EP0099842A1 - Reversible dobbies - Google Patents

Abstract

The lateral teeth (7a, 7b) integral with a loose gear on the shaft (4) drive those (9a, 9b) of the disc (2) wedged on this shaft (4) while being locked against any recoil untimely relative by a notch (12a) provided at the end of a rocking lever (11) articulated at (10) on the disc and biased in one direction or the other by a spring-loaded snap-in system (16) footprints (20) When the direction of rotation is reversed, the protruding pawl (23b), stopped against the stop (25b), meets the fixed stud (26), which forces (11) to switch releasing (7a) which then turns independently of the assembly (2-4) until it abuts against (9b) and clicks into the other notch (12b). The drive is thus provided with the phase shift necessary for the reverse of the mechanics. When we resume walking forward, everything works in reverse and we therefore return to the initial position.

Description

It is known that it is frequently necessary to turn a loom backwards to remedy defects appearing on the fabric. It is thus possible to practice what is called "untwisting", that is to say the removal one by one of the picks previously carried out until elimination of the defective zone and, after having remedied the cause of the defect found resume normal operation without this correction operation in any way affecting the appearance of the finished product. However, in the case of mechanical weaving looms, for example of the Verdol type, there is an essential difficulty, namely that the correct selection of warp threads no longer takes place if we limit ourselves to reversing the direction of rotation of the profession tree. Indeed during normal operation of such a mechanism there is first selection of the hooks, then lifting by the frame of claws of the hooks thus selected, so that if one did not modify the cycle, during the walking backward the claw frame would execute its lifting movement without the hooks having been selected. Depending on whether in the mechanics considered, the pushed hooks are either erased relative to the blades of the frame or else brought to the position of engagement with them, it would result either in that all the hooks come in the high position, or in that all remain in the low position. In either case it would be impossible to clear the last pick of the fabric in reverse.

To solve the problem thus posed by the irreversibility of the operating cycle of the mechanics of the genre in question (hook mechanics and the like), means are generally provided for reversing the respective positions of the selection of the hooks and of the lifting of the claws. in the mechanical operating cycle, that is to say in practice to phase the movement of the selection needles relative to the vertical back and forth of the claws. These means are often controlled by hand, which involves the operator's work and can give rise to incidents if he forgets to operate the control members before and after reversing the loom. We have also imagined mechanisms linked to the direction reversing lever and which automatically execute the necessary operations, but these mechanisms are complicated, expensive and sometimes subject to failures.

We have tried to remedy these drawbacks using a very simple device in which the mechanical shaft is driven by means of a coupling comprising an angular play equal to the necessary phase shift angle. When the direction of rotation of the loom is reversed, the two elements or components of this coupling rotate relative to each other by the angle provided. However, for such a device to function perfectly without the two aforementioned members oscillating with respect to one another under the effect of the vibrations and irregularities of the transmitted torque, it is necessary to brake quite strongly. 'driven organ and this leads to power losses with unacceptable heating, especially in modern high-speed trades. The brake must also include cooling members and its action must be constant, so that it happens to constitute an expensive accessory whose furthermore the linings wear out fairly quickly and must therefore be frequently replaced.

The present invention aims to improve this known device so as to retain the advantages of great simplicity and the absence of accessory mechanisms, while completely eliminating any braking and consequently any accessory component complicated with power losses and overheating. that it provokes.

In accordance with the invention, a coupling device with angular play capable of ensuring the drive phase shift necessary for the correct reverse of a loom mechanical, then for resuming its walking forward, includes means which, when reversing, lock the two coupling members with each other as soon as the device begins to rotate in a direction different from that which it had previously .

In a preferred embodiment, the two bodies in question are produced in the form of plates or discs, the facing faces of which are provided with lateral teeth capable of ensuring their angular connection while providing the necessary phase shift angle during the reverse gear. Furthermore, the driven disc carries a locking lever which is articulated thereto around a longitudinal axis suitably offset relative to the general axis of the device. The ends of this lever are shaped, for example by means of notches, so as to be able to come to engage on the adjacent tooth of the driving member in order to lock it in place to one or the other. of its two stop positions relative to the driven shaft. This lever carries at its ends return pawls, protruding towards the outside and suitable for cooperating with a fixed stop, that of these pawls which is located forward in the direction of movement being erased in the direction of the axis relative to the stop, while the other can freely erase itself by rotation around its axis when passing in front of this stop as long as one turns in the same direction, but on the contrary is blocked against an individual stop carried by the lever as soon as the direction of rotation is reversed, forcing the corresponding end of this lever to approach the center and thereby causing the tilting of said lever which then locks the adjacent tooth of the member leading to its new position (out of phase with the previous one). A suitable system of elastic snap keeps the lever in its end position and brings it back when it moves away from it. The lever itself is shaped in such a way that if it has completely tilted before the corresponding tooth has completely traversed the phase shift angle, it can push it back slightly to be able to move to its end position to which it returns to block it.

