Note: Descriptions are shown in the official language in which they were submitted.
~3~7~
FIBEF~ OPTIC COI~M TOR_O~L~
AND ~IETE:OD OF l~rl~UF~CTURING FI:i3ER OPTI(:: COl`J~ECTOl~S
_
TE~H~ICAL FIELD
The present invention rel~tes to fiber
optic connectors and, more particularly, to a
fiber optic connector for optically interconnecting
two high density sets of optical fibers and a
method of manuf~cturing fiber optic connectors.
BACKGROUND OF THE PRIO~ ~T
In recent years, fiber optic communi-
cation lines made up of parallel optically-
conductive fibers arxanged to form a flexible cable
for conveying li~ht ~rom one location to ano~her
lS have come into lncreasing use. The applications
have varied, althouyh one particularly significant
applica~ion has been conveying data from one loca-
tion to another by modulatîng a light source with
data to be transmitted at one end o$` the cable
and recoverin~ the data at the other end of the
cable with a photo sensitive detector. Since the
data is conveyed by a medium not subject to radio
~requency intererence or detection, fiber optic
commun~cation lines are particularly well adapted
for applications reauiring a high de~ree of
security li~e those found in the data processing
~ield~ ;
r~ith the increasing use of fiber optic~
communication lines, the need has developed for
connectors capa~le o joining segments o~ cables
with minimum detriment to the optical transmission
path. It has been found that precise axial and
angular alignment between a pair of fiber optic
cables can be achieved by terminating the optical
fibers of the cables in connector pin assemblies
in such a way that the optical fibers are con-
centrically ali~ned with respect to the outer
dimension of the connector pins. r~en a pair of
connector pins are concentxically aligned, the
~0 ultimate result is that the optical fibers will
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likewise be angularly and axially aligned for
efficient light 'cx~nsferO
Ti~hile tha connector art has been
developing-, the primary focus has been upon connec-
tors :Eor a small number of channelsO iiore recently,
there has been a srowing interest in and recogni-
tion of the need for, cleveloping a suitable fiber
optic connector for optically interconnecting two
high density sets of optical fibers, particularly
~or sinc;le fiber cables. Understandably, this
inte.rest has developed out of ~n appreciation for
the fac-t that the extremely high c~pacities assoc-
iatefl ~ith fiber optic cables can be expanded
dramatically by using high density sets or array~
of optic~l fibersO ~Iore particularly, there has
been ~n increasing awareness of the clesirability
of clevelopin~ ~ fiber optic connactox th~t will
expand c2pacity by sever~l or~ers of m~ynitude.
~ddition~lly, fiber optic connectors should
exhibit low loss ~nd minimum crosst~lk character-
istics.
~lthough the advantages o a fiber optic
connector fox high density ~pplic~tions have been
~pp.reciate~, the c~esirabililty an~ neefl has rem~ined
~or ~ pr~ctic~l embodiment~ It h~s not previously
been known or sugge~ted how to achieve the yoa~ of
a fiber optic connector for optic~lly inter-
connecting two high density sets of optical fibers
with low loss and crosstalk characteristics~
Accordingly, a practical fiber optic connector for
high density applications h~s never before been
a.v~ilable even ~hough desirability ~nd need therefor
have long been Xnown and appreciatedO
~RIEF SU~ RY OE T~E I~VEMTIOM
Accorclingly, the present invention, in
its broadest sense, is clirected to a fiber optic
connec~or for high density applications and a method
of manufacturing such ~ fibex optic connector. The
connector includes a p~ir of connector members e~ch
~3~?~4
~,
having a mating end and means associated with the mating
end for terminating one high density set of the optical
fibers; the terminating means each including a rela-
tively thin alignment plate having a plurality of opti-
5 cal Eiber receiving holes disposed in a predetermined :~ :
pattern for receiving individual ones of the optical
fibers and a back plate secured to the alignment plate :
to- provide support therefor, the back plate having an
enlarged opening of a size at least coextensive with the
10 entire pattern of optical fiber receiving holes, the : :
optical fibers all passing through the enlarged opening
to the alignment plate; and means for securing the con~
nector members together with the mating ends thereof
adjacent so that the optical fibers of the two high
density sets are in optical alignment.
Also in accordance with this invention, there is
provided a method of manufacturing a fiber optic connec-
tor for optically interconnecting two high density sets
of optical fibers, comprising the steps of providing a
pair of connector members each having a mating end; pro-
viding a thin alignment plate with a plurality of opti-
cal fiber receiving holes disposed in a predetermined ;~
pattern for receiving individual ones of the optical .:~
fibers; providing a backplate secured to the alignment
25 plate to provide support therefor with the backplate ;:~:
having an enlarged opening of a size at least coexten-
sive with the entire pattern of optical fiber receiving
holes in the alignment plate; securing the alignment and
backplates in the mating end of at least one of the
3Q connector members; and securing one high density set of
optical fibers in the enlarged opening of the backplatè
and the optical fibers of the one high density set in
the optical fiber receiving holes in the alignment
plate.
