EP1620589A1 - Systeme optique pour verifier la non-rupture des fils de chaines dans un metier a tisser - Google Patents

Systeme optique pour verifier la non-rupture des fils de chaines dans un metier a tisser

Info

Publication number
EP1620589A1
EP1620589A1 EP03815852A EP03815852A EP1620589A1 EP 1620589 A1 EP1620589 A1 EP 1620589A1 EP 03815852 A EP03815852 A EP 03815852A EP 03815852 A EP03815852 A EP 03815852A EP 1620589 A1 EP1620589 A1 EP 1620589A1
Authority
EP
European Patent Office
Prior art keywords
warp yarns
warp
optical system
yarn
image
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03815852A
Other languages
German (de)
English (en)
Inventor
Egidio Tasca
Eugenio Sarzilla
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
FIRST SpA
Original Assignee
FIRST SpA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by FIRST SpA filed Critical FIRST SpA
Publication of EP1620589A1 publication Critical patent/EP1620589A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • D03D51/20—Warp stop motions
    • 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
    • D03D51/20—Warp stop motions
    • D03D51/28—Warp stop motions electrical

Definitions

  • the present invention relates to an optical system for controlling warp yarns in a weaving loom. More particularly, the present invention relates to a system for controlling in a continuous manner the unbroken condition of warp yarns during weaving, thus functioning as a "warp stop motion device", as it is commonly referred to in the sector.
  • the warp stop motion device is a device mounted in every type of loom and apt to promptly locate the breaking of a warp yarn, just during weaving, so that the loom can be immediately stopped and the operator can proceed to repair said warp yarn (i.e. to knot the broken ends of the same) before defective fabric is produced.
  • Drop wire warp stop motion devices are provided with a plurality of thin steel blades, which are commonly referred to as “drop wires", each of which is positioned over and around a single warp yarn, from which - due to the tension applied to the warp yarns by the loom - the dropwire is kept lifted above a transversal rod called "bank".
  • Each bank - there are, in fact, usually several parallel banks in a loom - is provided with two conductive, usually metallic, elements consisting of an internal bar and an external shell having a U-shaped section, said conductors being reciprocally isolated, from an electric standpoint, by a film of insulating material.
  • the two bank conductors are connected to an electric control circuit, so that, whenever a warp yarn breaks or slackens, the respective drop wire, no longer held up by the tension of the yarn, falls onto the underlying bank and closes the electric circuit formed by the two conductive ele- ments of the bank.
  • an apposite electronic control device immediately stops the loom and, at the same time, emits a warning signal for the operator and a signal indicating the bank on which the drop wire has fallen and, sometimes, even the approximate location where the fall has taken place.
  • drop wire warp stop motion devices generally have the advantage of providing a prompt intervention upon breaking of the yarn, however, they also show several disadvantages. First of all, they require a long set-up time, since on every one of the thousands of yarns that make up the warp a drop wire must be inserted. Bigger weaving plants are often provided with special automatic machinery for this type of operation, but, in any case, it is a complicated, long and, therefore, very costly operation. Due to the high number of drop wires mounted on a bank - normally thousands or tens of thousands - searching the fallen drop wire, in spite of the numerous electronic and mechanical devices designed to simplify this task - always requires a certain level of expertise by the operator and a relatively long execution time.
  • the stop of the loom caused by false contacts signalled by the bank control circuit can occur as well because of bunching of electrostatic charges on the warp yarns - phenomenon caused by the rubbing of warp yarns against the drop wires and particularly evident when synthetic yarns are woven - which cause in an unpredictable manner discharge currents on the banks. These currents close the bank electric circuit momentarily and, therefore, give a temporary false indication of breakage of the warp yarns .
  • the bunching of electrostatic charges on the warp yarns is also responsible for a further inconvenience that is present in the drop wire warp stop motion device, i.e. that of the electrostatic adhesion of one or more warp yarns.
  • the electrostatic adhesion force is in fact sometimes sufficient to exceed the weight of a drop wire so that, even in the case of a breakage of a warp yarn, the relative drop wire is held up by the adjacent yarns and the breakage is not detected.
  • the rotating brush warp stop motion devices (shown in Figures 2 and 3) include a device G transversally positioned under the warp yarns - comprising a linear bristle brush C and a harmonic yarn D stretched in a position diametrically opposite to that of the brush C - that rotates continuously at a low speed, periodically brushing the warp yarns.
  • the brush C is apt to "capture" the same during its rotation and to drag it therewith by wrapping the broken yarn around the rotation axis of the device G.
