EP0161675B1 - Yarn-feeding device for textile machines - Google Patents

Description

The invention relates to a thread delivery device for textile machines with a thread drum carrying a storage reel with a vertical axis, to which the thread can be fed tangentially via an eyelet-like inlet guide element, the thread passage opening of which lies below the upper edge of the thread drum, and from which the thread can be fed at a thread removal speed corresponding to the thread feed speed an outlet guide element arranged laterally next to the thread drum can be pulled outwards, the outlet guide element being fixedly arranged at a distance below the lower edge of the thread drum and the thread drum having an inlet thread monitor in front of the inlet guide element which scans the incoming thread with an inlet sensor in the thread running direction and an outlet thread with a discharge sensor in the area of the discharge guide element, scanning discharge thread monitors are assigned.

Such a thread delivery device is known, for example, from DE-A-26 08 590. The inlet guide element is formed by a thread eyelet which is arranged fixed on the holder carrying the thread drum and is arranged downstream of the thread brake in the thread travel path. The inlet sensor scans the incoming thread on the thread path between the thread brake and this thread eyelet. The thread eyelet must be at a certain minimum distance from the circumference of the thread drum in order to avoid the thread being deflected too abruptly laterally on its path from the thread eyelet to the circumference of the thread drum. Because of this distance of the thread eyelet from the thread drum, the thread can change its running direction to the thread drum when the inlet thread tension decreases, which can adversely affect the accumulator winding structure on the thread drum.

In this known thread delivery device, the storage roll formed on the thread drum is inevitably axially advanced continuously by a feed device in the form of a feed wheel driven by the thread drum on the thread drum, which prevents the missing turns of the thread from winding upward of the storage roll over the edges of the thread drum.

In the case of yarn delivery devices which work without such an inevitable feed device for the storage reel and in which a special, in particular conical design of the yarn drum in the region of the running yarn ensures that the storage winder which is being formed is continuously axially displaced, there is a risk that that if the thread take-up is interrupted, the storage roll "overflows", ie that the newly formed turns of the running thread dodge upwards over the upper edge of the thread drum. Such thread drums are described, for example, in DE-C-2743749, DE-B-1760738 and DE-C-33 26 099, to name just a few examples.

The above-mentioned risk of windings of the storage roll going upward beyond the edges of the thread drum also exists when a knitting machine equipped with such thread delivery devices is blown off with a compressed air jet for cleaning lint. If the incoming thread is handled improperly, the compressed air jet can lead beyond the upper edge of the thread drum due to the large distance of the inlet eyelet, with the result that the thread is wound up above the thread drum.

However, this must be prevented under all circumstances.

The running conditions of the thread from the thread drum are also essential for the proper functioning of thread delivery devices of the type mentioned. If the even thread flow is disturbed, e.g. by tearing off filaments of the thread from below again on the thread drum, or by loops or loops forming in the running - heavily twisted - threads that lead to an uneven thread flow or even again are wound up, this affects the thread take-off from the storage reel and thus also the thread pick-up conditions. The result may be that the storage winder can no longer be properly shifted, particularly in the case of thread drums in which the axial advance of the storage winder takes place via a conical contact surface or the like, so that the newly formed windings build up in the region of the contact surface and finally the dreaded winding of the thread above the drum.

The object of the invention is therefore to provide a thread delivery device which, even when using a feed drum which only feeds the storage roll, ensures perfect delivery conditions only via the special design of its circumferential surface, is distinguished by a variety of possible uses, and also permits threads which are difficult to process and to supply yarns without major changes.

To achieve this object, the thread delivery device mentioned at the outset is characterized according to the invention in that the inlet guide element is designed in the form of a bracket having an elongated thread opening, the thread opening of which lies with its longitudinal extension transverse to the thread running direction and with its rear edge edge facing the thread drum below the upper edge and is arranged in the immediate vicinity of the thread drum.

