Yarn-feeding/recovering method for textile machines, and apparatus for carrying out such method

Description

[0001] The present invention relates to a yarn-feeding/recovering method for textile machines and to an apparatus for carrying out such method.

[0002] In the textile field, weft feeders are known which are provided with a stationary drum on which a motorized swivel arm winds a plurality of yarn loops forming a stock. The yarn, which is unwound from the drum upon request of a textile machine arranged downstream, is subject to a stabilizing brake that maintains the unwinding yarn under a slight tension. The stabilizing brake typically comprises a frustoconical hollow member which is biased with its inner surface against the delivery edge of the drum by manually adjustable elastic means.

[0003] As described in EP 2031106, in order to maintain the feeding tension substantially constant, a controlled brake may be arranged downstream of the feeder, e.g., a foil-based brake of the type described in EP 0622485. This brake is controlled by a feedback loop which receives a measured tension signal from a sensor, then compares it with a reference tension which is indicative of a desired tension, and finally modulates the braking action in such a way as to minimize the difference between the reference tension and the measured tension.

[0004] Feeders are also known in which the yarn is wound on a rotary drum, which draws the yarn from a reel and feeds it to the downstream textile machine. In this case, the tension of the yarn unwinding from the feeder is controlled by modulating the speed of rotation of the drum, always on the basis of a signal received from a tension sensor as in the previous case. Accordingly, in other words, the change of tension to be applied is determined by the difference between the yarn-feeding speed and the yarn-drawing speed set in the downstream machine.

[0005] As known, certain particular processes, e.g., weaving the heel of socks, require that the yarn fed to the machine is periodically recovered and then returned. This operation is usually carried out by a dedicated recovering device arranged upstream of the machine.

[0006] A recovering device of this type is described in EP 1741817 and essentially comprises a motorized reel having an oblique passage defined therein, through which the yarn runs. The passage extends between an inlet port which is axially formed on an end surface of the reel, and an outlet port which is formed on the cylindrical, lateral surface of the reel. When an amount of yarn must be recovered, the downstream machine sends a signal to the recovering device which enables the rotation of the reel, so that the yarn is wound upon the reel.

[0007] As well known to the person skilled in the art, a critical issue of the above systems consists in coordinating the operation of the braking system, which operates on the basis of the measured tension of the yarn, with the operation of the recovering system, which is enabled in response to commands sent from the downstream machine on the basis on a predetermined pattern, with consequent difficulties in accurately controlling the feeding parameters and the state of the yarn during the recovering steps, e.g., in relation to possible, accidental events which may occur, such as a yarn breakage.

[0008] It is a main object of the present invention to provide a method in which the yarn-feeding function and the yarn-recovering function are coordinated with each other in a more reliable and more accured manner with respect to the prior art, particularly in relation to the control of the yarn tension during the recovering step and to the reaction in case of accidental events, such as a yarn breakage; it is also an object to provide an apparatus for carrying out such method.

[0009] The above objects and other advantages, which will better appear from the following description, are achieved by a method having the features recited in claim 1, as well as by an apparatus having the features recited in claim 7, while the dependent claims state other advantageous, though secondary features, of the invention.

[0010] The invention will be now described in more detail with reference to a few preferred, non-exclusive embodiments, shown by way of non limiting example in the attached drawings, wherein:

Fig. 1 diagrammatically shows an apparatus for carrying out the method according to the invention;

Fig. 2 is a side elevation view of a recovering device of a known type used in the apparatus of Fig. 1;

Fig. 3 is a view similar to Fig. 2, which shows the recovering device in a different operative configuration;

Fig. 4 is a flowchart showing the steps of the method according to the invention;

Fig. 5 diagrammatically shows an apparatus for carrying out the method according to an alternative embodiment of the invention;

Fig. 6 is a perspective view of a yarn feeder with rotary drum, which is modified according to the invention to incorporate the apparatus of Fig. 5;

Fig. 7 is a front elevation view of the yarn feeder of Fig. 6;

Fig. 8 is a side elevation view of the yarn feeder of Fig. 6;

Fig. 9 is a broken away view similar to Fig. 8, showing the yarn feeder sectioned along axis IX-IX of Fig. 7;

Fig. 10 is a front elevation, broken away view of the yarn feeder of Fig. 6 sectioned along axis X-X of Fig. 8;

Fig. 11 is a Figure similar to Fig. 7, showing the yarn feeder to an enlarged scale and in a different operative configuration;

Fig. 12 is a flowchart showing the steps of the method according to the alternative embodiment of the invention.

