Metal cable coating system

Abstract

The invention relates to a system for coating at least one metal cable (1) with a coating substance (2), comprising: - a guiding device (10) provided for guiding the metal cable (1) in a substantially horizontal coating direction (De); and - an applicator device (20) for applying the coating substance (2) to the metal cable (1) guided by the guiding device (10), and comprising: - an applicator roller (21) having a cylindrical wall (211) with a circumferential groove (210) intended to receive the metal cable (1); and - a doctor-blade chamber (22) comprising a reservoir (220) containing the coating substance (2), and having an opening positioned facing the applicator roller (21) so as to fill the circumferential groove (210) with coating substance (2), the doctor-blade chamber (22) further comprising a doctor blade (222) intended to remove an excess of coating substance (2) present on the applicator roller (21); wherein the applicator roller (21) is arranged on the frame (30) such that the circumferential groove (210) is above the metal cable (1), so that, in operation, the metal cable (1) is coated from above.

Description

[0001] Wire rope coating system

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to the field of coating metal cables, in particular with a coating substance such as an adhesive, and which may in particular be used in the field of tires.

[0004] STATE OF THE ART

[0005] Metal reinforcements are often used in vehicle tires, and these metal reinforcements usually come in the form of metal cables. One of the existing problems concerns the adhesion of these metal cables to the rubber used to form the tire.

[0006] In this regard, it is known to use additives in the rubber, such as for example sulfur and / or cobalt salt, these additives reacting during the vulcanization step used during the formation of the tire, in order to make the rubber adhere to the metal cords. These additives are however polluting and there is an attempt to remove them from the rubbers to be used to form the tires.

[0007] It has been proposed to use textiles coated with an adhesive and used between the rubber and the metal cables, but such a solution is complex to implement, requires textile elements not necessarily desired in the tire, and does not allow for the industrial production rates of tires to be met.

[0008] STATEMENT OF THE INVENTION

[0009] An aim of the present invention is to provide a coating system which will allow one or more metal cables to be directly coated with a coating substance, such as an adhesive substance. The advantage of such a system is to provide metal cables which have been prepared to have an adhesive sheath, so that adhesion with the rubber of the tire can be done easily, in particular during the vulcanization step carried out during the manufacture of the tires.

[0010] In particular, an aim of the present invention is to propose a coating system for preparing metal cords at high production speeds and compatible with industrial tire manufacturing rates. In particular, a coating system is sought that allows the metal cords to be coated to travel at a speed of at least 80 m / min, or even at least 200 m / min.

[0011] Another object of the present invention is to provide a coating system which allows coating of several metal cables simultaneously, efficient coating of the metal cables, in particular without excessive loss of the coating substance, and regular and homogeneous distribution of the coating substance on each coated metal cable.

[0012] Another aim of the present invention is to propose a metal cable coating system whose installation is simple and at low cost, in particular to limit the overall cost of the tire production line. It is also sought to have a coating system with the most optimized and compact size possible, in particular compared to the industrial tire production site.

[0013] For this purpose, a system is proposed for coating at least one metal cable with a coating substance, comprising a frame on which are mounted:

[0014] - a guiding device provided to guide the metal cable in a coating direction substantially horizontal relative to the frame; and

[0015] - an applicator device provided for applying the coating substance to the metal cable guided by the guide device, the applicator device comprising:

[0016] - an applicator roller intended to be driven in rotation in a direction of application rotation and having a cylindrical wall in which a circumferential groove is formed, the circumferential groove being provided to receive the metal cable; and

[0017] - a doctor blade chamber comprising a reservoir provided for containing the coating substance, the reservoir having an opening positioned opposite the applicator roller for filling the circumferential groove with coating substance, the doctor blade chamber further comprising a doctor blade positioned downstream of the reservoir opening in the application rotation direction and being provided for removing an excess of coating substance present on the applicator roller; wherein the applicator roller is arranged on the frame so that the circumferential groove receiving the metal cable is above the metal cable, so that in operation the metal cable is coated from above.

[0018] Preferred but non-limiting aspects of this coating system, taken alone or in combination, are as follows:

[0019] - the guiding device is designed to guide the metal cable in a coating direction tangent to the circumferential groove.

