Drafting mechanism

Abstract

The invention relates to a drafting device (1) for drafting at least one sliver, comprising at least a first and a second drafting roller pair (7, 8; 9, 10) which together form an adjustable main stretching zone, the drafting mechanism has a suction device for fibers and dust, the suction device is arranged in the interior of a housing surrounding the drafting mechanism, the suction device is configured to be directly or indirectly connected to a suction part of a spinning preparation device, and the suction part is arranged in the housing. The suction device has at least a suction section for an upper roller (8, 10) of the drafting roller pair and a suction section for a lower roller (7, 9) of the drafting roller pair, characterized in that the suction section for the lower roller (7, 9) is arranged directly or indirectly on a support of the drafting roller pair, and the drafting roller pair is adjusted in order to adjust the main stretching zone.

Description

TECHNICAL FIELD

[0001] The invention relates to a drafting mechanism for drafting at least one sliver, which has at least a first pair of drafting rollers and a second pair of drafting rollers, which together form an adjustable main drafting zone, said drafting mechanism having a suction device for fibers and dust, which is arranged inside a housing surrounding said drafting mechanism, wherein said suction device is configured to be connected directly or indirectly to a central suction of a spinning preparation device, wherein said suction device has at least a suction for the upper roller of a pair of drafting rollers and a suction for the lower roller of said pair of drafting rollers. BACKGROUND

[0002] In the drafting of a sliver, fibers and dust are deposited inside the drafting mechanism, which must be sucked out. Suction elements are arranged in the area of the drafting mechanism rollers, which are connected to one another or individually to a tube connection, which is connected directly or indirectly to a suction of a spinning preparation device. The connection of the suction elements to one another or to the so-called tube connection is realized by means of individual tubes, which must be laboriously detached in the case of maintenance in order to provide space for the replacement of wear parts. In the case of a breakage of the sliver or a fiber jam, cleaning is also laborious, since it must be carried out around the tubes and the suction elements in order to clean them. Errors or non-sealing can occur in the case of installation, so that not all necessary components are cleaned by means of suction air. New deposits of fibers and dust can thereby be formed, which affect the error-free operation of the drafting mechanism. If the drafting mechanism has an adjustable zone width, the suction must be adapted to the changed position of the pairs of drafting rollers by means of great effort, if this is indeed possible. In the case of a non-adapted suction to the changed position of the pairs of drafting rollers, the air flow conditions inside the drafting mechanism change, and the suction will no longer be sufficient. SUMMARY

[0003] It is the task of the invention to eliminate the above-mentioned disadvantages and to improve the suction of a drafting mechanism.

[0004] The proposed task is solved by a drafting mechanism having the features indicated in claim 1. Advantageous further developments of the invention are defined in the dependent claims.

[0005] The invention relates to a drafting mechanism for drafting at least one sliver, the drafting mechanism comprising at least a first pair of drafting rollers and a second pair of drafting rollers, which together form an adjustable main draft zone. The drafting mechanism has a suction device for fibers and dust, which is arranged inside a housing surrounding the drafting mechanism. The suction device is configured to be directly or indirectly connected to a suction of a spinning preparation device, wherein the suction device has at least a suction for the upper roller of the pair of drafting rollers and a suction for the lower roller of the pair of drafting rollers. According to the invention, the suction for the lower roller is arranged directly or indirectly on a bearing of the pair of drafting rollers, which is adjusted for adjusting the main draft zone. By adjusting the area width of the main draft zone, the suction for the lower roller is also moved, so that the distance of the lower roller to the opening of the suction remains constant. Thus, the cleaning effect also remains constant, independent of the area width of the drafting mechanism.

[0006] At least a part of the housing of the drafting mechanism has an integrated channel or tube, by means of which the fiber and dust suction of the lower roller is connected to the suction of the spinning preparation device. With the opening of the housing section, the integrated channel or tube is also moved out of the area for maintenance and cleaning, which simplifies maintenance and cleaning.

[0007] Here, the suction for the lower roller is configured as a suction element, which has an opening for suctioning the lower roller and a further opening for suctioning a godet or an output gauge roller arranged subsequently in the material flow direction. Thus, all fiber-conveying components are cleaned by the suction air flow.

[0008] By connecting the suction element to the integrated channel or tube by means of a connecting tube, a compensation for the distance difference resulting from the adjustment of the area width and the associated displacement of the suction of the lower roller is also achieved. The connecting tube is correspondingly deeply sunk into the seal and / or the connecting tube is designed flexibly in order to receive the distance difference.

[0009] The suction for the upper roller can be configured as a suction hood, which is arranged on or integrated in the housing of the drafting mechanism, so that the suction hood is removed from the upper roller when the housing is opened. The space required for dismounting the upper roller is achieved directly by the opening of the housing. The dismounting of the tube is not necessary.

[0010] By having the suction device have a closed housing, wherein the closed housing is configured to interrupt the air flow between the suction for the upper and lower rollers and the suction of the spinning preparation device, the canister exchange is made easier, because for the period of time in which the first sliver is stored, no air disturbance for the sliver is formed, because compressed air is simultaneously blown into the drafting zone of the drafting mechanism by a thread building aid in the form of a second funnel.

