U.S. patent application number 16/481680 was filed with the patent office on 2019-12-26 for knitted fabric and method and device for producing the knitted fabric.
The applicant listed for this patent is TERROT GMBH. Invention is credited to JOHANNES BARTH, MICHAEL LAU, THOMAS MUTSCHLER, HERMANN SCHMODDE.
Application Number | 20190390378 16/481680 |
Document ID | / |
Family ID | 61094557 |
Filed Date | 2019-12-26 |
United States Patent
Application |
20190390378 |
Kind Code |
A1 |
MUTSCHLER; THOMAS ; et
al. |
December 26, 2019 |
KNITTED FABRIC AND METHOD AND DEVICE FOR PRODUCING THE KNITTED
FABRIC
Abstract
A method and device for producing knitted fabric include
supplying roving to a stretching unit with stretching roller pairs
and a spinning nozzle device and drawing the roving using the
stretching roller pairs. Inlet and outlet roller pairs of the
stretching unit are controllably driven, according to a pattern to
be formed on the machine, so that the thread thickness of the drawn
roving is varied by changing the relative speed between inlet and
outlet roller pairs. The drawn roving is supplied to the spinning
nozzle device and strengthened by applying compressed air, and the
drawn, strengthened roving is supplied to the machine. The thread
supply speed of the drawn, strengthened roving to the machine is
set depending on the loop size to be knit by the machine by
controlling rotation speed of at least one driven roller of the
outlet roller pair. A knitted fabric is also provided.
Inventors: |
MUTSCHLER; THOMAS;
(GEISLINGEN, DE) ; SCHMODDE; HERMANN; (HORB,
DE) ; LAU; MICHAEL; (CHEMNITZ / OT MITTELBACH,
DE) ; BARTH; JOHANNES; (NIEDERWIESA, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TERROT GMBH |
CHEMNITZ |
|
DE |
|
|
Family ID: |
61094557 |
Appl. No.: |
16/481680 |
Filed: |
January 18, 2018 |
PCT Filed: |
January 18, 2018 |
PCT NO: |
PCT/IB2018/050298 |
371 Date: |
July 29, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D04B 1/12 20130101; D04B
1/025 20130101; D04B 9/025 20130101; D04B 9/14 20130101; D04B 1/24
20130101; D10B 2403/033 20130101 |
International
Class: |
D04B 9/14 20060101
D04B009/14; D04B 1/02 20060101 D04B001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 27, 2017 |
DE |
10 2017 101 597.3 |
Claims
1-15 (canceled)
16. A method for producing a knitted fabric having a pattern, the
method comprising the following steps: supplying a sliver formed as
a roving of unstrengthened fiber bundles to a roving drawing and
strengthening unit including a stretching unit with at least two
stretching roller pairs successively disposed in a thread transport
direction and a spinning nozzle device disposed downstream of the
stretching unit in the thread transport direction and drawing the
roving using the at least two stretching roller pairs; controllably
driving at least one inlet roller pair and one outlet roller pair
of the stretching unit according to the pattern of the knitted
fabric to be formed on a knitting machine causing a thread
thickness of the drawn roving to be varied along its length by
changing a relative speed between the inlet roller pair and the
outlet roller pair; supplying the drawn roving exiting the
stretching unit to the spinning nozzle device and strengthening the
drawn roving by applying compressed air; then supplying the drawn,
strengthened roving to the knitting machine directly or by using a
transport or clamping device; and setting a thread supply speed of
the drawn, strengthened roving to the knitting machine depending on
a loop size to be knit by the knitting machine by controlling a
rotation speed of at least one driven roller of the outlet roller
pair of the stretching unit.
17. The method according to claim 16, which further comprises
setting the roller speed based on: the bigger the loop size to be
knit by the knitting machine, the smaller the relative speed
between the inlet roller pair and the outlet roller pair and the
bigger the rotation speed of the at least one driven roller of the
outlet roller pair is set, and the smaller the loop size to be knit
by the knitting machine, the bigger the relative speed between the
inlet roller pair and the outlet roller pair and the smaller the
rotation speed of the at least one driven roller of the outlet
roller pair is set.
18. The method according to claim 16, which further comprises
setting a relative speed between the inlet roller pair and the
outlet roller pair to be inversely proportional to the loop size to
be knit by the knitting machine and setting the rotation speed of
the at least one driven roller of the outlet roller pair to be
directly proportional to the loop size.
19. The method according to claim 16, which further comprises
supplying the drawn, strengthened roving to the knitting machine
with constant thread tension.
20. The method according to claim 16, which further comprises
supplying at least one auxiliary thread to the stretching unit, and
controlling an auxiliary thread supply speed to the stretching unit
depending on at least one of the loop size of the knitted fabric to
be formed on the knitting machine or stretch characteristics of the
auxiliary thread.
21. The method according to claim 16, which further comprises
forming a plurality of drawn, strengthened rovings on separate
roving drawing and strengthening units, supplying the drawn,
strengthened rovings to separate knitting systems of the knitting
machine by using the roving drawing and strengthening units, and
controlling and operating the roving drawing and strengthening
units independently of each other.
22. The method according to claim 16, which further comprises
combining a plurality of roving drawing and strengthening units
into one module and jointly electronically controlling the roving
drawing and strengthening units.
23. The method according to claim 21, which further comprises
supplying each respective knitting system of the knitting machine
with drawn, strengthened roving from at least two of the roving
drawing and strengthening units.
24. The method according to claim 22, which further comprises
supplying each respective knitting system of the knitting machine
with drawn, strengthened roving from at least two of the roving
drawing and strengthening units.