[0011] Fig. 1 diagrammatically shows a yarn-feeding/recovering apparatus 10 having a yarn feeder 12 provided with a stationary drum 14 and with a flywheel 16 driven to rotate by a motor 18. The flywheel draws yarn F from a spool 20 and winds it on drum 14 in the shape of loops forming a stock.

[0012] Yarn F, which is unwound from the drum upon request of a general textile machine 22 arranged downstream, is subject to the braking action of a stabilizing brake adapted to maintain the yarn under a slight tension. The stabilizing brake conventionally comprises a frustoconical hollow member 24 which is biased with its inner surface against the delivery edge of drum 14 by elastic means 26.

[0013] In a way known per se, yarn F coming out of stabilizing brake is further subject to the braking action of an electronic yarn-braking device (or brake) 28 which is controlled by a tension control block TC of a control unit CU (which is typically incorporated in yarn feeder 12). Control unit CU is programmed to modulate the braking action applied to yarn F by electronic brake 28, on the basis of a signal received from a tension sensor 30, in such a way as to maintain the tension of the delivered yarn substantially constant on a reference value T_ref.

[0014] The stock on drum 14 is controlled by a triad of sensors. A first sensor S1, preferably a Hall sensor, detects the passage of magnets M integral with flywheel 16 in order to determine the amount of yarn which is wound on the drum and the winding speed. A second sensor S2, preferably a mechanical sensor, provides a binary information about the presence of a minimum amount of yarn at an intermediate area of drum 14. A third sensor S3, preferably an optical sensor, generates one pulse UWP per each loop unwound from the drum. A speed-evaluating block SE processes signals UWP in order to calculate the yarn comsumption speed on the basis of the time interval between pulses UWP, and generates an enabling signal LE which enables tension control block TC when this speed is higher than a predetermined threshold value, which is preferably equal to zero in the present embodiment. An apparatus of this type is described in EP 2031106, to which reference should be made for a more detailed description.

[0015] A yarn-recovering device 32 of the type described in EP 1741817 and shown in detail in Figs. 2, 3, is arranged between electronic brake 28 and tension sensor 30.

[0016] Yarn-recovering device 32 comprises a reel 34 keyed to a drive shaft 36 of a motor 38, preferably a stepping motor or, alternatively, a brushless motor provided with an absolute sensor, in ordet to measure the real position based on techniques conventional in the field. Reel 34 is arranged with its axis A slanting at a first angle α with respect to the direction of yarn F, indicated by arrow D, so that its end surface 34a facing away from motor 38 obliquely faces the incoming yarn. Reel 34 has an axial cylindrical seat 40 at its end surface 34a. A passage 44 defined within reel 34 extends between an inlet port 44a open to axial cylindrical seat 40, and an outlet port 44b open to the lateral, winding surface 34b of the reel. Passage 44 is rectilinear and is slanting at a second angle β, which is substantially equal to first angle α, with respect to axis A of the reel. An internally rounded wearproof ring 46 made of ceramic is applied to the edge of cylindrical seat 40. An inlet yarn-guide eyelet 48 and an outlet yarn-guide eyelet 50 respectively applied upstream and downstream of reel 34 are arranged at the same level of wearproof ring 46.

[0017] Yarn F passes through upstream yarn-guide eyelet 48, cylindrical seat 40, passage 44 and downstream yarn-guide eyelet 50. By operating motor 38, as shown in Fig. 3, the yarn downstream of the yarn-recovering device is wound on reel 34. For a more detailed description of yarn-recovering device 32, reference should be made to EP 1741817.

[0018] With the method according to the invention, as described in the flowchart of Fig. 4, electronic brake 28 and yarn-recovering device 32 are alternately enabled as a function of the signals from third sensor S3, which are indicative of the yarn comsumption, indipendently from any other operative signals from downstream machine 22.

[0019] In detail, as long as signal LE indicates that yarn is being unwound (LE=1), control unit CU continues to modulate the braking action of electronic brake 28 in such a way as to maintain the tension substantially constant at reference value T_ref, while yarn-recovering device remains at a position of minimum interference with the yarn, as shown in Fig. 2. When signal LE indicates that yarn is no longer unwound from the drum (LE=0), which circumstance is indicative of the fact that the downstream machine has either stopped to draw yarn or started to return it, control unit CU "freezes" the braking action at the last value and, if measured tension T_meas is lower than a lower threshold tension T_lim_inf, than it enables yarn-recovering device 32 to recover yarn, while its speed V_RR is continuously modulated in such a way as to maintain the tension substantially constant on reference value T_ref. At this stage, the number of revolutions and fractions of revolutions N completed by reel 34 is monitored.