[0020] - the guide device comprises a lifting roller on which the metal cable is intended to be driven, the lifting roller being positioned upstream of the applicator roller relative to the direction of drive of the metal cable and below the applicator roller relative to the frame. - the scraper is provided for removing coating substance present in the circumferential groove in order to meter the quantity of coating substance available for coating the metal cable.

[0021] - the circumferential groove has a maximum depth defined in relation to the level of the cylindrical wall of between 50% and 200% of an average diameter of the metal cable, preferably of between 100% and 190% of the average diameter of the metal cable, and more preferably of the order of 180% of the average diameter of the metal cable.

[0022] - the circumferential groove has an outwardly open shape with side walls forming an angle a of between 35° and 90°, preferably of between 55° and 65°, and more preferably of the order of 60°.

[0023] - the circumferential groove has a rounded bottom defined by a radius greater than an average radius of the metal cable, preferably a radius greater than 110% of the average radius of the metal cable, and more preferably a radius between 110% and 120% of the average radius of the metal cable.

[0024] - the coating system comprises several metal cable guiding devices for guiding the metal cable in a coating direction substantially horizontal relative to the frame, and in which the applicator roller of the applicator device comprises several circumferential grooves arranged on the cylindrical wall parallel to each other, each circumferential groove being provided to receive a metal cable guided by one of the guiding devices.

[0025] - the applicator device is configured to drive the applicator roller at a rotation speed of between 0.1 and 2 times a drive speed at which the metal cable is driven.

[0026] - the applicator device is configured to drive the applicator roller at a rotation speed of the order of 1.5 times the drive speed at which the metal cable is driven.

[0027] - the coating system comprises a drive device configured to drive the metal cable at a drive speed of at least 20 m / min, preferably a speed of at least 80 m / min, more preferably a speed of at least 200 m / min.

[0028] - the coating system further comprises an oven device positioned downstream of the applicator device in the direction of drive of the metal cable and in which the metal cable coated with the coating substance is driven in the drive direction substantially horizontal relative to the frame. DESCRIPTION OF THE FIGURES

[0029] Other characteristics and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting and must be read in conjunction with the appended drawings, in which:

[0030] - Figure 1 is a perspective view from above of the proposed coating system, with its frame;

[0031] - Figure 2 is a schematic illustration of the proposed coating system in a top perspective view, in which the applicator roller is cut transversely along a groove;

[0032] - Figure 3 is a schematic illustration of the proposed coating system in a side view;

[0033] - Figure 4 is a schematic illustration of the proposed coating system in a perspective view from below, in which the applicator roller is cut transversely along a groove;

[0034] - Figure 5 is an enlargement of the view of Figure 1 at the level of the coating area by the proposed coating system;

[0035] - Figure 6 illustrates the relative speeds and flow rates at the coating zone of the coating system of Figure 1;

[0036] - Figure 7 illustrates the coating system of Figure 2 in the disengaged position;

[0037] - Figure 8 is a sectional view illustrating a section of an example of a groove provided in the applicator roller of the proposed coating system.

[0038] DETAILED DESCRIPTION OF THE INVENTION

[0039] The remainder of the description refers to the coating of one or more metal cables. By metal cable is meant a set of several metal wires, arranged together, in particular by braiding, to form the structure of the metal cable. A metal cable is generally made up of a few dozen metal wires, which limits the adhesion surface, unlike a textile cable, which generally has several thousand intertwined wires.

[0040] Typically 1mm wire rope 2in diameter and intended to be used to form a metal reinforcement of a tire may have about twenty intertwined metal wires, in particular 24 metal wires.

[0041] In the remainder of the description, we refer to a metal cable but we could just as well refer to a metal reinforcement, in particular for use of the proposed coating system in the field of tires. Figure 2 illustrates the proposed coating system intended to coat at least one metal cable 1 with a coating substance 2.

[0042] The coating substance 2 will preferably be an adhesive substance, in particular for an application in the field of tires, but could be any other type of coating substance. The viscosity of the coating substance is preferably between 100 cP and 1000 cP, for example between 400 cP and 500 cP.

