EP0600819A1 - Method for detecting the positioning of a thread in a multi-bar machine, in particular a Jacquard-lace machine, machine and detection device for carrying out the method - Google Patents

Abstract

Method for detecting the positioning of a yarn (thread) (3) in a multi-bar loom (machine) such as, in particular, a Jacquard-lace machine, comprising at least one movably mounted bar of needles (1) and at least one movably mounted knock-over (thread extraction) bar (bit) (2). According to the invention, a signal is emitted in the needle bar (1) zone and the variations in the signal after each passage of the needle bar (1) are detected. A further subject of the invention is a multi-bar loom such as, in particular, a Jacquard loom and a detection device for implementing the method. <IMAGE>

Description

The subject of the present invention is a method for detecting the positioning of a yarn in a multi-bar loom such as in particular a lace jacquard loom, such a loom as well as a detection device designed for implementing the method.

It will find its application in all sectors of economic activity in which one wishes to make lace by means of a multi-bar loom such as in particular a Jacquard loom.

Currently, to make lace, use is made of looms, and in particular of looms of the Jacquard type comprising at least one bar of needles movable substantially vertically and, at least one felling bar movable substantially horizontally which cooperate with a layer of threads to make the patterns or contours of the lace.

In practice, given the high rate of operation of these trades and, the large number of wires constituting the sheet, it is frequent that one of the wires breaks or is positioned in an undesired manner. Such a break in the thread or its poor positioning generates the production of embroidery articles which have defects and irregularities in the patterns, which can go as far as holes, which, we can see, diminishes the aesthetic appearance sought with such articles.

As soon as such a defect is detected, it is necessary to stop the operation of the loom and to detect with precision the location of the broken or badly positioned wire, which, we can see, is long, complex and tedious.

In addition, depending on the nature of the thread used (guimpe thread for making patterns, and embroidery threads for making outlines) as well as the type or nature of the pattern to be made, the number of stops in the multi-purpose trade -bars such as in particular a Jacquard loom can be high, which reduces the yield of the installation and generates an additional cost in the preparation of such articles.

Detectors, in particular optical detectors, are known for determining the positioning of the wires inside the ply at the level of the multi-bar loom such as in particular a lace jacquard loom. However, in practice, such optical detectors can only be used to determine the positioning or breakage of son of the warp type, which limits their usability.

Indeed, given the architecture and design of the multi-bar loom such as in particular a Jacquard loom, it is not possible to be able to use such optical detectors to determine the positioning of a yarn of a web when these threads are of the guimpe type.

The present invention aims to remedy the drawbacks of currently known devices by providing a method for detecting the positioning of yarns in a multi-bar loom such as in particular a Jacquard loom, such a loom and a detection device for its implementation. which make it possible to precisely determine the positioning of wires whatever their nature and their number within a sheet.

Another object of the present invention lies in the fact that the detection method and device, in accordance with the invention, allow an optical location of the broken or badly positioned wire, which facilitates its detection and the intervention of the operator. .

Another object of the present invention also lies in the fact that this method and the device for detecting the positioning of a thread ensures optimum operation in the multi-bar loom such as in particular a Jacquard loom, in particular avoiding unwanted stops resulting from the presence of faults in the wires or parasitic elements.

Another advantage of the method and of the device according to the invention is that they make it possible to detect, as a function of the nature of the yarn used, the faults liable to generate a stop in operation of the multi-bar loom such as in particular a Jacquard loom .

Another advantage of the method and of the device according to the invention is that they are simple to implement. work and that they provide reliable results whatever the operating capacity of the multi-bar loom such as in particular a Jacquard loom.

Other objects and advantages of the present invention will appear during the description which follows which is given only for information and which is not intended to limit it.

• on émet un signal dans la zone de la barre d'aiguilles,
• on détecte les variations du signal après chaque passage de la barre d'aiguilles.

To this end, the method for detecting the positioning of a thread within a ply in a multi-bar loom such as in particular a lace Jacquard loom comprising at least one movable needle bar and a movable felling bar is characterized by the fact that:

• we send a signal in the area of the needle bar,
• signal variations are detected after each pass of the needle bar.

• des moyens pour émettre un signal dans la zone de la barre d'aiguilles,
• des moyens pour détecter les variations du signal après chaque passage de la barre d'aiguilles.

The subject of the invention is also a multi-bar loom such as in particular a Jacquard loom for implementing the method which is characterized in that it comprises:

• means for transmitting a signal in the area of the needle bar,
• means for detecting the variations in the signal after each passage of the needle bar.

The invention also relates to a detection device designed for the implementation of the method.

