U.S. patent application number 09/988369 was filed with the patent office on 2002-05-23 for apparatus for measuring the tension of sliver running in a draw frame.
Invention is credited to Breuer, Achim.
Application Number | 20020059700 09/988369 |
Document ID | / |
Family ID | 7664083 |
Filed Date | 2002-05-23 |
United States Patent
Application |
20020059700 |
Kind Code |
A1 |
Breuer, Achim |
May 23, 2002 |
Apparatus for measuring the tension of sliver running in a draw
frame
Abstract
A draw frame includes a transport roll pair for simultaneously
guiding a plurality of slivers running in an advancing direction;
and a series of drafting roll pairs spaced from one another in the
advancing direction. One of the drafting roll pairs is a first
drafting roll pair as viewed in the advancing direction. The first
drafting roll pair is positioned downstream of the transport roll
pair. A measuring device is contacted by the running slivers and
includes a pressure-sensitive member exposed to a force derived
from the running slivers for emitting a signal representing the
force; and a deflecting arrangement for deflecting the running
slivers for causing them to be partially trained about the
deflecting arrangement to exert on the pressure-sensitive member a
pressing force proportional to a tension of the slivers prevailing
upstream and downstream of the pressure-sensitive member.
Inventors: |
Breuer, Achim; (Aachen,
DE) |
Correspondence
Address: |
VENABLE
Post Office Box 34385
Washington
DC
20043-9998
US
|
Family ID: |
7664083 |
Appl. No.: |
09/988369 |
Filed: |
November 19, 2001 |
Current U.S.
Class: |
19/239 ; 19/150;
19/236 |
Current CPC
Class: |
D01H 5/38 20130101 |
Class at
Publication: |
19/239 ; 19/236;
19/150 |
International
Class: |
D01H 005/32 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 21, 2000 |
DE |
100 57 699.0 |
Claims
What is claimed is:
1. A draw frame comprising (a) a transport roll pair for
simultaneously guiding a plurality of slivers running in an
advancing direction; (b) a series of drafting roll pairs spaced
from one another in said advancing direction; one of said drafting
roll pairs being a first drafting roll pair as viewed in said
advancing direction; said first drafting roll pair being positioned
downstream of said transport roll pair; and (c) a measuring device
contacting the running slivers; said measuring device including (1)
a pressure-sensitive member exposed to a force derived from the
running slivers for emitting a signal representing said force; and
(2) deflecting means for deflecting the running slivers for causing
the running slivers to be partially trained about said deflecting
means to exert on said pressure-sensitive member a pressing force
proportional to a tension of the slivers prevailing upstream and
downstream of said pressure-sensitive member.
2. The draw frame as defined in claim 1, wherein said
pressure-sensitive member comprises a piezoelectric element.
3. The draw frame as defined in claim 1, wherein said
pressure-sensitive member is rigidly supported on a stationary
component.
4. The draw frame as defined in claim 1, wherein said measuring
device is disposed between said transport roll pair and said first
drafting roll pair.
5. The draw frame as defined in claim 1, further comprising rider
rolls over which the slivers pass; said rider rolls being arranged
upstream of said transport rolls; a creel; supply rolls mounted on
said creel for advancing the slivers; said supply rolls being
spaced from said rider rolls upstream thereof; said measuring
device being disposed between said rider rolls and said supply
rolls.
6. The draw frame as defined in claim 1, wherein said measuring
device is disposed upstream of said transport roll pair.
7. The draw frame as defined in claim 6, further comprising rider
rolls over which the slivers pass; said rider rolls being arranged
upstream of said transport rolls; said measuring device being
disposed between said transport rolls and said rider rolls.
8. The draw frame as defined in claim 1, further comprising a
computer for controlling the draw frame operation; said measuring
device being connected to said computer for applying said signal to
said computer.
9. The draw frame as defined in claim 8, further comprising a
display device connected to said computer for displaying the
tension of said slivers based on said signal.
