EP0899367A1 - Selection device, three-position shedding mechanism and loom with such a mechanism - Google Patents

Abstract

The device for mechanical selection of the harness for the weaving pattern in a loom, with three positions, has an assembly of two electromagnets (8,9) for energized selection. There is at least one pair of swing levers (10,11,10',11') at the same side as the electromagnets, each with a magnetic fitting (15,16,15',16') to work selectively with the electromagnets. Each lever has a projection (30,31,30'.31') to immobilize a hook (1,2,1',2') of a pair of hooks to be shifted together with a griffe (3). The lever projections (30,31,30'.31') are positioned to act with the hooks (1,2,1',2'). The levers swing on axes (12,13,12',13') in a central zone (C) near the electromagnets (8,9). One lever (10), on a swing axis (12), has the electromagnetic fittings (15,15') on one leg (10a) and the projection (30) is at the other leg (10b) of the lever (10). A second lever (11) has movement in only one direction on its swing axis (13). The gap (d) between the projections (30,31) of the two levers is larger than when one of the electromagnets is energized than when one of them is not energized. Return springs (20,21,20',21') act on the levers (10,11,10',11') to bring their projections together. Each of the hooks has an opening (1a,2a,1a',2a') to take the lever projections facing each other.

Description

The invention relates to a selection device, to a Jacquard loom mechanics with three positions and one weaving loom equipped with such a weaving mechanism.

A weaving loom incorporating armor mechanics suitable for generating three positions of chain son is used for making special fabrics, such as including velvet or a carpet.

By European patent application 0 723 041, we know a three-position Jacquard mechanism in which the movable hooks associated with a determining funicular element the height of a beam can be selected using two superimposed electromagnets. This system is complex and induces repeated deformations of the movable hooks, which forbidden to give them adequate rigidity to guarantee a sufficient service life for industrial application and high speed operation. In addition, the deformations important imposed on these hooks require electromagnets powerful, so that the energy absorbed by the trade with which is associated the known armor mechanics, which has a large number of electromagnets, is important.

The invention aims to solve these problems and to propose a three position armor mechanics selection device simple, therefore economical, able to operate at speeds high and consuming little energy. Another objective of the invention is to provide a selection device capable of operating with hooks suitable for moved in pairs.

In this spirit, the invention relates to a device for selection of three position armor mechanics including two superimposed electromagnets capable of being selectively activated, characterized in that it comprises at least one pair of pivoting levers arranged on the same side of said electromagnets and each provided with a magnetic frame suitable for selectively cooperate with one of said electromagnets, each lever being provided with a immobilization spout of a hook belonging to a pair of hooks suitable for being moved together by a knife.

Thanks to the invention, each lever of a pair of levers can be controlled independently by one of the electromagnets to immobilize or not a hook belonging to a pair of hooks. This allows, depending on the activation of the electromagnets, to selectively immobilize one or the other of the hooks belonging to a pair, or even these two hooks to the times, or none of them. The pivoting of the two levers has place without deformation of these or movable hooks they allow selection, which avoids mechanical fatigue of these elements.

According to a first advantageous aspect of the invention, the lever spouts are adapted to be arranged on either side of the pair of hooks. Thanks to this aspect of the invention, the spouts enclose the two hooks belonging to a pair of hooks like pliers, which guarantees a particularly effective immobilization of hooks, including understood when the traction exerted by the arches is important.

According to another advantageous aspect of the invention, the levers are articulated around arranged pivot axes, in a central area, close to the electromagnets. This positioning of the pivot axes of the levers gives the device of the invention good compactness, which is important when a large number of hooks must be controlled by the device of the invention. this allows also to achieve, thanks to the two levers belonging to a pair, a movement of clamps for immobilizing the hooks belonging to a pair of hooks.

According to another advantageous aspect of the invention, a first lever extends on either side of its axis of pivoting, the magnetic armature of this lever being carried by a first branch of this lever, while the beak of this lever is carried by a second branch of this lever. This lever geometry allows, when its armature is arranged next to the upper electromagnet, to provide that activation of this electromagnet results in distance or keeping the spout of this lever far away by relative to a median axis of the device. In this case, we can also provide that a second lever extends globally in a single direction relative to its pivot axis. When the second lever is placed opposite an electromagnet lower, activation of the electromagnet results in the approximation of its beak or in maintaining the beak in a position close to the median axis of the device.

