FR2566008A1 - DEVICE FOR MAKING TISSUES ON PNEUMATIC WEAVING MACHINES - Google Patents

Abstract

A. DEVICE TO MAKE FABRIC ON PNEUMATIC TRADE. B. DEVICE CHARACTERIZED IN THAT FROM THE THRESHING SIDE 18, TEETH 7 IS CURVED AT LEAST PART OF ITS LENGTH IN THE DIRECTION AWAY FROM THE TIE POINT. C. THE INVENTION APPLIES TO ALL JET Looms TO IMPROVE THE QUALITY OF WEAVING BY ALLOWING BETTER USE OF THE WEFT GUIDING CHANNEL.

Description

Apparatus for making fabrics on looms

pneumatic weaving.-

  The present invention relates to a device

  The invention relates to a device for producing fabrics on pneumatic looms, wherein the weft is guided during insertion by a channel formed by the teeth of the threshing comb. The devices for producing fabrics as currently known, use different types of guide channels and in connection therewith also threshing combs. A device is known in which the guide is formed of guide plates whose orifices are mounted in the support beam of the threshing mechanism. Behind this formed guide channel

  of guiding plates, one fixed in the direction eli-

  With the threshing, on the support beam, a threshing comb formed of rectilinear teeth fixed to the frame of the comb. Between each tooth, one or more

  chain yarns which are continuously distributed by the teeth.

  The guiding channel guide plates are thicker than the comb teeth and thus their number in the shed support beam is not equal to the number of teeth, but is smaller. During weaving, when the shed is opened, when the comb returns from its threshing position, the warp threads are thus evenly distributed and the guide channel guide plates penetrate from below into the shed. Since the guiding guide plates are thicker and their number in the lengthwise direction of the comb is smaller, the number of warp threads in the gap can not be equal to that of the comb, so that it requires redistribution and regrouping. The chalk wires are redistributed by the guide plates and in a gap we have a greater number of wires

  between the teeth of the comb. This is a disadvantage,

  that this happens where the warp threads get

  break or can be damaged because of their

  on the guide plates of the guide channel. This disadvantage exists especially in the case of son without torsion or low torsion and in particular with single filament son whose fiber particles are torn off by the guide channel. When moving the comb in the threshing position, the weft yarn is removed from the guide channel through the passage slot and

  the guide channel again leaves the warp threads.

  The weft thread is taken by the rectilinear teeth of the

  comb and is beaten to the point of knotting. Another inconvenience

  This provision is the interval between the guide channel and the threshing comb because the usable insertion angle of the guide channel is decreased in this dimension. Another disadvantage of the canal formed by

  this way is the need to have a sufficient opening

  particularly large since attempts to reduce the diameter of the opening have an adverse effect on the passage slot when inserting the

  frame. Pressurized fluid escapes during the course of the in-

  tion of the weft yarn directly through the passage slot which disturbs the forward movement of the weft yarns and the short spikes thus formed. This disadvantage is remedied by various elastic locks provided on the guide plates. However, the locks for closing the slits through the guide plates are difficult to manufacture and each weft thread, once inserted must overcome their elastic resistance when passing over the locks. This results in friction of the weft yarn and the formation of fibers. For this reason, the guide channel plates provided for this purpose can be used only with certain types of wires. Another possibility to suppress the suction effect of the passage slot is to increase the actual opening of the guide channel. In this way, the overlap portion of the passage slot is reduced. The disadvantage of this embodiment is that it is necessary to have a higher pressure feed fluid and moreover, it is impossible to use the crowd for insertion at its small angular aperture; it does not allow to increase the speed of

  rotation of the machine and thus its performance.

  Another known embodiment of the dis-

  positive for fabric manufacturing comprises an open guide channel formed by the profile teeth of the threshing comb. The guide channel is in the form of a large, open, tilted U, whose missing outer wall of the channel is replaced during insertion of the weft yarn by auxiliary nozzles distributed over the entire length. The

  warp threads are distributed between the profiled teeth.

  Thus during the weaving, the warp threads, distinct, are distributed regularly and continuously. The crowd is introduced into the guide channel by the main nozzle and in the channel the advancement is provided by the auxiliary nozzles. The flow of pressurized fluid thus supplied

  simultaneously closes the open side of the guide channel.

