Title of Invention	"AIRJET SPINNING ARRANGEMENT FOR PRODUCING A SPUN THREAD"
Abstract	An airjet spinning arrangement for producing a spun thread comprises a vortex chamber through which a staple fibre strand travels. At least one air supply channel runs into this vortex chamber. This channel takes the form of a nozzle slit which is arranged in a nozzle body and lies in a radial plane in relation to the travel direction of the staple fibre strand. The nozzle slit completes the above mentioned air supply channel by means of the front surface of a cover. Directly adjacent to the mouthpiece, the cover comprises an air-deflecting surface inclined in the direction of the staple fibre strand, which air deflecting surface advantageously takes the form of 3 conical ring surface.

Title of Invention

"AIRJET SPINNING ARRANGEMENT FOR PRODUCING A SPUN THREAD"

Abstract

An airjet spinning arrangement for producing a spun thread comprises a vortex chamber through which a staple fibre strand travels. At least one air supply channel runs into this vortex chamber. This channel takes the form of a nozzle slit which is arranged in a nozzle body and lies in a radial plane in relation to the travel direction of the staple fibre strand. The nozzle slit completes the above mentioned air supply channel by means of the front surface of a cover. Directly adjacent to the mouthpiece, the cover comprises an air-deflecting surface inclined in the direction of the staple fibre strand, which air deflecting surface advantageously takes the form of 3 conical ring surface.

