US3529445A - Apparatus for controlling the operation of circular knitting machines - Google Patents

Apparatus for controlling the operation of circular knitting machines Download PDF

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Publication number
US3529445A
US3529445A US812136A US3529445DA US3529445A US 3529445 A US3529445 A US 3529445A US 812136 A US812136 A US 812136A US 3529445D A US3529445D A US 3529445DA US 3529445 A US3529445 A US 3529445A
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capacitor
needles
signal
signals
needle
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US812136A
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Peter Brose
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    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04B—KNITTING
    • D04B35/00—Details of, or auxiliary devices incorporated in, knitting machines, not otherwise provided for
    • D04B35/10—Indicating, warning, or safety devices, e.g. stop motions
    • D04B35/18—Indicating, warning, or safety devices, e.g. stop motions responsive to breakage, misplacement, or malfunctioning of knitting instruments

Definitions

  • a control apparatus for a circular knitting machine including a photoelectric device for directing a light beam upon the knitting needles passing thereby, the light beam being reflected by the needles back upon a photoelectric receiver producing electrical signals solely as a result of the reflections which normally occur in a predetermined time sequence when the machine is in proper operating condition.
  • an integrating electrical network produces a perceptible indication that the yarn is not being properly knit by the machine.
  • the invention relates to apparatus for controlling the operation of circular knitting machines and in which a photoelectric sensing facility detects reflections from needles passing by the facility, the sensing facility out putting to evaluating means operated by irregularities of an ac. signal input to such means.
  • Apparatus of this kind has been disclosed in an article entitled Photoelekthariting devistrolle an Dopplezylinder-Automaten by Christian Schwabe, which appeared in Wirkereiund Strickerei-technik, 1964, 478- 482.
  • an illuminating optical system forms a small light spot on a field of view through which the needles pass with the yarn on them.
  • the field of view is imaged on a photoelectric receiver, for instance, by a light source being imaged on the field of view by way of a half-silvered mirror which is inclined to the optical axis of the illuminating optical system, while the field of view is imaged by the same optical system on a photoelectric receiver disposed behind such mirror.
  • the basis for the apparatus described is that in the event of needles being damaged or missing, there is a change in the position of the yarn relatively to the particular needle concerned, and this change becomes perceptible as an irregularity of the resulting a.c. signal, which can be used to indicate a fault and, if required, to stop the machine.
  • the signal arising from the yarn-containing field of view has a pattern which, although periodic, is fairly irregular during a single period; also, various other factors, such as thickness of the particular yarn used, cause irregularities.
  • the evaluat- ICC ing means are responsive to the time interval between the consecutive signals delivered by the sensing facility on the basis solely of reflections from the needles.
  • the criterion for satisfactory operation of the machine is the sequence in time of the signals initiated purely by the reflections from the needles. If the needles are intact, such signals should follow one other at a particular known time interval. If any needle is bent, one of the pulses arrives either earlier or later, and so the time interval betwen the latter signal and the signals on either sideof it is shortened for one such adjacent needle and increased for the other. If a needle is missing, the time interval between two consecutive signals is twice the normal value. Needle supervision can therefore be based on a time measurement. There are a wide variety of ways of doing this. For instance, the signals produced by the re fiections from the needles could be compared with a sequence of set-value signals, so that an error signal is triggered off whenever the needle reflection signal varies from the set-value signal.
  • the evaluating means comprise an integrating network receiving a constant input signal and resettable by the pulses delivered by the sensing facility; and a tripper is provided and responds when the output of the integration network exceeds a desired threshold.
  • the integration member could be, for instance, a preselector counter whose input signal is a constant pulse frequency and which has been preselected to the desired threshold. The signals output by the sensing facility would zero-reset the counter.
  • the integration network comprises a capacitor which is charged by a constant current and which upon the appearance of a signal from the sensing facility, is discharged so that sawtooth signals are produced; and the tripper has a threshold value which is the same as, or slightly larger than, sawtooth signal amplitude at the normal needle interval.
  • FIG. 1 is a perspective and diagrammatic view of part of a conventional circular knitting machine having photoelectric needle sensers according to the invention
  • FIG. 2 shows the beam path of a needle senser according to the invention
  • FIG. 3 is a block schematic diagram of the associated evaluating circuitry
  • FIG. 4 shows details of the circuitry shown in FIG. 3, and
  • FIG. 5 shows various signal patterns to explain the operation of the invention.
  • FIG. 1 is a diagrammatic view of a cylindrical needle cylinder 30 such as is used in a large circular knitting machine. Rib needles 32 and cylinder needles 31 are disposed on cylinder 30, which rotates during knitting. The needles 32 are at right-angles to the needles 31. The needles take up different positions during knitting.
  • a needle senser 34 senses the rib needles 32 and a needle senser 33 senses the cylinder needles 31, such sensing being photoelectric and of a kind which will be described hereinafter.
  • FIG. 2 shows the beam path of one such needle senser.
  • a filament coil 1 of a lamp is imaged on a knitting needle 4 by a lens comprising lens elements 2, 3.
  • the image is bounced back from the needle 4 to a photoelement 6 through the lens elements 3, 2 and through another lens element 5 which is disposed in the central part of the lens element 2.
  • the photoelement 6 is mounted in an acrylic glass holder 7.
  • a diaphragm 8 converts the beam of light from the lamp 1 into an annular b am; consequently, the light reaching the needle 4 is in the form of an annular beam passing via the outer portions of the lens element 2, 3, whereas the image is bounced back from the needle 4 via the central portions of the lens elements 2, 3, 5.
  • Two such sensing facilities are provided for large circular knitting machines using two needle rowsi.e., rib needles and cylinder needles.
  • One facility supervises the rib needles and the other supervises the cylinder needles.
  • FIG. 3 there can be seen the two photoelements 6, 6' of the two sensing facilities.
  • One constant-current supply 9, 9 each charges up a respective capacitor 10, 10. The voltage across the capacitor therefore increases linearly.
  • the photoelements 6 detect a needle 4 and deliver a signal, the same is applied via an amplifier, and with opposite polarity to the capacitor charge, to the associated capacitor to discharge the same. Consequently, sawtooth signals such as the signals 19 in FIG. 5 are produced across the capacitors.
