WO2021228857A1

WO2021228857A1 - Method and prefabricated sealing assembly for sealing an electric cable joint

Info

Publication number: WO2021228857A1
Application number: PCT/EP2021/062488
Authority: WO
Inventors: Willem Ipenburg; Freek MICHEL; Miloud LAAMOUMI; Mark VISSER
Original assignee: Filoform B.V.
Priority date: 2020-05-11
Filing date: 2021-05-11
Publication date: 2021-11-18
Also published as: NL2025550B1; EP4150724A1

Abstract

Method for sealing an electric cable joint wherein use is made of a prefabricated sealing assembly which comprises an impervious sheet that is at least partially transparent stretchable in a direction between opposed transverse ends. An open structure spacer mat is fixed on the inner side of the sheet and is stretchable the same direction as the sheet. A pair of air-permeable and resin compound blocking strips is mounted to the inner side of the sheet so that the spacer mat is located axially between these strips. The assembly further comprises a resin compound transfer member secured to the sheet. The method comprises arranging the prefabricated sealing assembly relative to the electric cable joint, retaining a first transverse end of the sheet, and wrapping the sealing assembly circumferentially about the electric cable joint. Herein the sealing assembly overlaps itself. The wrapping involves the exertion of a stretching force away from the retained first transverse end so that the sealing assembly is locally stretched into conformity with the electric cable joint. The second transverse end is secured onto the wrapped sealing assembly. A liquid resin compound is introduced via the resin compound transfer member into the space delimited by the sealing assembly, so that the space is filled whilst air is expelled via said air-permeable and resin compound blocking strips and so that the cable joint becomes embedded in the resin compound, which resin compound hardens thereafter.

Description

METHOD AND PREFABRICATED SEALING ASSEMBLY FOR SEALING AN ELECTRIC CABLE JOINT

The invention relates to the field of sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors. The sealing insulates and protects the cable joint, e.g. the cable joint being buried in the ground.

The applicant currently markets under the name FiloSlim a low voltage cable branch-off joint system. In the known embodiment of the system an open structure spacer mat is wrapped around the cable joint and secured by a piece of adhesive tape. Then a separate resin compound transfer member is secured by tape to the spacer mat, which transfer member has an internal channel for passage of resin compound. Then, in several layers, transparent adhesive tape is wound helically over the spacer mat to obtain a sealed space wherein the joint is located. In a following step, a dual chamber bag filled with two resin components is provided. The temporary barrier between the chambers of the bag is removed and the components are mixed by kneading of the bag, so that the resin compound is obtained. The bag is then connected by a connector member thereof to the transfer member, e.g. as described in WO2014/126473. By squeezing the bag, e.g. manually of by means of a pump device, the resin compound is injected into the space. The liquid resin compound embeds the conductors of the cables as well as the connectors of the conductors. In the process, the spacer mat is also filled with resin and guarantees a minimum thickness of the insulation afforded by the resin compound. The resin compound is cold hardening, and will harden over time.

The known FiloSlim system is, for example, used to seal the branch-off connection between the electricity mains of a house to the main cable lying under or along the street. Other known applications are, for example, connecting a EV charging station or a street lighting device to the main cable. Normally, a hole is dug to create a working space for the electrician making the joint. Once the joint has been made, the electrician has to apply the FiloSlim system as explained above Herein, it is known to arrange an air-permeable resin blocking member between the parallel cables prior to the wrapping of the open structure spacer mat as described above. The present invention aims to enhance the installation of the electric cable joint sealing system. For example, it is an object of the invention to reduce the time required to install the sealing system. For example, it is an object of the invention to reduce the efforts required to install the sealing system.

The present invention achieves one or more of the objectives above by providing a method according to claim 1.

In the inventive method use is made of a prefabricated sealing assembly, which sealing assembly comprises:

- an impervious sheet of film material, said sheet having an inner side, an outer side, opposed axial ends, and opposed first and second transverse ends, said sheet being at least partially transparent, said sheet being stretchable in a direction between the opposed transverse ends,

- an open structure spacer mat that is fixed on the inner side of the impervious sheet and is stretchable in a direction between the opposed transverse ends of the impervious sheet,

- a pair of air-permeable and resin compound blocking strips mounted to the inner side of the impervious sheet, each at a respective axial end thereof so that the spacer mat is located axially between said resin blocking strips,

- a resin compound transfer member that is secured to the impervious sheet and that has an internal channel for passage of resin compound.

Instead of, as in the prior art, having the open structure spacer mat as a separate article to be installed, the invention envisages a prefabricated assembly wherein the spacer mat is integrated with the impervious sheet of film material. Also, the pair of air-permeable and resin compound blocking strips are part of the prefabricated assembly, as well as the resin compound transfer member. This assembly is thus to be handled as a unit when installing the sealing system.

