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(11) | EP 0 115 537 B1 |
| (12) | EUROPEAN PATENT SPECIFICATION |
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| (54) |
DEVICE FOR DETECTING END BREAKAGE OF FINE SPINNING FRAME VORRICHTUNG ZUM AUFSPÜREN DER GARNBRÜCHE EINER FEINSPINNMASCHINE DISPOSITIF DE DETECTION DE RUPTURES TERMINALES DANS UN METIER A FILER POUR FIL DE TITRE FIN |
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| Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). |
TECHNICAL FIELD
[0001] This invention relates to an apparatus for detecting yarn breakage in a spinning frame, more especially, to apparatus for detecting yarn breakage by detecting fibers floating forward in a pneumatic duct when yarn breakage occurs in the spinning frame.
BACKGROUND ART
[0002] The main method used hitherto to detect yarn breakage in a spinning frame has been to apply light upon the yarn moving between a front roller and a snail wire in the spinning frame and to detect the existence of the yarn in the light by a photocell. For example, Japanese Examined Patent Publication (Kokoku) No. 48-2569 discloses a method in which a detecting device having a photocell is arranged on a moving unit traversing between a plurality of frames of the spinning frames and yarn breakage of a spindle facing the moving unit is detected along with movement of the moving unit.
[0003] Methods of detecting yarn breakage other than detection of the yarn path by a photocell include detection by sensing the oscillation of the yarn during spinning using a snail wire and, as disclosed in Japanese Examined Patent Publication No. 48-4894, detection of yarn breakage by providing a lever equipped with a snail wire at one end and equipped with a light energy absorbing member at the other end and by absorbing the light flowing along the front of the spinning frame when yarn breakage and loss of support by the snail wire cause the lever to swing and the light energy absorbing member ta move downward.
[0004] Further, Japanese Examined Patent Publication No. 49-38372 discloses a method arranged a yarn breakage sensing member to travel at the front of the spinning frame or other textile machine at a constant speed and detecting yarn breakage by whether or not yarn contacts the sensing member when the sensing member travels along the frame of the textile machine.
[0005] These yarn methods for detecting yarn breakage either detect yarn breakage by means of a member contacting a yarn during spinning or detect the same without contacting the yarn but by using a photocell, wherein a moving unit mounted with a detecting device is arranged between frames of the spinning frames. Use of a member contacting the yarn during spinning has the risk of increasing yarn breakage by the yarn breakage detection operation. Also, use of a moving unit makes it possible to detect yarn breakage of only spindles in front of the moving unit. In either case, large equipment costs are required.
[0006] Recently, there have been proposed, for example, in Japanese Unexamined Patent Publicaiton No. 57-77328, a method for detecting yarn breakage by projecting light from a light projector into a pneumatic duct or a pipe branching from the duct and connecting to a flute and receiving by a light receiving device the light reflected when fibers pass through the light curtain formed by the projected light and, for example, in Japanese Unexamined Patent Publication No. 57-77329, a method for detecting yarn breakage by having light reflected due to the projected light received by a light receiver and detecting variation in the amount of reflected light due to interruption of the reflected light by floating fibers passing through a pneumatic duct when yarn breakage occurs. However, these methods are said to suffer from problems of detection accuracy and have still not reached the practical stage.
DISCLOSURE OF THE INVENTION
[0007] It is an object of the present invention to overcome the drawbacks of the known methods and to provide a practical and inexpensive apparatus for detecting with a high degree of accuracy yarn breakage in all spindles of a spinning frame.
The object is achieved by an apparatus according to claim 1.
[0008] Namely, the technical idea of the apparatus for detecting yarn breakage in accordance with the present invention is to apply a light beam emitted from a light projector at a predetermined position in a pneumatic main duct and, when fibers passing transversely through the light beam exist, to detect light scattered by the fibers as electrical pulse signals by a photo-electrical system and recognize the electrical pulse signals as yarn breakage when successively repeated more than a predetermined instances per unit time. The recognition of the electrical pulses signals is achieved by integrating the pulse signals in unit time and by comparing the integrated value with a predetermined value (voltage).
[0009] One necessary condition for a practical apparatus is reliability of operation as a detecton device. At issue with this type apparatus is whether it can reliably detect the light scattered when floating fibers pass through the pneumatic duct and pass through a detection position of this apparatus, i.e., if the floating fibers occurred due to yarn breakage or not. If it cannot detect this reliably, the apparatus of the present invention would not be practical. From this viewpoint, the apparatus for detecting yarn breakage in accordance with the present invention has a built-in system for checking the reliability of detection.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
Figure 1 is a perspective view of an apparatus for detecting yarn breakage in accordance with the present invention mounted on a pneumatic duct of a spinning frame;
Figure 2 is a cross-sectional view of a detecting device of the apparatus for detecting yarn breakage mounted in a cross-sectional plane of a pneumatic duct;
Figure 3 is a block diagram of the essential electrical circuit of the apparatus for detecting yarn breakage;
Figure 4A is a diagram of the output waveform of an amplifier 21;
Figure 4B is a diagram of an output waveform of comparator 22;
Figure 4C is a diagram of an output waveform of an integration circuit;
Figure 5 is a block diagram of a practical electric circuit of ther apparatus for detecting yarn breakage in accordance with the present invention; and
Figures 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H, and 61 are waveform diagrams of waveforms of electrical signals appearing at points A, B, C, D, E, F, G, H, and I of the electrical circuit illustrated in Fig. 5, respectively.
