Patent Description:
The disclosure is directed to fiber optic connectors along with methods for making fiber optic connectors. More specifically, the disclosure is directed to fiber optic connectors having improved or simplified designs along with methods of making.

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 outdoor environments hardened fiber optic connectors were developed. One of the most commercially successful hardened fiber optic connector is the OptiTap® connector sold by Corning Optical Communications LLC of Hickory, North Carolina, such as disclosed in <CIT> and <CIT> (the '<NUM> and '<NUM> patents). The OptiTap® connector is a hardened male plug connector for terminating a fiber optic cable and the assembly is configured for optical connection such as with a complementary 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 the well-known SC connector.

<FIG> are prior art depictions showing various stages of mating of a preconnectorized cable <NUM> having a plug connector <NUM> such as an OptiTap® connector with a receptacle <NUM>. Receptacle <NUM> mates plug connector <NUM> 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 <NUM> with the a non-hardened connector. Protection of the non-hardened connector side of the receptacle is typically accomplished by mounting the receptacle <NUM> 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 <FIG>, the other end of the receptacle <NUM> is accessible for receiving the plug connector <NUM> at the wall of the enclosure. Other applications may mount the receptacle <NUM> inside an enclosure on a bracket or the like.

Receptacle <NUM> 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 enclosed and protected space. Receptacle <NUM> is described in further detail in <CIT>. Receptacle <NUM> includes a receptacle housing and an adapter sleeve disposed therein. The receptacle <NUM> receives a non-hardened connector at a second end as represented by the arrow pointing to the left. The receptacle <NUM> typically requires mounting through a wall of a closure, or inside the closure, such as a closure mounted on the side of subscribers premises, disposed in an underground vault or on a pole for protecting the non-hardened connector for outside plant deployments.

Network operators face many challenges for building, deploying and connecting subscribers to outside plant communication networks such as Fiber-to-the-Home (FTTH) or Fiber-to-the-location (FTTx) networks. Besides right of way access for the communication networks, network operators may have limited space to available on existing poles or in existing vaults for mounting devices. Initially, conventional hardened fiber optic connectors were typically mounted on robust and relatively stiff fiber optic cables, and slack storage for these fiber optic cables may also consume limited space or become unsightly in aerial deployments. Further as outside plant deployments evolved many network operators desired to route the fiber optic cable assembly with the connector through an existing wall of a subscriber premises and into the building or route the fiber optic cable assembly with the connector through a buried duct. Thus, network operators because sensitive to the size of the fiber optic connector for these types of deployment applications.

Consequently, there exists an unresolved need for fiber optic connectors that allow quickly and easy deployment and connectivity in a simple and efficient manner while still being cost-effective.

<CIT> is directed to a rugged environmentally sealed connector. The fiber optic connector has a connector body and release sleeve. The connector body requires exterior shoulders on the front portion of the connector body for engaging with the structure on the first receptacle.

<CIT> is directed to hardened fiber optic connectors having separate fastening elements for securing the connector for optical mating. The hardened fiber optic connector requires fastening element having external threads that must rotate about an axis of the connector for optical mating.

<CIT> discloses a SC connector having a single-fiber ferrule. The SC connector has a grip with a key for quadrant optical tuning, thereby improving optical performance. Mating of the tuned SC connector with a similarly tuned SC connector for aligning the eccentricity to the same position such as pointing at the key of grip is required.

The disclosure is directed to fiber optic connectors and methods of making fiber optic connectors as described and recited in the claim. The concepts disclosed allow a compact form-factor for an optical fiber connector suitable for numerous applications and variations as desired.

The invention provides a fiber optic connector according to claim <NUM>.

It is to be understood that both the foregoing general description and the following detailed description 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 together with the description serve to explain the principles and operation.

Reference will now be made in detail to the fiber optic connectors of the disclosure, examples of which are illustrated in the accompanying drawings.

The concepts disclosed advantageously provide fiber optic connectors that allow streamlined manufacture and assembly along with easy and intuitive connectivity with other devices while still having a compact footprint. The fiber optic connectors disclosed are explained and depicted with various alternative components or optional features that may be incorporated into one or more of the fiber optic connector concepts as desired. By way of explanation, several different variations of housings are disclosed that can be modified to use with connector constructions where the ferrule loads from either the rear end of the housing or the ferrule load from the front end of the housing. Some fiber optic connectors may advantageously use fewer parts while providing robust and reliable optical performance. For instance, some of the fiber optic connectors disclosed may have the ferrule cooperate directly with an housing (e.g., assembled) without using a ferrule holder like conventional fiber optic connectors. Other constructions may increase the part count of the connectors for various reasons or could use a ferrule holder if desired.

In one aspect the fiber optic connectors (hereinafter "connector") disclosed advantageously comprise a housing and a ferrule. The housing provides a first connector footprint that interfaces with other devices for making an optical connection and various different first connector footprints are disclosed herein that may be used with the connector constructions disclosed. The first connector footprints may be defined by a housings having a rear portion (RP) and a front portion (FP). First connector footprints may also be further defined by a transition region (TR) disposed between the rear portion (RP) and the front portion (FP) of the housing.

In one explanatory example, the housing comprises a part of the rear portion (RP) having a round cross-section (RCS) and a part of the front portion having a non-round cross-section (NRCS). The front portion (FP) or the rear portion (RP) of the housing may be further defined in various configurations as disclosed herein while retaining a part of the rear portion (RP) with the round cross-section (RCS) and a part of the front portion (FP) having a non-round cross-section (NRCS). By way of explanation, the front portion (FP) may have a rectangular cross-section that provides a first orientation feature for the connectors for alignment during mating and inhibit insertion into a non-compliant device or port.

However, other variations of housings according to the concepts disclosed are possible. As an example of another housing disclosed herein for use with the connector constructions disclosed, the housing may be defined as comprising a part of the rear portion (RP) having a polygonal cross-section (PCS) and a part of the front portion having a non-round cross-section (NRCS). The front portion (FP) or the rear portion (RP) of this explanatory housing may be further defined in various configurations as disclosed herein while retaining a part of the rear portion (RP) with the polygonal cross-section (PCS) and a part of the front portion (FP) having a non-round cross-section (NRCS) such as shown in <FIG> and 79A. By way of example, the polygonal cross-section (PCS) may be a hexagon, a rectangle, a square or other suitable polygon as desired.

Housings disclosed herein define the mating interface for a complimentary device suitable for mating with the connector and the connector footprints disclosed are useful for inhibiting insertion into a non-compliant port or device and damaging either the connector or the device along with assuring a suitable optical operation for the optical connection since the connector and device are matched. Moreover, the housings may have features that aid in the proper alignment or orientation of the connector with the complimentary device such as markings, keys, keyways, etc. without significantly changing the primitive form-factors of the housings that are disclosed and claimed herein. By way of example, even though a round cross-section may include another feature such as a key or a keyway it is still considered to be a round cross-section. Additionally, housing may have other features such as locking features for securing the optical mating with a complimentary device or threads for securing a dust cap.

The housing footprints disclosed herein may be further defined by other geometry of the housing(s). By way of example, the transition region (TR) disposed between the rear portion (RP) and the front portion (FP). The transition region (TR) may have different configurations according to the concepts disclosed. The transition region (TR) may comprise a first transition portion (TP1) disposed on a first side of the housing and a second transition portion (TP2) disposed on a second side of the housing. The first transition portion (TP1) and the second transition portion (TP2) may be spaced apart by an offset distance (OD) in the longitudinal direction. However, other housings disclosed herein may have all of the transition portions of the transition region (TR) aligned along a common transverse plane of the connector as desired. The transition region (TR) of the housing comprises a threaded portion (TP).

Other variations may further define the housing footprints disclosed herein. By way of example and explanation for use with appropriate housings disclosed, the first transition portion (TP1) comprises a first riser dimension (FRD) from the non-round cross-section (NRCS) to the round cross-section (RCS), and the second transition portion (TP2) comprises a second riser dimension (SRD) from the non-round cross-section (NRCS) to the round cross-section (RCS), where the first riser dimension (FRD) is different that the second riser dimension (SRD).

By way of another example of non-round cross-section (NRCS) for use with appropriate housings disclosed herein, a part of the front portion (FP) of the housing having the non-round cross-section (NRCS) comprises a rectangular cross-section having rounded corners (RC). The rectangular cross-section with rounded corners (RC) is a non-round cross-section (NRCS) due to the rectangular cross-section. The rounded corners (RC) may be sized so they have a similar outer dimension (OD) as a dimension (D) for the round cross-section (RCS) or not. The rounded corners (RC) may provide stability and snug fit for the mated connector within a port or device when side-pull forces are experienced to inhibit undue optical attenuation by having the round corners transition between the front portion (FP) to the rear portion (RP). However, other geometry is possible such as chamfers or the like such as when the rear portion (RP) has a polygon cross-section (PCS).

The housing footprints disclosed herein may be still further defined by other geometry of the housing(s). For instance, the front portion (FP) of the housing may comprise another cross-section portion (ACSP). By way of explanation, the another cross-sectional portion (ACSP) may comprise a SC footprint. The SC footprint can, in part, be similar to the inner housing of a conventional SC connector. This particular housing footprint is useful for allowing the connectors disclosed to be backwards compatible into existing devices or ports using well-established connector footprints as desired.

Housings may also define further features such as a transition region disposed between the rear portion and the front portion with the transition region comprising an asymmetric transition with respect to a longitudinal axis of the housing. Likewise, other features on the housing may define the housing as asymmetric for orientation or mating with compliant devices or ports.

Another aspect for some of the advantageous connectors disclosed herein comprise one or more features allowing for rotation of the ferrule during assembly for tuning the connector and improving optical performance. Some of the connector designs disclosed also offer multi-stage tuning of the ferrule/assembly or infinite tuning of the ferrule/assembly to any desired rotational position for improving optical performance.

The concepts described herein are suitable for making both indoor and outdoor fiber optic cable assemblies using the connectors disclosed such as drop or distribution cables. Further, the fiber optic connectors disclosed may allow for the use of one or more additional components for changing the connector form-factor defined by the particular housing. By way of example, a conversion housing may cooperate with the housing of the connector for changing the fiber optic connector from the first connector footprint defined by the housing to a second connector footprint at least partially defined by the conversion housing. Consequently, the connectors disclosed herein may be converted to be compatible as other well-known commercial connectors for Fiber-to-the-Home applications such as an SC connector or an OptiTap® connector such as available from Corning Optical Communications of Hickory, NC. Of course the concepts disclosed herein may be used with other fiber optic connector types whether hardened or not and are not limited to these particular connector conversions. Likewise, the connector designs disclosed may be hybrid designs with both optical and electrical connectivity. Electrical connectivity may be provided by contacts on or in a portion of the housing of the connector and may be useful for power or data as desired for applications such as FTTx, <NUM> networks, industrial applications or the like. These and other additional concepts are discussed and disclosed in illustrative detail with reference to FIGS.

