Drafting device for textile machines

Abstract

The present invention relates to a stretching device for a textile machine, the stretching device is particularly used for an air spinning machine, and is used to stretch strip-shaped fiber slivers supplied to the stretching device. The stretching device comprises a plurality of roller pairs arranged front and rear in the travel direction (A) of the fiber slivers, each having an upper roller (3) and a lower roller (4) and a loading mechanism for loading the upper rollers (3) of the plurality of roller pairs, wherein each lower roller (4) is installed and retained in a housing (2) of the stretching device (1), and each upper roller (3) is installed and retained in the housing (2) of the stretching device (1) by means of an upper roller seat (30) that can pivot around a rotation axis. The stretching device (1) also comprises a pivotable loading arm (20) that can be placed in an open position and a closed position, and the loading arm (20) has an individually adjustable loading mechanism (40) for each roller pair, and the loading mechanism loads each pivotable upper roller seat (30) in the loading position when the loading arm (20) is closed.

Description

Technical Field

[0001] The present invention relates to a drafting device for a textile machine, especially an air spinning machine, comprising a plurality of roller pairs arranged one behind the other in the direction of travel of a fiber strip and a loading mechanism for loading the upper rollers of the plurality of roller pairs. Background Art

[0002] Drafting devices for textile machines are already known. They are used to draft a strip of fiber slivers that are fed to the drafting device. In the process, the fibers of the fiber sliver are torn into finer slivers. The basic principle of the drafting device is based on the drafting of the fiber sliver between at least two machine parts or roller pairs that rotate at different circumferential speeds.

[0003] While the bulk of the fiber material is being held by the first, slower roller pair, a portion of the fibers enters between the faster roller pair. This transports the fibers forward and thus produces thinner fiber strands. The capacity of a drafting arrangement consisting of two roller pairs is limited, so a drafting arrangement consisting of multiple roller pairs and so-called aprons is used. The aprons increase the fiber guidance and fiber retention. Such aprons were already described by Fernando Casablancas at the beginning of the 20th century.

[0004] CH683698 describes a drafting device for a spinning frame, which has at least three roller pairs including upper rollers and lower rollers. The lower roller is designed for at least two side-by-side drafting devices with the same drive device. The lower roller is fixed on both sides on an axle and installed in a housing for the two drafting devices. The upper roller is elastically mounted on a loading arm alone in a rotatable support and is arranged on the side of the loading arm. The rotatable support is mounted on an L-shaped support mounted on the loading arm without clearance by means of a support sleeve. This supporting loading arm therefore includes upper rollers for two drafting devices, which are arranged on both sides of the supporting loading arm. The problem with this drafting device is that the uneven loading of the upper roller leads to axially oriented forces acting on the fiber strips. It is also not possible to achieve independent adjustment of the roller pairs for individual spinning positions. In addition, it is not possible to achieve a separate external rotation of the upper roller.

[0005] Another variant of a drafting device for drafting a strip of fiber slivers fed to the drafting device is disclosed by CH712605 and CH713498, wherein the drafting device comprises at least two drafting device modules, which are arranged one behind the other in the conveying direction of the fiber sliver and include a lower roller and an upper roller. Each drafting device module has a separate support on which the upper and lower rollers are mounted. Here, the upper roller is mounted by means of a receptacle in such a way that it can move back and forth between a loading position and an unloading position independently of the rollers of the remaining drafting device modules. Unlike all rollers supported on a support arm supported only on one side by a swivel joint, in this variant the upper rollers are each mounted on their own supporting loading arms. The force transmission cooperation between the upper and lower rollers can be adjusted individually here. However, it is not possible to achieve a complete external rotation of the upper roller alone. Another disadvantage is that the rollers are designed to be loaded on one side, which may result in the axes of the upper and lower rollers not extending in parallel. In the event of a change in loading, this defect must be determined and corrected if necessary.

[0006] EP1431433 describes a drafting device with three roller pairs, in which the upper roller can be lifted from the lower roller. At least one upper roller can be lifted independently of the other upper rollers. For this purpose, the upper rollers are fixed to two supporting load arms. The upper rollers are each held in a guide mechanism of the upper roller yoke and are subjected to spring forces. However, such guide mechanisms are subject to friction, which causes the upper rollers to return to their original position too slowly or only to function poorly after being lifted, due to thick sections in the fiber sliver, roller out-of-roundness, etc. In addition, the upper rollers are subjected to the force of a spring on each side, which makes it almost impossible to achieve an exactly symmetrical force adjustment.

