EP2176455B1

EP2176455B1 - Method for tucking an end of a weft thread into a selvedge of a fabric, and pneumatic tuck-in device

Info

Publication number: EP2176455B1
Application number: EP08773887A
Authority: EP
Inventors: Jozef Peeters; Jean-Marie Bamelis; Filip Bafcop; Dirk Sampers
Original assignee: Picanol NV
Current assignee: Picanol NV
Priority date: 2007-07-12
Filing date: 2008-07-07
Publication date: 2011-05-25
Anticipated expiration: 2028-07-07
Also published as: BE1017684A3; WO2009007076A1; ATE510944T1; CN101743348B; CN101743348A; EP2176455A1

Abstract

The invention relates to a method for tucking an end (23) of a weft thread (19) into a selvedge (27) of a fabric (3) by means of a pneumatic tuck-in device (5) which blows an end (23) of an inserted and beaten up weft thread (19) extending past a selvedge (27) of the fabric (3) into a subsequent shed (1), whereby the tuck-in device (5) is moved back and forth along the selvedge (27) of the fabric (3) in synchronization with the reed (13) and blows in of this end (23) of the beaten-up weft thread (19) into a shed (1) while the tuck-in device (5) moves back and forth along the selvedge of the fabric.

Description

The invention relates to a method for tucking an end of an inserted weft thread into a selvedge of a fabric by means of a pneumatic tuck-in device which blows an end of a weft thread, which is beaten up at an edge of the fabric and extends past a selvedge of the fabric into a subsequent shed, and to a pneumatic tuck-in device.
Pneumatic tuck-in devices are known, for example, from US 4957144 and WO 01/86047 A1 . In order to be able to blow the ends of the weft threads into a subsequent shed, the pneumatic tuck-in devices are located at least partly on the side of the reed before the beat-up line or the edge of the fabric. In order not to prevent the beating-up movement of the reed, it is known to omit the reed in the region of the pneumatic tuck-in device, thus allowing the reed to move along the tuck-in device up to the beat-up line. In order not to have to interrupt the reed in the region of the tuck-in device, it is also known to move the tuck-in device with the reed back and forth and to provide for this purpose a means for driving the tuck-in device. This drive means is relatively complex, since this drive means requires precise synchronization with the movement of the reed or with the movement of the sley.
It is known from US 1426351 to mount a tuck-in device on the sley so that this tuck-in device moves together with the reed. This tuck-in device, which is arranged at the insertion side of the shed, interacts with a cutting apparatus which cuts off the weft threads next to the selvedge of the fabric during beating-up by the reed. A fork-shaped element, which overlaps the selvedge of the fabric in proximity to the insertion side, must bend the end of the weft th protruding beyond the selvedge as the sley moves back, which end must then be blown into the subsequent shed while the sley with the reed has at least moved back.
The object of the invention is to form a method of the aforementioned type wherein an uninterrupted reed can be used and wherein simple tucking-in of the ends of the weft threads can be carried out.
This object is achieved in that the tuck-in device is moved back and forth along the selvedge of the fabric in synchronization with the reed and in that this end of the beaten-up weft thread is blown into a shed while this end of the beaten-up weft thread is presented to the tuck-in device and the tuck-in device moves further along this end of the beaten-up weft thread.
The invention utilizes the effect that the blowing device moves during the tucking-in or blowing-in of the end of an inserted weft thread, which is beaten up by a reed, along the selvedge of the fabric, so that this movement assists the tucking-in or blowing-in of the end of the weft thread. In this case, the blowing-in of the end of the weft thread can commence while the reed moves away from the edge of the fabric. During the tucking-in or blowing-in, the tuck-in device moves in synchronization with the reed and along the selvedge of the fabric, past the extension of the edge of the fabric, thus allowing an uninterrupted reed to be used.
According to a further embodiment of the invention, provision is made for the blowing-in of the end of the weft thread to be completed while the reed moves back to the edge of the fabric. This blowing-in can continue until the shed is closed; this usually occurs before the reed beats the edge of the fabric. This ensures that the end of the weft thread that is tucked into the subsequently formed shed is securely held until the subsequent weft thread is beaten up and/or until the shed is closed, and that this subsequent weft thread is bound with the tucked-in end of a previously inserted weft thread.
According to a further embodiment of the invention, provision is made for the pneumatic tuck-in device to be provided with a plurality of blowing openings which are arranged next to one another in the direction of movement of the tuck-in device and which blow in various positions of the tuck-in device. The plurality of blowing openings allow the ends of the weft threads to be tucked in in a controlled manner.
According to one embodiment of the invention, provision is made for the weft thread to be cut while a stream of compressed air is directed on the end of the weft thread and while the reed was moved at a distance from the edge of the fabric, meaning that a distance is set apart from the edge of the fabric. The fact that cutting is in this case carried out only once a stream of compressed air is directed on the end of the weft thread rules out the risk of the weft thread moving in an uncontrolled manner and becoming lost. The stream of compressed air, which then still moves away from the edge of the fabric, ensures that the end of the weft thread is securely tucked into the subsequent shed.
The object is also achieved by a pneumatic tuck-in device with a blowing device for blowing in an end of a weft thread, which is inserted and beaten up and extends past a selvedge of the fabric, into a subsequent shed, the tuck-in device being hold by a sley, so that the tuck-in device moves back and forth in synchronization with the reed, and the tuck-in device comprising a blowing device for blowing on this end of the beaten-up weft thread during the movement of the tuck-in device along the selvedge of the fabric. Tuck-in devices of this type allow the end of the beaten-up weft thread to be blown on in such a way that this end is bent and blown into a subsequent shed while the tuck-in device moves in synchronization with the reed along the selvedge of the fabric.
