Drafting system

Abstract

The invention relates to a drafting system (1) for drafting at least one fibre sliver, comprising at least one first and one second drafting roller pair (7, 8; 9, 10), which together form an adjustable main drafting field, with a suction device for fibres and dust, which is arranged inside a housing surrounding the drafting system, with the suction device being designed to be connected directly or indirectly to the suction means of the spinning preparation, and with the suction device having at least one suction means for the upper rollers (8, 10) and one suction means for the lower rollers (7, 9) of the drafting roller pairs, characterised in that the suction means for the lower rollers (7, 9) is arranged directly or indirectly on the mounting for the drafting roller pair, which pair is adjusted to set the main drafting field.

Description

[0001] Title: Drafting system

[0002] Description

[0003] The present invention relates to a drafting system for drawing at least one fiber sliver, comprising at least a first and a second pair of drafting rollers, which together form an adjustable main drafting zone, with a suction device for fibers and dust, which is arranged within a housing surrounding the drafting system, wherein the suction device is designed to be connected directly or indirectly to the central suction of the spinning preparation, wherein the suction device has at least one suction for the upper rollers and one suction for the lower rollers of the pairs of drafting rollers.

[0004] When fiber slivers are drawn, fibers and dust build up inside the drafting system, which must be extracted. Suction elements are located in the area of ​​the drafting system rollers. These are connected to one another and / or individually via a pipe connection that is directly or indirectly connected to the extraction system in the spinning preparation. The extraction elements are connected to one another or to the aforementioned pipe connection using individual pipes, which must be laboriously removed during maintenance to make room for replacing wearing parts. Cleaning is also time-consuming in the event of a fiber sliver break or a fiber jam, as work must be carried out around and cleaned around the pipes and extraction elements. Errors and leaks can occur during assembly, meaning that not all necessary components are cleaned using suction air.This can lead to new deposits of fibers and dust, which impair the proper functioning of the drafting system. If the drafting system has an adjustable field width, the extraction system must be adapted to the changed position of the drafting roller pairs, if at all possible. Without adapting the extraction system to the changed position of the drafting roller pairs, the flow conditions within the drafting system will change, and the extraction will no longer be sufficient.

[0005] The object of the invention is to eliminate these disadvantages and to improve the suction of a drafting system.

[0006] The invention solves the stated problem by a drafting system having the features specified in claim 1. Advantageous developments of the invention are defined in the dependent claims. The invention relates to a drafting system for drawing at least one fiber sliver, comprising at least a first and a second pair of drafting rollers, which together form an adjustable main drafting zone. The drafting system has a suction device for fibers and dust that is arranged within a housing surrounding the drafting system. The suction device is designed to be connected directly or indirectly to the suction system of the spinning preparation, wherein the suction device has at least one suction system for the upper rollers and one suction system for the lower rollers of the drafting roller pairs. According to the invention, the suction system for the lower rollers is arranged directly or indirectly on the bearing for the pair of drafting rollers, which is adjusted to set the main drafting zone.By adjusting the field width of the main drafting section, the suction of the bottom rollers is also adjusted, so that the distance between the bottom rollers and the suction openings remains constant. This also ensures that the cleaning effect remains constant regardless of the field width of the drafting system.

[0007] At least part of the drafting system housing has an integrated duct or pipe that connects the fiber and dust extraction from the bottom rollers to the spinning preparation extraction system. Opening the housing section simultaneously removes the integrated duct or pipe from the maintenance and cleaning area, simplifying maintenance and cleaning.

[0008] The extraction system for the bottom rollers can be designed as a suction element that has an opening for the extraction of the bottom rollers and another opening for the extraction of the take-off rollers or output measuring rollers arranged downstream in the direction of material flow. All fiber-transporting components are thus cleaned by the suction.

[0009] By connecting the suction element to the integrated duct or pipe via a connecting pipe, compensation is created for the distance difference caused by adjusting the field width and the associated displacement of the suction of the lower rollers. The connecting pipe is recessed into a seal and / or is designed to be flexible to accommodate the distance difference.