The inlet guide element acts with its elongated thread opening in the manner of a lateral limiting bracket. The thread coming from the thread brake can open laterally to the right or left depending on the direction of rotation of the thread drum

to run the thread roll, the lateral edge edges of the thread opening preventing uncontrolled evasion of the thread.

In a preferred embodiment, the thread opening lies essentially in a plane which is inclined with respect to the axis of rotation of the thread drum and which, for example, can form an angle of the order of 80-90 ° with the axis of rotation. The incoming thread coming from the thread brake can thus be held in contact with the inlet sensor, which loads it, in contact with the front edge of the thread opening facing away from the thread drum, so that the thread can run in at a relatively low tension.

The thread opening can be delimited on the side facing away from the thread drum by a substantially straight front edge, which in a modified embodiment, but also approximately corresponding to a circumferential surface of the thread drum, can be curved.

The rear edge of the thread opening adjacent to the thread drum is arranged running in the immediate vicinity of the thread drum. This solves the task of preventing the thread from deflecting upward beyond the upper edge of the thread drum. On the side facing the thread drum, the thread opening can have two corners on both sides of the center line passing through the axis of rotation of the thread drum, in which the incoming thread can be held. These corners forming the outermost ends of the thread opening are placed close to the thread drum. This significantly increases the security that, due to a lack of thread removal from the storage reel or inadvertently when the thread delivery device is blown off with compressed air, no thread windings get beyond the upper edge of the thread drum and are wound up there. At the same time, the thread can change its direction to the thread drum only insignificantly when the inlet sensor drops, which is important for an orderly storage winding structure.

For the reasons mentioned, it is expedient if the rear edge of the thread opening, which partially forms the two corners of the thread opening and runs on the side adjacent to the thread drum and between the two corners, runs at least approximately adapted to the circumference of the thread drum. This results in simple manufacturing conditions if the rear edge is formed by two essentially straight edge pieces which form an obtuse angle with one another.

The lateral edge edges of the thread opening that partially form the two corners can be designed to diverge toward the thread drum. In addition, the stirrup containing the thread opening can have a thread insertion opening leading laterally into the thread opening from the outside in order to facilitate threading of the thread.

The risk of a disturbance of the run-out conditions and thus of the “overflow” of the storage roll with windings that extend beyond the upper edge of the thread drum can be reduced by supporting the outlet sensor at two spaced locations on the outlet thread, one of which, viewed in the thread running direction , one in front and the other behind the fixed outlet guide element.

For this purpose, the outlet sensor can have two support elements arranged at a distance, which are designed in the form of webs. When changes in the tension of the outgoing thread occur, the two webs of the outlet sensor, together with the fixed outlet guide element, form desired thread loops. In the event of a malfunction on the machine side, these thread loops make the precise operation of the thread delivery device considerably less sensitive to faults because the faults are not transmitted directly to the thread drum and thus to the storage roll. The front web in the direction of the thread also has the task of keeping the thread running loose from the thread drum near the thread drum and deep below its lower edge in order to ensure perfect rewinding.

In the case of heavily twisted yarns, which tend to form loops when the thread drum is unloaded, the webs in combination with the fixed outlet guide element cause these loops to be re-drawn before the thread runs into the work area on the machine.

In the thread running direction after the rear support point of the outlet sensor, a fixed thread guide element is advantageously arranged, which ensures that the thread coming from the thread delivery device is fed to the work station of the machine in a precisely defined way.

The outlet element is advantageously designed in the form of a bracket having a thread opening that is large compared to the thread thickness, the thread opening with its edge being at all distances from the thread running with normal tension. Only when the outlet sensor goes down due to a decrease in thread tension does the lower edge of the thread opening come into effect in the sense of the loop formation explained. For this purpose, the thread opening can have a substantially straight, lower edge edge running transversely to the thread, which ensures a certain lateral mobility of the thread running over it, which is important, for example, for pulling loops.

