CH688248A5 - A marking method of a conductive cable, the device for implementing this method and cable conductor having an identification mark obtained by this method. - Google Patents

Description

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Description

The invention relates generally to the marking of conductive cables formed by one or more internal conductors, such as light conductors.

More particularly, it relates to the marking of cables comprising at least two internal conductors formed in particular by optical fibers.

The invention relates, on the one hand, to a method for marking such a cable as well as to a device for implementing this method.

It also relates to a conductive cable of the aforementioned type provided with a marking of a pattern such as a trademark and / or an identification reference.

Conventional conductive cables consist of internal conductors and an external coating or overmolding intended to protect them and generally include one or more identification marks which are formed directly on the external coating by printing a pattern thereon. .

This type of marking has the disadvantage of being easily damaged, which leads to the alteration of the pattern and to a loss of identification of the cable.

Thus, the present invention aims to overcome this drawback using a method of marking such a cable and a device for the implementation of this method. The invention also aims to provide a conductive cable provided with an unalterable mark, produced by this method.

To this end, the subject of the invention is a method of marking a conductive cable comprising at least two internal conductors, for example light conductors, such as optical fibers, and at least one coating of a synthetic material, formed around said conductors, for example to protect them, this process being characterized in that it consists:

a) to mark said printing conductors with at least one pattern,

b) bringing said conductors thus marked and held therebetween to at least one coating station, and c) providing in the coating station on said marked conductors, at least one coating of a transparent material, to form a conductive cable marked and coated, so that it is formed under said coating at least one underlying internal pattern, this pattern being trapped in the conductor-coating assembly by inclusion and physically isolated from the outside of this cable by said coating.

According to a particular characteristic, the method according to the invention further consists in bringing said conductors to a bonding station, and in bonding said conductors by interstitial inclusion between them of a bonding material capable of ensuring the at least temporary maintenance of these conductors with each other, while forming on the conductor-adhesive assembly at least one substantially planar marking region capable of receiving at least one pattern.

The invention also relates to a device for implementing the above-mentioned marking method, characterized in that it comprises:

means for holding the conductors together,

- at least one coating station for coating said conductors with a transparent material, and

- At least one marking station for printing at least one pattern on the cable, this station being arranged upstream of said coating station to allow the printing of the pattern on the cable before the coating step .

According to a particular characteristic of the invention, this device further comprises at least one bonding station forming at least said means for holding the conductors, this station being capable of ensuring bonding of said conductors, said marking station being disposed between the bonding station and coating station.

The subject of the invention is also a conductive cable of the type comprising at least two internal conductors, for example light conductors, such as optical fibers, and at least one coating of a synthetic material, formed around said conductors, characterized in that that it comprises a marking of at least one pattern, this marking being provided by inclusion in the conductor-coating assembly underlying said coating which is produced by a transparent synthetic material.

According to a particular characteristic of the invention, this cable comprises at least one adhesive joint formed interstitially between the internal conductors, the marking of said pattern being disposed on this adhesive joint which has a substantially planar longitudinal surface.

However, other characteristics and advantages of the invention will appear better on reading the detailed description which follows, taken with reference to the appended drawings which are given by way of example, and in which:

- fig. 1 is a cross-sectional perspective view of a piece of the cable according to the invention, representing some of the internal conductors of this cable embedded in a bonding material, and on which is affixed a pattern for the marking of this cable;

- fig. 2 is a view similar to FIG. 1, but showing according to a first embodiment the piece of cable of FIG. 1 provided with an external coating depicted in torn away form;

fig. 3 is a sectional view of the cable according to the first embodiment, made according to arrows III-III of FIG. 2;

- fig. 4 is a schematic representation of a first embodiment of a device for implementing the method according to the invention enabling the cable of FIGS. 2 and 3;

- fig. 5 and 6 represent very dryly 5

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matic respectively a second and a third embodiment of the device according to the invention;

- fig. 7 and 8 are cross-sectional views showing a second and a third embodiment of the cable according to the invention obtained by the devices of FIGS. 5 and 6.

