U.S. patent application number 12/067256 was filed with the patent office on 2008-11-13 for air jet aggregate for an air jet spinning arrangement.
This patent application is currently assigned to MASCHINENFABRIK RIETER AG. Invention is credited to Volker Jehle, Gerd Stahlecker.
Application Number | 20080276594 12/067256 |
Document ID | / |
Family ID | 37114340 |
Filed Date | 2008-11-13 |
United States Patent
Application |
20080276594 |
Kind Code |
A1 |
Stahlecker; Gerd ; et
al. |
November 13, 2008 |
Air Jet Aggregate for an Air Jet Spinning Arrangement
Abstract
An air jet aggregate for an air jet spinning apparatus for
producing a spun thread from a staple fiber strand includes a
vortex chamber and a number of fluid-feeding injector channels
running into the vortex chamber. At least two injector channels are
provided, which have differing angles of inclination in relation to
a parallel to the axis of the spun thread. The at least two
injector channels having differing angles of inclination are
connectable to at least one pressurized air source. The injector
channels with differing angles of inclination are, preferably,
connectable to separately adjustable pressurized air sources.
Inventors: |
Stahlecker; Gerd;
(Eislingen/Filz, DE) ; Jehle; Volker; (Baeretswil,
CH) |
Correspondence
Address: |
CROWELL & MORING LLP;INTELLECTUAL PROPERTY GROUP
P.O. BOX 14300
WASHINGTON
DC
20044-4300
US
|
Assignee: |
MASCHINENFABRIK RIETER AG
WINTERTHUR
CH
|
Family ID: |
37114340 |
Appl. No.: |
12/067256 |
Filed: |
July 19, 2006 |
PCT Filed: |
July 19, 2006 |
PCT NO: |
PCT/EP06/07095 |
371 Date: |
March 18, 2008 |
Current U.S.
Class: |
57/403 ; 57/409;
57/415 |
Current CPC
Class: |
D01H 1/115 20130101;
D01H 4/02 20130101 |
Class at
Publication: |
57/403 ; 57/409;
57/415 |
International
Class: |
D01H 4/02 20060101
D01H004/02; D01H 1/115 20060101 D01H001/115 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 19, 2005 |
DE |
10-2005045-703.7 |
Claims
1-6. (canceled)
7. An air jet aggregate for an air jet spinning apparatus producing
a spun thread from a staple fiber strand, comprising: a vortex
chamber; at least two fluid-feeding injector channels operatively
arranged to run into the vortex chamber; wherein the at least two
injector channels are arranged at different angles of inclination
in relation to an axis parallel to an axis of the spun thread; and
wherein the at least two injector channels are connectable to at
least one pressurized air source.
8. The air jet aggregate according to claim 7, wherein the at least
two injector channels having the different angles of inclination
are connectable to separately adjustable pressurized air
sources.
9. The air jet aggregate according to claim 7, wherein at least one
injector channel is operatively arranged at a different distance
from an entry opening of a fiber feed channel than another of the
injector channels.
10. The air jet aggregate according to claim 8, wherein at least
one injector channel is operatively arranged at a different
distance from an entry opening of a fiber feed channel than another
of the injector channels.
11. The air jet aggregate according to claim 7, wherein at least
one injector channel for pressurized air has an angle of
inclination (.alpha.) of less than 5.degree. in relation to the
axis parallel to the axis of the spun thread.
12. The air jet aggregate according to claim 8, wherein at least
one injector channel for pressurized air has an angle of
inclination (.alpha.) of less than 5.degree. in relation to the
axis parallel to the axis of the spun thread.
13. The air jet aggregate according to claim 9, wherein at least
one injector channel for pressurized air has an angle of
inclination (.alpha.) of less than 5.degree. in relation to the
axis parallel to the axis of the spun thread.
14. The air jet aggregate according to claim 7, wherein at least
one injector channel for pressurized air has an angle of
inclination (.alpha.) of 0.degree. in relation to an axis parallel
to the axis of the spun thread.
15. The air jet aggregate according to claim 8, wherein at least
one injector channel for pressurized air has an angle of
inclination (.alpha.) of 0.degree. in relation to an axis parallel
to the axis of the spun thread.
16. The air jet aggregate according to claim 9, wherein at least
one injector channel for pressurized air has an angle of
inclination (.alpha.) of 0.degree. in relation to an axis parallel
to the axis of the spun thread.
