Note: Descriptions are shown in the official language in which they were submitted.
~S8~
The invention relates to releasable connectors and is
especially applicable to hermaphroditic connec-tors for connecting
optical fibers~
Whether the connector is for optical fibers or
electrical conductors, or other filaments, it is importan-t that dirt
or other foreign matter be kept from the mating surfaces since it can
increase attenuation and prevent complete mating.
In order to prevent the ingress of dirt, it is usual to
provide a cap which fits over the end surface of the connector when
the latter is not in use. The cap itself must be kept clean when it
is not in use. It has been proposed to have the caps of the mating
connectors secured by chains to their respective connectors and fitted
together after the connectors themselves have been connected
together. This is not entirely satisfactory since, in the field,
operators sometimes forget to connect the caps together. Also, the
chain sometimes snags when the cable is being drawn through cavities
or undergrowth. Sometimes the chain breaks and the cap gets lost,
with the consequence that the connector itself then gets dirty.
The present invention seeks to overcome these problems.
According to the present invention, a hermaphroditic
connector for optical fibers, electrical conductors and the like
comprises:-
a body having an end face formed for mating
hermaphroditically with the corresponding end face oF another such
connector.
The end cap is hingedly attached to said body and
pivotal between a closed position, the hinge axis extending
~S;8~3
substantially parallel to a plane through a male/female pair of
hermaphroditic formations, in which it covers the end face of the
body, and an open position, the arrangement being such that, when two
such connectors are mated hermaphroditically, their respective end
5 CdpS will cooperate with each other to prevent ingress of
contamination therebetween. Preferably the end cap is spring-urged
into the closed position.
Embodiments of the invention will now be described by
way of example only, and with reference to the accompanying drawings,
10 in which:-
Figure 1 is a sectional plan view of a connector;
Figure 2 is a side view of the connector;
Figure 3 is a perspective view of the connector;
Figure 4 is an exploded detail view;
Figure 5 shows two connectors fastened together;
Figure 6 is a perspective view of a bulkhead-mountable
connector in the open condition;
Figure 7 is a cross~sectional side view of the
connector of Figure 6;
Figure 8 is a side view of a bulkhead connector with a
plug connector attached;
Figure 9 is a side view of a second plug connector
embodying the invention;
Figure 10 is a part-sectional plan view of the second
plug connector;
Figure 11 is an end view of the end of the second
connector body, with its end cap in the open position;
Figure 12 is a part-sectional detail view of the end of
~ L258~ 3
the connector w;th the end cap closed;
Figure 13 is a part-sectional view of two connectors
connected together;
Figure 14 is a sectional view on the line AA of Figure
12;
Figure 15 is a part-sectional side view of a se~ond
bulkhead connector embodying the invent;on;
Figure 16 is a perspective view of the bulkhead
connector of Figure 15, with its end cap open;
Figure 17 is a perspective view of a modification of
the first connector;
Figure 18 is a partial side view of the modified
connector; and
Figure 19 is a modified plan view of the modified
connector.
Referring to Figures 1, 2 and 3, a hermaphroditic
connector, for connecting two optical fibers to a similar connector,
comprises a generally flat, elongate plug body 10. A cylindrical,
externally-screwthreaded boss 11 protrudes from one end of the plug
body 10.
An optical fiber cable 12 passes through the boss 11
and is secured thereto by a pair of nesting collets 13 and 14,
respectively, a conical washer 15 and a hollow nut 16 (see Figure 4).
The leading collet 13, i.e. that adjacent the plug body 10, is tapered
internally to receive the other collet 14 which is tapered externally
at the same angle. The narrow end of collet 14 is radiussed and its
bore is stepped to provide a narrow bore adjacent its narrow end and a
~25~19t`~
wider bore adjacent its wider end. The plastic sleeve of the cable 12
fits into the wider bore of collet 14 and butts up against the step~
The Kevlar (trademark) reinforcing or supporting strands 17 (see
Figure 4) extend through the narrow bore and are folded back and
trapped between the mating surfaces of the two collets 13 and 14.
