U.S. patent application number 15/736482 was filed with the patent office on 2018-06-28 for weaving machine.
The applicant listed for this patent is Lindauer DORNIER Gesellschaft mit beschraenkter Haftung. Invention is credited to Andreas RUTZ.
Application Number | 20180179675 15/736482 |
Document ID | / |
Family ID | 56133313 |
Filed Date | 2018-06-28 |
United States Patent
Application |
20180179675 |
Kind Code |
A1 |
RUTZ; Andreas |
June 28, 2018 |
Weaving Machine
Abstract
A weaving machine with a shedding arrangement (10, 25) for
forming loom sheds (3) between warp threads (1) drawn off from a
thread supply (9), a weft insertion arrangement (20) for inserting
weft threads (2) in the form of tapes into the formed loom sheds
(3), and a drawing-off arrangement (30) for drawing off the woven
fabric (4) formed by warp and weft threads (1, 2) after a weft
thread insertion. The weaving machine encompasses a measuring
arrangement (40) for detecting geometric parameters, especially the
width, of a weft thread (2) before its insertion in the loom shed
(3), as well as an evaluating arrangement (45) for evaluating the
detected measurement results. A control arrangement (50) for
controlling a motion of the woven fabric (4), including the
drawing-off, based on the evaluated measurement results, is present
on the weaving machine and is connected with the drawing-off
arrangement (30).
Inventors: |
RUTZ; Andreas; (Lindau,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lindauer DORNIER Gesellschaft mit beschraenkter Haftung |
Lindau |
|
DE |
|
|
Family ID: |
56133313 |
Appl. No.: |
15/736482 |
Filed: |
June 22, 2016 |
PCT Filed: |
June 22, 2016 |
PCT NO: |
PCT/EP2016/064457 |
371 Date: |
December 14, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D03D 47/12 20130101;
D03J 1/223 20130101; D03D 2700/1472 20130101; D03J 1/007 20130101;
D03D 41/008 20130101; D03D 49/20 20130101; D03J 2700/06 20130101;
D03D 47/34 20130101; D03D 15/0088 20130101 |
International
Class: |
D03D 47/12 20060101
D03D047/12; D03J 1/00 20060101 D03J001/00; D03D 15/00 20060101
D03D015/00; D03D 47/34 20060101 D03D047/34; D03D 49/20 20060101
D03D049/20 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 13, 2015 |
DE |
10 2015 213 015.0 |
Claims
1. A weaving machine comprising: a shedding arrangement (10) for
forming loom sheds (3) between warp threads (1) pulled off from a
thread supply (9), a weft insertion arrangement (20) for inserting
weft threads (2) in the form of tapes into the formed loom sheds
(3), a drawing-off arrangement (30) for drawing-off the woven
fabric (4) formed of warp and weft threads (1, 2) after a weft
thread insertion, a measuring arrangement (40) for detecting
geometric parameters, especially the width, of a weft thread (2)
before its insertion into the formed loom shed (3), an evaluating
arrangement (45) for evaluating the detected measurement results,
and a control arrangement (50) connected with the drawing-off
arrangement (30) for controlling a motion of the woven fabric (4)
including the drawing-off based on the evaluated measurement
results.
2. The weaving machine according to claim 1, characterized in that
the measuring arrangement (10) is based on at least one of the
following measuring methods: an optical measuring method, wherein
the measuring arrangement (10) is preferably embodied in the form
of an optical precision micrometer, and/or an acoustic measuring
method, especially operating by means of ultrasound, and/or a
tactile measuring method.
3. The weaving machine according to claim 1, characterized in that
the measuring arrangement (40) is embodied and configured to
continuously detect the width of a weft thread (2).
4. The weaving machine according to claim 1, characterized in that
the measuring arrangement (40) is arranged in such a manner so that
it is able to measure the width values of the weft thread (2) that
is next to be inserted or of a weft thread (2) during its
insertion, wherein the measurement can be carried out on the moving
weft thread (2).
5. The weaving machine according to claim 1, characterized in that
the measuring arrangement (40) is arranged on the insertion side of
the weft thread (2).
