiving the male plug connector  5  within the front end opening  161  for direct optical mating. Fiber optic connector  200  has a relatively small form factor and aligns the plug connector  5  in the proper orientation so it may only mates in one direction. Further, the optical coupling between the connector  200  and the plug connector  5  is environmentally sealed. Additionally, fiber optic connector  200  may be optically coupled and uncoupled with plug connector  5  as desired. 
     As best shown in  FIGS. 15 and 27 , female coupling housing  264  has an elongate structure with a passageway  263  extending from the opening at a front end  261  to a rear end  162  and sized so that the shroud of the plug connector  5  fits into the front end  261  of passageway  263  when properly aligned. The female coupling housing  264  comprises an opening for receiving a complimentary connector. Consequently, plug connector  5  may be directly mated with the fiber optic connector  200  for making an optical connection therebetween. As shown, female coupling housing  264  includes a first portion at the front end that includes the internal attachment feature such as internal threads  265  that cooperate directly with the complimentary external threads of plug connector  5 . Once the plug connector  5  is attached to the fiber optic connector  200  the assembly is suitable for making an optical connection therebetween. 
     Female coupling housing  264  includes features for aligning and securing connector sleeve assembly  236  along with alignment features for correctly orientating plug connector  5 . In one embodiment, female coupling housing  264  includes a stop ledge  264   a  integrally formed in a side wall (i.e., disposed on the side wall) that is disposed rearward of internal threads  265 . Stop ledge  264   a  is configured so that it only allows the shroud of plug connector  5  to fully seat within the female coupling housing  264  in one orientation for keying the optical coupling. In other words, the shroud of the plug connector  5  has alignment fingers having different shapes and the stop ledge  264   a  only allows the plug connector  5  to fully seat for optical coupling in one orientation by preventing insertion of the larger alignment finger into the female coupling housing  264  past the stop ledge  264   a . Female coupling housing  264  also comprises a first retention feature  264   b  and a second retention feature  264   c  (not visible). First retention feature  264   b  and second retention feature  264   c  have different sizes that cooperate with lugs or tabs  236   b , 236   c  disposed on connector sleeve assembly  236  so that it may only fully seat into the female coupling housing  264  in one orientation. Further, the stop ledge  264   a  has a specific orientation relative to first retention feature  264   b  and second retention feature  264   c.    
       FIG. 28  depicts an assembled view of fiber optic connector  200  with the dust cap  168  attached. When fully assembled the body  255  fits into female coupling housing  164  and may be keyed to direct the insertion of the same into the coupling housing  264  in the correct orientation. In this case, shells  255   a ,  255   b  include planar surfaces on opposite sides of body  255  to inhibit relative rotation between body  255  and female coupling housing  264 . In other embodiments, the body  255  may be keyed to the female coupling housing  264  using other configurations such as a complementary protrusion/groove or the like. 
     The rear end of housing  264  includes second portion (not numbered) having a reduced cross-section. The second portion is used for securing heat shrink tubing  267  (the heat shrink tubing is depicted in the shrunk form) for providing environmental protection between the housing  264  and the fiber optic cable  140  and weatherproofing the cable assembly. The other end of heat shrink tubing  267  is disposed about a portion of the cable, thereby inhibiting water from entering connector  200 . Further, the second portion allows for the attachment of boot  266  to the rear end of the female coupling housing  264 . After the heat shrink tubing  267  is attached, boot  266  may be slid over heat shrink tubing  267 . Specifically, boot  266  may be positioned over the shrink tubing  267  at rear end  262  of female coupling housing  264  for providing further bending strain relief for the cable assembly. 
     As discussed, boot  266  may be formed from a flexible material such as KRAYTON or the like. Heat shrink tubing  267  and boot  266  generally inhibit kinking and provide bending strain relief to the cable  140  near connector  200 . Boot  266  has a longitudinal passageway (not visible) and may have a stepped profile therethrough. Dust cap  268  has external threads for engaging the internal threads of female coupling housing  264  for attachment and thereby inhibit dirt and debris from entering the connector  200  via the front end  261  of female coupling housing  264  when not mated. Moreover, the dust cap  268  may include an O-ring for providing a weatherproof seal between fiber optic connector  200  and dust cap  268  when installed. The O-ring of a dust cap that seals the opening of the connector when not in a mated state should not be confused with the internal compliant member  256  that aids in tolerance stack-up of components in the connector. 
