CN111479960A

CN111479960A - Drafting device for spinning machine

Info

Publication number: CN111479960A
Application number: CN201880080033.8A
Authority: CN
Inventors: G·沙夫勒; 曼弗雷德·鲍尔; K·胡贝尔
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2017-12-15
Filing date: 2018-12-06
Publication date: 2020-07-31
Also published as: DE102017130215A1; WO2019115346A1

Abstract

In a drafting device for a spinning machine, having a top roller, a bottom roller, and having a load arm (19), on which the top roller of the drafting device is arranged, having a pair of delivery rollers (5), which is formed by a delivery top roller and a delivery bottom roller, and having a pneumatic compression device (20) which is arranged downstream of the pair of delivery rollers (5) of the drafting device (2) and is used for compressing a drafted fiber aggregate (8), the compression device having a suction tube (17) which can be suctioned, wherein the suction tube (17) is surrounded by a filter element (18), the compression device (20) having a fiber collection area (16) and the fiber collection area (16) being delimited by two clamping points (K1, K2), wherein a first clamping point (K1) is defined by the two rollers of the pair of delivery rollers (5), the second clamping point (K2) is formed by one of the two rollers of the delivery roller pair (5) and the screening element (18), the suction pipe (17) is arranged on a base (25), and the base (25) is arranged on the delivery upper roller (6) and the load arm (19). In a compression device for a drafting device, the suction tube (17) is arranged on a base (25), and the base (25) has recesses for fixing on an output top roller (6) and a load arm (19) of the drafting device.

Description

Drafting device for spinning machine

Technical Field

The invention relates to a drafting device for a spinning machine, comprising an upper roller, a lower roller, a load arm, on which the upper roller of the drafting device is arranged, a pair of delivery rollers, which is formed by a delivery upper roller and a delivery lower roller, and a pneumatic compression device, which is arranged downstream of the pair of delivery rollers of the drafting device, for compressing a drafted fiber aggregate, wherein the compression device comprises a suction tube that can be sucked, wherein the suction tube is surrounded by a filter element, wherein the compression device comprises a fiber collection area, which is delimited by two clamping points, wherein a first clamping point is defined by the two rollers of the pair of delivery rollers, and a second clamping point is formed by one of the two rollers of the pair of delivery rollers and the filter element.

Background

The drafting device for a spinning machine comprises at least two roller pairs, between which a fibre aggregate is drafted on the basis of the different rotational speeds of the roller pairs. When the fiber assembly drafted is separated from the draft device by the pair of rollers and sent to the spinning device, the pair of rollers is called a delivery roller pair. The delivery roller pair is composed of a delivery upper roller and a delivery lower roller, and the delivery upper roller and the delivery lower roller form a clamping point for the fiber aggregate to pass through. The device for compressing the drafted fiber aggregate is arranged downstream of the delivery roller pair. Mechanical or pneumatic compression means may be employed.

Devices of the same type are known from the prior art and are used for compressing fiber strands after a drawing process in spinning machines. A corresponding device is described, for example, in DE 10050089 a 1. The compression device disclosed in this case is of the pneumatic type and is mainly composed of a suction shoe (sautschuh) and an apertured carrying member. Wherein a pressing element is attached to one of the pair of delivery rollers, which pressing element forms a second clamping point with the roller, with the exception of the clamping point between the delivery top roller and the delivery bottom roller. DE 10050089 a1 does not discuss the fixing of the pressing element in the spinning machine. The disadvantage of the proposed device is that the fibre aggregate can be compressed irregularly as a result of the pressing element accidentally abutting against the rollers of the delivery roller pair.

