GB2480733A

GB2480733A - Watertight cable connection

Info

Publication number: GB2480733A
Application number: GB1107283A
Authority: GB
Inventors: Dafydd Thomas
Original assignee: i3 Group Ltd
Current assignee: i3 Group Ltd
Priority date: 2010-04-30
Filing date: 2011-05-03
Publication date: 2011-11-30
Also published as: WO2011135383A2; WO2011135383A3; EP2594000B1; GB201007171D0; GB201107283D0; EP2594000A2

Abstract

A cable connection system that introduces a cable through an opening provided in a water pipe comprises: a connector unit 100 and one or more ferrules 200 which interconnect with the connector unit 100. The connector unit 100 has a torso 101 with an exterior that engages and forms a watertight seal (e.g. via Q-rings 104) with internal edges of the opening, an axial bore 102 extending through the torso 101, and axially projecting passages 110 at either end of the torso 101. The internal edges of the passages 110 and the ends of the torso 101 define ferrule receiving sockets. The ferrule 200 comprises an outer skirt 210 which fits around the exterior of the passages 110, and a projecting plug 220 with an axial bore 221 to carry a cable. The exterior of the plug 220 is adapted to engage and form a watertight seal with the internal edges of the socket defined by the passages 110 of the connector unit 100. The passages 110 may have an outwardly projecting rim 111 which is adapted to engage an inwardly projecting rim 211 of the outer skirt 210 of the ferrule 200. These rims 111, 211 may disengage upon application of an axial force that is lower than the normal axial force required to either remove the cable from the axial bore 221 of the ferrule 200 or to break the cable.

Description

Wertight Cable Connections The present invention relates to watertight cable connections and in particular to such connections adapted to allow a cable to be introduced into a water pipe or similar.

In order to install a new node to a hardwired network or indeed to provide a new hardwired network, it is necessary to provide a cable linking the node to the various other nodes in the network. Often, such as in the case of cable television networks, this will require providing a branch cable connecting the new node to an existing trunk cable via which connection to the other nodes may be effected. The trunk cables will typically be laid in a pattern between one or more potential nodes, for instance the trunk cables may follow the local street pattern. The branch cables may then need to travel some distance from the trunk cable to reach the building in which the node is to be located.

In our co-pending application No PCT/0B2009/05 1172 there is provided a method of laying a branch cable between a trunk cable and a desired node location comprising the steps of: locating a pre-existing pipe for the node location adjacent to the trunk cable; introducing the branch cable into the pre-existing pipe; passing the branch cable along the pre-cxisting pipe; and removing the branch cable from the pre-existing pipe adjacent to the node location. This reduces disruption to the property of the homeowner by negating the requirement to dig a potentially expensive and/or unsightly trench through their garden in which to lay the cable.

To facilitate introduction of the cable to the pre-existing pipe a cable transfer means comprising a Y-junction inserted into a gap provided in the pre-existing pipe can be provided. In such cases, the leg and one ann of the Y-junction may be adapted to be connected to the pre-existing pipe and the other arm may be capped with an end closure having a cable passage provided therethrough.

The end closure must be watertight to prevent water leaking from the pipe.

This can be achieved by the use of a defonnable bung or similar inserted into the opening at the end of the ann. This does not however provide a ready means by which the cable can be changed or replaced in the event of damage, malfunction or JO upgrade of the network.

Jt is an object of the present invention to provide a watertight cable connection adapted to allow a cable to be introduced into a water pipe or similar that at Ikeast partly overcomes or alleviates the above problems.

According to a first aspect of the present invention there is provided a cable connection system suitable for use in introducing a cable through an opening provided into a water pipe or similar, the connection system comprising: a connector unit and one or more ferrules adapted to interconnect therewith wherein the connector unit comprises: a solid torso having an exterior adapted to engage and form a watertight seal with the internal edges of the opening and also having an axial bore extending thererthrough; and axially projecting passages provided at either end of the torso, the internal edges of the passage and the ends of the torso defining ferrule receiving sockets; and wherein the ferrule comprises: an outer skirt adapted to fit around the exterior of the projecting passages of the connector unit; and a projecting plug, the plug having an axial bore for carrying a cable and an exterior adapted to engage and form a watertight seal with the internal edges of the socket defined by the passages of the connector unit.

The above system provides a means by which a watertight connection may be formed between a length of cable within a pipe and a length of cable outside the pipe through a suitable opening. The positioning of the seal between the ferrule and the connector unit within the inner portion of the socket whilst the outer skirt engages with the exterior of the socket provides ease and certainty of connection and protects the seals from impacts and tension applied to the cable.