More specifically, the connector members preferably
each include a connector shell having an opening sized
and shaped to accommodate one high density set of opti~
cal fibers extending completely therethrough from the
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3~
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rear end to the forward, mating end. The connector
shells may each include means integral therewith for ~-
providing a sealed connector. The sealing means suit-
ably includes means associated with the rear ends and
means associated with the forward, mating ends when the
connector members are secured together. The terminating
means may each include surface means for disposing the
optical fibers of one high density set in a predeter-
mined pattern. The surface means suitably disposes the
optical fibers of the two high density sets in parallel
planes. Moreover, the surface means preferably each
include an alignment member having optical fiber receiv-
ing holes therein defining the predetermined pattern and - -
being at least sufficient in number to receive the opti-
cal fibers of one high density set.
In one embodiment, the connector preferably
includes means associated with at least one of the con~ `
nector members for biasing the terminating means of the
connector member forwardly therein. The connector mem-
ber then suitably includes stop means to limit Eorward
movement of the ~ ~
: '
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terminatin~ means caused by the biasing me~ns.
The biasing means is preferably a spring and the
stop means a retaining ring with the connector
member includiny a ring receiving ~roove for the
retainins ring forwardly of the termin~ting means
and a sprin~ supportin~ surface for the spring
rearwaxdly o the terminating means. The securing
me~ns suitably includes a Eirst coupling member
associated with one of the connector members and
a second coupling membex associated with the
other of the connector membersO The first coupling
memher is engageable with the second coupling
member to secuxe the connectox shells together.
Addi~ion~lly, the securincj means optionally includes~
means for limiting engagement of the fixst~co~pling
member with the second coupling member to control
saparation of the optical fibers of the two high
density sets.
Rdditionall features of this embodi-
ment include means for orienting the pair ofconnector members such that the optical fibers of
the kwo high density sets are in optic~l alignment
when th2 connector member~ ~re secured tagether
with the forward, matin~ ends thereof adjacent.
Als~, the orienting means m~y include 2t least
two pins associated with the termin~ting means of
one of the connector members and a corresponding
number of pin receiving openings associated with
the terminating means o~ the other of the connector
members~
In another embodiment, the fibes optic ;
connector is ~lso well suited for optically inter~
connecting two hi~h density sets of optica~l fibers.
The connector includes a pair of connector shells
each having a rear end and a forward, mating end~
and having an opening extending completely there-
throu~h from the rear end of the -forward, mating ;
end with the opening in each of the connector shells~
beln~ si~ed and shaped to accom date one high
.:
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~3~
--5~
density set of the optical fibers. It also
includes me~ns associated with the forward m~tincJ
end of each of the connector shells for terminating
one high density set of the optical fibers with
each of the terminating means including surface
means or disposing the optical fibers of one high
densi.ty set in a predetermined pa-ttern defined by
optical fibex receivinc~ holes in the surface means
at least suf*icient in number to receive t.he optical
fibers of one high density set. The connector al50
includes means associated with each of the connector
shells rearw~rclly o the surf~ce means for providing
stress relie~ for the optic~l fibers of one high
desnity set ~nd means for securing the connector
shells together with the forward, mating ends thereo~
adj~centO t.~.ith these features of construction,
the fiber optic connectox ~imilarly optically aliyns
the two hl~h density sets of optical ~ibers~
~dditional features oE this embodiment
include the connector shells each havin~ means
assoclate~ t~erewith for prc,vidincJ a sealed
connector~ The sealing means preferabl~ includes
ma~ns associate~ with the rear ènds and means
associate~ with the forward, mating ends when
the connector members are secured tocJether pre-
ferably in ~he form of a resilient 0-ring disposed
in a circumferentially extending groove in one o-E
the connector shellsO The terminatincJ means
prefer~bly each include ~n alignment plate com-
prisin~ the surface meens ~nd a backplate disposed
rearwarclly of the alicJnment plate to provide support :~
therefor. In addition, the alignment ~lates are
preferably secu.red to the backplates.
~/oxe particul~rly, the backplates pre- .
ferably each include an enlarged bore at least :~
coextensive with the corresponding ones o~ the
optical fiber receiving holes. The optical fibers
of one high density set then pass thxough the
enlarcjed bores of each o~ the backpl~tes to the
3~7~
-6
coxxesponding one of the aliynment plates where
they are secureclO The terminatiny means suitably
includes means for orienting the pair of connector
shells such that the optical fibers of the two high
density sets are in optical alignment when the
connector shells a.re secured together with the for-
ward, mating ends thereof adjacent with the orienting
means includiny at least two pins associated with
the terminating means of one of the connector sheIls
and a corresponding number of pin receiving openings
associated with the terminating means of the other
of the connector shellsO The pins are praferably
secured in pin receiving bores in the alignment ~ -
plate and backplate of one of the connector shells
lS and the aliclnment plate and backplate of the other
of the connector shells includes a corresponding
number of pin receiving openings. In one embodi-
ment, the pin reCeivincJ openings include an ~;
alignment hole and an alignment slot with the align-
ment hole and the alignment slot being adapted to
receive the pins Eor oriente!d and aligned inter-
engacJement of the connector shells.
