U.S. patent application number 15/774018 was filed with the patent office on 2018-11-08 for device and method for producing knitted fabric.
The applicant listed for this patent is TERROT GMBH. Invention is credited to JOHANNES BARTH, STEPHAN GEILER, MICHAEL LAU, HERMANN SCHMODDE.
Application Number | 20180320298 15/774018 |
Document ID | / |
Family ID | 57286759 |
Filed Date | 2018-11-08 |
United States Patent
Application |
20180320298 |
Kind Code |
A1 |
BARTH; JOHANNES ; et
al. |
November 8, 2018 |
DEVICE AND METHOD FOR PRODUCING KNITTED FABRIC
Abstract
Knitted fabric is produced with a knitting machine and a roving
drawing and strengthening unit. A roving supply unit provides a
roving and an auxiliary thread supply unit provides an auxiliary
thread. A stretching unit receives the roving and the auxiliary
thread. A spinning nozzle following the stretching unit in a roving
conveying direction forms a fiber strengthening segment by applying
compressed air and an end thread gripping roller pair rotatable in
opposite directions provided downstream from the spinning nozzle
device in the roving conveying direction delimiting the fiber
strengthening segment. A soft knitted fabric is formed by guiding
an auxiliary thread through an auxiliary thread gripping roller
pair with an adjustable rotational speed before the roving and
auxiliary thread enter the stretching unit. The gripping roller
pair holds the auxiliary thread so that the auxiliary thread is
subjected to tension of no more than 2 cN.
Inventors: |
BARTH; JOHANNES;
(NIEDERWIESA, DE) ; LAU; MICHAEL; (CHEMNITZ / OT
MITTELBACH, DE) ; GEILER; STEPHAN; (OBERLUNGWITZ,
DE) ; SCHMODDE; HERMANN; (HORB, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TERROT GMBH |
CHEMNITZ |
|
DE |
|
|
Family ID: |
57286759 |
Appl. No.: |
15/774018 |
Filed: |
November 3, 2016 |
PCT Filed: |
November 3, 2016 |
PCT NO: |
PCT/IB2016/056621 |
371 Date: |
May 7, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D04B 15/42 20130101;
B65H 59/388 20130101; D02G 3/367 20130101; B65H 59/18 20130101;
D04B 15/44 20130101; D04H 5/00 20130101; B65H 2701/31 20130101;
D04B 1/14 20130101; D04B 15/48 20130101; D04B 9/14 20130101; D01H
13/104 20130101 |
International
Class: |
D04B 15/48 20060101
D04B015/48; D04B 15/44 20060101 D04B015/44 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 5, 2015 |
DE |
102015119039.7 |
Claims
1-10. (canceled)
11. A device for producing knitted fabric with a knitting machine
and a roving drawing and strengthening unit, the device comprising:
a roving supply unit with at least one roving; an auxiliary thread
supply unit with at least one auxiliary thread; a stretching unit
coupled to said roving supply unit for supplying the roving and
said auxiliary thread supply unit for supplying the auxiliary
thread, said stretching unit including stretching roller pairs
arranged one after another in a roving conveying direction; a
spinning nozzle device following said stretching unit in the roving
conveying direction and forming a fiber strengthening segment by
applying compressed air; and an end thread gripping roller pair
rotatable in opposite directions and disposed following said
spinning nozzle device in the roving conveying direction delimiting
said fiber strengthening segment; at least one auxiliary thread
gripping roller pair disposed between said auxiliary thread supply
unit and said stretching unit, said at least one auxiliary thread
gripping roller pair having two auxiliary thread gripping rollers
that are rotatable in opposite directions and adjustable with
regard to a rotational speed, said auxiliary thread gripping
rollers being pressed or capable of being pressed to one another
and guiding the auxiliary thread towards said stretching unit, said
auxiliary thread gripping roller pair forming a clamping
lead-through for the at least one auxiliary thread, and wherein a
rotational speed of said auxiliary thread gripping rollers of said
auxiliary thread gripping roller pair is adjustable such that a
thread tension of the auxiliary thread exiting said auxiliary
thread gripping roller pair is smaller than 2 centinewtons.
12. The device according to claim 11, which comprises a device
control configured to adjust the rotational speed of at least one
of said auxiliary thread gripping rollers and to adjust a
rotational speed of said stretching rollers of said stretching
unit.
13. The device according to claim 11, wherein said auxiliary thread
gripping rollers include a first, profiled auxiliary thread
gripping roller and a second, rubberized auxiliary thread gripping
roller.
14. The device according to claim 11, further comprising an
auxiliary thread oscillation device before said at least one
auxiliary thread gripping roller pair in the roving conveying
direction of the device.
15. The device according to claim 11, further comprising at least
one optical thread sensor following the auxiliary thread gripping
roller pair in an auxiliary thread conveying direction.
16. The device according to claim 11, wherein said auxiliary thread
supply unit comprises a closed housing formed with at least one
opening for exiting the auxiliary thread.
17. A method for producing knitted fabric, the method comprising:
supplying at least one roving from a roving supply unit; supplying
at least one auxiliary thread from an auxiliary thread supply unit;
clamping the auxiliary thread between rollers of at least one
auxiliary thread gripping roller pair that rotate in opposite
directions, the rollers of the auxiliary thread gripping roller
pair having two auxiliary thread gripping rollers that are pressed
or capable of being pressed to one another; adjusting the
rotational speed of the auxiliary thread gripping rollers such that
a thread tension of the auxiliary thread exiting the auxiliary
thread gripping roller pair is less than 2 centinewton; guiding the
roving and the auxiliary thread to a stretching unit, the
stretching unit having stretching roller pairs arranged one after
another in a roving conveying direction; subjecting a drawn roving
with the auxiliary thread exiting the stretching unit to
pressurized air by a spinning nozzle device in a fiber
strengthening segment, to thereby strengthen the drawn roving,
wherein the fiber strengthening segment is delimited by an end
thread gripping roller pair rotating in opposite directions through
which the drawn and strengthened roving with the auxiliary thread
is led in clamped fashion and an end thread exiting the end thread
gripping roller pair is supplied to a knitting machine.
18. The method according claim 17, which comprises supplying the
auxiliary thread to the auxiliary thread gripping roller pair
oscillating in axis direction of the auxiliary thread gripping
rollers.
19. The method according to claim 17, which comprises optically
recording a thread tension of the auxiliary thread between the
auxiliary thread gripping roller pair and the stretching unit.