Another device of the same type is described in DE 10019436 a 1. The compression device disclosed therein is also of the pneumatic type, with a hollow profile and a perforated carrying member for the compression device. The fiber aggregate leaving the delivery roller pair of the drafting device is placed on a conveying member having a hole, and the fiber aggregate is guided through the hollow profile by the conveying member. The hollow profile can be pressed against one of the rollers by means of at least one press-fit element. The publication does not disclose how to construct this press-fit element and where to fix it. A disadvantage of such devices is that it is not yet ensured by only one press-fit element that the hollow profile is pressed against the roller in a defined manner. Furthermore, the hollow profile is pressed in a defined manner onto the delivery top roller, in this case in relation to the position of the delivery top roller, which in turn is in relation to the carrying pressure arm of the drafting device.

Disclosure of Invention

The object of the invention is to improve the known devices and to provide a compression device which is simple in construction and can be used in a single spinning position and which is distinguished by the fact that the fibre assembly can be compressed uniformly in a reliable manner.

This object is achieved by a drawing frame having the features of the independent claim.

The drafting device for a spinning machine according to the invention has a top roller and a bottom roller and a load arm, on which the top roller of the drafting device is arranged. The delivery roller pair is formed by a delivery upper roller and a delivery lower roller, which are usually delivery lower rollers extending over several drafting devices arranged parallel to one another. A pneumatic compression device for compressing the drafted fiber aggregate is provided downstream of the delivery roller pair of the draft device. The compression device has a suction pipe that can be sucked, wherein the suction pipe is surrounded by a screening element. The compression device also has a fiber bundling zone defined by two clamping points. The first nip point is defined by the two rollers of the delivery roller pair and the second nip point is formed by one of the two rollers of the delivery roller pair and the screening element.

According to the invention, the suction tube is arranged on the base. The base enables the suction tube to be received and secured in a defined manner. The base is arranged on the output top roller and the load arm. By arranging the base and the suction tube on the output upper roller and the load arm, the suction tube is lifted together with the load arm and moved away from the lower roller as the drafting device is opened, i.e. as the load arm is lifted. In this way, even when the draft device is opened, the suction pipe is kept set to the delivery top roller. Thereby preserving the settings once implemented. This achieves a reliable and uniform compression of the fiber assembly. Since the base is fixed both to the output top roller and to the load arm, the base produces a defined position of the suction tube. The suction tube is disposed on the base. After the output upper roller and the suction pipe are connected through the base, the corresponding relation between the suction pipe and the output upper roller is realized. This also ensures that the suction tube bears uniformly against the delivery top roller. No angular deviation occurs between the suction tube and the delivery top roller, to be precise, the suction tube and the delivery top roller are parallel to each other and further cause uniform compression of the fiber aggregate.

In an advantageous embodiment of the invention, the base accommodates two suction ducts. Each of the suction pipes corresponds to one of two adjacent drafting devices. The base is therefore arranged on the load arm and supplies the two drawing devices side by side (the upper rollers of which are carried by the load arm) with the underpressure required by the compression device via the suction tube. In the case of a pneumatic connection of the two suction pipes, the construction is particularly simple. This eliminates the need for two suction line connections for supplying the suction line with underpressure, but only one connection which simultaneously sucks in the two adjacent suction locations.

Preferably, the base is arranged on the load arm by means of a fixing element. The fastening elements are arranged on the base and the load arm and realize a defined position of the base relative to the output top roller and the load arm. In a preferred embodiment, the fastening element is arranged on the load arm and/or the base such that the distance of the suction tube from the delivery top roller is adjustable in the closed state of the drafting device or the load arm. This allows the suction tube to be positioned optimally with respect to both the delivery top roller and the delivery bottom roller, so that the fiber aggregate is compressed optimally. Furthermore, this position is maintained when the loading arm is opened and reclosed.

Preferably, the securing element is arranged centrally on one suction tube or between two suction tubes. By means of the central arrangement of the fixing element relative to the suction pipes, or, in the case of two suction pipes being present on the base between the two suction pipes, a certain pivoting movement is achieved which achieves an optimum orientation of the suction pipe or suction pipes relative to the output top roller or output top rollers. This enables precise positioning and application of a precise pressing force to the upper roller. Thereby preventing the suction pipe from inclining relative to the output upper roller.

