GB2332214A

GB2332214A - Guiding of fibre sliver through a textile machine

Info

Publication number: GB2332214A
Application number: GB9827251A
Authority: GB
Inventors: Josef Temburg
Original assignee: Truetzschler GmbH and Co KG
Current assignee: Truetzschler GmbH and Co KG
Priority date: 1997-12-13
Filing date: 1998-12-10
Publication date: 1999-06-16
Anticipated expiration: 2018-12-10
Also published as: IT1304157B1; GB2332214B; GB9827251D0; ITMI982664A1; CH693382A5; JPH11241235A; JP4230579B2

Abstract

A guide element (30) for fibre slivers, e.g. at the inlet of a drawing system (2), extends transversely to the direction in which the fibre sliver is being conveyed and has regions of different curvature over its circumference to provide different guiding effects when the element is set in different rotational positions about its axis. The positioning of the element may be under electronic closed-loop control.

Description

1 2332214 Guiding of Fibre Sliver through a Textile Machine The invention

relates to guiding of fibre sliver through a textile machine. More particularly the invention relates to a textile machine including a guide element that extends transversely to the direction in which the fibre sliver is being conveyed, and to a method of guiding fibre sliver through a textile machine.

In a known apparatus, a guide element is in the form of an arc-shaped, deformable element. To alter the width of the fibre sliver, pressure is exerted from both sides on the guide element, so that the shape of the arc is changed. It is a disadvantage that it is difficult to set a uniform (symmetrical) arc shape. To achieve a central-symmetrical arc shape, all applied pressures and constructional features must be completely symmetrical. If the are shape is asymmetrical, the fibre is drawn unevenly into the machine, which, particularly at high operating speeds, leads to uneven processing and consequently to quality loss in production. In addition, installation of the pressure-applying apparatus on both sides is expensive.

It is an object of the invention to produce an improved guiding arrangement and method that overcomes or mitigates at least some of the disadvantages mentioned.

is The present invention provides a textile machine including a guide element for guiding a plurality of fibre slivers over a surface thereof, wherein the guide element has a longitudinal axis extending across the path of the sliver and is rotatable about an axis substantially parallel to its longitudinal axis, the guide element including a plurality of curved guide surfaces angularly spaced around the axis of rotation of the guide element, whereby rotation of the guide element is effective to change the guide surface over which the plurality of fibre slivers are, in use, guided.

The present invention also provides apparatus on a textile machine for guiding a fibre sliver on a guide surface of a guide element that extends transversely to the direction in which the fibre sliver is being conveyed, in which apparatus the guide element is in the form of an arc-shaped element in a plane oriented transversely to the conveying direction of the fibre sliver, and is retained in the set position by way of retaining device, characterised in that at least one guide element is arranged at the inlet to the drawing system of a drawing frame, is in engagement with several slivers and is in the form of an axially rotatable element, the casing surfaces of which have different arc shapes.

Because an axially rotatable guide element having different arc shapes is used, different arc shapes are set in a simple and above all reliable manner. The guide element is simply turned so that a casing surface having a different arc shape engages with the slivers. In this connection, all arc shapes are determined beforehand and can consequently be absolutely symmetrical and exactly of the shape required.

Advantageously, the cross-section of the guide element is in the form of a polygon with rounded edges and surfaces. The cross-section of the guide element is preferably approximately elliptical. The camber of the casing surface is advantageously different. The radius of curvature of the crosssectional area preferably increases and decreases. A driving means, for example, a driving motor, is advantageously associated with at least one end face of the guide element. An indicating device, for example, a graduated disc, is preferably associated with the end face of the guide element. The driving means is advantageously able to turn the guide element through a predetermined distance. A continuously variable adjusting device is preferably associated with the retaining device. The driving means is advantageously connected to an electronic open-loop and closed-loop control system. Preferably the control of the driving means is automatic. Two guide elements arranged in succession in the operating direction are preferably provided, the slivers being in engagement with the respective spreading regions of the casing surfaces 4 thereof. The guide element is advantageously rotatable in at least one direction. The radii of curvature for the different arc shapes of the regions of the casing surfaces may be the same. The midpoints in the axial direction may be arranged eccentrically with respect to one another. The radii of curvature for the different are shapes of the regions different. The midpoints of the casing surfaces may be in the axial direction may be arranged concentrically with respect to one another.

