US3818236A - Apparatus for detecting broken threads or other disturbances in a fibre web - Google Patents

Apparatus for detecting broken threads or other disturbances in a fibre web Download PDF

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Publication number
US3818236A
US3818236A US00281424A US28142472A US3818236A US 3818236 A US3818236 A US 3818236A US 00281424 A US00281424 A US 00281424A US 28142472 A US28142472 A US 28142472A US 3818236 A US3818236 A US 3818236A
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Prior art keywords
light
improved apparatus
receiver
threads
emitter
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Expired - Lifetime
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US00281424A
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English (en)
Inventor
B Lind
M Mansson
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Nordiska Maskinfilt AB
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Nordiska Maskinfilt AB
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    • 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

  • An apparatus for the supervision of fibrous webs, or other sheet-like material, particularly within the textile and paper industries, with the purpose of detecting faults in webs An emitter is positioned at one side of the web and arranged to give off a beam of light essentially at right angles to the web extension.
  • a receiver positioned at the opposite side of the web, receives the beam of light.
  • the beam is imparted a particular movement covering an area of the web where faults are likely to arise and the immediate vicinity of said area.
  • Evaluation means register any disturbances and compare them with a predetermined value, and upon excess of said predetermined value an impulse is emitted to a warning and/or stopping mechanism.
  • these systems comprising an emitter giving off a beam of light at an angle essentially normal to the warp threads, which beam of light is received by a receiver positioned at the opposite side of the weave and arranged to measure the change of intensity of the beam of light occurring when the the light beam path is disturbed or interrupted by a warp thread.
  • Means are connected to said receiver to emit, at a predetermined disturbance, an impulse providing an alarm signal and/or stopping the weaving.
  • both the emitter and the receiver are fixed to the reed in such a way that the emitter gives off a beam of light which in response to the movement of the reed describes an arcuate motion path lying completely within the shed, i.e., between the warp threads of the upper and the lower part of the warp.
  • This broken thread will hang down within the shed and thus interrupt the beam of light when the latter travels to the receiver.
  • This disturbance, caused by the pendant thread will cause a decrease of intensity of the light reaching the receiver, this intensity decrease causing the means connected to the receiver to start functioning and thus stop the weaving. If, on the other hand, a thread of the lower part of the warp breaks, this thread will hang down below the area scanned by the beam and the weaving operation will continue, resulting in a deficient product.
  • the emitter of these earlier systems operates with a beam of light which originally has a diameter of between 2 and 3 centimeters and which diverges to a diameter of up to between 5 and 6 centimeters, dependent on the width of the weave.
  • the receiver only a smaller amount of this light is used for detecting purposes and the result is that disturbances occur as shadows in the receiver.
  • the shadowing caused by a broken thread positioned adjacent the emitter is much less than that caused by a broken thread having the same dimensions but positioned close to the receiver, and as a result great variations of shadowing will arise for the same degree of disturbance at different areas of the warp.
  • an apparatus in accordance with the present invention which is essentially characterised in that the emitter, which is positioned at one side of the web, is arranged to give off an essentially coherent light beam to which means impart such a movement that the light beam travels within an area of the web where disturbances are likely to arise, and in that the means connected to the receiver are arranged both to register the number of disturbances per time unit, to compare the number of registered disturbances per time unit with a predetermined value, and also, in case of deviation of the registered value from the predetermined value, to emit said impulse.
  • This apparatus thus provides supervision while making use of the emitted light fully for the scanning activity which embraces all warp threads.
  • a decrease of intensity which is proportional to the dimension of the disturbing object, irrespective of the distance between the receiver and the disturbing object.