In a particularly advantageous embodiment of the invention, the base is arranged on the axis of two connected delivery top rollers, so-called double-row rollers, of two adjacent parallel drafting devices. Preferably, the base is rotatably fixed on the axis of the output top roller. A particularly simple fixing of the base relative to the output top roller can thus be achieved by means of, for example, clips.

In the case of a rotatable and/or displaceable arrangement of the fastening element on the base and/or the load arm, an independent arrangement of the base relative to the load arm and of the suction tube relative to the output top roller and the output bottom roller is possible. The once selected positioning of the securing element on the base or the load arm can be fixed so that this positioning is maintained even when the load arm is opened and closed.

If the suction tube is arranged rotatably and/or movably on the base, the position of the suction tube relative to the output upper roller or the output lower roller can be adjusted precisely.

In an advantageous embodiment of the invention, a parallel orientation relative to the output top roller shaft is achieved if the suction tube is mounted in the base so as to be tiltable about a tilting axis transverse to the axis of the output top roller. The inclination of the suction tube thus effects an automatic orientation of the suction tube relative to the output top roller, in particular when the suction tube is pressed against the output top roller.

In order to be able to provide the suction tube in a simple manner, it is advantageous if the rotation point of the suction tube on the base is identical to the rotation point of the fastening element on the base.

In order to press the suction tube uniformly against the delivery top roller, the suction tube is preferably pressed elastically against the delivery top roller, in particular by means of a spring supported on the base. In a preferred embodiment, the pressure force can also be adjusted by a spring to achieve a uniform load on the suction tube and thus a continuous and uniform compression of the fiber aggregate.

Preferably, the suction pipe is connected to a tensioning element for the screening element. The screening element surrounding the suction pipe is preferably laid around the suction pipe with a defined tension. In this case, the tensioning device arranged on the suction pipe effects a defined uniform pretensioning of the screening element on the suction pipe.

Preferably, the suction tube (in particular a detachable suction tube) is arranged on the suction tube. The suction pipe is used for connecting the suction pipe with a suction source arranged in the spinning machine. The suction pipe and/or the suction pipe are arranged on the base by means of a suction pipe holder. The suction tube holder is capable of rotatably securing the suction tube to the base. Due to the separability of the suction tube from the suction tube, blockages of the suction tube, for example, due to fiber fly, can be removed.

Preferably, the draft tube is arranged stationary on the drafting device. The suction tube is thereby connected to a suction source which is also arranged in the spinning machine at rest. Alternatively or additionally, the draft tube can have a separation point, wherein a first part of the draft tube is deflectable together with the draft tube and the load arm and a second part is arranged in the region of the bottom roller on the drafting device or spinning machine in a stationary, at most elastically supported manner. Thereby, a connection is established between the movable load arm which moves away from the bottom roller in order to open the drafting device and the stationary part of the suction device which is arranged in the spinning machine.

In a particularly advantageous embodiment of the invention, connecting means are provided for connecting the first part and the second part of the draft tube. By means of this connecting device, which is, for example, funnel-shaped, the first portion of the draft tube is moved away together with the load arm, so that the first portion of the draft tube is separated from the second portion of the draft tube. During the closing of the drawing frame (in which the load arm is deflected downward toward the bottom roller), the first section of the draft tube is preferably automatically reconnected to the second section of the draft tube, so that the suction tube can be sucked in turn.

Preferably, two draft tubes for two adjacent draft tubes are arranged at the side of the base. In this way, each suction duct can be sucked independently of the adjacent suction duct. This enables an aspiration operation of the compression device which is independent and, as the case may be, also individually adjustable. Alternatively, two adjacent suction pipes lead into a common suction pipe. This allows a simple structural solution and in most cases is sufficient to achieve a uniform suction of two adjacent drawing or compression devices.

