GB2031962A

GB2031962A - Device for monitoring a bundle of parallel-running threads and tufting machine provided with such a device

Info

Publication number: GB2031962A
Application number: GB7930528A
Authority: GB
Original assignee: GOOSSENS GEB NV
Current assignee: GOOSSENS GEB NV
Priority date: 1978-09-07
Filing date: 1979-09-03
Publication date: 1980-04-30
Also published as: JPS5556952A; DE2936055A1; BE870280A

Abstract

A device for monitoring a bundle of threads 1 running in a parallel relationship to one another and lying in one plane has a light source arranged on one side of the plane at one side of the bundle, the light source generating a light beam 20 parallel to the plane and at right angles to the threads. A light responsive element is arranged on the same side of the plane as the light source but at the other side of the bundle. A tube 16 is arranged on the other side of the plane to the light source and has openings on which blow nozzles 17 are mounted. The tube is provided with air under pressure so that when a broken thread is blown between the light source and the light responsive element a control mechanism is operated. The nozzles may be set substantially right angles to the plane and a mechanism may be provided to move the tube backwards and forwards along its axis. <IMAGE>

Description

SPECIFICATION Device for monitoring a bundle of parallel-running threads and tufting machine provided with such a device This invention relates to a device for monitoring a bundle lying in one plane of threads running in parallel relationship to one another, with - a light source arranged on the one side of said plane and on the one bundle side, said source generating a beam in parallel relationship with the plane and at right angle to the threads, - a light-responsive element arranged on the same plane side but on the other bundle side, said element lying in the beam path, - a mechanism controlled by said light-responsive element, - a tube arranged on the other side of said plane with openings level with the bundle, and - a pressurized-air source which is connected to said tube.

Such a device is known from a Patent Application No 70-13536 in the Netherlands, said Application being open to public inspection.

In this known device, the air flows directly out of openings in the stationary tube. Said air should blow a broken thread to the light beam path between the light source and the light-sensitive element. As the air blown from the openings is not directed and as the threads which are present opposite those portions between said openings are not directly blown with said air, it did appear practically impossible to monitor reliably a bundle of parallel-running threads with the device as defined in said Dutch Application.

The invention has for object to obviate this drawback and to provide a device which insures a reliable monitoring of threads running in parallel relationship to one another.

For this purpose, blow nozzles are mounted on the tube openings.

Preferably the blow nozzle axes lie substantially at right angle to said plane.

In a preferred embodiment of the invention, the tube axis lies in parallel relationship with the plane, said axis lies at right angle to the threads and a mechanism is provided to impart an alternating movement to the tube along the axis thereof.

Usefully the alternating movement amplitude is substantially equal to the spacing between said openings.

In a particular embodiment of the invention, said mechanism imparts an alternating movement with a frequency in the range of 60 alternating motions per minute.

The invention does not pertain only to the above defined device, but also to a tufting machine provided with such a device.

In a very advantageous embodiment of the invention, the path of the light source and the tube lie between the last and penultimate thread-guides.

Other details and advantages of the invention will stand out from the following description of a portion of a tufting machine provided with a device for monitoring a bundle of parallel-running threads according to the invention; this description is only given by way of example and does not limit the invention, the reference numerals pertain to the accompanying drawings.

Figure lisa diagrammatic front view of a tufting machine provided with a device for monitoring a bun dle of parallel-running threads according to the invention.

Figure 2 is a cross-section through a portion of the same tufting machine, along line ll-ll in figure 1.

In both figures the same reference numerals pertain to the same elements.

From the tufting machine have only been shown in the figures but those elements which are used to guidethreads 1 from a collecting plate 3 to needles 13. Said collecting plate 3 is arranged in a fixed position relative to the machine frame from which but a portion has been shown in 2. From said collecting plate 3, the threads 1 run over a first thread-guide 4, thread-guide rollers 5 and 6, a second-thread-guide 7, a third thread-guide 8, an adjustable rod 11 and a guide plate 12, to the needles 13. Said third threadguide 8 can be replaced by the pulling rollers 9 and 10 also shown in figure 2. The third thread-guide 8 or the pulling rollers 9 and 10 form the penultimate guide for the threads 1. The last guide, naturally in front of guide plate 12, is formed by said adjustable rod 11, generally called "jerk rod".As shown diagrammatically in figure 2, rod 11 can be brought higher or lower relative to frame part 2 it is connected to. The needles 13 are guided by needleguides 14 which are also mounted relative to the frame. The web or fleece through which the threads 1 are passed by needles 13 is shown in 23. As far as this the tufting machine is not different from the known tufting machines.

