US3141202A - Regularity control in machines for continuously modifying a property of a material processed thereby - Google Patents

Regularity control in machines for continuously modifying a property of a material processed thereby Download PDF

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Publication number
US3141202A
US3141202A US130037A US13003761A US3141202A US 3141202 A US3141202 A US 3141202A US 130037 A US130037 A US 130037A US 13003761 A US13003761 A US 13003761A US 3141202 A US3141202 A US 3141202A
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United States
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signal
control
speed
machine
property
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Expired - Lifetime
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US130037A
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English (en)
Inventor
Linnert Arthur
Catling Harold
Barr Albert E De
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Shirley Institute
Cotton Silk and Man Made Fibres Research Association
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Cotton Silk and Man Made Fibres Research Association
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Assigned to SHIRLEY INSTITUTE reassignment SHIRLEY INSTITUTE CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). EFFECTIVE 5-2-80 Assignors: COTTON SILK AND MAN-MADE FIBRES RESEARCH ASSOCIATION, THE
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    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01H—SPINNING OR TWISTING
    • D01H5/00—Drafting machines or arrangements ; Threading of roving into drafting machine
    • D01H5/18—Drafting machines or arrangements without fallers or like pinned bars
    • D01H5/32—Regulating or varying draft
    • D01H5/38—Regulating or varying draft in response to irregularities in material ; Measuring irregularities
    • D01H5/42—Regulating or varying draft in response to irregularities in material ; Measuring irregularities employing electrical time-delay devices
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01G—PRELIMINARY TREATMENT OF FIBRES, e.g. FOR SPINNING
    • D01G23/00—Feeding fibres to machines; Conveying fibres between machines
    • D01G23/06—Arrangements in which a machine or apparatus is regulated in response to changes in the volume or weight of fibres fed, e.g. piano motions

