EP0045758A1 - Mechanical control for the shedding of warp ends of a loom and loom comprising such mechanical control. - Google Patents

Abstract

The lifting mechanism comprises a plurality of lifting threads (30) stretched on either side of the web of warp threads (10) and each provided with a thread lifting stitch (28) in which a thread passes. respective chain (10). Each lifting wire passes through the groove (36) of a respective pulley (32), with individual lifting means (54, 56) of the lifting wire (30) being associated with the respective wire and pulley to allow traction. and a wire return, these means being arranged on the side opposite to the side where the lifting wire (30) arrives on the pulley (32).

Description

Mechanism for controlling the lifting of warp threads in a loom and loom comprising such a mechanism -

The present invention relates to a machine for an industrial weaving loom capable of producing shaped fabrics, as a Jacquard loom can do, in which a sheet of parallel warp threads is progressively unwound step by step, some of the warp threads chosen by programming means as a function of the colored pattern or the weave of fabric to be produced, we pass a weft thread between the raised warp threads and the non-lifted warp threads of the web, we lower the threads or some of the threads raised and the weft thread thus passed is pressed by means of a weaving comb against the other weft threads already woven, that is to say against the front of the fabric already made, only during this time it is wound on a spool or beam as the weaving program advances step by step. This type of loom for shaped fabrics is of great interest because it makes it possible to manufacture fabrics of an infinite variety both with regard to the texture or weave of the fabric and with regard to the decoration which is produced by the the only game of skilfully studied intertwining of weft threads and warp threads. The whole problem of producing a pattern lies at each weaving step in the choice of those warp threads that must be raised before the passage of a specific weft thread.

In order not to be limited in precision in the realization of a drawing, in particular a colored drawing, it is theoretically necessary to be able to individually lift any or which of the warp threads for the passage of a weft thread, and this is, moreover, the basic principle of Jacquard's invention. But in practice, the weavings must be able to be very tight, which leads to having a spacing between warp threads so small that one cannot help but lift several threads at the same time even if one increases the spacing of the warp threads where the weft thread passes or if we realize the equivalent of increasing the spacing of the warp yarns by lifting them by lifting yarns stretched obliquely, diverging upwards. Indeed, the warp threads must be lifted by mechanisms whose bulk has never been reduced until now until corresponding to a weaving as tight as we would like, while allowing to weave a pattern over large widths (the present invention typically seeks to achieve a fabric width of 140 cm or more with 10 threads per millimeter, which has never been successful before, in order to manufacture for example upholstery fabrics panoramic decoration rather than a decoration repeated several times in a width of fabric as is currently done).

To achieve this performance as well as others, the present invention proposes a mechanical for a weaving loom of the type described above, that is to say comprising a system for advancing a plurality of warp threads arranged in a layer, a system for the selective lifting of selected warp yarns, coupled to means for programming the choice of warp yarns to be lifted, and a weft yarn insertion system between raised warp yarns and non-raised warp yarns, the system for lifting warp yarns comprising a plurality of lifting yarns (one per warp yarn ^ which are yarns stretched substantially perpendicular to the web of warp yarns, each lifting yarn comprising a loop or mesh through which a chain so that the chain wire can be lifted by pulling on one end of the corresponding lifting wire According to the invention, each tensioned lifting wire moves away from the chain wire ply and passes through the groove of a respective pulley, individual lifting wire displacement means being associated with the wire and the pulley to exert traction on the wire and allow a return of the wire, these means being arranged on the side opposite to the side where the lifting wire arrives on the pulley. In a preferred embodiment, the lifting wire is hooked to the pulley and the individual displacement means are able to rotate the pulley by an angle corresponding to the desired lifting height of the son. These means of movement specific to each wire and each pulley are therefore rejected behind the pulley with respect to the arrival side of the lifting wire so that they do not cause congestion of the lifting mechanism above the son of lifted, in line with the lifting stitches of the warp threads, as was the case with the mechanics known up to now.

