EP1219737A1 - Procedure for piecing up or joining a yarn created in a spinning station, said spinning station being equiped to carry out the procedure - Google Patents

Abstract

Following interruption of a spinning process, a new section of fibre is joined to an existing section by overlapping end sections. The incoming fibre is first drawn out (L.2) and presented to the existing drawn out terminal section (L.1) of prior thread (4) in the spinning machine in a synchronised action. Also claimed is a spinning machine has a spinning point at which the fibre feed is first drawn out, twisted and discharged as yarn. If the process is interrupted e.g. because of a thread break, the fibre drawing out process is halted at the drawing out inlet. The yarn (11) free end is drawn out, tapered, positioned prior to the twist unit. When the spinning process resumes, the movement of the incoming fibre is synchronised with that of the yarn (1) causing the two sections to overlap and combine.

Description

The invention is in the field of spinning technology and relates to a method the preamble of the first claim. The method according to the invention serves for attaching a yarn that is in a spinning machine or in a spinning station Spinning machine is formed from a staple fiber material, for example after a Can change, after a bobbin change, after a yarn break or after a other spinning disorder. The method can also be used for piecing means for the restart of a spinning process. The invention further relates to one for the Implementation of the method equipped spinning station according to the Preamble of the corresponding independent claim.

Spinning machines for spinning staple fiber materials usually have one large number of spinning stations, with one in each spinning station Longitudinal fiber a yarn is spun. The longitudinal fiber structure is the first refined, that is, the amount of fibers per unit length is reduced by warping. Then the refined fiber structure becomes a yarn by twisting spun which yarn is then drawn off and wound up. For the refinement the longitudinal fiber structure is stretched, for example, by means of a drafting system or with the help an opening roller. For twine formation are various methods known: e.g. Ring spiders, pot spiders, bell spiders, Friction spinning, rotor end spinning, air spinning etc.

After an interruption in the spinning process in which the connection between the spun yarn and the refined fiber structure to be spun is broken, this connection must be reestablished, not only with it the yarn produced is uninterrupted, but also so that the spinning process again can be started. For such a reconnection of yarn and fiber structure in the case of air spinning processes in particular, the free one resulting from the interruption End of yarn against the normal direction of yarn upstream over the Swirl issuing point pulled out and positioned. Then the yarn take-off and the Twist is put back into operation and the free start of the refined The fiber structure is fed to the twist in such a way that during a short transition period of the end area of the yarn and the beginning area of the Move the fiber assembly together through the twist distribution point. In doing so by the twisting the fibers of the fiber structure with the fibers of the yarn end area swirled and the beginning of the fiber structure with the End area of the yarn connected in a kind of splice, which makes the spinning process can be operated normally again.

When piecing, that means when restarting a spinning process, in proceed in the same way, instead of the end of the before An auxiliary yarn is used to produce spinning interruption.

• Damit die Ansetzstelle eine störungsfreie Fortsetzung des Spinnvorganges erlaubt, muss diese selbst und ihre Umgebung eine für diesen Zweck genügend grosse Reissfestigkeit aufweisen, das heisst üblicherweise, dass diese Reissfestigkeit mindestens so gross sein soll, wie die Reissfestigkeit des im vorliegenden Spinnvorgang hergestellten Garnes.
• Damit die Ansetzstellen die Garnqualität nicht mindern, darf die Fasermasse pro Längeneinheit in der Ansetzstelle und in deren Umgebung nur in vorgegebenen, meist engen Grenzen von der Fasermasse pro Längeneinheit des im vorliegenden Spinnvorgang hergestellten Garnes abweichen.

The following requirements are placed on the attachment point that arises when attaching or piecing using the method briefly described above:

• In order for the attachment point to allow the spinning process to continue undisturbed, it and its surroundings must have a tear strength sufficient for this purpose, which usually means that this tear strength should be at least as great as the tear strength of the yarn produced in the present spinning process.
• So that the attachment points do not reduce the yarn quality, the fiber mass per unit length in the attachment point and in its vicinity may only deviate from the fiber mass per unit length of the yarn produced in the present spinning process within specified, usually narrow limits.