17. The air jet aggregate according to claim 7, wherein the at
least two injector channels are operatively configured to generate
a helical curve-shaped vortex current with an alterable pitch in
the vortex chamber by flowing pressurized air out of the injector
channels.
18. The air jet aggregate according to claim 8, wherein the at
least two injector channels are operatively configured to generate
a helical curve-shaped vortex current with an alterable pitch in
the vortex chamber by flowing pressurized air out of the injector
channels.
19. The air jet aggregate according to claim 9, wherein the at
least two injector channels are operatively configured to generate
a helical curve-shaped vortex current with an alterable pitch in
the vortex chamber by flowing pressurized air out of the injector
channels.
20. The air jet aggregate according to claim 11, wherein the at
least two injector channels are operatively configured to generate
a helical curve-shaped vortex current with an alterable pitch in
the vortex chamber by flowing pressurized air out of the injector
channels.
21. The air jet aggregate according to claim 14, wherein the at
least two injector channels are operatively configured to generate
a helical curve-shaped vortex current with an alterable pitch in
the vortex chamber by flowing pressurized air out of the injector
channels.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
[0001] The present invention relates to an air jet aggregate for an
air jet spinning apparatus for producing a spun thread from a
staple fiber strand, including a vortex chamber and a number of
fluid-feeding injector channels running into the vortex chamber. At
least two injector channels are provided, which have differing
angles of inclination in relation to a parallel to the axis of the
spun thread.
[0002] In an air jet spinning apparatus, the fibers of a twist-free
fed staple fiber strand are imparted a spinning twist by way of an
air jet, which lends the formed thread its tensile strength. The
staple fiber strand is fed into a vortex chamber, in which a
rotating vortex current prevails, which is usually generated by
injector channels which run into the vortex chamber and to which
injector channels pressurized air is applied.
[0003] It is known, for example, in German published patent
application DE 41 22 216 A1, to arrange a number of injector
channels in the circumferential wall of the vortex chamber. In the
known air jet aggregates, all injector channels for pressurized air
always have the same angle of inclination in relation to a parallel
to the axis of the spun thread. The injector channels are usually
supplied with pressurized air from a joint pneumatic source via a
ring channel.
[0004] It is further known that the pressurized air injected into
the vortex chamber must fulfill two functions. First of all, the
pressurized air must form a rotating vortex current, which gives
the fibers of the fed staple fiber strand their twist. Secondly,
the pressurized air must flow into the vortex chamber in such a way
that a sufficiently strong vacuum occurs at the entry opening of
the fiber feed channel, through which the staple fiber strand is
transported from the delivery nipping line into the vortex
chamber.
[0005] A disadvantage in the known air jet aggregates is that the
angle of inclination of the injector channels must be predefined as
a compromise between two contradictory requirements. The smaller
the angle of inclination is, that is, the more it approaches the
parallel to the axis of the spun thread, the greater the vacuum at
the entry opening of the fiber feed channel and the better the
fiber take-over from the delivery roller pair. At the same time
however, the tangential forces of the vortex current which twist
the staple fiber strand around its axis decrease, and the spun
thread only has a low level of tensile strength. If a large angle
of inclination is selected for the injector channels, that is,
almost 90.degree. to the axis of the spun thread, the rotating
vortex current does generate a thread of high tensile strength, but
there is, however, less vacuum at the entry opening, which impairs
the suction action of the air jet aggregate and the fiber transport
into the vortex chamber, which in turn can lead to end breaks.
[0006] An air jet aggregate is also known in German patent
application DE 41 22 216 A1, in which a further injector channel
for a fluid is described, which is arranged coaxially to the axis
of the spun thread. This injector channel serves exclusively to
feed water into the vortex chamber, whereby the spun fiber material
is dampened. The aim is to improve the tensile strength of the spun
thread by means of direct dampening during spinning and to omit
large humidifiers for the atmosphere.
[0007] It is an object of the present invention to avoid the above
mentioned disadvantages and to create an air jet aggregate which
possesses a good twist distribution and a good suction action.
[0008] This object has been achieved in accordance with the present
invention in that at least two injector channels having differing
angles of inclination are connectable to at least one pressurized
air source.