Several different constructions of fiber optic cable assemblies <NUM> (hereinafter "cable assemblies") comprising connector <NUM> and variations of connector <NUM> are disclosed herein. The connectors <NUM> may use any of the suitable housings or different connector constructions as desired and appropriate. By way of explanation, <FIG>, <FIG>, <FIG> and <FIG><NUM> disclose connectors where a ferrule <NUM> is inserted from a rear end <NUM> of housing <NUM>, and <FIG> and <FIG> disclose connectors where ferrule <NUM> is inserted from a front end <NUM> of the connector <NUM>. However, housings <NUM> may be modified for using connector designs. <FIG> depict an explanatory housing <NUM> for discussing geometry that generally speaking may be used with any appropriate connector construction as well as have the housing modified or altered for the desired housing design or connector construction. Likewise, housing <NUM> of <FIG> with the threaded transition portion (TP) may be modified or altered for the desired housing design or connector construction. <FIG> disclose concepts related to alternative locking features <NUM> for use with housings <NUM> as appropriate. <FIG> disclose another cable assembly <NUM> comprising connector <NUM> concepts disclosing another cable adapter that may be used with appropriate connectors <NUM> disclosed herein. <FIG> depicts connector <NUM> according to the concepts disclosed having another housing footprint. <FIG> disclose cable assemblies <NUM> comprising connectors <NUM> having a first connector footprint where the connectors <NUM> may be convertible to connectors <NUM>' having a second connector footprint using a conversion housing <NUM>,<NUM>. <FIG> disclose cable assemblies <NUM> comprising connectors <NUM> having a first connector footprint where the connectors <NUM> may be convertible to connectors <NUM>" having a second connector footprint using a different conversion housing <NUM>. <FIG> disclose a connectors where ferrule <NUM> is disposed within a ferrule holder <NUM> and inserted from a front end <NUM> of the connector <NUM>.

<FIG> is a perspective view and <FIG> is an exploded view of cable assembly <NUM> having connector <NUM> and a fiber optic cable <NUM> (hereinafter "cable"). <FIG> are longitudinal sectional views of the cable assembly <NUM> of <FIG> showing details of the construction. <FIG> depicts cable assembly <NUM> having connector <NUM> with a housing <NUM> that is similar to the housing <NUM> for connector <NUM> of <FIG>, but the housing <NUM> of <FIG> has a different transition region TR. Specifically, the housing <NUM> of <FIG> has a transition region TR with a threaded portion TP and may be used with the connector constructions disclosed herein as appropriate.

Connector <NUM> comprises housing <NUM> and a ferrule <NUM>. Housing <NUM> comprises a rear end <NUM> and a front end <NUM> with a longitudinal passageway <NUM> extending from the rear end <NUM> to the front end <NUM>. As best shown in <FIG>, ferrule <NUM> comprises a fiber bore <NUM> extending from a rear end <NUM> to a front end <NUM>. Passageway <NUM> allows one or more optical fibers of cable <NUM> to pass through the housing <NUM> for insertion into fiber bore <NUM> of ferrule <NUM> such as depicted in <FIG>. Cable <NUM> comprises at least one optical fiber <NUM>, one or more strength components <NUM> and a cable jacket <NUM>.

Connector <NUM> or components of connector <NUM> as depicted in <FIG>, <FIG>, <FIG> and <FIG>-<NUM> allows ferrule <NUM> to be inserted into housing <NUM> from rear end <NUM> of housing <NUM>. Specifically, ferrule <NUM> is inserted into an opening 21A at the rear end <NUM> of housing <NUM>. Housing <NUM> depicted in <FIG> is similar to the housing <NUM> <FIG>, except it has a different transition region (TR). Specifically, the transition region (TR) of the housing <NUM> of <FIG> comprises a threaded portion; otherwise the concepts of the connector are similar to the other disclosed herein. The thread portion (TR) allows the securing of an appropriate dust cap <NUM> and also allows for the conversion of the connector footprint such as to a hardened connector footprint such as shown in <FIG>. However, the concepts of the rear inserted connector constructions may be used with any suitable housing disclosed herein.

As depicted, connector <NUM> of <FIG> comprises housing <NUM>, ferrule sub-assembly <NUM> and cable adapter <NUM>. The ferrule <NUM> is a portion of ferrule sub-assembly <NUM>. An opening 21A at the rear end <NUM> of housing <NUM> is sized for receiving a portion of ferule sub-assembly <NUM>. Ferrule sub-assembly <NUM> is configured to cooperate with the housing <NUM> for inhibiting the rotation of the ferrule sub-assembly <NUM> with respect to housing <NUM> when assembled. However, ferrule sub-assembly <NUM> may be configured to allow rotation of ferrule <NUM> for tuning as represented by arrows and angle θ as desired before the ferrule sub-assembly <NUM> is fully-seated within housing <NUM> as discussed herein.

Ferrule sub-assembly <NUM> also comprises a ferrule carrier <NUM>. Ferrule carrier <NUM> may have different configurations as disclosed herein. Ferrule <NUM> is tunable relative to housing <NUM> if desired and may have step-tuning in defined increments based on the ferrule geometry. However, other features or designs disclosed herein for the connectors may allow infinite tuning of the ferrule to any desired rotation position. Tuning ferrule <NUM> allows improved optical performance by turning the ferrule so that any eccentricity in the optical fiber, ferrule or connector is rotated to a known rotational position or quadrant in a uniform manner. Consequently, connectors or other mating devices can be tuned to similar relative rotational positions for improving optical performance such as reducing optical insertion loss of due to optical fiber core misalignment or the like as understood in the art. Fiber optic connectors disclosed herein may also have a plurality of interfaces between components for tuning of the connector as desired.

The design of connector <NUM> of <FIG> may also advantageously allow multi-stage tuning if desired. Ferrule <NUM> or other components/assemblies may be tunable in step increments such as by quadrants or be infinitely tuned as desired. By way of example, ferrule sub-assembly <NUM> may be may be configured to allow rotation of the sub-assembly with respect to cable adapter <NUM> (or other components) as desired for tuning ferrule <NUM> as represented by the arrows and angle ϕ as depicted. Moreover, multi-stage tuning may result in infinite tuning, which means that any desired rotational position desired for any eccentricity of the fiber core within the ferrule <NUM> is possible. The step or degree of tuning at different component interfaces may depend on the particular construction of the ferrule, ferrule carrier, cable adapter or housing with respect to the permitted of rotation and the possible increments of rotation for the components.

By way of example, a first-stage of tuning may be step-tuning by quadrant and a second-stage of tuning may be infinite tuning to allow infinite rotation as desired. More specifically, the first-stage step-tuning may be used for gross tuning of the eccentricity of the fiber core such as to the desired quadrant of the and then the second-stage provides infinite tuning by allowing the fine tuning of the eccentricity of the fiber core within the quadrant for precise rotational positioning. By way of explanation, infinite tuning may accomplished by having one or more components rotate through an angle of ±<NUM> degrees without step increments, thereby allowing any rotational position for ferrule <NUM>. Of course, other tuning schemes are possible using the concepts disclosed herein. Likewise, variations of ferrule carrier <NUM> or ferrule subassembly <NUM> are possible and disclosed herein for use with any suitable housing <NUM>.

Connector <NUM> of <FIG> allows ferrule <NUM> to be rotated or tuned within the ferrule subassembly <NUM> as depicted. Ferrule <NUM> may be configured to rotate as a step rotation or infinite rotation depending on the particular design. For instance, ferrule <NUM> could have a selectively tunable surface <NUM> that is round for providing infinite rotational positioning or selectively tunable surface of ferrule <NUM> could comprise a plurality of planar surfaces <NUM> for step tuning by only allowing certain rotation positions. Moreover, infinite tuning of ferrule <NUM> may be accomplished by tuning or rotating though an angle θ of ±<NUM> relative to the ferrule carrier <NUM> if desired. Being able to rotate one or more components in either direction allows for flexibility in tuning and inhibits excessive twisting of the optical fiber, which is generally undesirable.

Connector <NUM> of <FIG> also allows ferrule carrier <NUM> to be rotated for tuning the ferrule relative to housing <NUM> as depicted. Ferrule carrier <NUM> is
tunable relative to the housing <NUM> by way of the rotational position of ferrule carrier <NUM> relative to cable adapter <NUM> or rotational position of the cable adapter <NUM> with respect to the housing. Specifically, ferrule carrier <NUM> may be tunable though an angle ϕ of ±<NUM> relative to the housing <NUM> or in step-increments such as using ferrule carrier rotational key <NUM> (<FIG>) or the like as desired. For instance, a ferrule carrier rear end <NUM> may have one or more keys for cooperating with cable adapter <NUM> and only allowing certain positions for tuning, or the ferrule carrier rear end <NUM> may simply cooperate with the cable adapter <NUM> for providing infinite rotational positions for tuning. The details of tuning will be discussed in more detail below.

Likewise, it is possible for connector <NUM> of <FIG> to have to a third interface for tuning. Specifically, the cable adapter <NUM> may be tunable relative to the rear end <NUM> of housing <NUM>. Like the ferrule carrier rear end <NUM>, a flange portion (not numbered) of cable adapter <NUM> may have one or more keys for cooperating with the rear end <NUM> of housing <NUM> and only allowing certain positions for tuning, or the flange portion of cable adapter <NUM> may simply cooperate with the rear end <NUM> of housing <NUM> for providing infinite rotational positions for tuning. Thus, connector <NUM> of <FIG> provides several different tuning options for manufacturing depending on the desired requirements for the connector.

<FIG> depict an explanatory housing <NUM> for connectors and will be described in further detail to explain concepts and geometry of housings <NUM> suitable for use with connector concepts disclosed herein. Although the housing of <FIG> is a close-up perspective view of connector <NUM> having a different construction than the housing <NUM> depicted in <FIG> and <FIG>, the housing <NUM> of <FIG> is similar to housing <NUM> of the connector of <FIG> and <FIG>. Generally speaking, the footprint of housing <NUM> of <FIG> may be used with connector constructions that insert the ferrule <NUM> from the rear end <NUM> of housing <NUM> or connector constructions that insert the ferrule <NUM> from the front end <NUM> of housing with appropriate modification(s) for the connector construction. By way of explanation, the longitudinal passageway <NUM> of the housing <NUM> may need to be modified for the different connector constructions as appropriate.