The tufting machine is provided with a device for monitoring a break of said threads 1. This device lies between the last and penultimate guides for the threads 1, that is between the third thread-guide 8 or the pulling rollers 9 and 10 on the one hand, and the adjustable rod 11 on the other hand. At this level said threads 1 form a bundle which lies substantially in a plane. On the one side of this plane the device comprises a light source 18 and a light responsive element 19. Of course the path 20 which the light beam follows between the light-source 18 and the lightresponsive element 19 lies on that same plane side which is determined by the threads 1. On the other side of said plane, the device comprises a blowing system which is mainly formed by the tube 16 and the blow nozzles 17 mounted thereon.

As already mentioned above, the light source 18 and the light-responsive element 19 lie on one and the same side of the plane determined by the threads, but the light source 18 is arranged on one side of the bundle of threads 1 and the lightresponsive element 19 on the other side thereof. The beam 20 from the light source 18 is directed on the light-responsive element 19. Said beam 20 runs in parallel relationship to the plane of threads 1 and actually at right angle to said threads. The light beam has at right angleto its own direction a circular cross-section with a diameter in the range of 1 cm.

In practice good results have been obtained with a light source from the Mark Omron, type OPE-Y 20 L.

Said source requires a supply with 220 or 110 volts AC. The life expectancy of said source is 20,000 hours and after 5,000 operating hours the light strength has decreased but by 5 %.

As photo-sensitive element to cooperate with such a light source, use can be made of a receiver from Mark Omron, photo-electric switch type OPE-Y 20 D.

Such an element requires energizing with 220 or 110 volts. It switches over up to a distance of 20 meters under the action of the light beam originating from the above-defined light source. Further features of the light-responsive element are a ripple of 10%, a vibration sensitivity from 1 to 30 Hz and an impact resistance of 10 grams.

Even if mention is made above of a light beam, the radiation for said light source 18 lies in the range of infra-red and the light-responsive element 19 responds to a radiation in the infra-red range.

To the light-responsive element is connected an amplifier not shown in the figures, which acts on the electric motor of the tufting machine. The amplifier operates for example a relay which cuts-off the tufting machine motor when the light-responsive element 19 does not receive any radiation any more from light source 18. In combination with said light source 18 and said light-responsive element 19, use can be made from an amplifier of Mark Omron, type OPE-Q 110/220. Said amplifier requires an AC supply of 220 or 110 volts and can thereby supply a current of 1 ampere. The switching time is 30 milliseconds and the life expectancy is 3,000,000 switchings.

During the normal operation of the tufting machine, all of the threads 1 remain substantially in the same plane between the third thread-guide 8 or the pulling rollers 9 and 10 on the one hand, and the adjustable rod 11 on the other hand. With a normal operation no thread 1 thus does come to lie in light beam path 20.

As when a thread breaks, said thread 1 should actually come in the path 20 of the light beam, a blowing system has been provided. The tube 16 from said system is fastened by means of holders 15 on frame portion 2.

The tube 16 is connected through a connector 21 to a supply line 22 for pressurized air. Said supply line is fed from a pressurized air source not shown in the figures and in the supply line are cut in a pressure regulator and pressure gauge not shown either.

The pressure of the air fed to the tube 16 is regu lated according to the kind of thread with which the tufting machine works. The overpressure in tube 16 lies generally in the range of .6 kg/cm2.

The length of tube 16 is of course dependent on the tufting machine width. This length should be long enough to let the tube lie opposite the complete thread bundle. Such length is for instance of about 5 meters. The diameter of said tube is for example of about 112 inch. In said tube are provided 26 openings in a row. Said row is directed toward thread 1. The spacing between said openings is 19 cm in each case. In each opening is arranged a blow nozzle 17.

The inner diameter of said blow nozzles is in the range of 1.5 to 2 mm and the nozzle length is in the range of 15 mm. With an overpressure inside tube 16 of about .6 kglcm2, laminar constant air streams directed toward threads 1 flow out from said blow nozzles 17. The spacing between the nozzles 17 and threads 1 is in the range of cm. As it appears from figure 2, the axis of blow nozzles 17 are directed substantially at right angle to that plane which is determined by the threads 1. The tube 16 is not made fast in the holders 15, but it can be slid to-and-fro along a direction which lies in parallel relationship with the plane of threads 1 and at right angle to said threads.

For this purpose the device comprises a mechanism not shown in the figures which imparts to the tube an alternating movement along its own axis. The amplitude of the thus-imparted alternating movement is substantially equal to the spacing between adjacent openings or adjacent blow nozzles. Said amplitude is however somewhat larger and is for example in the range of 20 or 21 cm when the spacing between the openings is about 19 cm. In this way at each alternating movement at least one blow nozzle 17 comes opposite each thread 1. The alternating movement has a frequency of about 60 to-and-fro movements per minute. The path 20 of the light beam and the blow nozzles 17 determine together a plane which stands at right angle to the plane of threads 1. The spacing between path 20 and blow nozzles 17 is about 3 cm.

