Title of Invention

A PROCESS AND AN ARRANGEMENT FOR RESTARTING A PREVIOSLY INTERRUPTED SPINNING PROCESS

Abstract Described is a process and an arrangement for re-starting a previously interrupted spinning process in a spinning arrangement, which arrangement comprises a drafting unit which can be shut down and also an airjet aggregate comprising a vacuum chamber. For the purpose of removing an initially inhomogeneous fibre stream, a staple fibre strand, delivered by the re-operating drafting unit, is temporarily suctioned as waste via a deflecting device after it has left the drafting unit. Only then when a homogeneous fibre stream has formed is the staple fibre strand joined with a thread which is transported through the airjet aggregate. It is hereby provided that the inhomogeneous fibre stream is removed with the aid of the low pressure in the vacuum chamber.
Full Text BACKGROUND AND SUMMARY OF THE INVENTION
A process and an arrangement for restarting a previously interrupted spinning
process
The present invention relates to a process for re-starting a previously interrupted
spinning process in a spinning arrangement, which arrangement comprises a drafting
unit which can be shut down and an airjet aggregate comprising a vacuum chamber,
whereby, for the purpose of removing an initially inhomogenous fibre stream, a staple
fibre strand, delivered by the re-operating drafting unit, is temporarily suctioned as
waste via a deflecting device after it has left the drafting unit, the staple fibre strand
being joined with a thread which is transported through the airjet aggregate only
when a homogenous fibre stream has formed.
The present invention relates further to a spinning arrangement for carrying out the
process, comprising a drafting unit which can be shut down, also comprising an airjet
aggregate having a fibre feed channel, a thread withdrawal channel and a vacuum
chamber, also comprising a deflecting device for temporarily deflecting a fibre staple
strand, delivered by the drafting unit, from a thread to be joined thereto.
A process and an arrangement of this type is prior art in the international published
application 94/00626. This publication refers in general to airjet spinning
arrangements without their specific embodiments and deals with the re-starting of a
previously interrupted spinning process, when, for example an end break occurs for
some reason. In this case, the end of an already spun thread must be first guided
back to the drafting unit after an interruption in the spinning process has occurred.
The shut down drafting unit can then be set in operation again and the newly
delivered staple fibre strand be joined to the end of the thread. Because the staple
fibre strand has been torn in the drafting unit due to the interruption in the spinning
process and the associated shutting down of the drafting unit, a staple fibre strand
forms when the drafting unit is operating again which is initially relatively
inhomogeneous at its start. For this reason, it is provided in the known process and
in the known spinning arrangement that the initially inhomgeneous fibre stream is
temporarily sucked off as waste and not immediately joined with the end of the thread
fed back to the drafting unit. Only after a homogeneous fibre stream is formed is the
staple fibre strand joined with the thread transported through the airjet aggregate.
This permits the creation of a joining point of significantly improved quality for the
joining process - so-called piecing - of the re-delivered staple fibre strand with the
thread, in that, instead of an arbitrarily produced initial piece of the staple fibre strand
caused by tearing, a newly generated initial piece of the staple fibre strand is joined
with the thread, whereby the new initial piece is generated from a fibre stream which
is homogeneous again. A suction tube located between the drafting unit and the
airjet aggregate serves the temporary suction of the inhomogeneous fibre stream.
In non-generic European published patent 0 807 699, the piecing of a staple fibre
strand to the end of a thread in a very specific airjet spinning arrangement is known.
In the case of this spinning arrangement, the drafted staple fibre strand is first fed
through a fibre feed channel of the airjet aggregate into a vortex chamber, to which a
fluid device is arranged for generating a vortex current around the entry opening of a
thread withdrawal channel. Initially the front ends of the fibres held in the staple fibre
strand are guided into the thread withdrawal channel, while rear free fibre ends
spread out, are seized by the vortex current and wound around the front ends
already located in the entry opening of the thread withdrawal channel, that is around
the front ends already bound in, whereby a thread with a mostly real twist is formed.
In this known spinning arrangement also, the initial piece of the delivered staple fibre
strand is at first subjected to suction after the drafting unit is operational again,
however in a suction tube located between the drafting unit and the airjet aggregate
and, in addition, together with the end of the thread with which the staple fibre strand
