CN115704121A

CN115704121A - Drafting device and method for loading drafting device and opening drafting device

Info

Publication number: CN115704121A
Application number: CN202210917837.7A
Authority: CN
Inventors: M·库布勒; G·沙夫勒; 曼弗雷德·鲍尔
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2021-08-04
Filing date: 2022-08-01
Publication date: 2023-02-17
Also published as: DE102021120226A1; EP4130361A1; JP2023024347A

Abstract

A drafting device for drafting a fibre bundle for an air jet spinning machine has a frame for the drafting device and a plurality of drivable bottom rollers, each bottom roller being supported in a support region on the frame, each bottom roller corresponding to a top roller, the bottom rollers and the top rollers forming a feed roller pair, at least one middle roller pair and a delivery roller pair. A load carrier is arranged on the frame in a manner such that it can be pivoted in the rotary bearing. The load carrier has a pressure element for applying a load to the top roller and a holding element for holding and lifting the top roller during deflection of the load carrier. The frame is provided with a containing piece aiming at the spinning nozzle, and the spinning nozzle is arranged right behind the delivery roller pair. The delivery top rollers are supported in bearings connected to the support points of the respective delivery bottom rollers, are loaded by the load carrier, but are not fixed to the load carrier and remain in their bearings during deflection of the load carrier.

Description

Drafting device and method for loading and opening a drafting device

Technical Field

The invention relates to a drafting device for drafting fiber bundles for an air jet spinning machine, having a frame for the drafting device and having a plurality of drivable lower rollers, wherein each lower roller is supported in a support point on the frame, each lower roller corresponds to an upper roller, and the lower rollers and the upper rollers form a feed roller pair, at least one intermediate roller pair and a delivery roller pair, wherein a load carrier is provided on the frame in a manner that allows deflection in a rotary bearing, the load carrier having a pressure element for applying a load to the upper rollers and a holding element for holding and raising the upper rollers during deflection of the load carrier, and wherein a receptacle for a spinneret is provided on the frame for arranging the spinneret directly behind the delivery roller pair, and to a corresponding method for applying a load to the drafting device and opening it.

Background

A twin unit, which contains two drafting devices for drafting a fiber bundle and can be used in spinning machines, is known from DE 10 2005 027 193A1 of the generic type. The twin-subunit has a frame common to the two drivable drafting devices, wherein the frame is detachably mounted in the machine frame. The drafting device comprises several drivable bottom rollers and is arranged in a substantially mirror-symmetrical manner to one another. Each bottom roller has a region for drafting the fiber bundle and has two bearing points. The spinnerets can be arranged together with the drafting device and with the pair of draw-off rollers in the frame of the twin-subunit.

In order to control the air flow conditions in the drawing device and in particular around the fiber entry area on the spinning head, the upper roller and the spinning head are moved against the lower delivery roller in the case of air jet spinning machinesThe precise alignment of (a) is particularly important. Due to the high conveying speed and the resulting high surface speed on the delivery roller pair, turbulent air flows occur, which have a negative effect on the fiber flow. To limit air turbulence, the spinneret must be very close to the output top roller. The corresponding outer contour of the spinning nozzle should cover the delivery roller pair so as to prevent the generation of air dragging flow (Luft-

)。

With known spinning methods, such as described in JP S59204925A, it is necessary to lift the output top roller of one spinning station independently of the other stretching devices. Very complicated mechanisms are required for this. The output upper roller and the output lower roller are housed in different zones of the machine. The resulting tolerance chain is not ideal in terms of the roller accuracy sought to be achieved.

In the case of an output top roller which is accommodated in a load carrier and is lifted with this load carrier, the alignment and positioning of the output top roller relative to the output bottom roller and relative to the spinneret is made more difficult. The large distance of the deflection shaft from the lower output roller, the play of the load carrier in the swivel bearing, and the long rod of the load carrier extending to the upper output roller all make the upper output roller not precisely positionable. Even if constructive measures are taken in the rotary bearing of the load carrier and the manufacture is carried out more precisely, this disadvantage cannot be compensated for.

Disclosure of Invention

In view of the above, it is an object of the present invention to provide a draft device of an air jet spinning machine, in which an output upper roller can be accurately positioned with respect to an output lower roller and with respect to a spinneret, and a method of applying a load to and opening the draft device of an air jet spinning machine.

