Note: Descriptions are shown in the official language in which they were submitted.
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CONNECTOR WITH EXTERNAL PROT~CTION INTEP~CONNECTING
TWO INSULATED ELECTRIC CABLES
The inven-tion relates to a connector Eor connecting together
two insulated electric cables, particularly the medium voltage
cables,and which includes improved means for the external
protection of the junction.
A connector Eor connecting together two insulated electric
cables includes, in a way known ~r se, means Eor connecting
together the conducting cores oE the cables, means for connecting
together their respective insulating layers and possibly means
Eor connecting together their conducting screens when these
cables possess them.
One of the problems raised by the use Oe such a device is
providing an overall protection thereof so as to obtain sealing
of the junction between cables, and if they are provided, the
mechanical protection of the means connecting together the
conducting screens. Since the diameter oE the junction is
substantially larger than that of the cables, it is diEficult to
provide a one piece protection sleeve which can be Eirmly applied
both to the junction and to the cables.
In accordance with the known techniques, an independent
protection and sealing is thereeore provided Eor the ends
of the cables, and possibly a complementary protection oE the
junction is provided which is a time wasting, costly operation
and which correspondingly increases the risks oE Eailure.
Another problem raised is the accurate positioning oE the
protection sleeves on the junction. At the present time, these
sleeves are mounted manually and in an approximative way on the
junction.
One of the objects oE the invention is to provide a
connector Eor connecting together two insulated electric cables,
,
in which the means for the external protection of the junction is
assembled together in a simple manner and provides continuity o-
the protection Erom the end to be connected o-f one o~ the cables
to the end of the other cable
Another object oE the invention is to provide a junction
body eor connecting together two insulated electric cables which
allows such a protection to be readily obtained and which
provides the accurate positioning thereo-f.
In accordance with the invention, a connector Eor connecting
together two insulated electric cables, each having at least one
conducting core, a layer for insulating this core, a peripheral
conducting screen and a protective sheath Eor this conducting
screen, includes means for connecting said conducting cores
together, means for connecting said insulating layers together
and means Eor connecting said conducting screens together and is
characterized in that it further includes an envelope eor
protecting said means for connecting the conducting screens
together as well as two protective caps which are Eitted
respectively at the ends of the two cables and which are
sealingl~ applied to said protective sheaths, said protective
envelope and said protective caps including sealed mutual snap
fit means.
~ dvantageously, said protective envelope and said protective
caps are made Erom a resilient material and are force fit-ted,
respectively, on said means Eor connecting the conducting screens
together and on said protective sheaths.
In a preEerred embodiment, said snap e it means includes a
peripheral groove on the protective caps and a peripheral e lange
on the protective envelope which is housed in said peripheral
groove.
~ s an aid, the means for connecting said conducting screens
together may include a metal braid which surrounds said means Eor
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connecting the insula~ing layers together and whose ends are
turned back on these connecting means so as to be held between
them and said protective envelope.
Furthermore, each said protective cap may include an
opening formed in its lateral wall, the surface defining said
opening being sealingly applied to a ground conductor which
passes through said opening and which is connected to the
conductincJ screen of the corresponding cable.
The invention also relates to a junction body for
connecting together two insulated electric cables characterized
in that it includes a cover having at least one insulating
layer, a conducting screen surrounding said cover and extending
from both ends thereof, and a protective envelope which covers
said conducting screen except for the ends thereof and which
has on its outer surface and at both its end snap fit sealing
means for the protective caps.
Preferabl~i, said protective envelope is made ~rom a
resilient material and is force fitted on said conducting
screen.
Advantageously, said conducting screen includes a metal
braid whose two ends are bent back on said cover and are held
between it and said protective envelope.
The cover may include an insulating layer interposed
between two semiconducting layers.