[0020] It should be noted that, with the method according to the invention, reel 34 can rotate at a modulated speed in both directions. In fact, after an initial yarn-recovering step, during which the exceeding yarn is wound on reel 34 in order to maintain the tension at the desired level T_ref, the subsequent request of yarn from the downstream machine will cause reel 34 to rotate in the opposite direction always at a controlled speed, in order to return the yarn; however, before reaching the initial position (N=0) it could have to recover yarn again. When the reel reaches the initial position, control unit CU stops reel 34, enables electronic brake 28 again, and then the cycle is repeated.

[0021] As shown in the flowchart of Fig. 4, two emergency conditions are provided, by which the tension control is bypassed while yarn-recovering device 32 is enabled. A first condition occurs when N reaches a value N_max corresponding to the maximum amount of yarn which can be stored on the reel. In this case, the process is stopped and an alarm signal is generated. The second condition occurs when signal LE indicates that yarn is unwinding from the feeder; this means that the downstream machine is drawing yarn at a speed such that the yarn is sliding on reel 34. In this case, the tension control is bypassed and the reel is automatically driven to rotate to its resting position N=0.

[0022] Accordingly, with this embodiment, signal LE is used as a comsumption indicator that is indicative of the delivery of yarn from the feeder and, therefore, of the withdrawal of yarn by the downstream machine; on the basis of this indicator, electronic brake 28 and yarn-recovering device 32 are alternately enabled as discussed above.

[0023] Having now reference to Fig. 5, a weft feeder 100 is diagrammatically shown, which is provided with a motorized drum 102 on which yarn F' is wound. Motorized drum 102 draws yarn F' from a spool 104 and delivers it to a textile machine 106 arranged downstream. The tension of yarn F' unwinding from the feeder is conventionally controlled in such a way as to remain substantially constant on a reference value T_ref, by a control unit CU' (which is typically incorporated in yarn feeder 102) provided with a tension control block TC' that modulates the speed of rotation V_RP of drum 102 on the basis of the signals from a tension sensor 108 installed on the feeder. Accordingly, the change of tension to be applied is determined by the difference between the yarn-feeding speed and the yarn-drawing speed set in downstream machine 106.

[0024] A yarn-recovering device 120 is arranged between motorized drum 102 and the tension sensor; in the present embodiment, it is incorporated in housing 103 of feeder 100, as shown in more detail in Figs. 6-11. Yam-recovering device 120 comprises a motorized reel 122 lying with its axis parallel to the axis of motorized drum 102. Also in this case, the motor (not shown) of reel 122 is preferably a stepping motor or, alternatively, a brushless motor provided with an absolute sensor for measuring its real position. A passage 124 is defined within reel 122, which extends radially between an inlet port 126, which is formed at the middle of a free end 122a of the reel with its axis inclined with respect to the axis of reel 122, and an outlet port 128 formed on the lateral winding surface 122b of the reel. Inlet port 126 and outlet port 128 are internally rounded for reducing the wear by friction.

[0025] Yarn F' from spool 104 passes through an inlet yarn-guide eyelet 130 attached to the feeder, is wound between drum 12 and an arm 132 of a conventional tension limiter (which does not fall within the scopes of the present invention and, therefore, will not be further disclosed), runs through passage 124 which, at rest, lies at the resting position of Fig. 10 such that it substantially does not interfere with the path of the yarn, then engages a sensing element 134 of tension sensor 108, the latter being also incorporated in housing 103 of the feeder, and finally passes through an outlet yarn-guide eyelet 136 to feed the downstream machine. As shown in Figs. 6-11, control unit CU' is conventially received in a seat 138 of feeder 100, which also contains tension sensor 108, and is provided with programming push buttons 140 and with a display 142.

[0026] With the method according to this alternative embodiment of the invention, which is diagrammatically shown in the flowchart of Fig. 12, drum 12 of the feeder and reel 122 of yarn-recovering device 120 are alternately enabled as a function of speed V_RP of drum 102, independently from any other operative signal from the downstream machine.

[0027] In particular, as long as speed V_RP of drum 102 is higher than zero, which circumstance is indicative of the fact that yarn is being delivered by the feeder and, consequently, is being drawn by the downstream machine, drum 102 continues to rotate at a modulated speed, in such a way as to maintain the tension substantially constant on reference value T_ref, while reel 122 remains at its resting position of Fig. 10. When speed V_RP of the drum becomes equal to zero, which circumstance is indicative of the fact that the feeder has stopped to feed yarn and, therefore, the downstream machine has either stopped to draw yarn or started to return it, control unit CU' enables reel 122 to recover yarn at a speed V_RR modulated in such a way as to maintain the tension substantially constant on a reference value T_ref. At this stage, the number of revolutions and fractions of revolutions N completed by reel 122 is monitored.

