WO2014053377A2 - Device and method for monitoring a weft thread - Google Patents
Device and method for monitoring a weft thread Download PDFInfo
- Publication number
- WO2014053377A2 WO2014053377A2 PCT/EP2013/069994 EP2013069994W WO2014053377A2 WO 2014053377 A2 WO2014053377 A2 WO 2014053377A2 EP 2013069994 W EP2013069994 W EP 2013069994W WO 2014053377 A2 WO2014053377 A2 WO 2014053377A2
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- WO
- WIPO (PCT)
- Prior art keywords
- weft thread
- guide channel
- air guide
- monitoring
- detector
- Prior art date
Links
- 238000012544 monitoring process Methods 0.000 title claims abstract description 31
- 238000000034 method Methods 0.000 title claims abstract description 10
- 238000009941 weaving Methods 0.000 claims abstract description 34
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 15
- 238000003780 insertion Methods 0.000 claims description 31
- 230000037431 insertion Effects 0.000 claims description 31
- 238000001514 detection method Methods 0.000 claims description 27
- 239000004744 fabric Substances 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 4
- 229920002994 synthetic fiber Polymers 0.000 claims description 3
- 235000014676 Phragmites communis Nutrition 0.000 description 10
- 230000003247 decreasing effect Effects 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000007664 blowing Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
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- D—TEXTILES; PAPER
- D03—WEAVING
- D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
- D03D47/00—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms
- D03D47/28—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed
- D03D47/30—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed by gas jet
- D03D47/3066—Control or handling of the weft at or after arrival
- D03D47/3073—Detection means therefor
-
- D—TEXTILES; PAPER
- D03—WEAVING
- D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
- D03D47/00—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms
- D03D47/28—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed
- D03D47/30—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms wherein the weft itself is projected into the shed by gas jet
- D03D47/3066—Control or handling of the weft at or after arrival
- D03D47/308—Stretching or holding the weft
-
- D—TEXTILES; PAPER
- D03—WEAVING
- D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
- D03D51/00—Driving, starting, or stopping arrangements; Automatic stop motions
- D03D51/18—Automatic stop motions
- D03D51/34—Weft stop motions
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- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Looms (AREA)
Abstract
Device and method for monitoring a weft thread in a weaving machine comprising a second weft thread detector (10) for providing a signal when an inserted weft thread exceeds its length by a predetermined amount and an air guide channel (11) located upstream of the second weft thread detector (10), wherein the second weft thread detector (10) is mounted on a sley (500) of a weaving machine and wherein the air guide channel (11) is arranged stationary on the weaving machine.
Description
Device and Method for Monitoring a Weft Thread
Description
The invention relates to a device for monitoring a weft thread in a weaving machine comprising a weft thread detector for providing a signal when an inserted weft thread exceeds its length by a predetermined amount and an air guide channel located upstream of the weft thread detector, wherein the weft thread detector is mounted on a sley of a weaving machine. The invention further relates to a method for monitoring a weft thread in a weaving machine.
A weft thread detector arranged at the arrival side of a weaving machine for monitoring an arrival of an inserted weft thread is known and is called hereafter first weft thread detector or arrival detector for weft thread.
A weft thread detector for providing a signal when an inserted weft thread exceeds its length by a predetermined amount is called hereafter second weft thread detector. The expression "second weft thread detector" is not to be construed as an indication of the number of weft thread detectors. In one embodiment, the second weft thread detector is used as only weft thread detector, i.e. without a first weft thread detector.
The terms "first weft thread detector" and "second weft thread detector" rather denote an order in which the weft thread detectors are arranged in the insertion direction. The second weft thread detector is also called broken-weft thread detector.
A device for monitoring a weft thread in a weaving machine comprising a first weft thread detector and a second weft thread detector are known in the prior art. For example, GB 2 1 19 819 A discloses a device comprising a first weft thread detector, a suction device for weft thread and a second weft thread detector fixed in succession on a support of a sley of a weaving machine. The suction device is provided for catching and stretching inserted weft threads at the arrival side. A jet of air leaving the suction device without being deflected does not reach the detection zone of the second weft thread detector. The device comprises a deflection finger. The finger is located between the outlet of the suction device and the second weft thread detector and fixed to the frame of the weaving machine perpendicular to the insertion path. During beat-up, the finger is brought in the range of the jet of air and the jet of air is deflected towards the detection zone of the second weft thread detector. A weft thread present in the jet of air when the finger is located in the range of the jet of air, will be deflected towards the second weft thread detector and will be detected by the second weft thread detector.
