Information
-
Patent Grant
-
6829811
-
Patent Number
6,829,811
-
Date Filed
Monday, September 15, 200321 years ago
-
Date Issued
Tuesday, December 14, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Venable LLP
- Kinberg; Robert
-
CPC
-
US Classifications
Field of Search
US
- 019 150
- 019 152
- 019 157
- 019 159 R
- 019 236
- 019 237
- 019 238
- 019 239
- 019 240
- 019 260
- 019 261
- 019 287
- 019 288
- 019 291
- 019 292
- 019 258
-
International Classifications
-
Abstract
A drawing mechanism for the doubling and drafting of fiber slivers has a drawing mechanism frame for accommodating the drawing mechanism, which has at least two pairs of rollers each comprising an upper roller and a lower roller and has means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, in each case having a mounting device for accommodating the lower roller, lower rollers are arranged to be driven by a drive device comprising at least one drive element endlessly revolving around pulley wheels and each lower roller has a roller-driving pulley wheel.In order, by simple means in terms of construction, to make possible a considerable reduction in the work and time required for adjustment of the mounting devices and, accordingly, of the extent(s) of the drawing zone(s) without re-tensioning of the drive belt after the adjustment, at least one guide pulley wheel is attached to each mounting device, and the roller-driving pulley wheel and guide pulley wheel act, in each case one after the other, on both sides of the tensioned drive element.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from German Patent Application Nos. 102 42 390.3 and 103 29 835.5, which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The invention relates to an apparatus at a draw frame or other textile machine having a drawing mechanism for the doubling and drafting of fibre slivers.
Certain forms of draw frame have a drawing mechanism frame for accommodating the drawing mechanism, which has at least two pairs of rollers each comprising an upper roller and a lower roller, and means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, in each case having a mounting device for accommodating the lower roller, and lower rollers are arranged to be driven by at least one drive element endlessly revolving around pulley wheels and wherein each lower roller has a roller-driving pulley wheel.
In a known apparatus (DE-OS 20 44 996), the mountings of the intake and middle lower rollers are displaceable on the frame of the machine so that the extent of the drawing zone can be matched to the particular fibre staple. A tensioning pulley wheel, which is displaceable in a guideway in the frame of the machine, allows the length of the toothed belt to be modified in accordance with the changed spacing between the axes of the middle roller and a guide pulley wheel, brought about by displacement of the intake roller. The middle roller is driven by a further toothed belt. The latter toothed belt is tensioned by a tensioning pulley wheel which is fastened to the machine frame and which can pivot about one axis; as a result, it can also be matched to changed spacings between the axes of the intake roller and middle roller. It is disadvantageous that displacing devices for displacement of the intake roller and the middle roller and additional tensioning devices for re-tensioning of the toothed belts after the displacement operations are necessary, requiring a considerable outlay in terms of construction. In addition, it is disadvantageous that a number of work steps are required for the displacement operations and the subsequent re-tensioning operations. The belt tension is destroyed by the displacement process. Where the displacement is carried out manually, spacers are inserted between the mountings, the mountings being pushed against the spacers so that, in this case too, the amount of set-up work is considerable. Finally, the displacement and re-tensioning operations result in a doubling of potential error sources when setting the spacings and belt tensions.
It is an aim of the invention accordingly to provide an apparatus of the kind described at the beginning that avoids or mitigates the disadvantages mentioned and that especially is of simple construction and allows a considerable reduction in the work and time required for adjustment of the slider(s) and, accordingly, of the extent(s) of the drawing zone(s), without re-tensioning the drive belt after the adjustment.
SUMMARY OF THE INVENTION
The invention provides a drawing mechanism having a drawing mechanism frame, at least two pairs of rollers each comprising an upper roller and a lower roller and having a mounting device for accommodating the lower roller, means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, and at least one drive device comprising a drive element endlessly revolving around pulley wheels, wherein said pulley wheels comprise a guide pulley wheel provided on a said mounting device and a roller-driving pulley wheel for driving the lower roller accommodated by that mounting device, said roller-driving pulley wheel and said guide pulley wheel acting one after another on opposed sides of the drive element.
