Note: Descriptions are shown in the official language in which they were submitted.
w096107049 219 6 3 ~ U~
1 REINFnTrTen, V~r~T~r~r~Te-~TyT~n cOUPT.TNr- FOR CQNDUIT
3 FTT'T.n OF T~ INVENTION
The present invention relates generally to the
6 joining of two pieces of tubing, and more particularly,
7 to the joining of the end6 of polymeric conduit used to
8 insulate and protect electrical cables.
i3ACRGROUND OF THE INV~NTION
11 One method of protecting underground electrical
12 cables is by the use of polymeric conduit, usually
13 polyethylene, which surrounds the cable and provides
14 protection from envil, ~1 elements such as water and
dirt. The conduit may also provide electrical
16 insulation, although this function is not its primary
17 purpose. Since the conduit comes in finite lengths, it
18 is n~c~s~ry to join the ends of serial lengths of
19 conduit to ac -~ te long lengths of cable. The
present invention provides a means for joining the ends
21 of conduit which may be easily accomplished in the field.
22 Additionally, the present invention allows the
23 connection of the cable insulation itself in addition to
24 or instead of merely connecting the conduit which
c~n~n~ the cable.
26
27 S~MMARY OF THF INV~NTION
28 The present invention includes a connector
29 assembly for joining the ends of two lengths of conduit,
which connector assembly compri8es a spirally-wound,
31 reinforcing sleeve positioned to span the distance
32 between the ends of the conduits and overlie the conduit
33 ends and at least one elastic tube which covers the
34 sleeve and preferably extends beyond the ends of the
sleeve to contact the two conduits. The elastic tube may
W096/07049 219 6 3 0 ~ r~
1 be one tube having a length sufficient to extend from one
2 conduit to the other;br may be two elastic tubes, each of
3 which covers one~,conduit, the joint between the
4 reinforcing sleeve and the conduit and a portion of~the
sleeve.
6 The connector assembly may also include an
7 injector port as a part of the reinforcing, spirally-
8 wound sleeve, to permit the injection of waterproofing or
9 other fluid into the joint between the conduit ends or
into the gap between the ends of the insulation of two
11 cables.
12
13 RRT~ DES~RTPTION OF THE D~RAWINGS
14 The present invention will be more thoroughly
described with respect to the ac_ _ ~ing drawings,
16 wherein like numbers refer to like parts in the several
17 views, and wherein:
18 Figure 1 is a perspective view illustrating two
19 conduit ends and a connector assembly of the present
invention;
21 Figure 2 is a perspective view of a
22 reinforcing, spirally-wound sleeve forming a portion of
23 the c~nnect~r assembly of figure 1;
24 Figure 3 is a perspective view illustrating two
conduit ends and an elastic tube of:the connector
26 assembly of Figure l;
27 Figure 4 is a top view of an alternate
28 embodiment of the spirally-wound sleeve of the present
29 invention;
Figure 5 is a plan view of the sleeve of Figure
31 4 prior to coiling;
32 Figure 6 is an end view of the sleeve of Figure
33 4; and
34 Figure 7 is a side elevationaI view of an
alternate embodiment of the connector assembly of the
36 present invention.
e
~ 09610704g ' '' ' " P~ 3~
1 DES~TPTION OF T~E ~ ~K~ EM~O~IMEN~S
2 Figure 1 illustrates a connector assembly,
3 generally indicated as 10, of the present invention as it
4 is nt i 1; 7ed to cover and connect the ends of two conduits
12 and 14. Although the invention will be described
6 tl~uu~h~lL as joining two sections of hollow conduit, it
7 is equally applicable to joining two cable ends by
8 bridging the insulation of the cable, or, most generally,
9 joining any two substantially cylindrical or tubular
objects. The connector assembly 10 includes an outer,
11 elastic tu~e 16 and an inner, reinforcing, spirally-
12 wound 81eeve 18. The reinforcing sleeve 18 is also
13 illustrated in Eigure 2 where the spiral nature of the
14 sleeve 18 is more readily apparent. It is desirable that
the sleeve 18 be spirally wound, wherein a longitudinal
16 edge 20 of the sleeve 18 overlaps and covers a portion of
17 the sleeve 18, so that the sleeve 18 may accommodate a
18 wide variety of conduit 12 and 14 diameters by uncoiling
19 or more tightly coiling the spiral of the sleeve 18. The
sleeve 18 is preferably manufactured of a polymeric
21 material, such as high density polyethylene, but may also
22 be fashioned from sheet metal, if desired. A preferred
23 method of forming the sleeve 18 is longitudinally
24 slitting an extruded tube, but other methods, such as
coiling a flat sheet, are acceptable.