US 4,432,399 discloses a device for monitoring a weft thread in a weaving machine, comprising a first weft thread detector for providing a stop signal when the inserted weft thread does not reach its normal length and a second weft thread detector spaced from the first weft thread detector for providing a signal when the inserted weft thread exceeds its normal length by a predetermined amount. Between the two weft thread detectors, an air guide channel is arranged for bridging the
space between the two weft thread detectors, which air guide channel lies in the extension of the insertion path. The two weft thread detectors and the air guide channel are arranged in order to move with the reed. It is the object of the invention to provide a device and a method for monitoring a weft thread allowing a reliable detection of inserted weft threads that exceed their length by a predetermined amount, i.e. inserted weft threads extending too far outside the shed. This object is solved by a device and a method with the features of claims 1 and 15.
According to a first aspect of the invention, a device is provided for monitoring a weft thread in a weaving machine comprising a second weft thread detector for providing a signal when an inserted weft thread exceeds its length by a predetermined amount and an air guide channel located upstream of the second weft thread detector, wherein the second weft thread detector is mounted on a sley of a weaving machine and the air guide channel is arranged stationary on the weaving machine.
In other words, the air guide channel is arranged in a fixed position with respect to the frame of the weaving machine, whereas the second weft thread detector is mounted on the sley and moves with the reed during beat-up.
In preferred embodiments, an arrival detector for weft thread is provided upstream of the air guide channel, i.e. a weft thread detector for detecting the arrival of a weft thread is provided, more particularly a first weft thread detector.
The first weft thread detector and the second weft thread detector are both mounted on the sley in the extension of the reed, wherein the first weft thread detector is arranged upstream of the air guide channel and the second weft thread detector is arranged downstream of the air guide channel.
Weft thread detectors generally have a limited detection zone. A weft thread is only detected when the weft thread reaches the detection zone. The first weft thread detector is arranged close to the end of the reed, wherein relay nozzles provided for an insertion of a weft thread blow the weft thread in the detection zone of the first weft thread detector.
A second weft thread detector for detecting weft threads that extend too far outside a shed, for example broken weft threads, is also called broken-weft thread detector. Such a second weft thread detector is arranged downstream of the first weft thread detector in the insertion direction. By providing an air guide channel, the air flow is directed to an area allowing the second weft thread detector to detect a weft thread transported by the air flow. In accordance with the invention, the air guide channel is arranged stationary. Therefore, the weft thread end leaving the air guide channel is presented at a presenting area allowing a more reliable detection. The presenting area is determined by the shape and/or position of the air guide channel. The shape and/or position may be chosen to minimize the influence of the movement of the weft thread through the air guide channel and/or to minimize forces acting on the weft thread moving through the air guide channel at least in a zone of the air guide channel. Hence, an insertion of a weft thread upstream of the air guide channel is not or only slightly influenced by the transport of the weft thread through the air guide channel. In addition, a movement of the second weft thread detector with respect to the presented weft thread does not or only slightly influence the insertion of weft threads upstream of the air guide channel.
According to an embodiment, the air guide channel is configured to present a weft thread in a presenting area traversed by a detection zone of the second weft thread detector during beat-up. To this end, in one embodiment an air flow leaving the outlet opening of the air guide channel is channelled to the presenting area, which is chosen so that the detection zone of the second weft thread detector traverses the air flow leaving the outlet opening during beat-up. An end of for example a broken weft thread transported by the air flow will be presented in the presenting area. The second weft thread detector is mounted on the sley and moves during beat-up, wherein the detection zone traverses the presenting area. In result, an effective detection zone of the second weft thread detector is traversed. Therefore, a more reliable detection is ensured. In other words, during insertion the air guide channel does not necessarily guide the air flow towards the detection zone of the second weft thread detector, but rather to a presenting area in front of the detection zone during insertion, wherein during beat-up the detection zone is moved towards and across this presenting area and in this way traverses the presenting area. In the context of the application, a "presenting area in front of the detection zone" is defined an area that is located opposite the side of the second weft thread detector that in use is directed to the fabric and where a leading end-part of a weft thread extending outside the air guide channel can be located. In one embodiment, a weft thread stretching device is provided in the extension of an insertion path of the weft thread upstream of the air guide channel, which weft thread stretching device is configured for catching end-parts of inserted weft threads, wherein preferably the air guide channel bridges at least 50%, more preferably at least 70%, in particular at least 80% of the distance between the weft thread stretching device and the second weft thread detector. In one embodiment the weft thread stretching device comprises a suction
nozzle, more in particular a ring-jet suction nozzle. In the context of the application, a ring-jet suction nozzle is defined as a suction device, wherein a suction effect is obtained by blowing compressed air into the suction device. Compressed air used for catching inserted weft threads is used to transport a weft thread through the air guide channel. The air guide channel is in preferred embodiments provided in the extension of the cross-section of the suction nozzle at an outlet side of the suction nozzle. In one embodiment, the air guide channel fits well with the outlet opening of the weft thread stretching device, more particularly with the outlet opening of the suction nozzle of the weft thread stretching device. In this case, efficient use of the air flow through the suction nozzle is made to transport the weft thread towards the presenting area, in particular to a presenting area in front of the detection zone of the second weft thread detector.
