EP3683342B1 - Method for inserting a false twist into a thread and spinning machine and use of a device for inserting a false twist into a thread - Google Patents

Description

The invention relates to a method for introducing false twists into a thread, with a thread running plane being formed by the thread running largely directly in plan view through a drafting system to a spinning device and the thread leaving the drafting system at an exit nip point formed by an upper roller and/or a lower roller, whereby the thread runs between the output clamping point and the spinning point over a roller rotating about an axis of rotation that is at an angle to the plane of the thread running, the thread simultaneously rotating about its longitudinal axis and thereby introducing a first false twist into the thread, as well as a spinning machine and a device for carrying out the procedure.

The known false twist devices for introducing false twist into a thread are based on deflecting the thread from an originally stretched position with a rotating false twist element. A twist is applied to the thread which creates a false twist in the thread. The false twist is limited in time and place in the thread. It occurs above a false twist introduction between two fixed clamping points, for example a pair of output rollers of a drafting system and a rotating roller of the false twist device. Depending on the direction of rotation of the false wire (Z or S twists), the existing real twists between the two clamping points are increased or decreased by the twists of the false wire. The false twist makes the spinning process more stable by reducing end breaks.

From the U.S. 2,718,111 A such a false twist device is known. A friction wheel contacts a thread between the exit rollers of a drafting system and a ring spinning device. The axis of rotation of the friction wheel is arranged obliquely to the grain. This creates a force that acts tangentially on the thread and rotates it about its longitudinal axis. This creates a false twist between the exit rollers and the thread guide. The thread essentially continues to run in the plane of the thread. Only the force of the rotating friction wheel causes a small deflection of the thread, which, if it ceases to exist when the friction wheel is not rotating, causes it to move back into its thread running plane. The friction wheel does not cause a permanent deflection of the thread from its thread running plane. The introduced false wire is also very small.

Also from the DE 161971C a similar false twisting device on a ring spinning machine is known. Here, too, various friction wheels are disclosed which contact the thread and introduce a false twist between two clamping points. However, the spinning stability is not significantly improved even when different types of attrition wheels are used.

From the JP 2003 089932 A and the CN 102 839 453 B a false twisting device is known in each case, in which the thread is guided over two flanks of a double roller. This creates a double false twist in the thread. The twin roller is complicated in design. In addition, the distance between the flanks of the double roll is predetermined, which can affect spinning stability.

JP H11 21729 A discloses a false twist device on a ring spinning machine in which a first false twist is introduced into the thread by a first inclined roller and a second false twist by a second inclined roller.

The EP 0 741 198 A1 discloses a multi-stepped friction roller. This puts a lot of strain on the thread and the spinning stability and thus the thread quality can suffer.

The object of the present invention is to provide a method and a device which allow the spinning stability on a spinning machine to be significantly improved without the thread quality suffering as a result.

The object is achieved with a method for introducing false twist into a thread and a spinning machine and using a device for introducing false twist into a thread according to the independent claims. The method according to the invention serves to introduce false twist into a thread and thus to increase spinning stability. According to the invention, the thread runs over a rotating roller, in particular over a rotating cylinder, cone or paraboloid, hereinafter generally referred to as a roller, which serves as a twisting element. Due to the inclined roller, the thread rotates around its longitudinal axis at the same time. As a result, depending on the design of the device, in particular with regard to the arrangement of the roller in relation to the thread, a false twist can be introduced into the thread. The method is suitable for introducing a false twist into the thread, which improves the strength of the thread during spinning and thus also prevents thread breakage. If a false twist is produced in the thread as it runs over the rotating roller, the corresponding device can also be used to stabilize the thread. The false twist to be introduced into the thread is generated by the thread running obliquely over the roller, during which forces occur in the longitudinal and transverse direction of the thread and generate the false twist in the thread.

