Method for automatically piecing a sliver in a drafting system, and drafting system for drafting a carded sliver

Abstract

The invention relates to a method and to a drafting system for automatically piecing a single carded sliver in a drafting system before it is deposited in a can, wherein the sliver is produced in a carding machine (K) and runs continuously into the drafting system (1) which is arranged on the top side of the can changer (W) associated with the carding machine (K), the method comprising the following steps: - the carding machine (K) is operated with an outgoing sliver (FB) speed of 10 m / min to 100 m / min (or drum speed?), - the outgoing sliver (FB) is detected at the exit of the carding machine (K) by means of a sensor and the drafting system (1) is started using the control system of the carding machine, - an operator manually inserts the sliver (FB) into an upper first hopper (5) of the drafting system (1), - the beginning of the sliver (FB) is detected using a pair of entry measuring rollers (6a, 6b) and, by introducing compressed air, a suction effect is generated to a second hopper (14) arranged downstream in the material flow direction, - the sliver (FB) is gripped by a first pair of drafting rollers (7, 8) and forwarded to a second pair of drafting rollers (9, 10) arranged vertically below the first pair; - the sliver (FB) is suctioned through the second hopper (14) and the sliver is drawn into a deposition tube (40) of a rotating can plate (41).

Description

[0001] Title: Method for automatically piecing a sliver into a drafting system and drafting system for drawing a carded sliver

[0002] Description

[0003] The present invention relates to a method for automatically piecing a fiber sliver into a drafting system, as well as to a drafting system for drawing a single carded fiber sliver before depositing it in a can, wherein the fiber sliver is produced in a card and runs continuously into the drafting system, which is arranged on the upper side of the can changer belonging to the card.

[0004] According to the state of the art in textile technology, it is known to deposit carded fiber slivers in a can. For this purpose, a drafting system can be arranged between the card and the can depositor, resulting in considerable space savings and lower investment costs for the downstream process. Furthermore, the control of a separate draw frame located behind the card's can depositor and the time-consuming can transport are eliminated. The entire production line from the card to the air-jet spinning machine or open-end spinning machine is shortened by one line. These so-called "integrated draw frames" can be arranged within the card housing with a horizontal material flow direction, or they can be arranged above the can depositor with a vertical material flow direction.The integrated draw frames arranged above the can deposit have the advantage that card production can be throttled during can changes and a storage unit arranged between the card and the integrated draw frame can compensate for the reduction in speed of the sliver.

[0005] These integrated draw frames can be controlled or uncontrolled. In contrast to conventional draw frames, where multiple fiber slivers are drawn and doubled together, these integrated draw frames only process a single incoming fiber sliver. They often feature a two-zone draw frame consisting of a 3-over-3 or 3-over-4 roller arrangement with a limited draw field width. This restricts their use for certain fiber lengths, as the textile properties of the subsequently produced yarn are insufficient, particularly when processing short fibers (< 20 mm) with only one fiber sliver. Particularly when processing recycled textiles, the proportion of short fibers in the fiber blend increases, making processing more complex.

[0006] Threading the sliver from the card into the drafting system has traditionally been very laborious and error-prone, requiring considerable practice from the operator. Current technology requires the sliver to be fed from the card, which operates at a low delivery speed, into the drafting system. The drafting system housing must be opened, and the sliver is manually inserted until it is gripped by the first pair of already rotating drafting rollers. Only when the sliver is correctly fed into the delivery tube can the housing be closed, allowing the card to increase the delivery speed of the sliver to be produced.

[0007] Accordingly, the invention is based on the object of simplifying and automating the threading into the drafting system.

[0008] The invention solves the problem by a method having the features specified in claim 1, as well as by a drafting system having the features of claim 8. Advantageous developments of the invention are defined in the dependent claims.

[0009] The invention relates to a method for automatically piecing a single carded fiber sliver in a drafting system prior to depositing it in a can, wherein the fiber sliver is produced in a card and feeds uninterruptedly into the drafting system, which is arranged on top of the can changer (W) associated with the card. During piecing, the card is operated at a low delivery speed so that the fiber sliver exits the card at a delivery speed of 10 m / min to 100 m / min. At the card outlet, a sensor detects the exiting fiber sliver and transmits a signal to the card control system. The card control system starts the drafting system, and an operator inserts the fiber sliver exiting the card into an upper first funnel of the drafting system.

[0010] The beginning of the fiber sliver is then detected by a pair of input measuring rollers. Upon detection of the fiber sliver, a sensor on the input measuring roller pair sends a signal to the carding machine control system, which initiates the introduction of compressed air into a second funnel located at the lower end of the drafting system, downstream in the direction of material flow. This creates a suction draft within the drafting system.

[0011] The beginning of the fiber sliver is captured by a first pair of draw rollers and passed on to a second pair of draw rollers arranged vertically below. The suction draws the fiber sliver from the second pair of draw rollers into the second funnel, where it is guided by the exit measuring rollers arranged behind it into a delivery tube of a rotating can plate.

[0012] In contrast to the prior art, the operator can insert the beginning of the sliver into the closed housing, where it is automatically threaded or drawn through all components of the drafting system. The laborious process of threading the sliver through the open drafting system rollers is thus no longer necessary. This process reduces errors when threading the sliver and enables automatic and faster threading. The elimination of intermediate storage in a can is referred to as uninterrupted feeding from the card into the drafting system. In other words, the sliver emerging from the card is inserted into the drafting system with or without the use of an intermediate storage device.