10. The draw frame as defined in claim 1, further comprising a
pressing element for transmitting the pressing force from said
slivers to said pressure-sensitive member.
11. The draw frame as defined in claim 10, wherein said pressing
element is stationarily supported.
12. The draw frame as defined in claim 10, wherein said pressing
element and said pressure-sensitive member are rigidly connected to
one another.
13. The draw frame as defined in claim 10, further comprising a bar
extending perpendicularly to said running direction and being
positioned on said pressure-sensitive member, said bar constituting
said deflecting means and said pressing element.
14. The draw frame as defined in claim 10, wherein said deflecting
means includes a roller mounted on said pressing element.
15. The draw frame as defined in claim 14, wherein said roller is a
first roller; said deflecting means further including a second
roller supported upstream of said first roller for deflecting the
running slivers toward said first roller and a third roller
supported downstream of said first roller; said first roller
deflecting the slivers toward said third roller.
16. The draw frame as defined in claim 15, wherein said measuring
device comprises a stationarily supported frame; said second and
third rollers being carried by said frame; a first bar supported on
said frame and extending perpendicularly to said running direction;
said pressure-sensitive element being supported on said first bar;
a second bar extending parallel to said first bar and being
supported on said pressure-sensitive element; said second bar
constituting said pressing element; said second bar supporting said
first roller.
17. The draw frame as defined in claim 15, further comprising drive
means for rotating said first, second and third rollers.
18. The draw frame as defined in claim 15, wherein said first,
second and third rollers are idlers and are rotatable by the
running slivers by friction.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority of German Application
No. 100 57 699.0 filed Nov. 21, 2000, which is incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to an apparatus for measuring the
tension of sliver composed of cotton fibers, chemical fibers or the
like, as it runs in a draw frame. Upstream of the draw frame a
creel is situated below which coiler cans are positioned from which
sliver is withdrawn. Downstream of the creel, as viewed in the
direction of sliver advance, a rider roll assembly and a sliver
guide with transporting rolls are provided, followed downstream by
input rolls of the draw unit of the draw frame. The slivers running
into the draw frame from the coiler cans are in a tensioned
condition at least in the zone between the transport rolls and the
input rolls of the draw unit.
[0003] The sliver tension effected by the transport rolls is
derived from the ratio of the circumferential speed of the lower
input roll of the draw unit to the circumferential speed of the
transport rolls. A setting of the transport roll tension is
feasible by means of the transmission gearing associated with the
transport rolls. The transport roll tension should be set in such a
manner that the slivers between the transport rolls and the lower
input roll of the draw unit run with the smallest possible tension
which still ensures that the slivers do not undulate as they run on
the sliver guide table. Further, when setting the tension, it
should be taken into consideration that a satisfactory spread of
the sliver is ensured. The tension setting is based on a table in
which the different transmission gears are associated with a
respective transport roll tension; such table is based empirically
for different fiber materials. For the same transmission gear a
different transport roll tension may result in case an assortment
(fiber lot) change occurs. In practice, the run of the slivers is
visually observed and based on such observation, an appropriate
transmission gear is selected. In addition, the quality of the
drafted sliver at the output of the draw unit is taken into
consideration.
[0004] It is a disadvantage of the above-outlined conventional
arrangement that the tension setting requires substantial
experience and does not make possible a precise determination of
the transport roll tension.
SUMMARY OF THE INVENTION
[0005] It is an object of the invention to provide an improved
apparatus of the above-outlined type from which the discussed
disadvantages are eliminated and which, in particular, makes
possible a precise determination of the transport roll tension and
a setting for different fiber lots.