26 Figure 3 illustrates the conduit ends 12 and 14
27 as the conduit ends 12 and 14 are disposed prior to
28 assembly of the connector assembly 10. Figure 3 also
29 illustrates the elastic tube 16 in one form in which it
may be conveniently applied to the conduit 14. The
31 elastic tube 16 is in a form described in U.S. Patent No.
32 3,515,798, assigned to the assignee of the present
33 invention and herein incorporated by reference, wherein
34 the elastic tube 16 is pre-stretched and supported on a
removable core 24. The core 24 is scored along a helical
36 path 26 and may be removed in a long, c~ntinu~us strip by
:
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,~- 4
1 pulling on the end 28 which unwinds the core 24 along the
2 helical scoring 26. Removal of the core 24 allows the
3 tube 16 to contract to its original dimensions. Other
4 methods for retaining the tube 16 i~ the ~n~n~ state
have been proposed and could be used in the present
6 invention. Examples may be found in U.S. patents nos.
7 4,070,746 and 4,656,070 wherein the tube i9 held in the
8 ~ n~ state by an P~t~rn~l, rigid tube which is
g adhesively bonded to the tube. To allow the tube to
contract, the external tube may be broken and peeled away
11 from the tube or the adhesive bond between the tube and
12 the external tube chemically broken.
13 Eigure 3 illustrates an lnt~ ~;ate step in
14 the assembly of the connector assembly 10 to the conduit
ends 12 and 14 As shown in Figure 3, the tube 16, in an
16 ~ n~d condition, has been assembled to the conduit 14
17 by displacing one conduit end 14 from its alignment with
18 the other conduit end 12 and sliding the tube 16 along
19 the conduit 14.
The next assembly step is to position the
21 sleeve 18 over the conduit ends 12 and 14 by likewise
22 displacing one of the conduit ends 12 or 14 from
23 alignment with the other conduit end 12 or 14 and sliding
24 the sleeve 18 over the conduit 12 or 14. The sleeve 18
is then retracted along the conduit 12 or 14, the ends of
26 the conduit 12 and 14 again aligned and the sleeve 18
27 slid towards the other conduit end 12 or 14 to span the
28 gap therebetween and cover both conduit ends 12 and 14 to
29 a subst~nt;nlly ;d~nt;~l extent.
Once the sleeve 18 is positioned over the
31 conduit ends 12 and 14, the tube 16 is then slid to cover
32 the sleeve 18 and preferably extend beyond the ends of
33 the sleeve 18 to cover the conduit ends 12 and 14,
34 substantially as illustrated in Figure 1. Once the tube
16 is positioned over the sleeve 18, the core 24 is
36 removed from the tube 16 and the tube 16 thus permitted
Wo96l07049 21 ~63 0 ~ r~ c~
,}~ j.. ~
"
1 to contract to compress the reinforcing sleeve 18 and
2 seal to the conduit ends 12 and 14. It is preferable
3 that the ends of the tube 16 extend beyond the ends of
4 the sleeve 18 so that the tube 16 can provide a seal to
protect the connection from envi~, t~l cont~m;n~nt~.
