Patent Application
20250042690
The invention relates to a thread-splicing device for a workstation of a textile machine that produces cross-wound bobbins and has a splicing prism with a splicing channel to which pneumatic pressure can be applied, as well as thread-guiding plates arranged on both sides of the splicing channel, and which is equipped with thread-locking means.
Thread splicing devices designed in this way for pneumatically connecting two thread ends have been known for a long time in connection with the workstations of textile machines producing cross-wound bobbins, for example cross-winding machines, and are described in detail in numerous patent specifications.
In addition to a splicing prism, which is arranged on a so-called air distribution block and is equipped with thread guide plates, such thread splicing devices generally have thread locking and cutting devices and holding and unraveling tubes for preparing the thread ends to be spliced.
With such thread splicing devices, two thread ends which are produced, for example, by a thread breakage or by a controlled clearer cut, can be pneumatically connected in such a way that the connection point is almost the identical to the yarn.
After a thread breakage, for example, the upper thread that has run onto the surface of a cross-wound bobbin is picked up by a suction nozzle and inserted into the splicing channel of the splicing prism of the thread splicing device. Almost simultaneously, the lower thread is picked up by a gripper tube from an unwinding bobbin positioned in an unwinding position and also inserted into the splicing channel where the upper thread and the lower thread are then pneumatically intertwined.
However, in order for such thread connections to have an almost yarn-like appearance and approximate yarn strength, various requirements must be met. The two thread ends to be connected should, for example, initially be cut exactly to length and carefully prepared for the splicing process and subsequently positioned precisely in the splicing channel of the splicing prism.
For this purpose, the known thread splicing devices have different devices, for example thread locking and thread cutting devices, holding and unraveling tubes, and a thread feeder as indicated above.
In practice, the two thread ends are transported through the suction nozzle or the gripper tube into the region of the thread splicing device and, inter alia, are threaded there into the splicing channel guided by thread guide sheets which are arranged at the end of the splicing channel of the splicing prism. During the threading into the splicing channel, the thread ends are also positioned in associated thread locking devices and thread cutting devices.
The thread ends, precisely cut to length by the thread cutting devices and fixed by the thread locking devices, are then sucked into the holding and unraveling tubes where they are prepared pneumatically.
That is to say, the thread ends are initially largely freed of their yarn twist and then pulled into the splicing channel of the splicing prism by a thread feeder such that they lie parallel next to one another in the splicing channel approximately at the same height, but have an opposite alignment. The free thread ends, the length of which depends, for example, on the thread material and/or on the thread diameter, preferably in each case protrude from the splicing channel of the splicing prism on both sides.
Compressed air blasts are then introduced into the splicing channel via one or more inlet holes opening into the splicing channel of the splicing prism, which cause the fibers of the two yarn ends, which initially lie essentially parallel to each other in the splicing channel, to swirl, with the result that a durable yarn connection arises.
In these known thread splicing devices, the thread guide plates which are arranged at the end of the splicing channel also ensure that the thread ends to be spliced can easily be threaded into the splicing channel of the splicing prism, and that the thread ends are not blown out of the splicing channel during the splicing process.
The described thread splicing devices have proven themselves in practice, in particular when the threads do not exceed a certain yarn thickness. However, the situation is more difficult when coarse yarns are processed, i.e., when thread ends are to be spliced, which have a relatively large yarn diameter.
In the splicing of the thread ends of such coarse yarns, considerable thread vibrations often occur during the splicing process in the region between the thread guide plates and the thread locking devices, which result in the created thread splice not meeting the specified quality requirements either in terms of strength or in terms of appearance.
In order to be able to properly splice such coarse yarns, different proposals have already been made in the past on how to modify thread splicing devices, but the known proposals were not satisfactory.
It has been proposed, for example, to arrange additional locking means in the region of the holding and unraveling tubes which fix the thread ends by the thread cutting devices after cutting to length. These locking means are to prevent the cut-to-length thread ends from curling too much and not being properly prepared, or being blown out of the splicing channel of the splicing prism in whole or in part during the splicing process.