  • the apparatus does not suffer from any one of the disadvantages mentioned previously.
  • FIG. 1 illustrates in a highly schematic view from above the apparatus as applied to a weaving loom
  • FIG. 2 is a side view of the loom of FIG. 1, and
  • FIG. 3 is a diagrammatic basic circuit diagramme showing the underlying principle of the receiver part of the apparatus.
  • the loom illustrated in FIGS. 1 and 2 comprises generally a warp beam 1 on which warp threads 2 are wound. Only a small number of these threads 2 is shown in FIG. 1.
  • the warp threads 2 pass through healds 3 where, with the aid of shafts, they form an aperture 4 the shed through which weft threads are inserted and compacted with 'the aid of a weave reed 5, the latter having been excluded from FIG. 1 in order not to clutter the drawing and being shown only in FIG. 2.
  • the fabric web 6 formed during weaving is thereafter wound onto a fabric beam 7.
  • an emitter 8 is arranged at one longitudinal side of the loom, said emitter giving off an essentially coherent beam of light 9 and being mounted essentially immovably relative to the machine frame of the loom, either by being attached directly on the frame or in order to avoid machine vibrations on the machine base.
  • a receiver it is positioned in a similar manner, said receiver being provided with a collecting input screen corresponding to the path of movement of the light, and preferably comprising a photoelectric cell arranged to measure the intensity of the incoming beam of light.
  • the device 11 Adjacent the emitter 8 there is a device 11 which is arranged to impart a definite movement to the beam of light 9 from the emitter.
  • the device 11 comprises in accordance with the illustrated, preferred embodiment a hollow shaft 12 which is orientated in alignment with the direction of issue of the beam of light 9 in such a manner that the beam of light passes through the shaft.
  • a nonrotational optical element 13 At the shaft end remote from the emitter the shaft is provided with a nonrotational optical element 13 which may consist of mirrors, lenses or prisms and is arranged to effect a parallel movement of the beam of light over a short distance.
  • the shaft 12 is rotatably mounted and driven at a high speed by a motor 14, whereby the beam of light 9 is imparted a rapid rotational movement in a plane perpendicular to the warp threads 2.
  • these means extending essentially normally to the extension of the warp threads and consisting in their most simple version of wires suspended beneath the shed in a manner permitting a thread of the lower warp, when breaking, to remain in a pending position within the area being scanned by the moving beam of light 9 whereas the wires themselves are orientated in a way preventing them from interfering with or interrupting the rotational path of the beam of light at any point.
  • FIG. 2 illustrates in a more detailed manner the position of the catcher means 15 as also the extent of the path of movement 16 along which the beam of light 9 carries out its scanning action.
  • This Figure also shows the position of the reed 5 whereas the detecting apparatus is not illustrated here in order to give a clearer view of the scanned path 16.
  • FIG. 3 is a basic circuit diagramme showing the underlying principle of the construction of the receiver portion of the apparatus.
  • an amplifier 17 which amplifies the input pulses.
  • a filter 18 which forwards pulses having a determined frequency to a level-sensing unit 19.
  • the latter is adjustable such that pulses exceeding a predetermined value are permitted passage to a clock 20 determining the measuring interval and providing the measuring time to a counting device 21 counting the number of pulses per time unit. This number is compared in a comparator 22 to a predetermined value which is dependent on the speed at which the shaft 12 is rotated and on the measuring time.
  • the comparator 22 Upon occurrence of deviations of the measured value from the predetermined one, the comparator 22 emits an impulse to a means 23 arranged to control a switch 24 in the supply line to the loom drive motor 25.
  • the switch 24 is preferably arranged to close a circuit for an alarm signal apparatus 26 in connection with breaking the circuit of the drive motor 25.
  • each sequence of measuring thus comprises a large number of revolutions and the number is determined by the clock 20 in addition to which each measuring sequence lasts a comparatively short time in relation to the duration of the loom working stroke, i.e., the reciprocating movement of the reed.
  • the photo-electric cell of the receiver then receives a number of signals corresponding to the number of revolutions multiplied by four. Analogy is thus obtained in the comparator 22 between the predetermined value and the one registered by the counter. In this situation, the comparator does not issue an impulse to the breaking means 23.