[0011] Preferably, the housing has a shroud with two wings, and an upwardly pivotable flap with an opening for introducing the sliver into the drafting mechanism. Thus, the housing can be pivoted upwardly to such an extent by a few operations that the drafting mechanism can be cleaned and maintained without further disassembly.

[0012] The suction hood for the suction of the top roller is arranged on or in the wings of the shroud. By pivoting upwardly, the suction is removed at the same time, and thus free space is provided for the exchange or cleaning of the top roller.

[0013] By arranging the integrated channel or tube on or in the flap, it is ensured that the fibers and dust are cleaned from the lower roller suction to the central suction. By lifting the flap, the supply of suction air towards the lower roller is interrupted; by closing the flap, the supply of suction air towards the lower roller is restored, independently of the set zone width.

[0014] At least one suction opening is arranged in the opening region for the introduction of the sliver, which enables the suction of fibers and dust that would otherwise accumulate on the upper side of the drafting mechanism. The suction opening is likewise connected to the integrated channel or tube.

[0015] By means of the central suction of the spinning preparation, the working positions of the drafting mechanism described here are cleaned of fibers, dust and dirt by means of negative pressure. The connection of the suction can be directly connected to the central suction by means of a tube above the closed housing, or indirectly connected to the central suction by means of a carding machine suction, which is likewise connected to the central suction of the spinning preparation. BRIEF DESCRIPTION OF DRAWINGS

[0016] Further measures for improving the invention will be explained in detail below in connection with the description of a preferred embodiment of the invention according to the drawings.

[0017] shown:

[0018] Figure 1 : rotary flat card with subsequent sliver winder and integrated drafting mechanism;

[0019] Figure 2a , 2b : perspective view of the closed and open housing;

[0020] Figure 3 : front view of the main components of the drafting mechanism according to the invention;

[0021] Figure 4a : perspective view of the suction of the drafting mechanism;

[0022] Figure 4b : sectional view of the flap housing of the suction;

[0023] Figure 5 : illustration of the back side of the drafting machine with the drive assembly. DETAILED DESCRIPTION

[0024] Herein the drafting mechanism shown in Figures 1 to 5 the drafting mechanism shown herein is only exemplary shown as a 2 over 2 drafting mechanism. The suction integrated in the housing of the drafting mechanism can be used for any other drafting mechanism having a main draft zone (e.g. 3 over 3 or 4 over 3), independent of whether the drafting mechanism is oriented horizontally or vertically or the direction of the material flow of the sliver.

[0025] Figure 1 A rotary flat card K is shown, in which the produced sliver FB is guided via a plurality of deflection rollers R to the drafting mechanism 1. The drafting mechanism 1 is arranged on the upper side of the can changer W and integrated into the can changer W, so that the drafting mechanism is an integral part of the rotary flat card K. In this embodiment, a storage S for the sliver FB is arranged between the rotary flat card K and the drafting mechanism 1, which is configured to at least partially compensate for the difference in the supply speed of the sliver FB between the rotary flat card K and the drafting mechanism 1. The use or arrangement of the storage S is not essential for the present invention. For a better understanding of the subsequent arrangement of the components, a Cartesian coordinate system is used herein, in which the z-direction is the vertical line, along which the sliver FB enters the drafting mechanism 1. In the following figures, the y-direction corresponds to the longitudinal axis of the drafting mechanism rollers, and the x-direction is oriented orthogonal to the longitudinal axis of the drafting mechanism rollers. It is essential for the present invention that the individual sliver FB enters the drafting mechanism 1 vertically (z-direction) by means of gravity.

[0026] Figure 2a and Figure 2bThe closed and open cover 2 of a drafting machine 1 according to the application is shown, which has horizontally to be opened flaps 2a, 2b on the front side, so that access to the drafting mechanism is possible for maintenance work. The flaps 2a, 2b are pivotably fixed on the cover 2 by means of hinges. On the cover 2 likewise an upwardly pivotable flap 3 with an opening 3a is arranged. The flap 3 is integrated into the flaps 2a, 2b, so that the flaps 2a, 2b have a corresponding recess for the contour of the flap 3. On the flap 3 a deflection roller R is arranged, by means of which the fibre band FB can be deflected and introduced into the opening 3a of the flap 3 into the upper first funnel 5. On the upper side of the cover 2 a tube 37 is arranged, on which a line for the connection to the exhaust air of the spinning preparation device can be arranged. Through the tube 37 dust and unprocessed fibre material can be extracted. The drafting machine 1 is arranged on the upper side of a bobbin changer W, wherein on the upper side a storage A in the form of a recess is arranged. The storage A is configured in such a way that for the time of maintenance or cleaning the upper rollers 7, 8 of the drafting mechanism 1 can be stored. Unlike the prior art, no guide fibre or processed components are arranged on the inner side of the flaps 2a, 2b. By means of a magnetic lock, which can be detected by a sensor, the flap 3 and the flaps 2a, 2b can completely - apart from the opening 3a - close the cover 2, so that in the ongoing operation the control of the rotary cover plate card when the cover 2 is opened stops the drafting mechanism 1.

