Device and method for removing dust from an RL warp knitting machine

Abstract

Device (1) and method for removing dust from a working area (2) and from knitting tools of an RL warp knitting machine, a right-left flat warp knitting machine which does not have a take-off bar, but has a horizontal take-off (16), a needle bar and a take-off bar (13) with enclosed take-off plates (14) arranged thereon. The working area (2) has an operating side (6) and a rear side (4) facing away from the operating side (6), wherein at least one blow air duct (32) is fluidically connected to blow air openings (34) from which blow air streams (30) directed towards the working area (2) and the knitting tools exit. According to the invention, the air streams (30) are supplied from the rear (4) to the working point (2) and the working tools, and an extraction device (20) for extraction from the working point (2) and the working tools is arranged on the operating side (6) of the working point (2).

Description

The invention relates to a device and a method for removing dust from the working area and knitting tools of an RL warp knitting machine, a right-left flat warp knitting machine which does not have a take-off bar but has a horizontal take-off, a needle bar, and a take-off bar with enclosed take-off plates arranged thereon. The working area has an operator side and a rear side facing away from the operator side. At least one blow air duct is fluidically connected to blow air openings from which blow air streams directed at the working area and the knitting tools emerge. The knitting tools include plate sliders, slide needles, punch needles, and other elements that come into contact with threads and move and join them accordingly. The desire to remove dust from the working area and knitting tools of flat warp knitting machines has existed for some time and has led to solutions known from the prior art. For example, DE 107 729 A1 describes a solution for dust removal on warp knitting machines with tongue needles and a knock-off bar or milling plate. However, the design of the working area of ​​these warp knitting machines differs from that of a warp knitting automatic machine (KWA), which has a horizontal fabric take-off, combined inserting and knock-off plates, and inclined pusher needles. A warp knitting automatic machine is used to produce knitted fabrics at high production speeds of up to 4400 rpm. Even very fine, elastic yarns can be produced with very fine needle elements and a high needle density across the working width (machine fineness up to E28 or E32; E32 means 32 needles per inch).Currently, the processing of staple fiber yarns is rarely implemented because high production speeds are difficult to achieve due to dust generation. This dust leads to increased wear of the working elements due to contamination, as well as machine downtime required to remove the accumulated fiber dust. DD 107 729 A5 also concerns warp knitting machines with tongue needles and a knock-off bar or milling plate. If one were to transfer the solution from DD 107 729 A5 to RL warp knitting machines, several obstacles would arise. The direction of the airflow is directed towards the back of the needle. While this might provide sufficient cleaning functionality for tongue needles, it does not apply to compound needles with a blank slider, which are used in warp knitting machines due to the higher machine precision (higher needle density, higher number of needles per inch of width) and higher production speeds. There is also a risk of contamination of the blank slider's guide (slider groove). The airflow cannot enter the guide from the back, as proposed in DD 107 729 A5 and also DE 107 729 A1. Page 4, para.Paragraph 1 states that the knock-off bar, also called a knock-off comb bar, is "equipped with air outlet openings in the area of ​​the knock-off edge." However, KWA does not have a vertical knock-off edge in the sense of a knock-off bar or knock-off plate, but rather a completely differently designed knock-off bar with combined enclosing knock-off plates. Therefore, the solution cannot be applied to KWA. On the contrary, due to its shape and function, which is based on enclosing the knitted fabric, the stripping contours could even damage the knitted fabric. On page 5, paragraph 2, knock-off comb plates with stripping contours are mentioned. In KWA, the enclosing knock-off plate moves away from the working point during the downward movement of the needle. Therefore, the solution cannot be applied for this reason as well. Furthermore, with high machine fineness, i.e., with very fine needles, there is insufficient installation space. It is therefore an object of the invention to direct the airflow in such a way as to remove dust from a working area and from knitting tools, so that optimal dust removal can be achieved in RL warp knitting machines without impairing the quality of the knitted fabric and the ease of operation. The problem is solved by a device for removing dust from the working area and knitting tools of an RL warp knitting machine, a right-left flat warp knitting machine that does not have a take-off bar but does have a horizontal fabric take-off, a