Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04B—KNITTING
  • D04B15/00—Details of, or auxiliary devices incorporated in, weft knitting machines, restricted to machines of this kind
  • D04B15/38—Devices for supplying, feeding, or guiding threads to needles
  • D04B15/48—Thread-feeding devices

Definitions

• the invention relates to a yarn feeding device with thread monitoring.
• yarn feeding devices of the type of interest here serve to feed a yarn to a knitting point of a knitting machine in a controlled manner.
• yarn feeding devices are present in a correspondingly large number. These are usually placed on a support, a so-called machine ring, which is provided above the knitting points on the knitting machine and from which the individual yarn feeding devices protrude in the radial direction.
• Each yarn feeding device is usually mounted on the annular support by means of a clamp formed on a holder. This holder is penetrated by a vertical shaft, which is provided at the top with one or more pulleys and at the bottom with a thread supply drum. The thread supply drum is looped around by the thread.
• the thread supply drums of the yarn feeding devices are driven by a belt with the same speed, which runs over all pulleys.
• one or more yarn feeler are provided on the yarn feeding devices, which are designed as levers, which are held by the yarns in the rest position. If the thread hangs or tears, the corresponding lever falls down or is deflected. This closes an electrical switch.
• On the annular support is held a cable that extends through all the terminals of all yarn feeding devices. Connecting devices, such as in the form of piercing contacts, communicate with the wires of this line. When one of the switches closes, an electrical path is established between conductors of the cable or between a conductor of the cable and reference potential (ground).
• a signal lamp provided on the yarn feeding device can be provided in this current path, which then lights to signal the yarn breakage.
• the object underlying the invention is to provide a signaling device which can be used independently of the system and is compatible with previous signaling devices.
• the signaling device is connected to an electrical connection device which is located in or at the clamp of the yarn feeder.
• the signaling device includes a current source circuit for operating one or more light sources for display purposes.
• the current source circuit has the property within a predetermined voltage range, which forms a working area for the signaling device, to supply the light sources with a constant current, independently of the voltage supplied to it.
• the current source circuit thus has the property of drawing a constant current from the supply circuit connected to the cable of the machine ring when it is activated.
• the current source circuit is a Stromkonstanthalte- circuit.
• it is such a current source circuit in which the input current is substantially equal to the output current, i. a power source circuit with negligible internal power losses.
• the current source circuit is combined with a rectifier circuit.
• the yarn feeding device is then equally operable with DC and AC voltage.
• the polarity of the DC voltage is not important here. This results in a further increase in the versatility of the applications of the yarn feeding device.
• the rectifier circuit is a Voil- wave bridge rectifier circuit. This can be arranged, for example, between the connection device and the current source circuit.
• one or more switches are preferably used which open or close a circuit when the yarn feeler lever passes through a specific switching point.
• the switch is preferably arranged so that it simultaneously activates and deactivates the current source circuit with the light sources, so that the yarn feeding device then draws no current when the light sources do not light up.
• Light sources of the same or different colors can be provided.
• a plurality of cascaded light sources e.g. provided in series light emitting diodes. It is also possible to provide self-flashing LEDs.
• the light-emitting diodes are separated from the current source circuit independently of the operating voltage with a constant current of e.g. 20 mA supplied.
• the current source circuit is preferably constructed so that it can reduce its own voltage drop, if necessary, to low values of e.g. can only reduce 2.5V. This makes it possible to achieve a large operating voltage range for the signaling device.
• the supply voltage applied to the cable is interrupted periodically. This can be done permanently, or as it is preferred, only when at least one Absteller has addressed, the operating voltage then otherwise applied permanently.
• Figure 2 shows a signaling device of the yarn feeding device of Figure 1 in a first embodiment
• FIG. 1 illustrates a yarn feeding device 1 as an example of a textile-technical device which performs a signaling function.
• the yarn feeding device 1 serves to convey a yarn 2 to a yarn consumption point of a knitting machine.
• Such yarn feeding devices 1 are usually present in large numbers on knitting machines. They are seated on an annular carrier 3, which is cut in FIG. 1 and is also referred to as a "machine ring.”
• a clamp 4 is used which belongs to a holder 5 of the yarn feeding device 1.
• the holder 5 rests a shaft 6, which is preferably arranged vertically and rotatably supported, at a lower end in Figure 1 the shaft 6 carries a yarn feed wheel 7 around which the yarn 2 winds.
