A yarn-winding assembly mounted on a support is provided with a motorized spool and with an oblique spacing pin, between which a yarn is wound. The spacing pin is supported so that it can rotate about an axis of the motorized spool by unidirectional rotary support elements. The spacing pin rotates freely with respect to the spool when the latter rotates in the yarn unwinding direction and the former is retained from rotating by stop elements, and is instead integral with the spool when the spool rotates in the opposite yarn rewinding direction.
A textile machine receives a plurality of yarns from respective feeders, each provided with a control unit that calculates, for each garment produced, the amount of yarn consumed (YCmeas) and compares it with a reference consumption value (YCref). If the difference exceeds a preset limit value (% max) that indicates an anomaly, then an alarm is generated. Periodically, the control unit calculates an average consumption value (YCmed) on the basis of a preset number (Nmed) of already-finished garments, and compares it with the reference consumption value (YCref). If the difference exceeds a preset threshold value (% maxmed), then the reference consumption value (Yref) is set to the average consumption value (Ymed).
A yarn winding assembly installed on a support includes a motorized spool and an oblique spacer pin, between which a yarn is wound. The spacer pin is supported rotatably by a rotating supporting component so that it is entrained in two directions by the yarn wound between the spool and the spacer pin. The rotation of the spacer pin is delimited by an element of arrest at least in a direction of unwinding the yarn.
A motorized rotary drum supported on a motor housing bears a plurality of yarn loops wound thereon, such loops being adapted to be unwound upon request from a downstream machine. A yarn-unwinding sensor comprises light-emitting elements and light-receiving elements both of which are integral with the motor housing. Light-guiding elements which are integral with the drum guide the light from the light-emitting elements to a window which is defined on the rotary drum in a position such that it is repeatedly engaged by the yarn during its rotary unwinding motion, and vice versa. A reflecting surface reflects the light coming out of the window back towards the window. Light-deviating elements which are integral with the motor housing deviate the light coming back from the window towards the light-receiving elements. The unwinding of a yarn loop from the drum is determined on the basis of the variation of light resulting from the yarn transiting on the window.
B65H 51/22 - Bobines ou casiers, p. ex. cylindriques, avec des surfaces de stockage et d'avance constituées de rouleaux ou de barres
G01D 5/34 - Moyens mécaniques pour le transfert de la grandeur de sortie d'un organe sensibleMoyens pour convertir la grandeur de sortie d'un organe sensible en une autre variable, lorsque la forme ou la nature de l'organe sensible n'imposent pas un moyen de conversion déterminéTransducteurs non spécialement adaptés à une variable particulière utilisant des moyens optiques, c.-à-d. utilisant de la lumière infrarouge, visible ou ultraviolette avec atténuation ou obturation complète ou partielle des rayons lumineux les rayons lumineux étant détectés par des cellules photo-électriques
B65H 63/00 - Dispositifs d'alarme ou de sécurité utilisés pour le déroulage, le dévidage, le défilement, l'enroulage, le bobinage ou l'emmagasinage d'un matériau filiforme, p. ex. détecteurs automatiques de défectuosités ou mécanismes d'arrêt
5.
Stock-controlling method for a storage yarn feeder with rotary drum
A yarn feeder is provided with a drum which is driven to rotate by a motor controlled by a control unit for drawing yarn from a reel and winding it upon itself in the shape of loops forming a stock. The control unit estimates the stock on the drum on the basis of an information indicative of the amount of yarn which is unwound from the drum upon request from a downstream machine, and of an information indicative of the amount of yarn which is wound on the drum, and retroactively controls the motor to substantially stabilize the stock on a reference value. The control unit also performs a parallel correction routine in which compares the stock with the reference value to estimate a stock status RES
The yarn tension is modulated by a yarn-braking device controlled by a control unit which receives signals of measured tension from a tension sensor and compares them with a reference tension signal in a control loop; as long as the reference tension remains unchanged, a first set of coefficients is used in the control loop causing the control loop to have a relatively slow behavior in relation to the error-compensating action; when a change in the reference tension occurs, the system switches to a second set of coefficients causing the control loop to have a relatively fast behavior; the second set of coefficients is maintained as long as the difference between the second value of the reference tension and the measured tension remains greater or equal to a predetermined minimum value, then the system switches again to the first set of coefficients.
B65H 51/22 - Bobines ou casiers, p. ex. cylindriques, avec des surfaces de stockage et d'avance constituées de rouleaux ou de barres
B65H 59/06 - Réglage ou commande de la tension du matériau filiforme, p. ex. pour empêcher les vrillesUtilisation d'indicateurs de tension par régulation de la délivrance du matériau à partir du paquet d'approvisionnement par dispositifs agissant sur le matériau sortant du paquet
D04B 15/44 - Dispositifs de tension pour fils individuels
B65H 59/10 - Réglage ou commande de la tension du matériau filiforme, p. ex. pour empêcher les vrillesUtilisation d'indicateurs de tension par dispositifs agissant sur le matériau courant et sans liaison avec les dispositifs d'approvisionnement ou de prise
D03D 47/34 - Transport de la trame entre le point d'emmagasinage et le moyen d'insertion
A motorized yarn-winding drum holds a plurality of loops of yarn wound thereon and is driven to rotate for drawing said yarn from a reel and feeding it to a general downstream machine. A movable guiding member is biased to slideably engage the yarn unwinding from the drum and to deviate its path, by a spring acting in contrast to the tension of the yarn, thereby generating a reserve releasable in response to tension peaks on the yarn. The stroke of the guiding member is limited by a stop defining a position of maximum deviation of the yarn. The spring has one end operatively connected to the guiding member and one opposite end connected to driving elements operable for applying a load to the spring, with the guiding member abutting against said stop. The driving elements are controlled by a control unit which is programmed to adjust the load as a function of a desired feeding tension.