Full Text	BACKGROUND AND SUMMARY OF THE INVENTION Airjet spinnting arrangement The present invention relates to an airjet spinning arrangement for producing a spun thread from a staple fibre strand which travels through a vortex chamber, into which runs at least one air supply channel for compressed air having a nozzle-like mouthpiece, said air supply channel taking the form of a nozzle groove arranged in a nozzle body and lying in a radial plans in relation to the travel direction of the staple fibre strand, said nozzle groove completing the air supply channel by means of a front surface of a cover. An airjel spinning arrangement is prior art in German published patent application 37 32 708. In this publication two variations are disclosed with regard to the position of the air supply channels. In one variation, on which the generic part of the first claim in the present invention is based, a plurality of air supply channels lie in a radial plane in relation to the travel direction of the staple fibre strand. The compressed air which flows to the staple fibre strand has to be abruptly deflected, whereby it is more or less left to chance whether the airstream then flows in the direction of travel or in the opposite direction, in the other variation, the air supply channels are inclined in the running direction of the staple fibre strand in that the nozzle grooves are located in taper surfaces and are covered by laper surfaces arranged thereto. In this case there is a risk of insufficient seaianl, as the taper surfaces arranged to one another are never free from tolerances. Air supply channels are usually drilled in the case of non-generic airjet spinning arrangements. In contrast to this embodiment, the above mentioned airjet spinning arrangement has the advantage in that it can be manufactured very simply, as in a nozzle body nozzle grooves can be created in a very simple way lo a great degree of precision by means of milling, which are subsequently covered by a lay-on surface and thus complete the air suppty channels. Because air supply channels of this type are exposed before assembly, they can easily be tested with regard to precision and re-worked if necessary. Faulty pieces can also be removed during testing. The manufacture of such nozzle grooves is not limited to a milling process, but rather can also be generated by means of a stamping process. 3 it is an object of the present invention to produce for an airjet spinning arrangement the necessary air supply channels in principle as in the above mentioned prior art. while, however, providing at the same time together with good sealing properties also a stream component aligned in the running direction of the fibre strand. This object has been achieved in accordance with the present invention in that the cover comprises a sloped air-deflecting surface directly adjacent to the mouthpiece and inclined in the running direction of the staple fibre strand. As nozzle grooves extending in a radial plane in relation to the running direction of the staple fibre strand are supposed, the front surface of the cover as well as the surfaces of the nozzle body arranged thereto can each be a plane surface, so that no sealing difficulties arise. In addition, It is ensured that the compressed air directly adjacent to the mouthpiece of the at least one compressed air supply channel is deflected in the running direction of the staple fibre strand, so that unequivocal airflow conditions prevail. The air supply channels designed according to the present invention can be advantageously applied in airjet spinning arrangements which are designed, for example, according to European published patent application 12 17 109. The air-deflecting surface is advantageously designed as conical ring surface surrounding the staple fibre strand. The air-deflecting surfaces can be thus particularly easily manufactured. It is hereby practical when a plurality of mouth pieces are aligned tangentially to the ring surface. This leads not only to a good impariation of twist to the spun thread, but also has the advantage of an extended deflection path for the compressed air, as the air is initially aligned at the air- deflecting surface by a component in the circumferential direction of the ring surface. The ring surface itself can be very flat and narrow. It has been shown that it is sufficient when the conicity of the ring surface in relation to the radial piane lies between 10º and 20º. It has been further shown that the length of the air-deflecting surface can be in the order of magnitude of the width of the nozzie grooves. 4 BRIEF DESCRIPTION OF THE DRAWINGS These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein: Figure 1 is an axial section approximately ten limes enlarged, of an airjet spinning arrangement according to the present invention, Figure 2 is a smaller depiction in comparison to Figure 1 but still larger than the actual size of a section along the intersectional plane 11-II of Figure 1 of a nozzle body, Figure 3 is a view in the direction of the arrow [II of Figure 1 of the cover according to the present invention and in the same dimensions as in Figure 2. Figure 4 is a section of this cover along the intersectional plane IV-IV of Figure 3, DETAILED DESCRIPTION OF THE DRAWINGS Figure 1 shows an airjet spinning arrangement with which a loose staple fibre strand 2 fed through a feed channel 1 is imparted a twist in a vortex chamber 3, so that a spun thread 4 is formed which is withdrawn by a yarn withdrawal channel 5, The staple fibre strand 2 can be fed from a drafting unit or another drafting aggregate. A fluid device generates a vortex airflow in the vortex chamber 3 by means of the injection of compressed air through compressed air supply channels 6 which run tangentially into the vortex chamber 3. The compressed air exiting from the mouthpieces 7 of the air supply channels 6 is removed via an air evacuation channel 8. whereby the air evacuation channel 8 comprises a ring-shaped cross section arranged around the yarn withdrawal channel 5 and around a spindle-like stationary component 9. Downstream of the exit opening 10 of the feed channel 1, the edge 11 of a fibre guiding surface 12 is provided as a twist block, said edge 11 being arranged eccentric to the yarn withdrawal channel 5 in the area of