CA3214685A1

CA3214685A1 - Optical fiber connector

Info

Publication number: CA3214685A1
Application number: CA3214685A
Authority: CA
Inventors: Kim Leeson; Shaun Trezise
Original assignee: PPC Broadband Fiber Ltd
Current assignee: PPC Broadband Fiber Ltd
Priority date: 2021-04-09
Filing date: 2022-04-11
Publication date: 2022-10-13
Also published as: WO2022215060A1

Abstract

An optical fiber connector sub-assembly comprises a ferrule holder configured to hold a ferrule at a front portion of an optical fiber connector, a ferrule housing configured to slidingly receive the ferrule holder and configured to be coupled to an end of a fiber optic cable that includes an optical fiber, and a spring configured to be nonrotatably coupled with the ferrule holder and the ferrule housing. The spring is configured to prevent the ferrule from rotating relatively to the end of the fiber optic cable while permitting the ferrule holder to slide axially relatively to the ferrule housing. The spring is also configured to reduce a load on the ferrule when a load is applied to the fiber optic cable so as to prevent degradation of a signal being transmitted by the fiber.

Description

OPTICAL FIBER CONNECTOR
BACKGROUND
[0001] The present disclosure relates to optical fiber connectors, for example SC
fiber optic connectors, and to a mcthod of forming and using such connectors.

[0002] The mechanical tolerances involved in terminating single mode optical fiber are much tighter than those for multimode optical fiber. Therefore, while it is quite common for multimode optical fiber be terminated at the point of use, for example, at a user's premises or at an outside junction box, in most product applications, single mode optical fiber is not terminated in the field. When single mode fiber must be terminated in the field, then it can take a skilled tcchnician bctwccn about 15 to 20 minutcs to splice fibers togcthcr cithcr by using a V-groove clamp or expensive fusion welding equipment.

[0003] Single mode fiber is therefore often provided in a range of different lengths, pre-terminated at both ends with a connector plug ready to plug into a matching receptacle.
Commonly, eight or twelve single mode optical fibers may be bundled together in an optical fiber cable having an outer protective tube inside of which the optical fibers run.

[0004] An example of such a connector is the "Subscriber Connector," or SC
connector, originally developed by NTT . SC connectors have convenient push/pull style mating, and are approximately square in cross-section and with a 2.5 mm diameter ferule at the termination of the optical fiber, surrounded by a plastic housing for protection. SC
connectors are available in single or duplex configurations. The SC connector latches into a matching socket in a simple push motion. The push-pull design includes a spring against which the ferrule slides within a plastic inner housing. This arrangement provides a reliable contact pressure at the ferrule end and resists fiber end face contact damage of the optical fiber during connection. The connector can he quickly disconnected by first pulling hack an outer housing, which is slidable relative to the inner housing, to disengage a latch inside socket between the socket and the inner housing, before pulling the optical fiber connector from thc sockct. Until thc latch is thus discngagcd, the latch prevents withdrawal of the connector when the optical fiber cable is pulled in a direction away from the socket.

[0005] It is important to avoid bending optical fiber around curves having too sharp a bend radius, as this will increase optical losses and can permanently damage the optical fiber. Optical fiber cables are therefore often routed inside a protective outer tube or conduit, which can have minimum bend-limiting properties. Protective bend limiting conduits normally have an outer diameter of 8 mm or 10 mm tubes. The cross-section of a standard SC connector has dimensions of about 7 mm x 9 mm, and even a small form factor SC
conncctor is too large to fit insidc thc inncr diamctcr of a typical protective conduit.

[0006] Conventional optical fiber connectors comprise a rigid pushable structure to allow for limited movement of the connector parts while being pushed down stretches of duct.
However, duc to their rigid structurc, conventional optical fiber connectors suffer from signal degradation when weight is added to the cable and the connector while the connector is transmitting a signal..

