CN105151894B

CN105151894B - Method for eliminating loops of yarn and device for carrying out same

Info

Publication number: CN105151894B
Application number: CN201510353315.9A
Authority: CN
Inventors: J·斯劳潘斯基; M·莫拉维; M·斯图萨克
Original assignee: Rieter CZ sro
Current assignee: Rieter CZ sro
Priority date: 2014-06-09
Filing date: 2015-06-09
Publication date: 2020-11-13
Anticipated expiration: 2035-06-09
Also published as: EP2955142A1; CZ2014399A3; CN105151894A; CZ305860B6; EP2955142B1

Abstract

The invention relates to a method for eliminating loops of yarn when winding the yarn on a cross-wound bobbin on a spinning machine at a constant speed of the yarn being manufactured, wherein the length of the working path of the yarn varies in the space between the yarn take-off mechanism and the yarn winding device as a result of the yarn being deflected by a catching and guiding device of a compensating arm, said catching and guiding device being deflected by a reversible bidirectional control device. The position and/or direction and/or speed and/or force application of the reversible bidirectional control device is controlled according to the specific operation currently carried out at the operating unit, and during the transition from continuous spinning to the instantaneous state and vice versa, and during the participation in operation at the operating unit of the textile machine. The invention also relates to a device for eliminating the loop of the yarn when winding it on a cross-wound bobbin on a spinning machine at a constant speed of the yarn being manufactured.

Description

Method for eliminating loops of yarn and device for carrying out same

Technical Field

The invention relates to a method for eliminating loops of yarn when winding the yarn on a cross-wound bobbin on a spinning machine at a constant speed of the yarn being manufactured, wherein the length of the working path of the yarn is varied between a take-off mechanism and a winding device as a result of the yarn being deflected by catching and guiding means of a compensating arm, said catching and guiding means being deflected by reversible bidirectional control means.

The invention also relates to a device for eliminating the loops of a yarn when winding it on a cross-wound bobbin on a spinning machine at a constant speed of the yarn being manufactured, comprising a movable compensation arm having yarn catching and guiding means, the path of which intersects the path of the yarn between the drawing-off mechanism and the yarn winding device, while the compensation arm is fixedly mounted on the output element of a reversible bidirectional control device, which is connected to the control mechanism.

Background

During the winding of the yarn on a cross-wound bobbin on a spinning machine, for example on an open-end spinning machine or on an air-jet spinning machine, at a constant speed of the yarn being manufactured, a periodic relaxation of the yarn occurs due to the distribution of the yarn over the width of the bobbin. As a result, due to the constant speed of yarn production and the constant speed of yarn withdrawal from the spinning unit, it is necessary to compensate for this slack by lengthening and shortening the length of the yarn running path between the withdrawal mechanism and the yarn winding device. For this purpose, a plurality of compensators are used, comprising a compensation arm which acts on the yarn by one of its ends, so as to lengthen or shorten the working path of the yarn as required at the operating unit in the relevant section between the take-off mechanism of the yarn and the winding device of the yarn. In this way, the compensation arm also maintains a constant tension in the yarn, which is necessary for correcting the bobbin winding.

The known compensator comprises a reciprocating compensating arm which is mounted swingably and coupled to a spring which acts on the arm such that the compensating arm and its free end intersect the working path of the yarn transversely, acting on the yarn with a determined force in a spring-loaded manner, whereby not only is a tension required to be generated in the yarn, but at the same time the yarn, which is slack due to winding, is periodically and reversibly deflected from the linear working path, thereby eliminating the periodically formed yarn loop. Known solutions relate to springs which, due to their strength and properties, are "tuned" to the force development assumed during operation of the compensation arm, and which allow the preload of the spring to be additionally set/adjusted, thereby enabling readjustment of the setting of the compensator according to new parameters, for example in the event of a change in the type of yarn or in the size of the yarn, etc.

However, as it has become apparent in particular recently, the existing solutions for spring-operated compensators have their limitations, the deteriorations of which satisfy the technical requirements for forming cross-wound bobbins, while maintaining the simplicity of construction and allowing to set quickly and easily the individual parts of the device or the device itself, which is a specific need considering the actions carried out during the transient conditions at the operating unit and the manual handling operations, such as screwing in the yarn, yarn breakage, bobbin replacement, etc.