Such additional thread locking means in the form of serrated plates which are arranged at the level of the holding and unraveling tubes of a thread splicing device are, for example, described in EP 1 118 570 A2.
A comparable thread splicing device is also described in DE 101 24 832 A1 in which additional locking means for the cut-to-length thread ends are likewise arranged at the level of the holding and unraveling tubes. The locking means here are designed as vacuum-pressurizable screens which are intended to ensure that the cut-to-length thread ends are pneumatically fixed during the splicing process.
Thread splicing devices as described in DE 101 24 832 A1, however, have the disadvantage that they are not only relatively complex and thus expensive, but also relatively high maintenance.
Furthermore, for example, DE UP 1 535 828 or DE 42 26 025 C2 discloses thread splicing devices in which holding means are arranged directly in the region of the splicing channel and fix the thread ends during the splicing process.
In the thread splicing device according to DE UP 1 535 828, the thread ends are fixed during the splicing process, for example by two clamps arranged at a distance, whereas the thread ends in the thread splicing device according to DE 42 26 025 C2 are fixed by a centrally arranged cushion-like, air-permeable element.
Overall, the known thread splicing devices in connection with the processing of coarse yarns, in particular with the creation of proper splice connections, were not convincing and could definitely be improved.
Based on thread splicing devices of the type described above, the invention is based on the object of developing a thread splicing device which ensures that proper thread splices can be reliably produced, in particular with coarse yarns.
According to the invention, this object is achieved in that at least one interfering element is positioned on both sides of the splicing prism in a region between the thread guide plates and the thread locking device in such a way that the thread ends to be spliced contact the interfering element during the splicing process.
Advantageous embodiments of the thread splicing device according to the invention are the subject matter of the dependent claims.
The embodiment according to the invention has the advantage in particular that, during the splicing process, the interfering element resting against the thread ends reliably prevents excessive thread vibrations from being able to occur in the region in question. The interfering element thus positively influences the integration of the thread ends in terms of both strength and appearance.
The interfering element thus reliably ensures that during the splicing process, the thread ends in the area between the yarn guide plates arranged on the output side of the splicing channel of the splicing prism and the thread locking devices arranged at a distance are calmed. This means that large thread vibrations which can occur which, as is known, would have a negative effect on the strength and on the appearance of the thread splice, are prevented.
In an advantageous embodiment, it is also provided that the interfering element is always arranged on the larger of the two thread guide plates.
By mounting the interfering element on the larger thread guide plate, the thread ends to be spliced are pneumatically applied to the interfering element. This means that since the small yarn guide plate is connected to the splicing prism in such a way that the outlet opening of the pneumatically pressurized splicing channel is partially covered, an air flow is created in the region of the outlet opening in the direction of the larger yarn guide plate and therefore in the direction of the interfering element, and applies the thread ends to the disruptive element.
According to the present invention, the interfering elements can be designed differently. In a first embodiment, it is provided, for example, that the interfering element is designed and arranged such that the thread start or thread contact surface of the interfering element runs at a right angle to the side wall of the splicing prism. In such interfering elements, the thread contact surface of the interfering element is positioned relatively close in the region of the large thread guide plate. In a second embodiment, the interfering element has a wall part that is equipped with a thread contact surface and is arranged at an angle with respect to the side wall of the splicing prism. With such a design, the yarn contact surface of the interfering element is further away from the large thread guide plate, with the result that the interference factor which can be exerted by the interfering element on the yarn vibrations of the yarn ends is very effective.
Furthermore, however, it is also possible for the interfering element to have multiple wall parts each equipped with a thread contact surface. The wall parts and therefore the thread contact surfaces arranged on the wall parts can be arranged at right angles to the side wall of the splicing prism and/or have an angle with respect to the side wall of the splicing prism. Such interfering elements equipped with multiple thread contact surfaces are very effective with respect to thread vibration suppression.
