Unit for feeding and pre-treating the fibrous material fed to a textile machine, particularly for openers or cotton carders

Abstract

 The opening and pre-feed roller (11) is equipped with a first (18) and a second (19) toothed clothing of helical development. They are disposed adjacently and in such a way that the respective teeth (24, 25) have opposed inclination, and enable the fibres to be processed to be uniformly fed to the machine in the form of a pad of well opened flakes.

Description

[0001] The object of the present invention is a unit for pre-treating and feeding textile material in flakes to a textile machine, particularly to an opener or a cotton carder. The present invention may also be usefully applied in other textile machines for treating flake material.

[0002] The feed and pre-treatment units for textile machines and in particular for cotton carders comprise one or more feed rollers, known as lickers-in, which cooperate with a feed plate and with a treatment roller. The function of the said elements is uniformly to feed the fibres to be processed in the form of a pad, in addition to that of carrying out a pre-treatment of opening and cleaning the flakes. The fibres in flake form are taken by the feed unit from a condensation tank above, into which they are loaded substantially in bulk.

[0003] According to the clothing of their treatment roller, the feed and pre-treatment units of the prior art which are suitable for carrying out these functions belong to two characteristic types.

[0004] The first type provides to equip the feed roller with a toothed clothing formed by a plurality of parallel toothed annular portions. In the feed rollers of this type (commonly described as having no start) each tooth follows the path of the tooth which precedes it and always engages the material to be treated at the same point at which the teeth which precede it have engaged it and at which the teeth which follow it will engage it. Each tooth therefore has the same axial coordinate as the tooth which precedes it.

[0005] The mass of fibres processed by a roller of this kind is fed and pre-treated in a rather irregular manner, it tends to dispose itself randomly along the surface of the roller and has an unsatisfactory degree of opening of the flakes.

[0006] In order to improve the uniformity of the feed to the carder of the fibres to be processed in the form of a pad and to limit the drawbacks due to the random fluctuation of the fibrous mass being processed, from the prior art it is known to use feed and pre-treatment units in which the toothed clothing develops in spiral form on the feed roller. The cylinders or rollers of the said feed and pre-treatment units, which are commonly known as single-start feed cylinders, belong to a second type of feed rollers. Within this second type of rollers, those which are spiral-wound, they differ according to the extent of the angle of engagement or impact of their teeth with the material, or whether the tooth is inclined in the direction of movement or in the opposite direction according to the direction of rotation of the cylinder.

[0007] To illustrate these different configurations more satisfactorily, reference is made to the accompanying Fig. A which shows the two possibilities of inclination, with respect to the movement, of the adjacent teeth 1 of a feed cylinder denoted by 2.

[0008] If the cylinder 2 rotates anticlockwise (arrow "F"), it encounters the fibrous material with the surface 7, inclined according to the angle "α" of engagement or impact with the material which has a value between zero and 90° inclusive. Angle "α" thus varies in the range 0≤ α <90°. The angle "α" is geometrically included between the radial plane 3 and the plane 6 of the engagement surface 7. From the mechanical point of view "α" is an angle external to the tooth in that the phenomena of the impact and the cut are external to the tooth. The plane 3 is the radial plane which contains both the cutting edge 4 (generally cutting edge 4) and the axis of rotation 5 of the feed cylinder 2. 'Cutting edge' is intended to mean the contour or the point of the tooth which first encounters the fibrous material which moves tangentially to the feed cylinder which rotates about its own axis. The plane 6 is the plane which contains the cutting edge 4 and is tangential to the engagement surface or to the face 7 of the tooth 1.

[0009] The face of the tooth and the surface on which the portion of material removed by the penetration and cutting action exerted by the tooth in the fibrous material slides.

[0010] Still with reference to rotation according to arrow "F", the angle "β" is the angle of disengagement or withdrawal of the tooth with respect to the material.

[0011] The angle "β" is geometrically included between the plane 3 and a plane 8 and has a value in the range 90° ≤ β < 180°. The plane 8 is the plane which includes the cutting edge 4 and is tangential to the back 9 of the tooth 1. From the mechanical point of view (of the phenomenon of disengagement or of withdrawal of the tooth from the fibrous material) the angle "β" cannot be other than an angle external to the tooth. The clothing described thus far corresponds to a first class of toothing for spiral-wound clothings, the one constituted with the tooth 1 inclined towards the direction of rotary movement F.

