COMBING MACHINE AND METHOD FOR OPERATING A COMBING MACHINE

Description

[0001] The invention relates to a combing machine and a method for operating a combing machine according to the preamble of the independent claims.

[0002] In the classic combing method, e.g., according to Heilmann, cotton wool is removed from a cotton roll and fed to a pair of tongs by means of a feed roller. In a retracted position, the tongs are closed and hold a protruding front end section of the cotton wool in the form of a fiber beard. This protruding fiber beard is combed out by the round comb located below the tongs. The tongs are then moved to a forward, open position, whereby the tear-off rollers, by rotating backward, convey a previously combed-out fiber beard, along with its rear end section, towards the front end section of the cotton wool held by the tongs. The fiber beard combed out by the round comb lies on this rear end section and is drawn together into the clamping point of the tear-off rollers, as the tear-off rollers reverse their direction of rotation.During this rotation, where the angle of rotation is approximately twice that of the preceding reverse rotation, the fiber strand is torn from the cotton wool located in the clamping unit. The rear end of the torn fiber strand is then pulled through the fixed comb.

[0003] The stripping rollers perform a stepping motion, during which they return an end piece of the fiber stripped during the previous comb pass. The beginning piece of the fiber strip is placed onto this end piece and, after a reversal of rotation, soldered together by the pressure of the two stripping rollers. With each comb pass, the stripping rollers must not only change their direction of movement twice, but also travel a shorter distance on the return stroke than on the forward stroke. A cam disc, cam wheel, or cam groove is often used for this movement of the stripping rollers, which is rigidly coupled to the gripper movement via a gearbox. Alternatively, servo motors are used, which must continuously perform a reciprocating acceleration and deceleration motion. This reciprocating stepping motion of the stripping rollers is achieved with a gearbox coupling or an electric or...The servo-motor drive of the adjacent combing heads at combing cycles exceeding 400 per minute places extreme stress on the shafts, leads to significant vibrations in the combing machine, and consumes a great deal of energy. The drive motors for the stripping rollers must be very powerful and also require high-performance servo inverters to supply the motors. The constant acceleration and deceleration results in high power losses, which are reflected in the combing machine's energy consumption and necessitate water cooling of the electric motors at combing cycles exceeding 500 per minute. This makes the motors very expensive.

[0004] DE 197 13 225 A1 discloses a combing machine with a tearing device for tearing off fiber strands, which are combed out by a combing device and presented by a gripper unit, and with a soldering device downstream of the tearing device at a certain distance for soldering the torn and distorted fiber strands and for forming a combed fleece, wherein the tearing device has a pair of tearing rollers rotatably driven in the tearing direction and the soldering device has a soldering roller rotatably driven in the tearing direction, which can be loaded with a pressure roller.It is provided that the drive of the tear-off roller for the drive of the soldering roller is designed or controlled in such a way that the circumferential speeds of the tear-off rollers to the soldering roller differ at least in a partial section during a combing cycle, whereby the end of the formed combed fleece is clamped on the soldering roller with the pressure roller during the entire combing cycle and thereby ensures an uninterrupted removal of the combed fleece.

[0005] Starting from this known state of the art, the object of the invention is to create a combing machine and a method for combing out short fibers, with which these disadvantages are reduced.

[0006] The invention is solved by the features of claim 1 and claim 12. Advantageous embodiments of the invention are defined in the dependent claims.

[0007] The invention relates to a combing machine with several combing heads, wherein at least one cotton strip is fed to a feed cylinder and a gripper assembly at each combing head, the combed fibers are removed from the cotton strip and vacuumed up by means of fixed and circular combs, and the resulting fiber pile is formed into a fiber band by means of a funnel, which is stretched together with the other fiber bands from the other combing heads to form a single fiber band, and wherein a first pair of tear-off rollers and a second pair of tear-off rollers are arranged downstream of the gripper assembly. Both pairs of tear-off rollers are designed to be operated exclusively with a constant direction of rotation during a combing cycle. The first pair of tear-off rollers is operated at a higher speed than the second pair of tear-off rollers, at least at the beginning of a combing cycle.

[0008] The invention includes the technical teaching that both pairs of tear-off rollers are designed to reduce or increase their rotational speed to an identical value after the fiber beard of the cotton tape has reached an overlap length on the fiber pile.

[0009] Since the first pair of tear-off rollers no longer rotates back, the fiber strand of the cotton tape is torn from the gripper unit by an increased rotational speed and laid overlapping onto the fiber mat, which is conveyed at a lower rotational speed by the second pair of tear-off rollers. The higher rotational speed of the first pair of tear-off rollers relative to the second pair creates an overlap length with which the torn fiber strand can be laid onto the fiber mat. According to the invention, the soldering process thus takes place between the pairs of tear-off rollers. The connection between the torn fiber strand from the cotton tape and the formed fiber mat is therefore made at the clamping point of the second pair of tear-off rollers. This shifts the soldering process from before the first pair of tear-off rollers to after the first pair of tear-off rollers, or to before the second pair of tear-off rollers.Similarly, the clamping point has shifted from the first pair of tear-off rollers to the second pair of tear-off rollers.