The solution of the invention to achieve the above object is a drawing device and a method having the features of the independent claims.

The drafting device for drafting a fiber bundle for an air jet spinning machine according to the invention has a frame for the drafting device and has a plurality of drivable bottom rollers, wherein each bottom roller is supported on the frame in a support point. In order to adjust the distance of the bottom roller, the bearing point of the bottom roller can be mounted in a rail on the frame. Each lower roller corresponds to one upper roller, and the lower rollers and the upper rollers form an input roller pair, at least one middle roller pair and an output roller pair. Depending on the type of drafting device, it is also possible, for example, to provide two middle roller pairs, which in particular also comprise aprons and apron deflectors. Furthermore, a load carrier is arranged on the frame so as to be pivotable in the rotary bearing.

The load carrier has a pressure element for applying a load to the top roller and a holding element for holding and lifting the top roller during deflection of the load carrier. With the closed load carrier, the upper roller is pressed against the lower roller by means of the pressure element, thereby providing a clamping point for the fiber strand to be drafted. The holding element fixes the top roller on the load carrier, whereby the top roller is lifted from the bottom roller when the load carrier is opened, i.e. lifted. In this way, the drawing frame is opened and the fiber strand to be drawn can be inserted into the drawing frame manually, for example.

The frame is provided with a containing piece aiming at the spinning nozzle, and the spinning nozzle is arranged right behind the delivery roller pair. By arranging the spinneret and the delivery bottom roller on the frame, it is ensured that the distance between the spinneret and the delivery bottom roller is always maintained at the desired same distance. In this way, it is possible to position the spinneret very close to the delivery bottom roller, since it is not necessary to take into account the tolerances due to the relative movements to be performed.

According to the invention, the delivery top roller is supported in a bearing connected to the support point of the corresponding delivery bottom roller. The bearing of the output top roller and the bearing of the output bottom roller can be of one-piece design or at least connected fixedly, for example screwed, to one another. Therefore, no movement occurs between the bearing of the delivery upper roller and the support point of the delivery lower roller. This makes it possible to very precisely position the stationary supported delivery top roller relative to the stationary supported delivery bottom roller and thus relative to the spinning head which is likewise arranged stationary.

Furthermore, according to the invention, the output top roller is only loaded by the load carrier and not fixed to the load carrier, which also contributes to a very precise positioning. The load carrier thus presses the output top roller against the output bottom roller with only a defined force. During the opening of the drawing frame, i.e. during the deflection of the load carrier, the delivery upper roller is not lifted together with the load carrier from the delivery lower roller, but remains in its bearing. Thus, even when the draft device is opened, the accurate correspondence relationship between the delivery upper roller and the delivery lower roller and between the delivery upper roller and the spinneret is maintained. This significantly improves the correspondence and the accuracy of the position of the output top roller relative to the spinneret. If the drawing frame is closed again, i.e. the load carrier is returned to the position in which it presses the top roller against the bottom roller, the position of the delivery top roller relative to the delivery bottom roller and relative to the spinneret remains unchanged. This avoids tolerance chains and ultimately significantly improves the spinning result.

Particularly preferably, the bearing of the delivery top roller is a sliding guide. The sliding guide device is easy to manufacture and achieves excellent guidance of the output top roller in the bearing of the output top roller. The tolerances are thereby kept low and the correspondence of the output top roller with its output bottom roller and with the spinneret is still improved.

It is also preferred that the pressure element is a spring, in particular a leaf spring or a helical spring, or a pneumatic or hydraulic pressure element. The use of a leaf spring for applying a load to the output top roller is particularly preferred, since this makes it possible to achieve a simple construction, wherein the leaf spring only has to be pressed against the output top roller or its shaft when the drafting device is closed.

Preferably, the load carrier has a sliding guide, in particular widened, for the delivery top roller. The widened sliding guide enables a generally contactless wrapping of the output top roller or its shaft. The widened sliding guide intervenes in the positioning of the shaft only if the shaft is not exactly located in its bearing, in particular in its sliding guide. This prevents the drafting device from being damaged.

Preferably, the shaft of the output top roller has a collar for axial positioning in the bearing. The output top roller can thereby be positioned very simply in the axial direction. The collar can, for example, be laterally snapped onto a bearing or a sliding guide and thereby ensure that the output top roller is arranged precisely above the output bottom roller.

