EP0346376A1

EP0346376A1 - Process and device for joining a thread to a spinning device with pneumatic twister.

Info

Publication number: EP0346376A1
Application number: EP88902088A
Authority: EP
Inventors: Peter Artzt; Harald Dallmann; Kurt Ziegler; Gerhard Egbers
Original assignee: Schubert und Salzer Maschinenfabrik AG
Current assignee: Rieter Ingolstadt Spinnereimaschinenbau AG
Priority date: 1987-03-02
Filing date: 1988-03-02
Publication date: 1989-12-20
Anticipated expiration: 2008-03-02
Also published as: EP0346376B1; DE3706728A1; DE3706728C2; DE3744758A1; CN88101866A; DE3870618D1; US4893461A; JPH02504292A; DE3744757A1; JP2642180B2; WO1988006650A1; BR8806077A

Abstract

Afin de rattacher le fil à un dispositif de filage à organe tordeur pneumatique (3), une extrémité du fil (12) est retournée à travers l'organe tordeur (3) à un banc d'étirage (2) puis introduite entre les deux rouleaux de sortie (23, 230) du banc d'étirage (2) d'où elle est tirée, après avoir été reliée à une mèche (1), à travers l'organe tordeur, comme un fil continu (10). Lors du retour de l'extrémité du fil (12) à travers l'organe tordeur (3) situé avant les deux rouleaux de sortie (23, 230) du banc d'étirage (2) jusqu'à l'entrée (308) de l'organe tordeur (3), l'extrémité du fil (12) y est saisie et amenée à un crochet (7) adjacent au banc d'étirage (2) qui tire l'extrémité du fil (12) le long du banc d'étirage (2), à côté des deux rouleaux de sortie (23, 230), afin de l'introduire par la suite entre ceux-ci. Un serre-fil (6) guide l'extrémité du fil (12) quittant l'organe tordeur (3) par son entrée. Ce serre-fil (6) a la forme d'un ajutage d'air comprimé (60) essentiellement parallèle à la ligne de serrage des deux rouleaux de sortie (23, 230) et dont l'ouverture (600) est agencée du côté de l'organe tordeur (3) opposé au crochet (7), faisant face au crochet (7).In order to reattach the yarn to a spinning device with a pneumatic twist member (3), one end of the yarn (12) is returned through the twist member (3) to a draw bench (2) and then inserted between the two. output rollers (23, 230) of the drawing bench (2) from which it is drawn, after having been connected to a wick (1), through the twisting member, like a continuous wire (10). When returning the end of the wire (12) through the twisting member (3) located before the two output rollers (23, 230) of the drawing bench (2) to the input (308) of the twisting member (3), the end of the yarn (12) is grasped there and brought to a hook (7) adjacent to the drawing bench (2) which pulls the end of the yarn (12) along the drawing bench (2), next to the two output rollers (23, 230), in order to subsequently insert it between them. A thread clamp (6) guides the end of the thread (12) leaving the twisting member (3) through its entry. This thread clamp (6) has the form of a compressed air nozzle (60) essentially parallel to the clamping line of the two output rollers (23, 230) and the opening (600) of which is arranged on the side. of the twisting member (3) opposite the hook (7), facing the hook (7).

Description

Method and device for piecing a spinning device working with a pneumatic swirl element

The present invention relates to a method for piecing a spinning device working with a pneumatic twisting element, in which a thread end is returned from the exit side through the twisting element to a drafting system and then inserted laterally into the pair of exit rollers of the drafting system, from where it is integrated with a fuse is drawn off as a continuous thread through the swirl element, and a device for carrying out this method.

In a known method of this type, the swirl member is laterally displaced so that its entry side is accessible (DE-OSes 3.411.577 and 3.413.894). A thread end is then pulled off the bobbin and inserted into the swirl element from the exit side. A suction tube is fed to the inlet side of the swirl member, which pulls the thread end through the swirl member. The swirl member is then returned to its spinning position and the thread section extending from the swirl member to the suction tube is inserted into the pair of outlet rollers of the drafting system. Then the spinning process to be resumed. In this known piecing, it is disadvantageous that the swirl element for the return of the thread end to the drafting device has to be displaced laterally. On the one hand, additional space is required for this lateral displacement of the swirl element in addition to the swirl element, which prevents a compact design. On the other hand, when the swirl member is returned to its spinning position, there is a risk that it will not return exactly to its starting position, as a result of which the spinning process and the yarn failure are impaired.

Since in a spinning device the undisturbed spinning process is to be regarded as the normal case and the piecing process as an exceptional situation, the terms used in connection with the present invention, such as “inlet side” or “inlet mouth” or “outlet side” or “outlet mouth” of the swirl member always on this normal case. The "entry side" or "entry mouth" of the twist element is thus the side or mouth of the twist element facing the drafting system, since the thread in the take-off is during normal

Spinning process reaches the swirl element on this side and leaves the swirl element on its side facing away from the drafting system.

In the sense of the present invention, a "fuse" is to be understood as any band-like fiber material which can be warped by means of a drafting device and fed to the swirl element, regardless of whether it has a slight twist or not. This term does not only include flyers, but also card tapes etc. The object of the present invention is to provide a method and a device for spinning on a spinning device working with a pneumatic twisting device, by means of which an offset of the twisting device for returning the thread can be dispensed with, so that a space-saving construction of the spinning device is achieved and an optimal setting of the swirl organ is always guaranteed for spinning.

This object is achieved according to the invention in a generic method in that the thread end is conveyed through the swirl member located after the pair of exit rollers of the drafting device to its entry side, is grasped there and is fed to a gripper located next to the drafting device, which then feeds the thread end for later insertion pulls into the pair of outlet rollers past this next to the drafting system. Characterized in that the thread emerging from the swirl member on the entry side between the drafting device and the swirling device and fed to a gripper located next to the drafting device, it is not necessary to displace the swirling device laterally, so that it assumes its spinning position unchanged. In addition to the drafting device, there is only sufficient space for a gripper which can be moved essentially parallel to the direction of movement of the fiber material and thus does not require a lot of space. Because the twist element does not change its position in relation to the drafting system for spinning, it is ensured that the twist element assumes an optimal position with respect to the drafting system before and after the piecing process, which increases the spinning safety. Preferably, the thread end returned through the swirl member is exposed to a compressed air stream oriented essentially parallel to the clamping line of the pair of outlet rollers for the feed to the hook. As a result, a secure feeding of the thread end to the hook is achieved in a simple manner, without the need for exact control over time.

If the compressed air flow which feeds the thread end to the hook is turbulent, there is a risk that the thread end will be guided past the hook by the air turbulence and thus cannot be grasped by it. To avoid such malfunctions, it is therefore provided in an advantageous embodiment of the method according to the invention that the thread end returned through the swirl member is fed to the gripper with the aid of a laminar compressed air stream.

In order to increase the security for the feeding of the thread end to the gripper, it can alternatively or additionally be provided that a thread reserve is built up before the return of the thread end through the swirl member, which then during the return delivery of the thread end through the swirl member into the transverse to Thread flow acting compressed air flow is dissolved so slowly that the thread end is kept stretched by the compressed air flow while it is being fed to the hook. Due to the slow dissolution of the thread reserve, the end of the thread emerging from the entry opening of the swirl element is successively grasped by the compressed air flow, as a result of which this stretched thread supply to the hook is ensured. The air flow to which the thread end is exposed during its return delivery should be as weak as possible, so that on the one hand it ensures the return delivery but on the other hand does not dissolve the thread end. Air turbulence should also be avoided. For this reason, according to an advantageous feature of the method according to the invention, it is provided that the compressed air flow is switched off and the thread end has been gripped by the gripper.

At the start of thread withdrawal, individual fibers that detach from the fuse have a tendency to attach themselves to the thread. However, these individual fibers cannot be properly integrated and form unsightly knobs and sliders in the finished thread. If the beginning of the match is delivered to a suction device after it emerges from the drafting system, this match is subject to the suction effect of both the match suction and the swirl device after the spinning overpressure in the swirl element has been switched on. This creates undefined vacuum conditions in the area between the drafting system and the swirl element, which leads to malfunctions in the piecing process. In order to avoid these disadvantages, it is advantageous if, after resuming the thread take-off, the thread end and the fuse between the exit roller pair of the drafting device and the swirl element are exposed to a compressed air stream oriented essentially parallel to the clamping line of the exit roller pair.

If the compressed air flow oriented transversely to the thread take-off device remains switched on for too long, there is a risk of a thin spot in the newly spun thread following the piecing device. To avoid this, according to a further advantageous embodiment of the method according to the invention it is provided that the compressed air flow which is switched on after resumption of the thread take-off is switched off even before the thread end leaves the pair of exit rollers of the drafting system. It has been shown that individual fibers that are attached to the thread in the take-off can be blown off the thread particularly safely if the compressed air flow is tangentially removed from the core rotation of the thread extending from the drafting device to the swirl element.

In order to avoid that the returned thread end, while it is exposed to the compressed air flow directed against the looper, can turn up in the air flow, it is expediently provided that during the return of the thread a significantly weaker compressed air flow is brought to bear on the thread end than after resumption of the thread take-off . The strength of the compressed air flow is such that the thread end is still safely fed to the hook, but without the risk that the thread end will unwind.

During the spinning process, larger and larger deposits form in the swirl organ, which then detach from time to time and can be carried away by the thread in the take-off. For this reason, the swirl member is preferably cleaned in connection with the piecing process before or during the return of the thread end. This cleaning can in principle be carried out by compressed air, which is effective in the swirl element, even before the thread end has been inserted into the swirl element for return to the drafting unit. Such cleaning can also be combined with the return delivery process, for example by using a brush to return the thread end. However, a return delivery of the thread end according to the invention can be accomplished particularly simply by bringing it through a compressed air flow from the exit side of the swirl element through the swirl element into the region of the compressed air flow acting transversely to the thread path.

A simple control of the compressed air flow acting transversely to the thread path can be achieved according to the invention in that it only acts during the pneumatic return delivery of the thread end through the swirl element as long as the compressed air flow causing the thread return is effective in the swirl element.

