FR2765202A1 - Bobbin monitor - Google Patents

Abstract

The bobbin (1) has a horizontal core tube (10) of an electrically conductive material. At least one relief section (7) is at the bobbin (1) core (2), of an electrically conductive material, which can be covered wholly by an insulating yarn or filament wound round the bobbin when it is full, and which is exposed when the bobbin is nearly empty as the windings are consumed. The relief sections (7) are electrically connected to a conductor support (10) when the bobbin (1) is mounted to it. A moving conductive blade (16), also mounted to the bobbin support (10), rests against the bobbin windings when the bobbin is full, and makes contact with the relief sections (7) when the bobbin is nearly empty, to close an electrical circuit. A lamp system (13) registers a closed electrical circuit.

Description

 The present invention relates to a device for detecting the end of a wire on a spool. This device makes it possible to detect, automatically and reliably, the state of a reel during reeling and in particular the fact that the reel is almost empty, to indicate that this reel must be replaced by a new full reel. The invention finds its application in the field of the textile industry and, more particularly, on weaving looms equipped with a very large number of spools of thread, which is in particular the case of weaving looms of shaped velvet, whose canters support a high number of spools storing the threads necessary for the formation of the "pile" of velvet.

The shaped double piece velvet, which is more particularly referred to here, is obtained by weaving two independent pieces of fabric, one above the other, which are connected by pile threads which form the velvet of each of these two pieces of fabric. The realization of this kind of velvet requires on the one hand a chain, which has all the threads of fabric of the lower part and all the threads of canvas of the upper part, and on the other hand of the canters which support the reels which store and feed the pile threads. The shaped is obtained by a mechanical
Jacquard; each hair thread is caught in a mesh of this mechanism and is selected according to the drawing on the pique paper. The fabric is split in two during weaving, exactly in the middle of its development, by means of a cutting blade guided on a rail and cutting the pile threads, so as to make each piece independent of the other.

 The canters are traditionally constituted by simple vertical boards, on which are fixed slightly curved horizontal points at their free ends, which support the coils, the latter being made of wood or plastic.

Each weaving loom is commonly fitted with several thousand independent spools, which store the pile threads, the course of which depends on the pattern to be created.

 In the current state of the art, there is no automatic monitoring system for the unwinding state of these coils, and this requires operating personnel to constantly visually monitor the creels, while the personnel must also check at the same time the quality of the fabric produced on several machines.

 This difficulty is further increased by the recent appearance of looms fashioned velvet which have a higher rate, as well as an increased number of spools, such as the loom subject of French patent application nO 95 07794/2 735 796 of June 23, 1995 in the name of the Claimant.

In the case of these newly appeared weaving looms, the average quantity of spools becoming empty per creel, for a given period, can be multiplied by seven compared to the quantities traditionally observed.

The attention of the personnel must therefore be concentrated on the monitoring of the creels, which will no longer allow sufficient monitoring of the quality of the weaving.

 Thus, the current creel system constitutes a brake on the increase in productivity of the weaving looms concerned here, or a cause of decrease in the quality of the fabric, unless multiplying the workforce which would represent a prohibitive cost. .

 In a similar way, a complete automation of the change of the coils on the creels would represent a disproportionate investment, compared to the expected gains.

The present invention aims to solve the problem set out above, by providing an automatic monitoring device, but remaining relatively simple and economical, which allows
- detect the unwinding state of a spool of thread, in particular to indicate that the spool is almost empty, this with great reliability,
- simultaneously monitor the condition of a large number of coils, such as all the coils carried by the same creel, while individually signaling each empty coil,
- thus eliminating the visual scanning times of the coils, and allowing the staff to optimize the use of their time, by providing information allowing them to visit the canters only when necessary,
- consequently to provide a higher yield for the looms concerned, accompanied by an increase in the quality of the fabric and a reduction in thread losses.

