Note: Descriptions are shown in the official language in which they were submitted.
` " ~;~6
The present invention is generally directed to a
fiber optic cable connector assembly and more particularly
to fiber optic cable connectors which, when mated, form an
assembly which accurately aligns and spaces the terminal
ends of one or more fiber optic pairs to couple the optical
fibers of the cables together for efficient light transfer.
The virtues and advantages of fiber optics in
today's technology are well known and therefore need not be
alluded to herein. With the ever increasing use of fiber
optics, the need for efficient and readily usable and service-
able fiber optic connector assemblies has arisen
Fiber optic connector assemblies for optically
coupling the terminal ends of fiber optic cable pairs to-
- gether must properly align and closely space the terminal
- ends of the optical fiber pairs to achieve efficient, low
cost, light trans~er between the cables. Moreover, while the
terminal ends are spaced closely apart, they must not be
allowed to touch. Any touching of the fiber ends could re-
sult in scratching of the finely polished terminal end sur-
faces and consequent decrease in light transfer efficiency.
Hence, the terminal ends of fiber optic cables must be
aligned and spaced to very exact tolerances, and even more
so~ when the cables are of the single fiber variety.
Whenever it is required that connector components
be fabricated to closely held tolerances, manufacturing costs
rise making the connectors exhorbitantly expensive. Such
has been the case with prior art connectors.
As with any type of connector interconnection,
field service may become necessary When field service is
required, it is advantageous, for obvious reasons, if the
interconnection can be easily disassembled without dest oying
any of the connector component parts or damaging the compon-
.
~33'~96
ent parts to the extent that they cannot be re-used, Fiber
optic connectors have generally included terminating pins
constructed from rigid material which receive the optic
fibers and support them in the connector, When service is
required, it is usually necessary to remove the terminal
pins, Unfortunately, the fiber optic connectors which have
: come heretofore have included mechanisms for accurately
positioning the terminating pins within the connectors which
impede the e~traction of the terminating pins, Hence, in
many cases, damage to the pins or other connector components
result during servicing.
It is therefore a general object of the present
invention to provide improved connectors for a fiber optic
connector assembly,
It is a more specific object of the present inven-
- tion to provide a fiber optic connector which includes im-
proved optical fiber terminal end alignment and spacing means
to achieve efficient light transfer,
. The invention provides a fiber optic connector
for use in a fiber optic connector assembly of the type
which includes alignment means and stop means for aligning
and closely spacing the forward ends of the optical fibers
. of at least one pair of fiber optic cables to thereby opti-
cally couple the fiber optic cables together for efficient
light transfer, The connector comprises a rigid terminating
; member having a longitudinal bore dimensioned for receiving
:~ the forward end of one of the cables and having an outer
engageable portion, a channel having an inner surface dimen-
sioned for receiving the rigid member and having an interen-
gageable portion, and retainer means disposed between the
channel inner sur~ace and the rigid member, The retainer
means includes a forward end portion communicating wit~ the
. -2-
1133Z96
rigid melllher outcr cng~gc.lble l)ortion alld a le.lr l~ortion
- communiccltillg with the channel inner surface el~gageable portiol3.The rear portion of the retainer means inclu~es integral sl)rin~
mealls for urging the rigid me]nber in the forw~rd axial directio
against the connector assembly stop means to cause the forward
end of the rigid me]nber to be in continuous enBagement with the
stop means.
The present invention also provides a fiber optic
connector for use in a fiber optic connector ~ssembly which
aligns and closely spaces the forward ends of the optical fibers
of at least one pair of fiber otpic cables to thereby optically
couple the fiber optic cables together for e~ficient light
transfer. The connector includes a rigid body having a channel
therethrough, an alignment sleeve within the channel having an
inner abutment means intermediate the ends of the sleeve and an
interlocking protrusion at the rear end of the sleeve and a
rigid terminating member within the sleeve having a longitudinal
bore dimensioned for receiving the forward end of one of the
r cables and having an outer surface indentation communicating
with the alignment sleeve locking protrusion for locking the
sleeve and the terminating member together. The terminating
member also includes a front end abutting the sleeve abutment
means for accurately and closely spacing the forward end of the
optical fiber of the fiber optic cable within the longitudinal
bore with the forward end of an optical fiber carried within
- the terminating member of a mating connector which also abuts
the abutment means.