Definitions

  • control means for such machines which will enable a product of high regularity to be obtained.
  • a control device designed many years ago has almost always been fitted to the feed mechanism of the machine.
  • This control device operates on an open loop system, the varying deflection of pedals disposed beneath the feed roller according to the thickness of the material passing between the pedals and the feed roller being averaged transversely of the machine by a special linkage and the resultant movement being used as a ,controlling signal for speeding up or slowing down the feed roller to even out the feed of material.
  • the object of the present invention is to provide means for controlling the regularity of material processed by machines of the type referred to which is efficient in operation and which substantially avoids the disadvantages hereinbefore set out.
  • a machine in which a property of a continuous length of material being processed thereby is modified comprises means for continuously feeding material such as fibrous textile material thereto, means for continuously discharging said material therefrom, and adapted to modify a property such as the density or cross-sectional dimensions of said material during passage therethrough characterised by an openloop control means adapted continuously to produce a signal proportional to the actual value of the property ice to be modified of the material fed to the machine, and to alter, by varying said output characteristics, the modifying action of the machine on the material fed thereto in accordance with said signal to compensate for variations in said value, and a closed loop control means adapted continuosuly to produce a signal proportional at any time to the integral of variations in the value of the modified property of the material leaving the machine from a datum value with respect to time and to modify the signal produced by said open-loop control means in accordance With said integral signal in such a manner as will tend to
  • the open-loop signal may be produced by suitably modifying a signal proportional to the value of some other property of the material fed to the machine, which is a function of the value of the property to be modified (e.g. the Weight per unit length may be the property to be modified, and the signal in this case may be proportional to the thickness of the material as it passes under a roller), and the closed-loop signal may be arranged to be such as suitably to modify the parameters of said modified signal.
  • a signal proportional to the value of some other property of the material fed to the machine which is a function of the value of the property to be modified (e.g. the Weight per unit length may be the property to be modified, and the signal in this case may be proportional to the thickness of the material as it passes under a roller)
  • the closed-loop signal may be arranged to be such as suitably to modify the parameters of said modified signal.
  • the invention is particularly applicable to a machine which is adapted continuously to have fed thereto a fibrous textile material, continuously to modify the density of said material, and continuously to discharge said material in modified form, and especially such a machine in which the means for continuously discharging the material includes an output roller system, control of the Weight per unit length of the material being effected by Varying the speed of the latter.
  • a machine for example a scutcher
  • control means having the following features, namely:
  • (c1) Means for continuously producing a signal proportional to the input thickness T1 of the material fed thereto;
  • FIG. l is a diagrammatic representation of a scutcher with associated control means according to the invention.
  • FIG. 2 is a perspective View of part of the control means which is located at the output or front end of the scutcher;
  • FIG. 3 is a perspective view of another part of the control means located at the input or feed end of the scutcher, and
  • FIGS. 4 to 6 are circuit diagrams of certain of the electrical parts of the control means.
  • FIG. l Reference will first be made to FIG. l.
  • the feed roller R1 of a scutcher S is driven at a nominally constant speed by a motor CSM.
  • the speed is measured by a tachorneter TA1 arranged to give an electrical signal proportional to the speed V1 of the input rollers R1.
  • Delivery rollers Ro (and also the cages and the means for forming the nished lap) of the scutcher S are driven by a variable speed motor VSM to which is coupled a tachometer TA2 arranged to give an electrical signal proportional to delivery roller speed V2.
  • Open-loop control of the regularity and uniformity of the material delivered by the scutcher S is effected by an input thickness transducer TR1, acting through a pedal system (FIG. 3) to give a signal proportional to the input thickness T1.
  • This MT1) signal is fed to a motor speed controller MSC1 whose function is to maintain where T is the desired output thickness.
  • Closed loop control is through a transducer system TR2, measuring the error in input thickness, and giving a signal proportional to (T2-T) where T2 is the actual thickness of the delivery material.
  • This signal is fed to another motor speed controller MSC2 which causes a servomotor SM to rotate at a speed proportional to (T2-T).
  • a second subsidiary loop shown in dotted line, is provided through a tachometer TA3, coupled to the servomotor SM and feeding back to motor speed controller MSC2.
  • the final link in the closed loop is a mechanical coupling by shaft Sh between servomotor SM and function generator FG.
  • the control effected by the motor speed controller MSC1 is in response partly to an open loop system capable of detecting shortterm Variations in the controlled property of the material and partly to a closed loop system capable of detecting long-term Variations of the controlled property and causes the functioning of the scutcher to be adjusted to cornpensate for both types of variation. Since the control is effected by varying the speed of the front or output rollers it is not necessary to generate in inverse relationship for control purposes, nor Will a gradual exhaustion of supply of material be aggravated in the manner previously mentioned, but on the contrary the output speed will be slowed down as much as necessary to compensate therefor.
  • the motor speed controller MSC1 (which controls the speed of the variable speed motor VSM) and the motor speed controller MSC2 (which controls the speed of servo motor SM) may be of any suitable commercially available type.
  • a Velodyne motor speed controller in which a D.C. motor supplied with constant armature current has a degree of field excitation varied in accordance with the difference at any time existing between the voltage generated by a tachometer on the motor TA2 and a reference voltage (the demanded speed signal f(T 1)).
  • FIGS. 2 and 3 Reference will now be made to FIGS. 2 and 3 in order to describe in more detail certain of the mechanical features of the control system.
  • each support 15 is pivotally mounted one end of a detector arm 16 which itself carries a transducer TR2 the sensitive portion Of which bears on a bar 18 supported by bearings 11a.
  • an adjustment and comparator means which Will not be described in detail herein,
