| Title of Invention | " A DEVICE FOR PRODUCING A SPUN THREAD FROM A SLIVER" |
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| Abstract | An arrangement for producing a spun thread from a staple sliver comprises a drafting unit and an alt jel aggregate arranged downstream thereof. A vortex chamber with at air evacuation channel is located in the air jet aggregate. A cleaning channel s arranged to the delivery roller pair of the drafting unit, which cleaning channel s connected, together with the air evacuation channel to a joint vacuum source. The cleaning channel runs preferably into the air evacuation Channel in the inside of the air jet aggregate The cleaning channel is preferably aligned agairst the pressure roller of the delivery roller pair. Further suction openings can be additionaly arranged to the bottom rollers of the drafting unit, which suction openings are also connected to the joint vacuum source. |
| Full Text | BACKGROUND AND SUMMARY OF THE INVENTION An arrangement for producing a spun thread The present invention relates to an arrangement for producing a spun thread from in staple sliver, comprising a drafting unit comprising a delivery roller pair, also comprising an air jet aggregate arranged downstream of the drafting unit, which ar jet aggregate comprises an air evacuation channel and comprising a cleaning channel arranged to the delivery roller pair and comprising a suction opening. An arrangement of this type is known in European patent application 1 207 225- In the case of this arrangement, a staple sliver is drafted to a fibre strand, which iS imparted its spinning twist in the air jet aggregate. The fibre strand is fed first throug an entry channel of the air jet aggregate into a vortex chamber, to which is arranged a fluid device for generating a turbulent airflow around an inlet opening of a yarn withdrawal channel. The front ends of the fibres held in the fibre strand are herety first fed into the yarn withdrawal channel, while rear, free fibre ends are spread out, seized by the turbulent airflow and twisted around the bound-in front ends afreacy located in the entry opening of the yam withdrawal channel, whereby a thread with a mostly true twist is formed. An arrangement of this type permits high spinning speeds, whereby high demanc s are made above all on the drafting unit arranged upstream of the air jet aggregate, n particular, fibre fly tends to settle on the circumferential surfaces of the delivery roller pair, which rotates especially rapidly. For this reason, a suction opening of a cleanirg channel is arranged to the delivery roller pair of the known arrangement, which cleaning channel ensures that the delivery roller pair is kept clear of fibre fly, Tre above mentioned publication does not specify to which vacuum source the cleaning channel is connected, but it can be seen from the patent figures, that in the case of the air evacuation channel and the cleaning channel, different vacuum sources ae provided. It is an object of the present invention to provide a particularly simple design for the arrangement of the above mentioned type. This object has been achieved in that the air evacuation channel and the cleaning channel are both connected to the same vacuum source. It has been shown that the low pressures, which on the one hand are necessary to the air evacuation channel and on the other hand for the suctioning of ths delivery roller pair, do not differ from each other to such an extent that they could not be; achieved by means of a joint vacuum source, for example, a joint blower This measure results, from the point of view of the technical design, in significant space saving in an area which is already spatially very narrow, and also to a significant simplification of the production process. in an embodiment of the present invention it is provided that the cleaning channel runs into the air evacuation channel in the interior of the air jet aggregate. Where the cleaning channel runs into the air evacuation channel, the latter can Lake tne form cf a ring channel in this area. The air jet aggregate usually comprises an entry channel which leads to the vortex chamber, to which entry channel the cleaning channel advantageously extends at least approximately parallel. This permits the vortex chamber arranged downstream of the entry channel, as well as the cleaning channel, to be connected in a simpls manner to the air evacuation channel- The suction opening of the cleaning channel can be aligned at a distance from the entry channel against a pressure roller of the delivery roller pair. Tests have shown that the