Thread transfer device

Abstract

The invention relates to a thread laying device (1) for a thread joining unit of a cross-wound textile machine, comprising a gripper tube (2) with a gripper tube opening (12) that can be acted upon with suction air and a gripper tube flap (3) pivotably arranged on the gripper tube (2) between an open position releasing the gripper tube opening (12) and a closed position closing the gripper tube opening (12). To provide a thread laying device (1) that ensures reliable displacement of the gripper tube flap (3) towards the closed position, the gripper tube flap (3) is biased towards the closed position by a magnetic field.

Description

[0001] The invention relates to a thread laying device for a thread connecting unit of a textile machine producing cross-wound bobbins, with a gripper tube with a gripper tube mouth that can be acted upon by suction air, a gripper tube flap that is pivotably arranged on the gripper tube between an open position that releases the gripper tube mouth and a closed position that closes the gripper tube mouth, which flap is pretensioned in the direction of the closed position by a magnetic field.

[0002] In textile machines that produce cross-wound bobbins, a thread is transferred from a pay-off bobbin to a cross-wound bobbin. The pay-off bobbin used in this case can be, for example, spinning bobbins produced on a ring spinning machine, whose thread is rewound onto cross-wound bobbins for easier further processing.

[0003] In such textile machines, an automatic thread splicing system and, if necessary, an automatic bobbin change are activated in the event of a thread breakage or when changing the supply bobbins. First, a suction nozzle of the thread splicing unit is placed on the surface of the take-up bobbin, which is slowly rotating against the winding direction. After engaging the upper thread, the suction nozzle pivots to its starting position, where the suction nozzle opening is positioned below a splicing device, and inserts the upper thread into a splicing device.

[0004] Essentially simultaneously with the suction nozzle, a hook tube of the thread transfer device, which is also a component of the thread connecting unit, pivots from its initial position, in which it is located during normal winding operation, to a lower take-up position, where it picks up a bobbin thread drawn from the supply bobbin, which was previously held in a thread tensioner or clamping device. The hook tube then pivots to an upper transfer position, bringing the bobbin thread with it. When the hook tube pivots into its transfer position, the bobbin thread is positioned in the splicing device.

[0005] To take up the bobbin thread, the hook tube has a hook tube flap at the end. When the hook tube is pivoted into the take-up position, this flap is moved into its open position by means of a switching gate. In this position, negative pressure sucks the bobbin thread into the hook tube. When the hook tube leaves the take-up position, the hook tube flap closes again and clamps the thread so that it can be safely transferred to the splicing device. When the hook tube is pivoted up into the transfer position, the hook tube cuts the tension path of the upper thread with a thread laying hook, takes this thread with it and positions it correctly in the splicing device. When the hook tube moves into the transfer position, the hook tube flap is opened so that the upper and bobbin threads are taut and inserted into the splicing device.

[0006] In order to ensure reliable clamping of the thread by the looper tube flap, it is already known to pre-tension it towards its closed position. For this purpose, for example, torsion springs are used, against the pre-tension of which the looper tube flap is opened in the area of ​​the take-up position and the transfer position. Pre-tensioning in the direction of the closed position can also be ensured by a corresponding arrangement of the looper tube flap on the looper tube, in which the looper tube flap is pre-tensioned towards the closed position due to the force of weight. Pre-tensioning in the direction of the closed position is understood to mean an arrangement of the looper tube flap on the looper tube in which a force acts on the looper tube flap, displacing it towards the closed position.

[0007] Modern looper tube flaps are geometrically unfavorable, meaning they are no longer preloaded into the closed position by their weight. The use of springs, especially torsion springs, has the disadvantage that their spring force decreases or even breaks over time. Furthermore, the available space in modern thread-laying devices is so limited that torsion springs, in particular, do not have a sufficient number of spring coils to provide the necessary preload toward the closed position.

[0008] DE 10 2008 026 777 A1 discloses a suction nozzle for a workstation of a textile machine producing cross-wound bobbins for pneumatically picking up and handling a thread end that has run onto the surface of a cross-wound bobbin after a controlled thread clearing cut or after a thread break. In the area of ​​its suction opening, the suction nozzle has a movably mounted cover device that can be positioned precisely above the suction opening to partially cover the suction opening. The cover device can be magnetically secured.

[0009] EP 0 691 300 A1 discloses a gripper tube for a thread joining unit of a textile machine producing cross-wound bobbins, which has a pivotably mounted, spring-loaded gripper tube flap at its end, which can be adjusted between an open position releasing the gripper tube mouth and a closed position closing the gripper tube mouth, wherein the gripper tube flap is spring-loaded and pretensioned in the direction of the closed position.

