EP1590287B1 - Thread take-off device - Google Patents

Abstract

A yarn withdrawal apparatus for continuously withdrawing a yarn from a feed yarn package and then from a reserve package, where the trailing yarn end on the feed package is knotted to the leading end of the yarn on the reserve package. The transition of the yarn from the feed yarn package to the reserve yarn package is detected by a sensor, which includes a movable yarn guide, which moves during the transition from an inactive position to a signaling position in a first degree of freedom of movement. To prevent the movable yarn guide from rebounding when it reaches the signaling position, the yarn guide or an element connected thereto defines a second degree of freedom of movement which is different from the first degree of freedom of movement, and such that after the rebound the movement is of such a kind that a departure from the signaling position back toward the inactive position is geometrically not possible.

Description

The invention relates to a yarn withdrawal device according to the preamble of claim 1 and a texturing machine with a yarn withdrawal device according to the invention. Such thread take-off devices are known from the WO 00/21866 A2 or the US 5,137,059 known. In order to ensure a continuous process flow in a thread processing process in which a thread is withdrawn from a supply spool and further processed, the thread end of the supply spool is connected to the thread beginning of a reserve spool. The connection is carried out so that the thread runs smoothly after idling the supply spool from the reserve spool.

The connection is usually made by knotting or splicing. The resulting thickening in the thread represents an unavoidable reduction in quality in the subsequent process WO 00/21866 A2 to sense the transition from the feed bobbin to the reserve bobbin by a sensor and respond to it in the processing process.

This is sensed by a sensor which is provided between the coils and by means of a movable yarn guide whose movement is triggered by the yarn exchange between the coils and whose position is detected. The problem that arises here is that the moving thread guide is accelerated in a very short time by the fast-moving thread to a very high speed from the rest position towards the message position. It is possible that the thread guide is reflected in the message position at its stop and falls back into the rest position. Although it is possible to detect and electrically store this short stay, it is from the point of view of quick and easy operability and operational safety electrical interference undesirable that the thread guide is in the released state in the rest position.

Possible solutions such as soft damping impact materials do not lead to the goal. This also applies to bulk material fillings, which are integrated in the thread guide, or other damping applied additional masses. The reason is that due to the low mass of the yarn guide in combination with a high speed even a small unattenuated residual energy is sufficient to reflect the yarn guide in its rest position.

Also, air damping and electromagnetic damper are not suitable to apply the required high damping forces. As an additional difficulty here is the fact that the speed at which the thread guide is moved to the message position, scatters very strong. Therefore, it is hardly possible to set, for example, a friction brake so that it acts equally reliable both at high and at low speeds of the thread guide.

From the US 5,137,059 are also a sensor and a yarn guide with bistable position known to be used in the permanent magnet to produce the stable layers. However, in order to overcome the stabilizing forces at high yarn speeds already forces in the range of the usual yarn tensile forces are sufficient, so that a reflection of the yarn guide can not be safely excluded.

It is therefore an object of the invention to provide a yarn withdrawal device with a movable yarn guide, in which the yarn guide is reliably prevented from rebounding even at varying speeds.

This object is achieved according to the invention in that the sensor has a means which, due to its geometry, prevents the yarn guide from rebounding into the rest position. The advantage of the invention is that the thread guide, regardless of the speed with which it is moved to the message position, a rebound is prevented and thus works reliably. This is achieved in that in addition to the movement of the thread guide from the rest position to the message position, a second degree of freedom of movement is created. By an appropriate coordination of the second Freedom of movement with the first degree of freedom of movement is achieved so that the movement of the thread guide is different from the rest position to the reporting position than in the opposite direction. In the embodiment of the yarn withdrawal device according to the invention this is used to block the return of the yarn guide after rebounding.

In a variant of the yarn withdrawal device according to the invention the second degree of freedom of movement is realized by a pawl, which can run over a catch in the direction of the reporting position at high speed of the yarn guide, while blocking the movement in the reverse direction. This pawl can be integrated in both the fixed part of the sensor and be provided directly on the thread guide. At standstill, the lock must be able to be canceled or manually removed.