[0009] By use of at least two injector channels having different
angles of inclination, to all of which pressurized air is applied,
the vortex current in the vortex chamber can be influenced in an
advantageous way. At least one, but advantageously a number of
injector channels are arranged in position and angle of inclination
in such a way that a good distribution of twist for the fibers of
the staple fiber strand is guaranteed and a thread having high
tensile strength is formed. A relatively large angle of inclination
and an opening of the injector channels running tangentially into
the vortex chamber are particularly advantageous. To secure a good
suction action and to guarantee a reliable transport of the staple
fiber strand from the delivery roller pair into the vortex chamber,
at least one further injector channel supplied with pressurized air
is provided, which injector channel has a smaller angle of
inclination than the above mentioned injector channels for twist
distribution. The injector channel with the smaller angle of
inclination effects essentially the occurrence of a vacuum at the
entry opening of the fiber feed channel.
[0010] It can be advantageous that the minimum one injector channel
for generating a vacuum is at a different distance, in particular a
shorter distance, from the entry opening than the injector channels
for twist distribution. The proximity to the entry opening
intensifies the vacuum formation.
[0011] It is advantageous for a particularly good suction action of
the air jet that at least one injector channel for pressurized air
has an angle of inclination of less than 5.degree., preferably even
0.degree., that is, this injector channel extends essentially
parallel to the axis of the spun thread.
[0012] In an embodiment of the present invention, it can be
advantageous to arrange the injector channel in such a way that its
opening is directed towards the center of the rotating vortex
current. Disturbances in the rotation of the vortex current can
thus be avoided to a large extent.
[0013] It can be provided that all injector channels are connected
to a joint pressurized air source. In this case, the vortex current
can be adjusted accordingly, for example, based on the number and
diameter of the injector channels selected.
[0014] In an embodiment of the present invention, it is, however,
advantageous that at least two injector channels having different
angles of inclination are connectable to separately adjustable
pressurized air sources. The pressure and/or the amount of air
flowing through the different injector channels can be altered
during the spinning process due to the separately adjustable
pressurized air sources. This permits, in an advantageous way, the
generation of a helical curve-shaped vortex current with alterable
pitch in the vortex chamber from the pressurized air flowing out of
the injector channels. It is advantageous that the vortex current
follows a helical curve with a pitch, which is adapted to the
delivery speed of the spun thread and its twist.
[0015] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an axial section of an air jet aggregate of an air
jet spinning apparatus in greatly enlarged dimensions; and
[0017] FIG. 2 is an intersectional view taken along the
intersectional surface II-II of the air jet aggregate in FIG.
1.
DETAILED DESCRIPTION OF THE DRAWINGS
[0018] The air jet spinning apparatus according to FIGS. 1 and 2
includes a delivery device 1 for guiding a staple fiber strand 2 to
be spun, as well as an air jet aggregate 3, in which the necessary
twist for the spinning of a thread 4 is provided in the staple
fiber strand 2.
[0019] The delivery device 1 includes a delivery roller pair 5, 6,
which is arranged to the air jet aggregate 3 at a short distance
thereto and whereby the front roller pair of a drafting device (not
shown) can be involved. A drafting device of this type drafts a fed
sliver or roving to a staple fiber strand 2 of the desired degree
of fineness in a known manner. The delivery device 1 can, however,
alternatively be a nipping roller pair of another drafting device
or any other unit arranged upstream thereof. A nipping line is
denoted by the reference 7, at which the staple fiber strand 2, fed
in feed direction A, is nipped before running in to the air jet
aggregate 3. The air jet aggregate 3 generates the twist for the
thread 4 to be spun and delivers the thread 4 in thread withdrawal
direction B by way of a withdrawal roller pair (not shown).
[0020] The air jet aggregate 3 includes, among other things, a
fiber feed channel 8 and an essentially hollow cylindrical vortex
chamber 9. A fluid device generates, in the vortex chamber 9, a
vortex current by blowing in pressurized air through the injector
channels 10, which run into the vortex chamber 9. The injector
channels 10 extend from an annular space 11, which is supplied with
pressurized air via a pressurized air source 12 (shown only as a
conduit here). The current flow direction of the pressurized air is
denoted by the arrow C. The injector channels 10 have an angle of
inclination a in relation to a parallel 13 to the axis of the spun
thread 4, which lies advantageously between 30.degree. and
90.degree..
[0021] In addition, the injector channels 10--as can be seen in
FIG. 2--run tangentially into the vortex chamber 9, whereby a
rotating vortex current occurs. It should be mentioned at this
point that the injector channels 10, which lie skewed in space, are
here shown projected into the drawing plane for reasons of clarity
in FIGS. 1 and 2. The pressurized air exiting out of the injector
channels 10 is discharged via a waste channel 14, which surrounds,
ring-like, a spindle-shaped component 15. A thread withdrawal
channel 16 is arranged in the spindle-shaped component 15. In the
end area of the fiber feed channel 8, an edge 17 of a fiber guiding
surface 18 is arranged as a twist block, which edge 17 lies
eccentrically to the thread withdrawal channel 16 in the area of
its entry opening 19.