In the inventive compression device for a drafting device and having a suction tube which can be sucked, the suction tube is arranged on a base which has recesses for fastening to an output top roller and a load arm of the drafting device. The compression device can therefore be arranged subsequently on the load arm, whereby a compression device is added to an existing drafting device. This is particularly advantageous when retrofitting of existing spinning machines is required and it is desirable to improve the drafting device by means of a new type of compression device.

Drawings

Further advantages of the invention are described in the following description of the embodiments. Wherein:

FIG. 1 is a schematic view in longitudinal section of a spinning machine,

figure 2 is a side view of the compression device,

figure 3 is a cross-sectional view of the load arm in conjunction with the compression device of figure 2,

figure 4 is a view of another embodiment of the present invention,

figure 5 is a view of another embodiment of the present invention,

figure 6 is a front view of the load arm,

FIG. 7 is a perspective view of the suction tube holder, an

Fig. 8 is another embodiment.

Detailed Description

In the following description of alternative embodiments, the same reference numerals are used for features that are identical and/or at least similar in technical solution and/or operating principle. If these features are not explained in detail again, their technical solutions and/or operating principles are equivalent to those of the features already described above.

Fig. 1 is a schematic view in longitudinal section of a spinning machine, in particular a ring spinning machine, with a compression device 20. The drawing shows exemplary components of a spinning machine, namely a drafting device 2 and a spinning device 10. The draft device 2 is composed of three roller pairs, i.e., a feed roller pair 3, a belt roller pair 4, and a delivery roller pair 5. The delivery roller pair 5 is formed by a delivery upper roller 6 and a delivery lower roller 7. The two rollers of one roller pair come together and form a nip point at their contact point, wherein the nip point K1 is formed by the delivery roller pair 5 between the delivery top roller 6 and the delivery bottom roller 7. The clamping point K2 is formed by a suction tube 17 (fig. 2) which can be sucked and which is pressed against the top roller 6. The fiber aggregate 1 entering the drafting device 2 is clamped between the rollers of the roller pairs 3, 4 and 5 by a clamping point and drafted based on the different rotational speeds of the roller pairs 3, 4 and 5. The fiber assembly 1 is conveyed through the draft device 2 while being drafted. After leaving the drafting device 2, the drafted fiber aggregate 8 reaches a compression device 20, where the fiber aggregate is compressed. Between the clamping points K1 and K2, a fiber collecting zone is provided on the suction tube 17 with the suction slot, in which the fibers of the fiber aggregate 8 are collected or compressed. The fibre aggregate 8 then reaches the thread guide 9 and is further guided to the spinning device 10. The spinning device 10 is mainly composed of a ring plate 14 that carries a spinning ring 12, and a spindle rail 15 to which a spool 13 is fixed. The fiber assembly 8 reaches the reel 13 via the rotor 11. To weave the fiber aggregate 8, the reel 13 is rotated, which causes the rotor 11 to be rotated by the fiber aggregate 8 on the ring 12 as well. The fiber assembly 8 is rotated by the rotation of the spool 13 and the rotor 11, thereby forming a yarn, which is wound around the spool 13 by the vertical movement of the ring rail 14. To open the drafting device 2, the top roller can be lifted off the bottom roller. For this purpose, and for reclosing the drafting device, the load arm 19, to which the top roller is fixed in a known manner, is moved about the rotation point D in the direction of the arrow P.

