Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The invention is directed generally to connectors, and
more particularly to a connector for ~iber optic cable segments
which provides improved and more consistent coupling of light
between the segments ~;
In recent years fiber optic light transmission systems,
wherein a single optically-conductive fiber or a multiplicity of
parallel optically-conductive fibers are arranged to form a flex-
ible light-conductive cable bundle for conveying light from one
location to another, have come into increasing use, not only for
providing illumination, but also for conveying data from one location
to another. In the latter application a light source is modulated ;
with data to be transmitted at one end of the cable bundle, and
the data is recovered at the other end of the cable bundle by a
photo-sensitive detector. Since the data is conveyed by a medium
not subject to radio frequency interference or detection, such
light transmission systems are particularly well adapted for high
security applications, such as found in the data processing and
military communications fields
With the increasing use of fiber optic systems, the need
has developed for a connector for connecting segments of light-
conductive cable bundles with minimum detriment to the optical
transmission path. Prior art connectors for this purpose have not
been completely satisfactory, particularly where frequent connects
and disconnects must be made under adverse environmental conditions,
or where multiple fiber optic circuits must be connected in a
single connector because of the difficulty of maintaining an ac-
curate consistent alingment between the ends of coupled cable
segments under such conditions. The present invention is directed
to a connector which provides more accurate and consistent align- .
ment of the terminal ends of fiber optic cable bundle segments
under these conditions.
Accordingly, it is a general object of the present inven-
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tion to provide a new and improved connector for light-conductive
cable bundle segments,
It is another object of the present invention to provide
a connector for light-conductive cable bundle segments which
achieves improved and more consistent alignment between the ends
of such segments.
It is another object o~ the present invention to provide
a new and improved connector for connecting multiple pairs of
light-conductive cable bundle segments with improved efficiency
and consistency,
It is another object of the present invention to provide
a connector for light-conductive cable bundle segments which
achieves positive registration of corresponding segments to be
connected.
The invention is directed to a connector assembly for
joining the terminal ends of first and second segments of light-
conductive cable bundles, The connector assembly comprises a
receptacle including a shell having a forward mating end, and a
first recess extending rearwardly from the mating end, First
terminal support means including a first insert member are disposed
within the first recess for positioning the terminal end of one of
the cable bundle segments in a forwardly facing position, A plug
including a shell having a forward mating end, and a second
recess extending rearwardly from the mating end, is provided to-
gether with second terminal support means including a second in-
sert member disposed within the second recess for positioning the
termianl end of the other of the cable bundle segments in a for-
wardly facing position axially adjacent the terminal end of the first
cable bundle segment, The terminal ends of the cable segments
are maintained in axial, transverse and angular alignment to a
high degree by alingment means extending between the first and
second insert members,
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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 objects and advantages --
thereof, may best be understood by reference to the following des-
cription taken in conjunction with the accompanying drawings, in
the several figures of which like reference numerals identify like
elements, and in which:
Figure 1 is a perspective view of a connector constructed
in accordance with the inventlon in an unmated condition;
Figure 2 is a cross-sectional view of the plug portion
of the connector taken along line 2-2 of Figure l;
Figure 3 is a cross-sectional view of the receptacle
portion of the connector taken along line 3-3 of Figure l;
Figure 4 is a perspective view, partially broken away,
of a fiber optic termination pin utilized in the connector for
terminating the ends of light-conductive cable bundle segments;
Figure 5a is an enlarged side elevational view, partially
in cross-section, of the connector in an unmated condition;
Figure 5b is an enlarged side elevational view, partially
in cross-section, of the connector in a mated condition;
Figure 6 is a perspective view of the termination pin of
Figure 4 shown in conjunction with a pin removal tool;
Figure 7 is an enlarged cross-sectional view of a por-
tion of the connector illustrating the use of the pin removal tool
for removing a termination pin from the connector;
Figure 8 is a perspective view of an alternate embodiment
of the connector of the invention;
Figure 9 is a cross-sectional view of the receptacle
portion of the connector taken along line 9-9 of Figure 8;
Figure 10 is a cross-sectional view of the plug portion
of the connector taken along line 10-10 of Figure 8; and
Figure 11 is a side elevational view, partially broken
away, of the connector of Figure 8 in a mated state,
Referring to the figures, and particularly to Figures
1-3, a connector 10 is constructed in accordance with the inven-
tion includes a flange-mounted receptacle 11, and a cable-mounted
plug 12. Receptacle 11 could also of course be bulkhead-mounted
or cable-mounted as well without departing from the invention.
The receptacle includes a generally sleeve-shaped metal shell 13
having a front or mating end for receiving plug 12, and a flange
14 rearwardly of the mating end for mounting the receptacle to a
wall or bulkhead (not shown). Individual segments of light-conduc-
tive ~iber bundle cable 15 for which inter-Gonnections are to be
established by the connector enter the receptacle from the rear.
A plug-receiving recess 16 extends rearwardly from the forward end
of the receptacle. An insert assembly 17 positioned within shell -
13 supports the projecting ends of four female fiber optic alignment
sleeves 18 forming connecting assemblies associated with respective
ones of light-conductive fiber bundle cable segments 15.
