EP1331192A2 - Apparatus for pneumatically connecting the ends of yarns - Google Patents

Abstract

The invention relates to a device for pneumatic Connecting yarns, in particular elastane yarns, with a splice channel that can be pressurized with compressed air Splice prism and with holding and dissolving tubes for pneumatic preparation of the thread ends to be spliced, the central axes of the holding and dissolving tubes Cut the center longitudinal plane of the splice channel.

According to the invention it is provided that the holding and dissolving tubes (33, 34) are interchangeably fixed in bores (46, 47) of the splicing prism (25), that the inlet opening (48, 49) of the holding and dissolving tubes (33, 34) each is positioned in the immediate vicinity of one of the two exits (50, 51) of the splice channel (26) and that the inlet opening (48, 49) of the holding and dissolving tube (33, 34) has a funnel-like contour (52) which reliably swivels in a cut thread end of the upper or lower thread (31, 32) in the holding and dissolving tube (33, 34) guaranteed.

Description

The invention relates to a device for pneumatic Connecting yarns, especially elastane yarns, according to the preamble of claim 1.

Thread splicing devices for the pneumatic connection of Yarns have long been associated with winding machines known and in numerous patent specifications, for example in DE 40 05 752 A1 or DE 44 20 979 A1, in detail described.

With these known thread splicing devices, two thread ends created after a thread break or a controlled cleaner cut can be pneumatically connected in such a way that an almost identical connection point is created.
This means that the so-called upper thread, which has run onto the surface of the package in question, is picked up by means of a suction nozzle and inserted into the splice channel of the splice prism of the thread splicing devices.
Almost simultaneously, the so-called bobbin thread is also picked up by a hook tube, for example, from a pay-off spool positioned in a unwinding position and also inserted into the splice channel, where the upper and lower thread are then pneumatically connected.

This makes such a splice an almost identical connection represents and has approximately yarn strength, the both ends of the thread exactly cut to length and for the Be prepared for the splicing process.

For this purpose, the known thread splicing devices have corresponding thread clamping devices, thread cutting devices and so-called holding and opening tubes.
This means that while the two thread ends are being threaded into the splice channel by the aforementioned handling elements, they are also positioned between the holding jaws of a thread clamping device and the cutting tool of one of the thread cutting devices, the thread treatment devices belonging to a thread end being arranged on opposite sides of the splice channel ,

When both the upper thread and the lower thread are securely fixed in the associated thread clamping devices, the threads are cut to length by the corresponding thread cutting devices.
The cut ends of the thread are then sucked into the adjacent holding and opening tube and pneumatically prepared there.
This means that the thread ends are first largely freed of their twist and short fibers are removed.
Subsequently, the prepared thread ends are pulled into the splice channel of the splice prism by a so-called loop puller in such a way that they lie parallel to one another in the splice channel at approximately the same height, but have an opposite orientation.
A blast of compressed air introduced into the splice channel via corresponding inlet bores then swirls the initially essentially parallel fibers of the two thread ends, with the result that a splice of almost the same size is produced.

The described method and the corresponding device have become cleaner in practice, for example when splicing Cotton yarn or when splicing mixtures Cotton fibers and synthetic fibers, well proven.

The situation is more difficult, however, when so-called elastane yarns are to be spliced, which usually have a highly elastic core thread that is surrounded, for example, by cotton fibers.
Due to the highly elastic core thread, such elastane yarns tend to pull tightly together after a thread cut, that is to say to curl strongly.

When such elastane yarns are to be connected in one of the thread splicing devices described above, the problem frequently arises that the thread ends cannot be sucked into the holding and dissolving tubes due to their strong tendency to curl and accordingly cannot be prepared, or that the overlap of the thread ends within the splice channel of the splice prism the thread splicing device is insufficient.
As a rule, both events mean that either no splice can be created or that the splice does not meet the quality requirements.

In order to be able to splice elastane yarns, it has therefore already been proposed to arrange additional locking means in the area of the splice channel or the holding and opening tubes, which fix the thread ends after being cut to length by the thread cutting devices.
This means that they prevent the cut ends of the thread from curling too much.