Other details of this embodiment may
include 2 rigid insert in ~t least one connector ~-~
shell secured therein against rearward movement
with ~ circumferential groove ~efining a~spring
supporting surfaceO The spring supporting surface
is provic1ed to support a spring disposed between
the rigid insert and the backplate and biasing the
backpl~te forwardly within the connector shell
against a retaining riny disposed in a ring
receiving yroove in the connector shell. It will
be ~ppreciated tha~ the rigid insert is therefore
preferably spaced rearwardly of the backplate and,
also, the optical fibers are preferably free to
flex in the reyion between the backplate and the
rigid insertO The b~ckplate and alignment plate
preferably include a pair of pins coopera$ing with ~;
a pair of slots in the rigid insert to key the
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terminating means to the connector shell in a
manner permitting relative axial movement. Addi-
onally, the connector preferably includes spacer
means in the form of a planar sheet having an
opening therethrough at least coextensive with
the optical fiber receiving holes which cooperates
with the spri~ly to permit controlled separation
of the two high density sets of optic21 fibers,
the terminating means being located so as to be
in cont~ct with the spacer me~ns when the con
nector shells are secured to~etherD
0ther advantageous featltres may in-
clude a backplate support member disposed and
secured rearwardly of the backplate in each of
the connector shells. The terminating means may
each include a block having a front face defining
the surf~ce means and a rear face with boras
extending substantially through the blocks from
the rear face toward the front Eace and with the
blocks also each having precision ~ormed optical
fiber receivin~ holes in the front face in commu-
nication with the boresO The connector may also
include means for orienting the connector shells
in the form o a lip on on~ of the terminating
means and a lip receivin~ groove on the other of
the terminating means such that the optical fibers ;
of the two high density sets are in optical align~
ment when the lip is disposed in the lip receiving
grooveO The stress relief means may incl~e a
pottiny compound associated with e~ch of the con~
nector shells with an elastic compound preferably
bein~ located adjacent the rear ends thereof and
a rigid resin beiny locatecl forwaxd of the elastic
compoundD The securing means may include an ~ -
internally threaded coupling ring associated with
one of the connector shells and an externally
threaded surEace associate~ with the other of the
connector shells together with optional means for
limiting threading engagement of the internally
--8--
thxe~e~ couPling riny in the externally threadec3
surface to control sepaxation of the optical
fibers of the two high density sets. Finally,
the precletermined pattern may be defined by at
least one row o optical fiber receiviny holes,
xnd preferably a plurality of rows and columns
of optical fiber receiving holes, the surface
means each including a perforated metal alignment
pla~e having the rows and columns of optic~l
fiber receiving holes therein.
In the method of manufacturing a
fiber optic connector for optically intercon-
neckin~ two high density sets of optical fibers,
the steps are the following. First, a pair of
connector members each having a reax end and a
forward, mating end are provided. Second, a
terminating member for association with the for-
ward, mating end of e2ch of the connector member~
is provided. Third, optical fiber receiving
holes are placed in each of the terminating
members in a predetermined pattern. Fourth, one
of the terminating members is secured in the
forward, matiny end of each of the connector
members. Fifth, the optical fiber~s of one high
density set are secured in the optical fiber
receiving holes in each of the terminating membersO
Prefera~ly, the termin~ting members are metal and
the optical fib~r receiVinCJ hole~ are placed by
means of metal etching.
The present invention is therefore
directed in its broadest sanse to a fiber optic
connector for high density applications and a
method of manufacturing fiber optic connectors.
It includes features of construction well suited
for optic~lly interconnecting two high density
sets of optical ibers using a surprisingly
advantageous combination ~nd arrangement o
components which make it possible ~o increase the
capacity of prior fiber optic connectors by
'7~iL
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sevexal orders of magnitude~7 Other objects and
advantages of the present invention will be
appreciatecl from a consideration of ~he detail~
of construction and operation set forth in the
accornp~nying specification, c~aims and drawinys.
BRIEF 3~ESC3?~IPTIO~ OF THE DRAWIMGS
The features of the present invention
which ~re believed to be novel are set forth with
particulaxity in the appended claimsO The inven-
tion, to~ether w:ith the further objects and
advantayes thereo~, may best be understood b~
reference to the following description taken in
conjunction with the accompanying drawings. In
the drawin~s, like reference numer21s identify like
elements in the several figures in which: ~.