Plug 12 includes a genera~ly sleeve-shaped elongated
cylindrical shell having a front or mating end, and a recess 20
extending rearwardly from the front end of the plug for receiving
in ~elescoping relationship the forward end of the receptacle
shell 13. Fiber optic cable segments 21 to which interconnections
are to be provided extend into the rear of the connector. A
generally cylindrical insert assembly 22 dimensioned for telescop-
ing insertion into recess 16 is disposed within recess 20, and
includes four axially-extending apertures 23 in which four female
fiber optic connecting assemblies 24 (Figure 3) are positioned.
A locking ring 25 of conventional construction is concentrically
disposed over shell 19 to provide twist-lock engagement with pro-
tuberances 26 on shell 13 when the plug and receptacle are mated,in a manner well known to the art. A plurality of locating keys
27 on the side wall of insert assembly 22 coact with keyways 28
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provided on the inside wall of recess 16 to assure correct orien-
tatlon betweeD the two insert assemblies. -
Referring to Figures 4, 5a and 5, fiber optic cables 15
and 21 may be entirely conventional in design and construction,
having an outer jacket 30 and an inner light-conducting core of
a single fiber or plural fibers generally designated 31. The iiber
core can be constructed either of glass or a suitable plastic -~
material, such as that marketed under the trade name Crofon* by the
DuPont Company. In the later instance each fiber in the core 31
may consist of a central strand of polymethyl methacrylate sheathed
with a transparent polymer of lower refractive index. The outer
jacket 30 can be formed Yrom a polyethylene resin marketed under
the trade name Alathon* by the DuPont Company.
Referring to Figure 4, the ends of each of the light-
conductive cable segments 15 and 21 are individually terminated
by means of terminating piDS 32. Each of these pins comprises a
hollow generally cylindrical metal housing 33 having an axially
extending bore 34 within which the fiber core 31 of the cable is
disposed, A layer of adhesive such as epoxy 35 between the fiber
core and the wall of the aperture holds the core firmly in place.
The end of the fiber core extends along the bore 34 of
the terminating pin and is cut substantially flush with the open
end of the termination to provide a flat optical coupling surface
36.
The housing 33 of terminating pin 32 includes a front
portion of reduced diameter, and a rear portion of increased di-
ameter, and an annular flange 37 between these two portions Bore
34 has a corresponding front portion of reduced diameter and a
corresponding rear portion of increased diameter joined by a traD-
sition of convenient angle or taper, the jacket 30 of the fiberoptic cable abutting the tapered shoulder formed between these two
portions.
*Trade Mark
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V~31~
Referring to Figures 5a and 5b, the insert aQsembly 17
within receptacle shell 13 is seen to consist of a disc-shaped
face sealing member 40, a peripheral seal 40a, a cylindrical pin
insert member 41, pin retention disc 42, and a rear grommet 43,
which are preferably constructed of high temperature elastomeric
materials such as, for example, plastic and rubber, The face seal-
ing member 40 includes four apertures 44 which are aligned with
four apertures 45 in insert member 41, and with four apertures
46 in retention disc 42, and with four ribbed apertures 47 in ~-
grommet 43, to provide four continuous axially-extending bore-like
passageways for receiving the terminal piDS associated with respec-
tive ones of the four light-conducting cable segments 14.
The insert assembly 22 within the shell 19 of plug 12
is seen to include a cylindrical insert member 50, a retention disc :~
5~, and a grommet 52 (Figure 5b). The insert member 50 includes
an aperture 53 which is aligned with an aperture 54 in retention
disc 51, and with an aperture 55 in grommet 52 to form a continuous ~
axially-extending passageway for receiving the terminal pins asso- ~ -
ciated with respective ones of the four light-conducting cable
segments 21.
In accordance with the invention, accurate alignment
between the terminal pins associated with respective fiber optic
cables 15 and the terminal pins associated with corresponding ones
of fiber optic cables 21 is maintained by means of sleeves 60
positioned within the passageways formed in insert assembly 17,
The alignment sleeves, which may be formed from metal or similar
rigid material, are snugly received within these apertures.
The sleeves are resiliently held in place during inser-
tion or removal of plug 12 by means of annular flanges 61 on the
outside surfaces of the sleeves. Referring specifically to Figure
5a, the sleeve is allowed some resilient axial movement upon mating
by virtue of the flange 61 being captured in recess 62 formed in
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the elastomeric material of ~ace seal member 40. Thus, when
terminal cable ends are brought together, tines 63 push against
the rear of ring 37, the front of ring 37 bears tightly agaiDst
the end of the sleeve, and the sleeve axially moves within recess
45 achieving equilibrium between similar forces associated with
the other half of the mated connector pair.
The slight axial movement permits optimal alignment of
both terminating ends on a per channel basis, always maintaining
the proper axial separation between faces 36. This movement also
allows tiDes 63 to be freely separated from ring 37 in the unmated
condition, permitting unhindered removal of the terminating end
32 with the tool 70 of Figure 6.