[0007] It may be desirable to provide an optical fiber connector with improved signal transmission capability when a load or force is applied to the cable, the boot, or a rear end of the connector. It may be desirable to provide an optical fiber connector that mechanically isolates thc ferrule from thc fiber optic cable to improve signal transmission. It may be desirable to provide an optical fiber connector that prevents the ferrule and the fiber optic cable from rotating relative to one another. It may be desirable to provide a connector having a shortened length to reduce a load on the ferrule when a load or force is applied to the cable, the boot, or a rear end of the connector.
SUMMARY

[0008] In accordance with various embodiments of the disclosure, an optical fiber connector sub-assembly includes a ferrule configured to hold an optical fiber therein along an axis of an optical fiber connector, a ferrule holder configured to hold the ferrule at a front portion of the connector, a ferrule housing including a front portion configured to slidingly receive the ferrule holder and a rear portion configured to be crimped onto an end of a fiber optic cable that includes the optical fiber, an inner housing configured to be fixedly coupled with the ferrule housing, and a spring having a first end configured to be press fit onto a radially outer surface of the ferrule holder and a second end configured to be press fit into a radially inner surface of the ferrule housing. The ferrule holder, the ferrule housing, and the inner housing are configured to be rotatably fixed to one another, the ferrule holder is configured to slide axially relative to the inner housing, and the ferrule holder and the ferrule housing arc configurcd to move axially relative to onc another along thc conncctor axis between limits defined by an interaction between the ferrule housing, the spring, and the ferrule holder. The spring is configured to prevent the ferrule from rotating relative to the end of the fiber optic cable while permitting the ferrule holder to slide axially relative to the ferrule housing, and the spring is configured to reduce a load on the ferrule when a load is applied to the fiber optic cable so as to prevent degradation of a signal being transmitted by the fiber.

[0009] In some aspects, the spring is configured to bias the ferrule away from the ferrule housing along thc connector axis.

[0010] In various aspects, a Subscriber Connection (SC) optical fiber connector includes the aforementioned optical fiber connector sub-assembly and an outer housing. The inner housing is configured to define a receptacle that is configured to receive a socket that is configured to receive a projecting portion of the ferrule, and the spring is configured such that the projecting portion of the ferrule is spring biased along the connector axis towards the receptacle of the inner housing. The inner housing is configured to be engaged within the outer housing, and the inner housing and the outer housing are configured to move relative to each other along the connector axis between limits defined by an interaction between the inncr housing and thc outcr housing in ordcr to provide SC push/pull engagement/disengagement with a mating optical fiber socket.

[0011] According to various aspects of the connector, the ferrule is configured to be rotationally fixed with respect to the ferrule holder about the connector axis, the ferrule holder is configured to be rotationally aligned with respect to the outer housing so that the rotational orientation of the fen-ule with respect to the outer housing can be set during assembly of the connector at one of one or more predefined rotational orientations, and a rotational key is provided between the ferrule housing and the inner housing.

[0012] In accordance with various embodiment of the disclosure, an optical fiber connector sub-assembly includes a ferrule configured to hold an optical fiber therein along an axis of an optical fiber connector, a ferrule holder configured to hold the ferrule at a front portion of the connector, a ferrule housing including a front portion configured to slidingly receive the ferrule holder and a rear portion configured to terminate an end of a fiber optic cable that includes the optical fiber, and a spring having a first end configured to be nonrotatahly coupled with the ferrule holder and a second end configured to he nonrotatably coupled with the ferrule housing. The spring is configured to prevent the ferrule from rotating relative to the end of the fiber optic cable while permitting the ferrule holder to slide axially relative to thc ferrule housing, and the spring is configured to rcducc a load on the ferrule when a load is applied to the fiber optic cable so as to prevent degradation of a signal being transmitted by the fiber.

[0013] According to some aspects, the spring is configured to bias the ferrule away from the ferrule housing along the connector axis.

[0014] In some aspects, the ferrule holder and the ferrule housing are configured to move axially relative to onc another along the conncctor axis between limits defined by an interaction between the ferrule housing, the spring, and the ferrule holder.

[0015] In various aspects, the optical fiber connector sub-assembly further includes an inner housing configured to be fixedly coupled with the ferrule housing.
According to various aspects, the ferrule holder, the ferrule housing, and the inner housing are configured to be rotatably fixed to one another. In some aspects, the ferrule holder is configured to slide axially relative to the inner housing.

[0016] According to various aspects, a Subscriber Connection (SC) optical fiber connector includes the aforementioned optical fiber connector sub-assembly and an outer housing. Thc inncr housing is configured to define a receptacle that is configured to receive a socket that is configured to receive a projecting portion of the ferrule, the spring is configured such that the projecting portion of the ferrule is spring biased along the connector axis towards the receptacle of the inner housing, and the inner housing is configured to be engaged within the outer housing, the inner housing and the outer housing being configured to move relative to each other along the connector axis between limits defined by an interaction between the inner housing and the outer housing in order to provide SC push/pull engagement/disengagement with a mating optical fiber socket.