If the thread were not deflected, it would run from the drafting system to the spinning device through a thread running plane, which is formed by the thread running largely directly in plan view through a drafting system to a spinning device. The thread leaves the drafting system at an exit nip formed by an upper roller and/or a lower roller, the thread running according to the invention between the exit nip and the spinning position over a roller rotating about an axis of rotation oblique to the thread running plane. The thread rotates around its longitudinal axis at the same time and it becomes a first false twist introduced into the thread. According to the invention, the thread is moved laterally out of the thread running plane by the roller and the thread contacts the upper roller or the lower roller after the exit nip point in such a way that it introduces a second false twist into the thread. The thread and the roller as well as the thread and the upper roller or the lower roller thus cross one another, so that the thread nestles against the lateral surface of the roller and the lateral surface of the upper roller or the lower roller during the deflection. False twist is introduced into the thread both on the roller and on the upper and lower rollers. The spinning stability can be significantly increased by the two points at which the false twist is introduced into the yarn, without the quality of the yarn produced suffering as a result of the introduction of too high a permanent twist.

Preferably, the first false wire is directed in the same direction or in the opposite direction to the second false wire. Depending on the deflection of the thread, the upper or lower roller, which introduces the second false twist into the thread, can both support the false twist of the roll and reduce the false twist of the roll if it is directed in the opposite direction.

In order to be able to absorb the axial forces acting on the roller with particularly low friction, it is advantageous if the roller is mounted with an, in particular passive, magnetic axial bearing. The magnetic axial bearing is low-maintenance and particularly well suited to different levels of axial force. Driving or braking forces which act radially on the roller can thus be applied to the roller in a very targeted manner without the axial forces having a strong influence on the drive of the roller. In principle, an active magnetic axial bearing is also possible, but the technical complexity at this point is usually too great.

The roller can be made to rotate by the thread path itself. In a particularly advantageous embodiment of the invention, the However, the roller is powered by a motor. The speed of the roller can either correspond to the delivery speed of the thread or also run slightly faster or slower in order to have an influence on the stability of the thread or, if necessary, to be able to bring about the introduction of false twist into the thread.

In a preferred embodiment of the invention, the rotational speed of the roller is detected with a sensor and an electrical signal is thus generated. This rotational speed of the roller can be used, for example, as an indication that the textile machine is working incorrectly or that the thread is faulty.

If, in an advantageous embodiment of the invention, the thread is raised or lowered relative to the course of the thread without a roller in addition to the lateral deflection, the operation of the spinning station can be simplified either by an operator or by a robot. In addition, a collision of a robot with the thread can be avoided in particular when the thread is pressed into the spinning machine by means of the roller, ie is lowered.

The thread is preferably guided laterally on flanks of the roll. This reliably prevents the thread from slipping off the roll during spinning and leading to an error in the spinning process.

It is particularly advantageous if the thread experiences a third and optionally a fourth false twist through the flanks of the roll. If the thread is guided around the roller in such a way that it not only touches the circumference of the roller and receives its false twist through this, but that it also touches one or both flanks of the roller, then the Flanks each introduced a further twist in the thread. This further rotation can take place either in the direction of the true twist of the thread or in the direction of the false twist.

The spinning machine according to the invention has a drafting system, a spinning device and a false twist device for introducing a false twist into a thread. A thread running plane is formed by the course of the thread, which is largely direct in plan view, through a drafting system to the spinning device. The drafting system has an exit nip with an upper roller and/or a lower roller, where the thread leaves the drafting system. A roller with an axis of rotation aligned obliquely to the thread running plane is arranged between the output clamping point and the spinning device, with the running thread rotating about its longitudinal axis as it passes the roller and thereby receiving a first false twist. The role is in particular a cylinder, a cone or a paraboloid and has a lateral surface to which the running thread nestles. According to the invention, the roller is arranged in such a way that the thread is deflected laterally out of the thread running plane by the roller and the thread contacts the upper roller or the lower roller after the exit nip point in such a way that it introduces a second false twist into the thread. The device serves in particular to carry out the method described above.

