EXTRACTION OF A COMBING POINT IN A COMBING MACHINE

Description

[0001] The invention relates to a combing machine with a machine frame and with at least one combing station and with a suction channel running below the combing station in the machine frame and with a cover hood pivotably held on the machine frame above the combing station, wherein the combing station has a nipper unit and a circular comb as well as a pair of pressure rollers and a pair of take-off rollers, wherein the pair of take-off rollers consists of a lower take-off roller and an upper take-off roller provided with a stripper.

[0002] Today's combing machines utilize pivoting covers which, for safety reasons, prevent manual intervention in the combing device during operation and, for safety reasons, shield the combing station from fiber fly from the ambient air. In current combing machines, such a cover extends over four of the eight existing combing stations (combing heads), with the free end extending to a downstream conveyor table. For example, CH 704 372 A2 discloses such a cover. The disadvantage of this solution is that, although it shields the combing station from fiber fly from the environment, the fiber fly or dust resulting from the combing process can penetrate the combed fiber material within the cover.

[0003] Furthermore, it is known to use scrapers to prevent fiber transfer to the fiber material due to fiber adhesion to rollers used for processing or conveying the combed nonwoven fabric, such as calender rollers, detachment rollers, pressure rollers, or take-off rollers. For this purpose, knives or felt scrapers, for example, are applied to the roller surfaces and are sometimes provided with a spring load. The fibers adhering to the roller surfaces are captured by the scrapers. DE 100 50 974 A1, for example, discloses such a device.

[0004] Further combing machines from the prior art are described in DE 34 25 615 A1 and in EP 3 207 171 B1.

[0005] The invention is therefore based on the object of proposing a combing machine with a device that eliminates the known disadvantages and facilitates keeping parts of such a combing machine clean. In particular, the combing machine should be designed so that fibers and foreign bodies adhering to the peripheral surfaces of the take-off rollers, as well as fiber fly in general, are removed in a targeted manner during operation, so that the combing machine is comparatively low-maintenance.

[0006] To achieve this object, a combing machine is proposed with a machine frame and at least one combing station and with an extraction channel running below the combing station in the machine frame and with a cover hood pivotally mounted on the machine frame and extending over the combing station, wherein the combing station has at least one nipper unit and a circular comb and a top comb and a feed cylinder as well as a pair of take-off rollers, wherein the pair of take-off rollers consists of a lower take-off roller and an upper take-off roller provided with a stripper. Furthermore, depending on the design of the combing machine or its operating principle, the combing station can have a pair of tear-off rollers or a tear-off cylinder which cooperates with a tear-off segment. The combing station is provided with an extraction system, wherein the extraction system is attached to the cover hood and connected to the extraction channel via a coupling.Despite the individual extraction systems provided below the combing point, for example for cleaning the circular comb, the high-performance operation of the combing machine results in fiber flyaways that collect below the cover hood and lead to soiling of the combing point or parts of it. As a result, fiber residues accumulate on the combed fiber material and lead to a reduction in quality. This circumstance is taken into account by an extraction system attached directly to the extraction hood. The coupling in the connection between the extraction system and the extraction duct means that the cover hood can be swung open at any time. The extraction system and its attachment are swung together with the cover hood, ensuring unobstructed access to the combing point and ensuring that necessary repair and maintenance work is not hindered by the extraction system.

[0007] The cover can be routed over several combing points, with an extractor provided for each individual combing point. This eliminates long transport paths for the extracted materials, which can lead to blockages, and directs the extracted fiber residues or dust to the extraction duct as close as possible to the extraction point. A line from the extractor to the extraction duct is provided between the combing points and designed with as few bends as possible, so that the negative pressure prevailing in the extraction duct is sufficient for the operation of the extractor, eliminating the need for an additional negative pressure source.

[0008] Advantageously, the extraction system is provided for cleaning a space located between the combing point and the cover hood and is designed as a suction box attached to the cover hood and a suction pipe connecting the suction box to the extraction duct, wherein the suction pipe is divided into a first section and a second section by the coupling, with the first section being held on the suction box and the second section in the machine frame. In order to achieve efficient extraction of the entire interior space between the combing point and the cover hood, a correspondingly large suction box must be provided. The suction box can be of any design, although a rectangular design adapted to the geometry of the combing point is preferable. Dividing the suction pipe into a first section and a second section has the advantage that the position of the coupling within the combing point can be selected in an easily accessible location.The arrangement and length of the first section of the suction pipe must also be selected in such a way that after the cover is swung up together with the first section of the suction pipe, the work is not hindered by the second section of the suction pipe remaining on the machine frame.