In other words, this means those to be produced in the case of spinning interruptions Attachments should be the same with regard to strength and fiber mass per unit length differ as little as possible from the other areas of the yarn produced. They should be as little as possible visible or otherwise detectable and they should the continued use of the yarn, starting with the continuation of the Affect the spinning process as little as possible.

Various methods are known to try, the above To get closer to goals. These methods apply to the free end of the yarn, the free Start of the refined fiber structure and / or at the timing of the Movement of the yarn end area and the fiber assembly start area through the Swirl on.

For example, the yarn end region is known from publication DE-4240653-A1 to roughen, or fiber ends from the dense fiber structure of the yarn to loosen and spread from the yarn, causing the intermingling with the new fed fibers improved and the tear strength of the attachment point is increased.

From the same publication it is also known to use the yarn end region in such a way Prepare the splice that the fiber mass gradually towards the end of the yarn decreases so that the yarn tapers towards its end. Such a self tapering yarn end area is then used for splicing with a corresponding tapered beginning of a longitudinal fiber structure (gradually increasing fiber mass) overlapped through the swirl distribution point.

The use of a "tapered" initial area of a fiber assembly for the Preparation is described, for example, in publication US-5802831 (Murata). According to this publication, a fiber longitudinal structure is combined in one before the twist is given The drafting system warped, the drafting system being a draft zone and has a main draft zone on the outlet side. After an interruption of the Spinning process is the entry of the longitudinal fiber structure into the drafting system and the Early arrears stopped. By not stopping the main default, that becomes Longitudinal fiber structures torn between the pre-draft zone and the main draft zone and forms a free start there. After the interruption, the enema and the Advance delay is synchronized with the twist distribution and the yarn take-off coupled again to the corresponding drive. The beginning of the Longitudinal fiber structure, which is believed to become one by tearing off has a tapered shape, it is first subjected to the main default, whereby it is assumed that the mentioned taper is stretched accordingly and thereby providing an improved attachment point.

The method according to US-5802831 is according to the publications US-5809764 and US-5934058 (both Murata) still refined, in that the tapered Initial area of the longitudinal fiber structure before stretching by tearing off one small piece is shortened, and in that in a draft that is between Drafting device and swirl distribution point is used, the fiber mass of this Initial area is also specifically reduced.

It turns out that it is difficult to find a starting point with the methods mentioned create that can meet the highest demands. The after the named Yarns used in methods tend to be immediately after a point of attachment Show weak point with too small a fiber mass or the fiber mass is too big in the area of the attachment point.

For this reason, the attachment point is usually compared to the remaining yarn up to 200% increased fiber mass for piecing sufficient tear resistance is given and the attachment points are up to 200 mm can be long, subsequently detected with a yarn cleaner and subsequently created splices replaced. Obviously, this is a very complex process.

The object of the invention is now a method for preparation or piecing to show the method with which attachment points can be produced, which both to meet higher demands in terms of strength and fiber mass assets than is the case for attachment points manufactured according to known methods. Furthermore, it is the object of the invention to create a spinning station which is suitable for the Implementation of the method according to the invention is equipped.

These tasks are solved by the process and the spinning station as described in the Claims are defined.

The method according to the invention is based on the knowledge that usually a if the spinning process is interrupted by tearing one Longitudinal fiber structure produced initial area has no significant taper and / or that such an initial area is not suitable even for stretching Creation of a satisfactory location is sufficient. According to the invention So the process does not become a process created by tearing and thereby if necessary, the tapered initial area is subject to normal distortion, but it is controlled by the delay in the refinement step an initial area with an increasing fiber mass is specifically formed. To this Purposes is in the resumption of spinning during a The piecing phase advantageously entrains the longitudinal fiber structure in the refinement so controlled on the run of the refined fiber structure from the refinement agreed that the delay gradually decreases and thereby the expiring Fiber dressing has a gradually increasing amount of fibers over its length. It is essentially ensured by a run-in control that the delay gradually decreases in the refinement step (increasing inlet speed) until it assumes a value suitable for a normal spinning process. The Outfeed speed of the refined fiber structure from the refinement (or Delivery speed in the yarn formation) can decrease during the period of time Delay may be constant (as for normal spinning process) or may be in adjustment a corresponding increase in the yarn formation speed for a problem-free Spinning on your part will be gradually increased.