In another, preferred embodiment, the thread guide itself is movable in two degrees of freedom of movement. The thread guide cooperates with a curve that coordinates the degrees of freedom of movement of the thread guide. This curve is designed so that the yarn guide is initially guided on a first part of the curve during its movement from the rest position to the reporting position. Upon reaching the signaling position of the yarn guide is passed due to its speed and inertia in a second part of the curve in which a movement is blocked back to the rest position.

In a further development of this embodiment, the second part of the curve is shaped so that the thread guide can pass through this curve several times and thus degrades its kinetic energy by friction. In the ideal case, the second part of the curve has a circular path, which returns the thread guide repeatedly to the end position, so that it does not leave the message position. Once the yarn guide is at rest, it can then easily be returned to its home position on the first part of the curve by an operator changing the feed bobbins.

The thread withdrawal device according to the invention is used on a texturing machine for texturing and winding of threads by the texturing machine deducting the thread via a delivery mechanism of the thread withdrawal device.

An embodiment will be described in more detail below with reference to the accompanying drawings.

Fig. 1

Eine erfindungsgemäße Fadenabzugsvorrichtung sowie schematisch eine Texturiermaschine,

Fig. 2

eine Ausführungsvariante des Sensors der Fadenabzugsvorrichtung,

Fig. 3

eine weitere Ausführungsvariante des Sensors der Fadenabzugsvorrichtung.

They show:

Fig. 1

An inventive thread withdrawal device and schematically a texturing machine,

Fig. 2

a variant embodiment of the sensor of the thread take-off device,

Fig. 3

a further embodiment of the sensor of the thread withdrawal device.

FIG. 1 shows a thread withdrawal device 1 according to the invention and schematically a texturing machine (10 to 17).

In the yarn withdrawal apparatus 1, a continuous yarn 2 is provided. For this purpose, the thread 2 is withdrawn from a feed bobbin 4.1, which is provided at a first feed point 3.1, via a yarn guide 9. The thread end 5.1 of the feed bobbin 4.1 has been led out during winding of the feed bobbin in the interior of the coil from the stroke range and can therefore be connected to the thread beginning of a reserve coil 4.2, which is provided at a second presentation point 3.2 by means of a bond 5.3.

Now that the feed bobbin 4.1 is completely unwound, the connection of the thread end 5.1 and the thread beginning 5.2 spans, so that the thread 2 is pulled out of the sensor 6. This event is detected by the sensor 6 and forwarded as a signal 7 to a signal processor 8.

After leaving the thread withdrawal device 1, the thread 2 is first conveyed in the texturing machine by a first delivery mechanism 10, which also builds up the thread tension required for the thread take-off. In the texturing machine, the yarn is first heated in a heater 11 and cooled in a cooling rail 12 so that a swirl applied by the texturing unit 13 to the yarn 2 is fixed. Subsequently, the thread is withdrawn from a second delivery mechanism 14, heated again in a second heater 15, and fed via a third delivery mechanism 16 of the winding 17. The winding consists of a traversing 17.1, which alternates the thread 2 transversely to the axis of the coil 17.3 and a drive roller 17.2, which presses the thread 2 on the coil 17.3 and this drives at the same time. It will be understood that a bond 5.3 passing through the process represents a defect in textured yarn. Therefore, it is important to detect a bond 5.3 that has passed through the process with a sensor and to react accordingly. This can be done by classifying the coil 17.3 produced at this time as faulty, or by changing the coil 17.3 at this time, so that the faulty section of the yarn 2 is not coiled.

