Integrated drafting system

Abstract

The invention relates to a drafting system for drafting a carded sliver before it is deposited in a can, wherein the drafting system (1) is positioned on the top side of the can changer (W) associated with the carding machine (K), the drafting system comprising: a vertically arranged 2-over-2 drafting system having an upper first pair of drafting rollers (7, 8) designed to form a first nip point (P1); and a lower second pair of drafting rollers (9, 10) designed to form a second nip point (P2). The invention is characterised in that: the second pair of drafting rollers (9, 10) is positioned with its second nip point (P2) offset horizontally (V) from the first nip point (P1); and a pressure bar (13) is arranged below the first pair of drafting rollers (7, 8) in such a way that the sliver (FB) is guided vertically from a convex surface of the pressure bar (13) towards the second nip point.

Description

[0001] Title: Integrated drafting system

[0002] Description

[0003] The present invention relates to a drafting device for drawing a carded fiber sliver before depositing it in a can, wherein the drafting device is arranged on the upper side of the can changer belonging to the carding machine.

[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.Accordingly, the object of the invention is to create a draw frame for a carded fiber sliver that can process a large number of fibers with different fiber lengths in high quality.

[0006] The invention solves the stated problem by a system having the features specified in claim 1. Advantageous developments of the invention are defined in the dependent claims.

[0007] The invention relates to a drafting device for drawing a carded fiber sliver before depositing it in a can, wherein the drafting device is arranged on the upper side of the can changer belonging to the carding machine.

[0008] The draw frame according to the invention has a vertically arranged 2-over-2 draw frame, with an upper first draw roller pair which is designed to form a first clamping point. Below the first draw roller pair there is arranged a second draw roller pair which is designed to form a second clamping point.

[0009] The invention includes the technical teaching that the second pair of stretching rollers is arranged with its second clamping point at a horizontal offset from the first clamping point, and that a pressure rod is arranged below the first pair of stretching rollers in such a way that the fiber sliver is guided by a convex surface of the pressure rod to the second clamping point, wherein the contact point or deflection point of the fiber sliver on the pressure rod is arranged perpendicular to the second clamping point.

[0010] Although the contact point or deflection point of the sliver on the compression rod is arranged perpendicular to the second clamping point, due to the incoming sliver speed, the sliver will hit the surfaces of the second pair of draw rollers at an angle of ± 30° to the vertical and be drawn into the second clamping point. The angle of ± 30° to the vertical ensures that, regardless of the nip line spacing and the incoming sliver speed, the sliver is guided or pulled into the second clamping point. The horizontal offset allows the necessary installation space for the compression rod, which guides the sliver to the second pair of draw rollers. The sliver runs vertically through the first pair of draw rollers, hits the inclined side surface of the compression rod, and is guided by its convex contour perpendicular to the second clamping point.The offset arrangement of the second pair of draw rollers relative to the first pair of draw rollers, combined with the arrangement of the pressure bar, facilitates automatic threading of the vertically running fiber sliver. Because the pressure bar can be positioned between the first and second top rollers, the top rollers can be positioned slightly offset vertically below the corresponding bottom rollers, shifting the clamping points on the circumference of the bottom rollers. The slight downward shift of the clamping points and the horizontal offset of the second pair of draw rollers opposite to the x-direction allow the pressure bar to be installed between the top rollers.

[0011] If the horizontal offset of the second pair of drafting rollers were to occur in the opposite direction, i.e., in the x-direction, and at the same time the lower rollers were arranged vertically offset below the upper rollers, the compression rod could also be assigned to the first lower roller in a modified longitudinal orientation. However, the design shown here facilitates the disassembly of the upper rollers for cleaning and maintenance of the drafting system, since disassembling the upper rollers also allows the compression rod to be removed for cleaning the lower rollers.

[0012] The compression rod preferably has a rectangular or square base body with a convex contour on one outer surface. When installed, at least one outer surface is designed to deflect the fiber sliver passing through the first pair of draw rollers to the second pair of draw rollers. The outer surface with the convex contour is tangent to the fiber sliver in such a way that it is guided perpendicularly to the second clamping point. This ensures that the short fibers are guided even with a variable clamping line spacing.

[0013] 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 of 50° to 55°, promotes automatic piecing, since the fiber sliver from the first pair of draw rollers strikes the inclined upper side of the pressure bar and is thus guided along the convex contour to the second pair of draw rollers.

[0014] The fact that a center or symmetry line formed in the longitudinal direction of the pressure bar intersects the center of the first top roller results in a compact design, so that a clamping line distance of 35 mm is possible.

[0015] The offset arrangement of the upper rollers, vertically aligned with the lower rollers, shifts the clamping points along the circumference of the lower rollers. Due to the offset arrangement of the upper rollers below the symmetry line of the lower rollers, the clamping points are also shifted downward. This, in combination with the inclined arrangement of the pressure bar, promotes automatic piecing.

[0016] The horizontal offset (V) between the first clamping point (P1) and the second clamping point (P2) can be between 5 mm and 12 mm. The horizontal offset (V) allows the fiber sliver to be deflected by the convex contour of the compression rod, which improves the short fiber guidance. This results in textile-technical improvements, particularly for recycled fiber blends, which lead to higher yarn strength and lower IPI values ​​in the yarn.