The gripper expediently works pneumatically, a negative pressure being generated in it at least for the duration until the thread end is inserted into the drafting system. Such a pneumatic gripper offers the advantage that it can safely remove a thread end resulting from a thread break and that on the other hand it can also serve to remove fibers which are blown off the thread end after the thread take-off has been reinstated.

In principle, the thread end can be inserted into the drafting system in different ways. For example, the inclined position of the gripper, which is pulled back parallel or at an angle to the run of the fiber material, can suffice for this. In order to achieve a time-defined insertion of the thread end into the exit roller pair of the drafting system, in an advantageous embodiment of the method according to the invention it is provided that the thread end, after it has been drawn next to the drafting system, is in the form of a loop in the area between the last two pairs of rollers of the drafting system is pulled. It is It is advantageous if the thread end is simultaneously brought into the range of action of a thread brake during this loop-shaped pulling into the area between the last two roller pairs of the drafting system. In this way it is ensured that the thread end cannot suddenly jump together after being released by the gripper and thus can assume a non-parallel position with respect to the fuse, which would lead to an error in the piecing.

In order to achieve a safe and defined insertion of the thread end into the exit roller pair of the drafting device, it can be expediently provided that the thread end is brought into the region of the clamping line of the exit roller pair during insertion into the drafting device.

According to a preferred embodiment of the method according to the invention, the swirl element is replaced by a first, in

Direction cleaned from the trailing edge of the swirl member to the inlet side oriented compressed air flow. The thread end is then exposed to this first compressed air flow for return delivery to the entry side of the swirl element, in order to be exposed there to a second compressed air flow acting transversely to the transport direction, which feeds the thread end to a gripper, which then pulls the thread end past the pair of outlet rollers to the side of the drafting system. Then the previously stopped fuse is released and suctioned off between the drafting system and the swirl element.

The thread end extending to the hook is then looped into a thread brake in the area between the last two pairs of rollers of the drafting system and is inserted into the pair of exit rollers of the drafting system. The thread end is now subjected to a deduction again. At the same time, the fuse and loose fibers are sucked into the swirl organ by switching on again of the second compressed air flow is prevented. Then, before the end of the thread has reached the pair of outlet rollers of the drafting system, the suction of the fuse and the second compressed air stream are switched off. Finally, the spinning overpressure acting in the take-off direction is brought into effect again in the swirl element.

According to a further, likewise very advantageous method, the swirl element is cleaned by a first compressed air flow acting counter to the withdrawal direction and the thread end is then exposed to this first compressed air flow and brought by it from the exit side of the swirl element to its entry side. There, the thread end is exposed to a second stream of compressed air acting transversely to the transport direction and fed through this to a gripper, which then pulls the thread end past the pair of exit rollers to next to the drafting system. Subsequently, the thread end extending to the hook is fed in loop form to a thread brake in the area between the last two roller pairs of the drafting system, thereby being inserted into the pair of outlet rollers of the drafting system and subjected to a take-off again. Then the previously stopped fuse is released, while suction of the fuse and loose fibers into the swirl element is prevented by switching on the second compressed air stream again. When the thread end has been pulled out of the drafting system to a predetermined length, the suction of the sliver and the second compressed air flow are switched off again. Finally, the spinning overpressure acting in the take-off direction is brought into effect again in the swirl element.

To carry out the method is in a device with a pneumatic swirl member, a return delivery element for returning the thread end from the exit side of the swirl member to its entry side and with a gripper for retracting the thread end from the entry side of the swirl member past the pair of outlet rollers until, in addition to the drafting device, a thread feeder according to the invention is provided for detecting the thread end emerging from the entry end of the swirl member upon return and for feeding it to the gripper. This thread feeder makes it unnecessary for the twisting element to be moved laterally for piecing.

The thread feeder is preferably designed as a compressed air nozzle oriented essentially parallel to the clamping line of the pair of outlet rollers, the mouth of which is on the

The gripper is arranged on the opposite side of the swirl element and faces the gripper.

It has proven to be advantageous if the swirl element has an axial projection on its inlet side and the compressed air nozzle is arranged opposite the swirl element in such a way that the compressed air flow leaving the compressed air nozzle affects the end face of the projection. In this way, the air flow is deflected in the direction after the projection in the direction of the swirl organ due to the formation of eddies. As a result, the thread end moves somewhat away from the pair of outlet rollers of the drafting system, which increases the safety when feeding the thread end to the hook.

So that the swirl member can be arranged as close as possible to the rollers of the pair of outlet rollers, which has proven to be advantageous for the spinning process, it is provided in a further embodiment of the device according to the invention that the compressed air nozzle is at least partially arranged in the gusset of the outlet roller pair of the drafting unit facing the twister . In order to avoid lint deposits on the top roller of the pair of outlet rollers of the drafting system, it is expediently provided that the compressed air nozzle is at a distance of at least 1 mm from this top roller. A laminar flow of compressed air increases the safety when feeding the thread from the swirl element to the hook. It is therefore provided according to a further expedient feature of the invention that the mouth of the compressed air nozzle has an inner diameter with a constant cross section.

It has proven to be particularly expedient to arrange the compressed air nozzle tangentially to the thread end extending from the drafting device to the swirl element in such a way that the compressed air nozzle is directed against the flow direction of the compressed air flow causing the core rotation of the thread end, which is generated by the compressed air holes in the swirl element. This ensures that if the compressed air flow after resuming the thread take-off, but before the end of the thread has left the drafting device, the fuse or individual fibers are prevented from being drawn into the swirl member from the end of the thread.

If a swirl element is used that has only a single row of compressed air holes that tangentially open into the axial bore of the swirl element, then the compressed air nozzle is oriented tangentially to the elongated axial hole of the swirl element in the opposite direction to the flow direction of the compressed air flow leaving the compressed air holes. If, on the other hand, a swirl member is used which has two rows of compressed air bores in a row in the thread take-off direction, one row of which opens in one circumferential direction and the other row in the opposite circumferential direction into the axial bore of the swirl member, the invention provides that the compressed air nozzle is tangential to the extended one Axial bore of the swirl member is oriented in the opposite direction to the circumferential direction in which the compressed air holes of the second row in the thread take-off direction open into the axial bore of the swirl member. Since it has been shown that it is advantageous to use the weakest possible air flow for the feeding of the thread end to the hook so that the thread end does not open, while for the blowing off of individual fibers or the beginning of the sliver from the thread end in the take-off a stronger one Overpressure is advantageous, it is provided according to a further embodiment of the device according to the invention that the compressed air nozzle is assigned a device for optionally applying a higher or a lower overpressure.

It is advantageous if the compressed air nozzle is controlled as a function of the thread length still in the drafting system. For this reason, a control device is expediently assigned to the compressed air nozzle, and a thread monitoring device connected to this control device is assigned to the gripper.

According to a preferred embodiment of the subject matter of the invention, in addition to compressed air bores in which there is overpressure during the spinning process and which have a component in the take-off direction, the swirl element has further compressed air bores in which overpressure is present during the yarn return and which have a component in the return direction. These compressed air holes oriented in the return direction can be pressurized for the return of the thread end as well as for the cleaning of the swirl element.

If a twist organ is used for the pneumatic return of the thread end through the twist element to the area of the thread feeder, which has an injector nozzle in a thread take-off device and a twist brake separated by a gap, there is a risk that the thread end will return tion stuck in the area between the two nozzles of the swirl element. In order to prevent this, in a further expedient embodiment of the device according to the invention it can be provided that both the injector nozzle and the swirl nozzle each have at least one compressed air bore oriented in the return direction, wherein a stronger air flow can be generated in the injector nozzle than in the swirl nozzle. This can be achieved in various ways, for example by different inclination of the compressed air bores in the swirl nozzle and in the injector nozzle. It is preferably provided for this purpose that the compressed air bore in the injector nozzle has a larger diameter than the compressed air bore in the swirl nozzle.

Since the compressed air nozzle in the pneumatic return delivery of the thread end should only be effective for the duration of this return delivery in order to prevent the thread end from being unscrewed, it is provided according to a simple and expedient embodiment of the subject-matter of the invention that the return delivery of the thread end brings about compressed air bores of the swirl element and the Compressed air nozzle a common supply line and a common control valve are assigned.

It is not absolutely necessary for the thread to be pneumatically returned to the area of the thread feeder by the swirl element. In an alternative embodiment of the device according to the invention, a mechanical threading element can also be provided for returning the thread end through the swirl element into the stroke area of the thread feeder. This threading element is expediently designed as a clamp. However, in an alternative advantageous embodiment of the mechanical threading element, it is also possible to use this as Train brush, which brush can be assigned a wiper. Compared to a threading element designed as a clamp, a brush has the additional advantage that, during its relative axial movement in the swirl organ, it wipes off deposits that could have settled in the axial bore of the swirl organ, thus cleaning the swirl organ.

For an elongated feed of the thread end to the hook, which also ensures a secure pick-up of the thread end by the hook, it is advantageous if the thread end is slowly returned through the twist element. In addition, it is expedient that the return delivery length is defined, so that the length of the piecing can also be easily predetermined. In order to achieve this goal, a thread reserve device with a drive is advantageously provided on the outlet side of the swirl element, which drives the thread reserve device so slowly that the thread end leaving the mouth of the swirl element is stretched by the thread feeder during the feed to the gripper.

In principle, the gripper can be designed differently, for example as a pair of rollers, which grips the thread in a clamp-like manner and pulls it out of the swirl element due to its rotation and, after an axial displacement of the gripper for holding, also brings it into the region of a stationary suction air opening after release by the pair of rollers. However, the gripper is expediently designed as a suction air nozzle, which advantageously has a suction opening facing the thread feeder.

The gripper not only has the task of grasping the thread end fed to it from the thread feeder, but is also intended to insert this thread end into the pair of outlet rollers of the drafting system. In principle, this can also be done Different ways happen, for example, that in a gripper designed as a suction air nozzle, the thread end exits through an initially covered and later released slot and thus reaches the area of a thread insert, which then inserts the thread end into the drafting system. Expediently, however, the gripper can be moved from a receiving position, in which it works together with the thread feeder, into an insertion position next to the drafting system.

