Knot catchers for textile machines

Abstract

The present invention relates to a knot catcher (9) for textile machines, in particular for knitting machines, comprising a base part (18) forming a fastening section (19) and a knot catcher section (20), wherein the knot catcher section (20) has a slit-like thread guide opening (24) accessible at the edge, which has at its end a first opening section (25) extending in a particularly straight line with a first slot width (b1) constant over the length of the first opening section (25), which is adapted to the thickness (s F) of a thread (F) is adapted or adaptable, and forms a second opening section (26) extending from the first opening section (25) to the edge of the knot catcher section (20), having a second slot width (b2) that changes over the length of the second opening section (26), wherein the second slot width (b2) of the second opening section (26) is minimal in the region of a free end of a tongue-like projection (28) formed on the base part (18).

Description

[0001] The present invention relates to a knot catcher for textile machines, in particular for knitting machines, comprising a base part made from a sheet metal blank of uniform thickness, which forms a fastening section and a knot catcher section, wherein the knot catcher section has a slot-like thread passage opening accessible at its edge, which forms at its end a first opening section extending in a straight line, in particular with a first slot width constant over the length of the first opening section, which, considering the knot catcher section in a thread passage direction, is adapted or adaptable to the thickness of a thread passing through the first opening section during the intended operation of the textile machine, and a second opening section extending from the first opening section to the edge of the knot catcher section.to thread the thread into the first opening section, wherein the second opening section, the knot catcher section, viewed in the direction of thread passage, has a second slot width that changes over the length of the second opening section.

[0002] To ensure the proper operation of textile machines and the production of high-quality textiles, it is known in the prior art to guide a thread through a so-called knot catcher on its way from a spool to the processing point on the textile machine. This is designed in such a way that it cannot be passed by impurities in the thread, especially in the form of knots of a predetermined size.

[0003] A known embodiment of such a knot catcher is, for example, a component of a thread delivery device marketed by the applicant under the product name "MPF P", which is also referred to as a supplier. This knot catcher consists of a base part manufactured in one piece from a sheet of uniform thickness, forming a mounting section for attaching the knot catcher to a thread delivery device and a knot catcher section, wherein the mounting section and the knot catcher section are arranged perpendicular to each other. The knot catcher section comprises a slot-shaped thread feed opening accessible at its edge, which forms at its end a straight-extending opening section and a second opening section extending at least partially transversely to the first opening section.The first opening section has a constant slot width along its length. This slot width, viewed from the perspective of the knot catcher section in the direction of thread passage, is adapted to the thickness of a thread passing through the first opening section during normal operation of the textile machine. Accordingly, knots with a diameter larger than the slot width become caught in the knot catcher section, causing the thread to break. Thus, a knot cannot reach the processing point on the textile machine. The second opening section serves to thread the thread into the first opening section.

[0004] During operation of a yarn feeder, the thread runs from the spool towards the yarn feeder with little to no resistance in front of the knot catcher. Excess thread or loops can form in the thread, which can cause the thread to jump out of the thread guide opening unintentionally.

[0005] Further state of the art is represented by the publications DE 31 36 644 A1, DE 10 2011 053 824 B3 and DE 199 32 481 A1.

[0006] Based on this state of the art, it is an object of the present invention to create a knot catcher of the type mentioned above with an improved design.

[0007] To solve this problem, the present invention provides a knot catcher for textile machines, in particular for knitting machines, comprising a base part made from a sheet metal blank of uniform thickness, which forms a fastening section and a knot catcher section, wherein the knot catcher section has a slot-shaped thread passage opening accessible at its edge, which forms at its end a first opening section extending in a straight line, in particular with a first slot width constant over the length of the first opening section, which, considering the knot catcher section in a thread passage direction, is adapted or adaptable to the thickness of a thread passing through the first opening section during the intended operation of the textile machine, and a second opening section extending from the first opening section to the edge of the knot catcher section.to thread the thread into the first opening section, wherein the second opening section, considering the knot-catching section in the thread flow direction, has a second slot width that changes over the length of the second opening section, characterized in that the second slot width of the second opening section is minimal and smaller than the first slot width of the first opening section in the region of a free end of a tongue-like projection formed on the base part. The projection provided according to the invention forms a thread stop that effectively prevents the thread from unintentionally being threaded out of the thread guide opening. The second opening section preferably extends at least partially transversely to the first opening section.