[0006] This object and others to become apparent as the
specification progresses, are accomplished by the invention,
according to which, briefly stated, the draw frame includes a
transport roll pair for simultaneously guiding a plurality of
slivers running in an advancing direction; and a series of drafting
roll pairs spaced from one another in the advancing direction. One
of the drafting roll pairs is a first drafting roll pair as viewed
in the advancing direction. The first drafting roll pair is
positioned downstream of the transport roll pair. A measuring
device is contacted by the running slivers and includes a
pressure-sensitive member exposed to a force derived from the
running slivers for emitting, a signal representing the force; and
a deflecting arrangement for deflecting the running slivers for
causing them to be partially trained about the deflecting
arrangement to exert to the pressure-sensitive member a pressing
force proportional to a tension of the slivers prevailing upstream
and downstream of the pressure-sensitive member.
[0007] The measures according to the invention make possible a
precise determination particularly of the transport roll tension
and thus provide for an optimal setting of such tension even in
case of a fiber lot change. In this manner, tension values are
determined for the most important materials. Therefore, the actual
measured value for the tension draft may be compared with the
determined, desired value and the machine operator may receive an
indication whether the correct tension values have been
selected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1a is a schematic side elevational view of a draw frame
incorporating the invention.
[0009] FIG. 1b is a partial, schematic top plan view of the
construction shown in FIG. 1a.
[0010] FIG. 2a is a sectional side elevational view of a preferred
embodiment of the invention.
[0011] FIG. 2b is a fragmentary sectional front elevational view of
the construction shown in FIG. 2a.
[0012] FIG. 3 is a side elevational view of another preferred
embodiment of the invention.
[0013] FIG. 4 is a schematic side elevational view of a draw unit,
incorporating the embodiment of FIG. 3 and showing a block diagram
of the electronic draw frame control.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] FIG. 1 shows a draw frame DF which may be an HSR model
manufactured by Truttzschler GmbH & Co. KG, Monchengladbach,
Germany. The draw frame has an input region 1, a measuring region
2, a draw unit 3 and a sliver coiling unit 4. In the input region 1
two side-by-side extending rows of coiler cans are arranged, of
which one row of three coiler cans 5a, 5b and 5c are shown
underneath a creel 6. The slivers 7a, 7b and 7c withdrawn from the
respective coiler cans are guided by supply rolls 8a, 8b and 8c and
introduced into the draw unit 3. Each driven supply roll 8a, 8b and
8c is associated with a respective upper roll 9a, 9b and 9c
co-rotating with the supply rolls. As shown in FIG. 1b, the second
row of coiler cans (not visible in FIG. 1a) is associated with
additional supply rolls 8d, 8e and 8f, each cooperating with a
respective, non-illustrated upper roll similar to the rolls 9a-9c.
The six slivers 7a-7f withdrawn from the coiler cans are guided to
the draw frame proper along the creel 6.
[0015] After the slivers have been drawn and combined into a single
drafted sliver 10 in the draw unit 3, the sliver 10 is deposited in
coils into a receiving coiler can 11 by a rotary head of the coiler
unit 4.
[0016] In the region underneath each roll pair 8a, 9a, etc. which
crush the respective slivers 7a-7f, a non-illustrated guide for
each sliver is provided. The advancing direction of the slivers is
designated at A. Particularly at high withdrawing speeds the
slivers balloon and swing above the oiler cans. The slivers are
quieted after passing the supply rolls 8a-8f. Downstream of the
creel 6, at the input of the draw frame a driven roll assembly is
provided which is composed, for example, of two lower rider rolls
12a, 12b and three upper rider rolls 13. Each supply roll 8a-8f is
connected to a drive.
[0017] With reference to FIGS. 1a, 1b and 4, in the draw unit 3 the
length portion 7'" of the slivers 7a-7f is exposed to the transport
roll tension in the region between the cooperating transport rolls
15, 16 and the cooperating input rolls 26, III. The apparatus 17
structured according to the invention is disposed in this region
such that the length portions 7'" of the slivers 7a-7f, as they run
in the direction A, press down on the apparatus 17. The length
portion 7' of the slivers 7a-7f extends between the respective
supply rolls 8a-8f on the one hand and the rider rolls 12a, 12b, 13
on the other hand, while the length portions 7" of the slivers
7a-7f extend between rider rolls 12a, 12b, 13 on the one hand and
the cooperating transport rolls 15, 16, on the other hand. The
length portions 7', 7" and 7'" are all exposed to controlled
tensions.