[0013] Preferably, the fiber sliver can be guided into the upper gusset of the second pair of draw rollers by a pressure bar arranged between the pairs of draw rollers. The inclination of the pressure bar in its longitudinal direction from the horizontal by an angle (a) of 40° to 60° in the vertical direction, preferably 50° to 55°, can promote automatic piecing, since the fiber sliver strikes the inclined upper side of the pressure bar from the first pair of draw rollers and is thus guided along the convex contour to the second pair of draw rollers. This advantage is particularly evident when the pairs of draw rollers are arranged offset in the horizontal orientation.

[0014] Because the fiber sliver is drawn into the delivery tube by a pair of output measuring rollers, a separate take-off roller pair and a separate measuring system are no longer required, thus reducing the overall height of the drafting system. With the pair of output measuring rollers and the associated card control system, the drafting system becomes a regulated drafting system, as the mass deviation of the fiber sliver between the pair of input measuring rollers and the pair of output measuring rollers is recorded and the drafting system draft is adjusted.

[0015] Once automatic piecing has been successfully completed, the card can start up to operating speed. For this purpose, the output measuring roller pair can be equipped with a sensor whose signal, upon detection of the fiber sliver, is sent to the card control system, allowing the card to start up to operating speed. However, the sensor can also be located at a different location at the drafting system exit to detect that the fiber sliver is entering the delivery tube of the rotating can plate without sliver jamming or sliver breakage.

[0016] The drafting system can be stopped if the sensor of the output measuring roller pair does not send a signal to the card control system within a predetermined time difference after the fiber sliver has been detected by the input measuring roller pair. The time difference can be one to five seconds, depending on the sliver weight, the card delivery speed, and the draft.

[0017] In addition, the operation of the drafting system can be stopped by the card control system if a sensor located in front of or monitoring the delivery tube detects a sliver jam or sliver breakage.

[0018] The compressed air can be introduced during a can change at the second funnel for a predetermined time before, during, and after the creation of a thin spot in the fiber sliver. The length of the predetermined time can be entered in the carding machine's control system. This prevents the resulting fiber sliver from accumulating within the drafting system after the fiber sliver is torn apart.

[0019] The drafting system according to the invention is designed for drawing a single carded fiber sliver, wherein the fiber sliver is produced in a card and runs seamlessly into the drafting system, which is arranged on the upper side of the can changer associated with the card. The drafting system has an upper first funnel, followed in the direction of material flow by a pair of input measuring rollers with a sensor, and followed in the direction of material flow by a vertically arranged 2-over-2 drafting system with an upper first pair of drafting rollers and a lower second pair of drafting rollers. Downstream in the direction of material flow and below the second pair of drafting rollers is a second funnel, which is designed to generate a suction draft within the drafting system by introducing compressed air. Downstream below the second funnel is a pair of rollers, which is designed to draw the fiber sliver into the delivery tube of a can plate.The vertical arrangement of the drafting system components, combined with the suction system within the drafting system, enables automatic piecing with the housing closed. Unlike prior art, the operator can insert the beginning of the fiber sliver into the closed housing, where it is automatically threaded or drawn through all drafting system components. The laborious process of threading the fiber sliver through the open drafting system rollers is thus no longer necessary.

[0020] The second pair of draw rollers can be arranged at a horizontal offset from the first pair of draw rollers. To guide the fiber sliver from the clamping point of the upper pair of draw rollers to the clamping point of the lower pair of draw rollers, a pressure bar can be arranged below the first pair of draw rollers such that the fiber sliver is guided by a convex surface of the pressure bar perpendicular to the upper gusset of the second pair of draw rollers. The arrangement of the pressure bar with the draw roller pairs, which have a horizontal offset, not only facilitates automatic threading but also enables better processing of short fibers, for example, from recycled textiles.

[0021] The fact that the pair of rollers for drawing the fiber sliver into the delivery tube can be designed as an output measuring roller pair reduces the overall height of the drafting system, while also allowing the drafting system, in conjunction with the input measuring roller pair, to be used as a regulated drafting system. For this purpose, the output measuring roller pair can be equipped with a sensor whose signals are sent to the carding machine control system. Using the sensor signals, the automatic piecing process can be stored in the carding machine control system as "successfully completed," so that the carding machine's delivery speed automatically increases.

[0022] Preferably, a sensor can monitor the inlet of the delivery tube for a sliver break or jam. This allows the card control system to stop the drafting system in the event of a sliver break or jam, and reduce the card's operating speed.

[0023] The drafting system is preferably designed as a controlled drafting system. The input and output measuring rollers are designed to control and monitor the drawn sliver mass and can also be configured to detect errors during automatic piecing, sliver breakage, or sliver jams. To control the sliver mass, the upper and lower pairs of drafting rollers can be driven independently of each other. The drives can be designed as servo drives, eliminating the need to change gears when changing the drafting field width or draft depending on the fibers being processed.

[0024] The sliver accumulator between the drafting system and the carding machine has no influence on automatic piecing. Its function only becomes effective when a can is changed.

[0025] Further measures improving the invention are described in more detail below together with the description of a preferred embodiment of the invention with reference to the figures.

[0026] They show:

[0027] Figure 1 : a carding machine with a subsequent can deposit and an integrated

[0028] Route;

[0029] Figure 2a, 2b: a perspective view of the closed and opened

[0030] Housing;

[0031] Figure 3: a front view of the essential components of the line according to the invention;

[0032] Figure 4a, 4b: two representations of the stretching roller pairs with the pressure bar with different stretching field widths;

[0033] Figure 5: a first perspective view of the storage of the

[0034] pairs of stretching rollers;

[0035] Figure 6: a top view of the drafting system with the top rollers unlocked

[0036] Position;

[0037] Figure 7: a second perspective view of the storage of the

[0038] Pairs of stretching rollers with the removed top rollers;

[0039] Figure 8 shows a representation of the back of the track with the

[0040] Drive components.