To this end, the invention essentially relates to a device for detecting the end of the wire on a spool, which comprises in combination
- for the or each coil to be monitored, a fixed support in the form of a tube or rod, of substantially horizontal axis, made of electrically conductive material,
- On the core of the or each coil to be monitored, at least a raised portion of electrically conductive material, capable of being completely covered by an electrically insulating wire wound on the coil, when the coil is full, and to be made visible when this coil is almost empty, said conductive part being electrically connected to the conductive support, when the coil is mounted on said conductive support,
- an electrically conductive movable strip, disposed opposite the coil mounted on its support, and capable of resting on the wire wound on the coil, when the coil is full, or coming into contact with the electrically conductive raised part the core of the coil, when this coil is almost empty, so as to close an electrical circuit, and
- means for detecting and / or signaling the closure of said electrical circuit.

 According to a preferred embodiment of the invention, the or each coil to be monitored has a core of electrically insulating material, while said electrically conductive raised part consists of a metal wire wound with non-contiguous turns around the core of the coil, at least one end of this metal wire being connected to an electrically conductive ring inserted at one end of the core of the coil and capable of coming into contact with the conductive support, when the coil is mounted on said conductive support.

 Thus, each coil is equipped with a metal wire, such as a copper wire, wound around its core, and connected to at least one ring ensuring the electrical connection between the wire and the conductive support of the coil, an embodiment advantageous providing that the two ends of the metal wire are respectively connected to two conductive rings, inserted at the two ends of the core of the coil. As long as the coil is full, the metal wire remains "drowned" under the insulating wire, such as a textile wire, wound on the coil; the conductive strip then rubs only on this insulating wire, and the electrical monitoring circuit remains open. When the unwinding of the coil has been carried out to make the turns of the metal wire visible, the conductive strip comes to touch at least one of these turns, which closes the electrical circuit and makes it possible to detect the moment when a certain wire feed threshold has been reached by the coil. It will be noted that at the instant of the closing of the electrical circuit, the coil is still lined with textile thread situated between the non-contiguous turns of the metallic thread. The detection device, object of the invention, thus intervenes when the reel to be monitored still carries a certain reserve of textile thread, which makes it possible to alert the staff1 sufficiently in advance by warning them that a reel must be changed soon, without forcing him to take immediate action.

 It will also be noted that the conductive support in the form of a tube or rod, forming part of the device which is the subject of the present invention, can receive both a coil fitted with a metal wire as defined below, as well as a traditional coil. The realization of the coils with metallic wire can result either from a special manufacture, or from a rather simple transformation of existing coils.

 Insofar as the principle of the invention resides in the presence of at least one part in conductive relief on the core of the coil, variants can be envisaged, which do not use a metallic wire wound with non-contiguous turns .

 According to a first variant, the coil has a core at least partially made of electrically conductive material, and this core has at least one annular groove, the electrically insulating wire wound on the coil being wound at the start in this groove, while the movable conductive strip is provided to cooperate with a part of the core located outside the throat area. A particularly simple embodiment is thus obtained, as well by the elimination of any metallic wire to be wound around the core of the spool, as by the direct electrical contact made between the spool and its support, the reserve of textile thread still available at the time of the detection being contained in the annular groove.

 According to a second variant, the core of the coil carries a ring of electrically conductive material, intended to cooperate with the movable conductive strip.

The conductive ring, in particular a metal ring, constituting here the electrically conductive raised part, can be likened to a single turn of a metal wire wound around the core of the coil.

 In all cases, the movable conductive strip is advantageously a strip pivotally mounted above the location of the coil mounted on its conductive support, so as to rest, simply under the effect of its own weight, on the wire electrically insulation wound on the full coil, or on the electrically conductive raised part of the almost empty core of the coil.

 According to another aspect of the invention, the conductive support in the form of a tube or rod, forming part of the device which is the subject of the invention, carries at its free end a light indicator, serving as a means of signaling the closing of the electrical circuit , indicating that the coil mounted on the support is almost empty. The indicator light, which can be constituted by a light-emitting diode, thus directly signals each almost empty coil, which allows an easy individual identification of the almost empty coils, even in the case of a large number of coils to be monitored simultaneously.