The terminal pin 32 installed on the end of each of the
four fiber optic cables 15 is inserted into its respective sleeve
60 irom the rear, the annular flange 37 thereon abutting the rear
edge of the sleeve. The inside dimensions of sleeve 60 are such ~ -
that the terminating pin assembly 32 is snugly received therein
and maintained in accurate alignment with respect thereto. A pair
of tines 63 inwardly projecting from the wall of aperture 46 bear
against the rearwardly-facing surface of the annular flanges to
lock the terminating pin in position and foreclose axial movement
thereof.
In plug 12 the terminating pin 32 of each fiber optic
cable 21 is received in respective apertures 53 and 54 and locked
in place by means of tines 64 which project inwardly from the walls
of recess 54 against the rearwardly facing surface of the termin-
ating pin annular flange 37. The front of the annular flange bears
against a shoulder formed on the rear surface of insert member 50,
thereby preventing the termination pin assembly from being pulled
out during mating or unmating of the connector. Since no align-
ment sleeve is present in plug 12 the terminal pin assemblies
associated with fiber optic cables 21 are not rigidly held in place,
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but rather are free to move axially and laterally to a limited
extent.
When receptacle 11 and plug 12 are mated, as shown iD
Figure 5b, insert assembly 22 telescopes into recess 16 as the -~
shell 19 of plug 12 telescopes into the end of receptacle shell 13.
This causes the four alignment sleeves 60 associated with receptacle
11 to extend into respective ones of the apertures 53 of insert
assembly 22, in which the termination pin assemblies 32 associated
with fiber optic cables 21 are disposed. As a result, the reduced
10 diameter portions of the terminal pins associated with cables 21 ~-
are received in respective ones of sleeves 60. The resilient
mounting of the termination pins in shell 19 facilitates this by
enabling the pins to readily align themselves with the approaching
sleeves. As the plug and receptacle become fully mated, the end
faces 36 of the two terminal pin assemblies come into close, paral- -
lel, but non-abutting relationship, for high efficiency light
transfer. Since the alignment sleeves 60 determine the positions
of the termination pins, misalignment of the coating light trans-
fer surfaces 36 is precluded.
In addition, when the connector is fully assembled as
shown in Figure 5b, the grommets 43 and 52, the face seal 40, and
the peripheral seal 40a are placed in a state of compression. As
a result, the connector is completely sealed from impurities or
contaminants that might be encountered in the environments where
the connector is to be used.
In accordance with another aspect of the invention, the
fiber optic terminal pin assemblies 32 associated with each fiber
optic cable are removable from their respective passageways by
inserting a small sleeve-shaped tool 70 into the passageways from
the rear. This tool, as shown in Figure 6, serves in the case of
receptacle 11 to compress tines 63 against the sidewalls of aper-
ture 46, or, in the case of plug 12 to compress tines 64 against
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the sidewall of aperture 54, with the result that the pin assem-
blies are released and can be removed rearwardly from the connector
members. This is a significant advantage since it enables indi-
vidual fiber optic pins to be removed, as when correcting instal- -
lation errors or replacing damaged connectors or components thereof.
An alternate arrangement for maintaining alignment between
terminal pins in a shell-type connector is shown in Figures 8-11.
In this embodiment a receptacle 80 is provided having an elongated
shell 81 defining a recess 82 within which an insert assembly 83
is disposed having four flush-mounted fiber optic termination piD
assemblies 32, The receptacle 80 is adapted to mate with a plug
84 having an elongated shell 85 defining a recess 86 within which
~our additional termination pin assemblies 32 are flush mounted.
The shell 85 of plug 84 is dimensioned to extend in telescoping
relationship over the plug-receiving portion of shell 81. Insert
assemblies B7 and 88 similar to those provided in receptacle 11 and
plug 12 are provided within receptacle 80 and plug 84 for holding
the fiber optic termination pin assemblies in position.
Since the terminating pin assemblies 32 are positioned
with their coupling surface 36 parallel to the exposed surfaces of
the insert assemblies, the coupling surfaces of corresponding
terminal pins are brought into close abutting relationship when
the connector is mated, as shown in Figure 11 To maintain the
accurate alignment required between coupling surfaces 36 for good
efficiency, the insert assembly of the receptacle includes five
axially extending alignment pins 90 which extend into respective
ones of five alignment sockets 91 provided in the surface of the
insert assembly 88 of plug 84. By dimensioning these elements for
a snug but non-binding engagement, the surfaces of the two insert
assemblies are maintained in accurate alignment at all times
during their engagement, irrespective of movement of either in-
sert with respect to its shell
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It will be appreciated that while the invention has
been shown in con~unction with connectors having round shells and
four interconnections, it is also possible to practice the inven-
tlon in connection with a greater or lesser number of interconnec-
tions, and with shells having other shapes and sizes, including
rectangular and square cross-sections.
While particular embodiments of the invention have been
shown and described, it will be obvious to those skilled in the
art that changes and modifications may be made without departing
irom the invention in its broader aspects, and, therefore, the
aim in the appended claims is to cover all such changes and modi-
fications as fall within the true spirit and scope of the invention.
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