According to one embodiment of the invention, a holder, with which the tuck-in device can be attached to a sley, is attached for the tuck-in device. This allows in a simple manner the tuck-in device to move in synchronization with the sley and with the reed, thus allowing a continuous reed to be used and synchronization between the movement of the tuck-in device and the movement of the reed to be obtained in a simple manner. The latter aspect is advantageous above all in the case of high weaving speeds and/or on start-up of the weaving machine. According to a preferred embodiment, the tuck-in device is attached to a sley profile of the sley so as to be adjustable in the longitudinal direction of the sley. This allows the tuck-in device to be attached to a sley profile of the sley so as to be adjustable in the longitudinal direction of the sley, i.e. the direction of the width of the fabric. This allows the arrangement of the tuck-in device to be adapted to the width of the fabric in a simple manner, as a result of which the tuck-in device allows fabrics of differing width to be woven in a weaving machine. Particularly suitable for this purpose is a sley profile to which, in the case of an air weaving machine, auxiliary nozzles are attached or to which, in the case of a gripper weaving machine guide elements for a gripper band are attached.
According to one embodiment of the invention, the blowing device comprises a plurality of blowing openings which are arranged next to one another in the direction of movement of the tuck-in device. This allows a stream of compressed air to act continuously on the end of the weft thread during the movement of the tuck-in device and the end of the weft thread to be blown on continuously while the tuck-in device moves along the selvedge of the fabric. This also prevents the blowing device from blowing needlessly on the fabric which is formed and/or the fabric from becoming damaged as a result of this blowing. Provision may in this case also be made for the blowing openings of the blowing device to be assembled in groups which can each be activated independently of one another. For this purpose, the tuck-in device comprises activating elements which can be activated while the tuck-in device moves along the selvedge of the fabric.
According to one embodiment of the invention, the tuck-in device comprises a slot which runs in the direction of movement of the tuck-in device and which can take up an end of a beaten-up weft thread while the tuck-in device moves along the selvedge of the fabric. According to one embodiment, a number of blowing openings are arranged along the slot, and preferably blowing openings are arranged both above and below the slot in the direction of movement of the tuck-in device, which openings are preferably arranged next to one another in a row. These blowing openings are in this case preferably arranged in such a way that an end of a beaten-up weft thread can be blown into the subsequent shed. In this case, the slot is arranged in such a way that the slot is continuously movable over the extension of the edge of the fabric.
According to a preferred embodiment, a cutting apparatus for cutting an end of a beaten-up weft thread is attached to the tuck-in device at a distance from the selvedge of the fabric. Attaching the cutting apparatus to the sley profile of the sley so as to be adjustable in accordance with the width of the fabric allows the length of the end to be tucked in of the weft thread to be adjusted as desired. A cutting apparatus of this type, which moves together with the tuck-in device, can be activated during the movement of the tuck-in device along the selvedge of the fabric. According to a preferred embodiment, the cutting apparatus comprises a cutting blade which can be activated pneumatically.
Further advantages and features of the invention will emerge from the subsequent description of the exemplary embodiments illustrated in the drawings, in which:

Figure 1 shows a schematic plan view of a weaving machine comprising a plurality of tuck-in devices according to the invention;
Figure 2 shows a side view of a tuck-in device according to the invention from a first side in a position in which the reed is already set apart from the beat-up line;
Figure 3 shows a side view of the tuck-in device according to Figure 2 from a second side opposing the first side;
Figure 4 shows a plan view of the tuck-in device according to Figure 2;
Figure 5 shows a perspective view of the tuck-in device according to Figure 2 in which the first side can be seen;
Figure 6 shows a perspective view of the tuck-in device according to Figure 2 in which the second side can be seen;
Figure 7 shows a perspective view of two tuck-in devices according to the invention which are intended to be attached between two fabrics;
Figure 8 shows a plan view of the two tuck-in devices according to Figure 7;
Figures 9 to 16 show a tuck-in device according to the invention in various positions during a weaving cycle;
and
Figures 17 to 22 show a tuck-in device according to the invention in various positions during two weaving cycles.

In the weaving machine illustrated in Figure 1, two fabrics 2, 3 are woven next to one another. Said figure shows four pneumatic tuck-in devices 4 to 7 according to the invention, more particularly one tuck-in device 4 arranged in proximity to the insertion side 16 of the shed 1, one tuck-in device 5 arranged in proximity to the opposite side 17 of the shed 1 and two tuck-in devices 6 and 7 which are arranged next to one another between the fabrics 2, 3. Added to the tuck-in device 4 is a cutting apparatus 8, to the tuck-in device 5 a cutting apparatus 9 and to the tuck-in devices 6 and 7 a common cutting apparatus 10. The weaving machine further comprises a sley 11 comprising a sley profile 12 to which a reed 13 is attached. The tuck-in devices 4 to 7 are in this case attached to the sley profile 12. In this case, the cutting apparatuses 8 to 10 are also attached to the sley profile 12. In order to allow the weft threads to be inserted, warp threads 18 are used to form in a known manner a shed 1, in each case by means of shed-forming elements (not shown).