According to a broad aspect of the invention there is
provided a junction between electric cables, comprising: two
electric cables, each cable comprising at least one conducting
core, insulation around the core, a conducting screen around
the insulation and a protective sheath around said conducting
screen, and a connector interconnecting said cables, said
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connector including: first conduc~ive means conductively
interconnecti.ng the core of one of said cables with the core o~
the other of said cables; insulation means around said
conductive means and extending from the insulation of one of
said cables to the insulation of the other of said cables;
second conductive means around saicl insulation means and
conductively interconnecting the conducting screen of one of
said cables with the conducting screen of the other of said
cables; a protective tubular envelope of insulation around sald
second conductive means; and a pair of tubular caps of
insulation, one of said tubular caps extending around the
protective sheath of one of said cables and to one end of said
protective tubular envelope and the other o~ said tubular caps
extending around the protective sheath of the other of said
cables and to the other end o~ said protective tubular
envelope, said tubular caps and said protective tubular
envelope having snap fit means at their adjacent ends for
seallny and mechanically interconnecting said tubular caps with
said protective tubular envelope.
According to another broad aspect of the invention there
is provided a ~unction body for use in forminy a junction
between a pair of electric cables, said body comprising: a
tubular body of insulation having at least a layer of
insula~ion; a conductive screen around said tubular body, said
conductive screen haviny an axial lenyth greater than the axial
lencJth of said tubular body; a protective tubular envelope of
insulation around and coveriny said conductive screen except
for portions thereof at axially opposite ends thereof, said
protective tubular envelope having cap engaging portions at its
axially opposite ends of a diameter different from the portions
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67487-347
of said envelope adjacent to said cap engaging portions.
Other objects and advantages of the present invention will
be apparent from the following detailed description of the
presently preferred embodiments thereof, which description
sllould be considered in conjunction with the accompanying
drawings in which:
Fig. 1 is a longitudinal sectional vlew of a junction body
of the invention;
Fig. 2 is a half view, in partial longitudinal section of
a cable junction device using the junction
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body oE Fig. 1.
The junction body oE Fig. 1 includes a cover 1 which is
formed, in a way known ~_r se, oE a main insulating layer 2
interposed be-tween an internal semiconducting layer 3 and an
external semiconducting layer 4. The cover 1 is in the Eorm oE a
circular tube the two ends 5, 6 o which have an external tapered
shape so as to have a progressively reduced section.
~ metal screen, in the form oE a tubular braid 7, covers
externally the cover 1 and extends beyond the ends 5, 6 o the
cover. However, the braid 7 is bent back on the cover 1, so that
its ends 8, 9 bear on the tapered ends 5, 6 oE this cover.
A protective envelope in the Eorm oE a protective elastomer
tube 10 overlies the cover 1 and the braid 7 and is force Eitted
thereon so as to maintain braid 7 in position on the cover 1.
The protective tube 10 does not extend over the whole length oE
cover 1. The ends 11, 12 o-E the tube 10 are situated in line
with a median zone oE the tapering ends 5, 6 of cover 1. Each
' end 11, 12 oE the protective tube 10 includes a circular Elange
13, 1~ extending radially outwardly.
In a variant oE the embodiment shown in Fig. 1, the metal
screen 7 may be Eormed by a metal ribbon. The protective tube 10
is generally resilient, thermoshrinkable or mechanically
retractable. It may, however, be made Erom a rigid material such
as a rigid plastic material iE it is applied by molding.
Preferably, the junction body oE Fig. 1 is preassembled in
the Eactory beEore being used on the site. The protective
elastomer tube 10 of Fig. 1 is, Eor example, mounted on cover 1
by means oE a cylindrical vacuum tube. AEter introducing the
protective tube 10 in this tube, a vacuum is formed so as to
cause expansion oE the tube 10. Then, the cover 1 with the braid
7 is disposed inside the protective tube 10, and then, the vacuum
is released which causes retraction oE the tube 10 on the braid 7
and the cover 1.