Finally, a thread eyelet can be arranged on the bracket forming the outlet element below the thread opening, which lies lower below the lower edge of the thread drum than the thread opening. This thread eyelet is used to guide the thread running out of the thread drum only when synthetic continuous threads of poor quality are processed, in particular threads with torn or be damaged filaments. The low-lying thread eyelet results in a steeper pull-off angle of the thread than the thread opening above. This steeper take-off angle prevents torn-off filaments from separating from the entire thread and winding up on the thread drum into a separate wrap that disrupts the thread take-off. The thread drum therefore remains free of filament accumulations.

In order to facilitate the operation of a multi-system circular knitting machine equipped with the new thread delivery devices, the arrangement can be such that the inlet sensor and the outlet sensor each control an associated switch located in its own shutdown circuit and that at least the shutdown circuit of the outlet sensor controls an optionally operable additional one Contains switches, which may be designed as a switch. The fact that each of the sensors acts on its own shutdown circuit in the simplest possible way, e.g. shut down the outlet sensor and only keep the inlet sensor effective, as is desirable, for example, when setting work on multi-system knitting machines.

• Fig. 1 eine Fadenliefervorrichtung gemäss der Erfindung, in einer Seitenansicht,
• Fig. 2, 3
  das Einlaufleitelement der Fadenliefervorrichtung nach Fig. 1, in zwei verschiedenen Seitenansichten,
• Fig. 4 das Einlaufleitelement nach Fig. 2, in einer Draufsicht,
• Fig. 5 den Auslauffühler der Fadenliefervorrichtung nach Fig. 1, in einer Draufsicht,
• Fig. 6 den Auslauffühler nach Fig. 5, in einer Seitenansicht,
• Fig. 7 den Auslauffühler nach Fig. 6, in einer Ansicht in der Richtung Zder Fig. 6 und im Ausschnitt,
• Fig. 8 den Auslauffühler nach Fig. 5, in einer anderen Draufsicht,
• Fig. 9 das Auslaufleitelement der Fadenliefervorrichtung nach Fig. 1, in einer Draufsicht,
• Fig. 10, 11
  das Auslaufleitelement nach Fig. 9, in zwei verschiedenen Seitenansichten, und
• Fig. 12 die dem Einlauf und dem Auslauffühler der Fadenliefervorrichtung nach Fig. 1 zugeordnete elektrische Abstellerschaltung.

In the drawing, an embodiment of the object of the invention is shown. Show it:

• 1 is a side view of a yarn delivery device according to the invention,
• 2, 3
  1 in two different side views,
• 4 shows the inlet guide element according to FIG. 2, in a top view,
• 5 shows the outlet sensor of the thread feeding device according to FIG. 1, in a top view,
• 6 shows the outlet sensor according to FIG. 5, in a side view,
• 7 shows the outlet sensor according to FIG. 6, in a view in the direction Zder FIG. 6 and in a detail,
• 8 shows the outlet sensor according to FIG. 5, in a different top view,
• 9 is a top view of the outlet guide element of the thread delivery device according to FIG. 1,
• 10, 11
  9, in two different side views, and
• FIG. 12 shows the electrical shut-off circuit assigned to the inlet and the outlet sensor of the thread delivery device according to FIG. 1.

The thread delivery device shown in FIG. 1 has a holder 1 which can be placed on a corresponding holding ring, for example a circular knitting machine, by means of a fastening device 2. A continuous shaft 3 is rotatably mounted in the holder 1, which at one end carries a pulley 4 connected to it in a rotationally fixed manner and a coaxial thread drum 5 is also rotationally fixed to the other end.

At its end opposite the fastening device 2, the holder 1 carries two fixed, spaced-apart thread eyes 6, 7, through which the incoming thread 8 coming from a bobbin, not shown, via a thread brake 9 arranged on the holder 1 on the circumference of the thread drum 5 is directed. On the thread drum 5, the thread 8 forms a storage roll 10, from which the thread is drawn off, which runs from the thread drum 5 at the same speed at which it was wound on it. The running thread runs through a fixed thread eyelet 11, which is arranged on the holder 1 and is designed in the form of an open bracket, to the work station (not further illustrated) in the knitting machine equipped with the thread delivery device.