25. A device for producing a knitted fabric, the device comprising:
at least one knitting machine including a sinking depth adjustment
device; at least one roving drawing and strengthening unit disposed
upstream of said at least one knitting machine in a thread
transport direction, said at least one strengthening unit including
at least one stretching unit with at least two stretching roller
pairs being successively disposed in the thread transport direction
and at least one spinning nozzle device disposed downstream of said
at least one stretching unit in the thread transport direction,
said at least two stretching roller pairs including an inlet roller
pair and an outlet roller pair each having at least one respective
driven roller; at least one drive coupled to said at least one
driven roller of said inlet roller pair and to said at least one
driven roller of said outlet roller pair; a pattern control for
said at least one knitting machine, said pattern control being
coupled to said at least one drive; and said pattern control and
said at least one drive being coupled to said sinking depth
adjustment device.
26. The device according to claim 25, which further comprises at
least one thread tension measuring device for determining a thread
tension of a drawn, strengthened roving exiting said at least one
roving drawing and strengthening unit.
27. The device according to claim 25, which further comprises at
least one auxiliary thread supply device being connected to said at
least one stretching unit and being controllable by at least one of
said pattern control for said at least one the knitting machine or
in dependence on stretch characteristics of an auxiliary thread to
be supplied to said at least one stretching unit.
28. The device according to claim 25, wherein: said at least one
strengthening unit includes at least two separate strengthening
units being independently controlled; and said at least one
knitting machine includes knitting systems each being associated
with said at least two separate roving drawing and strengthening
units.
29. The device according to claim 25, wherein said at least one
strengthening unit includes a plurality of strengthening units
combined into one module and coupled for control.
30. A knitted fabric, comprising: a drawn, strengthened roving
having a thread thickness varying along its length; said thread
thickness of said drawn, strengthened roving being formed in
dependence on a respective loop size of the knitted fabric; and
said thread thickness increasing with increasing loop size and
decreasing with decreasing loop size.
31. The knitted fabric according to claim 30, wherein the knitted
fabric is a seamless, circularly-knitted, knitted fabric with
varying diameter and constant opaqueness.
Description
[0001] The present invention relates to a method for producing a
knitted fabric, whereby a sliver in form of a roving of fiber
bundles that have not been strengthened is supplied to a roving
drawing and strengthening unit, which comprises a stretching unit
with at least two stretching roller pairs being successively
arranged in thread transport direction and a spinning nozzle device
being arranged downstream of the stretching unit in the thread
transport direction and is drawn by the at least two stretching
roller pairs, wherein at least one inlet roller pair and one outlet
roller pair of the stretching unit are controllably driven
according to the pattern of the knitted fabric to be formed on the
knitting machine in such a way that the thread thickness of the
drawn roving is varied throughout its length by changing the
relative speed between the inlet roller pair and the outlet roller
pair, the drawn roving exiting the stretching unit is supplied to
the spinning nozzle device and is strengthened by it by means of
applying pressurized air, and thereupon the drawn, strengthened
roving is supplied to the knitting machine directly or by using a
means for transport or clamping.
[0002] The present invention furthermore relates to a device for
producing a knitted fabric which comprises at least one knitting
machine, at least one roving drawing and strengthening unit being
provided upstream of the knitting machine in thread transport
direction, which comprises at least one stretching unit with at
least two stretching roller pairs being successively arranged in
thread transport direction, wherein at least one driven roller of
an inlet roller pair and at least one driven roller of an outlet
roller pair of the stretching unit are coupled with at least one
drive, which is/are coupled with the pattern control for the
knitting machine.
[0003] Moreover, the present invention relates to a knitted fabric
which is formed of a drawn, strengthened roving with a thread
thickness varying along its length, wherein the thread thickness of
the drawn, strengthened roving is formed depending on the pattern
of the knitted fabric.
[0004] The document DE 10 2011 053 396 discloses a device and a
method for producing a knitted fabric, whereby a knitting machine
is directly coupled with a roving drawing and strengthening unit,
which comprises a stretching unit for drawing a roving and a
spinning nozzle device for temporarily strengthening the drawn
roving, wherein the length of thread strengthening segment
subsequent to the spinning nozzle device is defined by a clamping
roller pair. Hereby, the drawn, strengthened roving can be led
directly from the roving drawing and strengthening unit across a
long segment appropriate for industrial applications to the
knitting machine. Hereby, particularly soft and voluminous knitted
fabrics can advantageously be produced.
[0005] In addition, threads with varying thread thickness are known
from the prior art, however, the thread thickness of such so-called
knop threads is merely changed with regard to the look of the
knitted fabric being produced from the thread. Hereby, the knop
thread can comprise thickenings, so called knops, at regular or
irregular distances. Threads with knops varying in their length and
their distance to each other are especially used for the production
of knitted fabrics which are supposed to give the impression that
they have been hand-knitted.
[0006] In the document DE 1 910 034 A, a method and a device for
producing threads with randomly varying thread thickness is
described, wherein random changes of the thread thickness of the
basic thread are induced and the thickness and the length of the
produced knops are at the same time varied in a random way. For
this purpose, the device described in the document DE 1 910 034 A
comprises a controllable drive device running with a variable
rotation speed. During normal operation, the drive unit is
connected with a rear set of stretching devices in order to drive
it completely independently from a frontal set of stretching
devices allocated to this set, which is provided at a distance from
the rear stretching devices. The supply of a strand of a textile
material to the stretching zone extending between the sets of
stretching devices can thus be regulated completely independently
of the speed with which the drawn roving is delivered by the
frontal set of stretching devices. For generating the thickenings
of the knop thread, a randomly changing signal is generated
according to the method, which causes for the operating speed of
the rear set of stretching devices to be controlled completely
independently from the operating speed of the front set of
stretching devices. Although it is emphasized in document DE 1 910
034 A that the changes of the thread thickness do not generate a
repetitive pattern in the produced thread, it is, however, also
mentioned that there can be certain cases in which it is desired to
program the changes of the thread thickness in advance according to
a determinable pattern.