  • FIG. 5 shows the signals 17 delivered by the photoelements 6 and, in staggered relationship thereto, signals 18 delivered by the photo-elements 6.
  • the signals 17 cooperate with the integration network 9, 10 to produce sawtooth signals which are staggered relatively to, but have the same amplitude as, the sawtooth signals which the signals 18 produce in co-operation with the integration network 9, 10'.
  • the signals 17, 18 need not be accurately positioned relatively to one another since each type of signal co-operates with its own integration network 9, 10 and 9, 10' respectively. However, if, as denoted by the reference 20 in FIG. 5, a signal is missing because the particular needle concerned has broken oil, the associated capacitor 10' continues to be charged. The output voltage increases above the amplitude of the other sawtooth curves.
  • the sawtooth signals are delivered, with decoupling provided by a diode 13, to the input of a threshold tripper 14. While the input thereto remains below the threshold or critical value, the tripper 14 outputs no signals. If irregular needle spacing or the absence of a needle produces a voltage peak across the capacitor 10 or 10', the voltage peak 21 (FIG. 5) in excess of the threshold value operates the device 14, which outputs a signal 22; the same is transmitted to a break relay 15 which interrupts the machine circuit 16.
  • FIG. 4 shows a few details of the evaluating circuitry shown in block schematic form in FIG. 3.
  • the photoresistance 6 co-operates with a resistance R1 to form a voltage divider whose centre point is connected via a coupling capacitor C1 to the input of an amplifier 12 comprising a transistor T1 and resistances R2, R3, R4, R5.
  • an amplifier 12 comprising a transistor T1 and resistances R2, R3, R4, R5.
  • the voltage at the centre point of such voltage divider alters, and the voltage variation is amplified by amplifier 12 and delivered via coupling resistance R6 to a threshold switch 38 comprising a transistor T2 and resistances R7, R8, R9.
  • the threshold at which the transistor T2 operates is adjusted by means of the variable resistance R9.
  • the switch 38 ensures that voltage variations occasioned by random reflections do not cause accidental triggering. Accordingly, the threshold is set so that only voltage variations produced by needle reflections are greater than the threshold value.
  • a positive voltage step is produced at its output and goes, via a coupling resistance R10, an impedance converter comprising a transistor T3 and resistances R11, R12, and a coupling resistance R13 to the input of a transistor T4 co-operating with a resistance R14 and a diode D1 to form a discharge circuit for a capacitor C2 which corresponds to the integer 10 of FIG. 3.
  • the charging circuit (constant-current source 9) for capacitor C2 extends by way of a transistor T5, a variable resistance R16 and a resistance R15. Through the agency of a Zener diode Z1, the biasing of transistor T5 is so adjusted that the same is conductive, so that the capacitor C2 is being charged continuously.
  • the discharge circuit for capacitor C2 is closed and the sawtooth curves 19, 20 of FIG. 5 are produced.
  • the potential across capacitor C2 is transmitted via a decoupling diode D5 to the threshold switch 14 comprising a transistor T6 and resistances R17, R18, R19, R20, R21.
  • a variable resistance R20 is used to adjust the threshold of switch 14.
  • transistor T6 gates.
  • a negative voltage change is produced at the output of transistor T6 and goes, va a differentiating circuit comprising a capacitor C3 and a resistance R22, and a diode D2 to the base of a transistor T7.
  • transistor T7 When a negative signal is applied to its base, transistor T7, whose emitter bias is adjusted by way of diode D3 and whose base bias is adjusted by way of a resistance R23, gates and energises a relay 15 in its load circuit. To delay its dropping, relay '15 is connected in parallel with a diode D4. Relay 15 stops the machine and, if required, initiates alarm signals.
  • the second electronic evaluating circuitry (not shown) is connected to the circuitry shown by way of the diode 13. When the machine is restarted, the electronic evaluating circuitry is reset to its initial state by means which are familiar to the skilled artisan and which are therefore not shown in detail.
  • a control apparatus for circular knitting :machines having knitting needles and for producing an indication when the yarn is not properly being knit by the machines, which apparatus includes a photoelectric sensing means for directing a light beam which is reflected back to a photoelectric receiver to produce electric signals indicative of the operational condition of the machine, the improvement comprising:
  • said sensing means being positioned so that the electrical signals are produced solely as a result of reflection from the needles, whereby said signals normally occur in a predetermined time sequence when said machine is in proper operating condition;
  • detector means connected to said, sensing means for producing said indication when said signals vary from said predetermined time sequence.
  • an integrating network having an input, an output and a resetting connection
  • tripping means connected to said output of said integrating network to produce said indication when the output of the integrating network exceeds a predetermined threshold.
  • said integrating network includes a capacitor, said means connected to the input of the integrating network delivers a constant current to said capacitor, said means connected to said resetting connection efifecting a discharge of said capacitor upon the occurrence of each signal from the photoelectric receiver, whereby said capacitor produces a sawtooth series of output signals of a given amplitude at the output of the integrating network so long as said signals from the photoelectric receiver occur in said predetermined time sequence, said tripping means being responsive to the occurrence of an output signal in excess of said given amplitude.
  • a second photoelectric sensing means positioned for producing electrical signals solely as a result of reflections from the other row of needles
  • second detector means connected to said second sensing means and including:
  • a second integrating network having a second capacitor, means connected to said second capacitor for delivering a constant current to said second capacitor, and means connected to said second capacitor and to said second sensing means for discharging said capacitor upon the occurrence of the signals from the second sensing means;
  • connecting means connecting the two capacitors to said tripping means, said connecting means including decoupling means comprising a diode.
  • each of the means for discharging the respective capacitors includes an amplifier which applies a signal to the respective capacitor of the opposite Polarity from that of the current which charges the capacitor for thereby discharging the capacitor.
  • the means for discharging the capacitor includes an amplifier which applies a signal to the capacitor of the opposite polarity from that of the current which charges the capacitor for thereby discharging the capacitor.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Knitting Machines (AREA)
US812136A 1968-04-08 1969-04-01 Apparatus for controlling the operation of circular knitting machines Expired - Lifetime US3529445A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT338568A AT303949B (de) 1968-04-08 1968-04-08 Vorrichtung zur Überwachung von Rundstrickmaschinen