In a simpler assembly method, a lubricating bonding agent is
applied to the outer surface o cover 1 and the braid 7, and the
protective elastomer tube 10 is slid onto cover 1 and the braid 7
structure.
It will be noted that braid 7 and the protective tube 10 may
thus be accurately positioned usiny mechanical means, which will
facilitate assembly of the junction device on the site.
Fig. 2 shows a junction device of the invention which
includes the junction body oE Fig. 1 covering a symmetrical
junction between two cables, only one, 20, of which is visible in
this Fig. The description of the junction will therefore
be limited to the part visible in Fig. 2, this description also
applying to the symme-trical part not shown.
In a way known per se, the core 21 of the cable 20 is joined
to that of the other cable by means o a connecting sleeve 22.
An insulated grounding conductor 23 is connected to the metal
screen of cable 20.
The junction body, which includes the internal
semiconducting layer 3, the insulating layer 2, the external
semiconducting layer 4, braid 7 and the protective tube 10,
covers most of the junction but not the grounding conductor 23.
The insulating layer 2 and the semiconducting layers 3 and 4 of
the junction body are, in a way known ~er se, engaged with the
corresponding layers of the cable 20, with the interpositioning,
in this example, oE an elastomeric semiconductive split tube 24
and a tube 25 of elastomeric insulation Eor matching the inner
diameter of the junction hody to the outer diameter oE cable 20.
The braid 7 is connected to the metal screen oE cable 20 by
means oE a collar 26. A protective cap in the form oE a tubular
cap 27 covers the end o-E cable 20 and the tapered end 5 of the
junction body. The tubular cap 27 i5 made from elastomer. It has
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itselE a widened tapered end which includes a circular Eillet 31
inside which is Eormed a circular groove 28. Groove 28 snap fits
sealingly onto the circular Elange 13 of the protective tube 10
of the junction body. The other end oE the tubular cap 27 is
applied to the sheath oE the cable 20 with interpositioning oE a
sealing mastic 30. The ground conductor 23 extends laterally Erom
the tubular cap 27, passes through a tubular projection 33 on the
cap and extends outwardly thereoE. The inner surface o this
tubular projection 33 is applied sealingly to the ground
conductor 23.
In a simplified embodiment, the sealing mastic 30 may be
omitted, the tubular cap 27 being ~orce Eitted to the sheath oE
the cable 20 and itselE providing sealing.
During assembly of the junction on the work site, the
junction body, preferably assembled in the factory, and the tube
2S are slid over one of the cables, e.g. the cable 20, after the
tubular cap 27 has itself been positioned on the cable. A tubular
cap, like the cap 27, is also placed on the other cablen AEter
connection of the cores Oe the cables with the sleeve 22, the
split tube 24 is placed over the sleeve 22, and the tube 2S is
slid into the position shown in Fig. 2. The junction body is
then brought over the junction, and the tubular caps are then
engaged in their turn and snap Eit on the protective tube 10 oE
the junction body. IE the sealing mastic 30 is used, it is
applied beEore the tubular caps are positioned.
The relative positioning oE the diEEerent components o the
junction is controlled by the coniguration o the componentsO
The braid 7 and the protective tube 10 are already mounted on the
cover 1 and are, therefore, properly positioned. As for the
tubular caps, they are positioned accurately by means of the
e langes 13, 14 of the cover 1 over which they snap fit.
From one end oE one cable to the end o the other cable, the
protection Eormed by the two tubular caps 27 and by the
protective tube 1 is continuous.
It will be apparent that the mutual snap Eit means between
the tubular caps 27 and protective tube 10 is not limited to the
speciEic form described and may assume difEerent forms provided
that the connection obtained is sealed over the whole periphery
oE the junction.
The invention Einds its application more particularly in the
construction of underground electric cable junctions, at medium
voltage.
Although preferred embodiments oE the present invention have
been described and illustrated, it will be apparent to those
skilled in the art that various modiEications may be made without
departing from the principles of the invention.