• la figure 1 est une vue schématique qui représente le positionnement et le mouvement d'une barre d'aiguilles et d'une barre d'abattage dans un métier multi-barres tel que notamment un métier Jacquard à dentelles,
• la figure 2 est une vue schématique qui illustre le dispositif de détection du positionnement d'un fil conforme à l'invention,
• la figure 3 est une vue schématique qui illustre la focalisation du signal lumineux au moyen d'une lentille convergente,
• la figure 4 est une vue schématique qui illustre la variation de l'atténuation du signal lumineux dans le temps lorsque le fil ne casse pas,
• la figure 5 est une vue schématique qui illustre l'atténuation du signal lumineux en fonction du temps lorsque le fil est un fil cassé du type guimpe,
• la figure 6 est une vue schématique qui illustre l'atténuation du signal lumineux en fonction du temps lorsque le fil est un fil élastique cassé à base d'élasthanne tel que commercialisé sous la marque lycra cassé,
• la figure 7 est une vue schématique qui illustre l'organigramme de fonctionnement des moyens calculateurs du dispositif de détection conforme à l'invention,
• la figure 8 est une vue schématique qui montre un exemple de fonctionnement d'un métier multi-barres tel qu'un métier Jacquard équipé selon l'invention.

The present invention will be clearly understood on reading the following description, accompanied by the appended drawings among which:

• FIG. 1 is a schematic view which represents the positioning and the movement of a needle bar and a felling bar in a multi-bar loom such as in particular a lace jacquard loom,
• FIG. 2 is a schematic view which illustrates the device for detecting the positioning of a wire according to the invention,
• Figure 3 is a schematic view which illustrates the focusing of the light signal by means of a converging lens,
• FIG. 4 is a schematic view which illustrates the variation in the attenuation of the light signal over time when the wire does not break,
• FIG. 5 is a schematic view which illustrates the attenuation of the light signal as a function of time when the wire is a broken wire of the guimpe type,
• FIG. 6 is a schematic view which illustrates the attenuation of the light signal as a function of time when the thread is a broken elastic thread based on elastane as marketed under the brand broken lycra,
• FIG. 7 is a schematic view which illustrates the flowchart of operation of the calculating means of the detection device according to the invention,
• Figure 8 is a schematic view which shows an example of operation of a multi-bar loom such as a Jacquard loom equipped according to the invention.

The present invention relates to a method for detecting the positioning of a yarn in a ply in a multi-bar loom such as in particular a lace jacquard loom, such a loom and a detection device for its implementation.

Currently, to make lace, multi-bar looms are used such as for example Jacquard looms which comprise at least one needle bar 1 mounted, in particular substantially vertically, as illustrated by the arrow F1 in FIG. 1, and at least one felling bar 2 mounted, in particular substantially horizontally, as shown by the arrow F2 by cooperating with a multitude of threads 3 constituting a sheet in order to make the patterns and / or the contours of the lace.

• des moyens 4 pour émettre un signal dans la zone de la barre d'aiguilles 1,
• des moyens 5 pour détecter les variations du signal après chaque passage de la barre d'aiguilles 1.

According to the invention, as illustrated in FIG. 8, this multi-bar loom is equipped such as in particular a Jacquard loom in terms of the operation of the felling bar 2 and the needle bar 1 of a device including :

• means 4 for transmitting a signal in the area of the needle bar 1,
• means 5 for detecting the variations of the signal after each passage of the needle bar 1.

In addition, the means 4 emit a light signal substantially in the area of the needle bar 1 and, the means 5 detect, substantially in the area of the felling bar 2, the passage of the needle bar 1 and , with a delay, the passage if necessary of the wire 3.

The means 4 for emitting a signal consist of a laser diode 6 diffusing a visible light signal in the form of a beam 7.

For example, it may be a collimated laser diode with a power of 5 milli-Watt which emits a light beam 7 according to a wavelength of 670 manometers, that is to say corresponding to a radiation visible red, with a radius of divergence of 0.3 milliradians along a length of 32 millimeters and a diameter of 11 millimeters.

Of course, the specific characteristics of the laser diode 6 can be variable in particular on the basis of appropriate settings or, in other embodiments, the means 4 for emitting a signal can be of any other type capable of generating and emitting a signal. optical or not.

The means 5 for detecting the variations of the signal after each passage of the needle bar 1 are constituted here by a photodiode 8 associated with a converging lens 9, as more particularly shown in FIG. 3. The spectral amplitude of the photodiode is by way of example, between 350 and 1,150 manometers and, its field of determination of the light beam 7 is variable depending on its positioning and the specific characteristics of the converging lens 9, which here has a diameter of 20 millimeters and a distance also focal length of 20 millimeters.

A surprising and unexpected aspect of the use of an optical transmitter 4 such as a diode laser 6, is to allow signaling and optical identification of each wire, and in particular, broken or badly positioned wire, which facilitates its detection and operator intervention by limiting the downtime and non-operation of career.