  • the rotating brush warp stop motion devices offer the advantage of avoiding altogether the presence of drop wires along with relative inconveniences, but are characterized by the big drawback of being unable to promptly signal the breakage of the yarn, signal that, as a matter of fact, takes place with a delay depending from the relative position of the brush in respect of the warp yarns at the moment of breakage of the yarn. So it can happen that the stopping of the loom, following the breakage of the yarn, takes place only after several tens of beatings, causing thus obvious and serious defects in the fabric.
  • Object of the present invention is, therefore, to provide a new type of optical system for controlling the unbroken condition of the warp yarns in a weaving loom, apt to promptly signal the breakage or slacking of warp yarns, so as to avoid any warp defect in the fabric, and to eliminate the above discussed main inconveniences of the drop wire warp stop motion devices, i.e.: long set-up time, drop wire wear, warp yarn deterioration, false signals of broken warp yarns or, on the other hand, missed signals of said breakage due to electrostatic adhesion phenomena between the yarns.
  • an important object of the present invention is to eliminate the presence of metallic drop wires associated with every warp yarn. This way, both the warp long initial set-up step and the negative consequences due to the rubbing physical contact between drop wires and warp yarns would be automatically eliminated.
  • a system for controlling warp of this type would meet a highly-demanded need in the sector, a need that up till today has not been addressed, i.e. the possibility to have a warp stop motion device that has the same effectiveness in terms of a quick breakage detection, than the drop wire warp stop motion device, but that presents lower operational costs and that considerably contributes to the reduction of total num- ber of stops of the loom, just like the brush warp stop motion device does.
  • Such object is achieved, according to the present invention, through an optical system for controlling the unbroken condition of the warp yarns in a weaving loom having the fea- tures disclosed in claim 1) , appended below.
  • Figure 1 is a schematic side view of a loom, wherein a schematic block diagram of the optical system for controlling the unbroken condition of warp yarns according to the present invention is inserted;
  • Figure 2A is a front view of a prior art device of a brush warp stop motion device
  • Figure 2B is a side view of the warp stop motion device of Figure 2A, inserted among the main elements of a loom with which it works;
  • Figures 3A and 3B are views corresponding to Figures 2A and 2B during the detection of a broken warp yarn.
  • the optical reader 1 is mounted above the plane formed by warp yarns 0, so that a plan view of the same is taken, i.e. an image in which all warp yarns are clearly visible.
  • the image definition can be improved by having, in correspondence of the optical reader and on the opposite side of warp yarns 0, a light source L so as to increase, in the acquired image, the contrast between warp yarns 0 and the background of the image itself.
  • the ac- quired image can comprise the warp yarns as a whole or a subset of the same; in the latter case, i.e. when the shooting field of the optical reader 1 does not comprise all warp yarns, the complete monitoring of the same is achieved by using several appropriately offset optical readers.
  • the optical reader can be both a spot type such as, for example, a video camera, and a linear type such as, for example, a continuous bar of optical readers of the type used for scanners .
  • a preferred position, particularly from a mechanic point of view, for the installation of the optical reader and the relative light source is the one shown in the drawing, i.e. immediately upstream of the group of heald-frames in the direction of movement of the fabric; this area, in fact, is sufficiently free of other service devices and other loom accessories.
  • the fact that in that area the warp yarns are subjected to a strong and periodic spreading apart, caused by heald-frames Q for shed formation, does not constitute any. problem.
  • the position of the optical reader 1 is not, anyway, critical for the operation of the present invention. Where textile or installations reasons so request, it is, therefore, possible to install the same in other positions as well.
  • two other possible installation positions of the optical reader are shown: position 2, immediately downstream of the weft yarn cylinder F and position 3, immediately upstream of the comb P.
  • the images of warp yarns 0 are sequentially acquired by the optical reader with a minimum frequency equal to the working frequency of the loom, so that if a warp defect is detected, the loom can be stopped at the latest during the first or second beating after the detection of the defect and the defect can, therefore, quickly be eliminated after even- tually executing a corresponding number of reverse beatings of the loom.
  • the presence of a warp defect is detected by the processing unit U by measuring one or more parameters of the last acquired image and by comparing each of said parameters with a predetermined value for that parameter, or with the value that the same parameter had in one or more of the images before the last acquired image.
  • the considered parameter is the number of warp yarns.
  • the processing unit U counts, on the image acquired by the optical reader 1, the number of warp yarns and then compares the result of such calculation with a predetermined value that, in this case, is the total number of warp yarns mounted on the loom (or the total number of warp yarns the group of warp yarns resulting from the image, if the image does ' not include the warp yarns as a whole).