[0041] Figure 1 shows a card K in which the produced fiber sliver FB is guided over several deflection rollers R to the drafting system 1. The drafting system 1 is arranged on the upper side of the can changer W and integrated therein, making it a component of the card K. In this exemplary embodiment, a storage device S for the fiber sliver FB is arranged between the card K and the drafting system 1, which is designed to at least partially compensate for a difference in the delivery speed of the fiber sliver FB between the card K and the drafting system 1. The use or arrangement of the storage device S is not relevant to the invention. For a better understanding of the subsequent arrangement of the components, a Cartesian coordinate system is used here, in which the z-direction is the vertical along which the fiber sliver FB enters the drafting system 1.In the following figures, the y-direction corresponds to the longitudinal axis of the drafting system rollers, and the x-direction is orthogonal to the longitudinal axis of the drafting system rollers. Essential to the invention is that a single fiber sliver FB enters the drafting system 1 vertically (z-direction) under gravity.

[0042] Figures 2a and 2b show the closed and opened hood 2 of the draw frame 1 according to the invention, which has wings 2a, 2b that can be opened horizontally on a front side, so that the drafting system is accessible for maintenance work. The wings 2a, 2b are pivotally attached to the hood 2 by means of hinges. Also arranged on the hood 2 is an upwardly pivoting cover flap 3 with an opening 3a. The cover flap 3 is integrated into the wings 2a, 2b so that the wings 2a, 2b have a corresponding recess for the contour of the cover flap 3. A deflection roller R is arranged on the cover flap 3, by means of which the fiber sliver FB can be deflected and introduced into the opening 3a of the cover flap 3 in the upper first funnel 5. A pipe 37 is arranged on the upper side of the hood 2, to which a line for connection to the exhaust air from the spinning preparation can be arranged.The dust and unprocessed fiber material can be removed via the pipe 37. The draw frame 1 is arranged on top of a can changer W, with a deposit A ​​in the form of a recess arranged on the top. The deposit A ​​is designed such that the top rollers 7, 8 of the drafting system 1 can be deposited for the duration of maintenance or cleaning. In contrast to the prior art, no fiber-guiding or processing components are arranged on the inside of the wings 2a, 2b. By means of sensor-detectable magnetic closures, the cover flap 3 and the wings 2a, 2b can completely close the hood 2 - except for the opening 3a - so that if the hood 2 is opened during operation, the card control system stops the drafting system 1.

[0043] Figure 3 shows a first front view of the opened drafting system 1 after the hood 2 and the cover flap 3 have been removed. Only a front part of the upper drive housing 4a can be seen, which, according to the other figures, extends further behind the arrangement of the rollers and funnels and is not shown here. The fiber sliver FB, not shown here, runs vertically (z-direction) into the first funnel 5 and is grasped by the input measuring roller pair 6a, 6b. The funnel 5 is designed to be pivoted upwards in the vertical direction (Z-direction) away from the input measuring roller pair 6a, 6b in order to enable cleaning of the subsequent input measuring roller pair 6a, 6b or to eliminate faulty piecing.The subsequent input measuring roller pair 6a, 6b is designed to detect the deviation of the fiber sliver FB from a predetermined sliver mass and to transmit the measured values ​​to a control system (not shown) and to display them on a display, which can be, for example, the control system of the carding machine K. For this purpose, one input measuring roller 6b is mounted in a fixed, rotatable manner, while a second input measuring roller 6a is mounted displaceably relative to the first input measuring roller 6b. The displacement of the second input measuring roller 6a can be detected using, for example, a plunger coil or another sensor, and the change in travel can be converted into a mass deviation. Roller cleaners in the form of scrapers, with which the surface of the input measuring rollers 6a, 6b is cleaned, can be arranged on both sides of the input measuring roller pair 6a, 6b. The input measuring roller pair 6a, 6b can be designed as grooved / contact rollers or as stepped rollers, or can comprise two smooth rollers.A stripper 16 or another guide element can be arranged below the left measuring roller 6b shown in this view, with which the fiber sliver FB is released from the input measuring roller pair 6a, 6b and guided into the first draw roller pair 7, 8. A lever 36a can be used to release a pressure load (not shown) on the movable input measuring roller 6a, which can be moved away from the stationary input measuring roller 6b. This facilitates maintenance and cleaning of the input measuring roller pair 6a, 6b and the upper draw roller pair 7, 8 arranged below them. The lever 36a is shown in a locked position for the movable input measuring roller 6a.

[0044] The fiber sliver FB continues to run vertically downwards until it is gripped by the first bottom roller 7 and the first top roller 8. These two rollers 7, 8 form the first pair of draw rollers. With a slight offset counter to the x-direction, the fiber sliver FB strikes a pressure bar 13, is guided past it and reaches the second pair of draw rollers, which is formed by the second bottom roller 9 and the second top roller 10. The draw roller system 1 according to the invention is thus designed as a vertically arranged 2-over-2 draw roller system (single-zone draw roller system), with two bottom rollers 7, 9 and two top rollers 8, 10. Despite the vertical arrangement of the draw roller pairs to one another, here we speak of top and bottom rollers, comparable to a normal draw roller system with a horizontal material flow direction of the fiber sliver, since the bottom rollers have a metallic, corrugated surface and the top rollers are provided with a plastic or rubber covering.The fiber sliver FB is stretched lengthwise by the first and second pairs of stretching rollers due to different rotational speeds and guided into the second funnel 14. Also visible are a first and a second cylinder 11a, 12a, with which the upper rollers 8, 10 are pressed at one end against the lower rollers 7, 9 by the pistons of the cylinders 11a, 12a, counter to the x-direction.

