Thread laying device for a thread joining unit of a cross-wound bobbin-producing textile machine

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 arranged on the gripper tube, which can be adjusted between an open position that releases the gripper tube mouth and a closed position that closes the gripper tube mouth, a thread laying hook arranged in the region of the gripper tube flap and a thread laying hook (3) which is arranged such that it projects beyond an outer surface (19) of the gripper tube flap (2) in the closed position of the gripper tube flap (2) and is arranged at least flush with the outer surface (19) or set back from it in the open position of the gripper tube flap (2).

[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 adjusted to 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 the 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] During normal winding operation, the hook tube is positioned in its home position at a distance from the normal thread path. In this position, the hook tube is at such a great distance from the running thread that, for example, after a thread break, the falling thread should not wind around the hook tube or the hook tube flap, but instead falls past the hook tube. However, it has been shown that after a break or cut, the thread often does not remain in its regular path, but can move uncontrollably due to the thread tension, which suddenly drops. The distance from the regular thread path therefore does not offer sufficient protection against wrapping around the hook tube or the hook tube flap. The subsequent processes are negatively influenced by this wrapping, which means that the bobbin thread cannot be reliably grasped and therefore a secure splice cannot be created.In the worst case, the wrapping leads to a standstill of the textile machine, which requires manual intervention by the operating personnel to start it up.

[0007] EP 0 691 300 A1 discloses a looper tube whose special design and arrangement in the thread path provides a catching means, preferably in the form of a thread-laying hook, when the looper tube pivots into its upper working position and thus when the bobbin thread is fed forward. This means that the upper thread is also entrained and positioned in the splicing device. In one embodiment, the thread-laying hook is arranged directly on the looper tube and passes through a slot-like opening in the looper tube flap. As a result, the pivoting looper tube flap completely sweeps over the thread-laying hook in the thread take-up position, automatically freeing it of any thread loops or adhering thread remnants.

[0008] Based on this, the invention is based on the object of providing a thread laying device in which the probability of thread wrapping around the gripper tube or the gripper tube flap is significantly reduced compared to the thread laying devices known from the prior art.

[0009] The invention solves the problem by a thread laying device having the features of claim 1. Advantageous developments of the invention are specified in the dependent claims.

[0010] The thread laying device according to the invention for a thread connecting unit has the gripper tube with the gripper tube mouth acted upon by suction air, the gripper tube flap which is arranged so as to be adjustable between the open position releasing the gripper tube mouth and the closed position closing the gripper tube mouth, and the thread laying hook arranged in the region of the gripper tube flap, which is arranged such that in the closed position of the gripper tube flap it protrudes beyond an outer surface of the gripper tube flap and in the open position of the gripper tube flap it is arranged at least flush with the outer surface or set back from it, so that the thread laying hook then does not protrude beyond the outer surface of the gripper tube flap.As a component of a thread connecting unit, the thread laying device serves, in the manner described above, to arrange the lower thread from a position arranged below the splicing device for connection to an upper thread in a splicing device, wherein when the lower thread is positioned in the splicing device by pivoting the hook tube, the thread laying hook cuts the tensioning path of the upper thread arranged in the splicing device and positions it functionally in the splicing device.

[0011] A characteristic feature of the thread laying device according to the invention is that a thread guide element is arranged in the region of the gripper tube flap in such a way that, in the closed position of the gripper tube flap, it projects beyond the outer surface of the gripper tube flap and, in the open position of the gripper tube flap, is arranged at least flush with the outer surface or set back from it.

[0012] The thread guide element on certain textile machines equipped with circular magazines is used to insert the bobbin thread into the splicing device, unlike in the case of a "normal" thread break, namely during a bobbin change. During a bobbin change, if an empty bobbin is positioned on a bobbin mandrel, or if a bobbin cannot be unwound further without special preparation, it is removed via a conveyor belt. The circular magazine of a changeover device is then indexed so that one of the reserve bobbins is brought into the unloading position of the circular magazine and, via an opening in the magazine base, the bobbin chute, and the centering flap, is placed onto the bobbin mandrel, which is pivoted into the receiving position. The bobbin mandrel then pivots back into the unwinding position with the new unwind bobbin.The thread end of the pay-off spool held in the central suction nozzle of the round magazine forms a bobbin thread strand, which is moved by an auxiliary gripper towards a thread tensioner and held there.