The interfering elements of the thread splicing device are preferably made of an abrasion-resistant material, for example a ceramic material, or a high-strength metallic material. The use of such an abrasion-resistant material ensures that the interfering elements have a long service life, even under relatively high stress. The interfering elements can either be mounted on the splicing prism so that they can be easily replaced, for example using a screw connection, or they can be securely attached to the splicing prism, for example using an adhesive connection, but can be removed only with relative difficulty.
Different embodiments are also provided with respect to the thread contact surface of the wall parts of the interfering elements. In a first embodiment, the thread contact surface of the interfering element, arranged in the region of contact of the thread ends with the wall part, is largely straight. However, the thread contact surface of the interfering element arranged in the region of the contact of the thread ends can also have a recess. Such a recess results in the thread ends being centered in the region of the contact surfaces, with the result that the thread vibrations of the thread ends are disturbed and thus relatively strongly suppressed.
However, the thread splicing device for the workstation of a cross-winding machine can also be equipped with other advantageous devices. In addition to a pneumatic splicing prism equipped with interfering elements, such thread splicing devices can for example also have other devices, such as for example a cover plate equipped with locking means, an attachment plate equipped with locking means, or a special thread brake element. With thread splicing devices equipped in this way, even in the processing of coarse yarns it is always ensured that the created thread splice connections are always correct, i.e., the thread splice connections have yarn strength and a yarn-like appearance.
Further details of the invention are explained below with reference to an embodiment shown in the drawings.
In the drawings:
Such cross-winding machines 1 also have a logistics device in the form of a bobbin and tube transport system 3 in which the spinning cops 9 or unwound empty tubes circulate on transport plates 8. Of such a bobbin and tube transport system 3, only the cop feed line 4, the reversibly drivable storage section 5, one of the transverse transport paths 6 leading to the winding stations 2, and the tube return line 7 are shown in
Furthermore, such automatic cross-winding machines 1 usually have a central control unit 18 which is connected via a machine bus 35 both to the separate workstation computers 29 of the individual workstations 2 and (not shown) to a control device of the service unit.
The spinning cops 9 supplied via the bobbin and tube transport system 3 are wound into large-volume cross-wound bobbins 15 in unwinding positions UP, which are in each case located in the region of the transverse transport paths 6 at the workstations 2.
For this purpose, the individual workstations 2 are known to have different devices which ensure proper operation of these workstations 2. These devices are, for example, a suction nozzle 12 for handling the upper thread 31, a gripper tube 25 for handling the lower thread 32, and a thread connecting device designed as a pneumatic thread splicing device 10. The suction nozzle 12 and the gripper tube 25 are each connected via suction air connections to a machine-length suction air channel 37. The suction nozzle 12 is pivotably mounted to a limited extent about a pivot axis 16 and the gripper tube 25 about a pivot axis 26.
Further devices (not shown in detail) of such workstations 2 of cross-winding machines 1 are, for example, a thread tensioner, thread clearer, paraffinizing device, thread cutting device, thread tension sensor, and lower thread sensor.
The pneumatic thread splicing device 10 is set back slightly in relation to the regular thread path during normal winding operation, i.e., the thread splicing device 10 is not touched by the running thread during normal winding operation.
Such workstations 2 furthermore have a winding device 24 for winding a cross-wound bobbin 15. The winding device 24 has, among other things, a bobbin frame 28 which is movably mounted about a pivot axis 13 and has a device for rotatably holding a cross-wound bobbin tube. In the embodiment, the cross-wound bobbin 15, which is freely rotatable in the cross-wound frame 28, rests with its surface on a driven groove drum 14 and is entrained by the latter during winding operation by means of a frictional connection. The thread to be wound onto the cross-wound bobbin 15 comes from a spinning cop 9, which is positioned in an unwinding position UP in the region of the transverse transport line 6.
Accordingly, the thread locking and cutting device 17 below has a thread locking device 17A for fixing the lower thread 32, which is connected to the template spinning cop 9 and is fed through the gripper tube 25, as well as a thread cutting device 17B for cutting to length the upper thread 31 fed by the suction nozzle 12. For reasons of clarity and because it is not absolutely necessary for understanding the invention, a known thread feeder also arranged in the area of the thread splicing device 10 has not been shown.