[0017] The use of the pressure rod allows for an increase in the clamping line spacing, especially when processing short fibers. This spacing can be varied between 35 mm and 75 mm between the clamping points.

[0018] Preferably, the upper first pair of drafting rollers and the lower second pair of drafting rollers are each mounted in separate drive housings whose spacing is adjustable. The adjustment of the nip line spacing is achieved by shifting or changing the spacing of the drive housings from each other, so that neither the individual drafting rollers are moved separately nor are the drive components affected.

[0019] To maintain the geometry of the pressure bar arrangement when adjusting the clamping line spacing, it is positioned fixedly relative to the first top roller. This ensures that the automatic threading and guidance of the short fibers are not affected by a change in the clamping line spacing.

[0020] Preferably, each drive housing has its own drive, which is designed to drive both the respective bottom rollers and the associated input measuring roller pair or output measuring roller pair independently of the other drive housing. By changing the nip line spacing via an adjusting device acting on the drive housing, the drafting rollers do not need to be adjusted separately, nor do the drive components such as belts, deflectors, or gears need to be adjusted.

[0021] 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 designed to detect errors during automatic piecing, or sliver breakage or jamming. 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 to be processed. 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.

[0022] They show:

[0023] Figure 1 : a carding machine with a subsequent can deposit and an integrated

[0024] Route;

[0025] Figure 2a, 2b: a perspective view of the closed and opened

[0026] Housing;

[0027] Figure 3: a front view of the essential components of the line according to the invention;

[0028] Figure 4a, 4b: two representations of the stretching roller pairs with the pressure bar with different stretching field widths;

[0029] Figure 5: a first perspective view of the storage of the

[0030] pairs of stretching rollers;

[0031] Figure 6: a top view of the drafting system with the top rollers unlocked

[0032] Position;

[0033] Figure 7: a second perspective view of the storage of the

[0034] Pairs of stretching rollers with the removed top rollers;

[0035] Figure 8 shows a representation of the back of the track with the

[0036] Drive components.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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 deflection of the fiber band FB by the compression rod 13 can occur at an angle of ± 30° to the vertical.The contact point or deflection point of the fiber sliver FB on the compression rod 13 is arranged perpendicular to the second clamping point P2, but due to the incoming sliver speed, the fiber sliver FB will impact the surfaces of the second pair of draw rollers 9, 10 at an angle of ± 30° to the perpendicular and be drawn into the second clamping point P2. This angle ensures that, regardless of the clamping line spacing L1, L2 and the incoming sliver speed, the fiber sliver FB is guided or drawn into the second clamping point P2. This is illustrated in Figures 4a and 4b by a dashed fiber sliver guide. The compression rod 13 is arranged in a fixed position 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 allows the clamping line spacing to be increased from L1 of 35 mm (Fig. 4a) to L2 of 75 mm (Fig. 4b) when processing short fibers. In its longitudinal direction, the pressure rod 13 is inclined horizontally by an angle a from the vertical. The angle a 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 pressure rod 13, which comes into contact with the fiber sliver FB and guides the fibers, points diagonally downward in the z-direction. Preferably, the arrangement of the pressure rod 13 is such that the fiber band 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 pressure rod 13 and is guided by the convex surface of the pressure rod 13 preferably perpendicular to the second clamping point P2.The contact point or deflection point of the fiber sliver FB on the pressure rod 13 is arranged perpendicular to the second clamping point P2, but due to the incoming sliver speed, the fiber sliver FB will strike the surfaces of the second pair of draw rollers 9, 10 at an angle of ± 30° to the vertical and be drawn into the second clamping point P2. The convex surface of the pressure rod 13 thus touches a vertical line passing through the second clamping point P2 of the second pair of draw 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.

[0045] 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%.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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 the first end of which 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.

[0052] 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.

[0053] 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 drawing 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°. The upper bearing block 18a and the upper counter bearing 19a are arranged orthogonally on the upper support 22a. Also visible are the first lower roller 7 and, with an offset V opposite to the x-direction, the second lower roller 9 arranged underneath. Within the upper counter bearing 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.Shown hidden is cylinder 11a, which acts opposite to the x-direction on the second roller bearing 8.5 of the upper roller 8. In this position, this cylinder 11a is also retracted, allowing the upper roller to 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 moved in the x-direction in a bearing guide 25a, 25b (not shown) in the lower and upper drive housings 4a, 4b, thus being spaced apart from the lower rollers 7, 9.

[0054] 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.