The inserted weft threads 19 are beaten by the reed 13 against the edge 14 of the fabric 2 and against the edge 15 of the fabric 3. The inserted and beaten-up weft thread 19 comprises an end 20 which protrudes beyond the selvedge 24 of the fabric 2, an end 21 which protrudes beyond the selvedge 25 of the fabric 2, an end 22 which protrudes beyond the selvedge 26 of the fabric 3 and an end 23 which protrudes beyond the selvedge 27 of the fabric 3. The ends 20 to 23 should be tucked or blown into a subsequent shed by means of an associated tuck-in device 4 to 7. The cutting apparatus 8 cuts the end 20 of a beaten-up weft thread 19 at a distance from the selvedge 24 of the fabric 2, the cutting apparatus 9 cuts the end 23 at a distance from the selvedge 27 of the fabric 3 and the cutting apparatus 10 cuts the end 21 at a distance from the selvedge 25 of the fabric 2 and the end 22 at a distance from the selvedge 26 of the fabric 3. The ends 20 to 23 of a weft thread 19 which is inserted into a shed 1 and beaten up by the reed 13 protrude in this case next to an associated selvedge 24 to 27 of an associated fabric 2, 3.
As is shown in Figures 2 to 6, the tuck-in device 5, more particularly the tuck-in device 5 on the opposite side 17 of the shed 1, comprises a blowing device 29 for blowing into a subsequent shed an end 23 of a weft thread 19 which protrudes beyond the selvedge 27 of the fabric 3. The tuck-in device 5 comprises a slot 28 which runs in the direction of movement A of the tuck-in device 5 and which can take up an end 23 of a beaten-up weft thread 19 while the tuck-in device 5 moves along the associated selvedge 27 of the fabric 3. The slot 28 shows substantially the shape of an arc of a circle which extends during use of the tuck-in device 5 about the axis of rotation 75 of the sley 11 which is open toward the reed 13 and which is closed on the base away from the reed 13 at the level of a base 30. The slot 28 can be provided with a wearproof lining, for example a lining made of ceramic or steel.
A blowing opening 31, which during use is directed toward the shed 1 and toward the reed 13, is formed in proximity to the base 30. Along the slot 28, a number of blowing openings 32 to 37 are formed in the direction of movement A of the tuck-in device 5; more particularly, a plurality of blowing openings 32 to 34 are formed next to one another in a row 38 above the slot 28 and a plurality of blowing openings 35 to 37 are formed next to one another in a row 39 below the slot 28. During use, these blowing openings 32 to 37 are directed principally toward the shed 1. In this case, all of the blowing openings 32 to 37 can be directed in the same direction, for example in the longitudinal direction B of the sley 11. As the blowing openings 31 to 37 move together with the sley 11, the air jet from each blowing opening can cover a certain area.
The blowing opening 31 of the blowing device 29 can be provided separately with compressed air and is pneumatically connected to a connection piece 40. The blowing openings 32 to 37 of the blowing device 29 are assembled in groups which can be provided separately with compressed air. A first group comprising blowing openings 32 and 33 is pneumatically connected to a connection piece 41, a second group comprising blowing openings 35 and 36 is pneumatically connected to a connection piece 42 and a third group comprising blowing openings 34 and 37 is pneumatically connected to a connection piece 43. The tuck-in device 5 comprises a housing 44 in which the blowing openings 31 to 37 are formed and in which there are attached pneumatic connections which are formed by channels and can pneumatically connect said blowing openings to associated connection pieces.
The housing 44 comprising blowing openings and channels can be manufactured, for example, by metal casting, more particularly by die-casting an aluminium alloy. According to a variation, the housing 44 can be manufactured, for example, by the joining-together of powder metal, more particularly by the selective laser melting of powder material. According to a further variation, the housing 44 can also be manufactured with the aid of conventional operations such as drilling and milling.
The blowing opening 31 is formed in proximity to the base 30 of the slot 28. The base 30 and the blowing opening 31 are formed in such a way that they are located close to the end 23 of the weft thread 19 or even just enter into contact with this end 23 of the weft thread 29 when the reed 13 is in the rearmost position, i.e. the position in which the reed 13 is furthest away from the edge 15 of the fabric 3.
Furthermore, the tuck-in device 5 can be attached to a sley profile 12 of the sley 11 by means of the housing 44. The housing 44 comprising the slot 28 is arranged next to the selvedge 27 of the fabric 3 and can move along the selvedge 27 of the fabric 3 transversely to the longitudinal direction B of the sley 11. The sley profile 12 extends in this case in the longitudinal direction B of the sley 11 and comprises a slot 45 extending over the length of the sley profile 12. The slot 45 is used in this case not only to fasten what are known as auxiliary nozzles to the sley profile 12 but also to fasten a tuck-in device 5 according to the invention to the sley profile 12. Fastening of the tuck-in device 5 at the level of a slot 45 of this type allows the tuck-in device 5 to be attached to a sley profile 12 in an adjustable manner, i.e. as appropriate in a desired position in the longitudinal direction B of the sley 11. The blowing openings 32 to 37 are in this embodiment formed at the level of the side surface of the housing 44 that is directed toward the shed 1 or toward the fabric 3.
The housing 44 comprising the slot 28 is in this case arranged during operation transversely to the longitudinal direction B of the sley 11. In this case, the slot 28 is preferably formed and arranged in such a way that the slot 28 can move along an end 23 of a beaten-up weft thread 19 during a reciprocating movement of the sley 11 without the slot 28 in this case substantially entering into contact with this end 23 of the weft thread 19. This means that the slot 28 can move transversely over or along the end 23 of the beaten-up weft thread and in the longitudinal direction B in the extension of the edges 14 and 15 formed by the beaten-up weft thread 19 without substantially touching this end 23 of the weft thread 19. This means that the slot 28 makes almost no contact with the end 23, although this end 23 may just touch the slot 28.