FIGURE 1 is c~ cross-sectional v1ew
illu~tratiny a Eiber optic connector fox optically
interconnectiny two high density sets of optical
fibers in accordance with the present invention
~0 FIGU~E lA is a cros~-sectional view
illustrating an alternative embodiment for a
connector member constructad in accordance with
the present invention;
FIGURE 2 is an enlaryed detailed view
of a portion of one of the connector members
illustrated in FIGU~E l;
FIGURE 3 is an enlarged detailed vieT~ :
of a portion of the other connector member
illus~rated in FIGURE l;
FIGURE 3~ is an enlarged detailed view
of a portion of the connector member illustrated
in FIGU~E lA
EIGU~E 4 is a front elevational view
o~ one form of aliynment pl?te;
I~IGURE 5 is a front elevational view
of another form o aliynment plate;
FIGURE 6 is a front elevational view
of one ~orm o~ backplate,
EIGU3:~E 7 is a front elevational view
--10_
of another form of backpl~te;
FIGURE 8 is a front elevational view
of an ~lternative embodiment of terminating means;
FIGU~E 9 is a cross-sectional view of
an ~ltexnative embodiment of terminating means
FIGU~E 10 is an enlarged detailed view
of a portion of the terminating means illustrated
in FIGU~E 9;
FIGU~E 11 is an enlarged detailed view
of a portion of the terminating means illustrated
in FIGURE 9,
FIGURE 12 is an enlarged detailed view
of an alternative embodiment for controlling
separation of termlnating means
FIGUR~ 13 is a front elevational view,
Partially in section, illustratins splice boxes
and u~ion splicing useful with fiber opt~c con-
nectox~ for optically int~rconnectin~ two hiyh
density sets o~ optical fibers in accordance with
the pre~ent invention;
~ IGURE la is a front elevational view
of ~n alignment pl~te usefu:L with a high density
a.rray of optical ~ibers; and
FIGUP~E 15 is a front elevational view
of ~nother alignment plate useful with a high
density arr~y of optical fibers. ;~
DETPILED DESCRIPTIO~ OF THE INVE~TIOM ;~ ;~
With reference first to FIGURE 1, the
numer~l 20 designates generally a fiber optic
connactor for optically interco~necting two high ;~
den~i~y sets o op~ical ibers in accoxdance
with pre~ent inventionD The connector 20 include~
a pair of connector members 22 and 24 having rear
ends 26 and 28 and forward, mating ends 30 and 32.
It also includes means 34 and 36, raspectively, ~:
associated with the forward, mating ends 30 and
32 of the connector members 22 and 24 or termin-
ating one high density set o optical fiber~ ~such) ~ ;
as 38 ~nd 40, .respectively) with the terminating
~3~
--11--
means 3~' and 36 includin~ means ~2 and ~ld for
~isposing the optical fibers o-E one high density
set (such as 3a and ~0) in a predetermined pattern~
The connector 20 further includes means 46 for
securing the connector members 22 and 24 together
with the forward, mating ends 30 and 32 thereof
adjacentO With these features of construction,
the connector 20 optically aligns the two high
density sets 38 and ~0 of optical fibers.
~eferring to FIGURES 2 ~nd 3, the con- ;
nector members 22 and 2~ inclu~e connector shells
48 and 50 having openings 52 ~nd 54 sized and
shaped to accommodate one high density set of the
optical fibers exten~ing completely therethrough
from the rear encls 26 an~ 28 to the forward, m~ting
ends 30 and 32. The connector shells 48 ~nd 50
each include means integral therewith for providin~
?, sealed connector includin~ means 56 and 5B
associ~ted rearw~rdly of the forward, mating ends
30 and 32 and means 60 assoc:iated with the orward,
mating ends 30 and 32 when 1:he connectox members
22 and 2~ are secured together. The terminating
me~ns 3~ and 36 each include surface means ~2 and
d4, respectively, for disposing the optioal fibers
of one high ~ensity set in a predetermined pattern
The surf~ce means 42 and ~4 each include an align~
ment member having optical fiber receiving holes
62 and 6~ (as shown in FIGUP~ES ~ and 5) at least ;
sufficient in number to receive the optical fibers
of one high density set. l~îoreover, the surface
means ox alignment members 42 and ~a preferably
dispose the optical fibers of the two high density
sets 3B and ~0, respectively, in parallel planes
and ~he predetermined pattern is defined by the
optical fi~er receiving holes 62 and 64, respectively,
in the alignment members 42 and a~.
Referring to E`IGURE 3, the connector
20 also preferably includes means 66 associated
with at least one of the connectox members 24 for
397~ :
_12-
biasing the terminating means 36 foxwardly thexein.