The conical washer 15 is conical on both sides and fits
between a corresponding recess in the end of collet 14 and a similar
recess in the end of cylindrical nut 16. The conical washer 15 is of
synthetic plastics material and, as the nut 16 is tightened, washer 15
not only forces the collets 13 and 14 together, but also distorts to
clamp the cable sleeve.
A gland nut 18 fits over the end of boss 11 and clamps
a sealant body 19 (conveniently applied in strip form) against nut 18
to seal the cable sleeve to the plug body. A protective sleeve or
boot 20 surrounds the gland nut and extends along the cable to limit
flexing.
Within the plug body 10, adjacent the boss 11, is a
cylindrical chamber 21. The two optical fibers 22 and 24,
respectively, pass into the chamber 21 through the boss 11 and a hole
20 26 communicating between the boss 11 and the chamber 21. The chamber
21 is sealed by a cover plate 23 held in place by a screw 25 (see
Figure 2).
In the chamber 21, the fibers are coiled several times
and emerge tangentially, one at each side of the plug body 10. The
fibers 22 and 24 pass, in channels 28 and 30, respectively, either
side of an aperture 32, which extends through the plug body 10 between
its major surfaces.
~L~S 8 1 9~3
The ends of the fibers 22 and 24 are terminated in
ferrules 34 and 36, respectively, which protrude longitudinally from
the plug body 10. The ferrules 34 and 36 are retained relative to the
plug body 10 by a retainer plate 38 which is secured by screws to the
base of a recess 40 in the end of the plug body 10. Split sleeves 39
and 41 fit around the ferrules 34 and 36, respectively. The sleeves
are fitted sideways to locate internally of a central shoulder on the
ferrule. Coil springs 42 and 44, respectively, housed in
corresponding recesses 46 and 48, urge the split sleeves 34 and 41,
and hence the ferrules 34 and 36, respectively, towards the retainer
plate 38.
The outer ends of the Ferrules 34 and 36 extend through
an interface block 45 housed in the recess 40. The interface block 45
is hermaphroditically-formed, in that it has a boss 50 as the male
member and a complementary recess 52 as the female member. Boss 50
and recess 52 are equidistant from the longitudinal centre line of the
plug body 10. The ends of ferrules 34 and 36 extend into recess 52
and boss 50, respectively. In the boss 50, the ferrule 36 is located
by an alignment sleeve 54. As is usual with hermaphroditic
connectors, the interface member or block 45 is intended to mate with
an identical interface block of another connector.
An end cap 60 is attached to the mating end of plug
body 10 by a hinge 62 (see Figure 2). The hinge axis of hinge 62
extends along the width of the plug body 10. As shown in Figure 3,
the end cap 60 has a recess 64 to accommodate the male member or boss
50 and a screwthreaded hole 66 at a position corresponding to the
centre line of the plug body 10. A seal 70, in a groove 72, extends
~251~193
around the perimeter of the end cap mating surface and, when the end
cap 60 is closed, cooperates with a corresponding seal 74 in a groove
76 in the end face of the plug body 10 (as shown in Figure 3). The
seals 70 and 74 prevent the ingress of dirt or moisture onto the
opposed faces of the end cap 60 and plug body 10.
The end cap is locked or retained in the closed
position by a locking screw 80 which has a knurled thumb wheel 81 at
one end located in central aperture 32, and a shank 82 extending
longitudinally through a hole 83 in the plug body 10 to emerge from
the end face of interface member 45. The end of the shank 82 is
screwthreaded to fit the hole 66 in the end cap 60.
The end cap 60 can be opened very conveniently by
grasping the plug body 10 in the palm of the hand and using the thumb
to pivot the end cap 60. Full rotation to the position shown in
Figure 3 is facilitated by concave formation, as at 84, of the surface
of the end cap remote from the plug body 10.
To fasten two such connectors together, the screw 80 of
one only of the connectors is unscrewed as far as possible, so that
its screwthreaded end portion passes through a correspondingly
screwthreaded constriction 86 in the hole 83 through interface block
45. Each end cap is opened so that its end face is coplanar with the
end face of its plug body 10, as shown in Figure 3. The two
connectors are then brought together, as illustrated in Figure 5, so
that the plug bodies 10 mate and, at the same time, the two end caps
60 mate. Thus, the seals 74 (not shown in Figure S) in the plug
bodies will cooperate to stop ingress of dirt or moisture and the
seals 70 in the end caps will cooperate to keep the end caps 50 clean.