Description
[0001] The present invention relates firstly to a device for
producing knitted fabric with a knitting machine and a roving
drawing and strengthening unit which comprises a roving supply unit
with at least one roving, an auxiliary thread supply unit with at
least one auxiliary thread, a stretching unit linked to the roving
supply unit for supplying the roving and the auxiliary thread
supply unit for supplying the auxiliary thread, a spinning nozzle
provided downstream from the stretching unit in a roving conveying
direction of the device forming a fiber strengthening segment by
applying compressed air and an end thread gripping roller pair
rotatable in opposite directions provided downstream from the
spinning nozzle device in the roving conveying direction delimiting
the fiber strengthening segment. The invention further relates to a
method for producing knitted fabric, wherein at least one roving by
means of a roving supply unit and at least one auxiliary thread by
means of an auxiliary thread supply unit are supplied to a
stretching unit, compressed air being applied to a drawn roving
exiting the stretching unit comprising the auxiliary thread by a
spinning nozzle device in a fiber strengthening segment, said
roving being thus strengthened, wherein the fiber strengthening
segment is delimited by an end thread gripping roller pair rotating
in opposite directions through which the drawn, strengthened roving
comprising the auxiliary thread is led in clamped fashion and an
end thread exiting the end thread gripping roller pair is fed to a
knitting machine.
[0002] In order to be able to produce knitted fabric, which is
characterized by a particularly soft feel and fullness, various
approaches are known from the prior art. It is proposed in
particular not to use conventional, durably strengthened thread
provided on bobbins for the production of knitted fabric, but
instead to form an only temporarily strengthened thread bundle
which is supplied directly to the knitting needles of a knitting
machine by means of corresponding guiding tools and is there used
for knitting knitted fabric.
[0003] Such a temporarily strengthened thread bundle is also
referred to as false strand. A false strand is typically twisted in
itself, whereby the twist is released by pulling on both ends of
the false strand.
[0004] A device and method for producing such knitted fabric are
suggested inter alia in the document WO 2009/043187 A1. In this
document, a fiber assembly is drawn to a desired fineness in a
stretching unit and is strengthened by means of pneumatically
operating spinning nozzles in a section between the stretching unit
and the knitting needles and is transported to knitting needles of
a knitting machine. By means of the spinning nozzles, a permanently
strengthened false strand is formed comprising a core of fibers
that are primarily without twisting and mostly aligned parallel to
each other and which are surrounded by overlapping, interlocked
entwining fibers. Depending of the length of a transport section
between the spinning nozzles and the knitting needles, the twisting
of the entwining fibers can dissolve more or less. A final
strengthening of the fiber assembly only takes place by means of
the knitting needles within the manufactured knitted fabric. Due to
this, it is mandatory to position the knitting needles of the
knitting machine as close as possible to the spinning nozzles or to
provide guiding tubes in case of longer transport distances between
the spinning nozzles and the knitting needles in order to ensure a
safe and interruption-free transport of the fiber assembly
moderately strengthened by the spinning nozzles.
[0005] A similar approach for manufacturing soft knit fabrics
without the detour of classical yarn manufacturing is disclosed in
the document DE 10 2006 037714 A1. In this document, a drawn fiber
assembly is produced in a stretching unit and is supplied to the
knitting needles of a knitting machine by means of one or several
swirl devices and at least one active transport element. Spinning
tubes, each with a pneumatically operating swirl nozzle, are
suggested as swirl devices, by which a false swirl is given to the
drawn fiber assembly which dissolves again at the knitting point. A
supplier comprising a roller pair can be used as an active
transport element.
[0006] Problematic when manufacturing knitted fabrics by means of
such drawn and only temporarily strengthened rovings is, that their
strengthening can dissolve especially on longer transport distances
between the swirl device and spinning nozzle device and the
knitting needles of the knitting machine, whereby the production
process is interrupted in an unwanted manner.
[0007] Another approach for manufacturing soft knitted fabric is
disclosed in the document WO 2009/059438 A1. This document suggests
the use of a roving treatment device comprising a dissolving device
for dissolving the roving into single fibers and a friction
spinning device formed as a friction spinning reel for processing
the single fibers into a stable yarn of the desired fineness ready
for transport. In the friction spinning reel, the individual fibers
of the roving are twisted to a real, stable yarn ready for
transport which is transported to a collector nozzle by means of a
withdrawing roll pair and further to the knitting needles, which
knit a knitted fabric out of it. By withdrawing the formed yarn in
prolongation of the extension of the friction spinning reel, yarn
breakages due to changes of direction are prevented.
[0008] The document DE 10 2011 053 396 B3 furthermore suggests a
device according to type and a method according to type for
increasing a drawn, strengthened roving supplied to a knitting
machine, in which an auxiliary thread respectively core thread is
supplied to a roving during its drawing in the stretching unit,
whereby a so-called core-coat-yarn with a high stability is formed.
The auxiliary thread applied to a supply spool, is picked up by
means of an outlet roller pair of the stretching unit and bound
into the drawn roving. In the document DE 10 2011 053 396 B3, the
auxiliary thread is supplied to the stretching unit by means of a
tube in order to enable a draw-free and thus unscathed supply of
the auxiliary thread to the stretching unit.
[0009] In order to produce an even knitted fabric, it is necessary
to not only supply the drawn, strengthened roving, but also used
auxiliary threads with a constant thread tension to the production
process. The thread tension of the roving can be easily adjusted by
means of the rotation speed of the stretching unit rollers and the
air pressure on the swirl nozzles or spinning nozzles. In order to
be able to supply auxiliary threads or core threads with a constant
thread tension to a stretching unit, thread supply devices in form
of feeders are used in the auxiliary thread supply in the prior
art. A feeder typically comprises a thread winding reel on which
the thread coming from a supply reel can be wound up on. Thereby,
the thread windings are wound up on a thread winding reel
transversely to the actual thread conveying direction. The feeder
is operated electrically by means of a control device so that by
correspondingly turning the feeder by means of the control device,
if necessary, an excessive thread can be wound up or a thread
supply stored in the feeder can be unrolled for supplying a
knitting point with thread material.
[0010] However, due to its operating mode, a feeder has the
disadvantage that the thread supplied by it, is continuously under
a certain, not inconsiderable tension. In contrast, the insertion
of the auxiliary thread, which is for example disclosed in the
document DE 10 2011 053 396 B3, into the drawn roving works
reliably only then, if the auxiliary thread supplied to the
stretching unit comprises only a small thread tension, which cannot
be realized or not permanently realized by means of a feeder.
