EP0131481B1 - Weft mixer for looms - Google Patents

Description

The invention relates to weft yarn mixing devices which allow different wefts, possibly of different colors, to be inserted from a feed located outside a weaving machine.

Usually, devices of this kind include a support to be fixed on the machine and on which are mounted: a plurality of fingers for presenting the different weft threads adapted to each take, selectively, ie an active active position for presenting a thread corresponding frame, ie a retracted inactive position; first individual positive control means for bringing each presentation finger to the advanced active position; second individual positive control means for returning each presentation finger to its retracted inactive position; general control means of the aforementioned first individual control means, adapted to be connected to the main shaft of the machine to operate in synchronism with said shaft; means for selective connection between the general control means and the first individual control means; and programmed selection control means suitable for controlling said selective connection means.

A weft mixing device, as defined above, has been described for example in document GB-A-2099863 and its definition is repeated in the preamble of claim 1 appended.

However, for high speed weaving machines, such a device has the disadvantage that the individual return control means always act, on a presentation finger which has been brought into the active active position, to cause it to return to its position. inactive moved back.

It follows that, if the same weft yarn must be presented several times in succession, its presentation finger will be brought back, unnecessarily, several times in succession to the retracted position to return immediately to the advanced position. This causes unnecessary fatigue of the weft thread considered, which can go as far as a weft breakage on a high speed loom. This also leads to unnecessary setting in motion of mechanical members, increasing the inertia forces, which is harmful for a high-speed loom.

The object of the present invention is to remedy this drawback by allowing a presentation finger to remain, for several successive cycles, in the advanced position, without returning to the retracted position, if the same weft thread is used several times successively.

The device according to the invention is characterized in that the second individual means for controlling the return of each presentation finger to its retracted inactive position are also subjected to the action of the selective connection means, and in that each presentation finger is connected to a rocker arm subjected to the antagonistic actions programmed by the first and second individual control means.

Thanks to the fact that the second return control means are also subject to selective connection means and to the fact that a rocker arm, to which the presentation finger is coupled, is controlled by both the first and second control means, a presentation finger which has been advanced will remain in this advanced position, without being brought back each cycle to the retracted position, if the same weft thread is to be used for several successive cycles.

The invention will be better understood on reading the description which follows and on examining the appended drawings which show, by way of example, an embodiment of the invention.

• la figure 1 est une vue de profil d'un dispositif mélangeur de fils de trame suivant l'invention,
• la figure 2 est une vue en plan partielle montrant un détail de la partie supérieure gauche de la figure 1,
• la figure 3 est une coupe horizontale partielle faite suivant la ligne III-III de la figure 1, et
• la figure 4 représente la partie principale de la figure pour une position différente des moyens de liaison sélective.

In these drawings:

• FIG. 1 is a side view of a weft yarn mixing device according to the invention,
• FIG. 2 is a partial plan view showing a detail of the upper left part of FIG. 1,
• FIG. 3 is a partial horizontal section taken along line III-III of FIG. 1, and
• 4 shows the main part of the figure for a different position of the selective connection means.

The weft yarn mixing device for a weaving machine shown in FIG. 1 is mounted on a support 1 to be fixed on the machine; it includes a plurality of fingers such as 2, for presenting the different weft threads, eight in number, for example. The finger 2 can slide in a hole 3 of the support 1, its distal end has an eye 4 for receiving a weft thread, while its proximal end is articulated, by an axis 5, on a rocker arm 6 which can pivot on an axis 7 carried by the support 1. The finger 2 can selectively take either a remote inactive position which is that shown in solid lines in the drawing, or an advanced active position for presenting the corresponding weft yarn which is that shown in broken lines in 2A. It is brought positively from its inactive position to its active position by a pivoting movement of the rocker arm 6 in the direction of the arrow f and it is brought back, also in a positive manner, from its active position to its inactive position, by a pivoting movement of the rocker arm in the opposite direction to that of arrow f. In the drawing, finger 2 is shown rectilinear, while other fingers, such as 2B and 2C, are shown curved and this so that the different fingers present their weft threads in substantially the same location, moreover possibly several threads at the same time, for example two.

Each presentation finger is associated with a rocker arm; thus, the different fingers 2, 2B and 2C, for example, are associated, respectively, rockers 6, 6B and 6C (see also Figure 3).