[0007] The method described in the document DE 1 910 034 A as well
as the device described therein are solely used for producing
thread with varying thread thickness, which is subsequently
processed for the production of a textile, such as a fabric.
[0008] In the document WO 2016/091521 A1, a combination of spinning
device and knitting machine is used, wherein a fiber compound or a
thread of variable thickness can be produced out of a roving with
the spinning device and can be supplied to the loop forming
elements of the knitting machine. For this, at least two roller
pairs of a stretching unit of the spinning device comprise their
own driving units being controllable independently of each other,
by which the relative speed between an inlet and an outlet roller
pair of the stretching unit can be changed or friction spinning
devices with at least one feed roll are provided on the machine,
whose speed is controllable in relation to a pair of draw-off
rollers. With the known device and the known method, knitted fabric
with a pattern can be produced, which is generated by the formation
of loops with a varying fiber compound or thread thickness, wherein
the pattern is formed by variation of the fiber compound or thread
thickness in course direction and/or in wale direction.
[0009] It is the object of the present invention to provide a
method, a device and a knitted fabric with even higher variability
in the formation of patterns with a simultaneously optimized
material use.
[0010] The object is on the one hand solved by a method of the of
the above-mentioned type, whereby the thread supply speed of the
drawn, strengthened roving to the knitting machine is set depending
on the loop size to be knit by the knitting machine by controlling
the rotation speed of at least one roller of the outlet roller pair
of the stretching unit.
[0011] Advantageously, the material use when producing a knitted
fabric can be optimized by processing the drawn, strengthened
roving varying in its thickness. With the method according to the
invention, the thread thickness of the drawn, strengthened roving
exiting the roving drawing and strengthening unit is changed for
this purpose with the roving drawing and strengthening unit coupled
with the knitting machine according to a pattern knit by the
knitting machine.
[0012] For producing the drawn, strengthened roving varied in
thickness, a sliver in form of a fiber bundle that has not been
strengthened is supplied to a stretching unit of the roving drawing
and strengthening unit, which is drawn by at least two stretching
roller pairs of the stretching unit successively arranged in thread
transport direction and strengthened by a spinning nozzle device
provided subsequent to the stretching unit in thread transport
direction. For strengthening the roving drawn in the stretching
unit, it is applied with compressed air by the spinning nozzle
device. The strengthening segment can, for example, be closed by a
clamping roller pair subsequent to the spinning nozzle device in
thread transport direction, whereupon the drawn, strengthened
roving varying in thickness can be easily transported over long
distances directly from the roving drawing and strengthening unit
to the knitting machine arranged subsequent to it in thread
transport direction.
[0013] For changing the thread thickness of the drawn, strengthened
roving being produced in the roving drawing and strengthening unit,
at least one inlet roller pair, that is the first stretching roller
pair of the stretching unit in thread transport direction, and one
outlet roller pair, that is the last stretching roller pair of the
stretching unit in thread transport direction, are controllably
driven according to the pattern of the knitted fabric to be formed
on the knitting machine. The control thereby happens in such a way
that the thread thickness of the drawn roving generated by the
stretching unit is varied throughout its length by changing the
relative speed between the inlet roller pair and the outlet roller
pair. The thread thickness of the drawn roving can be varied
throughout its length according to pattern by changing the relative
speed between the inlet roller pair and the outlet roller pair.
[0014] For this, the rotation speed of the controlled inlet roller
pair is preferably changed that more or less sliver is supplied to
the stretching unit depending on the set rotation speed. The
rotation speed of the outlet roller pair can for example be kept
constant at the same time. However, in alternative embodiments, the
rotation speed of the outlet roller pair can also be varied
relative to an unchanging speed of the inlet roller pair depending
on the pattern to be knit. Furthermore, both the inlet and the
outlet roller pair can be controllably driven in such a way that
the thread thickness of the drawn roving exiting the stretching
unit can be adjusted to the pattern to be knit over the relative
speed between the inlet and the outlet roller pair. The rotation
speed of the controlled inlet roller pair can be changed according
to pattern.
[0015] With an increase of the rotation speed of at least one
driven roller of the inlet roller pair relative to the rotation
speed of at least one driven roller of the outlet roller pair, the
thread thickness of the drawn, strengthened roving to be produced,
increases. Vice versa, the thread thickness of the drawn,
strengthened roving to be produced decreases with a reduction of
the rotation speed of at least one driven roller of the inlet
roller pair relative to the rotation speed of at least one driven
roller of the outlet roller pair.
[0016] Advantageously, only one roller each of the stretching
roller pairs is driven, wherein the respective second roller by
pressing against the driven roller, is moving in opposite direction
to it. However, in alternative embodiments of the invention, both
rollers of a stretching roller pair can also be driven.
[0017] In alternative variants of the method according to the
invention, the sliver supplied to the stretching unit can
furthermore also be drawn by more than two, for example three or
four stretching roller pairs.
[0018] It is preferable for the spinning nozzles of the spinning
nozzle device to twist the drawn roving in thread transport
direction and convey it automatically, wherein the spinning nozzle
device preferably comprises at least two spinning nozzles which
work pneumatically and apply compressed air to the drawn roving
exiting the stretching unit with respectively opposite rotation
directions.
[0019] Furthermore, it is also preferable if the at least one
clamping roller of a clamping roller pair provided downstream of
the spinning nozzle device in thread transport direction is driven,
wherein, depending on the embodiment of the method according to the
invention, the rotation speed of the at least one clamping roller
can herein also be changed, for example depending on the pattern to
be knit. By leading the drawn, strengthened roving through the
clamping roller pair, the strengthening segment of the spinning
nozzle device can be limited, whereby the drawn, strengthened
roving can be transported up to the respective knitting spot with
sufficient strength.