[0010] The extraction system for the top rollers can be designed as an extraction hood, mounted on or integrated into the drafting system housing, so that when the housing is opened, the extraction hood is removed from the top rollers. The space required for disassembling the top rollers is created directly by opening the housing. Disassembling any piping is not necessary.

[0011] Because the suction device has a closure housing designed to interrupt the air flow between the suction for the upper rollers and lower rollers for the suction of the spinning preparation, the can change is made easier because no air turbulence is created on the sliver during the first sliver deposition period, since at the same time the piecing aid in the form of the second funnel blows compressed air into the take-off area of ​​the drafting system.

[0012] Preferably, the housing has a hood with two wings and a hinged cover flap with an opening for inserting the fiber sliver into the drafting system. This allows the housing to be opened wide enough in just a few simple steps to allow cleaning and maintenance of the drafting system without further disassembly.

[0013] The extraction hood for the top rollers is mounted on or integrated into a wing of the hood. When swiveled open, the extraction unit is simultaneously removed, thus creating space for replacing or cleaning the top rollers.

[0014] The integrated duct or pipe located on or in the cover flap ensures the disposal of fibers and dust from the bottom roller suction to the central suction system. Lifting the flap interrupts the supply of suction air to the bottom rollers and restores it when the flap is closed, regardless of the set field width.

[0015] The placement of at least one extraction opening near the fiber sliver insertion opening allows for the extraction of fibers and dust that would otherwise accumulate on top of the drafting system. The extraction openings are also connected to the integrated duct or pipe.

[0016] The central extraction system in the spinning preparation system uses negative pressure to clean the drafting system's work areas described here of fibers, dust, and dirt. The extraction system can be connected directly to the central extraction system via the pipe above the closure housing, or indirectly via the card extraction system, which is also connected to the central extraction system in the spinning preparation system.

[0017] 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.

[0018] They show:

[0019] Figure 1: a carding machine with a subsequent can deposit and an integrated

[0020] Route;

[0021] Figure 2a, 2b: a perspective view of the closed and opened

[0022] Housing;

[0023] Figure 3: a front view of the essential components of the line according to the invention;

[0024] Figure 4a: a perspective view of the extraction device of the line;

[0025] Figure 4b: a sectional view through a valve housing of the

[0026] suction device;

[0027] Figure 5 shows a representation of the back of the track with the

[0028] Drive components.

[0029] The drafting system shown here in Figures 1 to 5 is only shown as an example of a 2-over-2 drafting system. The extraction system integrated into the drafting system housing can be used for any other drafting system with a main drafting zone (e.g., 3-over-3 or 4-over-3), regardless of the horizontal or vertical orientation of the drafting system or the material flow direction of the fiber sliver.

[0030] 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 top of the can changer W and integrated therein and is thus 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.

[0031] Figures 2a and 2b show the closed and opened hood 2 of the draw frame 1 according to the invention, which has horizontally opening wings 2a, 2b 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 top 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 can be 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.

[0032] 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 (not shown here) can be used to release a pressure load (not shown) on the movable input measuring roller 6a, allowing it to 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.

[0033] 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.

[0034] 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, as a grooved / contact roller pair, or with stepped rollers. Roller cleaners in the form of scrapers, not further designated, can be arranged on both sides of the output measuring roller pair 15a, 15b to clean the surface of the measuring rollers. A lever 36b can be used to relieve a pressure load (not shown) on the movable output measuring roller 15a, allowing it to 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 beneath it. The lever 36b is shown in Figure 5 in a locked position for the movable output measuring roller 15a.

[0035] 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.

[0036] 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.

[0037] 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 captured and drawn into the second funnel 14 by the suction. 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 captured 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.

[0038] 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, removing 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 applying pressure to 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.

[0039] 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 has been 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 control system of the carding machine K. Instead of the output measuring rollers 15a, 15b, take-off rollers can also be used to discharge the fiber sliver FB into the depositing tube 40.