The measures according to the invention make it possible, by simple means, for the mountings and, as a result, the extents of the drawing zones (nip line spacings) to be adjusted in a short time. For the purpose of adjusting the extents of the drawing zones, elegant use is made of existing structural elements necessarily present in the drawing mechanism, namely a roller-driving pulley wheel and the drive belt. Separate apparatuses for adjustment are not required. As a result of the fact that the drive belt is in tension before, during and after adjustment, further apparatuses for re-tensioning the drive belt after the adjustment are not required, which allows the extents of the drawing zones of the drawing mechanism to be changed in a short time by means that are especially simple in terms of construction.
Advantageously, the drive device can be used for adjusting the position of the mounting device of said lower roller, whereby said adjustment of said spacing is effected. Advantageously, at least one pulley wheel and the tensioned drive element are used for adjusting the mounting device. Advantageously, the drive element is stationary and the pulley wheel is rotated. Advantageously, the pulley wheel is stationary and the drive element is moved. Advantageously, the rotation of the pulley wheel or the movement of the drive element is converted into the adjusting movement of the slider. Advantageously, at least one guide pulley wheel is attached to each slider (mounting); and the roller-driving pulley wheel or guide pulley wheel(s) act, in each case one after the other, on both sides of the tensioned drive element. Advantageously, the rotation of the pulley wheel or the movement of the drive element is accomplished manually. Advantageously, the slider is linearly displaceable.
Advantageously, the drive element is a toothed belt. Advantageously, an endless flexible toothed belt is present. Advantageously, the pulley wheels comprise toothed belt wheels. Advantageously, the pulley wheels comprise guide pulley wheels. Advantageously, at least one driving pulley wheel is provided. Advantageously, driven pulley wheels are present. Advantageously, the drive element loops around the pulley wheels. Advantageously, the drive element and the pulley wheel are in engagement with one another. Advantageously, the pulley wheel for adjustment of a slider is the drive pulley wheel of a lower roller (roller-driving pulley wheel). Advantageously, the slider is displaceable during adjustment. Advantageously, the slider is arranged to be stopped. Advantageously, the stopping arrangement is releasable. Advantageously, a display device for the position of the slider is present.
Advantageously, a drive motor is used for rotation of the pulley wheel. Advantageously, a drive motor is used for movement of the drive element. Advantageously, the drive motor is used for the lower rollers. Advantageously, a separate drive motor is used. Advantageously, belt shortening or belt lengthening is arranged to be automatically evened out during adjustment. Advantageously, the evening-out of belt length is carried out at a slider by two guide pulley wheels.
Advantageously, the lower rollers are arranged to be adjusted singly and independently of one another. Preferably, a roller-driving pulley wheel and a guide pulley wheel are attached to the slider of the intake roller and a roller-driving pulley wheel and a guide pulley wheel are attached to the slider of the middle roller. Advantageously, the drive element runs around the pulley wheels at the slider of the intake roller and around the pulley wheels at the slider of the middle roller in a mirror-reflected arrangement. Advantageously, the drive element is in tension before, during and after the displacement. Advantageously, the drive motor is in communication with an electronic control and regulation device. Advantageously, a measuring element is connected to the control and regulation device. Advantageously, the measuring element is capable of registering fibre-related and/or machinery-related measurement variables. Advantageously, adjustment of the slider is carried out when the drawing mechanism is in operation. Advantageously, adjustment of the slider is carried out when the drawing mechanism is not in operation. Advantageously, adjustment of the slider is carried out during can-changing. Advantageously, the draw frame is self-adjusting. Advantageously, adjustment of the slider is carried out by inputting adjustment variables. Advantageously, the adjustment variables can be input manually. Advantageously, a memory for adjustment variables is connected to the control and regulation device. Advantageously, the slider for the intake roller and the slider for the middle roller are arranged to be connected by a rigid connecting element. Advantageously, the connecting element is releasably connected. The spacing of the pairs of rollers in relation to one another may be adjustable without fibre material. The spacing of the pairs of rollers in relation to one another may be adjustable with fibre material. Advantageously, the extent of the preliminary draft zone can be adjusted. Advantageously, the extent of the main draft zone can be adjusted. Advantageously, the extent of the preliminary draft zone and the extent of the main draft zone can be adjusted. Advantageously, each lower roller has its own associated drive motor. Advantageously, the intake and middle lower rollers are arranged to be driven by one drive motor. Advantageously, a brake, stopping arrangement or the like is associated with the stationary pulley wheel. The brake, stopping arrangement or the like may be mechanical, electrical or electromagnetic. Advantageously, the drive motor is a self-braking motor. Advantageously, the drive motor drives a further drive train, which has a free-wheel arrangement or the like.