       FIG. 29  is a perspective view of the cable assembly  200  being aligned with a complimentary plug connector  5  for mating. As shown, the shroud of the male plug connector  5  has alignment fingers having different shapes and when mated the female coupling housing  264  only allows the plug connector  5  to fully seat for optical coupling in one orientation by preventing insertion of the larger alignment finger into the female coupling housing  264  past the stop ledge. In one embodiment, the correct mating orientation is marked on the female coupling housing  264  such as an alignment indicia so that the craftsman can quickly and easily mate connector  200  with the plug connector  5 . For instance, the alignment indicia may be an arrow or dot molded into the female coupling housing  264 , however, other suitable indicia may be used. Thereafter, the craftsman engages the internal attachment feature  265  such as internal threads of female coupling housing  264  with the complimentary external threads of plug connector  5  for making the optical connection. 
     Additionally, the optical connection is easily connected or disconnected by merely mating or unmating the plug connector  5  with the fiber optic connector  200  by threadly engaging or disengaging the coupling nut on the plug connector  5  with the attachment features  265 . 
       FIGS. 30-33  depict another fiber optic connector  200 ′ similar to fiber optic connector  200  but having with a one-piece body  355  with the internal compliant member  256  disposed thereon. Like connector  200 , fiber optic connector  200 ′ comprises connector assembly  52 , body  355  for securing a portion of the connector assembly  52 , an internal compliant member  256  disposed about a barrel portion of body  355  and abutting a shoulder of the body, connector sleeve assembly  236 , balancing resilient member  230  and housing  264  comprising a threaded portion as depicted in  FIGS. 30-33 . 
       FIGS. 34-37  depict schematic sectional views showing a representative fiber optic connector as disclosed herein mating along with complimentary connector to illustrate movement of components and tolerance compensation using the internal resilient member for a worse-case scenario.  FIG. 34  is a schematic representation of the female fiber optic connector on the right-side according to the concepts disclosed herein receiving a male connector such as an OptiTap connector  5  from the left-side as represented by the arrows.  FIG. 35  shows the connector  5  inserted into the female fiber optic connector until the mating ferrules between the connectors make contact. As the connector  5  is inserted the engagement from the ferrule displaces the ferrule sleeve to the far right in the housing of the connector sleeve assembly leaving the gap between ferrule sleeve and the housing as depicted by the circles; however, the connector  5  has not yet reached full insertion into the female connector housing.  FIG. 36  depicts further insertion of connector  5  that further pushes the ferrule assembly rearward against it biasing spring (as represented by the middle circles) until the connector assembly contacts the hardstop of the housing of the connector sleeve assembly (as shown by the circles on the far-right); however, the connector  5  has not yet reached full insertion into the housing of the female connector (as represented by the circles on the far-left). At this point, the coupling nut of connector  5  can still be tightened until the hardstop such as the shroud of connector  5  contacts the housing of the female connector as shown in the far-right circles of  FIG. 37 . It is at this point the connector assembly of the female connector hits a hardstop and the coupling nut of connector  5  is not yet fully-tightened so that the internal compliant member  256  may be compressed upon further tightening of the coupling nut of connector  5  to compensate for any needed stack-up of the tolerances of the components during mating. 
     Although the disclosure has been illustrated and described herein with reference to explanatory embodiments and specific examples thereof, it will be readily apparent to those of ordinary skill in the art that other embodiments and examples can perform similar functions and/or achieve like results. All such equivalent embodiments and examples are within the spirit and scope of the disclosure and are intended to be covered by the appended claims. It will also be apparent to those skilled in the art that various modifications and variations can be made to the concepts disclosed without departing from the spirit and scope of the same. Thus, it is intended that the present application cover the modifications and variations provided they come within the scope of the appended claims and their equivalents.