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US3529445A true US3529445A (en) 1970-09-22

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US (1) US3529445A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
AT (1) AT303949B (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
CS (1) CS153512B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
DE (1) DE1915362B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
FR (1) FR2005725A1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
GB (1) GB1224691A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3659437A (en) * 1969-07-25 1972-05-02 Reynolds Tobacco Co R Knitting machine defective needle detector
US3771325A (en) * 1971-04-30 1973-11-13 Rockwell International Corp Element position detector system
US3788105A (en) * 1972-03-08 1974-01-29 Sick Erwin Fa Needle monitoring device for circular knitting machines
US3796500A (en) * 1971-09-15 1974-03-12 Sick Erwin Method and arrangement for adjusting optical devices
US3937038A (en) * 1972-06-15 1976-02-10 Firma Erwin Sick Optik-Elektronik Device for the continuous monitoring of the condition of the needle heads on a circular knitting machine
US3946578A (en) * 1973-09-18 1976-03-30 Joseph Venczel Detection of defective knitting needles of a knitting machine
US4026128A (en) * 1975-12-12 1977-05-31 Universal Textile Machine Corporation Faulty needle sensing
US4027982A (en) * 1975-04-23 1977-06-07 Kyodo Denshi Kogyo Co., Ltd. Needle detector for circular knitting machines
US4035696A (en) * 1974-05-14 1977-07-12 Texmaco H.G. Kessler Gmbh Apparatus for monitoring machine parts subject to wear
US6691534B1 (en) * 1999-05-31 2004-02-17 Protechna Herbst Gmbh & Co. Kg Light-scanning head for knitting-machine needles, a corresponding light-scanning system and method for checking knitting-machine needles, using said light-scanning system
CN101535545B (zh) * 2006-11-13 2011-06-29 蒙明格-埃罗有限公司 用于针监控的方法和设备
CN103225166A (zh) * 2013-04-23 2013-07-31 慈溪太阳洲纺织科技有限公司 圆桶形针织机和圆桶形针织机上的织针损坏监测方法
CN103469472A (zh) * 2013-09-13 2013-12-25 中国科学院上海光学精密机械研究所 针织机织针在线检测装置及检测方法
CN103789922A (zh) * 2014-02-25 2014-05-14 杭州嘉拓科技有限公司 钩针件的检测方法、钩针件的检测装置及针织机
CN104480627A (zh) * 2014-10-22 2015-04-01 常州市第八纺织机械有限公司 铺纬针断针检测系统
US20180282915A1 (en) * 2017-03-31 2018-10-04 Nike, Inc. Knitting machine with electronic auxiliary component