Advantageously, the mounting device consists of the mounting and the slider. The mounting and the slider may be fastened to one another, for example by bolts. The mounting and the slider may be of integral construction.
The invention also provides an apparatus at a draw frame having a drawing mechanism for the doubling and drafting of fibre slivers, having a drawing mechanism frame for accommodating the drawing mechanism, which has at least two pairs of rollers each comprising an upper roller and a lower roller, having means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, in each case having a mounting device for accommodating the lower roller, wherein lower rollers are arranged to be driven by at least one drive element endlessly revolving around pulley wheels, characterised in that at least one guide pulley wheel is attached to each mounting device; and the roller-driving pulley wheel or guide pulley wheel act, in each case one after the other, on both sides of the tensioned drive element.
Moreover, the invention provides a draw frame comprising a drawing mechanism as defined above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a diagrammatic side view of an autoleveller draw frame for use with an apparatus according to the invention together with a general circuit diagram;
FIG. 2
is a perspective view of a side of the draw frame showing the displaceable mounting of the intake and middle lower rollers;
FIGS. 3
a
and
3
b
show the drive for the intake and middle lower rollers for the draw frame according to
FIG. 1
, in a side view (
FIG. 3
a
) and plan view (
FIG. 3
b
);
FIG. 3
c
is a partial side view of a drive belt;
FIGS. 4
a
to
4
d
show, in diagrammatic form, the sequential procedure for shortening of the preliminary and main draft zones;
FIGS. 5
a
and
5
b
show the intake and middle lower rollers before displacement (
FIG. 5
a
) and after displacement (
FIG. 5
b
);
FIGS. 6
a
and
6
b
show, in diagrammatic form, an electro-magnetic braking apparatus for a toothed belt wheel;
FIG. 7
shows a locking device for a slider;
FIG. 8
shows a connection element (bridge) for connecting two sliders;
FIG. 9
is a partial side view of an embodiment comprising a drawing mechanism having three roller combinations, each having its own drive motor;
FIG. 10
is a side view of a drawing mechanism with input devices for manual and/or memory-assisted input of adjustment values for changing the nip line spacings in the drawing mechanism; and
FIG. 11
is a front view of a roller pair with an upper roller lifted off from a lower roller.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with
FIG. 1
, a draw frame
1
, for example a draw frame known as an HSR draw frame (trade mark) made by Trüitzschler GmbH & Co. KG, has a drawing mechanism
2
, upstream of which is an intake
3
of the drawing mechanism and downstream of which is an exit
4
from the drawing mechanism. The fibre slivers
5
, coming from cans (not shown), enter the sliver guide
6
and, drawn by the draw-off rollers
7
,
8
, are transported past the measuring element
9
. The drawing mechanism
2
is designed as a 4-over-3 drawing mechanism, that is to say it consists of three lower rollers I, II, III (I delivery lower roller, II middle lower roller, III intake lower roller) and four upper rollers
11
,
12
,
13
,
14
. Drafting of the fibre sliver combination
5
′ from a plurality of fibre slivers
5
is carried out in the drawing mechanism
2
. Drafting is composed of preliminary drafting and main drafting. The roller pairs
14
/III and
13
/II form the preliminary draft zone and the roller pairs
13
/II and
11
,
12
/I form the main draft zone.
The attenuated fibre slivers
5
reach a web guide
10
in the exit
4
from the drawing mechanism and, by means of the draw-off rollers
15
,
16
, are drawn through a sliver funnel
17
, in which they are combined to form one fibre sliver
18
, which is then deposited in cans. Reference letter A denotes the work direction.