A cutting apparatus 9 for cutting an end 23 of a beaten-up weft thread 19 is attached at a specific distance next to the tuck-in device 5. The cutting apparatus 9 comprises a cutting blade 46 which is secured to a holder 48 by a screwed connection 47 and a cutting blade 49 which is attached via a screwed connection 50 so as to be able to move about an axis of rotation 77 with respect to the holder 48 and the fixed cutting blade 46 and which can be driven pneumatically. For this purpose, the cutting blade 49 interacts with a double acting piston system 51 which can command the cutting blade 49 in a desired direction about the axis of rotation 77. The distance between the holder 48 and the fixed cutting blade 46 can optionally be adjusted by attaching thickness plates at the level of the screwed connection 47 between the holder 48 and the fixed cutting blade 46. One plunger 52 of the piston system 51 is connected to a valve 54 via a connection piece 53 and the other plunger 55 of the piston system 51 is connected to a valve 57 via a connection piece 56. The valves 54 and 57 are connected to a source of compressed air 58. The valves 54 and 57 can consist of what is known as a 3/2 valve. According to a variation (not shown), the valves 54 and 57 can be replaced by one single valve which can perform the function of both valves 54 and 57, such as what is known as a 5/3 valve.
The movable cutting blade 49 is coupled via the screwed connection 50 to a lever 59 and movable by means of this lever 59 which is also arranged so as to be able to rotate about the axis of rotation 77. The lever 59 comprises a collar 76 which can interact with the plungers 52 and 55 of the piston system 51. Between the lever 59 and the movable cutting blade 49, a spring system 89 (as illustrated schematically in Figure 4) is, for example, attached at the level of the axis of rotation 77 in order to force the movable cutting blade 49 in a known manner against the fixed cutting blade 46.
The connection pieces 40 to 43 are further connected by pneumatic lines to associated valves 60 to 63 which are also pneumatically connected to at least one source of compressed air, for example to the compressed air source 58. The valves 54, 57, 60, 61, 62 and 63 can each be activated by a control unit, for example by a control unit 64. The valves 60 to 63 can activate the blowing device 29, whereas the valves 54 and 57 can activate the cutting apparatus 9. This activating can be carried out during the movement of the tuck-in device 5 along the selvedge 27 of the fabric 3. It will be clear that, according to a variation, the various valves 54, 57, 60, 61, 62 and 63 can each be connected to an associated source of compressed air and do not necessarily all have to be connected to the same compressed air source 58. The various sources of compressed air can in this case supply compressed air of differing pressure. Throttling valves 85, 86, 87 and/or 88 can also be provided to adjust the stream of compressed air from the various blowing openings. The throttling valves can likewise be controlled by a control unit 64.
As is illustrated in Figures 1 and 2, a transverse support 65 is attached to the weaving machine. A thread holder 66, which can take up an end 23 of a beaten-up weft thread 19, is in this case also attached in proximity to the opposite side 17 of the shed 1. This thread holder 66 can consist of a suction mouth which enters into a guide channel 69 of the reed 13 during the beating-up of a weft thread in order to take up the end 23 of the beaten-up weft thread 19. The thread holder 66 can be fastened to the transverse support 65. In this embodiment, the thread holder 66 bends the end 23 of the weft thread 19 while the weft thread is taken up in the thread holder 66. Also shown is a further main nozzle 67 and a thread holder 68 which is attached at the level of the transverse support 65 in proximity to the insertion side 16 of the shed 1. The thread holders 66 and 68 can each be controlled by a valve system in order to be able to exert from the moment of the beating-up of the weft thread 19 the necessary force, for example suction force, on an end of the weft thread. A cutting apparatus 83 in the form of weft scissors can be attached to the transverse support 65 in order to cut a beaten-up weft thread 19 during beating-up in proximity to the end of the main nozzle 67. Fabric supports can also be attached to the transverse support 65 below and/or above each fabric 2 or 3 in order to support the fabric 2 and 3 and to position it during beating-up with respect to the guide channel 69 of the reed 13. The length of the fabric supports can be adapted to the width of the associated fabric 2 or 3. The reed 13 is secured to the sley profile 12 in a known manner using a clamped connection 84. The function of the thread holder 66 or 68 can obviously also be performed by what are known as binding warp threads which can bind the respective end of the weft thread or by a mechanical clamp which is attached at the level of the transverse support 65 in order to hold the respective end of the weft thread. A mechanical clamp of this type can, for example, be driven pneumatically, electrically or in a different manner.
In the embodiment of Figures 2 to 6, the housing 44 is attached to a fastening block 70 by a screwed connection 71 and the fastening block 70 is attached to the sley profile 12 by a screwed connection 72 which interacts with a fastening piece 73. The fastening block 70 comprises a positioning piece 74 which allows the fastening block 70 to be attached precisely with respect to the slot 45 in the sley profile 12. The fastening block 70 and the fastening piece 73 can be configured similarly to the fastening block and the fastening piece such as are known from EP 0395132 A1 . The housing 48 of the cutting apparatus 9 is attached to the sley profile 12 in a similar manner to the housing 44 of the tuck-in device 5, by means of a fastening block 78, a screwed connection 79, a screwed connection 80, a fastening piece 81 and a positioning piece 82.
Figures 7 and 8 show what is known as a double tuck-in device or middle tuck-in device comprising two tuck-in devices 6 and 7 and a common cutting apparatus 10. The two tuck-in devices 6 and 7 are configured similarly to the tuck-in device 5 shown in Figures 2 to 6 and are each attached to the sley profile 12 by a fastening block 70. The cutting apparatus 10 can be attached to the sley profile 12 of the sley 11 in a similar manner using a fastening block 78. As the tuck-in devices 6 and 7 are relatively narrow in their configuration, the fabrics 2 and 3 can be woven at a short distance from one another, which distance is determined by the length of the ends 21 and 22 to be tucked in of the weft thread 19. As the tuck-in devices 6 and 7 and also the cutting apparatus 10 are arranged in each position of the reed 13 before the reed 13, a continuous reed 13 can be used.