is to be joined. The initial piece of the staple fibre strand and the end of the thread
fed back to the drafting unit are stored temporarily in one and the same suction
device. Thus a relatively arbitrary connection of the suctioned staple fibre strand with
the likewise suctioned thread is formed, whereby a good quality piecing point is not
specifically targeted. In the case of a spinning arrangement of this type in a real
embodiment, a splicing arrangement is provided - which is not mentioned in the
publication - which subsequently cuts out the connecting point after piecing of the
staple fibre strand to the thread and replaces it with a splice point of better quality.
It is an object of the present invention in the case of a process and a spinning
arrangement of the above mentioned type to create a homogeneous fibre stream and
to carry out the joining of the fibre staple strand with the end of the thread in a
particularly effective way.
This object has been achieved in that the inhomogeneous fibre stream is removed
with the aid of a vacuum prevailing in the vacuum chamber.
In the case of the spinning arrangement the object of the present invention is
achieved accordingly in that the vacumm chamber is incorporated into the deflecting
device, said vacuum chamber being connectable to the drafting unit via a connecting
channel.
Due to of the features of the present invention, the inhomogeneous fibre stream is
not deflected by an external suction device, but rather a device already present in the
spinning arrangement is used to remove the inhomogeneous fibre stream. The
vacuum chamber in the airjet aggregate is needed during normal operation in order
to evacuate the compressed air fed to the vortex chamber and simultaneously to
transport away the inevitable fibre waste unavoidable in this spinning process. This
vacuum can be utilized for the purposes of the present invention to initially deflect the
inhomogeneous fibre stream from the end of thread, with which a homogeneous fibre
stream is then joined. The vacuum present in the vacuum chamber during operation
is advantageously increased temporarily in order to remove the inhomogeneous fibre
stream. Thus the inhomogeneous fibre stream is easier to deflect from its
operational transport path, as travelled during the normal spinning process. With
correct timing, the overlapping area of the initial piece of the homogeneous fibre
stream with the end of the thread can be kept very narrow, so that only a very small
slub occurs, which can be regarded as an acceptable fault not visibile in the end
product, for example in woven material.
In one variation it is provided that the staple fibre strand is deflected from its
operational transport path inside the airjet aggregate. Initially, the inhomogeneous
fibre stream thus enters into the inside of the airjet aggregate as in normal spinning
operation, is however temporarily deflected as waste therein. As a result, the piecing
of the homogeneous fibre stream to the end of the thread also takes place in the
inside of the airjet spinning aggregate, as soon as the temporarily increased low
pressure is reduced again to the normal level for the spinning process.
In a further variation it is provided that the staple fibre strand is deflected between the
drafting unit and the airjet aggregate from its operational transport path. The
inhomogeneous fibre stream travels temporarily not on its normal path into the inside
of the airjet aggregate, but rather in another way. This is purposeful because the
entry opening into the airjet aggregate usually has very small dimensions and
therefore the fibre mass, including the piecing thread, cannot be threaded correctly
through this small opening, in particular in the case of coarse yarns and high delivery
speeds. In this case, the joining of the homogeneous fibre stream with the end of the
thread partly takes place before the airjet aggregate is reached.
In order that the amount of inhomogeneous fibre stream discharged as waste is kept
as small as possible, it is advantageously provided in the embodiment of the present
invention that the fibre mass of the staple fibre strand during the removal of the
inhomogeneous fibre stream is reduced. The staple fibre strand is fed from the
drafting unit initially at a reduced delivery speed, whereby in this way also, due to the
deflection of the staple fibre strand from the normal transport path, a homogeneous
fibre stream is achieved after a certain length of time.
Although in the course of the present invention, the end of the thread to be pieced
which is fed back to the drafting unit is fed back through the delivery roller pair of the
drafting unit, it should be expressly pointed out that the end of the thread can also be
held ready between the airjet aggregate and the drafting unit in a practical way.
In the spinning arrangement according to the present invention it is advantageously
provided that the vacuum chamber is equipped with a connecting element for
temporarily increasing the low pressure. This can be, for example, a suction
connection, which can be connected to a separate low pressure source, which is
either stationary or applied to a travelling maintenance device. It is advantageously