The structure of the thread drum is described in detail in D EA-33 26 099. The thread drum 5 designed as a rotating body has a first conical peripheral surface 12 with a straight generatrix, the largest diameter of which lies in the vicinity of the free end face 13 of the thread drum 5 and is separated from it by an axially short cylindrical surface 14. The first conical circumferential surface 12, which forms a thread contact surface, encloses an angle of approximately 30 ° with the thread drum axis 15. It cuts in the area of its smallest diameter, an annular surface 16, which is substantially perpendicular to the thread axis of the drum ^1. 5 On the inside of the ring surface 16 there is a second conical circumferential surface 17 which tapers inwards in the axial direction and which forms an angle of approximately 60-70 °, preferably 68 °, with the thread drum axis 15. The second conical circumferential surface 17 is followed in the axial direction of the thread drum 5 by a conical thread support surface which has a straight line and which lies in FIG. 1 below the storage roll 10 and serves to receive a part of the storage roll 10 comprising several adjacent turns; it forms an angle with the thread drum axis 15 of between 2 and 10 °. Connected to it is a cylindrical outer surface 18, which has a relatively large axial length and serves to receive the actual storage roll 10; it ends at a radially protruding, circumferential rim 19 arranged on the end of the thread drum 5, the cross-sectional shape of which can also be rounded.

The described special design of the thread drum 5 in the thread inlet area ensures that the thread 8 running tangentially onto the conical peripheral surfaces 12, 17 continuously places new windings on the storage reel 10, which windings are automatically pushed downward onto the cylindrical outer surface 18 by where is withdrawn from the thread 8 over the board 19.

• Der Bügel 20, der einenends eine Befestigungsöse 21 trägt, begrenzt eine längliche Fadenöffnung 22, die mit ihrer Längserstreckung quer zu der Fadenlaufrichtung liegend angeordnet ist, wie dies aus Fig. 1 zu entnehmen ist. Die Fadenöffnung 22 liegt in einer in Fig. 2 bei 23 angedeuteten Ebene, die gegenüber der Drehachse 15 der Fadentrommel geneigt ist und mit dieser einen Winkel in der Grössenordnung von 80 bis 90° (6° gegenüber der Horizontalen) einschliesst. Auf ihrer von der Fadentrommel 5 abgewandten Seite ist die Fadenöffnung 22 durch eine im wesentlichen gerade vordere Randkante 24 begrenzt, die rechtwinklig zu einer von der Fadenbremse 9 zu der Drehachse 14 der Fadentrommel 5 verlaufenden Linie sich erstreckt. Alternativ könnte die Fadenöffnung 22 auf dieser Seite auch durch eine etwa entsprechend der Umfangsfläche der Fadentrommel gekrümmte vordere Randkante 24 begrenzt sein.

Immediately next to the thread drum 5, in the area between the thread brake 9 and the thread drum 5, a fixed inlet guide element fastened to the holder 1 is arranged, which is designed in the form of a wire bracket 20, the shape of which is particularly evident from FIGS. 2 to 4 can be seen:

• The bracket 20, which carries a fastening eyelet 21 at one end, delimits an elongated thread opening 22, which is arranged with its longitudinal extension lying transversely to the thread running direction, as can be seen from FIG. 1. The thread opening 22 lies in a plane indicated at 23 in FIG. 2, which is inclined with respect to the axis of rotation 15 of the thread drum and includes an angle of the order of 80 to 90 ° (6 ° with respect to the horizontal). On its side facing away from the thread drum 5, the thread opening 22 is delimited by an essentially straight front edge 24 which extends at right angles to a line running from the thread brake 9 to the axis of rotation 14 of the thread drum 5. Alternatively, the thread opening 22 on this side could also be delimited by a front edge 24 which is curved approximately in accordance with the peripheral surface of the thread drum.