The assembly is configured to be stretched when being wrapped around the electric cable joint, as both the impervious sheet of film material and the open structure spacer mat allow for stretching in the direction between the transverse ends (so in circumferential direction about the cable joint during installation). The inventive method comprises:

- arranging the sealing assembly relative to the electric cable joint so that the axial ends of the sealing assembly are aligned with opposed axial ends of the electric cable joint to be sealed,

- retaining the first transverse end of the impervious sheet relative to the electric cable joint,

- wrapping the sealing assembly circumferentially about the electric cable joint, wherein the sealing assembly overlaps itself, wherein said wrapping involves the exertion of a stretching force away from the retained first transverse end so that the sealing assembly is locally stretched into conformity with the electric cable joint,

- securing the second transverse end onto the wrapped sealing assembly,

- introducing a liquid resin compound via the resin compound transfer member into the space delimited by the sealing assembly, so that the space is filled with said resin compound whilst air is expelled via said air-permeable and resin compound blocking strips and so that the cable joint becomes embedded in said resin compound, said resin compound hardening thereafter.

Through the use of the inventive prefabricated assembly, much time is saved in installation of the sealing system. Also less effort is required by the person performing the installation.

In an embodiment, the impervious sheet is made of polyurethane. Other sheet materials affording stretch, and preferably also a resistance against being punctured, are also possible. For example, the sheet is made as a multilayer sheet.

In an embodiment, the impervious sheet has a pressure sensitive adhesive on its entire inner surface, the spacer mat being stuck onto said inner side of the sheet. In another embodiment, the spacer mat is provided with an adhesive side that is stuck onto the sheet so as to integrate the sheet and the spacer mat. The spacer mat could be adhered by other processes to the sheet as well, e.g. heat sealing, etc.

In an embodiment, the spacer mat is non-stick on its inner side, which may facilitate application of the assembly about the cable joint. In another embodiment, the inner side of the spacer mat is provided with a pressure sensitive adhesive, e.g. only over one or more portions of the spacer mat at or along the first transverse end allowing for initial retention of said first end relative to the cable joint.

In an embodiment, the pair of air-permeable and resin compound blocking strips are embodied as strips of open celled foam material that allows for ventilation of air when resin compound is introduced, yet blocks the escape of resin compound. For example, each foam strip has a width of between 2 and 5 centimeters, e.g. about 4 centimeters. For example, the sheet is provided with an adhesive side to which these strips are stuck. In another embodiment, the strips are provided with an adhesive side that is stuck to the sheet.

In an embodiment, the air-permeable and resin compound blocking strips are embodied as integral part of the spacer mat, e.g. the spacer mat being provided with a less open structure along the axial edges thereof to form these strips, e.g. the mat being compressed in each axial edge zone to achieve the desired air-permeability combined with a blocking property for the resin compound that is introduced into the space enveloped by the prefabricated assembly.

The strips could be made of non-porous material in which small air passages are made.

Preferably, the strips are made of synthetic foam material, e.g. an open-celled foam material.

In an embodiment, the resin compound transfer member is provided with a valve that is closed, or closes, once the filling has been completed.

In an embodiment, the prefabricated sealing assembly is provided with a pressure sensitive adhesive portion at the second transverse end, e.g. extending as an elongated adhesive portion along a majority or entirety of the length of the second transverse end. In use, the step of securing the second transverse end onto the wrapped sealing assembly is done by means of the pressure sensitive adhesive portion. This allows the person performing the installation to keep the fabricated assembly wrapped under tension about the cable joint, as the person does not need to grasp, for example, a roll of adhesive tape to secure the second transverse end.

In an embodiment, the prefabricated sealing assembly also comprises a removable cover over the pressure sensitive adhesive portion at the second transverse end. The method then comprises the removal of said cover prior to securing the second transverse end onto the wrapped sealing assembly. This avoids any premature sticking of the adhesive portion on the wrapped assembly.

In an embodiment, the prefabricated sealing assembly is provided with a pressure sensitive adhesive portion at the first transverse end, e.g. also initially covered by a removable cover. Retaining the first transverse end is then done by means of the pressure sensitive adhesive portion. For example, this adhesive portion is stuck onto a connector block of the cable joint.

In an embodiment, the axial ends of the impervious sheet define a width of the prefabricated sealing assembly of at least 30 centimeters, e.g. between 30 and 55 centimeters, e.g. about 43 centimeters.

In an embodiment, the transverse ends of the impervious sheet define a length of the prefabricated sealing assembly of at least 20 centimeters, e.g. between 20 and 50 centimeters, e.g. about 40 centimeters.

In an embodiment, the electric cable joint is a branch-off joint, e.g. as disclosed in figure 3 of NL1002859 of the applicant. Herein the second cable extends generally parallel to the first cable at the electric cable joint. As preferred, use is than further made of a cable spacer member e.g. of a 3D open structure, and a resin blocking member, e.g. an air-permeable resin blocking member, e.g. an integrated cable spacer and resin blocking member. Prior to the provision of the prefabricated sealing assembly about the electric cable joint, the cable spacer member is arranged between the parallel first and second cables, so that resin compound can flow in between them. The resin blocking member is arranged axially outwards of the cable spacer member so as to contain the resin compound. As mentioned, these members can be provided as an integrated unit, which is preferred. After arranged these members, of this unit, the prefabricated sealing assembly is provided, As preferred herein, one axial end of the prefabricated sealing assembly is wrapped over the resin blocking member. Then liquid resin compound is introduced via the resin compound transfer member into the space delimited by the sealing assembly and the resin blocking member.

In an embodiment, the space to be filled with resin compound is reduced by tightening, after provision of the prefabricated sealing assembly about the electric cable joint and prior to the introduction of liquid resin compound via the resin compound transfer member, one or more strapping elements about the prefabricated sealing assembly. For example, the strapping element being an adhesive tape, e.g. a transparent adhesive tape, that is wound helically about the prefabricated sealing assembly from one axial end to the other axial end, preferably in one layer only.