Referring first to Figs. 2 and 3, the structure of a conductive cable 1 according to a first embodiment of the invention will be described below.

The conductive cable 1 comprises several internal conductors 2 which preferably consist of light conductors, such as optical fibers.

For reasons that will be understood on reading the description which follows, the internal conductors 2 are perfectly ordered since, thanks to the device and the method according to the invention, they are oriented with respect to each other in a parallel and coplanar manner .

Although in fig. 3 a conductive cable with seven internal conductors has been shown, it will be understood that the invention is not limited to this example, the cable according to the invention preferably comprising at least two internal conductors.

The conductive cable 1 comprises a number of glue joints 4 (only one of which has been referenced) formed respectively between two adjacent conductors. These glue joints 4 which are in the solid state in the cable 1, are constituted by a synthetic bonding material 6 or glue, such as an epoxy resin, which has been hardened by crosslinking following exposure to ultraviolet light rays.

The adhesive joints 4 firmly and stably hold the internal conductors 2 together, which constitutes, inside the cable 1, a conductor-adhesive assembly forming a heart C (fig. 1 and 2) in one piece, c ' that is to say of a monolithic nature.

As seen in fig. 2, the conductors 2 are embedded in the bonding material 6 which completely fills and completely fills the free space between the conductors 2 which are adjacent. The glue joints 4 formed by this material 6 are therefore formed interstitially between the adjacent conductors 2 and form, on either side of the heart C, a longitudinal surface 8 which is essentially flat and regular. It will be noted that in this preferred example the heart C and the cable 1 are essentially flat. The invention is not limited to flat cables but can be applied to the marking of other types of cables, for example of triangular or circular section.

The conductive cable 1 further comprises an identification mark M consisting of a pattern 10 which is shown here by way of example in the form of a capital T. This pattern 10 can for example consist of a number, indicating the reference of the cable 1, and / or a trade mark.

In the preferred embodiment of the invention shown in FIGS. 1 to 3, the mark M is arranged directly on one of the longitudinal surfaces 8 (only one being referenced), that is to say by direct affixing of the pattern 10 on the conductor-adhesive assembly forming the heart C.

The conductive cable 1 further comprises a coating 12a formed around the conductors 2, and more particularly around the heart C.

The coating 12a which is in this example an external coating is made of a synthetic material 14 of the same type as the bonding material, or even preferably of an identical material. This external coating 12a constitutes around the conductors 2 and around the core C a protective sheath. Cable 1 is therefore a coated conductive cable.

The material 14 constituting the external coating 12a is chosen to be transparent so as to allow it to see through it the pattern 10 affixed in this example directly on the core C, and more particularly on the glue joints 4, but also directly under the external coating 12a.

The mark M is therefore provided, by inclusion, in the cable 1 and in particular in the set of conductors-coating underlying the external coating 12a.

The pattern 10 is therefore protected and by being inaccessible from the outside, it cannot be damaged.

We will now refer to FIG. 4 which represents a preferred embodiment of a device 20 for implementing the method according to the invention.

The device 20 is preferably integrated into a conventional machine for manufacturing conductive cables, which is not shown here.

According to this preferred embodiment, the device 20 includes a bonding station 22 for bonding the conductors 2 to each other and for producing the core C in a monolithic form, a marking station 24 for printing a pattern in particular on the bonded conductors forming the core C and a coating station 26 for the coating or overmolding in particular of the conductors and therefore of the core C, once bonded and marked.

The conductors 2 before and after being bonded, as well as the cable 1 in its finished form are guided and moved along a travel path D whose advance is effected in a direction represented by the arrow A.

Advantageously, it is noted that in this embodiment the marking station 24 is arranged directly between the bonding stations 22 and the coating stations 26 respectively.

Thus, taking as reference the direction A of travel of the cable 1, the marking station 24 is arranged downstream of the bonding station 22 and upstream of the coating station 26 which in this embodiment is a station '' final coating.

The bonding station 22 which forms with the bonding material 6 means for at least temporarily holding the conductors together, comprises means 28 for gluing and pre-bonding the conductors 2.