Connectors <NUM> disclosed herein may use any suitable housing <NUM> with the desired footprint or construction. The disclosure describes several different housings that may be used with connector constructions as appropriate and other variations are also possible. <FIG> depicts housing <NUM> and connectors <NUM> may use a variety of different variations of the housing shown in <FIG> or other housings such as the housing <NUM> shown in <FIG> which has the locking feature on a separate component. Likewise, housing <NUM> may comprise one or more features for alignment during mating. Housing <NUM> comprises other features for securing or locking the connector in a suitable complimentary port or device. Housing <NUM> has a relatively compact form-factor such as having a length L of about <NUM> millimeters (mm) or less and a cross-section dimension of about <NUM> or less such as <NUM> or less, but other suitable dimensions are possible for the housing.

<FIG> are respective cross-sectional views of the housing of <FIG> taken along respective planes defined by line 4A-4A, line 4B-4B, line 4C-4C and line 4D-4D. Lines 4B-4B and 4C-4C are taken at the same cross-section. <FIG> is a side view of housing <NUM> that is similar to housing <NUM> shown in <FIG>, but further includes threads <NUM> like housing <NUM> depicted in <FIG> and <FIG>. Threads <NUM> are disposed on the front portion FR of housing <NUM> and are discontinuous.

Housing <NUM> comprises the rear end <NUM> and the front end <NUM> with a longitudinal passageway <NUM> extending from the rear end <NUM> to the front end as shown in <FIG>. Housing <NUM> of <FIG> comprises a part of the rear portion RP having a round cross-section RCS and a part of the front portion having a non-round cross-section NRCS. Transition region TR is disposed between the rear portion RP and the front portion FP of housing <NUM>. Transition region TR comprises a first transition portion TP1 disposed on a first side of the housing and a second transition portion TP2 disposed on a second side of the housing. In this version, the first transition portion TP1 and the second transition portion TP2 are spaced apart by an offset distance OD in the longitudinal direction of the housing <NUM> as best shown in <FIG>. The offset distance OD for the transition portion TP is useful since it allows connector only to fully-seat into complimentary devices or ports having the matching geometry. However, other housings <NUM> for connectors disclosed herein may omit the offset distance if desired.

Housings <NUM> may also have suitable features or structures for sealing connectors <NUM>. The sealing plane should be located at a suitable location along the housing <NUM> for providing suitable environmental protection as necessary for the desired environment. Illustratively, housing <NUM> may include one or more grooves <NUM>
for receiving an appropriately sized O-ring <NUM>. Housings <NUM> may include other feature or structures for aiding in sealing. For instance, the housing <NUM> may have a suitable surface for receiving a portion of a heat shrink <NUM> or the like for sealing between a portion of the cable <NUM> and the connector <NUM>. Any suitable heat shrink <NUM> may be used such as a glue-lined heat shrink. Moreover, other structures or features are possible for aiding in providing a robustly sealed cable assembly <NUM>.

As used herein, the transition region TR is disposed between the rear end <NUM> and the front end <NUM> where the housing <NUM> makes a transformational shift in the primitive cross-sectional shapes from a part of a rear portion RP to a part of the front portion FP. As used herein, a primitive cross-section means the outer perimeter of the cross-section without regard for the internal features of the cross-section. Further, portions of the cross-sections may include other features that modify the shape of the primitive cross-sections as desired such as a keying feature, retention feature or a locking feature, while still practicing the concepts of the transition region TR or front/rear portions as disclosed herein. For instance, a front portion FP may have rounded corners or chamfered corners while still being a rectangular cross-section.

The front portion FP of housing <NUM> may have a rectangular cross-section that provides a first orientation feature for the connectors for alignment during mating and inhibit insertion into a non-compliant device or port. The non-round cross-section NRCS has the rectangular cross-section with a width W1 and a height H1 as shown in <FIG>. The rectangular cross-section provides the first orientation feature since the rectangular portion may only be inserted into a complimentary device or port in certain orientations due to its rectangular shape, thereby inhibiting incorrect insertion or insertion into non-compliant devices or ports.

As best shown in <FIG>, housing <NUM> of <FIG> has the first transition portion TP1 that comprises a first riser dimension FRD from the non-round cross-section NRCS to the round cross-section RCS, and the second transition portion TP2 comprises a second riser dimension SRD from the non-round cross-section NRCS to the round cross-section RCS, where the first riser dimension FRD is different that the second riser dimension SRD. The riser dimensions are measured perpendicular from the mid-point of the cord defined by the surface of non-round cross-section NCRS as shown in <FIG> to the outer surface of the round cross-section RCS.

The geometry of housing <NUM> of <FIG> also comprises the non-round cross-section NRCS comprising a rectangular cross-section having rounded corners RC, and the rounded corners RC are sized so they have a similar outer dimension OD as a dimension D for the round cross-section RCS. The rounded corners (RC) may provide stability and snug fit for the mated connector <NUM> within a port or device when side-pull forces are experienced to inhibit undue optical attenuation by having the round corners transition between the front portion FP to the rear portion RP.

The front portion FP of housing <NUM> depicted has more than one primitive cross-sectional shape over its length. Specifically, the front portion FP of housing <NUM> of <FIG> also comprises another cross-section portion ACSP. By way of explanation, the another cross-sectional portion (ACSP) may comprise a SC footprint. The SC footprint can, in part, be similar to the inner housing of a conventional SC connector. This particular housing footprint is useful for allowing the connectors disclosed to be backwards compatible into existing devices or ports using well-established connector footprints as desired. Other fiber optic connectors may have connectors configured for LC connector or other known connector footprints as desired.

As best shown in <FIG>, the front portion FP of housing <NUM> may comprise another cross-section portion ACSP with a primitive cross-section that is different than the non-round cross-section NRCS depicted in <FIG>. More specifically, the non-round cross-section NRCS changes to another cross-section portion ACSP as shown. As depicted in <FIG>, the another cross-section portion comprises a rectangular cross-section with a width W2 that is less than W1 and a height H2 is similar to height H1. By way of example, height H2 may be equal to height H1. The another cross-section portion ACSP may have a primitive cross-section that is similar to a cross-section near a front end of a SC connector.

Likewise, the rear portion RP may have more than one primitive cross-section shape over its length as desired. Moreover, rear portion RP may include one or more retention features or locking features that alter or modify the cross-section. Housing <NUM> also includes a locking feature <NUM> so that the connector may secured
in an adapter, port or other suitable device. For instance, locking feature <NUM> may comprise features integrated into the housing such as one or more of a groove, a shoulder such as shown in <FIG> and <FIG>, a scallop such as shown in the housing <NUM> of <FIG>, a reverse bayonet such as depicted in <FIG>, or a ramp with a ledge such as shown in <FIG>. In these examples, the locking features <NUM> advantageously are integrated into the housing <NUM> and do not require extra components and may be used with any of the disclosed concepts. The locking features <NUM> are subtractive portions from the primitive geometry of the rear portion RP such as a notch in the round rear portion RP. Consequently, having the locking features integrated into the housing <NUM> (e.g., monolithically formed as part of the housing) may allow denser arrays of connectors in complimentary devices. Moreover, these locking features integrated into the housing <NUM> are rearward of the sealing location of connectors <NUM>. For example, the integrated locking features of housing <NUM> are disposed rearward of at least one groove <NUM> that seats O-ring <NUM>. Locking feature <NUM> cooperates with features of a complimentary mating device for securing the mating of the connector <NUM> with the complimentary mating device.

Housing <NUM> may also have features that aid in the proper alignment or orientation of the connector with the complimentary device such as markings, keys, keyways, etc. without changing the primitive form-factors of the housings that are disclosed and claimed herein. Additionally, housing may have other features for mating with a complimentary device or threads for securing a dust cap. <FIG> is a perspective view of connector <NUM> with a housing <NUM> similar to the housing <NUM> depicted in <FIG>, but it further includes threads <NUM> and keying feature <NUM>. <FIG> depict a fiber optic connector similar to <FIG> having an alternative housing 20A that may be used with any suitable fiber optic connector disclosed herein. Housing <NUM> further comprises a keying feature <NUM>. Keying feature <NUM> has a predetermined location with respect to an orientation of housing <NUM> for aligning the form-factor of the housing with a respective mating device. For instance, the housing <NUM> or keying feature <NUM> provides a proper orientation for connection in one orientation, which may be desired for connectors having angled ferrules. The keying feature <NUM> ensures correct rotational orientation of the connector <NUM> during insertion and mating with another device.

The housing <NUM> may be monolithically formed; however, other housing may be formed from one or more components as desired. Housing <NUM> having a plurality of components could be assembled by snap-fitting, adhesive, welding or the like. Illustratively, <FIG> and <FIG> depict a housing <NUM> having a plurality of components.

Returning to the description of connector <NUM> of <FIG> and its components, <FIG> is an exploded view of ferrule subassembly <NUM> shown in connector <NUM> of <FIG>. Ferrule subassembly <NUM> may have several different constructions as depicted herein and still practice the concepts disclosed. For instance, ferrule subassemblies <NUM> may use different ferrule carrier <NUM> constructions such as disclosed or desired while still practicing the concepts disclosed.

Ferrule <NUM> is a portion of ferrule subassembly <NUM>. In this case, an opening 21A at the rear end <NUM> of the housing <NUM> is sized for receiving a portion of the ferrule subassembly <NUM>. When assembled, the ferrule subassembly <NUM> is configured to cooperate with the housing <NUM> for inhibiting the rotation of the ferrule subassembly <NUM> with respect to the housing <NUM>. For instance, the ferrule subassembly may have a friction fit or interlocking structure that cooperates with the passageway <NUM> of the housing <NUM> that inhibits rotation of the ferrule subassembly <NUM> with respect to housing <NUM>. However, in other embodiments the ferrule subassembly <NUM> may be free to rotate for tuning or the like until the ferrule subassembly <NUM> is fixed in position relative to housing <NUM> such as with an adhesive or the like.

As depicted in <FIG>, ferrule subassembly <NUM> comprises a ferrule carrier and a resilient member <NUM>. Some ferrule subassemblies <NUM> may omit the resilient member <NUM> and not bias the ferrule <NUM> forward. If a resilient member <NUM> is used, ferrule carrier <NUM> may further comprise a resilient member pocket <NUM> as shown. As depicted, the resilient member pocket <NUM> may be configured for receiving the resilient member <NUM> in a direction transverse to a longitudinal direction of the ferrule carrier <NUM> (e.g., transverse to the optical fiber passageway) as represented by the arrow.