BEST MODE FOR CARRYING OUT THE INVENTION
[0011] To facilitate understanding of the present invention, the essential technical idea behind the apparatus for detecting yarn breakage in accordance with the present invention is described in detail with reference to the attached drawings.
[0012] A spinning frame is usually provided with a pneumatic device to suck up and hold fleece generated along with yarn breakage. As shown schematically in Fig. 1, the pneumatic device is comprised of pneumatic flutes 3 equipped with suction holes corresponding to the spindles of the spinning frame, pneumatic ducts 2 for transporting the air and the fleece from the pneumatic flute, and a case accommodating a pneumatic suction device 1 consisting of a reservoir for holding the fleece transported from the duct and a suction fan.
[0013] The pneumatic duct 2 is illustrated in Fig. 1 as two uniform-shape ducts. Each pneumatic duct 2, however, is actually formed with an increasingly large sectional area from the position farthest from the suction fan to the position closest to the suction fan so as to achieve uniform suction in accordance with the amount of air passing in the duct. Further, while one pneumatic duct is usually arranged on each side of the spinning frame near to the pneumatic suction device case 1, i.e., a total of two, sometimes the two pneumatic ducts are joined into one just in front of the case 1 for connection with the case 1.
[0014] The apparatus for detecting yarn breakage in accordance with the present invention is comprised of a detecting unit 10 of the detecting device and a panel box 4 housing electrical circuits. The panel box 4 is provided with lamps for indicating yarn breakage.
[0015] As illustrated, in Fig. 1, the detecting unit 10 of the detecting device is arranged on an end portion adjacent to the case 1 of the pneumatic duct 2. As illustrated in Fig. 2, the detecting unit 10 is comprised of a light projector 12 and a light collector 16. The light projector 12 and the light collector 16 are fixed on an attaching member 11 of the detecting device after being adjusted in inclined angles so that the focus of the light collector 16 substantially matches the passage of incident light from the light projector. In this case, to increase the sensitivity of the light collector 16, the light projector 12 and the light collector 16 are arranged so that the focus of the incident light from the light projector 12 substantially matches the focus of light collected by the light collector 16. Attachment of the detecting unit 10 to the pneumatic duct 2 is achieved by fixing the attaching member 11 to the pneumatic duct 2 by means of bolts or other suitable means. To facilitate alignment of the relative positions of the incident light and collected light, it is preferable to insert between the light projector 12 and the attaching member 11 and between the light collector 16 and the attaching member 11 an angle adjusting and fixing member capable of adjusting freely and fixing the angle between the light projector 12 and the light collector 16.
[0016] It is also possible to attach individually and directly the light projector 12 and the light collector 16 to the pneumatic main duct. In this case, it is also preferable to insert an angle adjusting and fixing member between the light projector 12 and the pneumatic duct and between the light collector 16 and the pneumatic duct.
[0017] The light projector 12 has a light source 14 and a projecting lens 13 collecting light emitted from the light source 14. The light source 14 is connected through a lead wire 15 to a power supply 30.
[0018] The light collector 16 has a light collecting lens 17 collecting light scattered from the fibers reflecting the incident light and has a photocell 18 connected through a lead wire 19 to an electric circuit housed in the panel box 4. As illustrated in Fig. 3, the electric circuit is comprised of an amplification circuit 21, a comparator circuit 22, an integration circuit 23, and a comparator circuit 24. A predetermined voltage Vr which acts as a comparative standard is supplied to the comparator circuit 24. For the convenience of explanation, the electric circuit will be called an amplification, comparison, and judgement circuit 20 (ACJ circuit 20) hereinafter. As illustrated in Fig. 3, an output of the ACJ circuit 20 is connected to an alarm circuit 25 having an alarm R.
[0019] Various devices may be used forthe alarm R of the alarm circuit 25. For example, as illustrated in Fig. 1, an alarm indicating lamp arranged on an end of the frame in the spinning frame may be used as the alarm.