[0028] Similarly to the previous embodiment, reel 122 can rotate in both directions at a modulated speed. In fact, after an initial yarn-recovering step, in which the exceeding yarn is wound on reel 122 in order to maintain the tension at the desired level T_ref, the next request of yarn from the downstream machine will cause reel 122 to rotate in the opposite direction, always at a controlled speed, in order to return the yarn; however, before reaching the initial position (N=0), it could have to recover yarn again. When the reel reaches the initial position N=0, control unit CU' stops reel 122, enables drum 102 again, and then the cycle is repeated.

[0029] With this embodiment, there is also provided an emergency condition, by which the tension control can be bypassed. In particular, when N reaches a value N_max corresponding to the maximum amount of yarn which can be stored on the reel, the process is stopped and an alarm signal is generated.

[0030] Accordingly, with this embodiment the speed V_RP of the drum is used as a comsumption indicator, which is indicative of the delivery of yarn by the feeder and, consequently, of the withdrawal of yarn by the downstream machine; on the basis of this indicator, drum 102 and reel 122 are alternately enabled according to the above method.

[0031] A few preferred embodiments of the invention have been described herein, but of course many changes may be made by a person skilled in the art within the scope of the claims. In particular, in the first described embodiment a stabilizing brake as described in EP 1059375, which applies a controlled braking action to the unwinding yarn, could be used in lieu of electronic brake 28. Moreover, in the described embodiments, the yarn-recovering device is always positioned in such a way that, at rest, it can assume positions not interfering with the yarn, as shown in Fig. 2 for the first embodiment and in Fig. 10 for the second embodiment. However, depending on the layout of the textile line, the reel could be arranged in such a way as to deviate the yarn even at its resting position in which it applies the minimum braking action upon the yarn.

Claims

1. A yarn-feeding/recovering method for textile machines, in which a textile machine (22, 106) receives yarn (F, F') from a yarn-feeding device (12, 100) via a yarn-recovering device (32, 120) provided with a motorized reel (34, 122) having a passage (44, 124) defined therein which is passed through by the yarn and extends between an inlet port (44a, 126) open to the middle of the free end (34a, 122a) of the reel and an outlet port (44b, 126) formed on the lateral surface (34b, 122b) of the reel, said yarn-recovering device (32, 120) being operable for temporarily recovering an amount of yarn already delivered to the machine and for giving it back at a later time,
and in which the tension of the yarn (F, F'), with said reel (34, 122) in a position of minimum interference with the yarn, is maintained substantially constant on a reference value (T_ref, T'_ref) by adjusting means (28, 102) on the basis of a measured tension signal (T_meas, T'_meas) generated by sensor means (30, 108),
characterized in
obtaining a consumption indicator (LE, V_RP), which is indicative of the delivery of yarn from said yarn-feeding device (12, 100) and is independent from any operative signals from said textile machine (22, 106) and, if said consumption indicator (V_RP, LE) indicates an interruption in the delivery of yarn,
temporarily disabling said adjusting means (28, 102) and temporarily enabling said yarn-recovering device (32, 120) to rotate at a speed modulated on the basis of said measured tension signal (T_meas, T'_meas) for maintaining the tension of the yarn substantially constant on said reference value (T_ref, T'_ref).

2. The method of claim 1, characterized in monitoring the position (N) of said reel (34, 122) with respect to said position of minimum interference with the yarn and, if said reel (34, 122) comes back to the position of minimum interference while said yarn-recovering device is enabled, disabling said yarn-recovering device and re-enabling said adjusting means (28, 128).

3. The method of claim 1 or 2, characterized in monitoring the position (N) of said reel (34, 122) with respect to said position of minimum interference with the yarn, and stopping said reel (34, 122) at the achievement of a predetermined maximum number of recovery revolutions.

4. The method of any of claims 1 to 3, characterized in that said yarn-feeding device (12) is provided with a stationary yarn-winding drum (14) from which the yarn (F) is unwound upon request from the textile machine (22) and said adjusting means consist of an electronic yarn-braking device (28) arranged downstream of said yarn-feeding device and controlled by a control unit (CU), and in which the withdrawal of yarn from said stationary drum (14) is monitored by sensor means (S3), characterized in that said consumption indicator consists of a consumption signal (LE) based on the signals (UWP) generated by said sensor means (S3).

5. The method of claim 4, characterized in monitoring the position (N) of said reel (34) with respect to said position of minimum interference with the yarn and, if said consumption signal (LE) indicates that yarn is withdrawn while said yarn-recovering device is enabled, automatically moving said reel (34) to its position of minimum interference, disabling said yarn-recovering device (32), and re-enabling said adjusting means (28).