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3360569D1 (en) * 1982-06-11 1985-09-19 Steiger Sa Atelier Constr Safety device for a knitting machine
DE102023112626B4 (de) * 2023-05-12 2025-08-21 Protechna Herbst Gmbh & Co. Kg Strickmaschine mit einer Überwachungsvorrichtung und Verfahren zur Überwachung von Nadeln im Betrieb der Strickmaschine

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2760363A (en) * 1951-07-30 1956-08-28 Borg George W Corp Defective needle spotter

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2760363A (en) * 1951-07-30 1956-08-28 Borg George W Corp Defective needle spotter

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3659437A (en) * 1969-07-25 1972-05-02 Reynolds Tobacco Co R Knitting machine defective needle detector
US3771325A (en) * 1971-04-30 1973-11-13 Rockwell International Corp Element position detector system
US3796500A (en) * 1971-09-15 1974-03-12 Sick Erwin Method and arrangement for adjusting optical devices
US3788105A (en) * 1972-03-08 1974-01-29 Sick Erwin Fa Needle monitoring device for circular knitting machines
US3937038A (en) * 1972-06-15 1976-02-10 Firma Erwin Sick Optik-Elektronik Device for the continuous monitoring of the condition of the needle heads on a circular knitting machine
US3946578A (en) * 1973-09-18 1976-03-30 Joseph Venczel Detection of defective knitting needles of a knitting machine
US4035696A (en) * 1974-05-14 1977-07-12 Texmaco H.G. Kessler Gmbh Apparatus for monitoring machine parts subject to wear
US4027982A (en) * 1975-04-23 1977-06-07 Kyodo Denshi Kogyo Co., Ltd. Needle detector for circular knitting machines
US4026128A (en) * 1975-12-12 1977-05-31 Universal Textile Machine Corporation Faulty needle sensing
US6691534B1 (en) * 1999-05-31 2004-02-17 Protechna Herbst Gmbh & Co. Kg Light-scanning head for knitting-machine needles, a corresponding light-scanning system and method for checking knitting-machine needles, using said light-scanning system
CN101535545B (zh) * 2006-11-13 2011-06-29 蒙明格-埃罗有限公司 用于针监控的方法和设备
CN103225166A (zh) * 2013-04-23 2013-07-31 慈溪太阳洲纺织科技有限公司 圆桶形针织机和圆桶形针织机上的织针损坏监测方法
CN103469472A (zh) * 2013-09-13 2013-12-25 中国科学院上海光学精密机械研究所 针织机织针在线检测装置及检测方法
CN103469472B (zh) * 2013-09-13 2016-03-09 中国科学院上海光学精密机械研究所 针织机织针在线检测装置及检测方法
CN103789922A (zh) * 2014-02-25 2014-05-14 杭州嘉拓科技有限公司 钩针件的检测方法、钩针件的检测装置及针织机
CN103789922B (zh) * 2014-02-25 2016-05-25 杭州嘉拓科技有限公司 钩针件的检测方法、钩针件的检测装置及针织机
CN104480627A (zh) * 2014-10-22 2015-04-01 常州市第八纺织机械有限公司 铺纬针断针检测系统
US20180282915A1 (en) * 2017-03-31 2018-10-04 Nike, Inc. Knitting machine with electronic auxiliary component
US10655254B2 (en) * 2017-03-31 2020-05-19 Nike, Inc. Knitting machine with electronic auxiliary component
US11286594B2 (en) 2017-03-31 2022-03-29 Nike, Inc. Knitting machine with electronic auxiliary component

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Publication number Publication date
DE1915362B2 (de) 1971-08-05
DE1915362A1 (de) 1969-10-23
AT303949B (de) 1972-12-11
GB1224691A (en) 1971-03-10
CS153512B2 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1974-02-25
FR2005725A1 (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1969-12-19

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