The connector member 24 then includes stop means
68 to limit forward movement of the terminating
means 36 caused by the biasing means 66 which is
preferably a spring with the stop means 68 preferably
being a retaining ring. r~Tith this construction,
the connector member 24 preferably includes a ring
receiving groove 70 for the retaininy riny 68
outwardly of the terminating means 36 and a spring
supporting surface 72 for the spring 66 rearwardly
of the terminating means 36~
It will be appreciated by referriny to
FIGU~E 1 that the securing means 46 preferably ~ ~
includes a first coupling member 7~ associated with ~ -
one of the connector members 22 and a second
coupling member 75 associated with the other of ;~
the connector members 24. The first coupling ~ ~;
member 74 i~ engageable with the second coupling
member 76 to secure the connector shells ~8 and
50 together. ~:loreover, the securing means 46
optionally advantageously includes means 80 for
limiting engagement of the first coupling member
74 with the second coupling member 76 and the
limiting means 80 thereby optionally comprises
means for controlling separ~Ltion of the optical
fibers of the two high density sets 38 and 40O
~ eferring again to FIGURES 2 and 3,
the connector members 22 and 24 pre~erably include
means 82 ~or orienting the pair of connector
members such that the optical fibers of the two
high density sets 38 and ~0 are in optical
alignment when the connector members are secured
together with the forward, mating ends 30 and 32
thereof adjacent. In a preerred embodiment, the
orienting means 82 includ~s at least two pins 8A~
associated with the terminating means 36 of one
of the connector members 24 and a corresponding
number of pin receiving openings 86 associated
with the terminating means 34 of the other of the
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connector members 22.
In a somewhat more specific sense, the
connector 20 includes means 88 and 90 associated
with the connector shells 48 and 50 rearwardly
of the surface means 42 and 44 or providing stre~s
relief for the optical fibers of one high density
set (such ~.5 38 ~nd 40). The stress relief means
88 and 90 preferably include a potting compound
~ssociated with each of the connector shells 48
and 50. ~ pottin~ compound suitably cooperates
with e~ch of the connector shells 48 and 50 and
preferably includes an elastic compound (such as
88~ ancl 90' associated with the rear ends 26 and
28, respectively, thereof and a rigid resin 88''
and 50'' forward of the elastic compound 88' and
90', respectivelyO The stress relie means 88
and g0 can also be utilized to secure the components
together in sealed relationship within the con-
nector members 22 and 24. As will be appreciated
from FIGIIR~ 1, the elastic compound 88' cooperates
with the rear end 26 of the connector member 22
and the elastic compound 90' coopexates with the
re~r end 28 of the connector member 2~ and, more
particularly, with the retaining nut 92 to captivate
the components within the connector members 22
~nd 24, respectively.
P~eferring still again to FIGURES 2 and
3, the texminating mean~ 34 and 36 include ali~n~
ment plates 42 and ~-~4 and back plates 94 and 96.
~ith alignment plates ~2 and 44 comprising the ;~
surface means and the back plates 94 and 96 being
disposed rearwardly of the alignment plates 42
alld 44 to provide support therefor. The back
plates 94 and 96 include enlarged openings 98
and 100 (see FIGURES 6 and 7) at least coexten-
sive with the corresponding ones of the optical
fiber receiving holes 62 and 64 illustrated in
EIGU?~ES 4 and 5, respectively. i~loreover, the
optic~l fibers of one hi~h density set ~such as
3~
--l~t
38 or ~.0) pass through the enlargecl opening 98
or 100 of the b?ck plate 94 or 96 to the
corresponding one of the alignment plates ~2
and 44, which are secured to the back plates 94
and g6 with the optical ~ibers, in turn, being
secured to the alignment plates.
As will be appreciated, the aliynment
plate ~.4 and back plate 96 of one of the connector
shells 50 include at least two pin receiving bores
102 with the pins 8~ being secured therein and
the alignment plate ~2 and back plate 94 of the
other of the connector shells ~.8 include 2
corresponding number of pin receiving openings 86.
Preferably, the pin receiving openings 86 include
an a:Lignment hole 86' and an alignment slot 86''
in the alignment plate ~'2 and back plate 94 of
the connector shell 48 with the allgnment hole 86'
and the alignment slot 86'' being adapted to receive
the pins 84 for oriented and aligned interengage-
~0 ment of the connector shells 48 and 50.
Reerring specifically to FIGURE 3,
the connector shell 50 can include therein a rigid
insert lO~i-. The rigid inse!rt 104 is preferr~bly
secured within the connector shell 50 against rer-
ward movement (as shown in FIGU~E 1). The rigid
insert 104 still ~urther prefer~bly has a circum-
ferential ~roove 106 defining the spring supporting
surface 72 (as shown in FIGURE 3)O The rigid
insert 10~ is further preferably spaced rearwardly
of the backplate 96 with the optical fibers ao
being free to flex in the region between the back-
plate 96 and the rigicl insert 104 (as shown in
FIG~.~ES 1 and 3)~ The rigicl insert 104 still
further prefera~ly includes a pair of slots 108
and 110 to cooperate with the pins 84 or keying
the terminating means 36 to the connector shell
50 in a manner permitting rel~tive axial movement
(as shown in l~IGURE 3). The rigid insert 104
also includes ?. circumferential groove 112
'7~
surrounding cpening 11~ for receiving a resilient
sealing grommet or 0-riny 580 l~ith the optical
fibers of each high density set 38 ~nd ~0 being
disposec3 in fiber optic cable 116 and 118 having
S outer jackets 120 and 122, respectively, the opening
11~1 in the rigid insert 104 is of sufficient dia-
meter along at least a portion of its length to
receive the outer jacket 122 of the fiber optic
cable 118 and the grommet or 0-ring 58 cooperates
with the outer jac]cet 122 of the fiber optic cable
118 to form a seal~
As best shown in FIGU~E 3, the connector
20 includes spacer means 124 associated with at
least one of the alignment plates d;40 The spacer
means 12~ cooperates with the biasing means or
spring 66 to permit cont~olled separation of the
two high clensity sets 38 and 40 oE optical fibers.