The guide element is preferably in the form of a roller.

The invention still further provides a textile machine including a guide element for guiding a fibre sliver over a surface thereof, wherein the guide element has a longitudinal axis extending across the path of the sliver and is rotatable about an axis substantially parallel to its longitudinal axis, the guide element being shaped such that rotation of the element is effective to change the shape and/or iocation of the surface over which the fibre sliver is, in use, guided.

The invention still further provides a method of guiding fibre slivers through a textile machine in which the fibre slivers pass over a curved guide surface of a guide element, the method including the step of altering the angular position of the guide element to change the curved guide surface of the guide element over which the slivers are guided.

By way of example, certain embodiments of the invention will now be described with reference to the accompanying drawings, of which:

Fig. 1 is a diagrammatic side view of a drawing frame; Fig. 2 is a plan view of part of the drawing frame shown in Fig. 1; Fig. 3 is a perspective view of a guide arrangement for use on the drawing frame of Figs. 1 and 2; Fig. 4a is a front view of a guide element suitable for use in the drawing frame of Figs. 1 and 2 and in roller form; Fig. 4b is a section along the lines I-I through the guide element shown in Fig. 4a; Fig. 5 Fig. 6 is a side view showing a graduated disc with a scale, which is associated with one end face of the guide element of Figs. 4a and 4b; is a side view showing two guide elements arranged one after the other; 6 Fig. 7a is a front view of a guide element having three angularly spaced, discrete, guide surfaces; Is Fig. 7b is a section along the lines II-II through the guide element shown in Fig. 7a; Fig. 8a is a perspective view of another guide element having three angularly spaced, discrete, guide surfaces; Fig. 8b is a section along the lines III-III through the guide element shown in Fig. 8a; Fig. 9a is a front view of a guide element including guide surfaces of different degrees of curvature; Fig. 9b is a front view of another guide element including guide surfaces of different degrees of curvature; and Fig. 10 is a sectional view of a guide element.

According to Fig. 1, a drawing frame, for example of the kind sold by TrUtzschler GmbH & Co. KG as an HSR 7 drawing frame, has a drawing system 2 with an inlet 3 to the drawing system arranged upstream. Slivers 5 coming from cans enter a sliver guide 6 and, drawn by take-off rollers 7, 8, are transported past a measuring 5 element 9. The drawing system 2 is designed as a 4over-3 drawing system, that is, it consists of three bottom rollers I, II, III (I being the bottom delivery roller, II being the middle bottom roller, and III being the bottom feed roller) and four top rollers 11, 12, 13, 14. Drafting of the fibre sliver bundle 5 comprising a plurality of slivers takes place in the drawing system 2. The draft comprises preliminary draft and main draft. The roller pairs 14/111 and 13/11 form the preliminary drafting zone and the roller pairs 13/11 and 11,12/1 form the main drafting zone.

The drawn slivers 5 reach a web guide 10 at the outlet 4 of the drawing system and are drawn by the take-off rollers 15, 16 through a sliver funnel 17, in which they are condensed to form a sliver 18, which is subsequently deposited in cans. The take-off rollers 7, 8, the bottom feed roller III and middle bottom roller II, which are linked mechanically, for example, by means of toothed belts, are driven by the variable speed motor 19, wherein a desired value can be pre-set.

(The associated top rollers, 14 and 13 respectively, are freely rotatable and therefore rotate with the above-mentioned rollers). The bottom delivery roller I and the take-off rollers 15, 16 are driven by the main 8 motor 20. The variable speed motor 19 and the main motor 20 each have their own controller 21, 22 respectively. The control (speed control) is effected by way of a respective closed control loop, a tachogenerator 23 being associated with the variable speed motor 19 and a tachogenerator 24 being associated with the main motor 20. At the inlet 3 of the drawing system, a variable that is proportional to the mass, for example, the cross-sectional size of the in-fed slivers 5, is measured by an intake measuring element 9. At the outlet 4 of the drawing system the crosssection of the emerging sliver 18 is measured by an output measuring element 25 associated with the sliver funnel 17. A central processor 26 (open-loop and closed-loop control system), for example, a microcomputer with microprocessor, sends a setting for the desired value for the variable speed motor 19 to the controller 21. The measured variables of the two measuring elements 9 and 25 are supplied during the drawing operation to the central processor 26. From the measured variables of the intake measuring element 9 and from the desired value for the cross-section for the emerging sliver 18, the central processor 26 determines the desired value for the variable speed motor 19. The measured variables of the output measuring element 25 serve for monitoring the emerging sliver 18 (output sliver monitoring). By means of this control system, fluctuations in the cross-section of - 9 the in-fed slivers 5 can be compensated for by appropriate regulation of the drawing operation, that is to say the sliver 18 can be rendered more uniform. A memory 27 where certain signals of the drawing equipment open-loop and closed-loop control system are stored for evaluation, is associated with the central processor 26 of the machine. The letter A denotes the running direction of the slivers.

