EP0160728B1 - Device for making leno shed in looms - Google Patents

Description

The invention relates to a lathe device for weaving machines.

Known leno devices are mounted on one (e.g. DE-GMS 82 27 336) or even on two different heald frames (e.g. FR-A-1 000 110). Turning devices that work during assembly on a single heald frame (e.g. DE-GMS 82 27 336) have complicated mechanisms for controlling the leno thread and are accordingly complex and expensive to manufacture.

Constructions such as in FR-A-1 000 110 may be mechanically less complex, but they require two shafts to control the leno thread relative to the upright thread, which often means that an extra shaft is used even for the control of one of the two threads must become.

Both designs (FR-A-1 000 110 and DE-GMS 82 27 336) have in common that the lathe device belongs to the moving mass of the shedding part of the weaving machine and is exposed to higher dynamic alternating loads, which requires a correspondingly robust design.

These leno devices are also relatively wide and require several times the width of a warp with a heald. This can be troublesome when weaving chains with a higher warp thread density.

When using these turning devices on jacquard weaving machines, special turning shafts are even necessary for edge formation.

The invention has for its object to provide a lathe device that is simple in construction and correspondingly inexpensive to manufacture. In addition, it should be universally applicable and can also be used on jacquard weaving machines without the otherwise required rotary shafts. This object is achieved according to the invention by the features specified in the characterizing part of claim 1. The subclaims relate to advantageous developments of the invention.

In the embodiment of the leno device according to the invention, only the leno threads can be controlled by means of ordinary healds in a heald frame or with a jacquard weaving machine on control cords. The rest of the leno device is fixed and has only one or more, possibly movable deflection elements for the leno thread. Since the dynamic alternating loads due to back and forth movements of the entire lathe device are eliminated, the design is simple and inexpensive.

Some exemplary embodiments of the subject matter of the invention are described below with reference to the drawings. It is:

• 1 shows a lathe devices, in particular for jacquard weaving machines according to the invention, in a front view;
• Figure 2 shows the upper part of the lathe device on an enlarged scale.
• 3a-3d show a turning operation;
• 4 shows a part of a fabric with an end bar;
• 5 shows a part of a modified device;
• 6 shows a part of a further modified device;
• Fig. 7 the cross section VII-VII in Fig. 6;
• Fig. 8 shows a lathe device in duplicate;
• 9 shows a part of a fabric with a double-bound bar;
• FIG. 10 shows a device modified compared to FIG. 1;
• 11.12 modified devices;
• 13 shows a lathe device, in particular for shaft weaving machines;
• 14 shows an end bar;
• 15 shows the top view XV-XV in FIG. 14;
• FIG. 16 shows a device modified with respect to FIG. 13;
• 17 shows a further modified device;
• 18 shows a part of the device according to FIG. 17 on an enlarged scale;
• 19 shows a part of a lathe device in the reverse arrangement compared to FIG. 17.

1, a lathe device 2 is fastened in the selvedge area to a fixed part 1 of a weaving machine (not shown). The leno device consists of a frame-shaped leno thread guide 3 and a standing thread needle 4 fastened therein with one end. On both sides of the needle 4 there are two thread guide lanes 5 and 6, which are connected to one another by a passage 6 '. A standing thread 7 comes from a supply spool through a thread guide 9 attached to the rear of the turning device in the foot area 8 and from there upwards and through a thread eyelet 10 in the needle 4 to the shed tip of the shed (not shown). The upright thread is a separate thread that accompanies the warp on the edge, but is not guided through a strand and therefore does not take part in changing the shed of the warp. The leno thread is identified by reference number 12. A leno thread is a normal warp thread that comes from the warp beam through a strand 13 of a (not shown) jacquard machine alternately through alleys 5 and 6 to the shed tip, as will be explained. If the leno thread is in the alley 6, it is denoted by 12 '. The leno thread guide 3 is provided with a switch 15 which can be freely rotated about a pin 16 between two stops 17 and 18. The switch 15 is provided with a notch 19 which bridges the alley 5. The standing thread needle 4 tapers to a tip 4 ', so that there is a space 20 between the tip and the switch 15.