needle bar, and a take-off bar with enclosed take-off plates attached to it. The working area has an operator side, which corresponds to the side of the machine from which the operation takes place, and a rear side facing away from the operator side, the main drive side. The main drive side houses the gearbox for the pusher needles and punch needles, as well as for the plate pushers and the enclosed take-off plates; these are all moving components, so little installation space is available, and the partially opposing movements of these components make the installation of additional elements impossible.For drive-related reasons, the available installation space is designed only for the necessary components, and to avoid large levers, there are no spaces usable for other tasks. The dust and dirt relevant to the invention arises at points where heavy abrasion occurs. In warp knitting, the greatest yarn tension and yarn friction occur when the stitch is cast off, i.e., during the downward movement of the needle (e.g., the slider needle). Over time, this fiber abrasion accumulates at constrictions in the working area. The constriction of a slide guide is a critical area, as it must be kept clear for the slide movement to function properly. Otherwise, damage, wear, and fabric defects will result. The airflow must therefore be directed towards the slide guide to clean this constriction and keep it free of dust. An air duct is fluidically connected to air outlets from which air streams directed towards the working area and the working tools emerge. According to the invention, the compressed air streams are directed from the rear of the working area, away from the operator side, onto the working area and the working tools. An extraction device for removing the dust from the working area and the working tools is arranged on the other, opposite side, the operator side of the working area. It has proven advantageous if the extraction device is removable, for example, by being swiveling, sliding, or folding, so that it can be moved out of position, allowing visibility of the work area and access to the threads and the knitted fabric formed from them. This avoids any obstruction to control and operation caused by the additional components of the dust removal device. The RL warp knitting machine is designed either with inclined pusher needles and a pusher bar or with point needles. The device according to the invention is used for both designs. In one initial design, at least one air duct runs through the knock bar, and the air streams exit through air vents located at least on some of the enclosing knock plates. This design saves installation space because the air is supplied within existing components. An air supply, for example a hose, provides the air duct with the air or air stream. As an alternative to direct routing through the striking bar, at least one blow air channel is integrated within the striking bar in the form of air-conducting elements (e.g., pipes), with blow air openings, for example, designed as blow air nozzles, blow air fan nozzles, or blow air slots. A particularly preferred solution is one in which several blow air channels run transversely to the longitudinal extent of the striking bar through the striking bar, and each of these blow air channels is connected to one of the blow air openings. In a second variant, the blast air duct is arranged separately along the striking bar, with the blast air openings branching off from the blast air duct. The blast air duct is designed as an independent air-conducting element, such as a pipe, but is mechanically fixed to the striking bar or at least partially integrated into it. With this embodiment, existing elements, such as the striking bar, do not need to be modified, or only minimally, so that neither a new design nor the manufacture of more complex components is necessary, thus reducing costs. The striking bar only needs to be extended by one air-conducting element, the blast air duct (e.g., designed as a pipe). Advantageously, the air streams are directed at the slide guides of the RL warp knitting machine with its inclined slide needles and slide bar to clean this narrow area and keep it free of dust. Each individual sheet slide has its own guide in the respective slide needle. The air streams allow for targeted cleaning of a problematic area when using inclined slide needles, which requires particularly careful cleaning to keep it free of contamination. It has proven advantageous to arrange the extraction device above the point of action, i.e., on the side of the point of action facing away from the floor. According to a first embodiment, the extraction device is arranged on a guide rail shaft. The guide rail shaft is the shaft to which the guide rails are attached and which performs the pivoting movement of the guide rails. Specifically, the guide rail receptacle is attached to the guide rail shaft, and the guide rails are in turn attached to the receptacle. Furthermore, according to the invention, the extraction receptacles are also arranged on the guide rail shaft and can be pivoted by means of the guide rail shaft. In a second embodiment, the suction device is