US 6375112B 1 discloses a device for controlling a compensator during a continuous spinning process. US 6375112B 1 solves this problem by relying only on a few sensors of other parts of the machine. For example, a sensor of the position of the traverse yarn guide of the winding device, a sensor of the winding speed, a sensor of the inclination angle of the arm holding the bobbin, and the like. From the data of all these sensors, a relatively high calculation procedure is required to calculate the direction of movement and the angle of rotation of the motor shaft on which the guide pulley is mounted. Furthermore, it is apparent that the exemplary stepper motor in US 6375112B 1 is not suitable for these applications because it is too difficult to control and does not have a stable and continuously adjustable position when a slight "jump" or overshoot or the like occurs due to a force action. Without the above-mentioned external sensors of the other working members of the operating unit, the solution according to US 6375112B 1 does not even satisfy its basic function of eliminating the yarn loop during winding of the yarn on the cross-wound cone bobbin.

The aim of the invention is mainly to improve the operation of removing the yarn loops when winding the yarn on a cross-wound bobbin on a spinning machine at a constant speed of the yarn being manufactured, and to improve the parameters of the device for eliminating the yarn loops.

Disclosure of Invention

The aim of the invention is achieved by a method for eliminating loops of yarn when winding yarn on a cross-wound bobbin on a spinning machine at a constant speed of the yarn being manufactured, the principle of which consists in that the position and/or direction and/or speed of a reversible bidirectional control device is controlled according to the specific operations currently carried out at an operating unit, and during the transition from continuous spinning to the instantaneous state and vice versa, and during the participation in operations at the operating unit of the textile machine.

The principle of the device for eliminating the loops of yarn when winding the yarn on a cross-wound bobbin at constant speed of the yarn being manufactured on a spinning machine is that the control mechanism is equipped with means for controlling the force applied and/or the speed and/or the direction and/or the position by the output element of the reversible bidirectional control device with respect to the specific operation currently carried out at the operating unit, and during the transition from continuous spinning to the instantaneous state and vice versa, and during the participation in operation at the operating unit of the textile machine.

The advantage of this solution is that the compensation arm is driven by independent means controlled via the control system, so that the speed of the compensation arm and the torque generated by it are controlled, if necessary, independently of the yarn movement speed and of the bobbin speed, which widens the possibility of using not only means for eliminating loops during the continuous winding of the cross-wound bobbin, but also for taking part in the automation of the operation at the operating unit of the textile machine that produces the cross-wound bobbin, at a constant speed of the yarn being produced. The angular momentum of the compensating arm is set according to the tension required in the yarn by means of its own independent bidirectionally controllable reversible device, and at the same time it is also slightly adjusted, for example by means of a sensor positioned close to the middle of the working path of the compensating arm, or by means of a detector of the reversible bidirectionally controllable device, whereby during the transition from continuous spinning to the transient state, and vice versa, the speed and momentum of the compensating arm depend on the requirements of the automated operation at the specific operating unit.

If the device for eliminating the loops of yarn comprises magnetic means, the compensation arm is deflected such that a compensation momentum is generated by the magnetic field of the permanent magnets, the basic compensation action of which does not have to be controlled, since the compensation arm is driven at its base by the tension force of the yarn only, a coil with a power supply and a control system for modifying the resulting compensation momentum, which counteracts the tension force of the yarn, making the entire device substantially universal for different types of yarn and different operating conditions.

A common advantage of the embodiments is that the characteristics of these compensators can be set according to the type of yarn that is automatically manufactured in the entire machine, without having to perform corrective operations at different operating units.

Drawings

The invention is illustrated schematically in the drawings, in which:

figure 1 shows a schematic structure of a compensator at the outlet of a yarn take-off mechanism from a side view,

figure 1a is a front view of the schematic structure of the compensator at the outlet of the yarn take-off mechanism seen from the front,

figure 2 shows a schematic structure of a compensator in the yarn running path between the yarn take-off mechanism and the yarn winding device,

figure 3 shows a block diagram of a magnetic or electromagnetic device for eliminating the yarn loops.

Detailed Description

The invention will become apparent from the description of an exemplary embodiment and from the description of the operation of the device for eliminating yarn loops at the operating unit of the spinning machine in the space between the take-off mechanism 1 of the yarn 0 coming from the spinning unit and the winding device a of the yarn 0 on the cross-wound bobbin.