As shown in <FIG>, ferrule carrier <NUM> comprises a ferrule carrier rear end <NUM>, a ferrule carrier front end <NUM> and a ferrule carrier passageway <NUM> extending from the ferrule carrier rear end <NUM> to the ferrule carrier front end <NUM>, where the ferrule carrier passageway <NUM> comprises a fiber buckling zone <NUM>. The fiber buckling zone allows the optical fiber <NUM> to have room to move rearward during mating without causing undue optical attenuation. In other words, during mating the ferrule <NUM> may be pushed rearward slightly cause the optical fiber <NUM> of the cable <NUM> to deflect and in order to inhibit optical attenuation the fiber buckling zone <NUM> provided for allowing fiber movement.

Ferrule carrier <NUM> may have several different designs. tThe ferrule carrier may comprise a ferrule carrier front end <NUM> with the ferrule carrier front end <NUM> comprising at least one cantilevered portion such as shown in <FIG>. Generally speaking, the at least one cantilevered portion extends from a medial portion of the ferrule carrier and allows the assembly of the ferrule <NUM> into the ferrule carrier <NUM>. The at least one of the first cantilevered portion 43A may also be configured to cooperate with the housing <NUM> for inhibiting the rotation of the ferrule <NUM> with respect to the housing <NUM> when the ferrule subassembly <NUM> is fully-seated in the housing <NUM>, and allow rotation of the ferrule <NUM> for tuning when the ferrule subassembly <NUM> is not seated in the housing <NUM>.

By way of explanation and example, the front portion of the longitudinal passageway <NUM> of housing <NUM> may be sized for snuggly fitting to shoulders <NUM> disposed on the ferrule carrier front end <NUM> so that one or more of the cantilevered portions either squeeze the ferrule <NUM> and inhibit rotation or inhibit the deflection of the at least one cantileved portion so that the ferrule <NUM> is inhibited from rotating beyond its desired location. However, the ferrule carrier <NUM> still allows the ferrule <NUM> to "float" to the desired degree so it can translate such as in the rearward direction (i.e., z-direction) or X-Y directions for allowing the ferrule to move slightly to the desired location for precise alignment during mating. For instance, the ferrule <NUM> is biased and may "float" on the resilient member.

The use of the ferrule carrier described herein should not be confused with a ferrule holder that fixes a conventional ferrule directly to the ferrule holder so there is no appreciable movement between the ferrule and the ferrule holder. Conventional connectors allow the entire assembly of the ferrule holder/ferrule to be biased by a spring. On the other hand, fiber optic connectors such as depicted in <FIG>, <FIG> and <FIG> allow the ferrule to float without using a ferrule holder. Moreover, the
use of the ferrule holder/ferrule assembly is another component interface where stack-up of tolerances may exist and impact geometry. Consequently, connectors disclosed herein may eliminate the conventional ferrule holder along with the expense and manufacturing time required by using a conventional ferrule holder.

<FIG> depicts the ferrule carrier front end <NUM> comprising a first cantilevered portion 43A and a second cantilevered portion 43B. <FIG> are longitudinal sectional views of ferrule subassembly <NUM> of <FIG> showing details of the design and assembly. <FIG> respectively are a perspective view and close-up perspective view of ferrule carrier <NUM> of <FIG> depicting details of the ferrule carrier.

In this case, at least one of the first cantilevered portion 43A or the second cantilevered portion 43B are configured to cooperate with the housing <NUM> for inhibiting the rotation of the ferrule <NUM> with respect to the housing <NUM> when the ferrule subassembly <NUM> is fully-seated in the housing <NUM>, and allow rotation of the ferrule <NUM> for tuning when the ferrule subassembly is not seated in the housing <NUM>. By way of explanation, ferrule carrier front end <NUM> of <FIG> may be sized to cooperate with the housing <NUM> by fitting into a passageway <NUM> that inhibits the cantilevered portions 43A,43B from deflecting outwards, thereby inhibiting the rotation of the ferrule <NUM> with respect to the ferrule carrier <NUM> when the ferrule carrier front end <NUM> is fully-seated in the housing <NUM> since some of the selectively tunable surfaces <NUM> (in this case the planar surfaces <NUM>) of ferrule <NUM> cooperate with ferrule retention structure 43C of the ferrule carrier <NUM>.

Ferrule subassembly <NUM> is assembled by placing the resilient member <NUM> into the resilient member pocket <NUM> by inserting the spring in the transverse direction to the ferrule carrier passageway as best shown in <FIG>. Ferrule carrier <NUM> of <FIG> allows ferrule <NUM> to be inserted from the ferrule carrier front end <NUM> as represented by the arrow. As ferrule <NUM> is inserted into the ferrule carrier front end <NUM> the first cantilevered portion 43A and the second cantilevered portion 43B deflect outward as represented by the arrows shown in <FIG>. As the ferrule <NUM> is seated in the ferrule carrier front end <NUM> the first cantilevered portion 43A and the second cantilevered portion 43B spring back toward their original positions to capture the ferrule <NUM>. As best shown in <FIG> and <FIG>, one of the first cantilevered portions 43A or the second cantilevered portions 43B comprise a ferrule retention structure 43C. Consequently, when the first and second cantilevered portions 43A,43B are inhibited from deflecting, then ferrule <NUM> is inhibited from rotating such as when the ferrule subassembly <NUM> is fully-seated within housing <NUM>. However, when the first and second cantilevered portions 43A, 43B are allow to deflect outwards such as shown in <FIG>, then the ferrule <NUM> may be rotated thru any desired angle θ for tuning.

Further, the rear end of ferrule carrier <NUM> may have other features that allow tuning if desired. For instance, ferrule carrier rear end <NUM> may have a ferrule carrier groove <NUM> or shoulder for cooperating with the cable adapter <NUM>, thereby allowing rotation between the two components in either step increments or infinite increments as desired and discussed herein. By way of example, ferrule carrier <NUM> may comprise one or more ferrule carrier rotational keys <NUM> to allow rotational step increments or the ferrule carrier <NUM> may omit ferrule carrier rotational keys <NUM> and allow infinite rotational positions relative to the cable adapter <NUM>, which may be keyed to the rear end 21of housing <NUM>. Ferrule carrier <NUM> may be attached to cable adapter in any suitable manner such as adhesive, welding, mechanical fitment, etc..

The ferrule carrier <NUM> and cable adapter <NUM> may be integrated into a monolithic component. However, using separate cable adapter <NUM> allows the connectors <NUM> to be adapted to different cables such as round, flat, different sizes by merely selecting the appropriate sized cable adapter <NUM> for the desired cable type. Additionally, cable adapter may include one or more flexures 59F at the rear portion for providing cable bending strain-relief if desired instead of using a conventional boot. The flexures as depicted are suitable for flat cables that have a preferential bend-characteristic.

Again, the connectors disclosed herein may allow the ferrule <NUM> to have a small amount of "float" within ferrule carrier or housing without using a ferrule holder like conventional fiber optic connectors. Conventional connectors mount the ferrule within a ferrule holder in a fixed position and then typically the ferrule holder is biased by a spring. On the other hand, some of the connector designs disclosed by the present application have the resilient member <NUM> directly bias the ferrule, which eliminates parts and also allows more flexibility for ferrule selection or tuning. Moreover, the ferrule may be tuned relative to the ferrule carrier or the housing depending on the connector design. Further, the high precision geometry ferrule holder is eliminated along with the tolerance stack-up using a conventional connector with a ferrule holder. However, the housings concepts disclosed herein may be used with connectors having ferrule holders such as disclosed in <FIG>.

Ferrule retention structure 43C is configured to cooperate with geometry on ferrule <NUM>. Specifically, ferrule <NUM> depicted in <FIG> has at least one selectively tunable surface <NUM> that cooperates with the ferrule retention structure 43C. Ferrule retention structure 43C is sized for snugly-fitting to one or more selectively tunable surfaces <NUM> of ferrule <NUM> as shown in <FIG>. However, when the ferrule carrier <NUM> is not seated in housing <NUM>, the ferrule <NUM> may be rotated within ferrule carrier <NUM> about an angle θ for optically tuning the assembly. Ferrule <NUM> may have a round selectively tunable surface <NUM> for infinite tuning, but that requires a tight fit between the ferrule carrier front end <NUM> and the appropriate portion of the passageway <NUM> of the housing <NUM>. If the ferrule <NUM> uses selectively tunable surfaces <NUM> comprising a plurality of planar surfaces <NUM>, then the appropriate portion of the passageway <NUM> merely has to inhibit deflection of the at least one cantilever arm so that the ferrule <NUM> is inhibited from rotation when fully assembled. <FIG> depict detailed views of the ferrule carrier <NUM> of <FIG>. As depicted, the first and second cantilevered portions 43A,43B of ferrule carrier <NUM> may have stepped down portions forward of shoulder <NUM>, thereby allowing robust seating and inhibiting of deflection of the cantilevered arms 43A,43B.

Ferrule <NUM> may have any suitable number of plurality of planar surfaces <NUM> as desired. By way of explanation, four planar surface <NUM> allows quadrant tuning and further planar surfaces allows finer tuning in a first-stage. However, ferrules <NUM> may have any number of planar surfaces as desired such as six or eight planar surfaces to increase the number of steps for tuning the ferrule. Generally speaking, quadrant tuning is sufficient and if coupled with an infinite second-stage tuning interface, then the connector advantageously may be tuned to any desirable rotational position in a quick and easy manner during manufacturing.

<FIG> is a perspective view of an alternative ferrule carrier <NUM>' that may be used in the ferrule subassembly <NUM> and <FIG> respectively are a partially exploded view and an assembled view of the alternative ferrule carrier <NUM>' in ferrule subassembly <NUM>. This ferrule carrier <NUM>' is similar to ferrule carrier <NUM>, but only has first cantilevered arm, and requires loading of the ferrule <NUM> from the transverse direction like the resilient member <NUM>. Ferrule <NUM> may still be rotated with respect to ferrule carrier <NUM>', but it may require a slightly larger rotational force to deflect the U-shaped portion or a slightly upward translation of the ferrule <NUM> to help reduce the rotational force required for the rotation.