[0011] The object of the present invention is therefore to further
develop a device and a method of the initially mentioned type in
such a way that soft knitted fabric can be reliably produced, using
at least one auxiliary thread for forming the roving.
[0012] The object is firstly solved according to the invention by a
device of the above-mentioned type, in which an auxiliary thread
gripping roller pair rotatable in opposite directions, comprising
an adjustable rotational speed is provided between the auxiliary
thread supply unit and the stretching unit, between whose auxiliary
thread gripping rollers the auxiliary thread is being led.
[0013] The auxiliary thread gripping roller pair forms a clamping
lead through for the at least one auxiliary thread supplied by the
auxiliary thread supply unit. By providing the auxiliary thread
gripping roller pair comprising adjustable rotational speed between
the auxiliary thread supply unit and the stretching unit, the
auxiliary thread, which serves especially for increasing the
stability of the end thread and for increasing the reliability of
the process carried out on the device according to the invention,
can be supplied to the stretching unit with differing tensions and
can be bound into the drawn roving. Due to the adjustability of the
rotational speed respectively the difference of the rotational
speed between the auxiliary thread gripping rollers, the thread
tension of the auxiliary thread can be adjusted extremely small
compared to the thread tension which can be adjusted with known
feeders. This has the advantage that the auxiliary thread running
through the auxiliary thread gripping roller pair, supplied to the
stretching unit is not tightly stretched but slightly lurches or
flaps. Surprisingly, due to the flapping of the auxiliary thread,
the fibers of the roving accumulate particularly well to the
spinning nozzle device arranged successively to the stretching
unit. As it turned out, the tension of the auxiliary thread
actually has a vital impact in how many fibers of the roving wind
themselves around the auxiliary thread. Corresponding to this, the
softness of the yarn and thus the soft touch of the produced
knitted fabric can be significantly influenced with the device
according to the invention by adjusting the rotation speed of the
auxiliary thread gripping rollers of the auxiliary thread gripping
roller pair and thus by adjusting the tension of the auxiliary
thread with which it is supplied to the spinning nozzle device. The
more stretched the auxiliary thread is, when being led through the
spinning nozzle device and thus during the actual connection of the
auxiliary thread and the roving, the less fibers of the roving can
wind around the auxiliary thread and the harder the formed yarn and
thus the subsequent knitted fabric become. In accordance with this,
it is desired to supply the auxiliary thread with as little thread
tension as possible to the roving stretched in the stretching
unit.
[0014] In contrast to a feeder, the auxiliary thread passes through
the clamping point between the auxiliary thread gripping roller
pair and does not wrap itself around them. The rotation axis of the
auxiliary thread gripping roller pair is aligned perpendicular to
the auxiliary thread conveying direction. Due to this, the
auxiliary thread is only clamped, wherein the clamping force can be
precisely adjusted by means of the rotational speed of the
auxiliary thread gripping roller pair.
[0015] The transport of the auxiliary thread via the auxiliary
thread gripping roller pair holds the advantage that the auxiliary
thread can be supplied to the stretching unit with a constant
thread tension, which positively affects the evenness of the
formation of the drawn, strengthened roving reinforced by the
auxiliary thread and thus a knit fabric formed from this
roving.
[0016] According to the invention, the auxiliary thread gripping
roller pair comprises two auxiliary thread gripping rollers pressed
to each other or pressable whose size, dimension, shape and
condition can be chosen application-specific. One or both auxiliary
thread gripping roller(s) can be driven with the device according
to the invention. If only one of the auxiliary thread gripping
rollers is driven, a rotation of n the non-driven auxiliary thread
gripping roller is achieved by pressing it against the driven
auxiliary thread gripping roller. If both auxiliary thread gripping
rollers are driven, they can either be moved independently of each
other or comprise connected or connectable drives.
[0017] The auxiliary thread gripping rollers can be permanently
pressed against each other. However, it is also possible that the
auxiliary thread gripping rollers do not permanently touch each
other, but can be brought into positions that are spaced apart from
each other so that an insertion of the auxiliary thread between the
auxiliary thread gripping rollers is eased and repair and
maintenance works on the other auxiliary thread gripping roller
pair is simplified.
[0018] It has also turned out to be advantageous if the auxiliary
thread gripping roller(s) is/are provided suchlike in the device
according to the invention that it/they or at least its/their
roller surface can be replaced. Hereby, the auxiliary thread
gripping rollers can either be replaced by identical auxiliary
thread gripping rollers or by auxiliary thread gripping rollers
comprising different dimensions and/or different characteristics.
Thus, the auxiliary thread gripping rollers can for example be
adjusted ideally to the used material of the auxiliary thread
and/or the auxiliary thread gripping rollers can be quickly and
easily replaced by new ones in case of abrasion or damage.
[0019] In order to be able to gently supply the auxiliary thread to
the roving even over long distances, in the desired quantity and
with the desired tension, the device according to the invention can
also comprise several, in conveying direction of the auxiliary
thread successively arranged, spaced apart auxiliary thread
gripping roller pairs. The number, form and arrangement of the
individual auxiliary thread gripping roller pairs can hereby be
chosen application-specific.
[0020] With the device according to the invention, it is generally
possible to supply the auxiliary thread to the roving before
traversing the stretching unit, during the stretching process or
directly after finishing the stretching process, that is, between
the stretching unit and the spinning nozzle device.
[0021] Insofar the stretching unit is formed of individual roller
pairs, successively arranged in conveying direction of the roving,
which are preferably operated with a speed that is increasing in
conveying direction, the auxiliary thread can be supplied to the
roving between two successive, preferably between a penultimate and
an outlet roller pair of the stretching unit. Preferably, the
auxiliary thread can hereby be ideally received by the outlet
roller pair and conveyed alongside the roving towards the spinning
nozzle device. Furthermore, the rotation speed of the auxiliary
thread gripping roller pair can be ideally bided to the rotation
speed of the outlet roller pair. It has proven to be especially
advantageous if the auxiliary thread coming from the back of the
stretching unit is pulled off tangentially from the outlet gripping
roller pair of the stretching unit. By supplying the auxiliary
thread only during the main drawing, it traverses only through one
clamping point on the stretching unit and can thus be bound into
the roving draw-free and unscathed.
[0022] In the present invention, the auxiliary thread is supplied
by means of a supply spool in an auxiliary thread supply unit which
is preferably a spool rack. The auxiliary thread gripping roller
pair to which the auxiliary thread is supplied, is preferably
provided near the stretching unit, however, it can also be arranged
on any other spot between the stretching unit and the auxiliary
thread supply unit.
