FR2648831A1 - WEFT YARN FEEDING DEVICE FOR WEAVING MACHINE WITH PNEUMATIC INSERTION - Google Patents

Abstract

The device on one side of the weaving machine constitutes a dual feed system, allowing automatic switching from one system to another in the event of a weft thread defect on one of the feed systems. This device comprises a first fixed nozzle 5 and a second fixed nozzle 14, each of these two nozzles being able to direct a weft thread 1, 11 towards a launching nozzle 6 movable with the comb of the machine. A movable introduction means 20 retains the end of the weft thread 11 placed on hold, and moves this thread end towards the launching nozzle 6, in the event of a fault in the supply of the weft thread used 1.

Description

"Weft feeder for weaving machine with

  pneumatic insertion "The present invention relates to a weft feed device for shuttleless weaving machine with pneumatic insertion. More particularly, this invention relates to a device constituting a double weft feed system, such so that when a weft thread defect is detected on one of the power supply systems while in use, it automatically switches to a

  another feeding system whose weft thread is kept on standby.

  Thus, this feeding device is in particular intended for a weaving machine provided with means allowing a specific detection of faults in the weft of the weft, for example means ensuring this detection in connection with a sequence of "unweaving" as described in a previous French patent application N 89 01 918 filed on February 7, 1989

in the name of the Applicant.

  With regard to double weft feed systems, the state of the art includes patent applications

  European publications N 0 195 469 and N 0 291 486.

  European patent application No. 0 195 469 indicates detectors placed in the path of the weft thread, in each of the two supply systems. The detectors monitor the state of the weft thread and, in the event of detection of a fault, they control via a unit of

  controls switching to the other supply system, on standby.

  However, this document does not indicate any concrete solution for the passage from one weft thread to another, in the case of a weaving machine with insertion.

pneumatic frame.

  Unlike the previous document, European patent application N 0 291 486 describes a double weft feed system, intended for pneumatic insertion and comprising, on the same side of the weaving machine: - a first associated pre-deliverer to a first nozzle, for the weft thread coming from a first supply reel, and - a second pre-deliverer associated with a second nozzle, for the thread

  weft from a second supply coil.

  The weaving machine here comprises a mobile launch nozzle with the comb, and the problem posed when switching from one supply system to another is to manage to bring the mobile launch nozzle into the weft thread previously stayed on hold. Indeed, there is already a general difficulty in introducing the free end of a wire at the inlet of a suction and blowing nozzle, this for pneumatic reasons, a harmful phenomenon of discharge which can occur at the nozzle entrance. In addition, in the particular configuration with three nozzles considered here, the axes of the first nozzle and of the second nozzle form an angle with the axis of the launch nozzle, and these first and second nozzles create diverging air jets. . Finally, there may be an imprecision of the stop position of the mobile launch nozzle, position o this nozzle

  must be brought when changing the weft thread.

  To solve this problem, it has been proposed in European patent application N 0 291 486 to make the first nozzle and the second nozzle movable in the direction of the launching nozzle. Thus, at the moment when the corresponding weft thread is to be introduced into the launching nozzle, the first nozzle or the second nozzle is moved as a whole and

  close to the launch nozzle.

  This arrangement remains mechanically complicated, in that it requires mobile mounting of the first and second nozzles, and control means moving each of these nozzles in a

  rotational or translational movement.

  The present invention aims to eliminate these drawbacks, by providing a new and simplified configuration, allowing entirely fixed mounting of the first and second nozzles, and reducing to the minimum the mobile elements necessary for the safe supply of one or other of the son

  weft at the entrance of the mobile launch nozzle.

  To this end, the invention essentially relates to a weft feed device for weaving machine without shuttle with pneumatic insertion, the device constituting a double feed system such that, when a fault in the weft thread is detected on one of the feed systems, it automatically switches to the other feed system whose weft thread is kept on standby, and this device comprising, on the same side of the weave, at least a first pre-feeder associated with a first nozzle, for the weft thread coming from a first supply spool and at least a second pre-deliverer associated with a second nozzle, for the weft thread coming from a second nozzle supply, each of these two nozzles being able to direct the corresponding weft thread towards a mobile launch nozzle with the comb of the weaving machine. for the insertion of this weft thread. the device being characterized in that the aforementioned first and second nozzles are nozzles mounted fixed on the side of the machine

  weave, and in that there is provided at least one mobile introduction means.