6. The method of any of claims 1 to 3, in which said yarn-feeding device (100) is provided with a motorized yarn-winding drum (102) having yarn wound theron which is to be fed to said downstream machine, and said adjusting means comprise a control unit (CU') which is programmed to adjust the speed of rotation of said yarn-winding drum, characterized in that said consumption indicator is the speed of rotation of said yarn-winding drum, and that the zeroing of said speed of rotation is construed as indicative of the interruption in the delivery of yarn to said textile machine (106).

7. An apparatus for feeding/recovering yarn to/from a textile machine (22, 106), comprising
a yarn-feeding device (12, 100) arranged to feed yarn (F, F') to said textile machine,
a yarn-recovering device (32, 120) arranged between said yarn-feeding device (12, 100) and said textile machine (22, 106) and provided with a motorized reel (34, 122) having a passage (44, 124) defined therein which is passed through by the yarn and extends between an inlet port (44a, 126) open to the middle of the free end (34a, 122a) of the reel and an outlet port (44b, 126) formed on the lateral surface (34b, 122b) of the reel,
adjusting means (28, 102) controlled by a control unit (CU, CU') for maintaining the tension of the yarn (F, F') substantially constant on a reference value (T_ref, T'_ref) on the basis of a measured tension signal (T_meas, T'_meas) generated by sensor means (30, 108), with said reel (34, 122) in a position of minimum interference with the yarn,
said yarn-recovering device (32, 120) being operable for temporarily recover an amount of yarn already delivered to the machine and for giving it back at a later time,
characterized in that said control unit is programmed for processing a consumption indicator (LE, V_RP), which is indicative of the delivery of yarn from said yarn-feeding device (12, 100) and is independent from any operative signals from said textile machine (22, 106), and, if said consumption indicator (V_RP, LE) indicates an interruption in the delivery of yarn, temporarily disabling said adjusting means (28, 102) and temporarily enabling said yarn-recovering device (32, 120) to rotate at a speed modulated on the basis of said measured tension signal (T_meas, T'_meas) for maintaining the tension of the yarn substantially constant on said reference value (T_ref, T'_ref).

8. The apparatus of claim 7, in which said yarn-feeding device (100) comprises a housing (103) supporting a motorized yarn-winding drum (102) as well as said sensor means (108), characterized in that said reel (122) is also supported by said housing (103) between said yarn-winding drum (102) and said sensor means (108) and is arranged with its axis parallel to the axis of the yarn-winding drum (102).

9. The apparatus of claim 8, characterized in that said inlet port (126) has an axis which is oblique with respect to the axis of the reel (122).

10. The apparatus of claim 8 or 9, characterized in that said inlet port (126) and said outlet port (128) have respective inner beveled surfaces.

Ansprüche

1. Garnzuführungs-/-rückholungsverfahren für Textilmaschinen, bei dem eine Textilmaschine (22, 106) Garn (F, F') von einem Garnzuführer (12, 100) über einen Garnrückholer (32, 120) erhält, der mit einer motorisierten Garnspule (34, 122) mit einem darin ausgebildeten Durchlass (44, 124) ausgestattet ist, durch den das Garn verläuft und der sich zwischen einer Einlassöffnung (44a, 126), die zur Mitte des freien Endes (34a, 122a) der Garnspule offen ist, und einer Auslassöffnung (44b, 126) erstreckt, die auf der Seitenfläche (34b, 122b) der Garnspule gebildet ist, wobei der Garnrückholer (32, 120) dazu betreibbar ist, eine bereits an die Maschine abgegebene Garnmenge vorübergehend zurückzuholen und sie zu einem späteren Zeitpunkt wieder abzugeben, und bei dem die Zugspannung des Garns (F, F'), wenn die Garnspule (34, 122) sich in einer Stellung minimaler Garnbeeinflussung befindet, mittels einer Einstelleinrichtung (28, 102) im Wesentlichen konstant auf einem Referenzwert (T_ref, T'_ref) gehalten wird, basierend auf einem von einer Sensoreinrichtung (30, 108) erzeugten, gemessenen Zugspannungssignal (T_meas, T'_meas),
gekennzeichnet durch
Beschaffen eines Verbrauchsindikators (LE, V_RP), der die Garnabgabe aus dem Garnzuführer (12, 100) anzeigt und unabhängig von jeglichen Betriebssignalen der Textilmaschine (22, 106) ist und, falls der Verbrauchsindikator (V_RP, LE) eine Unterbrechung der Garnabgabe anzeigt,
zeitweiliges Ausschalten der Einstelleinrichtung (28, 102) und zeitweiliges Einschalten des Garnrückholers (32, 120) zum Drehen mit einer Geschwindigkeit, die basierend auf dem gemessenen Zugspannungssignal (T_meas, T'_meas) moduliert wird, um die Zugspannung des Garns im Wesentlichen konstant auf dem Referenzwert (T_ref, T_ref) zu halten.

