Title of Invention	METHOD AND DEVICE FOR REVERSING THE HOOK POSITION OF FIBERS IN A COMBING MACHINE
Abstract	The invention relates to a method and device for the reversal of the hook position of the fibres (F) of a textile material for processing in a process line (PL). According to the invention, the correct hook position in the terminal spinning machine, even with an even number of textile material processing steps between the carder (K) and the ring spinning machine (RS) may be achieved, whereby the hooks (H) are reversed during the process on a combing machine (KM) provided in the process line (PL).

Title of Invention

METHOD AND DEVICE FOR REVERSING THE HOOK POSITION OF FIBERS IN A COMBING MACHINE

Abstract

The invention relates to a method and device for the reversal of the hook position of the fibres (F) of a textile material for processing in a process line (PL). According to the invention, the correct hook position in the terminal spinning machine, even with an even number of textile material processing steps between the carder (K) and the ring spinning machine (RS) may be achieved, whereby the hooks (H) are reversed during the process on a combing machine (KM) provided in the process line (PL).

Full Text	FORM 2 THE PATENTS ACT, 1970 (39 of 1970) As amended by the Patents (Amendment) Act, 2005 & The Patents Rules, 2003 As amended by the Patents (Amendment) Rules, 2006 COMPLETE SPECIFICATION (See section 10 and rule 13) TITLE OF THE INVENTION Combing Machine INVENTORS Names : Slavik Walter Nationality: Swiss Address : Stadacherstrasse 41, CH-8320 Fehraltorf, Switzerland Name : Stutz Ueli Nationality: Swiss national Address : Dattnauerstrasse 110, CH-8406 Winterthur, Switzerland Name : Sommer Daniel Nationality: Swiss national Address : Hauptstrasse 18, CH-8253 Diessenhofen, Switzerland APPLICANTS Name : MASCHINENFABRIK RIETER AG Nationality : Swiss Company Address : Klosterstrasse 20 CH-8406 Winterthur, Switzerland PREAMBLE TO THE DESCRIPTION The following specification particularly describes the nature of this invention and the manner in which it is to be performed: The invention relates to a method for reversing the hook position of the fibers by means of a combing machine in a process line processing textile material. In the process where fiber material is processed on a card, drag hooks are produced, as may be gathered, for example, from the literature reference "Die Kurzstapel-spinnerei" ["Short staple spinning"] by W. Klein; Volume 1: Allgemeine Technologie der Kurzstapelspinnerei [General technology of short staple spinning] from The Textile Institute (ISBN 3-908.059-1-1) on page 24. At the end of the process line, there stands, for example, the ring spinning machine on which a thread is formed. The thread is in this case wound onto a bobbin. To produce the thread on the ring spinning machine, it is advantageous, particularly for its drafting arrangements, if, in the fed fiber stock in the form of a roving, the fibers which still have hooks are in the form of drag hooks. The result of this is that there has to be an odd number of further processing steps between the card and the ring spinning machine, with the precondition that the hook position is maintained in each step. That is to say, when the fiber stock is taken off from the intermediate stores at the processing stages (for example, cans), the fibers are supplied in the opposite direction during the following process step. As a rule, in each case a drafting arrangement is provided upstream and downstream of the combing machine, with the result that, in conjunction with a preparation machine for lap formation and with a flyer, there is again an odd number of machines between the card and the ring spinning machine which ensure the correct orientation of the hooks (drag hooks) still present. However, as soon as one of the machines in the process line between the card and the ring spinning machine is removed, corresponding measures must be taken to ensure that the hook position is correct again at the ring spinning machine. It may be, for example, that one of the drafting arrangement passes is removed insofar as the necessary drafting is already carried out on the card or the combing machine itself. In this context, the expression "necessary drafting" refers to the drafting for achieving a high-quality intermediate product (for example, a sliver with a desired uniformity) which is processed further in the following process step. 2 To achieve an appropriate orientation of the hook position, for example, it has been proposed (DE-Al-41 36 908) that the fiber material (sliver) deposited into a can in a process step be transferred into another can. The take-off end of the sliver is thereby reversed for the following process step, with the result that the hooks are also in a position as drag hooks again on the ring spinning machine at the end of the process. Devices are also known in which the cans are filled from below and the sliver is taken off from above, the hook position remaining the same for the following process. Furthermore, devices are also known which tilt cans filled with a sliver at a process step in order to piece up the front end of the previously deposited sliver on the following textile machine. These versions are sometimes highly complicated and in view of the time stipulations demanded nowadays are no longer economically justifiable. Moreover, additional devices are required for this purpose. The object on which the invention is based, therefore, is to propose a simplified method and device for varying the hook position in at least one process step of a process line. This is to ensure that, even in the case of an even number of machines between the card and the spinning machine on which a thread is produced, the hooks in the fiber material supplied with the spinning machine are in a position as drag hooks, without additional devices being employed for influencing the hook position between the machines processing textile material. This object is achieved in that a method is proposed whereby the hooks are reversed during the processing process on a combing machine present in the process line. Preferably, the hooks are reversed after the combing process and before the formation of a combing machine sliver. 3 Furthermore, it is proposed that that end of a fiber mass which is supplied in steps and nipped on the combing machine be combed out, from which end is subsequently taken off a fiber bundle which is connected to a previously taken-off fiber bundle to form a fiber fleece, while, as seen in the take-off direction, the rear end of the fiber bundle is overlapped with the present rear end of the already previously taken-off fiber bundle or already present fiber fleece. Furthermore, it is proposed that, as seen in the take-off direction, the front end of the fiber bundle be oriented opposite to the transport direction of the fiber fleece during or after the take-off. This may be achieved, for example, in that the taken-off fiber bundle is rotated through at least 90°, as seen in the take-off direction, before connection to the end of the fiber fleece. This may also be achieved in that, as seen in the take-off direction, the front end of the fiber bundle is oriented opposite to the transport direction of the fiber fleece during or after the take-off. In this case, for example, the taken-off fiber bundle may be rotated through at least 90°, as seen in the take-off direction, before connection to the end of the fiber fleece. To carry out the method, a combing machine is proposed which has a means for reversing the hooks after the combing process and before the formation of a combing machine sliver. In this case, the combing machine has an assembly for supplying a fiber mass to a combing device, the combing device combing out that end of the fiber mass which is fed in steps and nipped by the assembly and from which a fiber bundle is taken off by means of a following take-off device which discharges the fiber bundle to a further device, in order to overlap the ends of the previously taken-off fiber bundle and of the new fiber bundle, the further device being provided with means which, as seen in the take-off direction, overlap the rear end of the new fiber bundle with the rear end of the already previously taken-off fiber bundle or the end of the already formed fiber fleece. 4 In known combers, the lap sheet taken off from a lap is fed via a nipper, by means of a feed roller, to a circular comb arranged below the nipper, in order to be combed out. During the combing operation, the nipper oscillating back and forth is closed, the lap end (also called a fiber fringe) which projects from the nip line of the nipper being grasped by a comb segment of the circular comb and being combed out. The nipper is subsequently pivoted into a front position and at the same time opens. In this case, the free end of the fiber fringe passes into the region of the end of a previously formed fiber fleece which has been conveyed back by a specific amount by a pair of detaching rollers via a reversing movement in order to piece up a new combed-out fiber bundle. In this piecing-up operation, the direction of rotation of the detaching rollers is again the transport direction. The combed-out fiber fringe then lies in the manner of a roof tile, with a predetermined overlap, on the end of the fiber fleece and enters the nip line of the detaching rollers as a result of the rotational movement of the detaching rollers. During this operation, as a rule, a fixed comb mounted on the nipper penetrates into the fiber fringe. This then has the task, during the detaching operation, of retaining husk parts and neps and also short fibers which are located particularly in that region of the fiber fringe which has not been grasped by the comb segment of the circular comb. During the further rotational movement of the detaching rollers, the fibers which are grasped by the nip line and are not retained in the nipper are taken off in the form of a fiber bundle and pieced to the end of the fiber fleece via the nipping action of the detaching rollers. This operation is repeated in each comb cycle. That is to say, the direction of rotation of the detaching rollers must be reversed before each new detaching or piecing-up operation (piecing operation). Since this operation has to be carried out approximately 350 to 400 times per minute, depending on the size of the number of comb cycles, complicated and stable gear units are necessary in order, on the one hand, to carry out a correspondingly necessary rotational movement and, on the other hand, to control the high accelerations and reversing movements occurring in this case. A device is therefore proposed, by means of which, on the one hand, the hook position can be reversed and, on the other hand, the reversing movement described above can be dispensed with. 5 In this case, it is proposed that the device have a first rotating means which is provided on its periphery, over its circumference, with orifices for an air passage and at least one part region of the inner space of the means be connected to a vacuum source, and a cladding be provided, which forms a space, partitioned off with respect to the surroundings, between the take-off device and the periphery of the rotating means, a part region of the partitioned-off space being formed by the periphery of the means and by the take-off device. By means of this device, it is possible to guide reliably the fiber bundle discharged by the detaching rollers, even in the case of high numbers of comb cycles, and to piece it up (or piece it) to the end of the previously formed fiber fleece after the reversal of the hook position. By means of the claimed design, it is possible to carry out the piecing-up operation for the piecing and reversing process in the space in which it is then possible to control the air flows exactly, with the result that disturbing and uncontrolled air circulations are avoided. Tests have shown that the control of the air flows in the discharge region of the fiber bundles is tremendously important so that controlled piecing and reversal can be carried out even at high discharge speeds. The expression "partitioned off with respect to the surroundings" does not mean that the claimed space is completely encased, "airtight", with respect to the ambient air. That is to say, there may still be orifices for air ingress, which serve, in particular, for compensating again the air volume sucked away via the vacuum source. Orifices of this type may be provided, for example, between the outer boundary of the cladding and the take-off device. By means of a directed mounting of orifices of this type, the air routing can also be oriented exactly and influenced with regard to the reversal and piecing-up of the discharged fiber bundle. Preferably, the partitioning-off of the space with respect to the ambient air amounts to between 80% and 99%, thus ensuring the delivery of air from the surroundings into the partitioned-off space. The size of the fraction of the orifices for air inlet into the partitioned-off space is governed, for example, by the vacuum required within the space during the reversing or piecing operation. 