[0010] The invention is based on the possibility that smaller motors and / or a simpler gearbox can be used with the continuous rotation of the tear-off rollers, while still enabling a higher number of combing cycles. A gearbox solution results in a significantly simpler gearbox for realizing the movement according to the invention. The elimination of acceleration, deceleration, and reversal of the tear-off rollers' direction of rotation reduces the energy consumption of the combing machine. The tear-off process of the fiber strip and the subsequent soldering process to the fiber pile occur more continuously, thereby significantly reducing or even eliminating the fiber pile warp compared to the prior art.Since both pairs of tear-off rollers are designed to reduce or increase their rotational speed to an identical value after the fiber beard of the cotton tape has reached an overlap length on the fiber pile, the soldering process is optimized, as otherwise a relative movement between the fiber pile and the fiber beard of the cotton tape would occur when passing through the second pair of tear-off rollers, which is avoided with the teaching according to the invention.

[0011] Preferably, the tear-off rollers are driven by at least one gearbox configured to change the rotational speed of one or both pairs of tear-off rollers at the beginning of a comb action and when the tear-off rollers reach a further position. The at least one gearbox can drive both pairs of tear-off rollers, or each pair of tear-off rollers can have its own separate gearbox. Regardless of the embodiment, the gearbox(s) is configured to adjust the start of the comb action depending on the movement of the gripper assembly. Furthermore, the at least one gearbox is also configured to adjust the rotational speed of each pair of tear-off rollers at the beginning of the comb action and to change this rotational speed again when a further adjustable rotational position is reached.This allows the fiber bead and the fiber web to enter the clamping point of the second pair of tear-off rollers at the same speed and without delay once a set overlap length has been reached. Similarly, the transfer point of the fiber bead, clamped by the clamping unit, to the first pair of tear-off rollers can be adjusted by aligning the gear(s) with the movement of the gripper unit. The uniformity of the fiber web is further influenced by coordinating the movement of the first pair of tear-off rollers with the gripper unit, by determining the tear-off point of the fiber bead from the cotton tape clamped by the gripper unit.

[0012] Alternatively, each pair of tear-off rollers has its own motor, which can be individually adjusted for speed, angle of rotation, and start time for each combing cycle. Furthermore, the combing machine has a control system designed to change the rotational speed of one or both pairs of tear-off rollers when an adjustable index position of the motors is reached. This allows the fiber beard and the fiber nap to enter the clamping point of the second pair of tear-off rollers at the same speed and without delay after a set overlap length has been reached. The overlap length between the fiber beard and the fiber nap can be adjusted via the motor control system. Likewise, the transfer point of the fiber beard, clamped by the gripper unit, to the first pair of tear-off rollers can be set via the motor control system.The uniformity of the fiber pile is further influenced by the coordination of the movement function of the first tear-off roller pair to the gripper unit, in which the tear-off time of the fiber beard from the cotton tape clamped by the gripper unit is determined.

[0013] Preferably, the position of the first tear-off roller pair relative to the gripper unit can be adjusted so that this geometry can be adjusted to the feed amount of the gripper unit and to the overlap length of the fiber beard on the fiber nap depending on the fiber quality or fiber length.

[0014] The adjustable spacing between the pairs of tear-off rollers also allows for precise control of the overlap length and thus the combing process. This ensures that the fiber beard is properly laid on top of the fiber nap.

[0015] In an advantageous embodiment, the control system can be designed to synchronize or adjust the tear-off time of the fiber beard from the cotton tape clamped by the gripper unit with the start of the comb action of the first tear-off roller pair.

[0016] Preferably, at least one guide plate or limiter can be arranged between the pairs of tear-off rollers to improve the brazing process.

[0017] In a further supplementary embodiment, at least one device for generating compressed air or a vacuum can be arranged between the pairs of tear-off rollers. This allows for deflection of the fiber beard and / or the fiber nap, thereby enabling a more precise soldering process.

[0018] Because the combing process is continuous and no piling motion moves the fiber web back and forth, no wave forms in the fiber web. This eliminates the need for a subsequent fleece bowl, allowing for a more compact fiber web discharge area after the second pair of tear-off rollers. At least one guide element can be positioned here to direct the fiber web to a hopper. This guide element can be rounded so that the edges of the fiber web fold over, resulting in a more uniform quality of the discharged fiber web.

[0019] Another space-saving embodiment can be designed such that at least one transverse belt pull-off can be arranged after the second pair of tear-off rollers, which is designed to guide the resulting fiber pile to a funnel.

[0020] The method according to the invention is characterized in that a first pair of tear-off rollers and a second pair of tear-off rollers are arranged downstream of the gripper unit. During a comb cycle, both pairs of tear-off rollers are operated exclusively with a constant direction of rotation. The first pair of tear-off rollers is operated at a higher rotational speed than the second pair of tear-off rollers, at least at the beginning of a comb cycle, thereby creating an overlap between a torn fiber beard and the emerging fiber nap between the pairs of tear-off rollers. This ensures that the soldering process occurs downstream of the first pair of tear-off rollers. The soldering process takes place between the pairs of tear-off rollers with the direction of rotation of the tear-off rollers remaining constant.

[0021] The invention has the advantage that the continuous rotation of the tear-off rollers allows for the use of a simpler gearbox and / or smaller motors, while still enabling a higher number of combing cycles. The elimination of acceleration, deceleration, and reversal of the tear-off rollers' rotation reduces the energy consumption of the combing machine. The tear-off process of the fiber strip and the subsequent soldering process to the fiber pile are more continuous, thus eliminating the nonwoven wave of the fiber pile compared to the prior art.