The invention is particularly directed toward a
retainer member for retaining a terminating mcmber within a
fiber optic connector against rearward movement and urging tlle
terminating member forward within the fiber o~)tic connector.
The retainer member comprises a forward end portion having a
.~
il33Z96
plllrillity of tincs cooperatively enga~ing the tclilliniltillg
: member and a rearward end ~ortion having integral rcsi]icnt
means rearward of the tines cooperatively engaging the fiber
optic connector.
The features of the present invention which are
believed to be novel are set forth with particularity in the
appended claims. The invention, together with further objccts
and advantages thereof, may best be understood by
: -3a-
reference to the following description taken in connection
with the accompanying drawings, in the several figures of
which like reference numerals identify like elements, and in
which:
Figure 1 is a partial cross-sectional view with
portions cut away showing a fiber optic connector assembly
incorporating fiber optic connectors embodying ~he present
invention to an enlarged scale;
Figure 2 is a side plan view with a portion broken
away of a principal component of the fiber optic connector
of the present invention which embodies the present inven-
tion; and
. Figure 3 is a cross-sectional view of another
.~
principal component of the fiber optic connector of the
present invention which embodies the present invention,
Referring now to Figure 1, it shows a partial
cross-section of a con~ector assembly embodying the present
invention and more particularly shows in cross-section the
structure associated with optically coupling one pair of
fiber optic cables. In actual practice, the connector as-
sembly may include additional structure for optically coup-
ling a plurality of fiber optic cable pairs,
The connector assembly 10 of Figure 1 includes a
plug connector 11 and a receptacle connector 12. The plug
connector 11 comprises a generally cylindrical outer shell
13, a rigid body comprising a forward section 14 and a rear
section 15, a rear grommet 16, and a fact seal 19. The
plug connector 11 also includes a fiber optic cable termina-
` ting pin assembly 17 and a retainer 18 for the terminating
pin assembly 17.
The receptacle connector 12 includes an outercylindrical shell 20, a bayonet ring 21, and a rigid body
--4--
1133~
comprising a forward section 22 and a rearward section 23
The receptacle connector 12 also includes a fiber optic
cable terminating pin assembly 24 and an alignment sleeve 25.
Referring more particularly to the plug connector
11, the outer shell 13, which is formed from aluminum, for
example, includes at its rear end an external thread 30 to
accommodate accessory mounting structure or coupling devices
(not shown). The outer shell 13 has a forward extension 31
which extends beyond the face seal 19 of the connector in
the forurard direction and carries a plurality of bayonet
pins one of which is shown at 32.
In a similar manner, the receptacle connector 12
includes an external thread 33 at its rear end and a forward
extension 34 which includes a plurality of alignment flanges
35 which are received within alignment slots 36 of the for-
ward e~tension 31 of the outer plug connector shell 13. The
bayonet ring 21 is retained on the outer periphery of shell
20 by retention ring 37 and an annular ~lange 38 of shell 20.
Between retention ring 37 and annular flange 38 is a washer
39. As the plug and receptacle connectors mate and the bay-
onet ring 20 is rotated, its ramped surface 40 acts upon the
bayonet pin 32 to cause the two connectors to be pulled to-
gether into full mating relation.
Referring again to the plug connector 11, the
terminating pin assembly 17 comprises a rigid terminating
.1 '
member taking the form of a generally cylindrical pin having
a forward extension 50 of minor diameter and a rear portion
51 of major diameter. Portion 51 includes a circumferential
flange 52 forming a rearwardly facing shoulder portion 53
which may also be described as an outer engageable portion.
The terminating pin assembly 17 also includes a plurality o~
axial slots 54 which terminate in forward curved portions 55.
_5_
:
. .. .
~3æ
The entire terminating pin assembly 17 includes a longitudi-
nal bore 56 which is dimensioned for receiving the one or
more optical fibers 60 of the fiber optic cable 61 Fiber
optic cable 61 also includes an annular layer of protective
material 62, a plurality of coaxial strength members 63, and
- an outer sheath 64.
The one or more optical fibers 60 extend through
the longitudinal bore of the terminating pin assembly 17 in
the forward direction and terminate at the terminal end face
of the pin assembly at 57.