It is therefore already possible by this means, using small width pulleys placed all side by side, to produce a fabric with a tight texture, tighter than one would manage to do with a series of all other actuating devices. individual lifting yarns placed side by side such as those that have already been proposed since 1948 (US Patent 2,558,284). In addition, to divide the spacing of the warp threads which it is possible to lift individually, provision is made for rows of pulleys joined side by side are superimposed, that is to say placed on stages of different heights at the above the chain son ply, while being shifted slightly progressively from one stage to the other in a direction parallel to the warp son. The pulleys of a row have their lifting wire arrival side immediately set back from the lifting wire arrival side of the pulleys of the row immediately above, so that there is no risk interference of the various lifting wires with each other and with the pulleys or their means of rotation (the lifting wire arrival sides also constituting the ultimate ends of each set of a pulley and its means of movement respective). The density of the warp threads is thus increased at will by increasing the number of superimposed and offset rows of adjoining pulleys.

To further improve, there is even the possibility of having two series of rows facing each other, that is to say that vis-à-vis the superposed rows already described there is a series of other rows superimposed and offset but turned in opposite direction to the first, that is to say that the arrival sides of lifting wire of the pulleys of the first series face the arrival sides of the lifting wires of the pulleys of the other series, without any object in the interval between the two series (otherwise the lifting wires themselves). At the very top, the facing pulleys are close to each other. The further one descends the more they move apart gradually since the progressive shifts between rows are in the opposite direction for the two series, and between them pass the lifting wires descending from the pulleys of the higher stages.

To fix the ideas, with two series of 25 rows of 280 pulleys each, we reach a density of 14,000 threads on 140 cm with pulleys at a pitch of about 4.5 mm which is perfectly achievable.

According to another particularly advantageous characteristic of the invention, aimed at reducing the energy deployed at each step to lift all the selected warp threads, a common drive means is provided for several pulleys (in practice a rotating shaft for all the pulleys of a row), and an individual coupling and decoupling means between each pulley and the drive means, suitable for authorizing or not the rotation of the respective pulley for the lifting of a warp thread, all of the coupling and decoupling means being controlled by the programming means.

Thus, only the pulleys of the wires to be lifted are driven and no energy is expended to move a heavy mechanism common to all the lifting wires as was the case in the old Jacquard looms.

The individual coupling and decoupling means is capable of causing a rotation of the pulley either in a first direction to a lifting position of warp thread, or in the opposite direction to a return position of warp thread, the choice being made by the programming means.

According to an advantageous characteristic, a bistable positioning system of the pulley is provided to maintain it in that of the angular positions where it has been placed following an actuation of the coupling means, only a new action of the latter, in a direction of movement of the pulley towards the other angular position being likely to cause a rotation of the pulley.

This bistable positioning system includes at least two notches or lugs for positioning the pulley, or parts linked to the rotation of the pulley, these notches or lugs cooperating with a fixed frame to define the two stable angular positions of the pulley, and a friction means acting between the frame and the pulley or parts related to the rotation of the pulley.

In a preferred embodiment, the coupling means comprises a thrust arm undergoing a back-and-forth movement with a possibility of oscillation in a direction transverse to the back-and-forth direction, a deflection means of the arm, actuable by the programming means being provided to orient the direction of movement of the arm, two thrust surfaces being provided, opposite one end of the thrust arm, these surfaces being linked to the rotation of the pulley in such a way that the pulley turns in one direction when the pushing arm pushes the first pushing surface and that it turns in the other direction when the arm pushes the second pushing surface. The pushing surfaces can each be situated at the end of a respective link, the other end of which is linked to the pulley, this other end being situated on one side of the axis of the pulley for one of the links. and diametrically opposite for the other link.

The rods comprise at this other end a rack cooperating with a toothed pinion in the center of the pulley, the two racks being diametrically opposite with respect to the axis of the pulley and of the pinion, and the rods being mounted to slide, substantially in the general direction back and forth of the thrust arm, relative to a fixed frame carrying the axis of the pulley.

As regards the means for deflecting the pushing arm, it preferably comprises a blade secured to the movable armature of an electromagnet, this blade having at one end a bevelled surface and being capable of taking, depending on whether 1 'electromagnet is actuated or not, two positions, at least one of which brings the bevelled surface on the path of a part secured to the thrust arm to deflect the movement of the latter accordingly.