provided however, that the connecting element comprises an injector channel which
can be charged with compressed air. This is a particularly effective way to increase
the low pressure, especially as a compressed air injection is advantageous for the
piecing process in any case.
In the case of the vacuum chamber connected to the drafting unit, a connecting
channel can, in one variation, be the fibre feed channel, used in the regular spinning
process, from which the thread withdrawal channel can preferably be separated. This
is a simple solution without any complicated additional technical steps, especially as
the separation of the thread withdrawal channel from the fibre feed channel for
threading the thread and for cleaning the vortex chamber is advantageous in any
case.
Particularly advantageous is, however, a separate bypass channel. This is
advantageously provided in one variation with a closing device, which closes the
bypass channel during the normal spinning process, while opening it for the purposes
of deflecting the inhomogeneous fibre stream. A travelling maintenance device can
actuate this process.
In a further variation, a cleaning channel directed against the drafting unit during
operation can function as the bypass channel. In this case, the bypass channel does
not need to be closed during operation, as the delivery roller pair of the drafting unit
is constantly cleared of fibre fly by means of suction action via this bypass channel.
In order to deflect the inhomogeneous fibre stream, the low pressure in the vacuum
chamber can be temporarily increased, so that the fibre stream is deflected easily
from its normal transport path by means of the cleaning channel.
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 shows an axial intersection of a spinning arrangement during operation in
the area concerning the present invention,
Figure 2 shows a spinning arrangement according to Figure 1 during removal of the
inhomogeneous fibre stream,
Figure 3 shows an axial intersection of another embodiment of a spinning
arrangement during removal of the inhomogeneous fibre stream,
Figure 4 shows the spinning arrangement according to Figure 3 during normal
spinning operation,
Figure 5 shows an axial intersection of a further spinning arrangement during
removal of the inhomogeneous fibre stream,
Figure 6 shows the spinning arrangement according to Figure 5 during operation ,
Figure 7 shows a diagram to illustrate the delivery speeds of the delivery rollers of
the drafting unit.
DETAILED DESCRIPTION OF THE DRAWINGS
The spinning arrangement shown in Figure 1, which shows the normal spinning
process, serves to produce a spun thread 1 from a staple fibre strand 2. The
spinning arrangement comprises a drafting unit 3 and an airjet aggregate 4.
The staple fibre strand 2 is fed to the drafting unit 3 in drafting direction A and
withdrawn as a spun thread 1 by withdrawal rollers (not shown) in withdrawal
direction B and guided to a winding device (not shown). The only partly shown
drafting unit 3 is preferably a three-cylinder drafting unit and comprises therefore
three roller pairs, each of which comprises a driven bottom roller and an upper roller
designed as a pressure roller. Only the delivery roller pair 5, 6 as well as an apron
roller pair 7,8 arranged upstream thereof, and having guiding aprons 9, 10 are
shown. In a drafting unit 3 of this kind, a staple fibre strand 2 is drafted in the known
way to the desired degree of fineness. Directly downstream of the drafting unit 3 a
thin fibre strand 11 is present, which is drafted and still twist-free.
The fibre strand 11 is fed via a fibre feed channel 12 to the airjet aggregate 4.
Downstream thereof lies a so-called vortex chamber 13, in which the fibre strand 11
receives its spinning twist, so that the spun thread 1 is formed, which is withdrawn
through a thread withdrawal channel 14.
A fluid device generates a vortex current during the spinning process in the vortex
chamber 13 by means of blowing in compressed air through compressed air nozzles
15, which run tangentially into the vortex chamber 13. The compressed air exiting out
of the nozzle openings is discharged via an evacuation channel 17, which runs into a
vacuum chamber 16, whereby the channel 17 has a ring-shaped cross section
around a spindle-shaped component 18, which is stationary during operation and
which comprises the thread withdrawal channel 14.
An edge of a fibre guiding surface 19, acting as a twist block, is arranged in the area
of the vortex chamber 9, said fibre guiding surface 19 being slightly eccentrically
arranged to the thread withdrawal channel 14 in the area of its entry opening 20.
In the airjet aggregate 4, the fibres to be spun are, on the one hand, held together in
a fibre strand 11, and thus fed from the fibre feed channel 12 into the thread
withdrawal channel 14 essentially without a spinning twist, while on the other hand
the fibres in the area between the fibre feed channel 12 and the thread withdrawal
channel 14 are exposed to the vortex current. The vortex current causes the fibres,
or at least their end areas to be driven away radially from the entry opening 20 of the
