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 arranged 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) and a lower second pair of drafting rollers (9, 10). The invention is characterised 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) and bearing blocks (18a, 18b), the distance between said drive housings and bearing blocks being adjustable.

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 have 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. To process different fiber blends, the nip line spacing between the draw frame rollers must be adjusted.According to the state of the art, this is complex because in addition to adjusting the drafting rollers, the associated drive components also have to be adjusted.

[0006] Accordingly, the invention is based on the object of creating a draw frame for a carded fiber sliver that can process a variety of fibers with different fiber lengths with high quality. To this end, the adjustment of the clamping line spacing should be simplified.

[0007] 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.

[0008] 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.

[0009] The draw frame according to the invention comprises a vertically arranged 2-over-2 draw frame with an upper first draw roll pair and a second draw roll pair.

[0010] The invention includes the technical teaching that the upper first pair of draw rollers and the lower second pair of draw rollers are each mounted in separate drive housings and bearing blocks, the distance between which is adjustable. This allows the adjustment of the nip line spacing between the draw roller pairs by moving or changing the distance between the drive housings, so that neither the individual draw rollers need to be moved separately nor do drive components need to be readjusted.

[0011] The bearing blocks extend parallel to the at least one drive housing and are each connected to it by a support. The lower and upper rollers are thus mounted on a U-shaped frame consisting of the respective drive housing, the parallel bearing block, and the connecting support. This arrangement of the upper roller bearings allows for free space for cleaning and maintenance of the drafting system.

[0012] Because an adjusting element is designed to adjust the distance between the upper drive housing and the lower drive housing, the nip line spacing between the drafting system rollers can be adjusted without readjusting the drive components. By changing the nip line spacing via an adjusting device that acts on the drive housing, the drafting system rollers do not need to be adjusted separately, nor do the drive components such as belts, deflectors, or gears need to be adjusted. A very rapid change of the nip line spacing is possible depending on the fibers to be processed, which can be done automatically or manually. The adjusting element can be designed, for example, as a manually operated threaded spindle or as a motor drive.

[0013] Because a pair of input measuring rollers and a funnel are located on the upper drive housing above the upper first pair of draw rollers, their distances from the upper first pair of draw rollers remain unchanged when the nip line spacing is adjusted. Automatic threading can continue unchanged, and the detection of a sliver break or fiber sliver wrap on the upper first top roller is also possible.

[0014] Similarly, a hopper and a pair of output measuring rollers are also arranged on the lower drive housing below the lower second pair of draw rollers. Their distances from the lower second pair of draw rollers also remain unchanged when the nip line spacing is adjusted. In addition to automatic threading and the detection of a fiber sliver break or fiber sliver lap on the lower second top roller, controlled draw frame draft is also ensured without adjusting these components.

[0015] Advantageously, each drive housing has a separate drive for the associated pair of drafting rollers. In addition to the advantage of adjustable nip line spacing, the bottom rollers can also be driven independently of each other, allowing for effortless adjustment of the drafting system despite the offset of the drafting roller pairs. Crossing drive belts, as is common in the prior art, are avoided, thus simplifying the adjustment of the drive components.

[0016] The nip line spacing between the upper first pair of draw rollers and the lower second pair of draw rollers can be varied between 35 mm and 75 mm by changing the distance between the drive housings. For this purpose, a pressure rod is arranged below the upper pair of draw rollers, fixed to the upper pair of draw rollers. This allows the nip line spacing to be increased, particularly when processing short fibers. This allows the processing of fiber blends with a high proportion of recycled fibers with improved quality. The automatic threading and guidance of the short fibers is thus not affected by a change in the nip line spacing.

[0017] The funnel above the upper pair of draw rollers and the funnel below the lower pair of draw rollers are designed to be pivoted out of the fiber sliver material flow path. This allows for improved cleaning of the draw roller system.

[0018] Preferably, the drive components are arranged between the drives and the associated pairs of drafting rollers on the rear side of the drafting system, with the drives being designed to drive the respective bottom rollers and the respective fixed input and output measuring rollers. Arranging the drive components on the rear side of the drafting system increases accessibility at the front for cleaning and maintenance work. At the same time, the drive area can be encapsulated in the housing, keeping out fiber fly and dirt. Crossing drives are avoided by driving the components of the upper drive housing (first bottom roller and pair of input measuring rollers) by their own upper drive, and the components of the lower drive housing (second bottom roller and pair of output measuring rollers) by their own lower drive.The drives can be controlled independently of each other so that the draft between the drafting rollers can be adjusted and regulated.

[0019] The movable measuring rollers are driven by belts from the stationary input and output measuring rollers. This indirect drive of the movable measuring rollers by separate drives easily ensures the correct direction of rotation and allows them to be driven independently of their position relative to the stationary measuring rollers. They are thus movable in the operating position and also in the maintenance position, into which they can be moved using the levers. This eliminates the need to disassemble or re-tension the drive belts.