[0022] Further measures improving the invention are described in more detail below together with a description of a preferred embodiment of the invention with reference to the figures.

[0023] They show: Fig. 1 a schematic side view of a combing head of a combing machine according to the prior art; Fig. 2 a representation of the tear-off roller movement according to the invention; Fig. 3 a movement diagram of the pairs of tear-off rollers not belonging to the invention; Fig. 4 a movement diagram of the pairs of tear-off rollers according to the invention; Fig. 5 an alternative movement diagram of the pairs of tear-off rollers according to the invention; Fig. 6 a movement diagram of the pairs of tear-off rollers not belonging to the invention; Fig. 7 a movement diagram of the pairs of tear-off rollers not belonging to the invention; Fig. 8 a view of the pairs of tear-off rollers before soldering; Fig. 9 a further view of the pairs of tear-off rollers before soldering; Fig. 10 a further view of the pairs of tear-off rollers before soldering; Fig. 11 a further view of the pairs of tear-off rollers during soldering; Fig. 12 shows a further illustration of the guidance of the fiber pile after the second pair of tear-off rollers; Fig.13 an alternative embodiment for guiding the fiber pile after the second pair of tear-off rollers; Fig. 14 a further alternative embodiment for guiding the fiber pile after the second pair of tear-off rollers.

[0024] The following are, with reference to the Fig. 1 the state of the art and in the Figures 2 to 14 Preferred embodiments of the combing machine according to the invention are explained. Identical features in the drawing are identified by the same reference numerals. It should be understood that the drawing is simplified and, in particular, not to scale.

[0025] In Figure 1A combing head 20 according to the prior art is shown, of which at least eight are mounted on a combing machine. For the sake of clarity, the exemplary embodiment is shown and described using only one combing head 20, wherein the details shown are installed on each of these combing heads, except for the common drive units and the tape storage. The combing head 20 consists, among other things, of two winding transport rollers 2, 3, on which a cotton roll 1 with a winding sleeve rests and from which the cotton tape 4 is unwound by a tensile load from a feed roller 7. The winding transport rollers 2, 3 can be driven individually or both together. The design of the winding transport rollers 2, 3, whether they are only rotating and not driven, or individually or both driven, is not relevant to the invention.

[0026] The cotton strip 4 is transferred to a feed cylinder 7 of a gripper assembly 5. The gripper assembly 5 is movable back and forth via levers and driven by a shaft 6, which is connected to a gearbox 17. According to the illustrated example, the gripper assembly 5 is in a forward position and transfers the combed-out fiber strand to a subsequent pair of tear-off rollers 10, 12, the first in the fiber transport direction. A circular comb 8 is rotatably mounted below the gripper assembly 5, and its comb segment combs out the fiber strand presented by the closed gripper. The circular comb 8 is also driven by the gearbox 17. A ratchet wheel (not shown) is mounted on the feed cylinder 7. The ratchet wheel is rotated incrementally by the back-and-forth movement of the gripper assembly 5 via a pawl (also not shown), thereby feeding the cotton strip 4 to the gripper jaws for combing.During operation, the cotton tape 4 is continuously unwound by the rotary motion of the cotton winding 1 over the winding transport rollers 2, 3 and reaches the feed cylinder 7. The cotton is then fed via the feed cylinder 7 to the gripper jaws of the gripper unit 5 for combing and subsequently discharged to the first pair of tear-off rollers 10, 12 in the fiber transport direction. The discharged fiber strand is drawn through the fixed comb 9 and soldered to the preceding fiber strand. The resulting fiber web 14 is transferred via a second pair of tear-off rollers 11, 13 in the fiber transport direction. The fiber web 14 formed here, which consists of individual soldered pieces of fiber strand, is drawn through a hopper 15 by means of take-off rollers 16 and formed into a fiber ribbon 21. This fiber ribbon, along with the fiber ribbons also formed at the other comb heads, is fed to a drawing unit (not shown).The fleece emerging from the drawing machine is gathered into a fiber strip, the so-called combing machine strip, and transferred to a strip tray for placement in a can.

[0027] In this state of the art, the gripper unit 5 is moved into a forward, open position, whereby the tear-off rollers 10, 12, by means of a reverse rotation, convey a previously combed-out fiber strand with its rear end section towards the front end section of the cotton wool clamped by the gripper. The tear-off rollers 11, 13 perform the same movement, so that the fiber pile 14 is moved back a short distance. The fiber strand combed out by the round comb 8 lies onto this rear end section and is drawn together with it into the clamping point of the tear-off rollers 10, 12, as the tear-off rollers 10, 12 and 11, 13 reverse their direction of rotation again. During this rotation, in which the angle of rotation is approximately twice that of the preceding reverse rotation, the fiber strand is torn from the cotton wool located in the gripper unit 5. The rear end of the torn fiber beard is pulled through the fixed comb 9.The tear-off rollers 10, 12, 11, 13 perform a stepping motion, retracting an end piece of the fiber stripped during the previous comb pass during a return rotation. The beginning piece of the fiber strip is placed onto this end piece and, after a reversal of rotation, soldered together by the pressure of the two tear-off rollers 10, 12. With each comb pass, the tear-off rollers 10, 12, 11, 13 must not only change their direction of movement twice, but also rotate a shorter distance on the return stroke than on the forward stroke.