[0007] Drafting devices are also known (DE 10 2019 115 905 A1), in which the upper roller is held laterally by means of two arms. This variant has the disadvantage that the upper roller load is introduced on both sides via two load structures and that the exact adjustment of the load force is difficult, since the two load structures must be adjusted exactly. In addition, lateral visibility and operability may be limited.

[0008] Drafting devices for air-spinning machines have a very high operating speed compared to other spinning machines and therefore have to be stopped individually and immediately, for example, in the event of a yarn breakage in the spinning position. It is therefore advantageous to drive the rollers individually and to be able to immediately and individually switch on the stopped drafting devices as required. Due to the high operating speed, an exact positioning of the rollers with small errors of, for example, up to 2 / 10 mm is advantageous. Such an exact positioning of the rollers is not possible or only barely possible with known drafting devices, or can be achieved at best with very high operating costs. Summary of the invention

[0009] The object of the present invention is to specify a drafting device for drafting a strip-shaped fiber sliver supplied to the drafting device, which also meets the requirements of air-spinning machines and avoids the above-mentioned problems.

[0010] This task is accomplished by a drafting device for a textile machine, in particular an air-spinning machine. The drafting device for drafting a strip-shaped fiber sliver supplied to the drafting device comprises a plurality of roller pairs, each having an upper roller and a lower roller, arranged successively in the direction of travel of the fiber sliver, and a loading mechanism for loading the upper rollers of the plurality of roller pairs. The lower roller is mounted and retained in a housing of the drafting device. The upper roller is mounted and retained in the housing of the drafting device by means of an upper roller seat that can be pivoted around a rotation axis. The drafting device also comprises a pivotable loading arm that can be placed in an open position and a closed position. The loading arm has an individually adjustable loading mechanism for each roller pair, which loads the respective pivotable upper roller seat when the loading arm is closed in the loading position.

[0011] Such a drafting arrangement has many advantages over known drafting arrangements.

[0012] The upper roller is not blocked in the loading arm, but is pivotably mounted in the drafting device housing. Accordingly, the positioning of the lower roller and the upper roller is independent of the loading mechanism, i.e. it is not linked to the positioning of the loading mechanism. The loading arm is only used to load the roller pair and not for positioning and mounting the upper roller. The position of the lower roller and the upper roller can be adjusted easily and independently of the loading. This results in smaller errors in the exact positioning of the rollers relative to each other.

[0013] In addition, each upper roller is loaded individually and its loading can be adjusted individually and / or together. Partial unloading is also possible, for example when the spinning position stops, so that the upper roller drops during the stop, but the fiber is still held by the roller pair.

[0014] The drafting arrangement has overall good accessibility for yarn placement or changing rollers and aprons. Here, the spinning station only has to be stopped and the adjacent spinning station can continue to operate smoothly. Overall, the drafting arrangement is clearly visible from one side. The drafting arrangement is designed in such a way that it is always clearly visible from the same side, so that it can be easily and quickly checked in the inspection circle around the spinning machine.

[0015] The housing of the drafting device is understood to be a load-bearing structure in which parts of the drafting device are directly or indirectly mounted or fixed.

[0016] In several embodiments, the lower rollers can be mounted on lower roller seats fixed in the housing. Generally, a pivotable upper roller seat can be connected to the lower roller seat rotatably around the rotation axis of the upper roller seat. Such a lower roller seat can be moved in the direction of travel of the fiber strip and fixed in a desired position so that the individual lower rollers can be placed in the desired position. As a positioning aid for the rollers, a known backing plate can be used.

[0017] In several embodiments, the rotation axis of the upper roller seat can be arranged behind or before the roller pair in the travel direction of the fiber strip, so that the upper roller seat can be turned outward in the travel direction and opposite to the travel direction. The roller pair can therefore be oriented in such a way that the upper roller remains turnable even when the roller pair is arranged adjacent to each other. The position of the rotation axis and the shape of the upper roller seat can be selected so that the upper roller can be moved basically upward away from the lower roller when turning outward. The roller seat can have a straight, bent or curved shape. Generally, it has a contact surface for the loading mechanism, which extends parallel to the plane of the drafting device.

