EP1402097B1 - Method for inserting weft threads and thread feed device - Google Patents

Abstract

The invention relates to a method for inserting weft yarn material, comprising an insertion system in a loom. According to the invention, for every insertion the insertion system (A) is supplied with a substantial part of the weft yarn required for the insertion in a loose and substantially tension-free manner so as to be intermittently pulled off. A tubular package of adjacent windings is produced from the weft yarn material on an inner mechanical support (S) by way of an at least substantially continuous winding process and is conveyed forward in withdrawal direction. For an insertion, a number of windings that corresponds at least approximately to the weft yarn section intended to be inserted is detached or set free from the support while maintaining its tubular configuration without yarn tension. The weft yarn material is withdrawn directly inwardly from the frontmost winding and then further along the tube axis (X).

Description

The invention relates to a method according to the preamble of patent claim 1 and a thread delivery device according to the preamble of patent claim 14.

In WO-A-92/04490 and EP-A-0 699 790 known method is formed on a storage body, a winding of adjacent or spaced turns. The entry system pulls the thread from the roll over the front end of the storage body. The windings on the storage body can be moved forward by different feed devices. The storage body is axially longer than the winding. Pulling off creates a thread balloon that produces significant thread tension variations and significant thread tension that slows down the entry. In order to achieve high entry speeds, considerable energy expenditure in the entry system is required. Conversely, this means a high mechanical load for the weft.

From US-A-4 002 190 a method is known in which the insertion system does not draw the weft yarn directly from the roll on a storage body, but weft yarn material is presented to the entry system loosely and substantially without tension. It omits the influence of a thread balloon, so that with lower energy consumption and for the weft thread material gently higher insertion speeds can be achieved. For example, the weft yarn is presented in zig-zag or loop form and released synchronously with the pull-off movement. This method requires high expenditure on equipment and is too slow for modern weaving machines because of the many movements of the mechanical elements to be controlled accurately and their mass inertia.

In the method known from WO-A-92/04490 and EP-A-0 699 790, the filament winding formed on the stationary support is constantly supported on the support from the inside, ie also during withdrawal after release of the stoppage element from its Intervention with the support. The thread is pulled off from the foremost turn in the withdrawal direction and beyond the front end of the support. In this case, considerable centrifugal forces act on the weft thread, which lead to an undesirable strong balloon effect. This means that the weft yarn lifts itself off the support and, in a free-flying spiral shape, looks for the way to extend the axis of the support. Significant kinetic energy is stored in the weft balloon which, on the one hand, undesirably increases the tension in the weft thread stream of the support and, on the other hand, undesirably prolongs the time required for an entry. The stop element is responsible for both initiating an entry and terminating it.

In the method known from US-A-4,132,370, the thread turns located in the withdrawal direction in the withdrawal direction in front of a stop element displaced by a positive drive with the forwardly moving thread windings are permanently supported on the stationary support from the inside. The weft yarn is withdrawn from the foremost take-off direction across the front end of the support, the weft yarn being exposed to high centrifugal forces and forming an undesirable yarn ballon. Inside the support several stop elements are incorporated into the positive drive, which are successively extended from the inside to the outside between turns of thread and retracted after a successful withdrawal back inside. This requires a high mechanical effort for the positive drive of the stop elements.

In the method known from DE-A-34 23 771, the weft thread is withdrawn from the rotationally driven measuring support via the forward end of the support in the withdrawal direction. During the withdrawal, all formed turns of thread on the support are supported from the inside. It therefore creates an undesirable balloon effect. For dimensioning of the weft thread length to be released for each entry, a catching and releasing element designed as a catching needle is pivotally mounted in the interior of the rotationally driven measuring support, which is pushed cyclically outwards through a lift arranged in the drive shaft and pulled inwards. As soon as the catching needle has been pushed outwards between two turns of thread, it is moved in the drawing-off direction through the enlarging thread winding into the catching position defined in the measuring support. The fishing pin is two-armed, so that one arm makes a sizing on every other trigger, while then the other arm by the force exerted on one arm adjustment the thread turns is moved back to the starting position. A yarn feeding device with a rotationally driven support can no longer meet the requirements of modern weaving machines in terms of yarn speed and picking frequency due to the large moving masses.

In the thread delivery device for jet looms known from EP-A-0 699 790 the stop element is moved in its engaged position in the stationary support by an electromotive force with a preprogrammed acceleration profile over a predetermined pivoting stroke in the unwinding of the weft thread from the support to the otherwise abrupt Damping the withdrawn weft yarn occurring to dampen stretch. This movement control of the stop element requires a high electronic and mechanical effort, since an exact vote on the weft thread movement is required to stop.

The invention has for its object to provide a method and a yarn feeding device of the type mentioned, with which with low energy consumption, even with high performance of modern weaving machines with high reliability optimally short entry times are possible.

The stated object is achieved with the features of claim 1 and the features of claim 14.

Surprisingly, the winding section released from the support for withdrawal in ordered turns shows, among other things because of its inertial behavior and the dimensional stability of the turns, a tendency to remain in space essentially without any mechanical inner support in such a way that the weft thread first pulls off without any balloon formation inside and continues to run centrally out of the tube and the turns successively clean consumes, down to the last nachgeförderte and possibly still supported on the support turn. The released winding section does not collapse. The turns do not tend to entangle or collapse, provided that the withdrawal is fast and accurate in time controlled tuning to the release of the winding section. The method can be surprisingly short insertion times achieve, with which it is possible to optimally use the performance of modern weaving machines in terms of high thread speeds and high insertion frequencies. Although it may be the released thread winding section from the outside if necessary. Be Supported. Such support But it is more a security measure. The winding speed of the at least substantially continuous winding process is expediently matched to the insertion frequency and the length of the respectively inserted weft thread section such that each entry consumes the released winding section before the next following winding section is released. Even at extremely high yarn speeds, it is surprisingly evident that the centrally drawn weft yarn consumes the foremost turn in the withdrawal direction substantially radially inwards and without a balloon and the tubular configuration of the turns in the released winding section is maintained until the end of the entry with optimum thread geometry. The released winding section may contain a number of turns of thread substantially corresponding to the weft length to be entered, or a larger number corresponding to a plurality of wefts to be inserted successively.

It may be appropriate to overlap the trigger time with the release of the winding section, so that the liberated winding section or its deduction windings have as little time as possible to give up the orderly tubular configuration of adjacent turns.

In terms of process technology, the turns in the winding section are released by overfilling the inner support beyond its discharge end. The released turns are consumed in the deduction, before the released winding section could collapse or mess up. The overfilling takes place by the continuous winding of the weft thread material.

Alternatively or additionally, the windings may be released by forward feeding of the roll on the support beyond its discharge end. In this case, feed devices of any kind can be consulted.

In order to keep the tubular configuration of the released filament winding part as stable as possible, possibly also to use adhesion between the adjacent turns, the filament winding and its released part can be conveyed in the withdrawal direction obliquely upwards or upwards.

As a further alternative, it is advisable to release the turns in the uncoupled winding section by an adjusting movement of at least part of the support therefrom. For this purpose, mechanical adjustment devices of the support are used.

For the procedure, it is important in the released winding section whose tendency, even without internal mechanical support, so to speak, to remain free in space, to extend as long as possible. This tendency also depends on the dimensional stability of the thread material and the turns inherent, at least temporarily, in the winding section. The dimensional stability is high when the turns are wound with a curvature of the thread material that corresponds at least approximately to the smallest natural and forced curvature storage capability of the weft thread material. This curvature storage capability can be explained as follows: If a section of the weft thread material is placed on a smooth surface, with the ends of the section being guided to each other as far as possible, then the weft thread section acquires a specific curvature. When the ends are released, the weft section relaxes to a residual curvature that represents its smallest natural curvature storage capability. Surprisingly, it turns out that different weft thread materials differ only slightly in this regard or behave very similarly. If the weft yarn material in the roll is curved at least substantially with the smallest natural curvature storage capability, then the windings in the released winding section have no appreciable tendency to increase or decrease the winding radius so that the released winding section will be the tubular configuration formed by winding on the inner support maintains relatively long. Mutual adhesion between the uniform and contacting turns may assist this.

In picking methods employing a picking system which is incapable of accurately measuring the length of each inserted weft section, it is convenient to mechanically size the weft section between the picking system and the winding section remaining on the support. Therefor can be used mechanical, in accordance with the Webtakt controlled systems.