[0020] The fixed input measuring roller can be integrated with a sensor to determine concentricity. Any possible runout can be compensated for by measurement. This allows for monitoring the accuracy of the measured strip mass deviation.

[0021] Preferably, the lower drive is designed to drive the can plate. Since the second lower roller and the can plate are indirectly coupled via the lower drive, the draft adjustment by the lower pair of draw rollers also simultaneously adjusts the speed for fiber sliver deposition in the can.

[0022] The drafting system is preferably designed as a controlled drafting system. The input and output measuring rollers are designed to control the drawn sliver mass and are also designed to detect errors during automatic piecing, as well as sliver breakage or jams. To control the sliver mass, the upper and lower pairs of drafting rollers can be driven independently of each other.

[0023] 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.

[0024] They show:

[0025] Figure 1 : a carding machine with a subsequent can deposit and an integrated

[0026] Route;

[0027] Figure 2a, 2b: a perspective view of the closed and opened

[0028] Housing;

[0029] Figure 3: a front view of the essential components of the line according to the invention;

[0030] Figure 4a, 4b: two representations of the stretching roller pairs with the pressure bar with different stretching field widths;

[0031] Figure 5: a first perspective view of the storage of the

[0032] pairs of stretching rollers;

[0033] Figure 6: a top view of the drafting system with the top rollers unlocked

[0034] Position;

[0035] Figure 7: a second perspective view of the storage of the

[0036] Pairs of stretching rollers with the removed top rollers;

[0037] Figure 8 shows a representation of the back of the track with the

[0038] Drive components.

[0039] 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 rollers and the x-direction is orthogonal to the longitudinal axis of the drafting rollers.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] The funnel 14 is designed as a piecing aid and has lateral twist 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 pair of output measuring rollers 15a, 15b. The pair of output measuring rollers 15a, 15b is also designed to detect the deviation of the sliver mass from a predetermined value. A first stationary, rotatable output measuring roller 15b interacts with a movably mounted, second, rotatable output measuring roller 15a, the change in distance of which from the first stationary (stationary and rotatable) output measuring roller 15b is converted into a

[0044] These values ​​are also transmitted to a control system, for example the carding machine, which compares the values ​​with the values ​​of the

[0045] input measuring roller pair 6a, 6b and can show it on a display. The output measuring roller pair 15a, 15b can be designed as a smooth roller pair or as a grooved / touch-contact roller pair or with stepped rollers. Roller cleaners in the form of scrapers, with which the surface of the measuring rollers is cleaned, can be arranged on both sides of the output measuring roller pair 15a, 15b (not further designated). A lever 36b can be used to relieve a pressure load (not shown) on the displaceable output measuring roller 15a, with which it 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 displaceable output measuring roller 15a, and in Figure 8 in an open position for the displaceable 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 successful. 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 may indicate a break in the fiber sliver FB or a failed automatic piecing process.

[0048] 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.

[0049] 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%.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] A lower support 22b is also arranged on the lower drive housing 4b, on which a lower bearing block 18b (shown concealed) 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 concealed adjusting element 23. For this purpose, the upper drive housing 4a is attached to a lateral, vertically aligned guide so that it can be adjusted in the vertical direction (z-direction). By adjusting the adjustment, the nip line distance L1, L2 of the drafting roller pairs can be adjusted to one another, so that the drafting system 1 can be adjusted in a few simple steps if the fiber quality changes.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.

[0055] 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.

[0056] 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.

[0057] 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 remain unchanged from 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°.

[0058] 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.

[0059] 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.

[0060] 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 adjusting the drafting rollers 7, 8, 9, 10 individually. Both the upper and the lower drive housing 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 that 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.

[0061] 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.Alternatively, an inductive proximity switch can be used, which delivers a pulse for each revolution of the measuring roller. This allows an anomaly in the concentricity that repeatedly occurs at the same point to be taken into account when assessing the volume fluctuation of the sliver. The first top roller 8 is pressed against the first bottom roller 7 by the pressure of the cylinders 11a, 11b on the roller bearings 8.4, 8.5 with the roller cover 8.1, and is thus driven by friction. The separation of the drives into an upper drive housing 4a with the first pair of draw rollers 7, 8 and a lower drive housing 4b with the two pairs of draw rollers 9, 10 enables the nip line spacing L1, L2 to be adjusted, whereby the draw roller pairs can be controlled separately in terms of the speed of the bottom rollers 7, 9 and the load pressure of the top rollers 8, 10.At the same time, the driven measuring rollers 6b, 15b are decoupled from each other in terms of drive technology, i.e. separated from each other in terms of drive technology, so that no crossed belts have to be used.