[0020] With the method according to the invention, the thread
supply speed of the drawn, strengthened roving to the knitting
machine is furthermore set depending on the loop size to be knit by
the knitting machine by controlling the rotation speed of at least
one driven roller of the outlet roller pair of the stretching
unit.
[0021] With the method according to the invention, the change of
the thread supply speed is thus enabled by adjusting the rotation
speed of the last stretching roller pair of the stretching unit in
thread transport direction, wherein the rotation speed of the
outlet roller pair is to be set higher for an increasing thread
supply speed and its rotation speed is to be set lower for
attaining a decreasing thread supply speed.
[0022] With the method according to the invention, both the thread
fineness or thread thickness, that is the mass of the thread per
thread section, and the thread supply amount are thus adjusted to
the respective loop size to be knit of the knit fabric to be
formed.
[0023] It has proven to be especially advantageous if only one
roller of the outlet roller pair is driven depending on the
according to the respective loop size to be knit and the necessary
thread supply amount to the knitting machine and the corresponding
roller is put into motion by pressing it against the driven roller.
Furthermore, both rollers of the outlet roller pair can also be
driven according to pattern.
[0024] By changing the thread supply speed, loops with different
sizes can be knit on the knitting machine, wherein the loop size to
be knit is facilitated by varying the sinking depth on the knitting
machine. By knitting loops with different sizes, transparent and
less transparent areas in a knitted fabric can be produced.
[0025] By proportionally changing the relative speed of the inlet
roller pair to the outlet roller pair and a resulting change in
thread thickness of the drawn, strengthened roving used on the
knitting machine for forming loops as well as an easily attainable
variation of the loop size by means of changing the thread supply
speed, knitted fabrics can furthermore be produced, which comprise
an almost constant surface weight and are characterized by a nearly
homogenous transparency or opaqueness.
[0026] Leggings or tights known from the prior art are, if they are
not assembled out of different parts, consistently formed out of
one knit fabric with consistent thread thickness. This leads to the
leggings or the tights being transparent or translucent, for
instance in the buttocks area due to an increased stretching. In
order to prevent for underwear and/or skin to shine through, the
leggings or the tights need to be bought correspondingly large,
which in turn has the disadvantage of it slipping more easily and
not being tight enough, for example in the calf area.
[0027] When producing a circular knit fabric, the diameter of the
knit fabric is largely defined by the constructive conditions, such
as cylinder diameter and number of needles. This can only be
changed within certain limits by variating the loop size. Producers
use this effect with leggings. With increasing loop size, the
diameter of the knit fabric is also increasing. Thus, a certain
shape can be given to a leggings leg. However, this shaping is only
possible with a previously set thread thickness. In the prior art,
the opaqueness is therefore higher with small loops and thus a
small diameter of the knit fabric than with big loops and thus a
big diameter of the knit fabric.
[0028] With the method according to the invention, it is in
contrast possible, to adjust the thread thickness as well as the
loop size to the knitting pattern to be formed. In a preferred
embodiment of the method according to the invention, the stretching
unit is therefore controlled in such a way that the larger the loop
size to be knit by the knitting machine, the smaller the relative
speed between the inlet roller pair and the outlet roller pair and
the larger the rotation speed of the at least one driven roller of
the outlet roller pair is set, and the smaller the loop size to be
knit by the knitting machine, the larger the relative speed between
the inlet roller pair and the outlet roller pair and the smaller
the rotation speed of the at least one driven roller of the outlet
roller pair is set. With knitted fabrics such as leggings or
tights, an unsightly show-through of underwear and/or skin, for
example in the buttocks area, can thereby be prevented due to an
increased stretching in this area.
[0029] When using the method according to the invention, the loops
in areas in which the produced knitted fabric is exposed to a
higher stretching during wear, such as the buttocks area, are
hereby on the one hand knitted larger and on the other hand the
thread thickness is enlarged depending on the size of the loops.
Accordingly, the thread thickness is adjusted depending on the size
of the loops to be formed, wherein the thread thickness of the
drawn, strengthened roving supplied to the knitting spot is
increasing with increasing loop size and with decreasing loop size
its thread thickness is decreasing. With the method according to
the invention, the loop size and the thread thickness of the
knitted fabric to be formed are thus set according to pattern.
[0030] Preferably, the relative speed between the inlet roller pair
and the outlet roller pair is therefore set inversely proportional
to the loop size to be knit by the knitting machine and the
rotation speed of the at least one driven roller of the outlet
roller pair directly proportional to the loop size.
[0031] In order to facilitate a particularly easy knitting of the
drawn, strengthened roving and to knit a knitted fabric of very
high quality, it has proven to be especially advantageous if the
drawn, strengthened roving is supplied to the knitting machine with
constant thread tension. In alternative embodiments of the method
according to the invention, the drawn, strengthened roving can also
be supplied to the knitting machine with a thread tension that is
not constant, but can for example be adjusted to the knitting
pattern.
[0032] With regard to the durability of the knitted fabric to be
produced, it has furthermore also proven to be helpful if at least
one auxiliary thread is supplied to the stretching unit, wherein an
auxiliary thread supply speed to the stretching unit is controlled
depending on the loop size of the knitted fabric to be formed on
the knitting machine and/or depending on stretching characteristics
of the auxiliary thread. The auxiliary thread supply speed to the
stretching unit can also be controlled depending on the pattern of
the knitted fabric to be formed on the knitting machine.
[0033] It has thereby proven to be particularly practical, if the
auxiliary thread is drawn by the last stretching roller pair of the
stretching unit in thread transport direction, that is the outlet
roller pair. Since the individual rollers of the stretching unit
are possibly moving with a differing rotation speed, the auxiliary
thread supplied to the last stretching unit roller pair of the
stretching unit is only exposed to a single rotation speed so that
the supply of the auxiliary thread can be suitably adjusted to this
rotation speed and thus to the pattern of the knitted fabric to be
formed on the knitting machine. In other variants of the method
according to the invention, the auxiliary thread can, however, also
be supplied to the roving on another spot, for example before
supplying it to the stretching unit. By supplying the auxiliary
thread to the roving, a core-sheath thread is advantageously
formed, in which the drawn, strengthened roving entwines the
auxiliary thread in bundles.