[0023] The auxiliary thread can be an inelastic thread or an
elastic thread, wherein the arrangement and/or the number and/or
the size of the at least one auxiliary thread gripping roller pair
can vary depending on the elasticity of the auxiliary thread.
[0024] The roving to be drawn by the stretching unit is preferably
provided on a so-called flyer spool in form of non-strengthened
fiber assembly and is pulled off from it by means of the stretching
unit. After the stretching of the roving in the stretching unit and
the supply of the auxiliary thread, the drawn roving is
strengthened to a drawn, strengthened roving by means of the
spinning nozzle device provided downstream from the stretching unit
in a roving conveying direction and is connected with the auxiliary
thread. The auxiliary thread is thereby preferably bound
approximately centric into the drawn, strengthened roving; however,
it can also lie in a peripheral area of the drawn, strengthened
roving.
[0025] Hereby, it is particularly preferable to form the device
according to the invention in such a way that the spinning nozzle
device comprises two successively arranged, pneumatically operating
spinning nozzles in roving conveying direction with opposing
rotation directions. The spinning nozzle device is thereby
preferably comprised of two air vortex nozzles, whose generated air
flows comprise opposing rotation directions. The spinning nozzle
arranged as second in conveying direction, is preferably a swirl
nozzle which creates a so-called false strand from the supplied
fiber material including the auxiliary thread. The spinning nozzle
arranged prior to the swirl nozzle, the injector nozzle, causes an
untwisting of the fiber material due to the opposing rotation
direction, whereby a bracing of the edge fibers ensues, which in
turn are wound around the fiber core and the auxiliary thread due
to the rotation generation of the swirl nozzle.
[0026] According to the invention, rotation intensity and/or
pressure of the air exiting the spinning nozzles are independently
adjustable, whereby the characteristics of the drawn, strengthened
roving with the integrated auxiliary thread can be ideally
influenced and the spinning speed of the spinning nozzles can be
adjusted to the knitting speed of the knitting machine provided
downstream from the roving drawing and strengthening unit.
[0027] In order to further enhance the strength of the drawn,
strengthened roving in which the auxiliary thread is bound in and
to prevent a disintegration of the drawn, strengthened roving with
the bound in auxiliary thread during the transport to the knitting
machine, the device according to the invention comprises an end
thread gripping roller pair rotatable in opposite directions
provided downstream from the spinning nozzle device in the roving
conveying direction delimiting the fiber strengthening segment. The
end thread gripping roller pair forms a clamping feedthrough for
the drawn, strengthened roving exiting the spinning nozzle device
comprising the auxiliary thread. Following the end thread gripping
roller pair, a supply to the knitting machine is provided for the
drawn, strengthened roving comprising the auxiliary thread.
[0028] The end thread gripping roller pair forms a clamping point
for the drawn, strengthened roving comprising the auxiliary thread
which delimits the fiber strengthening segment of the spinning
nozzle device. The end thread gripping roller pair can thereby be
arranged with a relatively small distance to the spinning nozzle
device in the device according to the invention, whereas the
distance of the end thread gripping roller pair to the knitting
needles of the knitting machine can comprise a larger distance and
thus a practical useful measure.
[0029] By means of the end thread gripping roller pair, a speed
decoupling of the technical system of the roving drawing and the
roving strengthening from the technical system of the thread supply
of the knitting machine is enabled, wherein the clamping point
formed by means of the end thread gripping roller pair blocks the
formation of the false strand realized by the upstream spinning
nozzle device. This means that the end thread gripping roller pair
determines one end of the rotation generated by the spinning nozzle
device and thus one end of the false strand, whereby the drawn,
strengthened end thread comprising the auxiliary thread exiting the
end thread gripping roller pair maintains its strength and a
disintegration of the end thread can be prevented. Accordingly,
transport ways of the end thread can be realized over relatively
long distances.
[0030] The arrangement of the end thread gripping roller pair can
happen application-specific. However, it has proven to be
particularly suitable, if at least one of the two end thread
gripping rollers is driven, wherein the second end thread gripping
roller does not comprise a separate drive and is set in motion by
pressing it against the driven end thread gripping roller.
[0031] In a particularly preferable embodiment of the device
according to the invention, the rotational speed of at least one of
the auxiliary thread gripping rollers is adjustable by means of a
device control, with which the rotational speed of the stretching
rollers of the stretching unit is adjustable as well. A shared
device control enables a continuous and coordinated transport of
the roving and the auxiliary thread through the device according to
the invention and thus ensures a consistent product quality of the
end thread. Furthermore, the programming and controlling effort of
the device according to the invention is reduced due to such a
shared device control, wherein the costs of the device can be kept
low.
[0032] With the device according to the invention, at least one of
the two auxiliary thread gripping rollers is drivable, wherein the
rotational speed of the at least one auxiliary thread gripping
roller can be regulated and controlled by means of the device
control according to the operation conditions. Hereby, the second
auxiliary thread gripping roller of the auxiliary thread griping
roller pair is preferably driven by pressing it against the driven
auxiliary thread gripping roller, however, in alternative
embodiments of the invention, it can also be driven by the device
control, which also drives at least one other auxiliary thread
gripping roller and the stretching rollers.
[0033] In further embodiments of the invention, also at least one
roller of the end thread gripping roller pair can be driven
speed-controlled by the device control apart from the auxiliary
thread gripping roller pair and the stretching rollers, whereby the
operating effort as well as the costs of the device according to
the invention can be further reduced.
[0034] In another preferred embodiment of the device according to
the invention, the auxiliary thread gripping rollers comprise a
first, profiled auxiliary thread gripping roller and a second,
rubberized auxiliary thread gripping roller, whereby the auxiliary
thread can be reliably transported without slipping out of the
auxiliary thread gripping roller pair or jamming or halting between
the auxiliary thread gripping rollers.
[0035] It is especially preferable if an auxiliary thread
oscillation device is provided in roving conveying direction of the
device prior to the at least one auxiliary thread gripping roller
pair through which a thread progression between the auxiliary
thread gripping rollers that is temporally variable can be
realized. Since the components of the device according to the
invention, especially also the auxiliary thread gripping rollers,
are exposed to high strain during the roving processing due to the
high production speeds, the efficiency of the device can be
increased by means of such an auxiliary thread oscillation device.