<FIG> respectively are a partial sectional view and a cross-sectional view of the alternative ferrule carrier <NUM>' of <FIG> depicted assembled into ferrule subassembly <NUM> and disposed in housing <NUM> of fiber optic connector. As depicted, the passageway <NUM> of housing <NUM> may include different geometry for seating the ferrule subassembly <NUM> within the housing and inhibiting the rotation of ferrule <NUM> relative to the housing <NUM> using the alternative ferrule carrier <NUM>'. As depicted, housing <NUM> comprises a passageway <NUM> with an internal key 20KI that cooperates with the U-shaped portion of the alternative ferrule carrier <NUM>'. Consequently, the alternative ferrule carrier is inhibited from further rotation with respect to the housing <NUM>.

<FIG> is an exploded view of another cable assembly <NUM> that is similar to the cable assembly <NUM> of <FIG> with a fiber optic connector having a different ferrule subassembly <NUM> and <FIG> is a partially exploded view of the cable assembly <NUM> of <FIG> with the fiber optic cable attached to the ferrule subassembly <NUM>. This cable assembly <NUM> comprises a connector <NUM> that has a ferrule carrier <NUM> that is monolithically formed with the cable adapter as depicted. Otherwise, the cable assembly <NUM> is similar to the cable assembly <NUM> of <FIG>.

The concepts disclosed herein may be used with other types and designs of connectors. For instance, <FIG> and <FIG> disclose connectors where ferrule <NUM> is inserted from a front end <NUM> of the connector <NUM>. These connectors designs are depicted without a ferrule holder as generally discussed herein, but may be used with a ferrule holder if desired. These connector designs are different from the earlier connector designs since they do not use a ferrule carrier; however, these designs can still be optically tuned if desired. Specifically, these connector designs comprise a ferrule <NUM> that "floats" relative to the housing <NUM> and uses a different structure for securing the ferrule while allowing the ferrule float. Any suitable housings <NUM> as described herein may be used for these connectors so long as they are suitably modified for securing the ferrule <NUM> as disclosed in more detail below.

Illustratively, <FIG> and <FIG> are perspective views of cable assembly <NUM> having a different fiber optic connector <NUM> with housing <NUM> that is similar to the housing shown with the fiber optic connector of <FIG>, but having ferrule <NUM> that loads from the front end <NUM> of housing <NUM> and secured a transverse ferrule retention member <NUM>. <FIG> is an exploded view of another cable assembly <NUM>, that is similar to that of <FIG> with the connector having a housing having threads on the housing that are discontinuous. <FIG> is an perspective assembled view of the cable assembly <NUM> of <FIG> and <FIG> is a perspective view of the cable assembly <NUM> of <FIG> with a dust cap <NUM> installed. <FIG> is a longitudinal sectional view of the cable assembly <NUM> of <FIG> in a vertical direction and <FIG> is a longitudinal sectional view of a front portion of the fiber optic connector <NUM> in a horizontal direction.

With reference to <FIG>, connector <NUM> comprises housing <NUM>, ferrule <NUM> and transverse ferrule retention member <NUM>. Housing <NUM> is similar to the other housings disclosed herein, but further comprises an opening <NUM> in an outer surface that is transverse to the longitudinal passageway <NUM> of housing <NUM>. The opening <NUM> is sized for receiving the transverse ferrule retention member <NUM> and securing the ferrule <NUM> in a manner that allows suitable movement so it may float as appropriate as depicted in <FIG>. Connector <NUM> may also comprise a band <NUM> for securing a cable <NUM> to the connector if desired.

<FIG> is a detailed exploded view of the front end of the cable assembly <NUM> of <FIG> and <FIG> is a cross-sectional view taken at the opening <NUM> of the housing <NUM> of <FIG> showing transverse ferrule retention member <NUM> securing the ferrule <NUM>. As depicted in <FIG>, ferrule <NUM> is loaded into the passageway <NUM> of housing <NUM> from the front end <NUM> and secured by the cooperation of the ferrule <NUM> with the transverse ferrule retention member <NUM> that is inserted into opening <NUM> for cooperating with at least one surface of the ferrule <NUM>. Specifically, ferrule <NUM> is inserted into the passageway <NUM> until the cooperating surface such as a ferrule retention feature aligns with the opening <NUM> so that the transverse ferrule retention member <NUM> may engage the surface and securing the ferrule. Additionally, the at least one surface of the ferrule <NUM> that serves as the ferrule retention feature cooperates with the transverse ferrule retention member <NUM> is sized relative to the transverse ferrule retention member so that the ferrule <NUM> may float. The ferrule retention feature may also be the same feature as the at least one selectively tunable surface <NUM>.

In this case, ferrule has at least one selectively tunable surface <NUM> so that ferrule <NUM> may have at least two rotational orientations with respect to the housing <NUM> (and which acts as the ferrule retention feature). However, ferrules <NUM> may have any suitable numbers of selectively tunable surfaces <NUM> so the ferrule <NUM> may have the desired number of rotational positions for tuning the ferrule. By way of example, ferrule may have four, six, eight or any suitable number of selectively tunable surfaces <NUM> as desired. More specifically, the longitudinal passageway <NUM> of housing <NUM> extending from the rear end <NUM> to the front end <NUM> also comprises a tuning pocket <NUM> in cooperation with the longitudinal passageway <NUM>. The tuning pocket <NUM> allow the rotation or manipulation of the ferrule <NUM> within the housing as needed. The transverse ferrule retention member <NUM> may be secured to the housing <NUM> using a pair of catches 140C disposed on the arms of the transverse ferrule retention member <NUM>. Catches 140C may snap-fit to portions of the housing <NUM> disposed in opening <NUM> such ledges. However, other variations for securing the ferrule <NUM> are possible. By way of example, <FIG> respectively depict a detailed view of an alternative transverse ferrule retention member <NUM> having catches 140C and cross-sectional view showing the alternative transverse ferrule retention member <NUM> for securing ferrule <NUM>. As best depicted in <FIG>, the catches 140C are disposed on a medial portion of the arms of this alternative transverse ferrule retention member <NUM>. Consequently, the catches 140C cooperate with a portion of ferrule <NUM> as depicted in <FIG>, instead of the housing <NUM> as depicted in <FIG>. <FIG> is a sectional view of a portion of the housing <NUM> having a width of opening <NUM> being larger than the width of the transverse ferrule retention member <NUM> so that the ferrule <NUM> may float. <FIG> is a sectional view depicting tuning pocket <NUM> of housing <NUM> that allows rotational tuning of the ferrule <NUM> during manufacture for improving optical performance. Specifically, when transverse ferrule retention member <NUM> is disengaged, then the ferrule <NUM> may be rotated relative to the ferrule. As depicted, tuning pocket <NUM> allows ferrule <NUM> to be rotated by a suitable angle θ for optical tuning to a
preferred rotational position as represented by the arrow. By way of example, ferrule <NUM> may be rotated by an angle θ of ±<NUM> degrees, but other suitable angles are possible.

<FIG> depict explanatory ferrules <NUM> having at least one selectively tunable surface <NUM>. <FIG> shows a ferrule that may be tuned to quadrants with four selectively tunable surfaces <NUM>. Generally speaking, the selectively tunable surfaces <NUM> are configured as planar surfaces as shown. More specifically, the selectively tunable surfaces <NUM> are formed by a plurality of planar surfaces that are recessed on the ferrule <NUM>. Finer tuning is possible with the concepts disclosed by having more selectively tunable surfaces such as six, eight, ten or twelve, thereby providing more rotational positions for securing the ferrule <NUM>. <FIG> depicts a ferrule <NUM> where the selectively tunable surfaces <NUM> are disposed adjacent to a free rotation portion 36A of the ferrule <NUM>, thereby allowing rotation of the ferrule for tuning during assembly without removing the transverse ferrule retention member <NUM>. By way of explanation, the ferrule <NUM> in <FIG> may be secured by transverse retention member <NUM> and when rotational tuning is required, then the ferrule <NUM> may be displaced rearward until free rotation portion 36A is aligned with the transverse retention member <NUM> allowing rotation of the ferrule in either direction and when the desired rotational position is reached the ferrule <NUM> is allowed to translate to the forward position where the selectively tunable portions <NUM> engage and cooperate with the transverse ferrule retention member <NUM> to inhibit rotation of the ferrule <NUM>. Consequently, the transverse ferrule retention member <NUM> does not need to be removed from housing <NUM> for tuning.

<FIG> are various views of depicting the housing <NUM> of the connector <NUM> of <FIG> comprising opening <NUM> and tuning pocket <NUM>. As depicted, housing <NUM> is similar to the other housings and may be modified for the desired housing configuration as desired. For instance, although the housing <NUM> depicts threads <NUM> that are discontinuous for attaching dust cap <NUM> such as shown in <FIG>, variations are possible that eliminate the threads <NUM> and use a push-on dust cap. Likewise, other variations to the housing <NUM> are possible such as changing the mating geometry and using the concepts disclosed with the mating geometry of the housing <NUM> depicted in <FIG>. Further, housings <NUM> may have different retention features or different locking features <NUM>. By way of comparison, housing <NUM> of <FIG> comprises a locking feature <NUM> disposed between rear end <NUM> and a front end <NUM> configured as a scallop and the locking feature <NUM> of the housing of <FIG> is configured by a shoulder. The shoulder comprises an enlarged annular portion <NUM> with a flat surface on the rear side.

By way of example, <FIG> is a perspective view of another cable assembly <NUM> with still another alternative connector <NUM> that is similar to connector <NUM> of <FIG>, but further comprises multi-piece housing <NUM> comprising a nosepiece <NUM>. <FIG> is a perspective view of the cable assembly <NUM> with dust cap <NUM> and <FIG> is an exploded view of the cable assembly <NUM>.

As best depicted in <FIG>, the connector <NUM> comprises a housing <NUM> having nosepiece that fits about a front end <NUM>. In this configuration, using the separate nosepiece <NUM> provides more access to the passageway <NUM> of the housing and allows more room and vision for assembly. Moreover, the opening <NUM> is disposed in a location that is covered by nosepiece <NUM> so that once the connector is tuned and the nosepiece <NUM> is secured the transverse ferrule retention member is not visible or accessible. Housing <NUM> of <FIG> also has a different locking feature <NUM> compared with the housing depicted in <FIG> and an aperture <NUM>. Locking feature <NUM> is configured as a groove for receiving a clip or other suitable locking feature from a complimentary device for retaining the connector in a mated state when secured. This connector also use cable adapter <NUM> so that the connector may accommodate different cable types by using the appropriately sized cable adapter for the given cable <NUM>.