Preferably, the shaft of the delivery top roller is held in the bearing of the delivery top roller by means of a holding device, in particular a holding spring. The holding device ensures that the delivery top roller remains securely in its bearing even in the event of lifting of the load carrier.

It is also preferred that the drafting devices are arranged in a twin sub-unit, in which two drafting devices with mutually independent drives are provided on the frame, and that the drafting devices are arranged substantially mirror-symmetrically to one another. The manufacturing costs can be reduced by means of a twin subunit compared to a single unit. The installation on the spinning machine can also be carried out more quickly with a twin unit than with a single unit.

Furthermore, it is preferred that at least the output top rollers of the two drafting devices are twin sub-rollers which are designed with a common axis. An output top roller is rotatably provided at both ends of the common shaft. Wherein the shaft may be held on the frame by one or two bearings. In this case, the two adjacent delivery upper rollers are positioned in the same manner with respect to their delivery lower roller and with respect to the two spinnerets.

Furthermore, the load carrier preferably jointly loads the top rollers of the two drawing frames. Here, the load carrier is implemented as follows: the load carrier can lift the top rollers (except for the output top rollers) of two adjacent drafting devices from the bottom rollers thereof at the same time. During the lowering of the load carrier and thus during the closing of the drafting devices, pressure is applied to all roller pairs of two adjacent drafting devices.

Particularly preferably, the bearing of the output top roller is arranged in the following manner: the position of which relative to the bearing point of the corresponding output bottom roller is adjustable. Adjustment can be made by means of elongated holes and fastening screws. The top roller diameter may vary because the facing layer must be worn away after a certain period of use. Thus, it may be necessary to adjust the bearings of the upper roller towards the spinneret or relative to the bearings of the lower roller.

Preferably, the bearings of the output top rollers of the twin sub-rollers designed with a common shaft are jointly adjustable. In this case, the bearings may be moved in pairs, for example in elongated holes. For the radius reduction range in the finish polishing, an adjustment range of a few millimeters is usually sufficient.

In the method of the invention for applying a load to a drafting device of an air jet spinning machine having a bottom roller and a top roller and opening the drafting device, each bottom roller corresponds to one top roller. The lower roller and the upper roller form an input roller pair, at least one middle roller pair and an output roller pair. A plurality of pairs of intermediate rollers may be provided in the draft device. The loading body of the upper roller provided with the drafting device can be deflected into an open position or a closed position. In the closed position of the load carrier, the load carrier applies a load to the top roller, i.e. presses the top roller against the corresponding bottom roller of the drafting device. In addition, in the open position of the load carrier, the load carrier lifts the top roller from the bottom roller and holds the top roller in the lifted open position. A spinneret for spinning the fiber bundle drafted in the draft device into a yarn is provided behind the delivery roller alignment.

According to the invention, the delivery upper roller is supported on the corresponding delivery lower roller. Thus, the corresponding relation between the output upper roller and the output lower roller is very accurately defined. When the drafting device is opened or closed, the two rollers do not move relative to each other, so that there is no tolerance chain which can cause the mutual correspondence to become inaccurate. Furthermore, if the delivery top roller is loaded by the load carrier, but is not fixed to the load carrier, so that the delivery top roller remains in its bearing during deflection of the load carrier, it is also ensured that the delivery top roller is always positioned precisely relative to the delivery bottom roller, and an excellent and also very fast spinning is achieved in the spinneret.

In a particularly advantageous embodiment of the invention, the output top roller pair is accommodated by an accommodating fork integrated in the frame of the drafting device, like the output bottom roller support. The receiving fork is a sliding guide which ensures the position of the output top roller relative to the output bottom roller and in which the diameter of the top roller, which changes after the finish has been polished, is taken into account. With the open load carrier, the delivery top roller remains in the plane of the drawing device in which the fiber strand to be drawn is located.

The delivery top roller is held in the slide guide and is prevented from falling off by a holding spring. The holding spring is designed to be able to engage and disengage the shaft of the top roller into and out of the sliding guide.

The top roller has a collar or recess on its shaft and is thereby axially oriented. The top roller is fed into a predetermined axial position on the sliding guide by means of a collar or a groove of the top roller.