[0009] The suction box is preferably made of transparent material. This has the advantage that the view through the cover into the combing station, which is necessary for monitoring, is not obstructed during operation. The cover hoods are provided with a transparent pane in an area above the combing station so that operating personnel can check the proper operation of the combing station at any time. By making the suction box attached to the cover hood out of a transparent material, preferably plastic, this function of the cover hood is not impaired. Depending on the arrangement and size of the suction box, a part of the first section arranged above the transparent part of the cover hood must also be made transparent.

[0010] Advantageously, a plurality of air inlet openings are provided on a side of the suction box facing the combing point. An arrangement of air inlet openings allows a portion of the suction box to be closed, thus increasing the suction effect at the air inlet openings compared to an open suction box. The air inlet openings are preferably slit-shaped. The arrangement and size of these slits must be adapted to the desired suction power.

[0011] It is advantageous to install air guide elements between the air inlets in the suction box. This directs the air drawn through the air inlets to the extraction duct, and the arrangement of these air guide elements can achieve an even pressure distribution in the suction box. An even pressure distribution ensures the same pressure conditions at all air inlets, resulting in the same suction power.

[0012] Advantageously, the suction system for cleaning the upper take-off roller is provided upstream of the stripper and is designed as a suction nozzle attached to the cover hood and a suction line connecting the suction nozzle to the suction channel. The suction line is divided into a first suction line section and a second suction line section by the coupling, with the first suction line section being held at the suction nozzle and the second suction line section in the machine frame. Modern machines are equipped with felt strippers on the upper take-off rollers. In a felt pressed onto the surface of the take-off roller, individual fibers or fiber residues adhering to the take-off roller remain trapped and do not reach the combed fiber material. However, these strippers must be cleaned or replaced regularly. As soon as the felt is completely covered with fibers, the rotation of the take-off roller works individual fiber tufts out of the felt and reach the combed fiber material.The suction nozzle prevents this. The suction nozzle, located in front of the stripper in the direction of rotation of the take-off roller, picks up fibers adhering to the surface of the take-off roller, preventing them from reaching the stripper. Fibers not captured by the suction nozzle are held in place by the stripper. This largely prevents the formation of fiber tufts or clumps and extends the service life of the stripper. The division of the suction line into a first section held by the cover hood and a second section attached to the machine frame follows the same principles as the division of the suction pipe of the suction box into a first section and a second section.

[0013] The suction nozzle preferably has a slot-shaped opening facing the take-off roller. The slot-shaped opening extends over the entire length of the stripper. By designing it as a suction slot, a high suction air velocity and thus a high suction power are achieved at the opening in the suction nozzle, which faces the surface of the take-off roller. The opening is preferably arranged after a part of the stripper that touches the take-off roller, as seen in the direction of rotation of the take-off roller. By arranging the suction nozzle as close as possible to the stripper, adhesion of fibers to the surface of the take-off roller between the suction nozzle and the stripper is avoided and contamination of the combed fiber material is minimized.

[0014] The suction line is advantageously arranged to the side of the suction nozzle. The lateral arrangement of the suction line has the advantage that as few deflections as possible are required in the suction line to reach the suction duct. Deflections pose a risk of blockage and increase pressure loss in the suction line, which leads to a reduction in suction power or requires a higher negative pressure in the suction duct. In addition, a lateral arrangement of the suction duct reduces the installation height required for suction. Since the cover hood is designed to be as close as possible to the take-off roller or the combing point, also in order to keep the space between the combing point and the cover hood as small as possible, the suction nozzle can be attached in such a way that the suction nozzle is located on a side of the cover hood facing away from the combing point and the slot-shaped opening through the cover hood reaches the surface of the take-off roller.