The oblique deduction of the thread from the exit nip causes the thread to partially wrap around a roller, depending on the arrangement of the roller, the upper or lower roller, of the exit nip. The wrapping does not take place perpendicularly to the axis of rotation of the upper or lower roller, so that a tangential force acts on the thread. This tangential force rotates the thread transversely to its longitudinal axis and creates its own twist on the thread. Depending on the arrangement of the roller in relation to the thread or the upper or lower roller, this twist can in turn be directed in the same or opposite direction to the first false twist be role. The false twist is thus either increased or decreased. This allows the spinning stability and the quality of the thread to be adjusted individually.

The axis of rotation of the rotating roller is preferably arranged at an angle, in particular between 30° and 60°, obliquely to the thread path when viewed in the plane of the thread path and engages in the straight thread path in such a way that the thread rotates about its longitudinal axis at the same time. This exerts a force on both the thread and the roller. This force causes the thread to rotate about its longitudinal axis and creates a false twist in the thread. This contributes to the spinning stability of the thread.

Advantageously, the axis of rotation of the rotating roller is arranged at an angle of between 30° and 60° to the thread path when looking at the plane of the thread path. Thus, on the one hand, the thread receives a reliable false twist and, on the other hand, the roller can also hold the thread well and introduce the false twist into the thread.

In a particularly advantageous embodiment of the invention, the roller is driven by a motor. The motor causes the roller to rotate, which corresponds to the delivery speed of the thread. Deviations from this thread delivery speed can be advantageous and change the force on the thread accordingly. A force can thus be applied to the thread, which introduces a false twist into the thread.

If, in an advantageous embodiment of the invention, several rotating rollers are arranged along the thread path, with the axes of rotation of the rotating roller being arranged at different angles to the thread path, the false twist can be inserted gently and with greater strength.

The roller is preferably arranged on the spinning machine in such a way that the thread is raised or lowered in comparison to the course of the thread without a roller in the plane of the thread run, in addition to the lateral deflection. The thread thus runs above or below the normal course of the thread, as it would be without the false twisting device according to the invention. If the thread path is raised, the operation of the spinning position is simplified, especially when attaching a thread. If, on the other hand, the yarn path is lowered, i.e. closer to the machine than with the normal yarn path, a robot patrolling along the spinning machine can drive past the spinning position without the risk of colliding with the yarn.

If, in a very particularly advantageous embodiment of the invention, the roller has at least one, preferably two, lateral flanks, the thread can be guided laterally very well and safely. It is thus possible for additional twists to be introduced into the thread when the thread is guided in such a way that it touches the flanks. In addition, this can reliably prevent the thread from slipping off the roll and the spinning process having to be interrupted or a defect being produced in the thread.

In order to ensure that the thread is reliably guided and that false twisting is introduced into the thread, it is advantageous if the roller has a length of at least 20 mm and a diameter of at least 10 mm.

It is particularly advantageous if at least one thread guide element is assigned to the roller in order to prevent the thread from slipping off the roller. In particular when the spinning position is at a standstill or when the spinning tension is too low or absent, it can be ensured that the thread does not fall off the roll. During spinning, however, the thread guide element should not touch the thread in order to speed up the spinning process not to disturb. In addition, the thread guide element can also be advantageous during piecing, in order to hold the thread when the thread is laid over the roller but the spinning tension has not yet been built up.

The device is arranged on the textile machine to the side of the non-deflected yarn path. It has a holder or a device carrier with which it can be attached to the spinning machine and advantageously the roll can be changed in terms of its inclination in relation to the holder or the attachment in the spinning machine or the thread path.

Advantageously, the assembly with the axis of the rotating roller is mounted on a mechanical device support. As a result, the assembly can be arranged very easily on the textile machine. It is also possible to retrofit an existing spinning machine with the device according to the invention.