<FIG> is a front end sectional view of the connector <NUM> of <FIG> showing the nosepiece <NUM> attached to the front end of housing <NUM> and <FIG> is a front end view of the housing showing an attachment interface (not numbered) such as a weld interface disposed on a front portion of the housing <NUM>. As depicted in <FIG>, once the nosepiece <NUM> is installed it inhibits the removal of the transverse ferrule retention member <NUM>. In other words, the transverse ferrule retention member <NUM> is not visible, nor is it accessible once the nosepiece is installed. Consequently, once the connector is tuned and the nosepiece is suitable installed, the transverse ferrule retention member <NUM> is tamper-resistant. The attachment interface of the housing provides a surface for attaching nosepiece <NUM>. Nosepiece <NUM> may be attached in any suitable manner such as adhesive, friction-fit, snap-fit, welding or the like as desired. The nosepiece <NUM> may be formed from a translucent material. Using a translucent material for nosepiece <NUM> allows the use of a UV curable epoxy for securing the nosepiece <NUM>.

Still other variations of connectors are possible using modified housings or other modified components. <FIG> are perspective and side views of a connector <NUM> similar to <FIG> having an alternative housing <NUM>. Here, housing <NUM> in does not have an offset distance among transition portions TP1-TP4. In other words, all of the transition portions TP1-TP4 are aligned. Additionally, this housing <NUM> comprises keying feature <NUM> for orienting the connector for mating. Keying feature <NUM> is a key, but other connectors may use other suitable structure such as a keyway or the like.

Other variations of housings disclosed herein are also possible such as having other shapes for the rear portion RP such as a polygon cross-section PCS, instead of the round cross-section RCS. Polygon cross-sections may have any suitable number of side such as four, five, six, seven or eight, but other suitable number of sides are also possible. Still other variations are possible with the housing concepts disclosed. For instance, the housing <NUM> of the connectors may be configured to work with other devices so that a retention feature or locking feature of the connector is intended to cooperate with different devices for maintaining the optical connection at the mating interface. By way of example, <FIG> are perspective views of portions of alternative housings <NUM> depicting other locking feature designs. The housings <NUM> depicted in <FIG> may be used with any suitable connectors disclosed herein. Likewise, locking or retention features may be selected with other features such as keying features <NUM>. Keying feature <NUM> has a predetermined location with respect to an orientation of housing <NUM> for aligning the connector form-factor with a respective mating device. Specifically, the housing <NUM> provides a proper orientation for connection in one orientation, which may be desired for angled ferrules. Here, keying feature <NUM> is disposed on a center line of fiber optic connector <NUM> and ensures correct rotational orientation during insertion and mating with another device.

Components or features of connectors may be selected as desired to form other variations of connectors. Illustratively, <FIG> is a perspective view of still another cable assembly <NUM> using a connector similar to the connector of <FIG>, but having a different cable adapter <NUM>. The connector also has a different type of locking feature <NUM> than the housing <NUM> of the connector of <FIG>. Like the cable adapter <NUM> of <FIG>, the cable adapter <NUM> fits into a rear opening 21A of the housing <NUM>. As discussed, using connectors with a separate cable adapter <NUM> allows the connector to be used with different types cables by merely changing out and selecting the cable adapter that is suitable for the desired cable <NUM>. <FIG> and <FIG> respectively are a perspective view and a cross-sectional view the cable adapter <NUM> of <FIG>. <FIG> is a vertical sectional view and <FIG> is a horizontal sectional view of the rear portion of cable assembly <NUM> showing the cable <NUM> disposed within the cable adapter <NUM>.

<FIG> and <FIG> are a perspective view and a cross-sectional view of another cable adapter <NUM>, that is similar to the cable adapter of <FIG>. As depicted, cable adapters <NUM> may comprise an aperture 59A, a recessed surface 59R, a shoulder <NUM>, a passageway 59P, and a cable saddle 59C or a cable adapter key <NUM> as desired for any particular cable adapter <NUM>. Generally speaking, cable adapter <NUM> comprises passageway 59P from a cable adapter front end 59F to a cable adapter rear end 59R. Passageway 59P allows the optical fiber <NUM> of cable <NUM> to pass therethrough. Shoulder <NUM> allows cable adapter <NUM> to have a snug-fit within the passageway <NUM> of housing <NUM> and inhibits adhesive from wicking or flowing forward of the shoulder <NUM>. Any adhesive or epoxy used for securing cable adapter <NUM> may wick around the recessed surface 59R for creating a sufficient bonding area and any excessive adhesive or epoxy may flow into the aperture 59A. Housings <NUM> may include one or more aperture <NUM> for injecting epoxy or adhesive or the adhesive or epoxy may be placed on the cable adapter before insertion into the housing. For instance, housing may include two apertures <NUM> such as show in <FIG> so that air may escape as adhesive or epoxy is injected. Additionally, the one or more apertures <NUM> may be aligned with the apertures 59A of the cable adapter so that the adhesive or epoxy also secures the strength members <NUM> of cable <NUM> to the cable adapter <NUM> that is secured to the housing <NUM>, thereby forming a robust cable/connector attachment and also providing sealing at the rear end. Cable saddle 59C is sized and shaped for the particular cable <NUM> that is intended to be secured using the cable adapter along with the appropriate components as appropriate such as depicted in
<FIG>. The rear portion of the cable adapter <NUM> may have a cable bend relief area such as a reverse funnel at entrance to the passageway, flexures or other suitable structure for inhibiting sharp bending of the cable near the rear of the cable adapter <NUM>. Further, cable adapters <NUM> may or may not include keys <NUM> as desired for cooperating with features of the housing. The rear portion 59R of the cable adapter <NUM> of <FIG> comprises one or more ribs 59RB suitable for receiving a boot or overmold on the rear portion 59R. The ribs 59RB aid in the retention of the boot or overmold.

<FIG> is perspective view of another cable assembly <NUM> according to the concepts disclosed and <FIG> is an exploded view of the cable assembly <NUM>. Housing <NUM> is similar to the housing disclosed herein, but further comprises a keying portion 20KP that extends into the transition region TR as shown, but housings without the keying portion 20KP are possible. The transition region TR of this housing is asymmetric. Specifically, the asymmetric transition region is a threaded portion TP, but other asymmetric geometries are possible as disclosed herein. The keying portion 20KP is configured as a female key or a subtractive portion on housing <NUM> such as a female keyway or a slice on the side of the connector leaving a D-shape. The keying portion 20KP extends into the transition region as shown. The keying portion 20KP cooperates with a suitable keying portion in a connection port of a device such as an additive or male portion for inhibiting non-compliant connectors from being inserted into the connection port. Although, the keying portion 20KP is disposed about <NUM> degrees from the at least one locking feature <NUM>, other arrangements are possible where the keying portion 20KP is disposed less than <NUM> degrees from the at least one locking feature <NUM>. Keying portion 20KP may be arranged as a subtractive portion that removes a side or slice of the housing <NUM> for creating a D-shaped cross-section over the length of the keying portion 20KP; instead of the female keyway shown.

The internal construction of connector <NUM> of <FIG> is similar to that of <FIG> where ferrule <NUM> disposed within a ferrule holder <NUM> and inserted from a front end <NUM> of the connector <NUM> and is discussed in more detail in relation to those FIGS. This connector also comprises a boot or overmold <NUM> disposed on the rear portion 59R of cable adapter <NUM> as best shown in <FIG>. Further, when assembled a
sealing element such a heat shrink <NUM> is disposed over the boot or overmold <NUM> as best shown in <FIG>. The sealing element may also be disposed over a portion of the housing <NUM> as shown. Placing the sealing element over boot or overmold and a portion of the housing <NUM> allows for sealing of the cable jacket to the rear of the connector. This may also improve the bending strain-relief for the cable assembly.

<FIG> is a rear perspective view of another cable assembly having cable adapter <NUM> with flexures 59F for bend-strain relief. <FIG> are a side and sectional views of the cable assembly of <FIG> showing heat-shrink <NUM> before and after being installed. As depicted, if the cable adapter <NUM> uses flexures 59F they are generally aligned with the flat portions of cable <NUM> for cable bend relief. Also the cable adapter <NUM> may or may be able to have more than one rotational position with respect to the housing <NUM> depending on how the ends of the components cooperate or not. As depicted in <FIG>, housing <NUM> may have a stepped down portion at the rear end <NUM> for receiving a portion of heat shrink <NUM> and may cover the flexures 59F while also providing further cable bending strain-relief.

Still other variations of housings <NUM> are possible using the connector concepts disclosed herein. The other connectors disclosed included locking features <NUM> that were integrated into the housing <NUM>; however, other connectors may use locking features that are separate and distinct components from the housing <NUM>. Although this may require a bigger connector footprint or more access space between connectors the concepts of separate and distinct components for the locking features are possible. <FIG> is a front perspective view of another housing <NUM> that may be used with the fiber optic connector concepts disclosed herein. In this housing, the securing feature is formed on a separate and distinct component from the housing <NUM>. Specifically, securing feature is disposed on a coupling nut <NUM> having threads and that rotates about an outer shaft of housing <NUM> for securing the connector to a complimentary device. Additionally, the housing <NUM> may not have offset distance between transition portions of the housing <NUM>.

Connectors disclosed herein may be portions of other cable assemblies as desired. For instance, <FIG> depicts a distribution cable <NUM>' having one or more connectors <NUM> on tether cables <NUM>' that extend from a mid-span access <NUM> of a distribution cable. Of course, other suitable assemblies may use the connectors according to the concepts disclosed herein.

By way of example, connectors disclosed herein may be converted from a first connector footprint to a second connector footprint. <FIG> is a perspective view of an explanatory connector <NUM>' that further comprises a conversion housing <NUM> attached about the housing <NUM> for changing the connector <NUM>' from a first connector footprint to a second connector footprint and <FIG> is a sectional view of the connector <NUM>'. By way of example, the connector <NUM>' may have a first connector footprint such as shown in <FIG> and be changed to a second connector footprint such as a SC connector by adding conversion housing <NUM>. However, any of the suitable connectors disclosed herein may be converted as described herein. Conversion housing <NUM> cooperates with housing <NUM> for changing from the first connector footprint to the second connector footprint. In this connector, the changing of the first connector footprint to the second connector footprint comprises the use of a single component.