In preferred embodiments, the air guide channel comprises a tube, in particular a straight tube. The tube provides a closed air guide channel, wherein an air flow through the tube is not or only slightly disturbed by external influences. In addition, when providing a straight tube, forces acting on the weft thread while the weft thread is moving through the tube are minimised and the movement of the weft thread through the tube does not or only slightly influences an insertion of the weft threads upstream of the tube. The air guide channel also allows guiding a weft thread through the air guide channel.
According to an embodiment, the tube has an inlet opening having a circular cross-section. In particular when providing a ring-jet suction nozzle a tube having a circular cross-section allows a smooth transition of the air flow from the suction nozzle to the air guide channel.
The air guide channel is shaped to channel the air flow towards the presenting area. For this purpose, in one embodiment, the air guide channel comprises a nozzle-shaped end-part arranged at an outlet side of the air guide channel. In order to limit the presenting area of the air flow leaving the air guide channel, in preferred embodiments, the nozzle-shaped end-part has a flattened outlet opening, in particular an outlet opening with an oval cross-section. In the context of the application, the height of the outlet opening is defined as the dimension in the direction perpendicular to the insertion path of a weft thread and perpendicular to the beat-up direction.
In one embodiment, the nozzle-shaped end-part and the tube are manufactured as separate parts and fixed to each other. The nozzle-shaped end-part in one embodiment is detachably fixed to the tube, allowing for a replacement of the end-part. In other embodiments, the nozzle-shaped end-part is permanently fixed to the tube, in particular glued or welded to the tube. In still another embodiment, the nozzle-shaped end-part and the tube are formed in one piece. The shape of the air guide channel is preferably optimized for minimizing a contact of internal walls with the weft thread. However, a weft thread may still make contact with the internal wall of the air guide channel, in particular at an end-part of the air guide channel. Therefore, in one embodiment at least in the vicinity of the internal wall of the air guide channel a wear-resistant coating and/or a wear-resistant insert is provided in a weft thread contact area of the air guide channel, more in particular in an area of the air guide channel directed to the fabric.
In one embodiment, the air guide channel is at least partly made, in particular at least in the vicinity of the internal wall, of a material having a low frictional resistance to air and weft threads, in particular a synthetic material, for example a polyvinyl chloride reinforced with fillers.
In still another embodiment, the first weft thread detector for detecting the arrival of a weft thread and the second weft thread detector for providing a signal when an inserted weft thread exceeds its length by a predetermined amount are configured for optically monitoring the weft thread. In preferred embodiments, both weft thread detectors work on the same operating principle. In particular, optical weft thread detectors as described in EP 0 943 024 B1 are used, the content of which is herewith incorporated by reference.
In one embodiment, a detection zone of a first and/or second weft thread detector extends between an upper part and a lower part of the weft thread detector. In the context of the application, the upper part and the lower part of the weft thread detector are defined as parts of the weft thread detector arranged above and below an insertion path as seen in a direction approximately perpendicular to a fabric, i.e. in the direction of the height of the air guide channel.
According to a second aspect, a method is provided for monitoring a weft thread with a device comprising a second weft thread detector for providing a signal when an inserted weft thread exceeds its length by a predetermined amount which is mounted on a sley of a weaving machine and an air guide channel, which air guide channel is located upstream of the second weft thread detector, wherein the air guide channel is arranged stationary on the weaving machine and channels an air flow to a presenting area, and a detection zone of the second weft thread detector is moved through the presenting area during beat-up.
Further features and advantages of the invention will emerge from the following description of the embodiments illustrated in the drawings, wherein
is a schematic top view of a part of a weaving machine with a device according to an embodiment of the invention; is a perspective view of a part of the weaving machine shown in figure 1 in a position during insertion of a weft thread; is a front view of an embodiment of a nozzle-shaped end-part; is a cross-section along a line A-A in figure 3; is a front view of a weft thread detector and the nozzle-shaped end-part during insertion; is a front view of a weft thread detector and the nozzle-shaped end-part of figure 5 during beat-up; is a front view of a weft thread detector and the nozzle-shaped end-part of figure 6 during further beat-up; figure 8: is a perspective view of a part of the weaving machine shown in figure 2 in a position during beat-up of a weft thread; figures 9 and 10; figures 1 1 and 12, figures 13 and 14;
figures 15 and 16; and figures 17 and 18
are respectively variant embodiments of figures 3 and 4; figure 19: is a top view of an air guide channel provided with the nozzle-shaped end-part of figures 17 and 18; figure 20 is a perspective view of figure 19.
