Abstract:
A weave system comprises a plurality of electric rotary actuators each of which is adapted to drive a pulley for winding a cord element controlling the position of at least one heddle, and wherein a removable cover is provided to isolate and protect a group of pulleys mounted on adjacent actuators. The cover is provided with means for releasably retaining at least one pulley in a position allowing it to be assembled on a corresponding actuator or dismantled with respect thereto as the cover is moved toward or away from a mounting position over the corresponding actuator and which releases the at least one pulley to freely rotate within the cover when the cover is completely seated in mounted relationship with respect to the actuators.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a weave system of Jacquard type as well as to a weaving loom equipped with such a system. The invention also relates to methods for assembly and dismantling of such a system. 
   2. Brief Description of the Related Art 
   It is known, for example from FR-A-2 772 792, to use a rotary motor such as a step-by-step motor or a servo-motor in order to linearly control a cord from which a heddle of a weaving loom is suspended. According to this prior art, different actuators may be disposed in a casing, the pulleys driven by each actuator being protected by a cover allowing them to be isolated, particularly against the flock of the ambient atmosphere. 
   It is known that a very large number of such actuators may be provided in a weaving loom of Jacquard type, in which case panel structures may be used, as described in FR-A-2 794 140. 
   When the number of electric actuators is high, for example of the order of 10 000, an equally large number of pulleys must be mounted on these actuators in order to allow the corresponding cords to be wound. Such an operation is long and tedious and requires qualified manpower, in order to respect the order of assembly of the pulleys and in order not to damage the pulleys or the ends of the output shafts of the actuators on which they must be mounted. 
   SUMMARY OF THE INVENTION 
   It is a more particular object of the invention to overcome these limitations by proposing a weave system in which the assembly of the different winding pulleys may be effected conveniently and rapidly. 
   In this spirit, the invention relates to a weave system of the Jacquard type for forming the shed on a weaving loom, this system comprising a plurality of electric rotary actuators adapted each to drive in rotation a pulley for winding a cord element controlling the position of at least one heddle, while a cover is provided to isolate from the outside and/or protect a group of pulleys mounted on adjacent actuators. This system is characterized in that this cover is provided with means for retaining at least one pulley in a position allowing its assembly on the corresponding actuator or its dismantling with respect thereto. 
   Thanks to the invention, the positioning of the cover opposite the actuators, particularly on a casing in which actuators are mounted, allows the pulley or pulleys that it bears to be placed in position simultaneously. 
   According to advantageous aspects, a weave system may incorporate one or more of the following characteristics:
         The retaining means are adapted to retain a plurality of pulleys in position of assembly/dismantling and are compatible with a simultaneous assembly/dismantling of these pulleys on the corresponding actuators. In other words, the retaining means make it possible to assemble a plurality of pulleys at the same time, hence a still more significant saving of time.   The retaining means are adapted to impose the angular orientation of the or each pulley, this making it possible to envisage an adjustment by default of the position of this pulley.   The retaining means comprise at least one elastically deformable tab defining with a corresponding member a zone for receiving a part of a pulley. In that case, this tab and this member are advantageously provided with elements in relief adapted to cooperate with elements in relief of corresponding shapes provided on the pulley, the cooperation of these elements in relief inducing an elastic catching of the pulley between the afore-mentioned tab and member. In addition, this tab and this member may define, with a bottom web of the cover, a zone for blocking a part of the pulley, such a zone being able to be used to firmly catch a pulley on the cover with a view to separating this pulley and the actuator on which it was previously mounted.   The cover bears, in the vicinity of the afore-mentioned retaining means, at least one element in relief adapted to cooperate with an element in relief of corresponding shape provided on the pulley, the cooperation of these elements in relief inducing a control of the angular orientation of the pulley about its central axis.   The cover is provided, in the vicinity of the afore-mentioned retaining means, with a housing for receiving the pulley without contact, this pulley being able to be displaced with respect to the cover between a first position in mesh with the retaining means and a second position disengaged from the retaining means and in which the pulley is in place in this housing, and vice versa, this displacement taking place thanks to a localised elastic deformation of the retaining means. The cover may be provided to be mobile with respect to a casing in which the actuators are mounted, in translation in a direction perpendicular to the axes of rotation of the output shafts of these actuators, between two positions in which the pulleys mounted on the actuators are either in the first position or in the second position mentioned above.       

   The invention also relates to a weaving loom equipped with a weave system as described hereinbefore. Such a weaving loom is more economical, easier to install and to maintain than those of the state of the art. 
   The invention also relates to a method for assembly of a weave system as described hereinabove and, more specifically, to a method which comprises steps consisting in:
         mounting at least one pulley on a cover for isolating and/or protecting the electric rotary actuators of the system;   bringing the cover and the actuators closer to one another by a movement of translation in a direction substantially parallel to the axes of rotation of the output shafts of these actuators;   connecting the pulley to the output shaft of the corresponding actuator at the end of the afore-mentioned movement of approach, and   displacing the cover in a direction substantially perpendicular to that of the movement of approach, while releasing the pulley with respect to the cover.       