  independent of these fixed nozzles, capable of retaining the end of a weft thread put on hold, this end being located downstream of one of the fixed nozzles, and of moving this end of the wire in the direction of the launching nozzle mobile. Thus, the invention makes it possible to have, in the weft yarn supply device, two fixed nozzles and a single mobile means ensuring the safe introduction of one or the other of the weft yarns into the nozzle. launch. The overall configuration of the supply device thus remains particularly simple, while perfectly ensuring the desired functions: - the mobile means, now holding a weft thread, can be put into action automatically following the detection of a defect, by being advanced towards the launching nozzle to introduce the yarn therein and allowing immediate weaving with this yarn - after retraction of the mobile introduction means, the free end of the unused weft yarn can be put in place manually, in "time

masked ", on this mobile medium.

  According to one embodiment of the invention, the movable introduction means is constituted by a jack, having a fixed body and a movable rod in the direction of the launching nozzle, the end of the movable rod facing towards this nozzle. launch being provided with an input device and

  holding the end of the weft thread put on hold.

  It is possible in particular to use a pneumatic or electric actuator, preferably controlled in such a way that its rod describes a movement.

  relatively slow towards the launch nozzle.

  Advantageously, the wire gripping and holding member, provided towards the end of the movable rod of the jack, is a vacuum cleaner supplied with pneumatic fluid. The presence of the vacuum cleaner facilitates the manual positioning of the end of the wire on said member, and ensures that this end is held in place as long as the weft thread remains on standby (if

  this vacuum cleaner is permanently powered).

  In the simplest configuration, there are two fixed nozzles, placed symmetrically with respect to the axis of the launching nozzle in its stopped position for changing the weft thread, and the movable introduction means . such as' erin, is disposed between the two fixed nozzles, its movement taking place substantially along the axis of the launching nozzle in said stop position. In particular, in the case where the axes of the two fixed nozzles form equal angles with respect to the axis of the launching nozzle, the movable introduction means such as a jack is arranged according to

  the bisector of the angle formed by the axes of the two fixed nozzles.

  This simplest arrangement corresponds to the organs necessary for the insertion of a single weft thread, in particular for a weaving of a single color, with the possibility of immediate repair thanks to the thread of the same kind.

  and of the same color kept in reserve.

  It is also possible to envisage the application of the invention to a weaving machine provided with a "weft mixer", that is to say supplied alternately with two identical weft threads. In this case, the weaving machine comprises two fixed nozzles, associated respectively with the two weft threads, and two corresponding mobile launching nozzles, arranged parallel to each other; for the implementation of the present invention, it suffices to have a third fixed nozzle, delivering a weft thread identical to the previous two, and the aforementioned mobile introduction means is provided for the introduction of this last thread into the either of the two launch nozzles. To this end, the mobile introduction means, keeping the weft thread on standby, is displaceable not only along the direction of the axes of the two launching nozzles, but also perpendicular to these axes, so as to bring said mobile means of introduction of one or other of the two launch nozzles onto the axis. The same organs thus ensure the immediate breakdown of the supply of one

  either of the two weft threads used by the mixer.

  The present invention is also applicable to a weaving machine with two or more colors, therefore to machines intended for the insertion of at least two threads of different wefts. In the particular case of a two-color machine, it is necessary to double by two not only the fixed nozzles and the mobile launch nozzles, but also the entire troubleshooting system; in other words, the supply device according to the invention comprises in this case, for each fixed nozzle - launch nozzle subassembly associated with a determined color, another fixed nozzle and a means

  mobile for introducing a weft thread in reserve of this color.

  In any case, the invention will be better understood using the

  description which follows, with reference to the appended schematic drawing representing,

  by way of nonlimiting examples. embodiments of this weft feed device for weaving machine with pneumatic insertion: Figure I is a plan view, very schematic, of a weaving machine equipped with the object feeding device of the present invention Figure 2 shows, in more detail. the set of nozzles of the weft feed device of the weaving machine of FIG. I; Figures 3,, 5. and 6 are diagrams illustrating the operation of the device of FIG. 2; Figures 7 and S are views similar to Figure 2, illustrating

  variant applications of the device which is the subject of the invention.