The terminating means 3~' c~nd 36 are preferably
located so ~s to be in cont:act with the spacer
means 12~ when the connector shells ~8 and 50
are secured tocJether. The spacer means 124 in-
cludes a planar sheet securecl to one of the
alignment plates ~ and having an opening there-
through (not shown) at least coextensive with the
optical iber receiving holes tsuch as 64). In
the altern~tive, the pl~nar sheet 124 can be a
transparent film separator in which case no
opening is required in the area of the optical
fi~er receiving holes~
~e~exring to FIGU~E 2, the connector
20 can include means 128 for supporting at least
one of the backpl~tes 940 The supporting means
12~ is preferably a back plate support member
disposecl rearwarclly of the backplate 9d. lt will
be appreciated that the backplate support member
128 illustr~ted in FIGU~E 2 is a ~enerally cy---
lindrical member just aclapted to fit within the
opening 52 in the connector shell housing the
rigid resin 88''~ The back plate support member
t;i~
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128 prefer~bly includes a pair of diametrically
opposed holes 130 directly in line with ~ pair o~
diametrically opposed holes 132 in the connector
shell 48 with this construction, the backplate
support member 128 can be secured within the con-
nector shell a;8 by means of pins 13~.
R~ferring to FIGUP~ES lA and 3A, an
alternative embodiment to the connector member
24 of FIGURES 1 and 3 is fully illustrated. The
connector member 24' is entirely identical to the
connectox member 2~ with one important difference.
It will be ~ppreciated that the biasing means or
spring 66 of FIGURES 1 and 3 has been eliminated
in FIGURES lA and 3A in favor of a rigid con-
struction. The connector member 24' thereforeincludes a somewh~t different shaped rigid insert
104' in the alternative embodimentO ~iore par-
ticularly, the rigid insert 104' is disposed
between an internal shoulder 136' in the con-
nector shell 50' ~nd the back plate 96'.
As will be appreciated, the back plate96' ~nd the ri~id insert 10~' are maintained in
the connector shell 50' by means of the retaining
ring 68'~ The back pl~te 96' and the rigid
insert 10A' are sized and shaped so as to fit
snugly together .in the connector shell 50'
~gainst the intern~l shoulder 136'. It will be
appreciatecl in contrast that the back plate 96
and the rigid insert 104 of the embodiment
illustrated in FIGURES 1 and 3 ~re spaced with the
riyid insert 104 in abutment with the internal
shoulder 136 in the connector shell 50. The rigid
insert 10~' is in ~butment with the back plate 96'
to provide rigidity. ~ccordingly, the connector
member 2~' provides a distinct alternative to the
connector member 2~l employing the same basic
techniques for high density applications.
Other details of the embodiment o-f
FIGURES 1~'~ and 3A are generally the same as the
~3~7~
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embodiment of FIGU~S 1 and 3 with minor exceptions~
One exception is the shape of the ricJid insert 104'
which includes a major diameter opening 13B an~ a
minor diameter opening 140. The major diameter
opening and the minor diameter opening are filled
with rigid potting resin to secure the set of
o~tical fibers 40' for a substantial distance rear-
wardly of the back plate 96~. Another exception
is the location at which the outer jacket 122' is
trimmed from the set of optical fibers 40' rear-
wardly of the rigid insert 104'~ l~ith this
construct.ion, the fiber optic cable 118' is fully
secured within the rigid potting resin rather than
in the ri~id insert 104~o
Referriny ag-ain to FIGURES 2 and 3,
the enlarged openings 98 and 100 are shown fillad
with epoxy at 142 and la4. This secures the sets
of optical fibers 38 and 40 within the back plates
94 and 960 It will. be appreciated that the alter~
native shown in F'IGUP~ES 1~ and 3A al50 includes
an enl~rged opening 100' filled with epoxy at 14~s~
in the back pl~te 96'~ similarly to secure the
set of optical fibers '~O' w.ithin the back plate
96'. This provides support for the set of optical
fibers 40' at a point immediately rearward of the
align~ent member 4A I, of course, the epoxy at
142 and 1~ in FIGUP~ES 2 and 3 provide support
for the ~ets of optic~l fibers immediately rear~
wardly of the ali~nment members a2 and 4~.