[0043] Adhesive substances that can be used for coating metal cables intended to be embedded in tire rubbers are, for example, water-based (or other solvent-based) glues, resins, etc.

[0044] The proposed coating system preferably comprises a frame 30 on which the various elements composing it are mounted, as illustrated in FIG. 1. It should be noted that this frame 30 could be broken down into several frame sections which are independent of each other but which can be coupled to each other.

[0045] The frame 30 is intended to be positioned on the floor of the building in which the coating is carried out. It is possible to define with respect to the frame 30 a horizontal direction which is a direction parallel to the floor on which the frame 30 is intended to be positioned, and a vertical direction which is orthogonal to the floor on which the frame 30 is intended to be positioned.

[0046] The coating system firstly comprises a guide device 10 for the metal cable intended to guide the metal cable 1 in a coating direction (De) substantially horizontal relative to the frame 30, as shown in FIGS. 2 to 6.

[0047] The coating direction (De) corresponds to the direction of travel of the metal cable 1 at the coating area, which will be described in detail later. We can say that the coating is carried out horizontally.

[0048] It is important that this coating direction is horizontal so that the coated metal cable 1 can continue to run horizontally at the exit of the coating system, without having to undergo any change of direction.

[0049] In fact, a change of direction is generally carried out with change of direction roller systems which would create contact zones with the coated metal cable 1, which would deteriorate the regularity and homogeneity of the coating produced.

[0050] Furthermore, it is particularly advantageous to have horizontal coating followed immediately by horizontal exit scrolling since the vulcanization ovens which are generally placed after the coating system are also horizontal, which saves space and once again avoids changing the direction of scrolling of the coated metal cable 1. The guidance system 10 also makes it possible to control the direction of scrolling (Dd) of the metal cable 1 upstream of the coating system relative to the direction of drive of the metal cable 1. This direction of drive is represented by the arrow associated with the direction of coating (De) illustrated in the figures.

[0051] This direction of travel (Dd) of the metal cable 1 upstream of the coating system can also be substantially horizontal relative to the frame 30, just like the coating direction (De).

[0052] Preferably, the direction of travel (Dd) of the metal cable upstream of the coating system is however inclined relative to the coating direction (De) as is for example shown in Figures 3 and 7. This makes it possible in particular to reduce the size of the coating system. Indeed, it is thus possible to envisage having a reel on which the metal cable to be coated is wound, which would be placed in the lower part of the coating system relative to the frame 30.

[0053] In this case, the guide device 10 may for example comprise a lifting roller 11 provided to effect a change of direction between the direction of travel (Dd) of the metal cable upstream of the coating system and the coating direction (De). Such a lifting roller 11 will be described in detail later.

[0054] In addition to the lifting roller 11, the guiding device 10 may comprise several guiding members, in particular in the form of rollers or pulleys, which control any change of direction of the metal cable 1.

[0055] As is apparent from the above, the guide device 10 preferably does not comprise any guide member downstream of the coating zone, in particular no guide member which would create a point of contact with the coated metal cable 1, and therefore would deteriorate the quality of the coating.

[0056] Furthermore, the coating system comprises an applicator device 20 provided for applying the coating substance 2 to the metal cable 1 guided by the guide device 10.

[0057] The applicator device 20 comprises an applicator roller 21 intended to be driven in rotation in an application rotation direction (Ra).

[0058] This applicator roller 21 has the particularity of having a circumferential groove 210 provided to receive the metal cable 1. The applicator roller being of substantially cylindrical shape, it has a cylindrical wall 211 in which such a circumferential groove 210 is formed.

[0059] As will be seen later, when it is desired to coat several metal cables 1 in parallel with the same coating system, it is sufficient to provide an applicator roller 21 having several circumferential grooves 210 arranged parallel to each other in the cylindrical wall 211.

[0060] Furthermore, applicator device 20 comprises a scraper chamber 22 comprising a reservoir 220 provided to contain the coating substance 2. This scraper chamber 22 makes it possible to transfer the coating substance 2 onto the applicator roller 21, and more particularly into the circumferential groove 210, in order to then be able to transfer this coating substance onto the metal cable 1.