Fig. 2 is a side view of the compression device 20 in the region of the delivery roller pair 5. The top roller 6 is pressed onto the output bottom roller 7 and forms a clamping point K1 with this output bottom roller. The top roller 6 is fixed in a known manner to the load arm 19 by means of a cage. A clamping point K2 is produced between the top roller 6 and the suction tube 17, which is pressed by the spring 21 against the output top roller 6. The suction duct 17 has a suction slit, whereby air is sucked in. The fiber assembly 8 is bundled and compressed on the suction slit. In order to prevent the fibers of the fiber aggregate 8 from being sucked into the suction slot, the suction slot is surrounded by the screen element 18. The screen element 18 surrounds the suction pipe 17 and is tensioned by means of a tensioning device 22. In the present exemplary embodiment, the tensioning device 22 is fastened to the suction tube 17 or the suction tube holder 23. In this way, the tensioning device 22 can move together with the suction tube 17, so that the movement of the suction tube 17 does not affect the tensioning of the screening element 18.

The suction pipe 17 is connected to a suction pipe 24. Air is sucked out of the suction tube 17 through the suction tube 24. The suction pipe 17 and the suction pipe 24 can be embodied in one piece in one structural unit. In the present exemplary embodiment, the suction tube 17, the tensioning device 22 and the suction tube 24 are fastened to the suction tube holder 23 or are embodied as a single structural unit. However, the suction pipe 17 is preferably connected separately to the draft pipe 24, so that any dirt that may be present can be easily removed, in that the suction pipe 17 is removed from the draft pipe 24, so that the suction pipe 17 and the draft pipe 24 are easily accessible for cleaning. Preferably, the suction tube 17 is inserted into an opening of the suction tube 24 or an opening of the suction tube holder 23 and optionally fastened there by means of, for example, screws.

In order to be able to remove the compression device 20 together with the delivery top roller 6 from the delivery bottom roller 7, the suction tube holder 23 and the suction tube 17 are arranged indirectly on the load arm 19. For this purpose, the suction tube holder 23 is fixed on the base 25 in a manner such that it can rotate about its rotation point DS. The base 25 is in turn rotatably fixed on the axis of the output top roller 6. Furthermore, the base 25 is connected to the fixing element 26 via a rotation point DF. The securing element 26 is itself fixed to the load arm 19. In this embodiment, the securing element 26 is secured to the load arm 19 by means of a securing element 27 and is secured in an elongate hole 28 in the load arm 19. The securing element 27 in particular allows a displacement of the securing element 26 in the elongated hole 28. Preferably, the securing element 26 is also capable of a rotational movement around the securing element 27. By adjusting the fixing element 27 in the elongated hole 28 and subsequently fixing the fixing element in the adjusted position, the position of the base 25 and thus of the suction tube 17 can be changed relative to the output top roller 6 and relative to the output bottom roller 7. This allows an optimum adjustment of the suction tube 17 relative to the output bottom roller 7 and also of the position of the clamping point K2 on the output top roller 6. This makes it possible to cope with different fibre materials of the fibre assembly 8 and to find an optimum arrangement for them. Furthermore, when the loading arm 19 is lifted to open the drafting device 2, it is ensured that the compression device 20 is also lifted. Wherein the suction pipe 17 is arranged unchanged relative to the delivery roller pair 5.

The spring 21 presses the suction pipe 17 against the output top roller 6 with a predetermined force. For this purpose, the spring 21 is fixed to the base 25. At the same time, a certain elasticity of the clamping point K2 is achieved, so that, for example, in the case of a solid nub of the fiber aggregate 8, there is no need to worry about damage to the compression device 20, since this can be relieved against the spring pressure.

Usually, two parallel top rollers 6 of the drafting system 2 are fixed to the load arm 19. These top rollers 6 are arranged on a load arm 19 by means of an axis in the form of a double-row roller. Each of the top rollers 6 laterally projects a load arm 19. Accordingly, two compression devices of adjacent drafting devices 2 are preferably also fastened to one load arm 19.

In the embodiment shown in fig. 2, each suction pipe 17 of the drafting device 2 has a suction pipe 24. There are two suction pipes 17 and two suction pipes 24 on one load arm 19. Each of which is fastened together with the tensioning device 22 to its own suction tube holder 23 and carries a screening element 18. The suction tube holder 23 is rotatably arranged on the central base 25 and the central fixture 26.