In principle, the thread end can be inserted into the drafting system by a corresponding movement of the gripper, but a thread insert is preferably provided for this purpose, which can be moved from a standby position next to the drafting system into an insertion position such that it extends the course of the swirling element to the gripper Crosses the thread end and introduces it into the drafting system as it moves further. A thread brake is expediently provided in this area of the drafting device, to which the thread end can be fed during its insertion movement. With this thread brake, the thread end can be retained even after release by the gripper, so that a parallel position of the thread end to the fuse is ensured during the entire thread take-off movement.

In principle, the thread brake can be located at any point on the thread path between the gripper and the pair of outlet rollers of the drafting system; however, the aim is to arrange this thread brake as close as possible to the pair of exit rollers of the drafting system so that the end of the thread is checked practically over the entire distance between the hook and the pair of exit rollers. For this reason, it is advantageously provided that this brake is located between the last two roller pairs of the drafting system. It is particularly advantageous if the thread insert in its one position together with the thread brake forms an elastic thread clamp. The thread brake, against which the thread insert presses the thread end, preferably has a clamping surface made of soft rubber or felt.

In order to ensure a safe and rapid insertion of the thread end into the exit roller pair of the drafting device, in a further embodiment of the device according to the invention it is provided that a thread guide is assigned to the top roller of the exit roller pair of the drafting device, which the thread end during the retraction next to that

The drafting system holds until it is inserted into the drafting system in the half of the face of the top roller facing the clamping line of the pair of exit rollers. In a simple embodiment, this can be done in that the thread guide is formed by an axial, essentially cylindrical projection of the top roller on its side facing the hook, the diameter of the projection being smaller than the diameter of the top roller. A rapid insertion of the thread end into the pair of outlet rollers of the drafting system can additionally be supported in that the top roller of the pair of outlet rollers has one or more notches in its edge facing the hook between the lateral surface and the end face.

Nowadays it is customary to carry out the spinning on spinning machines with the aid of a piecing carriage which runs along a machine with a large number of similar spinning positions. If the device according to the invention is used in connection with a machine with a large number of such spinning positions, it is also particularly advantageous here if one or more of the elements required solely for the piecing process are arranged on such a piecing carriage. The present invention makes it possible to carry out piecing in a safe manner without changing the arrangement and storage of the elements required for the normal spinning process, the invention permitting a space-saving design. The invention also enables precise control of the piecing process in such a way that the length of the attachment point in the thread can be kept very short and exactly predetermined. In this way, inconspicuous and secure piecing in the thread is achieved.

The device according to the invention is simple in construction and enables the use of a piecing carriage in a particularly simple manner, since it is not necessary to adjust elements on the swirl element or drafting system on the machine side in order to carry out the piecing process. All that is required is an electrical control of air pressures or a sliver stop device, which are already controlled from the spinning station even if the thread breaks. All other elements that are only required for piecing can thus be arranged on the piecing carriage.

The invention is explained in more detail below with reference to exemplary embodiments shown in the drawings. Show it:

Figure 1 is a schematic plan view of a spinning device designed according to the invention.

FIG. 2 shows the spinning device shown in FIG. 1 in a schematic side view;

3 shows a schematic illustration of a piecer from which the loose fibers were not blown off during the piecing process; Fig. 4 in a schematic representation another piecer, in which loose fibers were blown off during the piecing process;

Figure 5 is a functional timing diagram indicating the operations that are required after the laying of the thread end next to the drafting system for the attachment.

Fig. 5 in plan view the pair of exit rollers

Drafting system, the swirl element and a compressed air nozzle which is directed towards the thread end guided in the swirl element;

7a and 7b in cross section the swirl nozzle or the injector nozzle of the swirl element and the mouth of the compressed air nozzle;

8 shows in cross section the arrangement of the compressed air nozzle to form a swirl element with only a single set of compressed air bores;

9 is a top view of the arrangement of the compressed air nozzle relative to the pair of outlet rollers of the drafting system and the swirl element;

FIG. 10 shows the detail shown in FIG. 9 in a side view;

11 shows a swirl element with a threading element designed as a clamp;

12 shows a plan view of a modified device according to the invention;

13 shows a detail of a modified version of the

Subject of the invention with a cleaning and threading element designed as a brush in a schematic side view; and

Fig. 14 In cross section the swirl member shown in Fig. 1. First, the structure of the spinning device is explained with the aid of FIGS. 1 and 2.

In the spinning device shown, a sliver 1 or a fiber sliver is drawn to the desired strength by means of a drafting device 2 and then fed to a pneumatic twisting device 3, where the sliver 1 or the fiber sliver is spun into a thread 10. The thread 10 is drawn off from the swirl member 3 with the aid of a take-off device 4 and fed via a thread tension compensation bracket 40 to a winding device 41, where the thread is wound up into a bobbin 42. The drafting unit 2 shown has 4 pairs of rollers with the rollers 20 and 200, 21 and 210, 22 and 220 as well as 23 and 230. In front of the rollers 21, 210 of the third to last pair of rollers and before the rollers 20, 200 of the pair of rollers upstream of this pair of rollers is one Matching device 241 and 240 are arranged, to which a common drive device 24 is assigned (see operative connections 243 and 244).

The two rollers 22, 220 are each wrapped by a strap 221 and 222, respectively (see also FIG. 10).

A suction nozzle 25 is assigned to the lower roller 23 of the pair of outlet rollers 23, 230 in the area between the drafting unit 2 and the swirl element 3.

Due to the compressed air supplied to the pneumatic swirl element 3 via a controllable compressed air line 32, the thread 10 receives an incorrect twist, which is then largely canceled again. For this purpose, the swirl member 3 shown has an injector nozzle 30 and a swirl nozzle 31, seen in the thread take-off direction, which are carried by a common holder, not shown. 7b and 14 show, the injector nozzle 30 has two compressed air bores 300 and 301 which are tangential in open the axial bore 302 of the injector nozzle 30. 7a and 14 show that the swirl nozzle 31 has three compressed air bores 310, 311 and 312 which open tangentially into the axial bore 313 of the swirl nozzle 31. A comparison of FIGS. 7a and 7b shows that the compressed air bores 300 and 301 open into the axial bore 302 assigned to them in the opposite direction to the compressed air bores 310, 311 and 312. This is illustrated by arrows 303 in Fig. 7b and 314 in Fig. 7a.

The compressed air bores 300 and 301 as well as 310, 311 and 312 are inclined in the draw-off direction (see arrow 44 in FIGS. 1 and 14), so that the thread 10, when there is an excess pressure during the spinning process on the swirl element 3, a movement component in the direction thereof Arrow 44 is issued.

The compressed air bores 300, 301 and 310, 311 and 312, although arranged tangentially to the axial bore 302 and 313, are drawn in the sectional plane of the injector nozzle 30 and the swirl nozzle 31 for illustrative reasons.

The radially outer ends of the compressed air bores 300 and 301 are connected to an annular channel 304 surrounding the injector nozzle 30 and the compressed air bore 310, 311 and 312 of the swirl nozzle 31 are connected to an annular channel 315 surrounding this nozzle (FIG. 14). The two ring channels 304 and 315 are connected to one another by a line 320 and to the compressed air line 32 via a connecting line 321 and a changeover valve 90. The take-off device 4 consists, in the usual manner, of a driven take-off roller 45 and a pressure roller 450 (FIG. 2) that can be lifted off the latter and is elastically pressed against the take-off roller 45.

The spool 42 is driven by a winding roller 43. For oscillating laying of the thread 10 during winding, a traversing thread guide 46 is connected upstream of the winding device 41 in the usual way.

On its way between the swirl member 3 and the take-off device 4, the thread 10 is monitored by a thread monitor 91 for the presence of the spinning tension. The thread monitor 91 is connected in terms of control to the drive device 24 of the sliver clamping devices 240 and 241 in order to stop the sliver 1 in the event of a thread break while the drafting unit 2 continues to run. This operative connection 910 is shown as a line.

Immediately next to the thread run is in the vicinity of the twist 3 between the latter and the thread monitor 91, the mouth of a suction nozzle 92. This suction nozzle 92 has the task, during continuous spinning operation, loose fibers that leave the twist 3 as a flight, or in the event of a thread breakage to be sucked off from the drafting unit 2 in the form of a piece of thread.

Before going into the elements required for piecing, the function of the spinning device described above in the structure should first be explained:

During the undisturbed spinning process, a fiber sliver or a sliver 1 is fed to the drafting system. After leaving the drafting unit 2, the fiber material gets into the swirl element 3. By deflecting the edge regions of the warped fiber material between the rollers 23, 230 of the drafting system and the inlet mouth 305 of the swirl member 3, the ends of the outer fibers spread out from the band-like fiber material.

The pneumatic swirl member 3 provides the core 100 of the thread 10 with a certain wrong twist, which is then largely canceled again (see FIG. 3, zone IV). When the false wire is distributed and when it is removed, the protruding fiber ends bind into the core 100 of the thread 10 to form loops 101 and in this way cause the spun thread 10 to have the desired strength, the position of the fiber ends relative to the finished thread 10 the hairiness of it determines.

The finished spun thread 10 is drawn off from the swirl member 3 by the take-off device 4 and fed to the bobbin 42 for winding, the thread 10 being monitored by the thread monitor 91 during the take-off.

In order to be able to automatically fix a thread break in the described device, additional elements are required, which are described below:

For the return of the thread end 12 caused by a thread break to the swirl member 3, the swivelable suction tube 93, which can be lifted off the winding roller 43, can be fed in a known manner (see position 93 '), the drive device 930 of which is only indicated schematically in FIG. 2. This suction pipe 93 is connected via a valve 932 to a vacuum source, not shown. An auxiliary drive roller 94 can also be delivered to the spool 42 by means of a drive device 941, which can drive the spool 42 in the return delivery direction (see arrow 940 in FIG. 2). The suction tube 93 has on its side facing the swirl element 3 in a known manner a slot (not shown) through which the thread 10 can emerge when the suction tube 93 is pivoted back from the position 93 'into the position shown in FIG. 2. A pair of auxiliary rollers 95, which is arranged on a pivotable holder 950, is assigned to the suction tube 93 and the swirl element 3. This auxiliary roller pair 95 has the task of receiving the thread end 12 after it has partially left the suction tube 93 through the slot (see position 10 'in FIG. 2) and leading it in front of the outlet mouth 318 of the swirl element 3 (see position 95'). .