In Figure 2, the sensor 6 is shown in detail. The sensor 6 consists essentially of an inserted into a yarn guide carrier 18 insertion slot 19, and a yarn guide 20. The yarn guide 20 is rotatably mounted about the rotation axis 21. In the figure 2, the yarn guide 20 is shown in the rest position 20.1. The thread 2 is inserted behind the thread guide 20, that a thread tension, as occurs at the transition of the thread from the supply spool 4.1 on the reserve spool 4.2 of Figure 1, the thread 2 pulls out of the Anlegeschlitz 19 out while the thread guide 20 of the Rest position 20.1 in the message position 20.2 entrains. This change in position is detected by a switch 28. Representing other switching principles, such as optical, inductive, capacitive switches, a mechanical cam switch is shown here. The tip of the thread guide 20 in the region of the insertion slot 19 is fork-shaped here. This has the advantage that the thread guide 20 is moved during insertion of the thread 2 in the threading slot 19 in one operating step together with the thread 2 from the reporting position 20.2 in the rest position 20.1.

Subsequently, the movement of the yarn guide 20 during the transition of the yarn 2 from the supply spool 4.1 is described on the reserve coil 4.2. Due to the thread tension of the thread 2 is pulled laterally out of the insertion slot 19. At high yarn speeds of several hundred meters per minute very high accelerations act on the yarn guide 20. The yarn guide 20 rotates at high speed about the rotation axis 21 in the direction of the reporting position 20.2. The pawl 22, which is pressed by means of the pawl spring 23 against the latch curve 26, passes over the catch 27. The steep flank on the back of the latch 27 prevents the pawl 22 can drive over the catch in the reverse direction and thus prevents rebound of the Thread guide 20 in the rest position 20.1. An additional introduced into the yarn guide 20 system of a tension spring 25 and a mass 24, in which the pawl 22 and the pawl spring 23 are housed, causes the pawl 22 cooperates only at high speeds with the latch curve 26. Due to the friction between the mass 24 and the thread guide 20, this can not spring back into its rest position during rebounding. Only when the yarn guide 20 has come to rest, the mass 24 and thus the pawl 22 is withdrawn and the operator can move the yarn guide 20 as described above in its rest position 20.1. Also possible, but not further explained here, is an integration of the pawl 22 in the stationary yarn guide carrier 18. It is also possible to latch the elements described 22, pawl spring 23, mass 24 and spring 25, for example, by bending soft solid joints in the yarn guide 20 to integrate.

In Figure 3, another embodiment of the sensor 6 is described in detail. Here, the thread guide 20 is connected to a thrust rotary joint 29 with the yarn guide carrier 18. A cam 30, which is guided in a curve 31, coordinates the rotational and translational degrees of freedom. The curve 31 is subdivided into a first part 31.1 for the movement of the yarn guide 20 from the rest position 20.1 to the reporting position 20.2 and a second part 31.2 for the movement of the yarn guide 20 after reaching the reporting position 20.2.

Based on the description of Figure 2, the movement of the yarn guide 20 is described during the yarn change. First, the yarn guide, starting from the rest position 20.1, performs a movement which is determined by the guidance of the cam 30 in the first part 30.1 of the curve 31. In FIG. 3, this is a pivotal movement about the pivot point of the thrust rotary joint 29. This applies until reaching the signaling position 20.2. There, the cam 30 is guided in the second part 31.2 of the curve 31. The second part 31.2 of the curve 31 represents a circular path. This circular path is designed so that an orderly rebound of the thread guide 20 will allow, but prevents the thread guide 20 from leaving the area of the signaling position 20.2. Instead, the cam 30 passes through the circular path one or more times and thereby reduces the kinetic energy of the yarn guide 20. Due to the circular motion of the cam 30, the yarn guide 20 performs a combined small amplitude swing / push motion. Due to the thrust movement in the thrust rotary joint 29, the yarn guide 20 is deprived of energy due to the friction.

Because of the smaller space, the cam is ideally designed frusto-conical. As a result, a high bending strength of the cam can be achieved despite the small size.

LIST OF REFERENCE NUMBERS

1.