[0034] Depending on the embodiment of the method according to the
invention or the knitted fabric to be formed thereby, an inelastic
thread, a so-called core thread, or an elastic thread, a so-called
elastane thread, can be used as an auxiliary thread. By using the
auxiliary thread, the drawn, strengthened roving comprising the
auxiliary thread to be supplied to the knitting machine, can be
provided with heightened stability.
[0035] Furthermore, more than one auxiliary thread, for example two
or three auxiliary threads can also be supplied to the roving.
Hereby, it has shown to be advantageous if the respective auxiliary
threads are supplied to the stretching unit by separate auxiliary
thread supply devices. They can, however, also be transported to
the roving by means of a single auxiliary thread supply device.
[0036] By inserting the at least one auxiliary thread into the
roving and the thread thickness or thread count adjusted to the
respective loop size to be knit, a knitted fabric can preferably be
produced, with which an unsightly shimmer-through effect due to a
large stretching, which is, as stated above, often the case with
leggings or tights in the buttocks area, can be prevented. As a
result, a knitted fabric can be produced, which comprises a nearly
constant transparency or opaqueness and a nice even overall
appearance without unwanted shimmer-through effects, especially
when being worn.
[0037] With the present invention, the at least one auxiliary
thread, such as at least one elastane thread, can be inserted into
the roving as a core thread, that is an auxiliary thread being
encased by fibers of the roving. This has advantages in the future
product regarding clothing physiology for the person doing the
wearing. The elastane then does not lie on the skin, as is the case
with a plating, but is covered by the fibred sheathing.
[0038] In an especially advantageous embodiment of the method
according to the invention, several drawn, strengthened rovings are
formed on separate roving drawing and strengthening units and are
supplied to the knitting machine by these separate knitting
systems, wherein the roving drawing and strengthening units are
controlled and operated independently of each other. Such an
embodiment has especially proven to be advantageous with the use on
small circular knitting machines.
[0039] In alternative embodiments of the method according to the
invention, two or more drawn, strengthened rovings can, however,
also be formed by a shared roving and strengthening unit and be
subsequently supplied to one or several separate knitting system(s)
of the knitting machine.
[0040] It is also possible for several roving drawing and
strengthening units to be combined to a module and to be jointly
electronically controlled. Hereby, either all roving drawing and
strengthening units or only individual roving drawing and
strengthening units can be combined to a module. A modular
operation of the roving drawing and strengthening units has proven
to be particularly advantageous with regard to small circular
knitting machines.
[0041] In advantageous embodiments of the method according to the
invention, one knitting system each of the knitting machine is
supplied with drawn, strengthened roving by at least two of the
roving drawing and strengthening units. Hereby, two, three, four or
more than four strands of drawn, strengthened roving can be
generated separately and be joined on the respective knitting
system, that is the respective loop forming spot. Hereby, it is
possible to include different rovings of different materials and/or
with different thread characteristics in the knit fabric to be
formed.
[0042] The object of the present invention is furthermore solved by
a device of the above-mentioned type, whereby the knitting machine
comprises a sinking depth adjustment device, which is coupled with
the pattern control for the knitting machine and the at least one
drive for the at least one driven roller of an outlet roller
pair.
[0043] By the pattern controlled drive of at least one driven
roller of the inlet roller pair, that is the first stretching
roller pair in thread transport direction, of the stretching unit
relative to the drive of at least one driven roller of the outlet
roller pair, that is the last roller pair in thread transport
direction, of the stretching unit, a drawn, strengthened roving
with varying thread thickness can be formed by the device according
to the invention, whose material use is ideally adjusted to the
loop structure to be formed on the knitting machine.
[0044] For this, the knitting machine is coupled with a roving
drawing and strengthening unit, which comprises at least one
stretching unit with at least two clamping roller pairs
successively arranged in thread transport direction, a spinning
nozzle device provided downstream in thread transport direction and
preferably, but not necessarily, a clamping roller pair limiting
the strengthening segment of the spinning nozzle device.
[0045] For producing the drawn, strengthened roving, the first
clamping roller pair of the stretching unit in thread transport
direction is supplied with a sliver in form of a fiber bundle that
has not been strengthened, which is stretched by the individual
stretching roller pairs and strengthened by means of the spinning
nozzle device. The drawn, strengthened roving can obtain additional
stability by the successively arranged clamping roller pair.
[0046] With the device according to the invention, at least one
roller each of the respective stretching roller pair is driven by a
drive, wherein both rollers can also be driven. A change in thread
thickness is particularly achieved by varying the rotation speed of
the inlet roller pair relative to the outlet roller pair of the
stretching unit.
[0047] The spinning nozzle device being successively arranged to
the stretching unit in thread transport direction preferably
comprises two self-conveying spinning nozzles, whereby the
transport of the drawn roving takes place through an air current of
the spinning nozzles directed towards the working direction.
Advantageously, both spinning nozzles are successively arranged in
thread conveying direction, wherein they are working pneumatically
and comprise a rotary current opposing one another.
[0048] The clamping roller pair being preferably arranged
successively to the spinning nozzle device in thread transport
direction, can also be coupled or couplable with a drive, by which
at least one clamping roller of the clamping roller pair is driven.
By leading the drawn, strengthened roving through the clamping
roller pair, the drawn, strengthened roving obtains additional
stability and strength, whereby the drawn and, after the spinning
nozzle strengthening, clamped roving can be easily transported to
the knitting machine even across a relatively long distance without
the only temporarily strengthened roving disintegrating during that
transport. By that way of coupling of spinning device and knitting
machine, especially soft knitted fabrics can be produced very
efficiently, space-saving and at comparatively low costs.