The cable is preferably an optical cable. The cable is preferably provided with an insulating sheath. The cable may be a single core or multi-core cable as desired.

The cable may be provided within a cable duct or adapted to be laid within a cable duct. The cable duct may be of substantially elongate tubular form.

The exterior of the torso may be adapted to seal with the opening by the provision of one or more 0-rings within retaining grooves. The torso may further be provided with a radially projecting rib adapted to engage with the opening provided.

The ferrule is preferably adapted to form a substantially watertight seal around the cable or the cable duct, as appropriate. To achive this, the internal bore of the ferrule may be matched to the outer diameter of the cable or the cable duct, as -.4-appropriate. The cable or the cable duct may be retained within the internal bore of the ferrule by adhesive.

The passages may be provided with an outwardly projecting rim. The outer skirt may be provided with an inwardly projecting rim. The projecting rims of the passages and the skirts may be adapted to engage. This can help to retain the plug within the socket. The size and shape of the rims are preferably adapted to prevent the plug being withdrawn from the socket by a low level of axial force. Preferably the rims are adapted to disengage under the application of a higher level of axial force.

Preferably the axial disengagement force level is lower than the normal axial force required to remove the cable or cable duct from the axial bore of the ferrule or the normal axial force required to break the cable or cable duct. This may be achieved if the or both of the passage and the skirt are formed from a suitable resiliently deformable material.

The projecting plug may be formed integrally with the outer skirt or may be attached thereto by a suitable sealing ring. The plug may form a seal against one or more o-rings disposed at the base of the passage. The o-rings may be forced against the ends of the torso and the internal walls or the socket by the plug. The end portion of the plug may be adapted to engage with the 0-rings. Additionally or alternatively, the exterior of the end portion may be adapted to engage with the interior of the passage. -5..

The plug may comprise a single part construction. Alternatively, the end portion of the plug may be a separate component attached to the rest of the plug. In thrther embodiments, the plug may be provided with an extended barrel portion connecting a base portion of the plug incorporating the internal bore and the end portion of the plug.

According to a second aspect of the present invention there is provided a connector unit suitable for use in a connection system of the first aspect of the present invention, the connector unit comprising: a solid torso having an exterior adapted to engage and form a watertight seal with the internal edges of the opening and also having an axial bore extending thererthrough; and axially projecting passages provided at either end of the torso, the internal edges of the passage and the ends of the torso defining ferrule receiving sockets.

The connector unit of the second aspect of the present invention may incorporate any or all features of the first aspect of the present invention as desired or as required.

According to a third aspect of the present invention there is provided a ferrule suitable for use in a connection system of the first aspect of the present invention, the ferrule comprising: an outer skirt adapted to fit around the exterior of the projecting passages of the connector unit; and a projecting plug, the plug having an axial bore for carrying a cable or cable duct and an exterior adapted to engage and form a watertight seal with the internal edges of the socket defined by the passages of the connector unit.

The ferrule of the third aspect of the present invention may incorporate any or all features of the first aspect of the present invention as desired or as required.

According to a fourth aspect of the present invention there is provided a method of enabling the entry of a cable into a pipe comprising the steps of: providing a suitable opening in the pipe; inserting a connector unit according to the present invention within the opening in the pipe; providing a length of cable within the pipe and a length of cable outside the pipe with ferrules according to the present invention or providing a length of cable duct within the pipe and a length of cable duct outside the pipe with ferrules according to the present invention; and engaging the ferrules with the sockets of the connector unit.

The method of the fourth aspect of the present invention may incorporate any or all features of the first, second or third aspects of the present invention as desired or as required.

The pipe may be any suitable pipe. As an example, the pipe may be a water supply pipe or a waste water pipe such as a sewer, drain or similar. The method may comprise the further steps of forming a gap in the pipe, inserting a Y-Junction into the gap and inserting the connector unit into the open end of one arm of the Y-junction.

Preferably, the Y-junction comprises the leg and one arm adapted to be connected to the pipe and another arm capped with an end closure having a cable passage provided therethrough.

According to a fifth aspect of the present invention there is provided a network wherein one or more cables within the network are connected by a connector system according to the first aspect of the present invention, a connector unit according to the second aspect of the present invention, a ferrule according to the third aspect of the present invention or wherein one or more cables are introduced to pipes using a method according to the fourth aspect of the present invention.