Figur 1

eine Seitenansicht einer Spinnstelle einer Ringspinnmaschine,

Figur 2

eine Vorderansicht einer Spinnstelle einer Ringspinnmaschine gemäß Stand der Technik,

Figur 3

eine Vorderansicht mit nach rechts ausgelenktem Faden,

Figur 4

eine Vorderansicht mit nach links ausgelenktem Faden,

Figur 5

eine Seitenansicht mit in die Spinnstelle gedrücktem Faden mit einer ersten Neigung der Rolle,

Figur 6

eine Seitenansicht mit in die Spinnstelle gedrücktem Faden mit einer zweiten Neigung der Rolle,

Figur 7

eine Rolle mit umgelenktem Faden,

Figur 8a und 8b

eine Unterwalze mit umgelenktem Faden,

Figur 9a bis 9e

verschiedene Ausführungen der Rolle und

Figur 10

eine Rolle mit Magnetlagerung.

Further advantages of the invention are described in the following exemplary embodiments. It shows

figure 1

a side view of a spinning position of a ring spinning machine,

figure 2

a front view of a spinning position of a ring spinning machine according to the prior art,

figure 3

a front view with the thread deflected to the right,

figure 4

a front view with the thread deflected to the left,

figure 5

a side view with the thread pressed into the spinning position with a first inclination of the roll,

figure 6

a side view with the yarn pressed into the spinning position with a second inclination of the roll,

figure 7

a roll with deflected thread,

Figure 8a and 8b

a bottom roller with deflected thread,

Figure 9a to 9e

different versions of the role and

figure 10

a roller with magnetic bearings.

In the following description of alternative exemplary embodiments, the same reference symbols are used for features that are identical and/or at least comparable in their design and/or mode of operation compared to the other exemplary embodiments. If these are not explained again in detail, their design and/or mode of action corresponds to the design and mode of action of the features already described above. Said roller can have different lateral surfaces, which are, inter alia, in particular a cylinder, a cone or a paraboloid, even if only a cylinder should be mentioned in the individual case.

1 shows a side view of a spinning position 1 of a ring spinning machine. A fiber structure 2 runs through a drafting system 3 and is drafted in the process. He leaves the drafting system 3 at a pair of rollers, which consists of an upper roller 4 and a lower roller 5. Upper roller 4 and lower roller 5 form an output nip 6 in which the fiber structure 2 is clamped. In so-called compression spinning, instead of the upper roller 4 or the lower roller 5, a suction pipe can also be present, which is wrapped around by a small sieve belt and generates a negative pressure. The top roller 4 or the bottom roller 5 presses on the screen apron and clamps the fiber structure 2 also at a corresponding output clamping point 6. From the output clamping point 6, a thread 7 provided with a twist is formed from the fiber strand 2. The thread 7 loops around a roller 8 set at an angle to the thread path, then passes through a thread guide 9 and via a runner 10 onto a sleeve 11, onto which the thread 7 is wound. The thread 7 forms a thread balloon 12 between the thread guide 9 and the runner 10. The sleeve 11 rotates at the speed of the spindle carrying it about a spindle axis 14, while the runner 10 is dragged along a spinning ring 13 by the winding thread 7 at a slightly lower speed.

Between the output clamping point 6 and the thread guide 9, the thread 7 runs over the roller 8, which is rotatably mounted about an axis of rotation 15. The roller 8 deflects the thread 7 from its normal thread path 16 indicated by dashed lines and lifts it out of this thread path 16 . In this side view, the roller 8 is pivoted at an angle β of between 30° and 60° to the normal thread path 16 . The thread 7 thus does not contact the roller 8 perpendicularly to the axis of rotation 15 of the roller 8 but at an angle, so that tangential forces act on the thread 7 . The tangential forces cause the thread 7 to rotate, which creates a false twist between the exit nip point 6 and the thread guide 9 .

The figure 2 shows a front view of the spinning station 1 of a ring spinning machine according to the prior art. In this representation, the roller 8 can be seen as it is arranged on the spinning station 1 in a manner known from the prior art. The roller 8 is located in the area of a thread running plane 20. The thread running plane 20 is defined by the path of the fiber structure 2 through the drafting system 3 and further along this line through the spindle axis 14. As can be seen from this illustration, the thread 7 remains on its Away from the drafting system 3 to the thread guide 9 in this thread running plane 20. Smaller deviations from this due to the thread 7 clinging to the roller 8 or due to the rotation of the thread guide 9 are not taken into account here. The thread running plane 20 corresponds essentially to the plane of the drawing figure 1 .