[0008] Advantageously, the projection is curved upwards or downwards relative to adjacent areas of the base part. In particular, the inclination of the projection relative to adjacent areas of the base part is chosen such that, considering the knot catcher section in a thread-feed direction, the minimum second slot width is smaller than the first slot width of the first opening section of the thread guide opening, and that, considering the knot catcher section perpendicular to the thread-feed direction, the minimum distance between the free end of the projection and the area of ​​the base part opposite the projection is greater than or equal to the first slot width of the first opening section of the thread guide opening. Accordingly, the projection can be easily overcome when threading the thread by pulling the thread at a suitable angle perpendicular to the thread-feed direction.However, the thread is reliably prevented from coming loose as long as it extends in the direction of thread passage in the area of ​​the thread feed-through opening.

[0009] Preferably, the projection is located adjacent to the first opening section and thus as close to it as possible. In particular, the projection extends transversely to the first opening section. Accordingly, the projection prevents the thread from leaving the first opening section, through which the thread is guided during the normal operation of the textile machine.

[0010] Advantageously, the base part forms a guide bar leading to the beginning of the second opening section, serving as a threading aid and thus simplifying the threading process.

[0011] According to one embodiment of the present invention, an adjusting element is provided which is rotatably mounted on the base part in the area of ​​the knot catcher section and lockable in predetermined rotational positions. The adjusting element is designed such that the first opening section of the thread guide opening is formed jointly by the base part and the adjusting element, wherein the first slot width of the first opening section can be changed by appropriately selecting the rotational position of the adjusting element. Thanks to such an adjusting element, the first slot width can be adapted to different thread diameters. Consequently, it is not necessary to constantly replace the knot catcher depending on the thread thickness used.

[0012] The adjusting part is advantageously made from a sheet of metal with a uniform thickness. This makes the adjusting part easy and inexpensive to manufacture.

[0013] Preferably, locking means are provided on the base part and on the adjustment part, in particular in the form of a locking projection extending from the base part towards the adjustment part and several locking openings provided on the adjustment part, into which the locking projection engages depending on the rotational position.

[0014] Preferably, at least one sheet metal blank, in particular all sheet metal blanks, has a sheet thickness between 0.3 and 0.7 mm and / or is / are made of stainless steel.

[0015] Further features and advantages of the present invention will become clear from the following description with reference to the accompanying drawing. Therein is Fig. 1 a schematic side view of a thread delivery device; Fig. 2 a schematic perspective view of a knot catcher according to a first embodiment of the present invention; Fig. 3 a top view of the in Fig. 2 depicted knot catchers; Fig. 4 a side view of the in Fig. 2 of the depicted knot catcher in the direction of arrow IV in Fig. 3; Fig. 5 a side view of the in Fig. 2 of the depicted knot catcher in the direction of arrow V in Fig. 3; Fig. 6 a schematic perspective view of a knot catcher according to a second embodiment of the present invention; Fig. 7 a top view of the in Fig. 6 depicted knot catcher; Fig. 8 a side view of the in Fig. 6 of the knot catcher shown in the direction of arrow VIII in Fig. 7; Fig. 9 a side view of the in Fig. 6 of the depicted knot catcher in the direction of arrow IX in Fig. 7; Fig. 10 a schematic perspective view of a knot catcher according to a third embodiment of the present invention; Fig. 11 a top view of the in Fig. 10 depicted knot catchers; Fig. 12 a side view of the in Fig. 10 of the depicted knot catcher in the direction of arrow XII n Fig. 11; Fig. 13 a side view of the in Fig. 10 depicted knot catcher in the direction of arrow XIII in Fig. 11; Fig. 14 a schematic perspective view of a knot catcher according to a fourth embodiment of the present invention; Fig. 15 a top view of the in Fig. 14 depicted knot catcher; Fig. 16 a side view of the in Fig. 14 depicted knot catcher in the direction of arrow XVI in Fig. 15; Fig. 17 a side view of the in Fig. 14 depicted knot catcher in the direction of arrow XVII in Fig. 15; and Fig. 18 an exploded view of the in Fig. 14 depicted knot catchers.