[0020] An alarm indicating lamp is convenient for informing operators at positions far from the spinning frames of the existence of spinning frames with yarn breakage. Further, a blinking type alarm indicating lamp is useful for informing operators of the existence of spinning frames with yarn breakage more speedily. Further, central placement of the alarm indicating lamps of a plurality of spinning frames in a spinning room in a specific place of the spinning room and, thereby, central monitoring of the yarn breakage situation of the spinning frames in the spinning room is useful for discovering speedily frames having yarn breakage and for obtaining an overall grasp of the spinning conditions of all the spinning frames and managing the same.
[0021] The alarm used may also be a buzzer or a buzzer with an alarm indicating lamp. When there are only a few yarn breakage indications and, therefore, there are only relatively few operators in the spinning room, the sound of a buzzer is effective for informing the operators of the yarn breakage.
[0022] The gist of the present invention will become clear by the following explanation of the operation of the essential constitution of the apparatus for detecting yarn breakage of the present invention as illustrated in Fig. 1, Fig. 2, and Fig. 3. Namely, the apparatus for detecting yarn breakage of the present invention operates as follows.
[0023] When yarn breaks, fleece is delivered from a draft part corresponding to the yarn breakage spindle. The fleece is sucked from a hole 3 into the pneumatic flute and is sent through the successive larger diameter pneumatic duct toward the case 1 for final accumulation and storage in the pneumatic fleece reservoir (not shown).
[0024] The fleece passing through the apparatus for detecting yarn breakage, which apparatus is, as illustrated in Fig. 1, arranged at a position in the pneumatic main duct adjacent to the pneumatic suction device case 1, is dispersed into a plurality of fibers 40 or fiber groups consisted of a plurality of fibers (called simply "fibers 40" hereinafter) by an air stream passing inside the duct, as illustrated in Fig. 2, and floats forward in the duct.
[0025] When light is incidented by the light projector 12 in to the pneumatic main duct, in which the plurality of fibers 40 are irregularly distributed, the light is scattered by the fibers and, viewed in the direction inclined with respect to the direction of the incident light, the passage of the incident light may be seen as flickering. The photocell 18 of the light collector 16, focused toward the passage of the light in the incident light, therefore generates a pulse in response to each flicker of the light beam of the incident light due to the scattering of the light beam by the fibers, i.e., due to the Tyndall effect.
[0026] When there is no yarn breakage and there is only a small quantity of fibers floating in the pneumatic duct 2, the frequency of pulse generation is low, as illustrated in the time to, of Fig. 4B. However, when yarn breakage occurs in even one spindle of the spinning frame, the frequency of pulse generation increases, as illustrated in the time tb of Fig. 4B. On the other hand, when the yarn breakage is corrected and the quantity of fiber floating in the pneumatic duct 2 decreases, the frequency of pulse generation again decreases, as illustrated in the time t02 of Fig. 4B. In Fig. 4B, the vertical axis represents the intensity (V) of pulse (Voltage) and the horizontal axis represents the time (T).
[0027] The pulses output from the photocell 18 are supplied through the lead wire 19 to the ACJ circuit 20. The pulses pass through the amplification circuit 21 and the comparator circuit 22 to the integration circuit 23 for integration. Namely, when yarn breaks and numerous fibers 40 float forward in the pneumatic duct, the frequency of pulse generation per unit time is high. The integration of the pulses by unit time thereby results in an increased integrated voltage level in the integration circuit 23. When there is no yarn breakage, no rise is obtained in the integrated voltage level in the integration circuit 23.
[0028] The output signal of the integration circuit 23 is input to the comparator circuit 24. The predetermined setting voltage Vr, which functions as the standard, is supplied to the comparator circuit 24. The output signal from the integration circuit 23 and the setting voltager Vr are compared and, when the voltage level of the output signal is higher than the level of setting voltage Vr, the alarm circuit 25 is activated.
[0029] As apparent from the above description, when yarn breakage occurs simultaneously in two or more spindles in the same spindle row of the same spinning frame, the frequency of pulse generation becomes abnormally large compared with yarn breakage in one spindle. Therefore, adjustment of the setting voltage Vr to a comparatively large value enables adjustment of the apparatus so that the ACJ circuit does not output a signal upon yarn breakage in one spindle, in other words, enables the apparatus for detecting yarn breakage to accept single spindle yarn breakage. Experiments have shown, however, that reliable detection of single spindle yarn breakage is desirable in well managed spinning factories from the point of view of maintaining yarn quality and that doing this does not in the end lead to an increase in the operations necessary for running the spindle frames.
[0030] The apparatus for detecting yarn breakage of the present application is also characterized by projecting light into the pneumatic duct, receiving light scattered by the fibers floating through the duct by the light collector and converting it into pulse signals, continuously integrating the pulses by unit time to find the integrated value (electric quantity), comparing the integrated value with the standard value predetermined to correspond to control target number of yarn breakages, and, when the integrated value reaches the standard value, indicating this by electric signals.