The entire device being symmetrical, it functions in the same way when returning to the front gear as when switching from it to the reverse gear.

In any case, once the driving tooth is blocked, the coupling device according to the invention prohibits any significant relative angular displacement of the two driving and driven members and thus completely eliminates any brake system or the like.

• Fig. 1 est une vue en perspective montrant à l'état écartées l'une de l'autre les faces en regard des deux disques du dispositif d'accouplement suivant l'invention.
• Fig. 2 est une vue de côté de l'ensemble de l'accouplement.
• Fig. 3 est une coupe transversale par le plan de la base des dents du disque menant, le dispositif se trouvant en marche normale en avant.
• Fig. 4 est une coupe de détail du système d'encliquetage élastique du levier de verrouillage sur le disque mené.
• Fig.. 5 est une vue semblable à celle de fig. 3, mais montrant les pièces à l'instant où le cliquet non effacé vers l'axe est dévié par le goujon fixe de butée.
• Fig. 6 est également une vue semblable à celle de fig. 3, mais montrant les pièces au début de l'inversion du sens de rotation.
• Fig. 7 les montre un instant après, quand le cliquet non effacé vers l'axe vient buter contre le goujon fixe.
• Fig. 8 les représente à l'instant du dégagement de la dent menante précédemment verrouillée.
• Fig. 9 correspond au cas où lors de ce dégagement le disque mobile a quelque peu poursuivi sa course, par exemple par effet d'inertie.
• Fig. 10 montre les pièces après verrouillage de l'une des dents menantes, c'est-à-dire une fois le processus d'inversion complètement terminé.
• Fig. 11 reproduit fig. 10, mais en montrant comment le cliquet précédemment effacé vers l'intérieur et maintenant repoussé vers l'extérieur s'incline et s'efface au passage devant la goujon de butée.

The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is capable of providing:

• Fig. 1 is a perspective view showing the opposite faces of the two discs of the two discs of the coupling device according to the invention.
• Fig. 2 is a side view of the coupling assembly.
• Fig. 3 is a cross section through the plane of the base of the teeth of the driving disc, the device being in normal forward operation.
• Fig. 4 is a detail section of the elastic latching system of the locking lever on the driven disc.
• Fig. 5 is a view similar to that of fig. 3, but showing the parts at the moment when the pawl not erased towards the axis is deflected by the fixed stop stud.
• Fig. 6 is also a view similar to that of FIG. 3, but showing the parts at the beginning of the reversal of the direction of rotation.
• Fig. 7 shows them an instant later, when the pawl not erased towards the axis abuts against the fixed stud.
• Fig. 8 represents them at the instant of the release of the previously locked driving tooth.
• Fig. 9 corresponds to the case where during this release the movable disc continued somewhat its course, for example by inertia effect.
• Fig. 10 shows the parts after locking one of the driving teeth, that is to say once the inversion process is completely finished.
• Fig. 11 reproduced in fig. 10, but by showing how the pawl previously erased inwards and now pushed outwards tilts and is erased in passing in front of the stop pin.

The coupling shown in fig. 1 comprises a driving element and a driven element respectively designated by the general references 1 and 2. These two elements are in the form of discs of reduced thickness arranged at a slight spacing from each other along the same axis, as well as as shown in fig. 2 (they have been shown spaced from one another in FIG. 1 to allow the detail of their opposite faces to be seen). The first 1 is constituted by a flat toothed pinion 3 mounted idly on the common shaft 4 and driven by another pinion 5 suitably connected to the motor shaft of the loom, the inner face of this pinion 3, that is to say say that facing the disc 2, being integral with a projecting co-axial portion 6 in the form of a plate of smaller diameter than the aforementioned pinion and which carries two diametrically opposite lateral teeth 7a and 7b to each other, oriented towards the second disc 2. The latter is keyed onto the shaft 4, as indicated by the key 8. On its inner face (the one facing the first disc 1) are provided two lateral teeth 9a and 9b, which are also diametrically opposite one another and capable of cooperating with the teeth 7a and 7b mentioned above to ensure the angular connection between the two discs 1 and 2. The four teeth occupying 7a, 7b, 9a, 9b each significantly less than 45 °, it is understood that this connection has a fairly large angle of play or dead travel (of the order of 135 ° in the example shown).