At the inlet to the drawing system 2, between the take-off rollers 7, 8 and just before the roller pair 14/111, there is arranged a guide element 30, the casing surface of which engages with the slivers 5 and which is arranged to be rotatable about a longitudinal axis. The guide element 30 is connected to a driving means, for example, a stepping motor 31, which is electrically connected to the processor 26.

Before the slivers 5 enter the drawing system 23, they are guided, as shown in Fig. 2, over the guide element 30. During this, the slivers 5 are spread outwards (from 5a to 5b), viewed across the width. guide element 30 is in the form of a roller, which i rotatably mounted at its end regions 32a, 32b (not visible in Fig. 2) in retaining means 33a, 33b respectively.

As shown in Fig. 3, initially the slivers 5 may be positioned closely side by side beneath a first straight sliver guide rail 34 and then pass over an upwardly curved casing surface 30' of the guide element 30. The slivers 5 may subsequently be placed closely side by side beneath a second straight sliver guide rail 35.

As shown in Fig. 4a, the guide element 30 is in the form of a roller that is rotatable in the direction of arrow B. As shown in Fig. 4b, the arc form of the cambered casing surface 301 has varying radii of curvature r. Reference letter M denotes the point of the end face 30, around which the guide element 30 is rotatable in direction B. Thus reference letter M can also be regarded as showing the axis of rotation of the guide element 30. The guide element can also be rotated in the opposite direction, as illustrated in Fig. 7b, 8b.

Fig. 5 shows a fixed graduated disc 36 with scale, which can be associated with an end face 30, of the element 30. A pointer 37 is mounted on the rotatable end face 301 but is positioned on the outer side of the disc 36. In this way, the position of the guide element 30 can be seen from inspection and, if desired, adjusted manually according to requirement.

position of the guide element 30 can also be i visually by other means, if desired.

In the modified arrangement shown in Fig. 6, two guide elements 30a and 30b arranged in series in the operating direction are provided, the slivers 5 engaging with the respective spreading region of the casing surface 30' of each guide element. In this way, The ndicated - 11 a plurality of combinations for spreading can be set.

Referring now to Figs. 7a and 7b, the convexly curved casing surface of the guide element 30 shown therein has three regions 301, 30'' and 30. As shown in Fig. 7b, the radii of curvature for the three regions 30 1, 30 1 ' and 30' 1 1 are rj, r2, and r3 respectively and are the same in the sectional view shown in Fig. 7b. Furthermore, the axial curvature (the curving as one travels across the element parallel to the longitudinal axis) is the same for each region.

The point equispaced from each of the centres (the midpoint) of the radii of curvature r-, r2, r3 is marked M2. The midpoint M,, marking the axis around which the guide element 30 is rotatable in the directions of arrows B and C, lies (eccentrically) spaced from the midpoint M2. This construction in which each region has the same curvature is advantageous in terms of manufacturing engineering because, for example, one cutter having a concavely curved cutting surface can be 20 used for all three regions 301, 30'' and 30111. The eccentricity of the mounting means that despite the curvatures of the regions 301, 30'' and 30''' being the same the spreading effect on the slivers caused by each of the regions will be different. Figs. 8a and 8b show an alternative arrangement to that of Figs. 7a and 7b. The convexly curved casing surface of the guide element 30 again has three regions 301, 3W' and 30. The radii of curvature ri, r,and - 12 r, r3 for the three regions 301, 30'' and 30111 are in this case all different. The midpoint for the radii of curvature ri, r2 and r3 on the one hand (corresponding to the midpoint M2 in Figs. 7a and 7b), and the midpoint about which the guide element 30 is rotatable in the direction of arrows B and C on the other hand (corresponding to the midpoint M, in Figs. 7a and 7b), is identical and is marked M in Fig. 8b. Despite the identical (concentric) midpoint M, the arc curvatures of the regions 301, 3W' and 30 engaging with the slivers 5 are different and thus the spreading effect on the slivers caused by each of the regions will be different.