The spinning machine comprises at least one row of identical operating units arranged adjacent to each other, wherein each operating unit comprises a spinning unit in which a yarn is produced. The yarn 0 take-off mechanism 1 is located above the spinning unit. The yarn 0 take-off mechanism 1 comprises a pair of known take-

off rollers

2, 3 between which the yarn 0 passes and which are rotatably mounted in the frame of the machine. One of the draw-off

rollers

2, 3 is coupled to a drive, not shown, and constitutes a driven draw-off roller 2, whereby the other draw-off roller 3 is a pressure draw-off roller 3 which is rotatably mounted on a spring-loaded arm 30 so as to be pressed against the driven draw-off roller 2.

The winding device a of the yarn 0 on the cross-wound bobbin is located in the path of the yarn 0 after the drawing mechanism 1. The winding device a of yarn 0 comprises a dispensing device a1 of yarn 0, by which the yarn 0 to be wound is dispensed over the width of the bobbin a 2.

The device for eliminating the yarn loop is arranged at the operating unit in the path of the yarn 0 between the drawing mechanism 1 and the winding device a.

The means for eliminating the loops of yarn comprise reversible bidirectional control means 4, such as electric, magnetic or pneumatic rotation means 4, on the output shaft 5 of which there is fixedly mounted at one of its ends a compensation arm 6; or an electric or pneumatic or magnetic linear device 4, on the output rod of which a compensating arm 6 is mounted.

In the exemplary embodiment in fig. 1, 1a and 2, the compensating arm 6 is mounted on the shaft 5 transversely to the longitudinal axis of the shaft 5, i.e. transversely to the axis of rotation of the shaft 5. In an exemplary embodiment not shown, the compensation arm 6 is positioned obliquely with respect to the shaft 5. At the free end of the compensating arm 6 is fixedly mounted a catching and guiding device 7 of the yarn 0, which upon elimination of the loop of the yarn 0 transversely intersects the working path of the yarn 0 in the space between the take-off mechanism 1 and the winding device a, which allows the catching and guiding device 7 of the yarn 0 to act on the yarn 0 during elimination of the yarn loop 0.

When eliminating the yarn loop 0, the catching and guiding means 7 of the yarn 0 perform a bidirectionally controlled reciprocating movement along a circular path 9, said circular path 9 being shown by a broken line in the embodiment of fig. 1. In this exemplary embodiment, the catching and guiding device 7 of the yarn 0 is arranged directly at the outlet of the yarn 0 from the take-off mechanism 1 of the yarn 0, so that the circular path 9 of the catching and guiding device 7 of the yarn 0 passes along a part of the circumference of the driven take-off roller 2.

In the exemplary embodiment shown in fig. 2, the catching and guiding device 7 of the yarn 0 is arranged in the space between a pair of mutually spaced supporting guides 10 of the yarn 0, which allows a controlled formation of the yarn loop and a controlled control of the loop in the space between the take-off mechanism 1 of the yarn and the winding device a of the yarn 0. In this embodiment too, the catching and guiding device 7 of the yarn 0 performs a bidirectionally controlled reciprocating movement along the circular path 9 during the elimination of the yarn loop 0.

In an exemplary embodiment, not shown, which is a variant of the embodiment of fig. 2, the catching and guiding device 7 of the yarn 0 is arranged in the space between two supporting guides 10 of the yarn 0 spaced apart from each other, which allows for the controlled formation of loops and the control of the loops on the path of the yarn 0 in the space between the take-off mechanism 1 of the yarn 0 and the winding device a of the yarn 0. In this exemplary embodiment, not shown, the catching and guiding device 7 of the yarn 0 is mounted at the end of the linear reversible bidirectional control device 4 and performs a bidirectionally controlled reciprocating movement along a linear path during the elimination of the loop of the yarn 0.

In a further exemplary embodiment, not shown, which is basically a variant of the embodiment of fig. 1, the reversible bidirectional control device 4 is turned through 90 ° and its output shaft 5 has a vertical longitudinal axis. The catching and guiding device 7 of the yarn 0 on the compensating arm 6 crosses transversely the working path of the yarn 0 in the space between the drawing-off mechanism 1 and the winding device a, moving substantially along a circular path positioned in the horizontal plane. In another exemplary embodiment, not shown, the reversible bidirectional control device 4 is set to be skewed with respect to the horizontal and vertical directions. The longitudinal axis of its output shaft 5 is also positioned obliquely and the catching and guiding device 7 of the yarn 0 on the compensating arm 6 crosses transversely the working path of the yarn 0 in the space between the drawing-off mechanism 1 and the winding device a, moving substantially along a circular path positioned in an oblique (oblique) plane.

