WO2018193420A1

WO2018193420A1 - Cable transit module

Info

Publication number: WO2018193420A1
Application number: PCT/IB2018/052767
Authority: WO
Inventors: Massimo Spinelli
Original assignee: Wallmax S.R.L.
Priority date: 2017-04-21
Filing date: 2018-04-20
Publication date: 2018-10-25
Also published as: IT201700044246A1

Abstract

Cable transit module (10) comprising two half-shells (11, 11') having two respective semicylindrical seats (12) that, when the cable transit module (10) is assembled, form a cylindrical seat or duct for the passage of an electric cable (20), each half-shell (11, 11') comprising an elastically compressible body (13, 13') and a system of conductors (14, 14', 15, 15') that extend on the compressible body (13, 13') from the external surface to the surface of the semicylindrical seat (12) passing through the body (13, 13') itself, the conductors (14, 14', 15, 15') being co-moulded with the compressible body (13, 13'), each half-shell (11, 11') having on the semicylindrical seat (12) a stack of removable layers (18), which is divided into three sectors side by side, among which the central sector is intended, in the assembly configuration, to be overhung by said metal foils (14, 15; 14', 15'), said system of conductors (14, 14', 15, 15') comprising two metal foils (14, 15; 14', 15') that extend from two opposite portions of a cross-section of said compressible body (13, 13'), wrap such cross-section up to at least one passage portion (16) through which they penetrate into the compressible body (13, 13') and then extend, in the assembly configuration, towards opposite directions to each other folded onto the semicylindrical seat (12) identified by said central sector.

Description

CABLE TRANSIT MODULE

The present invention relates to a cable transit module intended to be mounted on a wall to allow cables, in particular electric cables, to pass through the wall itself .

The cable transit modules typically used today are, in particular, provided to ensure the sealed passage of liquids, gas or other particles.

In fact, these cable transit modules are very useful during the implementation of electric or hydraulic systems in structures such as ships or aeroplanes in which there are no walls where it is possible to integrate ducts for the passage of cables but only thin walls that separate the different environments and that must be passed through by the cables.

Generally, the cable transit modules known today consist of bodies of compressible elastic material that have a duct intended to be passed through by a cable or a pipe; such compressible bodies typically are composed of two half-shells coupled to each other and are usually housed in a seat realized on rigid frames intended to be applied stably to a wall. The seal against gases, liquids or particles of the ducts is obtained by appropriately compressing the modules themselves packed into the frame, so that the ducts are enclosed and compressed sealingly around the cables that pass through them.

In some cases, it may also be necessary to protect the passage of the individual cable transit module from any disturbance or electromagnetic interference that could be coupled with the cable that passes through the cable transit module. For that purpose, cable transit modules provided with conductor systems adapted to realize an electrical connection between a portion of cable housed inside the duct and a conductor body connected to ground outside the module, e.g. the support frame of the modules, are known. One of these conductor systems may be formed, for example, by a tape conductor element typically made of aluminium, that is arranged in the duct and that extends from the inside to the outside of the compressible body so as to be interposed between the compressible body and the cable that passes through it. In that case, the insulating sheath is removed from the portion of cable intended to be housed inside the cable transit module exposing the relative conductor stretch. In this way, once the assembly is complete, the conductor of the cable enters into direct connection with the tape conductor element which outside the module is then electrically connected to ground. Thus, any disturbance or electromagnetic interference do not pass through the cable transit module but are discharged to ground.

However, a solution of this type implies some drawbacks including, for example, that during assembly the tape conductor element must first be unwound and then re- wound onto two half-shells of the cable transit module with extreme precision so as to guarantee the aforesaid electrical continuity. This delicate operation implies a waste of time as well as the fact that it may not be particularly safe. In fact, it is necessary to consider that the tape conductor element is usually applied on the compressible body with adhesive and can therefore be subject to displacement, breakages or tearing during the compression of the cable transit module necessary to guarantee its seal against gases, liquids and particles .

An object of the present invention is that of overcoming the drawbacks mentioned above and in particular that of designing a cable transit module able to provide protection against disturbance or electromagnetic interference that is simple to assemble and guarantees the electrical continuity of the conductor system even if it is subjected to strong compressions .

