Technical Field

The present invention concerns a seal, lead-through or transit for cables, wires or pipes. The invention especially concerns a compressible part or parts of the seal or transition, which part or parts is to surround a cable or pipe.

Prior Art

In the prior art there are cable transitions or the like having a frame, inside which a number of modules to receive cables, wires or pipes are placed. The modules are made of an elastic material e.g. rubber or plastics and are thus compressible. Inside the frame normally a number of modules are received side by side in one or more rows together with some kind of compression unit. The compression unit is placed between the frame and the modules in such a way that when the compression unit is expanded the compressible modules will be compressed around the cables, wires or pipes.

For ease of description the expression "cable" is mainly used in this descrip- tion, but it should be construed broadly and a person skilled in the art realises that it normally also covers pipes and wires. The same applies for "seal", which should be construed broadly to include also lead-through and transit etc.

Another type of seal for cables etc. has a general cylindrical form and is to be received in a sleeve in a wall or an opening in a wall. To function in the desired way the seal should fit snugly into the sleeve or the opening of the wall in which it is received and the seal should be adaptable to the actual mounting dimension. The mounting dimension is dictated by the inner diameter of the sleeve or the opening. The seal has a cylindrical compressible body, which is compressed axially between fittings at the opposite ends of the compressible body. By the axial compression the cylindrical body will expand radially both inwards and outwards. Furthermore, the pipes or cables received may have different outer diameters, and, thus, the module should be adaptable to cables or pipes having different outer diameters.

Seals of both the above kinds are used for sealing in many different environments, such as for cabinets, technical shelters, junction boxes and machines. They are used in different industrial environments, such as automotive, telecom, power generation and distribution, as well as marine and offshore. The seals may have to seal against fluid, gas, fire, rodents, termites, dust, moisture etc., and may receive cables or wires for electricity, communication, computers etc., pipes for different gases or liquids such as water, compressed air, hydraulic fluid and cooking gas or wires for load retention.

The parts receiving a single cable etc. of both the types discussed above often have a pack of peelable layers or sheets on the inside. The layers or sheets are peeled off until the inner diameter of the part is adapted to the outer diameter of the cable received in said part. The sheets adhere strong enough to each other to stay together and at the same time loose enough to enable the sheets to be peeled off from the stack, either one- by-one or a number of sheets together. In some embodiments there are also peelable layers or sheets on the outside, making it possible to adapt the outer dimensions of for instance a circular seal to a specific opening or sleeve.

Today the layers or sheets to be peeled off are separate parts and are normally discarded after being peeled off.

It is also known to use different types of so-called EMC modules. EMC stands for electromagnetic compatibility, i.e. the ability of electrical or electronic devices to function properly in their intended electromagnetic environment. EMC modules are basically standard modules provided with means to improve electromagnetic compatibility and prevent unwanted electromagnetic fields as well as grounding a cable screen. In some installations it is vital to dampen electromagnetic disturbances to protect differ- ent electrical or electronic equipments on the inside or outside of a wall, partition etc. receiving a seal or transition.

A person skilled in the art realises that the exact shape and form of the different parts, including the layers, may vary without departing from the gist of the present invention. For example the pack of layers may have another cross section form than cir- cular.

Summary

According to one aspect of the present invention the layers or sheets to be peeled off stick together. That means that when an appropriate number of sheets have been peeled off they still stick together. The bundled of peeled off sheets may then be easily collected and the material may be reused. In that the sheets stick together there are fewer parts that need to be collected. To reuse material is an environmental advantage.

A further advantage with all sheets sticking together is that it makes production more efficient and facilitates mounting of a bundle of sheets in a module half. Still a further advantage is that installation is facilitated. It is possible to first lift up an appropriate number of sheets, without peeling them off, and then control against the actual cable to be received. Finally, when the appropriate number of sheets is established the redundant sheets are peeled off. The bundle of sheets may also according to one aspect of the present invention be used as part of an EMC protection. This may be done in that a wire or other conductive thread is embedded in the bundle of sheets going through all sheets. It is also possible to make the sheets of a conductive material.

Further objects and advantages of the present invention will be obvious to a person skilled in the art when reading the detailed description below of different embodiments.