[0028] Figure 2Figure 1 illustrates the basic principle of the invention, according to which both the first pair of tear-off rollers 10, 12 and the second pair of tear-off rollers 11, 13 rotate in the same direction during the entire combing process, thereby transporting the resulting fiber web 14 to the take-off rollers 16. An existing combed and formed fiber web 14 is transported towards the take-off rollers 16, to which a detached fiber strand of the cotton tape 4 is soldered after the first pair of tear-off rollers 10, 12. Since the first pair of tear-off rollers 10, 12 no longer rotates backward, the fiber strand of the cotton tape 4 is torn from the gripper unit 5 by an increased rotational speed and laid overlapping onto the fiber web, which is moved at a lower rotational speed by the second pair of tear-off rollers 11, 13. According to the invention, the soldering process takes place between the pairs of tear-off rollers 10, 12; 11, 13.The connection between the torn fiber strand from the cotton tape 4 and the formed fiber mat 14 thus takes place at the clamping point of the second pair of tear-off rollers 11, 13. The soldering process has therefore shifted from before the first pair of tear-off rollers 10, 12 to after the first pair of tear-off rollers 10, 12, or to before the second pair of tear-off rollers 11, 13. Likewise, the clamping point has shifted from the first pair of tear-off rollers 10, 12 to the second pair of tear-off rollers 11, 13. To support the highly dynamic soldering process between the pairs of tear-off rollers, according to the embodiments of the... Figures 2 and 8 to 12 Several constructive designs may be useful, which are described below. In the Figure 2For example, a guide plate 22 is arranged between the pairs of tear-off rollers, on the upper surface of which the torn fiber strand is laid overlapping onto the fiber pile 14. The guide plate 22 can, for example, have one or more passages for compressed air, i.e., be perforated. The combing process can be carried out as in conventional combing with the round comb 8, in which it combs out the next fiber strand protruding from the gripper unit 5. The fixed comb 9 is also used and pierces the end of the torn fiber strand when the first pair of tear-off rollers tears the fiber strand from the gripper unit 5 during acceleration. For this, only the geometry, namely the distances between the front position of the gripper unit 5 and the first pair of tear-off rollers 10, 12, needs to be adjusted so that the new fiber strand can be transferred from the gripper unit 5 to the clamping point of the first pair of tear-off rollers 10, 12.These distances, as well as the distances between the tear-off roller pairs, are adjustable and can be adapted to the overlap length L2 and the feed amount.

[0029] Preferably, the tear-off rollers 10, 12; 11, 13 are driven by means of at least one gearbox (not shown) configured to change the rotational speed of one or both pairs of tear-off rollers 10, 12; 11, 13 at the beginning of a comb action and when the tear-off rollers reach a further position. The at least one gearbox can drive both pairs of tear-off rollers 10, 12; 11, 13, or each pair of tear-off rollers 10, 12; 11, 13 can have its own separate gearbox. Regardless of the embodiment, the gearbox(s) are configured to adjust the beginning of the comb action depending on the movement of the gripper assembly 5. Furthermore, the at least one gearbox is also configured to adjust the rotational speed of each pair of tear-off rollers 10, 12; 11, 13 at the beginning of the comb action and to change this rotational speed again when a further adjustable rotational position is reached.This allows the fiber beard to enter the clamping point of the second tear-off roller pair 11, 13 at the same speed and without delay once a set overlap length has been reached. Likewise, the transfer point of the fiber beard clamped by the gripper unit 5 to the first tear-off roller pair 10, 12 can be adjusted by adjusting the gear(s) to the movement of the gripper unit 5. The uniformity of the fiber web 14 is further influenced by coordinating the movement function of the first tear-off roller pair 10, 12 with the gripper unit 5, by determining the tear-off point of the fiber beard from the cotton tape 4 clamped by the gripper unit 5.

[0030] The following examples of implementation of the Figures 3 to 7Figure 1 shows an example of the movement sequence of the tear-off roller pairs 10, 12; 11, 13 with a separate motor for each pair. The movement sequence is identical in a gearbox solution, where the index positions of the motor can then be represented by a gearbox position or the timing of the rotation of the tear-off rollers 10, 12; 11, 13. Accordingly, the gearbox is designed to operate the two tear-off roller pairs (10, 12; 11, 13) at a higher or lower rotational speed after the overlap length (L2) has been formed.

[0031] Although not shown in the following exemplary embodiments, the combing machine has a control system with which the drives or motors of the tear-off rollers 10, 12; 11, 13 can be controlled. Preferably, each pair of tear-off rollers 10, 12; 11, 13 has a separate motor, which can be designed as a servo motor or a motor-gearbox combination. The separate motors allow the pairs of tear-off rollers to be adjusted independently of each other, at least with regard to their rotational speed and the start of the combing action.