The network of the fifth aspect of the present invention may incorporate any or all features of the first, second, third or fourth aspects of the present invention as desired or as required.

The network may comprise one or more trunk cables and one or more branch cables. The connector system according to the first aspect of the present invention, connector unit according to the second aspect of the present invention, ferrule according to the third aspect of the present invention or method according to the fourth aspect of the present invention may be utilised in connection with any one or more of either the trunk cables or the branch cables. In some embodiments, the connector system according to the first aspect of the present invention, connector unit according to the second aspect of the present invention, ferrule according to the third aspect of the present invention or method according to the fourth aspect of the present invention may be utilised in connection with the branch cables. In such embodiments the trunk cable may be laid in a dedicated conduit or may be laid along a sewer. In particular, the trunk cable may be laid according to the disclosure of our co-pending application W02008/009969. In this prior application there is provided a method of laying a cable between two points comprising the steps of: laying a cable through one or more lengths of sewer between the two points; and where there is no convenient length of sewer or a gap between convenient lengths of sewer, providing a length of dedicated cable conduit between said lengths of sewer and laying said cable through said dedicated cable conduit. In this context, it should be understood that in addition to or in place of sewers, trunk cables may be laid along water supply pipes, roadside drains, storm drains or similar.

In order that the invention is more clearly understood, one embodiment will be described further herein, by way of example only, and with reference to the following drawings, in which: Figure t is a cross-sectional view of a connection system according to the present invention; Figure 2 is a partial cutaway view of an alternative embodiment of a connection system according to the present invention; Figure 3a is an exploded side view of the connection system of figure 2; Figure 3b is an exploded perspective view of the connection system of figure 2; Figure 3c is an exploded cutaway view of the connection system of figure 2; Figure 4 is a schematic illustration of the connection system of figure 1 in use to introduce a cable into a water pipe using a Y connector; and Figure 5 is a schematic illustration of the connection system of figure 2 in use to introduce a cable into a water pipe using a Y connector.

v" Referring now to figure 1, a cable connection system of the present invention comprises a connector unit 100 adapted to provide a watertight connection between 0 and two ferrules 200. The ferrules 200 are fitted either to the ends of a cable (not 0) shown in figure 1) or to the ends of a cable duct (also not shown in figure 1) carrying a cable therein.

The connection unit 100 comprises a torso 101 having a central bore 102 The torso has a pair of retaining grooves 103 within which are provided 0-rings 104. The 0-rings 104 enable the connector unit 100 to be inserted into a suitable opening and form a watertight seal with the opening. The connection unit 100 is further provided with an external projecting rib 105. This can also engage with an opening, if required.

At each end 106 of the torso 101 are provided axially extending passages 110.

The passages 110 are provided with an outwardly projecting end rim 111, Each end 106 of the torso 101 may comprise an abutting surface 107 and a recess 108. The passages 110 define sockets for receiving a corresponding plug provided by the ferrules 200.

Turning now to the ferrules 200, these comprise an outer skirt 210 and an S projecting plug 220. The skirt 210 is adapted to engage with the exterior of the passages 110 and is provided with an inwardly projecting rim 211 to engage with rim 111 of passages 110. The rims 111, 211 have corresponding snap-fitting features such that the plug 220 can readily be inserted into the socket Once inserted into the socket, the rims 111, 211 resist the withdrawal of the plug 220. The size and flexibility of the rims 111, 211 can be adapted to ensure that the connection is secure in normal use, The size and flexibility of the rims 111, 211 can also adapted such that disengagement occurs in response to a lower axial force than is required to break the cable or remove the cable from the ferrule 200.

The plug 220 of figure 1 has an inner bore 221 adapted to match the outer diameter of the cable or cable duct (as appropriate). Typically, the end of the cable or cable duct is inserted into the inner bore 221 and retained therein by means of adhesive. The adhesive also helps maintain a watertight seal between the cable or cable duct and the bore 221.

The plug 220 of figure 1 has an outer cover 222 and an end portion 223. The end portion 223 is adapted to engage with the passage 110 when the plug 220 is inserted thereto. In order to provide a watertight seal one or more socket 0-rings 109 may be provided which in use arc compressed between end portion 223 and abutting surface 107. The embodiment of figure 1 further provides an engagement ring 224 retaining the cover 222 in position relative to the bore 221.