The device also includes means 10 for processing the detected signal formed here by a computer 11 associated with an amplifier 12 to amplify the characteristics of the detected signal and facilitate its processing.

The computer 11 is here constituted by a microcontroller which operates according to an algorithm, as illustrated in FIG. 7, implementing the various steps of the method for detecting the positioning of a wire according to the invention.

According to this method, a signal is emitted in the area of the needle bar 1 and the variations in the signal are detected after each passage of the needle bar 1.

For this, after the emission of the light signal 7, the processing means of the computer 11 are initialized while waiting for the needle bar 1 to pass through the beam 7 and, while waiting for the needle bar to be taken out of the beam.

This initialization and this synchronization of the flow of the algorithm from the positioning of the needle bar 1, can in other embodiments also be obtained for example by means of a proximity detector or else of electrical signals emitted from the machine.

After this synchronization step, it is checked that, if necessary, the thread cuts the beam, in the direction of arrow F1, of the needle bar 1 for a period corresponding to the travel time.

If, as illustrated in FIG. 4, between two successive passages of the needle bar 1, no change in the light signal has been detected, that is to say no attenuation thereof, it is because there is no broken wire. So, according to the algorithm, we start again the synchronization step, i.e. waiting for the bar of needles 1 again crosses the beam.

On the other hand, if a wire has cut the beam, that is to say that a light attenuation has been detected, this means that this wire has irregularities corresponding either to its bad positioning or its breakage, or to the presence of thread defects such as a knot or parasitic elements on the needle bar 1.

To avoid an unwanted stoppage of the operation of the multi-bar loom such as in particular a Jacquard loom, resulting for example from an irregularity of the thread or of a parasitic element, several detections of the light attenuation of the signal are carried out successively, before to order the operation of the loom to stop. By way of example, in the embodiment shown, five successive detections of a beam cut by the wire are carried out before commanding the stopping of the multi-bar loom such as in particular a Jacquard loom.

As soon as the fault has been located, and the wire has been replaced, the algorithm is started again.

According to the invention, it should also be noted that one can determine the defect in positioning the wire or its breakage according to its nature.

Thus, the detection of the incorrect positioning or of the breakage of a gimp thread is obtained by a light attenuation of the signal as illustrated in FIG. 5 or, in the case of an elastic thread based on elastane. for example marketed under the brand Lycra by a light attenuation of the signal as illustrated in FIG. 6.

Of course, in other embodiments, it is entirely possible, depending on the operating capacities of the multi-bar loom such as in particular a Jacquard loom, to modify the different steps of this algorithm to obtain optimal operation of this job.

It should also be noted that, other forms of the present invention, could have been envisaged without departing from the scope thereof.

Claims (10)

Method for detecting the positioning of at least one ply yarn in a multi-bar loom such as in particular a lace jacquard loom, comprising at least one movable needle bar (1) and a felling bar (2 ) mobile, characterized in that: - a signal is emitted in the area of the needle bar (1), - the signal variations are detected after each passage of the needle bar (1). Method according to claim 1, characterized in that the signal obtained is discriminated to determine the positioning defect of the wire (3) according to its nature. Method according to claim 1, characterized in that: - a light signal is emitted substantially in the area of the needle bar (1), - the passage of the needle bar (1) is detected substantially in the area of the felling bar (2) and, with a delay, the passage of the thread (3), if necessary, - The detected signal is processed with calculating means to determine the successive variations of the signal. Method according to claim 1, characterized in that the broken or badly positioned wire is optically identified by said signal. Method according to claim 1, characterized in that the stop of the loom is ordered after the detection of several variations of the signal. Multi-bar loom such as in particular a lace jacquard loom, comprising at least one needle bar (1) mounted mobile and a felling bar (2) mounted mobile, authorizing the implementation of the method according to claim 1, characterized in that it comprises: - means (4) for transmitting a signal in the area of the needle bar (1), - Means (5) for detecting the variations of the signal after each passage of the needle bar (1). Multi-bar loom such as in particular a lace jacquard loom according to claim 6, characterized in that it comprises: means (4) for emitting a light signal substantially in the area of the needle bar 1, - Means (5) for detecting, substantially in the area of the felling bar (2), the passage of the needle bar 1 and, with a delay, the passage of the thread (3), if necessary. Multi-bar loom such as in particular a lace jacquard loom according to claim 6, characterized in that the means (4) for emitting a signal consist of a laser diode (6) diffusing a light beam 7. Multi-bar loom such as in particular a lace jacquard loom according to claim 6, characterized in that the means (5) for detecting the signal consist of a photodiode (8), cooperating with means (10) for tracking the signal constituted by a computer (11) associated with a signal amplifier 12. Device for detecting the positioning of at least one wire of a ply designed for the implementation of the method according to any one of claims 1 to 5.

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