U.S. patent application number 10/924525 was filed with the patent office on 2006-03-02 for fiber optic receptacle and plug assemblies.
Invention is credited to Martin E. Norris, Thomas Theuerkorn.
Application Number | 20060045428 10/924525 |
Document ID | / |
Family ID | 34961466 |
Filed Date | 2006-03-02 |
United States Patent
Application |
20060045428 |
Kind Code |
A1 |
Theuerkorn; Thomas ; et
al. |
March 2, 2006 |
Fiber optic receptacle and plug assemblies
Abstract
A fiber optic receptacle and plug assembly includes a receptacle
adapted to be mounted within a wall of an enclosure and a plug
mounted upon a fiber optic cable. The receptacle and the plug are
provided with mating keys that permit the receptacle to receive
only a plug of like ferrule configuration. The plug includes an
adapter sleeve operable for receiving and optically connecting at
least one plug ferrule and at least one receptacle ferrule when the
plug is inserted into the receptacle. The receptacle is configured
for use in a small volume enclosure requiring a minimal receptacle
penetration depth. The receptacle is provided with a shoulder that
engages the interior surface of the wall of the enclosure to
provide strain relief against tensile pulling forces of up to about
600 lb/ft. The receptacle is provided with a dust cap and the plug
is provided with a dust/pulling cap.
Inventors: |
Theuerkorn; Thomas;
(Hickory, NC) ; Norris; Martin E.; (Lenoir,
NC) |
Correspondence
Address: |
CORNING CABLE SYSTEMS LLC
P O BOX 489
HICKORY
NC
28603
US
|
Family ID: |
34961466 |
Appl. No.: |
10/924525 |
Filed: |
August 24, 2004 |
Current U.S.
Class: |
385/53 ;
385/60 |
Current CPC
Class: |
G02B 6/3847 20130101;
G02B 6/3887 20130101; G02B 6/3879 20130101; G02B 6/4465 20130101;
G02B 6/389 20130101; G02B 6/3831 20130101 |
Class at
Publication: |
385/053 ;
385/060 |
International
Class: |
G02B 6/36 20060101
G02B006/36 |
Claims
1. A fiber optic receptacle and plug assembly, comprising: a
receptacle adapted to be mounted within a wall of an enclosure, the
receptacle comprising a ferrule retainer and at least one
receptacle ferrule; and a plug mounted upon an end of a fiber optic
cable, the plug comprising an adapter sleeve and at least one plug
ferrule disposed within the adapter sleeve for mating with the
receptacle ferrule when the plug is inserted into the receptacle;
wherein the receptacle and the plug are keyed to permit the
receptacle ferrule and the plug ferrule to be mated in only one
orientation.
2. The fiber optic receptacle and plug assembly of claim 1, wherein
the at least one receptacle ferrule comprises a pair of
single-fiber, small form factor ferrules and the at least one plug
ferrule comprises a pair of single-fiber, small form factor
ferrules of like configuration.
3. The fiber optic receptacle and plug assembly of claim 1, wherein
one of the receptacle and the plug comprises a key for radial
alignment of the at least one receptacle ferrule relative to the at
least one plug ferrule.
4. The fiber optic receptacle and plug assembly of claim 1, wherein
the plug further comprises an inner housing for receiving and
strain relieving a fiber optic cable having at least one optical
fiber and an outer housing disposed about the inner housing.
5. The fiber optic receptacle and plug assembly of claim 1, wherein
the receptacle comprises a shoulder adapted to engage an interior
surface of the wall of the enclosure to provide stain relief
against tensile forces of up to about 600 lb/ft when the plug is
secured to the receptacle.
6. The fiber optic receptacle and plug assembly of claim 1, wherein
the receptacle comprises a receptacle boot that permits the
receptacle to be installed in a breathable enclosure.
7. The fiber optic receptacle and plug assembly of claim 1, wherein
the plug further comprises an overmolded boot operable for sealing
between the plug and a fiber optic cable.
8. The fiber optic receptacle and plug assembly of claim 1, wherein
the plug is secured to the receptacle by one of a threaded coupling
nut, a bayonet-style connection and a push-pull mechanism.
9. The fiber optic receptacle and plug assembly of claim 4, wherein
the fiber optic cable is one of a branch cable, a distribution
cable, an extended distribution cable, a flat dielectric drop
cable, a figure-eight drop cable and an armored drop cable.
10. The fiber optic receptacle and plug assembly of claim 1,
wherein the at least one receptacle female and the at least one
plug ferrule are selected from the group consisting of SC, LC,
MTRJ, MTP, SC-DC connector type ferrules.
11. A fiber optic receptacle and plug assembly, comprising: a
receptacle adapted to be mounted within a wall of an enclosure, the
receptacle comprising at least one receptacle ferrule for engaging
at least one plug ferrule of like configuration when a
corresponding plug is inserted into the receptacle, the receptacle
further comprising: a receptacle housing defining an internal
cavity opening through opposed first and second ends, the internal
cavity operable for receiving the at least one plug ferrule through
the first end of the receptacle housing and the at least one
receptacle ferrule through the second end of the receptacle
housing, the receptacle housing defining a radially extending
shoulder for engaging an interior surface of the wall of the
enclosure; and a ferrule retainer for positioning the at least one
receptacle ferrule within the opening in the second end of the
receptacle housing.
12. The fiber optic receptacle and plug assembly of claim 11,
wherein the receptacle housing has a peripheral groove medially
disposed between the first and second ends for receiving a
seal.
13. The fiber optic receptacle and plug assembly of claim 11,
wherein the receptacle housing comprises a feature for cooperating
with a corresponding feature provided on the ferrule retainer for
securing the ferrule retainer to the receptacle housing in a
predetermined orientation.
14. The fiber optic receptacle and plug assembly of claim 11,
further comprising a biasing means disposed between the receptacle
housing and the ferrule retainer such that the at least one
receptacle ferrule is biased in the direction of the first end of
the receptacle housing.
15. The fiber optic receptacle and plug assembly of claim 11,
wherein the shoulder is adapted to engage an interior surface of
the wall of the enclosure to provide strain relief against tensile
forces of up to about 600 lb/ft when the plug is secured to the
receptacle.