The second plate 2 also carries on its inner face an axis 10 located a short distance from its periphery and on which is articulated by its middle a double lever 11 curved in the shape of an arc of a circle. Each end of the inner edge of this lever (the edge facing the shaft 4) is notched so as to determine a notch 12a, 12b with a square profile. The lever 11 is dimensioned so that when the teeth 7a, 7b are in contact with the teeth 9a, 9b for driving the disc 2 in one direction (dextrorsum direction along arrow 13 in Fig. 3, for example), the notch 12a which is at the upstream end of the lever (the term "upstream" referring to the direction of rotation of this lever) can come to engage on that of the end angles of the periphery of the neighboring tooth 7a which does not is not in contact with the corresponding tooth 9a, as shown in fig. 3, thus trapping this tooth 7a between the tooth 9a and the lever 11, that is to say by positively locking the disc 2 relative to the disc 1.

It is understood that under these conditions the lever 11 has two locking positions, one for rotation in one direction (dextrorsum direction in fig. 3), the other for rotation in the opposite direction (sinistrorsum direction of arrow 14 in fig. 10). To avoid any untimely release under the effect of vibrations, slight imbalances or others, a ball and spring interlocking system is provided such as that indicated in fig. 4. Here we have provided in the lever 11 a bore 15 closed externally by a screwed plug 16 on which a spring 17 bears to clean a ball 18 against the inner face of the disc 2. This is hollowed out by two depressions 19 and 20 in each of which the ball can come snap. These depressions are joined to each other by a part 21 in the form of a double inclined plane so that as soon as the ball has exceeded the top of this double plane it tends to bring the lever to its closest end of travel, without keeping it in an intermediate position. In addition, the depressions 19, 20 are in the form of hemispheres so as to prevent the ball 18, and consequently the lever 11, from exceeding the intended useful stroke.

Each end of the lever 11 carries an axis 22a, 22b on which is articulated a pawl 23a, 23b that a spring 24a, 24b tends to bring against an individual stop 25a, 25b to a rest position for which the point of the pawl is oriented towards the outside with respect to the shaft 4. The arrangement of the springs 24a, 24b is such that at this resting position of the pawls they urge them to rotate in a direction bringing their points one of the other (ie in fig. 3 sinistrorsum for the ratchet 23a and dextrorsum for the other 23b).

The pawls 23a, 23b are further dimensioned so that when the lever 11 is in one of its locking positions, that of them which is at the end of the lever where the notch 12a or 12b is engaged with the tooth 8a or 8b is completely erased relative to the periphery of the disc 2 (pawl 23a in fig. 3), while the tip of the other protrudes significantly beyond it.

Finally, a stud 26 oriented parallel to the shaft 4 and located in the immediate vicinity of the periphery of the disc 2 is provided on the fixed mechanical frame.

• Si l'on suppose pour fixer les idées que pendant la marche normale du métier le disque 1 tourne dans le sens dextrorsum (flèche 13), le levier 11 a basculé dans ce même sens et son encoche 12a est venu verrouiller la dent 7a par rapport au disque 2, la bille d'encliquetage 18 se trouvant dans la dépression 19 pour retenir le levier à cette position. La pointe du cliquet 23a est effacée et celle de l'autre cliquet 23b dépasse au delà de la périphérie du disque 2. Aux très faibles jeux inévitables prés, l'accouplement fonctionne comme une pièce rigide et ne permet aucune oscillation quelles que puissent être les variations du couple transmis et même si celui-ci vient à s'inverser momentanément, comme cela peut parfois arriver avec les mécanismes d'armure, le tout sans qu'il soit besoin de prévoir un freinage de retenue.

The operation is as follows:

• If it is assumed to fix the ideas that during normal operation of the loom the disc 1 rotates in the dextrorsum direction (arrow 13), the lever 11 has rocked in this same direction and its notch 12a has come to lock the tooth 7a relative disc 2, the catch ball 18 being in the depression 19 to retain the lever in this position. The tip of the pawl 23a is erased and that of the other pawl 23b protrudes beyond the periphery of the disc 2. At very small inevitable games, the coupling functions as a rigid part and does not allow any oscillation whatever the variations in the transmitted torque and even if this momentarily reverses, as can sometimes happen with the armor mechanisms, all without the need for retaining braking.

Each time the pawl 23b passes in front of the stud 26, the latter comes into contact with its tip thereby tending to rotate it in the direction permitted by the stop 25b, that is to say to move it away from the tip of the other pawl 23a. The pawl 23a therefore disappears momentarily, as shown in FIG. 5 and the operation of the mechanics is in no way hampered.