When a thread 1 breaks, one end thereof or a thread pile-up comes from below the third threadguide 8 or below the pulling rollers 9 and 10. The air which is blown from that nozzle which moves toand-fro adjacent the broken thread, brings said broken thread in the path 20 of the light beam. As a result the light-responsive element 19 does not receive any more light from the light source 18 which causes stopping of the tufting machine motor.

It is then easy to mend the thread break by simply connecting the one end of the broken thread to the other one or by threading again the broken thread through the needle, while insuring that the mended thread is spanned as the machine is started again.

It is to be noted that sagging threads cannot come into the light beam path 20, as this path is far enough from that plane wherein the threads are normally present. The device is suitable for the monitoring of spun thread and of continuous filament.

The device according to the invention has large advantages which are not all given at the same time by the known devices for the monitoring of a bundle of parallel-running threads. The thread break is determined before it can cause a fault in the carpet being manufactured. The break can be mended fast and the machine can be started again rapidly as for the mending no additional auxiliary parts lie in the way and as the thread does not have to be threaded through a leaf or some other element. When working on the threads and when the threads are prepared, no single apparatus lies in the way. The monitoring device does not result in any additional mechanical strain to the threads; there is thus no additional ten sion on the thread which can result in a lowering of the carpet quality. Sagging threads remain without influence on the device operation, in such a way that only thread breaks are sensed. The presence of the light source and the light-responsive element com prises an additional safety for the machine operators. The device allows an economy in the operating costs of the machine. The device can be manufactured at low cost and be arranged on a textile machine, particularly on a tufting machine. The device is reliable in operation. The capital and maintenance costs of the device are very low. The device can easily be adjusted for any kind of thread or yarn and allows monitoring any such kind. The operation of the device is easy and said device can immediately be cut-out.

The invention is in no way limited to the above embodiment and many changes can be brought therein without departing from the scope of the invention, notably as regards the shape, the composition, the arrangement and the number of the components used to embody the invention. Naturally the invention is not limited to the embodiment with the dimensions as given. For instance the spacing between the blow nozzles, the frequency of the to-andfro motions and the amplitude of said alternating movement are adjustable and can vary within large limits.

Claims

1. Device for monitoring a bundle lying in one plane of threads running in parallel relationship to one another, with - a light source arranged on the one side of said plane and on the one bundle side, said source generating a beam in parallel relationship with the plane and at right angle to the threads.

- a light-responsive element arranged on the same plane side but on the other bundle side, said element lying in the beam path, - a mechanism controlled by said light-responsive element, - a tube arranged on the other side of said plane with openings level with the bundle, and - a pressurized-air source which is connected to said tube, in which blow nozzles are mounted on the tube openings.

2. Device as defined in claim 1, in which the blow nozzle axis stand substantially at right angle to said plane.

3. Device as defined in either one of the preceding claims, in which the tube axis is in parallel relationship with said plane and at right angle to said threads, and a mechanism is provided to impart to said tube an alternating movement along the axis thereof.

4. Device as defined in claim 3, in which the alternating movement amplitude is substantially equal to the spacing between said openings.

5. Device as defined in either one of claims 3 and 4, in which the mechanism imparts an alternating movement with a frequency of about 60 to-and-fro motions per minute.

6. Device as defined in any one of the preceding claims, in which the spacing between said openings is about 19 cm.

7. Device as defined in any one of the preceding claims, in which the inner diameter of the blow nozzles lies in the range from 1.5 to 2 mm.

8. Device as defined in any one of the preceding claims, in which the blow nozzles have a length of about 15 mm.

9. Device as defined in any one of the preceding claims, in which the spacing between said plane and the blow nozzles is about .5 cm.

10. Device as defined in any one of the preceding claims, in which the spacing between the blow nozzles and the light beam path is about 3 cm.

11. Device as defined in any one of the preceding claims, in which the blow nozzle openings and the light beam path lie in a plane which stands at right angletothethread plane.

12. Device as defined in any one of the preceding claims, in which between the pressurized air source and said tube is arranged a pressure regulator and at the level of said tube is arranged a pressure gauge.

13. Device as defined in any one of the preceding claims, in which the pressurized air source, the tube and the blow nozzles are so arranged that a laminar constant stream is formed on the threads.

14. Device as defined in claim 13, in which the pressurized air source and the tube are so arranged that an overpressure of about kg/cm2 prevails.

15. Device as defined in any one of the preceding claims, in which the light source generates a cylindrical infra-red radiation with a diameter of 1 cm and the light-responsive element is sensitive to said radiation and has a vibration sensitivity from 1 to 30 Hz.

16. Device for monitoring a thread bundle, as described above with reference to the accompanying drawings.

17. Tufting machine, which comprises a device as defined in the preceding claims.

18. Tufting machine as defined in claim 17, in which the light beam path and the tube lie between the last and penultimate thread-guides.

19. Tufting machine as described above with reference to the accompanying drawings.