[0045] The funnel 14 is designed as a piecing aid and has lateral swirl nozzles along the inner bore through which compressed air flows. This creates a suction draft at the funnel opening, with which the fiber sliver FB is drawn into the funnel and guided to the output measuring roller pair 15a, 15b. The output measuring roller pair 15a, 15b is also designed to detect the deviation of the sliver mass from a predetermined value. A first stationary output measuring roller 15a interacts with a movably mounted second output measuring roller 15b, the change in distance of which from the first stationary output measuring roller 15a is converted into a sliver mass deviation by a sensor (not shown), for example in the carding machine's control system. These values ​​are also transmitted to a control system, for example of the carding machine, which can compare the values ​​with the values ​​of the input measuring roller pair 6a, 6b and display them on a screen.The output measuring roller pair 15a, 15b can be designed as a smooth roller pair or as a grooved / contact roller pair or with stepped rollers. Roller cleaners in the form of scrapers, which are not further designated, can be arranged on both sides of the output measuring roller pair 15a, 15b, with which the surface of the measuring rollers is cleaned. A lever 36b can be used to relieve a pressure load (not shown) on the movable output measuring roller 15a, which can be moved away from the stationary output measuring roller 15b. This facilitates maintenance and cleaning of the output measuring roller pair 15a, 15b and the storage tube 40 arranged underneath. The lever 36b is shown in Figures 5 to 7 in a locked position for the movable output measuring roller 15a, and in Figure 8 in an open position for the movable output measuring roller 15a.

[0046] After the exit measuring roller pair 15a, 15b, the drawn fiber sliver FB is deposited into a can (not shown) by a known depositing tube 40, which is rotated by a can plate 41, for example, in the shape of a cycloid. A sensor 17 is arranged between the exit measuring roller pair 15a, 15b and the depositing tube 40, which is designed to monitor the entrance or opening of the depositing tube 40 for a possible sliver jam.

[0047] The signals from the input measuring roller pair 6a, 6b and the output measuring roller pair 15a, 15b can be processed in the control system of the carding machine K or in the control system of the spinning preparation system. The control system can output a signal when an automatic piecing process has been successfully completed. Then, both measuring roller pairs 6a, 6b; 15a, 15b generate a consistent signal for the sliver mass. If, after automatic piecing, only the input measuring roller pair 6a, 6b displays a consistent signal, while the output measuring roller pair 15a, 15b displays no signal or a significantly altered signal, this indicates a break in the fiber sliver FB.

[0048] To feed the fiber sliver FB into the drafting system 1, the card K is operated at a low delivery speed or operating speed, which can be, for example, between 10 m / min and 100 m / min speed of the outgoing fiber sliver. The card speed is preferably 10 m / min to 50 m / min. The carded fiber web is transferred from the card doffer, for example, to the downstream cross belt or the take-off rollers and fed into the integrated funnel. The downstream measuring rollers at the card outlet can already detect the sliver mass of the formed fiber sliver FB or the deviation of the fiber sliver mass from a reference, and the associated signal is processed in the card control system. When the sliver mass is detected, the control system of the card K automatically starts the drafting system 1 by the drives 21, 30 controlling the input measuring rollers 6a, 6b, the drafting roller pairs 7, 8; 9,10 and drive the output measuring roller pairs 15a, 15b.The drafting system 1 is locked, which means that the pneumatic loading of the top rollers 8, 10 is activated. At the same time, the drive 30 causes the can plate 41 of the can changer W to rotate. The operator manually removes the sliver FB running out of the card K and, with the hood 2 closed, feeds it through the opening 3a into the upper first funnel 5 of the draw frame 1. The beginning of the sliver FB is detected by the pair of input measuring rollers 6a, 6b and drawn into the draw frame 1. When the pair of input measuring rollers 6a, 6b is detected, the associated sensor sends a signal to the control system of the card K, which generates compressed air to create a suction draft at the second funnel 14. The suction draw assists the threading of the fiber sliver FB by gripping and pulling the fiber sliver FB into the first pair of draw rollers 7, 8.Due to the horizontal offset of the draw roller pairs 7, 8; 9, 10, the fiber sliver FB impacts the side surface of the pressure bar 13 and is guided to the upper gusset of the second draw roller pair 9, 10, where it is gripped and drawn into the second funnel 14 by the suction force. The rotational movement of the draw roller pairs 7, 8; 9, 10 also generates an air flow within the draw frame 1, which promotes automatic threading. Subsequently, the fiber sliver FB can be gripped by the output measuring roller pair 15a, 15b and guided into the delivery tube 40 to the already rotating can plate 41. When the fiber sliver is detected by the output measuring roller pair 15a, 15b, the associated sensor can transmit a signal to the control system of the card K, which recognizes the threading of the fiber sliver as successfully completed and can stop the introduction of compressed air to the second funnel 14.At the same time, the card's delivery speed is increased to the operating speed required for the fiber quality without operator intervention. The speed of draw frame 1 and can changer W are also adjusted to the production speed and delivery speed of the card, respectively.

[0049] If the automatic threading is unsuccessful, for example due to a sliver break or a sliver jam, this can be recognized by the fact that either no fiber sliver runs into the can via the delivery tube 40 or the output measuring roller pair 15a, 15b does not send a signal to the control system of the card K. The card control system switches off the drafting system 1 if the output measuring roller pair 15a, 15b does not send a signal to the card control system within a time of, for example, one to five seconds after the fiber sliver has been detected by the sensor of the input measuring roller pair 6a, 6b. Alternatively, in the event of a sliver jam or a sliver break, the sensor 17 can send a signal to the card control system to abort the automatic threading process. The draw frame 1 and the can changer W are stopped, while at the same time the card K continues to operate at the low delivery speed or operating speed.Sliver continues to slowly but continuously exit the card. Draw frame 1 is unlocked, releasing the pressure on the top rollers 8, 10. Hood 2 of draw frame 1 is opened, and the sliver residue can be removed. Closing hood 2 of draw frame 1 locks the system, thus releasing the pressure on the top rollers 8, 10. At the same time, drives 21, 30 start the input measuring rollers 6a, 6b, the draw roller pairs 7, 8; 9, 10, and the output measuring roller pairs 15a, 15b. The sliver FB from card K can be fed back into the upper funnel 5, and the automatic piecing process restarts.