The device works as follows:

Before the start of the leno movement, the leno thread 12 is in the left lane 5 of the device and the switch 15 in the position shown abuts the stop 17 (FIG. 3a). When the leno thread 12 is raised by the strand 13 during the high shed movement, it moves upwards in the alley 5, raising the switch 15 (FIG. 3b) until it reaches the stop 18 (FIG. 3c). The leno thread 12 is raised via the notch 19 and the space 20 over the tip 4 'of the standing thread needle 4. After a weft thread 23 (FIG. 4) has been inserted, the shed changes, the leno thread 12 being pulled down through the strand 13 and into the alley 6 until the leno thread 12 'reaches the low position. During this downward movement, the leno thread 12 ′ crosses the upright thread 7 and the just inserted weft thread 23 from left to right. The switch 15 falls back on the stop 17. The next weft thread 24 is now entered, followed by a shed change to the high shed position. The strand 13 lifts the leno thread 12 'through the alley 6 (FIG. 3d) and along an inclined inner edge 25 of the frame 4. Here, the leno thread 12 'first crosses over from right to left the last weft thread 24 entered and then crosses over the upright thread 7. When the leno thread has reached a niche 26 in the leno thread guide 3, the shed is changed to the low position, with the strand 13 down the leno thread 12 and pulls along an upper edge 27 of the switch 15 into the alley 5. The weft thread 24 is now bound between the upright thread 7 and the leno thread 12. This completes one leno cycle and the next can take place in the same way, so that an end strip 28 is finally formed on the fabric 29.

In order to prevent any possible hesitation or getting caught in the switch 15, it can be provided with a spring 30, as shown in FIG. 5. The spring 30 constantly exerts pressure on the switch 15, so that it returns with certainty in its starting position at the stop 17 after deflection to pass a leno thread.

6 and 7 show the upper part of a leno device which has a spoke wheel 35 instead of a switch as a deflecting element for the leno thread. The spoke wheel 35 is rotatable about a bush 36 which is fastened in a standing thread needle 37. The bushing 36 serves as a thread eyelet for a stationary thread 38. Guide brackets 39 and 40 for a leno thread 41 are attached on both sides of the spoke wheel 35, and are located on the front and rear of a leno thread guide 42. The operation of the device is similar to that described for FIGS. 1 to 4. When the leno thread 41 moves upward during the high shed movement in the left lane 43, it gets between two spokes of the spoke wheel 35 and sets it in clockwise rotation. The leno thread 41 is pushed onto the guide bracket 39 to the center of the leno thread guide 42 until it reaches the upper position in the leno thread guide. The leno thread is then located between the two upper spokes 35 'and 35 ". During the following shed change, the leno thread 41 moves downwards and is thereby moved by the momentum of the spoke wheel 35 via the tip 37' of the standing thread needle 37 into the right lane 44 of the leno thread guide 42 The vertical thread 38 is crossed over here, and when the shed is now changed, the leno thread rotates the spoked wheel 35 counterclockwise and is pushed toward the center by the guide bracket 40 and steered into the left lane 43 by the spoked wheel.

In the described turning devices, the end of every second weft thread remains free, i.e. it is not bound by the leno thread. In FIG. 4 it can be seen that one end 23 'of the weft thread 23 is not bound, probably one end 24' of the weft thread 24, because it is located between the upright thread 7 and the leno thread 12.

In order to ensure that all weft ends are tied in, the lathe device is carried out twice. 8 shows a device 45 which has two leno devices I and II. The leno device I consists of an leno thread guide 46 with a standing thread needle 47 and a switch 48. The leno device 11 consists of a leno thread guide 49 with a standing thread needle 50 and a switch 51. Both switches 48 and 51 can be rotated about a common pin 52 and in a raised position drawn. The switch 48, which is attached to the back, moves between two stops 53 and 54. The switch 51 is attached to the front and moves between the common stop 53 and a stop 55. The leno device I carries a standing thread 56 which Leno device II has a standing thread 57. Before the turning movement begins, there is a leno thread 59 in left lane 58 of device I, and a leno thread 61 in left lane 60 of device 11.

The device works as follows:

Each of the leno devices 11 and 11 operates in the same manner as shown and described for the leno device of Figures 1-4. The leno device I causes the upright thread 56 and a weft thread 62 (FIG. 9) to cross from left to right through the leno thread 59. At the same time, the leno device II causes the upright thread 57 to cross over and the weft thread 62 to also cross under from left to right through the Leno thread 61. The leno thread 59 'of the leno device I then crosses from the right to the left a weft thread 64 and crosses the upright thread 56, while the leno thread 61 'of the leno device II crosses the weft thread 64 and the upright thread 57 from right to left. This corresponds to half a spin cycle. The opposite process then follows until the entire turning cycle has been completed. Due to the opposite movement of the leno threads 59 and 61 of this device I and II, each weft end is bound, because each end is located between a pair of leno leno threads.

Instead of double, the device can be designed multiple times.

Fig. 10 shows the upper part of a lathe device which is provided with two switches 65 and 66. The switch 65 is located on the back, switch 66 on the front of the device. The turnouts 65 and 66 have the same task as the turnout 15 in FIG. 1. The device is shown during a turning movement from right to left of the turning thread 67 '. The leno thread 67 'first comes into the notch 66' of the switch 66. This is raised until it abuts a stop 68. The leno thread 67 'then slides to the left over a tip 69' of a standing needle 69. During its downward movement, the leno thread 67 passes through the space between the switch 65 and the needle point 69 'into a left-hand lane 70. The leno cycle is thus ended.