The suture delivery device is designed to perform the method of sizing the weft length for a loom that does not limit the weft length itself, e.g. for a jet loom. In order to influence the formation of the thread winding and the release of the filament winding part as little as possible, the serving of dimensioning stop element is moved in its engagement position without own drive through the forward funded filament winding into the stop position. The stop member is placed in the correct position for dimensioning the length in front of a turn just formed on the support in the engagement position, without affecting the conveying movement, and moves with the forwardly funded winding until it finally reaches the stop position in which it limits the withdrawn weft length. So that the stop element later returns to the starting position, a positive drive is provided, which adjusts the stop element exclusively in its release position substantially opposite to the take-off direction, while simultaneously thread turns can be deducted without obstruction by the stop element. This leads to a stepping sequence in which the positive drive causes the return of the stop element, and the filament winding causes the forward movement of the stop element. In the stop position, the stop element positioned in its engagement position is responsible for terminating the entry.

Conveniently, the stop element cooperates functionally with a thread clamp, which is responsible for the beginning of the entry and is controlled in time to the working movements of the stop element. The thread clamp holds the weft thread, while the stop element is moved back in the release position, in the starting position, and releases the weft thread exactly at the beginning of the entry process. The entry is terminated by the caught stop element in the stop pest before the thread clamp retains the thread in preparation for retracting the stop element.

Since after completion of the entry by the stop element in the stop position of the weft thread between the stop element and the entry device and optionally Even in the weaving machine remains subjected to significant tension, which is effective in the weft thread at least up to the stop element, and the weft thread section between the set in the clamping position, the thread holding thread clamp and the stop element under tension. If the stop element were brought from the engagement position to the release position in the stop position, then the tension-induced friction of the weft thread on the moving stop element could destroy the tubular configuration of the thread winding, and the thread relaxation inevitably occurring when the stop element is moved to the release position with the thread tensioned Disrupt configuration of thread turns. By means of the auxiliary drive, however, the thread clamp holding the thread is adjustable so that is relaxed by its Verstellhub towards the stop element located in the stop element of the present therebetween weft thread section and relaxed when the stop element is moved for the next entry in the release position. This adjustment of the thread clamp eliminates disturbances in the tubular configuration of the thread winding. In principle, it may be expedient to move the thread clamp at least in the final phase of an entry from the movement space of the thread, eg with a further actuator or even with the auxiliary drive. This would minimize the risk of the thread getting caught. If necessary. It is also sufficient to have a shield which has been moved over the clamping area for a short time, or a deflector on the thread clamp or in the vicinity of its clamping area, which leads the thread from the side on the clamping area from which the thread normally approaches the clamping area.

In order to have to move as little mass as possible at the taking place in the withdrawal direction of the stop element through the filament winding, a joint should be provided between the stop element and its drive. Furthermore, the stop element should be guided in the direction of movement in order to have exact positioning, at least in the stop position, which is important for the length dimensioning. This guide can either be a defined hinge axis perpendicular to the take-off direction, and / or a guide track extending exactly in this direction in the support or even in a structure adjacent to this on the outside.

Structurally simple and functionally safe is a positive drive on a magnetic basis. A stationary solenoid (solenoid) pulls or pushes the at least partially magnetically conductive stop element in the release position using the joint in the starting position. Alternatively, other drives can be used for this purpose.

A perfect positioning of the stop element in the stop position is achieved by a stop in the guide either in the support or in the structure adjacent to the outside. The filament winding moves the stop element in the conveying direction against the stop.

Since abruptly stopping the drawn weft thread in the stop position of the stop element in the weft thread forcibly a stretch or whip effect is associated with a momentary thread tension increase, a controlled thread brake (end-of-insertion brake) is used in this technique usually, which dampens the voltage increase. Such controlled thread brakes are expensive and require a complex control. For this reason, according to the invention structurally more easily attenuated in the stop position of the stop element exactly at the point that is responsible for the emergence of the stretch or whip effect, namely the stop element. The damping takes place in that the stop element is deflected against a predetermined elastic counterforce substantially in the circumferential direction of the support, under the energy which is transferred to the stop element when the weft thread is stopped. Due to the deflection against the elastic counterforce, the weft thread is slowed down more slowly or energy is consumed which eliminates or considerably reduces the weft tension tip. As a result, a controlled thread brake for this task can be omitted.

This function can be achieved, for example, in that the stop element itself is elastically restoring, for example, with a resilient joint region, so that it is deflected like a spiral spring only under the energy increase of the stretch and mitigates the thread tension increase. Alternatively, a lateral abutment for the stop element could be provided in the support or in a structure adjacent to the support, which laterally movable with the arranged stop element under the force of the weft thread against the predetermined counter force shifted to consume energy. Once the draft is over, the abutment or the stop element is back in the circumferential direction.

The thread clamp, which is responsible for the beginning of the entry, is of considerable importance, since the release time of the weft thread must be tuned very precisely to the operation of the loom and should pass as short time between the command of the initiation of the entry and the release of the weft , The thread clamp is therefore a trigger of the entry, wherein the thread clamp in the thread path takes up as little space and just so close to the front end of the support is effective that the released thread winding part can be provided undisturbed to the entry in the desired size. The adjustability of the thread clamp in the withdrawal direction, either linear or pivoting, is important in order to be able to relax the weft thread section present after the entry between the thread clamp holding the thread and the stop element located in the stop pest, and possibly also a disabling part of the thread clamp at least substantially to move out of the thread movement area. As a rotary drive, for example, a stepper motor is suitable. As a linear drive and a magnet assembly can be used.

An effective clamping in the narrowest space and with precisely dosed clamping force can be achieved by a notch-like clamping area in a slim extension of the thread clamp, wherein the clamping force is generated mechanically by spring force. Because the clamping of the thread is a process of secondary importance, because then the weft thread is trapped by the stop element anyway. The spring force must ensure that the clamping force is sufficient to hold the weft under the tension generated by the entry system.

However, it is important that the thread clamp releases the weft thread at the exact desired time and as quickly as possible when the entry is to be initiated. This can be functionally easily achieved by means of a switching magnet whose armature the weft thread clamped captive bolt with a predetermined distance opposite when the solenoid is energized. Thanks to the space between them, the fitting has enough time to overcome the breakaway friction and convert the magnetic force that builds up into high speed, building up high kinetic energy and accelerating it hard before it hits the bolt. The shift solenoid does not need to gradually overcome the spring force starting from the zero speed, but does so abruptly with the then already achieved acceleration and kinetic energy of the valve. It comes to the sudden release of the trapped weft. In practice, release times in the range of only one millisecond can be achieved.

Although the filament winding in its released and no longer supported from the inside part for a long time tends to maintain the tubular configuration, it may be appropriate to support the filament winding on guide surfaces from the outside at least partially. External support maintains the tubular configuration and allows the weft yarn to be withdrawn radially inward from the forwardmost turn in the haul-off direction and then along the extension of the support axis so as not to create a delaying and depleting balloon and the desired high picking speed or short entry time can be achieved.

The guide surfaces may be formed so as to support at least the lower half of the released filament winding part. Optionally, more or even the whole filament winding part is supported. In this case, the guide surface of part surfaces or rods or the like. Existence to generate as little friction on the released filament winding part, or only there friction, where it is considered appropriate, e.g. at the top of the foremost turns in the withdrawal direction to prevent them from tipping forward.

Alternatively or additionally, at least a part of the guide surface in the withdrawal direction may be inclined upward inclined obliquely. This favors keeping the released filament winding member compact and dense as it moves forward and also when the filament is withdrawn.

As a further alternative, it is advisable to move along the guide surface with the forward-fed filament winding in order to minimize friction between the two as possible. This can be achieved, for example, by a crawler-type training driven driving surfaces that hold like spaced gears from the outside and promote forward.

Since the last thread turn on the support is eaten up to the stop element in the stop plague at the entry end, and the dreaded stretch or whip effect can lead to an undesirable increase in weft yarn tension, a retaining element in the form of a lamella or a brush should be arranged above the yarn winding, the cooperates with the front end of the support to slow down the weft thread before it is brought to a complete stop at the stop element. This retaining element must be adjustable so that it comes into effect only at the desired time, namely at the end of the entry, and in the remaining time does not affect the released filament winding part.

Structurally simple, the support is a rod cage. The fingers have individual Exzenterverstellvorrichtungen with a Stellexzenter, which is accessible from the front of the support. In this way, diameter changes of the rod cage can be carried out conveniently. Since the support for carrying out the method has a relatively small diameter, approximately corresponding to the smallest natural and forced curvature storage capability of the weft thread material, a simple eccentric adjustment device is sufficient because a diameter variation corresponding to a thread turn length only requires a relatively small radial adjustment path.