[0050] During a can change, which is also initiated by the control system of the carding machine K, the compressed air can be introduced to generate a suction draft at the second funnel 14 before a thin spot is created in the fiber sliver FB. After the fiber sliver FB is torn off at the thin spot, the compressed air continues to be generated until the fiber sliver FB is at least again grasped by the pair of output measuring rollers 15a, 15b. The time for blowing the compressed air into the second funnel 14 before and after the thin spot is created in the fiber sliver FB can be set in the carding machine control system. Instead of the output measuring rollers 15a, 15b, take-off rollers can also be used to discharge the fiber sliver into the depositing tube 40.

[0051] Figures 4a and 4b show the arrangement of the drafting rollers 7, 8, 9, 10 in relation to one another in combination with the pressure rod 13. The drafting field between the clamping points P1 and P2 is offset from the vertical by the dimension V, opposite the x-direction. The value for V can be between 5 mm and 12 mm. In the first pair of drafting rollers 7, 8, the first upper roller 8 is arranged offset in the z-direction below the first lower roller 7. Likewise, the second upper roller 10 is arranged offset in the z-direction below the second lower roller 9. Due to the offset V of the upper to the lower drafting rollers 7, 8; 9, 10, the pressure rod 13 is arranged between the first and second upper rollers 8, 10, so that the fiber sliver FB is deflected by the pressure rod 13 onto the second clamping point P2.The pressure rod 13 is arranged in a stationary manner at a distance from the first pair of draw rollers 7, 8 and is formed by a rectangular or square base body, onto one outer surface of which a convex contour is placed. The convex contour can be designed as a semicircle or as a circular segment with a continuous radius. The pressure rod 13 can increase the nip line spacing when processing short fibers from L1 of 35 mm (Fig. 4a) to L2 of 75 mm (Fig. 4b). In its longitudinal direction, the pressure rod 13 is inclined by the angle α from the vertical in the horizontal direction. The angle α can be between 40° and 60°, preferably between 50° and 55°. The center line of the pressure rod 13 can intersect the center point of the first top roller 8. The convex surface of the compression rod 13, which comes into contact with the fiber band FB and guides the fibers, points diagonally downwards in the z-direction.Preferably, the compression rod 13 is arranged such that the fiber sliver FB from the clamping point P1 between the first pair of stretching rollers 7, 8 strikes the upwardly directed and inclined side surface of the compression rod 13 and is guided perpendicularly to the second clamping point P2 by the convex surface of the compression rod 13. The convex surface of the compression rod 13 thus touches a perpendicular line passing through the second clamping point P2 of the second pair of stretching rollers 9, 10. The inclined arrangement of the pressure rod by the angle a just behind the first pair of draw rollers 7, 8 favors the automatic insertion of the fiber sliver FB into the draw frame 1. The tangential arrangement of the convex surface of the pressure rod 13 to the vertical through the second clamping point P2, which is offset in the x-direction by the value V from the first clamping point P1, favors the guidance of short fibers, which can be drawn at a clamping line distance L1 of 35 up to and including L2=75mm.

[0052] Textile-technical improvements are achieved, particularly in recycled fiber blends, which consist of a high proportion of short fibers, due to fiber guidance through the compression bar, which are measurable down to the yarn. Yarn tenacity increases by up to 8%, whereas IPI (Total IPI) values ​​decrease by 10% to 20%.

[0053] Since the first drafting rollers 7, 8 are mounted together with the pressure rod 13 on or in an upper drive housing 4a, which is separate from the lower drive housing 4b of the second drafting rollers 9, 10, the clamping line spacing L1, L2 can be changed using simple adjustment means without decoupling and removing the drafting rollers 7, 8 from the drives. The distance between the pressure rod 13 and the first drafting rollers 7, 8 remains unchanged.

[0054] Figure 5 shows a perspective view of the drafting system 1 without the hood 2. A first drive 21 is arranged on an upper drive housing 4a, which drives the input measuring roller pair 6a, 6b and the first lower roller 7. The arrangement of the first hopper 5, which can be pivoted in the z-direction, can also be seen here. An upper support 22a is also arranged on the upper drive housing 4a, on which an upper counter bearing 19a with the first cylinder 11b is arranged orthogonally. The upper counter bearing 19a with the first cylinder 11b are designed to lock the bearing of a first end of the first upper roller 8 in an upper bearing block 18a. The second end of the first upper roller 8 is mounted in the upper drive housing 4a. Somewhat concealed behind the upper counter bearing 19a is the upper bearing block 18a, which supports the first end of the first lower roller 7 and the first upper roller 8.Here, too, the second end of the first lower roller 7 is mounted in the upper drive housing 4a. The first lower roller 7 is mounted in a stationary manner with its second end on or in the upper drive housing 4a. The other, first end of the first lower roller 7 is also mounted in a stationary manner on the upper bearing block 18a. The upper bearing block 18a extends parallel to the upper drive housing 4a and is connected to it by the upper counter bearing 19a. The first upper roller 8 is mounted so that it can be displaced in the x-direction toward the first lower roller 7, which is explained in more detail in Figure 7.