thread withdrawal channel 14. The threads 1 produced by the above described
spinning arrangement display a core comprising fibres or fibre areas extending
essentially in thread longitudinal direction without any significant twist, and an outer
area in which the fibres or fibre areas are wrapped around the core. A spinning
arrangement of this type permits very high spinning speeds, which lie in the range
between 300 and 600 m per minute.
The compressed air exiting out of the compressed air nozzles 15 into the vortex
chamber 13 is fed to the airjet aggregate 4 during operation via a compressed air
channel 21 in feed direction C. From the compressed air channel 21, the
compressed air reaches first a ring channel 22 which surrounds the vortex chamber
13, to which the above mentioned compressed air nozzles 15 are directly connected.
During the operational spinning process, there is a very small distance between the
entry opening 20 of the thread withdrawal channel 14 and the fibre feeding surface
19, which small distance can measure, for example, 0.5 mm. This small distance is
adjusted in that the spindle-shaped component 18 comprising the thread withdrawal
channel 14 is arranged in such a way that it is movable in axial direction. The
selected distance can be fixed during the operational state. In order to increase the
distance, as can be seen in Figure 2, the spindle-shaped component 18 is designed
partly as a piston-like component of a piston-cylinder unit.
When for any reason the fibre strand 11 or the thread 1 breaks, the compressed air
being fed to the vortex chamber 13 is first cut off, see the crossed arrow C in Figure
2. At the same time, all drives of the drafting unit 3 and of the thread withdrawal
rollers (not shown) and the winding device (not shown) are switched off.
Because the spindle-like component 18 is partly designed as piston-like component,
a moving away of the thread withdrawal channel 14 from the fibre feed channel 12
can be carried out using very simple means. Thus, for example, a ring channel 24
surrounding the spindle-like component 18 is provided, through which ring channel
24 the piston-like component 18 extends and which is connected to a conduit 25 for
compressed air. This compressed air, see arrow D in Figure 2, and the arrow
crossed through in Figure 1, is fed only when the spinning process is interrupted.
The compressed air entering into the ring channel 24 moves the piston-like
component 18 upwards as shown in the view in Figure 2, so that the ring channel 24
increases due to the piston stroke to become an enlarged ring chamber. The limiting
piston 23 affixed to the spindle-like component 18 thus borders the ring channel 24
during operation and the enlarged ring chamber when the spinning process is
interrupted. The limiting piston 23 acts hereby against a loading spring 26, which
presses the piston-like component 18 into a secure operational position when the
compressed air is cut off, that is, during the spinning process. The compressed air
fed in via the conduit 25 serves to move away the thread withdrawal channel 14 from
the fibre feed channel 12, while the loading spring 26 serves the return movement.
The very small distance between the fibre guiding surface 19 and the entry opening
20 of the thread withdrawal channel 14 during operation can be increased by the
moving away of the spindle-like component 18 when the spinning process is
interrupted, which permits the cleaning of the space between fibre guiding surface 19
and the entry opening 20.
When the thread withdrawal channel 14 is separated from the fibre feed channel 12,
the broken end 36 of the spun thread 1 can be fed back to the drafting unit 3 against
withdrawal direction B, see Figure 2. An injector channel 27 is provided as an
auxiliary means, which can be connected to the same pressure source as the ring
channel 24 and whose mouthpiece is connected to the thread withdrawal channel 14
and is directed towards its entry opening 20. Thus a suction current directed against
the drafting unit 3 is generated in the thread withdrawal channel 14, which suction
current guides the end 36 of the spun thread 1 to the delivery roller pair 5,6.
The compressed air fed via the conduit 25 to the ring channel 24 serves, as can be
seen, not only the moving of the spindle-like component 18 away from the fibre feed
channel 12, but also serves an injector air current via the injector channel 27, which
permits threading of the thread end 36 of the thread 1 to be pieced to the staple fibre
strand 2. The piston-like component is designed to a certain extent as a valve, which
is actuated by the feeding of compressed air and which establishes an effective
connection between the conduit 25 and the injector channel 27.
When the drives of the drafting unit 3, the thread withdrawal rollers (not shown) and
of the winding device are switched on again after an interruption in the spinning
process, a poor quality connection point between the staple fibre strand 2 and the
end 36 of the thread 1 would occur if particular measures were not taken. It is to be
taken into consideration that, when the spinning process is interrupted, the staple
fibre strand 2 in the drafting unit 3 tears in a relatively uncontrolled way between the