In the case of a twin sub-unit, the two bearing receptacles for the left and right delivery bottom rollers and the two sliding guides are integrated in the drafting device frame. This ensures very precise alignment of the top and bottom rollers. The precise positioning of the spinneret relative to the output upper roller and the output lower roller is ensured because the accommodating part of the spinneret is also arranged in the drafting device frame.

In the case of a closed carrier, the output top roller is preferably loaded by a spring element, in particular a leaf spring, accommodated in the load carrier. Of course, a coil spring may be used. Pneumatic or hydraulic loads may also be used.

The invention is constructed in accordance with the foregoing description, wherein the mentioned features can be applied individually or in any combination.

Drawings

Further advantages of the invention are described in the examples below. Wherein:

figure 1 is a schematic side view of a closed drafting device of the invention,

figure 2 is a schematic view of the drawing apparatus of figure 1 in an open state,

figure 3 is a schematic side view of the frame,

figure 4 is a schematic top view of the frame of figure 3,

figure 5 is a schematic top view of the support device of the output top roller,

FIG. 6 is a schematic side view of the movable supporting device of the delivery top roller, an

Fig. 7 is a schematic top view of the common movable support of the delivery top roller.

Detailed Description

In the following description of alternative embodiments, the same reference numerals are used for the same and/or at least similar features of the solution and/or the working principle compared to the other embodiments. 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. For clarity, reference numerals will sometimes be omitted in subsequent figures for components already described.

The drafting device 1 comprises a frame 2, which is arranged on a frame 3 of the air jet spinning machine. On the frame 2, movable support points 4 are provided for one feed bottom roller 5 and two intermediate bottom rollers 6. One of the middle bottom rollers 6 has a apron 7. The delivery bottom roller 8 is arranged adjacent to the apron 7, and its bearing point 4 is fixedly (in this case integrally) connected to the frame 2. Each of the

lower rollers

5,6 and 8 is driven by a motor 9 and a belt 10. Each

bottom roller

5,6,8 corresponds to one

top roller

11, 12 and 13 and apron 7 corresponds to one apron 17. The input bottom roller 5 and the input top roller 11 form one input roller pair 14, the two middle bottom rollers 6 and the two middle top rollers 12 form one middle roller pair 15, and the output bottom roller 8 and the output top roller 13 form one output roller pair 16. Downstream of the delivery roller pair 16, a spinneret 18 is arranged on the frame 2 in a receptacle 19. The receiver 19 allows the spinneret 18 to be tilted as necessary to perform maintenance work on the spinneret 18. The spinneret 18 is matched to the peripheral shape of the delivery bottom roller 8 and the delivery top roller 13, so that a flow is generated which does not disturb the fibers fed through the drawing device 1 and the spinneret 18.

The

top rollers

11 and 12 are arranged on a load carrier 20. The load carrier 20 can be deflected by the rotary bearing 21, so that the load carrier 20 can be moved from the closed position shown here, in which the

top rollers

11, 12 and 13 bear against their

bottom rollers

5,6 and 8, into the open position shown in fig. 2. In the closed position of the drawing frame 1, as shown in fig. 1, the pressure element 22 exerts a pressure on the

upper rollers

11, 12 and 13, so that a clamping line is produced between the

upper rollers

11, 12 and 13 and the corresponding

lower rollers

5,6 and 8, in which clamping line the fibers of the fiber bundle moved by the drawing frame 1 are clamped and drawn due to the mutually different speeds of the roller pairs 14, 15 and 16. The pressure element may act mechanically (for example in the form of a spring), but may also be a pneumatic or hydraulic pressure element.

The

top rollers

11 and 12 are fixed to the load carrier 20 by holding elements 23. When the load carrier 20 is opened, even if it is deflected about the rotary bearing 21, the holding element 23 lifts the

top rollers

11 and 12 together with the apron 17 from the

bottom rollers

5 and 6 and from the corresponding apron 7. In contrast, the delivery top roller 13 is not fixed to the load carrier 20 by a holding element 23. Only the pressure element 22 is fixed to the load carrier 20 and presses the output top roller 13 against the output bottom roller 8 in the closed state. In order to achieve a loose guidance of the delivery top roller 13 and the load carrier 20 during the opening and closing process, a widened sliding guide 24 is provided on the load carrier 20, which loosely laterally surrounds the shaft, not shown here, of the delivery top roller 13. Accordingly, during the opening of the load carrier 20, the delivery top roller 13 is not lifted from its delivery bottom roller 8, but rather remains resting against this delivery bottom roller 8.