[0017] In some aspects of the connector, the ferrule is configured to be rotationally fixed with respect to the ferrule holder about the connector axis, the ferrule holder is configured to be rotationally aligned with respect to the outer housing so that the rotational orientation of the ferrule with respect to the outer housing can be set during assembly of the connector at one of one or more predefined rotational orientations, and a rotational key is provided between the ferrule housing and the inner housing.

[0018] According to various embodiments of the disclosure, an optical fiber connector sub-assembly includes a ferrule holder configured to hold a ferrule at a front portion of an optical fiber connector, a ferrule housing configured to slidingly receive the ferrule holder and configured to be crimped onto an cnd of a fiber optic cable that includes an optical fiber, and a spring configured to be nonrotatably coupled with the ferrule holder and the ferrule housing. The spring is configured to prevent the ferrule from rotating relative to the end of the fiber optic cable while permitting the ferrule holder to slide axially relative to the ferrule housing, and the spring is configured to reduce a load on the ferrule when a load is applied to the fiber optic cable so as to prevent degradation of a signal being transmitted by the fiber.

[0019] In some aspects, the spring is configured to bias the ferrule away from the fcrrulc housing along thc connector axis.

[0020] In various aspects, the ferrule holder and the ferrule housing are configured to move axially relative to one another along the connector axis between limits defined by an interaction between thc ferrule housing, the spring, and the ferrule holder.

[0021] According to some aspects, the optical fiber connector sub-assembly may further comprise an inner housing configured to be fixedly coupled with the ferrule housing.
According to various aspects, the ferrule holder, the ferrule housing, and the inner housing are configured to be rotatably fixed to one another. In some aspects, the ferrule holder is configured to slide axially relative to the inner housing.

[0022] According to various aspccts, a Subscribcr Conncction (SC) optical fiber connector may include the aforesaid optical fiber connector with an inner housing and an outer housing. The inner housing is configured to define a receptacle that is configured to receive a socket that is configured to receive a projecting portion of the ferrule. The spring is configured such that the projecting portion of the ferrule is spring biased along the connector axis towards the receptacle of the inner housing. The inner housing is configured to be engaged within the outer housing, the inner housing and the outer housing being configured to move relative to each other along the connector axis between limits defined by an interaction between the inner housing and the outer housing in order to provide SC push/pull engagement/disengagement with a mating optical fiber socket.

[0023] In some aspects of the connector, the ferrule is configured to be rotationally fixed with respect to the ferrule holder about the connector axis, the ferrule holder is configured to be rotationally aligned with respect to the outer housing so that the rotational orientation of the ferrule with respect to the outer housing can be set during assembly of the connector at one of one or more predefined rotational orientations, and a rotational key is provided between the ferrule housing and the inner housing.
BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodimcnts of thc invention will now bc furthcr dcscribcd, by way of example only, and with reference to the accompanying drawings, in which:

[0025] FIG. 1 is an exploded perspective view of an exemplary prior art SC
connector;

[0026] FIG. 2 is a perspective view of the optical fiber connector sub-assembly of FIG. 1 when assembled;

[0027] FIG. 3 is an exploded perspective view of an exemplary SC connector in accordancc with various aspccts of thc disclosure;

[0028] FIG. 4 is a perspective view of the exemplary SC connector of FIG. 3;

[0029] FIG. 5 is an exploded perspective view of the exemplary SC connector of FIG. 3; and

[0030] FIG. 6 is a perspective cross-sectional view of the optical fiber connector sub-assembly of the connector of FIG. 3.
DETAILED DESCRIPTION OF EMBODIMENTS

[0031] FIGS. 1 and 2 show an exemplary prior art SC connector, such as the connectors disclosed in U.S. Patent Application No. 15/887,925. The exemplary SC
conncctor 100 includes an optical fiber cable 102, a ferrule housing sub-assembly 104, and an outer housing 140 to provide SC push/pull engagement/disengagement with a mating optical fiber socket (not shown).

[0032] The cable 102 holds an optical fiber 108, for example, a single strand of 125 m diameter single mode optical fiber, protected by primary and secondary buffering layers 110, about 900 ti m in diameter, and an outer sheath 112, typically 3 mm to 5 mm in diameter. The optical fiber 108 is terminated by a ferrule 114 in a manner well-known to those skilled in the art and defines a ferrule axis 105 that extends centrally through the SC
connector 100.