[0032] After Figure 3In the motion diagram (not part of the invention), the rotation angles of the tear-off rollers 10, 11, 12, 13 are shown on the ordinate, and the index position of the associated drive motor is shown on the abscissa. This index position can be converted into a comparable time for a comb pass. As an example, a comb pass is shown in the motion diagram using the index position of 40 positions (from 24 to 40 and from 40=0 to 24). The movement of the second pair of tear-off rollers 11, 13 in the fiber transport direction is shown as a solid line, and the movement of the first pair of tear-off rollers 10, 12 as a dashed line. At a value of 24 on the abscissa, both pairs of tear-off rollers 10, 12 and 11, 13 have a rotation angle of 0°. The gripper unit 5 is in the foremost position and the clamping line of the first pair of tear-off rollers 10, 12 captures the fiber beard.The second pair of tear-off rollers 11, 13 rotates at a constant speed and in a constant direction of rotation over one combing cycle, rotating 125°. During this process, a fiber web 14 is transported over the (circumferential) length L1 of the tear-off rollers 11, 13 towards the take-off rollers 16. Simultaneously, the first pair of tear-off rollers 10, 12 rotates at a higher speed and reaches a rotation angle of 225° at index position I1 (8.2). The torn fiber fiber of the cotton tape 4 from the gripper unit 5 is pushed onto the fiber web 14 with the overlap length L2 (= difference between the circumferential length of the first tear-off rollers 10, 12 and the circumferential length traveled by the second tear-off rollers 11, 13 in the same time). At the same time, the angle of rotation of the second pair of tear-off rollers 11, 13 in this embodiment is 75°, so that the difference in the angle of rotation results inThe difference in circumferential length results in the overlap length L2 of the torn fiber strand from the cotton tape 4 with the fiber pile 14, both of which are soldered to the second pair of tear-off rollers 11, 13 at the same rotational speed and direction. From index position I1, from 24 via 40 to 8.2, the overlap length L2 is formed due to the same direction of rotation but different rotational speeds of the pairs of tear-off rollers 10, 12; 11, 13. This overlap length is formed by the higher rotational speed of the first pair of tear-off rollers 10, 12. The soldering process takes place at index position I2, from 8.2 to 24, where both pairs of tear-off rollers 10, 12; 11, 13 have the same rotational speed, thus preventing any relative displacement of the torn fiber strand on the fiber pile 14. At index position 24, a new combing cycle therefore starts with a rotation angle of 0°.In summary, at the beginning of the combing cycle, the first pair of tear-off rollers 10, 12 rotates faster than the second pair of tear-off rollers 11, 13 to form the overlap length L2. During and after the soldering of the fiber strand from the cotton tape 4 to the fiber pile 14, both pairs of tear-off rollers rotate at the same speed. The first pair of tear-off rollers 10, 12 changes its rotational speed during the combing cycle, while the second pair of tear-off rollers 11, 13 maintains a constant rotational speed.

[0033] In the exemplary embodiment of the Figure 4 According to the invention, the second pair of tear-off rollers 11, 13 rotates at a higher rotational speed at the beginning of the comb action than according to the embodiment of the Figure 3and reaches a rotation angle of 100° at, for example, index position 8. Simultaneously, the rotation angle of the first pair of tear-off rollers 10, 12 is 250°, resulting in an overlap length of L2, which corresponds to a rotation angle difference of 150°. From index position 8 onwards, both pairs of tear-off rollers 10, 12; 11, 13 rotate again at the same speed, so that the overlap length L2 remains constant and thus the fiber end of the cotton tape 4 is soldered to the fiber pile 14 as it passes through the second pair of tear-off rollers 11, 13. According to this embodiment, the conveying path of the second pair of tear-off rollers 11, 13 is the same as in the first embodiment. Figure 3 The overlap length L2 is somewhat larger here, however, because the first pair of tear-off rollers 10, 12 rotates faster than in Figure 3 , and so much faster that, despite the increased speed of the second pair of tear-off rollers 11, 13, the difference is still greater than in Figure 3 . Both pairs of the tear-off rollers 10, 12; 11, 13 start with a different rotational speed and reduce this to the identical rotational speed when the necessary or set overlap length L2 is reached.

[0034] In summary, at the beginning of the combing cycle, the first pair of tear-off rollers 10, 12 rotates faster than the second pair of tear-off rollers 11, 13 to form the overlap length L2. During and after the soldering of the fiber strand from the cotton tape 4 to the fiber pile 14, both pairs of tear-off rollers reduce their rotational speed and rotate at the same speed.

[0035] In the exemplary embodiment of the Figure 5According to the invention, both pairs of tear-off rollers rotate at different speeds, with the first pair of tear-off rollers 10, 12 rotating faster than the second pair of tear-off rollers 11, 13 at the beginning of the combing cycle in order to form the overlap length L2. During and after the soldering of the fiber strand from the cotton tape 4 to the fiber pile 14, both pairs of tear-off rollers rotate at the same speed, which has been increased by both pairs. In contrast to the embodiments of the Figures 3 and 4The soldering process only occurs at a later index position because the second pair of tear-off rollers 11, 13 is driven at a very slow rotational speed. The soldering process only starts at index position 15, i.e., in approximately the last quarter of the combing cycle. In all embodiments, the overlap length L2 can be varied due to the difference in rotational speed between the pairs of tear-off rollers and by changing the rotational speed to the same or different index positions of the individual pairs of tear-off rollers. To optimize the soldering process, it is advantageous for both pairs of tear-off rollers to have the same rotational speed, as otherwise a relative movement occurs between the fiber pile 14 and the fiber beard of the cotton tape 4 as it passes through the second pair of tear-off rollers 11, 13.

[0036] In the embodiment not belonging to the invention of the Figure 6Both pairs of tear-off rollers 10, 12; 11, 13 rotate with an increasing rotational speed, which then decreases at index position 8, 2. This means that both pairs of tear-off rollers experience their highest acceleration at a rotation angle of 0°, which then decreases at least until index position I1, as the overlap length L2 is formed at this point. After the overlap length L2 is formed, the rotational speed of both pairs of tear-off rollers continues to decrease, but they then operate at the same rotational speed.