There are two possibilities. The location cam is either rotated in the carrier and displaces the finger outward or inward, or the location cam is rotated in the finger, and moves with his finger over its eccentric portion in the carrier.

For the support, an outer diameter between about 20 and 50 mm is appropriate, preferably between about 30 to 40 mm. This is a range of diameters within which the smallest natural and forced curl storage capability of most weft materials is.

Since, of course, any disturbance of the tubular configuration of the filament winding is to be avoided in order to achieve a homogeneous thread winding and a homogeneous and stable, released filament winding part, it is expedient to arrange the stop element on the underside of the support, where gravity helps, disturbing influences to avoid the stubble.

The thread clamp should be aligned approximately in the direction of the stretched thread with the area at which the stop element penetrates into the support.

According to a very important aspect of the invention, the reliability of the method can be significantly increased with a loop suppression body centrally located on the support and projecting approximately in alignment with the support axis in the withdrawal direction so that its free end protrudes at a position the support lies. The fundamental advantage of the method are extremely high entry speeds or short entry times. This positive effect results from the fact that the thread when pulling on the foremost turn of the liberated winding section without balloon formation runs directly substantially radially inward and then only in the axial direction in the loom. This movement takes place with very high speed and high dynamics. Since the turns in the released winding section are not supported from the inside, but remain free-standing in the room, snares (snarls) may form, in particular with lively thread qualities, which lead to tissue defects or cause disturbances in the entry system. The loop-suppression body supports the thread run where the thread from the foremost turn runs approximately radially inward and then in the axial direction on. In this area, the body of suppression prevents by its physical presence that a snare can twist. The at the running dynamics of the thread Resulting contact with the suppression body calms the thread, which moves relatively stretched in the axial direction in the entry system.

Suitably, the loop suppression body has a rotationally symmetrical lateral surface, which tapers in the direction of the free end. This facilitates the slipping of a sling and prevents its rotation. The shape also prevents the loop from tightening under the withdrawal tension.

Structurally simple, the loop-suppression body is a pin, preferably a conical pin. It also provides an ideal way to place a trigger sensor that registers each withdrawn turn.

The outer diameter of the pin should be at least near its free end, only a fraction of the diameter of the support.

The free end should protrude significantly beyond the front of the support to function in the area where the thread runs inward from the released lap section. Preferably, the free end in the withdrawal direction even downstream of the position of the thread clamp to reach into a range from which no looping and thus the risk of rotation of loops can occur more.

The lateral surface should be smooth and formed with low friction, optionally it has a low-friction support. Low friction in this case means low friction for the thread material. Because the suppression body needs only by its physical arrangement and extension in about withdrawal direction to cause that emerging in the loop loops can not twist, and should exert as little delaying mechanical load on the thread.

Appropriately, the forward funding of the yarn winding by means of a certain conicity of the support. When cone conveying the advantage results directly adjacent to each other and therefore also in the released thread winding part together adhering Thread windings. Moreover, this is a cost effective and reliable solution.

Alternatively, a feed principle can be used with a wobble element, which is driven synchronously with the winding element, but does not rotate, but only generates a wobbling motion by its inclined axis, which transmits it to the emerging from the winding element and formed on the support first thread turn, the then pushes the thread turns lying in front of it.

As a further alternative can be promoted with so-called thread separation, the feed elements between the rods of the rod cage use a common drive with a skew with respect to the axis of the support or the drive shaft of the winding element axis.

Basically, the tension-free and loosely presented thread winding part for triggering is released by overfilling the support. As an alternative, however, offers to withdraw the support relative to the filament winding and opposite to the withdrawal direction to release the filament winding part at the right moment. In doing so, a supporting wiper can assist in releasing the filament winding compactly with its tubular configuration from the retracting support.

In a further alternative, the support is associated with an auxiliary support at the front, which is first used to form an internally supported filament winding, but then pulled away from the support coaxially to release the filament winding part, which is intended for entry. Here, the auxiliary support can be supported by a scraper, which favors the compact holding the liberated Fadenwickelabschnitts.

The stretch or whip effect at the end of an entry in a jet loom supplied with a metering yarn feeding device with weft threads is due to the abrupt delay of the inserted weft yarn on the stopper. In order to avoid damage, in practice controlled thread brakes are used, leading the interception of the weft thread on the stop element begin to brake and gradually retard the weft. Controlled yarn brakes of this type require precise electronic control and are complex and expensive. According to an important aspect of the invention, the stopper responsible for the whip effect is itself used to dampen the voltage rise at the entry end. That is, the damping takes place in the weft exactly where the unwanted voltage increase would be generated. For this purpose, the stop element is deflectable substantially in the circumferential direction of the support against a predetermined elastic force over a damping stroke. Namely, the stopper is moved from a first catching position in which it starts to delay the weft thread and is acted upon by its reaction force through the damping stroke to a second catch position, wherein energy is consumed before the weft yarn comes to a complete halt. By the predetermined elastic force, the stop element is reset, which allows a total of a very clean thread control and leads to a subsequently cleanly stretched weft.

It is expedient to provide between the linear drive, which is responsible for the engagement position and the release position of the stop element, and the support, at least one joint area, which allows this lateral mobility or this degree of freedom of movement of the stop element, without the linear drive in each case adjusted would have to be. The damping element, which is accommodated movably in a stationary guide with a predetermined direction of movement and adjustable against spring force, is adjusted by the acted upon by the reaction force of the weft yarn stop element against the spring force on the damping stroke, so that energy consumed and the yarn is gradually braked, without a significant Increase in tension. The movement of the damping element need not be strictly oriented in the circumferential direction of the support, but it could quite well be an oblique direction of movement to be chosen, which approximately coincides with the direction of the resultant, resulting from the substantially circumferentially acting force in the thread from the last deduction-side winding to the stop element and the force acting substantially in the withdrawal direction force of the thread on the stop element results. The automatic reset of the damping element after the removal of the thread tension tip offers the advantage of withdrawing the weft thread at least a small piece.

In an alternative embodiment, the filament winding is already formed with a plurality of turns of thread which are larger than adjacent and define points of attack for each one of a plurality of stop elements. The stop elements are hook-shaped and, for example, rotationally adjustable and are brought in their co-movement with the thread winding sequentially engaged in the prepared for them enlarged turns. This is particularly useful when the filament winding is formed with a size that corresponds to a plurality of weft thread lengths to be successively entered.

Fig. 1

eine Schemaansicht zum Vertahrensablauf gemäß der Erfindung, d.h. bei einem Verfahren zum Eintragen von Schussfadenabschnitten in eine Webmaschine,

Fig. 2

eine perspektivische Schemaansicht zur Verdeutlichung der sogenannten kleinsten unerzwungenen Krümmungsspeicherfähigkeit eines Schussfadenmaterials,

Fig. 3

eine Detailvariante,

Fig. 4

eine weitere Detailvariante,

Fig. 5

eine weitere Detailvariante vor Beginn des Abzugs,

Fig. 6

die Detailvariante von Fig. 5 nach Beginn des Abzugs,

Fig. 7

eine Perspektivansicht einer Fadenliefervorrichtung,

Fig. 8

einen Radialschnitt zu Fig. 7,

Fig. 9

einen Radialschnitt ähnlich dem von Fig. 8 zu einer anderen Ausführungsform, in einer Ausgangslage eines beweglichen Stoppelements,

Fig. 10

eine Radialschnittansicht gemäß Anspruch 9 derselben Ausführungsform in einer anderen Stellung des Stoppelements,

Fig. 11

einen Detailschnitt in der Ebene XI-XI in Fig. 10,

Fig. 12

eine Schemaansicht einer weiteren Ausführungsform,

Fig. 13

einen Längsschnitt einer Fadenklemme, wie sie beispielsweise in Fig. 7 vorgesehen ist,

Fig. 14

ein Diagramm, das anhand von Kurven die Operation einzelner Komponenten bei dem Verfahren in gegenseitiger Zuordnung darstellt,

Fig. 15

eine perspektivische Frontansicht eines Details aus Fig. 7,

Fig. 16

ein Detail aus Fig. 15, perspektivisch und vergrößert,

Fig. 17

eine schematische Darstellung einer Verfahrens- und Vorrichtungsvariante,

Fig. 18

eine Draufsicht auf ein Detail einer Fadenliefervorrichtung gemäß Fig. 17,

Fig. 19

eine Perspektivansicht eines weiteren Details,

Fig. 20

perspektivisch eine Detailvariante, und

Fig. 21

perspektivisch eine weitere Variante.