A knitting line comprises a plurality of yarn feeders from which a downstream machine draws respective yarns. The machine is provided with selection elements adapted to vary the state of selection of the yarn feeders in relation to the angular position of the machine. Each of the yarn feeders is provided with a stationary drum and with a yarn count sensor arranged to generate a pulse per each yarn loop unwound from the drum. A selection signal is periodically sent to the yarn feeders, which is indicative of the state of selection of the individual feeders in relation to the angular position of the machine. For each of the selected feeders, a threshold time interval is continuously calculated, which corresponds to the maximum interval between two successive pulses, above which it should be regarded that an accidental stop of the yarn has occurred, and is updated in real time as a function of the yarn-drawing speed, the delay from the last pulse is continuously measured and compared with the updated threshold time interval, and the downstream machine is stopped when the measured delay exceeds the updated threshold interval.
G06F 19/00 - Équipement ou méthodes de traitement de données ou de calcul numérique, spécialement adaptés à des applications spécifiques (spécialement adaptés à des fonctions spécifiques G06F 17/00;systèmes ou méthodes de traitement de données spécialement adaptés à des fins administratives, commerciales, financières, de gestion, de surveillance ou de prévision G06Q;informatique médicale G16H)
10.
Method for detecting the stop of the yarn unwinding from a yarn feeder provided with a stationary drum
In order to detect the stop of the yarn unwinding from a yarn feeder provided with a stationary drum and with a sensor generating a pulse per each yarn loop unwound from the drum, a threshold time interval is continuously computed, which corresponds to the maximum interval between two successive pulses, above which it should be regarded that an accidental stop of the yarn has occurred. The threshold time interval is updated in real time as a function of the yarn-drawing speed. Then the delay from the last pulse is continuously measured and compared with the updated threshold time interval. The machine is stopped when the measured delay overcomes the updated threshold interval.
A motorized yarn-winding drum holds a plurality of loops of yarn wound thereon and is driven to rotate for drawing said yarn from a reel and feeding it to a general downstream machine. A movable guiding member is biased to slideably engage the yarn unwinding from the drum and to deviate its path, by a spring acting in contrast to the tension of the yarn, thereby generating a reserve releasable in response to tension peaks on the yarn. The stroke of the guiding member is limited by a stop defining a position of maximum deviation of the yarn. The spring has one end operatively connected to the guiding member and one opposite end connected to driving elements operable for applying a load to the spring, with the guiding member abutting against said stop. The driving elements are controlled by a control unit which is programmed to adjust the load as a function of a desired feeding tension.
The tension is modulated by a weft-braking device controlled by a tension control block programmed for comparing the measured tension with a reference tension, and for transmitting a braking level signal to the weft-braking device, which braking level signal is adapted to minimize the difference between the measured tension and the reference tension. The yarn consumption speed is calculated, then the yarn consumption speed is compared with a predetermined threshold speed, and if the calculated consumption speed overcomes the predetermined threshold value, the tension control block is enabled, while, if the calculated consumption speed is lower than the threshold value, the tension control block is disabled and the last signal generated by the latter is maintained as braking signal, until the yarn consumption speed overcomes again the threshold value.
G06F 19/00 - Équipement ou méthodes de traitement de données ou de calcul numérique, spécialement adaptés à des applications spécifiques (spécialement adaptés à des fonctions spécifiques G06F 17/00;systèmes ou méthodes de traitement de données spécialement adaptés à des fins administratives, commerciales, financières, de gestion, de surveillance ou de prévision G06Q;informatique médicale G16H)
A yarn recovering device for textile machines, arranged upstream of a textile machine for temporarily recovering a length of yarn previously fed to the machine, and for returning it subsequently. A motorized reel has a substantially axial inlet port and an outlet port on its lateral surface, with a passage for the yarn between the ports. The reel is operatable to rotate from a resting configuration, in which it is kept still, to an active, yarn-recovering configuration, in which it is driven in one direction for winding the yarn on itself and recovering it from the machine, to a subsequent active, yarn-unwinding configuration, in which it is driven in the opposite direction for unwinding the yarn from itself and returning it to the machine. A position sensor measures the position of the reel and sends a corresponding measured position signal to a position control loop which compares the measured position signal with a reference position signal corresponding to a desired position for the motorized reel, and drives the reel in such a way as to minimize the difference between the measured position and the desired position.