[0049] In an especially preferred embodiment of the device
according to the invention, the knitting machine comprises a
sinking depth adjustment device which is coupled to the pattern
control for the knitting machine.
[0050] The loop size to be knit can advantageously be varied by
means of the sinking depth adjustment device. The coupling of the
sinking depth adjustment device with the pattern control of the
knitting machine facilitates the loop size to be changed depending
on a pattern to be knit. Depending on the loop size to be produced,
a loop-forming needle is more or less driven out by means of the
sinking depth adjustment device.
[0051] Especially in combination with an adjustment of the thread
thickness, knitted fabrics, such as leggings or tights, can thus be
produced, which comprise a nearly identical level of transparency
or opaqueness, even when being worn. Hereby, an unsightly
show-through of skin and/or underwear due to an increased
stretching of the knitted fabric, for example in the buttocks area
of a female or male wearer, can be prevented. Expediently, the
loops are hereby formed larger in the areas, in which the knitted
fabrics are exposed to higher stretches, for example in the
buttocks area of a female or male wearer, wherein the thread
thickness of the knitted fabric is increased at the same time. For
forming an especially transparent knitted fabric, the thread
thickness can, however, also be reduced with increasing loop size.
The adjustment of the thread thickness can also take place
according to pattern.
[0052] In an advantageous embodiment of the device according to the
invention, the device comprises a measuring device for determining
a thread tension of a drawn, strengthened roving exiting the roving
drawing and strengthening unit. By means of the measuring device it
can be ensured that the drawn, strengthened roving is supplied to
the respective knitting spot of the knitting machine with constant
thread tension, whereby the drawn, strengthened roving can be
processed especially suitably and a knitted fabric with high
quality can be produced at the same time.
[0053] The measuring device can furthermore also be used for
determining a thread transport speed or another process parameter.
Advantageously, the spinning and/or knitting process is controlled
by means of the data determined by the measuring device, wherein
hereby one or several process parameters such as the rotation speed
of one or several stretching roller pairs can be adjusted.
[0054] In a preferred embodiment of the device according to the
invention, the device comprises at least one auxiliary thread
supply device connected to the stretching unit and controllable by
the pattern control for the knitting machine and/or depending on
the stretching characteristics of an auxiliary thread suppliable to
the stretching unit. By inserting an auxiliary thread into the
drawn, strengthened roving, it obtains an additional strength and
stability. Furthermore, stretching characteristics of the drawn,
strengthened roving can, for example, be influenced by the
auxiliary thread.
[0055] Advantageously, the auxiliary thread supply device comprises
a discharge realized by the outlet roller pair of the stretching
unit, that is the last roller pair in thread transport direction,
whereby the auxiliary thread can be received by the last stretching
roller pair and bound into the drawn thread. By supplying the
auxiliary thread only during the main drawing, the auxiliary thread
only runs through one clamping spot of the stretching unit. The
speed of the auxiliary thread supply device can thereby be ideally
adjusted to the rotation speed of the last stretching unit roller
pair and/or the pattern control of the knitting machine.
Furthermore, the auxiliary thread supply device can also be
controlled depending on the stretching characteristics of the
auxiliary thread.
[0056] Depending on the application, the auxiliary thread can be
formed elastic or inelastic. By supplying an auxiliary thread to
the drawn, strengthened roving, a core-sheath thread is preferably
formed, in which the core is formed by the auxiliary thread. In
alternative embodiments of the device according to the invention,
more than one auxiliary thread, for example two or three auxiliary
threads can be supplied to the drawn, strengthened roving.
[0057] By forming the drawn, strengthened roving as a core-sheath
thread, an unsightly shimmer-through effect of the produced knitted
fabric, such as a leggings or a tight, can advantageously be
prevented when the knitted fabric is stretched. Furthermore, a
shimmer-through effect can also be prevented by enlarging the loops
in combination with the increase of the thread thickness in areas
of high levels of stretching.
[0058] It has furthermore also proven to be especially advantageous
if at least two separate roving drawing and strengthening units
each, being independent of each other with regard to control, are
assigned to knitting systems of the knitting machine. Such an
embodiment has proven to be especially advantageous with regard to
the use with a small circular knitting machine.
[0059] However, in alternative embodiments of the device according
to the invention, several of the roving drawing and strengthening
units can also be combined to a module and be coupled with regard
to control. Such an application is to be considered as
advantageous, particularly with regard to the usage with large
circular knitting machine. Depending on the application, all or
only individual roving drawing and strengthening units can herein
be coupled with regard to control.
[0060] The object of the present invention is furthermore solved by
a knitted fabric of the above-mentioned type in which the thread
thickness of the drawn, strengthened roving is formed depending on
the respective loop size of the knitted fabric, wherein the thread
thickness increases with increasing loop size and the thread
thickness decreases with decreasing loop size.
[0061] By the pattern-controlled variation of the thread thickness,
the material usage can be ideally adjusted to the loop structure of
the knitted fabric. With the knitted fabric according to the
invention, the thread thickness of the drawn, strengthened roving
used for its production is furthermore formed depending on the
respective loop size of the knitted fabric, wherein the thread
thickness increases with increasing loop size and the thread
thickness decreases with decreasing loop size.
[0062] Especially preferably, the knitted fabric is a seamless,
circularly knitted knitted fabric with changing diameter and yet
constant opaqueness. Thus, the knitted fabric can for example be a
stocking, whose diameter increases from bottom to top in the calf
area, whereby the loop size increases from bottom to top in this
calf area and yet the opaqueness remains the same, since, according
to the invention, both more as well as thicker thread is supplied
to the knitting spot when knitting this calf area from bottom to
top, that is with loops increasing in size. The same applies vice
versa when knitting this calf area from top to bottom, where both
less as well as thinner thread is supplied to the knitting spot
with loops decreasing in size. The knitted fabric according to the
invention is thereby formed in such a way that it constantly
comprises the same transparency or opaqueness in a stretched or
worn state. In alternative embodiments of the knitted fabric
according to the invention, the thread thickness can, however, also
decrease with increasing loop size so that apart from especially
opaque, especially transparent areas can be produced.