[0013] At the time of bobbin change, the hook tube is in its starting position, spaced from the regular thread path. After the new supply bobbin is inserted, the hook tube pivots into the upper transfer position, with the hook tube mouth describing a circular path. The hook tube flap, located in the area of the hook tube mouth, grasps the bobbin thread with its thread guide element and lays it in the direction of the splicing device. Since the circular path also crosses the path of the upper thread, the upper thread is also grasped by the thread laying hook located on the hook tube and likewise laid in the direction of the splicing device. When the thread laying device is designed with a thread laying hook and a thread guide element, the thread laying hook usually protrudes from a front side of the hook tube flap when the hook tube flap is in the closed position, whereas the thread guide element protrudes beyond a rear side of the outer surface.

[0014] The arrangement of the thread guide element such that, in the open position of the looper tube flap, it is at least flush with the outer surface or set back from it ensures, when a thread guide element is used, that any wraps that may form on the looper tube flap when the looper tube flap is opened can be automatically wiped off via the outer surface after the wraps disengage from the thread guide element in the open position. When the thread laying device is designed with a thread guide element in addition to the thread laying hook, disruptions due to unwanted wraps around the looper tube flap are thus reliably avoided, while simultaneously increasing the application range of the thread laying device.

[0015] In the closed position of the looper tube flap, the thread laying hook protrudes beyond the outer surface of the looper tube flap and thus reliably ensures that when the looper tube is adjusted to the transfer position in which the looper tube flap is closed, the upper thread is reliably pressed into the splicing device via the thread laying hook.

[0016] At the same time, however, the thread laying hook carries the risk of wrapping around the hook tube flap, which can lead to malfunctions in the textile machine.

[0017] To prevent wraparound, the thread transfer hook is arranged at least flush with the outer surface or set back from it in the open position of the hook tube flap. This automatically eliminates any wraparound of the hook tube flap that may be present in the starting position of the hook tube as a result of the interaction of the bobbin thread with the thread transfer hook. When the hook tube is adjusted to the take-up position, in which the hook tube flap is opened to take up the bobbin thread in the hook tube mouth, the thread transfer hook is retracted from the outer surface until it is arranged at least flush with the outer surface or set back from it, whereby the thread transfer hook is disengaged from any wraparounds surrounding the hook tube flap.The wraps can then easily slide over the gripper tube flap, so that disruptions caused by wraps are reliably avoided.

[0018] When the hook tube is subsequently moved to the transfer position, the hook tube flap is closed upon leaving the lower take-up position, thereby mechanically securing the bobbin thread located in the hook tube opening to the hook tube flap. The thread transfer hook returns to a position protruding beyond the outer surface, reliably pressing the upper thread into the splicing device in the transfer position area.

[0019] The thread transfer device according to the invention thus reliably prevents malfunctions due to loops around the hook tube in the area of the hook tube flap. Existing loops due to interaction with the thread transfer hook are automatically released, as the loops can easily slide off the surface of the hook tube flap when the hook tube flap is in the open position. At the same time, the thread transfer hook ensures that the upper thread is reliably positioned in the splicing device.

[0020] The arrangement of the thread laying hook and / or the thread guide element such that they protrude beyond the outer surface of the gripper tube flap in the closed position and are arranged at least flush or retracted relative to it in the open position, so that wraps around it are avoided or are automatically released, is fundamentally freely selectable. According to a further embodiment of the invention, however, it is provided that the gripper tube flap is arranged pivotably between the open position and the closed position on a flap carrier connected to the gripper tube, wherein the flap carrier is connected to the thread laying hook and / or the thread guide element in such a way that they protrude through a slit-like passage opening on the gripper tube flap in the closed position and are arranged retracted in the passage opening in the open position.