A thread reserve device 47 is located between the swirl member 3 and the thread monitor 91. This thread reserve device 47 has two thread guides 470 and

471, between which a thread deflecting element 472 can be moved transversely to the thread path (see arrow 44). For this purpose "the thread deflecting element 472 is connected to a drive device 473.

In addition to the compressed air holes 300 and 301 or 310, 311 and 312 required for the spinning process, the injector nozzle 30 and the swirl nozzle 31 also have further compressed air holes 306 and 316 which, in contrast to the compressed air holes 300, 301, 310, 311 and 312, are not tangential , but open radially into the axial bore 302 or 313 (see FIG. 14) and are inclined opposite to the take-off device (arrow 44), so that when the thread end 12 is acted upon, they impart a component of movement in the direction of return. These compressed air bores 306 are connected to an annular channel 307 and the compressed air bores 316 to an annular channel 317, which are connected to one another by means of a line 322. The latter is connected to the compressed air line 32 via a connecting line 323 and the changeover valve 90. As shown in FIG. 1, a compressed air nozzle 60 is arranged on one side of the thread path between the swirl member 3 and the drafting unit 2, which is connected to the compressed air line 32 via a valve 900 and a connecting line 901. The compressed air nozzle is oriented essentially parallel to the clamping line of the rollers 23, 230 of the drafting unit 2. The compressed air nozzle 60 forms a thread feeder 6, as will be explained in more detail later.

In relation to the thread path defined by the axis of the swirl element 3, the suction opening 700 of a suction pipe 70, which forms a pneumatic gripper 7, is located opposite the mouth 600 of the compressed air nozzle 60. This gripper 7 is in its receiving position in the position 7 'and can be retracted with the aid of a drive device 71 next to the drafting device 2 in the direction oblique to its top rollers 200, 210, 220 and 230 up to the position shown in FIG. 1 (cf. Fig. 2).

If one imagines a plane E1 and E2 respectively laid down by the axes of the rollers 22, 220 and 23, 230 (see FIG. 2), these planes E1 and E2 enclose an area B between them. In this area B, a thread insert 8 is provided, which according to FIGS. 1 and 2 consists of a hook 80 which can be moved essentially parallel to the rollers 22, 220 with the aid of a drive device 82 and which extends from the swirl element 3 on the Roll 230 crosses over to the suction tube 70 extending thread end 12. The arrangement of the path of movement of the thread insert 8 is now such that the thread end 12 is out of reverberation! the sliver web between the straps 221, 222, ie on the side of the straps 222 facing away from the straps 221, is laterally laid so that the thread end 12 is deflected by the roller 230 becomes. As shown in FIG. 1, the thread end 12 is drawn so far into the drafting system 2 that the hook 80 is located essentially in the cross-sectional plane E3 through the drafting system 2 in the extension of the axial bores 302 and 313 of the swirl element 3.

Between the last two roller pairs 22, 220 and 23, 230 of the drafting unit 2, i.e. in area B, the thread layer 8 is assigned a thread brake 81, against which the thread end 12 can be brought into contact with the thread insert 8 during the insertion movement into the drafting system

To generate the compressed air and suction air flows required for spinning and piecing, a vacuum source 96 (FIG. 1) is provided, with the pressure side of which the aforementioned compressed air line 32 is connected via a pressure line 960 and a valve 324. The suction nozzle 92 is connected to the suction side of the vacuum source 96 via a line 920 and the suction pipe 70 via a line 973, possibly via valves (not shown). Furthermore, the suction nozzle 25 is connected to the suction side of the vacuum source 96 via a line 250 and a control valve 902.

To control the piecing process, a control device 9 is provided, with which the elements working during the piecing process are connected in terms of control. 1 and 2, the corresponding operative connections between the control device 9 and the element to be controlled are shown as lines. These are the operative connection 942 for the drive device 941 of the auxiliary drive roller 94, the operative connection 931 for the drive device 930 and the operative connection 933 for the valve 932 of the suction pipe 93, the operative connection 451 for lifting the pressure roller 450 off the take-off roller 45, the operative connection 951 for the swivel drive of the holder 950 of the auxiliary roller pair 95, the operative connection 474 for the drive device 473 of the thread reserve device 47, optionally an operative connection to a valve (not shown), which is possibly provided in the line 920 leading to the suction nozzle 92 , The operative connection 325 to the valve 324 between the vacuum source 96 and the compressed air line 32, the operative connection 905 to the switching valve 90 for switching the swirl member 3 from. Spinning on return delivery and back, the operative connection 904 to the valve 900 for controlling the compressed air nozzle 60, the operative connection 903 to the control valve 902 for the suction nozzle 25, the operative connection 72 to the drive device 71 for the gripper 7, possibly an operative connection to a possibly in the line 73 provided (not shown) valve for a gripper 7 designed as a suction pipe 70, the operative connection 83 to the drive device 82 for the thread insert 8, and the operative connection 242 to the drive device 24 of the two roving clamp devices 240, 241.

The operation of the device shown in Figs. 1 and 2 is discussed below:

If a thread break occurs during the spinning process, the thread monitor 91 is addressed, which then actuates the sliver clamping devices 240 and 241 via the operative connection 910, whereby the fuse 1 is pressed against the rollers 200 and 210 and is thereby held back. These two rollers 200 and 210 are lifted off the driven rollers 20 and 21. However, the following pairs of rollers 22, 220 and 23, 230 convey the fuse 1 more towards the swirl member 3, whereby it is between the rollers 21, 210 and 22, 220 break the fuse 1. Due to the swirl member 3, which is still pressurized, this part of the fuse 1, which is still supplied to the swirl member 3 by the drafting device 2, is spun into a short piece of yarn. Since this is not connected to the thread 10 wound on the spool 42, this short piece of thread is now sucked off by the suction nozzle 92.

Simultaneously with the actuation of the sliver clamping devices 240, 241, the thread monitor 91, by means not shown, causes the bobbin 42 to be lifted off the winding roller 43 and thereby stopped. In addition, the lifting of the pressure roller 450 from the take-off roller 45 is effected in a manner not shown. Furthermore, the supply of compressed air to the swirl element 3 is prevented by means of the valve 324 and the suction effect on the suction nozzle 25 is prevented by means of the control valve 902.

Now the spinning station is prepared for piecing with the help of the control device 9. For this purpose, the changeover valve 90 is switched over and the valve 324 is brought into the flow position, so that in the swirl element 3 a compressed air flow opposite to the extraction device, i.e. opposite to arrow 44, is generated. The swirl element is cleaned by this compressed air flow, with detached fibers and dirt components being removed through the suction nozzle 25.

The thread insert 8 is brought into its position 8 'from the position shown in FIG. 1. Once this has been done, the gripper 7 is moved from the position shown in FIG. 1 to the position 7 '. hazards. Subsequently, the auxiliary drive roller 94 takes over the support of the coil 42. The suction tube 93 is brought from the position shown in FIG. 2 into the position 93 ″ and a negative pressure is generated in it by actuating the valve 932. The auxiliary drive roller 94 is now driven in the return delivery direction and rotates the bobbin 42 in the direction of arrow 940, so that, in accordance with the backward rotation of the bobbin 42 by the action of the suction air flow acting in the suction tube 93, the thread end 12 formed during yarn breakage is unwound from the bobbin 42 and suctioned off 2 moves back, whereby the thread end 12 emerges from the slot (not shown) of the suction tube 93 and assumes the position 10 '. The auxiliary roller pair 95 is now moved from a standby position, not shown, to the position shown in FIG

Position 95 'pivots, gripping the thread end 12 located in position 10' and bringing it in front of the outlet mouth 318 of the swirl member 3 and thus into the effective range of the air flow acting in the swirl member 3. A thread reserve of a defined size is formed in a manner not shown between the thread guides 470, 471 with the help of the thread deflecting element 472. Then the auxiliary drive setpoint 94 and thus also the coil 42 are stopped.

By means of cutting means, not shown, the thread 10 has been brought to a suitable length.

The further return delivery of the thread end 12 into the swirl member 3 takes place by turning back the pair of auxiliary rollers 95 and by releasing the previously formed thread reserve. The compressed air flow acting in the compressed air bores 316 and 306 of the swirl element 3 supports the return delivery of the thread end 12 in the direction of the stretch 2. The valve 900 is now actuated, so that a compressed air stream also emerges from the compressed air nozzle 60, which is oriented transversely to the transport direction of the thread end 12 (opposite to arrow 44) and which detects the thread end 12 emerging from the inlet opening 305 of the swirl member 3 and feeds the pneumatic gripper 7, which waits in the position 7 ', so that the compressed air flow blows the thread end 12 precisely into the suction opening 700 of the suction tube 70.

The release of the thread reserve by means of the thread reserve device 47 takes place so slowly that the compressed air nozzle 60 is able to keep the thread end 12 leaving the inlet opening 305 always stretched while it is being fed to the gripper 7, which has a favorable influence on the attachment security and the appearance of the piecer.

The suction pipe 70 now sucks the thread end 12. As soon as the thread end 12 is held securely by the suction tube 70, the valve 324 is actuated and the compressed air supply to the swirl element 3 and to the compressed air nozzle 60 is thereby prevented, in order to return the thread end 12 as gently as possible and to avoid untwisting the thread end 12.