its entry opening 13, In the airjet spinning arrangement the fibres to be spun are held on the one hand in the staple fibre strand 2 and thus fed from the exit opening 10 of the feed channel 1 into the yarn withdrawal channel 5 essentially without being imparted a twist. On the 5 other hand the fibres are subject to the effects of the vortex airstream in the area between the feed channel 1 and the yam withdrawal channel 5, which causes them, or at least their end areas, to be driven radially eway from the entry opening 13 of the yarn withdrawal channel 5, As a result, the threads 4 produced in the process described comprise a core of essentially in thread longitudinal direction extending fibres or fibre areas without an essential twist and an outer area, in which the fibres or fibre ends are twisted around the core. Basing the formation of the thread structure on an idealized process for the purposes of greater clarity, the front ends of fibres, in particular those whose rear areas are held upstream in the feed channel 1, essentially reach the yarn withdrawsl channel 5 directly, but the follow-on fibre areas, in particular when they are no longer held in the entry area of the feed channel 1, are pulled out of the staple fibre strand 2 by the vortex formation and are then twisted around the formed thread 4. In any case fibres are at the same time bound inio the forming thread 4, through which they are pulled through the yarn withdrawal channel 5, and also subject to the vortex airslream which accelerates the fibres centrifugally, that is away from the entry opening 13 of the yarn withdrawal channel 5, and pulls them into the air evacuation channel 8. The fibre areas pulled out of the staple fibre strand 2 by the vortex airstream form a fibre vortex in the entry opening 13 of the yarn withdrawal channel 5, the longer parts of which fibre vortex wind themselves in a spiral-like manner around the spindle-shaped component 9 and in this spiral are pulled to the entry opening 13 of the yam withdrawal channel 5 against the force of the flow in the air evacuation channel 8. The air supply channels 6 are described in more detail below with the aid of Figure 1, supplemented by Figures 2, 3 and 4. According to the shown embodiment in the above mentioned Figures, there are per airjet spinning arrangement four compressed air supply channels 6 overall, each of which are provided with mouthpieces 7, and, as can best be seen in Figure 2, are, tangentially directed into the vortex chamber 3, These compressed air supply channels 6 are worked into a nozzle body 14 in the form of nozzle grooves 15 and, according to Figures 1, 3 and 4 are completed to form compressed air supply channels 6 by means of the front surface 16 of a cover 17, The nozzle grooves 15 6 extend in a plane E radial to the running direction A of the staple fibre strand 2, see Figure 1. An annular space 18 radially surrounding the nozzle body 14 is connected to a compressed air source in a way not shown. Via axial recesses 19 worked into the outer contour of the nozzle body 14, the compressed air travels from the annular space 18 to the individual air supply channels 6. The annular space 18 is sealed off from the outside by a wall of a housing 20. In accordance with the present invention, the cover 17 comprises directly adjacent to the mouthpieces 7 a sloped air-daffecting surface 21 inclined in running direction A of the staple fibre strand 2. Although the nozzle grooves 15 are very simple to manufacture as they !ie in the radial plane E, the compressed air exiting out of the moutopleces 7 is deflected by the air-deflecting surface 21 in rurning direction A of the fibe strand 2. As can be seen, the air-deflecting surface 21 is designed as a conical ring surface 22 which surrounds the staple fibre strand 2 and against which a plurality of mouthpieces 7 are tangentially directed. As can be seen in particular in Figures 2 and 4, the conicity a of the ring surface 22 in relation to the radial plane E is relatively low and lies between 10° and 20°, The length L of the air-deffecting surface 21 lies in the order of magnitude of the width B of the nozzie grooves 15. 7 CLAIMS: 1. Airjet spinning arrangement for producing a spun thread from a staple fibre strand which travels through a vortex chamber, into which runs at least one air supply channel for compressed air having a nozzte-like mouthpiece, said compressed air supply channel taking the form of a nozzle groove arranged in a nozzle body and lying in a radial plane in relation to the travel direction of the staple fibre strand, said nozzle groove completing the air supply channel by means of a front surface of a cover, characterized in that the cover (17) comprises a sloped air-deflecting surface (21) inclined in the running direction (A) of the staple fibre strand (2) directly adjacent to the mouthpiece (7). 2. Airjet spinning arrangement according to claim 1, characterized in that the air- deflecting surface (21) is designed as a conical ring surface (22) surrounding the staple fibre strand (2). 3. Airjet spinning arrangement according to claim 2, characterized in that a plurality of mouthpieces (7) are aligned tangentially toward the ring surface (22). 4. Airjet spinning arrangement according to claim 2 or 3, characterized in that the conicity (a) of the ring surface (22) in relation to the radial plane (E) measures between 10° and 20º. 5. Airjet spinning arrangement according to any one of the claims 1 to 4, characterized in that the length (L) of the air-deflecting surface (21) lies in the order of magnitude of the width (B) of the nozzle grooves (15). An airjet spinning arrangement for producing a spun thread comprises a vortex chamber through which a staple fibre strand travels. At least one air supply channel runs into this vortex chamber. This channel takes the form of a nozzle slit which is arranged in a nozzle body and lies in a radial plane in relation to the travel direction of the staple fibre strand. The nozzle slit completes the above mentioned air supply channel by means of the front surface of a cover. Directly adjacent to the mouthpiece, the cover comprises an air-deflecting surface inclined in the direction of the staple fibre strand, which air deflecting surface advantageously takes the form of 3 conical ring surface.