[0021] According to this embodiment of the invention, the thread transfer hook and / or the thread guide element are connected to the flap support or are formed integrally with it. In the closed position of the looper tube flap, the thread transfer hook and / or the thread guide element protrude through a suitable slot-like opening in the looper tube flap and, in the closed position, protrude beyond the outer surface of the looper tube flap.The looper tube flap is in turn pivotably connected to the flap carrier, wherein when the looper tube flap is adjusted from the closed position to the open position, the thread laying hook and / or the thread guide element are adjusted relative to the slot-like through-opening, which extends in the pivoting direction of the looper tube flap, in such a way that in the open position they are arranged in the slot-like through-opening in such a way that they no longer protrude beyond the outer surface of the looper tube flap.

[0022] This embodiment of the invention particularly reliably ensures a flat outer surface of the gripper tube flap in its open position, allowing wraps to slide reliably over the gripper tube flap. The use of a slot-like opening particularly ensures that the outer surface is free of projections that could promote wraps.

[0023] According to a further embodiment of the invention, the gripper tube flap has a guide section that rests against an outer side of the flap support. According to this embodiment of the invention, the gripper tube flap rests against a side of the flap support facing away from the gripper tube opening, thereby ensuring a particularly reliable, trouble-free pivoting movement of the gripper tube flap between the open position and the closed position. Jamming of the gripper tube flap due to a tilting pivoting movement between the open position and the closed position is thus particularly reliably prevented.

[0024] The looper tube flap closes the looper tube opening in the closed position and releases it in the open position, so that the bobbin thread can then be picked up in the take-up position via a suction flow applied to the looper tube opening. According to a particularly advantageous embodiment of the invention, the looper tube flap has a closure element that closes the looper tube opening in the closed position, which closure element particularly preferably has a shape adapted to the looper tube opening, in particular is designed as a plug arranged concentrically to the looper tube opening in the closed position.The use of a suitably adapted closure element ensures in a particularly reliable manner that the looper tube opening is closed when the looper tube flap is in the closed position, thereby interrupting the suction flow and simultaneously ensuring reliable mechanical clamping of a bobbin thread arranged in the looper tube opening. Furthermore, with a corresponding design of the closure element, it can be ensured in a particularly reliable manner that the looper tube flap is closed under the effect of the prevailing negative pressure at the looper tube opening.

[0025] According to a further embodiment of the invention, the gripper tube flap has a control cam that can be brought into engagement with a control link. According to this embodiment of the invention, the control cam serves to reliably open the gripper tube flap in the area of the pick-up position and the upper transfer position, wherein for this purpose the control cam engages with corresponding links arranged on the textile machine and, in cooperation with the links, causes a pivoting movement of the gripper tube flap. Separate opening devices for adjusting the gripper tube flap can thus be dispensed with, wherein a reliable movement of the gripper tube flap between the open position and the closed position in the pick-up position and transfer position can be ensured via the control cam and the corresponding design of the links.

[0026] For arranging the flap support on the gripper tube, an advantageous embodiment provides that the flap support has a clamping element for releasably fastening the flap support to the gripper tube. The use of the clamping element, e.g., a clamping ring coaxially enclosing the gripper tube in the area of the gripper tube mouth, enables simple and reliable assembly of the gripper tube flap, which is pivotably connected to the flap support, on the gripper tube. The clamping element allows the position of the gripper tube flap to be aligned particularly precisely relative to the gripper tube mouth. Furthermore, the use of a clamping element enables easy replacement of the gripper tube flap in the event of damage.