16. A fiber optic receptacle and plug assembly, comprising: a plug
adapted for optically connecting at least one plug ferrule mounted
upon an optical fiber of a fiber optic cable to at least one
receptacle ferrule of like configuration mounted upon an optical
fiber disposed in a receptacle within an enclosure when the plug is
inserted into the receptacle, the plug further comprising: an outer
housing defining an opening extending between first and second ends
of the outer housing; an inner housing disposed within the outer
housing; and an adapter sleeve for receiving the at least one plug
ferrule disposed within the outer housing adjacent the inner
housing.
17. The fiber optic receptacle and plug assembly of claim 16,
further comprising a coupling nut for securing the plug to the
receptacle with the at least one plug ferrule in a predetermined
orientation relative to the at least one receptacle ferrule.
18. The fiber optic receptacle and plug assembly of claim 16,
wherein the outer housing comprises a key for aligning the at least
one plug ferrule in a predetermined orientation relative to the at
least one receptacle ferrule.
19. The fiber optic receptacle and plug assembly of claim 16,
wherein the fiber optic cable is one of a branch cable, a
distribution cable, an extended distribution cable, a flat
dielectric drop cable, a figure-eight drop cable and an armored
drop cable.
20. The fiber optic receptacle and plug assembly of claim 16,
wherein the at least one receptacle ferrule and the at least one
plug ferrule are selected from the group consisting of SC, LC,
MTRJ, MTP, SC-DC connector type ferrules.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to fiber optic
receptacle and plug assemblies for interconnecting optical fibers,
and more specifically, to hardened fiber optic receptacle and plug
assemblies including optical connectors and alignment features for
interconnecting optical fibers at outside plant connection
terminals in a fiber optic communications network.
[0003] 2. Description of the Related Art
[0004] Optical fiber is increasingly being used for a variety of
broadband applications including voice, video and data
transmissions. As a result, fiber optic networks must include an
ever-increasing number of interconnection points in which one or
more of the optical fibers are interconnected or mated. For
example, fiber optic networks may include a number of connection
terminals, examples of which include, but are not limited to,
distribution enclosures, network access point (NAP) enclosures,
aerial closures, below grade closures, pedestals and network
interface devices (NIDs). These various types of connection
terminals provide protection, such as from moisture or other forms
of environmental degradation, for the optical fibers and, more
particularly, for the point at which the optical fibers are
accessed from a fiber optic cable and optically connected. These
various types of connection terminals may be used to provide
services to an end user, commonly referred to as a subscriber. In
this regard, fiber optic networks are being developed that deliver
"fiber-to-the-curb" (FTTC), "fiber-to-the-business" (FTTB),
"fiber-to-the-home" (FTTH) and "fiber-to-the-premises" (FTTP),
referred to generically as "FTTx."
[0005] In order to reduce installation labor costs in FTTx
networks, communications service providers are increasingly
demanding factory-prepared interconnection solutions, commonly
referred to as "plug-and-play" systems. In the current development
of plug-and-play systems, connection terminals are provided at
distribution and interconnection points to establish optical
connections between optical fibers accessed from a distribution
cable (also referred to herein as "terminated") and respective
optical fibers of one or more drop cables, extended distribution
cables or branch cables. Via these connection terminals, one or
more terminated optical fibers are interconnected with one or more
optical fibers of an extended distribution cable, branch cable or
drop cable, collectively referred to herein as a "drop cable."
Regardless of the type of connection terminal and cable provided at
the interconnection point, the connection terminal must include at
least one opening through a wall, typically an external wall,
operable for receiving one or more drop cables. At these openings,
referred to herein as connector ports, assemblies for readily
performing optical connections are needed. The assemblies should
also protect the optical connections (i.e., connectors, adapter
sleeves, ferrules, etc.) at which the optical fibers are
interconnected against adverse environmental conditions, such as
from water intrusion, and from mechanical influences, such as
tensile forces (i.e., pulling forces generated during installation
or by cable sag or wind or ice loading).
[0006] Conventional connector ports receive fiber optic receptacles
in which one or more optical fibers of a drop cable are connected
to respective optical fibers accessed within the enclosure. The
optical fibers within the enclosure may be terminated directly to
the receptacle or may be connectorized and terminated to the
receptacle. In the past, these receptacles have been rather large
in size because the enclosures in which they are held do not
require minimal receptacle depths. Without significant depth
restrictions, conventional receptacles include a receptacle housing
defining an internal cavity that houses a receptacle adapter
sleeve, also referred to herein as a "connector sleeve" or
"connector adapter sleeve." The adapter sleeve is designed to
receive a pair of ferrules, each of which is mounted upon the end
portions of one or more optical fibers. One of the ferrules is
attached to the end portions of one or more optical fibers
extending from a cable, ribbon or optical fiber device that extends
into or is located in the interior of the enclosure. The other
ferrule is mounted upon the end portions of one or more optical
fibers extending from a cable, ribbon, or optical fiber device that
extends outside or is located outside of the enclosure, such as the
optical fibers of a fiber optic drop cable. The adapter sleeve
assents in gross alignment of the ferrules, and ferrule guide pins
or other alignment means assent in detailed alignment of the
optical fibers on the opposing end faces of the ferrules.
[0007] In order to mate with a receptacle provided on a
conventional connection terminal, a fiber optic plug is mounted
upon the end portions of one or more optical fibers of the fiber
optic drop cable. Typically, the plug includes a generally
cylindrical plug body and a fiber optic connector including a
connector and/or a plug ferrule disposed within the cylindrical
plug body. In order to protect the plug ferrule, the cylindrical
plug body may partially or completely surround the lateral sides of
the fiber optic connector. The end of the cylindrical plug body is
open such that the end face of the ferrule is accessible. The
ferrule is mounted upon the end portions of the one or more optical
fibers of the fiber optic drop cable such that mating the plug with
the receptacle will align and optically connect the optical fibers
of the fiber optic drop cable with respective optical fibers
accessed within the connection terminal and terminated to the
receptacle.
[0008] In the process of mating the plug and the receptacle, the
plug ferrule is inserted into one end of the adapter sleeve housed
within the receptacle. The adapter sleeve therefore aligns the plug
ferrule with a receptacle ferrule that is attached to the end
portions of the one or more optical fibers of the fiber optic
cable, ribbon, or optical fiber device that extends into or is
located within the interior of the connection terminal. As a result
of the construction of a conventional fiber optic plug, the adapter
sleeve is minimally received within the open end of the plug body
as the plug ferrule is inserted into the receptacle. In addition,
in order to retain the plug ferrule within the adapter sleeve, the
connector of the fiber optic plug and the connector of the
receptacle are mechanically coupled.