[0037] Figure 7Figure 1 shows that both pairs of tear-off rollers 10, 12; 11, 13 continue to rotate at a constant but different speed even after reaching the overlap length L2; however, this illustration is not part of the invention. Since the rotational speed of the first pair of tear-off rollers 10, 12 increases further after reaching the overlap length L2 relative to the second pair of tear-off rollers 11, 13, the fiber strands of the cotton tape 4 are pushed onto or into the fiber pile 14 and can accumulate in front of the second pair of tear-off rollers 11, 13, at least with long fibers. With short fibers, this effect can be advantageous because the fiber ends are shifted into one another.

[0038] Figure 8Figure 1 shows the tear-off roller pairs 10, 12 and 11, 13, which are arranged at a greater distance from each other. In this method for soldering the fiber strand from the cotton tape 4 to the fiber web 14 between the tear-off roller pairs, this is technically possible and advantageous compared to the classic combing method, since, depending on the overlap length L2, the distance according to the prior art is too small to achieve good guidance of the fiber strand and good soldering to the fiber web 14. The size of the distance between the tear-off roller pairs is preferably adjustable so that, with a large overlap length L2, the fiber strand is well guided and can be precisely laid on the fiber web 14 without the fiber strand being simultaneously caught by the second pair of tear-off rollers 11, 13.With regard to short-staple or long-staple fibers, this allows for adjustments to the soldering of the fibers and the guiding of the formed fiber web in the clamping line of the second pair of tear-off rollers. The more generous spacing also has the advantage of reducing manufacturing costs, as the components and their bearings no longer need to be as compact. Additionally, this simplifies the maintenance of the combing machine.

[0039] Regardless of the adjustable distance between the tear-off roller pairs, it shows Figure 8 a pressurization of the fiber beard entering between the tear-off roller pairs by means of compressed air 23 from below, whereby the entering fiber beard is pushed upwards due to the higher rotational speed of the first tear-off roller pair 10, 12 and placed on the fiber web 14 and thus soldered on in an overlapping manner.

[0040] Figure 9Figure 1 shows a further embodiment in which compressed air 23 from above presses the peeled fiber layer 14 downwards, so that the incoming fiber beard of the cotton tape 4 lies on the fiber layer 14 and is thus soldered in an overlapping manner. This embodiment is advantageous with regard to the cleaning roller arranged above and between the pairs of peel rollers, since its rotational movement forces air from above between the pairs of working rollers. Advantageously, in this embodiment and the embodiment of the Figure 8 delivered in pulses, so that with each combing action a short pulse of compressed air is delivered between the tear-off roller pairs for the moment just before soldering.

[0041] Figure 10 This shows in Figure 2The guide plate 22, already arranged between the pairs of tear-off rollers, is angled downwards by an arc towards the second lower tear-off roller 11 in the horizontally arranged area, thus forming a gap to the second lower tear-off roller 11, which is sucked in by means of a vacuum 24. The vacuum 24 can be generated at this point by the system suction pressure of the combing machine, which, for example, is already present under all combing heads for the extraction of short fibers. With this arrangement of the guide plate 22, it is possible to operate without controlling the compressed air 23, as is the case, for example, in the embodiments of the Figures 8 and 9 This can be achieved by using the existing negative pressure 24 of the combing machine without having to do so in a pulsed manner. However, this can be intensified by a pulsed burst of compressed air 23, which is applied from above into the gap between the guide plate 22 and the second lower tear-off roller 11.

[0042] The application of compressed air or the generated vacuum causes the fiber beard or fiber nap to deflect, initially delaying the bonding of the two, but then creating a bond with the full overlap length. This results in the fibers being laid more evenly on top of each other and joined by the subsequent clamping point of the second pair of tear-off rollers. The designs of the Figures 8 to 10 They can be combined and varied in any way.

[0043] In Figure 11The fiber beard is already soldered to the fiber web 14 and, in the next step, is conveyed through the clamping point of the second pair of tear-off rollers 11, 13 and joined together. Above the two pairs of tear-off rollers 10, 12; 11, 13, a cleaning roller 25 is arranged – as is known from the prior art – which cleans both pairs of tear-off rollers simultaneously by its rotational movement. To prevent the air circulation caused by the cleaning roller 25 from interfering with the soldering process between the pairs of tear-off rollers, a limiter 26 is arranged vertically below the cleaning roller 25 but above the fiber web 14, and is located horizontally between the upper tear-off rollers 12, 13. In addition to preventing unwanted air circulation, the limiter 26 can also be designed to guide the fiber beard with the fiber web 14 on its upper side.The mechanical guidance of the fiber tip by the limiter 26 can improve the soldering process, as wavy thin and thick spots are avoided during soldering. A combination of the limiter 26 with the designs of the . Figures 2 and Figures 8 to 10 This is of course possible. The limiter 26 increases the uniformity of the fiber pile 14, as the fiber strand emerging from the first pair of tear-off rollers 10, 12 is guided without air turbulence, thus ensuring more even soldering. Instead of the single cleaning roller 25, which cleans both upper tear-off rollers 12, 13, two laterally offset cleaning rollers or other means for cleaning the tear-off rollers 12, 13 can also be used, which do not cause unwanted airflow onto the soldering area between the pairs of tear-off rollers.