[0022] In the air jet aggregate 3, the fibers to be spun are held,
on the one hand, in the staple fiber strand 2 and thus fed from the
fiber feed channel 8 essentially without receiving twist to the
thread withdrawal channel 16. On the other hand, the fibers in the
area between the fiber feed channel 18 and the thread withdrawal
channel 16 are subjected to the effect of the vortex current, which
drives the fibers (or at least their end areas) radially away from
the entry opening 19 of the thread withdrawal channel 16. The
threads 4 produced in this way have, therefore, a core of fibers
essentially extending in thread longitudinal direction (or fiber
areas without any significant twist) and an outer area in which the
fiber or fiber areas are twisted around the core.
[0023] The rotation of the vortex current in the vortex chamber 9
is influenced by the angle of inclination .alpha. of the injector
channels 10. The larger the angle of inclination .alpha. is made,
the stronger the rotation of the vortex current and the greater is
the tensile strength of the spun thread 4.
[0024] For the fault-free operation of the air jet aggregate 3, it
is, however, necessary that a sufficiently strong vacuum be present
at the entry opening 20 of the fiber feed channel 8. The vacuum at
the entry opening 20 ensures the transport of the staple fiber
strand 2 from the nipping line 7 of the delivery roller pair 5, 6
into the vortex chamber 9. The intensity of the vacuum at the entry
opening 20 can also be influenced by the angle of inclination
.alpha. of the injector channels 10, namely the smaller the angle
of inclination .alpha., the greater the vacuum. In the known air
jet aggregate 3 of prior art, the injector channels, to which
pressurized air was applied, were always arranged at the same angle
of inclination .alpha.. This angle of inclination .alpha. was
disadvantageously predefined as a compromise between the above
mentioned contradictory requirements.
[0025] In the case of the air jet aggregate 3 according to the
present invention, two further injector channels 21 for pressurized
air are provided. The injector channels 21 extend out from an
annular space 22 and run into the vortex chamber 9 at a smaller
angle of inclination than the injector channels 10. The injector
channels 21 shown in FIG. 1 have an angle of inclination of
0.degree., that is, they extend parallel to the axis of the spun
thread 4. The annular space 22 is, in turn, supplied with
pressurized air in flow direction D from a simplified pressurized
air source 23 (shown here in the form of a conduit).
[0026] By way of the presence of injector channels 10 and 21 having
different angles of inclination .alpha., the vortex current in the
vortex chamber 9 can be optimally adapted to the desired features,
as the rotation of the vortex chamber and the vacuum occurring at
the entry opening 20 can now be separately influenced. As a result,
a helical curve-shaped vortex current with alterable pitch can be
generated in the vortex chamber with the pressurized air flowing
out of the injector channels 10 and 21.
[0027] The separate influencing of the vortex current by use of the
different injector channels 10 and 21 can be achieved even more
effectively the shorter the distance is between the entry point of
the injector channels 21 in the vortex chamber 9 and the entry
opening 20, that is, the further upstream--as seen in transport
direction--the injector channels 21 are arranged. By providing a
smaller distance between the injector channels 21 and the entry
opening 20, a stronger vacuum can be achieved at the entry opening
20 at a lower airflow rate.
[0028] It is particularly advantageous to design the pressurized
air source 12 and the pressurized air source 23 in such a way that
the parameters of the in-flowing pressurized air, for example air
pressure or air volume, can be regulated separately during the
spinning process. It is then possible in an advantageous way to
adapt the vortex current in the vortex chamber 9 to the changing
parameters of the staple fiber strand 2 to be spun. For example, it
can be advantageous when, during the spinning process, the delivery
speed in direction A and the thread withdrawal speed in direction B
are increased, to simultaneously increase the air pressure of the
pressurized air flowing throw the injector channels 21, in order,
for example, to adapt the air speed in the fiber feed channel to
the increased speed of the staple fiber strands 2. The shown air
jet aggregate 3 demonstrates the great advantage of a very variable
application.
[0029] Finally reference is made to the fact that the shown number
of injector channels 10 and 21 is only an example and can be varied
according to requirements.
* * * * *