6. The weaving machine according to claim 1, characterized in that
the evaluating arrangement (45) is embodied to calculate the
minimum width and/or the maximum width of a measured weft thread
(2).
7. The weaving machine according to claim 1, characterized in that
the evaluating arrangement (45) is embodied to calculate a mixed
value on the basis of several measured values of a weft thread (2)
to be inserted or of a weft thread (2) during its insertion,
especially its width average value.
8. The weaving machine according to claim 1, characterized in that
the drawing-off arrangement (30) encompasses a drivable drawing-off
roll (32).
9. The weaving machine according to claim 8, characterized in that
the drawing-off arrangement (30) further encompasses an
oscillatingly or swingingly drivable deflecting roll (34) that is
arranged in the fabric path between the loom shed (3) and the
drivable drawing-off roll (32).
10. The weaving machine according to claim 1, characterized in that
the drawing-off arrangement (30) comprises a fabric clamp (36), and
in that the drawing-off arrangement (30) is actuatable in such a
manner by the control arrangement (50) so that the woven fabric (4)
together with the fabric clamp (36) is moved back contrary to the
weaving direction by a prescribed path distance (38), which is
preferably determined based on the evaluated measurement results,
preferably until contacting against the previously inserted weft
thread (2).
11. The weaving machine according to claim 1, characterized in that
by controlling the drawing-off arrangement (30) the woven fabric
(4) can be positioned before the next weft insertion in such a
manner so that the weft thread (2) is insertable according to one
of the following manners: over its entire weft length without any
gap formation with the fabric rear edge (5), or over its entire
weft length with a gap relative to the fabric rear edge (5), or
over its entire weft length while forming one or more gaps with the
fabric rear edge (5), and namely with area-wise contacting on the
fabric rear edge (5) and/or overlapping with the fabric rear edge
(5).
12. The weaving machine according to claim 1, characterized in that
the evaluating arrangement (45) and/or the control arrangement (50)
are embodied at least to stop the further weft insertion and the
drawing-off arrangement (30) upon exceeding and/or falling below
prescribed weft thread widths and/or to output a prescribed
signal.
13. The weaving machine according to claim 1, characterized in that
the evaluating arrangement (45) is embodied to recognize faults of
the weft thread (2) to be inserted, for example holes and/or
splices, and to trigger a prescribed action of the weaving machine.
Description
[0001] The present invention relates to a weaving machine for
processing tape-shaped weft threads--that is to say relatively wide
and flat band-shaped textile units, according to the preamble of
the claim 1. In this regard, the shedding arrangement or device,
the weft insertion arrangement or device, as well as the essential
parts of a drawing-off arrangement or device are known devices on
weaving machines. The construction of a woven fabric of warp and
weft threads in the form of tapes, for example of carbon or glass
fiber tapes, is also known for some time. Such tapes are produced,
for example, of carbon ravings, which are solidified with an
impregnation in the spread-out, parallelized condition. The width
of such tapes amounts to e.g. a few millimeters to more than one
centimeter. Woven fabrics of carbon tapes are utilized, for
example, for lightweight construction applications in the aircraft
or motor vehicle field.
[0002] Herein both the terms "weft thread" as well as "tape" are
used, because the invention relates to the insertion of weft
threads in the form of tapes.
[0003] Any desired threads can be used for the warp threads, for
example also wide and/or thick threads, preferably however threads
in the form of tapes.
[0004] For the insertion of weft threads in the form of tapes into
an opened loom shed formed by lifted and lowered warp threads,
gripping and clamping devices are provided, which grip or grasp the
forward tape end either from the insertion side or coming from the
opposite side (through the open loom shed), and pull it through the
loom shed.