[0009] Several different types of conventional fiber optic
connectors have been developed, examples of which include, but are
not limited to, SC, LC, DC, MTP, MT-RJ and SC-DC connectors. The
size and shape of each of these conventional connectors are
somewhat different. Correspondingly, the size and shape of the
adapter sleeve, the receptacle and the plug are also different. As
such, according to conventional practice, different fiber optic
receptacles are generally utilized in conjunction with the
different types of fiber optic connectors. In this regard, the
fiber optic receptacles generally define different sized internal
cavities corresponding to the sizes of the adapter sleeve and, in
turn, according to a ferrule of the fiber optic connector to be
inserted within the adapter sleeve. Accordingly, a field service
technician typically has to maintain several different types of
fiber optic receptacles in inventory so that the proper type of
receptacle can be installed depending upon the type of fiber optic
connector to be inserted into the receptacle. Obviously,
maintaining a number of different types of fiber optic receptacles
in inventory is not only difficult for the technician to manage,
but also increases the overall costs associated with maintaining a
sufficient inventory.
[0010] In addition to using different types of fiber optic
receptacles and/or plugs based upon the particular optical
connector utilized, conventional receptacle/plug combinations are
relatively large in size. Smaller and more space optimized
assemblies are needed for low form factor and high density
applications. Current smaller designs, however, are not dimensioned
for the high tensile loads typically specified for "FTTx"
applications (up to about 600 lb/ft). Contamination of the
receptacle ferrule is also a significant issue, since many FTTx
applications require that receptacles may remain unoccupied (i.e.,
not mated with a plug) for an extensive amount of time. Based on
the need for increased loads and contamination prevention, it would
be desirable to produce a small form factor, hardened fiber optic
receptacle and mating plug adapted for mounting in a connection
terminal defining an external wall through which optical fibers are
interconnected. As yet, however, there is an unresolved need for a
small form factor, hardened fiber optic receptacle that can receive
a mating fiber optic plug utilizing various types of optical fiber
connectors. There is a further unresolved need for a fiber optic
receptacle and plug assembly defining an internal structure adapted
to accommodate various types of optical connectors, and a hardened
outer structure that provides superior resistance against tensile
forces and superior contamination protection against adverse
environmental conditions.
BRIEF SUMMARY OF THE INVENTION
[0011] To achieve the foregoing and other objects, and in
accordance with the purposes of the invention as embodied and
broadly described herein, the present invention provides various
embodiments of fiber optic receptacle and plug assemblies, and more
particularly, fiber optic receptacles and corresponding plugs of
like optical connector configuration. Thus, the present invention
provides fiber optic receptacle and plug assemblies designed to
readily mate various types of optical connectors via the use of a
connector port provided in a wall of a connection terminal. The
present invention further provides a low form factor fiber optic
receptacle and plug assembly adapted to be secured within a
connector port of a connection terminal, while providing strain
relief against tensile forces of up to about 600 lb/ft and
protection against adverse environmental conditions.
[0012] In an exemplary embodiment, the present invention provides a
fiber optic receptacle and plug assembly comprising a fiber optic
receptacle adapted to be secured within a connector port of a
connection terminal and a corresponding fiber optic plug mounted
upon the end portions of one or more optical fibers of a fiber
optic cable. The fiber optic receptacle and the fiber optic plug
comprise keyed designs that allow the fiber optic receptacle to
receive only a fiber optic plug of like ferrule configuration. The
fiber optic plug engages a corresponding receptacle positioned
within a connector port provided in an external wall or an internal
wall of a connection terminal or other enclosure. The keyed design
of the fiber optic receptacle and plug assembly allows non-centric
positions of at least one ferrule and includes keys for radial
alignment of the at least one ferrule. The fiber optic plug
comprises an adapter sleeve operable for receiving and optically
connecting at least one plug ferrule and at least one receptacle
ferrule, thus minimizing the depth of the receptacle portion of the
assembly. The fiber optic receptacle comprises a shoulder that is
secured against a wall of the connection terminal in order to
provide strain relief against tensile forces of up to about 600
lb/ft. A receptacle boot allows the assembly to be installed in a
breathable enclosure.
[0013] In another embodiment, the present invention provides a
fiber optic receptacle and plug assembly comprising a fiber optic
receptacle adapted to be secured within a connector port of a
connection terminal. The fiber optic receptacle comprises a
receptacle housing defining an internal cavity opening through
opposed first and second ends, wherein the internal cavity is
operable for receiving an adapter sleeve of a corresponding fiber
optic plug through the first end. The receptacle housing further
defines a shoulder that is secured against an interior surface of
the wall operable for providing strain relief against tensile
forces of up to about 600 lb/ft. At least one receptacle ferrule is
disposed and mounted within the internal cavity via a ferrule
retainer disposed proximate the second end. The assembly further
comprises a fiber optic plug comprising a plug inner housing, a
plug outer housing, a coupling nut, at least one plug ferrule and
an adapter sleeve operable for receiving and optically connecting
the at least one plug ferrule and the at least one receptacle
ferrule. The fiber optic receptacle and the fiber optic plug
comprise keyed designs that allow the fiber optic receptacle to
properly receive only a fiber optic plug of like ferrule
configuration. The receptacle may further comprise a bias member
that operably engages the ferrule retainer to urge the at least one
receptacle ferrule toward the first end of the receptacle
housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other features, aspects and advantages of the
present invention are better understood when the following detailed
description of the invention is read with reference to the
accompanying drawings, in which:
[0015] FIG. 1 is an exploded perspective view of a single ferrule
(i.e., simplex) version of a fiber optic receptacle and plug
assembly in accordance with an exemplary embodiment of the present
invention shown with the receptacle and plug disengaged and with
the protective dust/pulling caps of the receptacle and plug
removed;
[0016] FIG. 2 is a perspective view of the fiber optic receptacle
and plug assembly of FIG. 1 shown with the plug engaging the
receptacle;
[0017] FIG. 3 is an exploded perspective view of the fiber optic
receptacle of FIG. 1 showing the receptacle body, the receptacle
ferrule, the ferrule retainer, the protective end cap and the
receptacle seal boot;
[0018] FIG. 4 is a cross-sectional view of the fiber optic
receptacle of FIG. 3 shown in its assembled configuration;
[0019] FIG. 5 is an exploded perspective view of the fiber optic
plug of FIG. 1 showing the plug body, the plug ferrule, the adapter
sleeve, the protective end/pulling cap, the crimp band and the
coupling nut;
[0020] FIG. 6 is a cross-sectional view of the fiber optic plug of
FIG. 5 shown in its assembled configuration;
[0021] FIG. 7 is an exploded perspective view of a dual ferrule
(i.e., duplex) version of a fiber optic receptacle and plug
assembly in accordance with another exemplary embodiment of the
present invention shown with the receptacle and plug disengaged and
with the protective dust/pulling caps of the receptacle and plug
removed;
[0022] FIG. 8 is a perspective view of the fiber optic receptacle
and plug assembly of FIG. 7 shown with the plug engaging the
receptacle;
[0023] FIG. 9 is an exploded perspective view of the fiber optic
receptacle of FIG. 7 showing the receptacle body, two receptacle
ferrules, the ferrule retainer, the protective end cap and the
receptacle seal boot;
[0024] FIG. 10 is a cross-sectional view of the fiber optic
receptacle of FIG. 9 shown in its assembled configuration;
[0025] FIG. 11 is an exploded perspective view of the fiber optic
plug of FIG. 7 showing the plug body, two plug ferrules, the
adapter sleeve, the protective end/pulling cap, the crimp band and
the coupling nut; and
[0026] FIG. 12 is a cross-sectional view of the fiber optic plug of
FIG. 11 in its assembled configuration.