Finally, it is expected that the thrust arm is subjected to the action of a spring acting in the transverse direction of oscillation of the arm to bring it back to a position corresponding to one of the two directions of movement of its end. The drive arm drive means preferably comprise a shaft which rotates continuously and which bears a look of the push arm with a sprocket with interrupted teeth meshing with a rack provided on the arm, a return spring serving to bring it back to an initial position after each movement of this arm by the drive means. The rotating shaft in principle drives several thrust arms each corresponding to a pulley and the shaft then has sprockets with toothed teeth opposite each thrust arm or it is fluted over a length corresponding to several thrust arms. Other characteristics and advantages of the invention will appear on reading the detailed description which follows and which is given with reference to the appended drawings in which:

Fig. 1 shows a general perspective view of a loom.

Fig. 2 shows a schematic transverse view showing the introduction of a weft thread between the warp threads.

Fig. 3 shows the hooking and lifting mechanism for individual warp thread according to the invention.

Fig. 4 shows a cross section of a pulley of the mechanism according to the invention.

Fig. 5 shows the juxtaposition in a compact module of a series of chain son lifting pulleys. Fig. 6 shows in longitudinal section an element of the chain yarn lifting mechanism according to the invention.

Fig. 7 shows a top view of several mechanism elements such as that of FIG. 6, juxtaposed to form a module. Fig. 8 schematically represents the advance movement of a thrust arm acting on a determined pulley, with the deflection action by electromagnet of this thrust arm.

Fig. 9 shows the layered layout with longitudinal offset of the chain hoisting mechanism elements.

To make the general framework of the invention understandable, FIG. 1 a weaving loom as it currently exists, and which comprises a series of warp threads 10 arranged parallel to each other and unwinding from a spool or "beam" 12 on which they have been previously wound at the weaving operation. The warp threads side by side are brought into a flat sheet 14 at the location of the weaving, that is to say at the place where the successive weft threads are to be inserted perpendicular to the warp threads and passing over certain warp threads and below certain others so as to make an interweaving and interweaving of the weft threads and the warp threads; the configuration of this interlacing optionally varies with each weft thread inserted so that a desired weaving pattern can be produced by programming this interlacing.

Each weft thread inserted by a shuttle 16 is pressed against the already inserted threads, that is to say against the bottom of the sheet of fabric 18 already manufactured, by a weaving comb 20 which can move back and forth. rear longitudinally.

The fabric 18 produced is wound on another spool or "beam" 22.

To achieve a particular crisscross configuration of weft yarns and warp yarns, a mechanical 24 for lifting warp yarns is provided which is capable of lifting each of the warp yarns individually and which is coupled to non-programming means shown who control this mechanism at each weaving step to choose which of the warp threads to lift at this step. The weft thread is inserted between the raised warp threads and the non-raised warp threads. In fig. 2, there is seen in transverse view a representation of the opening between the warp threads, with a warp thread 10 raised and a warp thread 10 'not lifted, the fabric 18 already formed, the weaving shuttle 16 which drives the weft yarn 26 moving perpendicularly to the warp threads on a sliding path 27. Each warp thread passes through an eyelet or mesh 28 fixed to a respective lifting wire (or arch) 30, this lifting wire being hooked on one side to the lifting mechanism 24 and on the other side to a counterweight, spring or other means of tension; each lifting wire 30 can be lifted individually by the mechanism 24 to lift the warp wire passing through its respective mesh 28.

In fig. 3, we see the system for hooking lifting wires according to the invention. It comprises a pulley 32 rotatably mounted about a fixed axis 34. The wire 30 passes through a groove 36 in the pulley and it is hooked to the pulley, for example by virtue of a bulge 38 retaining at its end, a bulge which prevents the wire from escaping from a hole through which it passes.

Preferably, as seen in FIG. 3, the wire 30 passes below the pulley in a bore formed in a fixed guide 40 which comprises a series of such bores to correctly position side by side each of the lifting wires descending from a respective pulley. This guide 40 replaces the upper drip board provided to date in Jacquard type lifting mechanisms. At the bottom of the lifting wire 30, we see the mesh 28 through which the respective chain wire 10 passes, and below the chain wire, the lifting wire 30 again passes through another fixed guide 42, drilled regularly as the guide 40 to also position the lifting wires at the bottom. The thread tension system is designated by the reference 44.