The draw-off rollers
7
,
8
, the intake lower roller III and the middle lower roller II, which are connected to one another mechanically, for example by toothed belts, are driven by the control motor
19
, it being possible, in the process, for a desired value to be specified. (The associated upper rollers
14
and
13
, respectively, revolve by virtue of the motion of the lower rollers.) The delivery lower roller I and the draw-off rollers
15
,
16
are driven by the main motor
20
. The control motor
19
and the main motor
20
each have their own controller
21
and
22
, respectively. Control (speed-of-rotation control) is carried out in each case by means of a closed control loop, a tachogenerator
23
being associated with the control motor
19
and a tachogenerator
24
being associated with the main motor
20
. At the intake
3
of the drawing mechanism, a variable proportional to the weight of the fibre slivers
5
fed in, for example their cross-section, is measured by an intake measuring element
9
known, for example, from DE-A-44 04 326. At the exit
4
from the drawing mechanism, the cross-section of the delivered fibre sliver
18
is ascertained by an exit measuring element
25
associated with the sliver funnel
17
and known, for example, from DE-A-195 37 983. A central computer unit
26
(control and regulation device), for example a microcomputer with a microprocessor, sends a setting for the desired value for the control motor
19
to the controller
21
. The measurement values of the two measuring elements
9
and
25
are sent to the central computer unit
26
during the drawing process. The desired value for the control motor
19
is determined in the central computer unit
26
from the measurement values of the intake measuring element
9
and from the desired value for the cross-section of the delivered fibre sliver
18
. The measurement values of the exit measuring element
25
are used for monitoring of the delivered fibre sliver
18
(delivered sliver monitoring). By means of this control system, it is possible for variations in the cross-section of the fibre slivers
5
fed in to be compensated, and for the fibre sliver to be made more uniform, by appropriately regulating the drafting process. Reference numeral
27
denotes a display monitor,
28
an interface,
29
an input device,
30
a pressure rod and
31
a memory.
With reference to
FIG. 2
, each of lower rollers II, III has an associated mounting device comprising a respective mounting
33
a
,
34
a.
The trunnions Ia, IIa, IIIa (see
FIG. 3
b
) of the lower rollers I, II and III are mounted so as to be capable of rotation in mountings
32
a,
33
a
,
34
a
(
32
b,
33
b
,
34
b
are located on the other side of the drawing mechanism and are not shown). The mountings
33
a
and
34
a
are bolted onto sliders
35
a
and
36
a,
respectively, which are displaceable in the direction of the arrows C, D and E, F, respectively, along a bar
37
a.
The two ends of the bar
37
a
are fixedly mounted in mounting blocks
38
′ (
38
″ not shown), which are attached to the frame
39
of the machine.
Displacement of the sliders
35
a,
35
b;
36
a,
36
b
at the same time causes the mountings
33
a
,
33
b
;
34
a,
34
b
and, as a result, the lower rollers II and III, respectively, to be displaced and moved in directions C, D and E, F, respectively. The associated upper rollers
13
and
14
are correspondingly moved (in a manner not shown) in directions C, D and E, F, respectively. By that means, the nip line spacings between the roller combinations are modified and set.
Locking of the sliders
35
a,
35
b;
36
a,
36
b
is accomplished by means of a catch device, stopping device or he like, one suitable form of stopping device being shown n FIG.
7
.
Referring to
FIG. 3
a
, the lower rollers II and III are driven from the right-hand side of the draw frame, seen in the direction of material flow A, by means of a common loop mechanism in the form of toothed belt wheels
40
,
41
and a toothed belt
47
. The different speeds of rotation of the lower rollers II and III are achieved by means of change-gearwheels at the drive trunnions IIa, IIIa provided with different numbers of teeth. The toothed belt
47
runs in direction B (that is to say contrary to the work direction) onto the control drive, which is in the form of a servo motor
19
. The lower roller I is driven from the left-hand side of the machine by means of a loop mechanism in the form of toothed belt wheels and a toothed belt
47
′. For that purpose, the toothed belt
47
′ runs on the left-hand side from the toothed belt disc
40
′ at the lower roller I in direction G onto the servo motor
20
.