arranged on a machine frame. The connection between the suction device and the machine frame is at least partially detachable, allowing the suction device to be moved from an area opposite or in front of the point of action, preferably either sliding or pivoting, for example upwards, so that after moving or pivoting the suction device, the threads can be accessed for maintenance or inspection. Pivoting is preferably achieved via the guide rail shaft if the suction device is connected to it. Moving the suction device away from the point of action is particularly necessary after a thread breakage, so as not to obstruct the necessary actions. According to a preferred embodiment, the extraction device comprises a plurality of suction openings for drawing in fiber dust, which, according to a first embodiment, are designed as an arrangement of several suction nozzles arranged side by side across the width, according to a second embodiment as a long tube, the length of which preferably corresponds to the width of the knock-off bar, with individual suction openings distributed side by side along the length of the tube, or according to a third embodiment as a preferably long tube with a suction slot extending axially along the longitudinal extent of the tube in the tube wall. The object of the invention is further achieved by a method for operating a device for removing dust from a working point and working tools of an RL warp knitting machine as described above or according to one of claims 1 to 9. According to the invention, the supply of blown air is coordinated with the extraction in time. In a first variant of the method, the extraction process operates continuously, and the compressed air is also supplied continuously. Alternatively, in a second variant, the extraction process operates discontinuously, for example, at predetermined time intervals, synchronized with the discontinuously supplied compressed air, particularly for the purpose of abrupt cleaning of the affected area. Furthermore, the invention would also encompass operation with a time delay, in which the compressed air is supplied before (or after) the extraction process. The invention is explained in more detail below with reference to the description of exemplary embodiments and their illustration in the accompanying drawings. The drawings show: Fig. 1: schematically a side view of an embodiment of an action point in a prior art RL warp knitting machine; Fig. 2: schematically a side view of an embodiment of an action point in an RL warp knitting machine with extraction according to the invention; Fig. 3: schematically a front view of an embodiment of an action point in an RL warp knitting machine with extraction according to the invention via suction nozzles; Fig. 4: schematically a front view of another embodiment of an action point in an RL warp knitting machine with extraction according to the invention via suction openings; Fig. 5: schematically a side view of an embodiment of an action point in an RL warp knitting machine with extraction according to the invention and blow air channels running through a knock-off bar; Fig.Fig. 6: schematically a side view of an embodiment of an action point in an RL warp knitting machine with extraction according to the invention and a blow air duct running along the knock-off bar; Fig. 7: schematically a perspective view of an embodiment of a knock-off bar according to the invention and blow air ducts running through the knock-off bar; and Fig. 8: schematically a perspective view of an embodiment of a knock-off bar according to the invention and a blow air duct running along the knock-off bar. Fig. 1 schematically shows a side view of an embodiment of a working unit 2 in a prior art RL warp knitting machine. In the working unit 2, threads 3 are fed via punching needles 12, in conjunction with guide rails 11, and manipulated in such a way that the knitted fabric 18 is formed and withdrawn from the working unit 2 by the fabric take-off 16. The threads 3 are manipulated by plate slides 8, slide needles 10, and inserting / discharge plates 14, which are repeated in large numbers throughout the depth of the illustration, thus across the width of the machine. The reverse side 4 of the operating point 2, which represents the main drive side, and the operating side 6, where the workpiece 18 is removed and from which access is possible in case of malfunctions, are each labeled. The labels are repeated in the same way in Fig. 2, Fig. 5 and Fig. 6. Fig. 2 schematically shows a side view of an embodiment of an action point 2 in an RL warp knitting machine with a suction device 20 according to the invention. The suction device 20 causes a suction airflow 26 which enters at a suction opening 28. To allow access to the working area 2, the suction device 20 is capable of performing a pivoting movement 23 in the direction of the arrow, or alternatively, a transverse upward movement. For this purpose, the suction device 20 is connected to a suction receptacle 22, which in turn is movably connected to a guide rail shaft 24. If the guide rail shaft 24 is rotated or the suction receptacle 22 is rotated around the guide rail shaft 24, the suction