[0016] The same reference numbers refer below to identical or similar components or component areas.

[0017] Fig. Figure 1 shows a yarn delivery device 1, which serves to feed a yarn F to a textile machine (not shown in detail), for example a circular knitting machine or the like, wherein the yarn F enters the yarn delivery device 1 in a Fig. The yarn feeder 1 comprises a support unit 2 with a mounting clamp 3. Furthermore, the yarn feeder 1 has a yarn feed wheel 4, which is arranged at a lower end of a shaft 5 extending through and supported in the support unit 2. Two pulleys 6 and a clutch (not shown in detail) with a handle 7 are arranged on the shaft 5. In the yarn feed direction X upstream of the yarn feed wheel 4, i.e., at the entry point of the yarn feeder 1, an entry eyelet 8, a knot catcher 9 designed according to the invention, a yarn brake 10, and an entry sensor 11 are arranged on the support unit 2. The support unit 2 comprises a support arm 12 and a housing with a first housing part 13 and a second housing part 14. In the yarn feed direction X downstream of the yarn feed wheel 4, i.e.,In the discharge area of ​​the yarn delivery device 1, a first yarn guide element and a second yarn guide element are arranged successively on the support unit 2. The yarn guide elements are designed to guide the yarn F supplied by the yarn delivery wheel. The first yarn guide element behind the yarn delivery wheel 4 is designed as a take-off element 15, and the second yarn guide element as a discharge element 16. The yarn delivery device 1 is equipped with a discharge sensor 17, which is rotatably mounted on the support unit 2 about a pivot axis.

[0018] The Fig. Figures 2 to 5 show a knot catcher 9 according to a first embodiment of the present invention. This consists of a base part 18, which is bent from a sheet metal blank of uniform thickness s, preferably in a range between 0.3 and 0.7 mm, preferably made of stainless steel. In the illustrated embodiment, the base part 18 comprises a fastening section 19, a knot catcher section 20, and a transition section 21 connecting the fastening section 19 to the knot catcher section 20, the individual sections being separated from each other by bend lines 22. The fastening section 19 is designed to attach the knot catcher 9 to the thread delivery device 1. The transition section 21 serves to align the fastening section 19 and the knot catcher section 20 relative to each other such that the knot catcher 9 is positioned in the Fig. The knot catcher section 20 can be mounted in the position shown on the thread delivery device 1. The length and bending angles of the transition section 21 are selected accordingly. The knot catcher section 20 comprises a slot-shaped thread feed opening 24 accessible at the edge, which forms a first opening section 25 at its end and a second opening section 26 adjoining the first opening section 25 and open towards the edge. The first opening section 25 extends in a straight line and has a first slot width b1 that is constant along its length and, considering the knot catcher section 20 in the thread feed direction X, corresponds to the thickness s. FThe first opening section 25 is adapted to the thread F passing through it during the intended operation of the textile machine. The second opening section 26 connects the first opening section 25 to the edge of the knot catcher section 20 and serves to thread the thread F into the first opening section 25. In this case, the second opening section 26 is L-shaped, with the leg of the L-shape adjacent to the first opening section 25 extending transversely to the first opening section 25, i.e., not continuing it in a straight line. A guide rib 27, formed by the base part 18, leads to the beginning of the second leg and serves as a threading aid. The second opening section 26 has a second slot width b2, which changes along the length of the second opening section 26 when viewed in the thread flow direction X of the knot catcher section 20.It is minimal in the region of a free end of a tongue-like projection 28 formed on the base part 18. The projection 28 is arranged at the beginning of the second opening section 26 as an extension of the first opening section 25 and extends transversely to the first opening section 25. In this case, it is bent downwards with respect to adjacent areas of the base part 18. The inclination of the projection 28 with respect to adjacent areas of the base part 18 is chosen such that, considering the knot catcher section 20 in the thread travel direction X, the minimum second slot width b. 2minsmaller than the first slot width b1 of the first opening section 25 of the thread passage opening 24, and that, considering the knot catcher section 20 perpendicular to the thread passage direction X, a minimum distance a between the free end of the projection 28 and the area of ​​the base part 18 opposite the projection 28 is greater than or equal to the first slot width b1 of the first opening section 25 of the thread passage opening 24.