[0018] In some embodiments, the upper roller shaft of the upper roller can be mounted on both sides in an upper roller yoke mounted on the upper roller seat. The upper roller shaft of the upper roller is thus loaded equally on both sides and a tilting of the upper roller shaft is prevented, even under asymmetrical forces with respect to the roller center.

[0019] The upper roller shaft of the upper roller can be fixed in the upper roller yoke, for example in a corresponding groove of the upper roller yoke, by means of an upper roller locking mechanism. The upper roller locking mechanism can preferably be separated by hand. In this way, a quick tool-free replacement of the upper roller can be achieved. The upper roller yoke can be fixed to the upper roller seat so that it can be moved in the direction of travel of the fiber strip, so that the upper roller can be placed in the desired position relative to the lower roller and can be fixed. In this way, a so-called convexity or retraction of the upper roller relative to the lower roller can be used. A template can also be used here as a positioning aid.

[0020] In several embodiments, the loading mechanism can have a loading element, preferably a pneumatic or spring-loaded loading element, selected from the group consisting of a pneumatic cylinder, an air spring, a spiral spring, a leaf spring, a diaphragm hydraulic cylinder, a diaphragm pressure element and a bellows. The loading element can act on a single roller seat or on a plurality of roller pairs simultaneously.

[0021] In several embodiments, the loading mechanism or loading element can be moved on the loading arm to different positions along the direction of travel of the fiber strip and fixed there, so that the loading point can be placed and fixed in the desired position of the upper roller seat by the loading mechanism. In this way, the loading effect can be optimized. Depending on the position, the lever ratio of the upper roller seat is increased or decreased. The force effect on the upper roller can be adjusted independently in each loading mechanism.

[0022] In some embodiments, the loading mechanism can have a convex loading head, wherein the loading head can be moved to different positions along the travel direction of the fiber strip on the upper roller seat and fixed, so that the loading point of the loading mechanism can be moved to a desired position relative to the upper roller seat and fixed there. The convex loading head can be designed to be hemispherical, dome-shaped or mushroom-shaped.

[0023] In several embodiments, the loading arm can be locked without play in the closed position. For this purpose, a hard stop is preferably provided in the housing of the loading arm.

[0024] In several embodiments, the loading mechanism can be placed in the loading position or the unloading position in the closed position of the loading arm. Here, the loading mechanism of the drafting device can be placed in the loading position or the unloading position individually or in a group.

[0025] In some embodiments, the point of action of the loading by means of the loading mechanism can be offset relative to the center of the upper roller along the upper roller axis. In other words, the point of action of the loading mechanism can be arranged in all roller pairs asymmetrically relative to the center of the upper roller and offset toward the same side along the upper roller axis, thereby improving the one-sided visibility and operability of the drafting mechanism. This improves the same-side visibility and leads to a simpler and faster inspection of the drafting mechanism in the inspection circle around the spinning machine.

[0026] In the drafting device described, the contact force of the roller pairs by means of the loading mechanism can be independently adjusted, since on the one hand the force of the loading element can be controlled and on the other hand the point of action of the loading mechanism on the upper roller carriage can be respectively set to the desired position.

[0027] In addition, one or more upper and / or lower rollers can be wound with aprons, as is known in the prior art. The respective aprons can be guided by one or more additional guides in addition to being guided by the corresponding roller or counter roller.

[0028] Furthermore, the bottom roller can be arranged transversely or on both sides in the drafting arrangement. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be explained in detail with reference to the accompanying drawings and embodiments, in which:

[0030] Figure 1 A schematic side view of the drafting device is shown;

[0031] Figure 2 Show Figure 1 Part of the drafting device;

[0032] Figure 3 A cross-sectional view showing the upper roller suspension with the loading mechanism;

[0033] Figure 4 A detail of a drafting device with a loading mechanism having a movable loading head is shown;

[0034] Figure 5a A loading mechanism with a movable loading head is shown;

[0035] Figure 5b Show Figure 5aDetailed picture of

[0036] Figure 6 A top view showing the loading head; and

[0037] Figure 7 A loading mechanism with loading elements for multiple roller pairs is shown.