The rear edge of the thread opening 22 which is adjacent to the thread drum 5 is arranged running in the immediate vicinity of the thread drum 5. It is formed by two essentially straight edge pieces 25 which form an obtuse angle with one another, which in the embodiment according to FIG. 4 is 150 °. As an alternative, a continuous rear edge 25 curved according to the peripheral surface of the thread drum 5 could also be provided here.

On both sides of the center lines mentioned, starting from the thread brake 9 through the axis of rotation 14 of the thread drum 5, two corners 26 are formed in the thread opening 22, which are delimited on the one hand by the rear edge running between them and on the other hand by two essentially straight, lateral edge 27 , which are arranged diverging towards the thread drum 5 and in the embodiment according to FIG. 4 form an angle of 50 ° with one another. The distance between the corners 26 is approximately half the diameter of the thread drum 5 in the corresponding area. Finally, in the region of the rear edge at 28 there is a thread insertion opening which leads laterally into the thread opening 22 from the outside and which facilitates threading the thread 8 into the thread opening 22.

In the area between the thread brake 9 and the thread opening 22, a spring-loaded inlet sensor 30 is supported on the incoming thread 8, which is pivotably mounted at 29 on the holder 1. As a result of the inclined position of the thread running opening 22, the thread 8 is elastically held and supported on the front edge 24 of the thread opening 22, so that it can run towards the thread drum 5 with a relatively low tension. The thread then runs, depending on the direction of rotation of the thread drum 5, through the right or left corner 26 of the thread opening 22, in which it is automatically held, so that it can change its direction to the thread drum 5 only insignificantly even when the thread tension decreases. This is important for an orderly winding structure. At the same time, the rear edge parts 25 prevent the thread from escaping upwards and from going beyond the upper edge of the thread drum 5. The thread is always guided from this rear edge 25 exactly onto the conical contact surface parts 12, 17 of the thread drum 5. At the same time, the thread drum 5 is wrapped relatively far, since the corners 26 are in the immediate vicinity of the adjacent circumference of the thread drum. As can be seen from FIG. 1, the rear edge 25 lies deeper than the upper edge of the thread drum 5; it is located approximately at the level of the upper end of the first conical peripheral surface 12.

• Der etwa L-förmig gebogene Bügel 31, der bei 32 an dem Halter 1 festgeschraubt ist, weist eine durchgehende, etwa rechteckige Fadenöffnung 33 auf, die auf ihrer Unterseite durch eine gerade, waagrechte Randkante 34 begrenzt ist und deren Abmessungen wesentlich grösser als die Fadendicke sind. Die Fadenöffnung 33 ist, wie aus Fig. 1 zu ersehen, etwa parallel zu der Drehachse 15 der Fadentrommel 5 ausgerichtet, während an dem stumpfwinklig abgebogenen Schenkel 35 des Bügels 31 endseitig eine Fadenöse 36 angeordnet ist, durch die der ablaufende Faden wahlweise geleitet werden kann.

On the thread outlet side of the thread drum 5, a fixed outlet guide element in the form of a bracket 31 is fixedly arranged on the holder 12 in the thread path in front of the fixed thread eyelet 11. The outlet guide element 31 can, by the way, also be arranged in a height-adjustable manner on the holder 1, like the inlet guide element in the form of the bracket 20. Its exact structure can be seen in Figs. 9-11:

• The approximately L-shaped bow 31, which is screwed to the holder 1 at 32, has a continuous, approximately rectangular thread opening 33 which is delimited on its underside by a straight, horizontal edge 34 and whose dimensions are substantially greater than the thread thickness are. The thread opening 33, as can be seen from FIG. 1, is oriented approximately parallel to the axis of rotation 15 of the thread drum 5, while a thread eyelet 36 is arranged at the end on the obtuse-angled leg 35 of the bracket 31, through which the running thread can optionally be guided .