In an embodiment, the resin compound is injected under pressure from a container that is temporarily coupled to the resin compound transfer member into the space to be filled. The container can be a rigid cartridge, e.g. a two component cartridge, that is placed in a pumping device.

In an embodiment, the container is a bag that is squeezed to inject the resin compound into the space to be filled. Preferably, the bag holds enough resin compound, or the components to be mixed into the resin compound, to fill the whole space of the sealed joint. This avoids the need for the person performing the installation to use multiple bags of resin compound for a single joint. For example, the bag holds at least 1 litre of resin compound, e.g. about 1.5 litre, e.g. between 1 and 2 litre.

In an embodiment, the squeezing of the bag comprises manually rolling up of the bag onto a rod member.

In an embodiment, the bag is a dual chamber bag, wherein a first chamber of the bag is filled with a first resin component and a second chamber of the bag filled with a second resin component, the first and second chamber being separated by a temporary barrier, e.g. a breakable seal or a removable clamp, allowing to bring the chambers into communication in order to mix the components prior to discharge of the mixed resin from the bag.

The present invention also relates to a prefabricated sealing assembly for sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, e.g. for use in a method as described above. Herein the sealing assembly comprises:

- an impervious sheet of film material, said sheet having an inner side, an outer side, opposed axial ends, and opposed transverse ends, said sheet being at least partially transparent, said sheet being stretchable in a direction between the opposed transverse ends,

In an embodiment, the prefabricated sealing assembly is further provided with a pressure sensitive adhesive portion at said second transverse end allowing for securing the second transverse end onto the wrapped sealing assembly by means of the pressure sensitive adhesive portion, for example wherein the prefabricated sealing assembly comprises a removable cover over the pressure sensitive adhesive portion at said second transverse that is to be removed prior to securing the second transverse end onto the wrapped sealing assembly.

In an embodiment, the prefabricated sealing assembly is provided with a pressure sensitive adhesive portion at the first transverse end allowing for retaining the first transverse end by means of the pressure sensitive adhesive portion.

The present invention also relates to a system for sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, e.g. for use in the method as described herein, wherein the system comprises a prefabricated sealing assembly according as described herein, and one or more of:

- cable spacer member, e.g. of a 3D open structure, and a resin blocking member, e.g. an air-permeable resin blocking member, e.g. an integrated cable spacer and resin blocking member for use in the method of claim 4,

- one or more strapping elements that are to be tightened about the prefabricated sealing assembly so that the space to be filled with said resin compound is reduced, e.g. the strapping element being an adhesive tape that is to be wound helically about the prefabricated sealing assembly from one axial end to the other axial end,

- a container filled with resin compound that is to be temporarily coupled to the resin compound transfer member for filling the space, for example wherein the container is a bag that is squeezed to inject the resin compound into the space to be filled, e.g. wherein the bag is a dual chamber bag, wherein a first chamber of the bag is filled with a first resin component and a second chamber of the bag filled with a second resin component, the first and second chamber being separated by a temporary barrier, e.g. a breakable seal or a removable clamp, allowing to bring the chambers into communication in order to mix the components prior to discharge of the mixed resin from the bag.

The present invention also relates to a dual chamber bag filled with two resin components to form a resin compound, e.g. the resin compound being configured for use in sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, wherein a first chamber of the bag is filled with a first resin component and a second chamber of the bag filled with a second resin component, the first and second chamber being separated by a temporary barrier, e.g. a breakable seal or a removable clamp, allowing to bring the chambers into communication in order to mix the components into a resin compound, e.g. a cold-curing electrically insulating resin, e.g. a two-component cold curing polyurethane resin, prior to discharge of the mixed resin from the bag, wherein the first chamber extends between the temporary barrier and a first end of the bag, and wherein the bag, optionally, has a valved connector member at said first end that is configured to be connected to a mating resin compound transfer member and to be opened on making said connection, and wherein the second chamber extends between the temporary barrier and a second end of the bag, and wherein bag has a handgrip at said second end, so that, in use, the temporary barrier is removed or broken, and the bag is held by its first end in one hand of a user and by its second end in the other hand of the user and is shaken back and forth to mix the resin components to create the resin compound that is to be expelled from the bag. The resin compound may also be used for other purposes than sealing an electric cable junction, e.g. for epoxy resin compounds that are used for, for example, as adhesive or as liquid tight sealant for the bottom of an (outdoor) electric equipment cabinet, etc.

In an embodiment, the dual chamber bag is devoid of sharp corners, e.g. devoid of corners delimited by perpendicularly arranged seals between film walls that make up the bag. For example, the corners, e.g. at least at the second end of the bag, are delimited by a diagonal seal between the film walls that make up the bag, thereby avoiding a sharp corner. The absence of sharp corners within the bag avoids that resin material located in such a corners does not become mixed and/or reduces the efforts required for proper mixing of the components initially stored in each of the chambers of the bag.