6 Furthermore, it is proposed to provide within the rotating means (T) at least one second means (Z), via which the free air passage is controllable, at least over a part region of the orifices (35), between the surroundings of the first means (T) and the vacuum source (Q) at time intervals in synchronization with the discharge of the fiber bundle (P). By the vacuum being applied via the vacuum source to the periphery of the first means in the directed manner at the correct time point, the discharged fiber bundle can be held correspondingly and subsequently be laid onto the end of the fiber fleece with the desired overlap and orientation of the remaining hooks. Preferably, the second means proposed within the first means is connected to a drive and is provided on its circumference with at least one orifice which extends approximately over the width of the taken-off fiber bundle and via which a connection between the air passages of the first means and the vacuum source can be made. The second means serves in this case as a kind of control element for the connection between the orifices of the first means and the vacuum source. To ensure the synchronization described, the drive of the second means is drive-connected to the drive of the take-off device. In order to partition off corresponding regions reliably with respect to the vacuum source, it is further proposed to provide additionally at least one covering element within the first means. Preferably, the first means consists of a rotatably mounted screen drum, within which the second means is arranged as a rotatably mounted cylinder. To influence the air flow necessary for the transfer operation, it is proposed that the rotational speed of the second means be a single or a multiple of the number of comb cycles of the combing machine. With the corresponding design of the second means, particularly in terms of the number of its orifices distributed on its circumference, it is also possible that the 7 rotational speed of the second means may be a fraction of the number of comb cycles of the combing machine. It is necessary merely to ensure the exact piecing-up of the fiber bundle newly discharged in each case. It is also conceivable, in this case, that the rotational speed of the first or the second means is controllable or adjustable, depending on the application. Particularly by varying the rotational speed of the second means, piecing (piecing distance) can be influenced. Moreover, it would also be conceivable to change the direction of rotation of the first or the second means. In this case, the directions of rotation of the two means may also be contradirectional. It is proposed, further, to mount a covering element or covering elements within the second means or, as a further solution, also between the first and the second means. A covering means of this type will be provided, for example, in the region in which a fiber fleece formed on the first means has to be taken off in order to supply it for the following further processing. Moreover, the second means may have two orifices arranged so as to be offset to one mother on its circumference, and at least two covering elements arranged so as to be offset to one another may be provided. This makes it possible to have a further design /ariant. in order to ensure that the fiber fleece already formed adheres on the circumference of he screen drum during discharge transport, it is proposed that further smaller orifices be provided, distributed on the circumference of the second means, which extend only over a part region with respect to the width of the taken-off fiber bundle. This gives ise continuously to a low vacuum on the periphery of the screen drum which builds lp in the gap between the screen drum and the cylinder, since the gap is continually connected to the vacuum source. However, the action of this low vacuum has no nfluence on the transfer of the fiber bundle from the detaching device onto the screen lrum and serves merely for holding the fiber fleece on the screen drum, as already iescribed. 8 The cladding may preferably consist of a transparent material, so that the operator is allowed a look into this region, without the cladding having to be demounted. This may also be advantageous in terms of possible cleaning work or for the prompt detection of fault sources. So that no fiber fly or other dirt can settle in the region of the cladding, it is proposed that at least parts of the cladding be produced from an antistatic material. To influence the air flows within the partitioned-off space actively and in a directed way, it is proposed that, in the region of the cladding, at least one adjustable element be provided, which is suitable for controlling at least one orifice for an air passage between the partitioned-off space and the ambient air of the cladding. In this case, the element may consist of a flap which is pivotable about a pivot axis and which, as seen transversely to the transport direction of the fiber fleece, extends essentially over the length of the take-off device. Advantageously, it is proposed in this case that the pivot axis of the flap be arranged in the region below the take-off device and that the free end of the flap point in the direction of take-off device. In order to ensure that the fiber bundle is deposited reliably on the screen drum, it is proposed to mount the flap in such a way that the free end of the flap forms a nip with the first means in the open position. Likewise to prevent undesirable air circulations in the discharge region of the take-off device, it is proposed that a cover (boundary), which at least partially closes the existing free space, be provided between the take-off device and the periphery of the first means. In order to doff the fiber fleece from the first means, it is proposed that a doffing device for doffing the fiber fleece formed on the first means be provided on said means. 9 Advantageously, the doffing device is arranged downstream of the boundary of the cladding. The doffing device may in this case be a pair of rollers. It is also conceivable to provide a doffing device in which a doffing roller cooperates directly with the screen drum. To form a sliver for subsequent further processing or for depositing into a can, the doffing device may be a sliver-forming device. For example, the pair of rollers may be followed by a known web funnel for sliver formation. So that the vacuum of the vacuum source is applied effectively mainly only in the region in which the fiber bundle is to be pieced up, the radial distance between the first means and the second means must be kept relatively short in order to avoid undesirable air flows. In this case, it is proposed that the radial distance between the screen drum and the cylinder be between 0.2 and 2 mm. Further advantages of the invention are indicated and described in more detail with reference to the following exemplary embodiments. Fig. 1 shows a diagrammatic part view in the take-off or piecing region of a combing machine according to the known prior art. Fig. 2 shows a diagrammatic side view of an exemplary embodiment according to the invention in the region of the take-off device. Fig. 2a shows a diagrammatic side view of a further exemplary embodiment of the invention. Fig. 2b shows a further view of the example according to fig. 2a. Fig. 3 shows a sectional illustration A-A according to fig. 2. 10 Fig. 4 shows a diagrammatic illustration of a known process line. Fig. 5 shows a diagrammatic illustration of a process line according to the invention. Fig. 1 shows an exemplary embodiment of the known prior art. In this case, the lap sheet 2 supplied by a nipper assembly 1 is supplied to a pair of take-off rollers 5 (also called a pair of detaching rollers) via a feed roller 3. The fiber fringe 7 projecting out of the open nipper 1 passes in this case onto the rear end 8 of a combed fleece or fiber fleece 10, as a result of which it passes into the nip of the take-off rollers 5 due to the forward movement of said take-off rollers. In this case, the fibers which are not held by the retaining force of the lap sheet or by the nipper are torn out of the composite structure of the lap sheet. During this detaching operation, the fiber fringe is additionally drawn through the needles of a fixed comb 9. The fixed comb 9 in this case causes the combing out of the rear end of the taken-off fiber fringe and also the retention of neps, impurities and the like. On account of the speed differences between the lap sheet 2 and the take-off speed of the detaching rollers, the taken-off fiber fringe is drafted to a specific length. A pair of guide rollers 6 is arranged downstream of a pair of detaching rollers. During this detaching operation, an overlap or doubling of the front end of the detached or taken-off fiber bundle with the rear end 8 of the fiber fleece 10 occurs. As soon as the detaching operation or piecing operation is ended, the nipper returns to a rear position in which it is closed and feeds the fiber fringe 7 projecting out of the nipper to a comb segment 12 of a circular comb 13 for combing out. Before the nipper assembly 1 returns to its front position again, the take-off rollers 5 and the guide rollers 6 execute a reversing movement, with the result that the rear end 8 of the fiber fleece 10 is conveyed back by a specific amount. This is required in order to achieve an overlap necessary for the piecing operation. Fig. 2 shows an exemplary embodiment according to the invention, in which the takeoff rollers 5 no longer have to execute a reversing movement. That is to say, the fiber bundle P taken off by the take-off rollers is discharged discontinuously to a following screen drum T under the influence of an air flow L and is pieced up to the end E of the fiber fleece V already formed, as is described in more detail below. 11 It may be gathered from fig. 3, in the sectional illustration A-A according to fig. 2, that the screen drum T is mounted rotatably on a flange 21 via a bearing 20. The flange 21 is connected fixedly to a cylinder Z. The cylinder Z is fastened fixedly in terms of rotation on a shaft 24 via the flange 21. The shaft 24 is mounted, overhung, in the machine stand MG via a bearing 22. The shaft 24 is, of course, also secured (not shown) in its axial position. In the end region of the screen drum T in which the bearing 20 is located, a belt pulley 26 is connected to the screen drum and at the same time forms a lateral termination with respect to the ambient air. Via a belt 27, illustrated diagrammatically, which lies on the belt pulley 26, the latter is driven via a drive wheel, not shown in any more detail, which is drive-connected to the gear G. The drive of the gear takes place via a motor M which is controlled by a control unit ST. Outside the inner space IR of the screen drum T, a drive wheel 30 is fastened fixedly in terms of rotation on the shaft 24. This drive wheel 30, which may be, for example, a gearwheel, a chain wheel or a belt pulley, is connected to the gear G via a drive connection 31 shown diagrammatically. A duct 33 is fastened to the machine stand MG on the shaft 24 on the end face lying opposite the bearing point 20. The tubular duct 33 projects with its end face 32 into the clear diameter of the cylinder Z and consequently partitions off the inner space IR with respect to the ambient air. Sealing elements 38 may be provided for further sealing off between the stationary duct 33 and the rotating screen drum T. It is also possible to design these elements as bearing means in order to support the screen drum T on the duct 33 additionally on this side. A duct 34 issues into the duct 33 and is connected to a vacuum source Q. That end face 32 of the duct 33 which projects into the screen drum T is provided with an orifice 36, via which, as indicated diagrammatically by arrows, the air flow can take place out of the inner space IR of the screen drum to the vacuum source Q. As shown diagrammatically, the screen drum T is provided with a multiplicity of orifices 35 which are formed so as to be distributed over its entire circumference. Instead of a screen drum made from metal, plastic or other solid materials, which is 12 provided with orifices on its circumference, it would also be conceivable to use a cloth or another fabric which has a specific air permeability. This fabric would then have to be drawn correspondingly onto a scaffold. The covering elements Al and A2 are fastened on the end face 32 of the duct 33 via fastening means, for example screws 37, and, as can be seen particularly from fig. 2, extend over a portion of the circumferential region on the inside of the screen drum T. In this case, the covering elements Al and A2 are arranged at a short distance on the inside of the rotating cylinder Z. It is also possible, however, to arrange the covering elements Al and A2 stationarily between the screen drum T and the cylinder Z. In the present example of fig. 3, a short radial distance a which may amount to between 0.2 and 2 mm is provided between the screen drum T and the cylinder Z. In this radial free space between the screen drum T and the cylinder Z, a low vacuum is generated as soon as the vacuum source Q is switched on actively. As is explained in more detail later, this low vacuum serves for retaining the fiber fleece V already formed on the screen drum, at least in the region in which no covering element Al or A2 is mounted. So that there is a connection between the inner space IR, connected to the vacuum source Q, and the radial free space between the drum T and the cylinder Z at any time, a plurality of small orifices 53 may be provided on the circumference of the cylinder Z. The size and number of these orifices 35 are selected in this case such that the piecing-up operation or piecing operation on the screen drum T is not thereby influenced. In the version shown, only three such orifices in one line are shown. However, a plurality of such orifices 53 may be arranged so as to be distributed on the circumference of the cylinder Z. Via the orifices S1 or S2 (fig. 2) which are formed in the cylinder Z, a portion of the screen drum T provided with orifices 35 can be connected to a vacuum source Q. The covering element A2 is mounted in the region of doffing rollers 40, so that the fiber fleece V can easily be doffed from the screen drum T via the driven rollers 40. This fiber fleece V is supplied by the rollers to a following web funnel 41 in which the fleece is gathered from the width B (fig. 3) into a sliver FB (combing machine sliver). 