From this representation of figure 2 it is clearly evident that the roller 8 is arranged inclined at an angle α to the thread running plane 20 . The thread 7 runs obliquely over the roller 8, as a result of which tangential forces arise on the thread 7, which introduce a false twist into the thread 7.

figure 3 shows one with figure 2 comparable representation, in which case the arrangement of the roller 8 according to the invention can be seen here. While according to the conventional arrangement figure 2 the roller 8 leaves the thread 7 substantially within the thread running plane 20, the thread according to the invention figure 3 moved out of the thread running plane 20. The thread 7 experiences not only tangential forces when it comes into contact with the roller 8, but also tangential forces in the area of the top roller 4. These tangential forces in the area of the top roller 4 are caused by the fact that the thread 7 is drawn off at an angle from the exit nip point 6, thereby touching the top roller 4 whose circumference also contacts and experiences further tangential forces here. Thus, not only rotations by the roller 8 but also rotations by the top roller 4 are introduced into the thread 7 . Depending on the arrangement of the roller 8 and the side to which the thread 7 is pulled out of the exit clamping point 6, Z or S twists occur in the thread 7, which support the true twist of the thread 7 or counteract this true twist. A higher false twist can thus be created or the false twist of the roll can be reduced.

While in accordance with the representation figure 3 the roller 8 is arranged to the right of the thread running plane 20 and accordingly deflects the thread 7 to the right, as shown in FIG figure 4 the roller 8 is arranged to the left of the thread running plane 20 and accordingly deflects the thread 7 to the left. In addition, the role is 8 according figure 4 also in their angle too the thread running plane 20 or in comparison to the embodiment according to figure 3 arranged rotated. The twist initiation of the role 8 according to figure 3 is thus the twisting device in the thread 7 of figure 4 opposite. The same applies to the initiation of twisting at the top roller 4 after the exit nip 6. After the thread 7 is drawn off in the other direction, the tangential forces of the top roller 4 also act in the opposite direction to carry out the figure 3 , so that twisting in the opposite direction into the yarn 7 also takes place here.

While in the previous embodiments the roller 8 lifts the thread 7 out of the normal path of the thread 16, the roller 8 pushes the thread 7 in the exemplary embodiments of FIG Figures 5 and 6 into spinning position 1. The thread 7 thus runs below the normal thread path 16. This can be advantageous, for example, when robots patrol the spinning machine along and a roller 8 arranged above the normal thread path 16 would impede the path of the robot. In the embodiments of Figures 5 and 6 the first twist is again generated by the roller 8, which cause tangential forces on the thread 7. In this case, the second twist on the thread 7 is brought about by the lower roller 5 , which is also contacted at an angle by the thread 7 and thus tangential forces act on the thread 7 . The reason for this is that the role 8 as well as in the Figures 3 and 4 the thread 7 is moved laterally out of the thread running plane 20 and thus causes an oblique deduction from the output nip point 6 and over the peripheral surface of the lower roller 5. Just like in the Figures 3 and 4 is the inclination of the roller 8 at the Figures 5 and 6 counteracted. As a result, the direction of the introduced false wire can be influenced. In addition, it is just like in the Figures 3 and 4 possible that the thread 7 runs both to the left and to the right of the thread running plane 20 .

In figure 7 the forces on the thread 7 and the roller 8 are shown. In this exemplary embodiment, the roller 8 rotates because of the thread 7 pulled over it. The thread 7 is deflected by the roller 8 . The thread tension F is divided into a component F _A in the axial direction and a component F _R in the radial direction. The roller 8 is driven by the radial force component F _R . Due to the axial component F _A, the thread 7 moves along the outer surface of the roller 8. The axial component F _A can in turn be broken down into a component _FL aligned in the direction of the thread run and a component F _T-WIRK perpendicular to the yarn axis. The component F _T-WIRK perpendicular to the yarn path corresponds to the force that acts on the outer diameter of the yarn 7 and with which the torsional moment for the false twist is introduced.