Correspondingly, fig. 2 is a schematic view of the drafting device 1 in fig. 1 in an open state. In this case, the load carrier 20 and the pivot bearing 21 are deflected, so that the

top rollers

11, 12 and the apron 17 are lifted off their

bottom rollers

5 and 6 and from the bottom apron 7. In this state, the fiber bundles located in the drawing frame 1, which are not shown here, can be removed or, if required, inserted. The delivery top roller 13 is still located on its delivery bottom roller 8 and thereby corresponds very precisely to the spinneret 18. The removal of the delivery top roller 13 is not necessary each time the drafting device 1 is opened or the load carrier 20 is lifted, so that the delivery top roller can be supported very precisely with small tolerances by a fixed correspondence of the delivery top roller 13 to the delivery bottom roller 8 and to the spinneret 18.

As can also be seen from fig. 2, the pressure element 22 and the holding element 23 are also connected to the

top rollers

11 and 12. However, the pressure element 22, which applies pressure to the output top roller 13, is detached from the output top roller 13 and lifted together with the load carrier 20. This pressure element 22 is surrounded by a widened sliding guide 24, which sliding guide 24 brings about a loose guidance of the load carrier 20 relative to the axis of the output top roller 13, in order to additionally lock the output top roller 13 and in order to ensure a proper closure of the load carrier 20.

Fig. 3 is a side view of the frame 2 of the previous fig. 1 and 2. The frame 2 is fixedly connected to the frame 2 at a support point 4 for the delivery bottom roller 8. The bearing point 4 has an opening 25, in which a rolling bearing, not shown, of the delivery bottom roller 8 can be arranged. Furthermore, a stationary part of the receptacle 19 and a stationary part of the rotary bearing 21 are provided on the frame 2.

As a component including the support portion 4 of the delivery bottom roller 8, a bearing 26 for the shaft 27 of the delivery top roller 13 is provided. The bearing 26 comprises a sliding guide 28, in which sliding guide 28 the shaft 27 is precisely guided and positioned. Since the sliding guide 28 is fixedly assigned to the frame 2 via the bearing 26 and the bearing point 4, and this frame 2 is fixedly assigned to the receptacle 19, it is ensured that only minor tolerances need to be adhered to, and that the entire delivery roller pair 16 can be positioned in such a way relative to the spinneret 18 that a constant, very small distance is achieved between the delivery roller pair 16 and the spinneret 18. As a result, there is little or no air turbulence during the transport of the fiber strand through the drawing frame 1 and the spinneret 18.

Fig. 4 is a top view of the frame 2 of the previous fig. 1, 2 and 3. The frame 2 is a component of a twin subunit in which two drafting devices 1 are provided on the frame 2. The

bottom rollers

5,6 and 8 of the two drafting devices 1 can be operated independently of one another, since they have separate drives which are independent of one another. The belt 10 (see fig. 1) is arranged, for example, in an interior 29 of the frame 2. The frame 2 also comprises guide rails 30 in which the bearing points 4 of the feed-in bottom rollers 5 and of the middle bottom roller 6 can be moved longitudinally. In this way the mutual distance of the

bottom rollers

5,6 and 8 can be adjusted. Between the guide rails 30 there is a stationary part of the rotary bearing 21 on which the load carrier 20 is supported in a deflectable manner. The load carrier 20 is used to apply a load to the

top rollers

11, 12 and 13 for the two drafting devices 1. The frame 2 also has two bearing points 4 for the two delivery bottom rollers 13, which are fixedly connected to the frame 2. Two receptacles 19 for the two spinnerets 18 are also provided, which correspond to the two drafting devices 1 of the frame 2.

A bearing 26 and a sliding guide 28 are fixedly arranged on each bearing point 4 of the frame 2. The frame 2 thus forms a preferably integral base for the bearing points 4 of the delivery bottom roller 8, which are not movable relative to one another, the receptacle 19, the pivot bearing 21 and the bearing 26 for the delivery top roller 13. This makes it possible to produce these support means very precisely, so that a very close and precisely fitting relationship of the delivery roller pair 16 to the spinneret 18 is achieved.