[0018] The supply rolls 8a-8f all have the same diameter, for
example, 100 mm. The rpm decreases in the working direction A from
supply roll to supply roll and is predetermined by a control and
regulating device 38. As a result, the circumferential speed of the
supply rolls decreases in the working direction A. The
circumferential speed of the supply rolls is set such that the
tension of the running slivers 7a-7f has the desired magnitude. The
supply rolls 8a-8f are rotated by non-illustrated drives or
transmission mechanisms. The supply rolls 8a-8f are conventional,
two-part constructions. As shown in FIGS. 1a and 1b, the slivers
7a-7f run from the creel 6 to the intake region 1 through the rider
roll assembly 12, 13, the sliver guide 14 which includes a
measuring device with the transport rolls 15, 16, the
tension-sensing apparatus 17 (to be described in detail later), the
draw unit 3, the sliver guide 27, the sliver trumpet 30 provided
with calender rolls 28, 29 and the coiler head which deposits the
sliver in the coiler can 11.
[0019] FIG. 2a and 2b illustrate an embodiment of the apparatus 17
according to the invention. A table-like frame 42 is provided whose
plate 42a is supported by two legs 42b, 42c on a fixed machine
component 41. In the region of the two ends of the plate 42a two
rotary deflecting rollers 44 and 45 are arranged in a series as
viewed in the working direction A. On the upper face of the plate
42a a support element 20 is secured which holds a
small-displacement measuring member 19, for example, a
piezoelectric element which functions as a force take-up device.
Opposite the supporting element 20 the measuring element 19
cooperates with a frame-like pressing element 18 composed of a
supporting element 43 contacting the measuring member 19 and a
rotary deflecting roller 46 secured to the upper region of the
supporting element 43. The length portions 7'" of the slivers 7a-7f
emerging from the transporting rolls 15, 16 are deflected, as they
run underneath a deflecting roller 44, from a horizontal position
to proceed upwardly at an oblique angle to the deflecting roller 46
and then, running above the deflecting roller 46, the slivers are
deflected at an angle to proceed downwardly to a deflecting roller
45 and are, as they run underneath the deflecting roller 45,
reoriented into a horizontal direction. The slivers exert, via the
deflecting roller 46 and the supporting element 43, a pressing
force on the measuring element 19.
[0020] In operation, first the frame 42 is set on the draw frame
cover 41 so that the length portions 7'" of the slivers 7a-7f
remain unaffected. Thereafter the frame-like supporting element 43
is passed within the frame 42 under the length portions 7'" and
above the force take-up device 19 and is positioned and immobilized
on the frame 42. The measuring process may be activated when the
intended delivery speed is reached. To eliminate the effect of the
free sliver length, the weight of the input portion of the sliver
and the loop-around friction, the slivers are deflected by the
rotatable rollers 44, 45 and 46 and thus the length of the raised
sliver portion is defined. The extent of draft and the output
number of the input weight are known data inputted into the control
device, so that the sliver weight may be subtracted from the
tensioning force.
[0021] According to the embodiment of the sensor device 17' shown
in FIG. 3, a supporting element 43' has a rounded upper face
directly engaged by the running sliver which, due to its tensioned
state, presses down with a force P on the measuring member 19
counter-supported by the supporting element 20 secured to the
machine frame 41. The measuring member 19 is disposed between the
support element 20 and the pressing element 18. This embodiment is
void of deflecting rollers which characterize the embodiment of
FIGS. 2a and 2b. The device 17' is inserted underneath the sliver
and the measuring process may be activated when the intended
delivery speed is reached.