The operation of the tuck-in device 5 for tucking an end 23 of a weft thread 19 into a selvedge 27 of a fabric 3 is further illustrated with reference to Figures 9 to 16 and Figures 17 to 22. In the exemplary embodiments shown in Figures 9 to 22, the edge 15 of the fabric 3 is for the sake of simplicity in each case shown in substantially the same position and the edge 15 is in all cases represented at the level of the beating-up position of the beaten-up weft thread 19, despite the fact that during weaving this edge of the fabric is displaced together with the most recently beaten-up weft thread 19 over a small distance in the direction of advancement of the fabric.
After the insertion of a weft thread 19 into a shed 1, the weft thread 19 is moved toward the edge 15 of the fabric 3, as shown in the position of Figure 9. Subsequently, as shown in the position of Figure 10, the weft thread 19 is beaten against the edge 15 of the fabric 3 and an end 23 of the beaten-up weft thread 19 protrudes past the selvedge 27 of the fabric 3. The tuck-in device 5 serves to blow this end 23 of the weft thread 19 into a subsequent shed. The end 23 of the weft thread 19 is in this case also taken up and held by the thread holder 66. In this case, the tuck-in device 5, which is held by the sley 11, is moved by the sley 11 away from the edge 15 and moves in this case in synchronization with the reed 13 and along the selvedge 27 of the fabric 3.
Subsequently, the tuck-in device 5 moves together with the reed 13 away from the edge 15 of the fabric 3, which is formed by the most recently beaten-up weft thread 19. During the further movement away from the edge 15, the end 23 of the weft thread 19 enters the slot 28 in the tuck-in device 5 and this end 23 of the weft thread 19 is present on the tuck-in device 5, as shown in the position of Figure 11. The illustrated shape of the slot 28 allows this end 23 of the weft thread 19 to move along the slot 28 without being pressed away by the slot 28; in other words, the slot 28 can move over this end 23 of the weft thread 19 and/or optionally just touch this end 23 of the weft thread 19. The shape of the slot 28 also allows the slot 28 to move continuously over the extension of the edge 15 of the fabric 3 in the direction of or toward the reed 13 and together with the reed 13. Furthermore, the slot 28 has a funnel-shaped inlet to allow the end 23 of the weft thread 19 to be taken up by the slot 28 in a simple and operationally secure manner.
The tuck-in device 5 and the reed 13 move further away from the edge 15 by means of the sley 11 until a position as shown in Figure 12 is obtained. Shortly before the position of Figure 12 is reached, the valves 60 and 63 are activated so that blowing is carried out from the blowing openings 31, 34 and 37. In this case, the tuck-in device 5 moves further along this end 23 of the beaten-up weft thread 19. In the position of Figure 12, the end 23 of the weft thread 19 is cut once the valve 57 has been activated by means of the plunger 55 for carrying out a cutting movement with the cutting apparatus 9. At the moment of this cutting, a stream of compressed air is directed on the end 23 of the weft thread 19. In this exemplary embodiment, the tuck-in device 5 can move together with the reed 13 still further away from the edge 15 of the fabric 3. The cut-off part of the end 23 of the weft thread 19 can subsequently be removed in a known manner via the thread holder 66.
Subsequently, the reed 13 remains in the rearmost position, as shown in Figure 13, while the end 23 of the weft thread 19 continues to be blown on. In the meantime, the valves 61 and 62 were each activated at a set moment, so blowing is also carried out from the blowing openings 32, 33 and 35, 36. In this case, the end 23 of the weft thread 19 is bent and this end 23 of the beaten-up weft thread 19 can continue to be blown into a shed 1. As a result of the movement from the position of Figure 12 to the position of Figure 14, the end 23 of the weft thread 19 is blown by the resulting stream of compressed air from the openings 31 to 37 into a subsequent shed which has formed in the meantime. In the meantime, the valve 54 can be activated in order to re-prepare the cutting apparatus 9 for a subsequent cutting movement by means of the plunger 52. According to a variation (not shown), the cutting or activating of the valve 57 can be carried out in the position of Figure 13.
Subsequentely, the reed 13 and the tuck-in device 5 move back to the edge 15 of the fabric 3 while blowing from the blowing openings 31 to 37 continues as shown in Figure 14. In the meantime, a subsequent weft thread 19A may already have been inserted. Subsequently, the tuck-in device 5 and the reed 13 move in synchronization to the position of Figure 15 and the valves 60 and 63 are not further activated in the meantime. During the further movement to the position of Figure 16, the valves 61 and 62 can remain activated. According to a variation, in this case only the valve 62 can, for example, remain activated. In this case, the end 23 of the weft thread 19 is blown, during the movement to the positions of Figures 15 and 16, against the edge 15 of the fabric 3 by the resulting air stream from the blowing openings 32, 33 and 35, 36 moving toward the edge 15 of the fabric 3. As a result, the blowing-in or tucking-in of the end 23 of the weft thread 19 is completed while the reed 13 moves back toward the edge 15 of the fabric 3. After the tucking-in of the end 23 of the weft thread 19, this tucked-in end is beaten up, together with a subsequent weft thread 19A, by the reed 13 and a position similar to the position of Figure 10 is obtained, wherein blowing is no longer carried out from the blowing openings 31 to 37. Subsequently, the method according to Figures 9 to 16 can be repeated.