13 Such devices for fleece gathering are already known in many variations in combers, cards or even drafting arrangements, and therefore they are not dealt with in any more detail here. The sliver FB formed in the web funnel 41 can be deposited into a can 44 via a funnel wheel 43. It is also conceivable to discharge the formed sliver FB onto a conveying table and supply it to a following drafting arrangement (not shown) together with further slivers of adjacent combing heads. A further covering element Al is arranged in the discharge region AG and serves particularly for controlling the air flows in conjunction with the orifices SI and S2, in order to reverse the fiber bundle appropriately for the reversal of the hook position. To control the air flow L which is essential for the piecing-up operation of the fiber bundle P to the fleece V, a stationary covering hood 46 is mounted above the screen drum T. As shown diagrammatically in fig. 3, the covering hood has lateral walls 47 which extend on both end faces of the covering hood 46 into the region of the circumference U of the screen drum T. This gives rise, in conjunction with the circumferential surface U of the screen drum T and with the take-off rollers 5, to a space AM partitioned off with respect to the surroundings. The distance between the covering hood 46 and the screen drum decreases as far as the region of the following doffing rollers 40 so as to avoid undesirable air flows. Below the screen drum T is provided a further covering hood 54 which, like the covering hood 46, is likewise provided with lateral walls 57 which project as far as the screen drum T. For partitioning off with respect to the surroundings, the covering hood 54 is provided on one end region with a bend 54a which is at only a short distance from the circumferential surface U. The opposite end of the covering hood 54 extends as far as the circumferential surface of the upper roller of the take-off rollers 5. The fiber fleece V is supplied by the rollers 40 to a following web funnel 41 in which the fleece is gathered from the width B (fig. 3) into a sliver FB. Such devices for 14 fleece gathering are already known in many variations in combers, cards or else drafting arrangements, and therefore are not dealt with in any more detail here. The sliver FB formed in the web funnel 41 may be deposited into a can 44 via a funnel wheel 43 or be supplied to a following drafting arrangement on a conveying table together with further slivers of adjacent combing heads. In the example shown in fig. 2, both the screen drum T and the cylinder Z have the same counterclockwise direction of rotation. The circumferential speed of the cylinder Z is identical to the circumferential speed of the take-off rollers 5. That is to say, the rotational speed of the cylinder Z must run synchronously with the comb cycle, so that the piecing-up operation or piecing operation can be carried out synchronously with the discharge of the fiber bundle. It is also possible, however, for the selected rotational speed of the cylinder Z to be a multiple of the comb cycle, without synchronization being lost. It is also likewise possible to drive the cylinder Z at a rotational speed which is a fraction of the circumferential speed of the cylinder in relation to the take-off rollers. In this case, however, it is necessary for the number of orifices in the cylinder to correspond to the fraction provided. If, for example, the circumferential speed of the cylinder Z corresponds to half the circumferential speed of the take-off rollers 5, the cylinder must have double the number of orifices SI in order to carry out the piecing-up operation. That is to say, two piecing operations are carried out during one revolution of the cylinder Z. The rotational speed of the screen drum T is substantially slower than that of the cylinder Z and is adjusted correspondingly to the piecing-up operation. With the change in rotational speed of the screen drum, the piecing distance or the overlap of the end E with the rear end HE of the fiber bundle P can be changed. In the example shown in fig. 2, the front end VE of the fiber bundle P is already located in the region of the screen drum T. Via the orifice S2 of the rotating cylinder Z, the space between the covering hood 54 and the screen drum T is connected via the orifices 35 of the screen drum T to the vacuum source Q which can be activated via a control unit ST. The air flow LI occurring thereby is oriented opposite to the direction of rotation to the screen drum and has the effect that the front end VE of the fiber 15 bundle P delivered by the take-off rollers is deflected downward. The positioning of the orifice S2 or SI is in this case coordinated exactly with the operation of delivering the fiber bundle P by means of the take-off rollers 5, in order to generate the air flow described. The orifice SI is still located behind the covering element Al and therefore has no connection to the vacuum source Q. The front end VE is held on the circumference U of the screen drum T by the air flow L1 As the procedure continues, the end HE of the fiber bundle P is released by the takeoff rollers 5. At the same time, the orifice S1 moves outside the covering range of the covering element Al and has the effect, due to the connection to the vacuum source Q and the orifices 35, that an air flow is generated, the released end HE of the fiber bundle P coming to lie on the screen drum T in its direction of rotation onto the end E of the fiber fleece V already formed or overlapping with said end. The orifice S2 has been displaced behind the covering element Al, with the result that the air flow LI has been interrupted. By virtue of this piecing-up operation, the fiber bundle has been rotated during piecing up, with the result that the hook position has also been reversed. This operation is repeated in each comb cycle, with the result that a new fiber bundle P is repeatedly pieced up to the fiber fleece V at a uniform rotational speed of the screen drum T and a reversal of the hook position is carried out. As soon as a new end VE is delivered by the take-off rollers 5, the first orifice SI is located in the region of the covering hook 54 in order to generate an air flow LI which deflects this end VE downward opposite to the direction of rotation of the screen drum. As soon as the orifice S1 disappears behind the cover Al, this function is assumed by the orifice S2, until the operation already described, where the rear end HE of the fiber bundle P is released. As already described, the overlap of the rear end HE of the fiber bundle P with the end E of the fiber fleece V may be determined by means of the rotational speed of the screen drum T. 16 The fiber fleece V is transferred due to the rotational movement of the screen drum T into the doffing region AB of the rollers 40 in which the stationarily mounted covering element A2 is also arranged. This ensures that this region is partitioned off with respect to the vacuum source Q, with the result that the fiber fleece can easily be lifted off from the circumferential surface U, in order to be transferred into the knit line between the take-off rollers 40. Via these driven rollers 40 (the drive is not shown), the fiber fleece V is discharged into a web funnel 41 which is likewise followed by driven take-off rollers 42. In the web funnel 41, the fiber fleece V is gathered in a known way into a sliver FB which is taken off by the take-off rollers 42 and deposited in loop form into a can 44 via a funnel wheel 43 shown diagrammatically. The sliver FB thus deposited can subsequently be transported for further processing, for example, to a flyer or an open-end machine, by means of the can 44. The exemplary embodiments of fig. 2a and fig. 2b differ from the example of fig. 2 and fig. 3 in the mounting of a pivotable flap KL in the region of the cladding 46, the mounting of the lower cladding 54 having been dispensed with. The cladding 46, in conjunction with the corresponding lateral walls 47 and the boundary caused by the screen drum T and the take-off rollers 5, gives rise to a space AM which is essentially partitioned off with respect to the ambient air and within which the operation of reversing delivered fiber bundles P and piecing them to the fiber fleece V already formed is carried out. In order to control this operation more effectively even at high delivery speeds of the fiber bundles, in the examples of fig. 2a and fib. 2b the use of a flap KL is proposed, which is mounted pivotably about a pivot axis S A. The pivot axis S A may in this case be mounted in the machine stand or directly on the covering hood 46. A pivoting device 70, which is activated by the control ST via the line 72, engages on the pivot axis SA which is pivotably mounted, for example, laterally in the region of the hood 46 or on the machine stand. This pivoting device may be, for example, a cylinder which is articulated on a lever connected fixedly in terms of rotation to the pivot axis. Via the control ST, the activation of the pivoting device 70 takes place 17 synchronously to the movement of the take-off rollers or, in particular, synchronously to the position of the orifices S1, S2 of the cylinder Z. In the position shown in fig. 2a, the flap KL is in a closed position, in which the free end of the flap is approximately tangent to the circumference of the lower take-off roller 5a. That is to say, there is only a short safety distance between the lower takeoff roller 5a and the flap KL. The front end VE of the fiber bundle P is deflected downward by the prevailing air flow indicated by arrows L. Under the action of the vacuum applied inside the screen drum and of the corresponding position of the orifice SI of the cylinder Z, the end VE is sucked onto the circumference U of the screen drum T. In this case, the front end VE in the fiber bundle P points opposite to the direction of rotation of the screen drum T. Between the covering hood 46 and the upper take-off roller 5b there is a gap 65 through which air can flow in from the surroundings. The air flow L occurring due to this arrangement ensures that the reversal of the fiber bundle and the laying of its front end VE onto the screen drum T take place without damage to the fiber mix, even at high delivery speeds. During the further rotation of the cylinder Z, the orifice SI is displaced behind the cover Al and is therefore partitioned off with respect to the vacuum source Q. With the displacement of the orifice SI, the orifice S2 is also displaced simultaneously into the position shown in fig. 2b, thus giving rise to an air flow in the direction of the doffing device 60, 61, as indicated by arrows L. Simultaneously with the displacement of the orifices SI and S2, the pivoting device 70 is activated by the control ST via the line 72 and causes the pivoting of the flap KL into the position shown in fig. 2b. This position is assumed shortly before the release of the rear end HE of the fiber bundle by the take-off rollers 5. A nip KS occurs between the screen drum T and the free end of the flap KL, with the result that the front end VE of the fiber bundle is held reliably in bearing contact on the screen drum when the rear end HE is released by the take-off rollers. Via the orifice 90 which has occurred due to the pivoting of the flap KL, a further air flow then takes place in the tangential direction to the rotational movement of the screen 18 drum T, with the result that the released end HE is overlapped with the rear end E of the fiber fleece V already formed. This air flow L results due to the corresponding position of the orifice S2 via which the front region of the hood 46 is put under a vacuum. The air volume sucked away in this case is, for example, delivered again partially via an existing gap 65 and mainly via the orifice 90, as indicated by corresponding arrows. The second orifice SI is located behind the cover Al and is therefore inactive. When this operation is concluded, the flap KL is pivoted into the position shown in fig. 2a again, with