2. Verfahren nach Anspruch 1, gekennzeichnet durch Überwachen der Stellung (N) der Garnspule (34, 122) bezüglich der Stellung minimaler Garnbeeinflussung und, falls die Garnspule (34, 122) in die Stellung minimaler Beeinflussung zurückkehrt, während der Garnrückholer eingeschaltet ist, Ausschalten des Garnrückholers und Wiedereinschalten der Einstelleinrichtung (28, 128).

3. Verfahren nach Anspruch 1 oder 2, gekennzeichnet durch Überwachen der Stellung (N) der Garnspule (34, 122) bezüglich der Stellung minimaler Garnbeeinflussung und Anhalten der Garnspule (34, 122) bei Erreichen einer vorbestimmten Maximalzahl an Rückholumdrehungen.

4. Verfahren nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass der Garnzuführer (12) mit einer stationären Garnwickeltrommel (14) versehen ist, von der das Garn (F) auf Anforderung von der Textilmaschine (22) abgewickelt wird, und dass die Einstelleinrichtung aus einer elektronischen Garnabbremsvorrichtung (28) besteht, die stromabwärts des Garnzuführers angeordnet und durch eine Steuereinheit (CU) gesteuert ist, wobei die Entnahme von Garn von der stationären Trommel (14) durch eine Sensoreinrichtung (S3) überwacht wird, dadurch gekennzeichnet, dass der Verbrauchsindikator aus einem Verbrauchssignal (LE) besteht, das auf den von der Sensoreinrichtung (S3) erzeugten Signalen (UWP) basiert.

5. Verfahren nach Anspruch 4, gekennzeichnet durch ein Überwachen der Stellung (N) der Garnspule (34) bezüglich der Stellung minimaler Garnbeeinflussung und, falls das Verbrauchssignal (LE) anzeigt, dass Garn entnommen wird, während der Garnrückholer eingeschaltet ist, automatisches Bewegen der Garnspule (34) in ihre Stellung minimaler Beeinflussung, Ausschalten des Garnrückholers (32) und Wiedereinschalten der Einstelleinrichtung (28).

6. Verfahren nach einem der Ansprüche 1 bis 3, bei dem der Garnzuführer (100) mit einer motorisierten Garnwickeltrommel (102) versehen ist, auf die Garn gewickelt ist, das der stromabwärtigen Maschine zugeführt werden soll, und bei dem die Einstelleinrichtung eine Steuereinheit (CU') umfasst, die dazu programmiert ist, die Drehgeschwindigkeit der Garnwickeltrommel einzustellen, dadurch gekennzeichnet, dass der Verbrauchsindikator die Drehgeschwindigkeit der Garnwickeltrommel ist und dass der Wert Null dieser Drehgeschwindigkeit als Unterbrechung der Garnabgabe an die Textilmaschine (106) interpretiert wird.

7. Vorrichtung zum Zuführen/Zurückholen von Garn zu/von einer Textilmaschine (22, 106), mit
einem Garnzuführer (12, 100), der dazu angeordnet ist, Garn (F, F') der Textilmaschine zuzuführen,
einem Garnrückholer (32, 120), der zwischen dem Garnzuführer (12, 100) und der Textilmaschine (22, 106) angeordnet und mit einer motorisierten Garnspule (34, 122) versehen ist, die einen darin ausgebildeten Durchlass (44, 124) hat, durch den das Garn verläuft und der sich zwischen einer Einlassöffnung (44a, 126), die zur Mitte des freien Endes (34a, 122a) der Garnspule offen ist, und einer Auslassöffnung (44b, 126) erstreckt, die auf der Seitenfläche (34b, 122b) der Garnspule gebildet ist, einer Einstelleinrichtung (28, 102), die von einer Steuereinheit (CU, CU') gesteuert ist, um die Zugspannung des Garns (F, F') im Wesentlichen konstant auf einem Referenzwert (T_ref, T'_ref) zu halten, basierend auf einem von der Sensoreinrichtung (30, 108) erzeugten, gemessenen Zugspannungssignal (T_meas, T'_meas), wobei die Garnspule (34, 122) sich in einer Stellung minimaler Garnbeeinflussung befindet,
wobei der Garnrückholer (32, 120) dazu betreibbar ist, eine bereits an die Maschine abgegebene Garnmenge vorübergehend zurückzuholen und sie zu einem späteren Zeitpunkt wieder abzugeben,
dadurch gekennzeichnet, dass die Steuereinheit dazu programmiert ist, einen Verbrauchsindikator (LE, V_RP) zu verarbeiten, der die Garnabgabe von dem Garnzuführer (12, 100) anzeigt und unabhängig von jeglichen Betriebssignalen der Textilmaschine (22, 106) ist, und, falls der Verbrauchsindikator (V_RP, LE) eine Unterbrechung der Garnabgabe anzeigt, zum zeitweiligen Abschalten der Einstelleinrichtung (28, 102) und zeitweiligen Einschalten des Garnrückholers (32, 120) zum Drehen mit einer Geschwindigkeit, die basierend auf dem gemessenen Zugspannungssignal (T_meas, T'_meas) moduliert ist, um die Zugspannung des Garns im Wesentlichen konstant auf dem Referenzwert (T_ref, T'_ref) zu halten.

