Textile machine for producing roving and method for starting the roving production on a corresponding textile machine

Abstract

A textile machine and associate method are provided for producing a roving, wherein a consolidating means produces a roving having a protective twist from a fiber bundle. A winding device is arranged downstream of the consolidating means in a transport direction of the roving and winds the roving onto a tube driven by a tube drive. An arrangement is disposed to bring the roving leaving the consolidating means during a roving production start procedure into contact with the tube. The arrangement includes a movably mounted suction unit with a suction opening that is configured to suck up the roving during ongoing roving production. Means are provided to bring the roving running between the consolidating means and the suction opening into contact with the tube during ongoing roving production. Means are further provided to cut the roving such that a section of the roving grasped by the suction unit is conveyed away by the suction unit and a section of the roving running between the consolidating means and the tube is wound onto the tube.

Claims

1. A textile machine for producing a roving, comprising: a consolidating means for producing a roving having a protective twist from a fiber bundle; a winding device arranged downstream of the consolidating means in a transport direction of the roving; a tube driven by a tube drive, the winding device configured to wind the roving onto the tube; an arrangement disposed to bring the roving leaving the consolidating means during a roving production start procedure into contact with the tube, the arrangement comprising: a movably mounted suction unit with a suction opening that is configured to suck up the roving during ongoing roving production; means for bringing the roving running between the consolidating means and the suction opening into contact with the tube during ongoing roving production; means for cutting the roving such that a section of the roving grasped by the suction unit is conveyed away by the suction unit and a section of the roving running between the consolidating means and the tube is wound onto the tube; wherein the cutting means comprises a movably mounted cutting unit that is movable from a resting position in which the cutting unit is not in contact with the roving during the start procedure to a cutting position in which the cutting unit comes into contact with and cuts the roving; and wherein in the cutting position, the cutting unit is brought into contact with the tube and presses the roving against the tube surface.

2. The textile machine according to claim 1, wherein the consolidating means comprises an air spinning nozzle, wherein the roving having the protective twist is produced from the fiber bundle by a swirled air flow within the air spinning nozzle.

3. The textile machine according to claim 1, further comprising a draw-off unit arranged downstream of the consolidating means in the transport direction of the fiber bundle to draw off the roving from the consolidating means, wherein the roving, during ongoing roving production, is sucked up by the suction unit after passing the draw-off unit, wherein the roving running between the draw-off unit and the suction opening is brought into contact with the tube during ongoing roving production, and wherein the roving, during ongoing roving production, is cut such that the section of the roving grasped by the suction unit is conveyed away by the suction unit and the section of the roving running between the draw-off unit and the tube is wound onto the tube.

4. The textile machine according to claim 1, wherein the bringing means comprises a traversing unit disposed so as to grasp the section of the roving running between the consolidating means and the suction opening during the start procedure and to move the roving to the tube.

5. The textile machine according to claim 1, wherein the cutting unit comprises a movable cutting arm.

6. The textile machine according to claim 1, wherein the suction unit comprises a suction nozzle that defines the suction opening, the suction nozzle pivotable about a rotation axle that encloses an angle of between 0 and 30 with a horizontal plane.

7. The textile machine according to claim 1, further comprising a control unit in communication with the arrangement.

8. A method for operating a textile machine to produce roving, comprising: at a beginning of a start procedure wherein the roving is produced by a consolidating means of the textile machine during ongoing roving production, the roving is sucked up by a suction unit after leaving the consolidating means; a section of the roving running between the consolidating means and the suction unit is brought into contact with a rotating tube of a winding device; and the roving is subsequently cut such that a section of the roving located in the suction unit after the roving has been cut is conveyed away by the suction unit, and a section of the roving that is located between the consolidating means and the tube is wound onto the tube.

9. The method according to claim 8, wherein the consolidating means comprises an air spinning nozzle and the roving is produced by a swirled air flow inside the air spinning nozzle.

10. The method according to claim 8, wherein, before the roving is cut, the section of the roving running between the consolidating means and the suction unit is transferred from the suction unit to a traversing unit that brings the roving into contact with the tube.

11. The method according to claim 10, wherein the section of the roving running between the tube and the suction unit is subjected to a tension generated at least partially by the suction unit that results in a cutting of the roving between the tube and the suction unit.

12. The method according to claim 10, wherein the roving is cut by a cutting unit that is brought into contact with the roving after the roving has been transferred to the traversing unit and after or during contacting of the roving with the tube.

13. The method according to claim 12, wherein when the section of the roving running between the consolidating means and the suction unit is brought into contact with the tube, a roving delivery speed of the consolidating means during the start procedure is at least 0.8 times the roving delivery speed for normal operation of the textile machine following the start procedure.