The time during which the delay of the inducted into the refinement Longitudinal fiber structure is reduced to a normal value, and that Speed profile of this draft reduction is based on the length and shape of the to match the tapering yarn end area. The movement of the yarn end area through the swirl issuing point is so timed on the movement of the initial area of the fiber structure delivered from the refinement that the two tapering areas overlapping each other as completely as possible through the Twist are moved and complement each other to form a fiber mass that as little as possible of the fiber mass during the normal spinning process created yarn differs.

One equipped for carrying out the method according to the invention Spinning station, like known spinning stations, has a refinement agent, a swirl imparting agent and a yarn take-off means. Here are inlet-side parts of the Refining agent independent of the outgoing parts of the refining agent controllable for a piecing routine, which piecing routine essentially therein there is, the distortion that the longitudinal fiber structure experiences in the refining agent from gradually reduce an increased value to a normal value. The parts of the refining agent on the outlet side and the means for pulling off the yarn can are operated at normal speeds during the piecing routine or also a piecing routine with gradually increasing speeds run through.

The spinning station equipped for carrying out the method according to the invention thus has its own controllable drive for the infeed side internally Parts of the refinement or a correspondingly controllable gear between this inlet-side parts of the refining agent and a central drive. The other parts of the spinning station to be driven can be connected simply to central drives or also through internal spinning stations, if necessary controllable drives are driven.

The spinning station is also equipped in a manner known per se so that the free End of yarn positioned upstream of the twist distribution point and with the Recommissioning of the refining agent can be deducted in a timed manner can, and for the fact that the supplied longitudinal fiber structure before the resumption of the Spinning process in a precisely defined and advantageously precise reproducible type is separated or torn.

Figur 1

eine nach dem erfindungsgemässen Verfahren hergestellte Ansetzstelle;

Figur 2

ein Schema einer Anspinnroutine zur Durchführung des erfindungsgemässen Verfahrens;

Figuren 3 und 4

im Schnitt schematisch dargestellte Beispiele von Spinnstellen, die für die Durchführung des erfindungsgemässen Verfahrens ausgerüstet sind.

The method according to the invention and the spinning station according to the invention are described in detail with reference to the following figures. Show:

Figure 1

a attachment point produced by the method according to the invention;

Figure 2

a diagram of a piecing routine for performing the method according to the invention;

Figures 3 and 4

Examples of spinning stations schematically shown in section, which are equipped for carrying out the method according to the invention.

FIG. 1 shows very schematically a tapering, free end region 1 of a yarn 11 to be drawn off in the drawing-off direction A and a free beginning region 2 of a refined fiber structure 10 fed in the feed direction Z with a fiber mass which increases in accordance with the tapering of the yarn, the end region 1 of the yarn 11 and the initial area 2 of the fiber structure 11 overlap for a piecing process. Furthermore, the figure shows an attachment point 3 in the finished yarn resulting from the connection of the two areas 1 and 2.
The yarn end region 1 has a fiber mass which decreases towards the yarn end over a taper length L.1. The fiber bandage initial region 2 is essentially adapted to the tapering of the end region of the yarn 11, the tapering being continuous or also more or less stepped, and has approximately the same length L.2. The lengths L.1 and L.2 are, for example, approximately 80 mm. The overlap of yarn end area 1 and fiber assembly start area 2 is advantageously such that the fiber mass in the attachment point 3 is slightly larger than in the normally spun yarn. With this increase in fiber mass, the somewhat reduced fiber adhesion can be compensated for in the attachment point 3. It has been shown that attachment points can be produced with the method according to the invention which have sufficient tear strength and which at no point have a fiber mass which is more than about 20% higher than the average fiber mass per unit length of the yarn. In particular, there is no need to reckon with places of significantly reduced fiber mass and therefore with reduced tear strength neither in the attachment point nor in its immediate vicinity.