[0033] The ferrule housing sub-assembly 104 includes the cylindrical ceramic ferrule 114, a ferrule basket 116 in which the ferrule is seated, a helical spring 117, a ferrule housing 155, and an inner housing 120. The ferrule housing 155 includes a cylindrical sleeve portion 136 and a ferrule basket carrier portion 150. The ferrule basket carrier portion 150 may include longitudinal slots 180 along the lengths of their outer surfaces that are keyed to projections (not shown) on an inner surface of the inner housing 120 to prevent the ferrule housing 155 from rotating relative to the inner housing 120.

[0034] The ferrule basket 116 has a base 115 and a cylindrical stem 122 which cxtcnds from thc base 115 in an axial direction away from thc ferrule 114 towards thc cylindrical sleeve portion 136, which is used to make a crimp connection around the optical fiber cable sheathing 112. The spring 117 is seated around the stem 122 between an annular shoulder 124 on the ferrule basket 116 and an annular surface 152 within a cylindrical recess 154 of the ferrule basket carrier portion 150. The stem 122 is slidably seated in a bore of the ferrule housing 155.

[0035] During assembly, the ferrule basket 116 and seated ferrule 114 are inserted axially into thc rcccss 154 of thc ferrule basket carricr portion 150. The ferrule basket carrier portion 150 has a pair of arms 156 that extend axially forwards of the stem 122 on opposite sides of the ferrule basket 116. Two pairs of curved fingers 158 are provided, each pair extending in oppositc circumferential directions at the end of each arm 156.
The fingers 158 extend transversely to the length of the arms 156 partially around the circumference of a portion of the ferrule 114 nearest a base 115.

[0036] The ferrule base 115 has four cycles of crenellations 162 spaced symmetrically around the circumference of the base and which provide four corresponding channels that extend parallel to the optical fiber axis 105. These crenellations 162 are in the form of alternating radially high 165 and low 166 cylindrically shaped regions with the circumferential and axial extent of each of the high 165 and low 166 regions being the same.
The high 165 and low 166 regions are separated by steps 167 that extend in a radial direction.
The arms 156 are seated in opposite radially low regions 166 in a sliding fit with the adjacent high regions 165 and reach axially forward of the base 115 and crenellations 162 so that the fingers 158 engage with the intervening radially high regions 165 on a side 161 of the base 115 opposite the annular surface 124 against which the spring 117 is engaged.

[0037] The aforementioned arrangement permits a degree axial movement of the ferrule basket carrier portion 150, with movement being therefore limited in one direction by the compression of the spring 117 between the two annular surfaces 124, 152 and in the other axial direction by the contact of the fingers 158 with the radially high regions 165 of the crenellations 162 on the base 115 of the ferrule basket 116. As can be seen from the drawings, the ferrule holder base 115 and ferrule basket carrier portion 150 also have a common cylindrical outer envelope.

[0038] The inner housing 120 has a forward portion 130 that coaxi ally extends around the axially projecting ferrule 114 to define a receptacle 132 for a socket (not shown) to receive a projecting portion of the ferrule 114.

[0039] The ferrule basket 116 is free to move backwards inside the ferrule basket carrier portion 150 and the inner housing 120 when an end face 134 of the ferrule 114 comes into contact with a similar end face (not shown) of another optical fiber ferrule when making an optical connection.

[0040] The ferrule basket carrier portion 150 has a central aperture (not shown) through which the optical fiber 108 and buffering 110 pass and has in a rear-most portion the sleeve 136 configured to receive and be crimped to the cable sheathing 112. In some aspects, a strain-relief sleeve (not shown), for example, a boot, may be provided around the junction of thc optical fiber cable 102 and thc ferrule housing sub-assembly 104.

[0041] An outer housing 140 is press-fitted axially over the assembled ferrule housing sub-assembly 104. Once the inner housing 120 and outer housing 140 are engaged together, the inner and outer housings are relatively moveable with respect to each other along the ferrule axis 105 between limits defined by an interaction between the inner housing 120 and the outer housing 140 provided by projections 142 on a pair of opposite sides of the inner housing 120 and a pair of apertures 144 in the outer housing. The projections 142 and apertures 144 interact with sprung features inside a matching socket (not shown) to provide SC push/pull engagement/disengagement configured to mate with an optical fiber socket.

[0042] The rotational orientation of the ferrule basket carrier portion 150 may be set at one of four orientations relative to the ferrule 114 in the ferrule basket 116 owing to the seating of the arms 156 in the crenellations. In this way, a first rotational key is provided between the ferrule basket 116 and the ferrule basket carrier portion 150 such that the ferrule basket 116 and the ferrule basket carrier portion 150 are rotatably fixed to one another (i.e., are not rotatable relative to one another).