[0027] Figure 3A first front view of the opened drafting mechanism 1 is shown after the removal of the shroud 2 and the flap 3. Only the front of the upper driver housing 4a can be identified, which, in line with the other figures, continues behind the arrangement of the rollers and the funnel and is not shown here. The fibre band FB, which is not shown here, enters the first funnel 5 vertically (z direction) and is detected by the input measuring roller pair 6a, 6b. The funnel 5 is configured to pivot away upwards in the vertical direction (z direction) from the input measuring roller pair 6a, 6b in order to be able to implement a cleaning of the subsequent input measuring roller pair 6a, 6b or to eliminate a defective end. The subsequent input measuring roller pair 6a, 6b is configured to detect deviations of the fibre band FB from a predetermined band quality and to transmit the measured value to a not shown controller and to display it on a display, which can be the controller of the rotary flat card K, for example. To this end, the input measuring roller 6b is rotatably supported position- fixedly, while the second input measuring roller 6a is movably supported relative to the first input measuring roller 6b. The displacement of the second input measuring roller 6a can be detected, for example, with a moving coil or another sensor and the path change can be converted into a mass deviation. Arranged on the input measuring roller pair 6a, 6b on both sides, without further designation, are roller cleaners in the form of doctor blades with which the surface of the input measuring rollers 6a, 6b is cleaned. The input measuring roller pair 6a, 6b can be configured as a groove / probe roller or as a stepped roller or comprise two smooth rollers. Below the measuring roller 6b shown on the left in this view, a stripper 16 or another guide element can be arranged with which the fibre band FB is loosened from the input measuring roller pair 6a, 6b and is guided into the first drafting roller pair 7, 8. The not shown pressure load acting on the movable input measuring roller 6a, with which the input measuring roller 6a can be moved away from the position-fixedly arranged input measuring roller 6b, can be eliminated by a lever, which is not shown here. As a result, it is possible to simplify the maintenance and cleaning of the input measuring roller pair 6a, 6b and the upper drafting roller pair 7, 8 arranged thereunder.

[0028] The fibre band FB continues to travel vertically downwards until it is captured by a first lower roller 7 and a first upper roller 8. These two rollers 7, 8 form a first drafting roller pair. With a slight offset in the x direction, the fibre band FB hits a pressure bar 13, passes by this pressure bar and reaches a second drafting roller pair, which is formed by a second lower roller 9 and a second upper roller 10. The drafting mechanism 1 according to the application is thus configured as a vertically arranged 2 over 2 under drafting mechanism (single-zone drafting mechanism) with two lower rollers 7, 9 and two upper rollers 8, 10. Despite the vertical arrangement of these drafting roller pairs relative to one another, it is still a matter of upper and lower rollers here, as the lower rollers have a grooved metal surface and the upper rollers are provided with a plastic or rubber covering. The fibre band FB is drawn in length by the first and second drafting roller pairs due to the different rotational speeds and is guided into a second hopper 14. In addition, a first and a second cylinder 11a, 12a can be identified, with which the upper rollers 8, 10 are pressed against the lower rollers 7, 9 at the end with the pistons of the cylinders 11a, 12a in the x direction.

[0029] The hopper 14 is configured as a piecing aid and has a side-ported spiral bore nozzle along the inner bore, which is traversed by means of compressed air. A suction is thus generated on the hopper opening, with which the fibre band FB is drawn into the hopper and guided towards an output measuring roller pair 15a, 15b. The output measuring roller pair 15a, 15b is likewise configured to detect deviations of the band mass from a predetermined value. A stationary first output measuring roller 15a cooperates with a second output measuring roller 15b, which is supported displaceably, the change in the distance of the second output measuring roller 15b from the stationary first output measuring roller 15a being converted into a band mass deviation by a sensor, which is not shown, for example in a controller of the rotary flat card, into a band mass deviation. These values are also transmitted to a controller, for example of the rotary flat card, which can compare them with the values of the input measuring roller pair 6a, 6b and can display them on a display. The output measuring roller pair 15a, 15b can be configured as a smooth roller pair or as a grooved / probing roller pair or as a stepped roller. Without further designation, roller cleaners in the form of doctor blades are arranged on both sides on the output measuring roller pair 15a, 15b, with which the surface of the measuring rollers is cleaned. A pressure load, which is not shown, acting on the movable output measuring roller 15a, with which the output measuring roller 15a can be moved away from the position fixedly arranged output measuring roller 15b, can be eliminated by means of a lever 36b. Thereby, it is possible to achieve a simplified maintenance and cleaning of the output measuring roller pair 15a, 15b and the lap tube 40 arranged thereunder. The lever 36b is shown in the position locked for the movable output measuring roller 15a. Figure 5 The hopper 14 is configured as a piecing aid and has a side-ported spiral bore nozzle along the inner bore, which is traversed by means of compressed air. A suction is thus generated on the hopper opening, with which the fibre band FB is drawn into the hopper and guided towards an output measuring roller pair 15a, 15b. The output measuring roller pair 15a, 15b is likewise configured to detect deviations of the band mass from a predetermined value. A stationary first output measuring roller 15a cooperates with a second output measuring roller 15b, which is supported displaceably, the change in the distance of the second output measuring roller 15b from the stationary first output measuring roller 15a being converted into a band mass deviation by a sensor, which is not shown, for example in a controller of the rotary flat card, into a band mass deviation. These values are also transmitted to a controller, for example of the rotary flat card, which can compare them with the values of the input measuring roller pair 6a, 6b and can display them on a display. The output measuring roller pair 15a, 15b can be configured as a smooth roller pair or as a grooved / probing roller pair or as a stepped roller. Without further designation, roller cleaners in the form of doctor blades are arranged on both sides on the output measuring roller pair 15a, 15b, with which the surface of the measuring rollers is cleaned. A pressure load, which is not shown, acting on the movable output measuring roller 15a, with which the output measuring roller 15a can be moved away from the position fixedly arranged output measuring roller 15b, can be eliminated by means of a lever 36b. Thereby, it is possible to achieve a simplified maintenance and cleaning of the output measuring roller pair 15a, 15b and the lap tube 40 arranged thereunder. The lever 36b is shown in the position locked for the movable output measuring roller 15a.