pressure roller of the delivery roller pair is particularly susceptible to fibre fly. The distance mentioned above corresponds for the purpose of the present invention approximately to the radius of the pressure roller. in a further embodiment of the present invention, further suction openings can be arranged to the driven bottom rollers of the drafting unit in the areas facing away from their respective pressure rollers, which suction openings are also advantageously connected to a joint vacuum source. Thus with one single vacuum source, net only can the sir involved in the spinning process be withdrawn from the air jet aggregate, but also the entire drafting unit is kept clean. DETAILED DESCRIPTION OF THE DRAWING These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof whan taken in conjunction with a spinning aggregate shown enlarged and schematically in intersection. The arrangement shown in the drawing serves the production of a spun; thread from a staple sliver 2. The arrangement comprises a drafting unit 3 as well as an air jet aggregate 4 as essential component parts. The staple sliver 2 to be spun is fed to the drafting unit 3 in deliver/ direction A and withdrawn as a spun thread 1 in withdrawal direction B and then guided further to 3 winding device (not shown). The drafting unit 3, shown only in part, is preferably a three-cylinder drafting unit and comprises overall three roller pairs, each having a driven bottom roller and an upper roller in the form of a pressure roller. Downstream of a front roller pair (not shown) s a roller pair 5,6 which is provided with guiding belts 7 and 8, as well as a deliveiy roller pair 9,10. The revelant, driven bottom rollers are denoted by the numbers 5 and 9, while the respective pressure rollers are denoted by the numbers 6 and 10. in a drafting unit 3 of this type, the staple sliver 2 is drafted to the desired degree of fineness in the known way. Directly downstream of the drafting unit 3, a thin fibre strand 11 is present, which is drafted, but not yet twisted. The air jet aggregate 4, arranged downstream of the drafting unit 3 at a she rt distance thereto, and which imparts the spinning twist, can, in the present invention be of any design, whereby, however, the design according to International published application 02/24993 is preferably considered, as this type of air jet aggregate permits particularly high delivery speeds. The fibre strand 11 is fed via an entry channel 12 to the air jet aggregate 4. Arranged downstream thereof is a so-called vortex chamber 13, in which the fibre strand 11 is imparted the spinning twist, so that the spun thread 1 is created, which is withdrawn through a yarn withdrawal channel 14. A fluid device generates turbulent air currerts in the vortex chamber 13 by means of blowing in compressed air through compressed air jets which run tangentially into the vortex chamber 13. The compressed air which exits out of the jet openings is guided through an evacuaton channel 15, whereby this channel 15 has a ring-shaped cross section surrounding a spindle-shaped stationary component 16, which comprises the yarn withdrawal channel 14. In the area of the vortex chamber 13, an edge of a fibre guiding surface is arrange: as a twist block, said edge being arranged slightly eccentrically to the yarr withdrawal channel 14 in the area of its entry opening. In the arrangement, the fibres to be spun are held on the one hand in the fibre strand 11 and thus are fed from the entry Chanel 12, essentially without being imparted and twist, to the yarn withdrawal channel 14- On the other hand, the fibres in the are:) between the entry channel 12 and the yarn withdrawal channel 14 are subject to the effect of the turbulent air currents, by means of which the fibres or at least their end areas are driven radially away from the entry opening of the yarn withdrawal channel 14. The threads 1 formed by means of the above described process thus have a core of essentially in thread longitudinal direction extending fibres or fibre areas without any significant twist, as well as an outer area, in which the fibres or fibrs areas are wound around the core area. Basing the formation of the thread structure on an idealized prgcess for the purpose; of greater clarity, it can be said that the structure of the thread 4 form;; because the front running ends of the fibres, in particular those whose rear areas are still held upstream by the entry channel 12, essentially reach the yarn withdrawal channel 14 directly, whereas the fibre areas following behind, in particular when they are no longer held in the entry area