The present invention also relates to a method for providing a resin compound, e.g. for use in sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, wherein use is made of a dual chamber bag as described herein and the bag is held by its first end in one hand of a user and by its second end in the other hand of the user and is shaken back and forth to mix the resin components to create the resin compound that is to be expelled from the bag. For example, herein, the bag is mainly held horizontally during said shaking back and forth. Preferably, the components in the chambers of the bag are each liquid and the total volume is at least 1 liter, e.g. between 1 and 4 liter.

The present invention also relates to a method for expelling a resin compound from a dual chamber bag, e.g. for use in sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, wherein a first chamber of the bag is filled with a first resin component and a second chamber of the bag filled with a second resin component, the first and second chamber being separated by a temporary barrier, e.g. a breakable seal or a removable clamp, allowing to bring the chambers into communication in order to mix the components into a resin compound prior to discharge of the mixed resin from the bag, wherein the first chamber extends between the temporary barrier and a first end of the bag, for example, wherein the bag has a valved connector member at said first end that is configured to be connected to a mating resin compound transfer member and to be opened on making said connection, and wherein the second chamber extends between the temporary barrier and a second end of the bag, wherein use is made of a rod member and wherein the bag is squeezed to expel the resin compound by manually rolling up of the bag onto the rod member.

For example, as known in the art, the clamp is composed of an axially slotted outer clamp member that is located at one side of the bag and an elongated inner clamp member, e.g. an inner tubular clamp member. Herein the bag is locally pinched between the inner clamp member and the outer clamp member as the inner clamp member along with a pinched section of the bag is pressed into the axially slotted outer clamp member.

In an embodiment of the above method, the rod member has a narrow slit, e.g. that extends to one axial end of the rod member, wherein the method comprises sliding the rod member over an emptied portion of the bag wherein the emptied portion is received in the narrow slit, sliding the rod member towards the first end of the bag so as to urge the resin compound in said direction of the first end, rolling up the bag about the rod member manually so as the pressurize and thereby expel resin compound from the bag.

The present invention also relates to the combination of a dual chamber bag filled with two resin components to be mixed to form a resin compound and a rod member as described herein to expel the mixture from the bag after mixing.

The present invention also relates to a method for sealing an electric cable joint wherein use is made of a prefabricated sealing assembly which comprises an impervious sheet that is at least partially transparent and is stretchable in a direction between opposed transverse ends. An open structure spacer mat is fixed on the inner side of the sheet and is stretchable the same direction as the sheet. A pair of air-permeable and resin compound blocking strips is mounted to the inner side of the sheet so that the spacer mat is located axially between these strips. The assembly further comprises a resin compound transfer member secured to the sheet. The method comprises arranging the prefabricated sealing assembly relative to the electric cable joint, retaining a first transverse end of the sheet, and wrapping the sealing assembly circumferentially about the electric cable joint. Herein the sealing assembly overlaps itself. The wrapping involves the exertion of a stretching force away from the retained first transverse end so that the sealing assembly is locally stretched into conformity with the electric cable joint. The second transverse end is secured onto the wrapped sealing assembly. A liquid resin compound is introduced via the resin compound transfer member into the space delimited by the sealing assembly, so that the space is filled whilst air is expelled via said air-permeable and resin compound blocking strips and so that the cable joint becomes embedded in the resin compound, which resin compound hardens thereafter.

The present invention also relates to an alternative for the prefabricated sealing assembly and associated method as described herein, e.g. as described in the claims, wherein in the alternative the pair of air-permeable and resin compound blocking strips are not mounted to the inner side of the impervious sheet of the sealing assembly. Instead, in this alternative, they are provided as separate items, e.g. embodied as open-celled foam strips that are to be fitted on the cable(s) prior to the application of the prefabricated sealing assembly. This is somewhat less efficient during installation than the sealing assembly of claim 1 , yet still is advantageous compared to the prior art approach. In yet another embodiment, these air- permeable and resin compound blocking strips are entirely absent, with ventilation holes being provided in-situ in the impervious sheet by the person performing the installation of the sealing system. These holes are then to be covered later on, e.g. using adhesive tape, to avoid undue leakage of resin compound before hardening is sufficient. This approach is known from the prior art, and is seen as even less efficient.

The present invention also relates to an integrated cable spacer and resin sealing member as described herein for use in the sealing of an electrical cable joint.

The invention will now be described with reference to the drawings. In the drawings:

Fig. 1 shows an electric cable branch-off joint that is to be sealed using a method and sealing assembly according to the invention,

Fig. 2 shows the application of spacer mat elements about exposed sections of the conductive overall shield of the first cable,

Figs. 3, 4, 5 show the application of the integrated cable spacer and resin sealing member between the first and second cables,

Fig. 6 shows an example of a prefabricated sealing assembly, Fig. 7 shows arranging the sealing assembly of figure 6 relative to the electric cable joint of figure 5,

Fig. 8 shows retaining the first transverse end of the impervious sheet relative to the electric cable joint,

Figs. 9, 10 show wrapping the sealing assembly circumferentially about the electric cable joint,

Fig. 11 shows removing the cover from the pressure sensitive adhesive portion at the second transverse end of the impervious sheet,

Fig. 12 shows the secured prefabricated sealing assembly after being wrapped around the electric cable joint and being locally stretched into conformity with the electric cable joint,

Figs. 13, 14, 15 show tightening a strapping element about the wrapped prefabricated sealing assembly so that the space to be filled with said resin compound is reduced,

Fig. 16 shows the electric cable branch-off joint wrapped by prefabricated sealing assembly prior to filling the resin compound,

Fig. 17 shows the dual chamber bag for use in sealing the electric cable joint of figure 16,

Fig. 18, 19 show the removal of the barrier between the chambers of the dual chamber bag, Fig. 20 shows the mixing of the resin components in the dual chamber bag,

Fig. 21 shows the bag of figure 20 connected to the transfer component of the prefabricated sealing assembly of figure 16,

Fig. 22 shows the rod member for use in expelling the resin compound from the bag of figure

20,

Fig. 23 shows the rod member of figure 21 being slid over the bag,

Fig. 24 shows expelling the resin compound by rolling up the bag about the rod member.