[0031] Next, a practical apparatus for detecting yarn breakage is described in detail with reference to Fig. 5.
[0032] Blocks 21, 22, 23, 24, and 25 illustrated by the chained lines in Fig. 5 correspond to circuit blocks 21, 22, 23, 24, and 25 of Fig. 3. Block 26, i.e., a circuit for detecting abnormalities 26 (described hereinafter) in Fig. 5, however, is not illustrated in Fig. 3. Below, the operation of the circuit in Fig. 5 is described with reference to waveform diagrams in Fig. 6A through Fig. 61. Now, Fig. 6A through Fig. 61 illustrate the waveforms of signals appearing in points A through I in Fig. 5, respectively.
(1) An output signal (A) from the photocell 18 is supplied to a capacitor C↑. This output signal from the photocell 18, as illustrated in Fig. 6A, consists of a direct current component and an alternating current component overlying the direct current component. Here, the direct current component expresses the light quantity corresponding to the usual luminous environment around the photocell 18, while the alternating current component expresses the light quantity corresponding to the light reflected by floating fibers. Therefore, the direct current component corresponds to outside disturbances. The only component really necessary for detection of yarn breakage is the alternating current component. Therefore, the output signal from the photocell 18 is supplied to a capacitor C, to eliminate the unnecessary direct current component. That is, only the alternating current component is obtained, as illustrated in Fig. 6B.
(2) The pulses of the alternating current component from the capacitor C, are amplified to the predetermined level in the amplification circuit 21. As illustrated in the drawings, the amplification circuit 21 is, for example, comprised of an amplifier 21-1 and a buffer amplifier 21-2. The output signal from the amplifier 21-2 have the waveforms illustrated in Fig. 6C and Fig. 6D, respectively.
(3) The output pulse signal sent out from the amplification circuit 21 is supplied to the comparator circuit 22. As illustrated in Fig. 6D, the output pulses from the amplification circuit 21 each have different amplitudes. This is a result of the fact that the distance between the focus of the light collector 16 and the floating fibers continually fluctuates during operation. To equalize the irregularity of amplitude of the output pulses due to the above-mentioned fluctuation, comparator circuit 22 corrects the irregularity of amplitude circuit 22 corrects the irregularity of amplitude illustrated in Fig. 6D to produce output pulses of a uniform amplitude as illustrated in Fig. 6E. Now, the comparator circuit 22 can also simultaneously eliminate noise and other needless signals. Namely, the comparator circuit 22 is supplied with the setting voltage V↑. The comparator circuit 22 outputs uniformly all pulses over the level of setting voltage V, as constant amplitude pulses, as illustrated in Fig. 6D, and removes noise and other needless signals not reaching the level of Vi. Accordingly, output pulses having a uniform amplitude and free of noise, as illustrated in Fig. 6E, are obtained.
(4) The output pulses from the comparator circuit 22 are supplied to the integration circuit 23 for integration. As described hereinbefore, the integrated voltage level changes according to the number of output pulses. The integration circuit 23 consists of a so-called CR integration circuit and has integration time constants determined by C2 and R4. Figure 6F illustrates that the integrated voltage level fluctuates according to the number of output pulses.
In this way, selection of the time constants of the integration circuit enables an integrated voltage level of a value proportional to as low as one yarn breakage. Therefore, this value can be used to detect occurrence of yarn breakage. In actuality, however, there is the following problem. With reference to Fig. 2, in the pneumatic duct 2, the focus of light collector 16 is converged into one point and floating fiber are detected by their passage through that one point. Namely, all the floating fibers are represented by the floating fibers passing through the one point. Therefore, if there are floating fibers, but the quantity of fibers to be represented is few, a valley portion as indicated by P in Fig. 6F appears. Consequently, the detecting system becomes unreliable. One possible method for solving the problem may be to set larger time constants C2. R4 in the integration circuit 23, namely to use time constants having a slow curve in which no valley is formed so as to cause the integrated voltage to rise. However, this method conversely has the problem of delayed response time, making speedy detection of yarn breakage impossible.
(5) Therefore, in the comparator circuit 24 of Fig. 5, a comparator 24-1 and a comparator 24-2 are introduced and a flip-flop 24-3 is provided downstream of the same. The comparator 24-1 and the comparator 24-2 are given a setting voltage Vr1 and a setting voltage V,2, respectively. The level of Vr1 and Vr2 are indicated in Fig. 6F. Vr1 is the so-called lower limit level, and Vr2 is the so-called upper limit level. Namely, integrated voltages over V,2 cause issuance of an alarm indicating the occurrence of yarn breakage, while integrated voltages under Vr1 cause cut-off of the alarm. This is the so-called hysteresis characteristic and prevents erroneous termination of the alarm by occurrence of the Valley P. Since the flip-flop 24-3 is set when the integrated voltage rises over Vr2 and is reset when the integrated voltage drops under Vr1, the output of the flip-flop 24-3 becomes as illustrated in Fig. 6G and the alarm is maintained in spite of the occurrence of the Valley P (as illustrated in Fig. 6F). This alarm signal drives the alarm circuit 25 to activate an alarm device (not illustrated in drawings).