EP 1 118 570 A2 shows and describes, for example, a thread splicing device, each of which has an additional thread locking means in the form of a serrated plate at the level of the holding and opening tubes.
These sheets, each of which fixes one of the thread ends, are arranged approximately halfway between the actual thread clamping device and the associated holding and opening tube.
This means that the free thread length, which tends to curl after the thread ends have been cut to length by the thread cutting device, is approximately halved by the known locking means.
With the thread splicing device designed in this way, the number of successful splice connections in elastane yarns could be increased somewhat, but the fundamental problem could not be eliminated.

This statement also applies, at least in part, to the thread splicing device described in the subsequently published DE 101 24 832 A1.
In this thread splicing device, locking means for the thread ends are arranged approximately at the level of the holding and opening tubes, by means of which the length of the lengthened thread ends, which tend to curl, is approximately halved.
The locking means according to DE 101 24 832 A1 are designed as sieves which can be pressurized and which pneumatically fix the cut thread ends on their surface.

DE 101 24 832 A1 also shows and describes an embodiment in which the locking means are positioned in the immediate vicinity of the associated holding and opening tubes.
With such an embodiment it has been possible to significantly increase the number of successful splices in elastane yarns.

The thread splicing devices according to DE 101 24 832 A1 have however, the disadvantage that they are relatively expensive and are therefore costly.

Furthermore, a thread splicing device is known from DE 34 05 304 A1, in which the splice channel arranged in the splice prism has so-called flow channels in addition to the usual compressed air injection openings.
The flow channels branch off between the compressed air injection openings and the splice channel exits laterally from the splice channel and are each connected to an injector device.
By means of this injector device, an air flow directed away from the splice channel can be generated in the flow channels, which, if necessary, should ensure that the cut thread ends are sucked into the flow channels and that the thread ends are pneumatically prepared.

However, since these flow channels branch off directly from the splice channel, the flow channels are very limited in terms of their diameter.
This means that the diameter of the flow channels must be, for example, well below the width of the corresponding splicing channel in order to ensure proper functioning of the splicing device.

Because of this relatively small diameter Flow channels have the thread splicing device according to DE 34 05 304 A1 in practice, especially when difficult, For example, relatively stiff yarn should be processed as proven almost unusable because of the small diameter of the Flow channels sucking in the usual thread loop prevents the flow channel.

Another disadvantage of these known thread splicing devices is that the flow channels are incorporated directly into the splicing prism, so that an individual adaptation of the flow channels to changing yarn parameters is very difficult and generally requires an exchange of the entire splicing prism.
In the known thread splicing device, for example, it is always necessary to replace the entire splicing prism if, for example, the thread number changes or if the thread rotation of the yarns to be processed changes, that is to say when changing from yarns with Z twist to yarns with S twist.

That means an individual adjustment of the holding and Tripping device makes known in these Thread splicers require large inventory.

Based on the aforementioned prior art, the Invention, the object of a device for pneumatic joining of yarns to create the If necessary, the splicing of problematic yarns, for example elastane yarns, and the holding and Dissolving tubes in a simple way on changing Yarn parameters are customizable.

This object is achieved by a device solved, as described in claim 1.

Advantageous embodiments of the device according to the invention are described in the subclaims.

The device according to the invention has the particular advantage that the thread ends of the upper and lower thread, which are fixed in thread clamping devices, which are arranged at a distance from the splicing prism above and below the thread splicing device, after being cut to length by appropriate thread cutting devices, immediately in the immediate vicinity the holding and dissolving tubes arranged at the outputs of the splice channel are sucked in and additionally pneumatically fixed there.
The additional pneumatic fixation of the thread ends, for example in the case of elastane yarns, also largely avoids the typical crimping of the thread ends and thus ensures the creation of proper splices in a simple and safe manner.

The funnel-like contour of the entrance opening of the holding and opening tubes ensures that even such difficult yarns are reliably sucked in.
Since the holding and dissolving tubes are interchangeably fixed in bores of the splicing prism, it is also possible at any time to adapt the holding and dissolving tubes to the respective yarn parameters, so that optimal preparation of the sucked thread ends for the subsequent splicing process can be achieved without great effort.
The necessary storage is limited to the holding and dissolving tubes.

