FR2655359A1 - DEVICE FOR WEAVING A CROSSED CHAIN THE SIDE EDGE OF A FABRIC IN A WEAVING MATERIAL. - Google Patents

Abstract

The device according to the present invention for cross-warp weaving the side edge of a fabric in a loom comprises an oscillating plate (10), pivotally mounted on a structure (7) driven vertically in a back and forth movement. -Comes by a cam (31) and biased by a spring (21), said plate (10) comprising along its vertical axis, in opposite actuation positions relative to its support axis (9), two holes (13, 14) through which two additional turn wires (11, 12) pass, and being rotated in a reciprocating motion in two symmetrical positions by a push bar (24) pivotally mounted on a fixed frame (1) and provided with a spring (28) for its return to the vertical position. In the aforementioned symmetrical positions, the two holes have switched position with respect to the needle (2) which, by means of a cam (36) is moved vertically in a reciprocating movement opposite to that of the structure (7).

Description

The present invention relates to a new device for warp weaving

  crossed the side edge of a fabric in a loom, which, in addition to being simple to build, economical and of small overall dimensions, so that it can be installed between the leaf and the first heald frame without that one has to move the position of this first frame backwards and without having to use auxiliary elements, further provides a resistant and reliable three-wire armor in the sense that the permutation of position or crossing of the turn threads over the straight or fixed thread of the needle can then be obtained by means of an independent positive control by cams, said position permutation or crossing taking place in the center of the crowd o is brought the tip of the needle, said weave consisting specifically of a straight or fixed thread which passes over the weft threads and two turn threads which cross the straight thread to pass under said weft threads which stabilize their interlacing Le device also makes it possible to obtain said weave for each inserted weft thread or, in a variant, for any set of two or more than two successive inserted weft threads simply by replacing said positive control cams and also makes it possible to weave with cross chain or false selvedge with only two threads As is well known, for

  prevent what is called "edge bangs", that is

  say the fraying of the side edges of the fabric due to the fact that the weft threads do not sufficiently bind the warp threads at the location of said edges, a cross warp weaving is generally carried out of the side edges of the fabric being formed by means of suitable devices, generally known in the textile industry under the designation of "splitz devices", and by using a certain number of additional weaving threads which have to be suitably intertwined with the weft threads inserted More specifically, when performing cross-chain weaving, that is, creating the gauze weave, it is essential that at least one additional side warp yarn, known as the lathe yarn, permute its position from right to left, or vice versa, of at least one other additional side warp thread, known as a straight or fixed thread, which generally passes through the eye of a vertical needle so as to extend parallel to the other warp threads of the fabric, said position permutation then being stabilized by interlacing with the weft threads which have been inserted between said additional lateral warp threads The said operations are carried out position switching generally using a plate provided with at least one slot at the ends of which the lathe thread is on the opposite sides of the needle supporting the straight thread. Various types of cross-chain weaving devices or splitz devices are known in the art, allowing various interlacing configurations.

  between two or more of two additional weaving threads.

  In a known type, the needle carrying the straight thread and the slit plate for the turn threads are driven in a vertical reciprocating movement opposed by the

  first two heald frames of the loom.

  However, this arrangement has a series of drawbacks, the most serious of which is that in addition to reducing the number of active heddles available for forming the fabric, it compromises the performance of the loom in the sense that the warp threads now be moved by the frames which are necessarily further from the comb or rather from the top of the fabric formation angle, which results in a greater probability of attachment or subjugation of the threads, given their greater length , under the effect of their filamentous nature which tends to stick them to each other and the fact that the frames must make a longer vertical path to reach the same crowd opening, this resulting in overloading the armor mechanics due to the significant acceleration required with obvious construction difficulties due to the high inertia involved and a significant increase in tension undesirable and, therefore, of a force exerted on the warp threads In addition, the splitz devices controlled by the heald frames cannot form the specific three-thread weave in which the straight thread always passes over the threads of weft and the two tower threads cross the straight thread to then pass under said weft threads which stabilize their interlacing. The above-mentioned drawbacks are overcome in another type of splitz device in which the complete assembly is kept at rest except as regards the slotted plate which is moved vertically by the movement of the leaf to which said plate is connected by a cable, the reminder being provided by a spring However, this known arrangement also has a series of drawbacks, the most serious of which is due to an uncertainty in the positioning of the additional turn wires at the end of the split plate, this positioning depending entirely on the particular shape slots which have a hook-shaped upper end The lathe has, in fact, a very great tendency to accidentally leave the hooked end and propel itself to the other end of the slot thereby compromising the Another disadvantage is that the needle is fixed with the consequence that the corresponding straight thread remains in a s eule and same position which, necessarily, corresponds to the upper end or to the lower end of the opening of the crowd On this subject, when the permutation of position of the turns wires must take place in a precise manner in the position o the tip of the needle is exceeded, a considerable raising or lowering of the lathe threads is necessary and these threads drive the inserted weft thread up or down, which results in the triple negative consequence of a loosening of the lathe yarns due to the tension of the entrained weft yarn resulting in the appearance of a slack and a weakly resistant weave, a gradual loosening of the lateral warp yarns resulting in the production of a mediocre fabric quality and weaving problems due to the need to stop the loom to catch up with the exaggerated slack of said threads, and ultimately a greater waste of weft thread as a result of its moving up or down from the fact that it is