the result that a new fiber bundle P can be supplied again by the take-off rollers 5 for further piecing up. By the flap KL being used, the operation of piecing the fiber bundles on the screen drum can be carried out easily and in a directed way even at high delivery speeds of the fiber bundles, without damage to the fiber bundles occurring during the piecing-up operation. Via the flap KL, it is possible, in particular, to control or to influence the air flows necessary for the piecing-up operation. Instead of the flap KL, it would also be conceivable to form additional orifices which can be closed or opened at the appropriate time point by means of a device via a corresponding control. Figs. 4 and 5 show diagrammatically a process line PL between a card KA and a ring spinning machine RS. The hook position of the hooks H of individual fibers F, such as are present in the individual process steps, is in this case shown diagrammatically. In the known process line according to fig. 4, the fibers discharged from the card KA are delivered with drag hooks and discharged into a can Kl. The can Kl serves as a reserve for a following drafting arrangement S I where the fibers F, after being taken off from the can Kl, pass with head hooks into the drafting arrangement S I. After the drafting operation, the fiber stock is deposited into a can K2 which serves as a reserve for a following lap-forming machine WM. This fiber stock, after being taken off from the can K2, passes with drag hooks into the lap-forming machine WM. The lap WW produced there is transferred to a following combing machine KM. The lap sheet 19 unwound from the lap WW on the combing machine has fibers with head hooks which are partly opened up on the combing machine. The sliver formed on the combing machine still has head hooks which have not yet been opened up. This sliver is deposited into a can K3 which serves as a reserve for a following second drafting arrangement pass S II. After being taken off from the can K3, the fibers still provided with hooks H are delivered with drag hooks into the drafting arrangement SII. The sliver formed in the drafting arrangement SII is deposited into a can K4. The can K4 is subsequently transferred to a flyer FL, in which the fibers are present with head hooks, after the sliver has been taken off from the can K4. The bobbin SP produced at the flyer FL is subsequently transferred to a ring spinning machine for further processing. During the unwinding of the bobbin SP on the ring spinning machine RS, the fibers still provided with hooks H are present in the form of drag hooks, this being advantageous for this last processing process. That is to say, if head hooks were present, the processing process on the ring spinning machine would be disrupted and under certain circumstances would lead to losses of quality in yarn production. For increasing efficiency and therefore also for a cost saving, there is always the attempt to shorten the process line PL, with the quality of the final product remaining the same. In this case, there are already proposals, for example, for avoiding the use of the second drafting arrangement step SII. This may be achieved, for example, by means of a regulated drafting arrangement on the combing machine. This, however, would cause a process step to be omitted, with the result that the hooks still present would be undesirable head hooks at the ring spinning machine. The invention comes in here and proposes to carry out the rotation of the hook position during the processing process on the combing machine KM, as shown diagrammatically in fig. 5. In this case, the fibers which are discharged in a sliver at the combing machine are present with drag hooks. During the subsequent process, with the drafting arrangement step S II being avoided, the fibers finally arrive via the flyer FL with drag hooks at the ring spinning machine. It is obvious that the fiber stock may also have mixed forms of drag and head hooks and also double hooks. If drag or head hooks have been referred to previously in the exemplary embodiments, these make up the predominant fraction of hook forms in the fiber mix present in each case. 20 The combing machine is particularly suitable for reversing the hook position, especially since, in the processing process carried out there, the fiber stock is separated into individual fiber bundles which can then be reversed correspondingly. 21 We claim: 1. A method for reversing the hook position of the fibers (F) of a textile material to be processed in a process line (PL), characterized in that, during the processing process, the hooks (H) are reversed on a combing machine (KM) present in the process line (PL). 2. The method as claimed in claim 1, characterized in that the hooks (H) are reversed after the combing process and before the formation of a combing machine sliver (FB). 3. The method as claimed in claim 2, characterized in that that end (7) of a fiber mass (2) which is supplied in steps and nipped on the combing machine (KM) is combed out, from said end being subsequently taken off a fiber bundle (P) which is connected to a previously taken-off fiber bundle (P) to form a fiber fleece (V), while, as seen in the take-off direction (AR), the rear end (HE) of the fiber bundle (?) is overlapped with the present rear end (E) of the already previously taken-off fiber bundle or already present fiber fleece (V). 4. The method as claimed in claim 2, characterized in that, as seen in the take-off direction (AR), the front end (VE) of the fiber bundle (P) is oriented opposite the transport direction of the fiber fleece (V) during or after the take-off. 5. The method as claimed in claim 2, characterized in that the taken-off fiber bundle (P) is rotated through at least 90°, as seen in the take-off direction, before connection to the end (E) of the fiber fleece. 6. A combing machine for carrying out the method as claimed in claim 1, characterized in that the combing machine (KM) has means (T, Z) in order to reverse the hooks (H) after the combing process and before the formation of a combing machine sliver (FB). 7. A combing machine as claimed in claim 6, characterized by an assembly (1) for supplying a fiber mass (2) to a combing device (12, 13), the combing device 22 combing out that end (7) of the fiber mass which is fed in steps and nipped by the assembly (1) and from which fiber bundle (?) is taken off by means of a following take-off device (5) which discharges the fiber bundle (P) to a further device (T, Z), in order to overlap the ends (E) of the previously taken-off fiber bundle and of the new fiber bundle (P), the further device being provided with means (T, Z) which, as seen in the take-off direction (AR), overlap the rear end (HE) of the new fiber bundle (P) with the rear end (E) of the already previously taken-off fiber bundle or the end of the already formed fiber fleece (V). 8. The combing machine as claimed in claim 7, characterized in that the further device has a first rotating means (T) which is provided on its periphery (U), over its circumference, with orifices (35) for an air passage, and at least one part region of the inner space of the means (T) is connected to a vacuum source (Q), and a cladding (46, 47) is provided, which forms a space (AM), partitioned off with respect to the surroundings, between the take-off device (5) and the periphery (U) of the rotating means (T), a part region of the partitioned-off space (AM) being formed by the periphery (U) of the means (T) and by the take-off device (5). 9. The combing machine as claimed in claim 8, characterized in that the partitioning-off of the space (AM) with respect to the ambient air amounts to between 80% and 99%. 10. The combing machine as claimed in one of claims 8 and 9, characterized in that, within the rotating means (T), at least one second means (Z) is provided, via which the free air passage is controllable, at least over a part region of the orifices (35), between the surroundings of the first means (T) and the vacuum source (Q) at time intervals in synchronization with the discharge of the fiber bundle (P). 11. The combing machine as claimed in claim 10, characterized in that the second means (Z) is connected to a drive (M, G) and has on its circumference at least one orifice (SI, S2) which extends approximately over the width (B) of the 23 taken-off fiber bundle (?) and via which a connection between air passages (35) of the first means (T) and the vacuum source (Q) can be made. 12. The combing machine as claimed in claim 11, characterized in that, within the first means (T), at least one stationarily arranged covering element (Al, A2) is mounted, which partitions off a part region of the air passages (35) of the first means (T) with respect to the vacuum source (Q) over the width (B) of the taken-off fiber bundle (P). 13. The combing machine as claimed in claims 10 to 12, characterized in that the first means consists of a rotatably mounted screen drum (T), within which the second means is arranged as a rotatably mounted cylinder (Z). 14. The combing machine as claimed in claims 10 to 13, characterized in that the rotational speed of the second means (Z) is a single or a multiple of the number of comb cycles of a combing machine (KM). 15. The combing machine as claimed in one of claims 10 to 13, characterized in that the rotational speed of the second means (Z) is a fraction of the number of comb cycles of the combing machine (KM). 16. The combing machine as claimed in one of claims 14 and 15, characterized in that means (ST, M, G) are provided in order to control or set the rotational speed of the first and/or the second means (T, Z). 17. The combing machine as claimed in claims 14 to 16, characterized in that means (ST, M, G) are provided in order to set the direction of rotation of the first and/or second means (T, Z). 18. The combing machine as claimed in one of the preceding claims 12 to 17, characterized in that the covering element (Al, A2) is arranged within the second means (Z). 24 19. The combing machine as claimed in claim 17, characterized in that the second means (Z) has two orifices (SI, S2) arranged so as to be offset to one another on its circumference, and at least two covering elements (Al, A2) arranged so as to be offset to one another are provided. 20. The combing machine as claimed in claim 11, characterized in that further smaller orifices (53) are provided, distributed on the circumference of the second means (Z), which extend only over a part region with respect to the width of the taken-off fiber bundle. 21. The combing machine as claimed in claim 8, characterized in that at least parts of the cladding (46,47, 54, 57) consist of a transparent material. 22. The combing machine as claimed in one of claims 8 or 21, characterized in that at least parts of the cladding (46,54) consist of an antistatic material. 23. The combing machine as claimed in one of claims 8 to 22, characterized in that, in the region of the cladding (46, 47), at least one adjustable element (KL) is provided, which is suitable for controlling at least one orifice (90) for air passage between the partitioned-off space (AM) and the ambient air of the cladding (46,47). 24. The combing machine as claimed in claim 23, characterized in that the element consists of a flap (KL) which is pivotable about a pivot axis (SA) and which, as seen transversely to the transport direction of the fiber fleece (V), extends essentially over the length of the take-off device (5). 25. The combing machine as claimed in claim 24, characterized in that the pivot axis (SA) of the flap (KL) is arranged in the region below the take-off device (5), and the free end (KE) of the flap points in the direction of the take-off device. 25 26. The combing machine as claimed in claim 24, characterized in that the free end (KE) of the flap (KL) forms a nip (KS) with the first means (T) in the open position. 27. The combing machine as claimed in one of the preceding claims 8 to 25, characterized in that a doffing device (40) for doffing the fiber fleece (V) formed on the first means (T) is provided for the means (T). 28. The combing machine as claimed in claim 26, characterized in that the doffing device (40) is arranged downstream of the boundary (54a) of the cladding (46, 54). 29. The combing machine as claimed in either one of claims 26 and 27, characterized in that the doffing device is a pair of rollers (40). 30. The combing machine as claimed in either one of claims 26 and 27, characterized in that the doffing device (40) is followed by a sliver (FB) forming device (41,42). 31. The combing machine as claimed in claim 13, characterized in that the radial distance (a) between the screen drum (T) and the cylinder (Z) is between 0.2 and 2 mm. 26 Abstract The invention relates to a method and a device for reversing the hook position of the fibers (F) of a textile material to be processed in a process line (PL). To obtain the correct hook position at the terminal spinning machine, even in the case of an even number of process steps processing textile material between the card (K) and the ring spinning machine (RS), it is proposed that the hooks (H) be reversed, during the processing process, on a combing machine (KM) present in the process line (PL). (Fig. 2)