As set out in claim 2, it is provided in an advantageous embodiment that the funnel-like contour is part of a locking means which, for example secured by an easily accessible screw bolt, fixes the associated holding and opening tube easily replaceable in a bore of the splice prism.
Such a locking means is relatively easy and inexpensive to manufacture, for example as a deep-drawn sheet metal part

In a preferred embodiment, it is also provided, as set out in claim 3, that the holding and dissolving tubes are installed in such a way that the central axis of the holding and dissolving tube runs at the level of the splice channel base.
This ensures that the thread ends fixed in the thread clamping devices are stretched centrally over the holding and opening tubes so that the thread ends are immediately subjected to the full suction of the holding and opening tubes, which has a very positive effect on the functional reliability of the holding and disintegrating tubes.

As described in claims 4 and 5, in a preferred embodiment, both the injection openings arranged in the splice channel and the holding and opening tubes are connected to a compressed air source via pneumatic lines, in which controllable valves are switched on.
The valves, for example 2/2-way valves, are connected to the winding station computer of the winding station concerned via corresponding control lines and can be controlled in a defined manner in this way without a large additional control effort being necessary.
This means that, if necessary, the opening times of the valve for the holding and dissolving tubes and the opening times of the valve for the injection openings arranged in the splice channel can be set exactly and, if necessary, adapted optimally.

As stated in claim 6, it is provided in an advantageous embodiment that the introduction of compressed air into the holding and dissolving tubes for fixing the thread ends and the introduction of compressed air into the splice channel for splicing the thread ends overlap.
Such an overlap in time prevents the thread ends of the upper and lower threads arranged in the splice channel from curling before blowing in splice air and thereby at least partially leaving the splice channel.
This means that the compressed air supply to the holding and dissolving tubes and thus the additional pneumatic fixation of the thread ends is maintained for at least a long time until it is ensured that the thread ends are already sufficiently connected to one another.

Further details of the invention are given below an embodiment shown in the drawings explained.

Fig. 1

eine Arbeitsstelle einer Kreuzspulen herstellenden Textilmaschine mit der erfindungsgemäßen Fadenspleißvorrichtung, in Seitenansicht,

Fig. 2

die erfindungsgemäße Fadenspleißvorrichtung in Draufsicht, teilweise im Schnitt,

Fig. 3

die erfindungsgemäße Fadenspleißvorrichtung gemäß Schnitt III - III,

Fig.4

ein Diagramm des zeitlichen Ablaufes der im Spleißkanal sowie in den Halte- und Auflöseröhrchen wirksamen Druckimpulse.

It shows:

Fig. 1

a side view of a textile machine producing cross-wound bobbins with the thread splicing device according to the invention, in side view,

Fig. 2

the thread splicing device according to the invention in plan view, partly in section,

Fig. 3

the thread splicing device according to section III - III,

Figure 4

a diagram of the time sequence of the pressure pulses effective in the splice channel and in the holding and dissolving tubes.

FIG. 1 schematically shows a work station 1 of a textile machine producing cross-wound bobbins, in the exemplary embodiment of a cross-wound winder, in a side view.
Such textile machines usually have a large number of such work stations 1 arranged in a row next to one another.
At the work stations 1, spinning bobbins 2, which were produced, for example, on ring spinning machines (not shown), are rewound into large-volume cross-wound bobbins 13.
For this purpose, the work stations 1 are equipped with various, schematically illustrated thread handling and thread testing devices and their own control device, a so-called winding station computer 5.

As indicated in FIG. 1, it runs from the spinning cop 2 pulled thread 3 on its way to the package 13, which in a coil frame 14 is rotatably supported and during the Winding operation frictionally via a so-called grooved drum 12 is driven, preferably by a Trigger accelerator 4, a thread tensioner 6, one Thread cleaner 8 with an associated Thread cutting device 9 and an optionally available Paraffinizing device 10.

Outside of this "regular" thread path 30 is also a thread splicing device 7 is arranged.

A suction nozzle 15 and a gripper tube 19 are also provided for handling the thread ends in the event of a thread break or a defined cleaner cut.
The suction nozzle 15, which handles the upper thread 31, has an orifice 16 which can be subjected to vacuum and is rotatably supported to a limited extent about a pivot axis 17.
The gripper tube 19, which is limitedly rotatable about a pivot axis 21 and brings the lower thread 32 to the thread splicing device 7, has a suction opening 20 which can be subjected to vacuum.