By means of the auxiliary thread oscillation device it can hereby
be ensured that the auxiliary thread does not constantly come into
contact with the same contact surface on the auxiliary thread
gripping rollers. A shrinkage of the used auxiliary thread gripping
rollers can thus be prevented. Preferably, a defined oscillation
path is provided for this purpose in order to ensure a safe
guidance of the auxiliary thread. The oscillation path should
especially be chosen and adjusted depending on the axial length of
the auxiliary thread gripping rollers.
[0036] In order to ensure that the auxiliary thread is supplied to
the stretching unit and not to increase the thread tension set by
the auxiliary thread gripping roller pair, at least one optical
thread sensor is provided downstream from the auxiliary thread
gripping roller pair in auxiliary thread conveying direction in an
appropriate embodiment of the device according to the invention,
through which the auxiliary thread can be optically recorded.
[0037] In a preferable embodiment example of the present invention,
the auxiliary thread supply unit comprises a closed housing with an
opening for exiting the auxiliary thread. The housing protects
especially the auxiliary thread, the spool carrying the auxiliary
thread and elements of the auxiliary thread supply unit necessary
for auxiliary thread conveying from fiber fly, which is especially
generated through the processing of the roving in the stretching
unit and the spinning nozzle device. The housing thus ensures a
safe process flow. The constructive form and material selection of
the housing can be chosen application-specific.
[0038] The object of the present invention is furthermore solved by
means of a method of the above-mentioned type in which the
auxiliary thread is led between the auxiliary thread supply unit
and the stretching unit through a rotational speed-variable
auxiliary thread gripping roller pair rotatable in opposite
directions.
[0039] The method according to the invention enables a particularly
preferable integration of the at least one auxiliary thread into
the roving, in order to be able to generate an end thread, which on
the one hand serves for forming a knit fabric with a very soft feel
and is on the other hand very strong itself.
[0040] With the method according to the invention the auxiliary
thread increasing the strength of the end thread is led between the
at least one rotational speed-variable auxiliary thread gripping
roller pairs rotatable in opposite directions towards the
stretching unit. Especially by adjusting the rotational speed of at
least one of the auxiliary thread gripping rollers, the speed and
the tension of the auxiliary thread with which it is transported to
the roving, can be controlled, whereby the characteristics of the
end thread and the process conditions can be influenced.
Furthermore, the auxiliary thread can be supplied to the stretching
unit according to demand and with a constant thread tension by
transporting the auxiliary thread from the auxiliary thread supply
unit to the stretching unit by means of the auxiliary thread
gripping roller pair, whereby a treated roving with constant
quality is produced, which in turn leads to a constantly good
knitting result on the knitting machine. By means of the used
auxiliary thread gripping roller pair, a relatively small thread
tension of the auxiliary thread supplied to the stretching unit can
be generated, which is not possible in the dimension according to
the invention when using a feeder. A tearing of the auxiliary
thread for example due to the gravitation or too high tension can
also be prevented due to the used auxiliary thread gripping roller
pair.
[0041] The auxiliary thread gripping roller pair thus forms an
auxiliary thread supply axis to the stretching unit, through which
the tension of the supplied auxiliary thread respectively core
thread is adjusted. The thread tension of the auxiliary thread is
adjusted as small as possible by means of a suitable rotational
speed setting of the auxiliary thread gripping rollers especially
because the auxiliary thread does not stretch during the supply to
the stretching unit and fibers of the roving accumulated around the
auxiliary thread later do not compress during a "relaxing" of the
auxiliary thread.
[0042] Thereby it is possible that the auxiliary thread is led by
more than one auxiliary thread gripping roller pair on very long
transport ways in order to be able to regulate the tension of the
auxiliary thread better and to prevent a tearing of the auxiliary
thread during the transport.
[0043] According to the invention, the auxiliary thread is for
example removed from the auxiliary thread supply unit by means of a
spool and is supplied to the roving drawn in the stretching unit.
Herein, the auxiliary thread can be supplied to the roving before
the stretching process, during the stretching process or directly
after finishing the stretching process. Especially if the auxiliary
thread is supplied to the roving only towards the end of the
stretching process, it can be ensured that the auxiliary thread is
supplied to the spinning process following the stretching process
with the desired tension. Especially by means of the tension with
which the auxiliary thread traverses the spinning process, the
quality and softness of the end thread can be significantly
influenced, since it is determined by the auxiliary thread tension,
how many fibers of the roving entwine the auxiliary thread and how
the fibers of the roving hold on the auxiliary thread. Thus, the
auxiliary thread should comprise a thread tension as small as
possible when traversing the spinning process in order to produce a
soft end thread.
[0044] In a particularly preferable embodiment of the method
according to the invention, two spinning nozzles of the spinning
nozzle device strengthening the roving with the auxiliary thread,
work pneumatic and apply compressed air to the drawn roving exiting
the stretching unit with respectively opposing rotation directions.
The tension condition of the drawn, strengthened roving is adjusted
in the area between the spinning nozzle device and the in roving
conveying direction succesively arranged end thread gripping roller
pair by adjusting the rotation intensity and/or the pressure of the
compressed air exiting the spinning nozzles of the spinning nozzle
device. The quality and especially the strength of the drawn,
strengthened end thread exiting the gripping roller pair comprising
the auxiliary thread can thus be ideally adjusted, whereby a smooth
process sequence can be ensured and a high-quality knitted fabric
can be produced on the knitting machine.
[0045] According to the invention, a clamping of the end thread is
provided downstream the strengthening process with the spinning
nozzle device, with which the drawn, strengthened roving comprising
the end thread is led clamped through the end thread gripping
roller pair rotating in opposite directions and the end thread
exiting the end thread gripping roller pair is supplied to the
knitting machine. By clamping the roving comprising the auxiliary
thread exiting the spinning nozzle device through the end thread
gripping roller pair, the formation of the false strand caused by
the spinning nozzle device is ended, whereby a subsequent twisting
of the end thread can be prevented. Accordingly, the end thread can
also be transported to the knitting needles of the knitting machine
over long distances with a constant quality.
[0046] In order to ensure an effortless transport of the end thread
to the knitting needles of the knitting machine, it has proven to
be particularly preferable if at least one of the two end thread
gripping rollers is driven. Herein the other, non-driven end thread
gripping roller is preferably set in rotation by pressing it
against the driven gripping roller. In alternative embodiments,
however, also both end thread gripping rollers can be driven,
wherein they are either driven independently of each other or
driven coupled together.