After a sufficient length of thread has been sucked into the suction pipe 70, the latter is withdrawn from the position 7 ′ into the position shown in FIGS. 1 and 2. By a corresponding movement of the gripper 7 during its retraction movement from the position 7 'into the position shown, the thread end 12 is then pulled past the top roller 230 of the pair of outlet rollers 23, 230 to next to the drafting device 2, the thread end 12 laterally resting against the Top roller 230 of the drafting unit 2 arrives. By appropriate design of the upper roller 230, for example a chamfer (not shown), it is secured ensures that the thread end 12 is held in the clamping line region of the rollers 23, 230 regardless of the direction of movement of the hook 7 during further retraction and of the subsequent movement of the thread insert 8.

When the gripper 7 has reached its position shown in FIG. 1, the return delivery of the thread end 12 is ended. The thread end 12 assumes a defined position in the suction tube 70, since the thread length returned has previously been precisely measured by the thread reserve device 47.

The compressed air supply to the compressed air bores 316 and 306 is now cut off.

Now the hook 80, which had previously been in the position 8 ', is pulled into the position shown in FIG. 1. As shown in FIG. 2, the thread end 12 is fed to a thread brake 81 to form a loop 102 on the side of the apron 222 facing away from the roller 22 and is brought to bear against it.

At the same time, with the aid of the auxiliary drive roller 94, the bobbin 42 is driven again in the take-off direction (arrow 44) and the pressure roller 450 previously lifted off the take-off roller 45 is brought back into contact with the driven take-off roller 45, so that the thread end 12 is pulled again through the swirl member 3 becomes. In addition, the valve 324 is operated again and the changeover valve 90 is switched over. A first compressed air stream oriented in the withdrawal direction 9 (arrow 44) thus acts in the swirl member 3, while a second compressed air stream acts transversely to the withdrawal direction (arrow 44). Now the fuse 1 which was previously stopped is released by the fuse clamping devices 240, 241.

The compressed air flow from the compressed air nozzle 60 blows onto the thread end 12 located in the draw-off during this time and prevents the thread end 12 from entraining individual fibers. The blown-off fibers are collected and sucked off by the suction pipe 70. For this purpose, the suction pipe 70 has been brought back into its position 7 'after the insertion movement of the thread insert 8 into the position shown in FIG. 1.

After a period of time by the control device

9 is determined, this compressed air flow in the compressed air nozzle 60 is switched off by actuating the valve 900, whereupon the suction pipe 70 can also return to its initial position shown in FIGS. 1 and 2. This time is determined by the control device 9 so that the thread end 12 has been drawn out of the drafting device 2 to a predetermined length.

After the compressed air flow in the compressed air nozzle 60 has been switched off, a compressed air flow in the withdrawal direction (arrow 44) is generated in the swirl element 3 by actuating the valve 324 and the reversing valve 90. Now also the fuse 1 comes together with the thread end 12 into the swirl member 3 and is incorporated into the swivel member 3 in the thread end 12, so that after the beginning of the match in the thread end 12 is now a new thread from the fuse 1

10 is spun.

The hook 80 resting on the thread brake 81 and the thread brake 81 together form an elastic thread clamp which brakes the thread end 12 during thread take-off, so that the thread end 12 cannot jump together even after being released by the gripper 7 and therefore not in a curled manner , ie undrawn state can get into the clamping line of the rollers 23, 230 and in the swirl element 3. This ensures a perfect piecing. The suction nozzle 25 is directed onto the lower roller 230 of the pair of outlet rollers 23, 230 of the drafting unit 2 and therefore has no or only an insignificant effect in the area of the thread path between the drafting unit 2 and the swirl element 3. Control of the suction nozzle 25 can therefore generally be dispensed with. If the suction air nozzle 25 was nevertheless switched off during the piecing process by means of a valve (not shown), it can now be switched on again, so that these loose fibers, which could have got stuck on the roller 23 of the drafting unit 2, are sucked off by the latter. A cleaning suction or brush can also be assigned to the top roller 230.

The function of the compressed air nozzle 60 after reinstalling the thread take-off is explained in more detail below with reference to FIGS. 3 and 4:

The beginning of a fuse 1 which was previously clamped by a sliver clamping device 240, 241 always has an irregular appearance. There is a build-up of material here that is not desired in piecer 11. The compressed air nozzle 60, when it is switched on after the thread take-off has been reinstated, therefore has the task of blowing off the excess material from the thread end 12.

FIG. 3 shows the piecing device 11 without the compressed air nozzle 60 having an effect when it is removed again, while the piecing device 11 according to FIG. 4 was formed with the aid of the compressed air nozzle 60.

As shown in FIG. 3, the piecer 11 can be divided into three zones I, II and III, to which the normally spun thread 10 is connected as zone IV:

In Zone I all arriving in the swirl organ 3

Fibers are wound in loose spirals around the stretched thread end 12 by the twisting action of the injector nozzle 30. The Thread spun in Zone I is therefore not very strong, so that there is a risk of deferment.

In zone II, the fiber stream forms a core 13, which lies almost parallel to the thread end 12. A smaller part of the fibers forms the wrapping fibers (loops 101), which loop around both cores (thread end 12 and new fiber material). The length of this zone II determines the strength of the piecer 11.

The thread end 12 is due to the fact that there is no longer between the

Rolls 23, 230 of the drafting device 2 is clamped, no longer integrated in the stretched position in the newly created thread in zone III.

Zone III is followed by zone IV, in which the thread 10 consists exclusively of fibers which are fed to it from the drafting device 2.

If, after the thread take-off is switched on again, the compressed air nozzle 60 is first activated for a certain period of time, this eliminates, as shown in FIG. 4, the fibers loosely wrapped around the yarn end 12 (zone I). There is only a relatively small amount of fiber accumulation here, since approx. 90% of the fibers supplied by the drafting device 2 are removed by the compressed air nozzle 60.

Since the effect of the compressed air nozzle 60 cannot be switched off suddenly due to the length of the lines 32 and 321, the compressed air nozzle 60 also acts into zone II of the piecing 11. Fibers are then also blown off here, which makes the mass profile of the piecing 11 more favorable. Zone II is similar to Zone II from FIG. 3. Zone III is also the same in the two methods described (see FIGS. 3 and 4). The compressed air nozzle 60 is switched off completely at the latest when the thread end 12 previously returned for piecing leaves the rollers 23, 230 of the drafting device 2 in order to avoid that a thin spot in the new thread 10 arises after zone III.

In the above-described method, in which the thread take-off starts before the fuse 1 is released again, there is the disadvantage that the piecer 11 is followed by a thread section which has been formed from an inexactly distorted length section of the fuse 1, since it

It always takes a certain amount of time until the delayed fuse 1 is regular again. In order to prevent this length section of the fuse 1 from getting into the piecing device 11, piecing is carried out as follows according to a modified method (see also FIG. 5):

After the return of the thread end 12 to the gripper 7, the fuse 1 241 released (t _o), by operating the Luntenklemmvorrichtungen 240. The beginning of the sliver leaving the rollers 23, 230 is sucked off by the suction nozzle 25. Simultaneously or shortly after the fuse 1 is released, the bobbin 42 is lowered onto the winding roller 43 (t ₁ ). Then the gripper 7 is brought out of its position 7 'into its position shown in FIG. 1 next to the drafting device 2 and the pressure roller 450 to rest against the driven take-off roller 45 (t ₂ ). Subsequently, the thread end 12 already in the take-off is inserted into the pair of outlet rollers 23, 230 and brought into contact with the thread brake 81 with the aid of the thread insert 8 (t ₃ ).

Now the compressed air nozzle 60 is also brought into effect again temporarily, so that entrainment of the fuse 1 and of loose fibers by the thread end 12 located in the draw-off is reliably excluded (t ₄ , t ₅ ). The Fuse 1 and the fibers blown off from the thread end 12 are sucked off through the suction nozzle 25 and / or the suction pipe 70 which has now been brought back into position 7 '. After the compressed air nozzle 60 is deactivated again, a compressed air flow in the withdrawal direction (see arrow 44) is finally generated by actuating the valve 324 and the reversing valve 90 in the swirl element 3.

The release time for the fuse 1 and the switch-on time for the thread take-off are coordinated with one another by the control device 9 such that the thread end 12 only reaches the rollers 23, 230 of the drafting device 2 after the length section of the fuse 1, which is caused by the stopping of the fuse 1 had suffered when the yarn breakage occurred, was sucked off through the suction nozzle 25.

As the description above shows, are one. A multitude of elements only required for piecing, but not for the normal spinning process. These are, in particular, the control device 9 and the auxiliary drive roller 94 controlled by this, the suction pipe 93, the auxiliary roller pair 95, the thread reserve device 47, the compressed air nozzle 60, the gripper 7 and the thread insert 8 and the thread brake 81 assigned to this thread insert 8. It is therefore possible and advantageous to place these elements on a service device 97 (see Fig. 2) which controls the piecing process. This maintenance device 97 can be moved along a large number of similar spinning positions A, B, C, ... (see FIG. 12) of the machine and, at any desired spinning position A, B, C, ..., corrects such a thread break.

14, the nozzles of the swirl element 3 (injector nozzle 30, swirl nozzle 31) arranged one behind the other in the take-off direction (arrow 44) are arranged at an axial distance from one another and form a gap 34 between them. In the pneumatic return of the thread end 12 by the Swirl element 3 through there is therefore the risk that the leading end in this return delivery gets caught on the outlet side of injector nozzle 30. In order to rule out this danger, it is provided that a stronger air flow in the return delivery direction is generated in the injector nozzle 30 than in the swirl nozzle 31. This can be done by a correspondingly stronger orientation of the compressed air bores 316 in the return delivery direction (opposite to arrow 44), compared to which the compressed air bores 306 have a smaller component in the return delivery direction. According to the exemplary embodiment shown in FIG. 14, the return air flow is throttled more in the swirl nozzle than in the injector nozzle 30. For this purpose, as shown in FIG. 14, the compressed air bores 306 in the injector nozzle 30 have a larger diameter than the compressed air bores

316 In the swirl nozzle 31. The same effect can also be achieved by a different number of compressed air bores 306, 316 in the injector nozzle 30 and in the swirl nozzle 31.

The pneumatic return of the thread end 12 can alternatively also take place, if desired, with the aid of a compressed air nozzle (not shown) which can be delivered to the outlet mouth 318.