[0063] The knitted fabric can be a knitted fabric comprising a
pattern.
[0064] Preferred embodiments of the present invention, their
structure, function and advantages are explained in more detail by
the following figures, wherein
[0065] FIG. 1 schematically shows a section of a drawn roving with
varying thread thickness formable as an intermediate product in an
embodiment of the method according to the invention in a side
view;
[0066] FIG. 2 schematically shows a possible embodiment of a device
according to the invention in a cut side view; and
[0067] FIG. 3 schematically shows another possible embodiment of a
device according to the invention in a cut side view.
[0068] FIG. 1 schematically shows a section of a drawn roving 4b
formable as an intermediate product of an embodiment of the method
according to the invention in a side view, wherein the roving 4b
comprises a length l in the shown example.
[0069] The roving section of the roving 4b shown in FIG. 1
comprises three areas 41, 41', 42, which are characterized by
different thread thicknesses d, d'. As depicted in FIG. 1, the
roving 4b comprises a larger thread thickness d' in the area 42
than in the areas 41, 41'. Hereby, thread thickness d, d' is
adjusted to a pattern to be knit on the knitting machine, to which
the roving 4b is supplied in a temporarily strengthened form as a
drawn, strengthened roving. The thread thickness d, d' and the
length of the areas in which the roving 4b comprises a larger or
smaller diameter, are thereby formed according to pattern. In
contrast to the depiction in FIG. 1, the roving 4b can hereby also
comprise a constant thread thickness d, d' over a long distance.
The thread thickness d, d' can also vary at very short distances.
The areas 41, 41', 42, in which the thread thickness d, d' changes,
can regularly recur or be formed irregularly according to
pattern.
[0070] The drawn roving 4b consists of individual fibers 40, which
encompass an auxiliary thread not visible here. Depending on the
application, the auxiliary thread can be formed elastic or
inelastic. A drawn roving, which does not comprise an auxiliary
thread or more than one auxiliary thread, can also be formed.
[0071] FIG. 2 schematically shows an embodiment of an embodiment of
a device 1 according to the invention in a cut side view, wherein
the same reference signs as in FIG. 1 describe the same component
and it is being referred to the above description in this
regard.
[0072] The device 1 shown in FIG. 2 comprises a knitting machine 2
as well as a roving drawing and strengthening unit 10 coupled with
the knitting machine 2.
[0073] The roving drawing and strengthening unit 10 comprises a
stretching unit 5, a spinning nozzle device 6 provided downstream
of the stretching unit 5 in a thread transport direction A and, in
the shown embodiment, a clamping roller pair 7 subsequent to the to
the spinning nozzle device 6 in the thread transport direction
A.
[0074] In the embodiment shown in FIG. 2, the stretching unit 5
comprises three stretching roller pairs 51, 52, 53 successively
arranged in the thread transport direction A, provided at distances
561, 562 to each other. In alternative embodiments, the device 1
can, however, also comprise only two stretching roller pairs 51, 53
or more than three stretching roller pairs 51, 52, 53. The
stretching roller pairs 51, 52, 53 are in turn formed by two
rollers 511, 512, 521, 522, 531, 532, respectively.
[0075] For producing a drawn, strengthened roving 4d, a sliver 4a
in form a fiber bundle that has not been strengthened, is supplied
to the first stretching roller pair 51 of the stretching unit 5 in
thread transport direction A, the inlet roller pair. In the shown
embodiment, the sliver 4a is provided by a roving supply unit 3,
which comprises a flyer bobbin 31 and is led to the inlet roller
pair 51.
[0076] In the stretching unit 5, the sliver 4a is stretched by
means of the stretching roller pairs 51, 52, 53. For this, one
roller 511, 521, 531 each of the respective stretching roller pair
51, 52, 53 is coupled with a drive 8, 8', 8'', which drives the
respective roller 511, 521, 531.
[0077] As shown in FIG. 2, the rollers 512, 522, 532 of the
respective stretching roller pair 51, 52, 53 which are not driven,
are pressed against the driven rollers 511, 521, 531 by means of a
stretching unit pressure arm 54 using springs 541 in the exemplary
shown device 1 according to the invention. Hereby, the rollers 512,
522, 532 are mounted in such a way that they can rotate in opposite
direction to the rollers 511, 521, 531.
[0078] For producing the drawn roving 4b with thread thickness d,
d' adjusted to the respective loop size, the drives 8, 8', 8'' are
coupled with a pattern control 9, wherein the rotation speed
x.sub.1 of the drive 8 of the roller 511 of the inlet roller pair
51 is particularly controlled relative to the rotation speed
x.sub.3 of the outlet roller pair 53 depending on a pattern to be
knit by the knitting machine 2 by changing the rotation speed
x.sub.1 of the inlet roller pair 51 in the shown example, wherein
the rotation speed x.sub.2 of the stretching roller pair 52 follows
that of the stretching roller pair 51 with a predefined or
selectable transmission ratio and the rotation speed x.sub.3 of the
stretching roller pair 53 is kept constant.
[0079] In order to be able to influence the loop size to be knit as
well, the pattern control 9 is furthermore coupled with a
schematically depicted sinking depth adjustment device 91 of the
knitting machine 2. Hereby, the process is advantageously
controlled in such a way that the thread thickness d' increases
with increasing loop size and the thread thickness d also decreases
with decreasing loops so that knitted fabrics such as leggings or
tights can be produced, which comprise a nearly constant
transparency or opaqueness even when being worn, whereby an
unsightly show-through on spots which are potentially more
stretched than others, can be prevented. In alternative variants,
the process can, however, also be controlled in such a way that the
thread thickness d, d' decreases with increasing loop size and vice
versa. Accordingly, particularly transparent areas in the knitted
fabric can be formed.