guiding aprons 9, 10 and the delivery roller pair 5, 6. The initial piece of the staple
fibre strand 2 which is initially fed at the re-start of the spinning process does not
possess the necessary regularity, whereby the irregularity is multiplied by the high
draft which takes place between the apron roller pair 7, 8 and the delivery roller pair
5, 6. An undesirable extreme variation in mass during piecing could occur. It is,
therefore, provided that the initial piece of the inhomogeneous fibre stream 32 (see
Figure 2) is removed as waste 33, namely until the moment that the staple fibre
strand 2 produces a homogeneous fibre stream 34 (see Figure 1). The
inhomogeneous fibre stream 32 is initially deflected by a so-called fibre stream
deflection, so that these deficient fibres are not joined to the end 36 of the thread 1 in
the critical piecing area. The fibre stream deflection thus ensures that the initial
unfavourable fibre mass distribution does not impair the piecing process.
A fibre stream deflection per se is already known from the above acknowledged prior
art. In the case of this known device, an external suction tube for discharging the
inhomogeneous fibre stream is provided between the delivery roller pair 5, 6 and the
entry of the fibre feed channel 12. In contrast thereto, it is provided in the present
invention to utilize the vacuum chamber 16 already present in the airjet aggregate 4
for deflecting the inhomogeneous fibre stream 32, instead of using a separate
external vacuum source.
According to the embodiment shown in Figures 1 and 2, the inhomogeneous fibre
stream 32 is deflected as waste 33 in the inside of the airjet aggregate 4. The low
pressure in the vacuum chamber 16 is maintained even in the case of an interruption
in the spinning process, while, as mentioned above, the compressed air feed via the
compressed air channel 21 is interrupted. In order to keep the inhomogeneous fibre
stream 32 away from the thread 1 to be pieced, it is provided in the embodiment of
the present invention that the low pressure present in the vacuum chamber 16 is
temporarily increased. The fibres to be removed as waste 33 can thus be easily
evacuated via a connecting vacuum channel 28 in suction direction E. When the
temporary increase in the low pressure present in the vacuum chamber 16 ceases
and the high pressure fed into the vortex chamber 13 is simultaneously fed in again,
the henceforth homogeneous fibre stream 34 of the staple fibre strand 2 follows on
its own accord the thread 1 through the yarn withdrawal channel 14, whereby a
sufficiently good quality piecing process takes place, which does not need to be
subsequently removed by a splice connection. If the end 36 of the thread 1 has
exact dimensions and is prepared in the known way, the piecing process can be
controlled in such a way that the overlapping area between the end 36 of the thread
1 and the initial piece of the staple fibre strand 2 is very short.
The temporary increase in low pressure in the vacuum chamber 16 can take place in
a variety of ways. According to the present invention, a connecting element 30 is
provided for the vacuum chamber 16. This connecting element 30 can comprise a
second injector channel 29 which can be charged with compressed air. In order to
remove the inhomogeneous fibre stream 32 a compressed air stream is initially fed
via the connecting element 30 in arrow direction F, whereby the compressed air
reaches first a ring channel 31 and then the second injector channel 29, which is
directed against the vacuum channel 28 and in suction direction E. This results in a
significant increase in the low pressure in the vacuum chamber 16, so that the
inhomogeneous fibre stream 32 is deflected in a simple way from its operational
transport path, that is, from the thread withdrawal channel 14.
In the embodiments according to Figures 1 and 2, the fibre feed channel 12 already
present is used as a connecting channel 35. In order to facilitate the separation of
the inhomogeneous fibre stream 32 and the thread 1, the spindle-shaped component
18 is moved a short distance from the fibre guiding surface 19, as already described
above, but only so far that the first injector channel 27 does not quite reach the ring
channel 24. The thread 1 is nevertheless hereby transported through the thread
withdrawal channel 14 in transport direction G due to its already present strength.
The piecing process is chronologically so programmed that the end 36, with which
the homogeneous fibre stream 34 is to be joined, reaches the area of the vortex
chamber 13 when the inhomogeneous fibre stream 32 is removed completely. At
this instant, the normal, lower spinning low pressure in the vacuum chamber 16 is
switched on again and the compressed air fed to the vortex chamber 13 is switched
on. The spindle-shaped component 18 must, of course, also be guided back into its
operational area, which takes place by means of cutting off the compressed air
stream D.
In the following descriptions of alternative embodiments of the present invention,
there is no repeat description of the individual components as long as the same