In operation, that is to say when the fibre slivers are running in direction A, the toothed belt
47
moves in direction G. Starting from the toothed belt wheel
47
arranged on the drive motor
19
, the toothed belt
47
runs successively over a toothed belt wheel
45
, a smooth guide pulley wheel
46
, the toothed belt wheel
40
(roller-driving pulley wheel for the lower roller III), the toothed belt wheel
41
(roller-driving pulley wheel for the lower roller II), a smooth guide pulley wheel
42
and a toothed belt wheel
43
. As shown in
FIG. 3
c,
the belt
47
has a toothed side
47
a
and a smooth side
47
b.
By means of its teeth, the toothed belt
47
, by means of teeth
47
a
(
FIG. 3
c
) is in positive engagement with the toothed belt wheels
40
,
41
,
43
,
44
, and
45
. The smooth side
47
b
(reverse) (
FIG. 3
c
) of the toothed belt
47
, opposite the toothed side, is in contact and in engagement with the smooth guide pulley wheels
46
and
42
. The toothed belt
47
loops around all the pulley wheels
40
to
46
. In operation (when the fibre slivers are running in direction A during drafting), the toothed belt wheels
40
,
41
,
43
,
44
, and
45
rotate clockwise and the guide pulley wheels
42
and
46
rotate anti-clockwise.
The toothed belt wheels
40
,
41
are associated with the mountings
34
a
and
33
a
, respectively, whereas the guide pulley wheels
42
,
46
are attached to the sliders
35
a
and
36
a,
respectively, in a manner allowing rotation. Because
20
of the rigid attachment between the mounting
34
a
and the slider
36
a
and between the mounting
33
a
and the slider
35
a
(for example, by means of bolts), there are associated with the lower rollers II and III, in each case, one toothed belt wheel
40
and
41
, respectively, and one guide pulley wheel
46
and
42
, respectively. The toothed belt
47
runs around the pulley wheels
40
,
46
, on the one hand, and around the pulley wheels
41
,
42
, on the other hand, in a mirror-reflection arrangement (see
FIG. 3
b
).
The zone between the pairs of rollers
13
/II and
14
/III is designated VV (preliminary drafting) and the zone between the pairs of rollers
12
/I and
13
/II is designated HV (main drafting) (see
FIG. 4
a
). When, in accordance with
FIG. 3
a
, the nip line spacing between the roller pairs
14
/III and
13
/II is to be increased, at least one pair of rollers must be moved away from the respective other pair of rollers. For that purpose the slider
35
a
may be displaced towards the right, which may be accomplished in two ways:
a) The slider
35
a
is unlocked. A pulley wheel, for example the toothed belt wheel
44
, is stopped so that there is no possibility of rotation. Stopping may be accomplished, for example, by mechanical or electromagnetic means. As a result the toothed belt
47
is stationary and cannot be moved. The toothed belt wheel
41
is then rotated anti-clockwise, for example manually using a crank or the like, whereupon the guide pulley wheel
42
likewise rotates, clockwise, as a matter of necessity. In the process, the rotary movement of the toothed belt wheel
41
is converted into a longitudinal movement of the slider
35
a
in direction C, the toothed belt wheel
41
and the guide pulley wheel
42
winding along opposite sides of the stationary toothed belt
47
, thereby “shortening”, as it were, the toothed belt
47
at one pulley wheel and “lengthening” it at the other pulley wheel. The length of belt required during that “winding along” at the toothed belt wheel
41
is made available at the guide pulley wheel
42
. The lower roller II is thereby displaced in direction C by means of the slider
35
a
and the mounting
33
a.
b) The slider
35
a
is unlocked. The toothed belt wheel
41
is stopped so that there is no possibility of rotation. As a result the guide pulley wheel
42
is also stopped of necessity. Then, clockwise rotation is brought about by means of the drive motor
19
. The toothed belt
47
moves in direction G, likewise “shortening” the belt
47
at one pulley wheel and “lengthening” it at the other pulley wheel. The length of belt actually required between the toothed belt wheels
40
and
41
is made available between the toothed belt wheels
43
and pulley wheel
42
. The rotary movement of the toothed belt wheel
44
and the movement of the toothed belt
47
is thereby converted into a longitudinal movement of the slider
35
a
in direction C. The lower roller II, mounted in the mounting
33
a
(which is rigidly connected to the slider
35
a
), is likewise moved in direction C as a result.