[0027] To specifically prevent disruptive wrapping of the gripper tube flap, a further development of the invention provides for the gripper tube flap to have a flat and / or convex outer surface. According to this embodiment of the invention, the outer surface of the gripper tube flap does not have a recess that promotes wrapping. A flat and / or convex outer surface particularly promotes smooth sliding off of wraps.Particularly advantageously, it is provided that a front side of the gripper tube flap, over which the thread laying hook protrudes in the closed position, and a rear side of the gripper tube flap, over which the optional thread guide element protrudes in the closed position, are connected to one another via an arc-shaped section of the outer surface, wherein an internal angle between the front side and the rear side of the gripper tube flap has an angle >90°, whereby wraps are avoided in a particularly reliable manner.

[0028] An embodiment of the invention is explained below with reference to the drawings. In the drawings: Fig. 1 shows a first perspective view of a thread laying device with a gripper tube flap arranged in a closed position; Fig. 2 shows a second perspective view of the thread laying device of Figure 1; Fig. 3 a third perspective view of the thread laying device of Figure 1 ; Fig. 4 a first perspective view of the thread laying device of Figure 1 with the looper tube flap arranged in an open position; Fig. 5 a second perspective view of the thread laying device of Figure 4 ; Fig. 6 a third perspective view of the thread laying device of Figure 4 ; Fig. 7 a first perspective view of the looper tube flap of the thread laying device of Figure 1 on a flap carrier; Fig. 8 a second perspective view of the looper tube flap of the thread laying device of Figure 1 ; Fig. 9 a third perspective view of the looper tube flap of the thread laying device of Figure 1 ; Fig. 10 a first perspective view of the gripper tube of the thread laying device of Figure 1arranged flap carrier and Fig. 11 a second perspective view of the flap carrier of the thread laying device of Figure 1 .

[0029] In Figure 1 A perspective view of a thread transfer device 18 for a thread joining unit (not shown here) of a textile machine producing cross-wound bobbins is shown. The thread transfer unit 18 has an angled gripper tube 1, which can be pivotally connected to a suction air source on the textile machine via a hollow gripper tube shaft 7.

[0030] At the end opposite the gripper tube shaft 7, the gripper tube 1 has a gripper tube flap 2 which is arranged between a Figures 1 to 3 shown locking position and one in the Figures 4 to 6In the open position shown, it is pivotably mounted on a flap carrier 5 connected to the gripper tube 1. In the closed position, the gripper tube flap 2 closes a gripper tube opening 8 of the gripper tube 1, whereas in the open position of the gripper tube flap 2, it releases the gripper tube opening 8. A bolt 6 serves for the pivotable arrangement of the gripper tube flap 2 in the area of the gripper tube opening 8, which bolt forms the pivot axis of the gripper tube flap 2 and extends through opposite bolt receptacles 10a, 10b of the gripper tube flap 2 and is fastened to the flap carrier 5 in a bolt receptacle 9 (cf. Figures 7 to 9 ).

[0031] An annular clamping body 11 is used to position the gripper tube flap 2 on the gripper tube 1 opposite the gripper tube mouth 8, which is connected to the flap carrier 5 via screws 17 and coaxially encloses the gripper tube 1 in the assembly position.

[0032] In the Figures 1 to 3 and 7 In the closed position of the looper tube flap 2 shown, a thread laying hook 3 and a thread guide element 4 protrude through a slot-shaped opening 13 on the looper tube flap 2, so that they protrude beyond an outer surface 19 of the looper tube flap 2. The thread laying hook 3 protrudes beyond a front side 21 and the thread guide element 4 protrudes beyond a rear side 22 of the looper tube flap 2.

[0033] When the gripper tube 1 is pivoted about the longitudinal axis of the gripper tube shaft 7, a control cam 16 in the area of a lower receiving position and an upper transfer position of the gripper tube 1 engages with a control link (not shown here) on the textile machine and causes the gripper tube flap 2 to pivot into the Figures 4 to 6illustrated opening position, in which the hook tube mouth 8 is released. When the hook tube flap 2 is adjusted to the open position, the thread laying hook 3 and the thread guide element 4 are relatively displaced within the slot-shaped passage opening 13 into a position in which they are retracted relative to the outer surface 19, i.e., they no longer protrude beyond the front side 21 or rear side 22. Any wraps present which rest against the thread laying hook 3 and / or the thread guide element 4 are stripped off via the outer surface 19 of the hook tube flap 2.