components as in Figures 1 and 2 are involved. The following description is limited
therefore to those components which occur in the variations of the embodiment and
which differ from those in Figures 1 and 2.
In the embodiment according to Figures 3 and 4, the inhomogeneous fibre stream 32
is not deflected in the inside of the airjet aggregate 4, but rather between the delivery
roller pair 5,6 of the drafting unit 3 and the airjet aggregate 4. For this reason a
bypass channel 37 is provided as a connecting channel between the drafting unit 3
and the vacuum chamber 16, which bypass channel 37 extends approximately
parallel to the fibre feed channel 12 in close proximity thereto. This bypass channel
37 can be closed during operation by means of a closing device 38, and during the
removal of the inhomogeneous fibre stream 32 temporarily opened, for example by
means of a travelling maintenance device. Figure 3 shows the opened state of the
bypass channel 37, while Figure 4 shows the closed state. With the aid of Figure 3, it
can be seen how the inhomogeneous fibre stream 32 reaches the vacuum chamber
16 by means of the the bypass channel 37, and how it gets from the vacuum
chamber 16 into the vacuum channel 28 and is removed in suction direction E. In
this embodiment it is also advantageous and therefore provided that, during the
removal of the inhomogeneous fibre stream 32, the low pressure in the vacuum
chamber 16 is temporarily increased in the way described above.
The embodiment in Figures 3 and 4 is particularly advantageous when there is a risk,
especially in the case of coarse yarns and high delivery speeds, that the entry of the
fibre feed channel 12 is too small for re-feeding the staple fibre strand 2. In contrast,
the opening of the bypass channel 37 can be designed sufficiently large.
It should be noted here that in all the embodiments described above, the airjet
aggregate 4 can, if required, also be swivelled out of its operating position, in order to
facilitate the deflection of the inhomogeneous fibre strand 32.
In the embodiments of Figures 5 and 6 a separate bypass channel is also provided
for the removal of the inhomogeneous fibre stream 32, which, however, in this case
cannot be closed, as it has a function during the normal spinning process. According
to Figures 5 and 6, a cleaning channel 39 directed against the delivery roller pair 5, 6
of the drafting unit 3 is used as a bypass channel.
During the spinning process, when the normal level of low pressure prevails in the
vacuum chamber 16, the cleaning channel 39 serves to continuously clean fibre fly or
other impurities from the top roller 6 which is, as a rule, rubber-coated. This cleaning
channel 39 can now be used for removing the inhomogeneous fibre stream 32
according to the present invention, which fibre stream 32 is fed into the vacuum
channel 28 as waste 33. In this embodiment, for the purposes of removing the
inhomogeneous fibre stream 32, the level of low pressure in the vacuum chamber 16
is also temporarily increased in the way described above. The fibres of the staple
fibre stream 2, which is transported again, do not initially follow the thread 1 into the
fibre feed channel 12, but rather a part of the periphery of the top roller 6 into the
cleaning channel 39.
With the aid of Figure 7, the speeds of the delivery roller pair 5, 6 and the apron roller
pair 7, 8 during the piecing process are illustrated. The term speed is understood as
the transport speed of the staple fibre strand 2, that is the respective peripheral
speed of the roller pairs 5, 6 and 7, 8.
The curve 40 shows the speed v for the delivery roller pair 5,6, while the curve 41
shows the speed v for the apron roller pair 7, 8. It should be mentioned at this point
that, during an interruption of the spinning process, controlled by the respective
drives, the staple fibre strand 2 was torn between the guiding apron 9, 10 and the
delivery roller pair 5, 6.
The abscissa of the diagram in Figure 7 shows the time T, and the ordinate shows
the speed v.
It is presumed that at a time T1 the piecing process is begun by switching on of the
drives of the delivery roller pair 5, 6. It can be seen that from a time T1 onwards the
speed of the delivery roller pair 5, 6 initially increases according to the curve 40,
namely up to a constant piecing speed v1A, which is reached by a time TA. From this
time TA onwards, the delivery roller pair 5, 6 initially runs at a reduced - in
comparison to the operational speed v1B - but constant piecing speed v1A.
Because the apron roller pair 7, 8 does not initially re-start, only the thread 1, but not
the staple fibre strand 2, is transported in withdrawal direction B. The delayed start-
up of the apron roller pair 7, 8 serves to bring the end 36 of the thread 1 to a defined
position, in which the actual piecing process, that is the joining of the homogeneous
fibre stream 34 with the end 36 of the thread 1, takes place. According to Figure 7 it
is provided that the start of the apron roller pair 7, 8 takes place at a time T2, that is,
slightly delayed in relation to the start of the delivery roller pair 5, 6.
As soon as the apron roller pair 7, 8 is set in motion, the transport of the staple fibre