DETAILED DESCRIPTION OF THE INVENTION
[0027] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings in which
exemplary embodiments of the invention are shown. However, this
invention may be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein. These
exemplary embodiments are provided so that this disclosure will be
both thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like reference numbers refer
to like elements throughout the various drawings.
[0028] In the various embodiments described below, the present
invention comprises fiber optic receptacle and plug assemblies
including one or more optical connectors or ferrules for
interconnecting optical fibers within a communications network. The
receptacle portion of each assembly is adapted to be mounted within
a wall of an enclosure or similar structure, such as a network
distribution or interconnection terminal, through which one or more
optical fibers of a fiber optic cable are routed. A rigid shoulder
of the fiber optic receptacle is mounted against the wall of the
enclosure, thus providing superior retention for external tensile
forces as compared to conventional threaded designs that use a nut
on the inside of the wall for securing the receptacle. In the
exemplary embodiments shown and described herein, the fiber optic
plug portion of each assembly includes a fiber optic cable
comprising one or more optical fibers for optically connecting a
corresponding plurality of optical fibers received within the
receptacle portion. As used herein, the fiber optic cable
associated with the plug portion is referred to as the "drop cable"
and is intended to include all types of fiber optic cables such as,
but not limited to, a branch cable, a distribution cable, an
extended distribution cable, a flat dielectric drop cable, a
figure-eight drop cable or an armored drop cable. The drop cable
typically comprises between one and about twelve optical fibers,
but may comprise up to about 24 fibers depending on the
construction of the drop cable and the number and type of optical
connectors. Furthermore, the particular components of the fiber
optic receptacle and plug assemblies described herein may be
modified to accommodate different cable and optical connector
types.
[0029] In all embodiments shown and described herein, different
types of fiber optic cables may function as the drop cable such as,
but not limited to, monotube, loose tube, central tube, ribbon,
flat dielectric and the like. However, in the exemplary embodiments
shown, the drop cable comprises a cable jacket, a strength
component and an optical transmission component disposed within the
cable jacket. In one embodiment, the strength component comprises
two glass-reinforced plastic (GRP) strength components and the
optical transmission component comprises an optical waveguide
disposed within a central buffer tube. The drop cable may also
comprise strength members that provide additional tensile strength.
As used herein, the term "strength component" refers to a strength
element having anti-buckling strength, while the term "strength
member" refers to a strength element lacking anti-buckling
strength. Furthermore, the term "tensile element" refers
generically to either a strength component or a strength member.
Strength members allow a fiber optic cable to have a smaller
cross-sectional footprint due to the fact that they allow the
strength components to have smaller diameters since they will not
provide all of the tensile strength to the cable. In other words,
the strength components and the strength members combine to carry
the tensile load. Moreover, by using strength members, the cable
remains relatively flexible and is easier to handle. It is
understood that other cable types may be used in conjunction with
the present invention. Moreover, various optical connectors may be
used with different fiber optic cables according to the concepts of
the present invention, thereby resulting in numerous
cable/connector combinations. The drop cable is preferably designed
to provide stable performance over a wide range of temperatures and
to be compatible with any telecommunications grade optical fiber.
As used herein, the term "optical fiber" is intended to include all
types of single mode and multi-mode light waveguides, including one
or more bare optical fibers, coated optical fibers, loose-tube
optical fibers, tight-buffered optical fibers, ribbonized optical
fibers or any other expedient for transmitting light signals.
[0030] The fiber optic connector and plug assemblies of the present
invention provide a hardened, fully-sealed configuration that
prevents adverse environmental conditions, such as moisture and
contamination, from reaching the end faces of the optical fibers
and the ferrules. In all the exemplary embodiments shown herein,
O-rings provide static seals, and their position combined with
relief features minimize vacuum build-up when removing the plug
from the receptacle and pressure build-up when mating the plug with
the receptacle. Generally speaking, most of the components of the
receptacle and plug are formed from a suitable polymer. Preferably,
the polymer is a UV stabilized polymer such as VECTRA.RTM. A130
liquid crystal polymer (LCP) available from Celanese AG Ticona of
Summit, N.J. or ULTEM.RTM. 2210 available from General Electric
Plastics Company of Pittsfield, Mass. However, other suitable
materials may also be used. For example, stainless steel or any
other non-corrosive or coated metal may be used for various
components.