This method enables reliable transmission of an alarm without lengthening the response time for detecting yarn breakage.
(6) Some output or another always appears at point E of Fig. 5. This is because some floating fibers pass through the pneumatic duct even when there is no yarn breakage. Seen from another viewpoint, this means the absence of some output at point E would be abnormal. For example, cut-off of the lamp of the light projector in the pneumatic duct, disconnection of the wiring to point E, or other abnormalities may cause a drop in the voltage at point E. Detection of this type of abnormality is done by an abnormality detecting circuit 26, in which the voltage at point E is successively kept at a capacitor C3. These circumstances are illustrated in Fig. 6H. If an abnormality occurs, the capacitor C3 begins to discharge through a resistance Rs, and its terminal voltage continues to fall with time constants C3 and Rs. Therefore, detection of the falling voltage from the setting voltage Vr3 enables determination of the occurrence of an abnormal condition. For this purpose, a comparator 26-1 having a reference voltage Vr3 is provided to emit an output as illustrated in Fig. 61 during an abnormal condition. This drives an abnormality alarm device circuit 26-2 to activate an abnormality alarm device (not illustrated in drawings).
The apparatus of the present invention described with reference to Fig. 5 and Fig. 6A through 61 was arranaed on eiaht soinnina frames (400 soindle per frame. 14.200 rpm). in which a combed cotton varn 405 is spun, for inspection of its reliability by the following method. All spindles, i.e., 3,200 spindles, were watched between 9:00 and to 12:00 noon and betweerr 12:40 pm to 3.40 pm at 20 minute intervals. Confirmation was made as to whether the alarm indicating lamps of the apparatus of the present invention went on when yarn breakage actually occurred and whether the alarm indicating lamps went off after repair of the yarn breakage by a piecing procedure. The number of erroneous operations was calculated. The reliability R is expressed by the following equation:
where,
n,: Number of times lamps did not go on
n2: Number of times lamps did not go off
n: Number of erroneous operations, i.e., n, plus n2
c: Number of inspection periods
m: Number of alarm indicating lamps per frame (in this case, m = 2).
[0033] Table 1 shows the results of a reliability inspection conducted over four days, i.e., April 27, 28, and 29, 1981, and May 18, 1981. As clearfrom the table, the apparatus of the present invention having the electrical circuit illustrated in Fig. 5 was confirmed to have a very high reliability, i.e., from 95% to 98%.
CAPABILITY OF EXPLOITATION IN INDUSTRY
[0034] The apparatus of the present invention detects fibers floating in the pneumatic main duct by applying light to the fibers and detecting the light scattered by those fibers and emits an alarm via the above-mentioned electrical circuit. Therefore, there is absolutely no need to touch the yarn during spinning, and yarn breakage can be detected without any influence on the spinning conditions. Further, there is no need to arrange a detecting member on each spindle of the spinning frame or to arrange a moving unit for moving the detecting member in the space between spinning frames. Therefore, the apparatus of the present invention can be made at a lower cost compared with ordinary apparatuses. Furthermore, the apparatus of the present invention can be easily attached to existing spinning frames with a simple remodeling. Thus, the practical effect of the apparatus of the present invention is extremely high.
1. An apparatus for detecting yarn breakage in a spinning frame comprising a light
projector (12) projecting a light into a pneumatic duct (2) of the spinning frame,
a photocell (18) photo-electrically detecting the existence of fibers in incident
light, an amplification circuit (21) amplifying electric pulse signals received from
said photocell (18), an integration circuit (23) integrating by predetermined time
constants amplified electric pulse signals received from said amplification circuit
(21), a first comparator unit (24) comparing an integrated voltage level of said integration
circuit (23) with a predetermined standard voltage level (Vr) and outputting signals
detecting an abnormal value when said integrated voltage is different from said standard
voltage level (Vr), and a yarn breakage alarm circuit (25) driven by said abnormal
value detecting signals received from said first comparator circuit (24), characterized
in that a projection lens (13) is provided between the pneumatic duct (2) and the
light source (14) and a light collecting lens (17) is provided between the pneumatic
duct (2) and the photocell (18), an axis of the light collecting lens (17) being arranged
in the direction inclined with respect to the direction of the incident light so that
the light source (14) and the photocell (18) are focussed at approximately the same
location within the pneumatic duct (2) and spaced from the walls thereof.