driven by the tower wires.

  The object of the present invention is to remedy the aforementioned drawbacks by providing a cross-chain weaving device for the lateral edge of a fabric in a loom, a device which is simple to construct and has small overall dimensions, in which the position permutation or crossing of the turn wires is positively and safely controlled, and in which this position permutation takes place in the center of the crowd. This objective is substantially achieved by the fact that the two turn wires pass through two axially opposite holes relative to the point of rotation of an oscillating plate which, pushed by a spring, is driven in rotation in a back and forth movement. - comes in two symmetrical positions by a push bar articulated on the fixed frame and provided with a spring for its return up to the vertical, positions in which two holes or permutated position relative to the needle

carrying the right thread.

  In this way, the lathe threads are guided positively and securely to the required position relative to the needle and, therefore, relative to the straight thread, any risk in the permutation operation.

position no longer exists.

  In addition, not only the aforementioned oscillating plate performs a vertical reciprocating movement but the needle carrying the straight wire is also moved in a vertical reciprocating movement but in the direction opposite to the direction of movement of said plate, these movements being obtained by two cams with opposite profiles fixed on the same shaft which is itself driven by the drive shaft of the loom, by means of an appropriate reducing link, said cams acting on the underside of follower rollers carried by said elements, contact being ensured by

springs.

  In this way, the permutation of position or crossing of the lathe threads now takes place in the center of the crowd with the consequence that the aforementioned thread problems no longer exist. Furthermore, the independent means of driving cams which, in addition to simplify the establishment of any displacement law and, in particular, therefore to provide a specific three-wire weave in which the straight wire always passes over the weft threads and the other two turn threads swap positions around straight yarn, also allows interlacing not only for each weft yarn inserted (1/1 weave) but also for both

  (2/2 weave) or more than two weft threads inserted,

  that is to say, it makes it possible to modify the frequency of armor simply by replacing the drive cams by other appropriately profiled cams Finally, the compactness and the autonomy of the device as produced mean that the device can be instantly and easily adjusted with regard to the axial position, this being essential when the weaving height of the loom is changed. The device for weaving a cross-warp or false selvedge from the lateral edge of a fabric in a loom therefore comprises a needle through the eye of which passes an additional lateral warp thread known by the designation of straight thread or thread. fixed and extending parallel to the other warp threads of the fabric being formed, and a plate to guide two additional lateral turn threads and mounted on a structure driven in a vertical reciprocating movement, this device being characterized according to the present invention in that said plate is mounted in an oscillating manner on said structure performing a back-and-forth movement vertically and comprises on its vertical axis two holes axially opposite one another relative to its pivot or support axis, the two aforementioned additional turn wires passing through said holes, said oscillating plate being pushed by a spring and being driven born in rotation following a back-and-forth movement in two symmetrical positions by a push bar articulated to a fixed frame and provided with a spring for its return to the vertical, the two holes, in these positions, having permuted position relative to

the needle carrying the straight thread.

  According to a preferred embodiment of the invention, the oscillating plate is rotated in a reciprocating movement in the two symmetrical positions mentioned above by the fact that the push bar cooperates with two lateral recesses formed in the plate oscillating and located symmetrically with respect to said vertical axis. The invention will appear more clearly in the

  description given below with reference to the drawings

  attached which show a preferred embodiment by way of nonlimiting example in that technical or construction modifications can be made without departing from the scope of the present invention For example, instead of using cams, it is possible to obtain the vertical reciprocating movement of the oscillating plate and the needle by using vertical racks integral with said elements and cooperating with toothed sectors fixed on said single shaft In addition, instead of three-wire armor, one can obtain armor comprising two additional wires simply by eliminating one of the two turn wires and, finally, instead of armor at the place of each weft thread inserted (armor 1/1), one can obtain armor with each pair of weft threads inserted (2/2 weave), this variation in the weave frequency simply requiring replacement of the control cams. The present invention will now be described with reference to the accompanying drawings, in which: FIG. 1 is a perspective view of the device for cross-weaving the side edge of a fabric, this device being produced according to the present invention; Figures 2 and 3 show the successive stages of the three-wire weaving cycle of the device of Figure 1; Figures 4 to 7 show on a larger scale the armor obtainable with the device of Figure 1, Figure 4 showing the specific armor 1/1 three-wire, Figure 5 showing the corresponding armor 2/2 with three wires, Figure 6 showing a 1/1 armor with two wires, and Figure 7 showing the armor

corresponding 2/2 to two wires.