Figure 2 shows very schematically the control of the piecing routine according to the inventive method. The spinning process is shown on the left, in which a longitudinal fiber structure 10 'is fed in, drawn into a refined fiber structure 10 and spun into a yarn 11. The fibers pass through a refinement inlet 12 (possibly combined with a pre-refinement), a refinement outlet 13 and the yarn formation 14 (twist distribution and yarn take-off).

On the left are the speeds G.1 (running-in speed) on each time axis, G.2 (discharge or delivery speed) and G.3 (yarn take-off speed) three levels are shown and in particular their change when the Spinning process and a subsequent piecing routine according to the invention. During a normal spinning process, these speeds are as in the Figure 2 shown before the time t.1, constant or they vary in one coordinated way. The ratio of G.1 and G.2 determines in essentially the delay of the refinement step, the ratio of G.2 and G.3 the spinning delay.

Time t.1 marks an interruption in the spinning process (can change, Bobbin change, spinning disorder) and the period between the times t.3 to t.5 or t.6 the piecing routine. There is a gap between the interruption and the piecing routine Interruption of the spinning process, in which the for the restart of the spinning process necessary measures are carried out, in particular the preparation of the free yarn end and its positioning upstream of the Twist imparting zone. This interruption can vary depending on the reason for the interruption and vary in length according to machine equipment.

t.1:

Anhand eines entsprechenden Unterbrechungssignals werden der Verfeinerungseinlauf 12 und die Garnbildung 14 (insbesondere der Garnabzug, gegebenenfalls auch die Drallerteilung) gestoppt.

t.1 bis t.2:

das zugeführte Faserlängsgebilde 10 wird an einer definierten Stelle zwischen Einlauf und Auslauf zerrissen und das abgerissene Stück aus der Verfeinerung läuft aus der Verfeinerung aus und kann entsorgt werden.

t.2:

Mit einer vorgegebenen Verzögerung gegenüber dem Verfeinerungseinlauf 12 wird auch der Verfeinerungsauslauf 13 gestoppt.

t.3:

Nach Durchführung der zur Wiederaufnahme des Spinnprozesses notwendigen Massnahmen, insbesondere nach der Positionierung des entsprechend vorbereiteten freien Garnendes mit Verjüngung werden der Verfeinerungsauslauf 13 und die Garnbildung 14 (insbesondere der Garnabzug) wieder in Betrieb genommen und zwar im wesentlichen sofort mit Geschwindigkeiten, wie sie für den normalen Spinnprozess eingestellt werden (durchgezogene Linien), oder nach einer Ansprinnroutine, die beispielsweise eine Geschwindigkeitssteigerung über eine vorgegebenen Zeit vorsieht (unterbrochene Linien). Vom Zeitpunkt t.3 an bewegt sich das Garnende gegen die Drallerteilung.

t.4:

Der Verfeinerungseinlauf 12 wird gestartet. Der Zeitpunkt t.4 wird für eine genaue zeitliche Übereinstimmung der Bewegungen von Garn-Endbereich und Faserverband-Anfangsbereich vorteilhafterweise durch sensorische Überwachung des Garnendes bestimmt. Dieses wird vom Zeitpunkt t.3 an gegen die Drallerteilung abgezogen und erzeugt ein Signal, wenn es eine vorgegebene Position erreicht. Der Zeitpunkt t.4 ist gegenüber dem Garnende-Signal verzögert, wobei die Verzögerung im wesentlichen durch die Position des Garnende-Sensors und des Anfangs des Faserlängsgebildes und durch die Länge (L.1, Figur 1) des sich verjüngenden Garnendes bestimmt ist.

t.4 bis t.5:

Während diesem Zeitraum wird die Geschwindigkeit des Verfeinerungseinlaufs 12 allmählich erhöht und erreicht zum Zeitpunkt t.5 einen Wert, der zusammen mit der momentanen Auslaufgeschwindigkeit den vorgegebenen (normalen) Verzug ergibt. Während dem Zeitraum t.4 bis t.5, dessen Länge auf die Länge (L.1, Figur 1) des vorbereiteten, sich verjüngenden Garnendbereichs abgestimmt ist, entsteht durch die relativ zur Auslaufgeschwindigkeit zunehmende Einlaufgeschwindigkeit eine Abnahme des Verzugs und damit die steigende Fasermasse des Faserverband-Anfangsbereichs (2, Figur 1).

t.5:

Zu diesem Zeitpunkt hat für die ausgezogen dargestellte Variante die Einlaufgeschwindigkeit den normalen Wert erreicht und die Anspinnroutine ist damit beendet.

t.5 bis t.6:

für die gestrichelt dargestellte Variante ist in diesem Zeitraum die Spleissung wie für die ausgezogen dargestellte Variante zwar beendet, wird aber noch die Spinngeschwindigkeit (G.1, G.2, G.3 und gegebenenfalls auch die Drallerteilungsgeschwindigkeit) auf ihren Normalwert hochgefahren, wobei die einzelnen Geschwindigkeiten sich zueinander verhalten wie während dem normalen Spinnprozess. Die Anspinnroutine gemäss der gestrichelt dargestellten Variante ist zum Zeitpunkt t.6 beendet.

The spinning interruption and the piecing routine run as follows for the successive steps of the spinning process according to the method according to the invention:

t.1:

The refinement inlet 12 and the yarn formation 14 (in particular the yarn take-off, optionally also the twist distribution) are stopped on the basis of a corresponding interruption signal.

t.1 to t.2:

the supplied longitudinal fiber structure 10 is torn at a defined point between the inlet and the outlet and the torn piece from the refinement runs out of the refinement and can be disposed of.

t.2:

With a predetermined delay compared to the refinement inlet 12, the refinement outlet 13 is also stopped.

t.3:

After carrying out the measures necessary to resume the spinning process, in particular after positioning the appropriately prepared free yarn end with a taper, the refinement outlet 13 and the yarn formation 14 (in particular the yarn take-off) are put into operation again, essentially immediately at speeds such as those for the normal spinning process can be set (solid lines), or according to a start-up routine that, for example, provides for an increase in speed over a predetermined time (broken lines). From time t.3 on, the end of the yarn moves against the twist.

t.4:

Refinement inlet 12 is started. The time t.4 is advantageously determined by sensory monitoring of the yarn end for an exact temporal correspondence of the movements of the yarn end area and the fiber bundle start area. This is subtracted against the moment of twist from time t.3 and generates a signal when it reaches a predetermined position. The time t.4 is delayed compared to the yarn end signal, the delay being essentially determined by the position of the yarn end sensor and the beginning of the longitudinal fiber structure and by the length (L.1, Figure 1) of the tapering yarn end.

t.4 to t.5:

During this period, the speed of the refinement inlet 12 is gradually increased and reaches a value at time t.5 which, together with the current outlet speed, gives the predetermined (normal) delay. During the period t.4 to t.5, the length of which is matched to the length (L.1, FIG. 1) of the prepared, tapering yarn end region, the warping speed increases relative to the outlet speed and thus the fiber mass increases of the fiber structure start area (2, Figure 1).

t.5:

At this point, the running-in speed has reached the normal value for the variant shown in full line and the piecing routine is ended.

t.5 to t.6:

for the variant shown in dashed lines the splicing has ended in this period as for the variant shown in full line, but the spinning speed (G.1, G.2, G.3 and possibly also the twist distribution speed) is increased to its normal value, the individual speeds are related to each other as during the normal spinning process. The piecing routine according to the variant shown in dashed lines ends at time t.6.

Possible variants for piecing routines, as illustrated in FIG. 2, exist for example in that the refinement outlet 13 during the Spinning interruption (t.1, or t.2 to t.3) is not stopped at all. Another variant is that the yarn formation 14 (especially the yarn take-off) only with the Outlet 13 can be stopped at time t.2 or even later. Another variant is that the piecing routine related to yarn formation is shorter than that Time required to create the attachment point (t.6 before t.5).