In Fig. 9a, it will be seen that the radial is distance (spacing) of the casing surface of the region 30 from the longitudinal axis of rotation defined by the line marked M varies longitudinally; thus the distance a is greater than the distance b. In corresponding manner, the radial distance (spacing) of the casing line of the region 30' from the longitudinal axis of rotation defined by the line marked M also varies but in a different way; thus the distance c is less than the distance d. By that means, an arcuate form (camber) is brought about in an axial direction, as a result of which the intended spreading of the slivers occurs. Fig. 9b shows a construction as in Fig. 9a but in which (like the arrangement of Figs. 7a and 7b) the axis of rotation of the guide element 13 - (marked by reference numeral 32 in Fig. 9b and by reference letter M, in Fig. 7b) and the axis containing the point equispaced from each of the centres of curvature of the surface regions (marked by reference letter M in Fig. 9b and by reference letter M2 in Fig. 7b) are arranged eccentrically with respect to one another.

In the arrangement shown in Fig. 10, the radii r2 and r3 are of equal length but, even though they intersect at the common midpoint M2. they do not originate at the midpoint M2. that is, they have no common point of origin. As a result of the fact that the midpoint M, of the axis of rotation of the guide element 30 is arranged eccentrically with respect to the midpoint M2 (compare Fig. 9b), the spacing, on axial rotation in operation, between the outer casing surface region 301, 301' and 30 and the axis of rotation will be different and, with that, the spreading in the lateral direction will be different.

From the description above referring to Figs. 7a,

7b, 8a, 8b, 9a, 9b and 10, it will be understood that there are a range of options for the nature of the variation of one surface region from another. Some of those options are listed below:

(i) each surface region may be spaced by a different amount from the axis of rotation of the guide element (the spacing being measured in a plane 14 perpendicular to the axis of rotation and midway between the ends of the element).

(ii) each surface region may have a different curvature about a longitudinal axis of the guide element 5 ("curvature about a longitudinal axis" being curving along a circumferential path). (iii)each surface region may have a different curvature about an axis generally parallel to the direction of travel of the sliver (referred to above as "camber" and as "axial curvature", and curving along a path parallel to a longitudinal axis of the element).

It will be understood that a mixture or combination of the variations referred to above can be adopted. Also it will be understood that the curvature need not be in the shape of an arc of a circle; other curvatures may be employed.

Claims

1. A textile machine including a guide element for guiding a plurality of fibre slivers over a surface thereof, wherein the guide element has a longitudinal axis extending across the path of the sliver and is rotatable about an axis substantially parallel to its longitudinal axis, the guide element including a plurality of curved guide surfaces angularly spaced around the axis of rotation of the guide element, whereby rotation of the guide element is effective to change the guide surface over which the plurality of fibre slivers are, in use, guided.

2. A textile machine according to claim 1, in which each of the curved guide surfaces is generally convex and curves in a direction along the path of the fibre slivers.

3. A textile machine according to claim 1 or 2, in which each of the curved guide surfaces is generally convex and curves in a direction parallel to the longitudinal axis of the guide element.

4. A textile machine according to any preceding claim, in which the shapes of two or more of the guide surfaces are the same but the distances of said two or more guide surfaces from the axis of rotation of the guide element are different.

5. A textile machine according to any one of claims 1 - 16 to 3, in which the shapes of the guide surfaces are different.

6. A textile machine according to claim 5, in which curvatures of the guide surfaces in a direction along 5 the path of the fibre slivers are different.

7. A textile machine according to claim 5 or 6, in which the curvatures of the guide surfaces in a direction parallel to the longitudinal axis of the guide element are different.

8. A textile machine according to any one of claims 5 to 7, in which the distances of central points of the guide surfaces from the axis of rotation of the guide element are the same.

9. A textile machine according to any one of claims 5 to 7, in which the distances of central points of the guide surfaces from the axis of rotation of the guide element are different.