[0010] Based on this, the object of the invention is to provide a thread laying device which ensures a reliable displacement of the gripper tube flap in the direction of the closed position.

[0011] The invention solves the problem by a thread laying device with the features of

[0012] Claim 1. Advantageous developments of the invention are specified in the dependent claims.

[0013] A characteristic feature of the thread laying device according to the invention is that the gripper tube and the gripper tube flap, in the open position, have permanent magnet units arranged opposite one another and repelling one another, forming a magnet pair.

[0014] According to one embodiment of the invention, a permanent magnet unit is arranged on each of the gripper tube and the gripper tube flap, said permanent magnet units being arranged opposite one another in the open position, i.e. having the smallest distance from one another in the open position. The arrangement of the permanent magnet units is such that they repel one another, so that the gripper tube flap is pretensioned from the open position towards the closed position due to the repulsive effect of the permanent magnet units and is held there in the closed position due to the magnetic field. The gripper tube flap is opened counter to the repulsive effect of the permanent magnet units, for example by the interaction of the gripper tube flap with a control link in the region of the take-up position and / or transfer position of the thread laying device.

[0015] The use of permanent magnet units makes it possible to generate a magnetic field that biases the gripper tube flap towards the closed position in a particularly simple and cost-effective manner, whereby the magnetic force can be determined via the fundamentally free selection of the permanent magnet units.

[0016] The use of a magnetic field represents a particularly convenient design for pre-tensioning the looper tube flap toward the closed position. The magnetic field extends between the looper tube flap and the looper tube in such a way that the looper tube flap is pre-tensioned toward the closed position by the magnetic field. By adjusting the strength of the magnetic field, the force acting on the looper tube flap, shifting it into the closed position or holding it there, can be adjusted particularly easily and conveniently, thus reliably clamping a thread arranged in the looper tube opening.

[0017] According to the above-described embodiment of the invention, the preload toward the closed position is based on a repulsive effect of the permanent magnet units on the gripper tube flap and the gripper tube. In addition, according to a further development of the invention, the gripper tube and the gripper tube flap have permanent magnet units arranged opposite one another in the closed position, attracting one another and forming a magnet pair.

[0018] According to this embodiment of the invention, the permanent magnet units of the gripper tube and the gripper tube flap are at their closest distance from each other in the closed position, and the biasing effect of the gripper tube flap toward the closed position results from the attraction of the permanent magnet units to each other. In the open position of the gripper tube flap, the permanent magnet units attract each other, whereby the gripper tube flap is moved into the closed position in an externally unloaded state and reliably held there.

[0019] The arrangement of the magnet pair on the gripper tube flap and the gripper tube can, in principle, be arranged in any desired manner, whereby even a single magnet pair is sufficient to generate a magnetic field that biases the gripper tube flap toward the closed position. However, according to a particularly advantageous embodiment of the invention, two magnet pairs are arranged on the gripper tube below the gripper tube flap, spaced apart from one another in the pivot axis direction of the gripper tube flap.

[0020] According to this embodiment of the invention, the gripper tube flap and the gripper tube have at least two pairs of magnets, which are arranged at a distance from one another along the pivot axis of the gripper tube flap, formed, for example, by a pivot pin, and thus jointly preload the gripper tube flap toward the closed position. By using at least two pairs of magnets, the preload can be adjusted and, if necessary, increased particularly reliably with particularly limited installation space. Furthermore, the spaced-apart arrangement of the pairs of magnets provided according to this embodiment of the invention ensures particularly reliable and trouble-free pivoting of the gripper tube flap between the open position and the closed position.

[0021] The permanent magnet units can generally be formed by a single permanent magnet, which generates a magnetic field sufficient for the intended purpose. However, according to a particularly advantageous embodiment of the invention, the permanent magnet units are each formed by a permanent magnet stack comprising at least two individual magnets. The use of permanent magnet stacks allows the use of several, generally inexpensive, individual magnets to provide the required magnetic field. Using a magnet stack increases the adhesive force or repulsion effect. For example, the magnetic field is essentially doubled when two individual magnets are used, so that a predetermined magnetic field can be generated particularly easily using inexpensive individual magnets.

[0022] According to a further embodiment of the invention, the permanent magnet unit is detachably attached to the gripper tube and / or the gripper tube flap. The detachable arrangement according to this further development of the invention allows the magnetic field generated by the permanent magnet unit to be adjusted, if necessary, by simply replacing it.