With reference to the drawings, a complete sequence for installation of the inventive electric cable branch-off joint seal will be explained.

Fig. 1 shows an electric cable branch-off joint that is to be sealed using a method and sealing assembly according to the invention, e.g. as the cable joint is to be buried in the ground.

The first cable 1 is, for example, a low voltage main cable as used in the electricity grid to which multiple consumers, e.g. domestic houses and/or electric vehicle charging stations are to be connected.

In this example, the cable 1 has four conductors for a three phase AC grid. The second cable 2 is the branch-off cable. As is common in the field, the cable 1 has been worked on to expose the relevant conductors, and connectors 3, 4 are used to make the relevant electrical connections to the ends of the conductors in the second cable 2.

The figure 1 also shows sections 5 of exposed conductive overall shield of the cable 1.

Once this has been completed, a waterproof, insulating, and protective seal of the cable joint is required e.g. as the sealed cable joint is arranged in the ground.

Figure 2 shows the application of spacer mat elements 8 about the exposed sections 5 of the conductive overall shield of the first cable 1. This guarantees is sufficiently thick electrical insulation about these sections 5.

Figures 3, 4, and 5 show the application of the integrated cable spacer and resin sealing member 10 between the parallel extending first and second cables 1, 2. This member 10 combines a cable spacer member 11 , here embodied as a 3D open structure, and a resin blocking member 12, here embodied as an air-permeable resin blocking member, e.g. of open celled foam. It is shown that - prior to the provision of a prefabricated sealing assembly about the electric cable joint - this integrated cable spacer member 11 is arranged between the parallel first and second cables 1, 2 and the resin blocking member 12 is axially outwards of the cable spacer member 11. For example, as shown, the member 12 has opposed cut outs to receive in each of them one of the cables 1, 2 with a central bridge portion in between. As preferred, the spacer member 11 extends inwards from the central bridge portion, e.g. of the same material as the spacer mat of the prefabricated assembly.

Figure 6 shows the prefabricated sealing assembly 20 before being installed.

The sealing assembly 20 comprises an impervious sheet 25 of film material, e.g. of polyurethane film material. The sheet 25 has an inner side (shown facing down in figure 6), an outer side, opposed axial ends 26, 27, and opposed first and second transverse ends 28, 29.

The sheet 25 is at least partially, preferably entirely, transparent. In use, this allows the person performing the installation whether the resin compound has fully filled the space. For example, the resin compound is black when mixed.

The sheet 25 is stretchable, preferably by hand, in a direction between the opposed transverse ends 28, 29, so circumferentially about the cable joint during installation. The assembly 20 further comprises an open structure spacer mat 30 that is fixed on the inner side of the impervious sheet 20 so as to be integrated with the sheet. The mat 30 is stretchable in a direction between the opposed transverse ends 28, 29 of the impervious sheet so as to be stretched along with the sheet 20 about the cable joint during the installation.

As discussed, preferably the sheet 25 has adhesive, e.g. pressure sensitive adhesive, on its inner side, e.g. the entire inner side, with the mat 30 being stuck onto said inner side by said adhesive on the inner side.

The assembly 20 further comprises a pair of air-permeable and resin compound blocking strips 40 that are mounted to the inner side of the impervious sheet, e.g. as they are stuck onto the adhesive inner side of the sheet 25 during fabrication of the assembly, so as to be integrated with the sheet. For example, the strips are embodied as strips of open celled foam material that allows for ventilation of air when resin compound is introduced, yet blocks the escape of resin compound. For example, each foam strip 40 has a width of between 2 and 5 centimeters, e.g. about 4 centimeters.

Each strip 40 is located at a respective axial end of the sheet 20 so that the spacer mat 30 is located axially between said resin blocking strips 40. As shown, it is possible for the mat 30 to extend beyond the first transverse end 28 when desired.

The assembly 20 is provided with a pressure sensitive adhesive portion 50 at the second transverse end 29. For example, as here, the portion 50 is formed by a portion of the adhesive inner side of the sheet 20 at said end 20.

It is shown that a user removable cover 55 is applied over the portion 50 to avoid premature sticking of the end 29.

The assembly 20 is provided with a pressure sensitive adhesive portion 60 at the first transverse end 28. Here just one centrally located portion 60 covered by removable cover 65 is depicted. Other arrangements, e.g. comprising further portions 60 at the axial ends of the sheet 20 are also envisaged.

The assembly 20 further comprises a resin compound transfer member 70 that is secured to the impervious sheet 25 and that has an internal channel for passage of resin compound, e.g. provided with a valve, e.g. embodied as disclosed in WO2014/126473 or in EP2645500.The member 70 can also be secured to the spacer mat.