Figure 1 is a schematic top view of a part of a weaving machine, more particularly of an air-jet weaving machine, with a device 1 for monitoring a weft thread comprising a second weft thread detector 10 according to a first embodiment of the invention during insertion of a weft thread 2. Fig. 2 shows a perspective view of a part of a weaving machine similar to Fig. 1 .
The weft thread 2 is inserted in a shed formed by selectively raising and lowering warp threads 3. During insertion, the weft thread 2 is supported by relay nozzles 4 and guided in an insertion channel 509 (see Fig. 2) through a reed 5. The insertion channel 509 mainly determines the insertion path of the weft thread. In the embodiment shown, a first weft thread detector 6, also called arrival detector for weft thread, is arranged on the sley 500 (see Fig. 2) at the end of the insertion channel 509 next to the reed 5 in order to detect the arrival of the weft thread 2.
The leading end-part 2f of the inserted weft thread 2 is caught and stretched with a predetermined tension by a weft thread stretching device 7, such as a suction nozzle. As schematically shown, the weft thread stretching device 7 is arranged stationary on the weaving machine in an extension of an insertion path of the weft thread 2, for example by means of a support beam 700.
The reed 5 is attached to the sley 500 and is moved in beat-up direction B towards a beat-up line 800 of a fabric 8 for a beat-up movement, in short beat-up. The weft thread 2, of which the leading end-part 2f is caught and stretched by the weft thread stretching device 7, as schematically shown in Fig. 1 , is moved with the reed 5 towards the beat-up line 800 and is beaten-up into the fabric 8.
In accordance with the embodiment shown in Fig. 1 , a weft thread holding device 9 is arranged stationary on the weaving machine in an
area of a beat-up line 800 for holding the leading end-parts of a number of beaten-up weft threads 2d. As mentioned above, the weft thread stretching device 7 is also arranged stationary on the weaving machine, at a distance from the beat-up line 800 in the extension of an insertion path of the weft thread 2. In one embodiment, a movable guiding device 91 is provided for guiding the caught leading end-part 2f of the weft thread 2 towards the weft thread holding device 9. The guiding device 91 is fixed on the sley 500. A cutting device 92 is provided between a fabric edge 801 of the fabric 8 and the weft thread holding device 9 for cutting the ends of the weft threads after they are bound by the warp threads 3. The cutting device 92 is arranged close to the fabric edge 801 for minimizing the length of the ends of the bound weft threads protruding from the fabric 8. The cut-off ends are removed via a duct (not-shown) provided to the weft thread holding device 9. Further also an optional suction device 12 for removing faulty inserted weft threads is shown schematically.
In the embodiment shown, the weft thread stretching device 7 is a ring-jet suction nozzle. The weft thread stretching device 7 is connected to a compressed-air tank (not shown) in order to obtain a suction effect.
The device 1 for monitoring a weft thread according to the invention comprises a second weft thread detector 10 for providing a signal when an inserted weft thread exceeds its length by a predetermined amount. The second weft thread detector 10 is mounted on the sley 500 of the weaving machine and moves together with the sley 500. In the embodiment shown, the second weft thread detector 10 is mounted on the sley 500 in line with the first weft thread detector 6. Further, an air guide channel 1 1 is provided, which is located upstream of the second weft thread detector 10 seen in the insertion direction of
the weft thread. The air guide channel 1 1 is arranged fixed in a position with respect to the frame of the weaving machine.
As schematically shown, the air guide channel 1 1 is arranged at the outlet side of the weft thread stretching device 7, in an extension of an insertion path of the weft thread 2 by means of a support beam 700. In the embodiment, the air guide channel 1 1 fits well with an outlet opening of the weft thread stretching device 7 configured as suction nozzle. The air guide channel 1 1 bridges mainly the distance between the weft thread stretching device 7 and the second weft thread detector 10, more in particular bridges at least 80% of the distance between the weft thread stretching device 7 and weft thread detector 10.