[0019] To put the thread delivery device 1 into operation, the thread F is threaded into the knot catcher 9. For this purpose, the thread F is moved along the guide rib 27 into the second opening section 26 of the thread feed opening 24. Before reaching the projection 28, the thread F, which Fig. 3, the thread F is pulled and tensioned to the left away from the free end of the projection 28, so that the thread F can easily pass the projection 28 thanks to the minimal distance a, and then moves further into the first opening section 25. If excess thread or loops form in the thread F during operation of the thread delivery device 1, the thread F moves towards the second opening section 26 and there collides with the projection 28, thus preventing the thread F from being threaded out of the thread feed opening 24.

[0020] Another embodiment of a knot catcher 9 according to the invention is shown in the Fig. 6 to 9, the design of which largely mirrors that of the one in the Fig. The knot catcher 9 shown in Figures 2 to 5 is similar. One difference is that the downwardly curved projection 28 is formed in a position in the middle of the second opening section 26 of the thread guide opening 24.

[0021] The Fig. 10 and Fig. Figure 13 shows a knot catcher 9 according to a third embodiment of the present invention, the design of which is largely the same as that of the one described in the Fig. The knot catcher 9 shown in Figures 2 to 5 is similar. One difference is that the downwardly curved projection 28 at the beginning of the second opening section 26 of the thread passage opening 24 is formed in extension of the guide rib 27.

[0022] The Fig.Figures 14 to 18 show a fourth embodiment of a knot catcher 9 according to the invention. This comprises, in addition to the base part 18, an adjusting part 29, which is produced here from a sheet metal blank of uniform thickness and has the shape of a hexagon in plan view. The sheet metal blank is preferably made of stainless steel and has a sheet thickness s between 0.3 and 0.7 mm. The adjusting part 29 is rotatably mounted on the base part 18 in the area of ​​the knot catcher section 20 about a pivot axis 30 and can be locked in predetermined rotational positions. It is designed such that the first opening section 25 of the thread passage opening 24 is formed jointly by the base part 18 and one of the edges of the adjusting part 29, wherein the first slot width b1 of the first opening section 25 can be changed by appropriately selecting the rotational position of the adjusting part 29.In this embodiment, the six edges of the adjusting element 29 allow for the adjustment of six different slot widths b1 of the first opening section 25. The base element 18 and the adjusting element 29 are each provided with corresponding locking means 31 and 32, in this case in the form of a locking projection extending from the base element 18 towards the adjusting element 29 and several locking openings provided on the adjusting element 29, into which the locking projection engages depending on the rotational position. In this embodiment, the downwardly curved projection 28 is positioned, similarly to the first embodiment, at the beginning of the second opening section 26, extending in line with the first opening section 25 and perpendicular to the first opening section 25.