[0044] Figure 12Figure 1 shows the transformation of the flat fiber web 14 into a fiber ribbon 21 behind the second pair of tear-off rollers, of which the upper tear-off roller 13 is visible in the top view. The fiber web 14 is guided along a guide element 27 to the hopper 15, formed therein into a fiber ribbon 21, and drawn off by means of the take-off rollers 16. The invention also affects the design of the combing machine here, since, due to the absence of the piling motion, the soldering process is more continuous, and thus the existing wave motion of the fiber web 14 no longer occurs. According to the prior art, the fiber web exhibits a nonwoven wave, which is generated by the periodic unevenness of the piling motion and the discontinuous soldering process.The existing section of the nonwoven bowl, where the wavy structure of the fiber web 14 was stabilized, can be made significantly shorter, allowing the fiber web 14 to be fed directly to the hopper 15 to form a fiber ribbon 21 after passing through the second pair of tear-off rollers 11, 13. The obliquely mounted guide element 27 can be designed as a rectangular or round rib or bridge and guides the fiber web 14 from one end of the tear-off rollers 11, 13 to the hopper 15. The existing nonwoven bowl for stabilizing the fiber web can be completely eliminated, allowing for a more compact combing machine. The guide element 27 can be positioned directly adjacent to the gusset of the second pair of tear-off rollers 11, 13 and be arranged obliquely. A rounded contour causes the lateral edges of the fiber web 14 to fold over, thus stabilizing them. Preferably, the guide element 27 can be adjustable.

[0045] In a further embodiment according to the Figure 13 and 14 The discharge area of ​​the fiber web 14 after the second pair of tear-off rollers 11, 13 can be further shortened by conveying the fiber web 14 to the hopper 15 via a cross-belt discharge 28. In the Figure 13 The transverse belt feeder 28 is arranged on one side, so that it conveys the fiber web 14 across almost the entire width or longitudinal extent of the tear-off rollers 11, 13 to the hopper 15. In the exemplary embodiment of the Figure 14 The transverse belt pull-off 28 is formed on both sides of the funnel 15, which is arranged more towards the center of the tear-off rollers 11, 13. The embodiments of the Figures 12 to 14 They not only shorten the area of ​​fiber ribbon formation after the tear-off rollers 11, 13, but also stabilize the edges of the fiber web. The off-center pull-off of the fiber web 14 compensates for any uneven structures resulting from the soldering process. Following this, the pull-off device of the Figures 12 to 14Sixteen further consolidation elements (not shown) can be arranged behind the take-off rollers to homogenize the fiber strip 21, for example pressure rollers whose surface can vary, such as rubberized rollers or rollers with a metallic surface.

[0046] The invention has the advantage that the continuous rotation of the tear-off rollers 10-13 allows the use of smaller motors and / or simpler gearboxes, while still enabling a higher number of combing cycles. The absence of acceleration, deceleration, and reversal of the tear-off rollers' direction of rotation reduces the energy consumption of the combing machine. The tear-off process of the fiber beard and the subsequent soldering process to the fiber web 14 are more continuous, significantly reducing or even eliminating the fiber web's ripple compared to the prior art. This can be influenced, among other things, by the timing of when the gripper unit 5 transfers the fiber beard to the clamping line of the first pair of tear-off rollers 10, 12. For this purpose, the position of the first pair of tear-off rollers 10, 12 relative to the gripper unit 5 is preferably adjustable.Regardless, the distance between the pairs of tear-off rollers can be adjustable to influence the soldering process by adjusting the overlap length of the soldered fibers. The uniformity of the fiber web 14 is further influenced by coordinating the movement of the first pair of tear-off rollers 10, 12 with the gripper unit 5, which determines the tear-off point of the fiber strip from the wadding tape 4 clamped by the gripper unit 5. The overlap length L2 can be increased for longer fibers and decreased for shorter fibers. The overlap length L2 can be adjusted by changing the speed profiles of the first and second pairs of tear-off rollers relative to each other. This allows direct adjustment of the nonwoven weight, and thus the tape number, as well as the Cv value of the respective combing head.Depending on the desired overlap length L2, a larger distance between the tear-off roller pairs may be necessary, for example, to ensure proper soldering of the fiber beard to the fiber web 14 and guiding of the fiber web 14 into the clamping line of the second tear-off roller pair 11, 13, thus influencing the subsequent uniformity of the fiber web 14. The soldering process can be supported by various means, as described in the details of the... Figures 2 and 8 to 11 This has been revealed. A further advantage is the creation of a uniform fiber pile without a fleece wave, allowing the fiber band formation area after the second pair of tear-off rollers to be shorter and simpler. The previously required fleece bowl for stabilizing the fiber pile can therefore be omitted. Reference sign

[0047] 1 Cotton winding 2 Winding transport roller 3 Winding transport roller 4 Cotton belt 5 Clamping unit 6 Shaft 7 Feed cylinder 8 Round comb 9 Fixed comb 10 First lower tear-off roller 11 Second lower tear-off roller 12 First upper tear-off roller 13 Second upper tear-off roller 14 Fiber web 15 Hopper 16 Take-off rollers 17 Gearbox 18 Motor 19 Control 20 Combing head 21 Fiber belt 22 Guide plate 23 Compressed air 24 Vacuum 25 Cleaning roller 26 Limiter 27 Guide element 28 Cross belt take-off L1 Conveyor path L2 Overlap length I1 Index position 1 I2 Index position 2