Fig. 5 is a plan view of the support device for the delivery top roller 13, the frame 2, which is only partially shown here, likewise forming the basis for a twin unit comprising two drafting devices 1 extending in parallel. Two bearing points 4 for the delivery bottom roller 8 are arranged fixedly on the frame 2. The bearing 26 for the delivery top roller 13 and its sliding guide 28 are arranged on the support 4. The slide guide device 28 guides a shaft 27, and the shaft 27 has output top rollers 13 of the draft device 1 at both ends thereof, like the twin rollers 31. Furthermore, a collar 32 is provided on the shaft 27 in the region of each bearing 26. The collar 32 supports the shaft 27 on the bearing 26 and correspondingly positions the twin sub-rollers 31 in the axial direction so that the output top rollers 13 are positioned above their output bottom rollers 8, respectively.

In addition, a retaining spring 33 is provided in the region of the bearing point 4. The retaining spring 33 serves to prevent the twin sub-roller 31 or the output top roller 13 from being accidentally dislodged from its bearing 26. In order to remove the twin roller 31 from the bearing 26, the holding spring 33 needs to be loosened or needs to be bent in such a way that the shaft 27 can be extracted from the bearing 26 and its sliding guide 28.

As can also be seen from fig. 5, the shaft 27 is pressed against its delivery bottom roller 8 by the pressure element 22 of the load carrier 20. In order to achieve a rough positioning of the load carrier 20 relative to the frame 2 and relative to the shaft 27 of the twin sub-roller 31, a widened sliding guide 24 is provided. These sliding guides 24 loop the shaft 27 in a loose manner, so that during the closing of the load carrier 20, in particular the pressure element 22 is normally arranged on the shaft 27.

As can be seen in particular from fig. 5, the shaft 27 and the respective delivery top roller 13 are supported very precisely in the axial and radial directions, as a result of which the gap between the delivery top roller 13 and the spinneret 18 can be kept constantly at a very small level. Thereby ensuring that an excellent spinning result is achieved by the present invention.

Fig. 6 is a side view of the displaceable support of the output top roller 13. The bearing 26 containing the slide 28 is embodied in a manner spaced apart from the bearing point 4 of the delivery bottom roller 8. The separating point is designed as a bearing surface 34, along which bearing surface 34 the bearing 26 can be adjusted relative to the bearing point 4 and thus relative to the spinneret 18. The adjustability is indicated by the double arrow V. After the position has been appropriately adjusted, the bearing 26 is fixedly connected to the support point 4 by means of a screw 35.

In the case of the used output top rollers 13 having different diameters, for example, due to grinding of the surface layer of the output top rollers 13, it may be necessary to adjust the bearings 26. Of course, the bearing 26 can also be fixed directly on the frame 2 in a fixed or movable manner. The bearing surface 34 may be inclined as shown here to allow both horizontal and vertical adjustment. However, it is also possible to achieve only horizontal and/or vertical adjustability by correspondingly forming the bearing surfaces and the attachment of the bearing 26. It is important here that the position of the delivery top roller 13 relative to the spinneret 18 is ultimately optimally adjustable.

Fig. 7 is a plan view of a common movable support for the twin sub-rollers 31 having a common axis 27 (fig. 5). In order to be able to adjust the shaft 27 and thus the two delivery top rollers 13 of the twin sub-unit simultaneously, the two bearings 26 are connected by a web 37. The entire unit can thus be moved in the elongated hole 36 according to the double arrow V and can be fixed by means of a respective screw 35.

The invention is not limited to the embodiments shown and described. Variations within the scope of the claims, and any combination of features shown and described, even in different parts of the description or claims, or in different embodiments, are possible without departing from the principle of the independent claims.

List of reference numerals

1. Drawing device

2. Frame structure

3. Frame

4. Bearing point

5. Input bottom roller

6. Middle bottom roller

7. Leather collar

8. Output bottom roller

9. Motor with a stator and a rotor

10. Transmission belt

11. Input top roller

12. Middle top roller

13. Output top roller

14. Input roller pair

15. Middle roller pair

16. Delivery roller pair

17. Leather collar

18. Spinning nozzle

19. Accommodating part

20. Load carrier

21. Rotary bearing

22. Pressure element

23. Holding element

24. Widened sliding guide device

25. Opening of the container

26. Bearing assembly

27. Shaft

28. Sliding guide device

29. Inner cavity

30. Guide rail

31. Double-roller

32. Collar

33. Retaining spring

34. Bearing surface

35. Screw nail

36. Elongated hole

37. Connecting sheet

Claims

1. A drafting device for drafting a fiber bundle for an air jet spinning machine,

having a frame (2) for the drafting device (1),

and having a plurality of drivable bottom rollers (5, 6, 8),

wherein each lower roller (5, 6, 8) is supported on the frame (2) in a support point (4),