[0015] If the suction nozzle is intended for cleaning the scraper of the upper take-off roller and the suction box is intended for cleaning a space between the combing point and the cover hood, it is advantageous if the first section of the suction pipe and the first suction line section are brought together and connected to a common connection on the extraction duct. The junction is thus provided in the respective suction line section and section of the suction pipe, which are attached to the cover hood and are moved out of the work area at the combing point with a pivoting movement of the cover hood. As a result, only one coupling is required for the two extraction systems to connect to the extraction duct, and the second section of the suction pipe, together with the second suction line section, is led from the coupling to the extraction duct in a common connecting section.This also takes into account the limited space available between the combing points for cable routing.

[0016] The coupling advantageously has an elastic element. The coupling is designed such that when the cover is closed, the two sections of the suction pipe, or the two suction line parts, meet and close the coupling with the help of the elastic element. The elastic element is deformed, creating a tight connection without the need for additional elements or a locking mechanism. For example, the elastic element can be provided as a funnel into which the pipe or line part to be sealed fits when the cover is closed. By deforming the elastic element, it nestles against the counterpart and seals the connection. Preferably, the coupling consists of two components, and the tightness of the coupling is ensured by the two components sliding into or pressing against one another.The coupling is formed, for example, from an elastic hose or bellows. The bellows can be provided with a support against which the other component, such as a flange, strikes when the cover is closed, which subsequently compresses the bellows and creates a seal between the components.

[0017] Advantageously, a baffle is provided between the coupling and the extraction duct. Using a baffle makes it possible to provide all extractions with the same cross-section and, by adjusting the baffle, to individually adjust the vacuum at each combing point along the length of the combing machine.

[0018] Advantageously, a control system and a shut-off device are provided in the second section of the suction pipe and in the second section of the suction line. The shut-off devices allow for targeted control of the extraction systems. This makes it possible to switch off or shut off the extraction systems when the cover is open or the combing station is at a standstill. Furthermore, an interval can be set for active extraction so that the extraction is not constantly active. For example, the extraction of the space between the cover and the combing station is opened for ten minutes at intervals of one hour. This has the advantage that, for example, the extraction systems of the individual combing stations of the combing machine can be operated sequentially, thus selecting an operating mode that avoids overloading the extraction channel or the vacuum source. The control of the extraction systems can also be adapted to the product being processed.

[0019] The invention is illustrated and explained in more detail using the following exemplary embodiments. They show: Fig. 1 is a schematic representation of a first embodiment of a combing point according to the prior art. Fig. 2 is a schematic representation of a second embodiment of a combing point according to the prior art. Fig. 3 is a schematic representation of a first embodiment of a suction system. Fig. 4 is a schematic representation of a second embodiment of a suction system. Fig. 5 is a schematic representation of a third embodiment of a suction system. Fig. 6 is a schematic representation of a first embodiment of a coupling. Fig. 7 is a schematic representation of a second embodiment of a coupling.

[0020] Figure 1 shows a schematic representation of a first embodiment of a combing station according to the prior art. Figure 1a combing station 2 with a nipper unit 5, a feed roller 8, a circular comb 6, a top comb 7, a pair of tear-off rollers 9, and a pair of pressure rollers 17. A batt 14 is fed into the nipper unit 5 by the feed roller 8. The nipper unit 5 can be moved back and forth between a rear end position (shown) and a front end position. In the rear end position, the nipper unit 5 is closed; a front end section or fiber tuft 15 of the batt 14 to be combed is clamped between the nippers of the nipper unit 5 and is combed out by the continuously rotating circular comb 6. The nipper unit 5 is then moved to the front end position (not shown) and opened. The combed-out fiber tuft 15 is combined with a previously formed fiber fleece 16 in the pair of tear-off rollers 9. The fiber beard 15 is pulled through the top comb 7 by forward rotation of the tear-off roller pair 9 and torn off from the batting 14 lying in the nipper unit 5.A pair of pressure rollers 17, which rotates back and forth synchronously with the pair of detachment rollers 9 (pilger step motion), deposits the fiber web 16 onto a web guide plate. The fiber web 16 runs to a pair of take-off rollers 10 and through a web funnel 18, where it is discharged as a fiber sliver 20 onto a guide table 21. In the web funnel 18, the fiber web 16 is gathered into the fiber sliver 20. Downstream of the web funnel 18, the formation of the fiber sliver 20 is assisted by a pair of calender rollers 19, and the thus formed fiber sliver 20 is transported away together with the fiber slivers 20 from the other combing stations of the combing machine for further processing. The take-off roller pair 10 is formed by a lower take-off roller 11 and an upper take-off roller 12, with the upper take-off roller 12 being provided with a scraper 13. The other rollers shown can also be provided with a scraper each, but this is not shown.