[0030] After the output measuring roller pair 15a, 15b, the drafted sliver FB is deposited via a known sliver tube 40 into a not shown can, which rotates the sliver tube 40, for example in the form of a cycloid, by means of a can bottom 41. Between the output measuring roller pair 15a, 15b and the sliver tube 40 a sensor 17 is arranged, which is configured to monitor the inlet or opening of the sliver tube 40 with respect to possible sliver blockages.

[0031] The signals of the input measuring roller pair 6a, 6b and of the output measuring roller pair 15a, 15b can be processed in the controller of the rotary flat card or in the controller of the spinning preparation. If the automatic piecing process is successfully run, the controller can emit a signal. Then both measuring roller pairs 6a, 6b; 15a, 15b generate regular signals about the sliver quality. If after the automatic piecing only the input measuring roller pair 6a, 6b shows regular signals, while the output measuring roller pair 15a, 15b shows no regular signals or signals that have changed significantly, this indicates that the sliver FB has broken.

[0032] The rotary flat card K is operated at a low feed speed or running speed, which can be counted for example between 10 m / min and 100 m / min of the output fibre sliver, in order to introduce the fibre sliver FB into the drafting mechanism 1. The carded fibre fluff is handed over by the doffer of the rotary flat card to for example a subsequent transverse band or stripping roller and is introduced into the integrated funnel. At the outlet of the rotary flat card a subsequent measuring roller can already detect the sliver quality or the deviation of the fibre sliver quality from a reference body and process the associated signals in the rotary flat card controller. In the case of a detected sliver quality, the controller of the rotary flat card K automatically activates the drafting mechanism 1 in such a way that the drives 21, 30 drive the input measuring rollers 6a, 6b, the drafting roller pairs 7, 8; 9, 10 and the output measuring roller pair 15a, 15b. The drafting mechanism 1 is locked, which means that the pneumatic load of the upper rollers 8, 10 is activated. At the same time, the can bottom 41 of the can changer W is turned by the drive 30. The operator takes out the fibre sliver FB from the rotary flat card K by hand and introduces the fibre sliver FB into the first funnel 5 in the upper part of the drafting mechanism 1 with the guard 2 closed. Here, the starting end of the fibre sliver FB is captured by the input measuring roller pair 6a, 6b and is pulled into the drafting mechanism 1. In the case of a detection of the input measuring roller pair 6a, 6b, the signal is conducted by the associated sensor to the controller of the rotary flat card K, which generates compressed air for generating a suction on the second funnel 14. The penetration of the fibre sliver FB is supported by the suction, wherein the fibre sliver FB is captured by the first drafting roller pair 7, 8 and is pulled in. Due to the horizontal offset of the drafting roller pairs 7, 8; 9, 10, the fibre sliver FB hits the side of the pressure bar 13 and is guided towards the wedge gap of the second drafting roller pair 9, 10, is captured by the wedge gap of the second drafting roller pair 9, 10 and is pulled into the second funnel 14 by the suction. The rotational movement of the drafting roller pairs 7, 8; 9, 10 likewise generates an air flow inside the drafting mechanism 1, which facilitates the automatic penetration. Next, the fibre sliver FB can be captured by the output measuring roller pair 15a, 15b and is introduced into the lap tube 40 and is conveyed to the already turned can bottom 41. In the case of a detection of the fibre sliver by the output measuring roller pair 15a, 15b, the associated sensor can transmit a signal to the controller of the rotary flat card K, which recognises the penetration of the fibre sliver as successfully completed and can stop the introduction of compressed air on the second funnel 14. At the same time, the feed speed of the rotary flat card is increased to the necessary running speed for the fibre quality without the need for an operator's operation. Here, the speed of the drafting mechanism 1 and the can changer W is also adapted to the production speed or feed speed of the rotary flat card.