Ps indicated, the sets of optic~l fibers
38 and 40 are secured within the back plates 94
and 96 with epoxy at 142 and 144~ This provides
support for the optical fibers within the en-
lar~ed bores 98 and 100 in the back plates 94
and 96 ~nd the epoxy provides stress relief for
th~ optical fibers. Moreover, the optical fibers
in each of the sets 38 and ~0 are secured to the
respective alignment members or plates 42 and d4
within the optical fiber receiving holes 62 and 64
7'~a
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by me~ns of epoxy.
Referring to FIGURES 8 through 10, an
alternative embodiment of terminating means is
illustrated~ The terminating means 146 and 1~-8
include blocks having front faces 150 and 152
defining the suxace means. The blocks 1~6 and
1~8 also include rear portions or faces 154 and
156 and have bores 158 and 160 extending sub-
stan~îally therethrough from the rear faces 154
and 155 towarcl the front faces 150 and 1520 The
blocks 146 and 1~8 further have precision-formed
optical fiber receiving holes 162 and 16~ (see
FIGU~E 10) in the front faces 150 and 152 in
communication with the bores 158 ancl 1600 i~ore-
over, the bores 158 and 160 may include large
diameter portions 158' and 160' and intermediate
diameter portions 158'' ancl 160'' leading very
nearly to the front faces 150 and 152 in which
the precision formed optical fiber receiving holes
162 ~nd 16~ are made.
~eferring to FIGURES 9 and 11, means
166 for orienting connector shells is illustrated.
The orienting means 166, which is ~n alternative
to the pins ~a and pin rec~iving openings 86
illustrated in FIGU~ES 2 and 3, can inclu~e a lip
168 on one of the termin~ting means 148 and a lip
receiving groove 170 on the other of the ~erminating
me2ns 1~6. r~ith this construction, the optical
fibers of the two hiyh density sets 38 ~nd 40 are
in optic~l alicJnment when the lip 168 is dispose3
in the lip receiving groove 170 and the lip 16a ~ :
~nd the lip receiving groove 170 can be dimensioned
so as to create a gap 172 between the terminating
means lar6 and 1~8 to control separation between
the optical fibers of the two high density sets
38 and -~=0.
l`eferring to FIGU~E 12, an alternative
means of controlling separation of the optical fibers
of two high density sets 38 and 40 is illustrated
~3~7g~
in enlarged detailO This may be substitutecl for
the lip 168 and lip receiving groove 170 arr~nge-
ment in FIGU~E 11. It simply includes utilizing
a t.ranspaxent film 174 ~etween the terminating
means 146 and 1~.8. This does not, however, provide
means for aligning the precision formecl optical
fiber receiving holes 162 and 164 in the front
faces 150 and 152 of the blocks 146 and 148. :
~ccordinyly, other means such as those previously
discussed could be utilized to accomplish this
objective.
~eferring once again -to FIGURE 1, the
securing means 46 preerably includes an inter-
n~lly threaded coupling ring 74 associated with
one of the connector shells ~8 and an externally
threaded surf~ce 76 associated with the other of
the connector shells 50. The internally threaded
coupling rin~ 74 is ~uitably threaclingly engage-
able with the externally threaded surface 760 It
will be appreciated that -the securing means ~6
may urther include means for limiting threaded
enga~ement o the internally threaded coupling
ring 74 and the externally threaded surface 76.
The limiting means 80 comprises means or con-
2S trolling separa~ion of the optic~l fibers o ~he
two high density sets 38 and ~0. More particu~
larly, the limiting means can optionally comprise
proper dimensioning oE the forward ends of the ~ ~
connector members 22 and 24 so that the surface : ;
176 of the connecto~ member 24 will engage the
surface 178 o~ the connector membex 22 to control
separation of the alignment members or plates
42 and 4~
F~eferring to FIGURE 13, the optical
fibers of each o~ the sets 38 and ~0 can suitably
be terminate~ in a splice box 180. The splice
box 1~0 includes openings 182 at each encl thereof
for receiving the optic21 fibers of a fiber optic
cableO It will also be ap~reciated that the : ~ ::
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splice box 180 includes tu~ulax extensions 184
throu~h which the optical fibers pass into the
splice box 180 for fusion splicing. The tubular
extensions 184 cooper~te wi-th crimp rings 185 to
crimp the outer jacket of the iber optic cable
so as to provide stxain relief. I~ith these
fe2tures of construction, the splice box makes
it possible to easily fusion splice optical fibers
in a fashion protecting the splice joint.
l~ore particularly, the splice box 180
permits factory termination of the most critical
components. It will be appreciated that the fiber
optic connector 20 can be fully assembled with
fiber optic cables 116 and 118 terminated in the
connector members 22 and 2~1. The splice boxes
180 can be applied to the ends of the fiber optic
cables 116 and 118 remote from the connector
members 22 and 2~1 to link the fiber optic cables
116 ancl 11~ to much longer runs of fiber optic
cable depending upon -the requirement of any
particular applicationO It will be appreciated
that this permits maximum quality control in the
hiyhly critical assembly and termination of high
clensity sets o optical fibers. ~ccordingly, the
splice box 180 adds a measure of versatility to
the fiber optic connectors of the present invention.