[0038] Reference numerals list

[0039] 1 Drafting device

[0040] 2. Drafting device housing (bearing structure)

[0041] 2a Lower roller seat

[0042] 3 upper rollers

[0043] 4 lower rollers

[0044] 20 Loading arm

[0045] 21 Rotation axis of loading arm

[0046] 23 Loading arm locking mechanism

[0047] 24 Stop

[0048] 30 Upper roller seat

[0049] 31 Rotating axis of upper roller seat

[0050] 32 Upper roller yoke

[0051] 33 Upper roller locking mechanism

[0052] 34 Upper roller

[0053] 35 double holes

[0054] 40 Loading mechanism

[0055] 41 Add-ons

[0056] 42 convex loading head

[0057] 43 pins

[0058] A fiber migration direction

[0059] B. Activity of add-on

[0060] C. Mobility of the upper roller yoke

[0061] D Loading head mobility DETAILED DESCRIPTION

[0062] Figure 1The drawing arrangement 1 has a plurality of roller pairs and is suitable in particular for air-spinning machines, where exact positioning and loading of the roller pairs are important due to the high spinning speeds. Figure 2 Show Figure 1 A portion having a roller pair.

[0063] The drafting device 1 comprises a plurality of roller pairs, each having an upper roller 3 and a lower roller 4, arranged one behind the other in the direction of travel A of the fiber strip. In addition, the drafting device can have aprons known from the prior art, not shown here. The lower roller 4 can be mounted in a known manner in the drafting device housing 2 on a bearing seat or a lower roller seat 2a. Generally, its positioning relative to the direction of travel A is adjustable and fixed.

[0064] Each upper roller 3 is respectively fixed to an upper roller seat 30 which can be pivoted about a rotation axis 31. The rotation axis 31 extends parallel to the rotation axis of the roller. The pivotable upper roller seat 30 is connected to the lower roller seat 2a of the bearing seat or the lower roller 4 or the housing of the drafting device. In order to mount the upper roller 3, the upper roller seat 30 can have an upper roller yoke 32, which is connected to the upper roller seat 30. The connection is designed in such a way that the upper roller yoke 32 can be moved relative to the upper roller seat 30 in the travel direction A of the drafting device and can be fixed in the desired position. This allows the upper roller 3 to be positioned precisely relative to the lower roller 4. In particular, the projection or retraction of the upper roller 3 relative to the lower roller 4 can be adjusted in this way. Movability Figure 2 and Figure 4 Indicated by arrow C.

[0065] The upper roller yoke 32 loads the upper roller shaft 34 on both sides, so that a uniform pressing force of the two rollers is achieved.

[0066] The rotation axis 31 of the upper roller seat 30 can also be arranged lower and closer to the rotation axis of the upper roller 3 than shown in the figure. Here, a bent or curved upper roller seat can also be used instead of the straight upper roller seat 30 shown.

[0067] In order to keep the upper roller 4 in the support of the upper roller yoke 32, especially when the upper roller seat 31 is turned outward, an upper roller locking mechanism 33 is provided in the embodiment shown, for example in the form of a leaf spring, which acts on the upper roller shaft 34. It is simply separated by hand, so that the upper roller shaft 34 and the upper roller 4 can be easily removed from the support on the upper roller yoke 32. Other designs of the upper roller locking mechanism 33 are also possible.

[0068] Arranged above the upper roller 4 is a loading arm 20 which is pivotably connected to the drafting stretching device housing 2 via a rotation axis 21. The rotation axis 21 also extends parallel to the rotation axis of the roller. The loading arm 40 can be moved back and forth between an open position and a closed position. In the closed position, the loading arm 40 preferably abuts against a fixed stop 24 and can be fixed in this position by means of a locking mechanism 23, so that it is in a precisely defined position without play in the closed position.