As can further be seen from
The splicing prism 19 is exchangeably fixed to the air distribution block 33, for example via a screw connection 39.
In the installed state of the splicing prism 19, blow-in openings leading into the splicing channel 20 are connected to a pneumatic bore in the air distribution block 33, which is connected to a compressed air source via a corresponding line in which, for example, a solenoid valve is connected.
As can be seen, for example, from
As shown in
The interfering element 30 shown in
The interfering element 30 shown in
The above-described interfering elements 30 also have, for example, a fastening hole 40 and can therefore be easily attached to the splicing prism 19 by means of a screw connection, which can be easily detached if necessary.
The invention is expressly not intended to be limited to the embodiments described above for interfering elements 30. The interfering elements 30 can, for example, also have more than two wall parts 41 equipped with thread contact surfaces 36. It is also conceivable that the wall parts 41 are formed only partially with a thread contact surface 36 and are at least partially hollow. This means that wall part 41 has, for example, a narrow edge designed as a thread contact surface 36, while the wall part 41 is hollow in the region of the thread contact surface 36. Furthermore, the design of the thread contact surface 36 could also have a different, for example, wavy shape.
Function of the thread splicing device designed according to the invention:
In the case of a interruption of winding, for example due to a regular clearer cut or a thread breakage above the thread tensioner, the lower thread 32 remains held in the thread tensioner of the workstation 2 since the thread clearer has triggered the thread clamping function of the thread tensioner due to the absence of a dynamic thread signal. The lower thread 32 held in the thread tensioner is then removed by the gripper tube 25, which is initially pivoted into the region of the thread tensioner for this purpose and sucks in the lower thread 32 there. The thread tensioner simultaneously releases the lower thread 32.
When the successful pick-up of the lower thread 32 is registered, for example by a sensor arranged inside the gripper tube 25 (not shown), the gripper tube 25 swivels into an upper position as indicated in
Approximately simultaneously, the upper thread 31 that has run onto the cross-wound bobbin 15 is picked up by the suction nozzle 12 and also inserted into the splicing channel 20 of the thread splicing device 10. The suction nozzle 12 threads the upper thread 31, as shown in
The thread ends of the upper thread 31 and the lower thread 32 projecting out of the splicing channel 20 of the splicing prism 19 are each sucked into one of the vacuum-pressurizable holding and unraveling tubes 34, and are at least partially freed there from their thread twist, preferably pneumatically.
Subsequently, the prepared thread ends of the upper thread 31 and lower thread 32 are pulled back into the splicing channel 20 by a so-called thread feeder (not shown) so that the thread ends are positioned next to each other in the splicing channel 20 with a predetermined overlap, i.e., the thread ends of the upper and lower threads 31, 32 are positioned so that they each protrude slightly from the splicing channel 20. By correspondingly controlling, for example, an electromagnetic valve, splicing air is subsequently blown into the splicing channel 20 of the splicing prism 19 via blow-in openings, and the fibers of the thread ends of the upper thread 31 and lower thread 32 located in the splicing channel 20 are entangled with each other.
During this splicing process, as indicated in
In particular in the case of coarse yarns, such uncontrolled thread movements have a very negative effect on the thread splice to be created, that is to say, coarse yarns can often hardly be spliced properly with the well-known thread splicing devices 10 shown in
In order to be able to ensure the creation of proper thread splices even with coarse yarns, the thread splicing devices 10 are modified with interfering elements 30 according to the invention.
That is to say, an interfering element 30, which has at least one wall part 41 with a thread contact surface 36 is attached to the larger of the two yarn guide plates 23 arranged on the output side of the splicing channel 20 of the splice prism 19.
As shown in
This contact of the thread ends on the interfering elements 30 yields a considerable calming of the thread ends, with the result that almost yarn-like yarn connections are created even when processing coarse yarns.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102021124152.9 | Sep 2021 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/074264 | 9/1/2022 | WO |