In terminating the fiber optic cable 61 with the
terminating pin assembly 17, the annular protective layer 62
is removed so that the one or more optical fibers 60 extend
through the longitudinal bore 5.6 of the terminating pin and
beyond the terminal end face 57 of the pin Thereafter a
suitable adhesive such as epoxy may be introduced into the
forward end of the pin to secure the optical fibers at the
pin forward end. Thereafter, the optical fibers are ground
and polished to a smooth surface within the plane of the
terminal end 57. Also, the strength members 63 are received
within the axial slot 54 and layed within the forward curved
portions 55 of the slots Thereafter, the strength members
63 are epoxied in the curved portions and a ring-shaped
retaining member such as a split ring ferrule 5~ is crimped
over the strength members in the curved portions 55 to
~ securely terminate the fiber optic cable 61 within the pin
assembly.
.. The grommet 16 includes an aperture 59 for each
:; fiber optic cable 61 and provides a t~ght moisture seal
,'! 30 therewith.
The rigid body portion 14 includes a first bore
17 dimensioned to accommodate the major diameter section 51
'
. ~ ~
~33296
of the terminating pin and a second bore 71 which is dimen-
sio~ed to allow the forward extension 50 of the pin to extend
therethrough, The rigid body portion 15 includes a first
bore 72 and a counterbore 73 forming a forwardly facing
shoulder 74 which may be described as an inner engageable
portion. Also, the bores 71, 70, 72 and 73 communicate wi,th
one another to form a channel for receiving the terminating
pin assembly 17.
The retainer 18 is of generally cylindrical con-
struction and is dimensioned to be received within the counter-
bore 73. The rear end 80 of the retainer is in abutment
against the forwardly facing shoulder 74 of counterbore 73
and includes at its forward end a plurality of axial slots
which form forwardly extending fingers 81 which are bent
towards the axis of the retainer and communicate with the
rearwardly facing shoulder 53 o~ flange 52 of the terminatiDg
pin assembly 17. The retainer 18 is shown in greater detail
-,,,.~
~, in Figure 2. As can be seen in Figure 2, the retainer in-
cludes the rearward portion 80 and the axial slots 82 with
the bent finger portions 81 which depend towards the axis
~' of the retainer in the forward direction. At the rearward
end of the retainer, the retainer also includes a plurality
",.
,; of slotted portions 83 which are axially and angularly
I ' spaced. In this preferred embodiment, the slots are angu~
` larly spaced by approximately 90. As can be seen, the
r~ slots extend into the retainer substantially normal to the
'~ axis of the retainer and thereby i~orm at the rearward end
of the retainer an integral spring means.
~, Referring again to Figure 1, it can be seen that
:
, 30 with the retainer coaxially disposed about the terminating
`,~r pin assembly 17 and communicating at its rearward end with
the forwardly facing shoulder 74 o~ counterbore 73 and
-7-
. ,
: ~ ,
communicating with the rearwardly facing shoulder 53 of
flange 52 of the terminating pin assembly 17, the retainer
retains the terminating pin assembly for rearward movement.
Also, the integral spring means formed by the slots 83
causes th~ retainer to urge the pin assembly 17 in the for-
ward direction so that the terminal end face 57 is in con-
- tinuous abutment with a spacer 90 carried by the mating
receptacle connector.
As can be seen from Figure 1, the retainer provides
the resilient urging of the pin assembly in the forward
direction without blocking the gap between the terminating
pin and the inner surface of the channel formed by the
bores 72 and 73. As a result, it is a simple manner to
extract the cable and terminating pin assembly by simply
introducing an appropriate tool which causes the tines or
fingers 81 to be displaced for releasing the flange 52.
Thereafter, the pin assembly can be easily removed. As a
result, the receptacle connector 11 is readily field service-
able, Inasmuch as there are no alignment components blocking
!~
access of the pin removal tool to the pin retaining mechan-
, isms, damage to any of the component parts of the connector
during removal of the pin assembly upon servicing is sub-
stantially precluded.
