AUTOLEVELLER DRAW FRAME, METHOD FOR OPERATING AN AUTOLEVELLER DRAW FRAME, AND METHOD FOR CONVERTING AN AUTOLEVELLER DRAW FRAME

Abstract

An autoleveller draw frame includes a drafting system having a plurality of roller combinations. A drive unit configured with the plurality of roller combinations has a main motor that drives a first roller combination at a constant main rotational speed. A regulating motor regulates a rotational speed of a second roller combination wherein, due to the regulation, the rotational speed of the second roller combination is changeable from a basic rotational speed into an autolevelling speed. The basic rotational speed depends on the main rotational speed and the autolevelling speed is independent of the main rotational speed, wherein the drafting of the fibrous web is adjustable. The regulating motor is drive-independent of the main motor to drive the second roller combination at the autolevelling speed according to an electrical signal that is based on the main rotational speed.

Claims

1-13: (canceled)

14. An autoleveller draw frame, comprising: a drafting system having a plurality of roller combinations situated one behind the other for drafting a fibrous web from one or more slivers; a drive unit configured with the plurality of roller combinations, the drive unit comprising: a main motor that drives a first of the roller combinations at a constant main rotational speed; a regulating motor that regulates a rotational speed of a second of the roller combinations, wherein, due to the regulation, the rotational speed of the second roller combination is changeable from a basic rotational speed into an autolevelling speed, the basic rotational speed depending on the main rotational speed and the autolevelling speed being independent of the main rotational speed, wherein the drafting of the fibrous web is adjustable; and the regulating motor being drive-independent of the main motor to drive the second roller combination independently of the main motor at the autolevelling speed according to an electrical signal that is based on the main rotational speed.

15. The autoleveller draw frame according to claim 14, wherein the drive unit comprises a speed sensor that detects the main rotational speed of the first roller combination or rotation of the main motor.

16. The autoleveller draw frame according to claim 15, wherein the drive unit comprises a transmission unit that transforms a signal from the speed sensor into a signal for the basic rotational speed of the second roller combination.

17. The autoleveller draw frame according to claim 14, further comprising a pair of scanning rollers that detect a thickness of the slivers entering the drafting system.

18. The autoleveller draw frame according to claim 17, further comprising a specification unit electrically connected to the pair of scanning rollers, the specification unit setting a superimposition speed for the basic rotational speed based on the thickness of the slivers.

19. The autoleveller draw frame according to claim 18, wherein the drive unit further comprises a control unit configured with the regulating motor, the control unit calculating the autolevelling speed from the superimposition speed and the basic rotational speed.

20. The autoleveller draw frame according to claim 19, wherein the autolevelling speed is transmitted to the regulating motor as an electrical signal.

21. The autoleveller draw frame according to claim 14, wherein the main motor comprises an induction motor and the regulating motor comprises a reluctance motor.

22. A method for operating an autoleveller draw frame, wherein the autoleveller draw frame includes: a drafting system having a plurality of roller combinations situated one behind the other for drafting a fibrous web from one or more slivers; a drive unit configured with the plurality of roller combinations, the drive unit comprising: a main motor that drives a first of the roller combinations at a constant main rotational speed; a regulating motor that regulates a rotational speed of a second of the roller combinations, wherein, due to the regulation, the rotational speed of the second roller combination is changeable from a basic rotational speed into an autolevelling speed, the basic rotational speed depending on the main rotational speed and the autolevelling speed being independent of the main rotational speed, wherein the drafting of the fibrous web is adjustable; and the method comprising driving the regulating motor independent of the main motor to drive the second roller combination independently of the main motor at the autolevelling speed on the basis of an electrical signal that is based on the main rotational speed.

23. A method for converting an autoleveller draw frame from an initial configuration to a final configuration, the initial configuration including: a drafting system having a plurality of roller combinations situated one behind the other for drafting a fibrous web from one or more slivers; a drive unit configured with the plurality of roller combinations, the drive unit including: a main motor for driving a first of the plurality of roller combinations at a constant main rotational speed; a differential gear that transmits a rotational speed of the main motor to a second of the plurality of roller combinations such a basic rotational speed of the second roller combination depends on the main rotational speed of the first roller combination; and a superimposition motor that superimposes a superimposition speed on the basic rotational speed by means of the differential gear such that, due to the superimposition, a rotational speed of the second roller combination is changeable from the basic rotational speed into an autolevelling speed; the method comprising: removing the differential gear from the drive unit; replacing the superimposition motor with a regulating motor that is drive-independent of the main motor; and wherein the regulating motor drives the second roller combination independently of the main motor at the autolevelling speed on the basis of an electrical signal that depends on the main rotational speed.