[0043] The optical fiber 108 is therefore terminated in a sub-assembly referred to herein as an optical fiber connector sub-assembly 160, as illustrated in FIG.
2. During assembly of the optical fiber connector sub-assembly 160, the arms 156 and the fingers 158, which each have a chamfered taper 164 on an inner forward surface, flex outwardly over the base 115 of the ferrule holder 114 until the fingers 158 snap radially inwards into engagement with the forwards surface 161 of the ferrule basket base 115.

[0044] In both cases, the resulting optical fiber connector sub-assembly 160 is therefore mechanically whole or integral, both as regards the components forming the sub-assembly and as regards the mechanical connection of the sub-assembly to the optical fiber cable 102. The sub-assembly cannot come apart without first prizing the fingers 158 back over the ferule basket base 115. The ferrule basket carrier portion 150 has an outer diameter which is preferably no more than that of the widest portion of the ferrule basket 116, i.e., the ferrule basket base 115.

[0045] After the insertion has been performed, the assembly of the SC optical fiber connector 100 is completed as follows. The inner housing 120 is inserted in an axial direction over the projecting ferrule 114 and surrounding ferrule basket carrier portion 150.
The external shape of the inner housing 120 where this interacts with the outer housing 140 is the same as with conventional connectors. The outer housing 140 therefore is snap-fitted over the inner housing 120, after which the SC connector 100 is fully compatible with conventional conncctors and conventional optical fiber sockets.

[0046] Refen-ing now to FIGS. 3-6, an exemplary optical fiber connector 400, for example, an SC connector, in accordance with various aspects of the disclosure is illustrated and described. Thc connector 400 includes an optical fiber cable 102, a ferrule housing sub-assembly 404, and an outer housing 440 to provide SC push/pull engagement/disengagement with a mating optical fiber socket (not shown).

[0047] The ferrule housing sub-assembly 404 includes a cylindrical ceramic ferrule 414, a ferrule basket 416 in which the ferrule 414 is seated, a helical spring 417, a ferrule housing 455, and an inner housing 420. The ferrule housing 455 includes a front tube portion 450 connected with a rcar tubc portion 436 via a press-fit connection 437. At the press-fit connection 437, the rear tube portion 436 has a smaller outside diameter than the front tube portion 450 such that the rear tube portion 436 is received in the front tube portion 450. The overlap of the front tube portion 450 relative to the rear tube portion 450 is limited by a flange 451 extending radially outward from an outer surface of the rear tube portion 450. At a rearward side of the flange 451 (i.e., on an opposite side of flange 451 relative to the front tube portion 450), the outer surface of the rear tube portion 450 may include an annular groove 453.

[0048] The ferrule basket 416 has a base 415 and a cylindrical stem 422 that extends from the base 415 in an axial direction away from the ferrule 414 towards the rear tube portion 436, which is used to make a crimp connection around the optical fiber cable sheathing 112. As shown in FIG. 6, crimping of the rear tube portion 436 creates a mushroom portion 113 at the front of the cable sheathing 112 to aid with cable retention. The spring 417 is pressed onto an outer surface of a portion of the stem 422 and into an inner surface of a forward portion of the rear tube portion 436. The spring is held between an annular shoulder 424 on the stem 422 and an annular surface 452 within a cylindrical recess 454 defined by an inwardly extending wall 459 of the flange 451 at a rearward end of the front tube portion 450. Thc stcm 422 slidably extends through an opening 439 at a forward end of the rear tube portion 436. A rearward end of the stein 422 is spaced radially inward from the inwardly extending wall 459, thereby permitting a degree of pivoting movement between the ferrule basket 416 and the ferrule housing 455.

[0049] The ferrule basket 416 is configured to be axially slidable in a recess 454 of the front tube portion 450. A forward end of the ferrule basket 416 includes a sloped surface 426, and a rearward directed wall at a forward end of the front tube portion 450 includes a similar sloped wall 456. The sloped wall 456 of the front tube portion 450 is sized and configured to relative to the sloped surface 426 of thc ferrule basket 416 to prevent the ferrule basket 416 from exiting through the forward end of the front tube portion. The aforementioned arrangement provides the ferrule 414 and ferrule basket 416 with freedom to pivot and float relative to the ferrule housing 455 and permits a degree of axial movement of the ferrule basket 416 and ferrule 414 relative to the front tube portion 450 of the ferrule housing 455. Such axial movement is limited in one direction by the compression of the spring 417 between the two annular surfaces 424, 452 and in the other axial direction by the contact of the sloped surface 426 and the sloped wall 456.