[0047] It is particularly appropriate to form the method according
to the invention in such a way that the rotational speed of the
auxiliary thread gripping rollers of the auxiliary thread gripping
roller pair is adjusted in such a way that a thread tension of the
auxiliary thread exiting the auxiliary thread gripping roller pair
is smaller than 2 cN. If the auxiliary thread is supplied to the
spinning nozzle device, through which the entwining of the
auxiliary thread with the fibers of the roving happens, with such a
small tension, especially many fibers can entwine the auxiliary
thread, whereby a very soft end thread and thus a knitted fabric
that is very soft to the touch can be produced on the knitting
machine.
[0048] In alternative embodiments of the method according to the
invention, thread tensions larger than 2 cN when exiting the
auxiliary thread from the auxiliary thread gripping roller pair can
of course also be realized, wherein here, however, no such soft
thread can be produced any more, since considerably less fibers of
the roving entwine the auxiliary thread than is the case with a
thread tension smaller than 2 cN. Preferably, the auxiliary thread
is supplied to the stretching unit with a thread tension smaller
than 2 cN, preferred with a thread tension less than 1 cN and
particularly preferred with a thread tension less than 0.5 cN.
[0049] In a particularly suitable version of the method according
to the invention, the auxiliary thread is supplied to the auxiliary
thread gripping roller pair, oscillating in axis direction of the
auxiliary thread gripping rollers, whereby a shrinkage of the
auxiliary thread gripping rollers due to the constant contact that
is happening under high strains between the auxiliary thread and
the auxiliary thread gripping rollers can be prevented. It is
especially preferable if the auxiliary thread can be oscillated
over the entire axial length of the auxiliary thread gripping
rollers, however, only so far that a secure course of the auxiliary
thread over the auxiliary thread gripping rollers can be
realized.
[0050] Furthermore, it has proven to be favorable for a safe
auxiliary thread supply with a tension as small as possible, if the
auxiliary thread tension between the auxiliary thread gripping
roller pair and the stretching unit is optically recorded.
[0051] Preferred embodiments of the present invention, including
their structure, function and advantages are explained in more
detail in the following using figures, wherein
[0052] FIG. 1 schematically shows an embodiment of the device
according to the invention in a side view;
[0053] FIG. 2 schematically shows auxiliary thread gripping roller
pair of an embodiment of a device according to the invention in a
side view; and
[0054] FIG. 3 schematically shows the auxiliary thread gripping
roller pair of FIG. 2 in a frontal view.
[0055] FIG. 1 schematically shows an embodiment of the device 1
according to the invention in a side view. Except for the auxiliary
thread supply, the shown device corresponds to the device which is
described in the document DE 10 2011 053 396 B3 and to whose
content it is herewith fully referred.
[0056] The device 1 comprises a roving drawing and strengthening
unit 3 for treating a roving 40a under formation of an end thread
40d. The roving drawing and strengthening unit 3 is coupled with a
knitting machine 2 for forming a knitted fabric from the end thread
40d on the knitting machine 2. Despite the description end "thread"
it should be noted that the end thread 40d is no conventional yarn,
but a drawn, temporarily strengthened roving comprising at least
one auxiliary thread 50, as described in detail in the
following.
[0057] The roving drawing and strengthening unit 3 comprises a
roving supply unit 4 with at least one roving 40a and an auxiliary
thread supply unit 5 with at least one auxiliary thread 50.
[0058] The roving supply unit 4 supplies the non-strengthened
roving 40a for the roving drawing and strengthening unit 3, which
is provided on flyer spools 9 encompassed by the roving supply unit
4. As FIG. 1 shows, the roving 40a is preferably supplied via a
transportation shaft 10 to the roving drawing and strengthening
unit 3 in a roving conveying direction A. In alternative
embodiments of the device 1 according to the invention, the roving
40a can also be supplied to the roving drawing and strengthening
unit 3 by means of several or without a transportation shaft 10
situated between the roving drawing and strengthening unit 3 and
the roving supply unit 4.
[0059] The roving drawing and strengthening unit 3 further
comprises a stretching unit 6 and a spinning nozzle device 70
provided downstream from the stretching unit 6 in roving conveying
direction A. The stretching unit 6 illustrated in FIG. 1 comprises
stretching roller pairs 601, 602, 603 arranged successively in
roving conveying direction A of the roving 40a, especially an inlet
roller pair 601, an intermediate roller pair 602 and an outlet
roller pair 603. In other embodiments of the device 1 according to
the invention, the stretching unit 6 can also comprise more than
one intermediate roller pair 602 or no intermediate roller pair 602
at all.
[0060] For drawing and thus for homogenizing the roving 40a, the
roving 40a is led through between stretching rollers 60a and 60b of
the individual stretching roller pairs 601, 602, 603. By driving
the stretching roller pairs 601, 602, 603 with varying speeds that
are increasing in the roving conveying direction A, a drawing of
the roving 40a to a drawn roving 40b is achieved. The stretching
roller pairs 601, 602, 603 are therein driven with such speeds that
the outlet roller pair 603 comprises a higher speed than the
intermediate roller pair 602 and the intermediate roller pair 602
in turn comprises a higher speed than the inlet roller pair 601.
Thus a pre-drawing happens between the inlet roller pair 601 and
the intermediate roller pair 602, whereas a subsequent main drawing
of the roving 40a is realized between the intermediate roller pair
602 and the outlet roller pair 603.
[0061] For generating the drawing of the roving 40a, the roving 40a
has to be transported in clamped fashion between the stretching
rollers of the stretching roller pairs 601, 602, 603. This happens
preferably by pressing a non-driven stretching roller respectively
upper roller 60b to a driven stretching roller respectively lower
roller 60a respectively. For pressing the upper rollers 60b to the
lower rollers 60a, the upper rollers 60b are connected to an
L-shaped stretching unit pressure arm 61. Accordingly, the
non-driven stretching rollers 60b can be easily collectively
pressed against the driven stretching rollers 60a or removed from
them by swinging the stretching unit pressure arm 61. The
stretching unit pressure arm 61 can be moved mechanically,
pneumatically or hydraulically.
[0062] In order to increase the strength of the drawn roving 40b
and to increase the reliability of the process carried out on the
device 1, at least one auxiliary thread 50 is supplied according to
the invention to the roving 40a. The auxiliary thread 50 is
provided by means of an auxiliary thread supply unit 5 typically
comprising several supply spools 52.
[0063] In the shown embodiment, the auxiliary thread supply unit 5
comprises a housing 8, which surrounds the supply spools 52
stocking the at least one auxiliary thread 50. The housing 8 of the
auxiliary thread supply 5 comprises at least one opening 81,
through which the auxiliary thread 50 can be supplied to at least
one auxiliary thread gripping roller pair 51 provided downstream
from the auxiliary thread supply unit 5 in an auxiliary thread
conveying direction B of the auxiliary thread 50. In alternative
embodiments of the device 1 according to the invention, the housing
8 can also comprise several openings 81, through which several
auxiliary threads 50 can be led out of the housing without
tangeling.