In the area in front of and behind the bracket 31, a spring-loaded outlet sensor bracket 38 pivotably mounted at 37 on the holder 1 is supported on the running thread in two places via transverse webs 39, 40. The exact shape of the outlet sensor bracket 38 can be seen from FIGS. 5-8.

As long as the tension of the thread running out of the thread drum 5 does not fall below a certain limit value, the state shown in FIG. 1 applies, in which the thread does not touch the edge of the thread opening 33, but is only guided through the thread eyelet 11.

If the thread tension subsides, the outlet sensor bracket 38 goes down, the threads being pulled out into loops via the two cross webs 39, 40 in cooperation with the lower edge 34 of the thread opening 33 of the outlet guide bracket 31.

The thread reserve created thereby keeps disturbances away from the storage roll 10. In addition, the one that runs loose in the event of a fault In this way, the thread is held deep under the lower edge of the thread drum 5, which ensures that the rewinding is correct. Strongly twisted yarn that tends to form loops can be processed without further ado, because these crosses 39, 40, in cooperation with the edge of the thread opening 33, pull these loops again until they leave the thread eyelet 11.

The ceramic thread eyelet 36 arranged at the lower end of the outlet guide bracket 31 picks up the thread running off the thread reel 5 when, for example, with an endless synthetic thread of poor quality, torn or damaged filaments have to be expected, which would otherwise result in winding on the thread drum 5 tend.

The inlet sensor 30 and the outlet sensor 38 belong to inlet and outlet thread monitors arranged in the housing-like holder 1. The inlet sensor 30 controls a switch 41 (FIG. 12), while the outlet sensor 38 can actuate a switch 42. The two switches 41, 42 are located in two separate single-pole circuits, which are connected via contact pins 43 of the holder 1 to an external circuit which forwards signals for shutting down the machine, etc. An indicator lamp 44 is located in each of the two separate shutdown circuits associated with the inlet sensor 30 and outlet sensor 38. lights up when switch 41 or 42 is closed. In addition to the switch 42, the shut-off circuit associated with the outlet sensor also contains a manually operated switch 45, which allows the outlet sensor 38 to be shut down, for example, when the machine is being set, and only leaves the inlet sensor 20 in action. The switch 45 is designed as a changeover switch and works together with a second power line. When switching from the operating position to the outlet sensor switched off, the indicator lamp 44 can light up without the machine shutdown coming into operation.

Claims (22)

1. Thread delivery device for textile machines, having a thread drum (5) with vertical axis carrying a reserve coil (10), to which drum the thread (8) is feedable tangentially by way of an eye-type inlet guide element (11), the thread passage opening of which lies below the upper edge of the thread drum (5) and from which the thread can be drawn off, directed outwards, by way of an outlet guide element (31 ) arranged laterally beside the thread drum (5), with a thread withdrawal speed corresponding to the thread feed speed, the outlet guide element being arranged stationarily at a distance below the lower edge of the thread drum (5) while with the thread drum there are associated an entry thread knock-off device exploring the arriving thread with an entry sensor (30) in the thread running direction before the entry guide element and an outlet thread knock-off device exploring the departing thread with an outlet sensor in the region of the outlet guide element, characterised in that the entry guide element is made in the form of a curved piece (20) having an elongated thread opening (22), which opening (22) is arranged with its longitudinal extent lying transversely of the thread running direction and with its rear marginal edge (25), which faces the thread drum (5), extending beneath the upper edge and in the immediate vicinity of the thread drum (5).

2. Thread delivery device according to claim 1, characterised in that the thread opening (22) lies essentially in a plane (23) inclined in relation to the axis (15) of rotation of the thread drum (5).

3. Thread delivery device according to claim 2, characterised in that the plane (23) includes with the axis (15) of rotation an angle of the order of size of 80 to 90°.

4. Thread delivery device according to one of the preceding claims, characterised in that the thread opening (22) is limited on the side remote from the thread drum (5) by a substantially straight forward marginal edge (24).