strand 2 begins, whose initial piece reaches the nipping point of the delivery roller
pair 5,6 very rapidly and is then, also slightly delayed, transported through this
delivery roller pair 5, 6. The staple fibre strand 2, however, initially comprises in the
described way an inhomogeneous fibre stream 32, which is to be deflected in the
way described above. In order that not too much fibre mass is removed as waste 33,
it is initially provided that the apron roller pair 7, 8 is not yet accelerated to its piecing
speed V2A, but rather to a much more reduced intermediate speed v2R. This
intermediate speed v2R is found between the times T3 and T4. In this timespan, a
greater part of the waste 33 is removed. At the time T4, the apron roller pair 7, 8 is
accelerated to its piecing speed v2A, which is reached at the time TA.
As soon as the delivery roller pair 5, 6 and the apron roller pair 7, 8 have both
reached their piecing speeds v1A and v2A, the last piece of the inhomogeneous fibre
stream 32 is removed as waste 33. Shortly thereafter, however, at a time TU, the
fibre stream deflection process described above takes place, that is the increased
level of low pressure in the vacuum chamber 16 is lowered again and the
compressed air feed in the vortex chamber 13 is started in via the compressed air
channel 21. From time TU onwards, a homogeneous fibre stream 34 is formed,
which, from this time on, takes up its operational transport path. Shortly thereafter, at
a time TD, the actual piecing takes place, that is, the joining of the homogeneous
initial piece of the staple fibre strand 2 with the end 36 of the thread 1. It is presumed
that the entire piecing process is completed at a time T5. From this time onwards, the
delivery roller pair 5, 6 and the apron roller pair 7, 8 will accelerate to their
operational speeds v1B and v2B. Then the piecing process is completed.
CLAIMS:
1. A process for re-starting a previously interrupted spinning process in a
spinning arrangement, which arrangement comprises a drafting unit which
can be shut down and an airjet aggregate comprising a vacuum chamber,
whereby, for the purpose of removing an initially inhomogenous fibre stream,
a staple fibre strand, delivered by the re-operating drafting unit, is temporarily
suctioned as waste via a deflecting device after it has left the drafting unit, the
staple fibre strand being only joined with a thread which is transported
through the airjet aggregate when a homogenous fibre stream has formed,
characterized in that the inhomogeneous fibre stream is removed with the aid
of the low pressure prevailing in the vacuum chamber.
2. A process according to claim 1, characterized in that the operational level of
low pressure prevailing in the vacuum chamber is temporarily increased for
the purpose of removing the inhomogeneous fibre stream.
3. A process according to claim 1 or 2, characterized in that the staple fibre
strand is deflected from its operational transport path in the inside of the airjet
aggregate.
4. A process according to claim 1 or 2, characterized in that the staple fibre
strand is deflected from its operational transport path between the drafting
unit and the airjet aggregate.
5. A process according to any one of the claims 1 to 4, characterized in that the
fibre mass of the staple fibre strand is reduced during removal of the
inhomogeneous fibre stream.
6. A spinning arrangement for carrying out the process according to any of the
previous claims, comprising a drafting unit which can be shut down when an
interruption in the spinning process occurs, also comprising an airjet
aggregate having a fibre feed channel, a thread withdrawal channel and a
vacuum chamber, also comprising a deflecting device for temporarily
deflecting a staple fibre strand, delivered by the drafting unit, from a thread to
be joined thereto, characterized in that the vacuum chamber (16) is included
in the deflecting device, said vacuum chamber (16) being connectable to the
drafting unit (3) via a connecting channel (35; 37; 39).
7. A spinning arrangement according to claim 6, characterized in that the
vacuum chamber (16) is provided with a connecting element (30) for
temporarily increasing the level of the low pressure.
8. A spinning arrangement according to claim 7, characterized in that the
connecting element (30) comprises an injector channel (29) which can be
supplied with compressed air.
9. A spinning arrangement according to claim 7 or 8, characterized in that the
fibre feed channel (12), used in the regular spinning process, is used as a
connecting channel (35), from which fibre feed channel (12) the thread
withdrawal channel (14) can be preferably separated.
10. A spinning arrangement according to any one of the claims 6 to 8,
characterized in that the connecting channel is a separate bypass channel
(37; 39).
11. A spinning arrangement according to claims 7 and 10, characterized in that a
cleaning channel (39), which is directed against the drafting unit (3) during the
spinning process, is provided as a bypass channel.
12. A spinning arrangement according to claim 10, characterized in that the
bypass channel (37) is provided with a closing device (38).