Fig. 3 shows a cross-sectional view of the load arm 19 together with the compression device 20 of fig. 2. An elongated hole 28 is again provided in the load arm 19, in which elongated hole the fastening element 27 of the fastening element 26 is movably and rotatably arranged. The fastening element 26 is rotatably connected at the other end to the base 25 in a rotation point DF. The base 25 also rotatably holds the suction pipe 24, the suction pipe 17 and the tensioning device 22 together with the screening element 18 at point DS by means of the suction pipe holder 23. The base 25 carries a spring 21 which presses the suction tube holder 23 and thus in particular the suction tube 17 against the output top roller 6. The base 25 is arranged rotatably on the axis 29 of the delivery top roller 6 by means of a receiving opening, which is shown here in the form of a fork-shaped recess. By adjusting the fastening element 26 along the elongated hole 28, an adjustment of the suction tube 17 relative to the output top roller 6 and the output bottom roller 7 is brought about. As a complement to the adjustment shown here, the suction tube holder 23 is arranged on the base 25, the suction tube holder 23 being both rotatable and longitudinally adjustable. In a further embodiment, the fastening of the fastening element 26 to the base 25 at the rotation point DF can also be adjusted in such a way that a longitudinal adjustment of the base 25 is achieved. When the fastening system of the suction tube 17 has corresponding adjusting means on the suction tube 24 and/or on the suction tube holder 23, the position of the suction tube 17 on the suction tube holder 23 can also be adjusted.

Fig. 4 shows another embodiment of the present invention. In the present exemplary embodiment, the suction pipe 17 is suctioned via a suction pipe 24, which here forms a first part of the entire suction pipe. The draft tube 24 is arranged between two draft tubes 17 of two adjacent drafting devices 2. This means that two suction pipes 17 are sucked through the suction pipe 24. The suction pipe 24 at the same time serves as a suction pipe holder 23 for the suction pipe 17. The tensioning device 22, which is not shown here but can be embodied as described in the preceding figures, can likewise be fastened there to the suction pipe 17 or the suction pipe 24. The draft tube 24 communicates at the rotation point DS with the connection of the second part of the suction device, i.e. the draft tube 30. The second portion 30 of the draft tube is statically fixed to the load arm 19 by means of, for example, a clamp 31. At the rotation point DS, the pneumatic connection of the first section of the draft tube 24 to the second section of the draft tube 30 can be used to guide the suction air. Nevertheless, the draft tube 24 can still be rotated about the rotation point DS and is pressed against the delivery top roller 6 by means of the spring 21, which is attached here to the second part of the draft tube 30. In order to enable the rotation point DS to be deflected slightly about the axis 29, the draft tube 30 has a flexurally elastic and/or longitudinally elastic portion, not shown. The position of the suction tube 17 can be changed by this freedom of movement by means of the securing element 26 (as depicted in fig. 5).

Fig. 5 shows an embodiment of the invention in which the fixing element 26, the base 25 and the suction tube holder 23 have a common rotation point DG. When the fastening element 26 is adjusted in the elongated hole 28, the base 25 is rotated about the axis 29 of the output top roller 6, so that the suction tube 17 is adjusted relative to the output top roller 6 and the output bottom roller 7. In this embodiment, a central draft tube 24 is provided, and in the case of this draft tube, two draft tubes 17 are connected to one draft tube 24. Wherein the suction pipes 17 of adjacent drafting devices 2 can be connected pneumatically or separate embodiments can be used. In the case of the separate embodiment, it is necessary to divide the mouth of the draft tube 24 in the region of the draft tube 17. In this case, a further connection of the draft tube 24 can be effected by means of a second part of the draft tube 30 which is fixed to the load arm 19, as shown in fig. 4. However, the connection to the stationary suction device can also be made in the region of the delivery bottom roller 7 on the spinning machine.