In practice, it is often the case that, in accordance with
FIGS. 4
a
to
4
d,
first the preliminary draft zone VV is modified and then the main draft zone HV. In the case of shortening of the draft zones VV and HV, the slider
36
a
is displaced in the direction of the arrow E from the position according to
FIG. 4
a
into the position according to
FIG. 4
b.
As a result, the nip line spacing in the preliminary draft zone VV is reduced from “a” to “a”. Then, in accordance with
FIG. 4
c,
the sliders
36
a
and
35
a
are rigidly connected to one another by means of a bridge
50
. Finally, the rigidly coupled sliders
36
a
and
35
a
are moved, in accordance with
FIG. 4
d,
in the direction of the arrows E and C, from the position shown in
FIG. 4
c
into the position shown in
FIG. 4
d.
As a result, the nip line spacing in the main draft zone HV is shortened from “b” to “b′”.—A corresponding procedure is used in the case of lengthening the preliminary and main draft zones, that is to say the coupled sliders
35
a
and
36
a
are displaced in the direction of the arrows F and D (see FIG.
2
), as a result of which the main draft zone HV is lengthened. Then, the sliders
35
a
and
36
a
are uncoupled from the bridge
50
. Finally, the slider
36
a
is moved in the direction of the arrow F (see FIG.
2
), as a result of which the preliminary draft zone VV is lengthened.
With regard to the fibre slivers
5
in the drawing mechanism
2
, it should be noted that, in the case of shortening of the draft zones VV and HV, a small amount of stretching, in direction B, of the fibre slivers
5
IV
upstream of the pair of rollers
14
/III can occur on displacement in accordance with
FIGS. 4
a,
4
b,
but because of the length (about 1.5 m) of the spacing between the transport rollers
7
,
8
and the pair of rollers
14
/III this is without significance. In the case of shortening, a sagging loop does not form in the preliminary draft zone VV because in the case of displacement referring to the pairs of rollers
14
/III and
13
/II either one or both pairs of rollers are rotatable because the drives to both pairs of rollers are coupled by way of the toothed belt
47
. In contrast, in the case of shortening of the main draft zone HV, a sagging loop is formed in fibre slivers
5
″, which is drawn out or drawn straight by rotation of the pair of rollers
12
/I in the work direction A by means of the main motor
20
.—In the case of lengthening of the draft zones VV and HV, the pair of rollers
12
/I is, in a first step, rotated backwards in direction B, whereupon a sagging loop is intentionally formed in the fibre slivers
5
″. When the main draft zone HV is subsequently lengthened by displacement of the coupled sliders
35
a
and
36
a
in direction D and F, the artificially formed loop is, in the process, once again drawn out or drawn straight. Finally, after uncoupling of the bridge
50
, the slider
36
a
is displaced in direction F. As a result of the above-mentioned coupling of the drives to the intake and middle lower roller pairs by means of the toothed belt
47
, the length of the fibre slivers
5
′ in the preliminary draft zone VV remains unaffected. Possible slight longitudinal compression of the fibre slivers
5
IV
upstream of the pair of rollers
14
/III is, in respect of the drafting and the constitution of the fibre slivers
5
IV
, without significance.
FIGS. 5
a,
5
b
show a suitable construction for bringing about the displacement of the sliders
36
a
and
35
a.
The nip line spacing in the preliminary draft zone VV is lengthened from “a” (
FIG. 5
a
) to “a” (
FIG. 5
b
). The sliders
36
a
and
35
a
are displaced one after the other according to the arrows E and C, respectively. Displacement is accomplished by stopping the toothed belt wheel
40
or fixing it with a holding brake or the like and then actuating the drive motor
19
, whereupon the toothed belt
47
moves. In continuation thereof, the sliders
36
a
and
35
a
are displaced in accordance with
FIGS. 4
a,
4
b
and, subsequently,
FIGS. 4
c,
4
d.