[0012] In contrast, in the case in which the rotation of the feed cylinder is clockwise (arrow "G"), there is a second class of toothing for spiral-wound clothings, the one which has the tooth 1 inclined in the direction opposite to the direction of the rotary movement G. In this case the cutting edge is still denoted by 4 but the angle "β" becomes the angle of engagement and the angle "α" becomes the angle of disengagement of the tooth.

[0013] The face and the back of the tooth are reversed.

[0014] Experience shows that the two classes of toothing described thus far for spiral-wound clothings behave in different ways. Where the direction of rotation is anticlockwise (arrow "F", Fig. A) or the angle of engagement "α" is between zero and 90° inclusive, the fibres taken by the feed cylinder 11 (class one toothing for spiral-wound clothings) from the machine's condensation tank above, and for the entire stretch guided by the plate opposite the feed cylinder, the fibres in flake form undergo a good preliminary take-up, opening and cleaning action but are not fed to the subsequent treatment roller 13 in a homogeneous and constant manner. The irregular delivery of the moving fibrous mass causes an irregular count of the pad of carded fibres which has a negative influence on the quality of the sliver produced by the carder. Now considering its behaviour in the phase of transfer of the pad to the next roller, at the end of the guide opposite the feed roller, this class of clothing easily releases the pad of fibres to the points of the next cylinder but does not satisfactorily control the mass of the pad released because it easily slides along the face of the tooth.

[0015] Where the direction of rotation is clockwise (arrow "G", Fig. A) or the angle of engagement "β" is greater than 90°, the fibres taken by the feed cylinder (class two toothing for spiral-wound clothings) from the machine's condensation tank above, and for the entire stretch guided by the plate opposite the feed roller, are not handled as effectively by the clothing teeth of the feed roller with respect to the opposed feed plate.

[0016] The result of this less effective take-up is a feed of the fibrous material to the next treatment roller 13 which is homogeneous and constant but a further result is the drawback of the reduction of the intensity of the preliminary cleaning and opening action which sends to the carder a material which is more tangled and less clean, which has a negative influence on the quality of the product of the carder.

[0017] Considering now its behaviour in the phase of transfer of the pad to the next roller, at the end of the guide opposite the feed roller, this second class of clothing tends to retain more greatly and release less easily the pad of fibres to the points of the next cylinder, but it controls the mass of the pad released much better because it is accompanied for a longer period because of the inclination of the face of the tooth.

[0018] The last clothing described above corresponds to the second class of toothing, the one in which the tooth 1 is inclined in the direction opposite to the direction of the rotary movement G.

[0019] The object of the present invention is therefore to improve the characteristics of the feed and pre-treatment unit, so as to overcome or reduce the disadvantages of the prior art, or a feed and pre-treatment unit capable of producing a constant feed of a pad which is uniform and formed of flakes which have already been efficiently opened and cleaned in the pre-treatment.

[0020] In these conditions the subsequent carding is carried out starting with a semi-processed product in the form of a pad which already has satisfactory textile properties or has a count which is substantially constant and an appreciable degree of opening of the fibres.

[0021] According to the present invention, these objects are achieved by a feed and pretreatment unit according to Claim 1, to which reference should be made for reasons of brevity.

[0022] According to the present invention, the contemporaneous presence on the same feed cylinder of two parallel helical clothings, having, alternately, one with teeth inclined in the same direction as the rotation of the cylinder and the other with teeth inclined in the direction opposite to the rotation of the cylinder, or, respectively, one having angles of engagement substantially between 0 and 90° inclusive and the other substantially greater than 90°, permits a substantial improvement in the quality of the pad obtained.

[0023] This effect may be attributed to the fact that on the one hand, the part of the helical clothing provided with teeth having an angle of impact greater than 90° is less aggressive and exerts a limited take-up and stretching action on the fibres, but permits a potentially homogeneous distribution of the said fibres on the work surface of the cylinder, promoted by the helical structure of both the clothings. At the same time the helical clothing provided with teeth having an angle of impact between zero and 90° inclusive is more aggressive and exerts a holding action of the fibres which is sufficiently forceful with respect to the feed plate, promoting the opening and preliminary cleaning of the fibres in flake form.

[0024] The geometrical properties of the teeth of the clothings, such as form, height, pitch as specified in the dependent Claims contribute to an increase in the efficiency of the embodiments of the invention in view of other operating parameters such as: quality and nature of the raw material to be treated (cotton or wool for example), temperature and ambient humidity.