This and other aims according to the present invention are achieved by making a cable transit module as outlined in claim 1.

Further features of the cable transit module are the subject matter of the dependent claims.

The features and advantages of a cable transit module according to the present invention will be more apparent from the following description, which is to be understood as exemplifying and not limiting, with reference to the schematic attached drawings, wherein:

- figure 1 is a perspective schematic view of a cable transit module according to the present invention in the assembled configuration with an electric cable;

- figure 2 is a sectional view along line II-II of the cable transit module of figure 1 ;

- figure 3 is a partial perspective schematic view of the cable transit module of figure 1 ;

- figure 4 is a perspective schematic view of a half- shell of a cable transit module according to the present invention;

- figure 5 is an exploded perspective schematic view of the half-shell of figure 4 ;

- figure 6 is a sectional view along the line VI-VI of the half-shell of figure 4 ;

- figure 7 is a perspective schematic view of a support frame for cable transit modules of the figure 1 type.

With reference to the figures, a cable transit module is shown, indicated overall with number 10. Such cable transit module 10 is, in particular, intended to be housed in a support frame 30, preferably made of metal. As can be seen in figure 7, the support frame 30 can be associated with a plurality of cable transit modules 10.

The cable transit module 10 comprises two half-shells 11, 11' that have two respective semicylindrical seats 12 that, when the module is assembled, form a cylindrical seat or duct for the passage of an electric cable 20.

Each half-shell 11, 11' comprises an elastically compressible body 13, 13' which may be electrically insulating.

In one embodiment, each half-shell 11, 11' comprises an elastically compressible and electrically insulating body 13, 13' .

For electrically insulating body it is meant a body having an electrical conductivity that is lower by various orders of magnitude than that of metals, i.e. a relatively electrically insulating body with respect to metals .

For example, the body may be comprised of EPDM rubber or of EPDM rubber with high carbon black content. In the latter case, particles of carbon black, carbon fibres and the like are incorporated into the EPDM rubber so that the electrical resistance of the rubber decreases although it never reaches the level of that of conducting metals such as copper and aluminium. In fact, rubbers with a high carbon black content can reach a resistivity in the order of 10² Qm which is much higher than that of copper which is about 1.68xlCT⁸ Qm and that of aluminium which is about 2.75xlCT⁸ Qm.

In the particular embodiment illustrated, such compressible bodies 13, 13' have a square outer profile so as to be able to be rested stably on a flat surface; however, more generally the compressible bodies 13, 13' of the half-shells 11, 11' can also have a curvilinear outer profile or however any other shaped profile.

According to the present invention, each half-shell 11, 11' comprises a system of conductors 14, 14', 15, 15' co-moulded with the related compressible bodies 13, 13'; such conductors 14, 14', 15, 15' extend on the compressible body 13, 13' from the outer surface to the surface of the semicylindrical seat 12 crossing the body itself.

In the particular embodiment illustrated, the system of conductors 14, 14', 15, 15' of a half-shell 11, 11' comprises two metal foils 14, 14', 15, 15', preferably made of copper or nickel, that can have thicknesses that depend on the particular application requirements or specific requests, e.g. a thickness of about 0.5 mm. For metal foil it is meant a continuous or mesh metal sheet such as, for example, a plurality of metal wires interwoven in a mesh arrangement.

In particular, such metal foils 14, 14', 15, 15' extend starting from two opposite portions of a cross-section of the related compressible body 13, 13' , wrap such cross-section up to at least one passage portion 16 through which they penetrate into the compressible body 13, 13' and extend, in the assembly configuration, folded on the semicylindrical seat 12 so as to be interposed between the cable 20 and the compressible body 13, 13' once the assembly is complete.

In particular, the metal foils 14, 14', 15, 15' of each half-shell 11, 11' are co-moulded with the related compressible body 13, 13' so as to be anchored at least to the outer surfaces of the body itself and, after crossing the compressible body 13, 13', they project free with two finned portions in the semicylindrical seat where they can be manually deformed to rest on the walls of the seat itself.