[0033] If the automatic threading in is not successful, for example due to a sliver break or a sliver jam, this can be identified in that either no fibre sliver enters the can via the sliver lap tube 40 or the output measuring roller pair 15a, 15b does not send a signal to the controller of the cylinder card K. If the output measuring roller pair 15a, 15b does not send a signal to the controller of the cylinder card within a time of for example one to five seconds after the fibre sliver has been detected by the sensor of the input measuring roller pair 6a, 6b, the controller of the cylinder card switches off the drafting mechanism 1. Alternatively, the sensor 17 can send a signal to the controller of the cylinder card to terminate the automatic threading in process when a sliver jam or a sliver break occurs. The drafting mechanism 1 and the can changer W are stopped, wherein the cylinder card K continues to run at a low feed speed or running speed at the same time. It thus continues to run slowly but continuously outputs the fibre sliver from the cylinder card. The drafting mechanism 1 is unlocked, wherein the pressure load acting on the upper rollers 8, 10 is removed. The shroud 2 of the drafting mechanism 1 is opened and the remaining sliver can be removed. Locking takes place with the shroud 2 of the drafting mechanism 1 closed, that is to say the pressure load is applied to the upper rollers 8, 10. At the same time, the drives 21, 30 start the input measuring rollers 6a, 6b, the drafting roller pairs 7, 8; 9, 10 and the output measuring roller pair 15a, 15b. The fibre sliver FB from the cylinder card K can again be introduced into the upper funnel 5 and the automatic piecing process is restarted.

[0034] When the can is changed, also initiated by the controller of the cylinder card K, compressed air for creating suction can be introduced on the second funnel 14 before a thin place is created in the fibre sliver FB. After the fibre sliver FB has been torn at the thin place, the compressed air continues to be generated until the fibre sliver FB is captured again by the output measuring roller pair 15a, 15b at least. The time for injecting compressed air on the second funnel 14 before and after a thin place is created in the fibre sliver FB can be adjusted in the controller of the cylinder card K. Instead of the output measuring rollers 15a, 15b, also a pull-off roller can be used to guide the fibre sliver FB out into the sliver lap tube 40.

[0035] Figure 4a A suction device of the drafting mechanism 1 is shown, in which at least a part of the suction elements is integrated in the shroud 2 and the flap 3. In Figure 4aThe lower side of the flap 3b shown in Fig. is configured, for example, as a deep-drawn or formed component made of sheet metal, plastic or fiber composite and has an integrated tube 55 and suction openings 55a, 55b, 55c. The lower side of the flap 3b can be configured as a separate component, which is then connected and sealed to the flap 3 by means of fixing elements. However, the integrated tube 55 and the suction openings 55a, 55b, 55c can also be connected to the flap 3 on the lower side as a separate single component. The suction hood 50 is configured to suck fibers and dust from the upper rolls 8, 10 of the main drafting zone. The suction hood 50 has an elongated, flat profile, on the end side of which pointing towards the upper rolls 8, 10, a vertically oriented slit 50a is arranged. The length of the slit 50a is configured such that the suction of the upper rolls 8, 10 is ensured both in the case of the minimum drafting zone width and in the case of the maximum drafting zone width of the main drafting zone. The suction hood 50 is arranged inside the pivotable wing 2b and is pivoted away from the upper rolls 8, 10 with the opening of the wing 2b, thereby ensuring the accessibility of the upper rolls 8, 10. The air-technical connection to the closed housing 52, through which the fibers and dust reach the suction system of the spinning preparation device directly via the tube 37 or indirectly via the rotary flat card K, is achieved by means of the channel 51. Typically, a negative pressure of 200 to 500 Pascal is applied in the rotary flat card K or in the suction device here of the drafting mechanism 1 by the suction system of the spinning preparation device. The disconnection of the connection between the suction hood 50 and the flip housing 52 is achieved when the wing 2b is opened. Alternatively, the channel 51 can be configured as a flexible or extendable hose.

[0036] The suction element 57, which cooperates with the lower rolls 7, 9, is fixed directly or indirectly on the adjustable drive housing, here the upper drive housing 4a, together with the first drafting roller pair 7, 8 by means of fixing elements 58. The suction element 57 has a first opening 57a, which is oriented downwards towards the output measuring roller pair 15a, 15b and is configured to suck fibers and dust from this area. A vertically, elongated configured second opening 57b is oriented towards the lower rolls 7, 9 of the drafting mechanism 1. With the adjustment of the drafting zone width in the main drafting zone, for example by means of the adjustment element 23, the suction element 57 is likewise adjusted or advanced in the vertical position, since it is fixed directly or indirectly, for example by means of the fixing elements 58, on the upper drive housing 4a. In the case of a horizontal arrangement of the drafting mechanism rollers, the suction element 57 is directly or indirectly coupled on the adjustable drafting mechanism roller pair. With a change in the drafting zone width, the suction element 57 is also displaced or rather adjusted with the change in position of the adjustable drafting mechanism pair. The suction element 57 is connected to the upper flap 3 by means of a connecting tube 56. With the upward pivoting of the flap 3, the sealed connection between the connecting tube 56 and the flap 3 is released.