Activating the valves 60 to 63 according to a preset pattern allows the various blowing openings 31 to 37, which are formed next to one another in the direction of movement A of the tuck-in device 5, to blow according to a set pattern in various positions of the tuck-in device 5 in order to blow in a controlled manner an end 23 of a weft thread 19 into a subsequent shed in proximity to the edge 15 of the fabric 3. This sequential blowing from blowing openings as a function of the position of the sley 11, to which a tuck-in device 5 is attached, is advantageous for allowing the tucking-in of the end 23 of the weft thread 19 to be carried out in a controlled manner. This controlled blowing by the blowing device 29 according to the invention on an end 23 of a beaten-up weft thread 19, which is carried out during the movement of the tuck-in device 5 along the selvedge 17 of the fabric 3, is advantageous for tucking an end 23 of a weft thread 19 into a subsequent shed in an optimum manner with respect to an edge 15 of the fabric 3. The sequential interruption of blowing from blowing openings also prevents the fabric from being blown on; this is advantageous not only for saving compressed air but also for preventing damage to the fabric as a result of blowing on the fabric. If it is assumed that a weft thread is beaten up in the 0° position and the reed 13 furthest away from the edge of the fabric is located between 150° and 210°, more particularly at 180°, then a tuck-in device 5 according to the invention can generate a stream of compressed air of between 120° and 330° and the end to be tucked in of the inserted weft thread is, for example, cut at approximately 150° . The 330° position is usually just after crossing of the warp threads. Further blowing after crossing of the warp threads does not contribute to the tucking-in of the end of the weft thread that has already been bound and tucked in. The cutting or severing of the end of the weft thread can be carried out, for example, at between 150° and 210° and, for example, at 180°.
In the embodiment shown in Figures 17 to 22, the end 23 of the weft thread 19 is not cut and not blown into the subsequent shed during a first weaving cycle; instead, this end 23 of the weft thread 19 is blown, together with the end 23A of the weft thread 19A, into a subsequent shed. As is shown in Figures 17 and 18, the end 23 is hold beyond the extension of the edge 15 of the fabric 3 next to the selvedge 27 of the fabric 3 in the thread holder 66 and the slot 28 in the tuck-in device 5 moves over this end 23 without substantially touching this end 23. In the position of Figure 17, the tuck-in device 5 moves away from the edge 15, whereas in the position of Figure 18 the tuck-in device 5 is moved back to the edge 15. In the position of Figure 18, the subsequent weft thread 19A is likewise moved to the edge 15 of the fabric 3. In the position of Figure 19, the ends 23, 23A of both weft threads 19, 19A are held in the thread holder 66. The illustrated shape of the slot 28 allows the end 23, 23A of the weft thread 19, 19A to move along the slot 28 without substantially touching the slot 28 or at least without being substantially pushed away by the slot 28.
The shape of the slot 28 also allows the slot 28 to move continuously, together with the reed 13, over the extension of the edge 15 of the fabric 3 in the direction of or toward the edge 15 of the fabric 3 and along the ends 23, 23A of the weft threads 19, 19A. The position of Figure 20 is similar to the position of Figure 12 and in this case both weft threads 19, 19A are cut while the ends 23, 23A are already being blow on. The positions of Figures 21 and 22 are similar to the positions of Figures 13 and 14 and show that both ends 23, 23A are together blown into a subsequent shed. In the position of Figure 22, a subsequent weft thread 19B has already been inserted.
It will be clear that in a similar manner three or more ends of weft threads can together be blown into a subsequent shed. The tuck-in device according to the invention is particularly suitable for carrying out a method of the type in which a plurality of ends are together tucked in as the slot 28 in the tuck-in device can move over an end of a beaten-up weft thread while this end is located in the extension of the edge of the fabric or is held at this location.
The operation of the tuck-in device 6 and of the tuck-in device 7 is similar to the operation of the tuck-in device 5. As the ends 21 and 22 are held between the fabrics 2 and 3, no separate thread holder is required in proximity to the tuck-in devices 6 and 7. Both ends 21 and 22 are cut off from one another by the cutting apparatus 10 in a manner similar to that in which the end 23 is cut off by the cutting apparatus 9. It will be clear that the tuck-in device 6 blows in a blowing direction like that of the tuck-in device 5 and that the tuck-in device 7 blows in a blowing direction opposing the blowing direction of the tuck-in device 5.
The operation of the tuck-in device 4 is similar to the operation of the tuck-in device 6. As, however, the weft thread 19 is guided by the main nozzle 67, the weft thread 19 should be cut by the cutting apparatus 83 during beating-up. In this case, the end 20 of the cut weft thread 19 can be taken up and held by a thread holder 68. The thread holder 68 can be configured and controlled in a similar manner to the thread holder 66. Before the end 20 of the weft thread 19 is tucked into a subsequent shed, this end can be cut to the desired length by means of the cutting apparatus 8. Such an embodiment can advantageously be used in a gripper weaving machine and is also possible in an airjet weaving machine.
In the embodiments shown, the distance between the cutting apparatuses and the selvedge of the fabric determines the length of the ends to be tucked in of the weft thread. The housing 44 of the various tuck-in devices if, for example, attached at a specific distance from the selvedge of the fabric irrespective of the length of the end to be tucked in of the weft thread. A tuck-in device according to the invention also has the advantage that the housing 44 can be relatively narrow in its configuration, thus allowing ends of a relatively short weft thread to be tucked in. In order to limit the width of the housing 44 comprising the connection pieces 40 to 43, the connection pieces 40 to 43 can be attached laterally toward the cutting apparatuses at the level of the housing 44. The latter aspect allows the housing 44 to be arranged relatively close to the fabric. The attaching of the connection pieces 40 to 43 in a row also allows the lines for supplying compressed air to the connection pieces to be ordered, so that said supply lines can be attached next to one another in a neat and compact manner.