~;~58~3
The two plug bodies 10 are locked together by screwing
the locking screw 80 of one into the screwthreaded constriction 86
(see Figure 1) of the other, which had been previously vacated by
withdrawing its own locking screw, as described previously.
The connector can also be connected to a
bulkhead-mounted receptacle. Such a receptacle is illustrated in
Figure 6 (open) and Figure 7 (closed). The receptacle 100 comprises a
body part 102 corresponding to the end portion of the previously
described plug body 10. Thus, the receptacle has a male member in the
form of a boss 104, a female member in the form of a recess 106, a
peripheral seal 108 and a central, screwthreaded hole 110. The
receptacle has flanges 112 and 114, respectively, whereby it is shown
secured to a bulkhead 116 by screws 118. An end cap 120, similar to
the end cap 60, previously described, is attached to the receptacle
body by a hinge 122, and has a peripheral seal 124. The end cap
differs in that it has a central screw 130, which protrudes through
the end cap and has a thumbscrew 132 at its rear face (see Figure 7).
When the end cap 120 is closed~ the screw 130 is tightened, engaging
in the central screwthreaded hole 110 of the receptacle body 102.
When a plug connector is connected to the receptacle,
as illustrated in Figure 8, the screw 130 in the end cap is withdrawn
to prevent it impinging on the end cap 60 of the plug connector 10.
The connector plug 10 is connected to the receptacle in the manner
previously described for plug-to-plug connection and locked by
screwing locking screw 82 into screwthreaded hole 110 in the bulkhead
connector.
The plug connector illustrated in Figures 9 to 14 is
~2S13193
similar to that shown in Figures 1 to 3, but differs because it has a
pawl locking mechanism instead of a screw 80 to lock the plug
connector to its end cap or another connector. Since most parts of
the connector are similar to that previously described, corresponding
parts are identified by a reference number that is higher by two
hundred than that used previously.
Referring to Figures 9 to 149 the plug connector has a
flat, elongate plug body 210 connected to an optical fiber cable 212
via a sleeve 220. Inside the plug body 210 two optical fibers 222 and
224, respectively, are coiled in a chamber 221 and leave it
tangentially, each adjacent a different edge of the plug body. The
fibers 222 and 224 terminate in ferrules 234 and 236, respectively,
which are located in interface block 245. A hole 300, of elliptical
cross-section, extends through the interface block 245 and into the
plug body 210, extending almost all the way to the chamber 221. The
hole 300 accommodates a detent lever 302 which is of circular
cross-section and is secured, at its innermost end, by a pivot pin 304.
Adjacent its distal end, the lever 302 is undercut or
notched at one side to form a lip 306. At the opposite side, the
lever 302 has a transversely-extending recess 308 which houses a coil
spring 310. The coil spring 310 acts between the bottom of recess 308
and the opposed sidewall of hole 300 to urge the lever 302, in the
direction of lip 306, against the other sidewall of the hole 300. In
this opposite sidewall of hole 300 is a circular cross-section recess
314 housing a spring-loaded ball 316. The ball 316 projects sideways
into the hole 300 and outwards into a shallow recess 318 in the flat
surface of the plug body. A diaphragm 320 (Figure 9), extending
~2~ 33
across the recess 318, retains the ball 315 in the recess 314.
Depression of the diaphragm 320, and therewith the ball 316, against
the action of spring 322 (see Figure 14), displaces the lever 302
against the action of spring 310, to release the detent.
Figure 13 shows two plug connectors connected together.
Their end surfaces and end caps mate as previously described.
However, they are locked together by their respective detent levers
302, the lips 306 of which interengage. The end of each lever 302 has
an inclined surface 324 extending away from the lip 306 so that, when
two connectors are being brought together end-to-end, the levers will
be biased apart by the inclined surface 324 of one acting against the
inclined surface 324 of the other. The detent levers 302 can be
released by depressing their associated balls 316.