In an embodiment shown, the air guide channel 1 1 comprises a straight tube 1 10 having an inlet opening having a circular cross-section and a nozzle-shaped end-part 1 12 arranged at the outlet side of the air guide channel 1 1 . In the embodiment shown, the nozzle-shaped end-part 1 12 is mounted on the straight tube 1 10. The air guide channel 1 1 is manufactured at least at the vicinity of the internal wall of a material having a low frictional resistance to air and a low frictional resistance to weft threads, for example a synthetic material.
Fig. 3 shows a front view and Fig. 4 a cross-section along a line A-A in Fig. 3 of an embodiment of a nozzle-shaped end-part 1 12. Other exemplary embodiments of nozzle-shaped end-parts 1 12 are shown in Figures 9 to 18 and will be described with reference to these figures below.
As shown in Figs. 3 and 4, the nozzle-shaped end-part 1 12 has a flattened outlet opening 1 12a. In the embodiment shown the outlet opening 1 12a has an oval cross-section. At the inlet opening 1 12b the nozzle-shaped end-part 1 12 has a circular cross-section that fits well
with the cross-section of the tube shown in Fig. 2. A channel 1 1 2c is provided between the inlet opening 1 1 2b having a circular cross-section and the flattened outlet opening 1 12a. In the context of the application, the length of the nozzle-shaped end-part 1 1 2 is defined as the dimension in the direction of an insertion path of a weft thread. The width of the nozzle-shaped end-part 1 1 2 is defined as the dimension in the beat-up direction B, i.e. in the direction of a movement path of the weft thread during beat-up. The height of the nozzle-shaped end-part 1 12 is defined as the dimension in the direction perpendicular to the insertion path and perpendicular to the beat-up direction B. As shown in the cross-section of Fig. 3, in this embodiment, a width of the channel 1 12c is approximately constant over the length of the nozzle-shaped end-part 1 1 2. A height of the channel 1 1 2c through the nozzle-shaped end-part 1 12 decreases for channelling the air flow through the nozzle-shaped end-part 1 1 2 to a presenting area. As seen in Fig. 3, the flattened outlet opening 1 1 2a is slightly curved upwards with respect to a center line in order to adapt the course of the flattened outlet opening 1 12a to the beat-up direction B. For fixing the nozzle-shaped end-part 1 12 an annular space 1 12d for receiving the tube 1 1 0 (see Fig. 2) is provided at the inlet side of the nozzle-shaped end-part 1 12. Further, an insert 1 1 2e, for example a rod, near the outlet opening 1 1 2a, is provided. The insert 1 1 2e is made wear-resistant, for example, comprises a wear-resistant coating and/or is made of a wear-resistant material. The insert 1 12e can co-operate during beat-up with an end-part 2f (see Fig. 1 ) of a weft thread 2 extending between the nozzle-shaped end-part 1 1 2 and the second weft thread detector 1 0. Herewith the wear-resistant insert 1 1 2e is provided in a weft thread contact area of the air guide channel 1 1 , more in particular in an area of the air guide channel 1 1 directed to the fabric 8.
During beat-up, the second weft thread detector 10 and the first weft thread detector 6 which are both mounted on the sley 500, are moved in the beat-up direction B as shown in Fig. 1 . Figs. 5 to 7 show a front view of a second weft thread detector 10 and the nozzle-shaped end-part 1 12 during the beat-up direction B at successive instants in time. The second weft thread detector 10 is configured for optically monitoring weft threads. The second weft thread detector 10 is, in a known way, fixed by fixation means 15 to the sley 500 (see Fig. 1 ). In the embodiment shown, the second weft thread detector 10 is provided with a guiding opening 10a arranged in the extension of the insertion channel 509 of the reed 5 (see Fig. 2). The shape of the guiding opening 10a of the second weft thread detector 10 is similar to the shape of the dents of the reed 5. The guiding opening 10a is limited by an upper leg 10b and a lower leg 10c, wherein light rays are directed transversely through the guiding opening 10a between the upper leg 10b and the lower leg 10c. In other words, a detection zone of the second weft thread detector 10 extends between an upper part and a lower part of the weft thread detector 10 perpendicular to an insertion path. The first weft thread detector 6 is, for example, configured similar to the second weft thread detector 10. Examples of weft thread detectors suitable to be used as the second weft thread detector 10 and/or the first weft detector 6 are described in EP 0 943 024 B1 . The air guide channel 1 1 , more in particular the nozzle-shaped end-part 1 12, is configured to present the weft thread in a presenting area. As shown in Figs. 5 to 7, the presenting area is chosen such that it is traversed by the detection zone of the second weft thread detector 10 during beat-up. As described above, the presenting area at which a weft thread is presented to the second weft thread detector 10 is determined by the position and/or the shape of the air guide channel 1 1 . In the context of the application, the presenting area is determined by the area
of the leading end-part 2f extending beyond the nozzle-shaped end-part 1 12. In the embodiment of Fig. 5, for example, the leading end-part 2f determining the presenting area is located approximately beyond the centre of the nozzle-shaped end-part 1 12. The presenting area is traversed in this embodiment by the detection zone of the second weft thread detector 10 in positions located near the positions shown in Figs. 6 and 7, such as the position of Fig. 8.