[0055] 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 generous free space to the remaining drafting system components for maintenance and cleaning. The upper drive housing 4a has a first drive 21, from which the second adjustable input measuring roller 6b and the first bottom roller 7 are driven 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 direction of the first and second input measuring rollers 6a, 6b is in opposite directions, so that the fiber sliver FB is transported vertically downwards by the input measuring rollers 6a, 6b.A sensor 27 is mounted on the stationary input measuring roller 6b. This sensor is designed to determine the concentricity of this roller 6b and to compensate for any possible non-circular running. This allows monitoring the measurement accuracy of the determined strip 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 an adjustment of the clamping line distance L1, L2, whereby at the same time the stretching roller pairs can be controlled separately in the speed of the lower rollers 7, 9 and in the load pressure of the upper rollers 8, 10.At the same time, the driven measuring rollers 6b, 15b are decoupled from each other in terms of drive technology, so that no crossed belts have to be used.

[0056] 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 deposition tube 40. A tensioning element 35 ensures the necessary belt tension. The second drive 30 drives a third belt 33, which rotates the can plate 41. Reference numeral

[0057] 1 drafting system

[0058] 2 hood

[0059] 2a, 2b wings

[0060] 3 Cover flap

[0061] 3a Opening

[0062] 4a, 4b drive housing

[0063] 5 first funnel

[0064] 6, 6a, 6b Input measuring roller pair

[0065] 7 first lower roller

[0066] 8 first top roller

[0067] 8.1 Roller cover

[0068] 8.2, 8.3 Roll neck

[0069] 8.4, 8.5 Roller bearings

[0070] 9 second lower roller

[0071] 10 second top roller

[0072] 11a, 11b first cylinder

[0073] 12a, 12b second cylinder

[0074] 13 compression rod

[0075] 14 second funnel

[0076] 14a Lever

[0077] 14b Pivot bearing

[0078] 15a, 15b Output measuring roller pair

[0079] 16 scrapers

[0080] 17 Sensor

[0081] 18a, 18b bearing block

[0082] 19a, 19b Counter bearing

[0083] 20a, 20b rocker arm

[0084] 21 first drive

[0085] 22a, 22b support

[0086] 23 Control element

[0087] 24 Guide plate

[0088] 25a, 25b Warehouse management

[0089] 26 first belt

[0090] 27 Sensor

[0091] 28 second belt

[0092] 29 pulley

[0093] 30 second drive

[0094] 31 first belt

[0095] 32 second belt

[0096] 33 third belt

[0097] 34 Deflection pulley 35 Tensioning element

[0098] 36a, 36b lever

[0099] 37 pipe

[0100] 40 storage tube

[0101] 41 jug plates

[0102] A filing

[0103] FB fiber ribbon

[0104] K Card

[0105] L1, L2 clamping line spacing

[0106] P1, P2 terminal point

[0107] R pulley

[0108] S memory

[0109] V Offset

[0110] W Can changer x, y, z direction a angle pressure rod

Claims

AMENDED CLAIMS received by the International Bureau on 29 May 2024 (29.05.2024) 1. A drafting device for drawing a carded fiber sliver before depositing it in a can, wherein the drafting device (1) is arranged on the upper side of the can changer (W) belonging to the carding machine (K), comprising a vertically arranged 2-over-2 drafting device, with an upper first pair of drafting rollers (7, 8) which is designed to form a first clamping point (P1), comprising a lower second pair of drafting rollers (9, 10) which is designed to form a second clamping point (P2), wherein the second pair of drafting rollers (9, 10) is arranged with its second clamping point (P2) by a horizontal offset (V) to the first clamping point (P1), and that a pressure bar (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 bar (13) to the second clamping point, wherein the The contact point or deflection point of the fiber band (FB) on the pressure rod (13) is arranged perpendicular to the second clamping point (P2),characterized in that the horizontal offset (V) between the first clamping point (P1) and the second clamping point (P2) is 5mm to 12mm., 2. Drafting device according to claim 1, characterized in that each pair of drafting rollers comprises a lower roller (7, 9) and a top roller (8, 10) and the pressure bar (13) is arranged between the first and the second top roller (8, 10).

3. Drafting device according to claim 2, characterized in that the pressure rod (13) is inclined in its longitudinal direction from the vertical by an angle (a) of 40° to 60°, preferably of 50° to 55° in the horizontal direction.

4. Drafting device according to claim 3, characterized in that a center or symmetry line formed in the longitudinal direction of the pressure bar (13) intersects the center of the first top roller (8).

5. Drafting device according to claim 1, characterized in that the upper rollers (8, 10) are arranged offset in vertical alignment to the lower rollers (7, 9).

6. Drafting system according to claim 1, characterized in that between the clamping points (P1, P2) there is a clamping line distance which can be varied between (L1) 35mm and (L2) 75mm.

7. A drafting device according to claim 6, characterized in that the upper first pair of drafting rollers (7, 8) and the lower second pair of drafting rollers (9, 10) are each mounted in separate drive housings (4a, 4b), the distance between which is adjustable. 19 AMENDED SHEET (ARTICLE 19) 8. Drafting device according to claim 1, characterized in that the pressure rod (13) is arranged stationary relative to the first top roller (8).

9. Drafting device according to claim 1, characterized in that the pressure rod (13) has a rectangular or square base body which has a convex contour on an outer surface.

10. Drafting system according to claim 1, characterized in that the drafting system (1) is designed as a controlled single-zone drafting system. 20 AMENDED SHEET (ARTICLE 19)

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