So that regardless of the fiber material to be spun or the thread size, it is always ensured that the thread leaving the inlet mouth of the swirl element 3 is also properly fed to the gripper 7, this thread pattern is carried out according to FIG. 1 with the aid of a compressed air nozzle 60, the mouth 600 of which has an inside diameter with constant Has cross section. A laminar flow of compressed air is generated in this way. If the slow return delivery of the thread end 12 to the compressed air nozzle 60 takes place through a corresponding reverse rotation speed of the auxiliary roller pair 95, the thread reserve device 47 can be dispensed with.

If a thread reserve device 47 is used, the thread guide 470 can be omitted if the swirl member 3 takes over its task.

To achieve a safe and gentle feeding of the thread end 12 to the gripper 7, so that the thread end 12th does not dissolve in the air flow, the compressed air flow leaving the compressed air nozzle 60 is set as weak as possible, especially when the gripper 7 operates pneumatically. On the other hand, for blowing off fibers and retaining the fuse 1 from the thread end 12 located in the draw-off, it is advantageous if the compressed air flow is stronger. For this reason, the compressed air nozzle 60 is assigned a device for optionally applying a lower overpressure during the return of the thread and a higher overpressure at the start of the thread withdrawal. This device can be formed by a changeover valve, which connects the compressed air nozzle 60 alternately with different pressure sources, or also by the valve 900, if this is designed as a throttle element and can also assume an intermediate position in addition to the closed and the open position.

In the interest of gentle feeding of the thread end 12 to the hook 7, it is appropriate to leave the compressed air nozzle 60 on only until the return delivery by the swirl member 3 has ended and, if possible, even switch it off earlier after the hook 7 the thread end 12 has grasped safely. For this purpose, both the swirl element 3 and the compressed air nozzle 60 according to FIG. 1 are connected upstream of a common control valve 324. In order to ensure when the returned thread 10 is fed to the gripper 7 that the thread end 12 cannot lie against one of the rollers 23, 230 of the drafting unit 2, the swirl element 3 is designed according to FIG. 9. As this figure clearly shows, the swirl element has on its inlet side 308 an axial projection 309 which receives the inlet mouth 305 of the swirl element 3. The compressed air nozzle 60 is arranged in such a way to the projection 309 of the swirl element 3 that the compressed air stream leaving the compressed air nozzle 60 touches the end face of the projection 309 of the swirl element 3. As seen in the direction of the compressed air flow, turbulence occurs behind the axial projection 309 of the swirl element 3, which deflect the thread end 12 in the direction of the swirl element 3 and thereby remove it from the rollers 23, 230.

It has been shown that particularly good spinning results are achieved if the swirl member 30 is arranged as close as possible to the rollers 23, 230 of the drafting unit 2. To make this possible, according to FIGS. 9 and 10, the compressed air nozzle 60 is at least partially in the

Swirl member 3 facing gussets 231 of the rollers 23, 230 of the drafting unit 2. In order to prevent the accumulation of flight on the top roller 230, it has proven to be advantageous if the compressed air nozzle 60, however, is at a minimum distance a from the top roller 230 of the drafting unit 2 1 mm.

As previously explained in connection with FIG. 3, the fibers are looped around the core 100 of the thread 10 by the injector nozzle 30. This balloon twist is identified by arrow 303 in FIG. 7b. However, the yarn core receives a core rotation in the swirl nozzle 31 (see arrow 319) which is opposite to the balloon rotation (see arrow 314) in the swirl nozzle 31. To be a special one 6 and 7a, 7b, it is provided that the compressed air nozzle 60 is arranged tangentially to the thread end 12 extending from the drafting device 2 to the swirl element 3 and the core rotation (arrow 319) of the thread end 12 is opposite. Since this core rotation is brought about by the compressed air bores 310, 311 and 312, the compressed air nozzle 60, as shown in FIG. 7a, is directed in the circumferential direction in which these compressed air bores 310, 311 and 312 open into the axial bore 313 of the swirl nozzle 31. As a comparison of FIGS. 7a and 7b with FIG. 8 shows, such a tangential arrangement of the compressed air nozzle 60 is not only possible if the swirl member 3 viewed in the thread take-off direction (see arrow 44) two rows of compressed air bores 300, 301 and 310, 311 and 312, but also in swirl devices with a single row of compressed air holes 330, 331. In the first case, the core rotation (arrow 319) is always through the second nozzle (swirl nozzle 31) with the second row of compressed air holes 310, 311 and 312, which for this purpose also acts to a greater extent on the thread end 12 (three compressed air holes 310, 311, 312 compared to two compressed air holes 300, 301 in the injector nozzle). However, if the swirl element 3 has only a single row of compressed air holes 330, 331, these compressed air holes cause both the balloon rotation (see arrow 332) and the core rotation (see arrow 319). In this case, the compressed air nozzle 60 is thus directed against the circumferential direction of the air flow in the swirl element 3 caused by the compressed air bores 330, 331.

This orientation of the compressed air stream leaving the compressed air nozzle 60 results in a particularly good detachment of loose fibers from the thread end 12 located in the draw-off and a particularly good retention of the fuse 1 supplied to the suction nozzle 25. It is not absolutely necessary, although particularly advantageous, that the suction opening 700 of the suction pipe 70 faces the compressed air nozzle 60. In particular in the case of a mechanical design of the thread feeder 6, it may well be expedient if the suction mouth 700 of the suction pipe 70 is provided concentrically with the axis of the suction pipe 70.

A gripper 7 designed as a suction tube 70 can also remain in its position 7 ′ during the entire piecing process if the suction tube 70 has a — possibly controllable — longitudinal slot (not shown) through which an intermediate section of the returned thread end 12 can exit To get into the path of movement of the thread insert 8.

If it is mentioned in the above description that the gripper 7 is retracted as far as the drafting system 2, this does not only mean a retraction of the gripper 7 laterally from the drafting system (according to FIG. 12). This should also be understood to mean another withdrawal of the gripper 7 outside of the drafting unit 2, for example above it, i.e. on the side of rollers 200, 210, 220 and 230 facing away from rollers 20, 21, 22 and 23.

If the thread end 12 is inserted into the pair of outlet rollers 23, 230 by appropriate shaping and / or movement of the gripper 7, the thread insert 8 can also be dispensed with. Depending on the design of the gripper 7, the thread brake 8 can also be dispensed with, in particular if the gripper 7 is of a mechanical design, or else in the gripper 7 if it is of a pneumatic design. It is advantageous if such a thread brake 81 is only effective when the thread is being drawn off again. The insertion of the thread end 12 in the clamping line of the rollers 23, 230 of the drafting device 2 can be ensured by a corresponding arrangement and / or retraction movement of the gripper 7, the threading of the thread end 12 in the clamping line being supported by a chamfering of the peripheral edge of the roller 230 can. Alternatively, one or more notches 232 can also be provided in the edge facing the gripper 7 between the lateral surface and the end surface of the roller 23. These notches 232 grip the inclined thread end 12 and then pull it into the nip line between the rollers 23, 230.

In order to make it even easier to insert the thread end 12 into the clamping line of the rollers 23, 230 of the drafting unit 2 when the gripper 7 is pulled back and / or during the insertion movement of the thread insert 8, it is expedient if the upper roller 230 is assigned a thread guide 26. This thread guide ensures that the thread end 12 is held in the half of the upper roller 230 facing the clamping line of the pair of outlet rollers 23, 230, regardless of the movement path of the gripper 7, and thus cannot reach the area of the upper half of the upper roller 230, whereby an insertion into the nip line of the rollers 23, 230 would not be possible.

Such a thread guide can be designed differently. In a simple embodiment, this thread guide according to FIGS. 1, 2 and 6 is designed in the form of an essentially cylindrical projection 260 of the roller 230. This projection 260 faces the path of movement of the gripper 7 and has a diameter d that is smaller than the diameter D of the roller 230 (see FIG. 6). Alternatively, instead of a cylindrical projection 260 of the roller 230, a thread guide 26 can also be provided, which has the shape of a bracket 261 (see FIG. 12). If desired, such a bracket can also be arranged on a maintenance trolley 97 (see dash-dotted illustration in FIG. 2), since this thread guide is only required during the piecing process.

In order to ensure that the returned thread end 12 is held securely by the pneumatic gripper 7, it is advantageous if the returned thread length is longer than required and the thread length required for piecing is only determined after the thread return has been completed. For this purpose, according to FIG. 1, the suction pipe 70 is assigned a cutting device 74 which controls the thread 10 extending in the suction pipe 70 by controlling the

Control device 9 (see operative connection 740) at the desired time to a desired length. For example, this cutting process can take place after the suction pipe 70 has reached its position shown in FIG. 2, but the thread insert 8 has not yet started its insertion movement.

It is advantageous if you can determine the piecing length. This is particularly advantageous since, depending on the material and yarn thickness, different minimum lengths are required for the piecing 11. For this reason, a thread monitoring device 75 is assigned to the suction pipe 70 according to FIG. 1, which is connected to the control device 9 in terms of control (see operative connection 750). In this way, the thread monitoring device 75, which is designed as a light barrier according to FIG. 1, can emit a signal to the control device 9 when the thread end 12 passes this thread monitoring device 75. In the control device 9 there is a timer, not shown, which can be set to different values and which controls the compressed air nozzle 60. As FIG. 1 shows, a control valve designed as a suction pipe 70 does not need to be assigned a control valve for controlling the negative pressure prevailing in it. However, if the vacuum effect is to be controlled, it is important to achieve a sufficient retention force for the thread end 12 when it is inserted into the drafting device 2 that the vacuum is only switched off after this insertion of the thread end 12. As mentioned, this insertion of the thread end 12 into the drafting unit 2 takes place through the retraction movement of the suction tube 70 and at the latest through the movement of the thread insert 8.

The thread brake 81 can be a retention set, e.g. in the manner of a burdock covering. However, as described, the thread brake 81 can also form an elastic thread clamp together with the thread insert 8 and for this purpose have a resilient clamping surface against which the thread insert 8, which for this purpose is connected to its drive device 82 via a spring (not shown) is brought elastically to the system. The resilient clamping surface of the thread brake 81 can consist of soft rubber, felt or the like.