Figs. 9 to 18 show exemplary embodiments of nozzle-shaped end-parts 1 12. The nozzle-shaped end-parts 1 12 shown in Figs. 3 to 4 and 9 to 18 are similar in shape and common reference numbers will be used for similar or common elements. In all embodiments, the nozzle-shaped end-part 1 12 has a flattened outlet opening 1 12a with an oval cross-section and an inlet opening 1 12b with a circular cross-section that fits well on the cross-section of the tube 1 10 shown in Fig. 2. A channel 1 12c is provided between the inlet opening 1 12b and the flattened outlet opening 1 12a. The presenting area at which weft threads are presented to the second weft thread detector 10 is determined by the shape of the outlet opening 1 12a, its width, its height and its position with respect to the insertion path.
As mentioned above, the presenting area is chosen such that the presenting area is traversed by the detection zone of the second weft thread detector 10 during beat-up. Therefore, the height of the flattened outlet opening 1 12a is chosen in order that the presenting area is located between the upper leg 10b and the lower leg 10c of the second weft thread detector 10 during beat-up (see Figs. 5 to 7). However, within these boundary conditions, it is possible to vary the height. The width of the flattened outlet opening 1 12a and/or its offset with respect to a longitudinal axis of the weft thread stretching device 7 (see Fig. 2) in the beat-up direction B can also be varied in order to ensure that the
presenting area is traversed by the detection zone of the second weft thread detector 10.
As the comparison of Figs. 3 and 4 and Figs. 9 and 10 shows, the embodiment of Fig. 9 differs from the embodiment of Fig. 3 in that a height of the flattened outlet opening 1 12a is decreased for decreasing the presenting area. However, a width of the channel 1 12c to the nozzle-shaped end-part 1 12 is kept constant. In the context of the application, the area of the channel 1 12c arranged closer to the beat-up line 800 (see Fig. 1 ) is referred to as front area, whereas the opposing area of the channel 1 12c is referred to as rear area. In the embodiment of Figs. 1 1 and 12, a sidewall of the channel 1 12c through the nozzle-shaped end-part 1 12 is provided with a convex bulge in the front area. By providing a convex bulge in the front area, an air flow flowing in the front area is deflected towards the rear area.
Figs. 13 and 14 show an embodiment of the nozzle-shaped end-part 1 12 similar to that of Figs. 1 1 and 12. In the embodiment shown in Figs. 13 and 14, a sidewall of the channel 1 12c through the nozzle-shaped end-part 1 12 is also provided with a convex bulge in the front area of the nozzle-shaped end-part 1 12, wherein a height of the flattening outlet opening 1 12a is decreased compared to the embodiment of Figs. 1 1 and 12.
Figs. 15 and 16 show a further embodiment of a nozzle-shaped end-part 1 12, wherein a channel 1 12c through the nozzle-shaped end-part 1 12 is curved towards a beat-up line 800 (see Fig. 1 ) in order to provide a presenting area which is closer to the beat-up line 800. In the embodiment shown, a curvature of the sidewalls of the channel 1 12c is not uniform. Rather, an area of the channel 1 12c closer to the beat-up
line 800 is provided with a more pronounced concave curvature for guiding an air flow towards to the rear area of the channel 1 12c.
Figs. 17 and 18 show an embodiment of a nozzle-shaped end-part 1 12 similar to that shown in Fig. 15 and 16. In the embodiment shown in Figs. 17 and 18, a curvature towards the beat-up line 800 is considerably more pronounced for bringing the presenting area closer to the beat-up line 800 (see Fig. 1 ). Figs. 19 and 20 show an air guide channel 1 1 with a tube 1 10, for example a straight tube, which is provided with a number of openings 1 15 for escaping compressed air out of the tube 1 10. In order to easy the fixing, the tube 1 10 is also provided with recesses 1 16 in the vicinity of the inlet opening where the tube 1 10 is intended to be fixed to the weft thread stretching device 7. The openings in the tube 1 10 can be arranged according to a variant not shown in other positions along the tube 1 10, for example similar as with a tube known from EP 0 273 473.