Reference to the drawings, embodiments of the subject invention will be explained. Show it:

Fig. 1

6 is a schematic view of the procedure according to the invention, ie in a method for inserting weft thread sections into a weaving machine;

Fig. 2

3 is a perspective schematic view illustrating the so-called smallest unforced curvature storage capability of a weft thread material;

Fig. 3

a detail variant,

Fig. 4

another detail variant,

Fig. 5

another detail variant before the deduction starts,

Fig. 6

the detail variant of Figure 5 after the start of the deduction,

Fig. 7

a perspective view of a yarn feeding device,

Fig. 8

a radial section to Fig. 7,

Fig. 9

a radial section similar to that of Fig. 8 to another embodiment, in a starting position of a movable stop element,

Fig. 10

a radial sectional view according to claim 9 of the same embodiment in a different position of the stopper,

Fig. 11

a detail section in the plane XI-XI in Fig. 10,

Fig. 12

a schematic view of another embodiment,

Fig. 13

a longitudinal section of a thread clamp, as provided for example in Fig. 7,

Fig. 14

a diagram illustrating, by means of curves, the operation of individual components in the method in association,

Fig. 15

a front perspective view of a detail of Fig. 7,

Fig. 16

a detail of Fig. 15, in perspective and enlarged,

Fig. 17

a schematic representation of a process and device variant,

Fig. 18

a top view of a detail of a yarn feeding device according to FIG. 17,

Fig. 19

a perspective view of another detail,

Fig. 20

in perspective, a detail variant, and

Fig. 21

in perspective another variant.

In Fig. 1, endless weft yarn material Y, for example, from a thread supply, not shown, into a displaceable by a drive M in a substantially continuous rotary winding movement R rotatable winding element W and pulled by this on an inner mechanical support S in successive or adjacent turns T is wound as a tube-like winding, which moves forward on the support S at a speed V in the arrow direction. The turns T are then released as a winding section B over the tail end of the support S away in the direction of the axis X and while maintaining the tubular configuration of the support S. In the uncovered winding section B, the turns T1 are loosely conveyed forward and essentially free of tension, and remain free in space due to inertia and due to the dimensional stability of the roll. In approximately in alignment with the axis X, an insertion system A of a loom L is provided, which withdraws the weft Y intermittently (indicated by individual arrows C) and enters into a loom L. Mechanical devices H and G for dimensioning the respective weft thread length for the entry can be provided between the insertion system A and the winding section B released by the support S on the one hand and / or in the region of the end of the support S on the other hand. These devices H, G are controlled in coordination with the Web clocks. The withdrawn from the released winding section B approximately coaxial with the axis X weft yarn Y consumes each deduction first turn without any ballooning, runs essentially radially inward and then axially until finally all turns T1 of the liberated winding section B are consumed at the entry end , As a result, the next winding section for the next entry is released.

The winding of the turns T and the winding section B have a round or polygonal tubular configuration with at least in the winding section B more or less close to each other, ordered and substantially uniform turns T1. The diameter of the roll denoted by D is chosen so that the winding curvature corresponds at least approximately to the smallest natural and unforced curvature storage capability of the weft thread material.

Fig. 2 illustrates what is meant by it. When a portion E of the weft yarn material Y is placed on a smooth surface 5 and the two ends 3, 4 are moved toward each other in the direction of the arrows 1 and then released, the portion E returns under its own elasticity in the direction of the dashed arrows 2 in FIG shown position in which it has a residual curvature whose radius of curvature R _N corresponds to the smallest natural and unforced curvature storage capability of this weft thread material. This radius of curvature R _N corresponds approximately to half of the diameter D of the roll in FIG. 1.

Fig. 3 illustrates schematically another variant for carrying out the method. The inner support S, on which the winding of the weft thread is formed by a substantially continuous winding process, has rear-lying, stationary elements 6 and in the withdrawal direction vorneliegende, inwardly displaceable elements 8, which are connected, for example via a respective joint 7 with the elements 6 , By a corresponding movement control in the direction of the dashed arrow 9, the forwardly wound during winding turns T1 are released by moving away the elements 8 from the support S to the deduction, which takes place as in Fig. 1.

In Fig. 4, the support S comprises several e.g. Retaining the carrier 11 in the direction of the arrow 13 releases a desired number of turns from the support S to the trigger. Alternatively, it would be conceivable to release the windings by moving the abutment 12 forward.

In Figs. 5 and 6, a further variant of the method is indicated. The support S consists of a stationary support section S1, on which the winding element W forms the winding with the turns T, T1 in its substantially continuous winding movement R. In the withdrawal direction in front of the support part S1 another, eg coaxial auxiliary support S 2 is provided. This is open on the inside and comprises mounted on a support 14, a cage-like configuration forming example rod-shaped elements 15 which extend the support member S1 in the withdrawal direction, as long as the carrier 14 remains in the position shown in Fig. 5. Optionally, a stationary scraper 16 is provided, although this is not essential. Once a predetermined number of turns T1 has been formed on the support member S2 of tubular configuration by overfilling the support member S1, the support 14 with the elements 15 in the direction of the arrow 17 is rapidly pulled away. As a result, the turns T1 are released. From the foremost in the withdrawal direction of the weft yarn Y runs inwards and in the withdrawal direction through the formed with an inner passage opening scraper 16 and the carrier fourteenth

In Fig. 6, the turns T1 are released. The support part S2 is adjusted in the right end position. Now, by the indicated by the arrow C deduction of the weft yarn Y successive consumption of the released turns T1 back to the support part S1. Thereafter, the support member S2 is returned to the position shown in Fig. 5, so that by overfilling the support member S1 again turns T1 can be brought into the tubular configuration and deported from the support member S1.

In the method variants of Figs. 3 to 6, means H, G can also be used to measure the weft length, for example for a picking system A which is unable to automatically measure the inserted weft length, e.g. in a jet loom. The e.g. device H cooperating directly with the support S may be a controlled stopping device with a stopping element for terminating an entry by catching the weft material Y, while the other device G may be a controlled thread clamp which, by opening, controls the entry beginning.

In the method variants described above, the winding produced by the winding process is pushed forward by the winding process itself. Alternatively or additionally, feed elements or feed devices can also be used to feed the windings forward. It can be worked on the support S with a separation between the turns of thread.

For safety (indicated by dashed lines in FIG. 1), a mechanical (or pneumatic) guide surface arrangement F can be provided for the winding section B released by the support S, which, however, only acts on the released windings from the outside. This support F is not essential, but may be advantageous to prevent the collapse or sinking of the released winding section. It would also be conceivable to provide on the upper side only externally on the released winding part B attacking devices that prevent forward tilting of the trigger side first turns T1 in the exposed winding section B. Both these devices and the support F have no influence on the balloon-free consumption of the turns T1 in the central withdrawal of the weft yarn Y in the direction of the axis X of the winding section B. The diameter D may, for example, in the range of 30 mm. However, individual yarn qualities may also require a larger or smaller diameter D. Experience has shown that a wide range of yarn qualities and yarn sizes have a similar minimum natural and unconstrained curvature storage capability corresponding to a radius of curvature of about 15 mm.

The method is not only intended for jet looms, but also e.g. applicable to rapier and projectile machines.

Fig. 7 shows a thread feeding device 18 suitable for carrying out the method, to which some details in Figs. 8, 9, 10, 11 and 13 are illustrated. For example, the yarn feeding device 18 in Fig. 7 serves to supply weft yarns Y to a jet loom, for example, an air-jet loom whose feed system A is unable to measure the weft yarn lengths themselves. Therefore, in the yarn feeding device 18, the means H, G are provided.

The drive motor M of the winding element W is housed in a housing. The winding element W rotates relative to the stationary support S, which is designed in the manner of a rod cage with distributed in the circumferential direction, substantially parallel to the drawing direction X extending, free-ending rods 19 is formed. The device H is located at the bottom of the support S and will be described with reference to FIGS. 8 to 10 in Detail explained while the device G downstream of the support S and arranged as a controlled thread clamp 20 is formed.