[0064] The auxiliary thread 50 removed from the spool 52 and led
through the opening 81 of the housing 8 of the auxiliary thread
supply unit 5, is supplied carefully and with a desired thread
tension to the drawn respectively partly drawn roving 40b by means
of the auxiliary thread gripping roller pair 51.
[0065] In the embodiment depicted in FIG. 1, the supply of the
auxiliary thread 50 to the drawn roving 40b happens during the
drawing of the roving 40a in the stretching unit 6. In the process,
the auxiliary thread 50 is supplied particularly preferred between
the intermediate roller pair 602 and the outlet roller pair 603 to
the stretching unit 6 and thus the roving 40b. Preferably, the
auxiliary thread 50 is hereby removed by the outlet roller pair 603
and is, along with the drawn respectively partly drawn roving 40b,
conveyed towards a spinning nozzle device 70 provided downstream
from the stretching unit in a roving conveying direction A. The
rotation speed of the auxiliary thread gripping roller pair 51 can
thus be adjusted ideally to the rotation speed of the outlet roller
pair 603.
[0066] In other, not shown embodiments of the device 1 according to
the invention, the auxiliary thread 50 can be supplied to the not
yet drawn roving 4a before traversing the stretching unit 6 or to
the drawn roving 40b only after leaving the stretching unit 6.
[0067] By adjusting the tension of the auxiliary thread 50 by means
of the auxiliary thread gripping roller pair 51, with which it is
supplied to the stretching unit 6, it is possible to significantly
influence the softness of the produced end thread 40d and the
thereof produced knitted fabric, since the thread tension of the
auxiliary thread 50 is inter alia responsible for how many fibers
of the drawn roving 40b entwine the auxiliary thread 50 and stick
to it in and after the spinning nozzle device 70. In the embodiment
of FIG. 1, the auxiliary thread 50 is supplied to the stretching
unit 6 with a thread tension smaller than 2 cN, since especially
many fibers of the drawn roving 40b wind themselves around the
auxiliary thread 50 with such a small thread tension and a
particularly high softness of the end thread 40d and thus also of
the knitted fabric is generated.
[0068] Furthermore, a tearing of the auxiliary thread 50 and thus
an unwanted process interruption can be prevented due to the
transport of the auxiliary thread 50 with small tension by means of
the auxiliary thread gripping roller pair 51.
[0069] In the embodiment illustrated in FIG. 1, the device
according to the invention only comprises one auxiliary thread
roller pair 51, however, in further embodiments it can also
comprise several auxiliary thread roller pairs 51 arranged
successively in auxiliary thread conveying direction B. The use of
several auxiliary thread gripping roller pairs 51 in a device 1 has
proven to be preferable especially with long transport distances of
the auxiliary thread 50 from the auxiliary thread supply unit 5 to
the stretching unit 6.
[0070] The drawn roving 40a exiting the stretching unit 6 is,
alongside the at least one supplied auxiliary thread 50, supplied
to a spinning nozzle device 70 provided downstream from the
stretching unit 6 in a roving conveying direction A. In the
spinning nozzle device 70, a rotation of the drawn roving 40b
comprising the auxiliary thread 50 takes place by means of air jets
exiting the spinning nozzle device 70 so that a formation of a
so-called false strand ensues.
[0071] In the embodiment of FIG. 1, the spinning nozzle device 70
comprises two air twirling nozzles 70a, 70b arranged successively
in roving conveying direction A. The air flow generated in the two
air twirling nozzles 70a, 70b comprise opposing rotation
directions. The first air twirling nozzle 70a provided downstream
from the stretching unit 6, a so-called injector nozzle, causes an
untwisting of fiber material of the drawn roving 40b, whereby the
peripheral fibers on the drawn roving 40b spread apart. The spread
apart peripheral fibers are wound around a fiber core of the roving
40a and/or the auxiliary thread 50 by means of a rotation
generation of the second air twirling nozzle 70b provided
downstream from the first air twirling nozzle 70a, a so-called
swirl nozzle, whereby the false strand is formed. The rotation
speeds of the air twirling nozzles 70a, 70b as well as an air flow
generated by the respective air twirling nozzle 70a, 70b can be
chosen depending on the knitting speed adjustable on the knitting
machine 2 and a respective roving conveying speed. Furthermore, the
distance of the spinning nozzle device 70 from the stretching unit
6 as well as the distance of the air twirling nozzles 70a, 70b to
each other can be chosen application-specific.
[0072] The roving 40b drawn by the stretching unit 6, comprising
the at least one auxiliary thread 50 and strengthened in the
spinning nozzle device 70 is removed by an end thread gripping
roller pair 71 provided downstream from the spinning nozzle device
70 in transport direction A of the roving 40a. The end thread
gripping roller pair 71 typically has a driven gripping roller 71a
and a non-driven gripping roller 71b pressed against the driven
gripping roller 71a. The end thread gripping roller pair 71 can
also comprise two driven gripping rollers 71a pressed against each
other in alternative embodiments of the device 1 according to the
invention. The end thread gripping roller pair 71 enables a speed
decoupling of the technical system of the roving drawing and
strengthening unit 3 from the technical system of the thread supply
to the knitting machine 2. Furthermore, the clamping point realized
by the end thread gripping roller pair 71 enables a diversion of
the drawn, strengthened roving 40c exiting the end thread gripping
roller pair 71 comprising the auxiliary thread 50 to the
operational level of the knitting machine 2.
[0073] FIG. 2 schematically shows an auxiliary thread gripping
roller pair 51 in an embodiment of the device 1 according to the
invention in a side view. The elements in FIG. 2 indicated with the
same reference signs as in FIG. 1 correspond to those of FIG. 1,
which is why here it is being referred to the above description of
these elements.
[0074] In the embodiment shown in FIG. 2, the auxiliary thread 50
stored in the auxiliary thread supply unit 5 is supplied to the
auxiliary thread gripping roller pair 51 by means of an auxiliary
thread conveying tube 53, whereby a destruction of the auxiliary
thread 50 during the transport can be largely excluded. Form,
position and dimensions of the auxiliary thread conveying tube 53
can hereby be chosen application-specific.