In
FIG. 6
a
there is shown an electromagnetic holding brake for braking the toothed belt wheel
44
. The brake has a rod-shaped iron core
53
surrounded by a plunger coil
54
. Mounted on one end face of the iron core
53
is a brake shoe
55
, for example made of plastics material or the like. The iron core
53
is displaceable in the direction of the arrows M, N. When current flows through the plunger coil
54
, the iron core
53
is moved in direction M, in accordance with
FIG. 6
b,
so that the brake shoe
55
is pressed against the smooth cylindrical surface of the shaft
44
a
of the toothed belt wheel
44
. As a result, the toothed belt wheel
44
is fixed (stopped) so that it cannot rotate, for as long as voltage is applied to the plunger coil
54
.
In
FIG. 7
there is shown a stopping device for slider
36
a
and corresponding lower roller III. A pneumatic cylinder
60
having a piston rod
61
is attached to the slider
36
a.
When subjected to pressure from the pneumatic cylinder
60
, the piston rod
61
is moved out in the direction of the arrow P and comes to rest, with a high degree of contact pressure, against the machine frame
61
. The slider
36
a
is fixed (stopped) so that it cannot be displaced with respect to the bar
37
a,
for as long as compressed air is applied to the pneumatic cylinder
60
. Lower roller II may be provided with an analogous arrangement.
In accordance with
FIG. 8
, there is provided, as the bridge
50
between the sliders
35
a
and
36
a,
a flat piece of metal (plate), which is fastened in the region of one of its ends
50
a
to the slider
36
a,
for example using bolts. In its region
50
b
facing the slider
35
a,
the flat piece of metal has an elongate hole
50
c,
through which a bolt
62
can engage in a threaded hole (not shown) in the slider
35
a.
By means of this bridge
50
, the sliders
35
a
and
36
a
can be rigidly connected to one another, releasably, at different spacings with respect to one another.
In accordance with
FIG. 9
, in contrast to
FIG. 1
, each lower roller I, II and III is driven by its own drive motor
20
,
52
and
19
, respectively, as shown, for example, in DE-OS 38 01 880. The motor
20
drives the toothed belt wheel
55
of the lower roller I by way of the toothed belt
56
; the motor
52
drives the toothed belt wheel
41
of the lower roller II by way of the toothed belt
57
; and the motor
19
drives the toothed belt wheel
40
of the lower roller III by way of the toothed belt
47
. Attached to the slider
36
a,
in addition to the smooth guide pulley wheel
46
, is a further smooth guide pulley wheel
51
. The endless toothed belt
47
loops around, in succession, the pulley wheels
44
,
46
,
40
,
51
and
43
. The toothed belt wheels
44
,
40
and
43
are in engagement with the teeth of the toothed belt
47
, whereas the smooth guide pulley wheels
46
and
51
are in engagement with the smooth reverse side of the toothed belt
47
. The sliders
35
a
and
36
a
are rigidly connected to one another, releasably, by means of the bridge
50
. When they are not connected by the bridge
50
, the sliders
35
a
and
36
a
are individually displaceable and when they are connected by the bridge
50
they are jointly displaceable.
In accordance with
FIG. 10
, the drive motor
19
for lower rollers II and III is in communication with the electronic control and regulation device
26
. Adjustment values for modification of the draft zones VV and HV (that is to say the extents of the drawing zones) either can be entered manually by way of the input device
29
or can be called up from a memory
31
for particular categories of fibre material.
Adjustment of the nip line spacing in the preliminary draft zone VV and/or the main draft zone HV can be carried out with the fibre slivers
5
inserted.
Displacement can be carried out with the upper rollers
11
to
14
in the loaded state.
FIGS. 1 and 10
show inserted fibre slivers
5
and loaded upper rollers
11
to
14
. With the fibre slivers inserted and the upper rollers
11
to
14
loaded, the sliders
35
a,
36
a
or mountings of at least one lower roller II, III are unlocked, the sliders or mountings are set to the desired nip line spacing a, a′; b, b′ by means of a displacement device, for example in accordance with
FIGS. 3
a
,
3
b
;
5
a,
5
b
and then the sliders
35
a,
36
a
or mountings are locked again (for example in accordance with FIG.
7
).