[0021] A cover hood 4 is arranged above the combing station 2. The cover hood 4 is provided with a handle 23 and can be pivoted about a rotation axis 22 with this. The rotation axis 22 is held stationary in a machine frame 1. The cover hood 4 projects above the combing station and the downstream components of the combing machine up to the guide table 21. This protects the entire area in which the combed-out fiber material in the form of fiber tuft 15, fiber fleece 16 or fiber sliver 20 is located and the area where the batting 14 is fed. By a pivoting movement 24, the cover hood 4 is pivoted about the rotation axis 22 into an open position 26, which provides access to the individual components of the combing machine.

[0022] Figure 2shows a schematic representation of a second embodiment of a combing station 2 according to the prior art. In this embodiment, the combing station is also provided with a nipper unit 5, a circular comb 6, a top comb 7, a feed roller 8, and a pair of detaching rollers 9. The operating principle by which a fiber tuft 15 is combed out of the batt 14 and transferred as a fiber fleece 16 to a pair of take-off rollers 10 is the same as in Figure 1described. The take-off roller pair 10 is also formed by a lower take-off roller 11 and an upper take-off roller 12, wherein the upper take-off roller 12 is provided with a stripper 13. A cover hood 4 is arranged above the combing station 2, wherein the cover hood 4, in the embodiment shown, covers the combing station 2 and the take-off roller pair 10. The cover hood 4 is provided with a handle 23 and is held stationary in a machine frame 1 on a rotation axis 22. By a pivoting movement 24, the cover hood 4 can be opened at the handle 23, thus creating maintenance access to the components of the combing station 2. In addition, the cover hood 4 is provided with a transparent area 26 so that an optical monitoring of the operating state of the combing station 2 is possible even during operation of the combing station with the cover hood 4 closed.

[0023] Figure 3shows a schematic representation of a first embodiment of an extraction system. The extraction system, intended for cleaning a space located between the combing point 2 and the cover 4, is formed by a suction box 27 and a suction pipe 28 connecting the suction box 27 to an extraction channel 3.

[0024] The suction channel 3 is located below the combing point 2 in the machine frame 1 and is standard on today's combing machines. The suction box 27 is attached to the cover 4 and provided with corresponding openings (not shown) that allow the space between the combing point 2 and the cover 4 to be suctioned. A first section 29 of the suction pipe 28 is attached to the suction box 27 and connected thereto. Alternatively, the first section 29 of the suction pipe 28 can also be attached to the cover 4. The first section 29 of the suction pipe 28 ends in a coupling 31 on a side of the first section 29 opposite the suction box 27. After the coupling 31, the suction pipe 28 continues in a second section 30 to the suction channel 3, with the second section 30 being held stationary in the machine frame 1.

[0025] The cover hood 4 is pivotally mounted in the machine frame 1 about a rotation axis 22 and projects at least beyond the combing point 2. Upon a pivoting movement 24 of the cover hood 4 into an open position 25, the suction box 27 and the first section 29 of the suction pipe 28 are also pivoted. This provides sufficient maintenance access to the combing point 2 despite the additional suction. With the pivoting movement 24, the first section 29 automatically detaches from the second section 30 of the suction pipe 28 at the location of the coupling 31. The coupling 31 is designed as a simple contact coupling without a locking mechanism.