  During the threshing operation, the crowd does not leave the open channel, but its threshing is done by the rear wall of the guide channel. As the guide channel is not closed, its missing wall is replaced by a fluid flow under pressure, which must be reinforced. This is a disadvantage because it increases the consumption of fluid under pressure, the loom becomes more complete in terms of power consumption and operation. In another known embodiment, a device for forming fabrics, the guide channel is also made of profiled teeth. The guide channel has a substantially rotatable shape with a semicircular front side and a vertically opposite side, the connecting line being straight and inclined downwardly towards the curved portion. The crossing slot is

  rectilinear in the same way as in the method of

  channel guide channel. Thus, there are the same disadvantages as those defined for the overlap of the slit of the guide plate channel. The body of the auxiliary nozzles is introduced from the front into the gap of the guide channel. The channel gap is formed by a number of teeth side by side, the guide channel not being closed by the curved portion. In addition, the symmetry of the channel reduces the insertion angle of the weft yarn, which decreases the time interval during which the weft yarn can be inserted into the shed. The teeth of the threshing comb are thus rectilinear except for the location of the guide channel. In addition, the bodies of the auxiliary nozzles can be introduced into the channel only from the front side, because otherwise, in a very short section, there would be a new distribution of

  weft threads with the bodies of the auxiliary nozzles.

  The present invention aims to overcome the disadvantages of known devices and proposes to create a device for fabric production on pneumatic looms, this device being characterized in that from the threshing side, the tooth is bent in the opposite direction of the point

  knotting on at least part of its length.

  According to another characteristic of the dis-

  positive according to the invention, at least a portion of the curve is

  of the labyrinth-shaped passage slot.

  According to another characteristic of the invention, the body of the auxiliary nozzles is introduced

  in the lower part of the guide channel, by

  below in the direction of the passage slot.

  The advantages of the device according to the invention

  tion consists in the curvature of the tooth, in the

  for the body of the auxiliary nozzles, the assembly of these nozzles and that of the control members. Thus the location of the crowd is better used especially in the vicinity of the knot tying point. By such a shaping of the teeth, it is possible to use the space below the guide channel for mounting the assembly of the auxiliary blowing nozzle mechanism, which releases volume forward teeth of the comb. This is particularly advantageous for the structure and the assembly of the templates for the pieces of fabric in-realization and which must

  be placed as close as possible to the knotting points.

  Another disadvantage of the device of the invention is that by bending outwards part of the teeth, this part becomes more rigid. This is important in

  particularly in the case of tight weaving of fabric.

  Another advantage of the device according to the invention is that by making a slot of passage in

  labyrinth, we reduce the suction effect of the channel.

  Thus, the progress of the weft during the insertion becomes softer without ripple or loop. In addition, the risk of removal of the warp threads during entry into the guide channel in the lower branch of the warp threads is reduced. This gives a more reliable machine during

  weaving and a better quality fabric.

  The present invention will be described in greater detail with the aid of the accompanying drawings, in which: - Figure 1 is a schematic overview of a pneumatic loom; - Figures 2 to 11 are side views of different types of teeth forming guide channels; FIGS. 12 to 14 are exemplary embodiments of comb teeth without a guide channel to which the auxiliary nozzle bodies are attached; FIGS. 15 to 22 show examples of teeth whose curved parts constitute

  a labyrinth-like continuation of the crack.

  The pneumatic loom according to FIG. 1 comprises a supply spool 1 carried by the frame 2 of the machine and from which the weft thread 3 is pulled during weaving by means of the measuring mechanism 4. Then the thread frame 3 is guided through tabs

  (not shown) in the main introduction nozzle.

  On the threshing comb 6 is carried on the cut frame portion (not shown); the comb 6 is formed of profiled teeth7. On the threshing side 18, the distinct teeth 7 are such as to form a closed guide channel 8 with a passage slot. In front of the initial portion of the guide channel 8, cutting members such as scissors 10 are provided adjacent to the main insertion nozzle 5.

  and at the end of the channel 8 there is provided a device

  pirant 11 in general of the ejector type. Depending on the length of the guide channel 8, the bodies of the auxiliary nozzles 12 are mounted in the vicinity of the teeth 7 and are directed into

  the channel 8 by their outlet openings (not shown).