As the blowing openings of a tuck-in device according to the invention blow for the most part substantially parallel to the longitudinal direction B of the sley 11 and are also attached at a distance from the reed 13, the stream of compressed air of the tuck-in device can never disturb the stream of compressed air for inserting a weft thread into a guide channel 69 at the level of the reed 13, as said streams of compressed air are in all cases generated at a distance from one another.
One advantage of the invention is that the reed 13 is arranged in all cases at a distance from the tuck-in devices; this allows use to be made of a reed 13 which is continuous in its configuration at the level of the tuck-in devices. This allows the tuck-in devices to be displaced along the longitudinal direction B of the sley 11 without the need for adaptation to the reed 13. This allows, inter alia, a narrow fabric to be woven with a longer reed. The ability to use a continuous reed is beneficial above all for the tuck-in devices 6 and 7, which are arranged between two fabrics, and for the tuck-in device 5 on the opposite side 17 of the shed 1. This also allows, with a single continuous reed, two or more fabrics, which can each be provided with tucked-in selvedges, to be woven next to one another using a tuck-in device according to the invention.
However, the tuck-in device in proximity to the insertion side 16 can usually be arranged next to the reed so that said tuck-in device used does not necessarily have to be a tuck-in device 4 according to the invention but can, for example, be a tuck-in device according to the prior art, such as a tuck-in device according to WO 01/86047 A1 . In the case of a tuck-in device 4 according to the invention, the cutting apparatus 8, which moves together with the sley 11, can be omitted according to a variation if the end 20 of the weft thread 19 can be cut to a desired length by the fixedly arranged cutting apparatus 83. In order to be able to adjust the length of the tucked-in ends, the cutting apparatus 83 can in this case be attached so as to be adjustable in the longitudinal direction B of the sley 11. If, in the case of an airjet weaving machine, the reed 13 is continuous in proximity to the main nozzle 67, a tuck-in device 4 according to the invention can advantageously be used.
It will be clear that the blowing openings 31 to 37 do not necessarily have to be provided in the form of holes in a housing 44. According to a variation, blowing openings of this type can likewise be formed so as to be adjustable with respect to a housing in order to be able to blow in a desired direction, for example in a manner such as is known from WO 01/86047 A1 . It will likewise be clear that the supply of compressed air is not limited to a system with the illustrated valves and source of compressed air but that use may likewise be made of a variant system comprising, for example, also throttling valves and the like. It will likewise be clear that, according to a variation (not shown), the various blowing openings 31 to 37 can, for example, each be provided with a separate valve system of compressed air or can be divided into different groups as desired. The various groups can comprise blowing openings which differ, for example, in number, in size and/or in blowing direction. According to a variation (not shown), the blowing openings can interact with one single valve system in order to provide compressed air at the blowing openings. According to a further variation (not shown), the blowing device 29 can comprise at least one blowing opening, more particularly just one single blowing opening. According to a further variation (not shown), the blowing device 29 can comprise at least one slotted blowing opening which is formed, for example, in proximity to the slot 28, more particularly above the slot 28 and/or below the slot 28.
According to a variation (not shown), the holders 44 and 48 can likewise be configured in one piece. One-piece holders of this type can likewise be fastened to the sley profile 12 using an associated fastening block. It will be clear that, according to a variation (not shown), the holders 44 and 48 can likewise be fastened to the sley profile 12 directly, i.e. without making use of a fastening block 70 or 78 attached therebetween. In this case, the holders 44 and 48 can, for example, be provided with an associated positioning piece.
The separate fastening of a tuck-in device and a cutting apparatus allows the distance therebetween to be adjusted in a simple manner and the length of the ends to be tucked in of the weft thread thus to be adjusted. If the tuck-in device and the cutting apparatus are mounted on a single holder, the length of the end to be tucked in can, for example, be adjusted using cutting blades extending over a specific axial distance with respect to their fastening, for example axially extended cutting blades.
According to a variation, the holder 44 can likewise be fastened to the holder 48 or the holder 48 can be fastened to the holder 44. The holder 44 and the holder 48 can then together be fastened to the sley. In this case, the distance from the end to be tucked in can, for example, be adjusted by attaching thickness plates between the holder 44 and the holder 48 or by displacing the assembly as a whole along the sley in accordance with the width of the fabric.
Although it is particularly advantageous, it will be clear that the cutting apparatuses 8 to 10 do not necessarily have to be activated pneumatically. According to a variation, cutting apparatus of this type can also be activated electrically, for example by an electric motor. A pneumatic drive device has the advantage that it can be configured so as to be light and compact and is suitable for moving in conjunction with the sley.
It will be clear that the invention can be used most advantageously for tuck-in devices 6, 7 which are arranged between two fabrics 2, 3, as such tuck-in devices 6, 7 according to the invention allow the use of a continuous reed 13. Although it is likewise advantageous to use a tuck-in device 5 according to the invention on the opposite side 17 of the shed 1, if use is made of a reed 13 having a suitable length, a known tuck-in device can likewise be used on the opposite side 17 of the shed 1, for example a tuck-in device such as is known from WO 01/86047 A1 . Obviously, it is also possible to attach a number of tuck-in devices according to the invention and a number of known tuck-in devices to a specific weaving machine in a different manner.