The thread clamp 20 is by means of an auxiliary drive 21 about an axis of rotation 21 'back and forth, which is perpendicular to the withdrawal direction X. The thread clamp 20 has a tubular extension 41 with a notch-like clamping region 42 for the weft. The extension 41 extends from the outside and perpendicular to the axis of rotation 21 'to approximately below the extension of the support axis. A double arrow 22 indicates how the thread clamp 20 can be moved back and forth by means of the auxiliary drive 21. The rotary drive 21 includes, for example, a responsive stepper motor. Alternatively, a linear drive device could be provided, which adjusts the thread clamp 20 parallel to the withdrawal direction Y according to the double arrow 22 back and forth. In axial overlap with the support S guide surfaces F are provided for the filament winding or the released filament winding part, which in this case from below and from both sides are available to guide the released filament winding part, if necessary, and support.

In principle, it may be expedient to temporarily largely remove the thread clamp 20 in the final phase of an entry from the movement space of the thread; e.g. by means of a separate actuator, not shown, or even by means of the auxiliary drive 21, e.g. in a position Q in Fig. 7. Alternatively, a cover could be brought over the clamping region 42 in the short term, or a permanent deflector may be provided. These measures prevent the thread imposed at the entry end of the thread clamp 20.

8 shows a radial section of a variant of the yarn delivery device 18, in which the device H is arranged below the support S and is designed as a stop device with a movable stop element 24. The rods 19 of the support S are freely cantilevered in a stationary support 23 about which the winding element W rotates. The carrier 23 is rotatably supported, for example, on the drive shaft of the winding element W; However, it is prevented by co-rotation with the drive shaft by means not shown magnet arrangements and is therefore stationary.

The stop element 24 is pin-shaped and connected via a joint 28 with a hinge axis perpendicular to the withdrawal direction X with a valve 25 of a magnetic drive 26 (linear drive) with which the stop element 24 in the direction of the double arrow 27 between the release position shown and an engagement position back and forth is. In the engagement position, the free end of the stop element 24 engages in a cutout or longitudinal guide 31 of a rod 19. At the left in Fig. 8 end of the longitudinal guide 31, a stop 32 is provided which defines the so-called stop position in the engagement position of the stop member 24, in which the stop member 24 prevents further weft thread from the turns on the support S is withdrawn. To the joint 28, the free end of the stop element 24, for example, in the direction of the double arrow 29 back and forth. A stop 30 defines the initial position of the stop element 24 shown in FIG. 8, in which it can be brought upwards from the release position shown into the longitudinal guide 31, such that it protrudes from the thread emerging from the winding element W and behind the support S located in the withdrawal direction first Fadenwindung is placed. Thanks to the joint 28, the stop element 24 is taken along by the thread winding in the further formation of turns of thread, until it is intercepted in the stop position on the stop 32. The entry is terminated as soon as the withdrawn weft thread is caught on the stop element 24. After the end of the entry, the stop element 24 is withdrawn by the magnetic drive 26 back into the release position, so that the filament winding can overfill the support S or again weft thread can be removed. For returning the stop member 24 to the initial position shown in Fig. 8, a positive drive 33 is stationary relative to the stop member 24, e.g. a controlled solenoid 33 (solenoid), which is active when the stop member 24 is to be moved back. Since the stop element 24 is only responsible for the entry end, the thread clamp 20 controls the start of entry.

9 and 10 illustrate a detail variant with a stop element 24, the joint 28 is formed as an elastic hinge portion 28 'with mobility in all directions. For example, the hinge portion 28 'consists of an elastomeric part. The adjustment of the stop element 24 from that shown in Fig. 10 Stopplage back into the starting position indicated in Fig. 9 is achieved by the elasticity of the joint portion 28 ', so to speak, automatically. The spring action in the hinge region 28 'should be as weak as possible in order to load the filament winding advancing the stop element 24 as little as possible. As a precaution, a permanent magnet 33 can be provided in order to ensure the starting position of the stop element 24 shown in FIG. 9 with a magnetic region 35.

Adjacent to the support S or its bars 19, a stationary structure 34 is provided here, which maintains a distance from the outer sides of the bars 19 and contains a longitudinal guide 31 'for the stop element 24. In the rod 19 or between two rods 19, a cutout 39 is provided as a longitudinal guide or passageway for the immersed in the support S stop member 24. An abutment 36 forming a damping element is arranged in the structure 34, which is explained with reference to FIG. 11 and serves to define the stop position of the stop element 24 and, in cooperation therewith, a damping device of the yarn delivery device 18.

In the sectional view in Fig. 11 it can be seen that the longitudinal guide 31 'is a slot which guides the submerged stop member 24, while the filament winding advances the stop member brought into the engagement position. In a transverse guideway 38, which is oriented substantially in the circumferential direction of the support S or in a direction obliquely to the withdrawal direction, the abutment 36 against the force of a spring 37 is displaceable. The abutment 36 forms on the one hand the stop 32 'for defining the stop pest, and on the other hand, a damping element which is elastically adjustable from the force exerted on the stop member in the stop position k reaction force of the delayed weft yarn from a first catch position k via a damping stroke in a second catch position , Through this stroke kinetic energy is consumed, with a voltage increase in the weft yarn Y is mitigated or eliminated at the entry end.

In an alternative, not shown, the stop element 24 itself could be elastically deflectable substantially in the circumferential direction of the support with a counterforce and directly form the damping device.

In FIG. 12, the support S is assigned a retaining element 39 (lamella or brush) which, in cooperation with the front end of the support S or the weft thread, which is about to be caught on the stop element 24 which has arrived in the stop pest, in FIG Pulling direction extends obliquely downwards The retaining element 39 can be adjusted, for example, in the direction of a double arrow 40 back and forth to actually act speed-reducing only towards the end of the entry on the thread.

Fig. 13 illustrates the structure of the controlled thread clamp 20 of Fig. 7. The tubular extension 41 is fixed to a housing which receives the electromagnetic drive 48, 49 for adjusting the thread clamp from the clamping position shown in the passive position, not shown. The notch-shaped clamping region 42 is defined by a boundary surface 43 of an outwardly open notch of the extension 41 and a clamping surface 44 on a shoulder of a displaceable in the extension 41 bolt 45. The bolt 45 is acted upon in the clamping direction by the force of a spring 46. The spring 46 is responsible to set the Y thread. In the electromagnetic drive 48, 49, a plunger-like armature is provided which occupies the non-energized electromagnet 48, the starting position shown in Fig. 13 and the bolt 45 maintains an intermediate distance 50. The spacing 50 allows the armature 49 to accelerate rapidly upon energization of the solenoid 48 and only then to strike the bolt 45 with full force so that the weft yarn Y is released abruptly (opening time on the order of 1 millisecond).

The thread clamp 20 is adjusted for example by means of a trig signal transmitted by the loom from the clamping position shown in Fig. 13 in the passive position, in which the weft yarn Y is released for deduction to initiate the entry process. By contrast, for example, the stop element 24 is withdrawn at a time after the adjustment of the thread clamp 20 in the clamping position from the stop position and engagement position by means of a signal which is generated by the unspecified highlighted control device of the yarn feeding device. For adjusting the thread clamp 20 is optionally also a signal of the control device the thread delivery device used. The adjustment of the Stoppelements 24 from the initial position into the engagement position is also caused by a signal from the control device of the yarn feeding device, for example, as soon as the number of wound thread turns has risen to a target number. For counting purposes, for example, a Hall sensor HS (FIG. 8) placed in the stationary part of the yarn delivery device, which is aligned with a permanent magnet PM arranged on the winding element W, is used.

The course of the procedure with the yarn feeding device 18 will be explained with reference to the diagram of FIG. 14 for two successive picking operations (curve I '). On the horizontal axis, the time t or the rotation angle of the weaving machine is plotted, while the vertical axis represents, among other things, lifts of the devices H, G in two mutually opposite directions.

The horizontal parts of the curve l 'represent times in which no thread consumption takes place, while the arcuate parts each represent an entry in which the predetermined weft length is entered from the entry system A into the loom of the loom.

The curve II illustrates the adjustment of the device H, ie the Stoppelements 24, between the release position a and the engagement position b. The curve III illustrates the adjustment of the device G, ie the clamping surface 44 relative to the boundary surface 43 of the thread clamp 20 in the longitudinal direction of the extension 41 between the clamping position d and the passive position c. The curve IV illustrates the path of Stoppelements 24 in the device H in and opposite to the withdrawal direction between the starting position f approximately in Fig. 8 and the stop position e approximately as shown in FIG. 10. The curve V illustrates the adjustment of the device G, ie the thread clamp 20, in the direction of the double arrow 22 in Fig. 7, ie in and opposite to the withdrawal direction between a position g, in which the thread clamp 20 is farthest from the support S, via a middle position h to a position i, in which the thread clamp 20 closest to Support S.