[0055] Not shown is a lower bearing block 18b, which is also arranged parallel to the lower drive housing 4b and is connected to it by means of a lower support 22b. The second lower roller 9 is mounted on the lower bearing block 18 in a stationary manner, and the second upper roller 10 is mounted so that it can move in the x-direction towards the second lower roller 9, respectively, at their first ends. The second lower roller 9 is mounted in a stationary manner, and the second upper roller 10 is mounted so that it can move in the x-direction towards the second lower roller 9, respectively, at their second ends in the lower drive housing 4b. A second cylinder 12b is arranged on a lower counter bearing 19b. The lower counter bearing 19b with the second cylinder 12b is designed to lock the mounting of a first end of the second upper roller 10 in a lower bearing block 18b.

[0056] The lower drive housing 4b accommodates the second lower roller 9, the second upper roller 10, as well as the pair of output measuring rollers 15a, 15b, and the second funnel 14 arranged above them. This second funnel 14 is pivotally mounted in a horizontal orientation by means of a lever 14a on a pivot bearing 14b. The compressed air supply, which creates the suction effect via the swirl nozzles (not shown), is supplied via the lever 14a. The pivotability of the second funnel 14 improves the cleaning of the drafting system 1.

[0057] A lower support 22b is also arranged on the lower drive housing 4b, on which a lower bearing block 18b (shown hidden) for the second upper and lower rollers 9, 10 and a lower counter bearing 19b for the second upper roller 10 are arranged. By separating the drive housings 4a, 4b from one another and by arranging and supporting the first and second pairs of drafting rollers 7, 8; 9, 10 separately, the distance between the upper drive housing 4a and the lower drive housing 4b can be adjusted by means of a hidden adjusting element 23. For this purpose, the upper drive housing 4a is fastened to a lateral, vertically aligned guide so that it can be adjusted in the vertical alignment (z-direction). By adjusting the adjustment, the nip line distance L1, L2 of the drafting roller pairs can be adjusted so that, if the fiber quality changes, the drafting system 1 can be adjusted in just a few steps.A lateral guide plate 24, for example, with an integrated dovetail or linear guide, corresponds to an outer surface of the upper drive housing 4a. The actuating element 23 can be designed, for example, as a threaded spindle or motor drive.

[0058] The first and second lower rollers 7, 9 are mounted with their second ends in the upper and lower drive housings 4a, 4b, respectively, in a stationary and rotatable manner. The drive elements on the rear side of the drive housing 4a, 4b engage here, as explained with reference to Figure 8. The respective first ends of the first and second lower rollers 7, 9 are mounted with their second ends in a stationary and rotatable manner in the bearing blocks 18a, 18b, which in turn are fastened to the associated supports 22a, 22b. The first and second upper rollers 8, 10 are also mounted with their second ends in the upper and lower drive housings 4a, 4b, respectively, so that they can move and rotate in the x-direction. The first ends of the first and second upper rollers 8, 10 are also mounted in the bearing block 18a, 18b so that they can move and rotate in the x-direction. The first and second upper rollers 8, 10 are each assigned a counter bearing 19a, 19b with an integrated cylinder 11b, 12b, wherein the counter bearings 19a, 19b are in turn arranged and fastened to the supports 22a, 22b.The pistons of cylinders 11b, 12b act in the x-direction, i.e., opposite to the force direction of cylinder pistons 11a, 12a shown in Figure 3. Each counterbearing 19a, 19b has a rocker arm 20a, 20b, against whose first end the piston rod of the respective cylinder 11b, 12b presses. The rocker arms 20a, 20b fix the top rollers 8, 10 in the bearing block 18a, 18b, but simultaneously adjust the load pressure between the drafting roller pairs 7, 8; 9, 10. The rocker arms 20a, 20b are shown in Figure 5 in a position in which no load pressure is exerted on the top rollers 8, 10; instead, they can be removed from the bearings. The longitudinally opposite arrangement of the cylinders 11b, 12b to the cylinders 11a, 12a creates a free space at the front of the drafting system 1, which facilitates the assembly / disassembly of the top rollers 8, 10 as well as the cleaning and removal of sliver jams or sliver breakage.

[0059] As is known from the prior art, the lower rollers 7, 9 are driven. The upper rollers 8, 10 are pressed onto the lower rollers 7, 9 at the second end directly by means of the cylinders 11a, 12a, and at their first end indirectly by means of the rocker arms 20a, 20b by means of the cylinders 11b, 12b, and are driven by friction. The rocker arms 20a, 20b thus redirect the direction of force of the cylinders 11b, 12b from the x-direction by 180°, counter to the x-direction. The lower rollers 7, 9 have the usual grooved metallic surfaces, whereas the upper rollers 8, 10 have a rubber or plastic coating.

[0060] Figure 6 shows a plan view of the already released top rollers 8, 10, whereby only the first top roller 8 with its upper components is fully visible. The bottom and top rollers 7, 9; 8, 10 correspond unchanged to the known state of the art. The top roller 8 shown here has a steel roller core on which an elastic roller covering 8.1, for example made of rubber or plastic, is arranged. Two roller necks 8.2, 8.3 accommodate the top roller 8 on both sides in a bearing guide 25a. The compressive force required for stretching is applied on both sides by the cylinders 11a, 11b to roller bearings 8.4, 8.5, which are arranged between the roller necks 8.2, 8.3 and the roller covering 8.1. In order to reduce the wear of the roller cover 8.1, the upper rollers 8, 10 are designed asymmetrically, whereby the roller cover 8.1 protrudes beyond the counter surface of the lower rollers 7, 9.This allows the top rollers 8, 10 to be installed rotated by 180° when the first effective surface for stretching the fiber sliver FB is worn. The same structure applies to the second top roller 10, even if this is not shown in the figures. According to the invention, the compressive force on the second roller bearing 8.5 is applied by the cylinder 11a, and the compressive force on the first roller bearing 8.4 is applied by the rocker arm 20a, which deflects the force of the cylinder 11b by 180°.

