KR20080011309A - Apparatus and method for in-line reading and control of warp threads in a loom - Google Patents

Abstract

Apparatus and method for reading and controlling warp threads in a loom, comprising the use of a device (14, 16) for the reading and acquisition of images, and the comparison between the acquired images and one or more predetermined samples to determine at least one state of defect in the work cycle based on the result of said comparison in order to instantly cut off the operation of the loom in response to the determined defect.

Description

APPARATUS AND METHOD FOR IN-LINE READING AND CONTROL OF WARP THREADS IN A LOOM}

It is an object of the present invention to provide a device for controlling warp threads during fabric production in looms.

As is well known, the fabric traverses the warp by lifting one or more warps relative to the rest of the warp by means of suitable instruments, so-called heddles, to form a channel for the passage of a weft-carrying shuttle. Obtained by interweaving the warp yarns, which are fed by corresponding beams and arranged parallel along the loom, with the weft thread passing through.

Cross weaving is done according to a scheme, a so-called texture, the texture substantially exhibiting a cross weaving pattern and corresponding to the repetition of warp jacking. Thus, the fabric formation in the loom is done in a continuous cycle, which is based on following the order indicated in the cross-weaving pattern, the formation of the shed by the inclined jacking, the opening of the reed and the weft. Insertion and finally closing and shooting of the leads.

At present, control devices such as so-called warp stops and weft stops are known, which block the operation of the loom by cutting threads or wefts in the event of deformation. However, if no signal is sent, then such cuts degrade the quality of work by creating defects and defects.

In the past, the inclination was controlled by a drop wire across the rod formed by two toothed plates reciprocating in the opposite direction and arranged over the inclined inclination, so that the corresponding drop in the case of thread cutting Apart and placed between the teeth of the plate to signal a break of the thread.

Recently, a mechanical lead wire has been replaced by an electrically connected lead wire to generate an electrical signal of the loom blocking.

More recently, laser sensors have been used instead of the lead line to form control lines placed on the side at right angles to the slope, which can read the passage of the cut thread across the control line when the thread is dropped. Can be.

However, this solution can only be applied to rigid yarns that can actually cut the control line while falling. This known solution has disadvantages in that the drop signal generation of the thread is delayed or not at all-especially when using non-rigid yarns.

For example, it often happens that a thread "winds" or cuts over an adjacent thread without falling. In such a case, both the lead wire and the sensor mechanism are not efficient.

As a result, the fabrics produced by the loom can have several types of defects, either repaired by darning or classified as defects, depending on the extension, which results in a deterioration of the finished product roll. .

Such somewhat repairable flaws include, for example, when a thread fails, when two or more wound slopes are formed, when knots are formed, and vertical scoring or thin-weft regions. When a weft region is formed and a reading's fault is formed, a case may occur.

The first object of the present invention is to overcome the disadvantages of the tilt control mechanism of known type.

The second object is to realize that in a reproducible and reliable manner the defects leading to interruption of the cycle and the defects involving different interventions, such as the fabrication or re-quality verification of the fabric.

Another object is to provide a continuous or periodic report of differences from the expected results in the quality of the fabric being formed.

The technical object and the specific object are substantially achieved by an apparatus and a method for reading and controlling the inclination including the technical features disclosed in one or more of the appended claims.

Further features and advantages of the present invention will become apparent from the accompanying drawings and the following implicit and non-limiting description of the preferred but non-exclusive embodiments of the present invention.

1, 1A and 2 show details of a prior art inclined stop mechanism and a drop wire conventionally used as a blocking means for stopping the loom in case of inclined breakage.

3 shows diagrammatically a laser mechanism of the prior art for identifying warp breakage.

4a / 4b and 5a / 5b diagrammatically show the reading and control device according to the invention in the absence of warp breakage and in the case of detecting the breakage of the loom respectively.

FIG. 6 shows an example of a texture having a cross weaving report for forming a fabric on a loom.

Figure 7 is a detailed view of the jacking and lowering area of a thread of a preferred embodiment of the device according to the present invention.

With reference to FIGS. 1 and 2, these figures show that the lead line 1 is arranged over the incline 2 raised by the carp 10 of the loom and cross-woven (or shoot) by the lid 11. A schematic illustration of a known type of technology for forming a woven fabric 12 by passing through a continuous weft 15 to be processed) is illustrated.