[0034] To close the gripper tube opening 8 in the closed position of the gripper tube flap 2, a closure element 12 adapted to the gripper tube opening 8 is arranged on an inner side of the gripper tube flap 2 on a closure element carrier 15, which closure element is arranged concentrically to the gripper tube opening 8 in the closed position. The closure element 12 is held on the gripper tube flap 2 by a screw (not shown here) that can be screwed into the closure element carrier 15 and extends through a bore 14 on the front side 21 of the gripper tube flap 2.

[0035] The gripper tube flap 2 rests with an underside on an outer side 20 of the flap carrier 5, so that a reliable pivoting movement about the pivot axis formed by the bolt 6 is ensured. List of reference symbols

[0036] 1Hook tube 2Hook tube flap 3Thread laying hook 4Thread guide element 5Flap carrier 6Bolt 7Hook tube shaft 8Hook tube mouth 9Bolt holder (flap carrier) 10a, 10bBolt holder (hook tube flap) 11Clamping body 12Closing element 13Through opening 14Borehole 15Closing element carrier 16Control cam 17Screw 18Thread laying device 19Outer surface 20Outside 21Front 22Rear

Claims

1. Thread-laying device (18) for a thread-joining unit of a textile machine producing cross-wound bobbins, comprising - a gripper tube (1) having a gripper tube mouth (8) to which suction air can be applied, - a gripper tube flap (2) arranged on the gripper tube (1), which gripper tube flap is movable between an open position uncovering the gripper tube mouth (8) and a closed position closing the gripper tube mouth (8), and - a thread-laying hook (3) arranged in the region of the gripper tube flap (2), the thread-laying hook (3) being arranged in such a way that it projects beyond an outer surface (19) of the gripper tube flap (2) in the closed position of the gripper tube flap (2) and in the open position of the gripper tube flap (2) is arranged at least flush with the outer surface (19) or set back relative thereto, characterized in that a thread guidance element (4) which is arranged in the region of the gripper tube flap (2) in such a way that it projects beyond the outer surface (19) of the gripper tube flap (2) in the closed position of the gripper tube flap (2) and in the open position of the gripper tube flap (2) is arranged at least flush with the outer surface (19) or set back relative thereto.

2. Thread-laying device (18) according to claim 1, characterized in that the gripper tube flap (2) is arranged so as to be pivotable between the open position and the closed position on a flap carrier (5) connected to the gripper tube (1), wherein the flap carrier (5) are connected to the thread-laying hook (3) and / or the thread guidance element (4) in such a way that they project through a slot-like through-opening (13) in the gripper tube flap (2) in the closed position and in the open position are arranged in the through-opening (13).

3. Thread-laying device (18) according to one or more of the preceding claims, characterized in that the gripper tube flap (2) has a guidance section resting against an outer side (20) of the flap carrier (5).

4. Thread-laying device (18) according to one or more of the preceding claims, characterized in that the gripper tube flap (2) has a closure element (12) which closes the gripper tube mouth (8) in the closed position.

5. Thread-laying device (18) according to one or more of the preceding claims, characterized in that the closure element (12) has a shape adapted to the gripper tube mouth (8), in particular is formed as a plug arranged concentrically with the gripper tube mouth (8) in the closed position.

6. Thread-laying device (18) according to one or more of the preceding claims, characterized in that the gripper tube flap (2) has a control cam (16) which can be brought into engagement with a slotted control guide.

7. Thread-laying device (18) according to one or more of the preceding claims, characterized in that the flap carrier (5) has a clamping body (11) for releasably fastening the flap carrier (5) to the gripper tube (1).

8. Thread-laying device (18) according to one or more of the preceding claims, characterized in that the gripper tube flap (2) has a planar and / or convex outer surface.