[0040] Figure 4a shows the extraction device of the drafting system 1, in which at least some of the extraction elements are integrated into the hood 2 and the cover flap 3. The element 3b shown in Figure 4a is the underside of the cover flap 3, which can be designed, for example, as a deep-drawn or deformed component made of sheet metal, plastic, or fiber composite and has the integrated tubes 55 and extraction openings 55a, 55b, 55c. This underside of the cover flap 3b can be designed as a separate component and is then connected and sealed to the cover flap 3 by means of fastening elements. The integrated tubes 55 and extraction openings 55a, 55b, 55c can, however, also be connected to the cover flap 3 on the underside as separate individual components. A suction hood 50 is designed to extract fibers and dust from the top rollers 8, 10 of the main drafting zone.The suction hood 50 has an elongated and flat contour, with a vertically aligned slot 50a arranged on its end face facing the top rollers 8, 10. The length of the slot 50a is designed such that suction from the top rollers 8, 10 is ensured at the minimum and maximum draw zone width of the main draft zone. The suction hood 50 is arranged within the pivotable wing 2b and, with the opening of the wing 2b, is pivoted away from the top rollers 8, 10, thus ensuring accessibility to the top rollers 8, 10. A duct 51 creates a pneumatic connection to a closure housing 52, through which the fibers and dust pass directly into the suction system of the spinning preparation system via the pipe 37 or indirectly via the card K. Usually, the extraction system of the spinning preparation plant in the card K orHere, a negative pressure of between 200 and 500 Pascal is created in the suction device of the drafting system 1. When the wing 2b is opened, a separation can occur in the connection between the suction hood 50 and the flap housing 52. Alternatively, the channel 51 can be designed as a flexible or expandable hose.

[0041] A suction element 57 cooperates with the lower rollers 7, 9 and is attached to the first pair of drafting rollers 7, 8 by means of a fastening element 58, directly or indirectly to the adjustable drive housing, here the upper drive housing 4a. The suction element 57 has a first opening 57a, which is directed downwards towards the pair of output measuring rollers 15a, 15b and is designed to suck fibers and dust from this area. A second vertical and elongated opening 57b is directed towards the lower rollers 7, 9 of the drafting system 1. By adjusting the drafting field width in the main drafting field, for example via the adjusting element 23, the suction element 57 is also adjusted or moved in the vertical position, since it is attached directly or indirectly, for example via the fastening element 58, to the upper drive housing 4a.With a horizontal arrangement of the drafting system rollers, the suction element 57 is directly or indirectly coupled to the adjustable drafting system roller pair. When the drafting field width changes, the suction element 57 also shifts or adjusts along with the change in position of the adjustable drafting system pair. The suction element 57 is connected to the upper cover flap 3 by a connecting tube 56. When the cover flap 3 is pivoted upwards, a sealed connection between the connecting tube 56 and the cover flap 3 is released.

[0042] Integrated into the cover flap 3 or arranged beneath the outer side of the cover flap 3 is an integrated tube 55 that extends around at least two outer sides of the cover flap 3. The integrated tube 55 accommodates the connecting tube 56 of the suction element 57 on an underside by means of a seal and guides the sucked-up fibers and dust from the lower rollers 7, 9 and the output measuring rollers 15a, 15b to a lateral connection to which a connecting tube 54 is detachably arranged by means of a sealing element. The fibers and dust are guided into the closure housing 52 via the connecting tube 54. As already described with Figures 2a and 2b, the cover flap 3 has an opening 3a for the fiber sliver FB.In this embodiment, two suction openings 55b, 55c are arranged laterally around the opening 3a for the fiber sliver, and above the opening 3a for the fiber sliver FB, another suction opening 55a is arranged, through which fibers and dust from the incoming fiber sliver FB can be suctioned off. As previously explained, fibers and dust from the drafting rollers 7, 8, 9, 10, the output measuring rollers 15a, 15b, and from the area of ​​the opening 3a are guided via the channel 51 and the connecting pipe 54 into the closure housing 52, which is connected directly or indirectly to the suction system of the spinning preparation via pipe 37.