[0037] The integrated tube 55 is integrated in the cover 3 or arranged below the outside of the cover 3, which extends at least around two outside sides of the cover 3. The integrated tube 55 receives the connecting tube 56 of the suction element 57 at the lower side by means of a seal and conducts the fibers and dust sucked from the lower rollers 7, 9 and the output measuring roller pair 15a, 15b to a lateral connection end, on which the connecting tube 54 is arranged releasably by means of a sealing element. The fibers and dust are conducted through the connecting tube 54 into the closed housing 52. As is shown by the arrows, the fibers and dust are conducted from the drafting mechanism rollers 7, 8, 9, 10, the output measuring roller pair 15a, 15b and the area of the opening 3a for the fiber strip FB into the closed housing 52 by means of the channel 51 and the connecting tube 54, which is connected directly or indirectly with the suction of the spinning preparation by means of the tube 37. Figure 2a and Figure 2b As already described, the cover 3 has an opening 3a for the fiber strip FB. In the present embodiment, two suction openings 55b, 55c are arranged laterally around the opening 3a for the fiber strip and a further suction opening 55a is arranged above the opening 3a for the fiber strip FB, through which the fibers and dust of the incoming fiber strip FB can be sucked. As already described previously, the fibers and dust are conducted from the drafting mechanism rollers 7, 8, 9, 10, the output measuring roller pair 15a, 15b and the area of the opening 3a for the fiber strip FB into the closed housing 52 by means of the channel 51 and the connecting tube 54, which is connected directly or indirectly with the suction of the spinning preparation by means of the tube 37.

[0038] According to Figure 4b , a closure element 53 is arranged inside the closed housing 52, by means of which the air-technical connection between the tube 37 and on the one hand the channel 51 and on the other hand the connecting tube 54 can be interrupted. 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 or motor drive. The air-technical connection is interrupted with the start of the can change and remains interrupted until the first complete layer of fiber strip (so-called "cake") is formed in the new can. The interruption of the suction can avoid air flow eddies in the interior of the drafting mechanism when the second funnel 14 in the form of a spinning jet is applied with compressed air. Furthermore, the storage of the fiber strip in the form of a pendulum is facilitated at the bottom of the new can, which can lead to an uneven fiber strip transport due to the negative pressure generated at the lap tube 41. The closure element 53 can be configured as a pivotable flap (as shown in Figure 4b ), a slide valve or a valve in order to interrupt the fluid flow to the tube 37. The closed housing 52 is open in normal operation so that fibers and dust can be sucked from the drafting mechanism 1 through the tube 37 by means of the negative pressure. At the predetermined time of the can change, the closed housing 52 is closed by means of the closure element 53 in order to avoid fluid eddies in the interior of the drafting mechanism 1.

[0039] At least a part of the suction device is integrated in the shroud 2 and the flap 3 and pivots with these assemblies when they are opened. With the opening of the wings 2a, 2b, at least the suction cover 50 pivots away from the upper rollers 8, 10, since the suction cover 50 is arranged on the inside of the wing 2b and is fixed thereto. The flap 3 also has further suction openings 55a, 55b, 55c in the area of the opening 3a. With the opening of the flap 3, the integrated tube 55 also pivots out of the suction device, thereby interrupting the connection between the suction element 57 for the lower rollers 7, 9 and the output measuring rollers 15a, 15b and the closed housing 52. By integrating the suction device in the housing of the drafting mechanism (shroud 2 and flap 3), it can be conveniently maintained and cleaned, since with the opening of the wings 2a, 2b and the flap 3, the assemblies belonging thereto are simultaneously removed. The maintenance time is reduced and space is provided for the replacement of the easily-wearing components. By means of the direct or indirect coupling of the suction element 57 with the support of the adjustable drafting roller pairs, the movable lower rollers can be at least constantly sucked, even when the drafting zone width is changed. Since this is usually the input roller pair in the main drawing zone due to the coupling of the drive, most of the fibers and dust also accumulate here.

[0040] Figure 5 The back side of a drafting machine according to the application with a drive concept is shown. The upper drive housing 4a is completely separated from the lower drive housing 4b and can be moved along the guide plate 24 by means of an adjustment element 23 not shown, so that the nip distance of the drafting mechanism pairs can be adjusted without the individual drafting mechanism rollers 7, 8, 9, 10 having to be adjusted. Not only the upper drive housing 4a, but also the lower drive housing 4b each have separate, independent drives, which are not affected by the adjustment of the nip distance. By arranging all the drive components on the back side of the drafting machine, a freely accessible front side is obtained, which provides sufficient space for maintenance or cleaning. It is thus not necessary to disassemble the drive components or their adjustment means. Additionally, the disassembly of the upper rollers 7, 9 is simplified by the support concept (in which the front cylinders 1 1 b, 12b are arranged in opposite directions to the rear cylinders 1 1 a, 12b), since a large free space is formed on the remaining drafting mechanism components for maintenance and cleaning if the upper rollers 7, 9 are disassembled.

[0041] The upper drive housing 4a has a first drive 21, by means of which the adjustable second input measuring roller 6b and the first lower roller 7 are driven by a first belt 26. Here the second belt 28 is driven by the driven second input measuring roller 6b over the first input measuring roller 6a and is deflected by a deflection roller 29. The drive direction of the first and second input measuring rollers 6a, 6b is here opposite, so that the fibre band FB is conveyed vertically downwards through the input measuring rollers 6a, 6b. A sensor 27 is arranged on the position-fixed input measuring roller 6b, which is configured to determine the runout of the roller 6b and to compensate a possible non-circular running in a measuring-technical manner. Thus, a check of the measuring accuracy of the determined band quality deviation is achieved. The sensor 27 can be configured, for example, as a moving coil or as a piezoelectric element. The first upper roller 8 is pressed by means of a roller cover 8.1 against the first lower roller 7 by a pressure acting onto the rolling bearings 8.4, 8.5 of the cylinder 11a, 11b and is thereby driven by friction. The separation of the drive into the upper drive housing 4a with the first drafting roller pair 7, 8 and the lower drive housing 4b with the two drafting roller pairs 9, 10 makes it possible to adjust the nip line distance in the main drafting zone, wherein at the same time the drafting roller pairs can be controlled individually in terms of the rotational speed of the lower rollers 7, 9 and the load pressure of the upper rollers 8, 10. At the same time, the driven measuring rollers 6b, 15b are uncoupled from one another in terms of the drive technology, so that the use of a cross belt is not necessary.