  Both the main nozzle 5 and the auxiliary nozzles 12 and, if appropriate, the suction device 11 are connected by their supply line 13 to the compressed air generator 14. Each supply line 13 is provided in the vicinity of the of the main nozzle 5 and the auxiliary nozzles 12 and the suction device 11 having an electromagnetic valve 15. To detect and control the operation of the loom, the valve comprises a control device 16 with

sensors (not shown).

  In FIGS. 2 to 11, there are shown

  examples of embodiments for curvatures of one or more

  sieurs parts of teeth 7 in the different positions relative to the guide channel 8. Figures 2, 3 and 4 show an embodiment in which the curvature

  of tooth 7 of comb 6 is made at the point of overlap

  of the slot 9 of the guide channel 8. The difference between the various embodiments is that in FIG.

  the adjacent wall of the guide channel 8 to the side

  threshing 18 of the tooth 7 follows the curvature over its entire length, while in Figure 3 it is only half of its length. In FIG. 4, the adjacent wall of the channel 8 forms a continuous rectilinear extension of the

  non-curved portion of threshing side 18 of tooth 7.

  In Figures 5, 6 and 7, there are embodiments in which the curvature of the tooth 7 is made at the point of the guide channel 8. The difference between FIGS.

  and 6, is that in Figure 5, the body of the nozzle

  12 forms the continuation of the threshing portion 18 rectilinear teeth 7, while in Figure 6 the body of the auxiliary nozzle 12 is adjacent to the bent portion

  teeth 7 constituting a wall of the guide channel 8.

  In FIG. 7, the adjacent wall of the channel 8 forms the continuous extension of the unreferenced threshing side 18 of the tooth 7. FIGS. 8, 9 and 10 show an embodiment in which the deformation of the tooth 7 is made to the place of the lower branch of the guide channel 8. FIG. 8 shows a guide channel 8 of

  36 trapezoidal shape in which the body of the nozzle

  12 is in the vicinity of the rear wall.

  FIG. 9 shows a triangularly shaped guiding channel

  the body of the auxiliary nozzles 12 being in the vicinity

  the rectilinear part of the teeth 7 at the rear side of the guide channel 8. In FIG. 10, the curvature from the knotting point 21 for both

  parts of the teeth are at the lower limb

  8 of the guide channel 8 of triangular shape.

  FIG. 11 shows an embodiment in which the teeth 7 are curved at two points, that is to say at the location of the passage slot 9 and at the base of the guide channel 8. The object of the present invention is not limited to the above exemplary embodiments and encompasses all possible variants within the scope of the present invention, since the shape of the guide channel at the curved tooth may be arbitrary. Similarly, the curvature of the teeth 7 is not necessarily straight; it can be curved or arched. The rear part of the tooth 7 does not have to follow only the curvature of the front side, but the thickness of the teeth 7 can be increased at the place of the channel 8 and the threshing part, or the rear part can be formed by a straight line at the insertion. The bodies of the auxiliary nozzles 12 may be constituted either by a straight rod, or as partially represented by a rod with a curvature which conforms to the curvature of the tooth 7 at least at the location of the guide channel 8. Moreover, the body of the auxiliary nozzles 12 may have the shape of the guide channel 8, or even at a point of the comb 6, there may be two auxiliary nozzle bodies 12, one being attached to the tooth 7, and other being formed at the point of the front part of the guide channel 8. The body of the auxiliary nozzles

  12 can also be done in the usual way, that is,

  to say coming from the front part of the knotting point 21

  in the upper part of the guide channel 8 in direction

  The body of the auxiliary nozzles 12 may have one or more outlets 19. At the location of the inserted portions of the auxiliary nozzles 12, the teeth 7 of the comb 10 have not formed a channel of the 8, but correspond to their original curvature or with their front contour going to the location of the channel 8, by their rear wall, as

  this is shown in Figures 12 and 13.