 The end of thread detection device, object of the invention, is thus particularly applicable to the automatic monitoring of the creels of a loom, in particular a weaving machine of shaped velvet, each creel having a substantially vertical plate of material. electrically insulating, which carries a multiplicity of substantially horizontal conductive supports each capable of receiving a coil equipped or produced as defined above, means for detecting the state of this coil being associated with each conductive support. The device thus makes it possible to signal almost empty coils at any time, whatever their number, avoiding any search for empty coils.

Within the framework of this application, the device which is the subject of the invention makes it possible not only to identify and individually identify each almost empty bobbin, but also to give a global indication of the state of the bobbins of the creels of the loom concerned, in particular thanks to the following provisions
- the conductive supports receiving the coils to be monitored, as well as the movable conductive lamellae, are distributed in rows and columns, and are connected to horizontal and vertical electrical conductors, connected to at least one electronic part, providing a multiplexing system , allowing to acquire the state of each coil,
the electronic part is connected to display means capable of indicating the total number of coils detected as almost empty, at each instant,
- This electronic part is also connected to successive tripping indicator lights as a function of the number of almost empty coils and / or of the time elapsed since the detection of at least one almost empty coil.

 The device thus makes it possible to interrogate all the detectors, to account for all the coils to be changed from the creel, and it provides a signal giving the emergency state of an intervention on the creel for the replacement of empty coils, thanks to an electronic part ensuring the management "of the whole.

In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended schematic drawing representing, by way of examples, some embodiments of this end of wire detection device on a coil, and illustrating the application of this device
Figure 1 is a perspective view of a coil provided with the end of wire detection device, according to the present invention
Figure 2 is a longitudinal sectional view of the coil of Figure 1, full of wire
Figure 3 is a longitudinal sectional view of the same coil, almost empty;
Figure 4 is an electrical schematic diagram of the end of wire detection device
Figure 5 is a general block diagram of a system comprising application of this end of wire detection device
Figure 6 is a longitudinal sectional view of a first variant of the invention
Figure 7 is a cross-sectional view along
Figure VII-VII
Figure 8 is a longitudinal sectional view of a second variant of the invention;
Figure 9 is a front view, with partial section, relating to this second variant.

 The coil shown in Figures 1 to 3, designated as a whole by the reference 1, has a tubular core 2 and two side cheeks 3 and 4, these parts being made of an electrically insulating material. Two rings 5 and 6 of electrically conductive material are inserted, respectively, at the two ends of the tubular core 2. Around this tubular core 2 are wound non-contiguous turns of copper wire 7, extending from a side cheek 3 to the other side cheek 4. A first end of the copper wire 7 is wedged between the corresponding end of the tubular core 2 and the conductive ring 5. The second end of the copper wire 7 is wedged between the corresponding end of the tubular core 2 and the other conductive ring 6. For this purpose, the ends of the copper wire 7 pass through radial slots 8 and 9, formed respectively in the two cheeks 3 and 4 of the coil 1.

 The coil 1 is intended to be supported by an electrically conductive tube 10, with a horizontal axis, one end of which is embedded in a vertical plate 11 of electrically insulating material. The conductive tube 10 passes right through the tubular core 2 of the coil 1 engaged on this conductive tube 10, the coil 1 resting on said conductive tube 10 by its two conductive rings 5 and 6, with a play allowing its free rotation.

 At its free end, projecting in front of the coil 1, the conductive tube 10 is provided with an insulating tip 12, serving as a support for a light-emitting diode 13.

 Above the location of the conductive tube 10, the vertical insulating plate 11 carries a fixed conductive strip 14, which passes right through it and which itself supports, pivotally around a point 15, a strip profiled conductor 16 which surmounts the coil 1 carried by the conductive tube 10.

 Inside this conductive tube 10, a short electrical conductor 17 connects the wall of said conductive tube 10 to a first terminal of the light-emitting diode 13.