14. The method according to claim 13, wherein after the section of the roving running between the consolidating means and the suction unit has been brought into contact with the rotating tube, a circumferential speed of the tube is adjusted such that the section of the roving running between the consolidating means and the tube sags under the effect of gravity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages of the invention are described in the following exemplary embodiments, in which:

(2) FIGS. 1 to 5 show a roving production start procedure according to the invention on a schematically shown textile machine according to the invention, in the form of an air-jet spinning machine, which serves to produce roving, and

(3) FIGS. 6 and 7 show a front view of a suction unit of a textile machine according to the invention, in the form of an air-jet spinning machine, in two different positions.

DETAILED DESCRIPTION

(4) Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

(5) First, it should be expressly pointed out that the air-jet spinning machine that is shown and described as an example of a textile machine according to the invention, as well as the illustrated components thereof, are not shown true to scale. Instead, the individual figures show only schematic diagrams which are intended to illustrate the basic structure of the respective assemblies. In particular, the mutual spacings and spatial relationships between the individual elements may differ from what is shown.

(6) FIGS. 1 to 5 show a schematic view of part of a textile machine according to the invention in the form of an air-jet spinning machine, which serves to produce a roving 1, at different points in time during a roving production start procedure. The air-jet spinning machine may, if necessary, include a drafting system 16 comprising a plurality of corresponding drafting system rollers 17 (only one of the drafting system rollers 17 has been provided with a reference sign for clarity reasons), to which there is fed a fiber bundle 3, for example in the form of a doubled-over draw frame sliver. The illustrated air-jet spinning machine also comprises in principle a consolidating means, spaced apart from the drafting system 16, in the form of an air spinning nozzle 2 having an internal vortex chamber (known from the prior art and therefore not shown) in which the fiber bundle 3 or at least a portion of the fibers of the fiber bundle 3, is provided with a protective twist.

(7) The air-jet spinning machine may also comprise a draw-off unit 4 including preferably two draw-off rollers 18, as well as a winding device 5 for the roving 1 arranged downstream of the draw-off unit 4 (the draw-off unit 4 is therefore not absolutely necessary). The winding device 5 in turn comprises preferably a tube drive 6 and a tube holder 21 connected to the tube drive 6, and is known in principle, by means of which a tube 7 can be fixed and set in a rotational movement by means of the tube drive 6.

(8) The air-jet spinning machine operates according to a special air-jet spinning process. In order to form the roving 1, the fiber bundle 3 is guided in a transport direction T via an inlet opening (not shown) into the vortex chamber of the air spinning nozzle 2. There, it is given a protective twist, that is to say at least a portion of the fibers of the fiber bundle 3 is grasped by a swirled air flow that is created by suitably placed air nozzles. A portion of the fibers is thereby pulled at least a little way out of the fiber bundle 3 and is wound around the tip of a yarn forming element which protrudes into the vortex chamber.

(9) Finally, the fibers of the fiber bundle 3 are drawn out of the vortex chamber via an inlet mouth of the yarn forming element and a draw-off channel arranged inside the yarn forming element and that adjoins the inlet mouth. In doing so, the free fiber ends are finally also drawn on a helical trajectory in the direction of the inlet mouth and wrap as wrapping fibers around the centrally running core fibers, resulting in a roving 1 that has the desired protective twist.

(10) Due to the only partial twisting of the fibers, the roving 1 has a (residual) draftability that is essential for the further processing of the roving 1 in a downstream spinning machine, for example a ring spinning machine. Conventional air-jet spinning devices, on the other hand, give the fiber bundle 3 such a pronounced twist that the required drafting following yarn production is no longer possible. This is also desired in this case since conventional air-jet spinning machines are designed to produce a finished yarn, which is generally intended to be characterized by a high strength.

(11) Before a tube 7 can be wound with roving 1, a start procedure must take place, during which the roving 1 leaving the air spinning nozzle 2 must be brought into contact with the tube 7. One possible start procedure according to the present invention is shown in FIGS. 1 to 5.

(12) Firstly, a fiber bundle 3 is fed into the air spinning nozzle 2 by starting the drafting system 16. The above-described roving production, during which the fiber bundle 3 is given a protective twist, takes place in the air spinning nozzle 2. Finally, the roving 1 leaves the air spinning nozzle 2 via an exit opening 20 (FIG. 7) and is grasped by the air flow of a suction unit 8. The suction unit 8 preferably has a suction nozzle 13 with a suction opening 9, via which air and thus also the roving 1 leaving the air spinning nozzle 2 is sucked up or sucked in. In this stage shown in FIG. 1, therefore, the roving 1 produced by the air spinning nozzle 2 leaves the air spinning nozzle 2 and is sucked into the suction unit 8 via the suction opening 9 (which is located, for example, in the region of the draw-off unit 4 that is preferably present or in the region of the exit opening 20 of the air spinning nozzle 2, cf. FIGS. 6 and 7), wherein the delivery speed of the air spinning nozzle 2 preferably corresponds to the delivery speed prevailing after the start procedure or is only slightly lower (preferably at most 20% lower) than said speed.