[0026] Figure 4shows a schematic representation of a second embodiment of a suction system. The suction system provided for cleaning the upper take-off roller 12 is formed by a suction nozzle 34 attached to the cover 4 and a suction line 35 connecting the suction nozzle 34 to the suction channel 3 held in the machine frame 1. The suction nozzle 34 is directed with its opening against a surface of the upper take-off roller 12, wherein the suction nozzle 34 is arranged in front of a scraper 13 resting against the surface of the upper take-off roller 12, viewed in a direction of rotation of the upper take-off roller 12 shown by an arrow. The suction line 35 is divided by the coupling 31 into a first suction line section 36 and a second suction line section 37. The first suction line part 36 is attached to the suction nozzle 34 or the cover hood 4 and the second suction pipe part 37 is held stationary in the machine frame 1 or on the exhaust duct 3.The cover hood 4 is pivotally mounted in the machine frame 1 about a rotation axis 22 and projects at least beyond the combing point (see . Figure 3 ) and the upper take-off roller 12. Upon a pivoting movement 24 of the cover 4 into an open position 25, the suction nozzle 34 and the first suction line section 36 of the suction line 35 are also pivoted. This provides sufficient maintenance access to the combing point despite the additional suction. With the pivoting movement 24, the first suction line section 36 automatically detaches from the second suction line section 37 of the suction line 35 at the location of the coupling 31. The coupling 31 is designed as a simple contact coupling without a locking mechanism.

[0027] Figure 5shows a schematic representation of a third embodiment of an extraction system. The extraction system comprises an extraction system for cleaning a space located between the combing point 2 and the covering hood 4 and an extraction system for cleaning the upper take-off roller 12. The extraction system provided for cleaning the space located between the combing point 2 and the covering hood 4 is formed by a suction box 27 attached to the covering hood 4, similar to the first embodiment. The extraction system provided for cleaning the upper take-off roller 12 is formed by a suction nozzle 34 attached to the covering hood 4, which, similar to the second embodiment, is arranged upstream of the stripper 13. In contrast to the previous embodiments, the first section 29 of the suction pipe of the suction box 27 is joined to the first suction line part 36 of the suction line of the suction nozzle 34 upstream of the coupling 31. Downstream of the coupling 31, a common connection 38 to the extraction channel 3 is provided.The connection 38 and the suction channel 3 are fixed in the machine frame 1. The cover 4 is guided over the combing point 2 and the upper take-off roller 12. When the cover 4 pivots 24 into an open position 25, the suction nozzle 34 with the first suction line part 36 and the suction box 27 with the first section 29 are also pivoted. This provides sufficient maintenance access to the combing point despite the additional suction. With the pivoting movement 24, the common channel formed by the first suction line part 36 and the first section 29 automatically detaches from the connection 38 at the location of the coupling 31. A baffle 45 is provided between the coupling 31 and the suction channel 3. By installing the aperture 45, a negative pressure prevailing in the connection 38 can be adjusted according to a position of the combing point within the combing machine, or a course of the suction channel 3.

[0028] Figure 6 shows a schematic representation of a first embodiment of a coupling 31. The coupling 31 is shown, by way of example, on an intake manifold having a first section 29 and a second section 30. A funnel-shaped elastic element 44 is attached to the second section 30 by a holder 39, for example in the form of a hose clamp. During a pivoting movement 24, which the first section 29 follows with the cover (not shown), the first section 29 slides out of the funnel-shaped element 44 and the coupling 31 disengages automatically.

[0029] Figure 7shows a schematic representation of a second embodiment of a coupling 31. The coupling 31 is shown by way of example on an intake manifold having a first section 29 and a second section 30. A flange 40 is fastened to each of the first section 29 and the second section 30. A bellows 41 is fastened to the flange 40 of the stationary second section 30 by fastening screws 42. The bellows 41 is provided with a support 43 on a side facing the first section 29. When the coupling 31 is closed, the bellows 41 is compressed by the support 43 by the flange 40 of the first section 29, thereby creating a seal between the first section 29 and the second section 30. During a pivoting movement 24, which the first section 29 follows with the cover (not shown), the first section 29 slides out of the funnel-shaped element 44 and the coupling 31 is automatically released.