Displacement can also be carried out with the upper rollers
11
to
14
lifted off. The upper rollers
11
to
14
may be lifted off completely from the lower rollers I to III in the manner shown in DE-OS 197 04 815, the upper roller
14
being swung out on a portal
58
about a pivot mounting
59
. However, it may also be sufficient for the upper rollers
11
to
14
to be unloaded and to be lifted off from the lower rollers I to III only to a slight degree such that the fibre slivers
5
are not caught by the pairs of rollers during displacement of the draft zones VV and HV but can slide through the roller nip without being advrsely affected.
The invention has been illustrated using the example of the adjustment of the nip line spacings of a drawing mechanism of a draw frame. It likewise encompasses the adjustment of drawing mechanisms of other machines, for example carding machines, combing machines, fly frames and ring spinning frames.
Claims
- 1. A drawing mechanism having a drawing mechanism frame, at least two pairs of rollers each comprising an upper roller and a lower roller and having a mounting device for accommodating the lower roller, means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, and at least one drive device comprising a drive element endlessly revolving around pulley wheels, wherein said pulley wheels comprise a guide pulley wheel provided on a said mounting device and a roller-driving pulley wheel for driving the lower roller accommodated by that mounting device, said roller-driving pulley wheel and said guide pulley wheel acting one after another on opposed sides of the drive element.
- 2. A drawing mechanism according to claim 1, in which the drive device can be used for adjusting the position of the mounting device of said lower roller, whereby said adjustment of said spacing is effected.
- 3. A drawing mechanism according to claim 1, in which the drive element comprises a toothed belt.
- 4. A drawing mechanism according to claim 3, in which the roller-driving pulley wheels comprise toothed belt wheels.
- 5. A drawing mechanism according to claim 1, in which the guide pulley wheels comprise smooth pulley wheels.
- 6. A drawing mechanism according to claim 1, in which a first guide pulley wheel and a first roller-driving pulley wheel are attached to a slider portion of a mounting device of a first, intake, lower roller and a second roller-driving pulley wheel and a second guide pulley wheel are attached to a slider portion of a mounting device of a second, middle, lower roller.
- 7. A drawing mechanism according to claim 1, in which a drive motor for the drive device is in communication with an electronic control and regulation device.
- 8. A drawing mechanism according to claim 1, in which there is a preliminary draft zone and a main draft zone.
- 9. A drawing mechanism according to claim 8, in which the extent of the main drafting zone can be adjusted.
- 10. A drawing mechanism according to claim 8, in which the extent of the preliminary draft zone can be adjusted.
- 11. A drawing mechanism according to claim 1, comprising a first mounting device for a first said lower roller and a second mounting device for a second said lower roller, each of said first and second rollers having a respective roller-driving pulley wheel and guide pulley wheel acting one after another on opposed sides of the drive element.
- 12. A drawing mechanism according to claim 1, in which the first lower roller is an intake roller of the drawing mechanism, the second lower roller is a middle roller of the drawing mechanism, and there is a further roller pair downstream of the middle roller.
- 13. Apparatus at a draw frame having a drawing mechanism for the doubling and drafting of fibre slivers, having a drawing mechanism frame for accommodating the drawing mechanism, which has at least two pairs of rollers each comprising an upper roller and a lower roller, having means for adjusting the spacing of at least one of the lower rollers in relation to another lower roller, in each case having a mounting device for accommodating the lower roller, wherein lower rollers are arranged to be driven by at least one drive element endlessly revolving around pulley wheels, characterised in that at least one guide pulley wheel is attached to each mounting device; and the roller-driving pulley wheel and guide pulley wheel act, in each case one after the other, on both sides of the tensioned drive element.
Priority Claims (2)
Number |
Date |
Country |
Kind |
102 42 390 |
Sep 2002 |
DE |
|
103 29 835 |
Jul 2003 |
DE |
|
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DE |
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Mar 1972 |
DE |
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May 1975 |
DE |
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DE |
3801880 |
Aug 1989 |
DE |
0 640 703 |
Mar 1995 |
DE |
19537916 |
Apr 1997 |
DE |
101 40 645 |
Mar 2002 |
DE |
10237725 |
Sep 1998 |
JP |