  • Each transducer TR2 consists of a linear variable dilferential transformer comprising a suitably excited primary and a secondary output coil, with a common movable core forming the portion thereof sensitive to movement of the calender rollers caused by varying thickness of the material passing therebetween.
  • the electrical output is proportional to the displacement of the core and thus to the thickness of the material coming from the scutcher.
  • the conventlonal pedal system 19 based on a piano linkage is modied for the purposes of the present invention.
  • the final link 20 is adapted to operate the transducer TR1, which is also in the form of a linear variable differential transformer, whereby the signal T1 is derived.
  • FIGS. 4 to 6 The mainly electrical parts of the control system hereinbefore particularly described are shown in more detail in FIGS. 4 to 6.
  • FIG. 4 is a schematic circuit diagram of the function generator FG and its associated parts.
  • the output signal T1 from TR1 is converted to a direct current signal by a rectifier and filter E and is then amplified by a D.C. amplifier A1. To this signal is then added (i) A bias voltage derived from VA and developed across resistance R1 the magnitude of which is fixed by means of variable resistance RV1 and (ii) A bias voltage derived from VB and dependent upon f(T2-T) dt and developed across part of a servo potentiometer RVE, the movable arm of the servo potentiometer being driven by servomotor SM, the magnitude of which voltage is fixed by means of variable resistance RV2.
  • Adjustment of the magnitude of bias voltage derived from VA by means of RV1 corresponds to adjustment of the parameter m
  • adjustment of the magnitude of bias voltage derived from VB by means of RV2 corresponds to adjustment of the proportionality constant n.
  • the total signal is fed into a second D.C. amplifier A2 through an input resistance R2 where the amplification is made dependent on f(T2-T) dt by having the other part of the servo potentiometer RVb in a feed back loop which also includes a variable resistance RV3.
  • Total amplification of the original signal T1 may then be expressed as p+qf(T2-T)df and the function parameters p and q can be set by adjustment of RV3 and RVb respectively.
  • the final output of the function generator FG may for practical purposes be expressed in the form:
  • FIG. 5 is a schematic circuit diagram of the motorised integrating system comprising the motor speed controller MSC2, the servomotor SM and the tachometer TA3.
  • This motor speed controller circuit to which signal T2-T is fed comprises a pre-amplifier A3 followed by an output amplifier A4 feeding into one coil of the bidirectional variable speed two-phase A.C. servomotor SM, the other coil being fed from a transformer through a phase correction network (not shown).
  • the speed of the servomotor SM will be approximately proportional to the input signal of A2 but this latter part of the circuit is linearized by feeding back a signal from a drag-cup tachometer TA3 through a phase-correcting network PC then
  • angular displacement of the shaft servomotor SM and K is a constant dependent upon the characteristics of the servomotor used and the gearing between the servomotor and the potentiometers of the function generator.
  • FIG. 6 is a schematic circuit diagram of the system comprising the motor speed controller MSCl, the variable speed motor VSM and tachometer TA1.
  • the motor VSM is a 2 H.P. D.C. motor and the means for controlling its speed consists of a conventional full wave thyratron armature type of control.
  • the input signal f(T1) from the function generator FG is amplified by amplifier A and fed into the grid circuit GC of the thyratron. Feedback is provided by a precision D.C. tachogenerator PT for ensuring linear response and for minimising inherent drift in this part of the apparatus. Further feedbacks from E and F are designed to ensure maximum rates of response. These are cornbinde in the network circuit NC together with the signal V1 from tachometer TA1 for compensating for any drift in the speed of the feed roller R1.
  • the conventional piano-link control of a scutcher is itself a function generator in the sense in which the term is used in the present specification, but of a mechanical nature.
  • the gain factor a is determined by the magnification effected by the linkage between the pedals
  • the bias factor b is determined by the setting of the usual turnbuckle adjustment which is provided. It is current practice, and has been for many years, to fix the factor a by trial and error methods when first setting up the scutcher, whilst in use frequent adjustments are made to factor b as indicated by errors in the weight of the finished lap.
  • the conventional piano-link motion operates on the principle that the correct linear relationship may be selected by merely, in use, adjusting factor b-in other words that the slopes of the family of curves are all the same. In fact this is not so, and therefore, for more accurate control, factors a and b should be altered.
  • the present invention provides for this, in the manner described hereinbefore.
  • the function generator of the present invention modifies both factors cz and .b in a manner indicated by the error in the delivered lap thickness to obtain a more accurately corrected function (aTl-j-b).
  • the main amplifier gain factor a and the bias voltage b are themselves generated by ancillary devices as function's of the error in delivered lap thickness (T2-T).
  • variable voltage and bias are combined to produce an electrical signal of the required magnitude.
  • the integral of the error signal Litri-T is obtained as the angular position of a motor shaft and this angular position is coupled mechanically to two electric potentiometers which provide the variable voltage components (Le. the q and n components of a and b respectively).
  • the p and m components are provided by preset bias voltages determined by considerations similar to those involved in the determination of b. In practice thickness/weight per unit length curves are determined experimentally and the variables adjusted accordingly.
  • a control means which comprises:
  • (l) means for producing a first electric signal continuously proportional to the input value of said characteristic
  • a control means as defined in claim l wherein said means (l) comprises- (i) a means for producing a signal proportional to the input value of a characteristic of the material other than that to be controlled, but a function thereof, and
  • control means as defined in claim 1, wherein the material is a fibrous textile material and the machine is one which acts upon it to modify its density.
  • a control means as defined in claim 6 having the following features namely:
  • (d) means adapted to receive the signals proportional to V1 and to (T1) and to control the speed at which said output roller system discharges material from said machine at a value and p, q, m and n being selected so that any error in the thickness of the material discharged from the machine causes a compensating variation of the speed of discharge of the output roller system.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Preliminary Treatment Of Fibers (AREA)
US130037A 1960-08-13 1961-08-08 Regularity control in machines for continuously modifying a property of a material processed thereby Expired - Lifetime US3141202A (en)