[0005] In the embodiment according to EP 1 838 911 A1, the inserted
tape is clamped in thread clamps at both sides of the loom shed and
is transported against the rear fabric edge or against the binding
or interlacing point of the woven fabric by movement of these
thread clamps by a fixedly prescribed path distance in the weaving
or drawing-off direction (machine direction). Because only the
outer ends of the tape-shaped weft thread are grasped and
transported in the direction toward the fabric rear edge, in the
method described in the EP 1 838 911 A1, in principle the danger
exists that the tapes are brought against the fabric rear edge not
absolutely straight or linearly over the weaving width, but rather
that the area of the weft tapes lying at the center of the woven
fabric forms a curve in the fabric plane. In the weaving machine
according to EP 1 838 911 A1, it is attempted to reduce this effect
in that the warp threads extend through the weaving machine in the
vertical direction, whereby the weft tapes are similarly arranged
with their width direction extending vertically and are inserted
into the loom shed above the already existing fabric rear edge. The
transport of the inserted tape-shaped weft treads to the fabric
rear edge is thus supported by the gravity acting on the tapes.
[0006] The DE 10 2011 009 765 B3 discloses an apparatus and a
method in which the woven fabric is moved back in the direction
toward the just-inserted tape-shaped weft thread by a prescribed
path distance contrary to the weaving direction, until the front
longitudinal edge of the tape and the rear fabric edge lie in
contact against one another.
[0007] In both cases, after the weft insertion, there follows a
crossing-over of the warp threads with the weft threads by closing
and opening the loom shed with the aid of the shed forming
arrangement. The woven fabric which is now lengthened by one tape
width is moved further or drawn off a small distance, in order to
achieve space for the next weft insertion.
[0008] It can be disadvantageous in thusly produced woven fabrics,
that after the weft insertion the subsequent positioning of the
tape-shaped weft threads with respect to the fabric rear edge takes
place independently of the actual momentary geometry of the
tape.
[0009] In practice, tapes with widths of for example 20 mm to 50 mm
also come into use. Such tapes have--caused by the manner of
production--a certain--no longer negligible--spreading or
scattering in the width over the length of the tape.
[0010] For certain application purposes it can also be
advantageous, to use tape-shaped weft threads with purposely
selected differing widths within one woven fabric in alternation or
in a prescribed sequence.
[0011] There are also woven fabrics in which a certain predefined
spacing distance shall remain between successive tape-shaped weft
threads. With a varying or fluctuating width of the tapes, the
danger exists that this spacing distance also does not uniformly
comprise the predefined value.
[0012] The EP 1 838 911 A1 discloses an apparatus with sensors that
measures the width of the tapes in the weaving operation. Dependent
on the measured width, special feed or supply devices for the warp
threads are actuated in such a manner so that the winding-up of the
woven fabric can take place in a tensionless manner or even with an
excess of warp threads. An exact positioning of the longitudinal
edge of the tape-shaped weft threads without spacing, or with a
prescribed spacing to the rear fabric edge dependent on different
widths of the tape-shaped weft threads, is thereby not
possible.
[0013] It is the object of the present invention to provide a
weaving machine in which the fabric formation through use of
tape-shaped weft threads can be adapted to various different
geometric parameters of the tapes, especially to various different
widths.
[0014] This object is achieved by the features of the claim 1. In
this solution, the advantages are especially seen in that the
actual width and especially the width fluctuations of the tapes to
be inserted into the woven fabric can be taken into consideration,
because the tape and the woven fabric can be moved toward one
another, on the basis of the evaluated measurement results, with a
varying--and not according to the prior art with a fixedly
prescribed--motion or distance feed advance. Thereby, for example,
a tighter or more-closed fabric appearance can be obtained, for
example in the case that the momentary width of the tape to be
inserted should be reduced.
[0015] Overall, through the invention, the flexibility for the weft
insertion is increased considerably, because on the basis of the
evaluated measurement results, commands for the weaving feed
advance can be given via the control arrangement to the drawing-off
arrangement, which commands take into consideration the respective
actual tape width.
[0016] Alternatively, but preferably in addition to the width
detection, the measuring arrangement is embodied for the detection
of other geometric measured values, for example of holes and/or
splices in the weft thread, whereby the latter arise due to
separations of individual or several filaments out of the tape
composite.
[0017] According to an advantageous embodiment of the invention,
the measuring arrangement is based on an optical measuring method.
In this regard, it can especially involve an optically scanned
measuring field which preferably extends over the width of the
tape. A corresponding measuring arrangement is, for example, an
optical precision micrometer.