Referring to FIGURES 4 and 5, the pre- ;
determined pattern is defined by at least one row
of optical fiber receiving holes 62 and 64. The
invention is particularly advantageous, however,
for predetermined patterns defined by a plurality
of rows and columns of optical fiber receiving
holes 62 and 6~ as illustrated in F'IGURES 14 and
15 where eight rows and eight columns have been
illustrated purely for purposes of illustration
since the exact number of rows and columns may
be varied depending upon the needs of a particular
application~ Prefer~bly, the surface means a2
and 4~ include pexforated metal alignment pl~tes
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havincJ the rows an~ columns oE optical fiber
receivincJ holes thereinO
In the method of manufacturing a
fiber optic connector for optically interconnecting
two high density sets of optical ~ibers, the steps
o optical -fibers, the steps are -the following.
First, ~ pair of connector members each having a
rear encl and a forward, mating end are provided.
Second, a terminatinCJ member for association with
the forward~ mating end of e~ch of the connector
members is provided~ Third, optical Eiber re-
ceiving holes are placed in each of the termin-
a~ing members in a predetermined patternO Fourth,
one of the t~rminating members is secured in the
forward, mating encl of each o~ the connector
members~ Fifth, the optical fibers of one high
density set are secured in the optical fiber re-
ceiviny holes in each of the terminating members.
Preferably, the terminating members are metal and
the optical fiber receivincJ holes are placed by
means of metal etching.
I~ith the fiber optic connector Eor high
clensity applications of the present invention, it
is possible to provid~ a fi~ler p~cking density
capable of being expanded to hundreds of channels
within the internal configuration of standard
hardware fittingsO The loss at the connector
interface and the maximum cross-talk between
channels is extremely low. ~eans of splicin~ pig-
~ailed connector assemblies into the cable runsis avail~ble as is means of potting the fiber~ into
standard hardware fittincjs. The loss at the con-
nec-tor interface can be further reduced by optical
anti-reflection coatings of the factory terminated
3S interfacesO l?hile threadecl couplings have been
illustrated, it is, o~ course, fully contemplated
that other couplincJs such as bayonet lock hardware
can be utili~ed with this invention.
r~ith respect to the connector interface,
~3~
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the a:LicJnment members or plates are highly effective.
These plates are sultably very thin precision
st~inless steel with the fiber array holes, the
pin alignment holes and the slots being precisely
fabricatedO The connector members can suitably
be supplied with one meter lenyth pig-tails for
fusion splicing into a cable harness. By so doing,
E~ctory fabric~tion is ~ossible to locate the
most critical ~ssembly and inspection operations
at the location of maximum talent leaving only
the fusion splice operatioll for field personnel.
ith the alternative embodiment illustrated in
~IGVRES 8 through 12, the production of a mating
face c~n be accomplisheæ according to the following
stepsO First, a photolithocJraphic mask of a fiber
optic ?rray is prep~red. Second 2 plate of a basic
material (for ex2mple~ copper) is machined. Thircl,
the plate is drille~ with yuide holes in the back
of the plate vesy nearly to the front of the plate.
2Q Fourth, the front o~ the plate is then lapped to
a mirror Einish and the photolithographic mask is
usecl to deposit an absorptive material upon it.
Fifth, ~ l~ser drill is ocused upon the darkened
are~s o~ ~he absorptive material to burn through
~5 the remainder o-f the pl2te from the front surface
until the holes drilled from the front and rear
surf~ces are in communicationO t~hile it is expected
that the holes drillecl from the front surface and
from the rear surf~ce will not share mutual axes,
the misalignmen~ will not be gre~t enough to pre-
clude the fibers being inserted -from the rear to
be yuided through the front of the plateO
With the various concepts and techni-
ques set forth herein, a fiber optic connector for
high density ~pplications and 2 method o manu-
facturincJ fiber optic connectoxs are provided.
The present invention includes features of constr-
uction well suited for optically interconnecting
two hiyh density sets o~ optieal fibers usiny 2
~3~
;:
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surprisingly advantayeous combination and arranye-
ment of components and alternatives thereto which
make it possible to increase the capacity of prior ~ ~
fiber optic connectors by several orders of magni- ~-
5 tudeO Accordingly, it will be appreciated that
the yoal of providing a fiber optic connector for
high density 2pplications approaching the loss and
cross-talk characteristics which are essential
in fiber optics has been accomplished.
While in the foregoing specification
a detailed description of the inventive concepts
has been set forth for purposes of lllustration,
the details herein given may be varied by those
skilled in ~he art without departiny from the
spirit and scope of the invention set forth in
the appended claims. ~ ~ ;
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