2. An apparatus according to Claim 1, wherein a capacitor removing a direct current
component from electric pulse signals from said photocell and passing only an alternating
current component is provided in an input portion of said amplification circuit.
3. An apparatus according to Claim 2, wherein amplitudes of amplified electric pulse
signals from said amplification circuit are equalized and unnecessary noise signals
having a level lower than the predetermined standard voltage are removed by providing
in the input portion of said integration circuit a second comparator circuit receiving
said amplified electric pulse signals as a first input and receiving said predetermined
standard voltage as a second input.
4. An apparatus according to Claim 3, wherein said first comparator circuit is comprised
of a pair of a first comparator and a second comparator and of a flip-flop using the
outputs of said first comparator and said second comparator as a set input and a reset
input, respectively, and, the first inputs of said first comparator and said second
comparator receive commonly said integrated voltage from said integration circuit
and their second inputs separately receive two predetermined standard voltages, i.e.
a lower limit level and an upper limit level.
5. An apparatus for detecting yarn breakage in a spinning frame comprising a photocell
detecting photo-electrically light scattered by floating fibers passing through incident
light projected through a projection lens into a pneumatic duct in a spinning frame
and outputting electric pulse signals, a light collecting lens between the pneumatic
duct and the photocell, an amplification circuit amplifying electric pulse signals
received from said photocell, an integration circuit integrating by predetermined
time constants amplified electric pulse signals received from said amplification circuit,
a first comparator circuit comparing an integrated voltage level of said integration
circuit with a predetermined standard voltage level and outputting signals detecting
an abnormal value when said integrated voltage passes over said standard voltage,
a yarn breakage alarm circuit driven by said abnormal value detecting signals received
from said first comparator circuit, and a second comparator circuit receiving said
amplified electric pulse signals as a first input and the predetermined standard voltage
as a second input to equalize amplitudes of said amplified electric pulse signals
from said amplification circuit and to remove unnecessary noise signals having a level
under the predetermined standard voltage and provided at the input portion of said
integration circuit; wherein said apparatus is further provided with a circuit for
detecting abnormalities comprising a charging capacitor successively charging output
from said second comparator circuit, a discharging resistance connected in parallel
to said charging capacitor, and a third comparator circuit receiving a charging voltage
of said charging capacitor as a first input and receiving the predetermined lower
level as a second input, occurrence of abnormalities in the circuit network for detecting
yarn breakage being detected by detecting, by means of said third comparator circuit,
that said charging voltage falls below said predetermined lower level, and in that
the light source and the photocell are focussed at approximately the same location
within the pneumatic duct and spaced from the walls thereof.
1. Vorrichtung zum Feststellen von Garnbrüchen bei Spinnmaschinen mit einem Licht
in ein pneumatisches Rohr (2) der Spinnmaschine projizierenden Lichtprojektor (12),
einer auf photoelektrischem Wege die Existenz von Fasern im einfallenden Licht anzeigenden
Photozelle (18), einem Verstärkerkreis (21) für die von der Photozelle erhaltenen
elektrischen Impulssignale, einem Integrationskreis (23), der mit einer voreingestellten
Zeitkonstante die von dem Verstärkerkreis erhaltenen, verstärkten elektrischen Impulssignale
aufintegriert, einem ersten Vergleichskreis (24), der die aufintegrierte Spannung
des Integrationskreises mit einer voreingestellten Standardspannung (Vr) vergleicht
und ein einen anormalen Wert anzeigendes Signal abgibt, wenn sich die aufintegrierte
Spannung von der Standardspannung (Vr) unterscheidet, und einem Garnbruchalarmkreis
(25), der von den einen anormalen Wert anzeigenden Signalen des ersten Vergleichkreises
(24) eingeschaltet wird, dadurch gekennzeichnet, daß zwischen dem pneumatischen Rohr
und der Lichtquelle eine Projektionslinse (13) sowie zwischen dem pneumatitischen
Rohr (2) und der Photozelle eine Lichtsammellinse (17) angeordnet ist, und daß eine
Achse der Lichtsammellinse (17) so winklig zur Richtung des einfallenden Lichtes verläuft,
daß die Lichtquelle und die Fotozelle auf ungefähr denselben, innerhalb des pneumatischen
Rohrs (2) befindlichen rohrwandfernen Punkt fokussiert sind.
2. Vorrichtung nach Anspruch 1, dadurch gekennzeichnet, daß ein Kondensator (C1) eine Gleichstromkomponente aus dem elektrischen Impulssignal der Photozelle (18)
filtert und nur ein Wechselstromanteil auf den Eingang des Verstärkerkreises (21)
gelegt wird.