As indicated schematically in FIG. 2, the thread splicing device 7 according to the invention essentially consists of an air distributor block 24 arranged on the winding unit housing, to which a so-called splice prism 25 is fixed by means of screw bolts 23.
As usual, the splice prism 25 has a splice channel 26 into which compressed air injection openings 29 open.
The compressed air injection openings 29 are connected to a compressed air source 11 via a pneumatic line 18 connected to the air distributor block 24, into which a valve, for example a 2/2-way valve 22, is connected.
The directional control valve 22 is in turn also connected via a control line 27 to the winding station computer 5 of the relevant work station 1.

Furthermore, a holding and dissolving tube 33 and 34 is arranged in the immediate vicinity of the outputs 50 and 51 of the splice channel 26 in corresponding receiving bores 46 and 47, respectively.
The holding and opening tubes 33 and 34 are each interchangeably fixed by a locking means 53 which has a funnel-like contour 52 and positioned so that the central axes 37 and 38 of the holding and opening tubes 33 and 34 are each at the level of Bottom 55 of the splice channel 26 are arranged and are orthogonal to a central plane 45 of the splice channel 26.
The locking means 53 can be fixed on the splice prism 25, for example, by means of screw bolts 54.

The holding and dissolving tubes 33 and 34, as usual have at least one tangential bore 56 or 57 via a pneumatic line 35 into which a valve 36 is switched on, connected to the compressed air source 11, the 2/2-way valve 36 via a control line 28 from Reel station computer 5 can be controlled.

As can also be seen from FIG. 2, the Splice prism 25 also thread guide devices 39 or 40, thread clamping devices 43 and 44 as well Thread cutting devices 41 and 42 arranged.

Function of the thread splicing device according to the invention:

During winding operation, the running thread 3 is monitored by the thread cleaner 8 shown schematically in FIG. 1, which detects every thread irregularity and reports it to the spool computer 5.
The reel computer 5 then immediately initiates a defined thread cut.
That is, the running thread 3 is separated into an upper thread 31 and a lower thread 32 by the thread cutting device 9.
While the upper thread 31 runs onto the surface of the cross-wound bobbin 13 with a braking torque, the lower thread 32 usually remains held in the thread tensioner 6.

To clean the damaged piece of thread and to create a new thread connection, the upper thread 31 that has run onto the package 13 is then taken up again.
That is to say, the suction nozzle 15 is pivoted upward, as indicated by dash-dotted lines in FIG. 1, and positioned with its mouth 16 which can be subjected to negative pressure in the region of the surface of the cheese 13.
At the same time the cheese 13 rotates slowly in the unwinding direction.
As soon as the suction nozzle 15 has picked up the upper thread 31, the defective thread piece is separated and disposed of by means of a thread cutting device (not shown) arranged in the region of the suction nozzle 15.
The upper thread 31, which is now free of defects, is then threaded through the suction nozzle 15 into the splicing channel 26 of the splicing prism 25 of the thread splicing device 7, as is indicated in FIG. 2.
The suction nozzle 15 also positions the upper thread 31 in the upper thread clamping device 44 and between the tools of the lower thread cutting device 41.

The lower thread 32 is also taken up at the same time or at a slightly different time from the take-up of the upper thread 31.
This means that the hook tube 19 picks up the lower thread 32, which is usually fixed in the thread tensioner 6 after a controlled thread cut, on the thread tensioner 6 and also places it in the splice channel 26 of the splice prism 25 of the thread splicing device 7.
Like the upper thread 31, the lower thread 32 is also threaded into an associated lower thread clamping device 43 and an upper thread cutting device 42.
As soon as the two threads 31 and 32 are inserted into the splice channel 26 and mechanically fixed in the thread clamping devices 43 and 44, the holding and dissolving tubes 33, 34 are acted upon with compressed air by appropriate actuation of a valve 22.
The threads 31 and 32 are then cut to length by the thread cutting devices 41 and 42, respectively.