[0061] In this regard, the reservoir 220 has an opening 221 positioned opposite the applicator roller 21 for filling the circumferential groove 210 with coating substance 2.

[0062] The scraper chamber 22 further comprising a scraper 222 positioned downstream of the opening 221 of the reservoir 220 in the direction of application rotation Ra. Such a scraper 222 is preferably provided for removing an excess of coating substance 2 present on the applicator roller 21.

[0063] Preferably, the scraper 222 is provided for removing coating substance 2 present in the circumferential groove 210 in order to meter the quantity of coating substance 2 available for coating the metal cable 1. By metering a quantity of coating substance 2, it is meant that the scraper 222 makes it possible to leave a precise quantity of coating substance 2 inside the circumferential groove 210 and to remove all the excess compared to this metered quantity.

[0064] The use of a scraper 222 allows precise, uniform and homogeneous dosing of the coating substance 2 in the circumferential groove 210, and this along the entire circumferential groove 210. It is in particular thanks to this precise dosing that the coating is regular, uniform and homogeneous along the metal cable 1.

[0065] Advantageously, the applicator roller 21 is arranged on the frame 30 so that the circumferential groove 210 receiving the metal cable 1 is above the metal cable 1, so that in operation the metal cable 1 is coated from above.

[0066] It is particularly advantageous to coat the wire rope 1 from above, i.e. from the upper side of the wire rope 1 , which is called the top or back of the wire rope 1 . The lower side of the wire rope 1 , which is called the underside or belly of the wire rope 1 , faces the ground. This is because, by coating the cable from above, the coating substance 2 is mainly transferred from the circumferential groove 210 onto the top of the wire rope 1 , this coating substance 2 can then be further distributed over the wire rope 1 by the effect of gravity. It has been found that the proposed coating system allows for a particularly uniform coating of wire ropes all around the wire rope, which is due in particular to this coating from above.

[0067] Furthermore, the proposed coating system allows for precise coating of the wire rope 1 such that there is no excess coating substance on the coated wire rope 1 that would need to be removed. No post-coating operation is required to remove excess coating substance; in particular, there is no subsequent scraping or wringing.

[0068] Figure 6 highlights the dynamic phenomena that take place within the contact zone between the metal cable 1 and the circumferential groove 210, after the metal cable 1 has been coated with the coating substance 2. The circular arrows in Figure 6 represent the circulatory movements taking place within the upper meniscus of coating substance 2 existing above the metal cable 1 just after it passes through the circumferential groove 210. As illustrated by these arrows, a portion of the coating substance 2 returns to the circumferential groove 210 upwards with a flow rate greater than the flow rate of the coating substance 2 leaving with the coated metal cable 1. This higher flow rate can in particular be imparted by an overspeed of the roller relative to the movement of the metal cable as will be seen later.

[0069] The guiding device 10 is therefore provided to guide the metal cable 1 below the applicator roller 21, the coating direction (De) imparted by this guiding device 10 being adjacent to the applicator roller 21, so that the metal cable 1 enters the circumferential groove 210 from the running direction (Dd) of the metal cable 1 upstream of the coating system.

[0070] Preferably, the guiding device is provided to guide the metal cable in a coating direction (De) tangent to the circumferential groove, as illustrated in Figure 3 in particular.

[0071] As indicated above, the guide device 10 preferably comprises a lifting roller 11 on which the metal cable 1 is intended to be driven. Such a lifting roller can be mounted in free rotation or be driven in rotation by specific drive means, the rotation (Re) of the lifting roller 11 accompanying the direction of travel of the metal cable 1.

[0072] Preferably, the lifting roller 11 is positioned upstream of the applicator roller 21 relative to the direction of drive of the metal cable 1.

[0073] More preferably, the lifting roller 11 is positioned below the applicator roller 21 relative to the frame 30.

[0074] As can be seen shown in Figures 3 and 5, it may be advantageous for the lifting roller 11 not to be entirely under the applicator roller 21. In other words, the highest position of the lifting roller 11 is higher than the lowest position of the applicator roller 21, all relative to the frame 30. Such a configuration allows the metal cable 1 to penetrate well into the circumferential groove 210, for better application of the coating substance 2 on the metal cable 1.