[0031] Referring now to FIGS. 1-6, a fiber optic receptacle and
plug assembly according to one embodiment of the present invention
is shown. The assembly includes a fiber optic receptacle 20 and a
corresponding fiber optic plug 22. The receptacle 20 is typically
mounted within a connector port (not shown) provided in an external
wall or an internal wall, referred to hereinafter as a "wall," of a
distribution or interconnection enclosure, such as a connection
terminal in a fiber optic communications network. The receptacle 20
is operable for connecting one or more optical fibers outside of
the wall with one or more optical fibers within the enclosure. It
should be understood, however, that the fiber optic receptacle 20
may be mounted to other structures, for example to a connector
panel, patch panel or similar substantially planar surface, without
departing for the intended scope of the invention. Each such
connector port is operable for receiving a receptacle 20 and at
least one connectorized optical fiber on the inside of the
connector port, and the plug 22 and at least one connectorized
optical fiber of a drop cable 24 on the outside of the connector
port. The plug 22 is mounted upon the end portion of the drop cable
24 and is adapted to mate with the corresponding receptacle 20. The
receptacle 20 and plug 22 are operable for aligning and maintaining
the opposing optical fibers in contact. A single connector port may
accommodate more than one optical fiber of the drop cable 24,
either by receiving a multifiber ferrule or by receiving multiple
single-fiber ferrules within the receptacle 20.
[0032] Referring specifically to FIG. 1, the receptacle 20 and the
corresponding plug 22 are shown disengaged from one another and
with their respective dust caps 28, 34 removed. A threaded coupling
nut 26 of the plug portion of the assembly, operable for securing
the plug 22 to the receptacle 20 upon engagement, may be used to
secure the protective dust cap 28 during installation. The dust cap
28 defines a threaded portion 29 at its rearward end and a pulling
grip 30 at its forward end. The dust cap 28 protects the optical
connector 32 of the plug 22 during installation and until
engagement with the receptacle 20. When removed, the dust cap 28
may be secured to the drop cable 24 using a tether 33, and may be
reused if the plug 22 is disengaged from the receptacle 20 at a
later time. In preferred embodiments, the pulling grip 30 should be
able to withstand pulling forces up to about 600 lb/ft. The pulling
grip 30 and the dust cap 28 have a generally rounded forward end to
facilitate installation through ducts or around pulleys. As with
the plug portion of the assembly, the receptacle portion may also
be covered and sealed with a threaded dust cap 34 that is removed
prior to inserting the plug 22. The receptacle dust cap 34 may also
be secured to the receptacle 20 using a tether 33. At the end of
the receptacle 20 opposite the threaded portion, a boot 36 protects
the receptacle 20, and in some embodiments may also provide
sealing. The protective boot 36 allows the receptacle 20 to be
installed in a breathable enclosure and may be unnecessary if the
receptacle 20 is otherwise reliably sealed from the
environment.
[0033] Referring specifically to FIG. 2, the plug 22 is mounted
upon the end portion of the fiber optic drop cable 24 and is
adapted to mate with the corresponding receptacle 20. To secure the
plug 22 and receptacle 20 together, the coupling nut 26 engages the
threaded end of the receptacle 20. The features that secure the
assembly within the connector port of the wall of the enclosure
will be described below.
[0034] Referring now to FIG. 3, the fiber optic receptacle 20
includes a receptacle housing 38 operable for mounting the
receptacle 20 to the wall of the enclosure, holding a ferrule
assembly and aligning both the receptacle ferrule assembly and the
fiber optic plug 22 so that they engage one another in only one
preferred orientation. This feature is advantageous for orientation
critical applications including angled physical contact (APC) type
ferrules where minimal angular offset is permissible, as well as
multi-fiber ferrules that often are not centric. The receptacle
housing 38 defines an internal cavity 40 opening through opposed
first end 42 and second end 44. Typically, the size of the opening
40 through the first end 42 is relatively large so as to receive
the corresponding fiber optic plug 22. Conversely, the size of the
opening through the second end 44 is typically smaller and, in one
advantageous embodiment, is sized to be only slightly larger than
the receptacle ferrule 46, such that the receptacle ferrule 46 can
be inserted, but is received through the opening 40 in a slight
loose fit. The relatively large size of the opening 40 at the first
end 42 allows the end face of the receptacle ferrule 46 to be
cleaned with a Q-tip or special tool. This is advantageous since
the receptacle 20, in contrast to the fiber optic plug 22, may be
exposed to weather when not used for a prolonged period of time and
may collect contamination. This embodiment allows for easy cleaning
and improved access without disassembly of the ferrule receptacle
46 from the receptacle housing 38.
[0035] Although the fiber optic receptacle 20 may house a variety
of fiber optic connector types including LC, MTRJ, MTP, SC-DC, and
the like, the receptacle 20 shown in FIGS. 1-6 houses, by way of
example and not by way of limitation, a single ferrule assembly of
the type utilized in a conventional SC type connector. Although not
included in this particular embodiment, the fiber optic receptacle
20 may also include an adapter sleeve disposed within the internal
cavity 40 defined by the receptacle housing 38. If present, the
adapter sleeve may have a sleeve member that defines a lengthwise
extending passageway having opposed ends for receiving and aligning
a plug ferrule (not shown) with the receptacle ferrule 46. In this
regard, the plug ferrule of the fiber optic plug 22 may be inserted
into one end of the adapter sleeve, while the receptacle ferrule 46
that is mounted upon the ends of optical fibers extending through
the enclosure may be inserted through the opening defined by the
second end 44 of the receptacle 20 and into the other end of the
adapter sleeve. In this embodiment, however, the adapter sleeve is
a component of the plug 22 and is inserted into the internal cavity
40 of the receptacle 20 upon mating the plug 22 with the receptacle
20.
[0036] The receptacle housing 38 in the embodiment shown is
cylindrically shaped and defines a shoulder portion 48 positioned
medially about midway between the first end 42 and the second end
44. Upon installation within a connector port of a wall, the first
end 42 of the receptacle housing 38 is inserted through the
connector port from the inside of the wall until the surface of the
shoulder portion 48 proximate the first end 42 comes into contact
with the interior surface of the wall. By securing the receptacle
20 within the wall using the shoulder 48, as opposed to a nut, the
receptacle 20 provides strain relief against tensile forces of up
to about 600 lb/ft. A seal may be provided between the receptacle
housing 38 and the interior surface of the wall using a
conventional O-ring seal (not shown), multi-point seal 50 or like
sealing means. The receptacle housing 38 defines a groove 52 for
receiving the multi-point seal 50. The groove 52 may further
receive a crescent ring 54 for retaining the multi-point seal 50 in
place and securing the receptacle 20 within the connector port. The
coupling nut 26 of the plug 22 is used to further secure the
receptacle 20 within the connector port.