   Thanks to the method of the invention, the positioning of the cover with respect to the actuators makes it possible both to connect the pulleys and the actuators then to release these pulleys in order to allow them to rotate without friction on the cover. 
   Connection of the pulley and of the corresponding shaft is advantageously effected by clipping. 
   Finally, the invention relates to a method for dismantling a weave system as described and assembled hereinbefore, in which:
         at least one pulley is oriented angularly by transmitting thereto a traction effort exerted by the cord element associated therewith,   the cover is displaced in translation in a direction substantially perpendicular to the axis of rotation of the pulley, until this pulley is engaged in a retaining zone made on the cover, and   the cover equipped with the pulley is displaced in translation in a direction substantially parallel to the afore-mentioned axis and in a sense of moving away with respect to the actuator.       

   At the end of this dismantling, the or each part is maintained angularly in position with a view to a subsequent assembly. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more readily understood and other advantages thereof will appear more clearly in the light of the following description of a form of embodiment of a weave system and of a weaving loom in accordance with its principle, given solely by way of example and made with reference to the accompanying drawings, in which: 
       FIG. 1  is a schematic view in vertical section of a weaving loom in accordance with the invention, incorporating a weave system according to the invention. 
       FIGS. 2A ,  2 B and  2 C are views in perspective of a group of actuators belonging to the weave system of  FIG. 1  and of an associated cover at different stages of assembly. 
       FIG. 3  is a view in perspective, in the direction of arrow F 3  of  FIG. 2A , of a part of the cover and of three pulleys in different positions corresponding to the assembly of the pulleys on the cover. 
       FIG. 4  is a front view of the lower right-hand corner of the cover shown in  FIG. 3  and of a part of a yarn-guide bar. 
       FIG. 5  is a section along line V—V of  FIG. 4 , and 
       FIG. 6  schematically shows an actuator and a pulley in the course of assembly, the cover being shown in dashed and dotted lines in order to render the drawing clearer. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   The weaving loom M shown in  FIG. 1  comprises a system formed by the mutual assembling of a plurality of casings  1  of which each contains sixteen electric rotary actuators  2  whose output shaft  3  may bear a pulley  4  for winding a harness cord  5  connected to a heddle  6  intended to control a warp yarn  7  of the loom M and associated with a spring  8  for return into lower position. 
   The different casings are assembled in rows perpendicular to the plane of  FIG. 1  and in columns parallel to this plane. They form two panels A and B disposed above the weaving zone. In a variant, one sole panel formed by casings  1  may be provided. In another variant, the panels A and B may be substantially vertical and parallel to one another. 
   As is visible in  FIG. 2 , each casing  1  contains sixteen actuators  2  of which the respective output shafts  3  are parallel and project with respect to the front face  11  of the casing  1 . 
   Each pulley  4  defines a volume  41  for receiving and wedging elastic tabs  31  provided at the end of each shaft  3 , this allowing an elastic clipping of a pulley  4  on a shaft  3 , in the direction of arrow F 1  in  FIG. 6 . 
   A cover  20  is provided to be mounted on the front face  11  of the casing  1  jointly with a bar  21  for guiding the harness cords  5 . 
   The cover  20  is configured in order to be able to retain in position the sixteen pulleys  4  intended to be mounted on the actuators  2  of the casing  1 . 
   As is more particularly visible in  FIG. 3 , the cover  20  forms a plurality of zones  22  in which the pulleys  4  may be clipped. Each zone  22  is bordered by an elastically deformable tab  23   a  and by a rigid stop  23   b  each provided with a bead  24  oriented towards the centre of the zone  22 . 
   Each pulley  4  is provided, at the level of a flange  42  of larger diameter, with two recesses  43  whose shapes correspond to those of the beads  24 . 
   In the vicinity of each zone  22  and thereabove in the representation of  FIG. 3 , there are provided zones  25  forming hollow housings of diameter slightly greater than that of the flanges  42 , which allows the pulleys  4  to be partially engaged in these housings without being in contact with the cover  20 . 
   The cover  20  is also provided with rigidifying ribs  26  which define individual compartments adapted each to receive a pulley, these compartments communicating with one another to allow passage of the harness cords  5 . 
   The pulleys  4  are assembled on the cover  20  by displacing each pulley towards a zone  25 , as represented by arrow-F 2  in  FIG. 3 , this making it possible to attain the position shown in the upper right-hand part of this Figure. It then suffices to exert a downwardly directed vertical effort on the pulley  4 , as represented by arrow F 4 , in order to attain the position of the pulley shown in the lower right-hand corner of  FIG. 3  where the tab  23   a  has been elastically deformed in order to allow the introduction between it and the stop  23   b  of the flange  42 . The beads  24  then come into engagement in the recesses  43 , this allowing an immobilization of each pulley  4  with respect to the cover  20  in a vertical direction. 