Fig. 6 is a front view of a load arm 19 comprising two drafting devices 2, 2' arranged in parallel on the load arm. Two delivery top rollers 6, 6' are fastened to the load arm 19 via a common shaft 29. A base 25 is fixed to the axis 29. The base 25 is in turn connected to a fixing element 26, which is fixed to the load arm 19. The fixation between the fixation element 26 and the base 25 allows the base 25 to tilt on the fixation element 26. This allows the relative delivery of the two suction pipes 17, 17 'to the top rollers 6, 6' to be automatically adjusted. This ensures that the suction ducts 17, 17 'are always parallel to the axis 29 and thus to the surface of the output top rollers 6, 6'.

The suction pipes 17, 17 'are rotatably fixed to the base 25 by means of suction pipe holders 23, 23'. The suction pipes 24, 24 'supply the suction pipes 17, 17' with a negative pressure. Furthermore, a tensioning device 22 or 22 'is provided on the suction tube holder 23 or 23' for tensioning the screen element 18, 18 'relative to the suction tube 17, 17'. The spring 21 is also fixed to the base 25.

Fig. 7 is a perspective view of an example of a suction tube holder 23, on which two suction tubes 17, 17' are arranged. The suction pipes 17, 17' may be of separate embodiments or may be of one-piece embodiment. Preferably, the suction tube is inserted into the receiving opening of the suction tube holder 23 and is fixedly attached thereto. Each suction tube 17, 17 'has a suction slit 32, 32', which leads to a bundling of the fiber aggregate. The tensioning device is furthermore fixed to the suction tube holder 23. This tensioning device is embodied here with two cylinders 33, 33', which are prestressed, for example, by means of springs. On the two cylinders 33, 33', a cross-bar 34 is provided around which the screening elements 18, 18' (see previous figures) are laid and tensioned against the suction pipes 17, 17 '.

In fig. 8, again, an embodiment is shown, which has a central draft tube 24. The central draft tube 24 is the first part of the aspiration device. The first portion 24 of the draft tube is connected to the second portion 30 of the draft tube by means of a connecting means 35. The draft tube 30 is fixed to the spinning machine and adopts a stationary embodiment. The attachment means 35 is of a separable embodiment so that the first portion 24 of the draft tube is separated from the second portion 30 of the draft tube when the load arm 19 is raised. The connecting device can be embodied as shown here and has a seal. Depending on the geometry, however, it is also possible to provide a connection aid, such as an insertion bevel or a guide rod, which enables a simple and preferably automatic connection of the first section 24 of the draft tube to the second section 30 of the draft tube and seals this connection.

The device is constructed according to the preceding description, wherein the mentioned features can be applied individually or in any combination.

The invention is not limited to the embodiments shown and described. Variations may be employed which are within the scope of the claims, and features may be combined, even if the features are disclosed and described in different embodiments.

List of reference numerals

1 fiber aggregate

2 draft device

3 input roller pair

4 belt roller pair

5 output roller pair

6 output top roller

7 output bottom roller

8 drafted fiber aggregate

9 wire guide

10 spinning device

11 rotor

12 ring

13 reel

14 Ring rail

15 spindle rail

16 fiber bundle region

17 suction tube

18 screening element

19 load arm

20 compression device

21 spring

22 tensioning device

23 suction tube holder

24 draft tube (first part)

25 base

26 securing element

27 fixing element

28-shaped hole

29 axis

30 draft tube (second part)

31 clamping piece

32 suction slit

33 cylinder

34 crossbar

35 connecting device

D load arm rotation point

Direction of arrow P

DS suction tube rotation point

DF fixing element rotation point

DG shared rotation point

K1 first clamping Point

K2 second clamping point

Claims

1. A drafting device for a spinning machine has

An upper roller and a lower roller; a load arm (19) on which the upper roller of the drafting device is arranged;

a pair of delivery rollers (5) consisting of a delivery upper roller and a delivery lower roller; and

a pneumatic compression device (20) arranged downstream of the delivery roller pair (5) of the drawing device (2) for compressing the drawn fiber aggregate (8); wherein