  • the predetermined value of the number of warp yarns can be known to the weaver and he can manually enter it into the process- ing unit U, or the unit itself can use the result of the calculation made on the first acquired image, at the very beginning of the weaving process and preferably when the loom is standstill, i.e. when all warp yarn are still perfectly unbroken.
  • the processing unit When, during the analysis the last acquired image, the processing unit detects that the number of warp yarns is different, by a pre-established quantity, from the above- mentioned predetermined value, it sends a stop command to the loom main engine M and, simultaneously, emits an alarm signal A to alert the weaver that a manual repair operation of the loom is requested.
  • the above pre-established quantity that causes the alarm mechanism to sound is usually equal to 1.
  • the considered parameter is the overall pattern formed by the warp yarns of the acquired image.
  • the processing unit U compares, pixel by pixel, the last acquired image with the one immediately preceding the same - or an image obtained by the average values of the last acquired n images - causing the loom to stop only when the number of pixel deviations between the two images is higher than a pre-established quantity.
  • Such a quantity will, in this case, have to be determined experimentally, according to the type of yarns used and other weaving conditions as well; in particular, such quantity will have to be high enough to exclude small lateral movements which warp yarns may undergo as possible causes of alarm conditions, and low enough to allow the signalling of deviations which a warp yarn undergoes due to slacking or breakage of the same. It should then be considered that by having completely eliminated - according to the present invention - metal drop wires of traditional warp stop motion devices, all electrostatic phenomena caused by the rubbing between warp yarns and such drop wires have correspondingly all the same been elimi- nated. It is, therefore, clear that in case of breakage or slaking of a warp yarn, said yarn will position itself in a much more deformed configuration than in a loom with a traditional drop wire warp stop motion device.
  • the considered parameter is the parallelism of warp yarns.
  • the position of every warp yarn detected in the image is, therefore, compared with that of an ideal yarn placed according to a predetermined direction, and the deviation between the two images is determined.
  • the predetermined direction can be manually input into the processing unit U; on the contrary, it can be automatically detected by the same, based on the direction of the warp yarns when the loom is standstill, before the beginning of weaving operations.
  • the deviation can, for example, be calculated as pixel percentage of the image of every single warp yarn that is aligned along said predetermined direction, by causing the loom to stop only when the value of said percentage is lower than a pre-established quantity.
  • said pre-established quantity will have to be experimentally determined according to the weaving type and conditions, and will have to be high enough to exclude error signals caused by small angular variations which warp yarns undergo due to movement of heald- frames, and instead low enough to comprise every possible deviation from said predetermined direction which a warp yarn undergoes due to slacking or breakage of the same.
  • the considered parameter is the position of every warp yarn, and such position is compared with that taken by the same warp yarn in the previous image, or in an image formed by the average data of the last previous n images, by detecting the deviation between the two images as the number of pixels of the representation of every single yarn which do not coincide with the ones of the previ- ous image.
  • the stop function of the loom and the determination of the predetermined deviation quantity above which such func- tion is determined are similar to those described in the above-mentioned third embodiment and are not, for the sake of brevity, further described herewith.
  • the stop command of the loom in the third and fourth embodi- ments is given following a verification of the deviation in respect of the predetermined values measured on every single warp yarn, instead of on the entire acquired image. It is therefore generally possible, in these embodiments, to dis- tinguish with a higher precision degree between small movements of warp yarns due to normal weaving operations and larger movements caused instead by a breakage or slaking of the yarns themselves.
  • the considered parameter is the theoretical diameter of the warp yarns.
  • a bar linear optical reader having a high number of optical readers is used, so that resolution is at least equal to the theoretical diameter of the warp yarn and preferably 1/2 or, even better, 1/4 of the same.
  • An opti- cal reader of this type is in fact capable of detecting not only the presence or absence of the yarn, but also of detecting a progressive thinning thereof - when a breakage occurs not all of a sudden but due to a progressive wear of the yarn - by anticipating therefore the error signal and the stop of the loom in respect of the moment of breakage.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Looms (AREA)