[0075] The auxiliary thread 50 exiting the auxiliary thread
conveying the tube 53 is, before it is supplied to the auxiliary
thread gripping roller pair 51 provided downstream in auxiliary
conveying direction B, led through an auxiliary thread guiding
device 56 arranged between the auxiliary thread conveying tubes 53
and the auxiliary thread gripping roller pair 51. The auxiliary
thread guiding device 56 is part of an auxiliary thread oscillation
device 57 through which the auxiliary thread 50 is moved sideways
back and forth vertically to the auxiliary thread transport
direction B, causing that the auxiliary thread 50 does not
constantly come into contact with the same contact surfaces of the
auxiliary thread gripping rollers 51a, 51b of the auxiliary thread
gripping roller pair 51. A shrinkage of the used auxiliary gripping
rollers 51a, 51b can thus be prevented.
[0076] The auxiliary thread gripping roller pair 51 preferably
comprises, as shown in FIG. 2, two opposing auxiliary thread
gripping rollers 51a, 51b working in opposite directions, pressable
against each other. In the shown embodiment, the first of the two
auxiliary thread gripping rollers 51a is fixed in the device 1,
whereas the second auxiliary thread gripping roller 51b is provided
in such a way in the device 1 according to the invention that it
can be pressed against and detached from the fixedly placed first
auxiliary thread gripping roller 51a. According to the embodiment
of FIG. 2, for example a spring activated pressing device 54 can be
used for this purpose, with which the second auxiliary thread
gripping roller 51b can be pressed against the first auxiliary
thread gripping roller 51a. In alternative embodiments of the
device 1 according to the invention, the pressure device 54 can,
however, also be formed differently and can, apart from a
mechanical operation, also be positioned hydraulically and
pneumatically.
[0077] Size, dimensions, form and texture of the auxiliary thread
gripping rollers 51a, 51b can be chosen application-specific. In
the shown embodiment, the first auxiliary thread gripping roller is
profiled and the second auxiliary thread gripping roller 51b is
rubberized. Such a form of the auxiliary thread gripping rollers
51a, 51b prevents a slipping out of the auxiliary thread 50 from
the space between the auxiliary thread gripping rollers 51a, 51b
and furthermore enables a gentle transport of the auxiliary thread
50. The second auxiliary thread gripping roller 51b can either be
formed completely of rubber or only comprise a rubber coating. The
profile and material of the profiled auxiliary thread gripping
roller 51a can be chosen freely depending on the operation
conditions of this auxiliary thread gripping roller 51a. Thus it is
for example possible that the profiled auxiliary thread gripping
roller 51a comprises a serrated pattern or grooves provided
contrary to the auxiliary thread transport direction B.
[0078] In the embodiment shown in FIG. 2, the first auxiliary
thread gripping roller 51a is driven, wherein its rotation
transmits to the non-driven second auxiliary thread gripping roller
51b. Accordingly, the auxiliary thread gripping rollers 51a, 51b
execute opposing rotation movements C, C'. In further embodiments
of the device 1 according to the invention, however, both auxiliary
thread gripping rollers 51a, 51b can be driven, wherein they can
either be driven independently of each other or linked to each
other or can be linked to each other. What is important here is
only that the two auxiliary thread gripping rollers 51a, 51b are
driven with opposing rotation directions.
[0079] In the embodiment of FIG. 2, a diversion device 55 is
provided downstream the auxiliary thread gripping roller pair 51,
which guides the auxiliary thread 50 towards the stretching unit 6.
The diversion device 55 prevents a too abrupt diversion and thus a
damage of the auxiliary thread 50, whereby the process safety of
the device 1 according to the invention can be increased. The
diversion device 55 is furthermore formed as an optical fiber
sensor in the shown embodiment, which serves for guaranteeing the
presence of the auxiliary thread 50 after the auxiliary thread
gripping roller pair 51. The detection of the auxiliary thread
happens optically and not mechanically at this point in order not
to increase the tension level of the thread tension of the
auxiliary thread 50 again after the traversing of the auxiliary
thread 50 through the auxiliary thread gripping roller pair 51.
[0080] In the shown embodiment, the auxiliary thread 50 exiting the
auxiliary thread gripping roller pair 51 and diverted by the
diversion device 55 is thereupon transported to the stretching unit
6 or the spinning nozzle device 70 through another auxiliary thread
conveying tube 53', whereby a particularly gentle and
process-stable transport of the auxiliary thread 50 is enabled.
[0081] FIG. 3 schematically shows the auxiliary thread gripping
roller pair 51 depicted in FIG. 2 in a frontal view, wherein here
the same reference signs as in the previous figures also indicate
the same elements, which is why it is being referred to their
previous embodiments at this point.
[0082] FIG. 3 shows the auxiliary thread 50 led through the
auxiliary thread conveying tube 53, the auxiliary thread gripping
rollers 51a, 51b and the diversion device 55 into the auxiliary
thread conveying tube 53'.
[0083] Furthermore, it is also apparent from FIG. 3, how the
auxiliary thread 50 passes through the auxiliary thread oscillation
device 57 comprising the auxiliary thread guiding device 56. By
moving the auxiliary thread oscillation device 57 in an oscillation
direction D, transverse to the auxiliary thread transport direction
B, the contact surface of the auxiliary thread 50 with the surfaces
of the auxiliary thread gripping rollers 51a, 51b can be varied,
whereby a shrinkage of the auxiliary thread gripping rollers 51a,
51b and their increased wear can be prevented. Especially the
guidance of the auxiliary thread 50 by means of the auxiliary
thread guiding device 56 of the auxiliary thread oscillation device
57 has proven to be especially preferable with regard to the
movement of the auxiliary thread 50 along the surface of the
auxiliary thread gripping rollers 51a, 51b, since the auxiliary
thread 50 can thus be moved controllably, without shifting, by
means of the auxiliary thread oscillation device 57.
[0084] The rotational speed of the auxiliary thread gripping
rollers 51a, 51b and/or the movement of the auxiliary thread 50 by
means of the auxiliary thread oscillation device 57 can be adjusted
by means of a device control 90. By means of this device control
90, the rotational speed of the end thread gripping roller pair 71
and/or the pressure of the compressed air exiting the spinning
nozzles 70a, 70b and/or the rotational speed of the rollers of the
stretching unit 6 and/or the knitting speed of the knitting machine
2 can be adjusted.
[0085] In the simplest embodiment, the auxiliary thread guiding
device 56 is formed as a drill in the auxiliary thread oscillation
device 57, which is for example formed as a shaft, however, in
other embodiments of the device 1 according to the invention, it
can also be formed differently.
* * * * *