If one comes to reverse the direction of rotation of the loom, therefore of the disc 1 (fig. 6, arrow 14), at the beginning the tooth 7a in engagement with the notch 12a will drive the lever 11 and consequently the disc 2 will turn back without any phase shift relative to the disc 1. But as soon as the pawl 23b comes into contact with the stud 26, it cannot be erased since to do this it would have to turn on its axis 22b in the direction which it prohibits the stop 25b. Due to the inclination of the side of this pawl relative to a radius, the corresponding end of the lever 11 will be pushed back towards the shaft 4. The lever will therefore tilt slightly and its notch 12a will release the tooth 7a (fig 8). From this moment the teeth 7a and 7b (which play the role of leading organs) will be able to rotate independently of the disc 2 until the first 7a came to bear against tooth 9b and the second against tooth 9a, as shown in fig. 10. The disc 1 will therefore drive the disc 2, the shaft 4 and the mechanics backwards, but with the predetermined phase shift (FIG. 10) compared to the case of forward travel. Here again the rotation will not be hindered by the pawls, the first 23a now being in the retracted position towards the axis with respect to the stud 26 and the second freely tilting in passing, as shown in FIG. 11.

• 1° Si les frottements sont relativement importants par rapport aux autres couples et notamment à ceux résultant des masses et/ou des poids des pièces mobiles, le disque 2 s'arrête immédiatement après que la dent 7a ait été dégagée et avant que le levier 11 n'ait basculé complètement. On se trouve donc à sa position de fig. 8. Aussitôt que la dent 7a aura commencé à entraîner la dent 9b, le disque 2 commencera à tourner en arrière, le cliquet 23b passera sous le goujon 26 en abaissant à fond l'extrémité correspondante du levier et l'on arrivera ainsi à la position de fig. 10.
• 2° Si au contraire les effets d'inertie et/ou les couples résultant du poids des pièces soulevées et agissant dans le sens arrière sont importants, le cliquet 23b ne s'arrêtera qu'après avoir dépassé le goujon 26 et provoqué ainsi le basculement complet du levier 11, comme montré fig. 9. La dent 7a viendra donc toucher le bord intérieur de ce levier dans sa partie située au delà de l'axe 10 dans le sens de rotation arrière. Elle soulèvera très légèrement celle-ci au passage, puis cette partie du levier s'abaissera derrière la dent de sorte qu'on se retrouvera là encore à la position de fig. 9. Il convient de noter à cet égard que le double plan incliné 21 de fig. 4 est de nature à favoriser ce retour à la position enclenchée du levier 11 momentanément déplacé très légèrement au passage de la dent 7a.
• 3° Enfin il peut arriver que le poids des pièces soulevées soit tel que dès que la dent 7a a été dégagée de l'encoche 12a, le disque 2 tourne de lui-même dans le sens avant (sens de la flèche 13). Dans ce cas le levier 11 n'aura pas basculé. La dent 7b viendra donc prendre l'encoche 12a pour entraîner le disque 2 en arrière. On se retrouvera à une position semblable à celles successives de fig. 6 et de 7, sauf que les dents entraînées 9a et 9b seront respectivement contre la face arrière des dents 7b et 7a. Mais comme l'arbre 4 aura eu le temps de prendre de la vitesse, lorsque le cliquet 23b se sera abaissé au passage sous le goujon 26, le disque 2 ne s'arrêtera pas immédiatement, de sorte que la dent 7b aura la possibilité de s'enclencher dans l'encoche 12a. On reviendra là encore à la position de fig. 10.

In fact the passage from the position of fig. 7 to that of FIG. 10 can be carried out in three ways depending on the inertias and the resistant torques involved.