According to another advantageous aspect of the invention, the distance between the spouts of the first and second levers is larger when at least one of the electromagnets is activated only when none of the electromagnets is activated. The activation of the electromagnet thus results in the opening a clamp formed by the two levers or in maintaining open position of such a clamp and, therefore, in the release total or partial of the pair of hooks likely to be immobilized by these two levers.

According to another advantageous aspect of the invention, the device comprises elastic return means of the levers in a direction of mutual approximation of the mouthpieces of the levers. These return means push the spouts of the levers towards a position for locking or immobilizing the hooks of a pair of hooks.

According to another advantageous aspect of the invention, the hooks of the pair of hooks each have an orifice receiving a spout from one of the levers, these orifices being arranged on either side of the pair of hooks. Each hook of the pair of hooks can thus be immobilized by one side of the pair of hooks, without interference from the other hook.

The invention also relates to a mechanical armor of Jacquard loom with three positions including a selection as previously described and a loom equipped with such armor mechanics.

• la figure 1 est une vue en coupe longitudinale d'un dispositif de sélection d'une mécanique d'armure conforme à l'invention dans une première position ;
• la figure 2 est une vue partielle de la partie droite du dispositif dans la figure 1 dans une seconde position et
• la figure 3 est une vue analogue à la figure 2, alors que le dispositif est dans une troisième position.

The invention will be better understood and other advantages of it will appear more clearly in the light of the following description of an embodiment of a device for selecting armor mechanics with three positions in accordance with its principle, given only by way of example and made with reference to the appended drawings in which:

• Figure 1 is a longitudinal sectional view of a device for selecting an armor mechanism according to the invention in a first position;
• FIG. 2 is a partial view of the right part of the device in FIG. 1 in a second position and
• Figure 3 is a view similar to Figure 2, while the device is in a third position.

The three armor mechanics selection device positions shown in Figure 1 is intended to immobilize, in the vicinity of the top dead center of their trajectory, two movable hooks 1 and 2 or 1 'and 2' able to be moved jointly supported on a knife 3 animated by a movement vertical alternative.

These mobile hooks 1 and 2 or 1 'and 2' are respectively connected to a 4 and 5 or 4 'and 5' cord constituting a funicular element allowing to move vertically a pulley controlling the altitude of a stringer belonging to a Jacquard harness. These hooks work in pairs, resting on each other, as described in French patent application 96 12329 in the name of the applicant. The mechanism includes two superimposed electromagnets 8 and 9 capable of being selectively activated by means of a command not shown.

On either side of the electromagnets 8 and 9 are arranged two pairs of levers 10 and 11, respectively 10 'and 11'. The levers 10 and 10 'are identical, as are the levers 11 and 11'. The levers 10 and 11 are respectively articulated around pivot axes 12 and 13. In the same way, the levers 10 'and 11' are articulated around axes 12 'and 13'. The lever 10 is provided with a magnetic armature 15 intended to cooperate with the core 8 a of the electromagnet 8 for the purpose of controlling the pivoting of the lever 10 around the axis 12. In practice, the armature 15 is constituted by a first branch 10 a of the lever 10 extending, from the axis 12, in the opposite direction of the hooks 1 and 2. In the same way, the lever 10 'is equipped with a frame 15' intended to cooperate with the core 8 a . The lever 11 also comprises an armature 16 constituted by a part of the lever 11 extending opposite the core 9 a of the electromagnet this armature being intended to cooperate with the core 9 a . An equivalent frame 16 'is provided on the lever 11'. The frames 16 and 16 'are provided in the upper part of the levers 11 and 11'.