[0018] According to an alternative, the measuring arrangement works
acoustically, especially with the aid of ultrasound. Depending on
the wave propagation of the ultrasound, a conclusion can be reached
about the width of the scanned tape.
[0019] Also conceivable is a line camera with combined pattern
recognition software.
[0020] A further measuring method is based, for example, on a
tactile--and thus not contactless--probing or scanning of the weft
thread (tape) to be inserted.
[0021] Especially preferably, the measuring arrangement is embodied
in such a manner so that the width of the weft thread to be
measured is continuously detected before and/or during its
insertion. In this manner, a continuous measurement is possible, in
which all fluctuations relating to the tape width can be detected.
Thereby, the corresponding evaluation possibilities are
considerably expanded.
[0022] The measuring arrangement according to the invention is
preferably arranged in such a manner so that it is able to measure
the width values of the next to be inserted and/or the momentarily
inserted weft thread, whereby the measurement can be carried out on
the moving weft thread over the entire length to be inserted.
Through this measurement, directly following after the weft
insertion on the basis of the evaluated measurement, the woven
fabric can be moved against this tape by a motion or path distance
dependent on the evaluation result.
[0023] Thereafter, the woven fabric including the previously
inserted tape is advanced in the warp direction. For these
transport processes, a drivable drawing-off roll and advantageously
also a woven fabric clamp are provided as part of the drawing-off
arrangement. The fabric clamp is advantageously arranged in the
area of the fabric rear edge extending in the weft direction, and
during the fabric's sliding displacement prevents a sliding
displacement of the tape-shaped weft threads last inserted into the
woven fabric.
[0024] In the case that the abovementioned relative motion of the
tape and the fabric toward one another is not carried out (for
example because the spacing distance between tape and fabric is
already as desired), the drawing-off arrangement can further move
or advance the fabric including the previously inserted tape
immediately in the drawing-off direction by a distance dependent on
the evaluation result.
[0025] For producing a reversing fabric sliding displacement it is
advantageous to provide an oscillating or swinging motion of
deflecting rolls intermediately positioned in the warp thread path
or in the fabric path, instead of a reversible rotation of the
drawing-off roll. In this case, the drawing-off arrangement
encompasses an oscillatingly or swingingly supported and reversibly
drivable deflecting roll that is arranged in the fabric path
between the loom shed or between the fabric clamp and the drivable
drawing-off roll.
[0026] Preferably the measuring arrangement is arranged on the
insertion side of the weft thread or tape, and in this regard is
advantageously oriented in the warp thread direction, i.e.
transversely or perpendicularly to the weft thread direction. Thus
the measuring arrangement can be accommodated also in a limited or
cramped space and is nonetheless in the position to reliably detect
the entire width of the weft threads.
[0027] Alternatively, the measuring arrangement is arranged below
and above the warp threads, and in this regard advantageously in
the area of that fabric longitudinal edge that is first crossed by
the tape during the weft insertion. In this manner, the tape that
is just now pulled through the loom shed can be measured with
regard to its width nearly over its entire length.
[0028] The evaluating arrangement is preferably embodied in such a
manner so that it is able to calculate the minimum width and/or the
maximum width of the weft thread to be inserted. These extreme
values can be determined in a simple manner from all detected
measurement data for one weft thread, in order to correspondingly
actuate the drawing-off arrangement depending on the desired fabric
image, for example for producing a desired constant spacing between
the respectively successive weft threads. For this, the maximum
width of the current weft thread is determined, and the fabric
transport in the forward direction (if applicable with previous
transport in the rearward or reverse direction toward the tape) is
adjusted corresponding to the desired spacing distance.
[0029] Alternatively or additionally, the evaluating arrangement is
advantageously embodied in such a manner so that it is able to
calculate a mixed value based on several measured values of a weft
thread to be inserted or that has been inserted, especially the
width average value thereof. With the use of this average value,
the drawing-off arrangement can be actuated in such a manner so
that a uniform optical weaving pattern with a spacing of the
current last-inserted weft thread or tape to the fabric rear edge,
is obtained, wherein this spacing is adapted to the said average
value. In this regard, this spacing can also be adjusted so that
the applicable weft thread lies against the fabric rear edge
corresponding to the determined mixed value, depending on the width
fluctuations of the tape and the contour of the rear fabric edge,
if applicable with gaps.