  Figure I shows, very schematically, a shuttleless weaving machine with pneumatic insertion of the weft yarn I into the fabric

  formation 2, from a fixed weft reserve located on one side of the fabric 2.

  More particularly, the weft thread I assumed during weaving comes from a supply spool 3, placed on one side of the weaving machine, and it first of all comes from a pre-feeder 4 which measures corresponding lengths of thread to a pick and which releases the wire in successive lengths each corresponding to a pick. The weft yarn I then passes through a fixed nozzle 5, then through a launching nozzle 6 movable with the comb (not shown), the fixed nozzles 5 and mobile 6 being supplied with compressed air.

  to give the wire the initial acceleration necessary for its insertion.

  In crossing the "crowd" formed by the warp threads, the weft thread I is guided inside an insertion channel, and its movement is maintained by relay nozzles not shown, distributed over the width of fabric 2 and supplied sequentially with compressed air. Once inserted, each pick is separated from the rest of the weft yarn I by a cutting means 7 placed at the edge of the fabric 2 on the side of the mobile launch nozzle 6, after

  whereby the following pick can be inserted in the same way.

  Optical control means 8 of the "weft breaker" type, disposed towards the edge of the fabric 2 remote from the launching nozzle 6, ensure the detection of the actual arrival of the weft yarn I up to this edge of the fabric 2 These control means 8 emit signals directed towards processing means 9, which are themselves connected to a central unit 10 of

control of the weaving machine.

  To take into account the possibility of breakage of the weft thread I during weaving. this weaving machine is equipped with additional supply means making it possible to maintain a second weft thread 11 on standby. These means include a second supply coil 12. a second pre-measuring device 13 and a second fixed nozzle 14, similar to

  those previously described and located on the same side of the weaving machine.

  Switching means 15 are provided for controlling, if necessary, the passage from the first supply means 3,4,5 to the other supply means 12,13,14, or vice versa, in particular for continuing weaving with the weft thread. 1 I remained on standby, when the weft thread I previously used is broken, these switching means being

  themselves under the control of the central unit 10.

  The mobile launch nozzle 6 is common to the two supply systems, each of the fixed nozzles 5 and 14 being able to direct the corresponding weft yarn I or 11 to this common mobile nozzle. Thus, as shown more precisely in FIG. 2, the respective axes 16 and 17 of the two fixed nozzles 5 and 14 converge symmetrically towards the inlet of the launch nozzle 6. assumed to be stopped in a predetermined position, and these two axes 16 and 17 form a certain acute angle A with the axis 18 of the nozzle

launch 6.

  The weaving machine is further provided with means 19 provided for the extraction of waste from a broken or defective weft thread. These include pneumatic movens movable over the entire width of the fabric 2, as described in a previous French patent application N 88 07257 filed May 25, 1988 in the name of the Applicant. These means 19 fulfill a so-called "untwisting" function, in association with a sequence of

blowing of relay nozzles.

  As described in another previous French patent application in the name of the Applicant, filed on February 7, 1989 under the N 89 01918, the combined action of the optical control means 8, the processing means 9 associated with the latter and "unweaving" means 19 makes it possible to detect a break in the weft thread I or 11 during weaving which occurs upstream of the launching nozzle 6, therefore in the supply system 3,4,5 or 12 , 13.14 in use. In addition, the intervention of the central processing unit 15 and the switching means 15 allows, in the event of the detection of such a breakage of the weft thread 1, automatic passage over the weft thread Il pending, delivered by the other feeding system, for the

immediate weaving.

  To introduce the weft yarn 11 previously put on hold.

  up to the entry of the launch nozzle 6. The feed device comprises, according to the invention, a mobile means designated as a whole by 20, and disposed following the axis 18 of the launch nozzle 6 placed in its stop position. as shown in Figure 2. Thus, the movable introduction means 20 is disposed between the two fixed nozzles 5 and 14, along the bisector of the angle 2A formed by the respective axes 16 and 17 of these two

fixed nozzles 5 and 14.

  The movable introduction means 20 is made in the form of a pneumatic cylinder, with a fixed body 21 and with a piston rod 22, movable along the axis IS, the outer end of the rod 22 being turned towards the launch nozzle 6. This end of the rod 22 is provided with a

  member 23 for gripping and holding the weft thread 11 put on hold.