FIG. 11 shows a device, the switches being formed by wire springs 75 and 76, which have a contour corresponding to that of the switches 65 and 66 in FIG. 10. The wire springs are each fixed on a fixed pin 77 or 78 on the front or on the back of the device. The mode of operation of the wire springs corresponds to that of the switches described above. The advantage of using such a wire spring as a switch is that, as soon as it is pushed upwards by a leno thread 79, it favors the movement of the leno thread lying in a notch 75 'over the tip of the standing thread needle by the notch carrying out a translational movement superimposed on the swivel radius .

FIG. 12 shows a leno device 81, the leno thread 82 or 82 ′ being changed from one side to the other in a foot region 83 of the device. For this purpose, two wire spring switches 84 and 85, one at the front and one at the rear, are attached. The mode of operation is completely in accordance with FIG. 11.

The above-described lathe devices are advantageously, but not exclusively, used in jacquard weaving machines, in particular because there was previously no possibility of using commercially available devices. The turning devices described below relate in particular to those for weaving machines, the weaving shed being changed by means of heald frames.

13, a leno device 90 consists of a standing thread needle 92 fastened to a heald frame 91 of the weaving machine and a leno thread guide 93 fixed to the weaving machine. The standing thread needle 92 has a thread guide 94 at the upper end and a thread eyelet 95 at the lower end. The leno thread guide 93 has a central lane 96 and two side lanes 97 and 98. The side streets 97 and 98 are connected to one another by an opening 99. A switch 100 is attached to the side of the right-hand lane 98 and is constantly pressed upwards by a spring 101. A standing thread 105 runs from the supply spool through the thread guide 94, the thread eyelet 95 and the central lane 96 to a fabric 106. A leno thread 107 comes from the warp beam through a strand 108 of the heald frame (not shown) behind the front heald frame 91 and from there through the leno thread guide 93 to the fabric 106. In the drawn high position of the strand 108, the leno thread 107 is in the left lane 97 of the leno thread guide 93; in the low position, it is in right Gasse 98.

The device works as follows:

The position drawn in FIG. 13 is assumed. When the strand 108 moves down to the low position, the leno thread 107 slides down through the alley 97 (indicated in FIG. 14 in an end bar 109 with 107 ') and ends in position 107' in the opening 99. At the same time, the standing thread needle 92 is with the Upright thread 105 has been moved from the heald frame 91 upwards (indicated in FIG. 14 with 105 ') into the high shed position. The leno thread 107 and the standing thread 105 have crossed each other. The upright thread 105 is now at the top in the central alley 96. A weft thread 111 is now inserted. During the following change of shed of the two heald frames, the upright and leno threads 105 and 107 intersect again, now including the weft thread 111. The leno thread 107 has passed the switch 100 above into the alley 98. The upright thread 105 is again located at the bottom in the alley 96. In FIG. 14 the movement of the upright thread is designated 105 ", that of the leno thread at 107". The weft thread 111 is thus bound in and a leno cycle is ended. The end bar 109 obtained according to FIG. 14 is also produced by the turning devices described below.

In FIG. 15, which is a top view of the end bar 109 in FIG. 14, it can be seen that in this leno device the upright thread 105 maintains its linear course during the turning process. The leno thread 107, however, changes from one side to the other of the upright thread 105 after each crossing of a weft thread 111. Each weft thread end is thus bound in.

In Fig. 13 is a dash-dotted line Standing thread needle 92 'drawn, which is located in front of the leno thread guide 93. With this arrangement, the central lane 96 in the leno thread guide 93 is unnecessary. This arrangement has the advantage that both the leno and the upright thread can lie in the same deep compartment plane.

FIG. 16 shows a leno device 115, the leno thread guide 116 and the standing thread needle 117 of which are reversed compared to the arrangement according to FIG. The mode of operation is the same as that described for FIG. 13. Such an arrangement may be necessary in connection with the space available on a weaving machine.

17 and 18, a leno thread guide 120 is provided in a transition region 121 between two alleys 122 and 123 with a spoke wheel 124 for a leno thread 125. The spoke wheel 124 is fastened on a central web 126 so that it can rotate freely. A thread guide bracket 127 is attached to the front of the leno thread guide 120, and a thread guide bracket 128 for the leno thread 125 is attached to the rear. Otherwise, the device is shown as shown in FIG. 13 with the arrangement of the standing thread needle 92 ′ in front of the leno thread guide 93. The way of working is also the same. When the leno thread 125 in the alley 122 moves from the drawn high position to the low position, the spoked wheel 124 is rotated counterclockwise by the leno thread. The leno thread 125 is thereby pushed sideways by the momentum of the idler wheel 124 via the guide bracket 127 until it has reached the lower position 125 'in the leno thread guide 120. The leno thread 125 'is then located between the spokes 129 and 130 to the right of the tip 126' of the central web 126 (FIG. 18). During the immediately following upward shed movement of the leno thread, the spoked wheel 124 is rotated further and the leno thread 125 'changes over into the alley 123 and slides upwards into position 125 ". During the subsequent shed change, the leno thread 125" rotates the spoked wheel 124 in the opposite direction and returns to alley 122.