Fig. 4 schematically represents the pulley in cross section. This pulley in fact comprises in the present case practically only a little more than a quarter of a pulley taking into account the height of the wire which is to be lifted, which facilitates the insertion of means for driving the pulley at the level of the 'axis of it. The pulley is in fact produced by two parallel flanges 46 and 48 between which is placed, around the axis 34 of the pulley, a toothed pinion 50 whose teeth are located between the flanges. The groove 36 is produced by providing a part of circular shape 52 forming a spacer between the flanges 46 and 48. The drive up or down the pulley is done by means of the toothed ring 50 also visible in FIG. 3, this ring gear cooperating with two racks with linear movement 54 and 56 each passing on one side of the ring gear 50 and working in phase opposition, that is to say that when the rack 54 is pushed, the rack 56 is pulled and vice versa, so that the rotation of the pulley in one direction is effected by pushing one of the racks and that its rotation in the other direction is effected by pushing the other rack. The racks 54 and 56 have a shape of a thin plate, toothed at their end facing the crown 50, and they are inserted between the flanges 46 and 48, which is possible due to the fact that the pulley has not been s 'extends only over a portion slightly greater than a quarter of a circle, or more precisely because the part forming a spacer 52 and groove 36 extends only over this portion of slightly more than a quarter of a circle, the flanges themselves which can extend over an entire circular surface. The radius of the groove 36 is chosen taking into account the height from which it is necessary to lift each warp thread (approximately 10 to 15 centimeters), so that a rotation of the pulley over an angle of approximately a quarter of a turn causes the lifting the wire to the desired height. As can be seen in fig. 3, the means for rotating the pulley (racks 54 and 56) are arranged on the side of the pulley opposite the side where the lifting wire arrives on the pulley so that practically the lifting wire is located completely at the end (in the longitudinal direction of the warp threads) of the mechanical lifting element of this thread, the space beyond the point of tangency between the thread 30 and the pulley being left free for the possible passage of other warp threads. The only elements projecting slightly beyond the wire 30 are on the one hand the end edges of the flanges 46 and 48 delimiting the groove 36, and on the other hand the end of the guide 40.

In fig. 5 is shown how one could assemble side by side a plurality of pulleys 32 each corresponding to the lifting of a respective wire 30. All the pulleys are mounted on a common axis 34 which is carried by a frame 58 also carrying the guide 40. The frame 58 is a frame for a module comprising a number of pulleys juxtaposed with their respective individual rotational drive systems. This module is mounted on a general frame of the lifting mechanism, and in this case, the frame 58 comprises two flanges 60 each pierced with two openings for the passage of two transverse guides, one of which, 62 is visible in the view front of fig. 5, and the other 64 is visible in the other figures. The module carried by a frame 58 is slidably mounted on the guides 62 and 64 and can therefore move parallel to the plane of the warp threads and perpendicular to the longitudinal direction of the latter. In fig. 6 a complete individual element of the traction and descent mechanics of a lifting wire 30 has been shown in more detail.

The wire 30 shown in the low position here, is hooked to the pulley 32 and passes through the ring 40 placed under the pulley, in a bore located in alignment with the vertical tangent to the groove 36 of the pulley.

The racks 54 and 56 for driving the pulley 32 are carried at the end of respective rods 66 and 68 carrying horizontal guide grooves cooperating with guide pins linked to the fixed frame 60 carrying the pulley and its actuation mechanism , so that the links 66 and 68 can move parallel to one another and substantially perpendicular to the direction of arrival of the wire 30 while being placed on the other side of the pulley with respect to this wire 30. The movements of the two rods 66 and 68 are completely linked to each other by means of the toothed ring of the pulley 32, and these movements are always in phase opposition, since the racks 54 and 56 mesh together. and on the other side of the toothed crown of the pulley.

The links 66 and 68 are formed by thin plates which can penetrate between the flanges of the pulley 32. Their respective ends 70 and 72 on the side opposite the pulley and the racks 54 and 56 constitute surfaces thrust on which can be applied the end 14 of a thrust arm 76 capable of moving back and forth in the direction of guide of the links 66 and 68. The thrust arm 76 is guided by a groove 78 and a nipple 80 to be able to move in this direction, but it can also oscillate in a direction transverse to this direction, under the effect of a means of deflection of the thrust arm, to be able to orient itself either in a position where its back and forth movement brings its end 74 opposite the end 70 of the link 66, without touching the end 72 of the link 68, that is to say in a position where its back and forth movement brings its end 74 facing the thrust surface 72 of the link 68 without touching the end 70 of the link 66. It is preferably provided that a return spring 82 acts on the thrust arm 74 to bring it permanently into the one of the two positions, for example the first, so that if the means arm deflection is not actuated, it is the rod 66 which can be pushed back, while if the arm deflection means is actuated, it will act against the spring 82 to move the end 74 towards the thrust surface 72 of the link 68.