[0023] An embodiment of the invention is explained below with reference to the drawings. In the drawings: Fig. 1 is a perspective view of a thread laying device with a looper tube flap arranged in an open position; Fig. 2 is an enlarged perspective view of the thread laying device of Figure 1 ; Fig. 3 a further perspective view of the looper tube flap of the thread laying device arranged in the open position of Figure 1, partly in section and Fig. 4 a perspective view of the looper tube flap of the thread laying device of Figure 1 , partly in section.

[0024] In Figure 1 A perspective view of a thread transfer device 1 for a thread joining unit (not shown here) of a textile machine producing cross-wound bobbins is shown. The thread transfer device 1 has an angled gripper tube 2, which can be pivotally connected to a suction air source on the textile machine via a hollow gripper tube shaft 5.

[0025] At the end opposite the gripper tube shaft 5, the gripper tube 2 has a gripper tube flap 3 which is arranged between a Figures 1 to 4shown open position, in which the gripper tube flap 3 exposes a gripper tube mouth 12, and a closed position, not shown here, in which the gripper tube flap 3 closes the gripper tube mouth 12 via a closure element 14 arranged on the inside. The adjustment movement takes place via a pivoting of the gripper tube flap 3 about a bolt 10 extending through the gripper tube flap 3 and a flap carrier 4, wherein the gripper tube flap 3 is aligned on the gripper tube 2 opposite the gripper tube mouth 12 via a clamping body 11 connected to the flap carrier 4 and arranged coaxially to the gripper tube 2.

[0026] To pre-tension the gripper tube flap 3 from the position in the Figures 1 to 4illustrated open position into the closed position not shown here, the gripper tube 2 and the gripper tube flap 3 each have a permanent magnet stack 8 formed from permanent magnets 9, which are aligned repulsively with respect to one another, wherein a first permanent magnet stack 8 is arranged via a receptacle 7 on the clamping body 11 in a fixed position relative to the gripper tube 2 and a second permanent magnet stack 8 is arranged in a receptacle 7 on the gripper tube flap 3. Due to their mutual repulsive effect, the magnetic field generated between the permanent magnets 9 causes a pretensioning force that pivots the gripper tube flap 3 about the bolt 10, by means of which the gripper tube flap 3 is pretensioned in the direction of the closed position. In the closed position, the closure element 14 is positioned concentrically to the gripper tube mouth 12 and closes it, so that anythread arranged in the gripper tube mouth 12 is clamped between the gripper tube 2 and the gripper tube flap 3. List of reference symbols

[0027] 1Thread laying device 2Gripper tube 3Gripper tube flap 4Flap support 5Gripper tube shaft 6Holder (permanent magnet unit for gripper tube flap) 7Holder (permanent magnet unit for flap support) 8Permanent magnet stack 9Permanent magnet 10Bolt 11Clamping body 12Gripper tube mouth 13Control cam 14Closing element

Claims

1. Thread-laying device (1) for a thread-joining unit of a textile machine producing cross-wound bobbins, comprising - a gripper tube (2) having a gripper tube mouth (12) to which suction air can be applied, - a gripper tube flap (3) which is arranged on the gripper tube (2) so as to be pivotable between an open position, which releases the gripper tube mouth (12), and a closed position, which closes the gripper tube mouth (12), which gripper tube flap is biased towards the closed position by a magnetic field, characterized in that the gripper tube (2) and the gripper tube flap (3) have permanent magnet units (6, 7) which are arranged opposite one another in the open position, are oriented so as to repel one another and form a magnet pair.

2. Thread-laying device (1) according to claim 1, characterized in that the gripper tube (2) and the gripper tube flap (3) have permanent magnet units (6, 7) which are arranged opposite one another in the closed position, are oriented so as to attract one another and form a magnet pair.

3. Thread-laying device (1) according to one or more of the preceding claims, characterized in that two magnet pairs, which are arranged at a distance from one another in the pivot axis direction of the gripper tube flap (3), are arranged on the gripper tube (2) and the gripper tube flap (3).

4. Thread-laying device (1) according to one or more of the preceding claims, characterized in that the permanent magnet units (6, 7) are formed by a permanent magnet stack (8).

5. Thread-laying device (1) according to one or more of the preceding claims, characterized in that the permanent magnet unit (6, 7) is detachably attached to the gripper tube (2) and / or the gripper tube flap (3).

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