19 shows the upper part of a leno thread guide 131, the spoke wheel 132 of which is arranged in the upper region. The associated standing thread needle, which is not shown, is now pointing upwards as shown in FIG. 16, but in the direction of view in front of the leno thread guide 130.

Claims (18)

1. A leno attachment for weaving machines, more particularly for jacquard machines, characterised by: a stationary frame-like leno yarn carrier (3; 42; 46; 49); and a standing-yarn needle (4; 37; 47, 50; 69) secured at one end in the leno yarn carrier and forming a central web and two leno yarn lanes (5, 6; 43, 44), the other end (4', 37') of the needle narrowing and cooperating in its narrowing part with the frame to bound a passage (6') for the leno yarn (12, 12'; 41; 59, 59'; 61, 61'; 67, 67"; 82, 82') fron one lane to the other lane; and by at least one deflecting element (15, 25; 35; 48, 51; 65, 66; 75, 76; 84, 85) which is engaged by the leno yarn for its deflection, is disposed near the passage on the leno yarn carrier and deflects the leno yarn from one lane into the other in synchronism with shed-changing and with simultaneous crossing of the standing yarn (7; 38; 56, 57) guided by the standing-yarn needle.

2. An attachment according to claim 1, characterised in that there are two deflecting elements and one of them is a junction (15) movable between two end positions by the leno yarn (12); and the other deflecting element is an inclined part (25) in the leno yarn carrier (3).

3. An attachment according to claim 2, characterised in that the junction (15) is formed with an indent (19) to catch the leno yarn (12).

4. An attachment according to claim 2, characterised in that the junction (15) has a spring (30) which biases the junction towards its normal position.

5. An attachment according to claim 2, characterised in that the junction (15) is a wire spring (65, 66; 75, 76; 84, 85) which is clamped at one end and whose shape corresponds to the contour of the junction.

6. An attachment according to any of claims 2 - 5, characterised in that the end positions of the junction (15; 48, 51) are formed by abutments (17, 18; 53, 54, 55) on the leno yarn carrier (3).

7. An attachment according to claim 1, characterised in that the two deflecting elements are junctions (65, 66; 75, 76; 84, 85) movable by the leno yarn (67, 67'; 79; 82, 82') between two end positions.

8. An attachment according to claim 7, characterised in that the junctions (84, 85) are disposed in the bottom part (83) of the leno yarn carrier.

9. An attachment according to claim 1, characterised in that the deflecting element is a pin wheel (35) rotatably secured to the standing-yarn needle (37).

10. An attachment according to claim 9, characterised in that the hub of the pin wheel (35) serves as eye for the standing yarn (38).

11. A leno attachment for weaving machines, more particularly for dobby weaving machines, characterised by: a stationary leno yarn carrier (93; 116; 120) having two lanes (97, 98; 122, 123) which are interconnected near a deflecting element (100; 124, 132) for the leno yarn and guide the leno yarn alternately in synchronism with shed-changing; and by a standing-yarn needle (92) which is secured to a shaft (91) centrally in relation to the two lanes of the leno yarn carrier, the free end of the latter needle moving in antisynchronism to shed-changing relatively to the leno yarn (107; 125).

12. An attachment according to claim 11, characterised in that the standing-yarn needle (92) is disposed after the leno yarn carrier (93) in relation to the direction of warp movement and the standing yarn (107) extends through a lane (96) disposed between the two lanes (97, 98) in the leno yarn carrier.

13. An attachment according to claim 12, characterised in that the standing-yarn needle (92') is disposed before the leno yarn carrier (93).

14. An attachment according to any of claims 11 - 13, characterised in that the deflecting element is a junction (100).

15. An attachment according to any of claims 11 - 14, characterised in that the junction (100) is disposed near the bottom part of the leno yarn carrier (93) and is biased by a spring (101) against gravity.

16. An attachment according to any of claims 11 - 13, characterised in that the deflecting element is a pin wheel (124; 132).

17. An attachment according to claim 16, characterised in that a guide stirrup (127, 128) for the leno yarn (125) is disposed on at least one side of the pin wheel.

18. An attachment according to any of claims 11 - 17, characterised in that the attachment is of multiple construction.

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