8. Vorrichtung nach Anspruch 7, bei der der Garnzuführer (100) ein Gehäuse (103) hat, welches eine motorisierte Garnwickeltrommel (102) und die Sensoreinrichtung (108) trägt, dadurch gekennzeichnet, dass die Garnspule (122) ebenfalls von dem Gehäuse (103) zwischen der Garnwickeltrommel (102) und der Sensoreinrichtung (108) getragen ist und mit ihrer Achse parallel zur Achse der Garnwickeltrommel (102) angeordnet ist.

9. Vorrichtung nach Anspruch 8, dadurch gekennzeichnet, dass die Einlassöffnung (126) eine Achse hat, die schräg zur Achse der Garnspule (122) verläuft.

10. Vorrichtung nach Anspruch 8 oder 9, dadurch gekennzeichnet, dass die Einlassöffnung (126) und die Auslassöffnung (128) zugehörige innere abgeschrägte Oberflächen aufweisen.

Revendications

1. Procédé d'alimentation/récupération en fil pour machines textiles, dans lequel
une machine textile (22, 106) reçoit un fil (F, F') en provenance d'un dispositif d'alimentation en fil (12, 100) via un dispositif de récupération du fil (32, 120) doté d'un dévidoir motorisé (34, 122) disposant d'un passage (44, 124) défini en son sein à travers lequel passe le fil et qui s'étend entre un orifice d'entrée (44a, 126) ouvert au milieu de l'extrémité libre (34a, 122a) du dévidoir et un orifice de sortie (44b, 126) formé sur la surface latérale (34b, 122b) du dévidoir, ledit dispositif de récupération du fil (32, 120) étant actionnable afin de récupérer temporairement une quantité de fil déjà délivrée à la machine et de la renvoyer ultérieurement,
et dans lequel la tension du fil (F, F'), avec ledit dévidoir (34, 122) dans une position d'interférence minimale avec le fil, est maintenue substantiellement constante par rapport à une valeur de référence (T_ref, T'_ref) en ajustant les moyens (28, 102) sur base d'un signal de tension mesuré (T_meas, T'_meas) généré par des capteurs (30, 108),
caractérisé en ce qu'il permet
d'obtenir un indicateur de la consommation (LE, V_RP) qui est indicatif de la libération du fil depuis ledit dispositif d'alimentation en fil (12, 100) et qui est indépendant de tout signal de commande provenant de ladite machine textile (22, 106) et, si ledit indicateur de la consommation (V_RP, LE) indique une interruption de l'alimentation en fil,
de désactiver temporairement lesdits moyens d'ajustage (28, 102) et de permettre temporairement audit dispositif de récupération du fil (32, 120) de pivoter à une vitesse modulée sur base dudit signal de tension mesuré (T_meas, T'_meas) afin de maintenir la tension du fil substantiellement constante par rapport à ladite valeur de référence (T_ref, T'_ref).

2. Procédé selon la revendication 1, caractérisé en ce que la position (N) dudit dévidoir (34, 122) est contrôlée par rapport à ladite position de l'interférence minimale avec le fil et en ce que, si ledit dévidoir (34, 122) revient à la position de l'interférence minimale alors que ledit dispositif de récupération du fil est activé, ledit dispositif de récupération du fil est désactivé et les moyens d'ajustage (28, 128) sont réactivés.

3. Procédé selon la revendication 1 ou 2, caractérisé en ce que la position (N) dudit dévidoir (34, 122) est contrôlée par rapport à ladite position de l'interférence minimale avec le fil, et en ce que ledit dévidoir (34, 122) est arrêté une fois qu'un nombre maximal prédéterminé de révolutions de récupération a été atteint.