The reciprocating movement of the thrust arm 76 is caused by a drive shaft 84 which rotates continuously and which has at its periphery an interrupted toothing 86 capable of meshing with a toothed rack 88 provided on the arm of thrust 76, the arm 76 being subjected to the action of a return spring 90 bearing on the frame 60 and tending to keep it back, spaced from the thrust surfaces 70 and 72 of the rods.

When the shaft 84 rotates, the interrupted toothing portion 86 comes at a moment to mesh with the rack 88 and advances the arm 76 against the spring 90. As soon as the interrupted toothing portion 86 ends, the arm returns back under the action of the spring 90, awaiting a new passage of a portion of interrupted toothing 86. Several portions of toothing may be provided on a circumference of the shaft 84, provided that these portions of toothing are separated a sufficient interval for allow the pushing arm 76 to go back before the next portion of the toothing passes.

The drive shaft 84 is of course synchronized with the step-by-step movement of the fabric and therefore of the means for passing the weft threads so that the thrust arm 74 undergoes a complete back-and-forth movement each no weaving, one of the movements used for the possible lifting of a warp thread, and the other for the possible return of this warp thread. In the example shown, two toothing portions 86 are provided, and the shaft 84 therefore makes a half-turn at each weaving pitch.

The means for deflecting the pushing arm 76 consist of an electromagnet 92, the movable armature 94 of which carries a blade 96 having at its end 98 a bevelled surface capable of taking, depending on whether the electromagnet is actuated or not. At least one brings the bevelled surface onto the path of a part 100 secured to the thrust arm to consequently deflect the movement of the latter and bring its end 74 into it. look of one of the links 66 and 68. Here, when the electromagnet is excited, the bevelled surface lowers the end 74 to bring it opposite the surface 72 of the lower link 68. In the absence of excitation of the electromagnet, the thrust arm can only come to bear against the thrust surface 70 of the upper link 66.

The part 100 forms a bridge over a sufficient distance above the end 98 of the blade 100 so that once this part 100 has engaged either above or below the end 98, it remains there for the entire duration of the path of the thrust arm in the direction of the rods, which makes it possible to excite the electromagnet only during the start of a back-and-forth cycle of the arm 76, in order to reduce the consumption of electrical energy by electromagnets during weaving cycles. The pushing arm 76, like the links 66 and 68, is constituted by a thin plate to have as little lateral space as possible, and preferably the pushing arm including the part 100 which forms a bridge above the blade 98, has a substantial thickness ment of the order of the thickness of the pulley and is arranged in a plane aligned with that of the pulley.

The coupling of the pushing arm 76 with one or the other of the links is done at will thanks to the electromagnet 92 which is of course controlled by the programming means of the loom.

Given that in certain cases, it is desired to be able to keep a warp yarn lifted for several consecutive weaving steps, it is provided according to the invention that the links 66 and 68 can be held by a bistable positioning system in the last position where they have been set by the push arm 76, so that at the next weaving pitch the rods remain in the same position without being actuated again by the push arm 76 if there is no need to change the position of the warp thread considered.

The bistable positioning system is simply constituted by a spring 102 fixed to the frame 60 and cooperating with notches 104 and 106 provided on at least one rod and defining the two angular positions that the pulley is capable of taking, lifting position or position of warp thread return; the end of the spring 102 is capable of engaging in one of the notches 104 and 106 and then exerts on the links sufficient friction in the longitudinal direction to prevent rotation of the pulley towards its other stable angular position, for example under the tension of the lifting wire 30.

Fig. 7 shows a top view of a group of elements of the actuation mechanism of several pulleys 32 located side by side. In fact, the pulleys and their respective mechanisms are preferably arranged in compact modules comprising, for example, twenty or thirty juxtaposed pulleys, all of the mechanism elements being rejected behind the pulleys, that is to say on the side opposite the side where the lifting wires 30 arrive.