The compression device has a suction tube (17) which can be sucked,

the suction pipe (17) is surrounded by a screening element (18),

the compression device (20) has a fiber bundling zone (16), an

The fiber bundling zone (16) is delimited by two clamping points (K1, K2),

wherein a first clamping point (K1) is defined by the two rollers of the delivery roller pair (5), and

a second clamping point (K2) is formed by one of the two rollers of the output roller pair (5) and the screen element (18),

it is characterized in that the preparation method is characterized in that,

the suction pipe (17) is arranged on a base (25), an

The base (25) is arranged on the output top roller (6) and the load arm (19).

2. Drafting device according to claim 1, characterised in that the base (25) houses two, in particular connected, suction pipes (17).

3. Drafting device according to one or more of the preceding claims, characterised in that the base (25) is arranged adjustably on the load arm (19) by means of a fixing element (26), in particular for varying the distance of the draft tube (17) from the output bottom roller (7).

4. Drafting device as in one or more of the previous claims, characterized in that said fixing element (26) is arranged substantially centrally on one suction duct (17) or between two suction ducts (17).

5. Drafting device according to one or more of the preceding claims, characterised in that the base (25) is arranged, in particular rotatably, on the axis (29) of two connected output top rollers (6) of two adjacent parallel drafting devices (2).

6. Drafting device according to one or more of the preceding claims, characterised in that the holding element (26) is arranged rotatably and/or movably on the base (25) and/or on the load arm (19).

7. Drafting device as in one or more of the previous claims, characterized in that said suction duct (17) is rotatably and/or movably arranged on said base (25).

8. Drafting device according to one or more of the preceding claims, characterised in that the suction duct (17) is mounted on a base (25) so as to be tiltable about a tilting axis transverse to the axis (29) of the output top roller (6) in order to be oriented parallel to the axis (29) of the output top roller (6).

9. Drafting device as in any one or more of the previous claims, characterized in that the rotation point (DS) of the suction pipe (17) on the base (25) is identical to the rotation point (DF) of the fixing element (26) on the base (25).

10. Drafting device according to one or more of the preceding claims, characterised in that the suction tube (17) is elastically pressed against the delivery upper roller (6), in particular by means of a spring (21) supported on the base (25).

11. Drafting device according to one or more of the preceding claims, characterised in that the suction pipe (17) is connected to a tensioning element (22) for the screening element (18).

12. Drafting device according to one or more of the preceding claims, characterised in that the suction tube (17), in particular in a detachable manner, is arranged on a suction tube (24) and/or in that the suction tube (17) and/or the suction tube (24) is arranged on the base (25) by means of a suction tube holder (23).

13. Drafting device as in one or more of the preceding claims,

the draft tube (24) is arranged stationary on the drafting device (2), in particular on the load arm (19), and/or

The draft tube (24) has a separation point, wherein a first part of the draft tube (24) is deflectable together with the draft tube (17) and the load arm (19), and the second part (30) is arranged on the drafting device (2) via the lower roller in a stationary, at most elastically supported manner.

14. Drafting device according to one or more of the preceding claims, characterised in that a connecting device (35) is provided for connecting the first part with the second part of the draft tube (24, 30) when the load arm (19) is rotated into its load position.

15. Drafting device as in one or more of the preceding claims,

two suction pipes (24) for two adjacent suction pipes (17) are arranged at the side of the base (25), and/or

Two adjacent suction pipes (17) communicate with a common suction pipe (24).

16. A compression device for a drafting device according to any one of the preceding claims, having a suction pipe (17) which can be sucked,

the suction pipe (17) is arranged on a base (25), an

The base (25) has recesses for fastening to the delivery top roller (6) and the load arm (19) of the drafting device.