[0022] While the tension-sensing device 17 or 17' was described as
being positioned to contact the sliver length portions 7'" between
the transport rollers 15, 16 and the input drafting roll pair 26,
III, it is to be understood that instead or additionally, the
tension sensing device 17 or 17' may be disposed between the supply
rolls 8a-8f on the creel 6 and the rider rolls 12a, 12b, 13 to
contact the sliver length portions 7' and/or between the rider
rolls 12a, 12b, 13 and the transport rolls 15, 16 to contact the
sliver length portions 7".
[0023] Turning to FIG. 4, the draw unit 3 of the draw frame has an
input 21 and an output 22. The length portions 7" of the slivers
7a-7f are moved through the measuring member 14 as they are pulled
by the transport rolls 15, 16.
[0024] The draw unit 3, in which the drafting of the slivers
occurs, is a 4-over-3 construction, that is, it has a lower output
roll I, a lower middle roll II and a lower input roll III as well
as four upper rolls 23, 24, 25 and 26. The draft is composed of a
preliminary and principal draft. The roll pairs 26, III and 25, II
constitute the preliminary drafting field whereas the roll pair 25,
II and the roll assembly 23, 24, I constitute the principal
drafting field. The drafted slivers reach, at the draw unit output
22, a sliver guide 27 and are, by means of calender rolls 28, 29,
pulled through a sliver trumpet 30 in which the slivers 7a-7f are
combined into a single sliver 10 which is subsequently deposited in
a coiler can 11.
[0025] The transport rolls 15, 16, the lower input roll III and the
lower mid roll II which are mechanically interconnected, for
example, by a toothed belt, are driven by a regulating motor 31
rotated by a desired rpm value which may be inputted. The
respective upper rolls 26 and 25 are driven by friction by their
respective lower rolls. The lower output roll I and the calender
rolls 28, 29 are driven by a main motor 32. The regulating motor 31
and the main motor 32 are provided with a respective regulator 33
and 34. The rpm regulation occurs by means of a closed regulating
circuit in which tachogenerators 35 and 36 are connected with the
regulating motor 31 and the main motor 32, respectively. At the
draw unit input 21 a mass-proportionate magnitude, for example, the
cross section of the slivers is measured by the input measuring
organ 14. At the draw unit output 22 the cross section of the
exiting sliver 10 is measured by an output measuring member 37
integrated in a sliver trumpet 30.
[0026] A central computer unit 38 (control and regulating device),
for example, a microcomputer with microprocessor, transmits a
setting of the desired value to the regulator 33 for the regulating
motor 37. The measured values of the measuring organ 14 are
transmitted to the central unit 38 during the drafting process.
From the measured magnitudes determined by the measuring organ 14
and from the desired value for the cross section of the exiting
sliver 10, the central unit 38 determines the setting value for the
regulating motor 37. The measured values determined by the output
measuring member 27 serve for monitoring the discharged sliver 10.
With the aid of such a regulating system fluctuations in the cross
section of the inputted slivers are compensated for by means of a
suitable regulation of the drafting process and thus an evening of
the sliver 10 may be achieved. 39 designates an inputting device
and 40 designates schematically the drive for the supply rolls
8a-8f. The measuring element 19 of the measuring device 17 is also
connected with the control and regulating device 38 to receive,
from the measuring device 17, electric signals x which represent
the pressure which the running sliver exerts on the measuring
element 19. Such a pressure is a function of the tension of the
running sliver upstream and downstream of the measuring device 17.
In the control and regulating device 38 the tension force exerted
on the running sliver is computed from the signals x. The resulting
signals are stored in a memory 47. In this manner tension values
for the most important materials [N/ktex input] are stored. As a
result, the actual measured tension value may be compared with the
inputted tension values and thus the machine operator may receive
an indication whether the correct tension values were selected.
[0027] While the invention is described in conjunction with a
regulated draw frame, it is to be understood that the invention may
find application in a non-regulated draw frame as well.
[0028] It will be understood that the above description of the
present invention is susceptible to various modifications, changes
and adaptations, and the same are intended to be comprehended
within the meaning and range of equivalents of the appended
claims.
* * * * *