3. Vorrichtung nach Anspruch 2, dadurch gekennzeichnet, daß die Amplituden der elektrischen
lmpulssignale des Verstärkerkreises (21) vereinheitlicht und Störsignale mit niedrigerer
Höhe als eine voreingestellte Standardspannung (V1) entfernt werden, indem vor dem Eingang des Integrationskreises (23) ein zweiter
Vergleichskreis (22) geschaltet ist, der die elektrischen Impulssignale als erste
Eingangsgröße und die voreingestellte Standardspannung als zweite Eingangsgröße erhält.
4. Vorrichtung nach Anspruch 3, dadurch gekennzeichnet, daß sich der erste Vergleichskreis
(24) seinerseits aus einem ersten Vergleichskreis, einem zweiten Vergleichkreis und
einem Flip-Flop, das die Ausgangsgrößen des ersten Vergleichskreises und des zweiten
Vergleichskreises als Setz- bzw. Rücksetzimpuls benutzt, zusammensetzt, und daß an
den jeweils ersten Eingängen des ersten und des zweiten Vergleichskreises die Ausgangsspannung
des Integrationskreises und an den jeweils zweiten Eingängen zwei voreingestellte
Standardspannungen (Vrl, Vr2) als unterer und oberer Grenzwert anliegen.
5. Vorrichtung zum Feststellen von Garnbrüchen bei Spinnmaschinen mit einer Photozelle
(18), die auf photoelektrischem Wege Streulicht wahrnimmt und elektrische Impulssignale
abgibt, wobei das Streulicht von Fasern herrührt, die durch von einer Projektionslinse
(13) in ein pneumatisches Rohr (2) einer Spinnmaschine projiziertes, einfallendes
Licht schweben, einer Lichtsammellinse (17) zwischen dem pneumatischen Rohr und der
Photozelle, einem Verstärkungskreis (21), der die von der Photozelle empfangenen elektrischen
Impulssignale verstärkt, einem Integrationskreis (23), der mit einer voreingestellten
Zeitkonstante die von dem Verstärkungskreis empfangenen, verstärkten elektrischen
Impulssignale aufintegriert, einem ersten Vergleichskreis (24), der die aufintegrierte
Spannung des Integrationskreises mit einer voreingestellten Standardspannung (Vr)
vergleicht und ein einen anormalen Wert anzeigendes Signal abgibt, wenn die aufintegrierte
Spannung über der Standardspannung liegt, einem Garnbruchalarmkreis (25), der von
den einen anormalen Wert anzeigenden Signalen, die von dem ersten Vergleichskreis
geliefert werden, eingeschaltet wird, und einem zweiten, vor dem Eingang des Integrationskreises
angeordneten Vergleichskreis (22), der die verstärkten elektrischen Impulssignale
als erste Eingangsgröße und eine voreingestellte Standardspannung (V1) als zweite Eingangsgröße erhält, um die Amplituden des verstärkten elektrischen
Impulssignales zu vereinheitlichen und um Störsignale mit niedrigerer Höhe als die
voreingestellte Standardspannung zu entfernen, dadurch gekennzeichnet, daß ein zusätzlicher
Schaltkreis (26) Unregelmäßigkeiten anzeigt und einen Kondensator (C3), der fortlaufend von der Ausgangsspannung des zweiten Vergleichskreises geladen
wird, einen Entladewiderstand (Rs), der zu dem Kondensator parallel geschaltet ist, und einen dritten Vergleichsschaltkreis
(26-1), der die an dem Kondensator anliegende Spannung als erste Eingangsgröße und
eine eingestellte untere Grenzspannung (Vr3) als zweite Eingangsgröße erhält, aufweist, und daß der zusätzliche Schaltkreis das
Auftreten von Unregelmäßigkeiten in dem gesamten Schaltkreis zum Aufspüren von Garnbrüchen
mit Hilfe des dritten Vergleichskreises aufspürt, indem die Ladespannung des Kondensators
unter die untere Grenzspannung fällt, und daß der Lichtprojektor (12) und die Photozelle
auf denselben, innerhalb des pneumatischen Rohrs liegenden, rohrwandfernen Punkt fokussiert
sind.