[0043] According to Fig. 4b, a closure element 53 is arranged within the closure housing 52, with which the air connection between the pipe 37 on the one hand and the channel 51 and the connecting pipe 54 on the other hand can be separated. The closure element 53 is shown as a broken line in the open position and as a dashed line in the closed position. The closure element 53 can be adjusted by means of a pneumatic cylinder or a motor drive. The air connection is separated when the can change begins and continues until a first complete layer of fiber sliver (a so-called cake) has formed in the new can. The interruption of the suction prevents turbulence in the air flow within the draw frame when the piecing nozzle in the form of the second funnel 14 is pressurized with compressed air.In addition, the deposition of the cycloidally deposited fiber sliver on the bottom of the new can is favored, which can lead to uneven conveyance of the fiber sliver due to the negative pressure then generated at the deposition tube 41. The closure element 53 can be designed as a pivoting flap as shown in Fig. 4b, as a slide or valve to interrupt the flow to the tube 37. The closure housing 52 is open during normal operation so that fibers and dust can be sucked out of the drafting system 1 via the tube 37 by means of negative pressure. At a predetermined time during the can change, the closure housing 52 is closed by means of the closure element 53 in order to prevent flow turbulence within the drafting system 1.

[0044] At least part of the suction device is integrated into the hood 2 and the cover flap 3 and is pivoted with these components when these components are opened. When the wings 2a, 2b are opened, at least the suction hood 50 is pivoted away from the upper rollers 8, 10, since the suction hood 50 is arranged on the inside of a wing 2b and is fastened to it. The cover flap 3 also has further suction openings 55a, 55b, 55c in the area of ​​the opening 3a. When the cover flap 3 is opened, the integrated pipe 55 is also pivoted out of the suction device, so that the connection between the suction element 57 for the lower rollers 7, 9 and the output measuring rollers 15a, 15b to the closure housing 52 is interrupted. The integration of the suction device into the housing (hood 2 and cover flap 3) of the drafting system makes it easy to maintain and clean, since the corresponding components are removed at the same time when the wings 2a, 2b and the cover flap 3 are opened.Maintenance times are reduced, and space is created for replacing wear-intensive components. With the direct or indirect coupling of the suction element 57 to the bearing for the adjustable draw roll pair, at least the movable bottom roll can be constantly vacuumed when the draw zone width changes. Since this is often the input roll pair in the main draft zone due to the coupling of the drives, a large portion of the fibers and dust also accumulate here.

[0045] Figure 5 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 between the draw frame pairs can be adjusted without individually adjusting the draw frame 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.

[0046] 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 top roll 8 is pressed against the first bottom roll 7 by the pressure of the cylinders 11a, 11b on the roller bearings 8.4, 8.5 with the roll cover 8.1, thereby driving it frictionally. The separation of the drives into an upper drive housing 4a with the first pair of drafting rolls 7, 8 and a lower drive housing 4b with the two pairs of drafting rolls 9, 10 enables the nip line spacing in the main drafting zone to be adjusted. At the same time, the speed of the bottom rolls 7, 9 and the load pressure of the top rolls 8, 10 can be controlled separately for the drafting roll pairs. At the same time, the driven measuring rolls 6b, 15b are decoupled from each other in terms of drive technology, eliminating the need for crossed belts.

[0047] 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 the draft depending on the fibers to be processed.