6 However, it has been found that a tube 16 which partially
7 covers the sleeve 18 produces adequate ~l;g ---t of the
8 conduit ends 12 and 14 and strength at the junction.
g In the past, it has been attempted to join the
conduit ends 12 and 14 by using only an elastic tube 16
11 such as that illustrated in Figure 3. This solution does
12 not work well because the tube 16 shrinks into the gap
13 between the conduit ends 12 and 14 where it may interfere
14 with the ability to pull cable through the conduit 12 and
14 and because the edges of the conduit ends 12 and 14
16 may puncture the tube 16. The addition of the sleeve 18
17 solves these problems and has been found to also aid in
18 the alignment of the conduit ends 12 and 14 and add a
19 great deal of stiffness to the junction of the cable ends
12 and 14.
21 Figures 4-6 illustrate an alternate embodiment
22 of a spirally-wound sleeve 30 of the present invention.
23 The spirally-wound sleeve 3Q includes injection ports 32
24 which are ~ ted by slots 34 in the sleeve 30.
As best seen in Figure 5, the slots 34 extend
26 from one longitudinal edge 36 and partially into the
27 width of the sleeve 30, in the direction which will
28 become the circumference of the sleeve 30 when it is
29 spirally wound, and in alignment with injection ports 32.
Figure 5 illustrates the sleeve 30 in a flat condition
31 while Figures 4 and 6 illustrate from the top and side,
32 respectively, the sleeve 30 as spirally wound for
33 assembly to the conduit ends 12 and 14. The slots 34 are
34 provided to allow the spiral of the sleeve 30 to be more
or less tightly wound and, as discussed above,
36 acc ~te a range of conduit 12 and 14 diameters. The
W096/07049
2 1 ~ 6 ~ ~ ~
1 injection ports 32 are provided to permit a waterproofing
2 or other useful fluid to be injected into the junction
3 between the conduits 12 and 14 or between two cable endQ
4 after the sleeve has been as8embled to the conduit 12 and
14.
6 If the sleeve 30 of figures 4-6 is nt;l i7~,
7 the tube 16 may be assembled over the sleeve 30 as shown
8 in Eigure 1, but the injection ports 32 may interfere
9 with the assembly of a single tube 16 to cover such a
sleeve 30. An alternative is to utilize two tubes 16 by
11 assembling one ex~anded tube to each conduit end 12 and
12 14 and positioning the sleeve 30 between the two tubes
13 16. Each tube 16 would then cover a conduit end 12 or 14
14 and the portions of the sleeve 30 which extend from the
injection ports 32 to the ends of the sleeve 30.
16 The sleeve 30 is shown provided with two
17 injection ports 32 to allow fluid to be injected into one
18 port 32 while air escape3 from the other. It i8 equally
19 possible to provide the sleeve 30 with only one injectio~
port 32 if air entrapment is not a problem. In this
21 case, only one slot 34 in alignment with the single
22 injection port 32 would be necessary. Also7 the
23 injection port 32 is illustrated as being a boss which
24 extends from the sleeve 30. The port 32 could equally
well be simply a hole in the sleeve 30.
26 Figure 7 illustrates an embodiment of a
27 connector assembly 40 which in~ q two features which
28 may make assembly of the connector as3embly 40 to the
29 conduit ends 12 and 14 more convenient. The first is
that the connector assembly 40 is provided with two
31 support cores 42 and 44. In this fashion, the cores 42
32 and 44 may be stripped from both ends of the connector
33 assembly 40 and neither need be pulled the entire length
34 of the cable assembly 40. Secondly, the rnnn~ctor
assembly 40 is provided with a spirally-wound sleeve 46
36 which is disposed between the elastic tube 48 and the
096l07049 '~ n ~ vJv
1 cores 42 and 44 which support tke tube 40. Thus the
r~nnrrt~ asgev~bly 40 may simply be positioned over the
3 conduit ends 12 and 14 as a unit rather than individually
4 as was descriked above. When the cores 42 and 44 are
removed, the tube contracts towards the conduit ends 12
6 and 14 and ~orces the sleeve 46. to wind into a tighter
7 spiral and contact the conduit 12 and lg.
.