  The double-acting pneumatic cylinder 20 has two internal chambers connected by respective conduits 24 and 25 to a supply and control unit 26. The block 26 is also connected. by a flexible conduit 27. to the member 23 for gripping and holding the wire, produced here in the form of a small vacuum cleaner. Figures 3 to 6, in which the previously described pneumatic supply system is not indicated for clarity, illustrate the operation of the device: Figure 3 shows the device in its normal position, during weaving performed at means of the weft thread I supplied by the reel 3 and by the pre-deliverer 4. The thread I successively passes through the fixed nozzle 5 and the launching nozzle 6. The other weft thread 11, kept on hold, passes through the fixed nozzle 14 and at its end retained in the vacuum cleaner 23, held in the retracted position, in other words distant from the launching nozzle 6, by the

  cylinder 20 whose rod 22 remains retracted.

  In the event of breakage of the weft thread I at the level of the feed device, as illustrated in FIG. 4, the other thread 11 held hitherto in standby is introduced into the stopped launch nozzle 6, by moving the vacuum cleaner 23 towards the entry of this launching nozzle 6, the jack 20 being

  actuated in the direction of the exit of its rod 22.

  The launching nozzle 6 is then put into action to suck the end of the weft thread 11 held as far as there by the vacuum cleaner 23, this

  phase being illustrated in FIG. 5.

  Then. the rod 22 of the eri, 20 is retracted. so that the vacuum cleaner 23 returns to its minimal hidden position. and weaving is continued with the reserve weft yarn II. supplied by the reel 12 and the pre-deliverer 13. An operator can then proceed manually, in "masked time", to the replacement of the unused weft yarn I, by introducing

  the end of this wire I in the vacuum cleaner 23 (Figure 6).

  Figure 7 shows a diagram of a weft feed.

  installed on a weaving machine with weft mixer, comprising a first fixed nozzle 5 'associated with a first mobile launching nozzle 6', for the insertion of a first weft thread 1 ', and a second fixed nozzle 5 "associated with a second launch nozzle 6". parallel to the first 6 ', for the insertion of a second weft thread 1 ". The two weft threads 1' and 1" are identical. and the machine is powered alternately with these two

sons1 'and 1 ".

  In this case, the device comprises a single set of troubleshooting.

  comprising a third fixed nozzle 14 and a single mobile means

  introduction 20 such as éerin. with a gripping and holding member 23.

  for a reserve weft thread 11 identical to the two threads 1 'and 1 ".

  The realization of the mobile introduction means 20 is similar to that of the previous embodiment; however. this movable means 20 is further provided here displaceable transversely, as indicated by arrows 28 and 29, in order to be able to introduce the weft repair thread We into one or the other of the two launch nozzles 6 'and 6 ". Thus, in the event of breakage of the first weft thread 1 ', the mobile means 20 is moved in the direction of arrow 28 to introduce the weft thread Il into the corresponding launching nozzle 6', and in the event of breakage of the second weft thread 1 ", the movable means 25 is moved in the direction of arrow 29 to introduce the thread

  weft it in the corresponding 6 "launch nozzle.

  In Figure 8 is shown schematically a weft feed device for a two-color weaving machine. A weft thread la of a first color is inserted here by passing through a first fixed nozzle 5a and a first movable launch nozzle 6a, while a weft thread lb of another color is inserted through a second fixed nozzle 5b and a

  second mobile launch nozzle 6b, parallel to the first 6a.

  In the latter case, it is necessary to also double the troubleshooting set. We thus provide: a third fixed nozzle 1a and a first 2% a. with a member 23a for gripping and holding, for a weft thread to be the same as the thread la: a fourth fixed nozzle 14b and a second thread 25b. has an organ 23b for gripping and holding. for another reserve weft yarn I lb identical to the yarn lb. The two jacks 20a and 2, b are arranged parallel to one another, their respective rods 22a and 22b being movable in the direction of the fixed nozzles 6a and 6b corresponding to introduce therein. if necessary, the reserve weft thread 1 la or I lb. In the case of a multi-color weaving machine, the principle illustrated in Figure 8 also applies. by providing as many cylinders as

  weft threads of different colors.