[0030] The present invention is not limited to the illustrated and described embodiments. Modifications and combinations of the features within the scope of the patent claims are also possible, even if they are illustrated and described in different embodiments. Legend

[0031] 1Machine frame 2Combing station 3Suction channel 4Cover hood 5Tong unit 6Circular comb 7Fixing comb 8Feed cylinder 9Pair of detaching rollers 10Pair of take-off rollers 11Lower take-off roller 12Upper take-off roller 13Scraper 14Wadded wool 15Fiber tuft 16Fiber fleece 17Pair of pressure rollers 18Fleece funnel 19Pair of calender rollers 20Fiber sliver 21Guide table 22Pivoting axis 23Handle 24Pivoting movement 25Open position 26Transparent area 27Suction box 28Suction pipe 29First section of suction pipe 30Second section of suction pipe 31Coupling 32First component 33Second component 34Suction nozzle 35Suction line 36First suction line section 37Second suction line section 38Connection 39Bracket 40Flange 41Bellows 42Fastening screws 43Support 44Elastic element 45Cover

Claims

1. A combing machine having a machine frame (1) and having at least one combing point (2) and having a suction channel (3) extending below the combing point (2) in the machine frame (1) and having a covering hood (4) which is pivotably held on the machine frame (1) and extends over the combing point (2), wherein the combing point (2) comprises at least one nipper unit (5) and a circular comb (6) and a fixing comb (7) and a feed cylinder (8) as well as a pair of draw-off rollers (10), wherein the pair of draw-off rollers (10) consists of a lower draw-off roller (11) and an upper draw-off roller (12) provided with a scraper (13), wherein the combing point (2) is provided with a suction means, wherein the suction means is attached to the covering hood (4) and is connected to the suction channel (3) via a coupling (31).

2. The combing machine according to claim 1, characterized in that the suction means is provided for cleaning a space extending between the combing point (2) and the covering hood (4) and is designed as a suction box (27) fastened to the covering hood (4) and a suction pipe (28) connecting the suction box (27) to the suction channel (3), wherein the suction pipe (28) is divided into a first segment (29) and a second segment (30) by the coupling (31), and the first segment (29) is held on the suction box (27) and the second segment (30) is held in the machine frame (1).

3. The combing machine according to claim 2, characterized in that the suction box (27) is made of transparent material.

4. The combing machine according to claim 2 or 3, characterized in that a plurality of air inlet openings is provided on a side of the suction box (27) facing the combing point (2).

5. The combing machine according to claim 4, characterized in that the air inlet openings are slot-shaped.

6. The combing machine according to claim 3 or 4, characterized in that air guide elements are arranged between the air inlet openings in the suction box (27).

7. The combing machine according to claim 1, characterized in that the suction means for cleaning the upper draw-off roller (12) is provided in front of the scraper (13) and is designed as a suction nozzle (34) attached to the covering hood (4) and a suction line (35) connecting the suction nozzle (34) to the suction channel (3), wherein the suction line (35) is divided into a first suction line part (36) and a second suction line part (37) by the coupling (31), and the first suction line part (36) is held on the suction nozzle (34) and the second suction pipe part (37) is held in the machine frame (1).

8. The combing machine according to claim 7, characterized in that the suction nozzle (34) has a slot-shaped opening facing the upper draw-off roller (12).

9. The combing machine according to claim 8, characterized in that the opening is arranged in front of a part of the scraper (13) contacting the upper draw-off roller (12) when viewed in the direction of rotation of the upper draw-off roller (12).

10. The combing machine according to at least one of claims 7 to 9, characterized in that the suction line (35) is arranged laterally on the suction nozzle (34).

11. The combing machine according to the claims 2 and 7, characterized in that the suction nozzle (34) is provided for cleaning the upper draw-off roller (12) and the suction box (27) is provided for cleaning a space extending between the combing point (2) and the covering hood (4), and in that the first segment (29) of the suction pipe (28) and the first suction line part (36) are merged and connected to a common connection (38) on the suction channel (3).

12. The combing machine according to at least one of the preceding claims, characterized in that the coupling (31) has an elastic element.

13. The combing machine according to at least one of the preceding claims, characterized in that the coupling (31) consists of two components (32, 33) and seal tightness of the coupling (31) is provided by sliding the two components (32, 33) into one another or by pressing them onto one another.

14. The combing machine according to at least one of the preceding claims, characterized in that a bezel is provided between the coupling (31) and the suction channel (3).

15. The combing machine according to at least one of the preceding claims, characterized in that a control means and, in the second segment (30) of the suction pipe (28) and in the second suction line part (37) each, a barrier are provided.