Full Text

BACKGROUND AND SUMMARY OF THE INVENTION
Airjet spinnting arrangement
The present invention relates to an airjet spinning arrangement for producing a spun
thread from a staple fibre strand which travels through a vortex chamber, into which
runs at least one air supply channel for compressed air having a nozzle-like
mouthpiece, said air supply channel taking the form of a nozzle groove arranged in a
nozzle body and lying in a radial plans in relation to the travel direction of the staple
fibre strand, said nozzle groove completing the air supply channel by means of a
front surface of a cover.
An airjel spinning arrangement is prior art in German published patent application 37
32 708. In this publication two variations are disclosed with regard to the position of
the air supply channels. In one variation, on which the generic part of the first claim
in the present invention is based, a plurality of air supply channels lie in a radial plane
in relation to the travel direction of the staple fibre strand. The compressed air which
flows to the staple fibre strand has to be abruptly deflected, whereby it is more or less
left to chance whether the airstream then flows in the direction of travel or in the
opposite direction, in the other variation, the air supply channels are inclined in the
running direction of the staple fibre strand in that the nozzle grooves are located in
taper surfaces and are covered by laper surfaces arranged thereto. In this case
there is a risk of insufficient seaianl, as the taper surfaces arranged to one another
are never free from tolerances.
Air supply channels are usually drilled in the case of non-generic airjet spinning
arrangements. In contrast to this embodiment, the above mentioned airjet spinning
arrangement has the advantage in that it can be manufactured very simply, as in a
nozzle body nozzle grooves can be created in a very simple way lo a great degree of
precision by means of milling, which are subsequently covered by a lay-on surface
and thus complete the air suppty channels. Because air supply channels of this type
are exposed before assembly, they can easily be tested with regard to precision and
re-worked if necessary. Faulty pieces can also be removed during testing. The
manufacture of such nozzle grooves is not limited to a milling process, but rather can
also be generated by means of a stamping process.

3
it is an object of the present invention to produce for an airjet spinning arrangement
the necessary air supply channels in principle as in the above mentioned prior art.
while, however, providing at the same time together with good sealing properties also
a stream component aligned in the running direction of the fibre strand.
This object has been achieved in accordance with the present invention in that the
cover comprises a sloped air-deflecting surface directly adjacent to the mouthpiece
and inclined in the running direction of the staple fibre strand.
As nozzle grooves extending in a radial plane in relation to the running direction of
the staple fibre strand are supposed, the front surface of the cover as well as the
surfaces of the nozzle body arranged thereto can each be a plane surface, so that no
sealing difficulties arise. In addition, It is ensured that the compressed air directly
adjacent to the mouthpiece of the at least one compressed air supply channel is
deflected in the running direction of the staple fibre strand, so that unequivocal
airflow conditions prevail.
The air supply channels designed according to the present invention can be
advantageously applied in airjet spinning arrangements which are designed, for
example, according to European published patent application 12 17 109.
The air-deflecting surface is advantageously designed as conical ring surface
surrounding the staple fibre strand. The air-deflecting surfaces can be thus
particularly easily manufactured. It is hereby practical when a plurality of mouth
pieces are aligned tangentially to the ring surface. This leads not only to a good
impariation of twist to the spun thread, but also has the advantage of an extended
deflection path for the compressed air, as the air is initially aligned at the air-
deflecting surface by a component in the circumferential direction of the ring surface.
The ring surface itself can be very flat and narrow. It has been shown that it is
sufficient when the conicity of the ring surface in relation to the radial piane lies
between 10º and 20º. It has been further shown that the length of the air-deflecting
surface can be in the order of magnitude of the width of the nozzie grooves.