A rod consisting of two toothed plates 3 driven in a reciprocating motion traverses the lead line so that the lead line corresponding to the case of thread 2 'failure falls and sticks between the teeth 4 of the plate. You will be signaled for the cut. FIG. 2 shows a lead wire 1 ′ with metal parts 5, 6, which are usually separated by an insulator 7 and electrically connected to thread failure.

FIG. 3 shows a control line 9 upstream of the hed 10 or between the hed 10 and the lid 11 that can “read” the passage of the cut warp crossing the control line when falling. It shows the use according to the known art of the laser sensor 8 which lies perpendicular to the side road of the inclination to limit to.

The device according to the invention is schematically illustrated in FIGS. 4a, 4b, 5a, 5b.

The device according to the invention comprises one or more telecameras 14 (or other image capture devices) which, in use, can be positioned over the lid 11 of the loom over part or all of the working height.

The telecamera is arranged to frame the order of the jacking of the warp 2 actuated by the carp of the loom according to a predetermined cross-weaving pattern (FIG. 6) and a TV-shot (TV- like) video board or processing unit 17. Interfaced with an electronic support 16 for controlling a shot, the processing unit may be comprised of a personal computer or other data-processing unit.

In other embodiments, data transmission from the telecamera 14 to the support device 16 and from there to the unit 17 is via cable 18 or wirelessly (infrared, optical, radio frequency or other interface). It is emphasized that the telecamera 14, the board 16 and the processing unit 17 may also be integrated into the same instrument meeting any application requirement.

Corresponding to at least all warp jacking, the telecamera 14, in which suitable optics are provided, is controlled by the electronic board 16 and preferably in an upstream region L1 or a lead close to the lid 11. One or more shots (marked 19 in the drawing) of the inclined image connected to the downstream region L2 close to the are performed.

The captured image is fed to the processing unit 17 and converted into a code 24, preferably in the form of a bar code, and compared with one or more preset sample codes corresponding to the predetermined shape of the slope.

Preferably, the sample codes corresponding to the appropriate various forms of warp are stored after the initial approval procedure of the fabric in the forming process (eg in the form of a barcode), such a procedure being applied to the cross weaving pattern in the board 16. This is done at the start of the work by sampling and remembering all relevant jackings (four in the case of the cross weaving pattern of FIG. 6), each of which produces a different code 24.

In addition, the oblique reading in the jacking process may be performed using a solid state light flash (not shown in the art) which is synchronized with continuous jacking and image shooting.

Preferably, the device may be provided with two final and initial read indicators 20, 21 arranged at the edge of the fabric, for example at the top bar 22 of the lid 11. .

Preferably, a millimeter scale may be provided on the bar 22 to facilitate the direct identification of defects on the formed rolls detected by the system.

During operation of the device according to the invention, a complete analysis of the inner and outer slanted edges and also the yarn pattern can be performed on all image codes by detecting possible local differences. Image processing, possibly based on tolerance limits that can be preset for any type of defect, allows for the coding of detected defects, and this is preferably carried out during monitoring synchronized with the jacking and along the reading area. Repeat several times to locate the defect and track every single defect in the fabric being formed.

4A, 4B and 5A, 5B show a first example in which an image captured by the telecamera 14 makes it possible to determine a suitable code 24, i.e., a code corresponding to a defect-free state. 4A) and a second example (FIG. 5A) which enables the readout image to determine the "wrong" code 24 'corresponding to the defect' break 'of the slope 2'.

According to the invention, in response to the code 24 'determination, the processing unit 17 can be programmed, for example, to stop the operating cycle and shut off the loom.

Preferably, however, whether or not the size and type of detected defects (breaking, fraying, winding, etc.) can be tolerated-for example based on the final desired quality of the fabric. Instead of pre-setting and consequently shutting off the loom, it is possible to continue working and to signal the presence or possible location of the defects in the report, only taking into account the reclassification or tanning of the fabric rolls.

Detecting differences from preset samples may also be performed for any crossweaving pattern each time during the jacking or periodically after a preset number of jackings.

It is also possible to provide a display for reading an image from the outside (continuously or periodically) and / or for sending a warning signal corresponding to one or more detected defects.

In a preferred embodiment, it is also possible to provide a central server for controlling a number of mechanisms, each associated with a fabric being formed.

In this embodiment, if there is a difference with the sample, the device according to the invention may be based on preset tolerances and criteria by defining the coordinates of the fabric being formed and the point on the millimeter bar 22 to intervene the danning. It is associated with a server that "determines" the intervention.