Described is a process and an arrangement for re-starting a previously interrupted spinning process in a spinning arrangement, which arrangement comprises a drafting unit which can be shut down and also an airjet aggregate comprising a vacuum chamber. For the purpose of removing an initially inhomogeneous fibre stream, a staple fibre strand, delivered by the re-operating drafting unit, is temporarily suctioned as waste via a deflecting device after it has left the drafting unit. Only then when a homogeneous fibre stream has formed is the staple fibre strand joined with a thread which is transported through the airjet aggregate. It is hereby provided that the inhomogeneous fibre stream is removed with the aid of the low pressure in the vacuum chamber.

Documents:

747-KOLNP-2006-(29-06-2012)-CORRESPONDENCE.pdf

747-KOLNP-2006-(29-06-2012)-OTHERS.pdf

747-KOLNP-2006-(29-06-2012)-PA.pdf

747-KOLNP-2006-ABSTRACT 1.1.pdf

747-kolnp-2006-abstract.pdf

747-KOLNP-2006-CLAIMS 1.1.pdf

747-kolnp-2006-claims.pdf

747-KOLNP-2006-CORRESPONDENCE 1.1.pdf

747-kolnp-2006-correspondence.pdf

747-KOLNP-2006-DESCRIPTION (COMPLETE) 1.1.pdf

747-kolnp-2006-description (complete).pdf

747-KOLNP-2006-DRAWINGS 1.1.pdf

747-kolnp-2006-drawings.pdf

747-KOLNP-2006-FORM 1.1.1.pdf

747-kolnp-2006-form 1.pdf

747-kolnp-2006-form 18.pdf

747-KOLNP-2006-FORM 2.1.1.pdf

747-kolnp-2006-form 2.pdf

747-kolnp-2006-form 26.pdf

747-KOLNP-2006-FORM 3.1.1.pdf

747-kolnp-2006-form 3.pdf

747-KOLNP-2006-FORM 5.1.1.pdf

747-kolnp-2006-form 5.pdf

747-KOLNP-2006-FORM-27.pdf

747-KOLNP-2006-OTHERS.pdf

747-KOLNP-2006-PETITION UNDER RULE 137.pdf

747-kolnp-2006-priority document.pdf

747-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

747-kolnp-2006-specification.pdf

747-KOLNP-2006-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf


Patent Number 240320
Indian Patent Application Number 747/KOLNP/2006
PG Journal Number 19/2010
Publication Date 07-May-2010
Grant Date 04-May-2010
Date of Filing 28-Mar-2006
Name of Patentee MASCHINENFABRIK RIETER AG
Applicant Address KLOSTERSTRASSE 20 CH 8406 WINTERTHUR
Inventors:
# Inventor's Name Inventor's Address
1 SCHAFFLER, GERNOT NARZISSENWEG 4 73116 WASCHENBEUREN
2 STAHLECKER, GERD AUF DER EBENE 30 73054 EISLINGEN/FITZ
3 SCHWEIER, PETER TECKSTRASSE 14 73312 GEISLINGEN/STEIGE
PCT International Classification Number D01H 4/48
PCT International Application Number PCT/EP2004/008603
PCT International Filing date 2004-07-30
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 103 53 317.6 2003-11-10 Germany