Oscillating movements of the rocker arms. such as 6, are ensured, from general control means, by means of selective connection means and individual control means.

The general control means comprise: a grooved cam 11, a shaft 12 which rotates in a bearing 13 integral with the support 1 and on which the cam 11 is fixed, a toothed pulley 14 also fixed on the shaft 12, a toothed belt 15 which passes over the toothed pulley 14 and over another pulley (not shown) connected to the main shaft of the machine, so that the cam 11 rotates in synchronism with said main shaft of the machine; a roller 17 housed in the groove of the cam 11, a lever 18 with two arms 19, 21 which pivots, by its top, on an axis 22 also carried by the support 1, an axis 23 which is mounted on the end of the arm 21 and which carries the roller 17, an axis 25 mounted on the end of the other arm 19 of the two-arm lever, a connecting rod 24, one end of which is articulated on the axis 25, a crank 26, the hub 27 (see also FIG. 2) is mounted for rotation and sliding on a shaft 28 which rotates on the support 1, a pin 29 mounted in the end of the crank 26 and on which the other end of the connecting rod 24 is articulated, another crank 32 fixed on the shaft 28 and the end of which has a central groove 33, and a transverse axis 34 engaged in the groove 33 and provided with pads 35 engaged in a slide 36 of the support 1. The connection between the hub 27 of the crank 26 and the shaft 28 is made by a disengageable system which comprises a pin 41 fixed transversely in the shaft 28 and engaged in a diametrical groove 42 formed in one face of the hub 27 of the crank. A spring 43, interposed on the shaft 28 between the support 1 and the hub of the crank, biases the latter axially against the pin 41. The disengagement of this system is obtained by an exerted thrust, in the direction of the arrow f2 ( FIG. 2), on the hub 27 of the crank, against the force of the spring 43. For this purpose, a mechanism is provided which makes it possible, at the same time, to disengage the general mechanical control which has just been describe, and replace it with a general manual command. This mechanism comprises: a bush 45 also mounted with free pivoting and sliding on the shaft 28 next to the hub 27 of the crank 26 and whose face adjacent to said hub also has a diametrical groove 46 capable of engaging on the pin 41, when the sleeve 45 is pushed against the hub 27 of the crank, under the action of a handle 47 which is pivotally mounted on a transverse axis 48 planted in the sleeve 45 and which has an extension 51 whose end is engaged in an arc-shaped lumen 52 formed in a guide 53 integral with the support 1, in the form of a portion of cylindrical surface, coaxial with the shaft 28, which makes it possible to rotate the shaft 28 by means of the lever previously pushed in the direction of arrow f2 to ensure the disengagement of the mechanical control.

The individual means for controlling the weft presentation fingers have a positive action in both directions. They comprise, for each finger, for example for finger 2 associated with the rocker arm 6, an active positioning drawer 56 and an inactive positioning drawer 57 connected to the rocker arm 6 by two pushers 58, 59, respectively. The two drawers 56 and 57 are slidably mounted in slides 61, 62 fixed on the support 1. The two pushers 58, 59 are engaged, by one of their rounded ends, in the bottom of corresponding rounded notches 63, 64 formed in the two drawers, and, at their other end, in the form of a cylindrical head 65, 66, in bores in the form of corresponding cylindrical surface portions 67, 68 formed in the rocker arm 6.

The means for selective connection between the general control means and the individual means for controlling the presentation fingers which have just been described comprise, for each finger, a push rod 71 whose proximal end is articulated on the axis 34 general control means, the distal end of which, cut at a bevel 72 (see also FIG. 4), can engage, selectively, either in a notch 73 of the upper drawer 56 for placing the corresponding finger in active position when said push rod occupies its high position shown in FIG. 4, or in a notch 74 in the lower drawer 57 for placing the finger inactive position when the push rod occupies its low position as shown in FIG. 1.