[0025] The invention is illustrated by way of non-exhaustive example with the aid of Figs. 1 and 2 which refer to a typical embodiment thereof.

[0026] Figure A is a partial view of a known feed cylinder to illustrate the structural parameters of a toothed clothing.

[0027] Figure 1 is a diagrammatic sectional view of the entire feed and pre-treatment unit 10 according to the invention with the subsequent treatment roller 13, which in the specific case is shown as an opener roller with straight teeth but may also be a carder cylinder.

[0028] Figure 2 shows a detail of the feed unit 11 according to the invention with the clothing formed with teeth 18 and 19 of alternate inclination.

[0029] The feed and pre-treatment unit 10 according to the invention essentially comprises, in the path of the fibres to be treated, a feed cylinder 11, a feed plate 12 and an opener roller 13. They are operated conventionally with motors which are not shown herein for reasons of simplicity. The feed cylinder 11 essentially comprises a cylindrical body 14 equipped with support pins 16 in rotation and the lateral surface 17 is equipped with two alternating spiral wrappings, one according to a first clothing 18 with teeth inclined in one direction and a second clothing 19 with teeth inclined in the opposite direction.

[0030] Both clothings have helical development and are disposed adjacently so that the respective starts are separate. They may be alternated according to a one to one, two to one, two to two etc. arrangement, notwithstanding the criterion of having - in the case of rotation according to arrow F - adjacent spirals of teeth 24 which are more aggressive, to take up and stretch the fibrous material, and teeth 25 which are less aggressive and promote the distribution of the material over the entire surface of the cylinder and supply a pad which is more regular and well distributed.

[0031] Reversing the direction of rotation and causing the cylinder to rotate according to arrow G, the more aggressive teeth would then be teeth 25 while the less aggressive teeth would be teeth 24.

[0032] In the case of rotation according to F, the angle of impact α₁ of the teeth 24 of the toothing of the first clothing 18 is 0° ≤ α₁ < 90°, whereas the angle of impact β₂ of the teeth 25 of the toothing of the second clothing 19 is 90° ≤ β₂ < 180°. The angle of withdrawal of the first teeth 24 has been denoted by β₁ while the angle of withdrawal of the second teeth 25 has been denoted by α₂. As long as the feed cylinder 11 rotates clockwise, denoted by the arrow F, the angles α₁ and β₂ are, respectively, the angles of engagement of the teeth 24 and 25 respectively of the first and the second clothing and the angles α₂ and β₁ are the withdrawal angles.

[0033] If, in contrast, the feed cylinder 11 rotates anticlockwise, denoted by the arrow G, the angles α₂ and β₁ are, respectively, the angles of engagement of the teeth 25 and 24 of the second 19 and of the first 18 clothing and the angles α₁ and β₂ are the withdrawal angles.

[0034] If it is intended to simplify the structure of the feed cylinder 11 and render it more economical, the clothings may be produced preferably from identical toothed belts coupled and alternated with opposing inclinations and then by applying them by wrapping and fixing to the base cylinder 11, by welding or brazing for example. The teeth 24 of the first toothed clothing 18 are specularly identical to the teeth 25 of the second toothed clothing 19 which alternate in spiral manner. The pitch 26 of the teeth 24 of the first type of clothing 18 is thus -also equal to the pitch 26A of the teeth 25 of the second type of clothing 19.

[0035] Fig. 2 shows an illustration of an embodiment in which, in order to increase the processing efficiency, the teeth 24 of the first clothing wrapping 18 and the teeth 25 of the second clothing wrapping 19 are disposed on the surface 17 of the feed cylinder 11 reciprocally staggered by half the value of their pitch 26, 26A. Different arrangements with different pitches are, however, possible.

[0036] In the case of application to the cotton carder the pitch 26, 26A is between 4 and 7 mm inclusive, preferably between 4.5 and 6 mm. The distance between the adjacent wrappings 18, 19 is kept in excess of the pitch 26, 26A existing between the teeth 24 and 25 of the said clothings 18 and 19. Generally speaking this distance between the alternate and adjacent wrappings of the first (18) and the second (19) clothing is between 1 and 20 mm inclusive and preferably between 3 and 8 mm.

[0037] The clothings 18, 19 have a helical development in agreement with the intended direction of rotation of the feed cylinder 11 and are applied to the surface 17 of the feed cylinder 11 in per se known manner. By way of indication they may be applied with forced insertion of the clothing in a thread of the cylinder with a groove of the dimension of the shape of the clothing, or by simple spiral wrapping and subsequent welding or braze welding.