[0061] The upper bearing block 18a and the upper counterbearing 19a are arranged orthogonally on the upper support 22a. Also visible are the first lower roller 7 and, with an offset V counter to the x-direction, the second lower roller 9 arranged below it. Within the upper counterbearing 19a, the cylinder 11b, which acts in the x-direction, can be seen in a retracted position, whereby the rocker arm 20a is in a relieving position. The cylinder 11a, which acts counter to the x-direction on the second roller bearing 8.5 of the upper roller 8, is shown hidden. In this position, this cylinder 11a is also retracted, so that the upper roller can be pushed out of the bearing guide in the x-direction. The situation described here is identical for the other hidden components 12a, 12b, 18b, 19b, 20b, 22b.The first and second upper rollers 8, 10 have been displaced in the x-direction in a bearing guide 25a, 25b (not shown) in the lower and upper drive housings 4a, 4b, and are therefore located at a distance from the lower rollers 7, 9.

[0062] Figure 7 shows a perspective view of the disassembled top rollers 8, 10. In the upper and lower drive housings 4a, 4b, a horizontally arranged (x-direction) bearing guide 25a, 25b can be seen for the second end of each of the top rollers 8, 10. The roll necks of the top rollers 8, 10 engage in these bearing guides 25a, 25b at the second end. The same arrangement applies to the roll necks of the top rollers 8, 10 at the first end, which engage in bearing guides (not shown) on the respective bearing blocks 18a, 18b. The cylinders 11a, 12a, 11b, 12b press the upper rollers 8, 10 with their roller covering against the metallic upper side of the lower rollers 7, 9 with constant force. If the roller covering of the upper rollers 8, 10 wears, these are pressed further towards the lower rollers 7, 9, so that over time the roller necks are moved further and further towards the lower rollers 7, 9 in the bearing guide 25a, 25b, counter to the x-direction.Figure 8 shows the rear of the draw frame according to the invention with the drive concept. The upper drive housing 4a is completely separate from the lower drive housing 4b and can be moved along the guide plate 24 by means of an adjusting element 23 (not shown), so that the nip line spacing L1, L2 can be adjusted without individually adjusting the drafting rollers 7, 8, 9, 10. Both the upper and lower drive housings 4a, 4b each have a separate, independent drive, which is not affected by the adjustment of the nip line spacing. The fact that all drive components are arranged on the rear of the draw frame results in a freely accessible front side, which offers sufficient space for maintenance or cleaning. Disassembly of drive components or their adjustment is therefore not necessary.In addition, the bearing concept of the top rollers 7, 9, in which the front cylinders 11b, 12b are arranged in opposite directions to the rear cylinders 11a, 12b, facilitates the disassembly of the top rollers 7, 9. Once the top rollers 7, 9 are disassembled, there is ample free space to the remaining drafting system components for maintenance and cleaning.

[0063] The upper drive housing 4a has a first drive 21, which drives the second adjustable input measuring roller 6b and the first lower roller 7 by means of a first belt 26. A second belt 28 drives the first input measuring roller 6a from the driven second input measuring roller 6b and is deflected by a deflection roller 29. The drive directions of the first and second input measuring rollers 6a, 6b are opposite, so that the fiber sliver FB is transported vertically downwards by the input measuring rollers 6a, 6b. A sensor 27 is arranged on the stationary input measuring roller 6b and is designed to determine the concentricity of this roller 6b and to compensate for any possible non-concentricity by measurement. This allows monitoring of the measurement accuracy of the determined sliver mass deviation. The sensor 27 can be designed, for example, as a voice coil or piezo element.The first upper roller 8 is pressed against the first lower roller 7 by the pressure of the cylinders 11a, 11b on the roller bearings 8.4, 8.5 with the roller cover 8.1, thereby driving it frictionally. The separation of the drives into an upper drive housing 4a with the first pair of stretching rollers 7, 8 and a lower drive housing 4b with the two pairs of stretching rollers 9, 10 enables the nip line spacing L1, L2 to be adjusted, while simultaneously allowing the speed of the lower rollers 7, 9 and the load pressure of the upper rollers 8, 10 to be controlled separately. At the same time, the driven measuring rollers 6b, 15b are decoupled from each other in terms of drive technology, eliminating the need for crossed belts.

[0064] The lower drive housing 4b also has its own second drive 30, which is also used to drive the can plate 41. A first belt 31 drives the second lower roller 9 and the fixed output measuring roller 15a. The adjustable output measuring roller 15b is driven by the fixed output measuring roller 15a via a second belt 32. The second belt 32 is deflected by the deflection roller 34, so that both output measuring rollers 15a, 15b are driven in opposite directions and pull the fiber sliver FB between them and transport it into the depositing tube 40. A tensioning element 35 ensures the necessary belt tension. The second drive 30 drives a third belt 33, which sets the can plate 41 in rotation. The drives 21, 30 can be designed as servo drives, which eliminates the need to change gears when changing the draw field width or draft depending on the fibers to be processed.