Figure 7 shows arranging the sealing assembly 20 of figure 6 relative to the electric cable joint of figure 5. The cover 65 has been removed already to allow the subsequent sticking of portion 60 onto a part of the cable joint to retain the first transverse end 28. This action is shown in figure 8.

Figure 9 illustrates that, with the end 28 being retained, the person performing the installation wraps the sealing assembly 20 circumferentially about the electric cable joint. As shown said wrapping involves the exertion of a stretching force in circumferential direction, effectively pulling on end 29, so in a direction away from the retained first transverse end 28.

As shown in figure 10 the wrapping is done so that the assembly 20 overlaps itself, preferably at most once or even just over a part. It is also shown that the sealing assembly 20 is locally stretched into conformity with the electric cable joint which clearly has a non constant cross-section over its length due to the presence of the conductors, connectors, etc. The stretching involves the stretching of the impervious sheet 25 in a direction between the opposed transverse ends, as well as of the open structure spacer mat 30 that is fixed on the inner side of the impervious sheet and is stretched along with the sheet 25 in the direction between the opposed transverse ends 28,29 of the impervious sheet.

Figure 11 shows that the stretching force is maintained, whilst the temporary cover 55 is removed at the second transverse end 29. Then this sticky portion 50 is stuck onto the wrapped assembly 20, so as to secure the second end 29.

Figures 10 and 11 also show that one axial end of the assembly 20 is wound over the member 10, with the permeable member 12 thereof remaining exposed to the exterior and thereby being functional in the later escape of air when the resin compound is injected.

Figure 12 shows the secured prefabricated sealing assembly after being wrapped around the electric cable joint and being locally stretched into conformity with the electric cable joint.

In order to further reduce the space to be filled with resin compound, a strapping element 80 is tightening about the wrapped prefabricated sealing assembly of figure 12. This is shown in figures 13, 14, and 15. Herein, as preferred, the element 80 is an adhesive tape, preferably a transparent adhesive tape, that is wound helically about the prefabricated sealing assembly from one axial end to the other axial end, as preferred in a single layer only.

The wrapping of the tape 80 does not require accuracy as it would in case the tape would form the impervious exterior of the sealing system as in the mentioned prior art approach.

Instead of, or combined with, tape 80 one could use a string, one or more cable binders, etc., to strap in the assembly 20.

Figure 16 shows the electric cable branch-off joint wrapped by prefabricated sealing assembly and tightened by tape 80 prior to filling the resin compound, e.g. a cold curing two- component polyurethane resin compound.

Figure 17 shows the dual chamber bag 100 of figure 16. A first chamber 101 of the bag is filled with a first resin component and a second chamber 102 of the bag filled with a second resin component, the first and second chamber being separated by a temporary barrier 105. The barrier here is embodied as a well-known removable clamp composed of an axially slotted outer clamp member that is located at one side of the bag and an elongated inner clamp member, e.g. an inner tubular clamp member. Herein the bag is locally pinched between the inner clamp member and the outer clamp member as the inner clamp member along with a pinched section of the bag is pressed into the axially slotted outer clamp member.

The first chamber 101 extends between the temporary barrier 105 and a first end 106 of the bag, and the bag has a valved connector member 110 at said first end 106 that is configured to be connected to mating resin compound transfer member 70 of assembly 20. The member 110 is configured to be opened on making said connection.

The second chamber 102 extends between the temporary barrier 105 and a second end 107 of the bag 100. The bag 100 has a handgrip 115 at said second end.

Figures 18 and 19 show the removal of the barrier 105 between the chambers 101, 102 of the dual chamber bag.

Once the temporary barrier 105 has been removed or broken, the bag 100 is held as shown in figure 19 by its first end in one hand of a user and by its second end in the other hand of the user and is shaken back and forth to mix the resin components to create the resin compound that is to be expelled from the bag. The mixing is enhanced by the presence of a substantial volume of components, e.g. at least 1 liter, e.g. between 1 and 2 liter, in the bag 100. With less filled volume, the sloshing of liquid back and forth in the bag does cause insufficient mixing, requiring the user to cause mixing primarily by kneading of the bag with requires more effort.

Mixing is further enhanced by avoiding sharp corners in the bag. For example, corners at the second end 1-7 of the bag 100 are bounded by diagonal seals 108 between the film walls that make up the bag 100. The absence of sharp corners within the bag avoids that resin material located in such a corners does not become mixed and/or reduces the efforts required for proper mixing of the components initially stored in each of the chambers of the bag.

Once mixing has been done satisfactory, e.g. witnessed by the uniform colour of the resin compound visible through the transparent film material of the bag 100, the connection between member 110 and resin compound transfer member 70 of assembly 20 is established, e.g. as described in WO2014/126473.

Figure 21 shows the bag of figure 20 being connected to the transfer component 70 of the prefabricated sealing assembly of figure 16.

Depending on the viscosity of the liquid resin compound, transfer of resin compound will start and the compound starts to fill the space enveloped by the assembly 20. Air is expelled via air-permeable strips 40 and air-permeable member 12.

Figure 22 shows the rod member 120 for use in expelling the resin compound from the bag 100 of figure 20. The rod member 120 has a narrow slit 121 that extends to one axial end of the rod member.