device 20 pivots out of the area of ​​the working area 2, providing access that is necessary, for example, in the event of a thread break. Alternatively, a connection to the machine frame is also provided, whereby the mobility can also be achieved in other ways, for example, by simple disassembly. Dust generated in the working area 2 during the manipulation of the threads 3 to form the knitted fabric 18 is extracted by the extraction device 20. To reliably transport this dust out of the working area 2 and towards the suction opening 28, a stream of blown air 30 is directed onto the working area 2. This is shown here only schematically as an arrow; its generation and supply to the working area 2 are explained in more detail in Figures 5, 6, 7 to 8 and the accompanying description. Figures 3 and 4 show that the points of action are repeated many times across the width of the machine (compare the corresponding explanation for Figure 1). A large number of sliding needles 10 and piercing needles 12 are shown in partial view, i.e., not the full width of the machine. Fig. 3 schematically shows a front view of an embodiment of the working point 2 in an RL warp knitting machine with a suction device 20 according to the invention. Suction nozzles 28' serve to extract dust from the working point 2 via the suction airflow 26, which is symbolized here by arrows. These are each connected to a separate suction air duct 27 and, by their width, each cover an area of ​​several slide needles 10 and punch needles 12. Fig. 4 schematically shows a front view of another embodiment of the working point 2 in an RL warp knitting machine with a suction device 20 according to the invention. In contrast to the solution according to Fig. 3, the individual suction air streams 27 open into a suction air duct 27 that runs continuously through the working point 2 and has a plurality of suction openings 28, so that the dust generated in the working point 2 is sucked in there. The front view shown clearly shows that the extraction device 20 obstructs the view of and access to the working points 2. Therefore, the illustrated part of the extraction device 20 is movable, in particular pivotable via the guide rail shaft 24, or at least partially detachable. This allows at least the part of the extraction device 20 that obstructs the view and access to be removed from the working points 2. Fig. 5 schematically shows a side, cutaway view of an embodiment of an action point 2 in an RL warp knitting machine with an extraction device 20 according to the invention and blow air channels 32 running transversely through a knock-off bar 13 across its narrow, horizontal extension. In the cutaway view of the knock-off bar 13, a single blow air channel 32 can be seen, into which the blow air stream 30 enters via a connection shown here in a stylized manner, is guided through the blow air channel 32 to the action point 2, and is directed onto the action point 2 in the area of ​​a blow air opening 34. The direction of the blow air stream 30 as it exits the blow air opening 34 is symbolized by several arrows. The airflow 30 thus striking the point of action 2 mobilizes the resulting dust towards the suction opening 28, where it is carried away with the suction airflow 26. Fig. 6 schematically shows a side, cutaway view of an embodiment of an action point 2 in an RL warp knitting machine with an extraction device 20 according to the invention and a blow air duct 32' running longitudinally along the knock-off bar 13. The function corresponds in principle to that explained with reference to Fig. 5. However, as can be seen from the section of the knock-off bar, there are no separate blow air ducts 32 leading through the knock-off bar, but rather a larger blow air duct 32' running longitudinally along the greatest extent of the knock-off bar 13, which has a plurality of blow air openings 34 directed towards the action point 2. The cross-section of the blow air duct 32' must be sufficiently large to transport a blow air flow 30 that supplies all the blow air openings 34. Instead of a multitude of blow air openings 34, a blow air slot along the longitudinal direction of the blow air channel 32' or several blow air fan nozzles arranged side by side can also be used. As an alternative to the blow air channel 32' shown, which is partially recessed into the striking bar 13, this channel is mounted completely in front of the striking bar 13 in the area of ​​the point of action 2, so that no structural modifications to the striking bar 13 are necessary. Fig. 7 schematically shows a perspective view of an embodiment of a knock-off bar 13 according to the invention and the blow air channels 32 running through the knock-off bar 13, as shown in Fig. 5. Since the knock-off bar 13 has a considerable length, extending over the entire width of the machine, only a section of it is shown here (as also in Fig. 8). The individual blowing air channels 32 are supplied separately with the blowing air stream 30 (see Fig. 2, Fig. 5 and Fig. 6) via their own blowing air supply 31, which in the illustrated embodiment are designed as hoses. Fig. 8 schematically shows a perspective view of an embodiment of a striking