[0023] It should be clear that the embodiments of the knot catcher according to the invention described above serve only as examples and are not to be understood as limiting. Rather, modifications and changes are possible without leaving the scope of protection defined by the accompanying claims. For example, the design of the fastening section 19 and / or the transition section 21 can be varied. The latter can also be omitted entirely, so that the base part 18 has only a fastening section 19 and a knot catcher section 20. Furthermore, the projections 28 can also be bent upwards. If necessary, the projections 28 can also be omitted entirely. REFERENCE NUMBER LIST 1 Thread delivery device 2 carrying units 3 Mounting clamp 4 Thread delivery wheel 5 wave 6 Pulley 7. Handling 8 Inlet eyelet 9 Knot Catchers 10 Thread brake 11 Inlet sensors 12 support arm 13 first housing part 14 second housing part 15 Deduction element 16 Outlet element 17 outlet sensors 18 Basic part 19 Fastening section 20 Knot Catcher Section 21 Transition section 22 Bending curve 24 Thread feed opening 25 first opening section 26 second opening section 27 Guide bridge 28 lead 29 Adjustment part 30 Rotary axis 31 locking devices 32 locking devices F thread X Thread flow direction sheet thickness s F Thread thickness b1 slot width b2 slot width a distance

Claims

[1] Knot catcher (9) for textile machines, in particular for knitting machines, comprising a base part (18) made from a sheet metal blank of uniform thickness (s), which forms a fastening section (19) and a knot catcher section (20), wherein the knot catcher section (20) has a slot-shaped yarn guide opening (24) accessible at the edge, which has at its end a first opening section (25) extending in particular in a straight line with a first slot width (b1) constant over the length of the first opening section (25), which, when considering the knot catcher section (20) in a yarn feed direction (X), corresponds to the thickness (s F) of a thread (F) passing through the first opening section (25) during the intended operation of the textile machine, and forms a second opening section (26) extending from the first opening section (25) to the edge of the knot catcher section (20) in order to thread the thread (F) into the first opening section (25), wherein the second opening section (26), considering the knot catcher section (20) in the thread passage direction (X), has a second slot width (b2) that changes over the length of the second opening section (26), characterized by , that the second slot width (b2) of the second opening section (26) in the area of ​​a free end of a tongue-like projection (28) formed on the base part (18) is minimal and smaller than the first slot width (b1) of the first opening section (25). [2] Knot catcher (9) according to claim 1, characterized by, that the projection (28) is curved upwards or downwards in relation to adjacent areas of the base part (18). [3] Knot catcher (9) according to claim 2, characterized by , that an inclination which the projection (28) has in relation to adjacent areas of the base part (18) is chosen such that, considering the knot catcher section (20) in the thread feed direction (X), the minimum second slot width (b 2min ) is smaller than the first slot width (b1) of the first opening section (25) of the thread passage opening (24), and that, considering the knot catcher section (20) perpendicular to the thread passage direction (X), a minimum distance (a) between the free end of the projection (28) and the area of ​​the base part (18) opposite the projection (28) is greater than or equal to the first slot width (b1) of the first opening section (25) of the thread passage opening (24). [4] Knot catcher (9) according to any one of the preceding claims, characterized by , that the projection (28) is arranged adjacent to the first opening section (25). [5] Knot catcher (9) according to any one of the preceding claims, characterized by , that the base part (18) forms a guide rib (27) leading to the beginning of the second opening section (26), serving as a threading aid. [6] Knot catcher (9) according to any one of the preceding claims, characterized by , that an adjusting part (29) is provided which is rotatably mounted on the base part (18) in the area of ​​the knot catcher section (20) and lockable in predetermined rotational positions and is designed such that the first opening section (25) of the thread passage opening (24) is formed jointly by the base part (18) and the adjusting part (29), wherein the first slot width (b1) of the first opening section (25) can be changed by appropriately selecting the rotational position of the adjusting part (29). [7] Knot catcher (9) according to claim 6, characterized by , that the adjusting part (29) is made from a sheet metal blank of uniform sheet thickness (s). [8] Knot catcher (9) according to claim 7, characterized by , that locking means (31, 32) are provided on the base part (18) and on the adjustment part (29) that are associated with each other, in particular in the form of a locking projection extending from the base part (18) towards the adjustment part (29) and several locking openings provided on the adjustment part (29) into which the locking projection engages depending on the rotational position. [9] Knot catcher (9) according to any one of the preceding claims, characterized by , that at least one sheet metal blank, in particular all sheet metal blanks, have a sheet thickness between 0.3 and 0.7 mm and / or are made of stainless steel.

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