(13) In general, it should be noted at this point that the entire start procedure preferably takes place without any break in roving production or roving delivery, that is to say while the drafting system 16 is active, the air spinning nozzle 2 is active and, if present, the draw-off unit 4 is active (that is to say is drawing a roving 1 out of the air spinning nozzle 2), so that a particularly high efficiency of the illustrated air spinning machine can be ensured.

(14) An illustrated control unit 15 is also provided, which is operatively connected to the described elements of the air-jet spinning machine in order to carry out the roving production start procedure according to the invention. The control unit 15 may be present for each spinning position of the air-jet spinning machine. It is also conceivable that one control unit 15 is responsible for a plurality of spinning positions.

(15) In the next step (see FIG. 2), the suction unit 8 is moved (preferably pivoted about a pivot axle or rotation axle 14) into a transfer position in which the suction opening 9 and thus also a section of the roving 1 (which is moreover still being delivered by the air spinning nozzle 2) are located in the region of the tube surface. Contact between the tube 7 and the roving 1 preferably does not yet exist at this stage.

(16) While the suction unit 8 is assuming its position shown in FIG. 2 (or shortly thereafter), the traversing unit 10 is moved into the position shown schematically in FIG. 3, in which the roving 1 is grasped and guided by the traversing unit 10. The traversing unit 10 thereby moves the roving 1 into the vicinity of the tube 7 or brings about direct contact between the tube 7 and the roving 1, during which the roving 1 (preferably under the effect of suitable rough surface sections of the tube 7) is grasped by the tube 7.

(17) At the same time or shortly thereafter, a cutting unit 11 is finally activated, which comprises for example a movable (preferably pivotable) cutting arm 12. The cutting unit 11 is thereby brought into contact with the roving 1, preferably with the section thereof that is located between the traversing unit 10 and the suction opening 9. At this moment, a local decelerating of the roving 1 occurs in the region that comes into contact with the cutting unit 11, so that the roving 1 finally tears between the tube 7 and the cutting element since it continues to be wound up by the rotating tube 7, that is to say has a tension applied to it (see FIG. 4). Due to the tearing of the roving 1, a section of the roving 1 on the suction unit side is obtained, which is conveyed away via the suction unit 8 (the section of the roving 1 that is located in the suction unit 8 after the cutting of the roving 1 is provided with reference number 19 in FIG. 4). A roving section on the air spinning nozzle side is also obtained, which is already grasped by the tube 7 and extends between the air spinning nozzle 2 and the tube 7.

(18) By virtue of the further rotation of the tube 7, the roving 1 still being delivered by the air spinning nozzle 2 is continuously wound onto the tube 7, wherein the traversing unit 10, by virtue of a movement in the direction of the rotation axle of the tube 7 (see arrow C), ensures that the roving 1 is uniformly wound onto the tube 7 (see FIG. 5). At this stage in which the cutting unit 11 and also the suction unit 8 have assumed their original positions, the air-jet spinning machine is finally in its normal operating mode following the start procedure, in which normal operating mode the tube 7 is wound with roving 1 until the desired bobbin size is achieved.

(19) One advantageous embodiment of the suction unit 8 or the suction nozzle 13 thereof is shown in FIGS. 6 and 7, wherein FIG. 6 shows the sucking position (that is to say the position in which the roving 1 is being sucked up after leaving the exit opening 20 of the air spinning nozzle 2cf. FIG. 1) and FIG. 7 shows the transfer position (that is to say the position shown in FIG. 2, in which the roving 1 has been moved into the vicinity of the tube 7) (the roving 1 is not shown in FIGS. 6 and 7).

(20) As can be seen from these figures, it may be advantageous if the suction nozzle 13 of the suction unit 8 is mounted such as to be able to move about a rotation axle 14 which encloses with the horizontal an angle which is other than 0 and is for example between 0 and 30, preferably between 0 and 20, particularly preferably between 0 and 15. The suction nozzle 13 can thus be pivoted obliquely downward in order to position the roving 1 to the side of the tube 7.

(21) The present invention is not limited to the exemplary embodiments that have been shown and described. Modifications within the scope of the claims are also possible, as is any combination of the described features, even if they are shown and described in different parts of the description or the claims or in different exemplary embodiments.

LIST OF REFERENCE SIGNS

(22) 1 roving 2 air spinning nozzle 3 fiber bundle 4 draw-off unit 5 winding device 6 tube drive 7 tube 8 suction unit 9 suction opening 10 traversing unit 11 cutting unit 12 cutting arm 13 suction nozzle 14 rotation axle 15 control unit 16 drafting system 17 drafting system roller 18 draw-off roller 19 section of the roving that is located in the suction unit after the roving has been cut 20 exit opening 21 tube holder T transport direction angle between the rotation axle of the suction nozzle and the horizontal