  The teeth 7 may also have a shape allowing optimal insertion of the bodies of the auxiliary nozzles 12 and their direction in the guide channel 8. However, the threshing side 18 must be identical to the threshing side of the other teeth 7 which form the channel 8 as shown in FIG. 14. FIGS. 22 and 22 show examples of embodiments of passage slots 9 for the guide channels 8, which slots are made at the point of curvature of the teeth 7. FIG. embodiment in which the rear wall 20 of the guide channel 8, which wall is furthest away from the knotting point 21 is offset from the threshing side 18 to the knot point 21, the junction line and front end of the side of threshing 18 forming with the end of the upper side of the guide channel 8 a labyrinth passage slot 9, defined by a curvature. Figure 16 shows a variant of

  realization of the passage slot 9 in the form of labyrinthine

  tea. FIG. 17 shows a labyrinth-like passageway shape 9, curved, with partial curvature of the tooth 7. In FIG. 18, there is a labyrinth-shaped passage shape 9 formed by a curved tooth portion 7. In FIG. 19, in the lower part, at the place of the folding of the tooth 7, corresponding to the rear wall 20 of the channel 8, the furthest away from the knotting point 21, there is an offset with respect to the threshing side 18 rectilinear, upstream from the knot tying point 21, while the connecting line constitutes by another curvature, a slit passage side 9 labyrinth inclined. Fig. 20 shows an alternative embodiment in which the inclined connecting line of the straight driving side 18 and the rear wall 20 of the channel 8 forming a side of the labyrinth passage slot 9 is extended, thus constituting

  partial folding of the threshing side 18 of the tooth 7.

  FIG. 21 shows an embodiment with an inclined threshing side 18 of the tooth 7, and the rear wall 20 of the guide channel 8 is shifted forward towards the protruding portion of the guide channel 8. FIG. connecting line of threshing side 18 and

  the rear wall 20 of the channel 8 forms a part and the end

  Before the curvature of the tooth 7 forms the other part of one side of a labyrinth passage slot 9. A la figure

  22, the tooth 7 is curved in the lower part.

  The rear wall 19 of the guide channel 8 is curved and the connecting line between this part and the rectilinear threshing side 18 forms one side of the passage shape 9. The second part of the slot 9 is formed by the free end

the threshold portion of channel 8.

  The object of the present invention can be applied to pneumatic looms and concerns

  not only the drawings shown and the modes of

  given by way of example, but all the others

  embodiments within the scope of the invention.

LIST OF REFERENCES

  1 - spool 2 - frame 3 - weft thread 4 - measuring mechanism - main nozzle 7 - teeth 8 - channel 9 - passage or exit slot - cutter (scissors) 11 - suction device 12 - body of auxiliary nozzles 13 - supply line 14 - compressed air supply - solenoid valve 16 - control device 17 - wire 18 - threshing side 19 - outlet ports - rear wall

21 - Tie point.

Claims (6)

  1) Device for producing the tissues   on pneumatic looms with a mechanism   a shedding mechanism with warp yarns, a pile comb mechanism having profiled teeth forming a closed guide channel for the weft yarn with a passage slot, a main nozzle provided near the end at the before the guide channel and the auxiliary nozzles distributed in the comb at predetermined intervals, their outlet openings being directed in the direction of insertion of the weft thread, inclined in the channel, characterized in that from the side of threshing (18), the tooth (7) is bent in the opposite direction of the tying point, on at least a portion of its length.   2) Device according to claim 1, characterized in that the tooth (7) is curved at the place the guide channel (8).   3) Device according to claim 1, characterized in that the curvature is made in the place of the passage slot (9).   4) Device according to any one of   1 and 3, characterized by a curvature of at least   part of the passage slot (9) formed of labyrinth.    ) Device according to any one of   Claims 1, 3 and 4, characterized in that a wall   the labyrinth outlet slot (9) is constituted by a partial curvature between the threshing side (18)   and the offset rear wall of the guide channel (8).   6) Device according to any one of   claims 1 and 2, characterized in that the body of   auxiliary nozzles (12) is introduced in the lower   guide channel (8) from below in the direction of the passage slot (9). 256600   7) Device according to any one   claims 1, 2 and 3, characterized in that   at least a portion of the backside length of the guide channel (8) of the tooth (7) is attached to an auxiliary nozzle (12).