Brief Description of the Drawings

The invention will be described more closely below by way of an example and with reference to the enclosed drawings. In the drawings:

Fig. 1 is a perspective view of a module half used in one type of seal or transition for cables or pipes,

Fig. 2 is an end view of the module half of Fig. 1,

Fig. 3 is a perspective view of a module half according to Figs, land 2, with a first embodiment for peelable sheets,

Fig. 4 is a perspective view of a module half according to Figs, land 2, with a second embodiment for peelable sheets,

Fig. 5 is an end view of a seal or transition receiving modules according to any of the Figs. 1-4, Fig. 6 is a perspective view of a circular seal or transition for a cable or pipe,

Fig. 7 is a perspective view of one half of a further embodiment of a circular seal,

Fig. 8 is an end view of the embodiment of Fig. 7 with sheets lifted, and Fig. 9 is an end view of one embodiment of a module half, illustrating one further aspect of the present invention.

Detailed Description of Embodiments

In Figs. 1 and 2 one half of a module is shown. The module half has a base part 1, with a generally rectangular outer shape. The base part 1 has a semi cylindrical groove on one side receiving a number of peelable sheets 2. In use two module halves are placed with the semi cylindrical grooves facing each other and with a cable or pipe received between the two module halves. Thus, a cylindrical opening of the module is formed of the semi cylindrical grooves of the two module halves placed in contact with each other. To adapt the inner diameter of the cylindrical opening to the outer diameter of the cable or pipe to be received, a suitable number of sheets 2 are peeled off from each module half. To give a good seal the inner diameter of the central opening should normally be slightly smaller than the outer diameter of the cable or pipe received.

In Fig. 3 a module half is shown having a number of peelable sheets 3. Each peelable sheet 3 is fixed to a lower sheet by means of a joint 4 at one end. As shown the joints 4 are placed at alternate ends.

In Fig. 4 a module half is shown having a number of peelable sheets 5. Each peelable sheet 5 is fixed to a lower sheet by means of a joint 6 at one side. As shown the joints 6 are placed at alternate sides.

Alternative embodiments of the modules are given in the simultaneously filed applications entitled "A Module of a Pipe or Cable Lead-Through having Grooves on Opposite Sides", "Pipe or Cable Lead-Through Blocks", "A Cable or Pipe Lead- Through having Modularized Modules" and "Modules of a Cable or Pipe Lead-Through having Alternating Geometry" filed by the applicant of the present application. In one embodiment the modules are separated from a stack of module halves sticking together, as described in the simultaneously filed application named "Modules of Pipe or Cable Lead-Through Sticking Together", filed by the applicant of the present application. These applications are hereby incorporated by reference.

As used in this description the "ends" of the sheets 3, 5 refer to the parts of the sheets 3, 5 placed at the ends or short sides of the semi cylindrical groove of respective base part 1. The "sides" of the sheets 3, 5 refer in the same way to the parts of the sheets 3, 5 placed at the long sides of the semi cylindrical groove of respective base part 1.

The joints 4, 6 may have any form, as long as they are relatively easy to break by hand. At the same time the joints 4, 6 should be strong enough to hold adjacent sheets 3, 5 together when they have been peeled off. One way to achieve this is to make weakenings or indications of fracture at the joints 4, 6, for example by perforations or making the joint 4, 6 of a thinner material than the adjacent sheets 3, 5. The indications of fracture are normally formed in the same process as when the sheets 3, 5 are formed. Another way for the fixation is to use an adhesive or a weld at the ends or sides of the sheets 3, 5. In a further embodiment the joints are placed at the same end or at the same side of all the sheets in a stack of sheets. Thus, the joints are placed on top of each other at adjacent sheets. Also in this case the discarded sheets will stick together when the stack of sheets is broken at the appropriate joint. A common type of seals or transitions for cables and/or pipes is indicated in

Fig. 5. It has an outer frame 7 received in a wall or any other type of partition. Inside the frame 7 a number of modules 11 are arranged to receive a single cable or pipe each. Furthermore, a compression unit 8 is received inside the frame 7. The modules 11 are separated by stay plates 10, which are arranged to position the modules 11 safely inside the frame 7. In the shown example the modules have a number of peelable sheets 13 and an appropriate number of sheets 13 are peeled off to adapt the inner diameter of the module 11 to the outer diameter of the cable or pipe to be received. Each module 11 normally has a central blind 12, which is removed when the cable or pipe is received. Thus, when a module 11 is to receive a cable or a pipe the blind 12 is first removed and then a number of sheets 13 are peeled off. When all pipes and/or cables have been placed in a module 11 each, the compression unit 8 is activated. The function of the compression unit 8 is to expand inside the frame 11. As the compression unit expands it will compress the modules 11, which are made of a compressible material such as rubber. The modules 11 will be compressed in one direction and expand in other direction, pressing the modules 11 against the frame 7 and against the cable etc. received inside respective module 11.