bar 13 according to the invention and a blow air channel 32' extending longitudinally along the striking bar 13, corresponding to the embodiment shown in Fig. 6. The blow air channel 32', which runs continuously along the length of the striking bar 13 and is supplied with the blow air stream 30 via the blow air supply 31, has blow air openings 34 on its side facing the point of action 2 (not shown here). The blow air channel 32' is partially recessed into the striking bar 13. Reference symbol list 1 Device 2 Working point 3 Thread 4 Back (main drive side) 6 Operating side 8 Board slider 10 Slider needle 11 Laying rail 12 Hole needle 13 Knock-off bar 14 Enclosing knock-off board 16 Product take-off 18 Knitted fabric 20 Extraction device 22 Extraction intake 23 Swivel movement 24 Laying rail shaft 26 Suction air flow 27 Suction air duct 28 Suction opening, suction slot 28' Suction nozzle 30 Blowing air flow 31 Blowing air supply 32 Blowing air duct (each blowing air opening individually) 32' Blowing air duct (for all blowing air openings) 34 Blowing air opening, blowing air fan nozzle, blowing air slot QUOTES INCLUDED IN THE DESCRIPTION This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature DE 107 729 A1 [0002, 0003]DD 107 729 A5

[0003]

Claims

Device (1) for removing dust from a working area (2) and from knitting tools of an RL warp knitting machine, a right-left warp knitting machine which does not have a take-off bar, but has a horizontal take-off (16), a needle bar and a take-off bar (13) with enclosed take-off plates (14) arranged thereon, wherein the working area (2) has an operating side (6) and a rear side (4) facing away from the operating side (6), wherein at least one blow air duct (32, 32') is fluidically connected with blow air openings (34) from which blow air streams (30) directed towards the working area (2) and the knitting tools exit, characterized in that the blow air streams (30) are supplied to the working area (2) and the knitting tools from the rear side (4), and wherein an extraction device (20) for extracting the dust from the The point of action (2) and the working tools are arranged on the operating side (6) of the point of action (2). Device according to claim 1, wherein the suction device (20) is designed to be removable, so that the visibility of the working area (2), the accessibility to threads (3) and to a knitted fabric (18) formed from the threads (3) become possible. Device according to claim 1 or 2, wherein the RL warp knitting machine is designed either with inclined slide needles (10) and a slide bar or with point needles. Device according to one of claims 1 to 3, wherein the blowing air stream (30) is supplied to the at least one blowing air channel (32) by means of a blowing air supply (31), wherein the at least one blowing air channel (32) passes through the knock-off bar (13) and the blowing air streams (30) exit at least at a part of the enclosing knock-off plates (14) through the blowing air openings (34) arranged on the knock-off bar (13). Device according to claim 4, wherein several blow air channels (32) extend through the knock bar (13) and each of the blow air openings (34) arranged on the knock bar (13) is connected to an associated blow air channel (32). Device according to one of claims 1 to 3, wherein the blow air channel (32') is arranged separately along the knock bar (13), wherein the blow air openings (34) are connected to the blow air channel (32'). Device according to one of claims 3 to 6, wherein the air jets (30) are directed towards a slide guide of the RL warp knitting machine with the inclined slide needles (10) and the slide bar. Device according to one of the preceding claims, wherein the extraction device (20) is arranged above the point of action (2) and, according to a first embodiment, on a guide rail shaft (24) or, according to a second embodiment, on a machine frame, wherein a connection with the machine frame is at least partially detachable and the extraction device (20) is designed to be movable from an area opposite the point of action (2). Device according to one of the preceding claims, wherein the suction device (20) comprises suction openings (28) for suctioning fiber dust, which according to a first embodiment are designed as an arrangement of suction nozzles (28') arranged over the width, according to a second embodiment as a tube with individual suction openings distributed over the width of the knock bar (13) or according to a third embodiment as a tube with a continuous suction slot. Method for operating a device for removing dust from an action point (2) and from working tools of an RL warp knitting machine according to one of claims 1 to 9, characterized in that the supply of the blowing air stream (30) is coordinated in time with the extraction by the extraction device (20). Method according to claim 10, wherein the extraction is carried out continuously and at the same time the blowing air stream (30) is also supplied continuously. Method according to claim 10, wherein the extraction is carried out discontinuously, synchronized with a discontinuously supplied airflow (30).

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