The false twist insertion depends on the diameter of the roller 8, the coefficient of friction of the outer surface of the roller 8, the deflection of the thread 7 or its angle of wrap around the roller 8, the inclination of the roller 8 to the undeflected thread 7, the number of rollers 8 used, the Ease of movement of the roller 8 or the positive or negative drive torque present on the roller 8, if it is driven by a motor, not shown. In this case, the rotational speed of the roller 8 can be detected by a sensor and an electrical signal can thus be generated for controlling the motor.

The optimum angle of inclination of the roller 8 for inserting the false twist is in the range of 30° - 60° to the line of the yarn path 16 of the undeflected yarn 7 (see Fig Figure 1, 2 ).

The surface of the roller 8 can be made of ceramic, of a steel body with a rough hard coating, or of a material such as rubber or a synthetic material such as elastomers, eg nitrile butadiene rubber (NBR, covering of top rollers).

The roller 8 should be easy to move. Suitable bearings for the roller 8 are small, oil-lubricated roller bearings, plain bearings with shafts smaller than 4 mm or aerostatic air bearings. However, rollers 8 with a defined positive or negative (braking) drive torque can also be used to optimize the false twist insertion.

The false twisting device with the roller 8 is preferably attached to the structure of the spinning machine by means of a device support 21 .

In order to introduce false twist into the yarn, in the prior art the thread 7 is often pulled over a web which is inclined relative to the thread path. Frictional forces occur due to the coefficient of friction and the inclination of the web as well as due to the wrapping of the thread 7 around the web. The thread friction to be overcome acts only to a small extent as a torsional moment for false twist initiation on the thread 7. The maximum possible initiation of false twist twists is limited by the maximum possible thread tension.

The thread tension increase as a result of the physical relationships described by the Euler-Eytelwein equation can be reduced if the sloping web is replaced by the easily rotatable roller 8. The thread 7 is pulled over the roller 8. The roller 8 rotates as a result. So that the thread 7 slides and/or rolls in the axial direction on the rotating roller 8. Since the friction of smooth-running bearings is much lower than the friction that occurs when the thread 7 is pulled over a fixed web, the rotating oblique roller 8 with reduced yarn tension forces, a significantly higher torsional moment can be exerted on the yarn 7.

In figure 7 is also shown that the roller 8 thread guide elements 23 are assigned. The thread guide elements 23 are, for example, pins which are arranged laterally next to the thread 7 during spinning.

When spinning with the intended spinning tension, the thread 7 does not touch the thread guide elements 23 . Only when the spinning tension is too low to keep the thread 7 on the inclined roller 8 does the thread 7 slip from the roller 8 in the direction of one or more of the thread guide elements 23 and get caught there. The thread guide elements 23 therefore prevent the thread 7 from sliding off the roller 8 and the spinning process having to be started again, which is a laborious process of placing the thread 7 on the roller 8 . The thread guide elements 23 also facilitate handling, in particular when the thread 7 is being piecing, in which the thread 7 must be placed on the roller 8 for the first time. The thread 7 can be placed very easily over the thread guide elements 23 and the roller 8 and the spinning process can then be started.

In the Figures 8a and 8b the forces are shown which occur on the thread 7 in the area of the lower roller 5. Of course, this behaves analogously when the thread 7 is deflected in a different direction, so that it contacts the top roller 4 . The thread 7 is pressed onto the bottom roller 5 so that normal forces F _N act on the thread 7 . How out Figure 8b can be seen, the thread 7 is drawn off obliquely to the axis of the lower roller 5. The thread _{7 is} pulled off at an angle _from the exit clamping point 6 _. This causes the thread 7 to twist about its longitudinal axis, which creates a twist in the thread 7 .