Full Text

FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
As amended by the Patents (Amendment) Act, 2005
&
The Patents Rules, 2003
As amended by the Patents (Amendment) Rules, 2006
COMPLETE SPECIFICATION (See section 10 and rule 13)
TITLE OF THE INVENTION
Combing Machine
INVENTORS
Names : Slavik Walter
Nationality: Swiss
Address : Stadacherstrasse 41, CH-8320 Fehraltorf, Switzerland
Name : Stutz Ueli
Nationality: Swiss national
Address : Dattnauerstrasse 110, CH-8406 Winterthur, Switzerland
Name : Sommer Daniel
Nationality: Swiss national
Address : Hauptstrasse 18, CH-8253 Diessenhofen, Switzerland
APPLICANTS
Name : MASCHINENFABRIK RIETER AG
Nationality : Swiss Company
Address : Klosterstrasse 20 CH-8406 Winterthur, Switzerland
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the nature of this invention and the manner in which it is to be performed:

The invention relates to a method for reversing the hook position of the fibers by means of a combing machine in a process line processing textile material.
In the process where fiber material is processed on a card, drag hooks are produced, as may be gathered, for example, from the literature reference "Die Kurzstapel-spinnerei" ["Short staple spinning"] by W. Klein; Volume 1: Allgemeine Technologie der Kurzstapelspinnerei [General technology of short staple spinning] from The Textile Institute (ISBN 3-908.059-1-1) on page 24.
At the end of the process line, there stands, for example, the ring spinning machine on which a thread is formed. The thread is in this case wound onto a bobbin. To produce the thread on the ring spinning machine, it is advantageous, particularly for its drafting arrangements, if, in the fed fiber stock in the form of a roving, the fibers which still have hooks are in the form of drag hooks. The result of this is that there has to be an odd number of further processing steps between the card and the ring spinning machine, with the precondition that the hook position is maintained in each step. That is to say, when the fiber stock is taken off from the intermediate stores at the processing stages (for example, cans), the fibers are supplied in the opposite direction during the following process step.
As a rule, in each case a drafting arrangement is provided upstream and downstream of the combing machine, with the result that, in conjunction with a preparation machine for lap formation and with a flyer, there is again an odd number of machines between the card and the ring spinning machine which ensure the correct orientation of the hooks (drag hooks) still present.
However, as soon as one of the machines in the process line between the card and the ring spinning machine is removed, corresponding measures must be taken to ensure that the hook position is correct again at the ring spinning machine. It may be, for example, that one of the drafting arrangement passes is removed insofar as the necessary drafting is already carried out on the card or the combing machine itself. In this context, the expression "necessary drafting" refers to the drafting for achieving a high-quality intermediate product (for example, a sliver with a desired uniformity) which is processed further in the following process step.
2

To achieve an appropriate orientation of the hook position, for example, it has been proposed (DE-Al-41 36 908) that the fiber material (sliver) deposited into a can in a process step be transferred into another can. The take-off end of the sliver is thereby reversed for the following process step, with the result that the hooks are also in a
position as drag hooks again on the ring spinning machine at the end of the process.
Devices are also known in which the cans are filled from below and the sliver is taken off from above, the hook position remaining the same for the following process. Furthermore, devices are also known which tilt cans filled with a sliver at a process step in order to piece up the front end of the previously deposited sliver on the following textile machine.
These versions are sometimes highly complicated and in view of the time stipulations demanded nowadays are no longer economically justifiable. Moreover, additional devices are required for this purpose.
The object on which the invention is based, therefore, is to propose a simplified method and device for varying the hook position in at least one process step of a process line.
This is to ensure that, even in the case of an even number of machines between the card and the spinning machine on which a thread is produced, the hooks in the fiber material supplied with the spinning machine are in a position as drag hooks, without additional devices being employed for influencing the hook position between the machines processing textile material.
This object is achieved in that a method is proposed whereby the hooks are reversed during the processing process on a combing machine present in the process line.
Preferably, the hooks are reversed after the combing process and before the formation of a combing machine sliver.
3

Furthermore, it is proposed that that end of a fiber mass which is supplied in steps and nipped on the combing machine be combed out, from which end is subsequently taken off a fiber bundle which is connected to a previously taken-off fiber bundle to form a fiber fleece, while, as seen in the take-off direction, the rear end of the fiber bundle is overlapped with the present rear end of the already previously taken-off fiber bundle or already present fiber fleece.
Furthermore, it is proposed that, as seen in the take-off direction, the front end of the fiber bundle be oriented opposite to the transport direction of the fiber fleece during or after the take-off.
This may be achieved, for example, in that the taken-off fiber bundle is rotated through at least 90°, as seen in the take-off direction, before connection to the end of the fiber fleece.
This may also be achieved in that, as seen in the take-off direction, the front end of the fiber bundle is oriented opposite to the transport direction of the fiber fleece during or after the take-off.
In this case, for example, the taken-off fiber bundle may be rotated through at least 90°, as seen in the take-off direction, before connection to the end of the fiber fleece.
To carry out the method, a combing machine is proposed which has a means for reversing the hooks after the combing process and before the formation of a combing machine sliver.
In this case, the combing machine has an assembly for supplying a fiber mass to a combing device, the combing device combing out that end of the fiber mass which is fed in steps and nipped by the assembly and from which a fiber bundle is taken off by means of a following take-off device which discharges the fiber bundle to a further device, in order to overlap the ends of the previously taken-off fiber bundle and of the new fiber bundle, the further device being provided with means which, as seen in the
take-off direction, overlap the rear end of the new fiber bundle with the rear end of the already previously taken-off fiber bundle or the end of the already formed fiber fleece.
4

In known combers, the lap sheet taken off from a lap is fed via a nipper, by means of a feed roller, to a circular comb arranged below the nipper, in order to be combed out. During the combing operation, the nipper oscillating back and forth is closed, the lap end (also called a fiber fringe) which projects from the nip line of the nipper being grasped by a comb segment of the circular comb and being combed out. The nipper is subsequently pivoted into a front position and at the same time opens. In this case, the free end of the fiber fringe passes into the region of the end of a previously formed fiber fleece which has been conveyed back by a specific amount by a pair of detaching rollers via a reversing movement in order to piece up a new combed-out fiber bundle. In this piecing-up operation, the direction of rotation of the detaching rollers is again the transport direction. The combed-out fiber fringe then lies in the manner of a roof tile, with a predetermined overlap, on the end of the fiber fleece and enters the nip line of the detaching rollers as a result of the rotational movement of the detaching rollers. During this operation, as a rule, a fixed comb mounted on the nipper penetrates into the fiber fringe. This then has the task, during the detaching operation, of retaining husk parts and neps and also short fibers which are located particularly in that region of the fiber fringe which has not been grasped by the comb segment of the circular comb. During the further rotational movement of the detaching rollers, the fibers which are grasped by the nip line and are not retained in the nipper are taken off in the form of a fiber bundle and pieced to the end of the fiber fleece via the nipping action of the detaching rollers. This operation is repeated in each comb cycle. That is to say, the direction of rotation of the detaching rollers must be reversed before each new detaching or piecing-up operation (piecing operation). Since this operation has to be carried out approximately 350 to 400 times per minute, depending on the size of the number of comb cycles, complicated and stable gear units are necessary in order, on the one hand, to carry out a correspondingly necessary rotational movement and, on the other hand, to control the high accelerations and reversing movements occurring in this case.
A device is therefore proposed, by means of which, on the one hand, the hook position can be reversed and, on the other hand, the reversing movement described above can be dispensed with.
5

In this case, it is proposed that the device have a first rotating means which is provided on its periphery, over its circumference, with orifices for an air passage and at least one part region of the inner space of the means be connected to a vacuum source, and a cladding be provided, which forms a space, partitioned off with respect to the surroundings, between the take-off device and the periphery of the rotating
means, a part region of the partitioned-off space being formed by the periphery of the means and by the take-off device.
By means of this device, it is possible to guide reliably the fiber bundle discharged by the detaching rollers, even in the case of high numbers of comb cycles, and to piece it up (or piece it) to the end of the previously formed fiber fleece after the reversal of the hook position. By means of the claimed design, it is possible to carry out the piecing-up operation for the piecing and reversing process in the space in which it is then possible to control the air flows exactly, with the result that disturbing and uncontrolled air circulations are avoided. Tests have shown that the control of the air flows in the discharge region of the fiber bundles is tremendously important so that controlled piecing and reversal can be carried out even at high discharge speeds.
The expression "partitioned off with respect to the surroundings" does not mean that the claimed space is completely encased, "airtight", with respect to the ambient air. That is to say, there may still be orifices for air ingress, which serve, in particular, for compensating again the air volume sucked away via the vacuum source. Orifices of this type may be provided, for example, between the outer boundary of the cladding and the take-off device. By means of a directed mounting of orifices of this type, the air routing can also be oriented exactly and influenced with regard to the reversal and piecing-up of the discharged fiber bundle.
Preferably, the partitioning-off of the space with respect to the ambient air amounts to between 80% and 99%, thus ensuring the delivery of air from the surroundings into the partitioned-off space.
The size of the fraction of the orifices for air inlet into the partitioned-off space is governed, for example, by the vacuum required within the space during the reversing or piecing operation.
6