[0050] As shown in FIGS. 4 and 5, the inner housing 420 has a forward portion that coaxially extends around the axially projecting ferrule 414 to define a receptacle 432 for a socket (not shown) configured to receive a projecting portion of the ferrule 414. The ferrule basket 416 is free to move backwards inside the front tube portion 450 and the inner housing 420 when an end face 434 of the ferrule 414 comes into contact with a similar end face (not shown) of another optical fiber ferrule when making an optical connection.

[0051] The front tube portion 450 of the ferrule housing 455 may include a keyed outer surface 470 at its front end. The keyed outer surface 470 is configured to match a keyed inner surface of the inner housing 420 to prevent the ferrule housing 455 from rotating relative to the inner housing 420. For example, the keyed outer surface 470 may include four flattened region spaced equidistantly about an outer periphery at the front end of the front tube portion 450, and the inner housing 420 may include a square receptacle configured to receive the keyed outer surface 470. As a result of the aforementioned structures of the keyed outer surface 470 and inner housing 420, the inner housing 420 and the ferrule housing 455 are rotatably coupled to one another.

[0052] The inner housing 420 may also include at least projection 428 projecting inwardly toward the ferrule axis 405. The at least one projection 428 is configured such that, as the inner housing 420 is slipped over the ferrule housing 455, the at least one projection 428 is aligned with the and received by the annular groove 453 to secure the inner housing 420 with the ferrule housing 455 to prevent relative axial movement. As shown in FIG. 5, in some embodiments, the inner housing may include two projections 428.

[0053] The ferrule housing 455 has a central aperture 457 through which the optical fiber 108 and buffering 110 pass and has in a rear-most portion the rear tube portion 436 configured to receive and be crimped to the cable sheathing 112. A boot 490 is provided around the junction of the optical fiber cable 102 and the ferrule housing sub-assembly 404 and includes at least one projection 492 extending radially outward and configured to be rccciving in an opcning 441 in an outcr housing 440 to interlock thc boot 490 with thc outcr housing 440. Compared with conventional SC connectors, where a strain relief boot is configured to be coupled with barbs that are spaced rearward from the rear end of the outer housing, in the present embodiment, a forward portion of the boot 490 is configured to be received by a rear end of the outer housing 440 such that the outer housing 440 overlaps the forward portion of the boot 490, which includes the at least one projection.
As a result, the outer housing 440 and the boot 490 are configured to shorten an overall length of the connector 400, thereby reducing a load transferred to the ferrule 416 when a load is applied to the cable 102 and/or the boot 490 and/or a rear end of the connector 400, for example, in a dircction transverse to thc conncctor axis, as would bc undcrstood by persons of ordinary skill in the art.

[0054] Once the inner housing 420 and outer housing 440 are engaged together, the inner and outer housings are relatively moveable with respect to each other along the ferrule axis 405 between limits defined by an interaction between the inner housing 420 and the outer housing 440 provided by projections 442 on a pair of opposite sides of the inner housing 420 and a pair of apertures 444 in the outer housing. The projections 442 and apertures 444 interact with spring features inside a matching socket (not shown) to provide SC push/pull engagement/disengagement configured to mate with an optical fiber socket.

[0055] The ferrule housing 455 and the ferrule basket 416 are rotatably fixed to one another (i.e., are not rotatable relative to one another) by the spring 417 being press fitted onto the ferrule basket 416 and into the rear tube portion 436 of the ferrule housing 455. The optical fiber 108 is therefore terminated in a sub-assembly referred to herein as an optical fiber connector sub-assembly 460. The resulting optical fiber connector sub-assembly 460 is therefore mechanically whole or integral, both as regards the components forming the sub-assembly and as regards the mechanical connection of the sub-assembly to the optical fiber cable 102.

[0056] Aftcr thc inscrtion has been performcd, thc assembly of the SC optical fibcr connector 400 is completed as follows. The inner housing 420 is slid in an axial direction over the projecting ferrule 414 and surrounding front tube portion 450. The inner housing 420 includes one or more projections 428 configured to deflect outwardly and when the annular groove 453 of the ferrule housing 455 reaches the projections 428, the projections 428 move inwardly toward the annular groove 453 to a position in the annular groove 453, thereby fixing the position of the ferrule housing 455 relative to the inner housing 420. The external shape of the inner housing 420 where this interacts with the outer housing 440 is the samc as or similar to conventional conncctors. Thc outcr housing 440 is thcn slid over the inner housing 420 and until the projection 492 of the boot 490 is snap-fitted into the opening 441 in the outer housing 440, after which the SC connector 400 is fully compatible with conventional connectors and conventional optical fiber sockets.