In the Figures 9a to 9e different forms of the roller 8 are shown. The roller 8 has a length L and a diameter D. The length L should be at least 20 mm, while the diameter D should be at least 10 mm. It is important that the thread can be safely guided over the roller 8 when it is deflected out of the thread running plane 20 .

The roll 8 in figure 9 has two conical flanks 22 . If the thread 7 is guided appropriately, it is possible for the thread 7 to contact the roller 8 at three different points. In the case shown here, the thread 7 is twisted to the right on the left flank 22, while on the central part of the roller 8, which is cylindrical, as on the right flank 22, it is twisted to the left. As a result, further, third and fourth twist introductions into the thread 7 are possible.

In the execution of the role 8 according Figure 9b only one flank 22 is arranged on the left side of the roller 8 . This lateral flank 22 can serve as protection so that the thread 7 does not slip off the roll 8 when it is deflected on it.

In the Figure 9c is similar to the Figure 9b only one lateral flank 22 is arranged. Here this flank 22 is rounded, so that under certain circumstances a gentle transition of the thread 7 to the cylindrical part of the roller 8 takes place.

The execution of the role 8 according to Figure 9d is such that it is concave. The resulting groove serves to guide the thread 7 in a particularly advantageous manner.

In Figure 9e For example, the roller 8 is provided with two lateral flanks 22 which are curved towards a central, cylindrical part. In particular, if the thread 7 usually runs in the middle, cylindrical part of the roller 8, a constant rotation of the thread 7 can be effected in this way.

Of course, other shapes of the roller 8 are also suitable for generating a good introduction of twist into the thread 7 .

The false twist device can be used in areas of spinning processes in which the yarn has insufficient strength and in which the strength can be increased by false twists and the spinning process can thus be stabilized. In this case, the roller 8 must be aligned in such a way that the false wire is in the same direction as the actual rotation. In this way, false twist and actual twist add up above the false twist device.

In ring spinning, yarn breaks occur mainly at the drafting system outlet in or shortly after the spinning triangle. For this reason, the false twist device is arranged below the drafting system in ring spinning. The strength of the thread 7 above the false twist device in the area of the drafting system outlet is increased by the additional false twists and the number of thread breaks during spinning is thereby reduced.

In figure 10 a roller 8 with a passive axial magnetic bearing 25 is shown. The roller is attached to the axis of rotation 15 . The axis of rotation 15 is in turn arranged radially rotatably in two radial bearings 26 . The magnetic bearing 25 serves as an axial bearing. The grooves 27 can be filled with plastic. There are webs 28 between the grooves 26. The grooves 27 are opposite magnets 29, which are spaced 30 from each other. The magnets 29 are fixed in the device carrier 21 . In interaction with the webs 28, the magnets 29 create an axial rigidity of the axis of rotation 15. The advantage of this bearing is that it is largely independent of an axial force which acts on the roller 8 through the thread. The drive of the roller 8 by the thread or by a motor assigned to the axis of rotation 15 (not shown here) is therefore not influenced by axial forces which could generate different resistances when driving the roller 8 . The roller 8 can thus be driven very evenly and in a targeted manner.

The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the patent claims are also possible.

Claims (15)