  • the comparator will likewise bring about stopping.
  • the probability that too low a disturbance impulse value caused by apparatus failure could be evened out by one or several thread breaks occurring simultaneously is negligible.
  • the movement which the coherent light beam 9 is imparted has been described in the aforegoing as a rotating movement.
  • This motion pattern is comparatively easy to achieve but what is essential to the functioning of the detecting apparatus is that the light beam 9 moves in such a way that the shed, the upper warp and the lower warp and the area closest to the lower warp are scanned, and for this reason it is also possible to use a very simple movement such as a rectilinear one.
  • the clock 20 is programmed to release measuring sequences at predetermined intervals and to prevent starting of measure sequences during exchange of the reeds.
  • the coherent beam of light 9 given off by the emitter 8 preferably is of laser type although it is also possible to use other kinds of light.
  • the emitter described above gives off a beam of light which is essentially normal to the threads to be supervised. This does not, however, necessarily mean that the emitter must be positioned at right angles to the warp but the beam of light may be forwarded to its point of departure via so called fibre optics.
  • the same technique may also be used to supervise several points with the aid of the very same emitter.
  • the clock 20 which decides the measuring intervals may also have the form of several clocks which connect and disconnect their individual counter for the registration of the situation at the various portions of the area within which the light beam moves. This makes possible emit tance of several kinds of impulses for disturbances occurring within different portions of the area of move ment of the light beam.
  • the invention thus is not limited to use in connection with looms to detect broken warp threads.
  • textile industry there are numerous processes where webs of threads or filaments run in one and the same plane.
  • spinning and twisting machines, winding machines, warping machines and knitting machines are numerous processes where webs of threads or filaments run in one and the same plane.
  • the invention may find applications such as for instance to scan or continuously supervise the paper web of a paper machine.
  • the apparatus in accordance with the invention may be used to scan any regular systems for detecting and registering disturbances.
  • An improved apparatus for detecting disturbances of a fibrous web, such as broken threads comprising an emitter giving off a beam of light directed essentially at right angles to the threads, a receiver positioned at the opposite side of the threads and arranged to measure a change of intensity to which said beam of light is subjected when the path of said beam of light is interrupted, e.g., by a thread, means connected to said receiver for emitting, in response to a predetermined disturbance, an impulse capable of providing circuit response, the improvement comprising the emitter giving off an essentially coherent beam of light, a device provided to impart to said beam of light a movement of travel within an area where disturbances are expected to occur, said means connected to said receiver including counting means to count the number of disturbances per time unit and comparatory means to compare said number of disturbances per time unit with a predetermined number, and to emit said impulse in case of any discrepancy between said number of disturbances per time unit and said predetermined number.
  • the improved apparatus as claimed in claim 1 utilized for detection of broken upper and lower warp 3.
  • said beam movement imparting device consists of a hollow shaft, being rotated, through which hollow shaft passes said beam of light from the emitter, an optical element being provided on said shaft to give said beam of light a back and forth movement of adjustable width.
  • the improved apparatus as claimed in claim 10, comprising means to interrupt measurings upon shift of weaving harness.
  • the improved apparatus as claimed in claim 1 comprising a unit coupled between the receiver and said counting means to emit an impulse to said counting means only upon change of intensity exceeding a predetermined value.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Looms (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Filamentary Materials, Packages, And Safety Devices Therefor (AREA)
US00281424A 1971-08-23 1972-08-17 Apparatus for detecting broken threads or other disturbances in a fibre web Expired - Lifetime US3818236A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE10637/71A SE355608B (fr) 1971-08-23 1971-08-23