Furthermore, it is proposed to provide within the rotating means (T) at least one second means (Z), via which the free air passage is controllable, at least over a part region of the orifices (35), between the surroundings of the first means (T) and the vacuum source (Q) at time intervals in synchronization with the discharge of the fiber bundle (P).
By the vacuum being applied via the vacuum source to the periphery of the first means in the directed manner at the correct time point, the discharged fiber bundle can be held correspondingly and subsequently be laid onto the end of the fiber fleece with the desired overlap and orientation of the remaining hooks.
Preferably, the second means proposed within the first means is connected to a drive and is provided on its circumference with at least one orifice which extends approximately over the width of the taken-off fiber bundle and via which a connection between the air passages of the first means and the vacuum source can be made. The second means serves in this case as a kind of control element for the connection between the orifices of the first means and the vacuum source. To ensure the synchronization described, the drive of the second means is drive-connected to the drive of the take-off device.
In order to partition off corresponding regions reliably with respect to the vacuum source, it is further proposed to provide additionally at least one covering element within the first means.
Preferably, the first means consists of a rotatably mounted screen drum, within which the second means is arranged as a rotatably mounted cylinder.
To influence the air flow necessary for the transfer operation, it is proposed that the rotational speed of the second means be a single or a multiple of the number of comb cycles of the combing machine.
With the corresponding design of the second means, particularly in terms of the number of its orifices distributed on its circumference, it is also possible that the
7

rotational speed of the second means may be a fraction of the number of comb cycles of the combing machine. It is necessary merely to ensure the exact piecing-up of the fiber bundle newly discharged in each case.
It is also conceivable, in this case, that the rotational speed of the first or the second means is controllable or adjustable, depending on the application. Particularly by varying the rotational speed of the second means, piecing (piecing distance) can be influenced.
Moreover, it would also be conceivable to change the direction of rotation of the first or the second means. In this case, the directions of rotation of the two means may also be contradirectional.
It is proposed, further, to mount a covering element or covering elements within the second means or, as a further solution, also between the first and the second means. A covering means of this type will be provided, for example, in the region in which a fiber fleece formed on the first means has to be taken off in order to supply it for the following further processing.
Moreover, the second means may have two orifices arranged so as to be offset to one mother on its circumference, and at least two covering elements arranged so as to be offset to one another may be provided. This makes it possible to have a further design /ariant.
in order to ensure that the fiber fleece already formed adheres on the circumference of he screen drum during discharge transport, it is proposed that further smaller orifices be provided, distributed on the circumference of the second means, which extend only over a part region with respect to the width of the taken-off fiber bundle. This gives ise continuously to a low vacuum on the periphery of the screen drum which builds lp in the gap between the screen drum and the cylinder, since the gap is continually connected to the vacuum source. However, the action of this low vacuum has no nfluence on the transfer of the fiber bundle from the detaching device onto the screen
lrum and serves merely for holding the fiber fleece on the screen drum, as already iescribed.
8

The cladding may preferably consist of a transparent material, so that the operator is allowed a look into this region, without the cladding having to be demounted. This may also be advantageous in terms of possible cleaning work or for the prompt detection of fault sources.
So that no fiber fly or other dirt can settle in the region of the cladding, it is proposed that at least parts of the cladding be produced from an antistatic material.
To influence the air flows within the partitioned-off space actively and in a directed way, it is proposed that, in the region of the cladding, at least one adjustable element be provided, which is suitable for controlling at least one orifice for an air passage between the partitioned-off space and the ambient air of the cladding.
In this case, the element may consist of a flap which is pivotable about a pivot axis and which, as seen transversely to the transport direction of the fiber fleece, extends essentially over the length of the take-off device.
Advantageously, it is proposed in this case that the pivot axis of the flap be arranged in the region below the take-off device and that the free end of the flap point in the direction of take-off device.
In order to ensure that the fiber bundle is deposited reliably on the screen drum, it is proposed to mount the flap in such a way that the free end of the flap forms a nip with the first means in the open position.
Likewise to prevent undesirable air circulations in the discharge region of the take-off device, it is proposed that a cover (boundary), which at least partially closes the existing free space, be provided between the take-off device and the periphery of the first means.
In order to doff the fiber fleece from the first means, it is proposed that a doffing device for doffing the fiber fleece formed on the first means be provided on said means.
9

Advantageously, the doffing device is arranged downstream of the boundary of the cladding.
The doffing device may in this case be a pair of rollers.
It is also conceivable to provide a doffing device in which a doffing roller cooperates directly with the screen drum.
To form a sliver for subsequent further processing or for depositing into a can, the doffing device may be a sliver-forming device. For example, the pair of rollers may be followed by a known web funnel for sliver formation.
So that the vacuum of the vacuum source is applied effectively mainly only in the region in which the fiber bundle is to be pieced up, the radial distance between the first means and the second means must be kept relatively short in order to avoid undesirable air flows. In this case, it is proposed that the radial distance between the screen drum and the cylinder be between 0.2 and 2 mm.
Further advantages of the invention are indicated and described in more detail with reference to the following exemplary embodiments.
Fig. 1 shows a diagrammatic part view in the take-off or piecing region of a
combing machine according to the known prior art.
Fig. 2 shows a diagrammatic side view of an exemplary embodiment according to the invention in the region of the take-off device.
Fig. 2a shows a diagrammatic side view of a further exemplary embodiment of the invention.
Fig. 2b shows a further view of the example according to fig. 2a.
Fig. 3 shows a sectional illustration A-A according to fig. 2.
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Fig. 4 shows a diagrammatic illustration of a known process line.
Fig. 5 shows a diagrammatic illustration of a process line according to the
invention.
Fig. 1 shows an exemplary embodiment of the known prior art. In this case, the lap sheet 2 supplied by a nipper assembly 1 is supplied to a pair of take-off rollers 5 (also called a pair of detaching rollers) via a feed roller 3. The fiber fringe 7 projecting out of the open nipper 1 passes in this case onto the rear end 8 of a combed fleece or fiber fleece 10, as a result of which it passes into the nip of the take-off rollers 5 due to the forward movement of said take-off rollers. In this case, the fibers which are not held by the retaining force of the lap sheet or by the nipper are torn out of the composite structure of the lap sheet. During this detaching operation, the fiber fringe is additionally drawn through the needles of a fixed comb 9. The fixed comb 9 in this case causes the combing out of the rear end of the taken-off fiber fringe and also the retention of neps, impurities and the like. On account of the speed differences between the lap sheet 2 and the take-off speed of the detaching rollers, the taken-off fiber fringe is drafted to a specific length. A pair of guide rollers 6 is arranged downstream of a pair of detaching rollers. During this detaching operation, an overlap or doubling of the front end of the detached or taken-off fiber bundle with the rear end 8 of the fiber fleece 10 occurs. As soon as the detaching operation or piecing operation is ended, the nipper returns to a rear position in which it is closed and feeds the fiber fringe 7 projecting out of the nipper to a comb segment 12 of a circular comb 13 for combing out. Before the nipper assembly 1 returns to its front position again, the take-off rollers 5 and the guide rollers 6 execute a reversing movement, with the result that the rear end 8 of the fiber fleece 10 is conveyed back by a specific amount. This is required in order to achieve an overlap necessary for the piecing operation.
Fig. 2 shows an exemplary embodiment according to the invention, in which the takeoff rollers 5 no longer have to execute a reversing movement. That is to say, the fiber bundle P taken off by the take-off rollers is discharged discontinuously to a following screen drum T under the influence of an air flow L and is pieced up to the end E of the fiber fleece V already formed, as is described in more detail below.
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It may be gathered from fig. 3, in the sectional illustration A-A according to fig. 2, that the screen drum T is mounted rotatably on a flange 21 via a bearing 20. The flange 21 is connected fixedly to a cylinder Z. The cylinder Z is fastened fixedly in terms of rotation on a shaft 24 via the flange 21. The shaft 24 is mounted, overhung, in the machine stand MG via a bearing 22. The shaft 24 is, of course, also secured (not shown) in its axial position. In the end region of the screen drum T in which the bearing 20 is located, a belt pulley 26 is connected to the screen drum and at the same time forms a lateral termination with respect to the ambient air. Via a belt 27, illustrated diagrammatically, which lies on the belt pulley 26, the latter is driven via a drive wheel, not shown in any more detail, which is drive-connected to the gear G. The drive of the gear takes place via a motor M which is controlled by a control unit ST.
Outside the inner space IR of the screen drum T, a drive wheel 30 is fastened fixedly in terms of rotation on the shaft 24. This drive wheel 30, which may be, for example, a gearwheel, a chain wheel or a belt pulley, is connected to the gear G via a drive connection 31 shown diagrammatically.
A duct 33 is fastened to the machine stand MG on the shaft 24 on the end face lying opposite the bearing point 20. The tubular duct 33 projects with its end face 32 into the clear diameter of the cylinder Z and consequently partitions off the inner space IR with respect to the ambient air. Sealing elements 38 may be provided for further sealing off between the stationary duct 33 and the rotating screen drum T. It is also possible to design these elements as bearing means in order to support the screen drum T on the duct 33 additionally on this side.
A duct 34 issues into the duct 33 and is connected to a vacuum source Q. That end face 32 of the duct 33 which projects into the screen drum T is provided with an orifice 36, via which, as indicated diagrammatically by arrows, the air flow can take place out of the inner space IR of the screen drum to the vacuum source Q.
As shown diagrammatically, the screen drum T is provided with a multiplicity of orifices 35 which are formed so as to be distributed over its entire circumference. Instead of a screen drum made from metal, plastic or other solid materials, which is
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provided with orifices on its circumference, it would also be conceivable to use a cloth or another fabric which has a specific air permeability. This fabric would then have to be drawn correspondingly onto a scaffold.
The covering elements Al and A2 are fastened on the end face 32 of the duct 33 via fastening means, for example screws 37, and, as can be seen particularly from fig. 2, extend over a portion of the circumferential region on the inside of the screen drum T. In this case, the covering elements Al and A2 are arranged at a short distance on the inside of the rotating cylinder Z. It is also possible, however, to arrange the covering elements Al and A2 stationarily between the screen drum T and the cylinder Z.
In the present example of fig. 3, a short radial distance a which may amount to between 0.2 and 2 mm is provided between the screen drum T and the cylinder Z. In this radial free space between the screen drum T and the cylinder Z, a low vacuum is generated as soon as the vacuum source Q is switched on actively. As is explained in more detail later, this low vacuum serves for retaining the fiber fleece V already formed on the screen drum, at least in the region in which no covering element Al or A2 is mounted. So that there is a connection between the inner space IR, connected to the vacuum source Q, and the radial free space between the drum T and the cylinder Z at any time, a plurality of small orifices 53 may be provided on the circumference of the cylinder Z. The size and number of these orifices 35 are selected in this case such that the piecing-up operation or piecing operation on the screen drum T is not thereby influenced. In the version shown, only three such orifices in one line are shown. However, a plurality of such orifices 53 may be arranged so as to be distributed on the circumference of the cylinder Z.
Via the orifices S1 or S2 (fig. 2) which are formed in the cylinder Z, a portion of the screen drum T provided with orifices 35 can be connected to a vacuum source Q.
The covering element A2 is mounted in the region of doffing rollers 40, so that the fiber fleece V can easily be doffed from the screen drum T via the driven rollers 40. This fiber fleece V is supplied by the rollers to a following web funnel 41 in which the fleece is gathered from the width B (fig. 3) into a sliver FB (combing machine sliver).
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Such devices for fleece gathering are already known in many variations in combers, cards or even drafting arrangements, and therefore they are not dealt with in any more detail here.
The sliver FB formed in the web funnel 41 can be deposited into a can 44 via a funnel wheel 43. It is also conceivable to discharge the formed sliver FB onto a conveying table and supply it to a following drafting arrangement (not shown) together with further slivers of adjacent combing heads.
A further covering element Al is arranged in the discharge region AG and serves particularly for controlling the air flows in conjunction with the orifices SI and S2, in order to reverse the fiber bundle appropriately for the reversal of the hook position.
To control the air flow L which is essential for the piecing-up operation of the fiber bundle P to the fleece V, a stationary covering hood 46 is mounted above the screen drum T. As shown diagrammatically in fig. 3, the covering hood has lateral walls 47 which extend on both end faces of the covering hood 46 into the region of the circumference U of the screen drum T. This gives rise, in conjunction with the circumferential surface U of the screen drum T and with the take-off rollers 5, to a space AM partitioned off with respect to the surroundings.
The distance between the covering hood 46 and the screen drum decreases as far as the region of the following doffing rollers 40 so as to avoid undesirable air flows.
Below the screen drum T is provided a further covering hood 54 which, like the covering hood 46, is likewise provided with lateral walls 57 which project as far as the screen drum T. For partitioning off with respect to the surroundings, the covering hood 54 is provided on one end region with a bend 54a which is at only a short distance from the circumferential surface U. The opposite end of the covering hood 54 extends as far as the circumferential surface of the upper roller of the take-off rollers 5.
The fiber fleece V is supplied by the rollers 40 to a following web funnel 41 in which the fleece is gathered from the width B (fig. 3) into a sliver FB. Such devices for
14