1. A method for inducing a false twist in a thread (7), a thread path plane (20) being formed by the largely direct course of the thread (7) through a drafting system (3) to a spinning device in a plan view, and the thread (7) exiting the drafting system (3) at a discharge clamping point (6) formed by a top roller (4) and/or a bottom roller (5), the thread (7) running between the discharge clamping point (6) and the spinning station across a roller 8) rotating about an axis of rotation (15) at an angle to the thread path plane (20), the thread (7) therein simultaneously rotating about the longitudinal axis thereof and therein inducing a first false twist in the thread (7), characterized in that the thread (7) is laterally displaced out of the thread path plane (20) by the roller (8) and the thread (7) is drawn off at an angle from the discharge clamping point (6) and the thread (7) therein clasps around the top roller (4) or the bottom roller (5) after the discharge clamping point (6) such that said roller induces a second false twist in the thread (7).
2. The method according to claim 1, characterized in that the first false twist is in the same direction or the opposite direction of the second false twist.
3. The method according to any one or more of the preceding claims, characterized in that the rotating roller (8) is driven by means of a motor and/or by the thread (7).
4. The method according to any one or more of the preceding claims, characterized in that the rotary speed of the roller (8) is captured by means of a sensor and an electrical signal is thus generated.
5. The method according to any one or more of the preceding claims, characterized in that the thread (7) is raised or lowered relative to the course of the thread (7) without a roller (8) in addition to the lateral deflection.
6. The method according to any one or more of the preceding claims, characterized in that the thread (7) is laterally guided at flanks (22) of the roller (8) and/or that the thread (7) undergoes a third and optionally a fourth false twist by the flanks (22) of the roller (8).
7. A spinning machine having a drafting system (3), a spinning device, and a false twist device for inducing a false twist in a thread (7), a thread path plane (20) being formed by the largely direct course of the thread (7) through a drafting system (3) to the spinning device in a plan view, and the drafting system (3) comprising a discharge clamping point (6) having a top roller (4) and/or a bottom roller (5) at which the thread (7) exits the drafting system (3), and a roller (8) having an axis of rotation (15) aligned at an angle to the thread path plane (20) being disposed between the discharge clamping point (6) and the spinning device, the running thread (7) rotating about the longitudinal axis thereof when passing the roller (8) and therein receiving a first false twist, characterized in that the roller (8) is disposed such that the thread (7) is laterally displaced out of the thread path plane (20) by the roller (8) and the thread (7) is drawn off at an angle from the discharge clamping point (6) and the thread (7) therein clasps around the top roller (4) or the bottom roller (5) after the discharge clamping point (6) such that said roller induces a second false twist in the thread (7).
8. The spinning machine according to the preceding claim, characterized in that the rotary axis (15) of the rotating roller (8) is disposed at an angle (a, β) between 30° and 60° to the thread path as seen in the thread path plane (20) and/or as seen in plan view of the thread path plane (20).
9. The spinning machine according to the preceding claim, characterized in that the roller (8) is supported by means of a magnetic, particularly passive, axial bearing (25).
10. The spinning machine according to any one or more of the preceding claims 7 to 9, characterized in that the roller (8) is driven by means of a motor and/or by means of the thread (7).
11. The spinning machine according to any one or more of the preceding claims 7 to 10, characterized in that a plurality of rotating rollers (8) are disposed along the thread path, wherein the axes of rotation (15) of the rotating rollers (8) are disposed at different angles to the thread path.
12. The spinning machine according to any one or more of the preceding claims 7 to 11, characterized in that the roller (8) is disposes such that the thread (7) is raised or lowered relative to the course of the thread (7) without a roller (8) in addition to the lateral deflection.
13. The spinning machine according to any one or more of the preceding claims 7 to 12, characterized in that the roller (8) comprises at least one lateral flank (22) for laterally guiding the thread (7) and/or that the roller (8) is associated with at least one thread guide element (23) in order to prevent the thread (7) from slipping off of the roller (8).
14. The spinning machine according to any one or more of the preceding claims 7 to 13, characterized in that the roller (8) has a length (L) of at least 20 mm and a diameter (D) of at least 10 mm.
15. Use of a device for inducing a false twist in a thread (7) on a spinning machine according to any one or more of the preceding claims 7 to 14, wherein the device comprises a roller (8) and a device support (21) for attaching the roller (8) rotating about an axis of rotation (15) at an angle to a structure of the spinning machine, and wherein the roller (8) is variable at its angle with respect to the device support (21) or the fastening in the spinning machine and the thread (7) is displaced laterally out of the thread path plane (20) by the roller (8) and the thread (7) is drawn off at an angle out of the delivery clamping point (6) and thereby clasps around the top roller (4) or the bottom roller (5) after the discharge clamping point (6) such that the top roller (4) or the bottom roller (5) introduces a second false twist into the thread (7).

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