A control unit must be provided to control the piecing routine. This is data to provide the length and profile of the tapering of the yarn end area or to transmit corresponding measurement data on-line from a mass sensor which Mass sensor detects the fiber mass of the yarn end area. The control unit controls at least the speed of the refinement inlet for execution the piecing routine.

FIG. 3 shows an exemplary embodiment of a spinning station for carrying out the method according to the invention. This spinning station is equipped for a so-called air spinning process with refinement by stretching. The spinning station has a nozzle block 21 with nozzles 22 embedded therein, a spindle 23 with a yarn channel 24 and a feed block 25 with a fiber feed channel 26 and a needle 27 directed towards the entrance of the yarn channel 24 for the purpose of twisting. For refinement, the spinning station has a drafting system 28 with, for example, three pairs of cylinders (inlet cylinder 29, middle cylinder 30 with straps 31 and outlet cylinder 32).

The inlet of the drafting system 28, for example the inlet cylinder 29 and the Center cylinder 30 with straps 31 are driven by a motor 33. The Motor 33 can be controlled by a control unit 34. The control unit 34 is used for Control of the motor 33 a ready signal 35 and a yarn end signal 36 one Yarn end sensor 37, as well as parameters and data relating to the spinning station Tapering of the yarn end area.

During the known spinning process in the spinning station according to FIG. 3 the fiber longitudinal structure 10 'fed in the feed direction Z runs between the Inlet cylinders 29 in the refinement, and is between inlet cylinders 29 and Center cylinders 30 an advance with a usually constant Stretching ratio and between center cylinders 30 and outlet cylinders 32 one Main default with a possibly variable stretch ratio. The refined fiber longitudinal structure 10 is from the outlet cylinders 32 through the Fiber feed channel 26 sucked against the entrance of the yarn channel 24. Through the Compressed air supplied to nozzles 22 produces, in addition to the aforementioned suction, in the area of the twine channel entrance is a vortex flow that serves to impart twist. That through this twist distribution resulting yarn 11 is through the yarn channel 24 in Trigger direction Z (trigger means not shown) deducted.

If the spinning process is interrupted, the motor 33 is stopped while the Outlet cylinder 32 at least for a limited period (t.1 to t.2, Figure 2) continue. As a result, the supplied fiber longitudinal structure 10 'between the Straps 31 and the outlet cylinders 32 torn and the downstream Piece conveyed away by the outlet cylinder 32 from the drafting system, so that it can be disposed of.

For the known positioning of the free yarn end after a Interrupting the spinning process are, for example, the upper part of the Feed blocks 25 and the top of outlet cylinders 32 from their working position can be lifted off such that the fiber feed channel 26 and the passage between the Outlet cylinders 32 for positioning the yarn end area 1 is accessible. The yarn end region 1 is in a spinning station equipped for this purpose Resumption of the spinning process up to the main warpage between Center cylinders 30 or straps 31 and outlet cylinders 32 withdrawn and hangs freely around the lower one of the outlet cylinder 32, where it is from the yarn end sensor 37 is monitored.

The yarn end area 1 can be used to resume the spinning process after a Interruption also between the outlet cylinders 32 and the feed block 25 or be positioned between the feed block 25 and the nozzle block 21, wherein for the latter case, a corresponding gap between the two blocks 25 and 21 must be provided through which the yarn end region 1 is positioned and then can be easily removed. These two variants are shown in FIG. 3 dash-dotted lines and the correspondingly positioned yarn end areas designated 1 'and 1 ". The yarn end sensor 37 is for the variants mentioned to position accordingly.