The above description shows that the described method and the described device can be modified in many ways within the scope of the present invention, for example by replacing individual features with equivalents or using them in other combinations. So it is not necessary to lift the pressure roller 450 for the insertion of the thread 10 from the take-off roller 45, if insertion of the thread into the take-off device 4 can be ensured in another way by guide elements and a suitable design of the pressure roller 450. It is also not absolutely necessary for threading or for grasping the thread end 12 to apply pneumatically working elements. Furthermore, it is possible to replace the thread insert 8, which is designed mechanically according to FIG. 1, and the mechanical thread brake 81 by pneumatic elements. Such an embodiment of the device is explained below with reference to FIG. 12.

In the embodiment shown in FIG. 12, the thread feeder 6 is designed mechanically, namely as a pin 61, which can be moved transversely to the elongated axis of the swirl element 3 essentially parallel to the rollers 23, 230.

This pin 61 has a retention set 610 on its outer circumference, which is designed, for example, like a Velcro. After the thread end 12 has left the swirl member 3 when it is returned, this thread end 12 is carried by the pin 61 during its movement from the position shown in FIG. 12 into its position 61 '. In order to ensure that the thread end 12 is securely received by the retention set 610, the pin 61 can, if desired, also be given a slight rotational movement.

Since the feed speed to the gripper 7 depends on the displacement speed of the thread feeder 6 in a mechanical configuration of the thread feeder 6, a thread reserve device 47 can be omitted.

According to FIG. 12, the gripper 7 is not designed as a suction pipe 70, but has a pair of rollers 76. After the pin 61 has reached its position 61 ', the gripper 7 with its pair of rollers 76 is brought into its position 7', with a suitable relative movement between the gripper 7 and the pin 61, or by means not shown

Thread guides ensure that the returned thread reaches the clamping area of the pair of rollers 76. After the thread end 12 is held securely by the pair of rollers 76, the gripper 7 is returned from its position 7 'to its starting position shown in FIG. The pair of rollers 76 reaches the area of a suction nozzle 77 which sucks in the free end of the thread end 12 held by the pair of rollers 76. If necessary, a thread cutting device (not shown) can also be assigned to this suction nozzle 77.

In the embodiment shown in FIG. 12, a compressed air nozzle 84 serves as the thread insert, while a sieve 85, which is subjected to a vacuum via a suction pipe 850, serves as the thread brake. This sieve also supports the work of the compressed air nozzle 84 when inserting the thread end 12, the thread length required for this being released by turning back the pair of rollers 76.

It is of course also possible to provide a mechanically designed gripper 7 in combination with a mechanical thread insert 8 and a mechanical thread brake 81, whereby it may be sufficient if the clamping pressure of the pair of rollers 76 is so low that the movement of the thread insert 8 and the Pull-off movement of the thread 10 is sufficient to pull the thread end 12 out of the roller pair 76 without opening or turning it back.

11 and 13 show further modifications of the device described above, in which the return of the thread end 12 through the swirl member 3 into the working area of the thread feeder 6 is not carried out with the aid of a compressed air flow, but in which a mechanical threading element 5 is used for this purpose is provided.

According to the exemplary embodiment shown in FIG. 11, the threading element 5 is designed as a clamp and consists of two parts 50 and 51 which can be moved relative to one another are. The two parts 50 and 51 have mutually facing guide surfaces 500 and 510, while their other peripheral surfaces 501 and 511 are adapted to the shape of the axial bore 302, 313 of the swirl element 3. To receive the thread end 12, the part 50 of the threading element 5 has on its side facing away from the part 51 a longitudinal groove 502 which merges into a transverse groove 503 at its end facing the inlet opening 305 of the swirl element 3.

11 shows the threading element 5 in its release position. This figure shows that the part 51 of the threading element has a recess 512 essentially in the extension of the transverse groove 503. This recess 512 is adjoined in the axial direction with respect to the part 51 by a clamping surface 513 which can be brought to bear against the end surface 504 of the part 50 of the threading element 5, but does not extend into the region of the longitudinal groove 502.

The thread end 12 is received in a manner not shown by the threading element outside of the swirl element 3, for example from its position 10 'shown in FIG. 2. The thread end 12, which has been brought to a predetermined length for this purpose so that it does not protrude beyond the recess 512, is held clamped between the clamping surface 513 and the end surface 504 of the threading element 5. The threading element 5 is now inserted axially into the swirl element 3 from the exit side of the swirl element 3 until it protrudes from the inlet mouth 305 of the swirl element 3. The part 50 is stopped in such a way that its end face 504 is essentially at the level of the entry side 308 of the swirl element 3. The part 51 is moved a little further, so that the free end of the thread end 12 is released by the clamping surface 513. When compressed air nozzle 60 is acted upon with excess pressure, the free end of the thread end 12 is blown out of the threading element 5 in the direction of arrow 62 and fed to the gripper 7 when a further length of thread is brought into the effective range of this compressed air stream leaving the compressed air nozzle 60 through the longitudinal groove 502. As soon as the thread end 12 has been gripped by the gripper 7, the threading element 5 can be withdrawn without the thread end 12 being taken along.

According to the exemplary embodiment shown in FIG. 13, the threading element 5 is designed as a brush 52. This brush 52 is pivotally mounted on a holder 520 so that it can be brought into the position 52 'shown for receiving the thread end 12 in position 10' and then be brought back into the position in which it is in Extension of the axial bore 302, 313 of the swirl element 3 is located. The brush 52 can thus be inserted into the swirl element 3 by an axial movement until the free end projects beyond the entry side 308 of the swirl element 3 facing the drafting device 2.

When the brush 52 is in its position 52 ', the thread end 12 is picked up from the position 10', which can be supported by a corresponding rotational movement of the brush 52. The brush 52 assumes a position with respect to the thread end 12 occupying the position 10 'in such a way that the thread end 12 is located at the free end of the brush 52 so that it can be easily removed by the thread feeder 6 after the brush 52 has been inserted into the swirl element can be. 13, this thread feeder 6 is therefore mechanically designed. After the thread end 12 has been picked up by the thread feeder 6 and / or the gripper 7, the brush 52 can be pulled out of the swirl member 3 again, the thread end 12 being prevented by the thread feeder 6 or the gripper 7 from following the brush.

In order to reduce the friction between the thread end 12 and the brush 52 during its retraction movement, a stripper 53 is assigned to the brush 52 according to the exemplary embodiment shown in FIG. 13, which by its design causes the thread end 12 to be lifted out of the brush 52. During the insertion and withdrawal movement of the brush 52 into or out of the swirl element 3, the brush 52 cleans the axial bore 302, 313 of the swirl element. This ensures that deposits that could have formed in the swirl member 3 are removed during the piecing process.

Claims

Patent claims

1. A method for piecing a spinning device working with a pneumatic twisting element, in which a thread end is returned from the exit side through the twisting element to a drafting system and then inserted laterally into the pair of exit rollers of the drafting system, from where it is integrated by a fuse by the D 'Rallorgan is drawn off as a continuous thread, characterized in that the thread end is conveyed through the swirl element located after the pair of exit rollers of the drafting device to its entry side, is grasped there and is fed to a gripper located next to the drafting device, which then feeds the thread end for later insertion pulls into the pair of outlet rollers past this next to the drafting system.

2. The method according to claim 1, characterized in that the yarn end returned by the swirl member is exposed to a substantially parallel to the nip line of the exit roller pair oriented compressed air flow for feeding to the gripper.

3. The method according to claim 2, d a d u r c h g e k e n n z e i c h n e t that the supply of the yarn end returned through the swirl member to the gripper is carried out with the aid of a laminar compressed air stream.

4. The method according to claim 2 or 3, characterized in that before the return of the thread end through the swirl member through a thread reserve is built up, which is then so slowly dissolved during the return delivery of the thread end through the swirl member into the compressed air stream acting transversely to the thread path that the thread end is kept stretched by the compressed air flow while it is being fed to the hook.

5. The method according to one or more of claims 2 to 4, d a d u r c h g e k e n n z e i c h n e t that the compressed air flow is switched off, and the thread end has been detected by the gripper.

6. The method according to one or more of claims 2 to 5, d a d u r c h g e k e n n z e i c h n e t that after resuming the thread take-off, the thread end and the sliver between the exit roller pair of the drafting unit and the swirl member are exposed to a compressed air stream oriented essentially parallel to the clamping line of the exit roller pair.

7. The method according to claim 6, characterized in that the compressed air flow switched on after resumption of the thread take-off is switched off even before the thread end leaves the pair of exit rollers.

8. The method according to one or more of claims 2 to 7, d a d u r c h g e k e n n z e i c h n e t that the compressed air flow is tangentially opposed to the core rotation of the thread extending from the drafting device to the swirl element.

9. The method according to one or more of claims 6 to 8, d a d u r c h g e k e n n z e i c h n e t that during the return of the thread a significantly weaker compressed air flow is brought into effect than after resumption of the thread take-off.

10. The method according to one or more of claims 1 to 9, d a d u r c h g e k e n n z e i c h n e t that the swirl member is cleaned before or during the return of the thread end.

11. The method according to one or more of claims 1 to 10, d a d u r c h g e k e n n z e i c h n e t that the thread end is brought by a compressed air stream from the exit side of the swirl member through the swirl member into the area of the compressed air flow acting transversely to the thread path.

12. The method according to claim 11, characterized in that during the pneumatic return delivery of the thread end through the swirl organ through the transverse to the thread flow compressed air flow only acts as long as in the swirl organ causing the yarn return compressed air flow is effective.

13. The method according to one or more of claims 1 to 12, d a d u r c h g e k e n n z e i c h n e t that the gripper works pneumatically and in it at least for the duration until the thread end is inserted into the drafting device, a negative pressure is generated.