[0030] Alternatively to, or following on, a relative motion of the
last inserted weft thread and the fabric, before insertion of the
next weft thread, the fabric can be moved further by means of the
actuated drawing-off arrangement in such a manner so that the next
weft thread is inserted, over its entire weft length, without any
gap formation with the fabric rear edge or with a spacing distance
to the fabric rear edge.
[0031] In the presence of width fluctuations of the tape, fabric
images are also realizable in which the tapes with both of their
longitudinal edges contact against the neighboring tapes in certain
regions, while narrower tape sections form corresponding gaps.
[0032] Advantageously the evaluating arrangement and/or the control
arrangement are embodied and configured in such a manner at least
to stop the further weft insertion and the drawing-off arrangement
and/or to output a prescribed signal upon exceeding and/or falling
below prescribed weft thread widths. The evaluating unit and/or the
control arrangement are thus preferably in the position to stop the
weaving process based on determined extreme values with respect to
the tape width, and thereby to avoid a faulty production.
[0033] Comparably to this, the evaluating arrangement is preferably
embodied in such a manner so that it is able to recognize faults of
the weft to be inserted, for example holes and/or splices, in order
to trigger a prescribed action of the weaving machine in its such
case. Such an action can for example be the stopping of the weft
insertion arrangement and/or the outputting of a signal, for
example in order to summon machine operating personnel.
[0034] In the following the invention will be described in further
detail in connection with an example embodiment. It is shown
by:
[0035] FIG. 1 a schematic top plan view onto a weaving machine,
[0036] FIG. 2 a schematic view of the weaving machine according to
FIG. 1 from the supply side of the warp threads,
[0037] FIG. 3 a schematic cross-section through the weaving machine
according to FIGS. 1 and 2 with a view direction in the weft
direction.
[0038] In FIGS. 1, 2 and 3, a weaving machine for warp and weft
threads in the form of tapes is schematically illustrated. The
tapes consist, for example, of carbon and/or glass fibers. Such a
weaving machine is also termed a tape weaving machine. The
embodiment of the weaving machine described here can alternatively
also be used for such woven fabrics in which merely the weft
threads are present in the form of tapes, while the warp threads
are utilized in a typical thread form, preferably however in the
form of coarse, that is to say thick and/or wide threads.
[0039] Several warp threads 1 running next to one another are
provided in rotating supply bobbins 9 and are transported in the
warp direction 6 (also named the machine direction or the weaving
direction) to a shedding arrangement 10, 25. This encompasses
heddles, which are not shown in further detail, and through which
the warp threads 1 are threaded-through. The heddles are preferably
inserted or combined together in heald frames 25--schematically
illustrated as frames--and are alternately lifted or lowered with
the aid of a drive 11, so that the warp threads 1 guided through
the heddles form a loom shed 3 between themselves in a known way
and manner. When one half of the warp threads 1 are deflected in
their upper maximum position and the other half are deflected in
their lower maximum position, a weft thread 2 can be guided through
the thusly formed loom shed 3.
[0040] For supplying the weft thread 2, present as a tape, a supply
bobbin or spool 7 rotating about a rotation axis 8 is provided,
which supply bobbin 7 is located on one side of the weaving
machine. The warp threads 1 can alternatively, instead of the
supply bobbin 9, also be provided on a common supply arrangement,
e.g. a warp beam.
[0041] For insertion of a weft thread 2 into a loom shed 3, a weft
insertion arrangement or device 20 is provided, which encompasses a
drive 22, a gripper rod or rapier 24 connected with the drive 22,
and a gripper head 23 provided on the free end of the gripper rod
24. The gripper rod 24 is drivable by means of the drive 22 back
and forth through the opened sheds 3. Instead of a gripper rod 24
it is alternatively also possible to use a gripper band or tape,
which, however, under certain circumstances must be guided on its
path through the loom shed.