[0037] The fiber optic receptacle 20 also preferably includes a
ferrule retainer 56 operable for retaining the receptacle ferrule
46 within the internal cavity 40 of the receptacle housing 38. The
ferrule retainer 56 and the receptacle housing 38 can be connected
in various manners, but, in one advantageous embodiment, the
ferrule retainer 56 includes hooks 58 that are received by features
60 that project outwardly from the receptacle housing 38. The
ferrule retainer 56 can be removed from the receptacle housing 38
in order to access the receptacle ferrule 46, such as for cleaning,
repair or replacement. The design of the ferrule retainer 56 allows
for easy removal without a tool at any point in time. Once the
receptacle ferrule 46 has been cleaned, repaired or replaced, the
receptacle ferrule 46 can be reinserted into the opening 40 of the
receptacle housing 38 and the ferrule retainer 56 can be
reconnected to the receptacle housing 38.
[0038] The fiber optic receptacle 20 of this particular embodiment
also includes a bias member disposed within the receptacle housing
38. The bias member is disposed between and operably engages the
ferrule retainer 56 and the receptacle ferrule 46 to urge the
receptacle ferrule toward the first end 42 of the receptacle
housing 38. Typically, the bias member is one or more linear coil
springs 62 as shown. Thus, the receptacle ferrule 46 is biased
towards the first end 42 of the receptacle housing 38, but is
allowed to move relatively freely within the opening 40 and the
adapter sleeve (not shown) of the plug 22, thus allowing a
compressive force to seat the receptacle ferrule 46 against the
mating plug ferrule (not shown). The boot 36 rests against the
shoulder portion 48 of the receptacle housing 38 and protects the
components of the receptacle 20 positioned adjacent the interior
surface of the wall of the enclosure. The boot 36 defines an
opening 64 for receiving the fiber optic cable (not shown) and/or
optical fibers (not shown) from within the enclosure.
[0039] FIG. 4 is a cross-section of the assembled receptacle 20
taken along line A-A of FIG. 3, the same or similar parts being
identified by like reference numerals. An O-ring 66 may be used to
provide a seal between the dust cap 34 and the receptacle housing
38. As is shown in FIG. 4, the multi-point seal 50 is retained
within the groove of the receptacle housing 38 and provides sealing
points between the receptacle housing 38 and the wall (not shown)
of the enclosure. The wall is positioned between the shoulder
portion 48 of the receptacle housing 38 and the crescent ring 54
with the shoulder portion 48 engaging the interior surface of the
wall. In one embodiment, the crescent ring 54 secures the
receptacle 20 in place. In an alternative embodiment, the dust cap
34 or the coupling nut 26 of the plug 22 is used to secure the
receptacle 20 in place.
[0040] Referring to FIG. 5, the fiber optic plug 22 comprises a
plug ferrule 70, an inner housing 72 with a crimp, an adapter
sleeve 74, an outer housing 68 and a coupling nut 26. There is also
a molded-on plug boot (not shown) made of a flexible (silicone-type
or other like) material secured over a portion of the outer housing
68 and a portion of the drop cable 24 in order to seal the exposed
portion of the drop cable 24 and generally inhibit kinking while
providing bending strain relief to the cable 24 near the plug 22.
The strength components 78 are terminated on the inner housing 72
and a crimp band 80 is secured around the strength components 78.
The crimp band 80 is preferably made from brass, but other suitable
deformable materials may be used. The strength members (not shown)
are cut flush with the stripped-back jacket 76, thereby exposing
the two GRP strength components 78 and optical component 82
adjacent the end of the cable 24. The crimp band 80 provides strain
relief for the cable 24. The inner housing 72 is assembled by first
crimping the crimp band 80 to the strength components 78 of the
cable 24. The outer housing 68 is then slid over the inner housing
72. As is well known ad understood in the art, the outer housing 68
is threaded onto the cable 24 before the cable 24 is crimped to the
inner housing 72. The adapter sleeve 74 secures the fit of the
parts and allows the plug 22 to be disassembled in a reverse
manner.
[0041] The plug ferrule 70 extends lengthwise and is at least
partially disposed within the inner housing 72. The plug ferrule 70
may therefore be mounted within the inner housing 72 such that the
front face of the plug ferrule 70 extends somewhat beyond the
forward end of the inner housing 72. As with the corresponding
fiber optic receptacle 20, the plug 22 may house a variety of fiber
optic connector types including LC, MTRJ, MTP, SC-DC, and the like.
However, the plug 22 of the particular embodiment shown houses a
single ferrule assembly of the type utilized in a conventional SC
type connector because the receptacle 20 can only receive a plug 22
of like ferrule configuration. The plug ferrule 70 is received
within the lengthwise passageway defined by the adapter sleeve 74
for mating the plug ferrule 70 and the receptacle ferrule 46. As
stated above, the adapter sleeve 74 may be a component of either
the receptacle 20 or the plug 22. As shown, the adapter sleeve 74
is a component of the plug 22 so as to minimize the overall size of
the receptacle 20, thereby providing a small form factor
receptacle.
[0042] The outer housing 68 has a generally cylindrical shape with
a forward first end 84 and a rearward second end 86. The outer
housing 68 generally protects the inner housing 72 and in preferred
embodiments also keys engagement of the plug 22 with the mating
receptacle 20. Moreover, the inner housing 68 includes a through
passageway between the first and second ends 84 and 86. The
passageway of the inner housing 72 is keyed so that the inner
housing 72 is inhibited from rotating when the plug 22 is
assembled. The first end 84 of the outer housing 68 includes a
keyed opening 88 defined by the housing 68 for aligning the plug 22
with the receptacle 20 for radial alignment of the plug ferrule 70
with the receptacle ferrule 46. The plug 22 and the corresponding
receptacle 20 are shaped to permit mating in only one orientation.
In preferred embodiments, this orientation may be marked on the
receptacle 20 and on the plug 22 using alignment indicia so that a
field technician can readily mate the plug 22 with the receptacle
20 even when the internal components of the fiber optic receptacle
and plug assembly are not visible. Any suitable indicia may be
used. After alignment, the field technician engages the internal
threads of the coupling nut 26 with the external threads of the
receptacle 20 to secure the plug 22 to the receptacle 20.
[0043] The outer housing 68 may further define a shoulder 90 that
provides a mechanical stop for both an O-ring 92 disposed on the
outer housing 68 and the coupling nut 26. The O-ring 92 provides a
weatherproof seal between the plug 22 and the receptacle 20. The
coupling nut 26 has a passageway sized so that it fits over the
second end 86 of the outer housing 68 and easily rotates about the
medial portion of the outer housing 68. In other words, the
coupling nut 26 cannot move beyond the shoulder 90, but is able to
rotate with respect to the outer housing 68. FIG. 6 is a
cross-section of the assembled plug 22 taken along line B-B of FIG.