4
BRIEF DESCRIPTION OF THE DRAWINGS
These and further objects, features and advantages of the present invention will
become more readily apparent from the following detailed description thereof when
taken in conjunction with the accompanying drawings wherein:
Figure 1 is an axial section approximately ten limes enlarged, of an airjet spinning
arrangement according to the present invention,
Figure 2 is a smaller depiction in comparison to Figure 1 but still larger than the
actual size of a section along the intersectional plane 11-II of Figure 1 of a nozzle
body,
Figure 3 is a view in the direction of the arrow [II of Figure 1 of the cover according to
the present invention and in the same dimensions as in Figure 2.
Figure 4 is a section of this cover along the intersectional plane IV-IV of Figure 3,
DETAILED DESCRIPTION OF THE DRAWINGS
Figure 1 shows an airjet spinning arrangement with which a loose staple fibre strand
2 fed through a feed channel 1 is imparted a twist in a vortex chamber 3, so that a
spun thread 4 is formed which is withdrawn by a yarn withdrawal channel 5, The
staple fibre strand 2 can be fed from a drafting unit or another drafting aggregate. A
fluid device generates a vortex airflow in the vortex chamber 3 by means of the
injection of compressed air through compressed air supply channels 6 which run
tangentially into the vortex chamber 3. The compressed air exiting from the
mouthpieces 7 of the air supply channels 6 is removed via an air evacuation channel
8. whereby the air evacuation channel 8 comprises a ring-shaped cross section
arranged around the yarn withdrawal channel 5 and around a spindle-like stationary
component 9.
Downstream of the exit opening 10 of the feed channel 1, the edge 11 of a fibre
guiding surface 12 is provided as a twist block, said edge 11 being arranged
eccentric to the yarn withdrawal channel 5 in the area of its entry opening 13,
In the airjet spinning arrangement the fibres to be spun are held on the one hand in
the staple fibre strand 2 and thus fed from the exit opening 10 of the feed channel 1
into the yarn withdrawal channel 5 essentially without being imparted a twist. On the

5
other hand the fibres are subject to the effects of the vortex airstream in the area
between the feed channel 1 and the yam withdrawal channel 5, which causes them,
or at least their end areas, to be driven radially eway from the entry opening 13 of the
yarn withdrawal channel 5, As a result, the threads 4 produced in the process
described comprise a core of essentially in thread longitudinal direction extending
fibres or fibre areas without an essential twist and an outer area, in which the fibres
or fibre ends are twisted around the core.
Basing the formation of the thread structure on an idealized process for the purposes
of greater clarity, the front ends of fibres, in particular those whose rear areas are
held upstream in the feed channel 1, essentially reach the yarn withdrawsl channel 5
directly, but the follow-on fibre areas, in particular when they are no longer held in
the entry area of the feed channel 1, are pulled out of the staple fibre strand 2 by the
vortex formation and are then twisted around the formed thread 4.
In any case fibres are at the same time bound inio the forming thread 4, through
which they are pulled through the yarn withdrawal channel 5, and also subject to the
vortex airslream which accelerates the fibres centrifugally, that is away from the entry
opening 13 of the yarn withdrawal channel 5, and pulls them into the air evacuation
channel 8. The fibre areas pulled out of the staple fibre strand 2 by the vortex
airstream form a fibre vortex in the entry opening 13 of the yarn withdrawal channel
5, the longer parts of which fibre vortex wind themselves in a spiral-like manner
around the spindle-shaped component 9 and in this spiral are pulled to the entry
opening 13 of the yam withdrawal channel 5 against the force of the flow in the air
evacuation channel 8.
The air supply channels 6 are described in more detail below with the aid of Figure 1,
supplemented by Figures 2, 3 and 4.
According to the shown embodiment in the above mentioned Figures, there are per
airjet spinning arrangement four compressed air supply channels 6 overall, each of
which are provided with mouthpieces 7, and, as can best be seen in Figure 2, are,
tangentially directed into the vortex chamber 3, These compressed air supply
channels 6 are worked into a nozzle body 14 in the form of nozzle grooves 15 and,
according to Figures 1, 3 and 4 are completed to form compressed air supply
channels 6 by means of the front surface 16 of a cover 17, The nozzle grooves 15