[0038] The feed plate 12 comprises a first portion 20 of concave frontal surface facing the working surface 17 of the feed cylinder 11 and a second portion 22 of frontal surface tangential to the treatment carder roller 13.

[0039] By way of example, the treatment roller 13 is equipped with needles 23 distributed in four lines disposed at 90° along the lateral surface of the roller. The needles 23 cooperate both with the teeth 24, 25 of the feed cylinder 11 and with the second portion 22 of frontal surface of the feed plate 12.

[0040] During operation the fibrous material in flake form is taken by the feed unit 10 from a condensation tank 27 above, into which the fibres are loaded in bulk. The material slides downwards due to the action applied by the feed cylinder 11 which rotates anticlockwise and processes it with the collaboration of the first portion 20 of the frontal surface of the feed plate 12. The needles 23 of the treatment roller 13 take the material from the teeth 24 and 25 of the clothing of the cylinder 11 and process it with the collaboration of the second portion 22 of the frontal surface of the feed plate 12.

[0041] The treatment roller preferably rotates anticlockwise.

[0042] When the material being processed on the roller 13 is no longer supported by the containment surfaces which surround it, it leaves the treatment roller 13 also due to the combined action of centrifugal force, gravity, and due to the effect of a current of air which passes into the interspace between plate 12 and the containment pan.

Claims

1. Unit for pre-treating and feeding (10) textile material in flake form to a textile machine, particularly to an opener or to a cotton carder, comprising a feed cylinder (11), a feed plate (12) and a treatment roller (13), in which the said feed cylinder (11) is equipped with pins (16) in rotation and the surface thereof (17) is equipped with a clothing of teeth, characterized in that the clothing of teeth of the feed cylinder (11) comprises a first clothing (18) with teeth inclined in one direction and a second clothing (19) with teeth inclined in the opposite direction, the said clothings being alternately spiral-wound and disposed in such a way that the respective starts are separate, and in that the angle of impact (α₁) of the teeth (24) of the toothing of the first clothing (18) is in the range 0° ≤ α₁ < 90° and the angle of impact (β₂) of the teeth (25) of the toothing of the second clothing (19) is in the range 90° ≤ β₂ < 180°.

2. Unit for pre-treating and feeding (10) textile material according to Claim 1, characterized in that the teeth (24) of the first toothed clothing (18) are specularly identical to the teeth (25) of the second toothed clothing (19).

3. Unit for pre-treating and feeding (10) textile material according to Claim 1, characterized in that the pitch (26) of the teeth (24) of the first clothing (18) and the pitch (26A) of the teeth (25) of the second clothing (19) are identical.

4. Unit for pre-treating and feeding (10) textile material according to Claim 3, characterized in that the teeth (24) of the first clothing (18) and the teeth (25) of the second type of clothing (19) are disposed on the surface (17) of the feed cylinder (11) reciprocally staggered by half the value of their pitch (26, 26A).

5. Unit for pre-treating and feeding (10) textile material according to one or more of the preceding Claims, characterized in that the pitch (26, 26A) is between 4 and 7 mm inclusive, and preferably between 4.5 and 6 mm.

6. Unit for pre-treating and feeding (10) textile material according to Claim 3, characterized in that the distance between the alternate and adjacent wrappings of the first (18) and the second (19) clothing is between 1 and 20 mm inclusive and preferably between 3 and 8 mm.

7. Unit for pre-treating and feeding (10) textile material according to Claim 1, characterized in that the clothings (18, 19) have a helical development in agreement with the intended direction of rotation of the feed cylinder (11).

8. Unit for pre-treating and feeding (10) textile material according to Claim 1, characterized in that the clothings (18, 19) are applied to the lateral surface (17) of the feed cylinder (11).

9. Unit for pre-treating and feeding (10) textile material according to Claim 1, characterized in that the clothings (18, 19) are produced from identical toothed belts first by coupling them in alternate manner with opposite inclinations and then applying them by wrapping onto the base cylinder 11.

10. Unit for pre-treating and feeding (10) textile material according to Claim 8 and/or 9, characterized in that the clothings are fixed with forced insertion of the clothing in a thread of the cylinder with a groove of the dimension of the shape of the clothing.

11. Unit for pre-treating and feeding (10) textile material according to Claim 8 and/or 9, characterized in that the clothings are fixed by spiral-winding and subsequent welding or braze welding.

Drawing