The passage of each push rod, such as 71, from its low position to its high position, is done under the control of programmed selection control means. These means comprise, for each push rod, an individual electromagnet 76 fixed on the support 1, assisted by a spring 77 which tends to move the push rod away from the poles of the electromagnet. In order to facilitate the work of the electromagnet, mechanical means are provided which bring automatically and positively each push rod into contact with the poles of the corresponding electromagnet, at the end of each movement of stem recoil. These means comprise a cam 78 on the push rod 71, which cooperates with a fixed stop 79 secured to the support 1, the locations of the cam on the push rod and the stop on the support, as well as the configuration and the dimensions. of said cam, being such that, only when the push rod reaches the end of its recoil stroke, under the action of the general control means, it is raised positively, under the effect of said cam, against the poles of the electromagnet 76.

In addition to the programmed selection control means by the electromagnets 76, the device comprises manual selection control means in the form of individual selection levers associated with each of the push rods; these levers such as 81 or 82, for example, associated with the push rods 71, 71 B for controlling the presentation fingers 2, 2B respectively, are pivotally mounted on a common axis 83 carried by the support 1, and are located just below the corresponding push rods. So. when exercising, by hand, on the outer end of these levers. a vertical thrust from top to bottom, that is to say in the direction of arrow f3 in FIG. 1, the inner end of the lever keeps the corresponding push rod 71, 71 B raised against the spring 77, as long as the manual push is maintained on the lever.

• On suppose que la machine à tisser sur laquelle il est monté est en fonctionnement et que la dernière trame qui vient d'être insérée dans la foule est celle qui a été présentée par le doigt 2B, la tige de poussée 71 B vient d'être amenée en position avancée par la came 11, de sorte que les organes correspondants (tiroir supérieur, poussoir supérieur et culbuteur) ont été amenés dans leur position active pendant que les autres organes, c'est-à-dire les tiges de poussée telles que 71, les tiroirs inférieurs tels que 57, et les poussoirs inférieurs tels que 59, également amenés en position avancée, ont placé tous les autres culbuteurs, tels que 6 et, par conséquent, les doigts de présentation correspondants, en position inactive (figure 1). La came 11 est entraînée en rotation en synchronisme avec l'arbre principal de la machine, de sorte que, lorsque la bosse de ladite came va s'engager contre le galet 17, elle va le repousser et tout l'ensemble des moyens généraux de commande décrits plus haut vont provoquer le recul de l'axe transversal commun 34 et. par conséquent, le recul de toutes les tiges de poussée telles que 71 et, en fin de course, leur remontée contre les électro-aimants tels que 76 sous l'effet des butées 78, comme représenté sur la figure 4. A ce stade du fonctionnement, deux hypothèses sont à envisager :
• Première hypothèse : le fil de trame à présenter maintenant est le même que précédemment. L'électro-aimant associé à la tige de poussée 71 B de commande du même doigt de présentation 2B est excité et maintient donc ladite tige de poussée soulevée contre ses pôles en regard du tiroir, tel que 56, de commande du culbuteur correspondant 6B. La poursuite du mouvement de rotation de la came 11 rapproche donc le galet 17 de l'axe de l'arbre 12 et toutes les tiges de poussée s'avancent simultanément ; seule la tige de poussée 71 B repousse un tiroir supérieur de mise en position active du doigt 28, tandis que les autres tiges de poussée, ramenées en position basse par leurs ressorts de rappel 77 en l'absence d'attraction de la part des autres électro-aimants, ne trouvent rien devant elles, les tiroirs inférieurs tels que 57 de mise en position inactive des autres doigts que le doigt 2B ayant déjà été avancés au cycle précédent. Au prochain passage de la bosse de la came 11 contre le galet 17. toutes les tiges de poussée reculent, puis remontent en fin de course, ce qui est sans effet sur les tiroirs et les culbuteurs, puisque les extrémités distales des tiges de poussée s'éloignent simplement des tiroirs.