Yarn withdrawal device

Second

thread

3.1 1

first submission point

3.2

second submission

4.1

supply bobbin

4.2

reserve package

5.1

thread end

5.2

thread start

5.3

binding

6th

sensor

7th

signal

8th.

signal processing

9th

thread guides

10th

first delivery plant

11th

stoker

12th

cooling rail

13th

texturing

14th

second delivery plant

15th

second heater

16th

third delivery plant

17th

rewind

17.1

traversing

17.2

drive roll

17.3

Kitchen sink

18th

Yarn guide

19th

insertion slot

20th

thread guides

20.1

rest position

20.2

annunciator

21st

axis of rotation

22nd

pawl

23rd

pawl spring

24th

Dimensions

25th

mainspring

26th

jack curve

27th

notch

28th

switch

29th

Thrust-swivel joint

30th

cam

31st

Curve

31.1

first part of the curve

31.2

second part of the curve

Claims (8)

1. Yarn withdrawal device (1) for continuously unwinding a yarn (2), with at least two creel positions (3.1, 3.2), wherein one of the creel positions (3.1) mounts a feed yarn package (4.1) and the other creel position (3.2) a reserve yarn package (4.2), wherein the yarn (2) can be unwound from the feed yarn package (4.1) and from the reserve yarn package (4.2), and wherein a trailing yarn end (5.1) of the feed yarn package (4.1) is knotted to the leading yarn end (5.2) of the reserve yarn package (4.2) by a tie (5.3), wherein a sensor (6) is provided between the two creel positions (3.1, 3.2), which detects and signals the transition from the yarn of the feed yarn package (4.1) to the yarn of the reserve yarn package (4.2), wherein the sensor (6) includes a yarn guide (20) that is movable by the yarn transition from an inactive position (20.1) to a signaling position (20.2), and a position sensor (28) that detects the position of the yarn guide (20), and wherein the sensor (6) includes a means, which prevents during the yarn transition a reflection of the yarn guide (20) from the signaling position (20.2) in the direction of the inactive position (20.1),
   characterized in that
   the means for preventing the reflection on the yarn guide (20) or on an element connected to the yarn guide (20) makes available a second degree of freedom of movement in addition to a first degree of freedom of movement of the yarn guide (20) between the inactive position (20.1) and the signaling position (20.2), and that the first degree of freedom of movement and the second degree of freedom of movement are coordinated with each other in such a manner that they prevent the reflection of the yarn guide (20) from the signaling position (20.2) in the direction of the inactive position (20.1).
2. Yarn withdrawal device of claim 1, characterized in that the second degree of freedom of movement is produced by a pawl (22), which is capable of overshooting a notch (27) during the movement of the yarn guide (20) in the direction of the signaling position (20.2), and which blocks in the direction of the inactive position (20.1).
3. Yarn withdrawal device of claim 2,
   characterized in that
   the pawl (22) is arranged on the yarn guide (20).
4. Yarn withdrawal device of claim 2,
   characterized in that
   the pawl (22) is arranged on the stationary part of the sensor (6).
5. Yarn withdrawal device of claim 1,
   characterized in that
   the yarn guide (20) is adapted for moving in the first and the second degree of freedom of movement, and that a curve (31) coordinates the degrees of freedom of movement in such a manner that during the movement of the yarn guide (20) to the signaling position (20.2), a first portion (31.1) of the curve is traversed, and that a rebound of the yarn guide (20) results in traversing a second portion (31.2) of the curve, the second portion (31.2) of the curve being shaped such that the mass forces of the yarn guide prevent it from reaching the inactive position (20.1).
6. Yarn withdrawal device of claim 5,
   characterized in that
   the second portion (31.2) of the curve is shaped such that it can be traversed several times.
7. Yarn withdrawal device of claim 5,
   characterized in that
   the second portion (31.2) of the curve corresponds approximately to a circular guideway.
8. Texturing machine for texturing and winding a yarn with at least one feed system (10), which unwinds the yarn from a yarn withdrawal device (1),
   characterized in that
   the yarn withdrawal device (1) is a yarn withdrawal device of at least one of the foregoing claims.

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