According to curve II, the stop element 24, which is in front of the entry in the release position a, moved at a time t1 in the engagement position b, and indeed according to curve IV in the starting position f of the stop element 24 near the winding element W. There will be successively new Thread turns formed so that according to curve IV, the stop member 24 until the time t3 gradually passes into the stop position e. If, at the time t1, the stop element 24 is moved into the engagement position b, the thread clamp 20 according to curve 3 is still in the clamping position d, so that it holds the weft thread. Over this period of time, the thread clamp 20 according to curve V is still the farthest away from the support S in the position g. At time t2, for example, a trig signal is transmitted. The thread clamp 20 is adjusted to the passive position c. The entry begins. In the passive position according to curve V, the thread clamp 20 is gradually adjusted to the middle position h, which it has taken, for example, at time t4. At time t3, the entry is to be terminated. The stop element 24 has arrived at curve IV in the stop position e and set so that the weft thread is caught. The entry is finished. At time t4, the thread clamp 20 is adjusted according to curve III back into its clamping position d, so that it holds the thread. Thereafter, the thread clamp 20 is adjusted according to curve V from the middle position h to the position i next to the support S, thereby relaxing the thread section between the stop member 24 and the thread clamp 20. After the thread relaxation, the stop element 24 is moved according to curve 11 in the release position at time t5, which runs because of the relaxed thread without significant friction on the thread and without jumping of the thread. Once the stop element 24 has reached the release position, it is adjusted according to curve IV by means of the positive drive 33 from the stop position e to the starting position f near the winding element W until the starting position is reached at time t1. Then it is moved back into the engagement position (curve II) before the next entry begins at time t2. After the stop element 24 has been brought into the release position at time t5 in curve II, the thread clamp 20 according to curve V in the withdrawal direction from the position i next to the support gradually adjusted to the position g, in which they (according to curve III) Thread holds until the time t2, ie the beginning of the entry.

According to curve V, the thread clamp 20 is initially adjusted gradually from the position g to the middle position h, which it reaches at time t4. Only then is the further adjustment to the position i as soon as the stop element 24 has been moved to the release position.

Alternatively, the thread clamp 20 could, in deviation from the curve V between the times t2 and t3 remain at least approximately in the position g, and only at the time t4 be continuously adjusted to the position i, which reaches it at or shortly before the time t5 should have.

Since the weft thread length is always an integer multiple of the circumferential length of the support S (diameter D ') with just one stop element 24, the diameter D' must be adjustable in order to adapt to the weaving width. For this purpose, according to FIGS. 15 and 16, the support S is designed with a variable diameter. The rods 19 are mounted, preferably in groups, on fingers 51 which are movably guided on the stationary support 23 in the radial direction. Their respective radial adjustment position can be determined by at least one fastening screw 52. Each finger has an individual eccentric adjusting device 53, with which the diameter D 'of the support S can be varied continuously. In the eccentric adjusting device, a setting eccentric 55 is provided, which passes through a cutout 56 in the finger 51, and whose function is explained with reference to FIG. 16.

In Fig. 16, the cam eccentric 55 is rotatably supported about its axis 57 in the carrier 23, with a pivot portion 58 (secured by a fuse element, not shown, which engages in a circumferential groove 61). The adjustment eccentric 55 has an eccentric region 59 with an eccentric axis offset with respect to the axis of rotation 57, and a handle 60 for attaching a rotary tool. The eccentric region 59 engages in the substantially circumferentially extending cutout 56 of the finger 51, preferably with a sliding fit. By rotating the adjusting cam 55, for example over a limited range of rotation of 180 °, the entire adjustment range of each finger 51 is defined. The adjustment is carried out after loosening the fastening screw 52 and fixed by re-tightening the fastening screw 52 again.

Alternatively (not shown), the adjusting eccentric 55 could only be rotatably mounted in the finger 51 and engage with its eccentric region 59 in a section analogous to the cutout 56 in the carrier 23.

In Fig. 17 is indicated schematically, as in the yarn package according to the method a number of turns is formed, which corresponds to a plurality of weft yarn lengths. For length measurement of each weft thread section, a plurality of stop elements 24 'are provided, which advantageously move along with the thread winding in the withdrawal direction and can be brought to attack on selected turns T'. The turns T are formed larger than the adjacent turns T, for example by means of a device 62, which is temporarily placed on the winding element W (double arrow 63), and then leaves such a larger turn arise each selected one of the stop elements 24 'engages one of the enlarged turns T to terminate the entry of the previous windings T in the withdrawal direction, and is later brought, for example by a rotational movement to its release position as soon as the next entry begins, which is terminated by the next, engaged stop element 24.

In Fig. 18, the stop members 24 'are hook-shaped and held in Drehlagem 65. Via sprockets 66, the stop elements 24 between their engagement positions and their release positions reciprocate. An arrow 64 indicates the co-movement of the stop elements with the forward-fed filament winding in Fig. 17.

In the thread path downstream of the thread clamp, a controlled thread brake may be present (not shown).

In a weaving machine, the entry system is automatically able to measure the weft length mechanically (projectile or rapier), the devices H, G may be omitted.

When removing the thread from the released winding section B, the thread moves directly initially approximately radially inward before it continues to run substantially in the axial direction. Depending on the adhesion between the turns of thread and the elasticity and the liveliness of the thread material, in some cases almost a whole turn can move inwards or the thread can spiral inwards from the foremost turn. This could mean that a loop forms on a case-by-case basis, which tends to twist where there is lively thread material. the thread crosses over. At the high take-off speed, such a loop (snarl) could then lead to a knot or not dissolve and be registered. This could cause a tissue defect or an entry failure. Referring to Fig. 19, therefore, there is provided a loop suppression body 68 which eliminates the aforementioned effect. The support S with its rods 19 on the fingers 51, which are mounted on the carrier 23, around which the winding element W, for example in the direction of arrow rotates, provide a bearing surface of a certain axial length and the aforementioned diameter. The loop suppression body 68 is fixed within the bars 19 with a foot portion 69 on the support S, for example, used easily interchangeable or even screwed. It extends approximately in the direction of the support axis beyond the front end of the support S, ie beyond the front end defined by the rods 19, to a free end 71. In the illustrated embodiment, a tapered, rotationally symmetric pin 70 is provided whose diameter is considerably smaller than the diameter of the support surface, and at least at the free end 71 is only a fraction of the diameter of the support surface. The pin 70 may be rectilinear conical or with a concave or convex generatrix. It can also be designed as a pointed cone or as a cylinder. Its lateral surface 72 should be smooth, optionally with a low-friction coating, in order to produce as little frictional resistance as possible for the thread. In the exemplary embodiment shown, the loop suppression body 68 extends with its free end 71 beyond the position of the thread clamp 20. The thread clamp 20 is otherwise positioned in the withdrawal path of the thread from the support S outside the support axis and substantially aligned with the stop member 24, so that the outgoing from the stop element 24 thread arrives safely in the clamping region 42. The guide slot 31 for the stop element 24 is shown in FIG 19 indicated.

The free end 71 of the pin 70 need not necessarily be downstream of the thread clamp 20. It is conceivable to place the free end 71 exactly at the position of the thread clamp 20, or between the thread clamp 20 and the support S. In any case, the loop suppression body 68 must protrude beyond the front end of the support S in order to prevent twist loops and possibly knot when kneading.

In operation, the withdrawn thread contacted the lateral surface 72 at least occasionally. Should a sling be created that tends to twist about its intersection, e.g. with lively thread material, this is prevented by the physical presence of the loop suppression body 68. A noose can not twist, but is opened and consumed. As a particularly positive effect of the loop suppression body 68 results surprisingly also a very smooth running of the thread into the entry device.

The loop suppression body 68 may be made of plastic or metal. It would also be conceivable, instead of a pin od several parallel or conically aspiring pieces of wire od. Like. To use; or form the conical pin 70 with concave or convex generatrix.

The loop suppression body 68 can be used to advantage for attaching a reliable thread take-off sensor (Figures 20 and 21) which detects each withdrawn turn. In Fig. 20, a reflective surface 73 (e.g., a mirror) for an opto-electronic sensor 74, 75 is placed on or in the lateral surface 72. In Fig. 21, a transverse passage 76 is formed in the pin 70, through which a detection beam of a transmitted light sensor 74 ', 75' is directed. In Fig. 20, each turn may be detected once, whereas in Fig. 21, twice.