   One is then in the position of  FIG. 4  where a part  44  of the flange  42  located in the vicinity of each recess  43  is engaged in a zone  27  defined between a bead  24  and the bottom  22   a  of the zone  22 . 
   In this way, as is more particularly visible in  FIG. 5 , the pulley  4  is firmly maintained in position with respect to the cover  20  when the cover is moved in the direction of arrow F 5  in this Figure. 
   It should be noted that the tab  23   a  is in one piece with a tongue  28  defined between two slots  29   a  and  29   b , which allows a deformation of the elements  23   a  and  28  in the direction of arrow F 6  in  FIG. 4 , thus allowing the pulley  4  to be positioned in the zone  22 . 
   The tab  23   a  and the tongue  28  work in flexion during the movement of introduction of the pulleys  4  in the zones  22  and during the movements of extraction. 
   According to a variant of the invention (not shown), the two elements  23   a  and  23   b  might be deformable with respect to the rest of the cover  20 . 
   The zone  22  is also bordered by a tooth  22   b  whose shape corresponds approximately to that of a cut-out  45  formed in the flange  42 . The cooperation of the elements  22   b  and  45  makes it possible to control the angular orientation of the pulleys  4  about their respective central axes X 4 –X′ 4  after assembly on the cover  20 . 
   In this way, the pulleys  4  mounted on the cover  20  may all be substantially in the same angular position about their respective central axes X 4 –X′ 4.    
   There are provided on the cover  20  as many retaining zones  22  as there are actuators  2  in the casing  1 . The zones are distributed as a function of the distribution of the actuators in the housing. 
   When the pulleys  4  are mounted on the cover  20 , the different harness cords are passed in the corresponding orifices  21   a  of the bar  21  then the bar  21  and the cover  20  are connected by any appropriate means, for example by introduction of lugs provided in the lower part of the cover  20  in corresponding housings in the bar  21 . 
   The organization in space of the pulleys  4  previously mounted on the cover  20  is in exact register with the organization in space of the actuators  2  in the casing. 
   The assembly formed by the elements  20  and  21  is then applied on the face  11  of the casing  1  in the direction of arrow F 10  in  FIG. 2A , i.e. in a direction substantially parallel to the central axes X 3 –X′ 3  of the shafts  3 . The direction of translation of the cover  20  with respect to the casing  1  is likewise parallel to the axes X 4 –X′ 4  of the pulleys  4 . 
   At the end of this movement of translation F 10 , the pulleys  4  are automatically clipped on the ends of the shafts  3 , by the cooperation of the teeth  31  and of the volumes  41 . 
   The position of  FIG. 2B  is then attained, in which screws  12  projecting from the face  11  are respectively engaged in an oblong slot  20   b  in the cover  20  and in notches  21   b  in the bar  21 . 
   It is then possible to subject the cover  20  and the bar  21  to a vertical movement downwardly directed in the direction of arrow F 11  in  FIG. 2B , this having the effect of causing the different pulleys  4  to slide from the zones  22  in which they were previously retained towards the zones  25  in which they may rotate, being driven by the shafts  3 , without contact with the cover  20 . The position of  FIG. 2C  is then attained. 
   In this way, the positioning of the cover  20  and of the bar  21  on the casing  11  allows, in particularly easy manner, the simultaneous catching of the pulleys  4  on the different actuators  2  and their simultaneous release with respect to the cover  20 . 
   When the different pulleys  4  of the actuators are to be withdrawn from a casing  1 , for example with a view to a standard exchange of this casing, the cover  20  is animated by an upwardly directed vertical movement represented by arrow F′ 11  in  FIG. 2C , this making it possible to attain the configuration of  FIG. 2B  again, the different pulleys  4  being again engaged in the zones  22  by this movement. The pulleys  4  are then subjected to a traction effort F 12  transmitted by the harness cords  5  and resulting from the action of the return springs  8 , this participating in their angular orientation, each about its axis X 4 –X′ 4 . The pulleys are then immobilized in rotation by the cooperation of the elements  24  and  43  which come into engagement. The effort F 12  therefore makes it possible to obtain a levelling of the angular position of the pulleys  4  at the beginning of dismantling, all the pulleys in that case having the same angular position. 
   It is then possible to separate the assembly formed by the cover  20  and the bar  21  with respect to the casing  1  by exerting a traction effort in the direction of arrow F′ 10  opposite that of arrow F 10 . As the parts  44  are captive behind the bead  24  of the tabs  23   a  and  23   b , the pulleys  4  are disconnected from the shafts  3 , simultaneously, and the configuration of  FIG. 2A  is attained again. 
   It is also possible to dismantle the cover from the configuration of  FIG. 2C , leaving the pulleys  4  and the bar  21  in place. To that end, it suffices to loosen the upper screw  12  and to pull on the cover  20  in the direction of arrow F′ 13  in  FIG. 2C . 
   This makes it possible to intervene individually on one or the other of the actuators in order to change the pulley and/or the harness cord associated therewith, and even the whole of the actuator.