5, the same or similar parts being identified by like reference
numerals.
[0044] Referring to FIG. 7, a dual ferrule (i.e., duplex) version
of a fiber optic receptacle and plug assembly is shown. In this
embodiment, the drop cable is not shown, however, it is understood
that the drop cable may include a branch cable, distribution cable,
extended distribution cable, flat dielectric drop cable,
figure-eight drop cable or an armored drop cable comprising two or
more optical waveguides. As with the embodiment shown in FIGS. 1-6,
the receptacle 20 is mounted within a connector port of a wall of
an enclosure, such as a network connection terminal. The plug 22 is
aligned with and engages only a receptacle 20 of like optical
connector configuration. The plug 22 shown allows a single
receptacle 20 to accommodate more than one optical fiber accessed
and connectorized for optical connection within the connection
terminal. At the same time, the drop cable associated with the plug
22 is strain relieved at the connector port.
[0045] The receptacle 20 and the corresponding plug 22 are shown
disengaged and with their respective dust caps 34, 28 removed. A
threaded coupling nut 26 of the plug portion of the assembly,
operable for securing the plug 22 to the receptacle 20 upon
engagement, may be used to secure the protective dust cap 28 during
installation. A protective boot 36 allows the fiber optic
receptacle 20 to be installed in a breathable enclosure and may be
unnecessary if the receptacle 20 is otherwise reliably sealed from
adverse environmental conditions. As in the previous embodiment,
the outer housing 68 of the plug 22 has a generally cylindrical
shape and keys engagement of the plug 22 with the mating receptacle
20. The outer housing 68 defines an alignment feature 94, which has
a specific shape so that the plug 22 and receptacle 20 mate in only
one orientation. In preferred embodiments, this orientation may be
marked on both the outer housing 68 and the receptacle housing 38
using alignment indicia so that a field technician can readily mate
the plug 22 with the receptacle 20 even when the internal
components of the receptacle 20 and plug 22 are not visible. The
alignment indicia on the plug 22 is aligned with the complimentary
alignment indicia disposed on the receptacle 20. Thereafter, the
field technician engages the internal threads of the coupling nut
26 with the external threads of the receptacle 20 to secure the
plug 22 to the receptacle 20.
[0046] Referring to FIG. 8, the fiber optic plug 22 may be mounted
upon any suitable fiber optic drop cable including more than one
optical fiber since the optical connector shown includes more than
one ferrule, such as two LC ferrules. To secure the plug 22 to the
receptacle 20, the coupling nut 26 engages the threaded end of the
receptacle 20. The plug 22 may be secured in the field without
special tools, equipment or training. Additionally, the physical
connection may be easily connected or disconnected by merely mating
or un-mating the plug 22 with the receptacle 20 and engaging or
disengaging threads of the coupling nut 26 with the threads of the
receptacle 20. Thus, the receptacle/plug assembly of the present
invention allows the deployment of multiple optical fibers, through
a connector port provided in a wall of a conventional network
connection terminal in an easy and economical manner. The concepts
of the present invention may be practiced with other fiber optic
cables, connectors and/or other cable configurations.
[0047] Referring to FIG. 9, as in the embodiment described above,
the fiber optic receptacle 20 includes a receptacle housing 38
operable for mounting to a wall, holding a pair of receptacle
ferrules and aligning both the internal receptacle ferrules with
the fiber optic plug 22 so that they engage in only one preferred
orientation. The receptacle housing 38 defines an internal cavity
40 opening through opposed ends, a first end 42 and a second end
44. The openings through the second end 44 are typically smaller
and, in one advantageous embodiment, are sized to be only slightly
larger than the receptacle ferrules 46, such that the receptacle
ferrules 46 can be inserted, but are received through the openings
in a slight loose fit. Although the fiber optic receptacle 20 may
house a variety of fiber optic connector types including LC, MTRJ,
MTP, SC-DC, and the like, the receptacle 20 shown in FIGS. 7-12
houses, by way of example and not by way of limitation, dual
ferrule assemblies of the type utilized in a conventional LC type
connector. As in the previous embodiment, the adapter sleeve 74 is
a component of the plug 20 and is inserted into the internal cavity
40 of the receptacle 20 upon insertion of the plug 22 into the
receptacle 20.
[0048] The receptacle housing 38 in the embodiment shown is
cylindrically shaped and defines a shoulder portion 48 positioned
medially about midway between the first end 42 and the second end
44. Upon installation within a wall of an enclosure, the first end
42 of the receptacle housing 38 is inserted through the connector
port from the inside of the enclosure until the surface of the
shoulder portion 48 proximate the first end 42 comes into contact
with the interior surface of the wall. A seal is provided between
the receptacle housing 38 and the wall using an O-ring (not shown),
multi-point seal 50 or like sealing means. The receptacle 20 also
includes a ferrule retainer 56 operable for retaining the
receptacle ferrules 46 within the internal cavity 40 of the
receptacle housing 38. The ferrule retainer 56 defines clips or
hooks 58 that grip features 60 defined by the receptacle housing 38
for securing the ferrule retainer 56 to the receptacle housing 38.
The ferrule retainer 56 can be removed from the receptacle housing
38 in order to access the receptacle ferrules 46, such as for
cleaning, repair, replacement or the like.
[0049] The fiber optic receptacle 20 further includes bias members
62 that engage the ferrule retainer 56 to urge the receptacle
ferrules 46 toward the first end 42 of the receptacle housing 38.
Thus, the receptacle ferrules 46 are biased towards the first end
42 of the receptacle housing 38, but are allowed to move relatively
freely within the opening 40 and the adapter sleeve (not shown) of
the plug 22, thus allowing a compressive force to seat the
receptacle ferrules 46 against the mating plug ferrules (not
shown). It should be understood, however, that the fiber optic
receptacle 20 can include other types of bias members 62, in
addition to or instead of the one or more linear coil springs shown
herein. The ferrule retainer 56 may also include one or more posts
(not shown) extending in a lengthwise direction such that a spring
can be mounted upon a respective post. In addition, each spring 62
would be longer than its respective post, even in the compressed
state. As such, the posts serve to position the springs 62 that, in
turn, contact the receptacle ferrules 46 and to provide additional
lateral stability. FIG. 10 is a cross-section of the assembled plug
22 taken along line C-C of FIG. 9, the same or similar parts being
identified by like reference numerals. A conventional sealing
O-ring 66 may be disposed between the dust cap 34 and the
receptacle housing 38. The fiber optic receptacle 20 is adapted to
receive a corresponding fiber optic plug 22 when the plug ferrules
70 of the fiber optic plug 22 are aligned with and inserted into
the first end 42 of the receptacle housing 38.