Claims

1. A combing machine having a plurality of combing heads (20) , wherein at least one lap (4) is unwound from a lap roll (1) at each comb head (20) and is supplied to a feed cylinder (7) and to a nipper assembly (5); the comber rollers are combed and sucked out of the lap (4) by means of a fixed comb and a circular comb (9, 8) and the produced nap is reshaped into a silver by means of a funnel (15), said silver being stretched with the other silvers of the other combing heads to form a single silver, and that a first pair of tear off rollers (10, 12) and a second pair of tear off rollers (11, 13) are arranged after the nipper assembly (5), with both tear off roller pairs (10, 12; 11, 13) being configured to be operated exclusively with an unchanging direction of rotation during a nip, and with the first pair of tear off rollers (10, 12) being operated at a higher speed than the second pair of tear off rollers (11, 13) at least at the start of a nip, characterized in that both pairs of tear-off rollers (10, 12; 11, 13) are designed to reduce or increase their rotational speed to a value identical to one another after an overlap length (L2) of the fiber beard of the lap (4) on the nap (14) has been reached.

2. A combing machine in accordance with claim 1, characterized in that the tear off rollers (10, 12; 11, 13) are driven by at least one transmission with the transmission being configured to vary the rotational speed of one or both tear off roller pairs (10, 12; 11, 13) at the start of a nip and on reaching a further position of the tear off rollers (10, 12; 11, 13) or that each pair of tear off rollers (10, 12; 11, 13) has their own motor and the combing machine has a controller that is configured to vary the rotational speed of one or both tear off roller pairs (10, 12; 11, 13) on reaching a settable index position of the motors.

3. A combing machine in accordance with claim 1, characterized in that the position or the spacing of the first tear off roller pair (10, 12) is settable with respect to the nipper assembly (5) or that the spacing of the tear off roller pairs (10, 12; 11, 13) from one another is settable.

4. A combing machine in accordance with claim 2, characterized in that the transmission or the controller is configured to synchronize or set the tear off time of the fiber beard from the lap (4) clamped by the nipper assembly (5) with the start of the nip of the first tear off roller pair (10, 12).

5. A combing machine in accordance with one of the preceding claims, characterized in that at least one guide plate (22) and / or a limiter (26) is / are arranged between the tear off roller pairs (10, 12; 11, 13) and / or that at least one device for producing compressed air (23) or a vacuum (24) is arranged between the tear off roller pairs (10, 12; 11, 13).

6. A combing machine in accordance with one of the preceding claims, characterized in that at least one guide element (27), by which the nap (14) is guided to a funnel (15), is arranged after the second pair of tear off rollers (11, 13) or that at least one crossover removal (28) is arranged after the second pair of tear off rollers (11, 13) and is configured to guide the produced nap (14) to a funnel (15).

7. A combing machine in accordance with one of the preceding claims, characterized in that the first upper tear off roller (12) and the second upper tear off roller (13) each have their own cleaning roller.

8. A method of combing a lap (4) using a combing machine having a plurality of combing heads (20), wherein a lap (4) is unwound from a lap roll (1) at each combing head (20) and is supplied to a feed cylinder (7),and to a nipper assembly (5); the comber rollers are combed and sucked out of the lap (4) by means of a fixed comb and a circular comb (9, 8) and the produced nap (14) is reshaped into a silver by means of a funnel (15), and characterized in that a first pair of tear off rollers (10, 12) and a second pair of tear off rollers (11, 13) are arranged after the nipper assembly (5) that are operated in the same direction of rotation, with the first pair of tear off rollers (10, 12) being operated at a higher rotational speed than the second pair of tear off rollers (11, 13) at least at the start of a nip and in so doing forms an overlap length (L2) between a torn off fiber beard and the produced nap (14) between the tear off roller pairs so that the soldering procedure takes place after the first tear off roller pair (10, 12), characterized in that after reaching an overlap length (L2) of the fiber beard of the lap (4) on the fiber nap (14), both pairs of tear-off rollers (10, 12; 11, 13) reduce or increase their rotational speed to a value identical to each other.

9. A method of combing in accordance with claim 8, characterized in that both tear off roller pairs (10, 12; 11, 13) are operated at the same rotational speed after forming the overlap length (L2) and / or that the two tear off roller pairs (10, 12; 11, 13) are operated at a higher or lower rotational speed after the formation of the overlap length (L2).

10. A method of combing in accordance with one of the claims 8 or 9, characterized in that the tear off time of the fiber beard from the lap (4) clamped by the nipper assembly (5) is set by the start of the nip of the first tear off roller pair (10, 12).

11. A method of combing in accordance with one of the claims 8 to 10, characterized in that the fiber beard and / or the nap (14) is / are deflected by means of compressed air (23) or a vacuum (24) prior to the soldering of the fiber beard to the nap (14).

12. A method of combing in accordance with one of the claims 8 to 11, characterized in that the produced nap (14) is guided to a funnel (15) by means of a guide element (27) after the second pair of tear off rollers (11, 13).

13. A method of combing in accordance with one of the claims 8 to 12, characterized in that the produced nap (14) is guided to a funnel (15) by means 10 of a crossover removal (28) after the second pair of tear off rollers (11, 13).