• 1 ° If the friction is relatively high compared to the other torques and in particular those resulting from the masses and / or the weights of the moving parts, the disc 2 stops immediately after the tooth 7a has been released and before the lever 11 has failed completely. We are therefore in its position in fig. 8. As soon as the tooth 7a has started to drive the tooth 9b, the disc 2 will start to rotate backwards, the pawl 23b will pass under the stud 26 by lowering the corresponding end of the lever as far as possible and we will thus arrive at the position of fig. 10.
• 2 ° If on the contrary the effects of inertia and / or the torques resulting from the weight of the parts lifted and acting in the rear direction are significant, the pawl 23b will not stop until after having exceeded the stud 26 and thus caused the tilting complete with lever 11, as shown in fig. 9. The tooth 7a will therefore come to touch the inner edge of this lever in its part located beyond the axis 10 in the direction of rear rotation. It will raise it very slightly in passing, then this part of the lever will lower behind the tooth so that we will again find ourselves in the position of fig. 9. It should be noted in this regard that the double inclined plane 21 of FIG. 4 is likely to favor this return to the engaged position of the lever 11 momentarily moved very slightly as the tooth 7a passes.
• 3 ° Finally, it may happen that the weight of the parts raised is such that as soon as the tooth 7a has been released from the notch 12a, the disc 2 rotates by itself in the forward direction (direction of the arrow 13). In this case the lever 11 will not have tilted. The tooth 7b will therefore come to take the notch 12a to drive the disc 2 backwards. We will find ourselves in a position similar to those successive of fig. 6 and 7, except that the driven teeth 9a and 9b will be respectively against the rear face of the teeth 7b and 7a. But as the shaft 4 will have had time to gain speed, when the pawl 23b has lowered when passing under the stud 26, the disc 2 will not stop immediately, so that the tooth 7b will have the possibility of snap into notch 12a. We will come back again to the position of fig. 10.

When after having operated the loom backwards to make a defect disappear, the operator resumes walking forward, as the device that we have just described is perfectly symmetrical, the operation remains, mutatis mutandis, identically the same as this one above exposed. The parts therefore return to the position of FIG. 3 and 5 after ensuring the phase shift in the opposite direction to what had happened at the start of reverse gear.

The discs 1 and 2 could be mounted on two shafts arranged end to end, or one on a central shaft, the other on a hollow shaft surrounding it. Instead of flat discs, any kind of member capable of having lateral teeth and a transverse face which could carry the rocking lever 11 could be provided.

Claims (9)

1. Coupling device interposed between a weaving loom and the claw drive mechanism of an armor mechanism and the selection movement, of the kind comprising at least one driving rotating member which drives a rotating member driven by abutment against a first part of it for a direction of rotation and against a second for the other direction, these two parts defining the phase shift angle necessary for the transition from forward gear to reverse gear and vice versa, characterized in that that it comprises means (12a, 12b) which automatically lock the driving member with respect to the driven member (2) at the start of each reversal of the direction of rotation of the first. 2. Device according to claim 1, characterized in that it comprises a tilting locking lever (11) articulated in its middle on one (2) of said members (1, 2) around a substantially longitudinal axis (10 ), one or other of the ends of this lever which engages behind a part (7a, 7b) of one of the abovementioned members (1, 2). 3. Device according to claim 2, characterized in that the locking lever (11) is carried by the driven member (2). 4. Device according to any one of claims 2 and 3, characterized in that the locking lever (11) carries at each of its ends an articulated pawl (23a, 23b) with stopper (25a, 25b) and spring (24a, 24b) reminding it against the latter, which pawls, oriented towards the outside, cooperate with a fixed stop (26) which tends to push one or the other as it passes in the direction of the axis of the device, the arrangement being such that when the lever (11) has locked said members (1, 2) for a direction of rotation, that of these pawls which, in contact with the stop (26), would tend to tilt the lever (11), disappears when passage by rotation against its return spring and does not intervene and that the other pawl is in the retracted position towards the axis with respect to said stop (26), but only if the direction of rotation is conversely, the first pawl (23b in fig. 3) is retained by its stop (24b) and thus causes the locking lever to tilt. 5. Device according to claim 4, characterized in that the members (1, 2) are in the form of discs whose opposite faces include teeth (7a, 7b - 9a, 9b) suitable for constituting the drive stops as well that the parts on which the locking lever (11) engages. 6. Device according to any one of claims2 to 5, characterized in that the locking lever (11) are associated with elastic latching means (18, 23, 21) which tend to remind one or the other from its extreme service positions. 7. Device according to any one of claims 2 to 5, characterized in that the locking lever (11) are associated with elastic latching means (18, 20, 21) at its two service positions, and which at the same time form stops to limit the stroke of said lever. 8. Device according to any one of claims 1 to 7, characterized in that the edge of the locking lever (11) facing the axis is shaped so that when said lever has tilted during a change of direction of rotation of the loom, the adjacent tooth (7a in fig. 9) of that (1 in fig. 9) of the two above-mentioned members (1, 2) which does not carry the locking lever (11) can move it slightly from its corresponding end-of-travel position to achieve abutment against the corresponding part (9b) of the other member. 9. Device according to claim 8, characterized in that the inner edge of the locking lever (11) has substantially the profile of an arc of a circle which, at the middle intermediate position of this lever, is substantially concentric with the axis of the device.

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