The means 28 comprising a tray 30 of glue-ge-pre-bonding provided with an inlet die 32, an outlet die 34 and an inlet 36 through which the synthetic material 6 for bonding is brought,

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in liquid form or preferably in viscous or semi-viscous form.

The conductors 2 are brought and are guided together by conventional means, not shown, such as pulleys, to the input die 32 through which they are introduced into the glue-pre-glue tank 30. The conductors 2 are, in this tray 30, fully coated with the bonding material 6 by being, for example, embedded therein. The bonding operation of the conductors 2 is thus carried out in this way.

The outlet die 34 is constituted by a shaped part such as a template having an oblong opening whose width (not shown) is substantially equal to the diameter of the conductors 2. Thus, passing through the outlet die 34, the conductors 2 are positioned relative to each other in parallel and coplanar fashion. This die 34 therefore forms a positioning guide for the glued-pre-glued conductors.

In addition, thanks to this arrangement, the bonding material 6 is forced to become encrusted between the conductors 2, so that it then perfectly fills the free spaces or interstices left between them.

The bonding material 6 by its adhesion to the conductors 2 and by its state, preferably semi-viscous, already ensures at this stage a certain strength or cohesion of the conductors between them. The pre-bonding of the conductors 2 is thus carried out by this operation. The conductive-adhesive assembly thus obtained forms a pre-bonded core C having the form of an essentially flat strip or ribbon, as shown in FIG. 1.

As mentioned above, the bonding material 6 is formed by a crosslinkable synthetic resin, that is to say which can harden and take its solid state when exposed to light rays, such as than ultraviolet rays.

This is why the bonding station 22 also comprises crosslinking means 38a and 38b allowing the crosslinking of the bonding material 6, these means 38a and 38b being arranged immediately downstream of the glue-pre-glue tank 30.

The crosslinking means 38a, 38b respectively comprise one or more sources of radiation 40a and 40b capable of supplying ultraviolet light radiation. These means also include emission heads 42a and 42b for emitting the ultraviolet radiation supplied by the sources 40a and 40b, to the pre-bonded core C leaving the container 30.

Between the radiation sources 40a, 40b and the emission heads 42a, 42b are arranged and connected light conductors 44a and 44b. It will be specified here that the emission heads 42a, 42b comprise for example a quartz emitting lens disposed opposite a parabolic reflecting surface (not shown) to irradiate the bonding material 6 entirely. The light conductors 44a and 44b as to them include for example a flexible conductor filled with a liquid such as water. Such an arrangement is more particularly described in the patent application

FR 9 115 055 filed in the name of the plaintiff.

The emission heads 42a and 42b are disposed in the immediate vicinity of the outlet die 34, which allows almost instantaneous crosslinking of the bonding material 6. Thanks to the rapid hardening of the bonding material 6, the conductors 2 which are positioned in pre-bonded form parallel to each other and coplanar thanks to the geometry of the outlet die 34, are held and fixed in this position due to the crosslinking which is carried out as soon as the conductors 2 of the outlet die leave 34.

The marking station 24 is constituted in particular by an inkjet printing system or by other printing means arranged on the travel path D of the cable 1, downstream of the bonding station 22. This station marking 24 includes a print head 50 and a positioning table 52 disposed opposite the head 50 for the support and positioning of the conductors 2 bonded together. It will be noted that the print head 50 and the table 52 comprise means for adjusting their relative position and their position relative to the cable 1 to ensure the printing of the pattern M on the heart C formed by the bonded conductors 2. These adjustment means are conventional and are therefore neither described nor shown.

The coating station 26 is similar in structure to the bonding station 22. This coating station 26 which is intended to coat the strip of bonded and marked conductors therefore comprises a coating pan 60 for coating the core C with a coating material 14, for example by embedding it in this material 14.

The tank 60 is likewise equipped with an inlet die 62 intended to receive the conductors 2 glued and marked, an outlet die 64 and an inlet 66 for the supply of the coating material 14. It will therefore be recalled that this coating material 14 is constituted by a transparent synthetic material, such as an epoxy resin. The bonding 6 and coating 14 materials respectively are preferably of the same nature.