fleece gathering are already known in many variations in combers, cards or else drafting arrangements, and therefore are not dealt with in any more detail here.
The sliver FB formed in the web funnel 41 may be deposited into a can 44 via a funnel wheel 43 or be supplied to a following drafting arrangement on a conveying table together with further slivers of adjacent combing heads.
In the example shown in fig. 2, both the screen drum T and the cylinder Z have the same counterclockwise direction of rotation. The circumferential speed of the cylinder Z is identical to the circumferential speed of the take-off rollers 5. That is to say, the rotational speed of the cylinder Z must run synchronously with the comb cycle, so that the piecing-up operation or piecing operation can be carried out synchronously with the discharge of the fiber bundle. It is also possible, however, for the selected rotational speed of the cylinder Z to be a multiple of the comb cycle, without synchronization being lost. It is also likewise possible to drive the cylinder Z at a rotational speed which is a fraction of the circumferential speed of the cylinder in relation to the take-off rollers. In this case, however, it is necessary for the number of orifices in the cylinder to correspond to the fraction provided. If, for example, the circumferential speed of the cylinder Z corresponds to half the circumferential speed of the take-off rollers 5, the cylinder must have double the number of orifices SI in order to carry out the piecing-up operation. That is to say, two piecing operations are carried out during one revolution of the cylinder Z.
The rotational speed of the screen drum T is substantially slower than that of the cylinder Z and is adjusted correspondingly to the piecing-up operation. With the change in rotational speed of the screen drum, the piecing distance or the overlap of the end E with the rear end HE of the fiber bundle P can be changed.
In the example shown in fig. 2, the front end VE of the fiber bundle P is already located in the region of the screen drum T. Via the orifice S2 of the rotating cylinder Z, the space between the covering hood 54 and the screen drum T is connected via the orifices 35 of the screen drum T to the vacuum source Q which can be activated via a control unit ST. The air flow LI occurring thereby is oriented opposite to the direction of rotation to the screen drum and has the effect that the front end VE of the fiber
15

bundle P delivered by the take-off rollers is deflected downward. The positioning of the orifice S2 or SI is in this case coordinated exactly with the operation of delivering the fiber bundle P by means of the take-off rollers 5, in order to generate the air flow described. The orifice SI is still located behind the covering element Al and therefore has no connection to the vacuum source Q. The front end VE is held on the circumference U of the screen drum T by the air flow L1
As the procedure continues, the end HE of the fiber bundle P is released by the takeoff rollers 5. At the same time, the orifice S1 moves outside the covering range of the covering element Al and has the effect, due to the connection to the vacuum source Q and the orifices 35, that an air flow is generated, the released end HE of the fiber bundle P coming to lie on the screen drum T in its direction of rotation onto the end E of the fiber fleece V already formed or overlapping with said end. The orifice S2 has been displaced behind the covering element Al, with the result that the air flow LI has been interrupted.
By virtue of this piecing-up operation, the fiber bundle has been rotated during piecing up, with the result that the hook position has also been reversed.
This operation is repeated in each comb cycle, with the result that a new fiber bundle P is repeatedly pieced up to the fiber fleece V at a uniform rotational speed of the screen drum T and a reversal of the hook position is carried out.
As soon as a new end VE is delivered by the take-off rollers 5, the first orifice SI is located in the region of the covering hook 54 in order to generate an air flow LI which deflects this end VE downward opposite to the direction of rotation of the screen drum. As soon as the orifice S1 disappears behind the cover Al, this function is assumed by the orifice S2, until the operation already described, where the rear end HE of the fiber bundle P is released.
As already described, the overlap of the rear end HE of the fiber bundle P with the end E of the fiber fleece V may be determined by means of the rotational speed of the screen drum T.
16

The fiber fleece V is transferred due to the rotational movement of the screen drum T into the doffing region AB of the rollers 40 in which the stationarily mounted covering element A2 is also arranged. This ensures that this region is partitioned off with respect to the vacuum source Q, with the result that the fiber fleece can easily be lifted off from the circumferential surface U, in order to be transferred into the knit line between the take-off rollers 40. Via these driven rollers 40 (the drive is not shown), the fiber fleece V is discharged into a web funnel 41 which is likewise followed by driven take-off rollers 42. In the web funnel 41, the fiber fleece V is gathered in a known way into a sliver FB which is taken off by the take-off rollers 42 and deposited in loop form into a can 44 via a funnel wheel 43 shown diagrammatically. The sliver FB thus deposited can subsequently be transported for further processing, for example, to a flyer or an open-end machine, by means of the can 44.
The exemplary embodiments of fig. 2a and fig. 2b differ from the example of fig. 2 and fig. 3 in the mounting of a pivotable flap KL in the region of the cladding 46, the mounting of the lower cladding 54 having been dispensed with.
The cladding 46, in conjunction with the corresponding lateral walls 47 and the boundary caused by the screen drum T and the take-off rollers 5, gives rise to a space AM which is essentially partitioned off with respect to the ambient air and within which the operation of reversing delivered fiber bundles P and piecing them to the fiber fleece V already formed is carried out.
In order to control this operation more effectively even at high delivery speeds of the fiber bundles, in the examples of fig. 2a and fib. 2b the use of a flap KL is proposed, which is mounted pivotably about a pivot axis S A. The pivot axis S A may in this case be mounted in the machine stand or directly on the covering hood 46.
A pivoting device 70, which is activated by the control ST via the line 72, engages on the pivot axis SA which is pivotably mounted, for example, laterally in the region of the hood 46 or on the machine stand. This pivoting device may be, for example, a cylinder which is articulated on a lever connected fixedly in terms of rotation to the pivot axis. Via the control ST, the activation of the pivoting device 70 takes place
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synchronously to the movement of the take-off rollers or, in particular, synchronously to the position of the orifices S1, S2 of the cylinder Z.
In the position shown in fig. 2a, the flap KL is in a closed position, in which the free end of the flap is approximately tangent to the circumference of the lower take-off roller 5a. That is to say, there is only a short safety distance between the lower takeoff roller 5a and the flap KL. The front end VE of the fiber bundle P is deflected downward by the prevailing air flow indicated by arrows L. Under the action of the vacuum applied inside the screen drum and of the corresponding position of the orifice SI of the cylinder Z, the end VE is sucked onto the circumference U of the screen drum T. In this case, the front end VE in the fiber bundle P points opposite to the direction of rotation of the screen drum T. Between the covering hood 46 and the upper take-off roller 5b there is a gap 65 through which air can flow in from the surroundings.
The air flow L occurring due to this arrangement ensures that the reversal of the fiber bundle and the laying of its front end VE onto the screen drum T take place without damage to the fiber mix, even at high delivery speeds.
During the further rotation of the cylinder Z, the orifice SI is displaced behind the cover Al and is therefore partitioned off with respect to the vacuum source Q. With the displacement of the orifice SI, the orifice S2 is also displaced simultaneously into the position shown in fig. 2b, thus giving rise to an air flow in the direction of the doffing device 60, 61, as indicated by arrows L. Simultaneously with the displacement of the orifices SI and S2, the pivoting device 70 is activated by the control ST via the line 72 and causes the pivoting of the flap KL into the position shown in fig. 2b. This position is assumed shortly before the release of the rear end HE of the fiber bundle by the take-off rollers 5.
A nip KS occurs between the screen drum T and the free end of the flap KL, with the result that the front end VE of the fiber bundle is held reliably in bearing contact on the screen drum when the rear end HE is released by the take-off rollers. Via the orifice 90 which has occurred due to the pivoting of the flap KL, a further air flow then takes place in the tangential direction to the rotational movement of the screen
18