each bottom roller (5, 6, 8) corresponding to a top roller (11, 12, 13), and the bottom and top rollers (5, 6,8, 11, 12, 13) forming a feed roller pair (14), at least one middle roller pair (15) and a delivery roller pair (16),

wherein a load carrier (20) is arranged on the frame (2) in a manner such that it can be deflected in a rotary bearing (21),

the load carrier (20) has a pressure element (22) for applying a load to the top rollers (11, 12, 13) and a holding element (23) for holding and lifting the top rollers (11, 12) during a deflection of the load carrier (20),

an accommodation part (19) for the spinning nozzle (18) is arranged on the frame (2) for arranging the spinning nozzle (18) right behind the delivery roller pair (16),

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

the delivery top roller (13) is supported in a bearing (26) connected to the support region (4) of the respective delivery bottom roller (8), and

the delivery top roller (13) is loaded by the load carrier (20) but is not fixed to the load carrier (20) and remains in the bearing (26) of the delivery top roller during deflection of the load carrier (20).

2. Drafting device according to claim 1, characterised in that the bearing (26) of the output top roller (13) is a sliding guide (28).

3. Drafting device according to one of claims 1 to 2, characterized in that the pressure element (22) is a spring, in particular a leaf spring or a helical spring, or a pneumatic or hydraulic pressure element.

4. Drafting device according to any of claims 1 to 3, characterised in that the load carrier (20) has a sliding guide (24), in particular widened, for the delivery top roller (13).

5. Drafting device according to any of claims 1 to 4, characterised in that the shaft (27) of the output top roller (13) has at least one collar (32) for axial positioning in the bearing (26).

6. Drafting device according to one of claims 1 to 5, characterised in that the shaft (27) of the output top roller (13) is held in the bearing (26) of the output top roller by means of a holding device, in particular a holding spring (33).

7. A drafting device as claimed in any one of claims 1 to 6, characterised in that the drafting devices (1) are arranged in a twin sub-unit in which two drafting devices (1) are provided on the frame (2), the two drafting devices (1) having mutually independent drives, and the two drafting devices (1) being arranged in a substantially mirror-symmetrical manner with respect to one another.

8. Drafting device according to any of claims 1 to 7, characterised in that at least the output top rollers (13) of the two drafting devices (1) are twin sub-rollers (31) constructed with a common axis (27).

9. Drafting device according to one of claims 1 to 8, characterized in that the load carrier (20) jointly loads the top rollers (11, 12, 13) of both drafting devices (1).

10. Drafting device according to one of claims 1 to 9, characterised in that the bearing (26) of the output top roller (13) is arranged in such a way that its position relative to the bearing (4) of the corresponding output bottom roller (8) can be adjusted.

11. Drafting device according to one of claims 1 to 10, characterized in that the bearings (26) of the output top rollers (13) of the twin sub-rollers (31) which are constructed with a common shaft (27) are jointly adjustable.

12. A method for loading and opening a drafting device of an air jet spinning machine having a bottom roller and a top roller (5, 6,8, 11, 12, 13), wherein each bottom roller (5, 6, 8) is assigned to a top roller (11, 12, 13) and the bottom roller and the top roller (5, 6,8, 11, 12, 13) form a feed roller pair (14), at least one middle roller pair (15) and a delivery roller pair (16),

the load carrier (20) can be deflected into an open position or a closed position,

the load carrier (20) applies a load to the top rollers (11, 12, 13) in the closed position thereof and holds and lifts the top rollers (11, 12) in the open position thereof,

and a spinneret (18) for spinning the fiber bundle drafted in the draft device (1) into a yarn is provided right behind the delivery roller pair (16),

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

supporting the output top rollers (13) on the corresponding output bottom rollers (8), and

the delivery top roller (13) is loaded by the load carrier (20) without fixing the delivery top roller (13) on the load carrier (20), so that the delivery top roller (13) remains in the bearing (26) thereof during the deflection of the load carrier (20).