[0069] On the loading arm 20, a loading mechanism 40 is provided for each roller pair. The loading mechanism 40 is used to load the upper roller 3. For this purpose, the loading mechanism 40 has a loading element 41 and a convex loading head 42. The loading element can be designed as a pneumatic or spring-loaded loading element (for example, as a pneumatic cylinder, an air spring, a spiral spring, a leaf spring, a diaphragm hydraulic cylinder, a diaphragm pressure element or a bellows). The loading head 42 ensures a precisely positionable loading action point 40 acting on the upper roller seat 30 by means of the loading mechanism 40. By moving this action point, the loading can be fine-tuned.

[0070] In the embodiment shown, the loading mechanism 40 or the loading element 41 is held movably and fixedly in the loading arm 20 so that it can be fixed in a desired position relative to the upper roller support 30 in the travel direction A of the drafting device. With this movability, the point of action of the loading element 41 relative to the upper roller support 30 or the upper roller 3 can be adjusted in order to achieve a fine adjustment of the pressing force of the upper roller 3 on the lower roller 3 by the lever action of the upper roller support 30. This movability is Figure 2 Indicated by arrow B.

[0071] Figure 3 A cross-sectional view of the aforementioned upper roller suspension with a loading mechanism 40 is shown. An upper roller shaft 34 of the upper roller 4 is mounted in an upper roller yoke 32. The upper roller yoke 32 is movably and fixably mounted on the upper roller seat 30. In the embodiment shown, the protrusion of the upper roller yoke 32 is guided in a guide mechanism of the upper roller seat 30. The upper roller yoke 32 can be fixed with screws. In the same way, the loading mechanism 40 can be connected to the loading arm 20.

[0072] By arranging the loading points of the loading mechanism 40 in all roller pairs asymmetrically relative to the center of the upper roller 3 and offset toward the same side along the upper roller axis 34 , the one-sided visibility and operability of the drafting device are improved.

[0073] Figure 4 A detail of a drafting device with another embodiment of a loading mechanism is shown. Figure 2With the loading mechanism of the present invention, the convex loading head 42 can be fixed to the upper roller seat 31 at different positions along the travel direction A of the drafting device and contacts the loading element 41 with the convex side. The above-mentioned fine adjustment can be achieved by displacement of the loading head 42 (arrow D). This embodiment has the advantage that when the lower roller seat 2a is moved, the loading point of the loading mechanism 40 is not displaced relative to the upper roller seat 31 and does not need to be fine-tuned again.

[0074] Figure 5a An embodiment of a loading mechanism is shown in which a diaphragm hydraulic cylinder is used as a loading member 41. In addition, a convex loading head 42 that can be fixed on the upper roller seat 30 at various positions is shown. Figure 5b Show Figure 5a A larger detailed image of .

[0075] In this variant, the loading head 42 has two pins 43 on the bottom side opposite the convex side, which can be inserted into the double holes 35 in the upper roller seat 30. In order to position the loading head 42 at various positions, the upper roller seat 30 has a plurality of double holes 35 (protrusions) arranged at the same distance. Figure 6 A top view showing the bottom side of the loading head.

[0076] The pins 43 are staggered at 1 / 4 of the distance between the double holes 35 and the axis of the loading head 42. By inserting the loading head 42 into the double holes 35 by rotating it 180° alternately, the number of protrusions can be doubled to the number of the double holes 35. In order to visually check the orientation of the loading head 42, a chamfer can be formed on the socket of the loading head 42.

[0077] The convex side of the loading head 42 is designed to be spherical, dome-shaped or mushroom-shaped, so that the diaphragm of the diaphragm hydraulic cylinder appears to have no hard surface at all. The basic structure of the loading head or the lower roller seat 2a can be slightly moved without having to drive the diaphragm hydraulic cylinder.

[0078] The pin can also be designed to be rectangular or oval, so that an automatic rotation of the loading head 42 is also prevented by only one pin.

[0079] To achieve higher loads, diaphragm cylinders can be designed in an oval or egg shape.

[0080] Figure 7 Different from Figure 5a and Figure 5b 1 shows an embodiment of a loading mechanism 40 with a membrane as loading element 41, which extends over a plurality of roller pairs. The membrane can be designed in the form of a hose or sausage and acts on a loading head 42 of a plurality of roller pairs. The force action can be adjusted independently by positioning the loading head 42 relative to the upper roller seat 30.