In other connector, the changing of the first connector footprint to the second connector footprint may comprise the use of a plurality of components. Illustratively, <FIG> is a partially exploded view of another connector <NUM>' that may be changed from a cable assembly <NUM> having first connector footprint <NUM> to a second connector footprint <NUM>' as shown assembled in <FIG>. Further, this second connector footprint <NUM>' comprises a hardened connector footprint. Hardened connector footprint means that the connector is suitable for outdoor environments without be protected within a closure. Any suitable connector <NUM> disclosed herein may be used for such a conversion from the first footprint to the second footprint. <FIG> depicts cable assembly <NUM> with connector <NUM> with the plurality of components for the conversion to the second footprint exploded for depicting the assembly of the components. In this particular connector, the plurality of components are suitable for converting connector <NUM> to a hardened OptiTap® compatible connector; however, the plurality of components may be configured for converting connector <NUM> into other hardened connectors as desired. In this connector, the plurality of components for the conversion to the hardened connector comprise an inner boot <NUM>, an outer boot <NUM>, a conversion housing <NUM> configured as a shroud, a retaining member <NUM>
configured as a retaining nut and a coupling nut <NUM>. To make the conversion to the hardened connector, the inner boot <NUM> is slid over up over part of connector <NUM> and the conversion housing or shroud <NUM> is slid rearward into position and then the retaining nut <NUM> is secured to the threads of connector <NUM>. The coupling nut <NUM> is slid onto shroud <NUM> and then outer boot <NUM> can be slid-up into position from the rear. Shroud <NUM> may include an O-ring <NUM> for sealing during mating. <FIG> is an assembled view of the fiber optic connector of <FIG> showing the hardened second connector footprint with the dust cap <NUM> installed thereon. <FIG> is a sectional view of the hardened connector of <FIG>.

Still other conversions of connectors <NUM> are possible according to the concepts disclosed herein. By way of example, connectors <NUM> similar to the connector <NUM> of <FIG> with the transition region TR having a threaded portion TP may be converted to other connectors. <FIG> depicts cable assembly <NUM> having connector <NUM> with a connector housing <NUM> comprising a transition region TR having a threaded portion TP similar to connector <NUM> of <FIG>. <FIG> shows the connector <NUM> of <FIG> with a conversion housing <NUM> attached about the housing <NUM> for changing connector <NUM> with a first connector footprint to a connector <NUM>" with second connector footprint. Second connector footprint for connector <NUM>" comprises a hardened connector footprint, thereby converting cable assembly <NUM> to cable assembly <NUM>''.

<FIG> is a partially exploded view of connector <NUM>'' of <FIG>. This particular conversion uses a plurality of components for converting connector <NUM> to a hardened OptiTap® compatible connector <NUM>''; however, the plurality of components may be configured for converting connector <NUM> into other hardened connectors as desired. The plurality of components for the conversion to connector <NUM>" comprise the conversion housing <NUM> configured as shroud, a retaining member <NUM> configured as a retaining clip, and a coupling nut <NUM>. Shroud <NUM> may include one or more O-rings <NUM> for sealing during mating with a complimentary device.

To make the conversion to the connector <NUM>'', the shroud <NUM> is slid into a passageway of coupling nut <NUM> as shown and then slid over connector <NUM> from the front end. Next, the shroud <NUM> is rotated so that the internal threads 82T of shroud <NUM> as best shown in <FIG> engage with the threaded portion TP of connector <NUM> until the shroud <NUM> is secured to connector <NUM>. Thereafter, retaining member <NUM> is aligned with the front end of the shroud <NUM> and then pushed onto the connector <NUM> until it is seated and retained on housing <NUM>, thereby inhibiting the shroud <NUM> from backing off the threaded portion TP of connector <NUM> as depicted in <FIG>.

<FIG> is a detailed sectional view of the front end of connector <NUM>" showing the retaining member <NUM> secured to connector <NUM> and <FIG> are perspective views of the retaining member <NUM>. As depicted, retaining member <NUM> comprises an opening 84O at the front for receiving a portion of housing <NUM> therethrough when installed. Additionally, retaining member <NUM> also has a front flange 84F shaped to the passageway of shroud <NUM> so it may be inserted and engage connector <NUM>. Retaining member <NUM> may also include one or more keyways <NUM> for allowing the retaining member to slide past keying feature <NUM> of connector <NUM>. Windows 84W disposed on opposite sides of retaining member <NUM> engage with ears <NUM> of housing <NUM> for securing the retaining member <NUM> to connector <NUM>. Once installed, retainer member <NUM> inhibits the shroud <NUM> from rotating and coming off connector <NUM>. Connector <NUM>" may also include a dust cap <NUM> like connector <NUM>' of <FIG>.

The connector concepts disclosed herein may be used with still other connector designs such as connectors using a ferrule disposed in a ferrule holder. <FIG> disclose a cable assembly <NUM> comprising connector <NUM>. Connector <NUM> of <FIG> is similar to other connectors <NUM> disclosed herein, but it has ferrule <NUM> disposed within a ferrule holder <NUM> and inserted from a front end <NUM> of the connector <NUM> as depicted in <FIG>. Housing <NUM> of the connector <NUM> of <FIG> is similar to other housings <NUM> discussed herein and differences with be described while other details will not be repeated for the sake of brevity.

<FIG> and <FIG> respectively are perspective and sectional views showing cable assembly <NUM> comprising connector <NUM> having a ferrule <NUM> disposed within a ferrule holder <NUM>, thereby forming a ferrule sub-assembly (not numbered) that is biased to a forward position by resilient member <NUM>. When assembled, ferrule sub-assembly (<NUM>) is configured to cooperate with the housing (<NUM>) for inhibiting the rotation of the ferrule subassembly (<NUM>) with respect to the housing (<NUM>) as best shown in <FIG>.

As depicted in <FIG>, connector <NUM> is configured so that conversion housing <NUM> may be attached to housing <NUM> for converting to an SC connector. Likewise, connector <NUM> has housing <NUM> with a transition region TR with a threaded portion TP similar to the housing <NUM> depicted in <FIG> so it may be converted to a hardened connector as depicted in <FIG>.

<FIG> are various views of the housing <NUM> of the connector <NUM> depicted in <FIG> and <FIG>. 72A is bottom perspective view showing the locking feature <NUM> of housing <NUM> configured as a ramp (not numbered) with a ledge (not numbered) as the retaining feature for cooperating with a suitable securing feature of a device. Housing <NUM> is similar to the housings <NUM> disclosed herein, but further comprises one or more latch arms 20LA disposed in a front portion FP of housing <NUM> as depicted. Moreover, the front opening of passageway <NUM> is sized for allowing the insertion of ferrule holder <NUM> from the front end <NUM> of housing <NUM> such as shown in the cross-section of <FIG>. Latch arms 20LA are connected at the front end and cantilevered at the rear end so they can be deflected when ferrule holder <NUM> is inserted and then spring back to retain the ferrule holder <NUM> once it is fully-inserted.

<FIG> is a partially exploded view of the front end of connector <NUM> prior to the ferrule holder <NUM> and ferrule <NUM> being inserted into housing <NUM>. <FIG> is a cross-sectional view of the front end of the connector <NUM> after the ferrule holder <NUM> and ferrule <NUM> are inserted into housing <NUM> and retained by latch arms 20LA. As depicted, latch arms 20LA have ramp portions for aiding portions of ferrule holder <NUM> to deflect the latch arms 20LA outward as the ferrule holder <NUM> is inserted into housing <NUM> and then spring back over ferrule holder <NUM> for retaining the same.

Referring to <FIG>, optical fiber <NUM> of cable <NUM> is assembled to extend past the front end <NUM> and resilient member <NUM> is threaded about optical fiber <NUM> and then the ferrule holder <NUM> and ferrule <NUM> are threaded over optical fiber <NUM>. Optical fiber <NUM> may be clamped in a suitable manner through bores 20C disposed on opposite side of housing <NUM> as represented by the arrows in <FIG> when ferrule holder <NUM> is being inserted into housing <NUM>. Clamping optical fiber <NUM> inhibits the optical fiber <NUM> from pushing rearward or buckling as ferrule holder <NUM> inserted. Ferrule holder <NUM> is aligned to a suitable rotational position and pushed rearward into housing <NUM> until retained by latch arms 20LA as depicted in <FIG>. Optical fiber <NUM> is secured to ferrule <NUM> in a suitable fashion and the end face of ferrule <NUM> is polished.

Additionally, ferrule holder <NUM> may be configured for tuning ferrule <NUM> relative to housing <NUM>. <FIG> is a perspective detailed view of the ferrule <NUM> disposed in ferrule holder <NUM>. As shown, ferrule holder <NUM> comprises a plurality of recesses 49R formed in flange 49F for tuning of the connector. Here, flange 49F has four recesses 49R allowing four different rotational positions for ferrule holder <NUM>/ferrule <NUM>, thereby allowing quadrant tuning. <FIG> is a detailed front end view of the connector <NUM> showing that the front opening of housing <NUM> is sized for allowing the insertion of the ferrule holders. Additionally, a portion of the passageway <NUM> is sized to cooperate with the flange 49F and allow different rotational positions. Consequently, after measurement of the end face profile of the ferrule <NUM> or measurement of the insertion loss, the ferrule <NUM> may be tuned if desired for improving performance such as to a Grade B standard. By way of explanation, the latch arms 20LA may be deflected outward to release the ferrule holder <NUM> and then the ferrule holder <NUM> is rotated to the desired position and inserted back into the housing <NUM> until it is retained by latch arms 20LA. Other ferrule holders <NUM> may have other suitable numbers of rotational positions as desired.

The concepts of the housings for connectors disclosed herein are used with multifiber connectors according to the present invention. By way of example, <FIG> is an assembled perspective view of a cable assembly <NUM> comprising a multifiber optic connector <NUM> according to the present invention having a housing <NUM>. Housing <NUM> is similar to other housings <NUM> disclosed herein comprising a rear end (<NUM>) and a front end (<NUM>) with a longitudinal passageway (<NUM>) extending from the rear end (<NUM>) to the front end (<NUM>). Housing <NUM> comprises a part of the rear portion (RP) having a round cross-section (RCS) and a part of the front portion (FP) having a non-round cross-section (NRCS). By way of explanation, the front portion (FP) may have a rectangular cross-section with rounded sides (RS) that provides a first orientation feature for the connector for alignment during mating and inhibit insertion into a non-compliant device or port as best shown in <FIG>.

Housing <NUM> also comprises a transition region (TR) disposed between the rear portion (RP) and the front portion (FP) as best shown in <FIG> and <FIG>. Transition region (TR) of housing <NUM> comprises a threaded portion TP like other housings <NUM> disclosed herein. Housing <NUM> also comprises a locking feature <NUM>
integrally-formed in housing <NUM> as best shown in <FIG>. <FIG> depicts multifiber optic connector <NUM> may use a dust cap <NUM> attached for protecting a ferrule <NUM> form dust, debris and the like when not connected. The dust cap <NUM> may be configured for attaching to the housing <NUM> using the threaded portion (TP).