In the embodiment shown, the means for eliminating the loop of yarn 0 further comprise a detector 8 of the position of the compensation arm 6, which, in the exemplary embodiment shown, is located in the central part of the path of the compensation arm 6 under consideration in the reciprocating movement during the operation of eliminating the loop of yarn 0. In this exemplary embodiment, the detector 8 is positioned eccentrically, the eccentricity e being oriented with respect to a line linking the rotation axis of the shaft 5 of the reversible bidirectional control device 4 and the rotation axis of the driven take-off roller 2. In an exemplary embodiment, not shown, the detector 8 is mounted in the frame of the device, at a point opposite to a suitable detection element positioned directly on the output member of the device 4, said detection element being formed by a transverse projection on the shaft 5 or the like. The detector 8 of the position of the compensating arm 6 allows to monitor the passage of the compensating arm 6 from the specific section being monitored and to adjust the action of the reversible bidirectional control device 4 accordingly, as will be described below. In a further exemplary embodiment, not shown, the means for eliminating the loop of the yarn 0 comprise a pair of detectors 8 spaced apart from each other, aligned with the compensation arm 6, for example in the end position of the oscillating movement of the compensation arm 6, or aligned with the path of the compensation arm 6, spaced apart from each other outside the end position of the oscillating movement of the compensation arm 6, or also in other suitable positions.

In another exemplary embodiment, the reversible bidirectional control device 4 is aligned with a detector of the position and/or speed of an output element of the reversible bidirectional control device 4, such as the shaft 5 of the rotating device 4, or the output rod of the linear device 4.

For example, by the position of the shaft 5, we know the displacement of the shaft 5 or more specifically the displacement angle, the number of rotations, etc. The detector of the speed and/or position of the movement forms part of the reversible bidirectional control device 4 or is formed by an external device which is aligned in a suitable position with the output element of the specific device 4, for example with the axis 5 of the reversible bidirectional control device 4. The detector of the speed and/or position of the movement, according to the direction of the control mechanism, and according to the transient requirements of the technological process at the specific operating unit, allows an accurate reversible bidirectional controlled active movement, acceleration, deceleration, stopping, etc. of the output device 4, said output device 4 being constituted by the catching and guiding device 7 of the yarn 0 and the compensation arm 6.

In another exemplary embodiment, the means for eliminating the loop of yarn 0 comprise a detector 8 of the position of the compensation arm 6 and a detector of the position and/or speed of the reversible bidirectional control device 4.

In the exemplary embodiment shown with the rotating means 4, the reversible bidirectional control means 4 consist of a brushless rotary electric drive with permanent magnets, a so-called BLDC motor, which has been provided with a detector detecting the rotational speed and/or position of its shaft 5. In an exemplary embodiment, not shown, the reversible bidirectional control means 4 are formed by a pneumatic rotary motor, or by other suitable drives, such as drives having only a limited range of linear reciprocating motion or bidirectional angular displacement or rotation. An example of a magnetic or more specifically electromagnetic device 4 having a limited range of bidirectional angular displacements is a device known as a rotary solenoid, for example.

Another example of a magnetic or more specifically electromagnetically reversible bidirectional control device 4 for a device for eliminating loops of yarn is shown in fig. 3 and 4, which show a cylindrical dipolar magnet 9, rotatably mounted about its longitudinal axis in a magnetic circuit, such as in a magnetically permeable stirrup (stinrup) 90, aligned with a coil 91 connected to an electric energy source for energizing the coil according to the instructions of a control mechanism. Due to its polarity, the magnet 9 generates a magnetic flux in the stirrup 90. The magnet 9 is connected to the compensation arm 6 and in the rest condition it is displaced so that the north pole of the magnet 9 is positioned opposite one pole extension of the stirrup 90 and the south pole of the magnet 9 is positioned opposite the other extension of the stirrup 90, so that the lines of force of the magnetic field pass through the stirrup 90, taking the shortest distance. This embodiment of the device 4 has the important function of generating, by magnetic force, a torque on the compensating arm 6, proportional to the displacement of the compensating arm 6, when the yarn 0 tries to turn the magnet 9 by means of the compensating arm 6, in other words the system itself counteracts this displacement by the action of the yarn 0 and stretches the yarn 0, thus counteracting the loops of the yarn. The connected coil 91, as excited by the current I (or by the variation of the current I), generates another magnetic flux which combines (according to the polarity, adds to it or subtracts from it) with the magnetic field of the rotating magnet, in such a way that the compensation characteristics of the device 4 of this embodiment are modified, thus enabling to vary the characteristics of the compensator from the point of view of the force F acting on it, which is automatically carried out according to the fabric parameters, and more importantly even enabling to optimize the process of compensation during one oscillation of the compensation arm 6 if the current I through the coil 91 is suitably varied over time, for example by using the method PWM. For suitable materials, it has been found advantageous to make the compensation arm 6 from a material that allows to achieve sufficient robustness and resistance while maintaining a minimum moment of inertia. For example, it is desirable to use a carbon composite material or the like. Furthermore, it is advantageous in terms of material to make the stirrup 90 of soft magnetic steel.