• yarn feeler levers 11, 12 are provided, which are pivotally mounted.
• the yarn feeler lever 11, which forms an infeed stopper is pivotable up and down during the yarn feeler lever 12, which forms a discharge stopper, transverse to the yarn 2, i. can be pivotally perpendicular to the plane in Figure 1.
• a housing 16 for example of transparent material, which, when it is illuminated from the inside, as Sig- nal flourish can serve.
• the signal light can be switched on and off via the thread feeler levers 11, 12.
• a corresponding control circuit is connected to a cable 17 in connection, which may be arranged on the holder 3 and is located in a recess of the terminal 4.
• the cable contains one or more, in the present embodiment two, conductors 18, 19. These are contacted by pointed contact needles 20, 21, which sit in the cable recess and are fixedly held on the carrier 5 and the terminal 4.
• the latter has a clamping screw 22, by means of which the holder 5 can be clamped to the carrier 3.
• FIG. 2 illustrates a signaling device 23, as it can be arranged in the housing 16 or in another suitable place, in order to monitor the thread 2 for thread breakage and to signal yarn breakages.
• the signaling device 23 is both adapted to generate an optical signal to the yarn feeding device 1 as well as to give an electrical signal via the cable 18 to a central machine control.
• the signaling device 23 includes an electrical connection means 24, which is preferably arranged on the terminal 4. It comprises the contact pins 20, 21 and optionally the clamping screws 22, if this is provided for the preparation of the ground contact. Of the contact pins 20, 21 lines 25, 26 run to a rectifier circuit 27, which is formed for example as a full-wave bridge rectifier. Such a full-wave bridge rectifier circuit is, for example, the Graetz bridge 28.
• switches 29, 30, for example in the form of SchutzrohrizoSchaltern 31, 32 may be arranged, which are actuated by magnets, which in turn moves from the yarn feeler levers 11, 12 become.
• the protective tube contact switches 31, 32 are normally open. Close when thread feeler lever from thread 2 is not in are held raised position.
• a current source circuit 33 is connected, which receives a constant current at its input 34, regardless of the applied voltage and outputs a constant current at its output 35 to a light source 36.
• the light source in the present embodiment consists of one or more colored e.g. red LEDs 37, 38, 39 connected in series with each other. Instead, incandescent or other light sources can be used.
• the current source circuit 33 contains at least one amplifier component 40, here for example in the form of a transistor, for example an NPN transistor 41, whose emitter is grounded via a current-determining resistor 42. Its base is at a constant voltage, which can be generated as a voltage drop across a corresponding electronic device, such as two diodes 43, 44 connected in series.
• the power supply for the diodes 43, 44 is a high-resistance resistor 45 (for example in the range of 10 to 100 k ⁇ ).
• the resistor 42 has a value of 50 ⁇ in order to supply the light source 36 with a current of 20 mA.
• This current remains technically constant as long as the voltage applied to the input 34 is greater than the sum of the minimum forward voltage of the LEDs 37 to 39 and a minimum voltage value of approximately 2 V for the current source circuit 33.
• the presented signaling device 23 without hesitation in the voltage range of 10 to 40 V, preferably 12 to 24 V, operated.
• other current-stabilizing components such as constant-current diodes, may also be used in series with the light source 36.
• the yarn feeding device 1 described so far operates as follows:
• the thread supply drum 7 conveys the thread 2 to the knitting machine.
• the yarn 2 holds both the yarn feeler lever 11 and the yarn feeler lever 12 in the operative position.
• the switches 29, 30 are open - they do not carry power.
• the light source 36 remains dark.
• the corresponding switch 29 and / or 30 closes.
• the voltage applied to the contact needles 20, 21 now passes rectified by the rectifier circuit 27 to the current source circuit.
• the diodes 43, 44 produces a constant voltage drop, whereby the transistor 41 emits at its collector a constant current to the light source 36, which thus shines independently of the input voltage with a given brightness.
• the signaling device 23 draws a defined current, which substantially coincides with the constant current flowing through the light source 36. This current is taken from the central supply circuit which feeds the cable 18. As a result, the central supply circuit can detect how many yarn feeding devices indicate a yarn breakage.
• Figure 3 illustrates a modified embodiment for a unipolar yarn feeding device. This has only a single piercing contact 20. As a result, the supply circuit can not distinguish between a thread break on the inlet sensor or the outlet sensor. Otherwise, however, the construction and the function are as described above, reference being additionally made to the circuit diagram according to FIG. 3. As FIG. 4 shows, it is also possible, in particular in the single-pole embodiment of the yarn feeding device 1, to arrange the switches 29, 30 at another suitable location, for example between the rectifier circuit 27 and the current source circuit 33. The function does not change anything essential.