This means that the winding unit computer 5 first controls the directional control valve 36 in the sense of "open" via the signal line 28, so that a relatively strong suction flow is present in the area of the inlet openings 48 and 49 of the holding and dissolving tubes 33 and 34.
After the upper and lower thread 31, 32 have been separated by the thread cutting devices 41 and 42, the cut thread ends are first disposed of via the suction nozzle 15 or the gripper tube 19, and at the same time the free thread ends of the upper thread 31 and the lower thread 32 via the funnel-like contour 52 Locking means 53 sucked into the holding and opening tubes 33 and 34, respectively.
The thread ends of the upper and lower threads 31, 32 are thereby fixed pneumatically and thus prevented from curling too much.
Due to the compressed air flowing in via the tangential bores 56 and 57 of the holding and opening tubes 33 and 34, the thread ends of the upper and lower thread are also pneumatically prepared in accordance with the regulations.
This means that the thread ends of the upper and lower threads sucked into the holding and dissolving tubes 33 and 34 are largely freed of their twist and of short fibers.

The prepared thread ends are then, as is known and therefore neither shown nor explained in detail, pulled into the splice channel 26 of the thread splicing device 7 by a so-called loop puller and pneumatically connected there.
That is, the winding unit computer 5 controls the 2/2-way valve 22 via a signal line 27 in such a way that splice air is blown into the splice channel 26 via the pneumatic line 18 and the compressed air injection openings 29, which initially largely parallel fibers of the two thread ends swirled together and thereby creates a thread connection.

While the thread ends through the loop puller in the Splice channel 26 are withdrawn, the holding and Dissolving tubes 33, 34 pressurized air, so that the Thread ends of upper and lower thread due to the in the holding and Dissolving tubes 33, 34 prevailing injector flow in Direction of the holding and dissolving tubes 33, 34 with a pneumatic holding force can be applied.

The injector flow in the holding and dissolving tubes 33, 34 remains at least until the introduction of the first Maintain splice of air into the splice channel 26.

In a preferred embodiment, the compressed air pulse 58 for fixing the thread ends in the holding and dissolving tubes 33, 34, as indicated in FIG. 4, is switched on at a time t ₁ and remains until the later time t ₃ .
In contrast, the compressed air pulse 59 for splicing the two thread ends at almost the same thread is present between times t ₂ and t ₄ .
This means that the compressed air pulse 58 for splicing the thread ends and the compressed air pulse 59 for fixing the thread ends in the holding and dissolving tubes 33, 34 overlap in time.

Claims (6)

Device for the pneumatic connection of yarns, in particular elastane yarns, with a splicing prism which can be pressurized with compressed air and with holding and dissolving tubes for the pneumatic preparation of the thread ends to be spliced, the central axes of the holding and dissolving tubes intersecting the central longitudinal plane of the splicing channel,
characterized in that the holding and dissolving tubes (33, 34) are interchangeably fixed in bores (46, 47) of the splice prism (25),
that the input opening (48, 49) of the holding and dissolving tubes (33, 34) is positioned in the immediate vicinity of one of the two outputs (50, 51) of the splice channel (26) and
that the input opening (48, 49) of the holding and dissolving tube (33, 34) has a funnel-like contour (52) which reliably swivels a cut thread end of the upper and lower thread (31, 32) into the holding and dissolving tube (33, 34) guaranteed. Device according to claim 1, characterized in that the funnel-like contour (52) is part of a locking element (53) which can be fixed on the splice prism (25) by means of at least one screw bolt (54). Device according to claim 1, characterized in that the central axis (37, 38) of the holding and dissolving tube (33, 34) runs at the level of the base (55) of the splice channel (26). Device according to claim 1, characterized in that injection openings (29) and tangential bores (56, 57) arranged in the splicing channel (26) of the splicing prism (25) in the holding and dissolving tubes (33, 34) via pneumatic lines (18 and 35) and controllable valves (22 or 36) are connected to a compressed air source (11). Apparatus according to claim 4, characterized in that the valves (22 or 36) are connected to a winding station computer (5) via control lines (27 or 28) and can be controlled so that the thread ends (31 or 32) into the holding and opening tubes (33 or 34) are pneumatically fixed at least until a first burst of splice air is introduced into the splice channel (26) of the splice prism (25). Apparatus according to claim 5, characterized in that the valves (22, 36) can be controlled in such a way that a compressed air pulse (59) introduced into the holding and opening tubes (33 or 34) and one into the splice channel (26) of the splice prism (25) the splicing air pulse (58) introduced overlap in time.

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