7 shows a preferred solution of the device according to the invention. This embodiment inserts a bar 25 parallel to the lead behind the lid 11 so that during the jacking there is only one support plane for the thread 2.

This approach suffers from inadequate reading, where the bar 25 may be present in the region near the acquisition field, where high-occurring threads will tend to partially or wholly interfere with low-height threads. By avoiding this, it is possible to determine the apparent error environment that causes the server to "determine" a production stop.

The above problem arises from the fact that the telecamera 14 is located at the center of the width some distance above the upper thread. In such an arrangement, the telecamera 14 creates a diverging cone shaped framing from which a portion of the lower thread offset in width relative to the upper thread may be excluded.

The bar 25 brings all the threads to the same height of the telecamera reading area, thus overcoming the above-mentioned problems.

Therefore, the advantages of the present invention from the foregoing are, in particular, that it is possible to suppress or reduce the traditional warp stoppers required in the loom, that it can be installed easily and quickly on any loom, and that the fabric forming process is continuous and real time. It can be seen that it can be controlled, that there are no or limited elements (wire drop of traditional tilt stopper) in direct contact with the warp, and that a complete defect map on the fabric roll formed can be made.

The invention thus devised is also capable of many modifications and variations, all of which may be replaced by technically equivalent elements within the scope of the invention.

Claims (26)

At least one device (14, 16) for reading and capturing images of a plurality of warps (2, 2 ') during a working cycle in the loom; Comparison means (17) for comparing the captured image with one or more predetermined samples and for determining defects of at least one state in a work cycle based on the comparison result; And means for immediately stopping operation of the loom in response to the found defect, or for generating a detected defect as a signal. The method of claim 1, Means for processing the captured image and converting the captured image into code (24, 24 ') that can be compared with sample code. The method of claim 1, Means for synchronizing successive captured images with the jacking movement of the warp along the work cycle. The method according to any of the preceding claims, And means for illuminating the image reading and capture area. The method of claim 4, wherein And said lighting means comprises a solid state flash synchronized with the warping movement of the warp yarns. The method according to any of the preceding claims, The means for reading and capturing an image (24) comprises at least one telecamera. The method according to any of the preceding claims, Said reading and capturing means comprises an electronic board (16) which can be interfaced with the processing unit (17). The method according to any of the preceding claims, The means for comparing the captured image with one or more preset samples and the means for determining a defect in at least one state of a work cycle, A processing unit 17 capable of comparing the captured image with one or more samples and producing information therefrom in connection with one or more working defects, And means for correlating the detected defect (s) with one or more interventions made on the loom's work cycle. The method according to any of the preceding claims, And an element (20, 21) for defining the beginning and the end of the reading area. The method according to any of the preceding claims, Means for displaying the captured image and reading and controlling the tilt in the loom. The method according to any of the preceding claims, Means for sending a warning in response to the determination of a work defect. The method according to any of the preceding claims, And means for outputting one or more reports on the difference between the fabric (12) being formed and a preset sample of the resulting fabric. The method according to any of the preceding claims, At least one said sample consists of a captured image of the original length of the fabric (12) in operation on the loom. Loom comprising a device according to at least one of the preceding claims. At least one step of reading and capturing images relating to a plurality of warps 2, 2 'during a warp jacking step, Comparing the captured image with one or more preset samples, Determining at least one defect in the work cycle based on the result of the comparison, Stopping and correcting the loom operation based on the determined defect. The method of claim 15, Converting the captured image into codes (24, 24 ') and comparing them with one or more sample codes is provided. The method according to claim 15 or 16, Said code is a bar code. The method according to any one of claims 15 to 17, Continuous image capture is synchronized with an inclined jacking motion in accordance with the working cycle. The method according to any one of claims 15 to 18, Correlating the detected defect (s) with one or more intervening tasks performed in a work cycle. The method of claim 15, wherein And outputting one or more reports about the differences between the fabric being formed and the one or more preset sample fabrics. The method according to claim 15 to 20, Wherein at least one of the samples is obtained by capturing an image of the original length of the fabric on the loom being in operation. The method according to any one of claims 15 to 20, Wherein said reading is done on a length defined by a region (L1) of warp included between heddles and reeds. The method of claim 15, wherein Wherein said reading is done on a length defined by a region (L2) of warp included between the lid and the formed fabric. A computer program comprising instructions for executing a method according to at least one of claims 15-23. The method of claim 24, A computer program comprising an electronic chart for correlating detected defects with interventions for correction and information. An electronic or optical support device for storage of a program according to claim 24.

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