Preferably, the passage portion 16 is the same for the two metal foils 14, 14', 15, 15'. Alternatively, each metal foil 14, 14', 15, 15' may pass through the compressible body 13, 13' at a respective passage portion 16.

As can be seen in the figures, the metal foils 14, 14', 15, 15' do not reach the free edges of the cross- section around which they are wrapped; the distance between the free edges and the corresponding proximal portions of the metal foils 14, 14', 15, 15' is comprised between 0.05 and 0.1 mm. In this way, the realization of an electrical contact with the metal foils 14, 14', 15, 15' is simplified.

When the two half-shells 11, 11' are coupled to each other, the portions of the metal foils 14, 14', 15, 15' extending on the semicylindrical seats 12 come into direct contact with each other as illustrated in figure 2. In a preferred embodiment of the present invention, the metal foils 14, 14', 15, 15' have a plurality of holes or openings 17 that imply improved anchoring of the foils 14, 14', 15, 15' themselves on the compressible body 13, 13' .

Alternatively, the metal foils 14, 14', 15, 15' are not provided with holes or openings 17 but are painted with primers that improve the anchorage of the foils 14, 14', 15, 15' themselves on the compressible body 13, 13' .

Preferably, each half-shell 11, 11' has on the semicylindrical seat 12 a stack of removable layers 18; in that case the metal foils 14, 14', 15, 15' extend above the stack of removable layers 18. In particular, the stack of removable layers 18 is divided into at least two sectors side by side, one of which is overhung by the metal foils 14, 14', 15, 15'.

In the embodiment illustrated, the stack of removable layers 18 is composed of three sectors among which the central sector is the one intended, in the assembly configuration, to be overhung by the metal foils 14, 14', 15, 15' . In this way, by removing a determined number of removable layers 18 from the sectors without metal foils 14, 14', 15, 15' it is possible to adapt the diameter of the duct to the diameter of the cable 20 which is desired to be passed through the cable transit module 10. In fact, a stretch of duct is obtained with a smaller diameter at the metal foils 14, 14', 15, 15' flanked by two stretches without metal foils 14, 14', 15, 15' with a larger diameter where the difference between the two diameters is substantially equal to the thickness of the insulating sheath 21 of the electric cable 20 intended to pass through the cable transit module 10.

The sector intended to be overhung by the metal foils 14, 14', 15, 15' has a slit in a position corresponding to the passage portion 16 so as to realize an extension of said passage portion 16: in this way the metal foils 14, 14', 15, 15' can pass through the passage portion 16 and the slit that constitutes the extension thereof, to then project with two finned portions into the semicylindrical seat with an adaptable diameter. Advantageously, therefore, the co-moulding of the compressible body 3, 13' of each half-shell 11, 11' and of the related metal foils 14, 14', 15, 15' is firstly performed, and then the stack of removable layers 18 is applied on the semicylindrical seat 12 threading the finned portions through the slit of the corresponding sector of the stack. The assembly process of a cable transit module 10 around an electric cable 20 will be described below.

In the first place, a circumferential portion of the insulating sheath 21 of the electric cable 20 is removed exposing a stretch of the conducting core 22 of the cable 20 itself; the stretch of electric cable 20 without insulating sheath 21 therefore has a smaller diameter than that of the cable 20 provided with the insulating sheath 21.

Then on each half-shell 11, 11' many removable layers 18 are removed from the stack as many as required to adapt the diameter of the duct to the diameter of the electric cable 20.

Considering the illustrated embodiment, the layers are removed from the three sectors so that the central sector identifies a semicylindrical seat with a smaller diameter than the other two sectors suitable for housing the stretch of cable 20 without insulating sheath 21. At this point, the finned portions of the metal foils 14, 14', 15, 15' are folded towards opposite directions so as to rest on the inner walls of the seat identified by the central sector of the stack of removable layers.

The electric cable 20 is housed on a semicylindrical seat 12 of one of the two half-shells 11, 11' so that the exposed conducting core stretch 22 rests on the semicylindrical seat stretch 12 provided with metal foils 14, 14', 15, 15'. Then the two half-shells 11, 11' are constrained, so as to close the cable transit module 10.