14. The method according to one or more of claims 1 to 13, d a d u r c h g e k e n n z e i c h n e t that the thread end, after it has been drawn next to the drafting system, is drawn in the form of a loop in the area between the last two pairs of rollers of the drafting unit.

15. The method according to claim 14, d a d u r c h g e k e n n z e i c h n e t that the thread end is pulled into the area between the last two pairs of rollers of the drafting system in the effective range of a thread brake when looping.

16. The method according to one or more of claims 1 to 15, that the end of the thread is brought into the region of the clamping line of the pair of exit rollers during insertion into the drafting system.

17. The method according to one or more of claims 1 to 16, characterized in that the swirl member is cleaned by a first, in the direction from the outlet side of the swirl member to the inlet side oriented compressed air stream that the thread end then this first compressed air stream for return delivery to the inlet side of the swirl member is exposed in order to be exposed there to a second compressed air stream acting transversely to the direction of transport of the thread end, which presses the thread end towards a gripper leads, which then pulls the thread end past the pair of outlet rollers to next to the drafting system, whereupon the fuse which has been stopped before is released and sucked off between the drafting system and the twisting device, so that the thread end extending to the hook is fed in a loop in the area between the last two pairs of rollers of the drafting system to a thread brake , is inserted into the pair of outlet rollers of the drafting system and subjected to a trigger again and at the same time suction of the fuse and loose fibers into the swirl element is prevented by switching on the second compressed air stream again, that even before the end of the thread reaches the pair of output rollers of the drafting system, the suction the fuse and the second compressed air stream are switched off, and that the spinning overpressure acting in the withdrawal direction is finally brought into effect in the swirl element.

18. The method according to one or more of claims 1 to 16, characterized in that the swirl member is cleaned by a first compressed air stream acting counter to the withdrawal direction, that the thread end is then exposed to this first compressed air stream and brought by this from the outlet side of the swirl member to its entry side, there a second acting transversely to the direction of transport

Compressed air stream exposed and fed through this to a gripper, which then pulls the thread end past the pair of exit rollers to next to the drafting system, that then the thread end extending to the gripper in the area between the last two

Roller pairs of the drafting system are fed in loop form to a thread brake and in the process are inserted into the pair of outlet rollers of the drafting system, whereupon the thread end is again subjected to a deduction that then the previously stopped sliver is released while sucking loose fibers into the swirl element is prevented by switching on the second compressed air flow again, and that when the thread end has been drawn out of the drafting device to a predetermined length, the second compressed air flow is switched off, and that finally the spinning overpressure acting in the withdrawal direction is brought into effect in the swirl organ.

19. Apparatus for carrying out the method according to one or more of claims 1 to 18, with a pneumatic swirl element, a return delivery element for returning the thread end from the exit side of the swirl element to its entry side and with a gripper for retracting the thread end from the entry side of the swirl element past the pair of exit rollers to next to the drafting system, characterized by a thread feeder (6) for grasping the thread end (12) emerging from the entry end of the swirl element (3) on return and for feeding it to the gripper (7).

20. The apparatus according to claim 19, characterized in that the thread feeder (6) as a substantially parallel to the clamping line of the outlet roller pair (23, 230) oriented compressed air nozzle (60) is formed, the mouth (600) on the opposite of the gripper (7) Side of the swirl member (3) arranged and facing the gripper (7).

21. The apparatus according to claim 20, characterized in that the swirl element (3) has an axial projection (309) on its inlet side and the compressed air nozzle (60) is arranged to the swirl element (3) such that the compressed air flow leaving the compressed air nozzle (60) Face of the projection (309) tangent.

22. The apparatus of claim 20 or 21, so that the compressed air nozzle (60) is at least partially arranged in the gusset (3) facing the swirl member (3) of the pair of outlet rollers (23, 230) of the drafting unit (2).

23. The device according to claim 22, so that the compressed air nozzle (60) has a distance (a) of at least 1 mm from the top roller (230) of the pair of outlet rollers (23, 230) of the drafting unit (2).

24. The device according to one or more of claims 19 to 23, d a d u r c h g e k e n n z e i c h n e t that the mouth (600) of the compressed air nozzle (60) one

Has an inner diameter with a constant cross-section.

25. The device according to one or more of claims 19 to 24, with a swirl member which has one or more core rotation of the thread effecting compressed air holes which open tangentially into the interior of the swirl member, characterized in that the compressed air nozzle (60) tangential to the from the drafting device (2) to the swirl member (3) extending thread end (12) is arranged and the flow direction of the core rotation (319) of the

The thread end (12) causing the compressed air bore, which is generated by the compressed air bores (310, 311, 312; 330, 331) in the swirl element (3).

26. The apparatus according to claim 25, with a swirl member having a single row of compressed air holes which open tangentially into the axial bore of the swirl member, characterized in that the compressed air nozzle (60) tangential to the elongated axial bore of the swirl member (3) in the opposite direction to that The flow direction of the compressed air flow leaving the compressed air bores (330, 331) is oriented.

27. The apparatus according to claim 25, with a swirl member having two rows of compressed air bores in succession in the thread take-off direction, one row of which opens tangentially into the axial bore of the swirl member in the circumferential direction and the other row in the opposite circumferential direction, characterized in that the compressed air nozzle ( 60) is oriented tangentially to the elongated axial bore (302, 313) of the swirl element (3) in the opposite direction to the circumferential direction in which the compressed air holes (310, 311, 312) of the second row in the thread take-off direction into the axial bore (313) of the swirl element ( 3) open.

28. The device according to one or more of claims 19 to 27, so that the compressed air nozzle (3) is associated with a device (900) for optionally applying a higher or a lower overpressure.

29. The device according to one or more of claims 19 to 28, characterized in that the compressed air nozzle (60) is assigned a control device (9) and the gripper (7) is associated with a thread monitoring device (75) connected to this control device (9).

30. The device according to one or more of claims 18 to 29, characterized in that the swirl member (3) in addition to compressed air bores (300, 301, 310, 311, 312), in which an overpressure is present during the spinning process and which a component in the withdrawal direction ( 44), has further compressed air bores (306, 316), in which there is overpressure during the return of the thread and which have a component in the return direction.

31. The device according to claim 30, having a swirl member which has an injector nozzle in the thread take-off direction and a swirl nozzle separated by a gap therefrom, characterized in that both the injector nozzle (30) and the swirl nozzle (31) each have at least one compressed air bore oriented in the return direction (306, 316), wherein a stronger air flow can be generated in the injector nozzle (30) compared to the swirl nozzle (31).

32. Apparatus according to claim 31, d a d u r c h g e k e n n z e i c h n e t that the compressed air bore

(306) in the injector nozzle (30) has a larger diameter than the compressed air bore (316) in the swirl nozzle (31).

33. Device according to one or more of claims 30 to 32, characterized in that the compressed air bores (306, 316) of the swirl element (3) for the pneumatic return of the thread end (12) and the compressed air nozzle (60), a common feed line (32) and a common control valve (324) are assigned.

34. The device according to one or more of claims 18 to 33, a mechanical threading element (5) for returning the thread end (12) into the stroke area of the thread feeder (6).

35. Apparatus according to claim 34, d a d u r c h g e k e n n z e i c h n e t that the threading element (5) is designed as a clamp.

36. Apparatus according to claim 35, so that the threading element (5) is designed as a brush (52).

37. Apparatus according to claim 36, so that the brush (52) is assigned a scraper (53).

38. Device according to one or more of claims 18 to 37, characterized by a thread reserve device (47) arranged on the outlet side of the swirl element (3) with a drive (473) which drives the thread reserve device (47) so slowly that the inlet mouth (305) of the twist element (3) leaving the thread end (12) is stretched by the thread feeder (6) during the feed to the gripper (7).

39. Device according to one or more of claims 18 to 38, characterized in that the gripper (7) is designed as a suction air nozzle (70).

40. Apparatus according to claim 39, so that the suction air nozzle (70) has a suction opening (700) facing the thread feeder (6).

41. Device according to one or more of claims 18 to 40, characterized in that the gripper (7) from a receiving position (7 '), in which it cooperates with the thread feeder (6), can be moved into an insertion position next to the drafting device (2) is.

42. Device according to one or more of claims 18 to 41, characterized by a thread insert (8) which can be moved from a standby position (8 ') next to the drafting device (2) into an insert position such that it adjusts the course of the swirl member ( 3) crosses to the hook (7) extending thread end (12) and introduces it into the drafting device (2) as it moves further.

43. Apparatus according to claim 42, g e k e n n z e i c h n e t d u r c h a thread brake (81), which the

Thread end (12) can be fed into the drafting device (2) during its insertion movement.

44. Apparatus according to claim 43, so that the thread brake (81) is arranged in the area between the last two pairs of rollers (22, 220, 23, 230) of the drafting system (2).

45. Apparatus according to claim 44, characterized in that the thread insert (8) forms an elastic thread clamp in its insert position together with the thread brake (81).

46. Apparatus according to claim 45, so that the thread brake (81) against which the thread insert (8) of the thread end (12) presses has a clamping surface made of soft rubber or felt.

47. Device according to one or more of claims 18 to 46, characterized in that the upper roller (230) of the pair of outlet rollers (23, 230) of the drafting device (2) is associated with a thread guide (26) which the thread end (12) during the reclining next to the drafting system (2) until it is inserted into the drafting system (2) in the half of the front side of the top roller (230) facing the clamping line of the pair of outlet rollers (23, 230).

48. Apparatus according to claim 47, characterized in that the thread guide (26) is formed by an axial, substantially cylindrical projection (260) of the upper roller (230) on its side facing the gripper (7), the diameter (d) of the Projection (260) is smaller than the diameter (D) of the top roller (230).

49. Apparatus according to claim 47 or 48, so that the top roller (230) has one or more notches (232) in its edge facing the gripper (7) between the lateral surface and the end face.

50. Device according to one or more of claims 18 to 49, characterized by a piecing carriage (97) which can be moved along a plurality of spinning positions (A, B, C), each with a swirl member (3) and a drafting unit (2), in which at least one the elements (94, 93, 95, 47, 60, 7, 8, 81, 5, 261) required solely for the piecing process are arranged.