1. Appareil pour détecter la rupture du fil dans un métier à filer, lequel comprend
un projecteur de lumière (12) qui projette un faisceau lumineux à l'intérieur d'un
conduit pneumatique (2) du métier à filer, une cellule photo-électrique (18) pour
détecter photo-électriquement la présence de fibres dans la lumière incidente, un
circuit amplificateur (21) pour amplifier les signaux d'impulsions électriques reçues
de ladite cellule photo-électrique (18), un circuit intégrateur (23) conçu pour intégrer,
suivant des constantes de temps prédéterminées, des signaux d'impulsions électriques
reçus dudit circuit amplificateur (21), un premier dispositif comparateur (24) qui
compare un niveau de tension intégrée dudit circuit d'intégration (23) avec un niveau
prédéterminé de tension de référence (Vr) et émet à sa sortie des signaux qui détectent
une valeur anormale lorsque ladite tension intégrée diffère dudit niveau de tension
de référence (Vr), et un circuit d'alarme casse-fil (25) actionné par lesdits signaux
de détection de valeur normale qui sont reçus dudit premier circuit comparateur (24),
caractérisé en ce qu'il est prévu un objectif de projection (13) entre le conduit
pneumatique (2) et la source lumineuse (14) et qu'une lentille collectrice (17) est
prévue entre le conduit pneumatique (2) et la cellule photo-électrique (18), l'axe
de ladite lentille collectrice (17) étant orienté dans une direction inclinée par
rapport à celui de la lumière incidente, de telle sorte que la source lumineuse (14)
et la cellule photo-électrique (18) soient focalisées sensiblement sur un même point
à l'intérieur du conduit pneumatique (2), espacé par rapport aux parois de ce conduit.
2. Appareil selon la Revendication 1, caractérisé en ce qu'il est prévu, dans une
partie entrée dudit circuit amplificateur, un condensateur qui détourne une composante
du courant continu des signaux d'impulsions électriques provenant de la cellule photo-électrique
et ne laisse passer qu'une composante de courant alternatif.
3. Appareil selon la Revendication 2, caractérisé en ce que certaines amplitides de
signaux amplifiés d'impulsions électriques provenant dudit premier circuit amplificateur
sont égalisées et que l'on supprime des signaux parasites inutiles d'un niveau inférieur
à ladite tension de référence prédéterminée dans la partie entrée dudit circuit d'intégration,
un second circuit comparateur recevant lesdits signaux amplifiés d'impulsions électriques
en tant que première entrée et recevant ladite tension de référence prédéterminée
en tant que seconde entrée.
4. Appareil selon la Revendication 3, caractérisé en ce que le premier circuit comparateur
se compose de deux comparateurs, à savoir un premier et un second comparateurs, ainsi
que d'une bascule utilisant les sorties dudit premier comparateur et dudit second
comparateur respectivement en tant qu'entrée de mise en marche et en tant qu'entrée
de remise à zéro, et que les premières entrées desdits premier et second comparateurs
reçoivent en commun ladite tension intégrée provenant dudit circuit ingégrateur, tandis
que leurs secondes entrées reçoivent deux tensions de référence prédéterminées, c'est-à-dire
un niveau-limite inférieur et un niveau-limite supérieur.
5. Appareil pour détecter une rupture de fil dans un métier à filer, lequel comprend
une cellule photo- électrique pour détecter de façon photo-électrique la lumière diffusée
par des fibres flottantes traversant le faisceau de lumière incidente projeté à travers
un objectif de projection à l'intérieur d'un conduit pneumatique dans un métier à
filer, et qui délivre des signaux d'impulsions électriques; une lentille collectrice
de lumière placée entre le conduit pneumatique et la cellule photo-électrique, un
circuit amplificateur qui amplifie les signaux d'impulsions électriques provenant
de ladite cellule photo- électrique, un circuit intégrateur qui assure l'intégration,
par des constantes de temps prédéterminées, des signaux d'impulsions électriques amplifiées
provenant dudit circuit amplificateur, un premier circuit comparateur avec un niveau
prédéterminé de tension de référence et qui délivre des signaux qui détectent une
valeur anormale lorsque cette tension intégrée dépasse ladite tension de référence,
un circuit d'alarme casse-fil commandé par lesdits signaux détecteurs de valeur anormale
qui sont reçus par le premier circuit comparateur, et un second circuit comparateur
prévu à la partie entrée dudit circuit intégrateur et qui reçoit lesdits signaux amplifiés
d'impulsions électriques en tant que première entrée et ladite tension de référence
prédéterminée en tant que seconde entrée afin d'égaliser les amplitudes desdits signaux
amplifiés d'impulsions électriques provenant dudit circuit amplificateur et pour supprimer
les signaux parasites inutiles ayant un niveau inférieur à la tension prédéterminée
de référence, cet appareil étant caractérisé en outre en ce qu'il comprend un circuit
conçu pour détecteur des anormalités et qui comprend un condensateur de charge qui
charge successivement la sortie dudit second circuit comparateur, une résistance de
décharge branchée en parallèle avec ledit condensateur de charge en tant que première
entrée et qui reçoit ledit niveau inférieur prédéterminée en tant que seconde entrée,
l'apparition d'anormalité dans le réseau des circuits pour la détection d'une rupture
de fil étant matérialisée par la détection, par ledit troisième circuit comparateur,
de la chute de ladite tension de charge au-dessous dudit niveau inférieur prédéterminé,
et que la source lumineuse et la cellule photoélectrique sont focalisés sensiblement
sur le même point situé à l'intérieur du conduit pneumatique et espacé par rapport
aux parois de ce conduit.