drum T, with the result that the released end HE is overlapped with the rear end E of the fiber fleece V already formed.
This air flow L results due to the corresponding position of the orifice S2 via which the front region of the hood 46 is put under a vacuum. The air volume sucked away in
this case is, for example, delivered again partially via an existing gap 65 and mainly via the orifice 90, as indicated by corresponding arrows. The second orifice SI is located behind the cover Al and is therefore inactive.
When this operation is concluded, the flap KL is pivoted into the position shown in fig. 2a again, with the result that a new fiber bundle P can be supplied again by the take-off rollers 5 for further piecing up. By the flap KL being used, the operation of piecing the fiber bundles on the screen drum can be carried out easily and in a directed way even at high delivery speeds of the fiber bundles, without damage to the fiber bundles occurring during the piecing-up operation.
Via the flap KL, it is possible, in particular, to control or to influence the air flows necessary for the piecing-up operation.
Instead of the flap KL, it would also be conceivable to form additional orifices which can be closed or opened at the appropriate time point by means of a device via a corresponding control.
Figs. 4 and 5 show diagrammatically a process line PL between a card KA and a ring spinning machine RS. The hook position of the hooks H of individual fibers F, such as are present in the individual process steps, is in this case shown diagrammatically. In the known process line according to fig. 4, the fibers discharged from the card KA are delivered with drag hooks and discharged into a can Kl. The can Kl serves as a reserve for a following drafting arrangement S I where the fibers F, after being taken off from the can Kl, pass with head hooks into the drafting arrangement S I. After the drafting operation, the fiber stock is deposited into a can K2 which serves as a reserve for a following lap-forming machine WM. This fiber stock, after being taken off from the can K2, passes with drag hooks into the lap-forming machine WM. The lap WW produced there is transferred to a following combing machine KM. The lap sheet
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unwound from the lap WW on the combing machine has fibers with head hooks which are partly opened up on the combing machine. The sliver formed on the combing machine still has head hooks which have not yet been opened up. This sliver is deposited into a can K3 which serves as a reserve for a following second drafting arrangement pass S II. After being taken off from the can K3, the fibers still provided with hooks H are delivered with drag hooks into the drafting arrangement SII. The sliver formed in the drafting arrangement SII is deposited into a can K4. The can K4 is subsequently transferred to a flyer FL, in which the fibers are present with head hooks, after the sliver has been taken off from the can K4. The bobbin SP produced at the flyer FL is subsequently transferred to a ring spinning machine for further processing. During the unwinding of the bobbin SP on the ring spinning machine RS, the fibers still provided with hooks H are present in the form of drag hooks, this being advantageous for this last processing process. That is to say, if head hooks were present, the processing process on the ring spinning machine would be disrupted and under certain circumstances would lead to losses of quality in yarn production.
For increasing efficiency and therefore also for a cost saving, there is always the attempt to shorten the process line PL, with the quality of the final product remaining the same. In this case, there are already proposals, for example, for avoiding the use of the second drafting arrangement step SII. This may be achieved, for example, by means of a regulated drafting arrangement on the combing machine. This, however, would cause a process step to be omitted, with the result that the hooks still present would be undesirable head hooks at the ring spinning machine. The invention comes in here and proposes to carry out the rotation of the hook position during the processing process on the combing machine KM, as shown diagrammatically in fig. 5. In this case, the fibers which are discharged in a sliver at the combing machine are present with drag hooks. During the subsequent process, with the drafting arrangement step S II being avoided, the fibers finally arrive via the flyer FL with drag hooks at the ring spinning machine.
It is obvious that the fiber stock may also have mixed forms of drag and head hooks and also double hooks. If drag or head hooks have been referred to previously in the exemplary embodiments, these make up the predominant fraction of hook forms in the fiber mix present in each case.
20

The combing machine is particularly suitable for reversing the hook position, especially since, in the processing process carried out there, the fiber stock is separated into individual fiber bundles which can then be reversed correspondingly.
21

We claim:
1. A method for reversing the hook position of the fibers (F) of a textile material to be processed in a process line (PL), characterized in that, during the processing process, the hooks (H) are reversed on a combing machine (KM) present in the process line (PL).
2. The method as claimed in claim 1, characterized in that the hooks (H) are reversed after the combing process and before the formation of a combing machine sliver (FB).
3. The method as claimed in claim 2, characterized in that that end (7) of a fiber mass (2) which is supplied in steps and nipped on the combing machine (KM) is combed out, from said end being subsequently taken off a fiber bundle (P) which is connected to a previously taken-off fiber bundle (P) to form a fiber fleece (V), while, as seen in the take-off direction (AR), the rear end (HE) of the fiber bundle (?) is overlapped with the present rear end (E) of the already previously taken-off fiber bundle or already present fiber fleece (V).
4. The method as claimed in claim 2, characterized in that, as seen in the take-off direction (AR), the front end (VE) of the fiber bundle (P) is oriented opposite the transport direction of the fiber fleece (V) during or after the take-off.
5. The method as claimed in claim 2, characterized in that the taken-off fiber bundle (P) is rotated through at least 90°, as seen in the take-off direction, before connection to the end (E) of the fiber fleece.
6. A combing machine for carrying out the method as claimed in claim 1, characterized in that the combing machine (KM) has means (T, Z) in order to reverse the hooks (H) after the combing process and before the formation of a combing machine sliver (FB).
7. A combing machine as claimed in claim 6, characterized by an assembly (1) for supplying a fiber mass (2) to a combing device (12, 13), the combing device
22

combing out that end (7) of the fiber mass which is fed in steps and nipped by the assembly (1) and from which fiber bundle (?) is taken off by means of a following take-off device (5) which discharges the fiber bundle (P) to a further device (T, Z), in order to overlap the ends (E) of the previously taken-off fiber bundle and of the new fiber bundle (P), the further device being provided with means (T, Z) which, as seen in the take-off direction (AR), overlap the rear end (HE) of the new fiber bundle (P) with the rear end (E) of the already previously taken-off fiber bundle or the end of the already formed fiber fleece (V).
8. The combing machine as claimed in claim 7, characterized in that the further device has a first rotating means (T) which is provided on its periphery (U), over its circumference, with orifices (35) for an air passage, and at least one part region of the inner space of the means (T) is connected to a vacuum source (Q), and a cladding (46, 47) is provided, which forms a space (AM), partitioned off with respect to the surroundings, between the take-off device (5) and the periphery (U) of the rotating means (T), a part region of the partitioned-off space (AM) being formed by the periphery (U) of the means (T) and by the take-off device (5).
9. The combing machine as claimed in claim 8, characterized in that the partitioning-off of the space (AM) with respect to the ambient air amounts to between 80% and 99%.
10. The combing machine as claimed in one of claims 8 and 9, characterized in that, within the rotating means (T), at least one second means (Z) is provided, via which the free air passage is controllable, at least over a part region of the orifices (35), between the surroundings of the first means (T) and the vacuum source (Q) at time intervals in synchronization with the discharge of the fiber bundle (P).
11. The combing machine as claimed in claim 10, characterized in that the second means (Z) is connected to a drive (M, G) and has on its circumference at least one orifice (SI, S2) which extends approximately over the width (B) of the
23

taken-off fiber bundle (?) and via which a connection between air passages (35) of the first means (T) and the vacuum source (Q) can be made.
12. The combing machine as claimed in claim 11, characterized in that, within the
first means (T), at least one stationarily arranged covering element (Al, A2) is
mounted, which partitions off a part region of the air passages (35) of the first means (T) with respect to the vacuum source (Q) over the width (B) of the taken-off fiber bundle (P).
13. The combing machine as claimed in claims 10 to 12, characterized in that the first means consists of a rotatably mounted screen drum (T), within which the second means is arranged as a rotatably mounted cylinder (Z).
14. The combing machine as claimed in claims 10 to 13, characterized in that the rotational speed of the second means (Z) is a single or a multiple of the number of comb cycles of a combing machine (KM).
15. The combing machine as claimed in one of claims 10 to 13, characterized in that the rotational speed of the second means (Z) is a fraction of the number of comb cycles of the combing machine (KM).
16. The combing machine as claimed in one of claims 14 and 15, characterized in that means (ST, M, G) are provided in order to control or set the rotational speed of the first and/or the second means (T, Z).
17. The combing machine as claimed in claims 14 to 16, characterized in that means (ST, M, G) are provided in order to set the direction of rotation of the first and/or second means (T, Z).
18. The combing machine as claimed in one of the preceding claims 12 to 17, characterized in that the covering element (Al, A2) is arranged within the second means (Z).
24

19. The combing machine as claimed in claim 17, characterized in that the second means (Z) has two orifices (SI, S2) arranged so as to be offset to one another on its circumference, and at least two covering elements (Al, A2) arranged so as to be offset to one another are provided.
20. The combing machine as claimed in claim 11, characterized in that further smaller orifices (53) are provided, distributed on the circumference of the second means (Z), which extend only over a part region with respect to the width of the taken-off fiber bundle.
21. The combing machine as claimed in claim 8, characterized in that at least parts of the cladding (46,47, 54, 57) consist of a transparent material.
22. The combing machine as claimed in one of claims 8 or 21, characterized in that at least parts of the cladding (46,54) consist of an antistatic material.
23. The combing machine as claimed in one of claims 8 to 22, characterized in that, in the region of the cladding (46, 47), at least one adjustable element (KL) is provided, which is suitable for controlling at least one orifice (90) for air passage between the partitioned-off space (AM) and the ambient air of the cladding (46,47).
24. The combing machine as claimed in claim 23, characterized in that the element consists of a flap (KL) which is pivotable about a pivot axis (SA) and which, as seen transversely to the transport direction of the fiber fleece (V), extends essentially over the length of the take-off device (5).
25. The combing machine as claimed in claim 24, characterized in that the pivot axis (SA) of the flap (KL) is arranged in the region below the take-off device (5), and the free end (KE) of the flap points in the direction of the take-off device.
25

26. The combing machine as claimed in claim 24, characterized in that the free end (KE) of the flap (KL) forms a nip (KS) with the first means (T) in the open position.
27. The combing machine as claimed in one of the preceding claims 8 to 25, characterized in that a doffing device (40) for doffing the fiber fleece (V) formed on the first means (T) is provided for the means (T).
28. The combing machine as claimed in claim 26, characterized in that the doffing device (40) is arranged downstream of the boundary (54a) of the cladding (46, 54).
29. The combing machine as claimed in either one of claims 26 and 27, characterized in that the doffing device is a pair of rollers (40).
30. The combing machine as claimed in either one of claims 26 and 27, characterized in that the doffing device (40) is followed by a sliver (FB) forming device (41,42).
31. The combing machine as claimed in claim 13, characterized in that the radial distance (a) between the screen drum (T) and the cylinder (Z) is between 0.2 and 2 mm.

26

Abstract
The invention relates to a method and a device for reversing the hook position of the fibers (F) of a textile material to be processed in a process line (PL). To obtain the correct hook position at the terminal spinning machine, even in the case of an even number of process steps processing textile material between the card (K) and the ring spinning machine (RS), it is proposed that the hooks (H) be reversed, during the processing process, on a combing machine (KM) present in the process line (PL).
(Fig. 2)

METHOD AND DEVICE FOR REVERSING THE HOOK POSITION OF FIBERS IN A COMBING MACHINE

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