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US3818236A true US3818236A (en) 1974-06-18

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US00281424A Expired - Lifetime US3818236A (en) 1971-08-23 1972-08-17 Apparatus for detecting broken threads or other disturbances in a fibre web

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US (1) US3818236A (fr)
CH (1) CH553270A (fr)
FR (1) FR2150357B1 (fr)
GB (1) GB1388588A (fr)
IT (1) IT964166B (fr)
SE (1) SE355608B (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3989068A (en) * 1974-09-28 1976-11-02 Toyo Boseki Kabushiki Kaisha Automatic control apparatus for weaving machine
FR2421973A1 (fr) * 1978-04-06 1979-11-02 Appalachian Electronic Instr Dispositif automatique d'arret pour metier a tisser
US4248272A (en) * 1979-10-25 1981-02-03 Appalachian Electronic Instruments, Inc. Shed sensing stop motion system for high speed looms
FR2588960A1 (fr) * 1985-10-17 1987-04-24 Sipra Patent Beteiligung Appareil de controle de les textiles destine a enregistrer des defauts
US4849643A (en) * 1987-09-18 1989-07-18 Eaton Leonard Technologies Optical probe with overlapping detection fields
US4976018A (en) * 1988-10-19 1990-12-11 Benninger Ag Device for monitoring threads on a textile machine
US5008555A (en) * 1988-04-08 1991-04-16 Eaton Leonard Technologies, Inc. Optical probe with overlapping detection fields
US5497335A (en) * 1991-09-10 1996-03-05 Zellweger Luwa Ag System for creating a fault diagnosis on production machines and application of the system on textile machines
GB2387434A (en) * 2001-12-14 2003-10-15 Arteva Tech Sarl Detecting and localising yarn defects in a moving yarn sheet
US7204137B1 (en) * 2003-08-20 2007-04-17 Essex, Inc. Thread breakage detection systems and methods
CN106498609A (zh) * 2017-01-10 2017-03-15 吴江市兴业纺织有限公司 一种喷水织机的二次探纬装置及其应用
US20190013225A1 (en) * 2017-07-07 2019-01-10 Tokyo Electron Limited Substrate Warpage Detection Device, Substrate Warpage Detection Method, and Substrate Processing Apparatus and Substrate Processing Method Using the Same

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2592067A1 (fr) * 1985-12-19 1987-06-26 Saurer Diederichs Sa Dispositif de detection de rupture des fils de chaine pour machine a tisser
IT1226331B (it) * 1988-07-15 1991-01-08 Vamatex Spa Dispositivo guardiaordito elettronico a raggi laser.
DE102006035251A1 (de) * 2006-07-26 2008-01-31 Vienco Gmbh Verfahren und Anordnung zur Bestimmung der Garnqualität und/oder Spulenqualität eines laufenden Fadens auf Basis der Laser-Doppler-Anemometrie
DE102006049088A1 (de) * 2006-10-13 2008-04-24 Kennametal Inc. Modulares Bohrwerkzeug und Verfahren zu seiner Herstellung

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB691069A (en) * 1950-08-01 1953-05-06 Gen Electric Co Ltd Improvements in or relating to optical apparatus for detecting the occurrence of broken threads, filaments or the like
US3124289A (en) * 1964-03-10 Detection system
US3345812A (en) * 1966-11-23 1967-10-10 Gen Time Corp Strand break detector
US3401267A (en) * 1964-06-26 1968-09-10 Milton A. Engle Yarn breakage detector
US3447213A (en) * 1967-01-11 1969-06-03 American Enka Corp Method and apparatus for detecting irregularities in a moving sheet of yarn
US3536926A (en) * 1966-04-22 1970-10-27 Exatest Messtechnik Electro-optical method and apparatus for measuring the lateral dimension of relatively narrow elements moving longitudinally of themselves
US3543360A (en) * 1968-12-13 1970-12-01 Appalachian Electronic Instr Yarn inspector
US3677307A (en) * 1969-06-27 1972-07-18 Georges P Fiorucci Arrangement provided with a photo-cell and controlling the detecting means and the stop motion in a loom upon breaking of a thread in the warping, weaving and knitting systems
US3717771A (en) * 1971-04-02 1973-02-20 Lindly & Co Inc System for detecting defects in continuous traveling material

