Patent Application
20130206169
The invention concerns the field of manufacturing metal wires designed to provide tire reinforcers. In general terms, these wires are used to constitute reinforcing plies made from lengths of wire coated with a rubber mixture, mutually parallel and describing a given angle with the longitudinal direction of the ply.
These wires can be single wires or assemblies of wires obtained by twisting single metal wires.
In order to improve their strength, some of these wires, of the type formed by assembly, have the particularity of incorporating a core coated in rubber. However, the manufacture of these particular wires can cause unevenness on the surface of the wire linked with overspill of the rubber used to sheath the wire core on the outer layers of the said wire.
This unevenness can cause anomalies when manufacturing the reinforcing plies by locally changing the pitch between two wires and impairing the quality of the rubber bridges that are intended to be produced between the wires to link them together.
It therefore proves necessary in certain cases to complete the manufacturing process of wires having a core sheathed in rubber with a cleaning stage designed to remove all traces of unwanted rubber.
The object of the invention is to propose a device and a method designed to accomplish this additional stage.
The device for scrubbing a metal wire according to the invention includes:
means for feeding and running the wire,
at least two pairs of rotary brushes having a radius r, the axes of which are substantially mutually parallel and perpendicular to the direction in which the wire runs,
application means, suitable for contacting the brushes with the wire via the circumferences thereof in order to exert a given pressure on the wire while the device is operating.
This device is characterised in that means of adjusting the tension of the wire are provided directly upstream and downstream of the assembly of brushes.
In this way, it is possible to exert a certain pressure on the wire with the brushes in order to enhance the scrubbing efficiency and to enable elimination of the rubber residues present on the surface of the wire, without the force of application of the brushes on the wire deforming the wire due to the tension exerted on it.
The description that follows enables the device to be described with reference to an embodiment example, and is based on
The device illustrated in
The wire F runs from an upstream unwinding means (not illustrated) to a downstream receiving means (not illustrated). However, it is quite possible to insert an equivalent device at the end of the line of a wire rubber-coating and assembling unit, or even upstream of a calendering process or a process for producing a rubber-coated wire.
The means for feeding the wire F into the device are composed of the transport rollers 310 and 320 and of the unwinding or feed means situated upstream, and the receiving means situated downstream, each incorporating its own drive motor.
In the specific case of the device that is the subject of this description, the assembly of brushes is composed of two pairs of rotary brushes 21 and 22. These pairs of brushes are installed on the trajectory of the wire, which runs in a rectilinear manner between two transport rollers 31 and 32. The brushes (210, 211, 220, 221) have a substantially circular shape having a radius r.
The axes of rotation of a pair of brushes are mutually parallel and substantially perpendicular to the direction C in which the wire runs. The axes of the two pairs of brushes are also mutually perpendicular.
When it is planned to have more than two pairs of brushes, the axes are then arranged such that the directions of the axes between them describe equal angles in order to reach the entire circumference of the wire to be scrubbed, as illustrated in
The axes of the brushes can be arranged in order to be situated in a plane P perpendicular to the direction C in which the wire runs as illustrated in
Each pair of brushes is mounted on a plate (41, 42), which supports the drive motor assembly for the brushes (not illustrated). At least one brush of the pair includes application means suitable for contacting the brushes with the wire.
In the present case, each of the brush axes is mounted mobile such that it runs in an opening 229 made in the plate 42. The trajectory of the brush is made along the direction, substantially circular, of the arrow T, as illustrated in
When the device is operating, the brushes 220 and 221 come to press on the wire, which is then placed simultaneously in contact with the circumferences of the two brushes of the pair, which then exert a given application pressure thereon. The application force of the brushes on the wire can usefully lie between 1 N and 8 N.
The brushes (210, 211, 220, 221) are driven in rotation by motors (not visible) installed under the plates 41, 42. The brushes of a given pair have identical speeds of rotation, but in opposite directions (see
The speed of rotation of the brushes can usefully lie between 3000 r.p.m. and 6000 r.p.m. It will be noted here that the higher the speed of rotation of the brushes, the better the wire scrubbing. Furthermore, at these speeds, advantage is taken of the effects of the centrifugal force to force the evacuation of the rubber particles torn from the surface of the wire.
To this effect, in order to be protected against projections of particles, the device can be placed in an enclosed space 5 in which air A is made to circulate by means of a forced ventilation means in order to ensure that the said rubber particles are evacuated into a suitable dust collecting means.
It is then important to ensure that the wire remains as rectilinear as possible so that the brushes work efficiently. To this effect, it is envisaged that means for adjusting the tension are provided upstream 31 and downstream 32 of the assembly of brushes, and which have the aim of maintaining a given and calibrated tension along the entire path of the wire along the pairs of brushes. These means are composed of an upstream transport roller 31 and a downstream transport roller 32, around each of which the wire is wound several times.
Each transport roller is driven in rotation by a motor 310, 320 of the asynchronous type. The motor of the transport roller situated downstream of the brush assembly has a speed of rotation dictated by the feed rate of the wire in the process. The speed of the upstream motor 310 is therefore made subject to the speed of the downstream motor 320, and a braking torque is imposed on the upstream motor 310 in order to place the wire under tension between the two transport rollers 31 and 32.
Good scrubbing results are obtained by imposing on the wire a tension of between 5 daN and 20 daN, determined in particular according to the diameter of the wire to be scrubbed.
Thus, in a general manner, the greater the tension in the wire, the better the possibility of applying the brushes with a high pressure, and the better the quality of the scrubbing performed will be.
The wire running speed in the device can vary between 50 m/min and 600 m/min, or even more. It will be noted that the running speed of the wire in the device can easily itself be made subject to the wire running speed in an upstream or downstream process without adversely affecting the quality of the scrubbing performed.
The bristles of the brushes are composed of radial metal wires arranged on the hub of the brush. It can prove to be prudent to choose brush bristles in a material whose hardness is suitable, in order to avoid damaging the coatings on the wire to be scrubbed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1053969 | Jun 2010 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP11/58913 | 5/31/2011 | WO | 00 | 4/16/2013 |