Return springs 20 and 21, 20 'and 21' are respectively provided for permanently pushing the levers 10 and 11, 10 'and 11' away from the frames 15 and 16, 15 'and 16' from the cores 8 a and 9 has electromagnets 8 and 9. The stiffness constant of the springs 20 and 21, 20 'and 21' is chosen so that, when the armature of one of the levers is distant from the electromagnet with which it must cooperate, the force generated by the activation of the electromagnet is not sufficient to overcome the force due to the spring. On the other hand, when the armature of one of the levers is in abutment against the core of one of the electromagnets, the magnetic force generated due to the activation of this electromagnet is much greater than the previous one, so that the electromagnet can keep the armature in abutment against the force of the return spring considered.

Each lever 10 and 11, 10 'and 11' is provided with a spout respectively referenced 30, 31, 30 'or 31'. These spouts constitute the end of the levers 10, 11, 10 'and 11' on the side of the hooks 1, 2, 1 'and 2'. The spout 30 is carried by a second branch 10b of the lever 10 which extends in the direction of the pair of hooks 1, 2 from the axis 12.

Note that the pivot axes 12, 12 'and 13, 13' are located in a central zone C of the device which includes the lower part of the upper electromagnet 8 and the part upper solenoid lower 9.

Given the geometry and the positioning of the levers 10 and 11, it is understood that when they are kept pressed between the cores 8a and 9a, their spouts 30 and 31 are kept apart, so that the pair of hooks 1 and 2 can descend by pressing on the knife 3 between these hooks from the top dead center of its trajectory shown in phantom on the right of FIG. 1. On the contrary, when the electromagnets are not activated, the springs 20 and 21 push back the levers 10 and 11, so that the spouts 30 and 31 tend to approach each other. They can then enter holes 1 a and 2 a provided respectively in the upper part of the hooks 1 and 2, on either side of the pair of hooks.

When the spouts 30 and 31 are in place in the openings 1 a and 2 a , the device is in the position shown on the left in FIG. 1 in which the spouts 30 and 31 'penetrate respectively into the openings 1' a and 2 ' has hooks 1' and 2 '.

It is noted that the orifices 1 a , 1 ′ a and 2 a , 2 ′ a are inclined relative to a median axis XX ′ of the device, which allows them to cooperate closely with the shape of the spouts 30, 30 ′ and 31, 31 '.

The operation of the device of the invention appears clearly by comparing Figures 1 to 3.

In the rest position, the electromagnets 8 and 9 are not not activated, so that under the effect of the return springs 20 and 21, the levers 10 and 11 are pushed in a direction of mutual approximation of the nozzles 30 and 31.

When the pair of hooks arrives near the top dead center of its trajectory, the head 1b constituting the upper part of the hook 1 engages between the spouts 30 and 31 and moves them apart due to its tapered shape and the slope of the hooks 30 and 31 on their outer faces. By moving aside the nozzles 30 and 31, the head 1b repels the armatures 15 and 16 of the levers 10 and 11 respectively in contact with the cores 8a and 9a of the electromagnets 8 and 9.

In this position, the electromagnets 8 and 9 may or may not be activated. When the two electromagnets 8 and 9 are activated, the armatures 15 and 16 remain pressed against the cores 8 a and 9 a against the force of the springs 20 and 21. The device is then in the position on the right of FIG. 1 in which the pair of hooks 1, 2 can, from its top dead center position shown in broken lines, come down again by pressing on the knife 3.

When only the electromagnet 8 is activated, the armature 15 remains pressed against the core 8 a while the lever 11 is pushed back by the spring 21. In this position, the spout 30 of the lever 10 does not oppose the downward movement of the hook 2 bearing on the knife 3, while the spout 31 enters the orifice 1 a of the hook 1, so that the latter remains immobilized in the vicinity of the top dead center of its trajectory. The device is then in the position of FIG. 2.

When none of the electromagnets is activated, the springs 20 and 21 push the levers 10 and 11 respectively, so that the nozzles 30 and 31 penetrate into the orifices 1 a and 2 has hooks 1 and 2 when passing these orifices opposite the spouts 30 and 31. The hooks 1 and 2 are then immobilized in the vicinity of the top dead center of their trajectory, as shown in FIG. 3. The hooks then remain in this position as long as the knife 3 does not not come back, at the end of an upward movement, raise the hooks 1 and 2 so as to release them from the spouts 30 and 31 and that the electromagnets 8 or 9 are not activated.