The frame 58 already mentioned is the frame on which the various mechanism elements and the respective pulleys are mounted. It is preferably provided that this frame 58 is not fixed with respect to the entire frame of the mechanical but, on the contrary, the modules can be moved laterally with respect to each other: a row of modules mounted on parallel bars 62 and 64 already mentioned with reference to FIG. 5 and these modules can be slid on the bars so as to bring them closer or separate them from one another according to the density of warp threads desired for weaving.

As can be seen in fig. 7, the pulleys 32 of a module are all mounted on a common axis 34 so that the front edges of the pulleys are aligned and that all the lifting wires 30 lie in the same plane completely at the front of the module (only the front edge of the guide 40 projecting slightly beyond the plane of the wires 30 since these wires pass through the holes in the guide 40). In fig. 8 for the clarity of the description, the manner in which the means for deflecting the pushing arm 76 is shown: in FIGS. 8a. and 8b, the electromagnet is not energized and its movable armature falls in a position where the bevelled end 98 is not in the path of the part 100 secured to the thrust arm. The latter therefore moves in a first direction towards which it is biased by its spring 82; in this direction it can come to touch the end of the upper link 66 but not that of the lower link 68. In Figures c and d, the electromagnet is excited and the bevelled surface 98 of the movable frame comes on the path of the part 100 and forces the arm 76 to move down during its advance movement. In this new position, the end of the thrust arm 76 can come to press on the link 68 but not on the link 66. It must be understood anyway that the push arm only pushes on a link 66 or 68 if this link has not already been pushed back, in the previous half weaving step, by the push arm. There has thus been described with reference to the preceding figures an embodiment of a chain son lifting mechanism in which each lifting wire 30 is hooked to a pulley which is rotated by rods and racks acting on a ring gear of this pulley. We can understand that it is also possible not to directly hook the lifting wire 30 to the pulley but pass it over the groove of the pulley to return it in a direction behind the arrival side of the wire 30 on the pulley, the wire then being hooked to a mechanism individual traction, the pulley only serving as a steering gear for the wire 30: for example, the links 66 and 68 may not act on a toothed ring of the pulley but simply on an independent toothed ring located between the links 66 and 68 to secure their respective movements in phase opposition, the lifting wire 30 being hooked to the end of one of the rods after having turned around the pulley by an angle of approximately 90 °. It will be noted that it is then necessary to provide that the groove of the pulley extends over at least a half-circumference and preferably a complete circumference, whereas in the previous case a quarter of circumference was sufficient.

It is ultimately possible to provide, taking into account the materials with a low coefficient of friction currently existing, that the pulley 32 is,. In this latter embodiment where it simply serves as an angle gear, a fixed roller for example of Teflon on which the lifting wire 30 can slide without friction by being pulled by a rod rejected behind the roller relative to the arrival side of the wire 30. In the latter case, it suffices to provide a roller having a groove extending over a quarter of circumference approximately to allow the wire 30 to arrive in this groove vertically and to be returned horizontally to be hooked to one of the rods arriving in alignment with the direction of longitudinal displacement thereof, a gear being further provided for securing in phase opposition the movements of the two links.

The use of pulleys or rollers for returning the traction direction of the lifting wires in a direction substantially perpendicular to the direction of arrival of these wires makes it possible to have a very large number of individual lifting mechanisms each associated with a respective pulley, without interference between the multiple lifting wires and these mechanism elements, this thanks to the arrangement which will now be described with reference to FIG. 9. Fig. 9 represents the overall construction of the lifting mechanism for the warp threads 10 which arrive in web from the spool 12 and which are wound after weaving on a spool 22, each warp thread being able to be lifted by a respective descending lifting thread 30 lifting mechanics. The lifting mechanism comprises a general frame 110 which essentially carries two mobile assemblies 112 and 114 each carrying a series of rows of modules of several mechanical elements for individual lifting of wires. The lifting wires 30 are suspended from the pulleys of the modules of each series 112 and 114 and these lifting wires pass between the two mobile assemblies 112 and 114, the direction of mobility of the assemblies 112 and 114 relative to the other being the general direction of the warp threads and this mobility being provided simply to allow the assemblies to be separated from one another and to allow the passage of a man between the assemblies for the purpose of maintenance and repair of lifting wires and mechanical components. In fig. 9, there is shown in dotted lines the assembly 112 separated from the assembly 114, and in solid lines the assembly 112 close to the assembly 114. We can also see in FIG. 9 that the modules of the 112 and 114 series are turned in opposite directions, so that they face each other and that the lifting wires which are suspended from them lie well between the two mobile assemblies, the mechanical elements being rejected at outside the gap between the lifting wires facing each other.