[0062] 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 15b. The adjustable output measuring roller 15b is driven by the fixed output measuring roller 15b by means of 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.

[0063] Reference symbol

[0064] 1 drafting system

[0065] 2 hood

[0066] 2a, 2b wings

[0067] 3 Cover flap

[0068] 3a Opening

[0069] 4a, 4b drive housing

[0070] 5 first funnel

[0071] 6, 6a, 6b Input measuring roller pair

[0072] 7 first lower roller

[0073] 8 first top roller

[0074] 8.1 Roller cover

[0075] 8.2, 8.3 Roll neck

[0076] 8.4, 8.5 Roller bearings

[0077] 9 second lower roller

[0078] 10 second top roller

[0079] 11a, 11b first cylinder

[0080] 12a, 12b second cylinder

[0081] 13 compression rod

[0082] 14 second funnel

[0083] 14a Lever

[0084] 14b Pivot bearing

[0085] 15a, 15b Output measuring roller pair

[0086] 16 scrapers

[0087] 17 Sensor

[0088] 18a, 18b bearing block

[0089] 19a, 19b Counter bearing

[0090] 20a, 20b rocker arm

[0091] 21 first drive

[0092] 22a, 22b support

[0093] 23 Control element

[0094] 24 Guide plate

[0095] 25a, 25b Warehouse management

[0096] 26 first belt

[0097] 27 Sensor

[0098] 28 second belt

[0099] 29 pulley

[0100] 30 second drive

[0101] 31 first belt

[0102] 32 second belt

[0103] 33 third belt

[0104] 34 Deflection pulley 35 Tensioning element

[0105] 36a, 36b lever

[0106] 37 pipe

[0107] 40 storage tube

[0108] 41 jug plates

[0109] A filing

[0110] FB fiber ribbon

[0111] K Card

[0112] L1, L2 clamping line spacing

[0113] P1, P2 terminal point

[0114] R pulley

[0115] S memory

[0116] V Offset

[0117] W Can changer x, y, z direction a angle pressure rod

Claims

Patent claims 1. Drafting device for drawing a carded fiber sliver before depositing it in a can, the drafting device (1) being arranged on the upper side of the can changer (W) belonging to the card (K), comprising a vertically arranged 2-over-2 drafting device, with an upper first pair of drafting rollers (7, 8) and a lower second pair of drafting rollers (9, 10), 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) and bearing blocks (18a, 18b), the distance between which is adjustable.

2. Drafting device according to claim 1, characterized in that the bearing blocks (18a, 18b) extend parallel to the at least one drive housing (4a, 4b) and are connected to it by a respective support (22a, 22b).

3. Drafting device according to claim 1, characterized in that an adjusting element (23) is designed to adjust the distance between the upper drive housing (4a) and the lower drive housing (4b).

4. Drafting device according to claim 1, characterized in that a pair of input measuring rollers (6a, 6b) and a funnel (5) are arranged on the upper drive housing (4a) above the upper first pair of drafting rollers (7, 8).

5. Drafting device according to claim 1, characterized in that a funnel (14) and a pair of output measuring rollers (15a, 15b) are arranged on the lower drive housing (4b) below the lower second pair of drafting rollers (9, 10).

6. Drafting device according to claim 1, characterized in that each drive housing (4a, 4b) has a separate drive (21, 30) for the associated pair of drafting rollers (7, 8; 9, 10).

7. Drafting device according to claim 3, characterized in that between the upper first pair of drafting rollers (7, 8) and the lower second pair of drafting rollers (9, 10) there is a clamping line distance which can be varied between (L1) 35mm and (L2) 75mm.

8. Drafting device according to claim 4 or 5, characterized in that a first funnel (5) is arranged above the upper pair of drafting rollers (7, 8) and a second funnel (14) is arranged below the lower pair of drafting rollers (9, 10), which are designed to be pivotable out of the material flow path of the fiber sliver.

9. Drafting system according to claim 6, characterized in that the drive components are arranged between the drives (21, 30) and the associated pairs of drafting rollers (7, 8; 9, 10) on the rear side of the drafting system (1), wherein the drives (21, 30) are designed to drive the respective lower rollers (7, 9) and the respective fixed input or output measuring roller (6b, 15b).

10. Drafting device according to claim 9, characterized in that the associated movable measuring rollers (6a, 15a) are driven by means of belts from the fixed input and output measuring rollers (6b, 15b).

11. Drafting system according to claim 9, characterized in that the fixed input measuring roller (6b) cooperates with a sensor (27) for determining the concentricity.

12. Drafting system according to claim 6, characterized in that the lower drive (30) is designed to drive the can plate (41).

13. Drafting system according to one of the preceding claims, characterized in that the drafting system (1) is designed as a controlled single-zone drafting system.

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