4. Procédé selon l'une quelconque des revendications 1 à 3, caractérisé en ce que ledit dispositif d'alimentation en fil (12) est doté d'un tambour stationnaire d'enroulement de fil (14) à partir duquel le fil (F) est déroulé à la demande de la machine textile (22) et en ce que les moyens d'ajustage consistent en un dispositif électronique de freinage du fil (28) disposé en aval dudit dispositif d'alimentation en fil et contrôlé par une unité de commande (CU), et dans laquelle le retrait du fil depuis ledit tambour stationnaire (14) est contrôlé par des capteurs (S3), caractérisé en ce que ledit indicateur de la consommation consiste en un signal de la consommation (LE) basé sur les signaux (UWP) générés par lesdits capteurs (S3).

5. Procédé selon la revendication 4, caractérisé en ce que la position (N) dudit dévidoir (34) est contrôlée par rapport à ladite position de l'interférence minimale avec le fil, et en ce que si ledit signal de consommation (LE) indique que le fil est retiré alors que ledit dispositif de récupération du fil est actionné, ledit dévidoir (34) est déplacé automatiquement vers sa position d'interférence minimale, en désactivant ledit dispositif de récupération du fil (32), et en réactivant lesdits dispositifs d'ajustage (28).

6. Procédé selon l'une quelconque des revendications 1 à 3, dans lequel ledit dispositif d'alimentation en fil (100) est pourvu d'un tambour d'enroulement de fil motorisé (102) disposant de fil enroulé autour de lui qui doit servir à alimenter ladite machine située en aval, et dans lequel lesdits dispositifs d'ajustement comprennent une unité de commande (CU') qui est programmée afin d'ajuster la vitesse de rotation dudit tambour d'enroulement de fil, caractérisé en ce que ledit indicateur de la consommation est la vitesse de rotation dudit tambour d'enroulement de fil, et en ce que la remise à zéro de ladite vitesse de rotation constitue une indication de l'interruption au niveau de la libération du fil au niveau de ladite machine textile (106).

7. Appareil d'alimentation/récupération en fil vers/depuis une machine textile (22, 106), comprenant un dispositif d'alimentation en fil (12, 100) prévu pour alimenter en fil (F, F') ladite machine textile, un dispositif de récupération du fil (32, 120) disposé entre ledit dispositif d'alimentation en fil (12, 100) et ladite machine textile (22, 106) et doté d'un dévidoir motorisé (34, 122) disposant d'un passage (44, 124) défini en son sein à travers lequel passe le fil et qui s'étend entre un orifice d'entrée (44a, 126) ouvert au milieu de l'extrémité libre (34a, 122a) du dévidoir et un orifice de sortie (44b, 126) formé sur la surface latérale (34b, 122b) du dévidoir,
des dispositifs d'ajustement (28, 102) commandés par une unité de commande (CU, CU') afin de maintenir la tension du fil (F, F') substantiellement constante par rapport à une valeur de référence (T_ref, T'_ref) sur base du signal de tension mesuré (T_meas, T'_meas) généré par des capteurs (30, 108), ledit dévidoir (34, 122) se trouvant dans une position d'interférence minimale avec le fil,
ledit dispositif de récupération du fil (32, 120) étant actionnable afin de temporairement récupérer une quantité de fil déjà délivrée à la machine et de la renvoyer ultérieurement,
caractérisé en ce que ladite unité de commande est programmée afin de traiter un indicateur de consommation (LE, V_RP) , qui est indicatif de la libération du fil depuis ledit dispositif d'alimentation en fil (12, 100) et qui est indépendant de tout signal de commande provenant de ladite machine textile (22, 106) et, si ledit indicateur de la consommation (V_RP, LE) indique une interruption de l'alimentation en fil, désactivant temporairement lesdits moyens d'ajustage (28, 102) et permettant temporairement audit dispositif de récupération du fil (32, 120) de pivoter à une vitesse modulée sur base dudit signal de tension mesuré (T_meas, T'_meas) afin de maintenir la tension du fil substantiellement constante par rapport ladite valeur de référence (T_ref, T'_ref).

8. Appareil selon la revendication 7, dans lequel ledit dispositif d'alimentation en fil (100) comprend un logement (103) abritant un tambour d'enroulement de fil motorisé (102) ainsi que lesdits capteurs (108), caractérisé en ce que ledit dévidoir (122) est également abrité par ledit logement (103) entre ledit tambour d'enroulement de fil (102) et lesdits capteurs (108) et en ce qu'il est placé sur un axe parallèle à l'axe du tambour d'enroulement de fil (102).

9. Appareil selon la revendication 8, caractérisé en ce que ledit orifice d'entrée (126) possède un axe qui est oblique par rapport à l'axe du dévidoir (122).

10. Appareil selon la revendication 8 ou 9, caractérisé en ce que ledit orifice d'entrée (126) et ledit orifice de sortie (128) possèdent des surfaces internes respectives biseautées.

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