Classifications

• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D47/00—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms
  • D03D47/34—Handling the weft between bulk storage and weft-inserting means
  • D03D47/36—Measuring and cutting the weft
  • D03D47/361—Drum-type weft feeding devices
  • D03D47/367—Monitoring yarn quantity on the drum
• • D—TEXTILES; PAPER
  • D03—WEAVING
  • D03D—WOVEN FABRICS; METHODS OF WEAVING; LOOMS
  • D03D47/00—Looms in which bulk supply of weft does not pass through shed, e.g. shuttleless looms, gripper shuttle looms, dummy shuttle looms
  • D03D47/34—Handling the weft between bulk storage and weft-inserting means
  • D03D47/36—Measuring and cutting the weft
  • D03D47/361—Drum-type weft feeding devices
  • D03D47/362—Drum-type weft feeding devices with yarn retaining devices, e.g. stopping pins

Definitions

• the present invention relates to a woof preparation device for pneumatic looms.
• Woof preparation devices which mainly con ⁇ sist of a stationary stock-drum on which the woof thread is wound and of mechanical means which, for every shot, separate the necessary number of windings from the following ones and release same for delivery to the main blower of the loom.
• the introduction speed of the woof on a pneumatic loom is sub ⁇ ject to variations from shot to shot and from one kind of thread to another.
• the object of the invention is now to eliminate the problems mentioned hereinabove.
• Figure 1 shows a schematic side view of a device accor ⁇ ding to claim 1
• Figure 2 shows a block diagram of the circuit of the sender-receiver located adjacent to the winding end
• Figure 3 shows a block diagram of the circuit of the other sender-receiver.
• a shaft 2_ is rotatably mounted in a support 1 mounted on the frame of a pneumatic loom.
• This shaft is made so as to be partially hollow and carries a thread winder 3_.
• a stock-drum 4 is rotatably mounted on the shaft 2 .
• the shaft 2_ can be driven by means of an electric motor 5, the feeding of which is controlled by two optic detectors 6 ⁇ and 1_.
• a magnet 8_ carried by the support 1_ cooperates with a little iron block 9 ⁇ provided in the drum 4 to prevent any rotation of the drum.
• a blocking component 14_ which can be shifted from the active to the pas ⁇ sive position and inversely by means of an electro-magnet 15.
• the motor 5_ is fed with current as long as detector 6 ⁇ does not detect thread and this feeding stops as soon as detector 1_ de ⁇ tects thread.
• Means not shown, known themselves in principle, may be provi- 15 ded to ensure the displacement of the windings from one end of the drum to the other.
• the electro-magnet 15_ is being controlled either through a determined angular position of the main shaft or by means of
• the drum 4 is preferably of a known type with a continuously adjustable diameter, so that the number of windings that are required per shot may remain constant, whatever the selected 35 weaving breadth. This, however, does not exclude the possibi ⁇ lity for the counter 18 to be adjustable.
• the controlling device according to the invention is descri ⁇ bed hereinafter.
• An oscillator 19_ (figure 2 ) controls an infrared diode of sen- der-receiver 6 ⁇
• the rays that are reflected on a reflecting plane 20 of the stock-drum 4 are received by a photo-transis ⁇ tor, which is amplified in 21_ and further rectified in 2_2 to be sent to the switch 2_3_.
• the plane 20 is covered by thread, the reflected signal is weak and the rectified signal is non-existent.
• Switch 23 ⁇ then remains open.
• a regulating circuit 24 controls a thyri ⁇ tor 2_5 ⁇ so that the motor 5_ starts rotating.
• a tachometer with impulse giver 26 delivers a signal which is compared by the regulation circuit 24 with a value set by means of 2_7. Via the thyri ⁇ tor 2 , the circuit 24 regulates the speed of the motor 5_ so that it be ⁇ comes equal to the set value.
• One may set 2J7, independently of the quantity of woof to be delivered, in such a way that the motor 5 ⁇ must start and stop a minimum number of times.
• the fixing of the length of woof that is unwound each time takes place through counting a determined number of windings of the drum 4 with a known circumference during the pulling off of the thread and, when this number is reached, control ⁇ ling the magnet 1 of the blocking component 14.
• the change of the aforesaid number of windings may be seen as a rough adjustement, whilst the fine adjustment is preferably carried out through modifying the circumference of the drum.
• the sender-receiver 16 ⁇ (figure 3) is a part of a regulating circuit 28_ which tries to adjust always in the same working area the signals received by 16 ⁇ this in order to eliminate the influence of dust deposition on the thread, undesired
• This signal is used as a "set" for a flip-flop 30 which via a power stage 3_1 controls the little magnet L5 either to clamp or to release the thread.
• the detected signal is transmitted to the counter 3_3 only when both the signal of the control 32_ and of the detection 16 are high.
• This counter 33_ is adjustable and will, for instance, send a reset signal to the flip-flop only at the third thread.
• the magnet L5_ becomes energized and the thread is braked.
• the adjustment of the detector 16_ and magnet 15 is such that the magnet, after a count of three, has just the time of a winding left to attract.
• An additional blower 3_4 is also controlled via a valve 3_5 by the time burst 2_9 and is used for increasing the speed of the thread when unwinding; (this blower is in fact an auxiliary blower of the main blower).
• a second valve 3_6 ensures that in the stopped position there still remains a slight pressure on the main blower 13_, so that the thread remains taut. In the case of the net falling out, the valve will be ruled out, whereby an unnecessary unwinding of the woof will be prevented.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Looms (AREA)

Priority Applications (2)

Applications Claiming Priority (4)

Publications (1)

Family

ID=25661765

Family Applications (1)

Country Status (4)

Cited By (11)

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Citations (5)

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• 1982
  • 1982-05-26 DE DE8282901581T patent/DE3263098D1/de not_active Expired
  • 1982-05-26 WO PCT/BE1982/000011 patent/WO1982004446A1/en active IP Right Grant
  • 1982-05-26 EP EP19820901581 patent/EP0081502B1/en not_active Expired
  • 1982-05-26 JP JP57501665A patent/JPS58500952A/ja active Granted

Patent Citations (5)

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