6
extend in a plane E radial to the running direction A of the staple fibre strand 2, see
Figure 1.
An annular space 18 radially surrounding the nozzle body 14 is connected to a
compressed air source in a way not shown. Via axial recesses 19 worked into the
outer contour of the nozzle body 14, the compressed air travels from the annular
space 18 to the individual air supply channels 6. The annular space 18 is sealed off
from the outside by a wall of a housing 20.
In accordance with the present invention, the cover 17 comprises directly adjacent to
the mouthpieces 7 a sloped air-daffecting surface 21 inclined in running direction A of
the staple fibre strand 2. Although the nozzle grooves 15 are very simple to
manufacture as they !ie in the radial plane E, the compressed air exiting out of the
moutopleces 7 is deflected by the air-deflecting surface 21 in rurning direction A of
the fibe strand 2. As can be seen, the air-deflecting surface 21 is designed as a
conical ring surface 22 which surrounds the staple fibre strand 2 and against which a
plurality of mouthpieces 7 are tangentially directed.
As can be seen in particular in Figures 2 and 4, the conicity a of the ring surface 22
in relation to the radial plane E is relatively low and lies between 10° and 20°, The
length L of the air-deffecting surface 21 lies in the order of magnitude of the width B
of the nozzie grooves 15.

7
CLAIMS:
1. Airjet spinning arrangement for producing a spun thread from a staple fibre
strand which travels through a vortex chamber, into which runs at least one
air supply channel for compressed air having a nozzte-like mouthpiece, said
compressed air supply channel taking the form of a nozzle groove arranged in
a nozzle body and lying in a radial plane in relation to the travel direction of
the staple fibre strand, said nozzle groove completing the air supply channel
by means of a front surface of a cover, characterized in that the cover (17)
comprises a sloped air-deflecting surface (21) inclined in the running direction
(A) of the staple fibre strand (2) directly adjacent to the mouthpiece (7).
2. Airjet spinning arrangement according to claim 1, characterized in that the air-
deflecting surface (21) is designed as a conical ring surface (22) surrounding
the staple fibre strand (2).
3. Airjet spinning arrangement according to claim 2, characterized in that a
plurality of mouthpieces (7) are aligned tangentially toward the ring surface
(22).
4. Airjet spinning arrangement according to claim 2 or 3, characterized in that
the conicity (a) of the ring surface (22) in relation to the radial plane (E)
measures between 10° and 20º.
5. Airjet spinning arrangement according to any one of the claims 1 to 4,
characterized in that the length (L) of the air-deflecting surface (21) lies in the
order of magnitude of the width (B) of the nozzle grooves (15).

An airjet spinning arrangement for producing a spun thread comprises a vortex
chamber through which a staple fibre strand travels. At least one air supply channel
runs into this vortex chamber. This channel takes the form of a nozzle slit which is
arranged in a nozzle body and lies in a radial plane in relation to the travel direction
of the staple fibre strand. The nozzle slit completes the above mentioned air supply
channel by means of the front surface of a cover. Directly adjacent to the
mouthpiece, the cover comprises an air-deflecting surface inclined in the direction of
the staple fibre strand, which air deflecting surface advantageously takes the form of
3 conical ring surface.

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Patent Number

219321

Indian Patent Application Number

01209/KOLNP/2005

PG Journal Number

18/2008

Publication Date

02-May-2008

Grant Date

30-Apr-2008

Date of Filing

22-Jun-2005

Name of Patentee

MASCHINENFABRIK RIETER AG.

Applicant Address

KLOSTERSTRASSE 20,CH-8406 WINTERTHUR,SWITZERLAND.

Inventors:

#	Inventor's Name	Inventor's Address
1	SCHWEIER,PETER	TECKSTRASSE 14,73312 GEISLINGEN/STEIGE,GERMANY.

PCT International Classification Number

D01H 4/02

PCT International Application Number

PCT/EP03/010994

PCT International Filing date

2003-10-04

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	102 56 344.6	2002-11-22	Germany