• FIG. 5 A further modification is illustrated in FIG. 5. It contains two light sources 36a, 36b of the same or different luminous color, each of which may consist of series-connected LEDs 37a to 39a and 37b to 39b.
• the switches 29, 30 may be individually associated with these light sources 36a, 36b in a circuit as illustrated in FIG.
• the switch 30 is connected in series with the light source 36a.
• the switch 29 is connected in series with the light source 36b.
• the two series circuits are connected in parallel and connected to the current source circuit 33.
• the current flowing through the diodes 43, 44 is tapped behind the switches 29, 30 via resistors 45a, 45b. If both switches are open, no light source 36a, 36b lights up and both resistors 45a, 45b are de-energized.
• one of the switches 29, 30 is closed, one of the light sources 36a, 36b illuminates at full current intensity. If both switches 29, 30 are closed, the respective half current flows through the light source 36a and the light source 36b. If the light sources 36a, 36b have different colors, a color change can be achieved by different responses of the switches 29, 30.
• the switch 30 may be designed, for example, as an electronic switch and connected in series with the resistor 45. This is especially true at single-pole devices possible.
• the electronic switch can be operated by one or two or more thread feeler levers.
• the switches 29a, 29b may also include an opener / closer pair or switch to form a two-pole changeover switch.
• These two switches 29a, 29b (in accordance with FIG. 6 opener and closer) are actuated by the magnet of one and the same depositor and, when properly operated, can be a first light source 36b having a first color (eg green) and a second light source 36a responsive to at least one switch energize with a different color (eg red).
• an additional resting power supply line may be provided, e.g. is tapped via the contact needle 21.
• the contact needle 21 continuously supplies an additional rectifier 27 'with voltage.
• the switch 29 is divided into two switches, namely a closer 29a and an opener 29b. Both are operated by one and the same yarn feeler, in normal operation the green LEDs 27b light up. When the yarn feeler responds, the opener 29b opens and the shutter 29a closes. The green LEDs go out and the red LEDs light up. At the same time the supply current commutes from the contact needle 21 to the contact needle 20.
• the circuit of Figure 6a represents an alternative using two switches 29a, 29b for a yarn feeler, the points A, B, C and D of the circuit of FIG 6 auzuschlose is to replace the local opener / closer pair.
• At least one of the light sources can be designed as a self-acting flashing light source, for example by the LED 37a being designed as a flashing LED is. It then flashes the entire series circuit consisting of the LEDs 37a, 38a, 39a.
• FIG. 7 A further modification of the signaling device 23 is shown in FIG. 7.
• the switches 29, 30 can be arranged according to each of the types discussed so far.
• the light source 36, a further light source 46 for example in the form of a flashing LED be connected in parallel or in series. This then flashes in common mode (series connection) or alternately (parallel connection) with the light source 36. If the flashing LED 46 and the light source 36 are different in color, this results in a visually perceptible periodic color change, i. a clear signal effect. Color changes can e.g. green / red, yellow / blue, red / blue, white / red, white / blue.
• Figure 8 illustrates another embodiment of the signaling device 23 according to the invention. It uses, as a current source circuit, a circuit which generates a constant voltage at the emitter of the transistor 41 irrespective of the magnitude of the input voltage (at least if the permissible operating range is not exceeded).
• the current-determining resistor 42 ' is connected in series with the light source 36 to ground. The transistor keeps the voltage across this series circuit and thus the current through the series circuit constant. Accordingly, the current taken from the rectifier 27 is substantially constant - i. it is independent of the input voltage. In this way, the voltage constant holding circuit according to FIG. 9 acts as a current source circuit 33.
• the presented circuits can be equipped with LEDs as light sources or with other light sources, such as incandescent lamps.
• a signaling device 23 for a yarn feeding device 1 a signaling circuit is proposed which uses a constant current source for operating one or more light sources 36. On the one hand, this enables use with fluctuating or differently set operating voltages and, on the other hand, the detection of the number of responsive yarn feeding devices 1 by the central supply circuit.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Knitting Machines (AREA)
• Circuit Arrangement For Electric Light Sources In General (AREA)

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Citations (4)

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• 2007
  • 2007-07-10 CN CN2007800537043A patent/CN101730764B/zh active Active
  • 2007-07-10 WO PCT/EP2007/006111 patent/WO2009006922A1/de active Application Filing
  • 2007-07-10 EP EP07785974.2A patent/EP2173934B1/de active Active
  • 2007-07-10 BR BRPI0721825A patent/BRPI0721825B1/pt active IP Right Grant
  • 2007-12-14 TW TW096147796A patent/TWI398560B/zh active

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