[0042] Before the weft insertion, first the weft thread 2 that has
been prepared or presented from the weft thread bobbin 7 is tightly
held in the area of its free end by means of a clamping and cutting
arrangement or device 21 that is only schematically illustrated,
whereupon the gripper head 23 drives or moves through the loom shed
3 and grasps and clamps this free end of the weft thread 2. On its
part, the clamping and cutting arrangement 21 lets go the free end
of the weft thread 2, so that the gripper head 23 can pull the weft
thread 2 through the loom shed 3. Then the loom shed 3 is closed in
that the warp threads 1 are moved downwards or upwards
respectively. Moreover, the clamping and cutting arrangement 21
clamps the weft thread 2 on the side of the weft thread bobbin 7
and separates the previously inserted weft thread 2 from the
endless weft thread 2 supplied from the weft thread bobbin 7.
[0043] In FIG. 2, the loom shed 3 is schematically illustrated from
the rear side of the weaving machine, which loom shed 3 is formed
by warp threads 1 that are alternately moved up and down, so that
weft thread 2 subsequently or followingly supplied from the weft
thread bobbin 7 can be conveyed through the loom shed 3. For
clamping and releasing, the clamping jaws of the gripper head 23
comprise a pivot point 29 that is only schematically indicated. Of
course, purely linear motions of the clamping jaws of the gripper
head 23 are also conceivable. Clamping and releasing of the
clamping jaws can occur, for example, with the aid of a mechanical
control arrangement that is arranged outside of the loom shed;
however pneumatic or electro-mechanical control arrangements are
also possible.
[0044] In an alternative that is not illustrated, the weft thread 2
is gripped by a gripper that is previously not driven or moved
through the loom shed in the direction of the weft thread, but
rather is arranged on the side of the weft thread bobbin, there
grasps the weft thread end, transports it through the loom shed,
lets go the weft thread, and then moves back in the direction of
the weft thread bobbin without the weft thread.
[0045] The inserted weft thread 2 is still to be bound onto the
woven fabric 4. For this purpose, before or during the closing of
the loom shed 3, the fabric rear edge or the binding or interlacing
point 5 with the woven fabric 4 is moved in the direction toward
the inserted weft thread 2. For this, the woven fabric 4 over its
entire width is pushed contrary to the warp direction 6 by a
rearward or reverse path distance 38 to the previously inserted
weft thread 2, until, for example, the fabric rear edge 5 lies in
contact on the longitudinal edge of the said weft thread 2.
Preferably in that regard, the woven fabric 4 is clamped by means
of a fabric clamp 36 driven by a drive 35 (see FIGS. 1 and 3).
Next, the clamping by the fabric clamp 36, which exists if
applicable, is released, and this clamp is pushed or advanced still
further contrary to the warp direction 6 so far that the fabric
clamp 36 can also grasp and clamp the said weft thread 2. Next the
fabric clamp 36 together with the clamped woven fabric 4 is moved
in the warp direction 6 by the forward path distance 39 so that the
next loom shed 3 can be formed.
[0046] The thereby constantly growing woven fabric 4 is rolled or
wound up on a drawing-off roll 32 that is rotationally driven by a
drive 31 about a rotation axis 33. In order to produce the forwards
and backwards motion of the woven fabric 4, in the present example
embodiment an oscillating or swinging motion of intermediately
arranged deflecting rolls 34, 37 is realized in the warp thread
path or course or in the woven fabric path or course. This
oscillating or swinging motion of the deflecting rolls 34, 37 is
presently realized actively with a reversing oscillating drive (not
illustrated in the figures) that synchronously moves both
deflecting rolls 34, 37.
[0047] The drawing-off roll 32 as well as the fabric clamp 36 and
if applicable the deflecting roll 34 are part of a drawing-off
arrangement or device 30, whereby the drives of these devices must
be exactly adapted to one another. This is carried out by a control
arrangement 50 (in this regard see below in connection with the
explanation of the invention).
[0048] The deflecting roll 34 is arranged in the fabric path
between the loom shed 3 and the drawing-off roll 32. The fabric
clamp 36 is also located in this area, and is preferably arranged
in the area of the fabric rear edge 5.