[0042] The lower drive housing 4b likewise has its own second drive 30, which is used at the same time to drive the band can bottom 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 means of a second belt 32 by the fixed output measuring roller 15a. The second belt 32 is deflected by a deflection roller 34, so that the two output measuring rollers 15a, 15b are driven counter to one another and the fibre band FB is passed between them and is conveyed into the banding tube 40. A tensioning element 35 ensures that the necessary belt tension is provided. A third belt 33 is driven by the second drive 30, which rotates the band can bottom 41. The drives 21, 30 can be configured as servo drives, whereby a change of the gear is dispensed with when the drafting zone width or the twist is changed in accordance with the fibre to be processed.

[0043] List of reference signs

[0044] 1 drafting mechanism

[0045] 2 guard

[0046] 2a, 2b wing

[0047] 3 flap

[0048] 3a opening

[0049] 3b underside of the lid

[0050] 4a, 4b driver housing

[0051] 5 first funnel

[0052] 6, 6a, 6b input measuring roller pair

[0053] 7 first lower roller

[0054] 8 first upper roller

[0055] 9 second lower roller

[0056] 10 second upper roller

[0057] 11a first cylinder

[0058] 12a second cylinder

[0059] 13 pressure rod

[0060] 14 second funnel

[0061] 15a, 15b output measuring roller pair

[0062] 16 stripper

[0063] 17 sensor

[0064] 21 first drive

[0065] 23 adjustment element

[0066] 24 guide plate

[0067] 26 first belt

[0068] 27 sensor

[0069] 28 second belt

[0070] 29 deflection roller

[0071] 30 second drive

[0072] 31 first belt

[0073] 32 second belt

[0074] 33 third belt

[0075] 34 deflection roller

[0076] 35 tensioning element

[0077] 36b lever

[0078] 37 tube

[0079] 40 bobbetube

[0080] 41 bobbetray

[0081] 50 suction hood

[0082] 50a slit

[0083] 51 channel

[0084] 52 closure housing

[0085] 53 closure element

[0086] 54 connecting tube

[0087] 55 integrated tube

[0088] 55a, 55b, 55c suction opening

[0089] 56 connecting tube

[0090] 57 suction element

[0091] 57a first opening

[0092] 57b second opening

[0093] 58 securing element

[0094] A storage

[0095] FB fibre band

[0096] K rotating flat-top card

[0097] R deflection roller

[0098] S memory

[0099] W bobbetray changer

[0100] x, y, z direction CLAIM (AMENDED IN ACCORDANCE WITH ARTICLE 19 OF THE TREATY) 1. Drafting mechanism (1) for drafting at least one 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, having a suction device for fibers and dust, which is arranged inside a housing surrounding the drafting mechanism, wherein the suction device is configured to be connected directly or indirectly to a central suction of a spinning preparation device, wherein the suction device has at least a suction for the upper rollers (8, 10) of the drafting roller pairs and a suction for the lower rollers (7, 9) of the drafting roller pairs, wherein the suction for the lower rollers (7, 9) is arranged directly or indirectly on a bearing for the drafting roller pairs and has a constant distance to the lower rollers (7, 9) under any adjustment of the main drafting zone, characterized in that at least a part of the housing of the drafting mechanism (1) has an integrated channel or tube (55) by means of which the suction for the lower rollers (7, 9) is connected to the suction of the spinning preparation device. 2. Drafting mechanism (1) according to claim 1, characterized in that the suction for the lower rollers (7, 9) is configured as a suction element (57) having an opening (57b) for suctioning the lower rollers (7, 9) and a further opening (57a) for suctioning a subsequent draw-off roller or output gauge roller (15a, 15b) in the direction of the material flow. 3. Drafting mechanism (1) according to claim 1, characterized in that the suction element (57) is connected to the integrated channel or tube (55) by means of a connecting tube (56). 4. Drafting mechanism (1) according to any of the preceding claims, characterized in that the suction for the upper rollers (8, 10) is configured as a suction hood (50) which is arranged on or integrated in the housing of the drafting mechanism (1) in such a way that the suction hood (50) is removed from the upper rollers (8, 10) when the housing is opened. 5. Drafting mechanism (1) according to any of the preceding claims, characterized in that the suction device has a closed housing (52) which is configured to interrupt the air flow between the suction for the upper and lower rollers and the suction of the spinning preparation device. 6. Drafting mechanism (1) according to any of the preceding claims, characterized in that the housing has a shroud (2) with two wings (2a, 2b) and an upwardly pivotable flap (3) having an opening (3a) for introducing the sliver (FB) into the drafting mechanism (1). 7. Drafting mechanism according to claim 6, characterized in that the suction hood (50) for suctioning the top roller (8, 10) is arranged on or integrated in the wing (2a, 2b) of the shroud. 8. Drafting mechanism according to claim 1, characterized in that the integrated channel or tube (55) is arranged on or in a flap (3). 9. Drafting mechanism according to claim 6, characterized in that at least one suction opening (55a, 55b, 55c) for suctioning fibers and dust is arranged around the opening (3a) for guiding the sliver (FB), which at least one suction opening is connected with the integrated channel or tube (55). 10. Drafting mechanism according to claim 3, characterized in that the integrated channel or tube (55) receives the connecting tube (56) on the underside by means of a seal, wherein the connecting tube (56) sinks into the seal in correspondence with the adjustment of the zone width.