Then, once the assembly is complete, the electrical continuity between the exposed conducting core 22 of the electric cable 20 and the portions of metal foils 14, 14', 15, 15' that extend outside the compressible body 13, 13' is guaranteed. In this way, by electrically connecting such metal foils 14, 14', 15, 15' to ground, any electromagnetic disturbance associated with the electric cable 20 is not propagated through the cable transit module 10.

Furthermore, in the event that the body of the half- shells 11, 11' is made of rubbers with a high carbon black content, electromagnetic shielding is obtained against the disturbances deriving from high frequency electromagnetic waves that hit the walls or frames where the cable transit modules are mounted.

From the above description the features of the cable transit module object of the present invention, as well as the advantages thereof, are evident.

In fact, the cable transit module according to the present invention is simpler to assemble with respect to the modules already known in the state of the art since it does not require the delicate operation of unwinding and re-winding a metal tape on the half- shells .

The system of conductors envisaged in the present invention is moulded as a single piece with the compressible bodies of the half-shells and is therefore already fixed stably thereon. This implies greater safety during assembly as the metal foils cannot be torn or moved by the action of the typical compression to which the cable transit modules are subjected in the related frames. The safety is increased thanks to the thickness of the metal foils that is greater than the thickness of the metal tapes commonly used in the state of the art.

The fact, then, that the metal foils project into the semicylindrical seats in the form of two fins allows a plurality of removable layers to be applied onto the seats themselves, in order to be able to adapt the diameter of the seats to the diameter of the cable 20 intended to be received therein.

Further, the cable transit module according to the present invention guarantees greater electrical safety with respect to the prior art as the metal foils are preferably made of copper or nickel and not aluminium. The metal foils have a larger section with respect to the aluminium sheets generally used and therefore for the same amount of current they will be affected by a lower current density; the metal foils, therefore, at high currents are stronger and less inclined to melt than thin sheets of aluminium.

Finally, the metal foils can be easily produced in different thicknesses and, therefore, adaptable to the most varied needs.

Finally, it is clear that the cable transit module as conceived herein is susceptible to many modifications and variations, all falling within the invention; furthermore, all the details are replaceable by technically equivalent elements. In practice, the materials used, as well as their dimensions, can be of any type according to the technical requirements.

Claims

1) Cable transit module (10) comprising two half-shells (11, 11') having two respective semicylindrical seats (12) that, when the cable transit module (10) is assembled, form a cylindrical seat or duct for the passage of an electric cable (20), each half-shell (11, 11') comprising an elastically compressible body (13, 13') and a system of conductors (14, 14', 15, 15') that extend on said compressible body (13, 13') from the external surface to the surface of the semicylindrical seat (12) passing through the body (13, 13') itself, said conductors (14, 14', 15, 15') being co-moulded with said compressible body (13, 13'), each half-shell (11, 11') having on the semicylindrical seat (12) a stack of removable layers (18), which is divided into three sectors side by side, among which the central sector is intended, in the assembly configuration, to be overhung by said metal foils (14, 15; 14', 15'), said system of conductors (14, 14', 15, 15') comprising two metal foils (14, 15; 14', 15') that extend from two opposite portions of a cross-section of said compressible body (13, 13'), wrap such cross-section up to at least one passage portion (16) through which they penetrate into the compressible body (13, 13') and then extend, in the assembly configuration, towards opposite directions to each other folded onto the semicylindrical seat (12) identified by said central sector .

2) Cable transit module (10) according to claim 1 wherein said elastically compressible body (13, 13') is electrically insulating.

3) Cable transit module (10) according to claim 1 or 2, wherein each metal foil (14, 15; 14', 15') passes through said compressible body (13, 13') at a respective one of said passage portions (16) .

4) Cable transit module (10) according to one of the preceding claims wherein said metal foils (14, 15; 14',

15' ) do not reach the free edges of the cross-section around which they are wrapped.

5) Cable transit module (10) according to claim 4, wherein the distance between said free edges and the corresponding proximal portions of the metal foils (14, 15; 14', 15') is less than or equal to 0.5 mm.

6) Cable transit module (10) according to one of the preceding claims wherein said metal foils (14, 15; 14', 15') have a plurality of holes or openings (17) .