[0049] The optional deflecting roll 37 is arranged in the rear area
or region of the weaving machine between the heald frames 25 and
the supply bobbins 9.
[0050] In principle it is also possible to avoid an oscillating or
swinging motion of the deflecting rolls 34 and 37, whereby then the
forward and backward motion of the woven fabric 4 must be achieved
by corresponding control of the drive 31 for the drawing-off roll
32. For the compensation in the rear area of the machine, then e.g.
corresponding drives for the supply bobbins 9 would be
required.
[0051] It has now been found that especially the width of the weft
threads 2 fluctuates due to the production thereof, so that
non-uniform fabric appearances arise with fixedly prescribed path
distances 38 (for the reverse or reward motion) and 39 (for the
subsequent forward motion), which is not desirable for all
applications.
[0052] Therefore, according to the invention, a measuring
arrangement 40 for detecting geometric parameters, especially the
width, of the weft threads 2 before their insertion in the
respective formed loom shed 3 is provided. In the present example
embodiment, the measuring arrangement 40 is provided between the
weft thread bobbin 7 and the clamping and cutting arrangement 21
below the weft thread 2.
[0053] The measuring arrangement 40 presently is based on an
optical measuring principle and in this regard probes or scans the
weft thread 2. For example the measuring arrangement 40 can be
embodied as an optical precision micrometer. The optical signals
reflected back from the weft thread 2 are received by the measuring
arrangement 40. Alternatively or additionally, a receiver 41 (shown
in dashed lines in FIG. 2) is arranged above the weft thread 2. In
principle, measuring arrangements 40 for detecting geometric
parameters of an elongated surfacially shaped structure, such as
that of a tape, are known and do not need to be explained in
further detail here.
[0054] The measurement values or measurement results detected by
the measuring arrangement 40 are presently provided further to an
evaluating arrangement or device 45, which evaluates the
measurement results and provides the results of the evaluation
(which are presently also referred to as evaluated measurement
results) further to a control arrangement or device 50. The control
arrangement 50 is connected with the drawing-off arrangement 30 and
controls the motions of the woven fabric 4 in that it controls the
oscillating or swinging back and forth motion of the deflecting
rolls 34, 37 and if applicable of the fabric clamp 36 and also
controls the winding or rolling up of the woven fabric 4 onto the
drawing-off roll 32. In this regard, the control arrangement 50 is
connected with the drive for the oscillating motion of the
deflecting rolls 34, 37 and if applicable with the drive 35 that
drives the fabric clamp 36, as well as also with the drive 31 that
drives the drawing-off roll 32.
[0055] Generally it is noted that the signal and control lines in
FIGS. 1 and 2 are illustrated with dash-dotted lines.
[0056] The measuring arrangement 40 is preferably embodied for the
continuous measurement of the geometry of the weft thread 2.
Thereby all deviations from the ideal form or shape (width, holes,
lateral chipping or spalling) are reliably detected. In this
regard, the measurement is preferably carried out when the weft
thread 2 is guided past the measuring arrangement 40.
[0057] In this regard, the continuous measurement suitably also
encompasses the measurement values of that section of the weft
thread 2 located in the measurement area, which belongs to the weft
thread 2 that is to be inserted next), while this is still clamped
by the clamping and cutting arrangement 21. The measured values in
this regard are preferably also taken into consideration by the
evaluating arrangement 45, so that measured values are present over
the entire length of the next to-be-inserted weft thread 2.
[0058] The evaluating arrangement 45 is preferably embodied in such
a manner so that it is able to calculate the minimum width and/or
the maximum width of the weft thread to be inserted. Alternatively
or additionally, the evaluating arrangement 45 can calculate, for
example, a mixed value based on several measured values of a weft
thread 2, especially the width average value thereof.