 The coil 1 is designed to receive, around its core 2 and between its two lateral cheeks 3 and 4, textile thread 18 wound in turns over a certain thickness, the textile thread 18 being electrically insulating.

When the coil 1 is full of textile wire 18, or at least as long as the thickness E of this textile wire 16 is sufficient to drown all the turns of the copper wire 7, the pivoting conductive strip 16 rests, under the effect of its own weight, on the single insulating textile thread 18 (see FIG. 2). An electrical circuit passing through the bar 14, the pivoting strip 16, the copper wire 7, the conductive rings 5 and 6 and the conductive tube 10 then remains open.

 When the coil 1 is almost empty, and more particularly when the thickness e of the textile wire 18 becomes less than the diameter of the section of the copper wire 7, the pivoting conductive strip 16 comes into frictional contact with at least one of the turns, become apparent, of the copper wire 7 of the coil 1 (see Figure 3). This contact then closes the electrical circuit passing through the bar 14, the pivoting strip 16, the copper wire 7, the conductive rings 5 and 6 and the conductive tube 10. By closing this electrical circuit, the almost empty state of coil 1 is automatically detected. This state is indicated by the lighting of the light-emitting diode 13.

 The end of wire detection device has been described so far for a single coil 1, in order to explain the principle of the invention in a clear and simple manner. In reality, the vertical insulating plate 11 carries a multiplicity of horizontal conductive tubes 10, distributed in rows and columns in a regular pattern, and designed to support a multiplicity of coils 1 equipped with the same device. The electrical assembly partially visible in Figures 2 and 3, and also shown in Figure 4, is suitable for this multiplicity of coils.

 For each line of coils 1, there is provided a common horizontal electrical conductor 19, in contact with all the conductive tubes 10 of this line, and allowing both the acquisition of the state of the wire detector and the ignition of the light-emitting diode 13, for all the coils 1 of the line considered.

 In each column of coils 1, the fixed conducting bars 14 are connected, at a connection point 20, to a common vertical electrical conductor 21 which allows the acquisition of the state of the wire detector, by feeding the pivoting strip 16, for all the coils 1 of the column considered.

 For each conductive tube 10, the second terminal of the light-emitting diode 13 is connected, by an electrical conductor 22 extending inside the tube 10, to a connection point 23 located on another vertical electrical conductor 24, common to a column of coils 1 and used to control the ignition of the light-emitting diodes 13 of this column.

The electrical diagram in principle, allowing the acquisition of the state of each detector and the ignition control of the corresponding light-emitting diode 13, is more particularly shown in FIG. 4, on which are still indicated
- at 25, an electrical resistance associated with an output 26 of the electronic part, which controls via the electrical conductor 22 the lighting of the light-emitting diodes 13 for the column considered
- at 27, another output from the electronic part, which allows the light-emitting diodes 13 to be ignited for the line in question, via the conductor 19 in contact with the conductive tubes 10
- at 28, an output of the electronic part connected to the conductor 21, therefore to the pivoting conductive strips 16, and allowing the scanning of the detectors of the column considered (more particularly the detector of a particular line, selected by setting "zero" state of the corresponding conductor 19)
- at 29, another electrical resistance connecting the conductor 21 to the supply voltage source V
- at 30, an input of the electronic part which allows the acquisition of the state of the coils of the column considered.

 FIG. 5 illustrates the application of the end of thread detection device described above to a weaving loom, the edges of which carry, in total, a very large number of bobbins 1. These bobbins 1 are distributed according to a certain number of modules 31 all identical, each having a predetermined number of rows and columns, and each associated with an electronic part 32 which performs the functions described above. Each electronic part 32 is associated with a button 33 for testing the light-emitting diodes 13 of the associated module 31, and a reset button 34.