[0075] The applicator device 20 may be movable relative to the guide device 10, in particular relative to the lifting roller 11. This makes it possible, for example, to more easily clean the applicator device 20, or may be advantageous for any maintenance operation, for example. Figure 7 illustrates the coating system in the disengaged position, i.e. when the applicator device 20 is at a distance from the guide device 10, and therefore from the metal cable 1. To begin coating, the coating system must be placed in an engaged position by moving the applicator device 20 relative to the lifting roller 11 of the guide device 10, for example in a movement as illustrated with the dotted arrow in Figure 7.

[0076] The very precise dosage of the coating substance 2 in the circumferential groove 210 made possible in particular by the scraper 222 of the scraper chamber 22, in combination with the specific arrangement of the applicator device 20 relative to the metal cable 1 which allows coating from above the metal cable 1 is particularly advantageous since it also allows quality coating of the metal cable 1 regardless of the running speed of the metal cable 1, in particular for high running speeds.

[0077] Thus, the metal cable 1 can be run at a speed of at least 20 m / min, preferably a speed of at least 80 m / min, more preferably a speed of at least 200 m / min. In this regard, the coating system may comprise a drive device configured to drive the metal cable 1 at a corresponding drive speed (Ve).

[0078] Furthermore, the speeds of the different elements of the coating system can be adjusted to further optimize the quality of the coating and the operating rate.

[0079] Advantageously, the applicator device 20 is for example configured to drive the applicator roller 21 at a rotation speed (Va) of between 0.1 and 2 times the drive speed (Ve) at which the metal cable 1 is driven.

[0080] Preferably, the applicator device 20 is configured to drive the applicator roller 21 at a rotation speed (Vr) of the order of 1.5 times the drive speed (Ve) at which the metal cable 1 is driven. As mentioned above, if it is desired to coat several metal cables 1 in parallel, an applicator roller 21 may be provided comprising several circumferential grooves 210 arranged on the cylindrical wall and parallel to each other. The coating system in this case comprises several guiding devices 10 for different metal cables 1, each circumferential groove 210 of the applicator roller 21 being provided to receive a metal cable 1 guided by one of the guiding devices 10.

[0081] It is furthermore possible but not necessary for the coating system to comprise heating elements provided and arranged to heat the applicator roller 21, in particular at the circumferential groove 210, and / or to directly heat the reservoir 220 of the doctor blade chamber 20.

[0082] Such heating elements make it possible in particular to heat the coating substance 2, which can be advantageous for fluidifying a coating substance 2 which would be too viscous to be applied, such as for example for a resin or a solvent-free coating substance.

[0083] Such heating elements may, for example, include heating resistors or heating cartridges specifically arranged in the coating system.

[0084] To further improve the coating achieved by the proposed coating system, the shape of the circumferential groove 210 can be optimized.

[0085] Thus, the circumferential groove 210 preferably has a maximum depth (P) defined relative to the level of the cylindrical wall of between 50% and 200% of the average diameter of the metal cable 1. More preferably, the maximum depth (P) is between 100% and 190% of the average diameter of the metal cable, and more preferably of the order of 180% of the average diameter of the metal cable.

[0086] The circumferential groove 210 may also have a shape open towards the outside with side walls forming an angle α of between 35° and 90°, preferably of between 55° and 65°, and more preferably of the order of 60°.

[0087] Finally, the circumferential groove may have a rounded bottom defined by a radius (R) greater than an average radius of the metal cable 1. The radius (R) defining the rounded bottom of the circumferential groove may for example be greater than 110% of the average radius of the metal cable 1, and preferably be between 110% and 120% of the average radius of the metal cable 1.

[0088] Figure 8 illustrates a particular example of a circumferential groove profile particularly suitable for coating wire ropes with the proposed coating system. According to this example, the maximum depth (P) is of the order of 180% of the average diameter of the wire rope 1 , and the angle a defining the opening of the circumferential groove is of the order of 60°.