[0059] Based on the evaluations of the evaluation arrangement 45,
the drive of the deflecting rolls 34, 37 and if applicable the
drive 35 of the fabric clamp 36 can be actuated by the control
arrangement 50, in order to drive or move the woven fabric 4 back
by an adapted path distance 38 contrary to the warp direction 6
based on the determined weft thread width (for example based on the
determined extreme values relating to the weft thread width or a
mixed value). The subsequent counter motion 39 of the woven fabric
4 in the warp direction 6 is also correspondingly adapted, so that
the forward path distance 39 just like the rearward path distance
38 varies depending on the evaluation. Contrary to the prior art,
thus no constant prescribed motions of the woven fabric 4 are
provided after each weft insertion, but rather motions that are
adapted to the actual width of the respective previously inserted
weft thread. Also the winding or rolling-up of the woven fabric 4
onto the drawing-off roll 32 as well as the oscillating motion of
the deflecting roll 34 between drawing-off roll 32 and fabric clamp
36 are controlled dependent on the actual current determined weft
thread width.
[0060] The drives with which the various different motions of the
previously described structural assemblies of the weaving machine
are controlled are preferably embodied as individually actuatable
motors or as motor-transmission combinations, which preferably
receive their signals from the control arrangement 50. These drives
are embodied so that they--as needed--carry out reversing pivoting,
rotating or linear motions.
[0061] The control arrangement 50 can actuate the drawing-off
arrangement 30, especially the deflecting roll 34 and the fabric
clamp 36, in such a manner so that the woven fabric 4 is positioned
in the most varied manner before the next weft insertion. For
example in this regard it is possible that the woven fabric
4--through continuous consideration of the width of the respective
weft threads 2--comprises no gaps. Alternatively, the woven fabric
4 is positioned before the respective next weft thread insertion in
such a manner so that a spacing distance of each weft thread 2
relative to the fabric rear edge 5 is always present, so that a
fabric appearance with gaps between successive weft threads 2
results. Corresponding to a further alternative, the drawing-off
arrangement 30 is controlled in such a manner so that along the
currently inserted weft thread 2 that fluctuates in its width, one
or more gaps are formed with the fabric rear edge 5, whereby in the
remaining areas this weft thread 2 contacts against the fabric rear
edge 5 and/or even forms overlapping regions with the fabric rear
edge 5.
[0062] Mixed forms of the abovementioned fabric appearances are
also possible without difficulty through corresponding adjustment
of the control arrangement 50.
[0063] The evaluating arrangement 45 and/or the control arrangement
50 are preferably embodied and configured in such a manner so as at
least to stop the further weft insertion as well as the drawing-off
arrangement 30 in the event of exceeding and/or falling below
prescribed weft thread widths, and/or to output a prescribed
signal. Similarly it is advantageous if the evaluating arrangement
45 can recognize faults of the weft thread 2 to be inserted, for
example holes and/or splices, and can trigger a prescribed action
of the weaving machine, especially via the control unit 50.
[0064] The present invention is not limited to the illustrated and
described example embodiments. Derivations or modifications within
the scope of the patent claims are also possible just like a
combination of the features, even when these are illustrated and
described in different example embodiments.
REFERENCE NUMBER LIST
[0065] 1 warp threads
[0066] 2 weft threads (tapes)
[0067] 3 loom shed
[0068] 4 woven fabric
[0069] 5 fabric rear edge
[0070] 6 warp thread direction
[0071] 7 weft thread bobbin
[0072] 8 rotation axis
[0073] 9 supply bobbins
[0074] 10 shedding arrangement
[0075] 11 drive for shedding arrangement
[0076] 20 weft insertion arrangement
[0077] 21 clamping and cutting arrangement
[0078] 22 drive for gripper
[0079] 23 gripper head
[0080] 24 gripper rod
[0081] 25 heald frame
[0082] 29 pivot point
[0083] 30 drawing-off arrangement
[0084] 31 drive for drawing-off roll
[0085] 32 drawing-off roll
[0086] 33 rotation axis
[0087] 34 deflecting roll
[0088] 35 drive for fabric clamp
[0089] 36 fabric clamp
[0090] 37 deflecting roll
[0091] 38 rearward path distance
[0092] 39 forward path distance
[0093] 40 measuring arrangement
[0094] 41 receiver
[0095] 45 evaluating arrangement
[0096] 50 control arrangement
* * * * *