Claims

1. Drafting mechanism (1) for drafting at least one sliver, comprising at least a first pair of drafting rollers and a second pair of drafting rollers (7, 8; 9, 10) which together form an adjustable main draft zone, having suction means for fibers and dust arranged inside a housing which surrounds the drafting mechanism, wherein The suction device is configured to be connected directly or indirectly to a central suction of a spinning preparation device, wherein the suction device has at least a suction for the upper rollers (8, 10) of a drafting roller pair and a suction for the lower rollers (7, 9) of the drafting roller pair, characterized in that the suction for the lower rollers (7, 9) is arranged directly or indirectly on a support for the drafting roller pair and has a constant distance to the lower rollers (7, 9) under any adjustment of the main draft zone.

2. Drafting mechanism (1) according to claim 1, characterized in that At least a part of the housing of the drafting mechanism (1) has an integrated channel or tube (55) by means of which the fiber and dust suction of the lower rollers (7, 9) is connected to the suction of the spinning preparation device.

3. Drafting mechanism (1) according to claim 2, characterized in that The suction for the lower rollers (7, 9) is configured as a suction element (57) having an opening (57b) for suctioning the lower rollers (7, 9) and a further opening (57a) for suctioning a godet or output measuring roller (15a, 15b) arranged subsequently in the material flow direction.

4. Drafting mechanism (1) according to claim 2, characterized in that The suction element (57) is connected to the integrated channel or tube (55) by means of a connecting tube (56).

5. Drafting mechanism (1) according to any one of the preceding claims, characterized in that The suction for the upper rollers (8, 10) is configured as a suction hood (50) which is arranged on or integrated in the housing of the drafting mechanism (1) such that the suction hood (50) is removed from the upper rollers (8, 10) when the housing is opened.

6. Drafting mechanism (1) according to any one of the preceding claims, characterized in that The suction device has a closed housing (52) which is configured to interrupt the air flow between the suction for the upper and lower rollers and the suction of the spinning preparation device.

7. Drafting mechanism (1) according to any one of the preceding claims, characterized in that The housing has a shroud (2) with two wings (2a, 2b) and an upwardly pivotable flap (3) having an opening (3a) for introducing the sliver (FB) into the drafting mechanism (1).

8. Drafting mechanism according to claim 7, characterized in that The suction hood (50) for suctioning the upper rollers (8, 10) is arranged on or in the wings (2a, 2b) of the shroud.

9. The drafting mechanism of claim 2 wherein, The integrated channel or tube (55) is arranged on or in the flap (3).

10. Drafting mechanism according to claim 7, characterized in that At least one suction opening (55a, 55b, 55c) for suctioning fibers and dust is arranged around the opening (3a) for guiding the sliver (FB), which is connected to the integrated channel or tube (55). The suction device is configured to be connected directly or indirectly to a central suction of a spinning preparation device, wherein the suction device has at least a suction for the upper rollers (8, 10) of a drafting roller pair and a suction for the lower rollers (7, 9) of the drafting roller pair, characterized in that the suction for the lower rollers (7, 9) is arranged directly or indirectly on a support for the drafting roller pair and has a constant distance to the lower rollers (7, 9) under any adjustment of the main draft zone. At least a part of the housing of the drafting mechanism (1) has an integrated channel or tube (55) by means of which the fiber and dust suction of the lower rollers (7, 9) is connected to the suction of the spinning preparation device. The suction for the lower rollers (7, 9) is configured as a suction element (57) having an opening (57b) for suctioning the lower rollers (7, 9) and a further opening (57a) for suctioning a godet or output measuring roller (15a, 15b) arranged subsequently in the material flow direction. The suction element (57) is connected to the integrated channel or tube (55) by means of a connecting tube (56). The suction for the upper rollers (8, 10) is configured as a suction hood (50) which is arranged on or integrated in the housing of the drafting mechanism (1) such that the suction hood (50) is removed from the upper rollers (8, 10) when the housing is opened. The suction device has a closed housing (52) which is configured to interrupt the air flow between the suction for the upper and lower rollers and the suction of the spinning preparation device. The housing has a shroud (2) with two wings (2a, 2b) and an upwardly pivotable flap (3) having an opening (3a) for introducing the sliver (FB) into the drafting mechanism (1). The suction hood (50) for suctioning the upper rollers (8, 10) is arranged on or in the wings (2a, 2b) of the shroud. The integrated channel or tube (55) is arranged on or in the flap (3). At least one suction opening (55a, 55b, 55c) for suctioning fibers and dust is arranged around the opening (3a) for guiding the sliver (FB), which is connected to the integrated channel or tube (55).

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