  In the figures, the reference 1 designates the fixed frame of the weaving device of the invention, this frame acting as a vertical guide for a needle 2 through the eye 3 from which passes an additional warp thread 4, which is known under the designation of straight wire or fixed wire because it arrives from a feeding device not shown in the figure and extends along a straight line parallel to the other wires of

  chain 5 of fabric 6 being formed.

  The needle 2 is also guided vertically by a Z-shaped structure 7 comprising a hole 8 through which the needle passes, this structure itself being guided vertically by the fixed frame 1 and supporting a plate 10 mounted so oscillating by the axis 9, a plate 10 for guiding the two additional lateral turn wires 11 and 12 which pass respectively through the two holes 13 and 14 axially opposite one another with respect to said axis 9 of the plate 10 , and through two corresponding curvilinear slots 15 and 16 formed in said structure 7, and intersect under the weft threads 17, 17 ', 17 "passing on either side of the straight wire 4, while this straight wire 4 should always pass over these

weft yarn.

  The plate 10 is articulated, at its upper end, on the end of a rod 18 which can slide telescopically inside a block 19 mounted

  pivotally on the structure 7 using a pin 20.

  A compression spring 21, which is coaxial with the rod 18 and which acts between the block 19 and the fork 22 by means of which the rod 18 is articulated on the plate 10, tends to push the rod 18 into its position of maximum extension which can be adjusted using the stop nut 23 which can be positioned along the thread of the free end of the rod 18 and, consequently, to rotate the plate 10 as far as the one of the two extreme positions which are symmetrical with respect to the vertical and in which the two holes 13 and 14 of the plate 10 have swapped their positions around the needle 2, these positions corresponding to the lateral ends A and B of the

  curved slots 15 and 16 respectively.

  In this regard, the assembly constitutes a bistable system which, under the action of the spring 21, finds a stable equilibrium only in one or the other of the two positions of maximum rotation of the plate 10 which are symmetrical with respect to vertical, the tower wires 11 and 12 being brought, in these positions, to pass through the

  ends A or B of slots 15 and 16.

  The lower end of said plate 10 is suitably profiled to facilitate the sliding of a push bar 24 inside one or the other of two lateral recesses 25 and 26 formed in the sides of the plate 10 in order to rotate this plate from one to the other of said symmetrical extreme positions The push bar 24 is articulated on the fixed frame 1 by the axis 27, a flat return spring 28 tending to keep it permanently in a perfectly vertical position by acting on a lug 29 of the push bar 24, the vertical being provided towards the stop block 30 fixed to the frame 1, which block cooperates with the flat parts of the return spring 28 This verticality guarantees that the bar thrust 24 will always act alternately on one

  and the other of the two recesses 25 and 26.

  In addition, the cooperation between the plate 10 and the push bar 24 is made possible by the fact that the structure 7 and, consequently, the plate 10, are moved back and forth by a cam 31 fixed on an auxiliary shaft 32 rotatably supported by the fixed frame 1 and driven by the drive shaft of the loom, not shown in the figures, by means of an appropriate reducing link of which only the toothed wheel 33 integral with the shaft 32 is visible in the figures The cam 31 acts on a follower roller 34 that comprises the structure 7, the contact being ensured by a spring 35 acting between the structure

7 and the fixed frame 1.

  Finally, the needle 2 is driven in a vertical reciprocating movement but in opposition to the movement of the structure 7 by a cam 36 also fixed on the auxiliary shaft 32 but having a profile opposite to that of the cam 31 and acting on a follower roller 37 which comprises the needle 2, the contact being ensured by a spring 38 acting between the needle 2 and the

fixed frame 1.