As shown in figure 23, the method comprises sliding the rod member 120 over an emptied portion of the bag 100 wherein the emptied portion is received in the narrow slit 121. Then the rod member 120 is slid towards the first end of the bag 100 so as to urge the resin compound in said direction of the first end. In a further stage, the bag is rolled up about the rod member manually so as the pressurize and thereby expel resin compound from the bag. This is shown in figure 24.

The resin compound is expelled until the entire space is filled with the resin compound, so that all conductors and connectors are fully embedded in the resin compound and the mat 30 is saturated with the resin compound. The person making the installation can easily see this through the transparent sheet 25. Once filling is completed, the bag 100 is disconnected. As preferred, a valve in the member 70 then closes. The resin compound is, preferably, cold hardening, so that the resin cures and hardens over time.

It is noted that the same assembly 20 can also be used for a double branch-off arrangement, wherein two instead of one branch-off cable is connected to the same first cable at one and the same junction. For example, the two branch-off cables extends in opposed axial directions from the junction. In this case a second member 10 is provided between the second branch-off cable and the first cable 1 and the assembly 20 is wrapped around the junction.

Claims

C L A I M S

1. Method for sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, wherein use is made of a prefabricated sealing assembly (20), which sealing assembly comprises:

- an impervious sheet (25) of film material, said sheet having an inner side, an outer side, opposed axial ends (26,27), and opposed first and second transverse ends (28,29), said sheet being at least partially transparent, said sheet being stretchable in a direction between the opposed transverse ends (28,29),

- an open structure spacer mat (30) that is fixed on the inner side of the impervious sheet and is stretchable in a direction between the opposed transverse ends (28,29) of the impervious sheet,

- a pair of air-permeable and resin compound blocking strips (40) mounted to the inner side of the impervious sheet (25), each at a respective axial end thereof so that the spacer mat is located axially between said resin blocking strips,

- a resin compound transfer member (70) that is secured to the impervious sheet and that has an internal channel for passage of resin compound, wherein the method comprises:

- arranging the prefabricated sealing assembly (20) relative to the electric cable joint so that the axial ends (26,27) of the sealing assembly are aligned with opposed axial ends of the electric cable joint to be sealed,

- retaining the first transverse end (28,60) of the impervious sheet relative to the electric cable joint,

- wrapping the sealing assembly (20) circumferentially about the electric cable joint, wherein the sealing assembly overlaps itself, wherein said wrapping involves the exertion of a stretching force away from the retained first transverse end (28) so that the sealing assembly is locally stretched into conformity with the electric cable joint,

- securing the second transverse end (29,50) onto the wrapped sealing assembly,

- introducing a liquid resin compound via the resin compound transfer member (70) into the space delimited by the sealing assembly (20), so that the space is filled with said resin compound whilst air is expelled via said air-permeable and resin compound blocking strips (40) and so that the cable joint becomes embedded in said resin compound, said resin compound hardening thereafter.

2. Method according to claim 1, wherein the prefabricated sealing assembly is provided with an adhesive portion (50) at said second transverse end (29), and wherein securing the second transverse end onto the wrapped sealing assembly is done by means of the adhesive portion (50), for example wherein the prefabricated sealing assembly comprises a removable cover (55) over the adhesive portion (50) at said second transverse end and the method comprises the removal of said cover prior to securing the second transverse end onto the wrapped sealing assembly.

3. Method according to claim 1 or 2, wherein the prefabricated sealing assembly (20) is provided with an adhesive portion (60) at said first transverse end (28), and wherein retaining the first transverse end is done by means of the adhesive portion.

4. Method according to any one or more of claims 1 - 3, wherein the electric cable joint is a branch-off joint, wherein the second cable (2) extends generally parallel to the first cable

(I) at the electric cable joint, and wherein use is further made of a cable spacer member

(II), e.g. of a 3D open structure, and a resin blocking member (12), e.g. an air-permeable resin blocking member, e.g. an integrated cable spacer and resin blocking member (10), wherein the method comprises - prior to the provision of the prefabricated sealing assembly about the electric cable joint - arranging the cable spacer member (11) between the parallel first and second cables (1,2) and arranging the resin blocking member (12) axially outwards of the cable spacer member, after which the prefabricated sealing assembly is provided, wherein upon said introduction of liquid resin compound via the resin compound transfer member into the space delimited by the sealing assembly and the resin blocking member.

5. Method according to any one or more of claims 1 - 4, wherein - after provision of the prefabricated sealing assembly (20) about the electric cable joint and prior to the introduction of liquid resin compound via the resin compound transfer member - one or more strapping elements (80) are tightened about the prefabricated sealing assembly so that the space to be filled with said resin compound is reduced, e.g. the strapping element being an adhesive tape that is wound helically about the prefabricated sealing assembly from one axial end to the other axial end.

6. Method according to any one or more of the claims 1 - 5, wherein the resin compound is injected under pressure from a container (100) that is temporarily coupled to the resin compound transfer member into the space to be filled.

7. Method according to claim 6, wherein the container is a bag (100) that is squeezed to inject the resin compound into the space to be filled, e.g. wherein the squeezing comprises manually rolling up of the bag onto a rod member.

8. Method according to claim 7, wherein the bag (100) is a dual chamber bag, wherein a first chamber (101) of the bag is filled with a first resin component and a second chamber (102) of the bag filled with a second resin component, the first and second chamber being separated by a temporary barrier, e.g. a breakable seal or a removable clamp (105), allowing to bring the chambers into communication in order to mix the components prior to discharge of the mixed resin from the bag.