The operation of the frame mixing device is as follows:

• It is assumed that the weaving machine on which it is mounted is in operation and that the last weft which has just been inserted into the crowd is that which was presented by the finger 2B, the push rod 71 B has just been brought into the advanced position by the cam 11, so that the corresponding members (upper drawer, upper pusher and rocker arm) have been brought into their active position while the other members, that is to say the push rods such as 71, the lower drawers such as 57, and the lower pushers such as 59, also brought into the advanced position, have placed all the other rocker arms, such as 6 and, consequently, the corresponding presentation fingers, in the inactive position (FIG. 1 ). The cam 11 is rotated in synchronism with the main shaft of the machine, so that when the hump of the said cam will engage against the roller 17, it will push it back and all of the general means of command described above will cause the common transverse axis 34 and. consequently, the retraction of all the push rods such as 71 and, at the end of the race, their ascent against the electromagnets such as 76 under the effect of the stops 78, as shown in FIG. 4. At this stage of the operation, two hypotheses are to be considered:
• First hypothesis: the weft thread to present now is the same as before. The electromagnet associated with the push rod 71 B for controlling the same presentation finger 2B is excited and therefore keeps said push rod raised against its poles opposite the drawer, such as 56, for controlling the corresponding rocker 6B. The continued rotational movement of the cam 11 therefore brings the roller 17 closer to the axis of the shaft 12 and all the push rods advance simultaneously; only the push rod 71 B pushes an upper drawer for putting the active position of the finger 28, while the other push rods, brought back to the low position by their return springs 77 in the absence of attraction from the others electromagnets, find nothing in front of them, the lower drawers such as 57 for placing inactive other fingers than finger 2B having already been advanced to the previous cycle. At the next passage of the bump of the cam 11 against the roller 17. all the push rods retreat, then go up at the end of the stroke, which has no effect on the drawers and the rocker arms, since the distal ends of the push rods s simply pull away from the drawers.

Second hypothesis: the weft thread to be presented is another thread than that which has just been presented by the finger 2B. for example that threaded into the eye of finger 2. It is then the electromagnet 76, associated with the push rod 71, which is excited; it maintains this rod in the raised position (FIG. 4) while the continued rotational movement of the cam 11 causes all of the push rods to advance. Only the rod 71, held in the high position by the electromagnet, will push the upper drawer 56 for placing the active position of the finger 2, while all the other push rods, lowered by their return springs 77 into the absence of excitation current in the corresponding electromagnets, advance at the level of the lower drawers such as 57 and, in particular, the push rod 71 B meets the lower drawer for setting the inoperative position of the rocker arm 6B which had just been put in active position at the previous frame insertion stroke; the other push rods in the low position meet nothing in front of them, since the corresponding lower drawers were already in the advanced position resulting from the inactive position of the corresponding rockers.

In general, it can be said that each rocker arm is brought into a positive position in a timely manner in the active position under the action of a push rod in the high position, and that it is also automatically and positively brought into position inactive, under the action of the same push rod in the low position. It can also be said that each rocker arm is returned to the inactive position when another rocker arm is placed in the active position, so that any presentation finger remains permanently in the active position as long as the wire frame it controls must be inserted successively several times.

• Si les tiges de poussée 71 ne sont pas dans leur position reculée représentée sur la figure 4, on commence par les y amener ; à cet effet, on saisit la manette 47 (figure 2) et on la tire dans le sens de ta flèche f2, la douille 45 repousse le moyeu 47 appartenant aux moyens généraux de commande et s'engage, par sa rainure 46, sur la goupille 41. Dès lors, cette manette est solidaire en rotation de l'arbre 28. On appuie sur celui des leviers, tels que 81 ou 82 (figure 1 ) qui correspond au doigt de présentation du fil de trame désiré, afin de soulever la tige de poussée, telle que 71, correspondante, puis on imprime à la manette un mouvement de rotation dans le sens de la flèche f4 (figure 1) pendant que son extrémité intérieure glisse dans la lumière fixe 52, afin de faire avancer l'axe transversal commun 34 emprisonné dans la manivelle 32 solidaire de l'arbre 28. La tige de poussée sélectionnée et maintenue en position haute repousse le tiroir supérieur de mise du culbuteur correspondant en position active, pendant que les autres tiges de poussée repoussent éventuellement le tiroir inférieur de remise en position inactive d'un culbuteur précédemment mis en position active. Enfin, on remet la commande manuelle au repos, c'est-à-dire que, d'une part, on relâche le levier tel que 81 et, d'autre part, on refait pivoter la manette 47 en sens inverse pour ramener l'arbre 28 dans sa position angulaire pour laquelle la goupille 41 peut retrouver sa place normale dans le moyeu 27 repoussé par le ressort 43 après qu'on a relâché complètement la manette 47. Le mécanisme mélangeur est alors de nouveau prêt à fonctionner en commande automatique.