Each mobile assembly comprises a series of several rows of modules such as those of FIG. 7, the rows being superimposed and each row comprising several modules carried by common parallel bars 62 and 64 on which the modules can slide as has already been said. The superimposed rows of modules are offset slightly progressively with respect to each other in a direction parallel to the warp threads, the offset being made in the opposite direction for the two series of sets 112 and 114. This offset is made in a meaning such that the pulleys of a row have their lifting wire arrival side immediately set back from the lifting wire arrival side of the pulleys of the row immediately above it. Thus, the facing pulleys are close to each other at the top of the general frame 110 and they move away progressively downwards, the pulleys of the lower row being the most spaced apart from each other in the direction of warp threads.

The purpose of this progressive shift, which can exist both in the case where a single set 112 is provided and in the case where two sets 112 and 114 are provided, is to ensure that not only the lifting wires are located not all in the same plane but in slightly offset planes which facilitate the separation of the wires from each other, but also that the wires coming from the upper rows do not fall on parts of the lifting mechanism of the wires from the rows which are at below, the shift is always in the same direction from one row to the row immediately below. The progressive shift must not be too great from one row to the next row so as not to carry out too large a spread (in the direction of the warp threads) of the lifting points of the warp threads. The progressive offset must however be sufficient to avoid any interference between the lifting wires coming from a row and the lifting wires coming from the immediately lower row: in particular, an offset must be provided at least sufficient for a lifting wire 30, passing through a guide 40 which corresponds to this wire, does not come to touch the front edge of a guide 40 (or the front edges of the flanges of the pulleys) of the row immediately below the row considered.

For example, 25 rows of pulleys can be provided on each of the facing assemblies, each row comprising 10 sliding modules and each module comprising 28 pulleys. However, the invention makes it possible to further increase this number as well by increasing the number of modules juxtaposed laterally as by increasing the number of superimposed rows. It should also be understood that the description which above was given only by way of example and that it in no way limits the field of the invention from which one would not depart by replacing the details of execution described by any other equivalent.

Claims

R E V E N D I C A T I O N S

l. ^'' Industrial weaving machine comprising a system for advancing a plurality of warp threads (10) arranged in a sheet (14 _), a selective lifting mechanism (24) for the chosen warp threads, coupled with means for programming the choice of warp threads to be lifted, and a weft thread insertion system (16) between the raised warp threads and the non-lifted warp ply, the warp lifting mechanism comprising a plurality of threads yarns stretched on either side of the warp ply and each provided with a yarn lifting mesh (28) through which a respective warp yarn (10) passes, characterized in that each yarn lift (30) passes through the groove (36) of a respective pulley (32), individual means (54, 56) of lifting wire (30) being associated with the wire and the respective pulley (32) to allow a pull of the wire and a return of the wire, these means (54-56) being arranged on the side opposite to the side where the lifting wire (30) arrives on the pulley (32). ^''

2. ^' weaving loom according to claim l, characterized in that the lifting wire (30) is hooked to the respective pulley (32) and that the individual displacement means (54, 56) are capable of rotating the pulley (32) at an angle corresponding to the desired lifting height of the wire (30).

3. ^' Trade according to one of claims 1 and 2, characterized in that the pulleys (32) are arranged in rows stepped in height above the ply (14) of warp son (10), the successive rows being shifted slightly, gradually from one floor to another in a direction parallel to the warp threads. ^''

4.'Weaving loom according to claim 3, characterized in that two series of rows facing each other are provided, the pulleys (32) and their displacement means (54-56) being turned in opposite directions for the two series, the arrival sides of the lifting wires (30) of the pulleys (32) of the first series facing the arrival sides of the lifting wires of those of the second series, and the offsets progressive rows of pulleys in the direction of warp threads (10) being in opposite directions for the respective rows of the two series.

5. Weaving machine according to one of claims 2 to 4, characterized in that there is provided a drive means (34) common for several pulleys (32) and means (76-92) for coupling and individual decoupling between each pulley and the drive means, capable of authorizing or not the rotation of the respective pulley for the lifting of a warp thread (10), all of the individual coupling means and decoupling being controlled by the programming means.