[0057] Additional embodiments include any one of the embodiments described above, where one or more of its components, functionalities or structures is interchanged with, replaced by or augmented by one or more of the components, functionalities, or structures of a different embodiment described above.

[0058] It should be understood that various changes and modifications to the cmbodimcnts dcscribcd herein will be apparcnt to thosc skilled in thc art.
Such changcs and modifications can be made without departing from the spirit and scope of the present disclosure and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

[0059] Although several embodiments of the disclosure have been disclosed in the foregoing specification, it is understood by those skilled in the art that many modifications and other embodiments of the disclosure will come to mind to which the disclosure pertains, having the benefit of the teaching presented in the foregoing description and associated drawings. It is thus understood that the disclosure is not limited to the specific embodiments disclosed herein above, and that many modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although specific terms are employed herein, as well as in the claims which follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the present disclosure, nor the claims which follow.

Claims

WHAT IS CLAIMED IS:

1. An optical fiber connector sub-assembly, comprising:
a ferrule holder configured to hold a ferrule at a front portion of an optical fiber connector;
a ferrule housing configured to slidingly receive the ferrule holder and configured to be coupled with an end of a fiber optic cable that includes an optical fiber;
a spring configured to be nonrotatably coupled with the ferrule holder and the ferrule housing;
wherein the spring is configured to prevent the ferrule from rotating relative to the end of thc fiber optic cable while permitting thc ferrule holder to slide axially relative to the ferrule housing; and wherein the spring is configured to reduce a load on the ferrule when a load is applied to the fiber optic cable so as to prevent degradation of a signal being transmitted by the fiber.

2. The optical fiber connector sub-assembly of claim 1, wherein the spring is configured to bias the ferrule away from the ferrule housing along the connector axis.

3. The optical fiber connector sub-assembly of claiin 1 or claim 2, wherein the ferrule holder and the ferrule housing are configured to move axially relative to one another along the connector axis between limits defined by an interaction between the ferrule housing, the spring, and the ferrule holder.

4. The optical fiber connector sub-assembly of any of claim 1-3, further comprising an inner housing configured to he fixedly coupled with the ferrule housing.

5. The optical fiber connector sub-assembly of claim 4, wherein the ferrule holder, thc ferrule housing, and thc inncr housing arc configured to bc rotatably fixcd to onc another.

6. The optical fiber connector sub-assembly of claim 4, wherein the ferrule holder is configured to slide axially relative to the inner housing.

7. A Subscriber Connection (SC) optical fiber connector comprising:
thc optical fiber conncctor sub-assembly as claimed in claim 4;
an outer housing;
wherein the inner housing is configured to define a receptacle that is configured to receive a socket that is configured to receive a projecting portion of the ferrule;
wherein the spring is configured such that the projecting portion of the ferrule is spring biased along the connector axis towards the receptacle of the inner housing; and wherein the inner housing is configured to be engaged within the outer housing, the inner housing and the outer housing being configured to move relative to each other along the connector axis between limns defined by an interaction between the inner housing and the outcr housing in ordcr to provide SC push/pull engagement/disengagement with a mating optical fiber socket.

8. The SC optical fiber connector of claim 7, wherein the fenule is configured to be rotationally fixed with respect to the ferrule holder about the connector axis;
wherein the ferrule holder is configured to be rotationally aligned with respect to the outer housing so that the rotational orientation of the ferrule with respect to the outer housing can be set during assembly of the connector at one of one or more predefined rotational orientations; and wherein a rotational key is provided between the ferrule housing and the inner housing.

9. An optical fiber connector sub-assembly, comprising:
a ferrule configured to hold an optical fiber therein along an axis of an optical fiber connector;
a ferrule holder configured to hold the ferrule at a front portion of the connector;
a ferrule housing including a front portion configured to slidingly receive the ferrule holder and a rear portion configured to be crimped onto an cnd of a fiber optic cable that includes the optical fiber;
an inner housing configured to be fixedly coupled with the ferrule housing;
a spring having a first end configured to be press fit onto a radially outer surface of the ferrule holder and a second end configured to be press fit into a radially inner surface of the ferrule housing;

wherein the ferrule holder, the ferrule housing, and the inner housing are configured to bc rotatably fixed to onc anothcr;
wherein the ferrule holder is configured to slide axially relative to the inner housing;
wherein the ferrule holder and the ferrule housing are configured to move axially relative to one another along the connector axis between limits defined by an interaction between the ferrule housing, the spring, and the ferrule holder;
wherein the spring is configured to prevent the ferrule from rotating relative to the end of the fiber optic cable while permitting the ferrule holder to slide axially relative to the ferrule housing;
wherein the spring is configured to reduce a load on the ferrule when a load is applied to thc fiber optic cable so as to prevent degradation of a signal bcing transmitted by thc fiber.