24. The method for converting an autoleveller draw frame according to claim 23, wherein at least one drive element or output element of the differential gear is reused as a transmission element of the regulating motor.

25. The method for converting an autoleveller draw frame according to claim 23, further comprising removing a mechanical or electromagnetic brake of the drive unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Further advantages of the invention are described in the following exemplary embodiments, wherein:

[0033] FIG. 1 shows a schematic view of an autoleveller draw frame according to the prior art, and

[0034] FIG. 2 shows a schematic view of an autoleveller draw frame according to the invention.

DETAILED DESCRIPTION

[0035] In the following description of the alternative exemplary embodiments represented in the figures, the same reference signs are utilized for features that are identical or at least comparable in terms of their configuration and/or mode of operation. Provided the features are not described in detail again, their design and/or mode of operation correspond/corresponds to the design and mode of operation of the above-described features. For the sake of greater clarity, reference signs for previously described components have not been individually included in the figures.

[0036] FIG. 1 shows a schematic view of an autoleveller draw frame 1 according to the prior art. In the autoleveller draw frame 1, one or multiple supplied sliver(s) 2 is/are evened out and drafted and, thereafter, deposited in a can (not shown here), in a known way. The slivers 2 are supplied to a drafting system 4 via a pair of scanning rollers 3. It is also possible that the slivers 2, before being supplied to the pair of scanning rollers 3, are condensed to form one sliver 2 by means of a condenser (not shown here). The drafting system 4 includes multiple roller combinations 6, 6, 6, which are situated one behind the other. The roller combinations 6, 6, 6 are designed to draft a fibrous web 7, which is formed from the at least one sliver 2.

[0037] The roller combinations 6, 6, 6 can be formed as roller pairs having two rollers or as a roller combination having three rollers. In the exemplary embodiment shown, three roller combinations 6, 6, 6 are present in the form of an input roller combination 6, a middle roller combination 6 and an output roller combination 6.

[0038] The input roller combination 6 and the middle roller combination 6 form a pre-drafting field. The middle roller combination 6 and the output roller combination 6 form a main drafting field. All roller combinations 6, 6, 6 are driven by a drive unit 8.

[0039] The output roller combination 6 in the exemplary embodiment shown is driven as the first roller combination 6 at a constant rotational speed by means of a main motor 9 of the drive unit 8. The output roller combination 6 rotates at a constant main rotational speed. The input roller combination 6 and the middle roller combination 6 are formed as a second roller combination 6, 6, respectively, and are regulated.

[0040] As described above, the exemplary embodiment from FIG. 1 is the autoleveller draw frame 1 according to the prior art, in which a differential gear 10 transmits the rotational speed of the output roller combination 6 to the input roller combination 6 and to the middle roller combination 6 such that a basic rotational speed of the input roller combination 6 and of the middle roller combination 6 depends on the main rotational speed of the output roller combination 6. The differential gear 10 can be formed, for example, as a planetary gear.

[0041] The differential gear 10 includes a first drive element 11, a second drive element 12 and an output element 13. A constant rotational speed is introduced by the main motor 9 by means of the first drive element 11. By means of this constant rotational speed, the input roller combination 6 and the middle roller combination 6 can be driven at the basic rotational speed. A superimposition speed can be introduced by a superimposition motor 14 by means of the second drive element 12. Due to the superimposition speed being superimposed on the basic rotational speed, the input roller combination 6 and the middle roller combination 6 can be driven at an autolevelling speed. The autolevelling speed is thus essentially the sum of the basic rotational speed and the superimposition speed. For this purpose, the input roller combination 6 and the middle roller combination 6 are connected to the output element 13.

[0042] Different rotational speeds can be achieved by means of different drive shafts of the roller combinations 6, 6, 6, as a result of which the basic rotational speed and/or the autolevelling speed of the regulated roller combinations 6, 6 can differ from one another. Additional gear stages and/or belt drives can also lead to the individual roller combinations 6, 6, 6, as a result of which the rotational speeds can differ.

[0043] Changing the superimposition speed and, as a result, the levelling speed, allows the draft of the fibrous web 7 to be adjustable and changeable. Changing the autolevelling speed therefore results, in particular, in a change in the main draft from the middle roller combination 6 to the output roller combination 6. The thickness of the incoming slivers 2 is detected by the pair of scanning rollers 3. The pair of scanning rollers 3 is electrically operatively connected to a specification unit 15, which specifies the superimposition speed for the superimposition motor 14 and/or determines this from the thickness of the sliver 2. The specification unit 15 is also electrically operatively connected to the superimposition motor 14.