[0089] The profile of the circumferential groove 210 is thus optimized so that the coating substance 2 easily fills this circumferential groove 210 from the opening 221 of the doctor blade chamber 22. It is also appropriate not to saturate this circumferential groove 210 with the coating substance 2, which is favored by the particular profile described.

Claims

CLAIMS 1. System for coating at least one metal cable (1) with a coating substance (2), comprising a frame (30) on which are mounted: - a guide device (10) provided for guiding the metal cable (1) in a coating direction (De) substantially horizontal relative to the frame (30); and - an applicator device (20) provided for applying the coating substance (2) to the metal cable (1) guided by the guide device (10), the applicator device (20) comprising: - an applicator roller (21) intended to be driven in rotation in a direction of application rotation (Ra) and having a cylindrical wall (211) in which a circumferential groove (210) is formed, the circumferential groove (210) being provided to receive the metal cable (1); and - a doctor blade chamber (22) comprising a reservoir (220) provided for containing the coating substance (2), the reservoir (220) having an opening positioned opposite the applicator roller (21) for filling the circumferential groove (210) with coating substance (2), the doctor blade chamber (22) further comprising a doctor blade (222) positioned downstream of the opening of the reservoir (220) in the application rotation direction (Ra) and being provided for removing an excess of coating substance (2) present on the applicator roller (21); wherein the applicator roller (21) is arranged on the frame (30) so that the circumferential groove (210) receiving the metal cable (1) is above the metal cable (1), so that in operation the metal cable (1) is coated from above.

2. System according to claim 1, in which the guiding device (10) is provided to guide the metal cable (1) in a coating direction (De) tangent to the circumferential groove (210).

3. System according to any one of claims 1 and 2, in which the guide device (10) comprises a lifting roller (11) on which the metal cable (1) is intended to be driven, the lifting roller (11) being positioned upstream of the applicator roller (21) relative to the direction of drive of the metal cable (1) and below the applicator roller (21) relative to the frame (30).

4. System according to any one of claims 1 to 3, in which the scraper (222) is provided for removing coating substance (2) present in the groove. circumferential (210) in order to dose the quantity of coating substance (2) available for coating the metal cable (1).

5. System according to any one of claims 1 to 4, in which the circumferential groove (210) has a maximum depth (P) defined relative to the level of the cylindrical wall (211) of between 50% and 200% of an average diameter of the metal cable (1), preferably of between 100% and 190% of the average diameter of the metal cable (1), and more preferably of the order of 180% of the average diameter of the metal cable (1).

6. System according to any one of claims 1 to 5, in which the circumferential groove (210) has an outwardly open shape with side walls forming an angle α of between 35° and 90°, preferably of between 55° and 65°, and more preferably of the order of 60°.

7. System according to any one of claims 1 to 6, in which the circumferential groove (210) has a rounded bottom defined by a radius (R) greater than an average radius of the metal cable (1), preferably a radius (R) greater than 110% of the average radius of the metal cable (1), and more preferably a radius (R) between 110% and 120% of the average radius of the metal cable (1).

8. System according to any one of claims 1 to 7, comprising several guiding devices (10) for the metal cable (1) for guiding the metal cable (1) in a coating direction (De) substantially horizontal relative to the frame (30), and in which the applicator roller (21) of the applicator device (20) comprises several circumferential grooves (210) arranged on the cylindrical wall (211) parallel to each other, each circumferential groove (210) being provided to receive a metal cable (1) guided by one of the guiding devices (10).

9. System according to any one of claims 1 to 8, wherein the applicator device (20) is configured to drive the applicator roller (21) at a rotation speed (Vr) of between 0.1 and 2 times a drive speed (Ve) at which the metal cable (1) is driven.

10. System according to claim 9, wherein the applicator device (20) is configured to drive the applicator roller (21) at a rotational speed (Vr) of the order of 1.5 times the drive speed (Ve) at which the metal cable (1) is driven.

11. System according to any one of claims 1 to 10, comprising a drive device configured to drive the metal cable (1) at a drive speed (Ve) of at least 20 m / min, preferably a speed of at least 80 m / min, more preferably a speed of at least 200 m / min.

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