In view of the above, the distance d between the spouts 30 and 31 is variable depending on the activation of the electromagnets. As is apparent from Figures 1 to 3, this distance d is greater when at least one of the electromagnets is activated (Figures 1 and 2) than when none of them is activated (Figure 3).

Note that the geometry of the spout 30 which includes a front face 30 a oblique to the axis XX 'allows it to cooperate with the head 1 b of the hook 1 to cause an erasing movement of the lever 10 on approach of the pair of hooks 1, 2 near the top dead center of its trajectory. This aspect of the device of the invention makes it possible to provide that the elastic return force of the spring 20 is overcome mechanically thanks to the force transmitted by the knife 3, the pair of hooks 1, 2 and the lever 10, while the force electro-magnetic only serves to maintain the lever 10 in the position of FIG. 1. The electromagnets must therefore generate only an electromagnetic force for immobilizing the lever 10, this electromagnetic force being much less than that which would be necessary for attract such a lever from its remote position obtained under the effect of the restoring force due to the spring 20.

In the same way, the geometry of the spout 31 allows also the erasing of the lever 11 and therefore the use of a electromagnet 9 able to generate only a force electromagnetic immobilization of the lever 11 in position.

The electrical consumption of an armor mechanic incorporating a large number of selection devices according to the invention is therefore not too important in the measurement where the electromagnets are dimensioned according to above criteria.

Armor mechanics of a three-loom positions according to the invention includes a multiplicity of selection devices as previously described and can operate with high reliability at high speeds and consuming little energy.

A loom equipped with such a mechanism allows thus obtaining, at lower cost, special fabrics such as velvets or carpets.

Claims (10)

Three armor mechanics selection device positions with two superimposed electromagnets (8, 9) able to be selectively activated, characterized in that it includes at least one pair of pivoting levers (10, 11, 10 ', 11 ') arranged on the same side of said electromagnets and provided each of a magnetic frame (15, 16, 15 ', 16') suitable for selectively cooperate with one of said electromagnets, each lever being provided with a spout (30, 31, 30 ', 31') immobilization of a hook (1, 2, 1 ', 2') belonging to a pair of hooks able to be moved jointly by a knife (3). Selection device according to claim 1, characterized in that said spouts (30, 31, 30 ', 31') of said levers (10, 11, 10 ', 11') are able to be arranged on the side and other of said pair of hooks (1, 2, 1 ', 2'). Selection device according to claim 1, characterized in that said levers are articulated around pivot axes (12, 13, 12 ', 13') arranged in an area central (C), near said electromagnets (8, 9). Selection device according to one of claims previous, characterized in that it comprises a first lever (10) which extends on either side of its pivot axis (12), the magnetic armature (15, 15 ') of said lever being worn by a first branch (10a) of said lever while the spout (30) of said lever is carried by a second branch (10b) of said the sink. Selection device according to claim 4, characterized in that it comprises a second lever (11) extending globally in a single direction relative to its pivot axis (13). Selection device according to claim 5, characterized in that the distance (d) between the spouts (30, 31) of said first and second levers (10, 11) is greater when at least one of said electromagnets (8, 9) is activated only when none of said electromagnets is active. Selection device according to one of claims previous, characterized in that it comprises means (20, 21, 20 ', 21') of elastic return of said levers (10, 11, 10 ', 11 ') in a direction of mutual approximation of said spouts (30, 31, 30 ', 31') of said levers. Selection device according to one of the preceding claims, characterized in that said hooks (1, 2, 1 ', 2') of said pair of hooks each have an orifice (1 a, 2a, 1 ', 2' a ) receiving a spout (30, 31, 30 ', 31') of one of said levers (10, 11, 10 ', 11'), said orifices being arranged on either side of said pair hooks. Three-position Jacquard loom mechanic comprising a selection device according to one of the previous claims. Weaving loom equipped with an armor mechanism according to claim 9.

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