<FIG> depicts an exploded view of cable assembly <NUM> having multifiber connector <NUM>. As depicted, connector <NUM> comprises housing <NUM>, multifiber ferrule <NUM>, a ferrule holder <NUM>, a ferrule holder retainer <NUM>, a resilient member <NUM>, a cable adapter <NUM>, and a nosepiece <NUM>. Connector may include other components such as one or more O-rings <NUM> that fit on housing <NUM>. Connector <NUM> may have other components, arrangements or configurations depending various factors such as the cable or other considerations. Cable <NUM> is similar to the other cables disclosed herein, but it has a plurality of optical fibers. Cable assemblies <NUM> may use any suitable cable design.

<FIG> show the details and construction of cable assembly <NUM>. <FIG> respectively are a detailed exploded and assembled view showing a pre-assembly of components of multifiber connector <NUM> before cable <NUM> is threaded through the pre-assembly. The pre-assembly comprises ferrule holder <NUM>, ferrule holder retainer <NUM>, resilient member <NUM>, and cable adapter <NUM>. Ferrule holder retainer <NUM> comprises an aperture 245A sized for receiving a portion of ferrule holder <NUM> therethrough when attached to cable adapter <NUM> as shown in <FIG>. Ferrule holder retainer <NUM> also comprises one or more attachment features 245W for securing ferrule holder retainer <NUM> to a front portion of cable adapter <NUM>. Cable adapter <NUM> comprises a passageway 259P from the rear end to the front end for receiving the optical fibers <NUM> therethough. The opening at the front end of cable adapter <NUM> is sized for receiving resilient member <NUM> and has a backstop for seating the resilient member <NUM>. When ferrule holder retainer <NUM> is attached to cable adapter <NUM> the resilient member <NUM> biases ferrule holder <NUM> to a forward position. Attachment features 245W of ferrule holder retainer <NUM> cooperate with attachment features 259F such as protrusions of cable adapter <NUM> for securing the ferrule holder retainer <NUM>. As depicted in <FIG>, forward portions of cable adapter <NUM> are exposed between arms of ferrule holder retainer <NUM> and the forward portion of ferrule holder <NUM> having recessed portion 249R is exposed. Cable adapter <NUM> may also include a strain-relieve portion <NUM> for inhibiting sharp cable bends near connector <NUM>.

<FIG> is a perspective view showing cable <NUM> prepared for insertion into the pre-assembly of <FIG> with suitable lengths of strength components <NUM> and optical fibers <NUM> exposed. <FIG> respectively depict a perspective view and a sectional view of cable <NUM> threaded through the pre-assembly of <FIG> so that optical fibers <NUM> extend well beyond the ferrule holder <NUM>. As depicted, cable adapter <NUM> has bores on opposite side so that strength components <NUM> extend through the bores and into grooves <NUM> of cable adapter <NUM>. Adhesive or other fastener may be applied to the strength components <NUM> to fix them to the cable adapter <NUM>. <FIG> depicts a detailed perspective view of the assembly of <FIG> after a portion of the coating of optical fibers <NUM> is removed in preparation for inserting the ends of optical fibers <NUM> into the multifiber ferrule <NUM>. Waiting to strip the coating from optical fibers <NUM> until this point in the assembly provides protection to the optical fibers <NUM> until they are ready to be inserted into the multifiber ferrule <NUM>.

<FIG> shows the multifiber ferrule <NUM> attached to optical fibers <NUM> and the rear end of the multifiber ferrule <NUM> seated into the recess 249R of ferrule holder <NUM>. Multifiber ferrule <NUM> may be a MPO ferrule, but other types of ferrules are possible such as a MT ferrule. Optical fibers <NUM> are attached to comprising a plurality of fiber bores (<NUM>) of multifiber <NUM> in a suitable manner known in the art such as adhesive or the like. <FIG> shows the housing <NUM> aligned with the cable adapter <NUM> before being attached. Housing <NUM> may include any suitable locking feature <NUM> disclosed herein.

<FIG> and <FIG> respectively show a perspective view and a sectional view of the of the multifiber connector after being attached to the cable adapter <NUM>. Optical fibers <NUM> extend beyond the front face of the multifiber ferrule <NUM> so they may be cleaved and polished after the multifiber ferrule is stabilized by the housing <NUM> as shown in <FIG>. As depicted, opening <NUM> aligns over a groove of cable adapter <NUM> so that an adhesive may be injected into the opening <NUM> and wick about the cavity between the components and also contact the strength components <NUM>. A second opening <NUM> is also provided in housing <NUM> so that air may escape when injecting the adhesive. <FIG> depicts a perspective view of the assembled multifiber connector after the nosepiece <NUM> is attached housing <NUM>. Like the other nosepieces disclosed herein, nosepiece <NUM> may be attached in a similar fashion. Such as adhesive, welding and/or a mechanical means such as cooperating window and protrusions.

Other variations of housings <NUM> according to the concepts disclosed are possible. As an example of another housing for use with the multifiber connector, the housing may be defined as comprising a part of the rear portion (RP) having a polygonal cross-section (PCS) and a part of the front portion having a non-round cross-section (NRCS). The front portion (FP) or the rear portion (RP) of this explanatory housing may be further defined in various configurations as disclosed herein while retaining a part of the rear portion (RP) with the polygonal cross-section (PCS) and a part of the front portion (FP) having a non-round cross-section (NRCS). By way of example, the polygonal cross-section (PCS) may be a hexagon, a rectangle, a square or other suitable polygon as desired. Likewise, the complimentary device or port would be configured to mate in a suitbable manner with the housing.

Other variations of the housing <NUM> for connectors <NUM> are possible. <FIG> depict perspective view and cross-sectional views of another connector housing that may be used with any of the suitable concepts disclosed. The rear portion RP is non-round, and has a polygonal cross-section PCS as shown by the cross-section in <FIG> shows that this housing <NUM> may have a keying feature <NUM> which may take any suitable form or may a keying portion 20KP as desired. Likewise, this housing <NUM> may use any suitable locking feature <NUM> as desired.

According to a first aspect of the present application the invention provides a fiber optic connector <NUM>, comprising a housing <NUM> comprising a rear end <NUM> and a front end <NUM>, and a longitudinal passageway <NUM> extending from the rear end <NUM> to the front end <NUM>, wherein a part of the rear portion RP of the housing <NUM> comprises a round cross-section RCS and a part of the front portion FP of the housing <NUM> comprises a non-round cross-section NRCS with a transition region TR disposed between the rear portion RP and the front portion FP, and the housing <NUM> comprises a locking feature <NUM> integrally formed in the housing <NUM>; and a multifiber ferrule <NUM> comprising a plurality of fiber bores <NUM>.

In connection with the fiber optic connector <NUM> of the first aspect, the multifiber ferrule <NUM> may comprise an MPO ferrule. The fiber optic connector <NUM> may comprise a cable adapter <NUM>, wherein the cable adapter <NUM> may receive a portion of a resilient member <NUM> and a portion of a ferrule holder <NUM>, and a ferrule holder retainer <NUM> may be attached to the cable adapter <NUM>. The cable adapter <NUM> may comprise a strain-relief portion <NUM>.

According to a second aspect of the present application the invention provides a fiber optic connector <NUM>, comprising a housing <NUM> comprising a rear end <NUM> and a front end <NUM>, and a longitudinal passageway <NUM> extending from the rear end <NUM> to the front end <NUM>, wherein a part of the rear portion RP of the housing <NUM> comprises a round cross-section RCS and a part of the front portion FP of the housing <NUM> comprises a non-round cross-section NRCS with a transition region TR disposed between the rear portion RP and the front portion FP, and the housing <NUM> comprises a locking feature <NUM> integrally formed in the housing <NUM>; and a MPO ferrule <NUM> comprising a plurality of fiber bores <NUM>.

In connection with the fiber optic connector <NUM> of the second aspect, the fiber optic connector <NUM> may further comprise a cable adapter <NUM>. The cable adapter <NUM> may receive a portion of a resilient member <NUM> and a portion of a ferrule holder <NUM>, and a ferrule holder retainer <NUM> may be attached to the cable adapter <NUM>. The multifiber ferrule <NUM> may comprise an MPO ferrule.

According to a third aspect of the present application the invention provides a fiber optic connector <NUM>, comprising a housing <NUM> comprising a rear end <NUM> and a front end <NUM>, and a longitudinal passageway <NUM> extending from the rear end <NUM> to the front end <NUM>, wherein a part of the rear portion RP of the housing <NUM> comprises a round cross-section RCS and a part of the front portion FP of the housing <NUM> comprises a non-round cross-section NRCS with a transition region TR disposed between the rear portion RP and the front portion FP, and the housing <NUM> comprises a locking feature <NUM> integrally formed in the housing <NUM>; a MPO ferrule <NUM> comprising a plurality of fiber bores <NUM>; a cable adapter <NUM>, wherein the cable adapter <NUM> receives a portion of a resilient member <NUM> and a portion of a ferrule holder <NUM>, and a ferrule holder retainer <NUM> is attached to the cable adapter <NUM>.

In connection with the fiber optic connector <NUM> of the first, second and third aspect, the transition region TR may comprise a threaded portion TP. The threaded portion TP may extend from the non-round cross-section NRCS to the round cross-section RCS. The threaded portion TP may comprise less than three threads. The less than three threads <NUM> are preferably continuous. The fiber optic connector <NUM> of the first, second and third aspect may further comprise nosepiece <NUM> and/or an O-ring <NUM> and/or a dust cap <NUM>. The fiber optic connector <NUM> of the first, second and third aspect may be a portion of a cable assembly <NUM> and/or a portion of a distribution cable <NUM>'.

Claim 1:
A fiber optic connector (<NUM>), comprising:
a housing (<NUM>) comprising a rear end (<NUM>) and a front end (<NUM>), and a longitudinal passageway (<NUM>) extending from the rear end (<NUM>) to the front end (<NUM>), wherein a part of the rear portion (RP) of the housing (<NUM>) comprises a round cross-section (RCS) and a part of the front portion (FP) of the housing (<NUM>) comprises a non-round cross-section (NRCS) with a transition region (TR) disposed between the rear portion (RP) and the front portion (FP), and the transition region (TR) comprises a threaded portion (TP), and the housing (<NUM>) comprises a locking feature (<NUM>) integrally formed in the rear portion (RP) of the housing (<NUM>); and
a multifiber ferrule (<NUM>) comprising a plurality of fiber bores (<NUM>).