Referring now to the receptacle connector 12 of
Figure 1, the terminating pin assembly 24 is formed in the
; shape of a hollow cylindrical pin and includes a forwardly
extending minor diameter portio~ 100 and a rearward major
diameter portion 101. The major diameter portion 101 in-
cludes a circumferential flange 102 which has a rearwardly
facing shoulder portion 103. The rear rigid body portion
23 includes a bore 105 having depending fingers or tines
- 106 which communicate with the rearwardly facing shoulder
portion 103 o~ flange 102 for retaining the pin assembly 24
; within the connector,
The forward rigid body portion 22 includes a bore
110 which is dimensioned for receiving the alignment sleeve
25. The alignment sleeve 25 is shown in greater detail in
Figure 3. The alignment sleeve 25 is generally cylindrical
iD shape and is formed from a resilient material such as
Teflon* or a suitable plastic. It includes a rear bore 111
and a forward bore 112 which are separated by the peripheral
inner flange 90 which forms a spacer or stop means between
the bores. The rear bore 111 includes an inner circumferen-
tially V-shaped ridge 113 which coacts with a V-shaped cir-
,~ cumferential notch 107 of the forward pin extension 100 for
captivating the forward extension 100 within the rear bore
111. The flange 90 and the ridge 113 are so spaced apart
that when the pin extension 100 is received within the
bore 111 so that the notch 107 receives the ridge 113, the
forward terminal end face 108 of the pin assembly 24 is in
abutment with the rearwardly facing shoulder portion 91 of
flange 90.
- At its forward end, the alignment sleeve 25 in-
, cludes a plurality of axial slots 114 and a conical opening
;'`l
115, The conical opening 115 guides the mating forward end
50 of pin assembly 17 into the forward bore 112 and the
slots 114 provide resilient surface contact between the
bore and the pin to further secure the pin within the bore.
The terminal pin assembly 2~ includes along its
entire length a longitudinal bore which is dimensioned for
receiving the fiber optic cable which it terminates (not
shown), Its cable also includes one or more optical fibers
which are epoxied at the forward end of the pin assembly
- and ground and polished to a smooth surface at the terminal
*Trade Mark
~. ~33296
end face 108. Thus, when the plug and receptacle connectors
are joined in the fu]ly mated relation as shown in Figure 1,
the terminal end faces of the pins and thus the optical
fibers will be closely and accurately spaced apart by the
width dimension of the flange 90 to achieve efficient light
transfer Also, the bores 111 and 112 are dimensioned for
tightly receiving the forward ends of the pin assemblies
and are aligned relative to one another so that the terminal
ends of the pin assemblies will also be in aligned relation
for effecting efficient light transfer.
The plug and receptacle connectors comprising the
fiber optic connector assembly of the present invention
enables accurate alignment and close spacing of the forward
ends of the optical fibers which are optically coupled to-
gether to achieve efficient light transfer while at the same
time minimizing the number of component parts which must be
manufactured to a tight tolerance. Because the retainer 18
includes the integral spring means for urging the pin as-
sembly 17 in the forward direction so that its terminal end
face 57 is in abutment with flange 90 of alignment sleeve 25,
axial manufacturing tolerances are absorbed Also, the
alignment sleeve 25 may be so dimensioned as to float within
the bore 110 of rigid body portion 22 so that neither the
; bore 110 nor the outer dimension of sleeve 25 is critical.
~ The critical dimensions which must be tightly controlled are
.
only the dimensions of the bores 111 and 112 of the alignment
sleeve, which is a plastic or Teflon* part, and thus easily
manufacturable Even these dimensions are not extremely
v~
critical inasmuch as the alignment sleeve is constructed
from a resilient material.
As previously mentioned, the connector assembly
` of the present invention is readily field serviceable
.
-10-
*Trade Mark
'~` ` 1~33~6
inasmuch as there is no alignment structure blocking access
of a removal tool to the retaining fingers 81 which retain
~; the pin assembly 17 Similarly, there are no alignment
: components which block access of the removal tool to the
.` tines 106 which retain the pin assembly 24. As a result,
the fiber optic connector assembly of the present invention
may be readily field serviceable without consequent damage
` to its individual component parts.
While a particular embodiment of the invention
has been shown and described, modifications may be made,
and it is in$ended in the appended claims to cover all such
changes and modifications which fall within the true spirit
of the invention.
. ~0