 All the electronic parts 32, associated respectively with the various modules 31, are connected by a communication network 35 to a main or master electronic part 36, which is itself connected on the one hand to a permanent display 37, and on the other hand shares in a group of three LEDs 38, 39 and 40. The main electronic part 35 centralizes the detection results given by the electronic parts 32 associated with the different modules 31.

This main electronic part 35 controls the display 37, so as to permanently display on the one hand at 41 the total number of almost empty coils 1, therefore to be changed, and on the other hand at 42 the remaining time of use for the first coil 1 to have been detected as almost empty. As for the three indicators 38, 39 and 40, also controlled by the main electronic part 35, these include
- a first indicator 38 consisting of a green lamp, the illumination of which indicates the presence of a coil to be changed or a small number of coils to be changed, without an emergency situation
- a second indicator 39 consisting of an orange lamp, the illumination of which indicates that an average time (for example of the order of 40 to 50 minutes) has elapsed since the detection of a first almost empty coil, without emergency situation
a third indicator 40 constituted by a red lamp, the illumination of which indicates that a longer time (for example of the order of 60 to 70 minutes) has elapsed since the detection of a first almost empty coil, or that a large number of spools have to be changed, which corresponds to an emergency situation, with the risk of stopping the loom.

 Thus, a simple glance at the display 37 and / or on the indicators 38, 39 and 40 makes it possible to globally assess the state of the creels as well as the necessity and the urgency of changing certain coils 1, each coil 1 to be replaced being additionally individually indicated by the illumination of the light-emitting diode 13 of the conductive tube 10 supporting this coil.

 Of course, the remaining time of use of a coil 1, from the moment when the conductive strip 16 comes into contact with the copper wire 7 of the coil 1, depends on various factors such as: the size of this copper wire 7, the size of the textile wire 18 wound around the core 2 of the coil 1, and the quantity of this textile wire 18 that can be stored between the turns of the copper wire 7, this quantity itself being a function of the no winding of said turns.

 Figures 6 and 7 show a first variant of the coil 1, in which the core 2 and the two side cheeks 3 and 4 are made of an electrically conductive material, the core 2 here carrying no turn of copper wire. This core has, in its middle, an annular groove 43. The insulating textile thread 18 is wound at the start in the only groove 43, then in normal fashion over the entire length of the core 2. During the unwinding of the coil 1, the strip swiveling conductor 16 is first applied to the insulating textile thread 18, so that the electrical circuit remains open. It is only at the end of reeling, when only the textile thread 18 wound at the start in the groove 43 remains, that the conductive strip 16 comes into contact with the fully released core 2, and then closes the electrical circuit.

At this moment, the coil 1 still carries a reserve of textile thread 18, housed in the groove 43. It will be noted that the conductive strip 16 is here pivotally mounted around an axis 15 parallel to the axis 44 of the coil 1, and is situated outside the middle zone comprising the groove 43.

 In this variant, the coil 1 could also be made of an electrically insulating material, such as a synthetic material, and be simply covered with an electrically conductive paint.

 Figures 8 and 9 show another variant of the coil 1, in which the core 2 and the two side cheeks 3 and 4 are also made of electrically conductive material. The core 2 here carries, at a length, an open metal ring 45, engaged by its two ends in two small retaining bores formed on this core 2. The conductive strip 16 is pivotally mounted around an axis parallel to the axis 44 of the coil 1, and is located opposite the ring 45.

When the coil 1 is full, the strip 16 rests on the textile thread 18 which isolates it from the ring 45, which keeps the electrical circuit open (see FIG. 8).

When the coil 1 is almost empty, the strip 16 comes into contact with the ring 45, which closes the electrical circuit (see FIG. 9). This variant can be likened to a coil as shown in Figures 1 to 3, but carrying only one turn of copper wire.

 It goes without saying that the invention is not limited to the sole embodiments of this end of wire detection device on a spool which have been described above, by way of examples; on the contrary, it embraces all of the variant embodiments and applications respecting the same principle.