  It goes without saying. and as is clear from the above.

  the invention is not limited to the sole embodiments of this weft feed device for weaving machine with pneumatic insertion which have been described above, by way of examples; on the contrary, it embraces all of the variant embodiments and applications respecting the same principle. So. one would not depart from the scope of the present invention by the use of all equivalents, the actuator 20 equipped with the vacuum cleaner 23 (or each actuator thus equipped) being in particular replaceable by any mobile means of equivalent introduction capable of to hold the end of the weft thread put on hold and to move this end of

  wire to the mobile launch nozzle.

Claims (9)

  1. Weft feed device for weaving machine without pneumatic insertion mat, the device constituting a double feed system such that, when a weft thread defect is detected on the '' one of the feeding systems, there is automatically a switching to the other feeding system whose weft thread is kept on standby, and this device comprising, on the same side of the weaving machine, at least a first pre-deliverer (4) associated with a first nozzle (5). for the weft thread (1) coming from a first supply coil (3). and at least a second pre-deliverer (13) associated with a second nozzle (14), for the weft thread (II) coming from a second supply coil (12), each of these two nozzles (5,14) being able to direct the corresponding weft thread (1,11) towards a launching nozzle (6) movable with the comb of the weaving machine, for the insertion of this weft thread, characterized in that the first nozzle (5 ) and the second nozzle (14) above are nozzles mounted fixed on the side of the weaving machine, and in this   that at least one mobile introduction means (20) is provided. independent of.   these fixed nozzles (5.14) capable of retaining the end of a weft thread (1,11) placed on standby, this end being located downstream of one of the fixed nozzles (5.14), and of depleting this end of wire towards the nozzle of mobile launch (6).   2. Weft feed device according to claim 1.   characterized in that the movable introduction means is constituted by a jack (20), having a fixed body (21) and a rod (22) movable in the direction of the launching nozzle (6), the end of the rod mobile (22) facing this launching nozzle (6) being provided with a gripping and holding member (23)   from the end of the weft thread (1, Il) put on hold.   3. Weft feed device according to claim 2.   characterized in that the movable introduction means is constituted by a pneumatic or electric actuator (20), controlled in such a way that its rod (22) decreases a relatively slow movement in the direction of the nozzle launch (6).   4. Weft feed device according to claim 2 or 3, characterized in that the thread gripping and holding member (1, 1 1), provided towards the end of the movable rod (22) cylinder (25), is a vacuum cleaner   (23) supplied with pneumatic fluid (at 27).   5. Weft feed device according to any one li   of claims I to 4. characterized in that the fixed nozzles (5,14) are at   number two. placed symmetrically with respect to the axis (18) of the launching nozzle (6) in its stopped position for the change of weft thread (1.1 I). and in that the movable means of introduction. such as a jack (20), is disposed between the two fixed nozzles (5, 14), its movement taking place substantially along the axis (18) of the launching nozzle (6) in said stop position.   6. Weft feed device according to claim 5, characterized in: e that the axes (16,17) of the two fixed nozzles (5,14) form equal angels (A) relative to the axis ( 18) of the launching nozzle (6), and in that the mobile introduction means such as a jack (20) is arranged along the bisector of the angle (2A) formed by the axes (16,17) of the two fixed nozzles (5.14).   7. Weft feed device according to any one of claims I to 4, for a weaving machine provided with a "weft mixer", characterized in that it comprises two fixed nozzles ( 5 ', 5 "), associated respectively with the two weft threads (l', l"), and two corresponding mobile launching nozzles (6'.6 "). Arranged parallel to each other. As well as a third fixed nozzle (l), delivering a weft thread (I l) identical to the two previous ones (1 ′, 1 "), the aforementioned mobile introduction means (20) being provided for the introduction of this last thread ( II) in one or the other of the two launch nozzles (6 ', 6 "), and being for this purpose displaceable not only along the direction of the axes of the launch nozzles (6', 6"), but also   perpendicular to these axes (arrows 28,29).   8. Weft feed device according to any one   of claims I to 4. for a two or more color weaving machine,   characterized in that it comprises, for each fixed nozzle - launching nozzle assembly (5a, 6a, 5b, 6b) associated with a determined color, another fixed nozzle (lia.14b), and a movable means (20a, 20b ) introduction of a weft thread   in reserve (lla, llb) of this color.   9. Weft feed device according to claim 3 or 4, characterized in that it comprises, for the mobile introduction means constituted by a pneumatic cylinder (20), a power supply and control unit ( 26), itself placed under the dependence of switching means (15) called upon in the event of detection of a fault in one of the supply systems.