The piecing routine, as shown in solid lines in FIG. 2, is shown in one Spinning station, as shown in Figure 3, controlled as follows: If that Yarn end (1, 1 'or 1 ") positioned and all relevant parts of the spinning station in their Are repositioned, the control unit 34 is, for example, by Staff or a piecing robot transmits the ready signal 35. The The control unit then starts the refinement outlet, the twist distribution and the Yarn take-off (if necessary with a predetermined staggering) so that the yarn end begins to move against the swirl issuing point. As soon as the yarn end sensor 37 detects the passing of the effective yarn end, the control unit receives it End of yarn signal 36, by which the actual piecing routine is started. To one by the relative position of yarn end sensor 37 and beginning of Longitudinal fiber structure (relevant spinning station parameters) and by the length of the prepared, tapered yarn end area is the delay Motor 33 started and after a to the taper profile of the yarn end area adjusted ramp raised.

So that the ramp mentioned can be specified, it is necessary that prepared yarn end areas a reproducible and well-known taper exhibit. If this is not the case, it is also possible to use one accordingly positioned mass sensor to measure the yarn end area online and the To control the increase in the running-in speed on the basis of the generated measurement signal. For example, the yarn end sensor 37 can also function as the mass sensor take.

For a piecing routine, as shown in broken lines in FIG Control unit 34 also contains data relating to the start-up profile of outlet cylinders 32 and To provide yarn take-off and, if necessary, measurement data from accordingly arranged speed sensors.

If necessary, the swirl can be issued, that is to say in the present case Speed of the air supplied from the nozzles 22 for the production of the Position changed compared to the normal spinning process, for example for one stronger fiber interlacing can be increased.

The drafting system 28, which is connected upstream of a twist in a spinning station, can also have only two or more than three pairs of cylinders, with one Spinning interruption is an inlet-side part of the cylinder pairs in front of an outlet-side Part of the cylinder pairs is stopped and at least after the spinning interruption the inlet-side part of the cylinder pairs according to a predetermined or based on Sensor signals determined ramp is raised.

The above description of the spinning station shown in FIG. 3 shows that the piecing routine according to the inventive method in particular the Refinement concerns and that the effective yarn formation in many cases does not is affected. For this reason, the method according to the invention for Applying or piecing can also be used for other spinning processes.

FIG. 4 shows a spinning station in which the twist is again generated by a vortex flow, as has already been described in connection with FIG. 3. The supplied longitudinal fiber structure 10 'is not refined by stretching in a drafting system but by fiber separation. The refining agent therefore has a feed roller 40 and a dissolving roller 41 and can furthermore have a suction roller 42 and a take-off roller 43. The spinning station shown in FIG. 4 and in particular the refining agent and its function are described in Swiss patent application No. 0753/00 (Obj. 2828). The warping takes place between the feed roller 40 and the opening roller 41. The further rollers following the opening roller 41 serve to separate dirt particles and to collect the individual fibers to form a fiber structure. In any case, the feed roller 40 represents the refinement inlet and the further rollers (41, 42, 43) following the feed roller 40 represent the refinement outlet.

If the spinning is interrupted, the feed roller 40 (motor 33) is stopped and will be the opening roller 41 and the subsequent rollers 42 and 43 as long as necessary continue to operate until they are substantially free of fibers. Then it will prepared yarn end 1, for example, positioned around the suction roller 42 (or between feed block 25 and suction roller 42 or between nozzle block 21 and Feed block 25), in which area the yarn end sensor 37 is arranged. After this has been carried out, the spinning process can be restarted All parts of the spinning station except for the feed roller 40 are in operation taken and operated at speeds necessary for a normal spinning process are common. This starts the end of the yarn towards the twist distribution point move. The feed roller is after the yarn end signal and a suitably long Delay started and its speed increased via a suitable ramp, as this in connection with Figure 3 for the inlet cylinder and central cylinder of the Drafting system was described.

For a piecing routine according to the variant shown in broken lines in FIG Description of Figure 3 applicable accordingly.