The inlet die 62 has substantially the same geometry and the same dimensions as those of the outlet die 34.

The outlet die 62 however has a geometry and dimensions corresponding to those of the cable 1 of FIGS. 2 and 3.

The coating station 26 comprises crosslinking means 68a and 68b allowing the crosslinking of the coating material 14 directly at its outlet from the tank 60. The crosslinking means 68a and 68b are identical to the crosslinking means 38a and 38b of the bonding station 22. They therefore also include radiation sources 70a and 70b for supplying ultraviolet radiation, light conductors 74a and 74b, and emission heads 72a and 72b. The crosslinking means of this coating station 26 different from those of the bonding station 22 only in that they comprise, arranged on either side of the cable 1, four heads 72a and 72b provided with their source

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respective and not just two, as is the case with the bonding station 22. The number of transmission heads is therefore not limited and can be extended.

The conductors 2 bonded together and forming the heart C therefore pass through the tank 60 via the dies 62 and 64 to be completely coated with the coating material 14. The conductor-adhesive assembly in its pre-coated form is then brought before the emission heads 72a, 72b which ensure the crosslinking of the coating material 14. A cable 1 is therefore produced which is wrapped in a coating forming a protective overmolded sheath directly covering a printed pattern.

It is therefore understood that, thanks to the device which has just been described, it is possible to implement a marking process in which:

the conductors 2, held between them by the bonding material 6, are brought to the coating station 26,

the bonded conductors 2 are marked, during their passage through the marking station 24, and

- In the coating station 26, on the bonded and marked conductors 2, an external and final coating of a transparent material is formed to form a coated conductive cable 1 provided with at least one underlying pattern.

Thus, in this process, the cable 1 is marked by printing at least one pattern before the coating step or to form an underlying internal pattern under the final coating 12a which is trapped in the conductor-coating assembly. by inclusion and which is physically isolated from the outside of the cable 1 by said coating 12a.

More precisely, before marking the cable 1, the conductors 2 are brought to the bonding station, and bonding of the conductors 2 is carried out by interstitial inclusion between them of the bonding material 6 which ensures that these conductors are maintained at least temporarily 2 with each other, while forming on the conductor-adhesive assembly at least one substantially flat marking region 8 capable of receiving the pattern M.

In this step, the conductors 2 are positioned in a relative parallel and coplanar position, and the conductors 2 are coated in the container 30 with the adhesive material 6. It will also be noted that the conductors 2 are coated with the bonding 6 before or at the same time as they are positioned in parallel and coplanar fashion by means of a positioning guide formed by the outlet die 34.

It will also be noted that the cable 1 is marked by direct printing of the pattern M on the bonding material 6 which forms said substantially planar marking region 8.

Preferably, this marking is carried out in particular directly on the adhesive joints 4.

In addition, before marking the pattern M, the bonding material 6 is hardened, in particular by exposure to a light beam, by virtue of the crosslinking means 38a, 38b.

Fig. 5 shows a second embodiment of the device according to the invention allowing the implementation of a method and a cable (fig. 7)

both according to a second embodiment.

The device according to this second embodiment comprises two coating stations 26 of the type of those previously described between which a marking station 24 is arranged.

In this case, it is understood that the marking M is carried out between two coating steps. The pattern 10 is therefore printed in the cable by being sandwiched between two coatings 12a and 12b, one intermediate (12b) produced by the first coating station arranged upstream and the other final (12a) which is produced by the coating station located downstream. The mark M is therefore no longer formed here directly on the core C of the cable 1 but directly on the intermediate coating 12b. However, this mark remains underlying, being protected by the final coating 12a.

Fig. 6 shows a third embodiment of the device according to the invention making it possible to implement a method and to obtain a cable (FIG. 8) both according to a third embodiment.

The device of fig. 6 comprises two marking stations 24, one disposed directly downstream of the bonding station 22 as shown in FIG. 4 and the other arranged, as in the previous example, between two coating stations 26. In this case, the cable 1 in its finished form has two marks made respectively on two levels, one which is made directly on the conductor-adhesive assembly as in the first embodiment of FIG. 3, but which is covered by an intermediate coating 12b produced by the intermediate coating station 26, and the other which is produced directly on the intermediate coating 12b but under the final coating 12a.