[0080] The drawn roving 4b exiting the stretching unit 5
subsequently enters a spinning nozzle device 6. In the spinning
nozzle device 6, a rotation of the drawn roving 4b by means of air
jets takes place. The spinning nozzle device 6 thereby consists of
two successively arranged spinning nozzles 61, 62 which are air
twirling nozzles. The air currents generated by the two spinning
nozzles 61, 62 comprise opposing rotation directions B, C so that a
false twist is formed.
[0081] In the shown embodiment, a clamping roller pair 7 is
provided subsequent to the spinning nozzle device 6 in the thread
transport direction A, which comprises two clamping rollers 71, 72
being rotatable in opposite directions to each other. The drawn,
strengthened roving 4c exiting the spinning nozzle device 6, is led
through the clamping rollers 71, 72 pressed against each other, so
that on the one hand a passage and on the other hand a clamping
spot for the roving 4c is formed. Hereby, the clamping spot limits
the fiber strengthening segment after the spinning nozzle device 6.
The drawn, strengthened roving 4d exits the clamping roller pair,
which is subsequently directly supplied to the knitting machine
2.
[0082] In the embodiment of the device 1' according to the
invention depicted in FIG. 3, an inelastic auxiliary thread 22 is
supplied to the roving 4b by means of an auxiliary thread supply
device 220, which serves for increasing the strength of the drawn,
strengthened roving 4d. The inelastic auxiliary thread 22 is
thereby drawn off a spool 24 by an auxiliary thread clamping roller
pair 23, in the shown embodiment supplied to the stretching unit 5
via a thread guiding tube 26 and integrated into the roving 4b. In
the shown example, the inelastic auxiliary thread 22 is supplied to
the last stretching roller pair of the stretching unit 5 in the
thread transport direction A, that is the outlet roller pair 53,
whereby the thread supply speed v.sub.4 of the auxiliary thread 22
thus only needs to be adjusted to the rotation speed x.sub.3 of the
outlet roller pair 53.
[0083] The thread tension of the inelastic auxiliary thread 22 can
be checked by means of a thread tension measuring device 43
provided between the auxiliary thread clamping roller pair 23 and
the stretching unit 5. Especially with regard to the quality of the
produced knitted fabric as well as the execution of the knitting
process, it has proven to be advantageous if the device 1, 1'
comprises the thread tension measuring device 43 for determining a
thread tension of a roving 4d exiting the auxiliary thread clamping
roller pair 23 so that the roving 4d can be supplied to the
knitting machine 2 with constant thread tension.
[0084] In the embodiment of FIG. 3, an elastic auxiliary thread 25,
for example an elastane thread, is furthermore supplied to the
roving 4d by means of an additional auxiliary thread supply device
210. This elastic auxiliary thread 25 is led over a thread tension
measuring device 42 by means of a circumferential drive with the
possibility of setting the exact auxiliary thread tension and then
supplied to the stretching roller pair 53. In the shown embodiment,
the elastic auxiliary thread 25, along with the inelastic auxiliary
thread 22, is supplied to the stretching unit 5 via the thread
guiding tube 26 with a thread supply speed v.sub.5.
[0085] It is also advantageous if the auxiliary thread supply
device 220, 210 is controlled by means of the pattern control
and/or the stretching characteristics of the auxiliary thread 22,
25. Particularly if the auxiliary thread supply device 220, 210 is
coupled with the pattern control, the auxiliary thread 23, 25 can
be inserted according to pattern. Depending on the individual
application, it can be chosen whether an elastic auxiliary thread
25 or an inelastic auxiliary thread 22 is used. Depending on the
individual application, it can also be decided whether only one
auxiliary thread 22 or 25 or, if necessary, several auxiliary
threads 22, 25 are supplied to the roving 4b. Insofar as several
auxiliary threads 22, 25 are inserted, they should, as shown in
FIG. 3, be supplied to the stretching unit 5 by means of separate
auxiliary thread supply devices 220, 210 with regard to potentially
differing auxiliary thread tensions. In alternative embodiments,
however, several auxiliary threads can also be supplied by means of
a single auxiliary thread supply device.
[0086] Advantageously, knitted fabrics with loops of different
sizes can easily be produced with the device 1, 1' according to the
invention, whereby very transparent or opaque knitted fabrics can
be provided with regard to the thread thickness d, d' variable
depending on the loop size. For changing the loop size, the thread
supply speed from the roving drawing and strengthening unit to the
knitting machine is varied which is realized by changing the
rotation speed of the last stretching roller pair in thread
transport direction A, that is the outlet roller pair 53.
[0087] With the present invention, it is also possible to produce
different compression zones in one knit fabric tube by changing the
loop size.
[0088] With the present invention, a knitted fabric with differing
technical characteristics can furthermore be produced by changing
the thread thickness or thread count. When changing the thread
thickness, the fiber content in the finished thread is changed in
the method according to the invention. During the process, the
auxiliary thread fineness is set. Thus, conductive auxiliary
threads can for example be sheathed with a different number of
fibers which generates partially different characteristics in the
respectively produced knitted fabric.
[0089] With the present invention it is possible to influence the
rub resistance of a knitted fabric by adjusting the loop size and
the thread count. The present invention can furthermore be used to
influence the functional characteristics of a knitted fabric such
as their moisture transport characteristics and/or heat retention
properties. Furthermore, the thermal conductivity and/or the
thermal isolating characteristics of knitted fabric can furthermore
also or alternatively be influenced by means of the present
invention.
* * * * *