The use of the manual selection control is as follows:

• If the push rods 71 are not in their retracted position shown in FIG. 4, we start by bringing them there; for this purpose, we grab the handle 47 (Figure 2) and pull it in the direction of your arrow f2, the sleeve 45 pushes the hub 47 belonging to the general control means and engages, by its groove 46, on the pin 41. Therefore, this lever is integral in rotation with the shaft 28. It is pressed on that of the levers, such as 81 or 82 (Figure 1) which corresponds to the presentation finger of the desired weft thread, in order to raise the push rod, such as 71, corresponding, then a rotary movement is imparted to the lever in the direction of the arrow f4 (FIG. 1) while its inner end slides in the fixed light 52, in order to advance the axis common transverse 34 trapped in the crank 32 integral with the shaft 28. The selected push rod and held in the high position pushes the upper drawer for setting the corresponding rocker arm in position active, while the other push rods possibly push the lower drawer back into the inactive position of a rocker arm previously placed in the active position. Finally, the manual control is put back to rest, that is to say that, on the one hand, the lever is released as 81 and, on the other hand, the lever 47 is again pivoted in the opposite direction to bring back the shaft 28 in its angular position for which the pin 41 can return to its normal place in the hub 27 pushed back by the spring 43 after the lever 47 has been completely released. The mixing mechanism is then again ready to operate in automatic control .

Claims (7)

1. A weft mixer for looms, comprising a support to be fixed on the loom and on which there are mounted : a number of presenting fingers of different wefts adapted to take each one, selectively, either a corresponding active advanced weft presentation position, or an inactive withdrawn position ; first individual positive control means (56-58) for moving each presentation finger to the active advanced position ; second individual positive control means (57-59) for returning each presentation finger to its inactive withdrawn position ; general control means for said first individual control means, adapted to be connected to the main shaft of the loom to operate in synchronism with said shaft ; selective connection means (71) between the general control means and the first individual control means ; and programmed selection control means adapted to control said selective connection means, characterised in that the second individual control means for returning each presentation finger (2. 2B. 2C) to its inactive withdrawn position are also subjected to the action of the selective connection means (71) and in that each presentation finger (2, 28, 2C) is connected to a rocker (6, 6B, 6C) subjected to opposing programmed forces of said first and second individual control means (56, 58 and 57, 59).

2. A device according to Claim 1, characterised in that each rocker (6) is connected to a slide (56) for placing a presentation finger in its active position and a slide 57 for placing said finger in its inactive position ; and in that the selective connecting means has a plurality of pushrods (71) in number equal to that of the rockers the proximal end of which is articulated to an entrainement shaft (34) provided with a transverse to-and-fro movement by the general control means (11, 18, 24, 26, 28, 32, 34) and the distal end of which, selectively, is either in the active position in relation to the corresponding active position slide, or an inactive position in relation to the corresponding inactive position slide, in accordance with whether or not the respective push-rod is acted upon by the selection control means (76).

3. A device as claimed in Claim 2, characterised in that the selection control means is constituted by a plurality of individual electro-magnets (76) in number equal to the number of push-rods (71) situated immediately adjacent the respective push-rods and adapted to selectively attract them to maintain them temporarily in the active position.

4. A device as claimed in Claim 2, characterised in that each push-rod (71) is urged by a spring (77) towards its inactive position.

5. A device as claimed in Claim 3, characterised in that each push-rod (71) is provided with a cam (78) which cooperates with a fixed stop (79) integral with the support (1) ; the positioning of the cam on the push-rods and of the stop on the support as well as the shape and dimensions of said cam being such that, only when the cam reaches the end of its withdrawn position under the action of the general control means, it is positively pushed under the action of said cam against the corresponding selection electro-magnet.

6. A device as claimed in Claim 1, characterised in that it includes disconnecting means (27, 41) for the general control means (28. 32, 34) as well as manual control means (41. 45. 46, 47) for the said selective connection means (71) and manual selection means (81, 82).

7. A device as claimed in Claims 2 and 6, characterised in that the manual control means for the selective connection means comprises an operating lever (47) for the engagement shaft (28) of the push-rods, and in that the manual selection control means comprises individual levers (81, 82) for selective placing in the active position of said pushrod (71).

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