Claims (53)

1. Method for intermittently inserting weft yarns by means of an insertion system (A) into a weaving machine (L), according to which method from endless weft yarn material (Y) at least a considerable part of the weft yarn length needed for an insertion is presented loosely and substantially without yarn tension for withdrawal by the insertion system (A) such that a tubular winding package consisting of adjacently lying windings (T, T1 ) is formed from the weft material (Y) on the outer side of a drum-shaped support (S) by an at least substantially continuous winding process, the yarn winding package being conveyed forward substantially in withdrawal direction, characterised in that for the withdrawal a number of at least substantially equally formed windings (T1), the number substantially corresponding with the or a multiple of the weft yarn length to be inserted, is set free from the support (S) at the withdrawal side of the yarn winding package loosely and substantially without yarn tension such that the windings (T1) maintain the tubular configuration and are consumed during the withdrawal before they collapse, and that the weft yarn is withdrawn from the respective front most winding (T1) at the withdrawal side inwardly towards the and further substantially along the tube axis (X) of the tubular configuration.
2. Method as in claim 1, characterised in that the weft yarn is withdrawn in timewise overlap with the process of setting the windings free.
3. Method as in claim 1, characterised in that the windings (T1) are set free by axially overfilling of the support (S) by the yarn winding package.
4. Method as in claim 1, characterised in that the windings (T1) are set free over the withdrawal side of the support (S) by conveying the yarn winding package forward on the support (S).
5. Method as in claim 3 or 4, characterised in that the yarn winding package and the set free windings (T1) are conveyed in withdrawal direction obliquely upwards.
6. Method as in claim 1, characterised in that the windings (T1 ) are set free by a dispensing movement of at least a part (S1, 8) of the support (S) relative to the yarn winding package.
7. Method as in claim 1, characterised in that the weft yarn material (Y) is wound into the windings (T, T1) in the yarn winding package with a curvature (D) corresponding at least approximately to the smallest natural and unforced capability of the weft yarn material (Y) to store a curvature (RN).
8. Method as in claim 1, characterised in that the weft yarn is mechanically measured upstream of the insertion system (A) with the weft yarn length.
9. Method as in claim 1, characterised in that the weft yarn length is mechanically measured mainly by the insertion system (A).
10. Method as in claim 1, characterised in that the set free windings (T1) exclusively are supported from the outer side.
11. Method as in claim 1, characterised in that the set free windings (T1) are supported at least from the lower outer side, preferably also from the side and/or from the top.
12. Method as in claim 1, characterised in that the set free windings (T1) are supported from the outer side by a suspension which moves approximately in synchronism with the windings conveyed forwards in withdrawal direction.
13. Method as in claim 1, characterised in that the yarn winding package is formed with several selected windings which are enlarged in relation to adjacent windings for defining engagement locations for mechanical length measuring assemblies (H).
14. Yarn feeding device (18) for a weaving machine (L), particularly a jet weaving machine, including a winding element (W) being rotatably driven in relation to a stationary, substantially drum-shaped support (S) for forming a tubular yarn winding package consisting of adjacently lying windings (T, T1 ) of substantially equal form which yarn winding package is conveyed forwards in withdrawal direction on the support (S), and a mechanical weft yarn length measuring assembly (G, H) having at least one stop element (24) co-operating with the support (S), the stop element (24) being adjustable between an engagement position (b) where it engages from the outer side into the support (S), and a retracted release position (A), characterised in that for the withdrawal at the withdrawal side of the yarn winding package a number of at least substantially equally formed windings (T1) substantially corresponding with the or a multiple of the weft yarn length to be inserted is set free from the support (S) loosely and substantially without yarn tension such that the windings (T1) maintains the tubular configuration and are consumed during the withdrawal before they collapse, that the weft yarn is withdrawn from the respective front most winding (T1) at the withdrawal side of the set free windings (T1) inwardly towards the and further substantially along the tube axis (X) of the tubular configuration, that the stop element (24) is movable in withdrawal direction relative to the support (S), that a power drive (33) is provided for moving the stop element (24) opposite to the withdrawal direction into a predetermined home position (f) close to the winding element (W), and that the stop element (24) when in the engagement position (b) is exclusively movable by the growing yarn winding package from the home position (f) in withdrawal direction to a predetermined stop position (e).
15. Yarn feeding device as in claim 14, characterised in that a part of the mechanical weft yarn length measuring assembly (G, H) in the yarn path downstream of the stop element (24) is a yarn clamp (20), which is adjustable between a clamping position (d) and a passive position (c), that the yarn clamp comprises a drive (48, 46) for adjusting the yarn clamp (20) from the clamping position (d) into the passive position (c) after an adjustment of the stop element (24) from the release position (a) into the engagement position (b), and for adjusting the yarn clamp (20) from the passive position (c) again into the clamping position (d) to hold the yarn prior to an adjustment of the stop element (24) from the engagement position (b) back into the release position (a), and that the yarn clamp (20) releases the first firmly held weft yarn for the insertion by the adjustment from the clamping position (d) into the passive position (c).
16. Yarn feeding device as in claim 15, characterised in that the yarn clamp (20) includes an auxiliary drive (21) for displacing the yarn clamp (20) back and forth substantially in and counter to the withdrawal direction, and that the auxiliary drive (21), the drive (48, 46) of the yarn clamp (20) and a drive (26) of the stop element (24) are correlated in this respective driving movements such that the yarn clamp (20) when in its clamping position (d) is movable opposite to the withdrawal direction or in the direction towards the stop element (24), respectively, prior to a movement of the stop element (24) from the engagement position (b) into the release position (a).
17. Yarn feeding device as in claim 14, characterised in that a hinge (28) is provided between the stop element (24) and the drive (26) serving to adjust the stop element (24) between the engagement position and the release position, and that the stop element (24) is movably guided in withdrawal direction either about a hinge axis extending perpendicular to the withdrawal direction and/or in a guide (30, 31') extending in withdrawal direction, the guidance (30, 31') being provided either in the support (S) or in a structure (34) located adjacent to the support (S).
18. Yarn feeding device as in claim 14, characterised in that the power drive (33) includes a controlled solenoid (33') which is stationarily provided in relation to the stop element (24) and which, when activated, produces a force acting at a portion (33) of the stop element (24) in a direction opposite to the withdrawal direction.
19. Yarn feeding device as in claim 14, characterised in that the support (S) or a stationary structure (34) located adjacent to the support (S) has a stop (32, 32') for defining the stop position (e) of the stop element (24).
20. Yarn feeding device as in claim 14, characterised in that the stop element (24) when in the stop position (e) is deflectable in circumferential direction of the support (S) against a predetermined resilient counter force.
21. Yarn feeding device as in claim 20, characterised in that the stop element (24) itself is formed such that it is deflectable in circumferential direction of the support against a predetermined counter force and is resiliently returnable, preferably by means of a springy section (28') of the hinge (28).
22. Yarn feeding device as in claim 20, characterised in that a sidewardly positioned retainer (36) is provided in the support (S) or in the stationary structure (34) located adjacent to the support (S), the retainer (36) forming the stop (32') for defining the stop position (e), that the retainer (36) is displaceable in circumferential direction of the support by the stop element (24) and against the predetermined resilient counter force (37), and that the retainer (36) automatically returns under the force (37).
23. Yarn feeding device as in claim 15, characterised in that the yarn clamp (20) is provided with a tubular small diameter projection (41) including a notch-shaped yarn clamping region (42), that the clamping region is placed close to the front end of the support (S), that the projection (41) extends freely ending from a support location outside of the axial projection of the outer diameter (D) of the yarn winding package essentially crosswise to the withdrawal direction through the yarn withdrawal path, and that the auxiliary drive (21) of the yarn clamp (20) is arranged in the support location, and is either constituted by a rotational drive having a rotation axis (21') oriented substantially perpendicular to the withdrawal direction and to the longitudinal axis of the projection (41) or is constituted by a linear displacement drive for a displacement direction essentially parallel to the withdrawal direction.
24. Yarn feeding device as in claim 23, characterised in that the notch-shaped clamping section (42) is defined by a boundary surface (43) of an outwardly open notch formed in the projection (41) and by a clamping surface (44) of a bolt (45) which is longitudinally displaceable received in the projection (41), and that the bolt (45) in the clamping position (d) of the yarn clamp (20) is loaded by spring force (46) and is pressed with its clamping surface (44) against the boundary surface (43) with the weft yarn (Y) held in-between.