5. Thread delivery device according to one of claims 1 to 3, characterised in that the thread opening (22) is limited on the side remote from the thread drum (5) by a forward marginal edge (24) curved approximately in conformity with a circumferential surface of the thread drum (5).

6. Thread delivery device according to one of the preceding claims, characterised in that on the side facing the thread drum (5) the thread opening (22) possesses, on both sides of the centre line passing through the axis (15) of rotation of the thread drum (5), two corners (26) in which the arriving thread (8) can be held.

7. Thread delivery device according to claim 6, characterised in that the rear marginal edge (25) of the thread opening (22), which partially forms the two corners (26) and extends on the side adjacent to the thread drum (5) between the two corners (26), has a course at least approximately adapted to the circumference of the thread drum (5).

8. Thread delivery device according to claim 7, characterised in that that rear marginal edge is formed by two substantially straight marginal edge pieces (25) which together include an obtuse angle.

9. Thread delivery device according to one of claims 6 to 8, characterised in that the lateral marginal edges (27) of the thread opening (22) which partially form the two corners (26) are made divergent towards the thread drum (5).

10. Thread delivery device according to one of the preceding claims, characterised in that the curved piece (20) comprises a thread introduction opening (28) leading from the exterior laterally into the thread opening (22).

11. Thread delivery device according to one of the preceding claims, characterised in that the arriving thread (8) is held, by the entry sensor (30) loading it, in abutment on the forward marginal edge (24), remote from the thread drum, of the thread opening (22).

12. Thread delivery device according to one of the preceding claims, characterised in that the outlet sensor (38) is supported at two spaced points (at 39, 40) on the departing thread, of which points, seen in the running direction of the thread, one lies before and the other behind the stationary outlet guide element (31).

13. Thread delivery device according to claim 12, characterised in that the outlet sensor (38) comprises two spaced abutment elements which are made in the form of cross bars (39,40).

14. Thread delivery device according to claim 12, characterised in that a stationary thread guide element (11) is arranged, in the thread running direction, after the rear support point.

15. Thread delivery device according to claim 14, characterised in that the outlet guide element (31) is made in the form of a curved piece having a thread opening (33) which is large in comparison with the thread thickness, the thread opening (33) of which piece is placed with its edging spaced on all sides from the thread running through with normal tension.

16. Thread delivery device according to claim 15, characterised in that the thread opening (33) comprises a substantially straight lower marginal edge (34) extending transversely of the thread.

17. Thread delivery device according to claim 15, characterised in that on the curved piece below the thread opening (33) a thread eye (36) is arranged which lies lower beneath the lower edging of the thread drum (5) than does the thread opening (33).

18. Thread delivery device according to one of the preceding claims, characterised in that the entry sensor (30) and the outlet sensor (38) each control an associated switch (41, 42) lying in a pertinentshut-off current circuit and in that at least the shut-off current circuit of the outlet sensor contains an optionally actuatable additional switch (45) which may be formed as change-over switch.
claim 12, characterised in that a stationary thread guide element (11) is arranged, in the thread running direction, after the rear support point.

15. Thread delivery device according to claim 14, characterised in that the outlet guide element (31) is made in the form of a curved piece having a thread opening (33) which is large in comparison with the thread thickness, the thread opening (33) of which piece is placed with its edging spaced on all sides from the thread running through with normal tension.

16. Thread delivery device according to claim 15, characterised in that the thread opening (33) comprises a substantially straight lower marginal edge (34) extending transversely of the thread.

17. Thread delivery device according to claim 15, characterised in that on the curved piece below the thread opening (33) a thread eye (36) is arranged which lies lower beneath the lower edging ofthethread drum (5) than doesthethread opening (33).

18. Thread delivery device according to one of the preceding claims, characterised in that the entry sensor (30) and the outlet sensor (38) each control an associated switch (41, 42) lying in a pertinent shut-off current circuit and in that at least the shut-off current circuit of the outlet sensor contains an optionally actuatable additional switch (45) which may be formed as change-over switch.

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