Claims (18)

Method for attaching or piecing after an interruption of a spinning process in a spinning station of a spinning machine, in which spinning process a longitudinal fiber structure (10 ') is refined by warping with a predetermined value, a yarn (11) is produced from the refined fiber structure (10) by twisting and the yarn (11) is withdrawn from the twist distribution, the longitudinal fiber structure (10 ') being torn between a refinement inlet and a refinement outlet for the attachment or piecing, a tapering yarn end region (1) is produced at a free yarn end, the free end of the yarn is positioned upstream of the twist distribution and a fiber bundle start region (2) and the yarn end region (1) are fed to the twist distribution in such a timed manner that they are subjected to the twist distribution overlapping one another, characterized in that in order to produce a to the tapering of the yarn end area ( 1) adapted increasing fiber mass in the fiber bandage initial area (2) the warping of the longitudinal fiber structure (10) is reduced from an increased value to the predetermined value in an initial phase of the spinning process. Method according to Claim 1, characterized in that data relating to the length and profile of the tapering yarn end region (1) or measurement data of a mass sensor which registers the fiber mass of the yarn end region (1) on-line is used to control the reduction of the warp. A method according to claim 1 or 2, characterized in that to reduce the delay, the speed (G.1) of the refinement inlet is increased until the ratio of the speeds (G.1 and G.2) of refinement inlet and refinement outlet has a delay with the predetermined one Result in value. Method according to one of claims 1 to 3, characterized in that the speeds (G.2 and G.3) of the refinement outlet and the yarn take-off are kept constant while increasing the speed (G.1) of the refinement inlet. Method according to one of claims 1 to 3, characterized in that the speeds (G.2 and G.3) of the refinement outlet and the yarn take-off are also increased while the speed (G.1) of the refinement inlet is increased. Method according to one of claims 1 to 5, characterized in that the reduction of the delay is initiated by a sensor-determined yarn end signal (36). Method according to one of claims 1 to 6, characterized in that a vortex flow is used to impart swirl. Method according to one of claims 1 to 7, characterized in that the refinement is an extension between successive pairs of cylinders (29, 30, 32). A method according to claim 7, characterized in that the stretching comprises a preliminary delay and a main delay, the preliminary delay remaining unchanged during the reduction of the delay. Method according to one of claims 1 to 7, characterized in that the refinement comprises a fiber separation by means of an opening roller (41) and that to reduce the distortion the speed of a feed roller (40) feeding the longitudinal fiber structure (10 ') of the opening roller (41) increases becomes. Spinning station of a spinning machine with a refining agent which has drivable parts on the inlet and outlet sides, with a means for imparting twist and with a means for extracting yarn from the twist imparting, characterized in that the inlet-side parts (29 and 30, 40) of the refining agent are independent of others Parts (32, 41 and 42) of the refining agent and the spinning station and can be driven in a controlled manner independently of other spinning stations and that the spinning station has a control means (34) with which the speeds of the inlet-side parts (29 and 30, 40) of the refining agent after one predetermined profile or can be increased on the basis of sensor-acquired data. Spinning station according to Claim 11, characterized in that parts (32, 41 and 42) of the refinement means on the outlet side and the means for thread take-off for carrying out a piecing routine can also be driven independently of other parts. Spinning station according to claim 11 or 12, characterized in that the spinning station has a yarn end sensor (37) for the initiation of a piecing routine. Spinning station according to one of claims 11 to 13, characterized in that the control means (34) is equipped to receive a ready signal (35) and / or further data, and to adapt the piecing routine accordingly. Spinning station according to one of claims 11 to 14, characterized in that the means for imparting swirl comprises nozzles (22) which are arranged to generate a vortex flow. Spinning station according to one of claims 11 to 15, characterized in that the refining means is a drafting device (28) with at least two cylinder pairs (29, 30, 32) and that the speed of at least one inlet cylinder pair (29) can be increased in a controlled manner. Spinning station according to claim 16, characterized in that the drafting device has a pair of inlet cylinders (29), a pair of central cylinders (30) with straps (31) and a pair of outlet cylinders (32) and in that the speed of the inlet cylinders (29) and the central cylinder (30) with the straps (31) can be increased in a controlled manner. Spinning station according to one of claims 11 to 15, characterized in that the refining means has a feed roller (40) and a dissolving roller (41) and that the speed of the feed roller (40) can be increased in a controlled manner.

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