[0050] Referring to FIG. 11, the corresponding plug 22 for the
receptacle 20 shown in FIGS. 9-10 generally includes a plug inner
housing 72, plug ferrules 70, an adapter sleeve 74, an outer
housing 68 and a coupling nut 26. There is also a molded-on plug
boot (not shown) made of a flexible (silicone-type or other like)
material secured over a portion of the outer housing 68 and a
portion of the drop cable (not shown) in order to seal and provide
bending strain relief to the cable near the plug 22. The crimp band
80 is secured around the strength components (not shown) of the
cable and provides strain relief for the cable. The plug ferrules
70 extend lengthwise and are partially disposed within the inner
housing 72. To match the corresponding receptacle 20, the fiber
optic plug 22 may include a variety of fiber optic connector types
including SC, LC, MTRJ, MTP, SC-DC, and the like. The plug 22 of
the particular embodiment is shown to include dual LC ferrules
which are smaller than SC connectors, thus allowing the overall
diameter of the fiber optic receptacle and plug assembly to remain
the same as the embodiment described above. The plug ferrules 70
are received within the lengthwise passageway defined by the
adapter sleeve 74 that mates the plug ferrules 70 with the
receptacle ferrules 46. The receptacle ferrules 46 are inserted
into the forward end of the adapter sleeve 74. Thus, the adapter
sleeve 74 serves to align the plug ferrules 70 inserted into the
adapter sleeve 74 with the receptacle ferrules 46 inserted into the
other end of the adapter sleeve 74. As such, the optical fibers
upon which the opposing ferrules are mounted are correspondingly
aligned and optically interconnected.
[0051] The outer housing 68 generally protects the inner housing
72, and in preferred embodiments, also keys engagement of the plug
22 with the mating receptacle 20. Moreover, the outer housing 68
includes a through passageway that is keyed so that the inner
housing 72 is inhibited from rotating when the plug 22 is
assembled. The outer housing 68 includes a keyed opening 88 for
aligning the plug 22 with the receptacle 20 for radial alignment of
the opposing ferrules. The plug 22 and the corresponding receptacle
20 are shaped to permit mating in only one orientation. In
preferred embodiments, this orientation may be marked on the
receptacle 20 and on the plug 22 using alignment indicia so that a
field technician can readily mate the plug 22 with the receptacle
20. Any suitable indicia may be used. After alignment, the field
technician engages the internal threads of the coupling nut 26 with
the external threads of the receptacle 20 to secure the plug 22 to
the receptacle 20.
[0052] The outer housing 68 may further define a shoulder 90 that
provides a mechanical stop for both an O-ring 92 and the coupling
nut 26. The O-ring 92 provides a weatherproof seal between the plug
22 and the receptacle 20. The coupling nut 26 has a passageway
sized so that it fits over the end of the outer housing 68 and
easily rotates about the medial portion of the outer housing 68.
FIG. 12 is a cross-section of the assembled plug 22 taken along
line C-C of FIG. 11, the same or similar parts being identified by
like reference numerals.
[0053] In alternative embodiments, the coupling threads may be
replaced with a bayonet style or a push-pull mechanism to hold the
plug 22 within the receptacle 20. Alternatively, a clip may be
added to engage the outer housing 68 of the plug 22 and the
receptacle housing 38 of the receptacle 20 to hold them together.
Sealing features may be relaxed or eliminated entirely based upon
the particular application. The plug boot may be pre-manufactured
and assembled, or may be overmolded as is known in the art.
Further, heat deformable tubing may be used to fulfill the same
purpose as the boot when aesthetics are less important and bend
characteristics less stringent. As stated above, the adapter sleeve
74 may be integrated into the receptacle 20 instead of the plug 22
when the overall diameter of the receptacle 20 is not restricted,
while maintaining the same assembly technique, allowing for easy
removal for cleaning, repair and replacement.
[0054] Designs for several types of ferrules (including
multi-fiber) can be derived from this base design relatively
easily. Multi-ferrule designs driven by the available space and
requirements are possible, such as MTP, MTRJ, DC, multiple 1.25 mm,
multiple 2.5 mm, etc. Additional strain relief may be added to the
receptacle 20 if needed. Crimping solutions may differ depending on
the drop cable type and requirements. If the drop cable does not
include the dual GRP dielectric strength members as shown in the
first embodiment, the methods of coupling the strength member to
the plug body may include glue or other means of fastening, such as
clamps or cable ties.
[0055] The embodiments described above provide advantages over
conventional fiber optic receptacle and plug assemblies. For
example, the low form factor of the embodiments described above
allows for their use in about a 38 mm diameter package for FTTx
distribution cables and permits their use in enclosures requiring a
very low receptacle penetration depth. One example of a low
penetration depth application is described in co-pending U.S.
patent application Ser. No. 10/855,179, filed May 27, 2004,
entitled DISTRIBUTION CABLE HAVING ARTICULATED OPTICAL CONNECTOR
NODES and assigned to the assignee of the present invention. The
direct key alignment of these fiber optic receptacle and plug
assemblies also makes them fully compatible with APC type ferrules,
and the unique fit prevents assembly errors during production and
installation. By locating the adapter sleeve 74 within the plug 22
as opposed to the receptacle 20 in the exemplary embodiments shown
and described herein, the receptacle volume and overall diameter is
reduced and the receptacle ferrule(s) may be readily accessed for
cleaning, repair or replacement. The overmolded boot eliminates the
need for heat shrinkable tubing and also improves the assembly's
integrity under adverse environmental conditions in which a
preformed boot may disengage.
[0056] The foregoing is a description of various embodiments of the
invention that are given here by way of example only. Although
fiber optic receptacle and plug assemblies have been described with
reference to preferred embodiments and examples thereof, other
embodiments and examples may perform similar functions and/or
achieve similar results. All such equivalent embodiments and
examples are within the spirit and scope of the present invention
and are intended to be covered by the appended claims.
* * * * *