Claims (11)

 1 - End of wire detection device on a spool, characterized in that it comprises in combination  - for the or each (1) to be monitored, a fixed support (10) in the form of a tube or rod, of substantially horizontal axis, made of electrically conductive material,  - on the core (2) of the or each coil (1) to be monitored, at least one raised part (7; 45) of electrically conductive material, capable of being entirely covered by an electrically insulating wire (18) wound on the coil (1), when the coil is full, and to be made visible when this coil (1) is almost empty, said conductive part (7; 45) being electrically connected to the conductive support (10), when the coil (1 ) is mounted on said conductive support (10),  - an electrically conductive movable strip (16), disposed opposite the coil (1) mounted on its support (10) and able to bear on the wire (18) wound on the coil (1), when the coil is full, or coming into contact with the electrically conductive raised portion (7; 45) of the core (2) of the coil (1), when this coil is almost empty, so as to then close an electrical circuit, and  - Means (13, 19 to 42) for detecting and / or signaling the closing of said electrical circuit.  2 - Detection device according to claim 1, characterized in that the or each coil (1) to be monitored has a core (2) of electrically insulating material, while said electrically conductive raised part consists of a metal wire (7 ) wound with non-contiguous turns around the core (2) of the coil (1), at least one end of this metal wire (7) being connected to an electrically conductive ring (5,6) inserted at one end of the core ( 2) of the coil (1) and able to come into contact with the conductive support (10), when the coil (1) is mounted on said conductive support (10).  3 - Detection device according to claim 2, characterized in that the two ends of the metal wire (7) are respectively connected to two conductive rings (5,6), inserted at the two ends of the core (2) of the coil (1 ).  4 - Detection device according to claim 1, characterized in that the coil (1) has a core (2) at least partially made of electrically conductive material, and in that this core (2) has at least one annular groove (43 ), the electrically insulating wire (18) wound on the coil (1) being wound at the start in this groove (43), while the movable conductive strip (16) is provided to cooperate with a part of the core (2) located outside throat area (43).  5 - Detection device according to claim 1, characterized in that the core (2) of the coil (1) carries a ring (45) of electrically conductive material, intended to cooperate with the movable conductive strip (16).  6 - Detection device according to any one of claims 1 to 5, characterized in that the movable conductive strip (16) is a pivotally mounted strip (at 15) above the location of the coil (1) mounted on its conductive support (10), so as to rest, under the effect of its own weight, on the electrically insulating wire (18) wound on the full coil (1), or on the raised part (17; 45) electrically conductive of the core (2) of the coil (1) almost empty.  7 - Detection device according to any one of claims 1 to 6, characterized in that the conductive support (10) in the form of a tube or rod carries, at its free end, an indicator light (13) serving as a means of signaling of the closing of the electrical circuit, indicating that the coil (1) mounted on the support (10) is almost empty.  8 - Detection device according to any one of claims 1 to 7, characterized in that it is applied to the automatic monitoring of the creels of a loom, in particular a loom shaped velvet, whose creels support a high number of coils storing the threads necessary for the formation of the "pile" of the velvet, each creel having a substantially vertical plate (11) of electrically insulating material, which carries a multiplicity of substantially horizontal conductive supports (10) capable of receiving each a coil (1), means for detecting the state of this coil (1) being associated with each conductive support (10).  9 - Detection device applied to a weaving loom according to claim 8, characterized in that the conductive supports (10) receiving the coils (1) to be monitored, as well as the movable conductive strips (16), are distributed in lines and columns and are connected to horizontal (19) and vertical (21,24) electrical conductors, connected to at least one electronic part (32,36), providing a multiplexing system making it possible to acquire the state of each coil ( 1).  10 - Detection device according to claim 9, characterized in that the electronic part (36) is connected to display means (37) capable of indicating (at 41) the total number of coils (1) detected as almost empty , at all times.  11 - Detection device according to claim 9 or 10, characterized in that the electronic part (36) is connected to indicator lights (38,39,40) successively triggered according to the number of coils (1) almost empty and / or the time elapsed since the detection of at least one almost empty coil (1).