Abstract

Cette invention se rapporte à un système optique qui sert à vérifier la non-rupture des fils de chaînes dans un métier à tisser. Dans ce système, un dispositif de lecture optique (1) est capable de détecter une succession continue d'images des fils de chaînes (0) dans leur ensemble, ou un sous-ensemble de celles-ci, et une unité de traitement (U) est capable de mesurer en continu un ou plusieurs paramètres de chacune de ces images. L'unité de traitement envoie une instruction d'arrêt au métier à tisser et, le cas échéant, un signal d'avertissement, lorsque l'un des paramètres relatif à la dernière image acquise diffère, selon une quantité préétablie, d'une valeur prédéterminée de ce paramètre ou de la valeur de ce paramètre mesurée dans une ou plusieurs des images précédant la dernière image acquise.
EP03815852A 2003-02-17 2003-02-17 Systeme optique pour verifier la non-rupture des fils de chaines dans un metier a tisser Withdrawn EP1620589A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/IT2003/000081 WO2004072342A1 (fr) 2003-02-17 2003-02-17 Systeme optique pour verifier la non-rupture des fils de chaines dans un metier a tisser

Publications (1)

Publication Number Publication Date
EP1620589A1 true EP1620589A1 (fr) 2006-02-01

Family

ID=32866024

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03815852A Withdrawn EP1620589A1 (fr) 2003-02-17 2003-02-17 Systeme optique pour verifier la non-rupture des fils de chaines dans un metier a tisser

Country Status (4)

Country Link
EP (1) EP1620589A1 (fr)
CN (1) CN1742124A (fr)
AU (1) AU2003215896A1 (fr)
WO (1) WO2004072342A1 (fr)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ITFI20050080A1 (it) * 2005-04-29 2006-10-30 Pietro Gironi Dispositivo e metodo di lettura e controllo in linea dei fili d'ordito in un telaio
CN102383233A (zh) * 2010-09-02 2012-03-21 上海驰网工业科技有限公司 整经机断纱自停装置和方法
DE102015110519B3 (de) * 2015-06-30 2016-06-16 Protechna Herbst Gmbh & Co. Kg Überwachungseinrichtung zum Überwachen einer Fadenschar an einer Textilmaschine
CN106048865B (zh) * 2016-08-03 2017-12-19 江苏宋和宋智能科技有限公司 一种织造经纬视觉监控智能***
CN107657613A (zh) * 2017-11-01 2018-02-02 扬州远睿精密机械有限公司 一种经纱状态检测装置及其工作方法
CN108918544A (zh) * 2018-09-21 2018-11-30 广东溢达纺织有限公司 自动检测纱线撞筘装置、方法及浆纱***
FR3094380B1 (fr) * 2019-03-28 2022-01-07 Safran Aircraft Engines Contrôle du positionnement et de la continuité de fils dans un métier à tisser
CN110258008A (zh) * 2019-07-11 2019-09-20 台嘉玻璃纤维有限公司 一种薄织物断经感应装置
JP7339910B2 (ja) * 2020-03-23 2023-09-06 日本毛織株式会社 織物の製造方法、経糸の検査方法及び経糸の検査装置
CN113005608A (zh) * 2021-02-04 2021-06-22 江苏博雅达纺织有限公司 基于无接触经纱断经检测的织机的控制方法
WO2023147168A2 (fr) * 2022-01-31 2023-08-03 Unspun, Inc Fabrication de produits textiles tissés à la demande
CN115161857B (zh) * 2022-06-24 2023-10-13 台嘉蚌埠玻璃纤维有限公司 一种经停片精准定向感应的织布机