The device and the method according to the invention are not limited to the embodiments described and illustrated in the drawings by way of example. The device and the method can also be configured within the claims according to variant embodiments, shapes and dimensions.
Combinations of the illustrated embodiments that come under the claims are also possible.
Claims
Device for monitoring a weft thread in a weaving machine comprising a second weft thread detector (10) for providing a signal when an inserted weft thread exceeds its length by a predetermined amount and an air guide channel (1 1 ) located upstream of the second weft thread detector (10), wherein the second weft thread detector (10) is mounted on a sley (500) of the weaving machine
characterized in that
the air guide channel (1 1 ) is arranged stationary on the weaving machine.
Device for monitoring a weft thread according to claim 1 , characterized in that the air guide channel (1 1 ) is configured to present a weft thread (2) in a presenting area traversed by a detection zone of the second weft thread detector (10) during beat-up.
Device for monitoring a weft thread according to claim 1 or 2, characterized in that a weft thread stretching device (7) is provided in the extension of an insertion path of the weft thread (2) upstream of the air guide channel (1 1 ), which weft thread stretching device (7) is configured for catching end-parts (2f) of the inserted weft threads (2).
Device for monitoring a weft thread according to claim 3, characterized in that the air guide channel (1 1 ) bridges at least 80% of the distance between the weft thread stretching device (7) and the second weft thread detector (10).
5. Device for monitoring a weft thread according to claim 4, characterized in that the air guide channel (1 1 ) fits well on the outlet opening (1 12a) of the weft thread stretching device (7).
6. Device for monitoring a weft thread according to any one of claims 1 to 5, characterized in that the air guide channel (1 1 ) comprises a tube (1 10), in particular a straight tube (1 10), wherein the tube (1 10) preferably comprises an opening with a circular cross-section at the inlet side.
7. Device for monitoring a weft thread according to any one of claims 1 to 6, characterized in that the air guide channel (1 1 ) comprises a nozzle-shaped end-part (1 12) arranged at an outlet side of the air guide channel (1 1 ).
8. Device for monitoring a weft thread according to claim 7, characterized in that the nozzle-shaped end-part (1 12) has a flattened outlet opening (1 12a), in particular an outlet opening (1 12a) with an oval cross-section.
9. Device for monitoring a weft thread according to claim 7 or 8, characterized in that the nozzle-shaped end-part (1 12) and the tube (1 10) are formed in one piece.
10. Device for monitoring a weft thread according to any one of claims 1 to 9, characterized in that a wear-resistant insert (1 12e) is provided in a weft thread contact area of the air guide channel (1 1 ), more in particular in an area of the air guide channel (1 1 ) directed to the fabric (8).
1 1 . Device for monitoring a weft thread according to any one of claims 1 to 10, characterized in that the air guide channel (1 1 ) is at least in the vicinity of the internal wall made of a material having a low frictional resistance to air and weft threads, in particular a synthetic material.
12. Device for monitoring a weft thread according to any one of claims 1 to 1 1 , characterized in that a first weft thread detector (6) for detecting the arrival of a weft thread is provided, wherein the first weft thread detector (6) is mounted on the sley (500) of the weaving machine upstream of the air guide channel (1 1 ).
13. Device for monitoring a weft thread according to any one of claims 1 to 12, characterized in that the first weft thread detector (6) for detecting the arrival of a weft thread and the second weft thread detector (10) for providing a signal when an inserted weft thread exceeds its length by a predetermined amount, are configured for optically monitoring a weft thread.
14. Device for monitoring a weft thread according to claim 13, characterized in that a detection zone of a weft thread detector (6, 10) extends between an upper part and a lower part of the weft thread detector (6, 10).