A tuck-in device according to the invention allows suitable blowing openings to be formed as desired and blowing to be carried out in a suitable manner as desired via blowing openings, even while the tuck-in device is moving, so that even at high weaving speeds there is still sufficient time to blow an end of a weft thread into a subsequent shed.
The invention can be used in a plurality of types of weaving machines such as, for example, airjet weaving machines, gripper weaving machines, projectile weaving machines, water jet weaving machinges and other types of weaving machines. A tuck-in device according to the invention can be attached to a weaving machine as a module.
A tuck-in device and a method according to the invention are obviously not limited to the exemplary embodiments which have been illustrated and described but can also include variations and combinations thereof which fall under the scope of the claims. A pneumatic tuck-in device according to one of the claims is particularly suitable for carrying out a method according to one of the claims.

Claims

Method for tucking an end (20, 21, 22, 23, 23A) of a weft thread (19) into a selvedge (24, 25, 26, 27) of a fabric (2, 3) by means of a pneumatic tuck-in device (4, 5, 6, 7) which blows an end (20, 21, 22, 23, 23A) of an inserted and beaten-up weft thread (19) extending past a selvedge (24, 25, 26, 27) of the fabric (2, 3) into a subsequent shed (1), characterized in that the tuck-in device (4, 5, 6, 7) is moved back and forth along the selvedge (24, 25, 26, 27) of the fabric (2, 3) in synchronization with the reed (13) and in that the blowing in of this end (20, 21, 22, 23, 23A) of the beaten-up weft thread (19) into a shed (1) is carried out while the tuck-in device (4, 5, 6, 7) moves along the selvedge of the fabric.
Method according to Claim 1, characterized in that the blowing-in of the end (20, 21, 22, 23, 23A) of the weft thread (19) is completed while the reed (13) moves back to the edge (14, 15) of the fabric (2, 3).
Method according to Claim 1 or 2, characterized in that the pneumatic tuck-in device (4, 5, 6, 7) is provided with a plurality of blowing openings (31; 32, 33, 34; 35, 36, 37) which are formed next to one another in the direction of movement (A) of the tuck-in device (4, 5, 6, 7) and which blow in various positions of the tuck-in device (4, 5, 6, 7).
Method according to one of Claims 1 to 3, characterized in that the weft thread (19) is cut while a stream of compressed air is directed on the end (20, 21, 22, 23, 23A) of the weft thread (19) and while the reed (13) is moved away from the edge (14, 15) of the fabric (2, 3).
Pneumatic tuck-in device for tucking an end (20, 21, 22, 23, 23A) of a weft thread (19) into a selvedge (24, 25, 26, 27) of a fabric (2, 3), comprising a blowing device (29) for blowing in an end (20, 21, 22, 23, 23A) of an inserted and beaten-up weft thread (19) extending past a selvedge (24, 25, 26, 27) of the fabric (2, 3) into a subsequent shed (1), characterized in that the tuck-in device (4, 5, 6, 7) is held by a sley (11), so that the tuck-in device (4, 5, 6, 7) moves back and forth in synchronization with the reed (13), and in that the tuck-in device (4, 5, 6, 7) comprises a blowing device (29) for blowing on this end (20, 21, 22, 23, 23A) of the beaten-up weft thread (19) during the movement of the tuck-in device (4, 5, 6, 7) along the selvedge (24, 25, 26, 27) of the fabric (2, 3).
Tuck-in device according to Claim 5 characterized in that the tuck-in device (4, 5, 6, 7) is attached to a sley profile (12) of the sley (11) so as to be adjustable in the longitudinal direction (B) of the sley (11).
Tuck-in device according to one of Claims 5 or 6, characterized in that the blowing device (29) comprises a plurality of blowing openings (32, 33, 34; 35, 36, 37) which are arranged next to one another in the direction of movement (A) of the tuck-in device (4, 5, 6, 7).
Tuck-in device according to one of Claims 5 to 7, characterized in that the blowing openings (31; 32, 33, 34; 35, 36, 37) of the blowing device (29) are combined in groups which can be activated independently of one another.
Tuck-in device according to one of Claims 5 to 8, characterized in that the tuck-in device (4, 5, 6, 7) comprises a slot (28) which extends in the direction of movement (A) of the tuck-in device (4, 5, 6, 7) and which can take up an end (20, 21, 22, 23, 23A) of a beaten-up weft thread (19) while the tuck-in device (4, 5, 6, 7) moves along the selvedge (24, 25, 26, 27) of the fabric (2, 3) .
Tuck-in device according to Claim 9, characterized in that a number of blowing openings (31; 32, 33, 34; 35, 36, 37) are arranged along the slot (28), preferably above and below the slot (28) in the direction of movement (A) of the tuck-in device (4, 5, 6, 7).
Tuck-in device according to one of Claims 9 or 10, characterized in that blowing openings (32, 33, 34; 35, 36, 37) are arranged next to one another in a row (38; 39).
Tuck-in device according to one of Claims 9 to 11, characterized in that the slot (28) is arranged in such a way that the slot (28) is continuously movable over an extension of the edge (15) of the fabric (3).
Tuck-in device according to one of Claims 5 to 12, characterized in that a cutting apparatus (8, 9, 10) for cutting an end (20, 21, 22, 23, 23A) of a beaten-up weft thread (19) is attached at a distance from the selvedge (24, 25, 26, 27) of the fabric (2, 3).
Tuck-in device according to Claim 13, characterized in that the cutting apparatus (8, 9, 10) comprises a cutting blade (49) which can be activated pneumatically.
Tuck-in device according to one of Claims 5 to 12, characterized in that the tuck-in device (6, 7) can be arranged between two fabrics (2, 3).