to the entry channel 12, are pulled out of the ftbre stran 3 11 due to the rotating air current and then are twisted around the forming thread 1. In any case, fibres are bound into the forming thread 1, whereby they are pulled through the yarn withdrawal channel 14, and are simultaneously subject to the effects of the rotating current, which centrifugally accelerate the fibres, that is; from the inlet opening of the yam withdrawal channel 14 onwards, from where they are sucked in-o the air evacuation channel 15. The fibre areas pulled out of the fibre strand 11 by the circulating air currents form a fibre vortex, the so-called sun, which runs into the entry opening of the yarn withdrawal channel 14, the longer parts of which so-callec sun winding themselves spiralike around the spindle-shaped entry area of the yarr withdrawal channel 14 and this spiral being drawn against the entry opening of the yarn withdrawal channel 14 contrary to the force of the current in the air evacuation channel 15. An arrangement of this type permits particularly high spinning speeds, which lie in the range of 600 metres per minute. It is clear that the drafting unit 3 is subject to great pressures, because the delivery roller pair 9,10 must rotate very fast due to the required high drafting performance. This results inevitably in the delivery roller pai 9,10 and in particular its pressure roller 10 being susceptible to heavy fibre fly causec by fibre loss. For this reason, a suction opening 17 of a cleaning channel 18 is arranged to the pressure roller 10 of the delivery roller 9,10. In contrast to the above described prior art, the cleaning channel 18 provided for the present invention runs into the inside of the air jet aggregate 4 ir the air evacuation channel 15, This is designed as a ring channel 20 in the running in area 19 of the cleaning channel 18, said ring channel 20 surrounding the spindle-shaped component 16. As can be seen, the cleaning channel 18 extends at least approximately parallel 13 the entry channel 12 leading into the vortex chamber 13. This permits the suctioi opening 17 of the cleaning channel 18 to be aligned against the pressure roller 10 of the delivery roller pair 9,10 at a certain distance from the entry channel 12. This distance should correspond approximately to the radius of the pressure roller 10. This embodiment of the arrangement permits the air evacuation channel 15 and the cleaning channel 18 to be connected to a joint vacuum source 21, which is shown here as a suction tube, but which for the purpose of the present invention leads to a blower (not shown). Further suction openings 22 and 23 coutd be connected to this joint vacuum source 21, which openings are arranged to the driven bottom rollers 59 as well as to the front bottom roller arranged upstream (not shown) in areas facirg away from the relevant pressure rollers 6, 10. Thus in a simple way, the spinning air is expelled and the drafting unit 3 is kept clean. An arrangement for producing a spun thread from a staple sliver comprises a drafting unit and an alt jel aggregate arranged downstream thereof. A vortex chamber with at air evacuation channel is located in the air jet aggregate. A cleaning channel s arranged to the delivery roller pair of the drafting unit, which cleaning channel s connected, together with the air evacuation channel to a joint vacuum source. The cleaning channel runs preferably into the air evacuation Channel in the inside of the air jet aggregate The cleaning channel is preferably aligned agairst the pressure roller of the delivery roller pair. Further suction openings can be additionaly arranged to the bottom rollers of the drafting unit, which suction openings are also connected to the joint vacuum source. |
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| Patent Number | 215536 | ||||||||
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| Indian Patent Application Number | 01780/KOLNP/2005 | ||||||||
| PG Journal Number | 09/2008 | ||||||||
| Publication Date | 29-Feb-2008 | ||||||||
| Grant Date | 27-Feb-2008 | ||||||||
| Date of Filing | 07-Sep-2005 | ||||||||
| Name of Patentee | MASCHINENFABRIK RIETER AG. | ||||||||
| Applicant Address | KLOSTERSTRASSE 20, CH-8406 WINTERTHUR SWITZERLAND | ||||||||
Inventors:
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| PCT International Classification Number | D01H 1/115 ; D01H 4/02 ; D01H 5/66 | ||||||||
| PCT International Application Number | PCT/EP2004/001402 | ||||||||
| PCT International Filing date | 2004-02-14 | ||||||||
PCT Conventions:
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