[0044] In addition, the drive unit 8 has a brake 16 in the area of the differential gear 10 or between the differential gear 10 and the superimposition motor 14, which can, in particular, completely decelerate the superimposition motor 14 and/or the second drive element 12. In this way, the current rotational speed of the input roller combination 6 and of the middle roller combination 6 can be decelerated toward the basic rotational speed as quickly as possible.

[0045] It is also pointed out that the view of the drive unit 8 from FIG. 1 and also of the following FIG. 2 are highly simplified models. The belt drives or the drive elements, output elements and transmission elements are shown purely schematically at the main motor 9, at the superimposition motor 14, at the differential gear 10, at the pair of scanning rollers 3 and at the roller combinations 6, 6, 6.

[0046] FIG. 2 shows a schematic view of an autoleveller draw frame 1 according to the invention. In comparison to the exemplary embodiment from FIG. 1 according to the prior art, among other things, the differential gear 10 has been removed and the superimposition motor 14 has been replaced by a regulating motor 17, which is drive-independent of the main motor 9 such that the regulating motor 17 drives the input roller combination 6 and the middle roller combination 6 independently of the main motor 9 at the autolevelling speed on the basis of an electrical signal 18, which depends on the main rotational speed. The regulating motor 17 is preferably in the form of a reluctance motor. The main motor 9 is preferably in the form of an induction motor, and so this is driven at a constant rotational speed.

[0047] A speed sensor 19 for detecting the rotational speed of the main motor 9 and/or of the output roller combination 6 is arranged in the area of the main motor 9 and/or of the output roller combination 6 of the autoleveller draw frame 1 according to the invention. The speed sensor 19 is electrically operatively connected, for example, by means of transmission lines, to a transmission unit 20, which converts the detected rotational speed into the basic rotational speed of the input roller combination 6 and/or of the middle roller combination 6 or into the rotational speed of the regulating motor 17 required therefor.

[0048] In addition, the drive unit 8 of the autoleveller draw frame 1 according to the invention, in the exemplary embodiment shown in FIG. 2, includes a control unit 21, which can calculate or control the autolevelling speed of the regulating motor 17. For this purpose, the control unit 21 is electrically operatively connected to the specification unit 15, to the transmission unit 20 and to the regulating motor 17. The control unit 21 calculates the autolevelling speed on the basis of the basic rotational speed from the transmission unit 20 and on the basis of the superimposition speed from the specification unit 15. The specification unit 15 is preferably reused from the autoleveller draw frame 1 according to the prior art.

[0049] When converting the autoleveller draw frame 1 according to the prior art (FIG. 1) into the autoleveller draw frame 1 according to the invention (FIG. 2), preferably at least one of the drive elements 11, 12 and/or one of the output elements 13 of the differential gear 10 is/are reused as the transmission element 22 of the regulating motor 17. The transmission element 22 transforms the rotational speed of the regulating motor 17 such that the input roller combination 6 and the middle roller combination 6 are driven at the autolevelling speed. The autolevelling speed of the input roller combination 6 and of the middle roller combination 6 can also differ from each other in the exemplary embodiment from FIG. 2. In the present exemplary embodiment, the second drive element 12 of the differential gear 10 has been reused as the transmission element 22 of the regulating motor 17. Due to the reuse of the second drive element 12 as the transmission element 22 of the regulating motor 17, the permanent gear ratios (according to FIG. 1) used in the autoleveller draw frame 1 having the differential gear 10 and the superimposition motor 14 can be very easily adapted to the autoleveller draw frame 1 having the independent regulating motor 17.

[0050] The present invention is not limited to the represented and described exemplary embodiments. Modifications within the scope of the claims are also possible, as is any combination of the features, even if they are represented and described in different exemplary embodiments.

LIST OF REFERENCE SIGNS

[0051] 1 autoleveller draw frame [0052] 2 sliver [0053] 3 pair of scanning rollers [0054] 4 drafting system [0055] 6, 6, 6 roller combinations [0056] 7 fibrous web [0057] 8 drive unit [0058] 9 main motor [0059] 10 differential gear [0060] 11 first drive element [0061] 12 second drive element [0062] 13 output element [0063] 14 superimposition motor [0064] 15 specification unit [0065] 16 brake [0066] 17 regulating motor [0067] 18 electrical signal [0068] 19 speed sensor [0069] 20 transmission unit [0070] 21 control unit [0071] 22 transmission element