In use, cables or cable ducts (as appropriate) fitted with ferrules 200 can be S inserted into each passage of the connection unit 100. As such, a water tight connection is fonned between the ferrules 200 and the passages 110. If the connection unit 100 is inserted into a corresponding opening in a water pipe (or any other suitable opening such as an open end of an arm of a Y-junction), this allows a watertight connection to be fonned between a cable lying in the pipe and a cable outside the pipe. Typically, the connector unit and ferrules are adapted to be used with single core or multi-core optical cables having an insulating sheath.

Turning now to figures 2 and 3, fUrther views of a connection unit 100 are shown, the connection unit engaged with a first ferrule 200 of the type described in relation to figure 1 and also engaged with a second type of ferrule 300.

The second type of ferrule 300 has an outer skirt 310 and a projecting plug 320 having an inner bore 321. The skirt 310 however omits an inwardly projecting rim and is instead adapted to directly abut the rim 111.

The plug 220 is provided with a barrel potion 322 extending from the bore 321. The end of the barrel portion is adapted to engage with an 0-ring 109. In the example shown in the diagram, an abutting spacer rim 324 is provided between the abutting surface 107 and the 0-ring 109. It is of course possible for a second 0-ring 109 to be substituted for the abutting spacer rim 324, if desired.

An example of the connection system of figure 1 in use is shown in figure 4.

In this example, a cable is laid along a water supply pipe 6. In order to allow the cable to exit the pipe 6, the water supply to pipe 6 is turned off and a pair of cuts are made in the pipe 6 leaving a gap 6g. A Y-junction 10 is inserted in the gap 6g in pipe 6. The Y-junction 10 comprises a leg 11 and two arms 12 and 13. Leg 11 and arm 12 are aligned along a common axis. Arm 13 projects from the Y-junction at an angle to the common axis. The ends of leg 11 and are 12 are open and provided with fittings 14a, 14b to enable watertight connection to open ends 6a, 6b in water supply pipe 6.

When connected thus, a water flow path is provided between 6a and 6b along leg 11 and ann 12.

The arm 13 is capped with a connector unit 100, a watertight seal being fonned between 0-rings 104 and the arm 13. The connector unit 100 is secured in position using fitting 16. This allows a length of cable fitted with a ferrule 200 laid within the pipe 6 to be connected in a watertight maimer to a second length of cable fitted with a ferrule 200 but laid outside the pipe 6.

Figure.5, provides a further illustration of the invention in use, this time also showing a cable 5 fitted with a ferrule 300 laid within pipe 6. The skilled man will of course appreciate that cable 5 could equally be replaced by a tubular cable duct, along which a cable could lie.

-13 -It is of course to be understood that the present invention is not to be limited to the details of the above embodiment which are described by way of example only. -14