Thus and as can be understood from all these embodiments, the cable 1 has been marked by printing at least one pattern before the coating or overmolding step, whether this step is intermediate or final, to form under at minus one coating, intermediate or final, an underlying internal pattern which is trapped in the conductor-coating assembly by inclusion and which is physically isolated from the outside of the cable by one or other of these coatings.

It is therefore understood that the invention is not limited to the provision of a single coating station, nor to the provision of a single marking station. Nor is it limited to a cable having a single coating or a single mark.

Claims (12)

Claims 1. A method of marking a conductive cable comprising at least two internal conductors (2), and at least one coating (12a, 12b) of synthetic material (14), formed around said conductors (2), this method being characterized in what it consists of: a) marking said conductors (1) by printing at least one pattern (10), b) bringing said conductors thus marked and held therebetween to at least one coating station (26), and 5 10 15 20 25 30 35 40 45 50 55 60 65 5 9 CH 688 248 A5 10 c) to be provided in the coating station on said marked conductors (2), at least one coating (12a, 12b) of a transparent material (14), to form a conductive cable (1) marked and coated, so that it is formed under said coating (12a, 12b) at least one underlying internal pattern (10), this pattern being trapped in the conductor-coating assembly by inclusion and physically isolated from the outside of this cable by said coating (12a, 12b). 2. Method according to claim 1, characterized in that it consists before step a): d) bringing said conductors (2) to a bonding station (22), and e) bonding said conductors (2) by interstitial inclusion between them of a bonding material (6) capable of ensuring at least temporary maintenance of these conductors with each other, while forming on the conductor-adhesive assembly at least one substantially planar marking region (8) capable of receiving at least one pattern (10). 3. Method according to claims 1 and 2, characterized in that it consists in step a): f) marking the cable (1) by direct printing of the pattern (10) on the bonding material (6) which forms said substantially planar marking region (8). 4. Method according to claims 1 and 2, characterized in that it consists before step a) and after step e): g) hardening the bonding material (6) before marking it by exposure to a light beam. 5. Method according to claim 2, characterized in that it consists in step e): h) positioning the conductors (2) in a relative parallel and coplanar position, and i) coating the conductors (2) with the bonding material (6). 6. Method according to claim 5, characterized in that it consists in steps h) and i): j) coating the conductors (2) with the bonding material (6) before positioning them in parallel and coplanar fashion by means of a positioning guide (34). 7. Device for implementing the cable marking method according to any one of the preceding claims, characterized in that it comprises: - means (22) for holding the conductors together, - at least one coating station (26) making it possible to coat said conductors (2) with a transparent material (14), and - at least one marking station (24) for printing at least one pattern (10) on the cable (1), this station (24) being arranged upstream of said coating station (26) to allow printing the pattern (10) on the cable before the coating step. 8. Device according to claim 7, characterized in that it further comprises at least one bonding station (22) forming at least said means for holding the conductors, this station being capable of ensuring bonding of said conductors (2) , said marking station (24) being arranged between the bonding station (22) and the coating station (26). 9. Device according to claim 8, characterized in that the marking station (24) is constituted by an ink jet printing system (50, 52). 10. Conductive cable obtained by the method according to one of claims 1 to 6 of the type comprising at least two internal conductors (2), and at least one coating (12a, 12b) of a synthetic material (14), arranged around of said conductors, characterized in that it includes an identification mark (M) formed by at least one pattern (10), this mark being formed by inclusion in the conductor-coating assembly underlying said coating (12a , 12b) which is made of a transparent synthetic material (14). 11. Conductive cable according to claim 10, characterized in that it comprises at least one adhesive joint (4) formed interstitially between the internal conductors (2), the pattern (10) being disposed on this adhesive joint ( 4) which has an essentially flat longitudinal surface. 12. Conductive cable according to claim 10, characterized in that it comprises at least two internal light conductors. 5 10 15 20 25 30 35 40 45 50 55 60 65 6