10. The optical fiber connector sub-assembly of claim 9, wherein the spring is configured to bias the ferrule away from the ferrule housing along the connector axis.

11. A Subscriber Connection (SC) optical fiber connector comprising:
the optical fiber connector sub-assembly as claimed in claim 9 or claim 10;
an outer housing;
wherein the inner housing is configured to define a receptacle that is configured to receive a socket that is configured to receive a projecting portion of the ferrule;
wherein the spring is configured such that the projecting portion of the ferrule is spring biased along the connector axis towards the receptacle of the inner housing;
wherein the inner housing is configured to be engaged within the outer housing; and wherein the inner housing and the outer housing are configured to move relative to each other along the connector axis between limits defined by an interaction between the inner housing and the outer housing in order to provide SC push/pull engagement/disengagement with a mating optical fiber socket.

12. The SC optical fiber connector of claim 11, wherein the ferrule is configured to be rotationally fixed with respect to the ferrule holder about the connector axis;
wherein the ferrule holder is configured to be rotationally aligned with respect to the outer housing so that the rotational orientation of the ferrule with respect to the outer housing can be set during assembly of the connector at one of one or more predefined rotational orientations; and wherein a rotational key is provided between the ferrule housing and the inner housing.

13. An optical fiber connector sub-assembly, comprising:
a ferrule configured to hold an optical fiber therein along an axis of an optical fiber connector;
a ferrule holder configured to hold the ferrule at a front portion of the connector;
a ferrule housing including a front portion configured to slidingly receive the ferrule holder and a rear portion configured to terminate an end of a fiber optic cable that includes the optical fiber;
a spring having a first cnd configured to bc nonrotatably coupled with thc ferrule holder and a second end configured to be nonrotatably coupled with the ferrule housing;
wherein the spring is configured to prevent the ferrule from rotating relative to the end of the fiber optic cable while permitting the ferrule holder to slide axially relative to the ferrule housing; and wherein the spring is configured to reduce a load on the ferrule when a load is applied to the fiber optic cable so as to prevent degradation of a signal being transmitted by the fiber.

14. The optical fiber connector sub-assembly of claim 13, wherein the spring is configured to bias the ferrule away from the ferrule housing along the connector axis.

15. The optical fiber connector sub-assembly of claim 13 or claim 14, wherein the ferrule holder and the ferrule housing are configured to move axially relative to one another along the connector axis between limits defined by an interaction between the ferrule housing, the spring, and the ferrule holder.

16. The optical fiber connector sub-assembly any of claims 13-15, further comprising an inner housing configured to be fixedly coupled with thc ferrule housing.

17. The optical fiber connector sub-assembly of claim 16, wherein the ferrule holder, the ferrule housing, and the inner housing are configured to be rotatably fixed to one another.

18. The optical fiber connector sub-assembly of claim 16, wherein the ferrule holder is configured to slide axially relative to thc inner housing.

19. A Subscriber Connection (SC) optical fiber connector comprising:
the optical fiber connector sub-assembly as claimed in claim 16;
an outer housing;
wherein the inner housing is configured to define a receptacle that is configured to receive a socket that is configured to receive a projecting portion of the ferrule;
wherein the spring is configured such that the projecting portion of the ferrule is spring biased along the connector axis towards the receptacle of the inner housing; and whcrcin thc inncr housing is configured to bc cngagcd within the outer housing, thc inner housing and the outer housing being configured to move relative to each other along the connector axis between limits defined by an interaction between the inner housing and the outer housing in order to provide SC push/pull engagement/disengagement with a mating optical fiber socket.

20. The SC optical fiber connector of claim 19, wherein the ferrule is configured to be rotationally fixed with respect to the ferrule holder about the connector axis;
wherein the ferrule holder is configured to be rotationally aligned with respect to the outer housing so that the rotational orientation of the ferrule with respect to the outer housing can be set during assembly of the connector at one of one or more predefined rotational orientations; and wherein a rotational key is provided between the ferrule housing and the inner housing.