The control means control the shown rotary reversible bidirectional control device 4 and its control action on the yarn 0, for example in the so-called torque speed mode, whereby the control means are constituted by separate control means for one operating unit, or by means of the control means of an operating unit, or by control means common to a plurality of operating units, for example common to sections of the machine, or by control units common to all operating units of the machine, or by means of control means of the entire machine, etc.

The above described torque-speed control mode of the reversible bidirectional control device 4 allows, if necessary, to control the speed of movement of the compensating arm 6 and, therefore, also of its catching and guiding device 7, independently of each other, and, moreover, to control the amount of torque on the shaft 5, i.e. to control the force exerted by the compensating arm 6, or more specifically, by its catching and guiding device 7, on the yarn 0. Furthermore, during winding of the yarn 0, this is achieved irrespective of the speed of movement of the drawn-off yarn 0 and the speed of rotation of the bobbin a 2.

The torque of the shaft 5, which is converted by the compensation arm 6 and its catching and guiding device 7 into a force acting on the yarn 0 being manufactured and wound, is set during the continuous spinning of the yarn 0 according to the desired tension in the yarn 0 and is further adjusted slightly by means of the detector 8 of the position of the compensation arm 6, or more specifically by means of its catching and guiding device 7, and/or by means of the detector of the rotational speed and/or position of the shaft 5 of the reversible bidirectional control device 4. During the transition from the continuous spinning to the instantaneous state of the yarn 0 and vice versa, the control of the speed and/or of the torque of the shaft 5, and thus of the force exerted by the catching and guiding device 7 of the compensating arm 6 on the yarn 0 being manufactured and wound, is carried out at the present time and according to the specific requirements of the automatic operation being performed at the operating unit, for example as a result of the occurrence of the instantaneous state at the operating unit.

In the continuous spinning mode, the torque of the shaft 5 of the reversible bidirectional control device 4 is controlled, for example, by using a modified vector control method, in which there are two separate regulator circuits, one of which is intended to monitor and control the torque of the compensating arm 6, or more specifically the torque of the shaft 5 of the control device 4. For example, if the control device 4 is constituted by a motor, it is the case of controlling the magnetic flux of the motor. In addition, the two regulator circuits are manufactured such that they do not interfere with each other. The principle of modified vector control of an electric motor is to transform the space vector of the stator current into two perpendicular components in a rotating coordinate system, which may be oriented with respect to the space vector of the stator or rotor flux, or optionally with respect to the space vector of the resulting flux. The components of the stator motor current space vector then define the torque and magnetization effects of the motor that constitutes the device 4. The torque of the motor is defined by the torque forming component of the stator current vector and by the corresponding vector of the magnetic flux. Methods for vector control of electric motors are described in the literature, for example in the following scientific publications: chiasson, John Nelson, Modeling and high performance control of electric machines, ISBN 0-471-.

Claims

1. Method for eliminating loops (0) of yarn when winding a yarn (0) on a cross-wound bobbin (a2) on a spinning machine at a constant speed of the yarn (0) being manufactured, wherein the length of the working path of the yarn (0) varies between the take-off mechanism (1) of the yarn (0) and the winding device (a) of the yarn (0) due to the yarn (0) being deflected by the catching and guiding means (7) of a compensating arm (6), the yarn (0) being acted upon in a controlled manner by said catching and guiding means (7), said catching and guiding means (7) being deflected by reversible bidirectional control means (4), the position and/or direction and/or speed and/or application of the reversible bidirectional control means (4) being controlled according to the specific operation currently carried out at the operating unit, characterized in that the position and/or direction and/or speed and/or application of the reversible bidirectional control means (4) are controlled from the position and/or direction and/or speed and/or application of the reversible bidirectional control means (4) at the same time of the yarn being wound During the transition from continuous spinning to the instantaneous state and from the instantaneous state to the continuous spinning, and during the participation in operation at the operating unit of the textile machine, wherein the control of the reversible bidirectional control device (4) is carried out according to the instantaneous position of the catching and guiding device (7).