25. Yarn feeding device as in claim 15, characterised in that a drive of the yarn clamp (20) includes a switching solenoid (48) inclusive a plunger-shaped armature (49), that the armature (49) engages at the bolt (45) opposite to the spring force (46) when current is supplied to the switching solenoid, and that in the clamping position (d) of the yarn clamp (20) a predetermined intermediate distance (50) is formed between the armature (49) and the bolt (45), when no current is supplied to the switching solenoid and while the armature (49) maintains a predetermined initial position.
26. Yarn feeding device as in claim 14, characterised in that at least one outer guiding surface (F) for the yarn winding package section (B) set free during overfilling of the support (S) is arranged in withdrawal direction following the support (S), that the guiding surface (F) extends substantially in withdrawal direction, and that, preferably, The guiding surface (F) extends in withdrawal direction beyond the yarn clamp (20) and overlaps the front end of the support (S).
27. Yarn feeding device as in claim 26, characterised in that the guiding surface (F) at least surrounds the lower half of the yarn winding package from the outer side, preferably surrounds more than the lower half of, preferably, even the entire yarn winding package.
28. Yarn feeding device as in claim 26, characterised in that the guiding surface (F) consists in circumferential direction of the yarn winding package of single partial surfaces or finger-shaped or rod-shaped elements.
29. Yarn feeding device as in claim 26, characterised in that at least a part of the guiding surface (F) surrounding the lower outer side of the set free yarn winding package section (B) is inclined obliquely upwardly in withdrawal direction.
30. Yarn feeding device as in claim 26, characterised in that a drive is provided for moving at least part of the guiding surface (F) substantially in withdrawal direction together with the yarn winding package.
31. Yarn feeding device as in claim 14, characterised in that a back holding element (39) is provided over the top side of the yarn winding package, that the back holding element (39), preferably, is a lamella, a brush or a lateral arm, that the back holding element (39), preferably, is movable from a raised neutral position to a lowered holding position, and that the back holding element (39) in the holding position is in contact with the weft yarn material and/or the support while the back holding element (39) extends obliquely downward from the top side over the end of the yarn winding package at the withdrawal side while the end of the yarn winding package remains supported by the support (S).
32. Yarn feeding device as in claim 14, characterised in that the support (S) is formed as a diameter variable rod cage having rods (19) extending substantially parallel to the withdrawal direction, that the outer peripheries of the rods (19) form a support surface for the yarn winding package, that the rods (19), preferably in rod groups, are provided on fingers (51) which are adjustably guided substantially radially with respect to the axis of the support in a stationary carrier (23) and which can be fixed in different radial adjustment positions, and that each finger (51) is equipped with an individual eccenter adjustment device (53) including an adjusting eccentric portion (55) accessible from the front side of the support (S).
33. Yarn feeding device as in claim 32, characterised in that the adjusting eccentric portion (55) is supported in the carrier (23) for rotation about an axis parallel to the axis of the support (S), preferably for an adjustment over a limited rotational range of e.g. 180°, and that the adjusting eccentric portion (55) engages by an eccentric portion (59) into a cut-out (56) of the finger (51) which cut-out is oriented in circumferential direction.
34. Yarn feeding device as in claim 32, characterised in that the adjusting eccentric portion (55) is supported in the finger (51) for rotation about an axis parallel to the axis of the support, preferably over a limited rotational range of e.g. 180°, and that the adjusting eccentric portion (55) engages with an eccentric section into a cut-out in the carrier (23) which cut-out is oriented in circumferential direction.
35. Yarn feeding device as in claim 14, characterised in that the support (S) has an outer diameter (D') between about 20 mm and 50 mm, preferably between about 30 mm and 40 mm.
36. Yarn feeding device as in claim 14, characterised in that the stop element (24) is located at the lower side of the support (S).
37. Yarn feeding device as in claim 23 or 36, characterised in that the clamping section (42) of the yarn clamp (20) is positioned at the outer side of the axis of the support (S) and in withdrawal direction of the weft yarn (Y) substantially in alignment with the stop element (24).
38. Yarn feeding device as in claim 14, characterised in that a snarl suppressing body (68) is centrally provided at the support (S), preferably replaceably, that the snarl suppressing body (68) extends from the support (S) at least approximately in alignment with the axis of the support in withdrawal direction, and that the snarl suppressing body (68) has a free end (71) located at a position in distance ahead of the front of the support (S).
39. Yarn feeding device as in claim 38, characterised in that the snarl suppressing body (68) has a rotation symmetrical coat surface (72) tapering in the direction towards the free end (71) and that, preferably, a yarn withdrawal sensor (73, 74, 75, 74', 75', 76') is structurally associated to the snarl suppressing body (68).
40. Yarn feeding device as in claim 38, characterised in that the snarl suppressing body (68) is a pin (70), preferably a conical pin.
41. Yarn feeding device as in claim 40, characterised in that the outer diameter of the pin (70), at least close to the free end (71), amounts to a fraction of the diameter (D') of the support (S) only.
42. Yarn feeding device as in claim 38, characterised in that the free end (71) is located close to the position of the yarn clamp (20), preferably in withdrawal direction downstream of the position of the yarn clamp (20).
43. Yarn feeding device as in claim 39, characterised in that the coat surface (72) is smooth and formed with low friction, preferably by providing a low friction overlay.
44. Yarn feeding device as in claim 14, characterised in that the surface of the support (S) is formed with a conical tapering in withdrawal direction, preferably with an inclination of about 1 °.
45. Yarn feeding device as in claim 14, characterised in that an advance element is provided between the winding element (W) and the surface of the support (S), and that the advance element is driven for a wobbling motion in synchronism with the winding element (W).
46. Yarn feeding device as in claim 14, characterised in that advance elements are provided between the rods (19) of the rod cage of the support (S), that the advance elements are connected to a common drive driving the advance elements in synchronism with the winding element (W) in withdrawal direction back and forth in oscillating fashion such that each advance element during the forward motion protrudes relative to the adjacent rods (19) and beyond the rods outwardly and returns during the backward motion relative to the adjacent rods (19) again inwardly and behind the rods (19).
47. Yarn feeding device as in claim 14, characterised in that the support (S) is arranged such that it can be pulled back relative to the yarn winding package and opposite to the withdrawal direction to set the yarn winding package section free.
48. Yarn feeding device as in claim 47, characterised in that a substantially stationary strip-off member (12) is provided, and that the support (S) is arranged such that it can be pulled back relative to the strip-off member (12)
49. Yarn feeding device as in claim 14, characterised in that a coaxial ring-shaped auxiliary support (S2) is structurally associated to the front end of the support (S, S1), that the auxiliary support (S2) has at least about the same outer diameter (D') as the support (S, S1), that the auxiliary support (S2) is arranged such that it can be adjusted between a yarn winding position at the front end for prolonging the support (S, S1) into a gap position axially out of the yarn winding package, such that it forms an intermediate distance with the front end in the gap position for withdrawing the weft yarn through the interior of the auxiliary support (S2).
50. Yarn feeding device as in claim 49, characterised in that the auxiliary support (S2) is arranged such that it can be shifted into the gap position relative to a substantially stationary, ring-shaped strip-off member (16).
51. Yarn feeding device as in claim 14, characterised in that a cyclically drivable device (62) is arranged between the winding elements (W) and the support (S) for selectively forming single enlarged windings (T'), that several hook-shaped stop elements (24') are arranged such that they can be moved together with the yarn winding package and that they can be moved, preferably, turned in and outwardly, and that each stop element is movable into an engagement position in which it engages into one of the larger windings (T') which are formed in the yarn winding package among other smaller adjacent windings.
52. Yarn feeding device as in claim 14, characterised in that the stop element (24) is arranged in the engagement position (b) such that it is deflected by the weft yarn (Y)against a predetermined resilient force from a first catching position (k) over a damping stroke in circumferential direction of the support (S) into a second catching position (1).
53. Yarn feeding device as in claim 52, characterised in that the stop element (24) is connected with a linear drive (25, 26) for adjusting the stop element (24) between the engagement position (b) and the release position (a), that the stop element (24) includes a hinge section (28, 28') between the support (S) and the linear drive, and that an automatically returning damping element (36) is provided in a stationary circumferentially oriented guidance (38), the damping element (36) being displaceable by the stop element (24) against a spring force (37).

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