[0048] Reference symbol

[0049] 1 drafting system

[0050] 2 hood

[0051] 2a, 2b wings

[0052] 3 Cover flap

[0053] 3a Opening

[0054] 3b Underside cover flap

[0055] 4a, 4b drive housing

[0056] 5 first funnel

[0057] 6, 6a, 6b Input measuring roller pair

[0058] 7 first lower roller

[0059] 8 first top roller

[0060] 9 second lower roller

[0061] 10 second top roller

[0062] 11a first cylinder

[0063] 12a second cylinder

[0064] 13 compression rod

[0065] 14 second funnel

[0066] 15a, 15b Output measuring roller pair

[0067] 16 scrapers

[0068] 17 Sensor

[0069] 21 first drive

[0070] 23 Control element

[0071] 24 Guide plate

[0072] 26 first belt

[0073] 27 Sensor

[0074] 28 second belt

[0075] 29 pulley

[0076] 30 second drive

[0077] 31 first belt

[0078] 32 second belt

[0079] 33 third belt

[0080] 34 pulley

[0081] 35 clamping element

[0082] 36b lever

[0083] 37 pipe

[0084] 40 storage tube

[0085] 41 jug plates

[0086] 50 Extractor hood

[0087] 50a Slot 51 Channel

[0088] 52 bolt housing

[0089] 53 Closure element

[0090] 54 connecting pipe

[0091] 55 Integrated pipe 55a, 55b, 55c Extraction opening

[0092] 56 connecting pipe

[0093] 57 Suction element

[0094] 57a first opening

[0095] 57b second opening

[0096] 58 Fastening element

[0097] A filing

[0098] FB fiber ribbon

[0099] K Card

[0100] R pulley

[0101] S memory

[0102] W Can changer x, y, z direction

Claims

AMENDED CLAIMS received by the International Bureau on 02 July 2024 (02.07.2024) 1. A drafting device (1) for drawing at least one fiber sliver, comprising at least a first and a second pair of drafting rollers (7, 8;9, 10), which together form an adjustable main drafting zone, with a suction device for fibers and dust, which is arranged within a housing surrounding the drafting system, wherein the suction device is designed to be connected directly or indirectly to the central suction system of the spinning preparation, wherein the suction device has at least one suction system for the upper rollers (8, 10) and one suction system for the lower rollers (7, 9) of the drafting roller pairs, wherein the suction system for the lower rollers (7, 9) is arranged directly or indirectly on the bearing for the drafting roller pair, and has a constant distance from the lower rollers (7, 9) in every setting of the main drafting zone, characterized in that at least a part of the housing of the drafting system (1) has an integrated channel or pipe (55) with which the suction of fibers and dust from the lower rollers (7, 9) is connected to the suction system of the spinning preparation.

2. Drafting device (1) according to claim 1, characterized in that the suction for the lower rollers (7, 9) is designed as a suction element (57) that has an opening (57b) for the suction of the lower rollers (7, 9), and a further opening (57a) for the suction of the take-off rollers or output measuring rollers (15a, 15b) arranged downstream in the material flow direction.

3. Drafting device (1) according to claim 1, characterized in that the suction element (57) is connected to the integrated channel or pipe (55) by means of a connecting pipe (56).

4. Drafting system (1) according to one of the preceding claims, characterized in that the suction for the upper rollers (8, 10) is designed as a suction hood (50) which is arranged or integrated on or in the housing of the drafting system (1), so that when the housing is opened, the suction hood (50) is removed from the upper rollers (8, 10).

5. Drafting device (1) according to one of the preceding claims, characterized in that the suction device has a closure housing (52) which is designed to interrupt the air flow between the suction for the upper rollers and lower rollers for the suction of the spinning preparation.

6. Drafting device (1) according to one of the preceding claims, characterized in that the housing has a hood (2) with two wings (2a, 2b), and a 18 AMENDED SHEET (ARTICLE 19) swing-open cover flap (3) with an opening (3a) for inserting the fiber sliver (FB) into the drafting system (1).

7. Drafting system according to claim 6, characterized in that the suction hood (50) for suctioning the upper rollers (8, 10) is arranged or integrated on or in a wing (2a, 2b) of the hood.

8. Drafting system according to claim 1, characterized in that the integrated channel or tube (55) is arranged on or in the cover flap (3).

9. Drafting device according to claim 6, characterized in that around the opening (3a) for introducing the fiber band (FB) there is arranged at least one suction opening (55a, 55b, 55c) for suctioning fibers and dust, which is connected to the integrated channel or pipe (55).

10. Drafting system according to claim 3, characterized in that the integrated channel or pipe (55) receives the connecting pipe (56) on a lower side by means of a seal, wherein the connecting pipe (56) dips into the seal in accordance with the adjustment of the field width. 19 AMENDED SHEET (ARTICLE 19)

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