Claims

Claims 1. A cable connection system suitable for use in introducing a cable through an opening provided into a water pipe or similar, the connection system comprising: a connector unit and one or more ferrules adapted to interconnect S therewith wherein the connector unit comprises: a solid torso having an exterior adapted to engage and form a watertight seal with the internal edges of the opening and also having an axial bore extending thererthrough; and axially projecting passages provided at either end of the torso, the internai edges of the passage and the ends of the torso defining ferrule receiving sockets; and wherein the ferrule comprises: an outer skirt adapted to fit around the exterior of the projecting passages of the connector unit; and a projecting plug, the plug having an axial bore for carrying a cable and an exterior adapted to engage and form a watertight seal with the internal edges of the socket defined by the passages of the connector unit.
2. A cable connection system as claimed in claim 1 wherein the cable is provided with an insulating sheath.
3, A cable connection system as claimed in claim I or claim 2 wherein the cable is provided within a cable duct of substantially elongate tubular form.
4. A cable connection system as claimed in any preceding claim wherein the exterior of the torso is adapted to seal with the opening by the provision of one or more 0-rings within retaining grooves.-
5. A cable connection system as claimed in any preceding claim wherein the torso is provided with a radially projecting rib adapted to engage with the opening provided.
6. A cable connection system as claimed in any preceding claim wherein the internal bore of the ferrule is matched to the outer diameter of the cable or the cable duct.
7. A cable connection system as claimed in any preceding claim wherein the cable or the cable duct is retained within the internal bore of the ferrule by adhesive.
8. A cable connection system as claimed in any preceding claim wherein the passages are provided with an outwardly projecting rim; the outer skirt is provided with an inwardly projecting rim and the projecting rims of the passages and the skirts are adapted to engage.
9. A cable connection system as claimed in claim 8 wherein the rims are adapted to disengage under the application of a level of axial force lower than the normal axial force required to remove the cable or cable duct fiDm the axial bore of the ferrule or the normal axial force required to break the cable or cable duct.
10. A cable connection system as claimed in any preceding claim wherein the projecting plug is formed integrally with the outer skirt or is attached thereto by a sealing ring.
11. A cable connection system as claimed in any preceding claim wherein the plug forms a seal against one or more 0-rings disposed at the base of the passage. -16-
12. A cable connection system as claimed in any preceding claim wherein the plug is provided with an extended barrel portion connecting a base portion of the plug incorporating the internal bore and the end portion of the plug.
13. A connector unit suitable for use in a connection system of any one of claims 1 to 112, the connector unit comprising: a solid torso having an exterior adapted to engage and form a watertight seal with the internal edges of the opening and also having an axial bore extending thererthrough; and axially projecting passages provided at either end of the torso, the internal edges of the passage and the ends of the torso defining ferrule receiving sockets.
14. A connector unit as claimed in claim 13 wherein the torso is provided with a radially projecting rib adapted to engage with the opening provided.
15. A connector unit as claimed in claim 13 or claim 14 wherein the torso is provided with a radially projecting rib adapted to engage with the opening provided.
16. A connector unit as claimed in any one of claims 13 to 15 wherein the passages are provided with an outwardly projecting rim adapted to engage with an inwardly projecting rim of an outer skirt of said ferrule.
17. A connector unit as claimed in claim 16 wherein the rims are adapted to disengage under the application of a level of axial force lower than the normal axial force required to remove the cable or cable duct from the axial bore of the ferrule or the normal axial force required to break the cable or cable duct.
18. A ferrule suitable for use in a connection system of according to any one of claims 1 to 12, the ferrule comprising: an outer skirt adapted to fit around the -17 -exterior of the projecting passages of a connector unit; and a projecting plug, the plug having an axial bore for carrying a cable or a cable duct and an exterior adapted to engage and form a watertight seal with the internal edges of the socket defined by the passages of the connector unit.
19. A ferrule as claimed in claim 18 wherein the internal bore of the ferrule is matched to the outer diameter of the cable or the cable duct.
20. A ferrule as claimed in claim 19 wherein the cable or the cable duct is retained within the internal bore of the ferrule by adhesive.
21. A ferrule as claimed in any one of claim.s 18 to 20 wherein the outer skirt is provided with an inwardly projecting rim adapted to engage with an outwardly projecting rim of the passage.
22. A ferrule as claimed in claim 21 wherein the rims are adapted to disengage under the application of a level of axial force lower than the normal axial force required to remove the cable or cable duct from the axial bore of the ferrule or the normal axial force required to break the cable or cable duct.
23. A ferrule as claimed in any one of claims 18 to 22 wherein the projecting plug is formed integrally with the outer skirt or is attached thereto by a sealing ring.
24. A ferrule as claimed in any one of claims 18 to 23 wherein the plug forms a seal against one or more 0-rings disposed at the base of the passage.
25. A ferrule as claimed in any one of claims 18 to 24 wherein the plug is provided with an extended barrel portion connecting a base portion of the plug incorporating the internal bore and the end portion of the plug.

-18 -
26. A method of enabling the entry of a cable into a pipe comprising the steps of: providing a suitable opening in the pipe; inserting a connector unit according to any one of claims 13 to 17 within the opening in the pipe; providing a length of cable within the pipe and a length of cable outside the pipe with ferrules according to any one of claims 18 to 25 or providing a length of cable duct within the pipe and a length of cable duct outside the pipe with ferrules according to any one of claims 18 to 25; and engaging the ferrules with the sockets of the connector unit.
27. A method as claimed in claim 26 wherein the pipe is a water supply pipe or a waste water pipe
28. A method as claimed in claim 26 or claim 27 wherein the method comprises the further steps of forming a gap in the pipe, inserting a Y-Junction into the gap and inserting the connector unit into the open end of one arm of the Y-junction.
29. A method as claimed in claim 28 wherein the Y-junction comprises the leg and one ann adapted to be connected to the pipe and another ann capped with an end closure having a cable passage provided therethrough.
30. A network wherein one or more cables within the network are connected by a connector system according to the first aspect of the present invention, a connector unit according to the second aspect of the present invention, a ferrule according to the third aspect of the present invention or wherein one or more cables are introduced to pipes using a method according to the fourth aspect of the present invention.