6. A weaving machine according to claim 5, characterized in that the means (92) for individual coupling and decoupling is capable of coupling the means (54, 56) for driving to the pulley (32) corresponding either by causing a rotation of the pulley (32) in a first direction to a wire lifting position (30) either by causing a rotation of the pulley in a second direction to a return position of the warp wire (10), the choice being made by the programming means.

7. Loom according to one of claims 5 and 6, characterized in that there is provided a bistable positioning system (102) of the pulley (32) to maintain it in one of the two angular positions where it was put following an actuation of the coupling means (92), only a new actuation of the coupling means, in a direction of movement of the pulley towards the other angular position, being capable of causing a rotation of the pulley (32).

8. Loom according to claim 7, characterized in that the bistable positioning system (102) comprises at least two notches (104, 106) or lugs for positioning the pulley (32) or of parts (54, 56 ) linked to the rotation of the pulley (32), these notches or lugs cooperating with a fixed frame (58) to define the two stable angular positions of the pulley, and a friction means

(102) acting between the frame (58) and the pulley (32) or the parts (54, 56) linked to the rotation of the pulley (32).

9. Weaving machine according to one of claims 5 to

8, characterized in that the coupling means (76-92) comprise a thrust arm (76) undergoing a back-and-forth movement with the possibility of oscillation in a direction transverse to the direction of back-and-forth - comes, a means (92) for deflecting the arm, actuable by the programming means, being provided to orient the direction of movement of the arm, two thrust surfaces (72-70) being provided opposite one end (74 ) of the pusher arm (76), these surfaces (72-70) being linked to the rotation of the pulley (32) in such a way that the pulley rotates in one direction when the pusher arm (76) first pushes thrust surface (72) and that it rotates in the opposite direction when the arm (76) pushes the second thrust surface (70).

10. Weaving machine according to claim 9, characterized in that the thrust surfaces (72, 70) are each located at the end of a respective link (56, 54), the other end of which is linked to the pulley, this other end being located on one side of the axis (34) of the pulley (32) for one of the rods and diametrically opposite for the other.

11. Loom according to claim 10, characterized in that the links (54, 56) comprise at said other end a rack cooperating with a toothed pinion (50) in the center of the pulley (32), the two racks being diametrically opposite with respect to the axis (34) of the pulley (32) and the pinion (50), and the rods being slidably mounted substantially in the general direction back and forth of the thrust arm (76), relative to a fixed frame (58) carrying the axis (34) of the pulley (32).

12. A weaving machine according to one of claims 9 to 11, characterized in that the deflection means (92) comprises a blade (96) integral with the movable frame (94) of an electromagnet (92 ), this blade (96) having at one end a beveled surface and being capable of assuming, depending on whether the electromagnet is actuated or not, two positions, at least one of which brings the beveled surface onto the path of a piece (100) secured to the push arm (76) to deflect the movement of the latter accordingly.

13. A weaving machine according to claim 12, characterized in that the thrust arm (76) is subjected to the action of a spring (82) acting in the transverse direction of oscillation of the arm (76) for the return to a position corresponding to one of the two directions of movement of its end.

14. Weaving machine according to one of claims 12 and 13, characterized in that the electromagnet (92) is excited only during part of a back-and-forth cycle of the thrust arm (76), its actuation being interrupted after the thrust arm has been engaged definitively in the direction corresponding to this actuation.

15. A weaving machine according to one of claims 9 to 14, characterized in that the thrust arm (76) comprises a rack (88), that the drive means comprise a shaft (84) rotating continuously, this shaft bearing opposite the rack (88) of the thrust arm (76) a pinion (84) with teeth (86) interrupted, and that there is provided a means (90) for returning the arm (76) to a initial position after each arm movement by the drive means.

16. A weaving machine according to claim 15, characterized in that the return means of the push arm is a spring (90) acting in the longitudinal direction of the reciprocating arm (76), this spring acting when the drive shaft (84) arrives in a position where the rack (88) of the arm (76) is opposite a zone of interruption of toothing of the pinion (84) of the shaft. 17. Weaving machine according to one of claims 9 to 16, characterized in that each pulley (32) comprises two flanges (46, 48) close together, that the thrust arm (76) consists of a plate thickness substantially less than the thickness of the pulley and disposed in a plane located between the flanges of the pulley.