Method for monitoring a weft thread with a device according to any one of claims 1 to 14 comprising a second weft thread detector (10) for providing a signal when an inserted weft thread exceeds its length by a predetermined amount which is mounted on a sley (500) of a weaving machine and an air guide channel (1 1 ) located upstream of the second weft thread detector (10),
characterized in that
the air guide channel (1 1 ) which is arranged stationary on the weaving machine channelling an air flow to a presenting area, and that a detection zone of the second weft thread detector (10) is moved through the presenting area during beat-up.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201380051476.1A CN104822869B (en) | 2012-10-01 | 2013-09-25 | Apparatus and method for monitoring weft yarn |
| EP13766355.5A EP2904136B1 (en) | 2012-10-01 | 2013-09-25 | Device and method for monitoring a weft thread |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE2012/0655A BE1021449B1 (en) | 2012-10-01 | 2012-10-01 | DEVICE AND METHOD FOR MONITORING AN IMPOSITION WIRE |
| BEBE2012/0655 | 2012-10-01 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| WO2014053377A2 true WO2014053377A2 (en) | 2014-04-10 |
| WO2014053377A3 WO2014053377A3 (en) | 2014-07-03 |
Family
ID=47189644
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2013/069994 WO2014053377A2 (en) | 2012-10-01 | 2013-09-25 | Device and method for monitoring a weft thread |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP2904136B1 (en) |
| CN (1) | CN104822869B (en) |
| BE (1) | BE1021449B1 (en) |
| TR (1) | TR201907833T4 (en) |
| WO (1) | WO2014053377A2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104178888A (en) * | 2014-07-28 | 2014-12-03 | 吴江万工机电设备有限公司 | Scale integration method of high-speed four-bar beating-up mechanism |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105671752B (en) * | 2016-04-08 | 2018-03-16 | 青岛百佳机械有限公司 | Water-jet loom photoelectric weft-finder telecontrol equipment and the water-jet loom with the device |
| BE1024545B1 (en) * | 2016-09-02 | 2018-04-05 | Picanol Nv | Device and method for catching and stretching weft threads |
| CN107090650B (en) * | 2017-04-19 | 2018-09-14 | 张赓 | A kind of Weft search unit and its application method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2119819A (en) | 1982-05-03 | 1983-11-23 | Saurer Diederichs Sa | Device for receiving and checking the weft on a shuttle-less loom in which the weft is inserted pneumatically |
| US4432399A (en) | 1980-11-25 | 1984-02-21 | Ruti Machinery Works Ltd. | Filling-thread monitoring device for jet looms |
| EP0273473A1 (en) | 1986-12-02 | 1988-07-06 | Picanol N.V. | Main injector with increased tensioning force for airjet looms |
| EP0943024B1 (en) | 1996-12-02 | 2003-01-29 | Picanol N.V. | Method for the optical monitoring of weft yarn passed into a weaving shed and a weft break motion-stop |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH611658A5 (en) * | 1974-09-26 | 1979-06-15 | Enshu Seisaku Kk | |
| EP0204093B1 (en) * | 1985-04-05 | 1989-08-02 | Kabushiki Kaisha Toyoda Jidoshokki Seisakusho | A method and an apparatus for detecting the weft yarn in a jet loom |
| DE10115172C1 (en) * | 2001-06-08 | 2002-12-19 | Dornier Gmbh Lindauer | Process for monitoring weft insertion in air jet weaving machines and device for carrying out the process |
| BE1019614A3 (en) * | 2009-07-01 | 2012-09-04 | Picanol | DEVICE AND METHOD FOR THE CATCHING AND PIECE OF IMPACT WIRES IN WEAVING MACHINES. |
| KR101226503B1 (en) * | 2010-08-17 | 2013-01-25 | 신상대 | The industrial used weaving machine for lattice type |
-
2012
- 2012-10-01 BE BE2012/0655A patent/BE1021449B1/en active
-
2013
- 2013-09-25 WO PCT/EP2013/069994 patent/WO2014053377A2/en active Application Filing
- 2013-09-25 TR TR2019/07833T patent/TR201907833T4/en unknown
- 2013-09-25 EP EP13766355.5A patent/EP2904136B1/en active Active
- 2013-09-25 CN CN201380051476.1A patent/CN104822869B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4432399A (en) | 1980-11-25 | 1984-02-21 | Ruti Machinery Works Ltd. | Filling-thread monitoring device for jet looms |
| GB2119819A (en) | 1982-05-03 | 1983-11-23 | Saurer Diederichs Sa | Device for receiving and checking the weft on a shuttle-less loom in which the weft is inserted pneumatically |
| EP0273473A1 (en) | 1986-12-02 | 1988-07-06 | Picanol N.V. | Main injector with increased tensioning force for airjet looms |
| EP0943024B1 (en) | 1996-12-02 | 2003-01-29 | Picanol N.V. | Method for the optical monitoring of weft yarn passed into a weaving shed and a weft break motion-stop |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104178888A (en) * | 2014-07-28 | 2014-12-03 | 吴江万工机电设备有限公司 | Scale integration method of high-speed four-bar beating-up mechanism |
Also Published As
| Publication number | Publication date |
|---|---|
| TR201907833T4 (en) | 2019-06-21 |
| CN104822869B (en) | 2016-09-14 |
| CN104822869A (en) | 2015-08-05 |
| EP2904136A2 (en) | 2015-08-12 |
| WO2014053377A3 (en) | 2014-07-03 |
| BE1021449B1 (en) | 2015-11-25 |
| EP2904136B1 (en) | 2019-03-06 |
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