2. Method according to claim 1, characterized in that the force exerted by the reversible bidirectional control device (4) acting on the yarn is controlled so as to maintain a constant tension in the yarn (0) thanks to said catching and guiding device (7), said catching and guiding device (7) acting on the yarn (0) during the continuous spinning of the yarn (0) at the operating unit.

3. Device for eliminating loops of a yarn (0) when winding the yarn (0) on a cross-wound bobbin (A2) on a spinning machine at a constant speed of the yarn being manufactured, comprising a movable compensation arm (6), said movable compensation arm (6) having a catching and guiding device (7) of the yarn (0) whose path intersects the path of the yarn (0) between a take-off mechanism (1) of the yarn (0) and a winding device (A) of the yarn (0), while said compensation arm (6) is fixedly mounted on an output element of a reversible bidirectional control device (4), said reversible bidirectional control device (4) being connected to a control mechanism equipped with first means controlling the position and/or direction and/or speed and/or the force exerted by the output element of said reversible bidirectional control device (4) with respect to a specific operation currently carried out at the operating unit, characterized in that the control mechanism is equipped with second means for controlling the position and/or direction and/or speed and/or the force exerted by the output element of the reversible bidirectional control device (4) with respect to the control during the transition from continuous spinning to instantaneous state and vice versa, and during the participation in operation at the operating unit of the textile machine, wherein the control of the reversible bidirectional control device (4) is carried out according to the instantaneous position of the catching and guiding device (7).

4. A device according to claim 3, characterized in that the output element of the reversible bidirectional control device (4) is aligned with the detector of its position.

5. A device according to claim 3 or 4, characterized in that the output element of the reversible bidirectional control device (4) and/or the compensating arm (6) is aligned with at least one detector of the position of the compensating arm (6).

6. Device according to claim 5, characterized in that the detector of the position of the compensation arm (6) is located in the middle of the path of the compensation arm (6) during the reciprocating movement when eliminating the loop of yarn (0), or it is aligned with a detection element located directly on the output member of the reversible bidirectional control device (4).

7. Device according to claim 3 or 4, characterized in that the compensating arm (6) with its catching and guiding device (7) of the yarn (0) is arranged transversely to the path of the yarn (0) at the outlet of the yarn (0) of the take-off mechanism (1) of the yarn (0), whereby the working path of the catching and guiding device (7) of the yarn (0) is formed by a radial circular path (9), which radial circular path (9) extends over a part of the circumference of the driven take-off roller (2).

8. Device according to claim 3 or 4, characterized in that the compensating arm (6) with its catching and guiding device (7) of the yarn (0) is arranged transversely to the path of the yarn (0) in the space between two mutually spaced supporting guides (10) of the yarn (0), whereby the supporting guides (10) are arranged between the take-off mechanism (1) of the yarn (0) and the winding device (A) of the yarn (0), and the working path of the catching and guiding device (7) of the yarn (0) is formed by a radial circular path (9), or it constitutes a straight path.

9. Device according to claim 3 or 4, characterized in that the reversible bidirectional control means (4) are constituted by a rotating brushless motor with permanent magnets and a built-in detector of the position of its shaft (5).

10. A device according to claim 3 or 4, characterized in that the reversible bidirectional control means (4) are constituted by a rotary solenoid.

11. Device according to claim 3 or 4, characterized in that the reversible bidirectional control device (4) comprises a cylindrical dipolar magnet (9) on which the compensation arm (6) is mounted and which is rotatably mounted about its longitudinal axis in a magnetic circuit with a coil (91), said coil (91) being connected to a source of electric energy to energize said coil (91) according to the instructions of a control mechanism.

12. Device according to claim 11, characterized in that the magnetic circuit with the coil (91) comprises a stirrup (90), wherein the position of the cylindrical dipolar magnet (9) in the rest state is such that the north pole of the magnet (9) is positioned opposite one pole extension of the stirrup (90) and the south pole of the magnet (9) is positioned opposite the other pole extension of the stirrup (90).