9. A prefabricated sealing assembly (20) for sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, e.g. for use in a method according to one or more of claims 1 - 8, which sealing assembly comprises:

- an impervious sheet (25) of film material, said sheet having an inner side, an outer side, opposed axial ends, and opposed transverse ends, said sheet being at least partially transparent, said sheet being stretchable in a direction between the opposed transverse ends,

- an open structure spacer mat (30) that is fixed on the inner side of the impervious sheet and is stretchable in a direction between the opposed transverse ends of the impervious sheet,

- a pair of air-permeable and resin compound blocking strips (40) mounted to the inner side of the impervious sheet, each at a respective axial end thereof so that the spacer mat is located axially between said resin blocking strips,

- a resin compound transfer member (70) that is secured to the impervious sheet and that has an internal channel for passage of resin compound.

10. Prefabricated sealing assembly according to claim 9, further provided with an adhesive portion (50) at said second transverse end (29) allowing for securing the second transverse end onto the wrapped sealing assembly by means of the adhesive portion, for example wherein the prefabricated sealing assembly comprises a removable cover (55) over the adhesive portion at said second transverse that is to be removed prior to securing the second transverse end onto the wrapped sealing assembly.

11. Prefabricated sealing assembly according to claim 9 or 10, wherein the prefabricated sealing assembly (20) is provided with an adhesive portion (60) at said first transverse end allowing for retaining the first transverse end by means of the adhesive portion.

12. A system for sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, e.g. for use in the method according to one or more of claims 1 - 8, wherein the system comprises a prefabricated sealing assembly (20) according to any one or more of claims 9 - 11, and one or more of:

- a cable spacer member (11) e.g. of a 3D open structure, and a resin blocking member (12), e.g. an air-permeable resin blocking member, e.g. an integrated cable spacer and resin blocking member (10) for use in the method of claim 4,

- one or more strapping elements (70) that are to be tightened about the prefabricated sealing assembly so that the space to be filled with said resin compound is reduced, e.g. the strapping element being an adhesive tape that is to be wound helically about the prefabricated sealing assembly from one axial end to the other axial end,

- a container (100) filled with resin compound that is to be temporarily coupled to the resin compound transfer member for filling the space, for example wherein the container is a bag that is squeezed to inject the resin compound into the space to be filled, e.g. wherein the bag is a dual chamber bag, wherein a first chamber of the bag is filled with a first resin component and a second chamber of the bag filled with a second resin component, the first and second chamber being separated by a temporary barrier, e.g. a breakable seal or a removable clamp, allowing to bring the chambers into communication in order to mix the components prior to discharge of the mixed resin from the bag.

13. A dual chamber bag (100) for use in sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, wherein a first chamber (101) of the bag is filled with a first resin component and a second chamber (102) of the bag filled with a second resin component, the first and second chambers being separated by a temporary barrier, e.g. a breakable seal or a removable clamp (105), allowing to bring the chambers into communication in order to mix the components into a resin compound prior to discharge of the mixed resin from the bag, wherein the first chamber extends between the temporary barrier and a first end of the bag, and wherein bag has a valved connector member (110) at said first end that is configured to be connected to a mating resin compound transfer member (70) and to be opened on making said connection, and wherein the second chamber extends between the temporary barrier and a second end of the bag, and wherein bag has a handgrip (115) at said second end, so that, in use, the temporary barrier is removed or broken, and the bag is held by its first end in one hand of a user and by its second end in the other hand of the user and is shaken back and forth to mix the resin components to create the resin compound that is to be expelled from the bag.

14. Method for providing a resin compound for use in sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, wherein use is made of a dual chamber bag according to claim 13 and the bag (100) is held by its first end in one hand of a user and by its second end in the other hand of the user and is shaken back and forth to mix the resin components to create the resin compound that is to be expelled from the bag.

15. Method for expelling a resin compound from a dual chamber bag (100) for use in sealing an electric cable joint, e.g. a branch-off joint, wherein a first and second electric cable, each having one or more insulated conductors have been connected by one or more connectors, wherein a first chamber of the bag is filled with a first resin component and a second chamber of the bag filled with a second resin component, the first and second chamber being separated by a temporary barrier, e.g. a breakable seal or a removable clamp (105), allowing to bring the chambers into communication in order to mix the components into a resin compound prior to discharge of the mixed resin from the bag, wherein the first chamber extends between the temporary barrier and a first end of the bag, and wherein bag has a valved connector member at said first end that is configured to be connected to a mating resin compound transfer member and to be opened on making said connection, and wherein the second chamber extends between the temporary barrier and a second end of the bag, wherein use is made of a rod member (120), and wherein the bag is squeezed to expel the resin compound by manually rolling up of the bag onto the rod member.

16. Method according to claim 15, wherein the rod member (120) has a narrow slit (121) that extends to one axial end of the rod member, wherein the method comprises sliding the rod member over an emptied portion of the bag wherein the emptied portion is received in the narrow slit, sliding the rod member towards the first end of the bag so as to urge the resin compound in said direction of the first end, rolling up the bag about the rod member manually so as the pressurize and thereby expel resin compound from the bag.