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE902741A (nl) * 1985-06-26 1985-12-30 Picanol Nv Werkwijze om in een weverij een optische kontrole op de gefabriceerde weefsels uit te oefenen en kontrole-inrichting hierbij aangewend.
JPH03161555A (ja) * 1989-11-20 1991-07-11 Toyota Autom Loom Works Ltd 織機における経糸通し検出装置
TW210363B (fr) * 1992-01-24 1993-08-01 Tsudakoma Ind Co Ltd
FR2785625B1 (fr) * 1998-11-05 2000-12-22 Visioreg Systeme d'acquisition inspection tissus
BE1014133A3 (nl) * 2001-04-20 2003-05-06 Picanol Nv Werkwijze voor het optimaliseren van een textielproductieproces en inrichtingen die deze werkwijze toepassen.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004072342A1 *

Also Published As

Publication number Publication date
WO2004072342A1 (fr) 2004-08-26
CN1742124A (zh) 2006-03-01
AU2003215896A1 (en) 2004-09-06

Similar Documents

Publication Publication Date Title
WO2004072342A1 (fr) Systeme optique pour verifier la non-rupture des fils de chaines dans un metier a tisser
US9499926B2 (en) On-loom fabric inspection system and method
SK279731B6 (sk) Spôsob zisťovania chýb v textilnej tovarovej dráhe
CN111433399B (zh) 用于触发织机上织物检查的方法和***
JP5195004B2 (ja) 走行糸条の検査方法、および、それを用いた炭素繊維の製造方法
JPS60231850A (ja) 布、特に織布を自動的に監視する方法と装置
US3818236A (en) Apparatus for detecting broken threads or other disturbances in a fibre web
JPH07172699A (ja) 糸パツケージの巻き上げ品質をチエツクするための装置及び該装置のワインダ又は精紡機上での使用
US4384596A (en) Means and method for sensing loom conditions indicative of potential fabric defects
US11814755B2 (en) Method of contactless optical detection of yarn at a workstation of a yarn manufacturing textile machine, an optical sensor of yarn and a textile machine
US4911207A (en) Method for monitoring warp breaks on weaving machines, and a device which uses this method
CN113874571A (zh) 具有检测成绒变化的装置和方法的织机
JP2000177931A (ja) 紡績機又はワインダにおける無接触式の紡績糸監視のための方法及び装置
KR102615697B1 (ko) 표면 마모용 센서 원리
CN111719233B (zh) 经编机
JPH08109549A (ja) 織機の経糸異常検知装置
JP2020122233A (ja) 筬汚れ試験方法
JP7454593B2 (ja) 針を用いる繊維機械において破損した針の存在を検出するための方法及びシステム
US4396040A (en) Quality monitoring system for looms
GB2090619A (en) Means and method for sensing loom conditions
KR102569694B1 (ko) 직물의 피복 표면 상태를 바탕으로 즉시 편직기 상태를 알리기 위한 원형 편 직기
CA1146047A (fr) Dispositif de commande de fonctionnement d'un metier a tisser, et methode connexe p.r.
KR101569102B1 (ko) 직물제직장치용 경사 및 위사 오류감지장치
JP2019203748A (ja) 繊維束の監視方法、この監視方法を用いた監視装置及び、この監視方法または監視装置を用いた繊維束の製造方法
JPH04148853A (ja) 検反装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20050908

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE CH DE FR IT LI TR

DAX Request for extension of the european patent (deleted)
RBV Designated contracting states (corrected)

Designated state(s): BE CH DE FR IT LI TR

17Q First examination report despatched

Effective date: 20090127

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20090807