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3124289A (en) * 1964-03-10 Detection system
GB691069A (en) * 1950-08-01 1953-05-06 Gen Electric Co Ltd Improvements in or relating to optical apparatus for detecting the occurrence of broken threads, filaments or the like
US3401267A (en) * 1964-06-26 1968-09-10 Milton A. Engle Yarn breakage detector
US3536926A (en) * 1966-04-22 1970-10-27 Exatest Messtechnik Electro-optical method and apparatus for measuring the lateral dimension of relatively narrow elements moving longitudinally of themselves
US3345812A (en) * 1966-11-23 1967-10-10 Gen Time Corp Strand break detector
US3447213A (en) * 1967-01-11 1969-06-03 American Enka Corp Method and apparatus for detecting irregularities in a moving sheet of yarn
US3543360A (en) * 1968-12-13 1970-12-01 Appalachian Electronic Instr Yarn inspector
US3677307A (en) * 1969-06-27 1972-07-18 Georges P Fiorucci Arrangement provided with a photo-cell and controlling the detecting means and the stop motion in a loom upon breaking of a thread in the warping, weaving and knitting systems
US3717771A (en) * 1971-04-02 1973-02-20 Lindly & Co Inc System for detecting defects in continuous traveling material

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3989068A (en) * 1974-09-28 1976-11-02 Toyo Boseki Kabushiki Kaisha Automatic control apparatus for weaving machine
FR2421973A1 (fr) * 1978-04-06 1979-11-02 Appalachian Electronic Instr Dispositif automatique d'arret pour metier a tisser
US4177838A (en) * 1978-04-06 1979-12-11 Appalachian Electronic Instruments, Inc. Stop motion system for high speed looms and the like
US4248272A (en) * 1979-10-25 1981-02-03 Appalachian Electronic Instruments, Inc. Shed sensing stop motion system for high speed looms
FR2588960A1 (fr) * 1985-10-17 1987-04-24 Sipra Patent Beteiligung Appareil de controle de les textiles destine a enregistrer des defauts
US4849643A (en) * 1987-09-18 1989-07-18 Eaton Leonard Technologies Optical probe with overlapping detection fields
US5008555A (en) * 1988-04-08 1991-04-16 Eaton Leonard Technologies, Inc. Optical probe with overlapping detection fields
US4976018A (en) * 1988-10-19 1990-12-11 Benninger Ag Device for monitoring threads on a textile machine
US5497335A (en) * 1991-09-10 1996-03-05 Zellweger Luwa Ag System for creating a fault diagnosis on production machines and application of the system on textile machines
GB2387434A (en) * 2001-12-14 2003-10-15 Arteva Tech Sarl Detecting and localising yarn defects in a moving yarn sheet
GB2387434B (en) * 2001-12-14 2006-03-15 Arteva Tech Sarl Process and apparatus for continuous detection and localization of yarn defects in a yarn sheet travelling in a plane
US7204137B1 (en) * 2003-08-20 2007-04-17 Essex, Inc. Thread breakage detection systems and methods
CN106498609A (zh) * 2017-01-10 2017-03-15 吴江市兴业纺织有限公司 一种喷水织机的二次探纬装置及其应用
CN106498609B (zh) * 2017-01-10 2018-04-17 吴江市兴业纺织有限公司 一种喷水织机的二次探纬装置及其应用
US20190013225A1 (en) * 2017-07-07 2019-01-10 Tokyo Electron Limited Substrate Warpage Detection Device, Substrate Warpage Detection Method, and Substrate Processing Apparatus and Substrate Processing Method Using the Same
US10763147B2 (en) * 2017-07-07 2020-09-01 Tokyo Electron Limited Substrate warpage detection device, substrate warpage detection method, and substrate processing apparatus and substrate processing method using the same

Also Published As

Publication number Publication date
DE2240112A1 (de) 1973-03-01
FR2150357B1 (fr) 1976-08-13
GB1388588A (en) 1975-03-26
IT964166B (it) 1974-01-21
SE355608B (fr) 1973-04-30
FR2150357A1 (fr) 1973-04-06
DE2240112B2 (de) 1977-04-07
CH553270A (de) 1974-08-30

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