Figures 11 and 12 show the end cap of the detent
lever-type of connector. The cap is hermaphroditically adapted to
mate with the plug-connector end face, as before, but in this case
has a pawl 330 mounted in a recess 331 to engage the lip 306 on lever
302 when the cap is closed. The pawl 330 is of right-angled shape and
is pivotally mounted at its corner portion on a pivot pin 332. A
torsion spring 334, also mounted on the pivot pin 332, acts between
the base of recess 331 and a lug 332 on the pawl to bias the latter
into engagement with the lever 3G2 when the cap is closed. The end
cap is released by displacing the lever 302 by means of its associated
ball 316 (see Figure 9).
The detent lever-type of connector may be coupled to a
bulkhead connector which is illustrated in Figures 15 and 16. The
bulkhead connector 350 has a body part 352 with two flanges 354 and
A
~L 2~3~
356, respectively, for fasten;ng it to a bulkhead or plate. The body
part 352 has a male coupling part in the form of boss 358 and a
complementary female coupling part in the form of recess 360. Between
them is an elliptical hole 362 accommodating a detent 364. The detent
364 comprises a round rod which protrudes outwards from the end face
of the body part 352 and has a lip 366 and inclined surface 368 -
similar to those on the lever 302 in the plug connector. The end cap
370 of the bulkhead connector has a pawl 372, in the form of a
right-angled lever mounted in a shallow recess 374. One arm 376 of
the lever lies along the bottom of the recess 374 and the other arm
378 protrudes from the recess 374 to engage the lip 366 on the
undercut end of the detent rod.
A further recess 382, on the outer surface of the end
cap 370, houses a ball 384 and an overlying diaphragm 386. The ball
384 is located in a hole 388 extending between recess 382 and the
recess 374 housing the pawl 372. The ball rests against the arm 376
of the pawl 372 so that depression of the diaphragm, and hence the
ball 384, will pivot the pawl out of engagement with the detent rod.
Figures 17, 18 and 19 show d modified plug connector
which has a plug body 410 similar to that of the connector illustrated
in Figures 1, 2 and 3, in that it has a connector boss 436 and
complementary recess 360, a locking screw 480 and a hinged end cap
460. The locking screw 480 serves to lock two connectors together so
that they will withstand a load of more than 400 pounds when the cable
is being drawn. In addition, the connector has a latch 488 to secure
the cap in the closed position, whether the locking screw is used to
secure the cap or not.
1 ~2~3 1 9 3
The latch 4~8 comprises a right-angled lever 490
mounted on a pivot pin 492 in a recess 494 in the end cap 460. The
pivot axis extends widthways transversely to the longitudinal centre
line of the connector. One arm 496 of the latch 488 is pointed
and undercut at one end to form a pawl 498. As can be seen from
Figure 19, the pawl 498 is arranged to engage behind a lip formed by
str;ker plate 500 secured to the plug body by screw 502.
The latch 488 can be released by pivoting the
right-angled lever 490 to release pawl 498. The release mechanism
comprises a shaft 504 mounted in a cylindrical hole 506 with its
longitudinal axis parallel to the pivot axis of pawl 498. The shaft
~04 protrudes laterally into the recess 494 to engage the arm 508 of
lever 490 adjacent the base of recess 494. The shaft 504 has a neck
portion 510 of lesser diameter with inclined shoulders. When the
latch is in the "closed" position, with pawl 498 engaged behind plate
or lip 500, the arm 508 lies against the neck portion 510. The ends
of the shaft 504 project beyond the sides of the end cap. Depression
of one end of the shaft 504 to slide the shaft 504 longitudinally
causes the pivot arm 508 to ride up one of the shoulders, causing the
lever to pivot and relase the pawl 498.
A ball 512 is located in a hole 514 communicating with
the hole 506 containing the shaft and is biased by a spring 576 into
contact with the shaft 504. The spring-loaded ball 512 locates in the
neck portion to locate the shaft positively in the position
corresponding to engagement of the pawl 498.