The module halves of Figs. 1 to 4 are mainly intended for use in a frame 11 as described in connection with Fig. 5 above. However, they may also be used in other types of seals, for example cylindrical seals with an outer compressible body, inside of which one or more modules are placed. An alternative system including a frame is described in the simultaneously filed application entitled "Sealing System", filed by the applicant of the present application. This application is hereby incorporated by reference. The cross sectional form of the modules may also vary from the shown rectangular cross section. Thus, in other embodiments the modules have a polygonal cross sec- tion with at least three sides.

In Figs. 6 to 8 general examples of two further cylindrical seals or transitions are shown. The only difference between the two embodiments is that the cylindrical seal of Figs. 7 and 8 has peelable sheets 19 on the outside, making it possible to adapt the outer diameter of the seal to an opening or a sleeve in which the seal is to be received. The shown seals have a compressible body 14 and fittings at both ends. Only a forward fitting 15 is visible in Figs. 6 to 8. A number of screws 16 go between the fittings and through the compressible body 14. By means of the screws 16 the fittings may be moved toward each other, compressing the compressible body 14 in axial direction, whereby the compressible body 14 will expand in radial direction, both inwards and outwards. The radial expansion of the compressible body 14 will press inwardly against a cable or pipe and outwardly against an opening or a sleeve receiving the cylindrical seal or transition. The compressible body 14 is formed of two identical semi cylindrical halves or base parts 18. In other embodiments the partition between the base parts are off-centre, in which case the base parts are not identical. On the inside of the com- pressible body 14 an opening is formed, in which a number of peelable sheets 17 are placed. A suitable number of sheets 17 are peeled off to adapt the inner diameter of the compressible body 14 to a cable or pipe to be received. A person skilled in the art realises that also in this case each sheet 17 may be fixed to a lower sheet at a joint 20. The joints 20 between the sheets may be placed at one end or at one side of each sheet 17. The joints 20 are normally placed at alternate ends or sides. Also the peelable sheets 19 on the outside may be fixed to each other at a joint placed at alternate ends or sides. In the embodiment of Fig. 9 a conductive wire 21 is indicated. The wire 21 goes through all of the sheets 22. The wire 21 is placed at the surface of each sheet 22 facing the cable or pipe to be received. A person skilled in the art realises that the con- ductive wire 21 is to be connected to a conductive part of the module half and/or a frame etc. receiving the modules. Furthermore, for a cable to be received in the module an outer shell is normally taken away, in order to give contact between the wire and the cable.

In a further embodiment the sheets are made of a conductive material, whereby no wire is needed in the sheets.

The sheets may be arranged in many different ways and with different features as reflected in the simultaneously filed applications entitled "A Pipe or Cable Lead- Through having Layers of Different Thickness", "A Pipe or Cable Lead-Through having a Part Indicating Compression", "Cohering Between Layers of a Pipe or Cable Lead-Through", "Identification of Layers of a Pipe or Cable Lead-Through", "A Pipe or Cable Lead-Through having Penetrateable Modules", "A Pipe or Cable Lead-Through having Modules with a Dimensioning Function" and "A Pipe or Cable Lead-Through having Layers of Alternating Geometry", filed by the applicant of the present application. These applications are hereby incorporated by reference. In further alternative embodiments the seal, lead-through or transit of the present invention is furnished with means for lubrication as shown in the simultaneously filed application entitled "Lubrication of a Pipe or Cable Lead-Through", filed by the applicant of the present application. This application is hereby incorporated by refer- ence.

In still further alternative embodiments the seal, lead-through or transit of the present invention is furnished with eccentrically placed openings for a cable, pipe or wire as shown in the simultaneously filed application entitled "Eccentric Part of a Pipe or Cable Lead-Through", filed by the applicant of the present application. This applica- tion is hereby incorporated by reference.

In use the number of sheets 3, 5, 17, 22 to be peeled off from each base part 1, 18 of the compressible body 14 is first decided. This may be done by first pulling up a number of sheets, while they still hang together, then testing with the actual cable etc., whether an appropriate number of sheets have been pulled up. If too many sheets have been pulled up one or more sheets are pushed back and if too few sheets have been pulled up further sheets are pulled up. Finally, when the appropriate number of sheets has been decided the redundant sheets are torn off as one unit. If the exact number of sheets to be torn off is known the appropriate joint 4, 6, 20 may be broken directly. The peeled off sheets 3, 5, 17, 22 will stick together, which will facilitate handling of the discarded sheets 3, 5, 17, 22.

A person skilled in the art realises that the different parts of the embodiments described above may be combined in many different ways. For example sheets having a conductive wire may be used with circular seals.