Claims

1. A stretching device (1) for a textile machine, the stretching device (1) being used for stretching a strip of fiber slivers supplied to the stretching device, the stretching device (1) comprising a plurality of roller pairs respectively having an upper roller (3) and a lower roller (4) arranged front and rear in the travel direction (A) of the fiber slivers, and a loading mechanism for loading the upper roller (3) of the plurality of roller pairs, wherein: The corresponding lower roller (4) is installed and retained in the housing (2) of the stretching device (1), and wherein the corresponding upper roller (3) is installed and retained in the housing (2) of the stretching device (1) by means of an upper roller seat (30) that can pivot around a rotation axis, characterized in that the stretching device (1) also includes a pivotable loading arm (20), and the loading arm (20) can be placed in an open position and a closed position, wherein the loading arm (20) has an individually adjustable loading mechanism (40) for each roller pair, and the loading mechanism loads the corresponding pivotable upper roller seat (30) in the loading position when the loading arm (20) is closed, and the corresponding upper roller (3) is installed independently of the loading mechanism (40) and the loading arm (20) and can be positioned in the housing of the stretching device (1).

2. The drafting device according to claim 1, characterized in that: Each of the lower rollers (4) is mounted on a lower roller seat (2a) fixed inside the housing (2).

3. The drafting device according to claim 2, characterized in that: The lower roller seat (2a) can be moved along the travel direction (A) of the fiber strip and can be fixed at a desired position.

4. The drafting device according to claim 2 or 3, characterized in that: The pivotable upper roller seat (30) is pivotally connected to the lower roller seat (2a) about a rotation axis (31) of the upper roller seat (30).

5. The drafting device according to claim 1, characterized in that: The rotation axis (31) of the upper roller seat (30) is arranged before or after the roller pair in the movement direction (A) of the fiber strip, so that the upper roller seat (30) can be pivoted outward in the direction of movement (A) accordingly.

6. The drafting device according to claim 1, characterized in that: The upper roller shaft (34) of the upper roller (3) is mounted on both sides on an upper roller yoke (32) fixed on the upper roller seat (30).

7. The drafting device according to claim 6, characterized in that: The upper roller shaft (34) of the upper roller (3) is fixed in the upper roller yoke (32) by means of an upper roller locking mechanism (33).

8. The drafting device according to claim 6 or 7, characterized in that: The upper roller yoke (32) is fixed on the upper roller seat (30) in a manner that allows it to move along the travel direction (A) of the fiber strip, so that the upper roller (3) can be placed and fixed in a desired position relative to the lower roller (4).

9. The drafting device according to claim 1, characterized in that: The loading mechanism (40) has a loading component (41), which is a pneumatic or spring-actuated loading component. The loading component (41) is selected from a pneumatic cylinder, an air spring, a helical spring or a leaf spring.

10. The drafting device according to claim 9, characterized in that: The loading member (41) can be moved and fixed in different positions on the loading arm (20) along the moving direction (A) of the fiber strip, so that the loading point of the loading mechanism (40) can be placed and fixed at the desired position on the upper roller seat (30).

11. The drafting device according to claim 1, characterized in that: The loading mechanism (40) has a convex loading head (42), wherein the loading head (42) is movably fixed on the upper roller seat (30) at different positions along the moving direction (A) of the fiber strip, so that the loading point of the loading mechanism can be placed and fixed at a desired position relative to the upper roller seat (30).

12. The drafting device according to claim 1, characterized in that: The loading arm (20) can be locked without play in the closed position.

13. The drafting device according to claim 1, characterized in that: The loading mechanism (40) is placed in a loading position or an unloading position in the closed position of the loading arm (20).

14. The drafting device according to claim 10, characterized in that: The loading mechanisms (40) of the drafting device can be placed individually or in a group into a loading position or an unloading position.

15. The drafting device according to claim 1, characterized in that: The loading action point of the loading mechanism (40) is offset relative to the center of the upper roller (3) along the upper roller axis (34).

16. The drafting device according to claim 1, characterized in that: The drafting device (1) is used for the drafting device of an air spinning machine.

17. The drafting device according to claim 7, characterized in that: The upper roller locking mechanism (33) can be separated by hand.

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