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Application Number Priority Date Filing Date Title
GB28101/60A GB959448A (en) 1960-08-13 1960-08-13 Improvements in or relating to scutchers

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US3141202A true US3141202A (en) 1964-07-21

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CH (1) CH400854A (de)
DE (1) DE1272784B (de)
GB (1) GB959448A (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3252415A (en) * 1962-07-09 1966-05-24 St Regis Paper Co Zoned tension control for printing press
FR2126327A1 (de) * 1971-02-26 1972-10-06 Hergeth Kg Masch Apparate
US4030635A (en) * 1972-12-05 1977-06-21 Rieter Machine Works, Ltd. Method and apparatus for producing a continuous even strand of fibers
DE3143285A1 (de) * 1981-10-31 1983-05-11 Trützschler GmbH & Co KG, 4050 Mönchengladbach Verfahren und vorrichtung zum erzeugen eines gleichmaessigen faserbandes an einer karde
FR2595722A1 (fr) * 1986-03-14 1987-09-18 Truetzschler & Co Dispositif prevu sur une carde ou machine equivalente pour regulariser le ruban ou voile de fibres
FR2599053A1 (fr) * 1986-05-24 1987-11-27 Truetzschler & Co Dispositif d'egalisation d'un ruban ou d'une nappe de carde
US4753379A (en) * 1982-07-23 1988-06-28 Goetze Ag Method and apparatus for regulating the length of workpieces
US5018248A (en) * 1988-08-09 1991-05-28 Hollingsworth (U.K.) Limited Drafting apparatus with autolevelling

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH627498A5 (de) * 1978-04-26 1982-01-15 Zellweger Uster Ag Verfahren und vorrichtung zur ausregulierung von bandgewichtsschwankungen an karden, krempeln und strecken.
CN108695890B (zh) * 2018-05-30 2021-01-26 广东电网有限责任公司电力科学研究院 一种虚拟同步机阻尼配置方法及装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2531644A (en) * 1945-08-14 1950-11-28 Western Electric Co Differential drive assembly for article-handling devices
US2981986A (en) * 1955-12-27 1961-05-02 Special Instr Lab Inc Control apparatus and methods
US3013313A (en) * 1958-06-19 1961-12-19 British Cotton Ind Res Assoc Production of textile yarns

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE720200C (de) * 1938-07-01 1942-04-28 Aeg Vorrichtung an Strecken zur Regelung des Verzuges
US2770843A (en) * 1952-01-26 1956-11-20 Deering Milliken Res Corp Picker lap analyzer
CH328036A (de) * 1954-12-31 1958-02-28 Zellweger Uster Ag Verfahren und Vorrichtung zur automatischen Regulierung des Gewichtes pro Längeneinheit von Textilmaterial der Spinnerei
US2930084A (en) * 1955-10-28 1960-03-29 Bates Mfg Co Apparatus for corrective drafting of strands of discontinuous fibers
NL99739C (de) * 1958-01-09
GB936178A (en) * 1958-10-07 1963-09-04 Cotton Silk & Man Made Fibres Improvements in or relating to the spinning of textile yarns

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2531644A (en) * 1945-08-14 1950-11-28 Western Electric Co Differential drive assembly for article-handling devices
US2981986A (en) * 1955-12-27 1961-05-02 Special Instr Lab Inc Control apparatus and methods
US3013313A (en) * 1958-06-19 1961-12-19 British Cotton Ind Res Assoc Production of textile yarns

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3252415A (en) * 1962-07-09 1966-05-24 St Regis Paper Co Zoned tension control for printing press
FR2126327A1 (de) * 1971-02-26 1972-10-06 Hergeth Kg Masch Apparate
US4030635A (en) * 1972-12-05 1977-06-21 Rieter Machine Works, Ltd. Method and apparatus for producing a continuous even strand of fibers
DE3143285A1 (de) * 1981-10-31 1983-05-11 Trützschler GmbH & Co KG, 4050 Mönchengladbach Verfahren und vorrichtung zum erzeugen eines gleichmaessigen faserbandes an einer karde
US4497086A (en) * 1981-10-31 1985-02-05 Trutzschler Gmbh & Co. Kg Regulating method and system for producing a uniform sliver in a carding machine
US4753379A (en) * 1982-07-23 1988-06-28 Goetze Ag Method and apparatus for regulating the length of workpieces
FR2595722A1 (fr) * 1986-03-14 1987-09-18 Truetzschler & Co Dispositif prevu sur une carde ou machine equivalente pour regulariser le ruban ou voile de fibres
FR2599053A1 (fr) * 1986-05-24 1987-11-27 Truetzschler & Co Dispositif d'egalisation d'un ruban ou d'une nappe de carde
US5018248A (en) * 1988-08-09 1991-05-28 Hollingsworth (U.K.) Limited Drafting apparatus with autolevelling

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Publication number Publication date
GB959448A (en) 1964-06-03
DE1272784B (de) 1968-07-11
CH400854A (de) 1965-10-15

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