  The method of actuating the device is as follows. Starting from the stage during which a new weft thread 17 'is inserted in the open crowd, the corresponding situation is that in which the needle 2 is at the top dead center of its travel (see especially the Figure 1) with its straight wire 4 thus passing over the weft thread 17 ', while the structure 7 is at the bottom dead center of its travel, the resulting interaction between the push bar 24 and the recess 26 having generated a rotation, anti-clockwise, of the plate 10 with the result of the permutation of position of the turn wires 11 and 12 which pass respectively through the end A of the slot 15 and through the end B of the slot 16 This permutation of the position of the lathe threads 11 and 12 cannot, however, propagate to the edge during the formation of the fabric 6 due to the presence of the needle 2 In this regard, the parts of the wires Il and 12 lying between the fabric 6 e t the slot 15 and 16 are not influenced by the position changeover action resulting from the sudden tilting movement of the bistable system but, on the other hand, by remaining in their previous positions relative to the straight wire 4, it rotates

around needle 2.

  During the next step, the needle 2 and the structure 7, controlled by the respective cams 36 and 31, begins to descend with respect to the needle and to rise with regard to the structure until these elements reach the other dead center of their respective course On descending, the needle 2 causes the rotation of the straight wire 4 around and above the weft thread inserted 17 '(see especially Figure 2), the free end from the push bar 24 emerging from the plate 10 and the push bar returning to the vertical position under the push of the return spring 28, so that the two turn wires 11 and 12, which are no longer hampered by the 'needle 2, can finally swap their position, i.e. cross, passing under the inserted weft thread 17' and on the straight thread 4 (see Figure 2, but taking into account that the two tower wires 11 and 12 have in fact swapped positions even though this may not be apparent in the particular perspective view). At this stage, again under the control of the corresponding cam 36, the needle 2 returns to its top dead center and, with its straight thread 4, it drives the position permutation point or crossing point 39 of the turn 11 and 12 against the edge of the fabric 6 being formed (see Figure 3) The structure 7 descends to its bottom dead center and the interaction between the push bar 24 and the recess 25 generates a rotation in the clockwise direction of plate 10 resulting in another sudden tilting of the bistable system into its other equilibrium position, the turn wires 11 and 12 permuting their positions at the ends A and

  B of the respective slots 15 and 16 (see Figure 3).

  However, here again the permutation of position cannot take place due to the presence of needle 2 and, as a result, the cycle has again reached the starting state described initially, but with the difference that the wires turn Il and 12 are now at the other ends of their slots due to the opposite position

taken by the bistable system.

  The cycle described is repeated after the insertion of a

another 17 "weft thread.

  In this way, by rotating the auxiliary shaft 32 at half the speed of the loom drive shaft, we obtain a three-wire gauze weave of the 1/1 type as illustrated in FIG. 4, while that by eliminating one of the turn wires, for example wire 12, we again obtain a 1/1 armor but do not

  comprising only two wires as illustrated in FIG. 6.

  Finally, by simply replacing the cams 31 and 36 with other cams having an appropriate profile, it is possible to obtain a 2/2 weave, that is to say weave with every two weft threads inserted successively, either with three wires as illustrated in Figure 5, either with two wires as

illustrated in figure 7.

Claims (3)

  1 Device for a cross warp weaving of the lateral edge of a fabric in a loom, comprising a needle (2) through the eye (3) through which an additional lateral warp thread (4) known as straight or fixed wire and extending parallel to the other warp threads (5) of the fabric (6) being formed, and a plate (10) to guide two additional lateral turn threads (11, 12) and connected to a structure (7) driven in a vertical reciprocating movement, characterized in that the plate (10) is articulated in an oscillating manner on the structure (7) vertical reciprocating drive and comprises on its vertical axis two holes (13, 14) axially opposite each other with respect to its support axis (9), the two additional turn wires passing through the holes (13, 14), the oscillating plate (10 ) being biased 3 by a spring (21) and being rotated back and forth in two symmetrical positions by a push bar (24) articulated on a fixed frame (1) and being provided with a spring (28) for its return to the vertical, positions in which the two holes have swapped position by relative to the needle (2) of straight or fixed wire, independent means being present to drive the structure (7) and the needle (2) in a vertical reciprocating movement in opposite directions.   2 cross-chain weaving device according to claim 1, characterized in that the above-mentioned independent means for driving the structure (7) and the needle (2) in a vertical reciprocating movement in opposite directions consist of two cams (31, 36) with opposite profiles fixed on the same shaft (32) which is driven by the drive shaft of the loom via an appropriate reducing link (33), said cams acting by the underside against follower rollers (34, 37) present on the structure (7) and on the needle (2), the contact being ensured by a spring (35).   3 cross-chain weaving device according to claim 1, characterized in that the oscillating plate   (10) is rotated in a downward movement   back and forth to the two aforementioned symmetrical positions in that the push bar (24) cooperates with two lateral recesses (25, 26) formed in the oscillating plate and arranged symmetrically around said vertical axis.