[0065] Reference symbol

[0066] 1 drafting system

[0067] 2 hood

[0068] 2a, 2b wings

[0069] 3 Cover flap

[0070] 3a Opening

[0071] 4a, 4b drive housing

[0072] 5 first funnel

[0073] 6, 6a, 6b Input measuring roller pair

[0074] 7 first lower roller

[0075] 8 first top roller

[0076] 8.1 Roller cover

[0077] 8.2, 8.3 Roll neck

[0078] 8.4, 8.5 Roller bearings

[0079] 9 second lower roller

[0080] 10 second top roller

[0081] 11a, 11b first cylinder

[0082] 12a, 12b second cylinder

[0083] 13 compression rod

[0084] 14 second funnel

[0085] 14a Lever

[0086] 14b Pivot bearing

[0087] 15a, 15b Output measuring roller pair

[0088] 16 scrapers

[0089] 17 Sensor

[0090] 18a, 18b bearing block

[0091] 19a, 19b Counter bearing

[0092] 20a, 20b rocker arm

[0093] 21 first drive

[0094] 22a, 22b support

[0095] 23 Control element

[0096] 24 Guide plate

[0097] 25a, 25b Warehouse management

[0098] 26 first belt

[0099] 27 Sensor

[0100] 28 second belt

[0101] 29 pulley

[0102] 30 second drive

[0103] 31 first belt

[0104] 32 second belt

[0105] 33 third belt

[0106] 34 Deflection pulley 35 Tensioning element

[0107] 36a, 36b lever

[0108] 37 pipe

[0109] 40 storage tube

[0110] 41 jug plates

[0111] A filing

[0112] FB fiber ribbon

[0113] K Card

[0114] L1, L2 clamping line spacing

[0115] P1, P2 terminal point

[0116] R pulley

[0117] S memory

[0118] V Offset

[0119] W Can changer x, y, z direction a angle pressure rod

Claims

AMENDED CLAIMS received by the International Bureau on 07 June 2024 (07.06.2024) 1. A method for automatically piecing a single carded sliver in a drafting system prior to depositing it in a can, wherein the sliver is produced in a card (K) and runs continuously into the drafting system (1) arranged on top of the can changer (W) associated with the card (K), comprising the following steps: - Operation of the card (K) with a delivery speed of the outgoing sliver (FB) of 10 m / min to 100 m / min, - detecting the outgoing sliver (FB) at the exit of the card (K) by means of a sensor and starting the drafting system (1) by the control of the card, - manual insertion of the sliver (FB) into an upper first funnel (5) of the drafting system (1) by an operator with the drafting system housing closed, Detecting the beginning of the fiber sliver (FB) by a pair of input measuring rollers (6a, 6b) and generating a suction draft to a second funnel (14) arranged downstream in the material flow direction by introducing compressed air, - gripping the sliver (FB) by a first pair of stretching rollers (7, 8) and forwarding it to a second pair of stretching rollers (9, 10) arranged vertically below, - Suction of the fiber sliver (FB) through the second funnel (14) and withdrawal of the fiber sliver into a deposit tube (40) of a rotating can plate (41).

2. Method according to claim 1, characterized in that the fiber band (FB) is guided into the upper gusset of the second pair of stretching rollers (9, 10) by a pressure rod (13) arranged between the pairs of stretching rollers (7, 8; 9, 10).

3. Method according to claim 1, characterized in that the withdrawal of the fiber sliver (FB) into the deposition tube (40) is carried out by a pair of output measuring rollers (15a, 15b).

4. Method according to claim 3, characterized in that the output measuring roller pair (15a, 15b) has a sensor, the signal of which is passed to the control of the card (K) upon detection of the fiber sliver (FB), so that the card (K) can run up to the operating speed.

5. Method according to claim 4, characterized in that the operation of the drafting device (1) is stopped if the sensor of the output measuring roller pair (15a, 15b) does not react after a predetermined time difference after detection of the fiber sliver (FB) by 22 AMENDED SHEET (ARTICLE 19) the input measuring roller pair (6a, 6b) sends a signal to the control of the card (K).

6. Method according to claim 1, characterized in that the operation of the drafting system (1) is stopped by the control of the card (K) when a sensor (17) in front of the depositing tube (40) detects a sliver jam or sliver break of the fiber sliver (FB).

7. Method according to claim 1, characterized in that during a can change at the second funnel (14) compressed air is introduced for a predetermined time before, during and after the creation of a thin point in the fiber sliver (FB), wherein the predetermined time can be entered in the control of the card (K).

8. Drafting system for drawing a single carded fiber sliver (FB), wherein the fiber sliver is produced in a card (K) and runs uninterruptedly into the drafting system (1) arranged on the upper side of the can changer (W) associated with the card (K), comprising a hood (2) and a cover flap (3), an upper first funnel (5), downstream in the material flow direction an input measuring roller pair (6a, 6b) with a sensor, downstream in the material flow direction a vertically arranged 2-over-2 drafting system, with an upper first pair of drafting rollers (7, 8) and a lower second pair of drafting rollers (9, 10), and downstream in the material flow direction a second funnel (14) arranged, which is designed to generate a suction draft within the drafting system (1) by introducing compressed air, and downstream a pair of rollers designed to draw the fiber sliver (FB) into the deposition tube (40) of a can plate (41),wherein the drafting system (1) is designed to carry out the method according to one of claims 1 to 7., 9. Drafting system according to claim 8, characterized in that the second pair of drafting rollers (9, 10) is arranged at a horizontal offset (V) to the first pair of drafting rollers (7, 8), and that a pressure rod (13) is arranged below the first pair of drafting rollers (7, 8) in such a way that the fiber sliver (FB) is guided by a convex surface of the pressure rod (13) perpendicular to the upper gusset of the second pair of drafting rollers (9, 10).

10. Drafting device according to claim 8, characterized in that the pair of rollers for drawing off the fiber sliver (FB) into the depositing tube (40) is designed as an output measuring roller pair (15a, 15b).

11. Drafting system according to claim 10, characterized in that the output measuring roller pair (15a, 15b) has a sensor whose signals are passed to the control of the card (K). 23 AMENDED SHEET (ARTICLE 19) 2. Drafting system according to claim 8, characterized in that a sensor (17) monitors the inlet of the depositing tube (40) for a sliver break or sliver jam of the fiber sliver (FB). 24 AMENDED SHEET (ARTICLE 19)

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