10. A textile machine according to any preceding claim, in which the cross-sectional shape of the guide element is generally polygonal with each of the sides of the polygon being curved and defining a respective guide surface.

11. A textile machine according to any one of claims 1 to 9, in which the curvature of the exterior of the guide element varies smoothly around the element whereby rotation of the guide element continuously varies the guide surface for guiding the slivers.

12. A textile machine according to any preceding claim, further including drive means for rotating the guide element.

13. A textile machine according to claim 12, in which the drive means is arranged to rotate the guide element through a predetermined angle corresponding to the angular separation between adjacent guide surfaces on the guide element.

14. A textile machine according to claim 12 or 13, further including an electronic control system, the drive means being controlled by the control system.

15. A textile machine according to any preceding claim, further including means for indicating the angular position of the guide element.

16. A textile machine according to any preceding claim, in which two or more guide elements are provided in series along the path of the fibre slivers.

17. A textile machine according to any preceding claim, in which the machine is a drawing frame.

18. A textile machine including a guide element for guiding a fibre sliver over a surface thereof, wherein the guide element has a longitudinal axis extending across the path of the sliver and is rotatable about an axis substantially parallel to its longitudinal axis, the guide element being shaped such that rotation of the eiement is effective to change the shape and/or location of the surface over which the fibre sliver is, in use, guided.

19. A textile machine substantially as herein described with reference to and as shown in the accompanying drawings.

20. A method of guiding fibre slivers through a textile machine in which the fibre slivers pass over a curved guide surface of a guide element, the method including the step of altering the angular position of the guide element to change the curved guide surface of the guide element over which the slivers are guided.

21. Apparatus on a textile machine for guiding a fibre sliver on a guide surface of a guide element that extends transversely to the direction in which the fibre sliver is being conveyed, in which apparatus the guide element is in the form of an arc-shaped element in a plane oriented transversely to the conveying direction of the fibre sliver, and is retained in the set position by way of a retaining device, characterised in that at least one guide element is arranged at the inlet to the drawing system of a drawing frame, is in engagement with several slivers and is in the form of an axially rotatable element, the casing surfaces of which have different arc shapes.

22. Apparatus according to claim 21, characterised in that the cross-section of the guide element is in the form of a polygon with rounded edges and surfaces.

23. Apparatus according to claim 21 or 22, characterised in that the cross-section of the guide element is approximately elliptical.

24. Apparatus according to any one of claims 21 to 23, 19 - characterised in that the camber of the casing surface is different.

25. Apparatus according to any one of claims 21 to 24, characterised in that the radius of curvature of the cross-sectional area increases and decreases convexly.

26. Apparatus according to any one of claims 21 to 25, characterised in that a driving means, for example, a driving motor, is associated with at least one end face of the guide element.

27. Apparatus according to any one of claims 21 to 26, characterised in that an indicating device, for example, a graduated disc, is associated with the end face of the guide element.

28. Apparatus according to any one of claims 21 to 27, characterised in that the driving means is able to turn the guide element through a predetermined distance.

29. Apparatus according to any one of claims 21 to 28, characterised in that a continuously variable adjusting device is associated with the retaining device.

30. Apparatus according to any one of claims 21 to 29, characterised in that the driving means is connected to an electronic open-loop and closed-loop control system.

31. Apparatus according to any one of claims 21 to 30, characterised in that two guide elements arranged in succession in the operating direction are provided, the slivers being in engagement with the respective spreading regions of the casing surfaces.

32. Apparatus according to any one of claims 21 to 31, characterised in that the guide element is rotatable in at least one direction.

33. Apparatus according to any one of claims 21 to 32, characterised in that the radii of curvature for the different arc shapes of the regions of the casing surfaces are the same.

34. Apparatus according to any one of claims 21 to 33, characterised in that the midpoints in the axial direction are arranged eccentrically with respect to one another.

35. Apparatus according to any one of claims 21 to 34, characterised in that the radii of curvature for the different arc shapes of the regions of the casing surfaces are different.

36. Apparatus according to any one of claims 21 to 35, characterised in that the midpoints in the axial direction are arranged concentrically with respect to one another.

37. Apparatus according to any one of claims 21 to 36, characterised in that the guide element is in the form of a roller.